The seven-year research project entitled “Development of workflow for integrated 3D geological site descriptive modeling” is being carried out from 2023. This research is funded by Ministry of Trade, Industry, and Energy (MOTIE). Progress of the research is discussed here. The integrated 3D geological SDM (site descriptive model; GSDM hereafter) consists of three part; 1) three dimensional representation of geologic elements, 2) database for material properties and modeling results from SDMs of other disciplines (e.g., rock mechanics), and 3) a visualization tool for geology, material properties and modeling results. The GSDM is comparable to the GDSMs of SKB and POSIVA in its representation of geology by volume of geologic elements. However, our GSDM is different in that extra information of material properties and an extra tool for visualization is included in the GDSM. The rationale for incorporating material properties and a visualization tool into the GSDM is to expedite the development of the GSDM and SDMs of other disciplines by allowing single institution to integrate database and visualization with the GSDM. SKUA-GOCAD is used for representation of geologic surfaces for ductile and brittle shear zones, and also for surfaces for delineation of volumes of rock units. We have adopted SKUAGOCAD because the program offers powerful functions of interpolation including borehole data and geophysical prospecting. So far, we have tested the program for five different geologies, including sedimentary, high-grade metamorphic, and intrusive igneous geology. The test results are promising. Incorporation of data and modeling results for the SDMs of other disciplines is at conceptual stage. The working conceptual model involves the following steps, 1) to provide the modeler of other disciplines with surface information representing geologic elements, 2) the modeler returns not only material properties but the results of numerical analysis, and 3) incorporation of material properties and modeling results into database. Since the numerical codes in other disciplines adopt different types of formats for 3D geology, we plan to adopt the widely used FEM format prepared by Gmsh. The visualization tool will also adopt Gmsh for graphical representation of 3D geology as well as database for material properties and modeling results. When the working model of GSDM becomes available, rapid and significant progress is expected in the SDMs of other disciplines and related areas, for example, geotechnical investigation for deep geological repository.

The effectiveness of a crystalline natural barrier in providing sealing capabilities is based on the behavior of numerous fractures and their intersections within the rock mass. It is important to evaluate the evolving characteristics of fractured rock, as the hydro-mechanical coupled processes occurring through these fractures play a dominant role. KAERI is actively developing a true tri-axial compression test system and concurrently conducting hydro-mechanical experiments using replicated fractured rock samples. This research is focused on a comprehensive examination of coupled processes within fractures, with a particular emphasis on the development of true tri-axial testing equipment. The designed test system has the capability to account for three-dimensional stress conditions, including vertical and both maximum and minimum horizontal principal stresses, realizing the disposal conditions at specific underground depths. Notably, the KAERI-designed test system employs the mixed true tri-axial concept, also known as the Mogi-type, which allows for fluid flow into fractures under tri-axial compression conditions. This system utilizes a hydraulic chamber to maintain constant stress in one direction through the application of oil pressure, while the other two directional stresses are applied using rigid platens with varying magnitudes. Once these mechanical stress conditions are established, control over fluid flow is achieved through the rigid platens in contact with the specimen section. This pioneering approach effectively replicates in-situ mechanical conditions while concurrently observing the internal fluid flow patterns within fractures, thereby enhancing our capacity to study these coupled phenomena. As future research, numerical modeling efforts will be proceeding with experimental data-driven approaches to simulate the coupled behavior within the fractures. In these numerical studies, two distinct fracture geometry domains will be generated, one employing simplified rough-walled fractures and the other utilizing mismatched rough-walled fractures. These investigations mark the preliminary steps in the process of selecting and validating an appropriate numerical model for understanding the hydro-mechanical evolution within fractures.

It is crucial to understand the hydro-mechanical behavior of rock mass to assess the performance of natural barriers. As rock fractures serve as both mechanically weak planes and prominent pathways for hydraulic flow, they significantly influence the hydro-mechanical behavior of the rock mass. Hence, understanding the characteristics of rock fractures is necessary to analyze the long-term behavior of natural barriers. In particular, fracture apertures are crucial parameters directly associated with groundwater flow and consequently hold significant importance in determining the hydro-mechanical behavior of natural barriers. Fracture apertures are defined as mechanical and hydraulic apertures, and various studies have been conducted to measure and analyze them. However, direct measurement of mechanical aperture according to changes in normal stress is known to be a challenging task. For this reason, there has been a scarcity of direct comparative findings between mechanical and hydraulic apertures under various normal stress conditions. This study aims to analyze the characteristics of the mechanical and hydraulic apertures according to changes in normal stress based on experimental results. A digital analysis technique using a pressure film image was applied to analyze the mechanical aperture characteristics of the fracture. This technique can be applied by performing a pressure film compression test and a normal stiffness test on a fracture specimen, and has the advantage of being able to derive mechanical apertures under various normal stress conditions. The hydraulic aperture characteristics of the fracture were analyzed based on Cubic law after measuring the flow rate by performing a constant pressure injection test under triaxial compression conditions. By applying various confining pressures, it was possible to examine the hydraulic apertures according to changes in normal stress conditions. Through the experimental results, the relationship between the mechanical and hydraulic apertures of the fracture was summarized under various normal stress conditions. In addition, the experimental results were used to examine the applicability of various empirical equations for mechanical and hydraulic apertures proposed in previous studies. The characteristics of the fracture aperture resulting from this study are significant because they are required in the hydro-mechanical model of natural barriers. Future studies will entail further experiments, with the objective of establishing novel relationships based on the accumulation of experimental data.

The nuclide management process for reducing the environmental burden being developed by the Korea Atomic Energy Research Institute is performed in molten salts, resulting in contaminated salt wastes containing fission products such as Cs, Sr, Ba, and rare-earth nuclides. In addition, the spent fuel of a molten salt reactor (MSR) contains a variety of fission products, and a purification process may be required for the reuse of the salt and the separation and disposal of the fission products in the spent nuclear fuel. The melt-crystallization method is a technique used for the purification and separation of chemicals or metals based on the different melting points of the different substances. In a recent study, our group developed a reactive-crystallization method using Li2CO3 precipitation agent to precipitate metal corrosion from the reactor through a chlorination reaction by HCl and Cl2, which may occur in chloride molten salt, and successfully precipitated the metal precipitate and purified and recovered LiCl salt. In this study, reactive-crystallization method has been established for removing fission products and corrosive materials. Using the reactive crystallization method, white LiCl-KCl salt that was not discolored by metal corrosion was recovered through the crystallization plates, and fission products and metal elements were shown to be suppressed to several ppm in the purified salt. Consequently, high-purity salts were recovered with high nuclide and corrosive separation efficiencies. The reactive crystallization procedure can also be applied to other salt waste systems, such as MSR nuclear fuel treatment and molten salt chemistry for the elimination of corrosive substances.

The solid-state chemistry of uranium is essential to the nuclear fuel cycle. Uranyl nitrate is a key compound that is produced at various stages of the nuclear fuel cycle, both in front-end and backend cycles. It is typically formed by dissolving spent nuclear fuel in nitric acid or through a wet conversion process for the preparation of UF6. Additionally, uranium oxides are a primary consideration in the nuclear fuel cycle because they are the most commonly used nuclear fuel in commercial nuclear reactors. Therefore, it is crucial to understand the oxidation and thermal behavior of uranium oxides and uranyl nitrates. Under the ‘2023 Nuclear Global Researcher Training Program for the Back-end Nuclear Fuel Cycle,’ supported by KONICOF, several experiments were conducted at IMRAM (Institute of Multidisciplinary Research for Advanced Materials) at Tohoku University. First, the recovery ratio of uranium was analyzed during the synthesis of uranyl nitrate by dissolving the actual radioisotope, U3O8, in a nitric acid solution. Second, thermogravimetric-differential thermal analysis (TG-DTA) of uranyl nitrate (UO2(NO3)2) and hyper-stoichiometric uranium dioxide (UO2+X) was performed. The enthalpy change was discussed to confirm the mechanism of thermal decomposition of uranyl nitrate under heating conditions and to determine the chemical hydrate form of uranyl nitrate. In the case of UO2+X, the value of ‘x’ was determined through the calculation of weight change data, and the initial form was verified using the phase diagram for the U-O system. Finally, the formation of a few UO2+X compounds was observed with heat treatment of uranyl nitrate and uranium dioxide at different temperature intervals (450°C-600°C). As a result of these studies, a deeper understanding of the thermal and chemical behavior of uranium compounds was achieved. This knowledge is vital for improving the efficiency and safety of nuclear fuel cycle processes and contributes to advancements in nuclear science and technology.

In nuclear fuel development research, consideration of the back-end cycle is essential. In particular, a review of an in-reactor performance of nuclear fuel related to the various degradation phenomena that can occur during spent fuel dry storage is an important area. The important factors affecting the degradation of zirconium-based cladding during dry storage are the cladding’s hydrogen concentration and rod internal pressure after irradiation. In this study, a preliminary analysis of the in-reactor behavior of the HANA cladding, which has been developed and is currently undergoing licensing review, was performed, and based on this result, a comparative analysis between nuclear fuel with HANA cladding and current commercial fuel under storage conditions was performed. The results show that the rod internal pressure of nuclear fuel with HANA cladding is not significantly different from that of commercial cladding, and the hydrogen concentration in the cladding tends to reduce due to the increased corrosion resistance, so fuel integrity in a dry storage conditions is not expected to be a major problem. Although the lack of cladding creep data under dry storage conditions, the results from the Halden research reactor test comparing in-reactor creep behavior with Zircaloy-4 showed that there is sufficient margin for degradation due to creep during storage.

Once discharged, spent nuclear fuel undergoes an initial cooling process within deactivation pools situated at the reactor site. This cooling step is crucial for reducing the fuel’s temperature. Once the heat has sufficiently diminished, two viable options emerge: reprocessing or interim storage. A method known as PUREX, for aqueous nuclear reprocessing, involves a chemical procedure aimed at separating uranium and plutonium from the spent nuclear fuel. This separation not only minimizes waste volume but also facilitates the reuse of the extracted materials as fuel for nuclear reactors. The transformation of uranium oxides through dissolution in nitric acid followed by drying results in uranium taking the form of UO2(NO3)2 + 6H2O, which can then be converted into various solid-state configurations through different heat treatments. This study specifically focuses on investigating the phase transitions of artificially synthesized UO2(NO3)2 + 6H2O subjected to heat treatment at various temperatures (450, 500, 550, 600°C) using X-ray Diffraction (XRD) analysis. Heat treatments were also conducted on UO2 to analyze its phase transformations. Additionally, the study utilized XRD analysis on an unidentified oxidized uranium oxide, UO2+X, and employed lattice parameters and Bragg’s law to ascertain the oxidation state of the unknown sample. To synthesize UO2(NO3)2 + 6H2O, U3O8 powder is first dissolved in a 20% HNO3 solution. The solid UO2(NO3)2 + 6H2O is obtained after drying on a hotplate and is subsequently subjected to heat treatment at temperatures of 450, 500, 550, and 600°C. As the heat treatment temperature increases, the color of the samples transitions from orange to dark green, indicating the formation of different phases at different temperatures. XRD analysis confirms that uranyl nitrate, when heattreated at 500 and 550°C, oxidizes to UO3, while the sample subjected to 600°C heat treatment transforms into U3O8 due to the higher temperature. All samples exhibit sharp crystal peaks in their XRD spectra, except for the one heat-treated at 450°C. In the second experiment, the XRD spectra of the heat-treated UO2 consistently indicate the presence of U3O8 rather than UO3, regardless of the temperature. Under an oxidizing atmosphere within a temperature range of 300 to 700°C, UO2 can be oxidized to form U3O8. In the final experiment, the oxidation state of the unknown UO2+X was determined using Bragg’s law and lattice parameters, revealing that it was a material in which UO2 had been oxidized, resulting in an oxidation state of UO2.24.

The developmental biology and morphological characteristics of the immature stages of Hypolimnas bolina were studied in the laboratory using host plant, Ipomoea batatas (L.) Lam. This species has six larval stadia, with an egg period of 2.4 ± 0.54 days, a larval period of 16.8 ± 2.3 days, and a pupal period of 10 ± 1 days. It takes approximately 30 days to mature from egg to adult. Illustrations and descriptions of the various immature stages and their behaviors are provided.

농가 현장에서는 미소 해충의 약제저항성 발달로 인하여 방제에 어려움을 겪고 있다. 본 연구는 약제저항성 수준을 효율적으로 진단하고, 화학적 방제 의사결정을 지원할 수 있는 약제저항성 관리 플랫폼을 구축하고자 수행하였다. 플랫폼은 크게 ⅰ) 농가 맞춤형 약제 추천, ⅱ) 지역별 약제저항성 지도로 구성되어 있다. 이용자는 잔류접촉법 기반의 생물검정법 RCVpW(Residual Contact Vial plus Water) 결과를 현장에서 입력하면 PLS에 부합 한 약제 정보를 제공받을 수 있다. 또한 생물검정 결과는 DB화를 통해 지역별 약제 저항성 정보 지도를 보여줌으 로써 해충별, 작물별, 연도별 저항성 패턴 결과를 확인할 수 있다. 본 플랫폼을 활용한다면 약제의 오남용을 줄임 은 물론 해충의 약제저항성 발달 지연 및 약제저항성 발달 양상을 확인할 수 있어 향후 방제전략 수립에 활용할 수 있을 것으로 생각된다.

참깨는 건전 유기 종자생산을 위해서는 Corynespora cassicola 등과 같은 종자전염 병원균의 감염을 최소화해 야 하므로 비가림하우스 내에서의 종자생산이 필수적이다. 그러나 비가림하우스 재배 시 진딧물의 대발생으로 참깨의 생산량 저하 되므로 본 연구에서는 참깨 비가림하우스 내 유기 재배 시, 진딧물에 대한 효과적인 유기농업 자재를 선발하고자 한다. 등록된 유기농업자재 8종 중 4종을 기내에서 선발하였으며 선발된 유기농업자재 4종을 참깨 재배기간 중 주 1회 처리한 결과, 처리 간 유의한 차이가 나타났다. 수확기인 8월 3일 기준 무처리구 대비 데리스추출물 70%와 데리스 20%+시트로넬라 30%+계피추출물 10%은 12.3%, 9.0%만이 고사하여 우수한 방제 효과를 나타냈다. 본 연구 결과는 참깨 재배 시 농림현장에서 발생하는 복숭아혹진딧물에 대한 유기농업자재 효과를 검정함으로써 유기재배 농가의 자재 선택에 대한 정보를 제공하고자 한다

본 연구는 벼 화분에 잔류한 네오니코티노이드계 약제가 꿀벌 봉군 내로 유입하여 만성적으로 피해를 주는지 에 대해 실험적으로 검증하고자 한다. 벼 꽃 개화기에 맞춰 논 인근의 세 지역에 각 6개 봉군을 설치하였다. 3개의 지역 중 두 지역은 벼 꽃 개화기 항공 방제 수행지역이고, 1개 지역은 미수행 지역이다. 지역마다 봉군 3개에는 채분기를 설치하여 벌통 내 화분 유입을 차단한 그룹과 미설치 그룹 간 봉세와 꿀벌 면역 및 수명 관련 유전자 발현량을 비교하였다. 약제 방제가 수행된 지역에서 채분기를 설치한 봉군의 봉세는 미설치 봉군보다 상대적으 로 강한 것을 확인하였다. 또한, 약제 처리 지역에서 채분기 설치 봉군에서 채분기를 설치한 봉군의 봉세는 미설치 봉군보다 상대적으로 강한 것을 확인하였다. 또한, 약제 처리 지역에서 채분기 설치 봉군에서 채집된 꿀벌의 면역 및 수명 관련 유전자 발현량이 미설치 그룹과 차이가 있는 것을 확인하였다.

생활권 수목이란 주민들이 생활하는 지역에 식재된 수목으로, 가로수, 학교수목, 아파트 수목 등 종류가 다양 하며 도시경관과 생활환경 개선의 이점을 제공한다. 그러므로 생활권 수목의 유지와 관리에 있어서도 인근 주민 에 혐오감이나 피해가 없도록 방제를 수행하는 것이 매우 중요하다. 일반적인 경엽살포의 경우, 약액 비산에 의해 주민들의 활동 제한, 안전사고 및 재산상 피해가 발생할 수 있으므로 사용이 제한적이다. 이러한 문제를 해결하기 위해, 나무에 약제를 직접 주입하는 나무주사(trunk injection)가 보편적인 생활권 수목 방제법으로 주목 받고 있으며, 이는 주입물질의 손실이 없고, 외부환경에 크게 영향 받지 않는다는 장점이 있다. 하지만 생활권 수목 전반에 대한 나무주사 처리방법이 명확하지 않아 약효가 일부 가지에서만 나타나는 등 사후 검증 및 관리가 미흡한 실정이다. 본 연구는 생활권 수목 병해충 방제 나무주사 제품의 효과제고를 위한 기존 처리방법 개선 및 최적의 약제처리 방법을 검증하였다. 느티나무외줄면충(Colopha moriokaensis)을 대상으로 시험을 진행하였 으며, Acetamiprid을 시험약제로 사용하였다. 느티나무에 대하여 약제처리 위치, 주입량, 천공수, 주사시기에 따른 약효 및 약해를 확인하였으며, 이를 바탕으로 최적의 약제처리 방법을 제시하였다.

Climate change and biological invasions are the greatest threats to biodiversity, agriculture, health and the global economy. Tomato leafminer(Tuta absoluta) (Meyrick) (Lepidoptera: Gelechiidae) is one of the most important threats to agriculture worldwide. This pest is characterized by rapid reproduction, strong dispersal ability, and highly overlapping of generations. Plants are damaged by direct feeding on leaves, stems, buds, calyces, young ripe fruits and by the invasion of secondary pathogens which enter through the wounds made by the pest. Since it invaded Spain in 2006, it has spread to Europe, the Mediterranean region, and, in 2010, to some countries in Central Asia and Southeast Asia. In East Asia, Tomato leafminer was first detected in China in Yili, Xinjiang Uygur Autonomous Region, in 2017. There is a possibility that this pest will invade South Korea as well. This study provides this by the use of MaxEnt algorithm for modelling the potential geographical distribution of Tomato Leafminer in South Korea Using presence-only data.

The rate of resistant pest emergence has accelerated due to the continuous use of pesticides. Therefore, it is important to formulate insecticide resistance management measures and effective control methods for pest. Bemisia tabaci, a greenhouse pest, causes direct damage to crops such as growth inhibition and leaf discoloration at all developmental stages except for eggs. It also indirectly damages plants by secreting honeydew, which covers surrounding leaves and fruits, leading to sooty mold development. In this study, eight insecticides with high usage rates, categorized by their mode of action, were selected. Samples of Bemisia tabaci were collected from six regions, and resistance analysis were conducted. The results showed that Flonicamid exhibited a resistance ratio of 8.91 in Sejong, while Pyriproxyfen showed a high resistance ratio of 63.56 in Gunwi. Fluxametamide, Spinetoram, Cyantraniliprole, Dinotefuran, Pyridaben, and Milbemectin displayed resistance ratio ranging from 0.02 to 1.14 in most regions, except for Flonicamid and Pyriproxyfen.

The utilization of methyl bromide (MB) for quarantine purposes has been hampered by its designation as an ozone-depleting substance under the Montreal Protocol. The International Plant Protection Convention's (IPPC) call for alternatives to MB and a reduction in its usage. There is an urgent need to explore and implement substitutes. Despite some substitute agents like EDN being developed for wood, EDN has been limited due to various factors such as occupational risks. This study focuses on evaluating the efficacy of Sulfuryl Fluoride (SF) as a viable alternative fumigant against Reticulitermes speratus, one of major wood destroying pests. Experimental trials conducted at ambient temperature (23°C) revealed promising results, with SF demonstrating LCT50 and LCT99 values of 30.87 mg·h/L and 42.53 mg·h/L, respectively. Under low-temperature conditions (5°C), SF remained effective but with slightly higher LCT50 and LCT99 values of 151.62 mg·h/L and 401.90 mg·h/L, respectively. The penetration test, conducted using R. speratus-infested pine wood cubes, further highlighted SF's efficacy, with LCT50 and LCT99 values of 31.59 mg·h/L and 53.34mg·h/L at 23°C, indicating powerful penetration capabilities. When tested at a loading ratio of 90% (v/v) at 5.0mg/L for 24 hours in a 500L chamber as a middle-scale trial, SF achieved a 100% mortality, showing its potential as a suitable replacement for MB. These findings suggest that SF could open new markets as an MB substitute and enhance safety at quarantine sites when applied to imported and exported timber.

This study investigated which factors impact esports viewership for League of Legends matches through Live and highLight streaming video. This research anaLyzed League of Legends viewership factors' differences between the three Leagues (LCK, LCS, and LEC) where viewership factors infLuence esports viewership demand through LOL’s Live and highLight streaming video. League of Legends not onLy has the highest audience among different various esports, aLso has formed a huge market from diverse countries. In order to soLve each League's unbaLance viewership trend issue between the three Leagues, and facing worLdwide viewership decrease, this study examined viewership impact factors from three Leagues with the highest viewership ratings: Korea's LCK, North America's LCS, and Europe's LEC. After that, differences in viewership impact factors for the research were anaLyzed and compared to each League. SpecificaLLy, this study investigated which factors impact esports viewership for League of Legends (LOL) matches. Data (N=1581) of reguLar season matches from the LCK, LCS, and LEC Leagues (2020 spring to 2021 summer) were coLLected and anaLyzed. This study anaLyzed the average number of visitors per minute of Twitch Live streaming and the number of views on YouTube highLights. Five main viewership factors(the uncertainty of match, consumer preferences, match importance, team attributes, match content, and controL variabLes), and seventeen independent variabLes were verified by muLtipLe regression anaLysis using STATA 15. As a resuLt of the anaLysis, the modeL with the number of reaL-time audience as the dependent variabLe demonstrated different trends between Leagues in terms of the uncertainty of match factors (rank difference, win rate difference, goLd difference, kiLL difference, object difference), and consumer preference factors(fan, operating period of both teams, number of worLd championship wins, the number of championship semifinaL advances). WhiLe the match importance factors(week, top-rank matches) and match content factors (the sum of kiLLs, the sum of assists, the sum of objects) indicated somewhat simiLar tendencies between Leagues. In the modeL with the number of highLights views as the dependent variabLe, consumer preference factors and match importance factors tended to be somewhat simiLar, but match content factors prone to be sLightLy different between Leagues. In addition, the uncertainty of the match factors did not show a significant infLuence across the three Leagues. Findings from this research expand and appLy the variabLes derived from the demand determination theory of traditionaL sports to e-sports demand research. This study heLps stakehoLders understand various esports cuLtures from different regions. Furthermore, it is meaningfuL in that it provides information that wiLL contribute to the growth of the entire League of Legends market through baLanced deveLopment between Leagues.

Blockchain is an immutable ledger that records transactions and tracks assets using a common communication protocol. It stores a copy of the blockchain and implements a consensus function to verify transactions. Blockchain is applied to industries beyond finance, such as retail, to maintain security and transparency. Consumers with knowledge of blockchain technology are likely to be affected when evaluating products with blockchain embedded, impacting their product evaluation. The study investigates the impact of blockchain technology on consumers' product evaluation and how knowledge of blockchain and product quality moderate its effects.