As an alternative technology for the efficient disposal of spent nuclear fuel, various process flows can be selected based on the recovered and separated radioactive nuclide group. This is to examine the efficiency of the disposal area of spent nuclear fuel when various disposal technologies and several treatment processes are applied to spent nuclear fuel, compared to the deep geological disposal of burying the entire spent fuel in the ground. Above all, the biggest advantage of the optional treatment processes is that it can be applied to various disposal methods (deep borehole disposal, deep geological disposal) because it can process spent fuel in various sizes and separate into some groups according to the properties of radionuclides. These optional processes are not new technology and currently available as of today, and the level is classified based on the stepwise separation of high heat emission nuclides and long half-life nuclides. This is to increase the efficiency of the disposal of spent nuclear fuel by separating and managing high-risk radionuclides separately. Relatively various optional processes are possible depending on the level, and characteristic analysis is performed on wastes treated with alternative technologies. The mass balance for each option process is completed, and the amount of waste is also calculated accordingly. These are used as basic data for waste disposal area and economic evaluation. Besides it is easy to process spent fuel of various sizes suitable for deep geological disposal or deep borehole disposal technology when an optional treatment technology is applied to spent fuel. However, since this selective process is based on the process structure constructed in a broad framework, it is considered that additional follow-up studies are needed not only on detailed technology but also on the flow and amount of waste.

For safe management of spent nuclear fuels, they should be delivered to repository or waste disposal site. As the amount of spent nuclear fuel transportation is expected to increase in the future due to the provision of an intermediate storage facility, the necessity to secure transportation cask is emerging. In order to secure the spent nuclear fuel transportation cask, it is necessary to analyze the regulatory processes for domestic and foreign spent nuclear fuel transportation cask. In this study, the regulatory processes for domestic and foreign spent nuclear fuel transportation cask was analyzed. In this study, the IAEA, US, and Korea spent nuclear fuel transportation cask regulatory processes were analyzed. The domestic and foreign spent nuclear fuel transportation cask regulatory processes consist of design phase, manufacturing phase, and operation phase. In the design stage, the transport requirements are designed in accordance with the safety requirements of international organizations and countries. The application to be submitted when applying for approval should include a safety analysis report, evidence proving compliance with safety requirements et al. In the manufacturing stage, it is a stage to check whether the safety requirements are satisfied before the first use after manufacturing the transportation cask. Inspections include welding inspection, leakage inspection, shielding inspection, and thermal inspection. In the operation stage, it is a stage of periodically performing inspections for continuous maintenance of the package when the transportation cask is used. The inspection items to be performed are similar to the manufacturing stage and typically include performance inspection of components and leakage inspection. In this study, domestic and foreign spent nuclear fuel transportation cask regulatory processes were analyzed. It was found that the domestic and foreign spent nuclear fuel transportation cask regulatory processes consist of the design phase, the manufacturing phase, and the operation phase. The results of this study can be used as basic data for policy decision-making for the spent nuclear fuel cask.

In this study, additive manufacturing of a functionally graded material (FGM) as an alternative to joining dissimilar metals is investigated using directed energy deposition (DED). FGM consists of five different layers, which are mixtures of austenitic stainless steel (type 316 L) and low-alloy steel (LAS, ferritic steel) at ratios of 100:0 (A layer), 75:25 (B layer), 50:50 (C layer), 25:75 (D layer), and 0:100 (E layer), respectively, in each deposition layer. The FGM samples are successfully fabricated without cracks or delamination using the DED method, and specimens are characterized using optical and scanning electron microscopy to monitor their microstructures. In layers C and D of the sample, the tensile strength is determined to be very high owing to the formation of ferrite and martensite structures. However, the elongation is high in layers A and B, which contain a large fraction of austenite.

Graphene, the wonder material has brought a revolutionary change in the field of nanotechnology owing to its tremendous properties. Though different methods for the synthesis of graphene have been reported, the chemical synthesis route offers a scalable and high-volume production of graphene. The unreliability of graphite and hydrocarbon resources to serve as steady supplies of carbon resources and further in the synthesis of graphene has led to the exploration and use of alternative low-cost carbon-rich resources (coal, graphite, rice husk, sugarcane bagasse, peanut shells, waste tyres, etc.) as precursors for graphene synthesis. The use of untraditional carbon resources reduces dependence on traditional resources (coal, graphite), reduced cost, increased reliability, and provides a way for the management of waste biomass. This review hence focuses on the synthesis of graphene by the most common approachable method, oxidation–reduction of graphite, along with the various other chemical methods of synthesis from varied carbon resources.

A methodology is under development to restore and predict the long-term evolution of the natural barrier comprise the site of radioactive waste disposal for surface geological outcrop, tunnel face and drill core. Considering the condition that the radioactive waste repository should be located in the deep part, the drill core is an important subject that can identify deep geological properties that could not be confirmed near the surface. In this study, we investigated proper age dating methods to construct lithological model of the disposal site with regard to the long-term safety. Also, preliminary age dating locations were selected using the lithological distribution results by depth through geochemical and micro-structural analysis for the deep drill cores excavated around KURT. In the study area, the dikes presumed the Cretaceous were intruded by Jurassic granites. As for the granotoids, U-Pb age dating for zircon, which is resistant to deformation or metamorphism and has loss, is often used. In the case of the dikes, K-Ar and 40Ar/39Ar age dating for the argon captured in the rocks after magmatism is often used. Through U-Pb zircon ages of KURT site granotoids, we expect to solve the clustering problem (granite and granodiorite), which is different from precious chemical analysis (XRF) results and TAS-diagrams. 40Ar/39Ar age dating to be used for the dikes is suitable for the perspective of lithological model of the disposal site. Because, it can compensate for accuracy problems such as sample heterogeneity in K-Ar age dating and is used for volcanic rocks. In the further study, we plan to determine the appropriate sampling locations by the selected age dating methods from the perspective of disposal in this study.

Korea Atomic Energy Research Institute (KAERI) has investigated Pyroprocessing technology in order to decrease the burden of disposal system and increase availability of useful radionuclides in the spent nuclear fuel (SNF) for future. The treatment and the disposal of SNF, however, are very sensitive issues socially. In addition, under the energy transition policy phasing out nuclear energy gradually there have been demands for alternatives so far. Thus various alternatives should need to be investigated in preparation for unexpected situations. This study has been conducted roughly in effectiveness point of view of alternative pre-managements for SNF, not pyroprocessing technology, in disposal system, consisting of three stages according to the degree of burden in disposal system. Stage I is the case for making safety increase with removing highly-mobile radionuclides from SNF. Stage II is the case for eliminating high-heat radionuclides additionally, alleviating thermal risk in the disposal system. And Stage III is the case for recovering Uranium in addition to Stage II. These options of pre-management are thought to be able to provide an intuitive strategy for effective diversification of the disposal system. Because several types of waste form from pre-management make it possible to develop the effective, newly-composed waste disposal system according to the properties of radionuclides. And the processability of SNF through pre-management might be combination with available core-drilling technology, being able to design various disposal system as well. Even though the whole, detailed unit processes have not designed yet, mass balance and distributions of radionuclides are performed under the appropriate assumption of engineering processes. As a first step the alternative approaches for SNF pre-management for disposal system might be expected to be widely used in implementing SNF management policy in the future.

자기공명영상(MRI) 장비의 조영제로 흔히 사용되는 가돌리늄(Gd)은 매우 안정된 상태로 하수처리과정에서 거의 제거되지 않고 수환경으로 유입된다고 알려져 있다. 따라서 본 연구에서는 세 가지의 공법으로 하수처리를 하는 부산 수영 하수처리장에서 채취한 하수 시료의 공정별 용존 희토류 원소의 제거율 및 수환경으로 배출되는 인위적 기원 Gd (Gdanth)의 배출량을 평가하고자 하였다. 용존 희토류 원소는 공정별 처리 단계에 따라 무거운 희토류 원소(Tb-Lu)에 비 해 가벼운 희토류 원소(La-Eu)에서 농도가 감소하는 경향을 보였다. 또한 일부 시료에서 나타난 음의(negative) Sm anomaly (<1)는 생물학적 제거 과정에서 Sm이 입자나 인산염과 흡착되어 함께 제거되었을 가능성을 시사한다. 모든 시 료에서 양의(positive) Gd anomaly (149±50, n=9)를 보였으며, 공정별로 측정된 Gd의 총 농도 중 Gdanth은 약 97% 이 상을 차지하는 것으로 나타났다. 이는 하수처리과정에서 Gdanth 이 거의 제거되지 않고 수영강 하류로 배출된다는 것을 의미한다. 일별 처리용량을 고려하여 각 공정에서 배출되는 Gdanth의 배출량은 259 mmol/day로 추정할 수 있다. 본 연 구의 결과는 하수처리장을 통해 수영만 연안으로 Gdanth이 지속적으로 배출될 것으로 예상되며, 향후 Gd의 중장기적인 관측이 필요함을 시사한다.

In this study, the PBL class was applied to a Vietnamese video class. 13 learners were divided into 3 groups, and it was examined whether all learners grew toward their learning goals, and if so, through what process they grew. When group 1 announces a task, groups 2 and 3 perform peer evaluation and submit a peer evaluation sheet. For this, group 1 categorized the contents of peer evaluation into reflecting, partially reflecting, revised, and not reflecting to prepare the presentation evaluation sheet. Further, they were required to write a reason why “not reflecting.” A reflection log was also submitted. As a result of the above, the assignments were immediately revised, supplemented, and developed every week through peer and instructor evaluation. Through this process, the instructor learned in detail what kind of reflection the presenter and team members were doing each week. In particular, learners achieved ‘up-leveling’ with the activeness of immediately accepting each other’s strengths while conducting peer evaluations on each other’s presentations. This shows that the weekly assignments are improved, while the competencies of both the presentation team and peers are developed at the same time.

본 연구에서는 한국 전통 과자인 유과와 강정을 원·부재료와 기기 및 도구, 작업자의 개인위생, 제조공정별 원료에 대한 미생물학적 오염을 분석하였다. 유과제조 과정 중 현장에서 사용하고 있는 세척 방법과 횟수에 따른 미생물 저감효과를 확인하고자 하였다. 강정의 제조 공정 중 튀밥에서 일반세균수 1.2 Log CFU/g, 완제품의 경우 3.7 Log CFU/g까지 점차 증가하였다. 유과의 제조 공정 중 일반세균수는 불림공정에서 일반세균 최대 6.5 Log CFU/g 수준으로 증가하다가 튀김공정에서 1.3 Log CFU/g수준으로 감소하였으나 완제품에서 4.0 Log CFU/g 수준으로 재오염되는 것으로 확인되었다. 이는 제조과정 중에 작업도구와 기기 또는 작업자 등에 의한 교차오염으로 판단되었다. 작업 도구인 주걱의 경우 일반세균 약 4.4 Log CFU/g, 대장균군 4.2 Log CFU/g으로 매우 오염도가 나타났다. 유과의 불림단계에서 7일동안 일반세균 수가 최대 10 Log CFU/g 이상, 대장균군의 경우 6.8 Log CFU/g으로 증가하였다. 손 또는 도구를 이용한 세척 방법과 흐르는 물에 세 척한 방법을 비교하였을 때, 손을 이용하여 수돗물로 10 회 세척하였을 때 일반세균 5.0 Log CFU/g, 대장균군 2.8 Log CFU/g 감소한 것으로 확인되었다. 이상의 결과로 볼 때, 소규모 업체의 전통 한과 제조 시 작업자나 작업 도 구 및 기기 사용 후 세척 및 소독하는 과정이 요구되며 완제품의 미생물 오염도를 감소시키기 위해 현장에 적용할 수 있는 저감화 방법이 필요한 것으로 판단되었다.

This study aims to analyze the types of cognitive process required to perform vocabulary learning activities in Middle School English textbooks. For this purpose, 26 middle school English textbooks were examined, including 13 for the first year and another 13 for the second year of middle school. The results indicated that vocabulary learning activities emerged in the phase of reading, and then were categorized into pre-reading vocabulary activities and post-reading ones. Eight types of cognitive process emerged in the pre-reading phase and three types in the post-reading phase. That is, the number of vocabulary activities in pre-reading phase was larger than that in the post-reading phase. In addition, the diversity of vocabulary activities in the pre-reading phase was higher than that in the post-reading phase. Based on these results, this study suggests a new model of vocabulary learning activity in middle school English textbooks. A few implications on how to teach new words in English classrooms are discussed.

멤브레인 기반의 MBRWG (Membrane Bioreactor for Waste Gas) 처리기술은 폐가스 흐름에 대한 높은 선택성을 바탕으로 효과적인 생물학적 제거를 수행할 수 있다. MBRWG에는 몇 가지 잠재적 이점이 있는데, 이 중 가장 두드러진 점은 기상과 액상이 멤브레인 양쪽으로 명확히 분리되어 액상 내 생물막의 최적제어가 용이하고 이를 통해 효과적인 생분해와 생물막의 활성화를 도모할 수 있다는 것이다. MBRWG 처리기술은 특히 xylene 같은 소수성 독성 기체 성분 제거에 유리한데 이는 소수성 기체의 물질전달속도, 독성 및 제거율이 생물막 인근의 액상흐름 및 수분제어에 민감하게 변화하기 때문이다. MBRWG 처리에 쓰이는 다양한 멤브레인 중에서 PDMS-중공사막(hollow fiber)이 가장 높은 기체 물질 전달을 제공한다고 보고되었다. Capillary 형태도 중공사막형태에 비해 비표면적은 낮지만 비교적 활발한 연구가 진행되고 있다. 소수성 기체성분 제거 외에도 기존 생물학적 폐가스 처리 장치에서 배출된 잔류 기체 혼합물이나 먼지를 제거하기 위한 후단 공정에서 멤브레인 활용을 고려할 수 있다.

본 연구에서는 가물치(Channa argus) 추출물의 신경세포 분화와 산화 스트레스에서의 효능을 분석하기 위하여 녹차와 효소를 이용한 다양한 추출 방법(상온 추출물, RE; 녹차 상온 추출물, GRE; 효소 상온 추출물, ERE; 녹차 효소 상온 추출물, GERE)을 사용하여 제조 된 추출물의 아미노산 조성과 항산화 활성을 비교 분석하였고, 신경성장인자 (NGF) 유도 신경세포 분화 및 과산화수소 처리에 의해 유도된 PC12 세포 독성에 대한 보호효과를 규명하고자 하였다. 총 아미노산 함량은 RE 및 GRE보다 효소 추출물인 ERE 및 GERE에서 훨씬 더 높았다. 효소 가수 분해물 (ERE 및 GERE)에서 ABTS 라디칼 소거 활성은 RE 및 GRE보다 높았다. 또한, RE와 ERE는 PC12 세포에서 neuronal growth factor (NGF) 매개 신경 돌기 성장뿐만 아 니라 growth associated protein (GAP)-43 및 synapsin-1의 발현을 현저하게 향상 시켰다. 과산화수소(H2O2)에 의해 손 상된 PC12 세포에 4가지 유형의 Channa argus 추출물을 첨가한 후 PC12 세포의 생존율을 측정하였다. PC12 세포 의 생존율은 RE, GRE, GERE에서 각각 77.5±1.9%, 84.0±0.8%, 81.1±0.9%이였다. 이러한 세포 생존율은 H2O2 만을 처리 한 음성 대조군(70.0±2.0%)에 비해 더 높았다. H2O2 처리에 의해 유도 된 세포 독성도 RE, GRE 및 GERE 처리에 대한 반응으로 상당히 완화되었다. 종합하면, Channa argus 추출물은 산화 스트레스와 신경 손상을 감소시키는 기능성 물질로 유용하다는 것을 시사하며, 향후 이들 소재를 활용한 다양한 기능성 제품의 개발이 필요할 것으로 판단된다.

The present study investigated newly recruited native-speaking teachers of the English Programin Korea (EPIK) with a focus on their individual characteristics, their perceptions on second language (L2) learning and teaching processes, and their teaching experience as a variable (novice vs. expert) in their understanding of language learning and teaching processes. A questionnaire wasgiven to 244 EPIK teachers. Analysis of the self-reported data revealed that EPIK teachers were mostly in their 20s who were recruited from six inner-circle countries withteaching certificates. Results also demonstrated the importance of a teacher’s teaching experience, where subsequent mean-difference models of novice and expert teachers revealed significant differences in their understanding of L2 learning and teaching processes. Findings showed that teachers with experience had beliefs aligned with thebest teaching practices. These findings open discussions about the necessity of adequate subsequent support for native-speaking teachers.

온도와 CO2 농도는 버섯의 생육과 품질에 영향을 미친다. 특히, 버섯의 호흡에 의한 고농도 CO2는 버섯의 생리 장해를 발생시킨다. 본 연구에서는 생육 시기와 솎아내기 여부에 따른 새송이 버섯(Pleurotus eryngii (DC.) Quél)의 CO2 발생 속도를 정량화 하였다. 버섯의 자실체를 포함하는 배지의 CO2 발생 속도는 솎아내기 전에 비해 후에 통계적으로 유의미한 상승을 보였다. 호흡 모델에서 자실체의 유지 계수와 CO2 발생 계수는 온도에 따른 이차식으로 표현되었다. 버섯 1병의 CO2 발생 속도 모델에 의한 추정치는 실측치와 검증을 통해 R 2 = 0.71의 결과를 나타내었다. 이로부터 버섯의 CO2 발생 속도는 생육 시기에 따라 지수적으로, 16℃에서 25℃ 범위에서 이차함수 형태로 증가함을 확인하였다. 본 연구에서 정립한 새송이 버섯의 CO2 발생 속도 모델은 새송이버섯을 재배사의 CO2 와 온도 관리를 위해 사용될 수 있다.