Since the importance of integrated pest management to minimize environmental damage and maximize pest control effectiveness has emerged, efforts to put it into practice have continued. To implement IPM, it is necessary to estimate the economic injury level to determine the control method by identifying pests and weeds that damage the quantity and quality of crops in the field, investigating the occurrence level, and calculating the ratio of cost and effectiveness. Also, damage to host plants caused by increased density of insect pests appears to change plant’s health that key factor for managing crops. Therefore, understanding the relationship between the density of pests and the damage to the host plants is necessary. This study aims to analyze the causal relationship between the density of insect pests and damage to the host plants for estimating the economic injury level of insect pests on the host plants and investigating the possibility of pest control decision-making using plant health status.

Civil defense originally refers to the protection of civilians in the events of war-related disasters. Today, it encompasses a wide range of protection, rescue, and recovery activities not only aimed at minimizing the damage caused by war but also addressing natural and man-made disasters such as wildfires, typhoons, and floods. Civil defense uniforms are worn by volunteers who participate in civil defense training organized by practitioners, government officials, and military personnel. Therefore, more than 3,350,000 persons (+6.5 % of the Korean population) likely should wear civil defense uniforms. As such, the functionalities of civil defense uniforms need to be reexamined and improved in response to the wider and newer responsibilities of the civil defense system to protect the civil defense personnel from potential hazards and to help better serve the Korean citizens. The essential functions of civil defense uniforms were proposed by analyzing various civil defense activities. Per the level and type of safety hazards, the design and materials for civil defense uniforms should ideally differ, similar to civil defense uniforms in other countries. We surveyed the current Korean civil defense uniforms’ design, material compositions and important functionalities such as water repellency, water pressure resistance, and flame resistance. Compared to common functional workwear, we suggest room for improvement in the functional properties of civil defense uniforms. This research paves a new road for the functional design of civil defense uniforms to address a wider range of hazards, potentially leading to rational guidelines for protective workwear and government uniform development.

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.

This paper examines how consumers evaluate digital products with multiple Non-fungible Tokens (NFTs), which are blockchain-enabled cryptographic assets that represent proof-of-ownership for digital objects. The study predicts that people prefer fractioned NFTs (unique fractions of a digital object) versus duplicated NFTs (identical digital objects with distinct numbers) due to their preference for uniqueness. The study also examines the moderating role of product attributes, predicting that preferences for fractioned NFTs will be reduced when the product provides unique aspects, such as a serial number.

The spread of COVID-19 changes consumer preferences and behaviors greatly across the world. Extant literature has demonstrated that when there is a threat to disease, people stay away from those who do not seem healthy as they can be potentially infectious. Based on the previous literature, this research shows that individuals exposed to disease threat avoid products of which designs are high in visual complexity. When disease threat was present, individuals had lower purchase intention for products with complex designs. The perceived uncleanliness mediated the effect of visual complexity and disease threat on purchase intention. The findings provide a novel insight into the effect of disease salience on consumer perception of product design.

The Animal and Plant Quarantine Agency conducts a targeted sampling plan and analysis for veterinary drugs within the country every year. Target compounds included tetrachlorvinphos as an organophosphate, diminazene as an anti-infective medication, ketoprofen as a nonsteroidal anti-inflammatory drug, triclabendazole and clorsulon as flukicides in 2022. These compounds were not included in National Residues Program (NRP), despite their high sales ranking. A total of 94 bovine muscle samples and 20 equine muscle samples were collected from various locations across the country. The analysis of target compounds in muscle was performed using LC-MS/MS coupled with Food code 8.3.1 revised in 2022. A 2 g sample of muscle tissue was extracted using a water: acetonitrile (1:4, v/v) solution, then cleaned up with C18 and hexane saturated with acetonitrile. Compounds were separated with C18 column and mobile phases consisted of 0.1% formic acid in water (A) and 0.1% formic acid in acetonitrile (B). All analytes exhibited good linearity with correlation coefficients (R2) higher than 0.992. The limit of quantification (LOQ) of these compounds ranged from 0.21 to 2.79 μg/kg except for diminazene (3.85~6.86 μg/kg). The average recoveries of these analytes were 89.45~129.13% in muscle at spiked level of 10 or 20 μg/kg. Relative standard deviations (%) (intra-day and inter-day) were lower than 20% for all target compounds, except for diminazene and triclabendazole, whose intra-day RSD % was slightly higher than 20% in equine muscle. Testing confirmed that all 94 bovine and 20 equine muscle samples from 9 provinces were free from residues of veterinary drugs. Monitoring of compounds not included in the NRP should continue to ensure consumer health and food safety.

Molten salt is one of the promising medium materials for molten salt reactors and energy storage systems. Molten salt is advantageous for better physical properties such as low melting point and high boiling point, high energy capacity, high thermal conductivity, and high thermal stability than other medium materials such as water or liquid metals. However, the corrosivity of the molten salt is one of the main factors that disturbs the various applications of the molten salt. On the other hand, metallic 3-D printing technologies have developed by leaps and bounds over the past 20 years and show potential for use in cutting-edge industries such as aerospace and military purposes. However, the biggest problem of 3-D printed products is that the mechanical and physical properties are very weak along the laminated plane that was generated during the manufacturing process. In particular, other research showed that corrosion is vulnerable through the laminated surface, and corrosion along the laminated plane is not completely mitigated through a general heat treatment process although the microstructure of the surface is evaluated to be partially mitigated by the heat treatment. In this study, molten salt corrosion behaviors of simple Ni-based alloy with a composition of 80Ni- 20Cr were analyzed. Ni-based alloys were fabricated by casting and 3-D printing, and some of the 3-D printed specimens were thermally treated at 1,273 K for 1 hour to examine the effects of heat treatment on corrosion behaviors. In molten eutectic NaCl-MgCl2 melts at 973 K, Ni-based alloys were corroded for 1, 3, 7, and 28 days and their microstructural changes were analyzed by SEM-EBSD-EDS and OM. The corrosion behaviors of the alloy were also evaluated by the salt composition measured with ICPOES. 3-D printed alloy with post-treatment showed more resistivity to the molten salt corrosion than as-fabricated 3-D printed alloy. However, the corrosion rate of the 3-D printed specimen after heat treatment was still higher than that made by casting.

A molten salt reactor (MSR) is a conceptual nuclear reactor that uses molten salt with liquid fuel as its primary coolant. Based on the thermophysical and neutronic properties, MSR has advantages such as high efficiency, safety, combustion of transuranic (TRU) elements, and availability of miniaturization and on-power refueling. Various research on MSR such as system development, neutronic analysis, material development, and molten salt property analysis has been conducted, but the biggest problem is the molten salt corrosion. The molten salt corrosion on structural materials can be explained by two processes; electrochemical and chemical reactions. The reduction of oxidative ions such as fuel and TRU elements is one of the major causes of molten salt corrosion. Contamination by humidity and oxygen is also known as the accelerating factor of molten salt corrosion. Also, molten salt corrosion behaviors on structural material deteriorate when dissimilar alloys are introduced in the molten salt system. Various techniques to mitigate molten salt corrosion in fluoride system has been developed, but these are not well-verified in chloride system. In this research, various methodologies to mitigate molten salt corrosion are studied. The corrosion behaviors of 80Ni-20Cr alloy in molten eutectic NaCl-MgCl2 salt at 973 K are analyzed with various applications such as salt purification, sacrificial metal injection, and salt redox potential control. Oxygen and water impurities that can accelerate molten salt corrosion have been removed by electrochemical and chemical methods; Applying the reduction potential for H+/H2 and oxidation potential for O2-/O2, introducing HCl and CCl4 gas, and introducing the metallic Cr and recovering the ionized Cr. Corrosion acceleration/deceleration effects were analyzed when introducing the reducing reagent such as Mg and Nb or oxidizing reagent such as metallic Mo and the effect of inert metallic element (W) was also investigated. The salt potential was controlled by applying the potential to the salt and adjusting the Eu3+/Eu2+ ratio.

During the decommissioning of a nuclear power plant, the structures must be dismantled to a disposal size. Thermal cutting methods are used to reduce metal structures to a disposal size. When metal is cut using thermal cutting methods, aerosols of 1 μm or less are generated. To protect workers from aerosols in the work environment during cutting, it is necessary to understand the characteristics of the aerosols generated during the cutting process. In this study, changes in aerosol characteristics in the working environment were observed during metal thermal cutting. The cutting was done using the plasma arc cutting method. To simulate the aerosols generated during metal cutting in the decommissioning of a nuclear power plant, a non-radioactive stainless steel plate with a thickness of 20 mm was cut. The cutting condition was set to plasma current: 80 A cutting speed: 100 mm/min. The aerosols generated during cutting were measured using a highresolution aerosol measurement device called HR-ELPI+ (Dekati®). The HR-ELPI+ is an instrument that can measure the range of aerodynamic diameter from 0.006 μm to 10 μm divided into 500 channels. Using the HR-ELPI+, the number concentration of aerosols generated during the cutting process was measured in real-time. We measured the aerosols generated during cutting at regular intervals from the beginning of cutting. The analyzed aerosol concentration increased almost 10 times, from 5.22×106 [1/cm3] at the start of cutting to 6.03×107 [1/cm3] at the end. To investigate the characteristics of the distribution, we calculated the Count Median Aerodynamic Diameter (CMAD), which showed that the overall diameter of the aerosol increased from 0.0848 μm at the start of cutting to 0.1247 μm at the end of the cutting. The calculation results were compared with the concentration by diameter over time. During the cutting process, particles with a diameter of 0.06 μm or smaller were continuously measured. In comparison, particles with a diameter of 0.2 μm or larger were found to increase in concentration after a certain time following the start of cutting. In addition, when the aerosol was measured after the cutting process had ended, particles with a diameter of 0.06 μm or less, which were measured during cutting, were hardly detected. These results show that the nucleation-sized aerosols are generated during the cutting process, which can explain the measurement of small particles at the beginning of cutting. In addition, it can be speculated that the generated aerosols undergo a process of growth by contact with the atmosphere. This study presents the results of real-time aerosol analysis during the plasma arc cutting of stainless steel. This study shows the generation of nucleation-sized particles at the beginning of the cutting process and the subsequent increase in the aerosol particle size over time at the worksite. The analysis results can characterize the size of aerosol particles that workers may inhale during the dismantling of nuclear power plants.

Several tests should be performed to estimate the structural and chemical stability of the radioactive waste. Among the tests in Gyeongju LILW repository, the leaching test which follows ANS 16.1 standard test method should be conducted for Cs, Sr, and Co radionuclides and must satisfy leachability index larger than 6 which applies deionized water as a leachant. However, the expected leachant inside the silo is groundwater that contains various ions and a high pH condition is predicted due to the concrete structures inside the silo. According to the chemical environment of the leachant, the chemical form of the radionuclides varies from precipitate to ion. Cobalt precipitates when the leachant has high pH environment which is similar condition to the cement-saturated leachant. Unlike the cobalt, cesium is preferred to exist as ion in the high pH condition. Therefore, the significant effect of the chemical environment of the leachant on the leachability of the radionuclides should be considered for the waste acceptance criteria of the radioactive waste repository. From the ‘NRC, Technical position on the waste form, rev1’, the leaching test method should follow the ANS 16.1 methods by using deionized water as leachant, however, a new leachant showing more aggressive leachability can be applied instead of deionized water. In the other hand, ASTM C1308 leaching test method recommends applying actual groundwater of the repository as a leachant. FT-04-020, the leaching test method of France, suggests the ion composition of the groundwater including the pH value. Therefore, the adequacy of using deionized water as leachant for the leaching test method of Cs, Sr, and Co should be re-examined. In this study, the leaching behavior of Cs, Sr, and Co under the several leachant types is estimated. The cement solidified specimen containing single Cs, Sr, and Co were manufactured. The leaching test following ANS 16.1 was performed by applying deionized water, simulated groundater, and cement-saturated groundwater. As a result, a leachability index difference according to the leachant type was discussed. The result of this study is expected to be a background data that helps understanding the actual leaching behavior of the Cs, Sr, and Co in the Gyeongju LILW repository.