본 연구는 국립수목원 내 전문전시원에 발생한 이입식물을 대상으로 2015년부터 2023년까지 이입식물 분포조사를 시행 하였다. 그 결과 자생식물 299종, 귀화식물 49종, 재배식물 13 종 총 63과 214속 361종이 조사되었다. 국화과가 63종으로 가장 많았고, 벼과, 사초과 순으로 발생하였다. 이입식물의 이입 경로를 분석하기 위하여 광릉숲에 분포하는 식물상과 비교 분석 한 결과 309종이 광릉숲에 분포하는 식물로 확인되었으며, 전 문전시원 내 식재 식물이 확산된 경우가 17종으로 조사되었다. 조사된 귀화식물 49종을 원산지별로 구분하면 유럽과 북아메리카가 69.4%, 이입 시기별 1기와 3기의 비율이 90%를 차지하였 다. 귀화식물의 귀화도 분포 등급을 적용한 결과 4등급 이상이 면서 이입 시기가 3기인 식물 9종은 빠르게 확산할 우려가 큰 식물이므로 지속적인 모니터링이 필요하다. 국립수목원에 어느 정도 귀화식물이 분포하는지를 가늠하는 도시화지수를 산출한 결과 15.0%로 나타났으며, 환경부 지정 생태계교란 야생식물 중 돼지풀, 단풍잎돼지풀, 애기수영, 미국쑥부쟁이가 출현하였 다. 이입식물은 자생식물군락과 전문전시원 내 관람로에 침입하 여 세력권을 확장하고 우점하는 경향이 있어 각각의 생태적 특 성을 고려한 제거 방법이 필요하다.
The development of thermoelectric (TE) materials to replace Bi2Te3 alloys is emerging as a hot issue with the potential for wider practical applications. In particular, layered Zintl-phase materials, which can appropriately control carrier and phonon transport behaviors, are being considered as promising candidates. However, limited data have been reported on the thermoelectric properties of metal-Sb materials that can be transformed into layered materials through the insertion of cations. In this study, we synthesized FeSb and MnSb, which are used as base materials for advanced thermoelectric materials. They were confirmed as single-phase materials by analyzing X-ray diffraction patterns. Based on electrical conductivity, the Seebeck coefficient, and thermal conductivity of both materials characterized as a function of temperature, the zT values of MnSb and FeSb were calculated to be 0.00119 and 0.00026, respectively. These properties provide a fundamental data for developing layered Zintl-phase materials with alkali/alkaline earth metal insertions.
Background: This study focused on reproductive traits in Hanwoo cattle, specifically the environmental factors affecting gestation length and birth weight. Methods: The records of 1,540 cows calved at the Hanwoo Research Institute from 2015 to 2023 were examined. This study analyzed two populations, linebreeding Hanwoo (LBH) and general Hanwoo (GH), with all cows undergoing estrus synchronization and artificial insemination. The R software was used to compare the differences between the two populations and analyze the environmental factors affecting each trait. Results: The results showed that the average gestation length for LBH was 283.28 ± 5.93 days, which was significantly shorter than that of the GH, which had an average of 285.63 ± 6.21 days (p < 0.001). The average birth weight of LBH calves was 25.10 ± 3.69 kg, significantly lighter than GH calves, which weighed 27.26 ± 4.11 kg on average (p < 0.001). Analysis of environmental factors revealed significant differences in the gestation length of LBH based on dam parity, year, and season of calving. However, no significant differences were observed based on calf sex. For LBH, birth weight showed significant differences based on dam parity, year of calving, and sex of the calf, but not the season of calving. In GH, gestation length varied with dam parity and calving season, but not with calving year or calf sex. The GH birth weight showed differences based on dam parity, year of calving, and calf sex, but not the season of calving. Conclusions: Reproductive traits in the Hanwoo cattle industry are economically vital but are heavily influenced by environmental factors due to their low heritability. An accurate evaluation of the genetic potential of these traits requires an analysis of the environmental factors affecting them. The results of this study serve as foundational data for predicting the potential for genetic improvement in the gestation length and birth weight of Hanwoo cattle.
광릉 숲의 곤충상 조사는 1932년으로 거슬러 올라간다. 광릉 숲의 경로조사법에 의한 나비상 모니터링 연구는 1998년부터 2023년까지 지속되었다. 26년 동안 총 223회 조사를 실시한 결과 118종, 20,181개체가 확인되었다. 봄철 출현하는 나비중 8종(노랑나비, 대만흰나비, 먹부전나비, 멧팔랑나비, 쇳빛부전나비, 애호랑나비, 큰줄흰나 비, 흰줄표범나비)은 첫 출현일이 빨라지는 경향을 보였으며, 평균 5.2일 빨라졌다. 조사된 나비중에서 큰줄흰나 비, 뿔나비, 남방부전나비 순서로 많은 개체수가 확인되었으며, 연 출현 빈도는 큰줄흰나비가 26회로 가장 많았다. 확인된 나비의 분포, 서식지, 식성에 따라 분류한 결과 분포는 북방계 27%, 남방계 14%이며, 서식지는 산림 경계 36%, 산림 내부 33%, 초지 30% 그리고 식성은 다식성 8%, 단식성 42%, 협식성 51%로 이루어진 것이 확인되었다. 또한, 기후변화 따른 나비류 생활주기 변화 여부를 검토하여 지구온난화 지표 자료로 활용할 계획이다.
Three species belonging to two families of minute-sized spiders, viz, Theridiosoma fulvum (Araneae: Theridiosomatidae), Microdipoena ogatai and Microdipoena shenyang (Araneae: Mysmenidae), were discovered for the first time in Korea. Previously T. fulvum and M. ogatai were known to distribute only in Japan, M. shenyang only in China. All former records of Microdipoena jobi from Korea are misidentifications of M. shenyang. Detailed descriptions and photographs of three species are provided.
Nemophora Hoffmannsegg, 1798 is a relatively large group in Adelidae, including about 350 species worldwide. Only 13 species are known to Korean insect fauna up to date. The present study is to report N. ochsenheimerella, which is new to Korea. N. ochsenheimerella is externally similar to N. wakayamensis but can be distinguished by having characters in male genitalia as follows: cucullus longer than N. wakayamensis and N. ochsenheimerella has two rows of curnus consisting of numerous minute spines.
This study focused on the genomic analysis of Anopheles kleini and Anopheles pullus, both vectors of vivax malaria within the Anopheles Hyrcanus group. Using Illumina NovaSeq600 and Oxford Nanopore platforms, we identified 126 and 116 contigs, along with 40,420 and 32,749 genes from An. kleini and An. pullus, respectively. The assembled genome sizes were 282 Mb for An. kleini and 247 Mb for An. pullus, which are within a similar range to the sizes previously estimated by digital PCR (249 Mb and 226 Mb). We are currently also estimating the genome sizes of other Anopheles spp. and manually curating key genes determining vectorial capacity.
Fall armyworm (FAW, Spodoptera frugiperda) is a major pest worldwide, and since its first domestic invasion was confirmed in 2019, its damage has been steadily increasing in crops such as corn until recently. In order to provide basic data for the management of FAW, we conducted a comparison of host preference and nutritional composition analysis of corn varieties. A total of 12 varieties of corn were selected for the experiment. To investigate the preference among the varieties, we examined the host preferences at the population level and the individual level, and found no statistically significant differences. In the population-level experiment, the highest damage rate was observed for Saekso 4 and the lowest for Heukgeom 2. In the individual-level experiment, the highest damage rate was found for Kangilok and the lowest for Oryun 2 when using leaves, and the highest for Saekso 1 and the lowest for Dreamok when using stems. As a result, the population-level and individual-level results were not consistent, suggesting that FAW's corn variety preference is not clear and may vary depending on various conditions such as corn tissue. Composition analysis of the 12 varieties showed no correlation between composition and FAW preference among the varieties, and considering the feeding behavior of FAW, which are highly polyphagous, it is recommended to control FAW as early as possible to improve control effectiveness.
Chromosomal level of Korean Diadegma fenestrale (Jeju strain, JK-2023a) of genome assembly was achieved through a combined approach utilizing Nanopore long-read sequencing and Illumina NovaSeq short-read sequencing (approximately 217.2× coverage). The assembled genome spans 221.1 Mb, comprises 68 scaffolds, with most of the genome contained within 11 chromosomal level scaffolds. The completeness of the assembly is reflected in BUSCO assessment, with values reaching 99.6%. Scaffold N50 was 17.4 Mb, and GC % was 40%. RNAseq was performed using RNA extracted from larvae, pupae, and adults at various developmental stages (trimmed RNA-Seq data, 11.3 Gb), and a total of 13,544 genes were predicted by synthesizing the transcriptome information with the annotation information of five closely related species such as, Campoletis sonorensis (GCA_013761285.1), Venturia canescens (GCF_019457755.1), and Nasonia vitripennis (GCF_000002325.3, and GCF_009193385.2). Of these, 13,498 genes were identified by BLAST and are being further analyzed. Although the frequency of DfIV genome integration into the host’s 11 chromosomes varies from 0 to 32%, it was confirmed that all 62 DfIV genome fragments were inserted into the Hymenopteran host genome.
Synthesis of extremely competent materials is of great interest in addressing the energy storage concerns. Manganese oxide nanowires ( MnO2 NWs) are prepared in situ with multiwall carbon nanotubes (MWCNT) and graphene oxide (GO) using a simple and effective hydrothermal method. Powder XRD, Raman and XPS analysis are utilized to examine the structural characteristics and chemical state of composites. The initial specific discharge capacity of pure MnO2 NWs, MnO2 NWs/ MWCNT and MnO2 NWs/rGO composites are 1225, 1589 and 1685 mAh/g, respectively. The MnO2 NWs/MWCNT and MnO2 NWs/rGO composites showed stable behavior with a specific capacity of 957 and 1108 mAh/g, respectively, after 60 cycles. Moreover, MnO2 NWs/rGO composite sustained a specific capacity of 784 mAh/g, even after 250 cycles at a current density of 1 A/g showing outstanding cycling stability.
KEPCO KPS is the contractor for the full system decontamination (FSD) of Kori Unit 1 and under preparation such as modification, lay out for equipment installation, setting up tie-in/out point for chemical injection and way to pressurize the system, of its successful performance. In this research, KPS introduced how KPS has designed and prepared for the FSD project and how will the chemical decontamination process be implemented. As described in the previous research, chemical decontamination process is planned to be conducted for three cycles and each cycle is consisted of oxidation, reduction, decomposition, and purification. Oxidation and reduction process were conducted at 90°C. Chemical decomposition and purification process were conducted at 40°C due to the damage of IX by the heat. If the decontamination result does not meet the target DF and the dose rate, additional cycle can be conducted. Expected volume of process water for FSD is 200 m3. Three systems have been designated as decontamination targets: reactor coolant system (RCS), residual heat removal system (RHRS), chemical volume control system (CVCS). For the steady flow rate, existed plant equipment such as reactor coolant pump (RCP) will be operated and modifications on some components will be conducted. Due to the limited space for installation, decontamination equipment and other resources are distributed to three different places. KPS designed the layout of equipment installed inside the containment vessel. The layout contains the information of shielding for highly radiated equipment such as IX and filter skid.
Conducting a TSPA (Total System Performance Assessment) of the entire spent nuclear fuel disposal system, which includes thousands of disposal holes and their geological surroundings over many thousands of years, is a challenging task. Typically, the TSPA relies on significant efforts involving numerous parts and finite elements, making it computationally demanding. To streamline this process and enhance efficiency, our study introduces a surrogate model built upon the widely recognized U-network machine learning framework. This surrogate model serves as a bridge, correcting the results from a detailed numerical model with a large number of small-sized elements into a simplified one with fewer and large-sized elements. This approach will significantly cut down on computation time while preserving accuracy comparable to those achieved through the detailed numerical model.
Due to the saturation of spent fuel pool of nuclear power plant in Korea, temporary storage for spent fuel will be installed, and spent fuel will be stored and managed in dry cask for a considerable period of time. Since spent nuclear fuel must withstand continuous decay heat, radiation and high internal pressure of the fuel rod in the cask, behavior of spent nuclear fuel is needed to be reviewed. Spent nuclear fuel used in Pressurized Water Reactor (PWR) in Korea is stored in a wet storage currently, but it is going to store a temporary dry-storage facility on Kori site. Therefore, it is very important and meaningful to evaluate the behavior of nuclear fuel with realistic modeling. Also, domestic PWR nuclear fuel has various burn-up. In the past, the burn-up of nuclear fuel in light water reactors was low, but in order to increase power generation efficiency, the concentration of uranium was increased and the number of new fuel was increased. Therefore, a large amount of nuclear fuel with burn-up of 45,000 MWD/MTU or higher, generally called high burn-up, is also stored in the spent fuel pool (SFP). Therefore, it is necessary to evaluate by dividing three different burn-up such as, low, medium, and high burn-up. Thus, this study will review the behavior of nuclear fuel at different burn-up during the temporary storage period with FALCON (EPRI), computational code and analyze the factors affecting the integrity of nuclear fuel, including when the temporary storage is extended its additional lifetime. And this evaluation will contribute developing the spent fuel management plan in Korea.
A lot of CANDU Spent Fuels (CSFs) have been stored in spent nuclear fuel pools and dry storage facilities. In accordance with the enhanced nuclear regulations, the initial characteristics of CSF should be inspected to ensure the integrity of CSF and the reliable operation of storage system before loading it into a cask for long-term dry storage. For the inspections, an initial characteristics measurement equipment was designed, which is used for Pool-Side Examination (PSE) in the spent fuel pool of the pressurized heavy water reactor nuclear power plant. Measurements using the equipment consist of non-contact inspections and contact inspections. The non-contact inspections do not affect CSF integrity, whereas the integrity of CSF can be reduced during the contact inspections under abnormal operating conditions because the probe of equipment may apply specific loads to the CSF. Therefore, the structural integrity evaluations of equipment and CSF are performed using Finite Element (FE) analyses for four combinations based on two abnormal conditions and two probe positions. The used abnormal conditions are the pressing load condition and the scratching load condition, and two probe positions are the center and bottom of the fuel rod in the longitudinal direction, respectively. In this evaluation, the bottoms of the fuel rod or CSF are defined as the regions facing the bottom surface of equipment. The analysis of the pressing load condition is performed by pressing the probe of the equipment in radial direction of the CSF fuel rod. That of the scratching load condition is carried out by applying a specific radial load to the CSF fuel rod using the probe and then applying the load to the surface of the fuel rod while moving axially along the surface. All combinations are analyzed considering geometric, boundary and material non-linearity under the dynamic load, which is dependent on the equipment operating velocity. The stresses of CSF and equipment components were obtained from these analyses. The maximum stress of each component was generated at the combination on the scratching load condition for the bottom position among the four combinations. The obtained maximum stresses are lower than the yield stress for each component material. Also, the CSF is not overturned due to the support plate of the equipment in all analyses. Therefore, the structural integrity and safety of the equipment and the CSF are maintained under abnormal operating conditions during the inspection using the initial characteristic measurement equipment.
Recently, the status of North Korea’s denuclearization has become an international issue, and there are also indications of potential nuclear proliferation among neighboring countries. So, the need for establishment of nuclear activity verification technology and strategy is growing. In terms of ensuring verification completeness, sample collection-based analysis is essential. The concepts of Chain of Custody (CoC) and Continuity of Knowledge (CoK) can be defined in the process of sample extraction as follows: CoC is interpreted as the ‘system for managing the flow of information subjected by the examinee’, and CoK is interpreted as the ‘Continuity of information collection through CoC subjected by the inspector’. In the case of sample collection process in unreported areas for nuclear activity verification, there are additional risks such as worker exposure/kidnapping or sample theft/tampering. Therefore, the introduction of additional devices might be required to maintain CoC and CoK in the unreported area. In this study, an Environmental Geometrical Data Transfer (EGDT) was developed to ensure the safety of workers and the CoC/CoK of the samples during the collection process. This device was designed for achieving both mobility and rechargeability. It is categorized into two modes based on its intended users: sample mode and worker mode. Through the sensors, which is positioned in the rear part of device, such as radiation, gyroscope, light, temperature, humidity and proximity sensors, it can be easily achievable various environmental information in real-time. Additionally, GPS information can also be received, allowing for responsiveness to various hazardous scenarios. Moreover, the OLED display positioned on the front gives us for checking device information such as the current status of the device such as the battery level, the connectivity of wifi, and etc. Finally, an alarm function was integrated to enable rapid awareness during emergency situations. These functions can be updated and modified through Arduino-based firmware, and both the device and the information collected through it can be remotely controlled via custom software. Based on the presented design conditions, a prototype was developed and field assessments were conducted, yielding results within an acceptable margin of error for various scenarios. Through the application of the EGDT developed in this study to the sample collection process for nuclear activity verification purposes, it is expected to achieve a stable maintenance of CoC/CoK through more accurate information transmission and reception.