노지 나방류 해충인 담배거세미나방 방제를 위한 유충기생성 천적 2종인 긴등기생파리와 예쁜가는배고치벌 의 방사조건을 확립하고자 콩 재배포장에서 방사거리 및 방사밀도별 기생율을 조사하였다. 긴등기생파리는 방사 후 24시간 이내 방사지점으로부터 10m까지 이동하여 나방류 유충을 기생하였으며, 예쁜가는배고치벌도 방사지점으로부터 15m에서도 기주유충에 산란하여 고치가 형성된 것이 확인되었다. 긴등기생파리는 면적당 방사밀도가 높아질수록 기생율이 증가했으며, ㎡당 0.15마리(천적:해충=1:5) 방사했을 때 평균기생율 63.1%로 나타났다. 예쁜가는배고치벌은 긴등기생파리와 같은 방사밀도에서 평균기생율 47.8%로 확인되었으나, 방사 밀도에 따른 기생율 차이는 없었다.

M. pruinosa has been found on 98 families and 345 species of plants, indicating a wide host range. Since its first report in a persimmon orchard in Gimhae in 2009, it had spread to 126 municipalities over 12,429 ha. Because of powerful dispersal ability, it’s difficult to control with insecticides. Therefore, it is necessary to reduce the population density through the release of M. pruinosa’s natural enemy, N. typhlocybae. N. typhlocybae females prey on or externally parasitize the nymphs of M. pruinosa. This natural enemy was introduced from Italy in 2017 through an international cooperative project between National Institute of Agricultural Sciences and University of Padova for controlling the sporadic pest, Metcalfa pruinosa. This study reported the results of mass rearing N. typhlocybae indoors and releasing them outdoors from 2020 to 2023 in 21 regions nationwide, showing an average parasitism rate of 27.3% and an average production of 7.9 cocoons per host, suggesting the possibility of their establishment in Korea.

Determining the number of operators who set up the machines in a human-machine system is crucial for maximizing the benefits of automated production machines. A man-machine chart is an effective tool for identifying bottlenecks, improving process efficiency, and determining the optimal number of machines per operator. However, traditional man-machine charts are lacking in accounting for idle times, such as interruptions caused by other material handling equipment. We present an adjusted man-machine chart that determines the number of machines per operator, incorporating idleness as a penalty term. The adjusted man-machine chart efficiently deploys and schedules operators for the hole machining process to enhance productivity, where operators have various idle times, such as break times and waiting times by forklifts or trailers. Further, we conduct a simulation validation of traditional and proposed charts under various operational environments of operators’ fixed and flexible break times. The simulation results indicate that the adjusted man-machine chart is better suited for real-world work environments and significantly improves productivity.

Background: This study investigated quadriceps femoris muscle activity by comparing concentric and eccentric contractions with self-selective squat speed. Objectives: Study participants agreed in advance and included 30 male college students in their 20s without musculoskeletal system disease. Design: A randomized controlled trial. Methods: Participants who participated in this study agreed in advance and recruited 30 male college students in their 20s who had no disease with musculoskeletal system to conduct this study. When squatting at a self-selected speed, the subjects were evaluated using one-way ANOVA to compare concentric and eccentric contraction muscle activity. Results: There were significant differences between the rectus femoris, vastus medialis, and vastus lateralis regarding concentric contractions.contractions. There was a significant difference in vastus medialis but no significant difference between rectus femoris and vastus lateralis for eccentric contractions. Conclusion: During concentric contraction, all muscles and eccentric contractions indicated significant improvement in the vastus medialis. Therefore, to minimize knee joint injury and maximize efficient muscle activity, self-selected slow and moderate speeds based on self-selection speed when performing the sit-down motion during a squat and moderate speed with fast motions when performing the standing motion should be considered as high muscle activities.

The initial development plans for the six reactor designs, soon after the release of Generation IV International Forum (GIF) TRM in 2002, were characterized by high ambition [1]. Specifically, the sodium-cooled fast reactor (SFR) and very-high temperature reactor (VHTR) gained significant attention and were expected to reach the validation stage by the 2020s, with commercial viability projected for the 2030s. However, these projections have been unrealized because of various factors. The development of reactor designs by the GIF was supposed to be influenced by events such as the 2008 global financial crisis, 2011 Fukushima accident [2, 3], discovery of extensive shale oil reserves in the United States, and overly ambitious technological targets. Consequently, the momentum for VHTR development reduced significantly. In this context, the aims of this study were to compare and analyze the development progress of the six Gen IV reactor designs over the past 20 years, based on the GIF roadmaps published in 2002 and 2014. The primary focus was to examine the prospects for the reactor designs in relation to spent nuclear fuel burning in conjunction with small modular reactor (SMR), including molten salt reactor (MSR), which is expected to have spent nuclear fuel management potential.

Amorphous In-Ga-Zn-O (a-IGZO) thin film transistors (TFTs) with a coplanar structure were fabricated to investigate the feasibility of their potential application in large size organic light emitting diodes (OLEDs). Drain currents, used as functions of the gate voltages for the TFTs, showed the output currents had slight differences in the saturation region, just as the output currents of the etch stopper TFTs did. The maximum difference in the threshold voltages of the In-Ga-Zn-O (a-IGZO) TFTs was as small as approximately 0.57 V. After the application of a positive bias voltage stress for 50,000 s, the values of the threshold voltage of the coplanar structure TFTs were only slightly shifted, by 0.18 V, indicative of their stability. The coplanar structure TFTs were embedded in OLEDs and exhibited a maximum luminance as large as 500 nits, and their color gamut satisfied 99 % of the digital cinema initiatives, confirming their suitability for large size and high resolution OLEDs. Further, the image density of large-size OLEDs embedded with the coplanar structure TFTs was significantly enhanced compared with OLEDs embedded with conventional TFTs.

With South Korea increasingly focusing on nuclear energy, the management of spent nuclear fuel has attracted considerable attention in South Korea. This study established a novel procedure for selecting safety-relevant radionuclides for long-term safety assessments of a deep geological repository in South Korea. Statistical evaluations were performed to identify the design basis reference spent nuclear fuels and evaluate the source term for up to one million years. Safety-relevant radionuclides were determined based on the half-life criteria, the projected activities for the design basis reference spent nuclear fuel, and the annual limit of ingestion set by the Nuclear Safety and Security Commission Notification No. 2019-10 without considering their chemical and hydrogeological properties. The proposed process was used to select 56 radionuclides, comprising 27 fission and activation products and 29 actinide nuclides. This study explains first the determination of the design basis reference spent nuclear fuels, followed by a comprehensive discussion on the selection criteria and methodology for safety-relevant radionuclides.

해사노동협약은 선원 인권 보호에 있어 전 세계적으로 성공적인 성과로서 국제노동기구에서 채택하였다. 특히, 이 협약의 선원근로계약 규정은 선원에게 양질의 근로와 생활 환경을 보장하기 위한 규정으로서 해사노동협약의 핵심으 로 인정되고 있다. 이러한 규정에도 불구하고 많은 회원국은 자국의 법률 시스 템에 핵심 규정을 완전히 반영하지 못하거나 실질적인 이행을 하지 못하고 있 는 상황이다. 특히 대표적인 선원 공급국이자 개발도상국인 베트남은 더욱 어 려운 실정이다. 따라서 이 논문에서는 해사노동협약의 선원근로계약에 관한 규 정을 중심으로 비교법적 연구 방법론을 통해 베트남 법제도의 차이를 분석하 고, 나아가 대표적인 해운 선진국인 대한민국의 선원법을 비교하여 베트남 법 제도의 문제점을 분석하고자 한다. 이를 통해 베트남의 해사노동협약 이행을 증진하기 위한 개선방안에 대해 논의하고자 한다.

The nuclear fuel that melted during the Fukushima nuclear accident in 2011 is still being cooled by water. In this process, contaminated water containing radioactive substances such as cesium and strontium is generated. The total amount of radioactive pollutants released by the natural environment due to the nuclear accident in Fukushima in 2011 is estimated to be 900 PBq, of which 10 to 37 PBq for cesium. Radioactive cesium (137Cs) is a potassium analog that exists in the water in the form of cations with similar daytime behavior and a small hydration radius and is recognized as a radioactive nuclide that has the greatest impact on the environment due to its long half-life (about 30 years), high solubility and diffusion coefficient, and gamma-ray emission. In this study, alginate beads were designed using Prussian blue, known as a material that selectively adsorbs cesium for removal and detection of cesium. To confirm the adsorption performance of the produced Prussian blue, immersion experiments were conducted using Cs standard solution, and MCNP simulations were performed by modeling 1L reservoir to conduct experiments using radioactive Cs in the future. An adsorption experiment was conducted with water containing standard cesium solution using alginate beads impregnated with Prussian blue. The adsorption experiment tested how much cesium of the same concentration was adsorbed over time. As a result, it was found that Prussian blue beads removed about 80% of cesium within 10-15 minutes. In addition, MCNP simulation was performed using a 1 L reservoir and a 3inch NaI detector to optimize the amount of Prussian blue. The results of comparing the efficiency according to the Prussian volume was shown. It showed that our designed system holds great promise for the cleanup and detection of radioactive cesium contaminated seawater around nuclear plants and/or after nuclear accidents. Thus, this work is expected to provide insights into the fundamental MCNP simulation based optimization of Prussian blue for cesium removal and this work based MCNP simulation will pave the way for various practical applications.

Copper hexacyanoferrate (Cu-HCF), which is a type of Prussian Blue analogue (PBA), possesses a specific lattice structure that allows it to selectively and effectively adsorb cesium with a high capacity. However, its powdery form presents difficulties in terms of recovery when introduced into aqueous environments, and its dispersion in water has the potential to impede sunlight penetration, possibly affecting aquatic ecosystems. To address this, sponge-type aluminum oxide, referred to as alumina foam (AF), was employed as a supporting material. The synthesis was achieved through a dip-coating method, involving the coating of aluminum oxide foam with copper oxide, followed by a reaction with potassium hexacyanoferrate (KHCF), resulting in the in-situ formation of Cu-HCF. Notably, Copper oxide remained chemically stable, which led to the application of 1, 3, 5-benzenetricarboxylic acid (H3BTC) to facilitate its conversion into Cu-HCF. This was necessary to ensure the proper transformation of copper oxide into Cu-HCF on the AF in the presence of KHCF. The synthesis of Cu-HCF from copper oxide using H3BTC was verified through X-ray diffraction (XRD) analysis. The manufactured adsorbent material, referred to as AF@CuHCF, was characterized using Fourier-transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). These analyses revealed the presence of the characteristic C≡N bond at 2,100 cm-1, confirming the existence of Cu-HCF within the AF@CuHCF, accounting for approximately 3.24% of its composition. AF@CuHCF exhibited a maximum adsorption capacity of 34.74 mg/g and demonstrated selective cesium adsorption even in the presence of competing ions such as Na+, K+, Mg2+, and Ca2+. Consequently, AF@CuHCF effectively validated its capabilities to selectively and efficiently adsorb cesium from Cs-contaminating wastewater.

Plasma melting technology uses electrical arc phenomena such as lightning to create hightemperature sparks of about 1,600 degrees or more to meet waste disposal requirements through treatment and reduction without distinguishing radioactive waste generated during nuclear power plant operation and dismantling according to physical characteristics. Decommissioning radioactive waste scabbed concrete occurs when polishing and cutting the contaminated structure surface to a certain depth. In this study, Scabbed concrete containing paint was confirmed for volume reduction and disposal safety using plasma treatment technology, and it is planned to be verified through continuous empirical tests.

Once decommissioning begins, it is expected that large amount of radioactive wastes will be produced in a short period of time. The expected amount of radioactive wastes from Kori unit 1 NPP are approximately 80,000 drums (base on 200 L). By minimizing the amount of radioactive wastes generated through decontamination and reduction, KHNP has set the final target for the amount of radioactive wastes to be delivered to the disposal site at approximately 14,500 drums. Here, plasma torch melting technology is an essential technology for radioactive wastes treatment during nuclear power plants decommissioning and operation, because of its large volume reduction effects and the diversity of disposable wastes. KEPCO KPS was able to secure experience in operating Plasma Torch Melter (PTM) by conducting a research service for ‘development of plasma torch melting system advancement technology’ at KHNP-CRI. This study will compare kilo and Mega-Watt class PTM, largely categorized into facility configurations, operating parameters, and waste treatment. Based on this study, it would be desirable to operate PTM with approximate capacity according to the frequency and amount of waste production, and suggest volume for a kilo and Mega-watt class plasma torch in the melting furnace respectively. This plays to its strengths for both a kilo and Mega-watt class PTM.

A disposal of radioactive wastes is one of the urgent issues in worldwide. Considering upcoming plans for decommissioning of nuclear power plants, this problem is unavoidable and should be discussed very thoughtfully before long. There are variety of methods to deal with radioactive wastes, including Incineration process, conventional gasification process and plasma gasification process and so on. Among them, plasma gasification process is in the limelight due to its ecofriendly features and very large volume reduction effects. So, lots of countries like Japan, Taiwan, Russia, Bulgaria are already utilizing commercial plasma melting facilities and researching their own characteristics & disposal abilities and so on. Within the scope of this paper, I would like to introduce other countries current status of plasma melting facilities, and reach the conclusion on the directions to go for realistic radioactive wastes treatment.