• Nuclear Engineering and Technology
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• v.51 no.3
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• pp.922-929
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• 2019

This paper presents the drop performance test of the control rod assembly which is one of the main components strongly related to the safety of the prototype generation IV sodium-cooled fast reactor. To investigate the drop performance, a real-sized control rod assembly that was recently modified based on the drop analysis results was newly fabricated, and several free drop tests under different flow rate conditions were carried out. Then the results were compared with those obtained from the previous tests conducted on the conceptually designed control rod assembly to demonstrate the improvement in performance. Moreover, the drop performance tests under several types and magnitudes of seismic loadings were also conducted to investigate the effect of the seismic loading on the drop performance of the modified control rod assembly. The results showed that the effects of the type and magnitude of the seismic loading on the drop performance of the modified control rod assembly were not significant. Also, the drop time requirement was successfully satisfied, even under the seismic loading conditions.

• Nuclear Engineering and Technology
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• v.39 no.3
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• pp.187-192
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• 2007

The basic research on fast reactor technology was started in the mid-1960's in China. The emphasis was put on fast reactor neutronics, thermohydraulics, sodium technology, materials, fuels, safety, sodium devices and instrumentation. In 1987, the research turned to applied basic research with the conceptual design of a 60 MW experimental fast reactor as a target. The Project of the China Experimental Fast Reactor(CEFR) with a thermal power 65 MW was launched in 1993. The R&D of fast reactor technology then carried out to serve a design demonstration connected with the different phases of the conceptual, preliminary and detailed design of the CEFR. Recently, three directions of fast rector technology R&D activities have been considered, and some research programs have been developed. They are: (1) R&D related to the CEFR, i.e. experiments to be conducted on the CEFR for its safe operation, (2) R&D related to the projects of a prototype and the demonstration of fast reactors, and(3) advanced SFR technology within the framework of the international cooperation of INPRO and GIF.

• Proceedings of the Korean Society of Toxicology Conference
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• 2002.05a
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• pp.107-107
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• 2002

It has been reported that antinatriuresis is induced by acute cadmium intoxication. However, the mechanisms related to the increase in renal sodium reabsorption by cadmium exposure is not clear yet although it has been suggested that the elevated aldosterone might involve in this process.(omitted)

• The Korean Journal of Food And Nutrition
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• v.28 no.3
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• pp.376-386
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• 2015

The purpose of this study was to evaluate the sodium-related dietary attitudes, behaviors, and nutritional knowledge in university students according to the practice of dietary guidelines for Koreans established by the Ministry of Health and Welfare, Republic of Korea. Based on the total practice score related to the dietary guidelines (PDG), we classified subjects into a "low practice of the dietary guidelines (LPDG)" group (n=94, male=43, female=51) (total score of PDG ${\leq}13$) and a "high practice of the dietary guidelines (HPDG)" group (n=56, male=32, female=24) (total score of PDG >13). Subjects were asked about general characteristics, lifestyle, salt-related dietary attitudes, behaviors, and nutritional knowledge using a questionnaire. The LPDG group had more subjects who were breakfast skippers (p<0.001) compared to the HPDG group. The LPDG group (31.26) had a significantly lower score in terms of salt-related dietary attitudes compared to the HPDG group (33.77) (p=0.0042). The score for salt-related dietary attitudes was significantly higher in the HPDG (32.52) group than in the LPDG (29.91) group (p=0.0041). There was no significant difference in the total score for salt-related nutrition knowledge between the groups. The correlation analysis indicated that the dietary guidelines practice score had a positive correlation with the salt-related dietary attitude score (r=0.3593, p<0.0001) and the dietary attitude score (r=0.3443, p<0.0001) after adjustments for sex. These results show that the degree of adherence to the dietary guidelines for adults may be related to sodium-related dietary attitudes, behaviors, and nutrition knowledge.

• Korean Journal of Community Nutrition
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• v.27 no.5
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• pp.397-405
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• 2022

Objectives: This study examines the effect on the frequency of ramyeon consumption based on who checks nutrition labels and on the levels of sodium-related nutrition knowledge among middle school students in the Incheon area. Methods: Self-administered questionnaires were completed by 359 students (143 males and 216 females) from May to October 2021. General information as well as ramyeon-eating behaviors were surveyed. The frequency of ramyeon consumption was compared depending on who checks nutrition labels and on the amount of sodium-related nutrition knowledge students have. Both 𝛘² tests and t-tests were conducted for categorical and mean comparisons. Results: Regarding the consumption of ramyeon, 46% of the students replied that they eat it alone at home. The criteria for choosing the kind of ramyeon to eat were taste (79.4%), price (9.2%), brand and new products (4.5%), nutrition (2.2%), weight control (2.2%), and other factors (2.5%). When purchasing ramyeon, more students replied that they did not read nutrition labels (66.0%) compared to those who did read labels (34.0%). Answers to questions on sodium-related nutrition earned an average of 6.84 out of nine points (males, 6.72 points, females, 6.91 points, ns). The average frequency of ramyeon consumption was 1.67 times per week (males, 1.66, females, 1.68, ns). The frequency of ramyeon consumption by students who checked nutrition labels was lower than for students who did not check labels (1.44 times per week vs. 1.79 times per week, P < 0.05). Conclusions: Students who checked nutrition labels reported a lower frequency of ramyeon consumption than students who did not check them. Education on checking nutrition labels may reduce the consumption of processed foods such as ramyeon and may lead to making healthy choices when purchasing food.

• Journal of Nutrition and Health
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• v.20 no.1
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• pp.25-37
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• 1987

The purpose of this study was to estimate the sodium and potassium intakes and their metabolisms of preschool children, and to evaluate the relationship between the blood pressure and the related variables. The subjects consisted of ninety-five preschool children aged two to six years (male 57, female 38). Twenty-four hour urines of subjects were collected for the measurements of their volume, sodium, potassium, creatinine and urea nitrogen. At the same time, the questionnaire was designed to assess the sodium and potassium intakes. The' results obtained were as follows; 1) The urinary excretion of sodium in 24 hours was 54.6$\pm$22.4mEq(orI255.8mg)and dietary sodium intake was 2147.0$\pm$518.4mg. The dietary sodium intake significantly increased with increasing age(p=O.0151). However, daily sodium intake per unit body surface area did not show significant difference by age. 2)The urinary excretion of potassium in 24 hours was 14.2$\pm$7.6 mEq (or 555.2mg) and the potassium intake was 1133.8mg. 3) The urinary excretions of creatinine and urea nitrogen were 240.2$\pm$126.2mg and 2946.7$\pm$1693.9mg, respectively. 4) The principal food SOUTce of sodium intake was the seasoning group, which con\ulcornertributed 49.9% to total sodium intake. 5) The main food source of potassium intake was milk and milk products; from which 28.6% of total potassium intake was obtained. 6) The blood pressure showed highly positive correlations with height, weight and body surface area (p$\leq$O.OOl) . In addition, the blood pressure was found to be correlat\ulcornered with urinary sodium excetion and dietary sodium intake (p$\leq$O.Ol).

• Nutrition Research and Practice
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• v.17 no.4
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• pp.812-825
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• 2023

BACKGROUND/OBJECTIVES: This study investigated the importance and performance level of sodium reduction practices in school meal service by school nutrition teachers and dietitians, and compared them according to school level and placement of the school nutrition teacher. SUBJECTS/METHODS: An online survey was conducted with 608 nutrition teachers and dietitians in schools in the Republic of Korea from September 28 to November 12, 2021 (response rate: 57%). The questionnaire comprised 11 items related to sodium reduction practices (purchasing, food preparation and serving, and education). The importance and performance level of each item was rated on a 5-point scale. The mean differences were analyzed using t-tests or one-way analyses of variance and Duncan's post-hoc tests. An importance-performance analysis was performed on sodium reduction practices. RESULTS: Participating in sodium reduction education, sodium reduction education for cooks, and sodium reduction education for students were assessed to have high importance but low performance. Overall, the higher the school level, the lower was the importance level of sodium reduction practices. The performance in kindergartens and elementary schools was higher than that in middle and high schools. The importance in the purchasing category perceived by dietitians was lower as compared to nutrition teachers. In addition, the performance in the purchasing, food preparation and serving, and education categories perceived by dietitians was lower than those of nutrition teachers. CONCLUSION: Sodium reduction education for nutrition teachers and dietitians, cooks, and students should prioritize practicing sodium reduction in school meal service. Specific guidelines for managing sodium reduction at all stages-purchasing, food preparation, and serving-should also be developed. The results could be used as basic data to reduce the sodium content in school meals.

• Journal of Nutrition and Health
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• v.50 no.6
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• pp.664-678
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• 2017

Purpose: To identify the effectiveness of policy evaluation, consistent monitoring is necessary. This study aimed to carry out mid-term evaluation of objectives and programs related to comprehensive plans for sodium intake reduction by 2020 for Seoul city and then reestablish the objectives of the sodium intake reduction plans. Methods: Literature reviews, data analysis, and reviews of expert focus-groups were performed to evaluate objectives, to develop a new goal, and to identify the priority subjects of the sodium intake reduction programs. In order to examine target populations for the programs, awareness and behaviors related to sodium intakes among Seoul citizens were examined by sex, age, and income level using the 2008~2013 Korea National Health and Nutrition Examination Survey data. Results: Current objectives of the sodium intake reduction plan by 2020 for Seoul city were not appropriate, so objectives were reset to 3,600 mg of sodium intake by 2020 among Seoul citizens with 2% reduction per year. Although sodium intake showed a decreasing trend by year, it was still high, especially in men. The sodium intake reduction programs currently in progress have not been assessed at multiple levels across multiple sectors and have only been assessed fragmentarily. For dietary behavior related to sodium intakes by sex, age, and income level, sodium intake was higher in the group with less than 100 g of fruit intake compared to the group with 100 g or more. Subjects aged 30~59 years and the low household income group showed relatively higher sodium intakes. Based on the data analysis and the expert review, the priority subject of the sodium intake reduction programs was determined to be adult men. In terms of a program strategy for sodium intake reduction, multi-level and setting approaches, including work sites, home, and restaurants, were suggested to reduce sodium intakes of the target subject. Conclusion: The suggested objectives should be consistently monitored by data analysis, and the determined programs need to be phased in over 5 years.

• Journal of Nutrition and Health
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• v.52 no.5
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• pp.475-487
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• 2019

Purpose: With the increase of going out to eat, reducing the sodium in restaurant foods has a crucial impact on reducing sodium intake. This study aimed to assess the current status and perceptions of restaurant staffs related to reducing sodium use in restaurants. Methods: Restaurant managers and chefs (n = 312) in Seongnam area completed a questionnaire on the current status related to sodium use, the barriers to practice for reducing sodium use, support needs, and the practicability of methods for reducing sodium use in restaurants. Results: The percentage of restaurants in the preaction stage (including the precontemplation, contemplation, and preparation stages) for reducing sodium use was 79.7%. Logistic regression analysis showed that measuring salinity while cooking was associated with measuring seasoning (OR, 4.761; 95% CI, 2.325 ~ 9.751), action/maintenance stages of behavior change (OR, 2.829; 95% CI, 1.449 ~ 5.525) and providing salinity information of restaurant foods (OR, 6.314; 95% CI, 2.964 ~ 13.45). Maintaining taste and hindering the cooking process were the main barriers to reduce sodium use. The total practicability of actions for reducing sodium was higher in staffs who worked in restaurants that measured seasoning and salinity while cooking (p < 0.05 and p < 0.01, respectively). The hardest item to practice was 'purchase foods after comparing sodium content in the nutrition labeling'. 'Avoid serving salt-fermented foods as side dishes', 'serve small portions of kimchi and less salty kimchi', and 'put up promotional materials for reducing sodium intake' were selected as easy items to perform. The majority (82%) was willing to reduce sodium in restaurant foods under the support of local government and they desired the promotion of participating restaurants and education on cooking skills to reduce sodium. Conclusion: Measuring seasoning and salinity while cooking is a meaningful practice that is associated with stages of behavior change and the practicability of actions for reducing sodium. It is necessary to provide support and education with a gradual approach to staffs for reducing sodium in restaurant foods.

• Journal of the Korean Ceramic Society
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• v.13 no.1
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• pp.20-24
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• 1976

These are many kinds of self-hardening methods for sand mold using sodium silicate. When sodium silicate solution is mixed with calcium-orthosilicate powder hardening reaction occurs, which is based for self-hardening method at high temperature. The high temperature strength and resicual strength of mold are related to the mole ratio of sodium silicate and the contents of calcium-orthosilicate powder. The results obtained in this study were as follows: 1) The high temperature strength of mold was maximum at about $600^{\circ}C$, and at higher temperature showed lower value on the contrary. 2) The high temperature strength of mold was increased by increasing the amount of sodium silicate having lower mole ratio and high concentration. 3) The residual strength of mold was reduced by increasing the mole ratio of sodium silicate and increasing the concentration of calcium-orthosilicate.