Molten salt reactors represent a promising advancement in nuclear technology due to their potential for enhanced safety, higher efficiency, and reduced nuclear waste. However, the development of structural materials that can survive under severe corrosion environments is crucial. In the present work, pure Ni was deposited on the surface of 316H stainless steel using a directed energy deposition (DED) process. This study aimed to fabricate pure Ni alloy layers on an STS316H alloy substrate. It was observed that low laser power during the deposition of pure Ni on the STS316H substrate could induce stacking defects such as surface irregularities and internal voids, which were confirmed through photographic and SEM analyses. Additionally, the diffusion of Fe and Cr elements from the STS316H substrate into the Ni layers was observed to decrease with increasing Ni deposition height. Analysis of the composition of Cr and Fe components within the Ni deposition structures allows for the prediction of properties such as the corrosion resistance of Ni.
This study aimed to investigate the dietary changes among adults living alone during the COVID-19 pandemic in the Republic of Korea. An online survey was conducted to examine dietary changes before (in 2019) and during (in 2021) the pandemic. The data from 337 adults living alone who responded to the survey were used for analysis. The proportion of the respondents reporting frequent food consumption at convenience stores (≥3 times/week) increased during the pandemic (p=0.024), and the proportion of those frequently eating ready-to-eat and ready-to-cook food (≥3 times/week) was more than doubled (p<0.001). Additionally, the proportion of those frequently consuming delivered food (≥3 times/week) increased by 2.5 times (p<0.001). In conclusion, the dietary habits of adults living alone changed significantly during the COVID-19 pandemic, which may have a negative impact on their health. Therefore, the development of customized nutrition management programs to improve the dietary habits of adults living alone during emergencies like a pandemic is deemed necessary. This study can serve as a foundation for understanding the dietary changes of adults living alone in prolonged crisis.
This study was conducted to explore the change in the market issues on HMR (Home Meal Replacements) using local foods after the COVID-19 outbreak. Online text data were collected from internet news, social media posts, and web documents before (from January 2016 to December 2019) and after (from January 2020 to November 2022) the COVID- 19 outbreak. TF-IDF analysis showed that ‘Trend’, ‘Market’, ‘Consumption’, and ‘Food service industry’ were the major keywords before the COVID-19 outbreak, whereas ‘Wanju-gun’, ‘Distribution’, ‘Development’, and ‘Meal-kit’ were main keywords after the COVID-19 outbreak. The results of topic modeling analysis and categorization showed that after the COVID-19 outbreak, the ‘Market’ category included ‘Non-face-to-face market’ instead of ‘Event,’ and ‘Delivery’ instead of ‘Distribution’. In the ‘Product’ category, ‘Marketing’ was included instead of ‘Trend’. Additionally, in the ‘Support’ category, ‘Start-up’ and ‘School food service’ appeared as new topics after the COVID-19 outbreak. In conclusion, this study showed that meaningful change had occurred in market issues on HMR using local foods after the COVID-19 outbreak. Therefore, governments should take advantage of such market opportunity by implementing policy and programs to promote the development and marketing of HMR using local foods.
Conservation of Arctic Flora and Fauna (CAFF) is the biodiversity working group of the Arctic Council. CAFF conducts Monitoring, Assessment, Policy, and expert group activities to preserve Arctic biodiversity and ensure the sustainability of biological resources and communicates the results to governments and indigenous peoples. The main tasks of CAFF consist of monitoring (Circumpolar Biodiversity Monitoring Program), assessment (Arctic Biodiversity Assessment) and strategic projects (Arctic Migratory Bird Initiative, AMBI). Korea has been directly participating in the AMBI since 2015 after acquiring observer status of the Arctic Council in 2013. The AMBI aims to preserve habitats on migration routes used by breeding birds in the Arctic and prevent illegal hunting. Thus, observer countries on migratory routes are directly participating in the project. When selecting priorities for participation in Arctic cooperation projects by 2030, Korea should consider continuing participation in AMBI and participating in the “CAFF Youth Program” in connection with the Arctic Academy program operated by Korea’s public institutes.
The Ministry of Agriculture, Food and Rural Affairs introduced the Agrifood Voucher in 2020. The Agrifood Voucher is the program that provides vouchers to purchase selected food items with dietary management education. This study aimed to explore value and meaning of dietary management based on the Agrifood Voucher. First, the Supplemental Nutrition Assistance Program of the United States and the Agrifood Voucher of Korea were reviewed. Second, various terms used for describing the purpose of food assistance programs were comparatively reviewed and ‘food and nutrition security’, together with the corresponding Korean term, was proposed to be the most appropriate term for the purpose. Subsequently, the value and meaning of dietary management based on the Agrifood Voucher were presented as enhancing food and nutrition security of the vulnerable. Diverse education programs should be developed and implemented to improve the dietary management capacity of the Agrifood Voucher recipients in order to properly realize the meaning and value of dietary management based on the Agrifood Voucher in the future.
In this study, additive manufacturing of a functionally graded material (FGM) as an alternative to joining dissimilar metals is investigated using directed energy deposition (DED). FGM consists of five different layers, which are mixtures of austenitic stainless steel (type 316 L) and low-alloy steel (LAS, ferritic steel) at ratios of 100:0 (A layer), 75:25 (B layer), 50:50 (C layer), 25:75 (D layer), and 0:100 (E layer), respectively, in each deposition layer. The FGM samples are successfully fabricated without cracks or delamination using the DED method, and specimens are characterized using optical and scanning electron microscopy to monitor their microstructures. In layers C and D of the sample, the tensile strength is determined to be very high owing to the formation of ferrite and martensite structures. However, the elongation is high in layers A and B, which contain a large fraction of austenite.
2000년 이후 금융산업의 학력별 노동시장구조를 살펴보면 전체적인 고용자수는 거의 변동은 없는데 고학력노동(대졸이상, 전문대졸 이상)은 증가하고 저학력노동(고졸이하)은 감소하고 있고, 학력별 임금격 차는 지속적으로 확대되고 있다. 학력을 근거로 고학력노동과 저학력노동으로 구분하여 생산요소를 물적 자본(K), 저학력 노동(L)과 고학력 노동(E)로 하는 다요소 콥-다글라스 생산함수를 가정하고, 외생변수로 산출량(Q), 세계화(G)와 기술진보(t)를 포함한 학력별 노동수요함수를 유도하였다. 이 함수를 바탕으로 로그선형회귀추정모형을 구성하고 학력별 노동수요에 영향을 미치는 요인분석을 시행하였다. 추정결과 생산요소의 상대가격(R/WL , R/WE, WL/WE)과 세계화(G)는 금융산업의 학력별 노동수요에 거의 영향을 미치지 못하였다. 반면 산출량과 기술진보 등 금융산업의 외생적 요인 변화가 금융산업의 학력별 노동수요에 통계적으로 유의미하게 영향을 미치는 것으로 나타났다. 산출량변화는 금융산업의 학 력별 노동수요에서 저학력노동 수요에 비해 고학력노동 수요에 미치는 영향이 더 크지만 그 영향력은 미미하였다. 반면 기술진보는 고학력노동에서 고용증가효과를, 저학력노동에서 고용구축효과를 유발하여 금융산업의 노동시장이 고학력노동 중심으로 구조변화가 진행 중인 것으로 판단된다. 이런 연구결과를 바탕으로 금융산업의 고용에 대해 다음과 같은 시사점을 제공한다. 첫째, 상대임금 변화는 학력별 노동수요에 거의 영향을 미치지 않기 때문에 이와 관련된 정책은 상당히 제한적일 수 있다. 둘째, 기술변화와 세계화가 진전되고 있는 상황에서 고학력노동의 고용증가에 부응하는 인재양성정책이, 반면 저학력노동의 고용감소에 따른 고용안정정책이 필요하다.
This study examined Korean employees’ meal structure characterized by mealtime, meal places, and companions. The data from 19,692 time diaries, recorded by 9,846 employees aged 19-64 years for two days in the 2014 Korean Time Use Survey, were analyzed for working days and non-working days. Approximately two-thirds of Korean employees ate meals three times a day on both working and non-working days. The breakfast and lunch-times on working days were distributed within two hours, but the dinner time on working days and all three meals on non-working days were dispersed across a three-hour range. Male employees spent three minutes on meal preparation on working days, whereas females spent 30 minutes. On working days, 88% of breakfasts and 67% of dinners were eaten at home. For lunches, 46% were eaten at restaurants, and 42% were at workplaces. The breakfast on working days showed the highest percentage of eating alone (40%) and the dinner on non-working days appeared highest in the percentage of eating with families (69%). The characteristics of Korean employees’ meal structure appeared different on working days and non-working days. Such characteristics should be considered in the process of planning nutrition policies and programs for employees.
This study investigated the effect of offering eco-friendly fashion items on consumers’ perceived image of stores and their intention to purchase food in a hybrid cafe setting. The data were collected using an online survey of 465 adults aged 20 to 49 years. In order to compare ‘a general cafe’ where only food is sold and ‘a hybrid cafe’ which offers eco-friendly fashion items as well as food, we developed two store types (general×hybrid) with two store designs (modern×eco-friendly) as stimuli, resulting in four scenarios. The results indicated that offering eco-friendly fashion items at a cafe did not significantly affect consumers’ perceived eco-friendly image of the store. Further, this negatively affected consumers’ perceived healthy and tasty images of the store and intention to purchase food. Such negative effects on the healthy and tasty images of the store increased in the store with a modern design. In conclusion, offering eco-friendly fashion items at cafes may not contribute to enhancing the stores’ images or sales.
PURPOSES: The objective of this study was to investigate the effect of short-term aging level on the moisture resistance of a dense-graded asphalt mixture by measuring its deformation strength ratio (SDR).
METHODS : Three short-term aging (STA) durations (1, 2, and 4 h) at two different temperatures (160℃ and 180℃) were used for the normal dense-graded hot-mix asphalt (HMA) mixtures prepared using PG 64-22 asphalt and 13mm aggregate with and without hydrated lime (HL). The specimens were prepared using a gyratory compactor, after each STA, to achieve a WC-1 gradation as defined by the Korean guide. The SDR was measured after freezing-and-thawing (F-T) conditioning, and submerging the specimen into water at 60℃ for 72 h.
RESULTS: The results indicated that the moisture resistance decreased with the increase in STA duration. After STA at 160℃ and 180℃, the SDR values, measured after F-T treatment, or after submerging into 60℃ water for 72 h, decreased with the increase in STA duration. However, when HL was used in the same asphalt mixtures, the SDR improved, for identical STA conditions. Therefore, the moisture resistance of the asphalt mixture was affected by the short-term aging duration, and decreased with the increase in aging duration. However, HL effectively retarded aging, and the moisture resistance, as indicated by the SDR, improved in the HL-added mixes, which had aged lesser than the normal mixes.
CONCLUSIONS : It was concluded that the moisture resistance of the asphalt mixture decreased with the increase in aging level, and hydrated lime was effective in preventing the degradation of the moisture resistance by reducing the age-hardening of the binder. However, since this study used a limited range of materials, further studies using more materials are required to reach a more generalized conclusion.
This study aimed to assess the nutritional quality of breakfast among Korean school-aged children and adolescents depending on eating together as a family, based on the 2013-2014 Korea National Health and Nutrition Survey. One day 24-hour recall data of 1,831 children and adolescents aged from 6 to 17 years were collected. The nutritional quality of breakfast was analyzed and compared between Family Breakfast Group (FBG, n=1,410) and Eating-alone Breakfast Group (EBG, n=421). The results showed that age, family structure, number of family members, and frequency of breakfast were associated with eating breakfast as a family. The calorie intake from breakfast explained 19% and 16% of the daily intake for FBG and EBG, respectively. The percentages of children and adolescents consuming Vitamin A, Vitamin B1, Vitamin B2, Vitamin C, Niacin, and Iron less than 1/4 of the Estimated Average Requirements were significantly lower in FBG than in EBG. The average numbers of serving for “Grains” and “Vegetables” food groups and the average Dietary Diversity Score were significantly higher in FBG than in EBG. Overall, the results indicated that eating breakfast as a family is positively associated with nutritional quality of breakfast among Korean school-aged children and adolescents.
This study examined the historical changes of and dietitians’ needs for the Life Cycle-based Dietary Guidelines for Koreans. Content analysis of relevant documents, a survey of 307 dietitians, and in-depth interviews with eight dietitians were conducted. The dietary guidelines published between 2003 and 2004 included one set of common guidelines and several sets of dietary action guides corresponding to six target groups: pregnant and lactating women, infants and toddlers, children, adolescents, adults, and the elderly. The guidelines were revised between 2008 and 2011 and consisted of six sets of guidelines for the target groups without common guidelines. The dietitians considered five or six as appropriate numbers of guidelines for each group. Needs for separate guidelines for women of child-bearing age and male workers were reported. The dietitians preferred one set of common guidelines with specific action guides for each target group and wanted easier and more specific messages to be included in the new guidelines. It is suggested that the Life Cycle-based Dietary Guidelines for Koreans should be revised to reflect such dietitians’ needs.
This study aimed to evaluate the genotoxicity of Litsea japonica fruit-hexane extract (LJF-HE). In order to examine the genotoxicity, we carried out bacterial reverse mutation assay, chromosome aberration assay, and a micronucleus induction (MN) test according to the OECD and the Korea Ministry of Food and Drug Safety (MFDS) toxicity test guidelines. In the bacterial reverse mutation assay, no significant increase in revertant colonies, nor bacterial toxicity, was observed in the LJF-HE treatment group, regardless of the absence or presence of metabolic activation by the S9 mixture. However, in the positive control group, revertant colony counts were shown to be more than twice that of the negative control group. The chromosome aberration test showed that the repetition rate of abnormal chromosome aberration was less than 5%, regardless of the treatment time, and with or without the S9 mixture. No significant change was observed when (p < 0.05) compared with the negative control group. The micronucleated polychromatic erythrocytes (MNPCE) repetition rate of the polychromatic erythrocytes (PCE) showed no significant changes when compared with the negative control group (p < 0.05). The PCE portion of total erythrocytes also showed no significant changes (p < 0.05). These results showed that LJF-HE had no significant genotoxic effects.