With the infusion of advanced technology, interactions between customers and firms’ representatives take place in brick-and-mortar stores, 2D online sites, and even 3D metaverse environments. In the metaverse, a firm’s sales avatars interact with other users while representing the firm, recommend, and sell virtual items. Previous literature about the effectiveness of sales representatives agrees that a firm representatives’ smiling faces engender customer satisfaction and better interactions. However, it is unclear whether smiling faces of sales avatars will work the same way in the metaverse as they do in the real world. The current research examines whether a firm’s sales avatars with sad facial expression (vs. those with smiling facial expression) stimulate higher user intentions to interact with firm representative avatars, to purchase virtual items from the representative avatars, and to spread positive WOM about their experience in the metaverse. Moreover, focusing on subcultural appeal, we investigate why this unconventional phenomenon happens in the metaverse unlike in real world. We conducted two experiments to manipulate a firm representative avatar’s facial expression (smiling vs. sad) in the metaverse. We newly designed a metaverse place, and participants who put on a virtual reality headset are exposed to either a hat (Experiment 1) or shoes (Experiment 2) store where they can purchase a virtual hat or shoes. Experiments 1 and 2 basically tested the same things repeatedly. However, to improve internal validity and generalizability, Experiment 2 used human-like sales avatars instead of cartoon character-like sales avatars in Experiment 1, changed virtual stores from a hat store to shoes store, and finally controlled for various extraneous variables such as attractiveness, warmth, and competence of sales avatars, and user’s previous experience about metaverse. Sales representatives with a smile are believed to contribute to beneficial consumers’ attitudes and behaviors in offline stores. However, our experiments demonstrate that this well-received belief does not necessarily apply in the metaverse, where subcultural appeal plays a more critical role. In the metaverse, users evaluate sales avatars with sad facial expression (vs. with smiling facial expression) as more unique and cool (i.e., higher subcultural appeal), leading to their higher intention to interact with the sad sales avatar, to purchase a virtual item, and to spread positive WOM about their experiences. Our results imply that previous findings supported in the offline or 2D online sites may not work the same way in the 3D metaverse.

This study was conducted to examine the effect of a diet supplemented with dried Bacillus subtilis culture on broilers' productivity and blood characteristics. Broiler feeding experiments were conducted twice. The diet fed to the control group was supplemented with 0.2% Palm MateⓇ commercially available probiotics (B. subtilis), and the diet fed to the experimental group was supplemented with ThekerⓇ 0.05% dried B. subtilis culture (DBC) in experiment 1, and 0.1% DBC in experiment 2. Treatment was administered for four weeks in both groups. A higher average daily gain was observed in the group treated with 0.05% DBC in experiment 1 compared with the control group, which was significantly higher in the group that received 0.1% DBC in experiment 2 compared with the control group. A higher production index was observed in the groups that received treatment than in the control group and was higher in the 0.1% DBC group than in the 0.05% DBC group. Significantly lower serum triglyceride (TG) was observed with increased DBC content. Although the findings showed no statistical significance, lower total cholesterol (T-C) was observed in the treated group than in the control group. HDL-cholesterol (HDL-C) content showed a significant increase in the DBC-treated groups. A significantly opposite outcome was observed for LDL-cholesterol (LDL-C) content. These findings demonstrated that the atherogenic index (AI) and cardiac risk factor (CRF) decreased in the DBC-treated groups. Significantly lower serum levels of glutamic-oxaloacetic transaminase (GOT: aspartate aminotransferase, AST) and glutamate pyruvic transaminase (GPT: alanine transaminase, ALT) were detected with an increase in DBC content in the treated groups compared with the control groups. To summarize the findings described above, adding ThekerⓇ dried B. subtilis culture to broiler feeds positively improved productivity through weight gain of broilers and the production of healthier functional broilers through the improvement of blood lipids and liver function. It is expected that the findings of this study will be helpful in the effort to increase the profitability of broiler chicken farming and promote human health.

In recent years, India has consistently increased its production of small fruits. India is the second-largest producer of fruits and vegetables globally, with a diverse range of small fruits grown across the country. Small fruits, such as kiwifruit and blueberries, are in high demand due to the growing popularity of healthier food options and increased awareness of their associated health benefits. However, the current status of small fruit production in India is substantially lower than that of other fruit crops. Nonetheless, there has been a growing interest in small fruit production, particularly in regions with suitable climatic conditions. Currently, only two types of small fruit are commercially produced in India: grapes and Indian jujube/ber. Three other fruit types, strawberries, blueberries, and kiwi, have production areas of less than 10,000 ha each. Despite the growing interest in small fruit production, several challenges, such as the lack of good planting materials, productivity issues, lack of packaging facilities, and marketing networks for farmers, need to be addressed to enhance the prospects for small fruit production in India. Future studies should focus on several areas to overcome these challenges. Firstly, it is crucial to understand the specific resource constraints that small fruit producers face and develop strategies to improve their access to essential resources, including planting materials, land, water, and financial support. Secondly, innovative marketing strategies tailored to the unique characteristics of small fruit production in India should be employed to expand domestic and international market opportunities. Lastly, adopting appropriate technologies and sustainable production practices is necessary to improve productivity and mitigate environmental impacts. Overall, the prospects for small fruit production in India appear promising, given the growing demand for healthier food options and the expanding domestic and international markets for small fruits.

Metals such as stainless steel and alloy 600 are used as structures and materials in nuclear power plants due to their excellent mechanical properties and heat resistance. And recently thermal and mechanical cutting technologies are being actively researched and developed for dismantling NPP. Among them, the mechanical cutting method has the advantage of less secondary waste generation such as fume and fine dust, but according to the wider the cutting range, the reaction force and the cutting device size are increased. In this paper, plasma assisted milling has been proposed to reduce the reaction force and device size, and the plasma efficiency was measured for SUS 316L. The plasma torch was operated at the level of 3 to 4 kW so that it was heated only without cutting. And the feedrate was set at 150 to 250 mm/min. The test confirmed that the plasma efficiency was 35% about SUS 316L, and it is expected that the numerical analysis using these test results can be used as basic data for plasma assisted milling.

In order to start decommissioning domestic nuclear facilities, the Final Decommissioning Plan (FDP) must be prepared and approved by the regulatory agency. The contents of domestic FDP consist of 12 chapters, and there is the decommissioning feasibility design that should be described in Chapter 5 as contents to be considered from the construction stage of nuclear facilities. The design of decommissioning feasibility for nuclear facilities seems to be largely divided into three items. In summary, there ae minimization of contaminations to facilities and the environment, easy of dismantling, and minimization of the radioactive waste generation. In addition, the design characteristics to which the ALARA principle is applied in terms of optimizing the exposure dose of workers and residents may also correspond to the decommissioning feasibility design. The design characteristics for decommissioning feasibility during the period leading up to the design, operation, and decommissioning of nuclear facilities can be listed as the main points as follows. Minimization of facility contamination will include contents related to the leakage of systems and components, minimization of effluents to the environment will involve gaseous and liquid effluents from systems and components to the environment, easy of dismantling will involves history and inspection records during operation, and minimization of radioactive waste generation can be the contents related to the radioactive waste management plans. The design characteristics of facilities and equipment to meet the ALARA principles can be listed as follows. It means taking into account the benefits and costs of the design improvement plan, and the elimination of unnecessary radiation exposure can be maintained at the exposure dose ALARA, which is in line with the decommissioning feasibility design. Among the requirements of licensing documents for decommissioning domestic nuclear facilities is the decommissioning feasibility design. This item relates to the design characteristics for decommissioning considered in the construction stage of the facility and should present the effectiveness of measures for them until operation and decommissioning. In this study, the regulatory requirements presented in the construction and operation stage and the contents presented in the U.S. case were reviewed, and it is hoped that it will be used as reference for the preparation of FDP.

Various cutting technologies such as thermal and mechanical are being researched and developed to dismantle shutdown nuclear power plants. Each technology has the following advantages and disadvantages. The thermal cutting method has low reaction force and fast cutting speed, but secondary waste such as fume, dross, and fine dust is generated. The mechanical cutting method has the advantage of low generation of secondary waste such as fume, dross, and fine dust, but has the disadvantage of increasing the size of the device due to its large reaction force. In this study, the performance of plasma milling robot cutting technology for nuclear power plant materials was evaluated. First, before applying plasma auxiliary milling to the robot, tests were conducted on SUS 316 L and Alloy 600 to secure processing conditions such as plasma torch output and transfer speed. The test have shown that the mechanical strength was decreased of each material at the output power of the plasma torch of 4.4 and 8.4 kW, the transfer speed of 200 and 100 mm/min. Based on the test results, a plasma milling was attached to the robot and tested, and it was confirmed that even a small robot with a load of 140 kg can cut without any major problems.

Normally, non-metallic wastes, such as sands, concrete and asbestos are regarded as electrically non-conductive materials. However, when the temperatures are increased up to the melting point, their electrical conductivities can be greatly improved, flowing arc current. Accordingly, these nonmetallic wastes can be efficiently treated by heating them up to the electrically conducting temperatures by using a non-transferred type plasma torch, and then, melting them completely with arc currents in transferred mode of plasma torch. For this purpose, we propose a convertible plasma torch consisting of three cylindrical electrodes (rear electrode, front electrode and exit nozzle). Compared with conventional plasma torch with two cylindrical electrodes (rear electrode and front electrode), the proposed plasma torch can provide more stable plasma jet in high powered and non-transferred mode due to the presence of exit nozzle, resulting in rapid heating of the non-conductive materials.

Nowadays, transferred type arc plasma torches have been widely present in industrial applications, in particular, using melting pool of electrically conducting materials such as arc furnace, welding and volume reduction of radioactive wastes. In these applications, the melting pools are normally employed as an anode, thus, heat flux distributions on anode melting pool need to be characterized for optimum design of melting pool system. For this purpose, we revisited the one-dimensional model of the anode boundary layer of arcs and solved governing equations numerically by using Runge-Kutta method. In addition, the direct melting process of non-combustible wastes in the crucibles were discussed with the calculation results.

In this work, we report test results for direct melting of non-combustible wastes by using a 100 kW class transferred type plasma torch. For this purpose, non-combustible wastes consisting of metals and sands were prepared, weighed and melted by a transferred arc in a ceramic crucible with inner diameter of 150 mm. Test results reveal that 75wt% M6 iron bolts mixed with 25wt% sands were completely melted down within 140 seconds at the plasma power level of 83.8 kW, producing melting speed of 100 kg/hr and volume reduction rate of 62.8%. In addition, for simulated wastes consisting of 77.3wt% metal chips and 22.7wt% sands, the volume reduction rate high than 88% was achieved at 50 kW plasma power. These results indicate that non-combustible wastes can be treated efficiently when directly melting them by using transferred type plasma torch.

Depending on the type of waste, DC plasma torch uses a transfer type operation for conductive waste and a non-transfer type operation for non-conductive waste. The transfer mode plasma torch can secure high throughput because the arc directly contacts the object and has high thermal efficiency. However, since the non-transfer mode does not have a higher thermal efficiency than the transfer mode, higher output is required to secure high throughput. A method of increasing the output of the plasma torch is increasing the current or extending the length of the plasma arc. However, the method of increasing the current affects the life of the electrode, and there is a limit to extending the arc length in the positive polarity plasma torch. Therefore, it is effective to design the plasma torch with reverse polarity to secure life and extend the arc length. In the reverse polarity plasma torch, the front electrode serves as the cathode, and the cathode point is not easy to control compared to the anode point, which may cause abnormal arcing and damage the plasma torch. This paper was conducted to investigate the conditions for securing the safety of these non-transferable reverse polarity plasma torch. The plasma torch is designed to have an output of 100 kW or less and to use the detachable nozzle to control the cathode point. The test showed that the shape of the nozzle prevented the cathode point moving outside of plasma torch and the excessive extension of the arc. Thanks to this, it was confirmed that plasma could be stably formed and abnormal arcing could also be prevented.

It is important that the plasma torch used in the waste treatment field has a high output to increase throughput. In order to increase the output of the plasma torch, there is a method of increasing the current or extending the length of the plasma arc. Among these methods, high power can be easily achieved simply by increasing current, but it is difficult to ensure electrode life. Therefore, it is necessary to check the appropriate current and arc length conditions to achieve high power and stable operation. In this paper, the power performance according to the arc length, current, and operation mode was confirmed in the transfer mode plasma torch. The test conditions are the distance (arc length) between the plasma torch and the external electrode was set to 5-180 mm, and the current was set to be in the range of 90-460 A. As a result of the test, it was confirmed that the reverse polarity operation had a maximum output of 159 kW depending on the arc length and current, and the positive polarity operation had a maximum output of 138 kW. Through this result, it was confirmed that the arc length had an effect on increasing the output, and that the reverse polarity operation had a longer arc than the positive polarity operation.

DC plasma torch is reported as a technology that can be treated regardless of waste types because it can select transfer or non-transfer operation modes depending on the electrical conductivity of waste. Thanks to this characteristic, countries that operate nuclear power plants such as Switzerland, Japan, and Taiwan have developed high-power DC plasma torch to dispose of radioactive waste. And also in korea, a plasma torch is being developed to dispose of radioactive waste. This study was conducted to investigate the characteristics of the reverse polarity plasma torch according to the conditions of interelectrodes. The inter-electrodes of plasma torch used in the study was designed to be 25, 37 mm in diameter and 180 to 400 mm in length. As a result of the test, it was confirmed that the smaller the diameter and the longer the length of the inter-electrode, the more advantageous it was to achieve a high output power. And it was confirmed that the power torch would be 500 kW when the diameter of the inter-electrode was 25 mm, the length was 400 mm, and the current was 500 A.

The Korea Laboratory Accreditation Scheme (KOLAS) is the national accreditation body responsible for providing accreditation services to testing and calibration laboratories. The primary objective of KOLAS is to promote the quality and reliability of laboratory testing by providing nationally and internationally recognized accreditation services. Laboratories accredited by KOLAS are required to meet rigorous international standards set by the International Organization for Standardization (ISO) and are subject to regular assessments to ensure ongoing compliance with the standards. KOLAS accreditation is highly regarded both domestically and internationally, and is recognized for providing high-quality and reliable testing services. The nuclear analysis laboratory at KINAC has been working to establish a quality management system to ensure the external reliability of analytical results and to secure its position as an authorized testing agency. To achieve this, a detailed manual and procedure for nuclear material analysis were developed to conform to the international standards of ISO/IEC 17025. This study presents the preparation process for establishing the management system, focusing on meeting technical and quality requirements for the implementation of the ISO/IEC 17025 standard in the KINAC nuclear analysis laboratory, specifically in the field of chemical testing (dosimetry, radioactive, and neutron measurement subcategories). The preparation process involved two tracks. The first track focused on satisfying technical requirements, with Thermal Ionization Mass Spectrometer (TIMS) and Inductively Coupled Plasma-Mass Spectrometer (ICP-MS) selected as the major equipment for analysis. Analytical methods for determining isotope ratios and concentrations of nuclear materials were determined, and technical qualification was ensured through participation in proficiency test programs, inter-experimenter comparison tests, and uncertainty reports. The second track focused on developing the quality system, including quality manuals, procedures, and guidelines based on the requirements of the ISO/IEC 17025 standard. Various implementation documents were produced during the six-month pilot period, in accordance with the three levels of documents required by the standard. Implementation of ISO/IEC 17025 is expected to have a systematic quality management process for the analysis lab’s operations and to increase confidence in KINAC’s nuclear analysis.

The purpose of this study is to detect future signals and changes in nuclear-related research to apply safeguards by design to new nuclear facilities or to determine nuclear fuel cycle-related research and development (R&D) activities. First, a total of 2,029 scientific articles published between 2015 and 2022 in the journal of “Nuclear Engineering and Technology” by the Korean Nuclear Society were collected. The authors of the scientific article used their expertise and knowledge to select keywords that can properly represent the article. Therefore, in this study, the keywords of each scientific article were analyzed using the technique of text mining. We then calculated the “word frequency” and “term frequency-inverse document (TF-IDF)” values of the keywords. Consequently, significant words such as “reactor,” “nuclear,” and “fuel” were extracted, which were represented as word clouds. Furthermore, keywords extracted through text mining were quantitatively classified into weak or strong signals using a keyword emergence map (KEM). The KEM is a tool that can explore future signals because essential keywords have a high frequency of appearance, and newer keywords are more important than older keywords. The KEM results showed no keywords in the strong-signal area in the field of nuclear academia. However, keywords such as “deep learning,” “earthquake,” “zircaloy,” and “CFD” were confirmed to be distributed in the weak signal area. A weak signal indicates the most probable topic that could become a strong signal in the near future. The weak signal methodology can be applied to predict future nuclear scientific trends in the rapidly changing world. Based on the results of the study, changes in the subject of nuclear-related scientific articles over the past eight years and future signals were interpreted. The results confirmed that this method can be applied to safeguards measures of new nuclear facilities in the design stage and can be used to detect R&D activities related to the nuclear fuel cycle in advance.

The domestic representative nuclear fuel cycle facilities are post-irradiation examination facility (PIEF) and Irradiated Examination Facility (IMEF) at KAERI. They have regularly operated since 1991 and 1993, respectively. Due to the long period of use, the facilities are ageing, and maintenance costs are increasing every year. The maintenance methods have mainly been breakdown maintenance (BM) and partially preventive maintenance (PM). They involve replacing components that have problems through periodic inspections by on-site inspectors. However, these methods are not only uncertain in terms of replacement cycles due to worker’s deviation on the inspection results, but also make it difficult to respond accidents developed through failures on the critical equipment that confines radioactive material. Therefore, an advanced operation and maintenance studied in 2022 through all of nuclear facilities operated at KAERI. Advancement strategy in four categories (safety, sustainability, performance, innovativeness) was analyzed and their priorities according to a facility environment were determined so a roadmap for advanced operation and maintenance could be developed. The safety and sustainability are higher importance than the performance and innovativeness because facilities at KAERI has an emphasis on research and development rather than industrial production. Thus, strategy for advancement has focused even more on strengthening the safety and sustainability. To enhance safety, it has been identified that immediate improvement of aged structures, systems, and components (SSCs) through large-scale replacement is necessary, while consideration of implementing an ageing management program (AMP) in the medium to long term is also required. Facility sustainability requires strengthening operation expertise through training, education, and cultivation of specialized personnel for each system, and addressing outstanding regulatory issues such as approval of radiation environment report on the nuclear fuel processing facilities and improvement work according to fire hazard analysis. One of the safety enhancement methods, AMP, is a new maintenance approach that has not been previously applied, so it had to be thoroughly examined. In this study, an analysis was conducted on the procedure and method for introducing an AMP. An AMP for nuclear fuel cycle facilities was developed by analyzing the AMP applied to the BR2 research reactor in Belgium and modifying it for application to nuclear fuel cycle facilities. The ageing management for BR2 has the objective to maintain safety, availability and cost efficiency and three-step process. The first step is the classification of SSCs into four classes to apply graded approach. Secondly, ageing risk is assessed to identify critical failure modes, their frequency and precursors. Final step involves defining measures to reduce the ageing risk to an acceptable level in order to integrate the physical and economic aspects of ageing into a strategy for inspection, repair, and replacement. Similar approach was applied to the nuclear fuel cycle facility. Firstly, the SSCs of nuclear fuel cycle facilities have been classified according to their safety and quality classifications, as well as whether they are part of the confinement boundary. The SSCs involved in the confinement boundary were given more weight in the classification process, even if they are not classified as safety-class. A risk index for ageing was introduced to determine which prevention and mitigation measure should be chosen. By multiplying the health index and the impact index, the ageing risk matrix provides a numerical score that represents guidance on the prevention and mitigation of ageing effect. The health index is determined by combining the likelihood of failure and engineering evaluation of the current condition of SSCs, whereas the impact index is calculated by taking into account the severity of consequences and the duration of downtime resulting from a failure. This ageing management has to be thoroughly reviewed and modified to suit each facility before being applied to nuclear fuel cycle facilities.

The characterization of nuclear materials is crucial for global nuclear safeguards efforts, as these materials can potentially be used for illicit purposes. In this study, we evaluated the applicability and performance of the In-Situ Object Counting System (ISOCS) equipment for the characterization and quantification of uranium, including uranium pellets and radioactive wastes. Our methodology involved using ISOCS to measure samples with different enrichments and total amounts of uranium, and to analyze the results in order to evaluate the ISOCS’s effectiveness in accurately characterizing the various uranium samples. To this end, we compared the ISOCS results with those of the Multi-Group Analysis for Uranium (MGAU) system, which is currently used in the field of international safeguards. The results of this study showed that the ISOCS was sensitive enough to analyze small amounts of uranium pellet, with %differences ranging from -0.7% to 19%. However, when analyzing shielded nuclear materials like in concrete waste, the uncertainty was relatively high, with %differences ranging from 11% to 67%. On the other hand, the MGAU system was unable to analyze uranium for the same spectrum, indicating the superiority of the ISOCS in terms of usability. The ISOCS instrument was also found to be effective in analyzing uranium in various types of samples without the need of standard sources. Overall, the findings of this study have important implications for the development of more effective safeguards strategies for the characterization of nuclear materials. The ISOCS instrument could be a reliable tool for analyzing nuclear materials, contributing to global safeguards efforts to reduce the risk of nuclear proliferation.