• Journal of the Korean Ceramic Society
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• v.34 no.12
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• pp.1235-1239
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• 1997

Sodium niobate single crystals were grown by high temperature solution growth with Na2O/B2O3 flux. The phase transitions and domain structures of sodium niobate were observed using transmission polarizing microscope from room temperature to $650^{\circ}C$. There was imperfect extinction region within as-grown crystals and this area could be removed by heat treatment. The area existed within crystal till 3$65^{\circ}C$, in which temperature the space group of sodium niobate is changed from Pbma to Pmnm. The phase transition from Pbma to Pmnm happened abruptly with changing domain structure. At 48$0^{\circ}C$, 52$0^{\circ}C$ and 572$^{\circ}C$, the colors and walls of domains were changed. All domains disappeared and the space group of sodium niobate was changed from P4/mbm to Pm3m at 64$0^{\circ}C$. When sodium niobate changed from high temperature phase to low temperature phase, the memory effect of domain structure was not observed.

• The Korean Journal of Community Living Science
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• v.26 no.1
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• pp.167-176
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• 2015

This study compares salt-related dietary patterns according to sodium intake. A survey was conducted with 257 college students(130 male and 127 female students) in the Busan area. Dish Frequency Questionnaire 70(DFQ 70) was used to quantitatively estimate sodium intake. A short dish frequency questionnaire(DFQ 15) was used to screen subjects with high or low- salt intake. The sodium intake of male students based on DFQ 70 was significantly higher than that of female students(p<0.05). Sodium intake has significant negative effects on systolic and diastolic blood pressure(p<0.05). In the high-salt intake(HS) group, classified by DFQ 15, the number of male students was significantly higher than that of female students(p<0.01). The systolic blood pressure of the HS group was significantly higher than that of the low-salt intake(LS) group(p<0.05). Salt-related dietary behavior score and eating habit score for the HS group were significantly higher than those for the LS group(p<0.01). The sodium intake of the HS group based on DFQ 70 was significantly higher than that of the LS group(p<0.01). In these results, college students in Busan area showed high blood pressure and high sodium intake compared to Korean DRIs. The results indicate a need for various education programs to help college students practice a low-sodium diet.

• The International Journal of Costume Culture
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• v.4 no.2
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• pp.86-93
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• 2001

Agricultural drainage salt generated during irrigation of crops in San Joaquin Valley, California exceeds 600,000 tons annually and cumulates in the field in a rapid rate. As a result, the waste is taking out more farmlands for salt storage and disposal, imposing serious concerns to environment and local agricultural industry. in searching for a potential solution to reduce or eliminate the waste, this research explored feasibility of producing a value-added product, sodium sulfate, from the waste and utilizing the product in textile dyeing. The result indicated that sodium sulfate could be produced the salt and could be purified by a recrystalization method in a temperature range within the highest and lowest daily temperatures in summer in the valley. Re recovered sodium sulfate samples, with purifies ranging from 67% to 99.91, were compard with commercially available sodium sulfate in directive dyeing of cotton fabrics. Direct Yellow 27 and direct Blue 1 had similar exhaustions among Na₂So₄Ⅰ, Na₂So₄Ⅱ, Na₂So₄Ⅲ and V which had similar ratios of sodium sulfate and sodium chloride in recovered salts. Na₂So₄Ⅳ had high exhaustion despite low ratios of sodium sulfate and sodium chloride. In direct Red 80, exhaustion depends more on the ratios of sodium sulfate and sodium chloride than sodium chloride. Na₂SO₄Ⅳ and Na₂SO₄V with high ratios of sodium chloride had more exhaustion than Na₂So₄and Na₂So₄Ⅲ with low ratios of sodium chloride. Generally, directive dyeing using recovered salts from farm drainage has similar or more excellent exhaustion than directive dyeing using commercial sodium sulfate.

• Journal of Wellbeing Management and Applied Psychology
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• v.6 no.3
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• pp.33-36
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• 2023

Purpose: Since the food wastewater contains a high concentration of nitrogen, it is very important to find a way to efficiently remove it. Research design, data and methodology: A total of four experiments were conducted under different conditions to remove ammonia nitrogen present in the food wastewater. The experiment was designed by adding sodium hypochlorite to the raw food wastewater and varying conditions such as pH control, aeration/precipitation, and stirring. Results: The ammonia nitrogen removal rate in Experiment 1 was about 12% (sodium hypochlorite added), ammonia nitrogen increased about 4.7% in Experiment 2 (sodium hypochlorite added after aeration/precipitation in a bioreaction tank, stirring), and decreased about 52.5% (sodium hypochlorite added after controlling and stirring). Conclusions: When the concentration of sodium hypochlorite was high, ammonia nitrogen was best removed, and the pH was adjusted to 12, and sodium hypochlorite was added after stirring, and the removal was the second best. If the method of this study is further studied and developed, it can be basic data for ammonia nitrogen removal in the future.

• Journal of the Korean Dietetic Association
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• v.19 no.2
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• pp.173-181
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• 2013

This study used survey data to identify the use of salimeters and the prevalence of sodium reduction education in the Gyeonggi region. A survey with 211 dietitians working in school foodservice (106 in elementary schools, 69 in middle schools, and 36 in high schools) was conducted from August 6 to August 17, 2012. The data were analyzed using the SPSS program. Though 86.6% of school kitchens had salimeters, the rate for checking the sodium content of soup or stew was just 62.7% and the rate for checking the sodium content of kimchi and solid food was very low. Since salimeters are mostly used to measure sodium in liquid foods, it is urgent to provide an education and manual on using salimeters and to promote salimetry for kimchi and side dishes. It is also important to provide students with nutritional information by clearly posting the sodium content of food on menus and compelling students to notice them. Sodium reduction education for cooks was conducted in the 70.3% of the kitchens; however, the dietitians perceived that the cooks did not understand the importance of the education. Also, sodium reduction education for students was mostly provided through indirect methods, rather than face-to-face education, resulting in poor educational data (only 36.4% comprehending). By providing detailed guidelines for sodium reduction and labelling accurate content of sodium of the menus, we will be able to enforce practices for sodium reduction in school lunches.

• Preventive Nutrition and Food Science
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• v.18 no.3
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• pp.222-225
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• 2013

To help reduce high intake of sodium in the Korean diet, sodium-reduced fried fish cakes (SRFFCs) were prepared and evaluated with regard to color, textural properties, and sensory attributes as indicators of quality. The quality characteristics of 30% SRFFCs were not notably different from those of full sodium FFCs; however, substitution of sodium with potassium altered the color and decreased consumer acceptance on sensory evaluation items. These results suggest that the SRFFCs that will be accepted by consumers can be prepared without compromising the quality.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2000.11a
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• pp.107-110
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• 2000

This paper deals with the design of the electronic ballast for high pressure sodium lamp, which consists of the ignitor and the resonant converter for driving the lamp. Also it contains PFC(Power Factor Controller) to improve such as power factor, low distortion etc. In this paper, we design the electronic ballast for the 150 watt high pressure sodium lamp.

• Journal of the Korean Society of Food Culture
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• v.34 no.3
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• pp.316-324
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• 2019

The purpose of this study was to investigate dietary behavior and nutritional knowledge related to sodium intake in high school students. A questionnaire survey was conducted in 400 high school students (200 boys) in Incheon, Korea. Survey data were analyzed according to gender and degree of obesity. The distribution of the degree of obesity was the highest in 231 normal weight individuals (57.8%), followed by 89 underweight (22.3%), 41 overweight (10.3%), and 39 obese (9.8%). The sodium-related undesirable dietary behavior score was 2.9 points out of 5 points. The detailed dietary behavior scores of 'I eat kimchi when I eat instant noodles or noodles' and 'I like dried fish with salt' were significantly higher in boys than in girls (p<0.05). It was found that boys consumed more frequently high sodium foods, such as pizza, hamburger, and hotdog than girls. According to the degree of obesity, the underweight group consumed more kimchi fried rice and potato chips frequently than the other groups (p<0.05). Preference for salty taste was not significantly different among the groups by gender and degree of obesity. Sodium-related nutritional knowledge score was 5.3 points out of 10 and which was significantly higher in girls or normal weight group than in boys or obesity group. These results suggest that nutritional education on sodium intake is needed because the nutritional knowledge of adolescents is relatively low. Moreover, intensive nutritional guidance is required, especially in boys or adolescents with undesirable degree of obesity.

• 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.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1999.11a
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• pp.99-102
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• 1999

The object of this paper is design and to make a high efficiency magnetic ballast for high pressure sodium lamp. The results show the efficiency is 10[%] up compared with standard ballast in best case.