High-entropy alloys (HEAs) have been reported to have better properties than conventional materials; however, they are more expensive due to the high cost of their main components. Therefore, research is needed to reduce manufacturing costs. In this study, CoCrFeMnNi HEAs were prepared using metal injection molding (MIM), which is a powder metallurgy process that involves less material waste than machining process. Although the MIM-processed samples were in the face-centered cubic (FCC) phase, porosity remained after sintering at 1200°C, 1250°C, and 1275°C. In this study, the hot isostatic pressing (HIP) process, which considers both temperature (1150°C) and pressure (150 MPa), was adopted to improve the quality of the MIM samples. Although the hardness of the HIP-treated samples decreased slightly and the Mn composition was significantly reduced, the process effectively eliminated many pores that remained after the 1275°C MIM process. The HIP process can improve the quality of the alloy.
Technosignature, previously known as SETI(search for extraterrestrial intelligence), is the scientic evidence of past or present extraterrestrial civilizations. Since NRAO's Project Ozma was performed in 1960, most of the noticeable technosignature searches have been done by radio telescopes, hoping to find strong and narrow bandwidth signals that cannot be explained by known natural processes. Recently, the Breakthrough Listen project has opened a new opportunity for technosignature by utilizing both optical telescopes, radio telescopes, and next-generation radio telescope arrays. In this review, mainly based on NASA Technosignatures Workshop (2018), we review the current trends of technosignature surveys, as well as other possible methods for detecting technosignature. Also, we suggest what the Korean community could contribute the technosignature research, including the new SETI project with Korea VLBI Network (KVN).
Kori unit 1, the first PWR (Pressurized Water Reactor) in Korea, was permanent shut down in 2017. In Korea, according to the Nuclear Safety Act, the FDP (Final Decommissioning Plan) must be submitted within 5 years of permanent shutdown. According to NSSC Notice, the types, volumes, and radioactivity of solid radioactive wastes should be included in FDP chapter 9, Radioactive Waste Management, Therefore, in this study, the types depending on generation characteristics and radiological characterization methods and process of solid radioactive waste were analyzed. Solid radioactive waste depending on the characteristics of the generation was classified into reactor vessel and reactor vessel internal, large components, small metals, spent nuclear fuel storage racks, insulation, wires, concrete debris, scattering concrete, asbestos, mixed waste, soil, spent resins and filters, and dry active waste. Radiological characterization of solid radioactive waste is performed to determine the characteristics of radioactive contamination, including the type and concentration of radionuclides. It is necessary to ensure the representativeness of the sample for the structures, systems and components to be evaluated and to apply appropriate evaluation methods and procedures according to the structure, material and type of contamination. Therefore, the radiological characterization is divided into concrete and structures, systems and components, and reactor vessel, reactor vessel internal and bioshield concrete. In this study, the types depending on generation characteristics and radiological characterization methods and process of solid radioactive waste were analyzed. The results of this study can be used as a basis for the preparation of the FDP for the Kori unit 1.
The aim of this study was to determine the therapeutic effects of beauty care on negative mental health, including stress and depression. Nail care, massage care, and makeup were used as programs for beauty therapy. Qualitative research was conducted with six female participants over five-month period. After interviewing the subjects in advance, beauty care treatments were performed every week 4 weeks in the following order: nail care, massage, and makeup. The results are as follows, First, the participants perceived beauty care in the form of 4 concepts: “courtesy in social life,” “investment in oneself,” “self-satisfaction,” and “self-care.” Second, the effects of beauty therapy were categorized as “psychological effects,” “confidence,” “behavioral changes,” “evaluation of others,” and “positive social effects.” Third, each subject showed different psychological effects during the process when the function of the therapy took effect through the beauty care treatment. It was confirmed that confidence levels increased as a result of treatment through the process of becoming re-aware of oneself. Positive statements from the participants included: “I want to go out,” “I have become kind and positive to others,” “I have become more active in a given task,” and “It seems that my work ability is improving.” Finally, t-test results for selfesteem, depression, and stress showed there were significant differences in self-esteem and depression. This confirmed that self- esteem increased, and depression decreased after the beauty care treatment.
The sensory stimulation of a cosmetic product has been deemed to be an ancillary aspect until a decade ago. That point of view has drastically changed on different levels in just a decade. Nowadays cosmetic formulators should unavoidably meet the needs of consumers who want sensory satisfaction, although they do not have much time for new product development. The selection of new products from candidate products largely depend on the panel of human sensory experts. As new product development cycle time decreases, the formulators wanted to find systematic tools that are required to filter candidate products into a short list. Traditional statistical analysis on most physical property tests for the products including tribology tests and rheology tests, do not give any sound foundation for filtering candidate products. In this paper, we suggest a deep learning-based analysis method to identify hand cream products by raw electric signals from tribological sliding test. We compare the result of the deep learning-based method using raw data as input with the results of several machine learning-based analysis methods using manually extracted features as input. Among them, ResNet that is a deep learning model proved to be the best method to identify hand cream used in the test. According to our search in the scientific reported papers, this is the first attempt for predicting test cosmetic product with only raw time-series friction data without any manual feature extraction. Automatic product identification capability without manually extracted features can be used to narrow down the list of the newly developed candidate products.
Unarmored dinoflagellates, in the family Kareniaceae, include harmful or toxic bloom-forming species, which are associated with massive fish kills and mortalities of marine organisms worldwide. The occurrence and distribution of the toxigenic species in the family Kareniaceae were investigated in the brackish and coastal waters of Korea between July 2018 and October 2020. During the survey, we collected seven newly recorded species; Karenia papilionacea, Karlodinium digitatum, Karl. veneficum, Karl. zhouanum, Takayama acrotrocha, T. helix, and T. tasmanica. A total of fifteen strains of the seven taxa were successfully established as clonal cultures and examined using LM, SEM, and molecular phylogeny inferred from LSU rDNA sequences. Herein, we present the taxonomic information, morphological features, and molecular phylogenetic positions of the unrecorded dinoflagellate species collected from Korean coastal waters.
This study aims to identify the differences between Korean and Chinese and males and females in terms of female image preferences. The survey was conducted for 1 month targeting male and female Korean and Chinese subjects. Among the 350 completed questionnaires, 309 were used for analysis. For the analysis, 11 female images were chosen based on theoretical study, then a t-test and a paired t-test were carried out using SPSS 19.0. The results of this study are as follows: First, differences in female image preferences were observed to depend on nationality and gender. Koreans prefer urban images while Chinese prefer cute, intelligent, and sexy images. Second, males prefer innocent or sexy images, while females prefer sophisticated images. Third, Korean males prefer innocent, active, sophisticated, gentle, cute, sexy, urban, natural, intelligent, spectacular, and neutral images in order. Chinese males prefer gentle, innocent, sexy, active, sophisticated, intelligent, cute, natural, urban, spectacular, and neutral images in order. Fourth, Korean females prefer sophisticated, gentle, urban, natural, intelligent, innocent, active, sexy, cute, spectacular, and neutral images in order. Chines females prefer sophisticated, intelligent, cute, gentle, innocent, active, natural, sexy, urban, spectacular, and neutral images in order. Using these results, it will be possible to design marketing strategies for global consumers.
A simple, but effective means of tailoring the physical and chemical properties of carbon materials should be secured. In this sense, chemical doping by incorporating boron or nitrogen into carbon materials has been examined as a powerful tool which provides distinctive advantages over exohedral doping. In this paper, we review recent results pertaining methods by which to introduce boron atoms into the sp2 carbon lattice by means of high-temperature thermal diffusion, the properties induced by boron doping, and promising applications of this type of doping. We envisage that intrinsic boron doping will accelerate both scientific and industrial developments in the area of carbon science and technology in the future.
Hair style allows consumers to express their aesthetic sense and individual beauty. However, due to the attributes of hairdressing services and the high expectations of consumers, complaints are increasing rapidly. This study examined the complaint behavior, compensation and hair salon patronage of consumers. Then, a model is presented that explains the complaint behavior for hairstyling, forms of compensation, and hair salon patronage through empirical analysis. This study was conducted by a survey method. A total of 399 questionnaires were used for the analysis. The data were analyzed using SPSS 23.0 and AMOS 23.0 statistical software. The dimension of complaint behavior for hair style included verbal complaints, non-verbal complaints in the salon and private complaints outside the salon. The forms of compensation included re-procedure, psychological, and material compensation. Hair salon patronage was one-dimensional. These results were obtained through exploratory and confirmatory factor analysis. Then the conceptual model was empirically analyzed by covariance structure analysis and obtained in final form through model modification. Verbal complaint behavior positively influenced re-procedure compensation. In addition, non-verbal complaint behavior had positive effects on psychological and material compensation. Hair salon patronage was positively affected by re-procedure and psychological compensation. However, private complaint behavior had a negative effect on hair salon patronage. The direct and indirect effects of the paths among variables were verified by analyzing the mediating effects of different forms of compensations. It is possible to establish differentiated marketing strategies with these findings for consumers with complaint behaviors by considering the forms of compensation.