• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.12 no.1
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• pp.107-114
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• 2016

Four cylindrically shaped IHXs(Intermediate Heat Exchangers) are installed in the PHTS(Primary Heat Transfer System) of the PGSFR(Prototype Gen IV Sodium cooled Fast Reactor). As for the IHX, the temperature difference of structure is inevitable result caused by heat transfer between primary coolant sodium and IHTS(Intermediate Heat Transport System) sodium. It is necessary to evaluate the high temperature structural integrity of IHXs which operate at the elevated temperature condition over the creep temperature. In this paper, the high temperature structural integrity of IHX under assumed loading conditions has been reviewed according to ASME code.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.15 no.4
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• pp.7-13
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• 2001

In this paper, the external-exciting electronic ballast for an 100[W] high pressure sodium lamp using full-bridge inviter is designed. The L-C parallel full-bridge invert circuit for P-SPICE simulation is designed. The values of inductor and capacitor in the proposed equivalent L-C parallel resonant tank circuit are calculated theoretically. Then the ballast for high pressure sodium lamp is implemented using the simulated results. In the experimental results, that is confirmed which the results of implemented ballast are really same with the of simulated one.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.103-104
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• 2019

The aim of the research is assessing the possibility of recovering the compressive strength of the mortar mixture replaced excessively high volume of blast furnace slag accidently. As a result of the experiment, in the case of compressive strength, painting sodium oxide showed higher compressive strength recovery effect than painting calcium oxide. As a curing temperature, 20℃ showed advanced result rather than 65℃. From the wet curing, the reaction was confirmed, deeper penetration depth was checked at 20℃ than 60℃ temperature. Therefore for the concrete mixture with excessively high volume of blast furnace slag, it is considered that painting sodium hydroxide and curing 20℃ can recover the compressive strength effectively.

• Journal of Nutrition and Health
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• v.52 no.2
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• pp.185-193
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• 2019

Purpose: This study was conducted to develop standards for the salinity and sodium content in representative Korean foods high in sodium. Methods: A total of 600 foods from four seasonings (soy sauce, soybean paste, red pepper paste, and ssamjang) and 16 representative Korean foods high in sodium were collected from 10 households, 10 industry foodservice establishments, and 10 Korean restaurants in 10 cities nationwide and analyzed for their salinity and sodium content. Based on the findings, the standards with a 20% ~ 30% reduced sodium content and salinity from the current level were presented. Results: The suggested standards of salinity (and sodium content per 100 g) were less than 12% (4,500 mg) for soy sauce, 9% (3,500 mg) for soybean paste, 5% (2,000 mg) for red pepper paste, and 6% (2,500 mg) for ssamjang. The reduced standards of salinity for soups were suggested to less than 0.5% for clear soup and 0.7% for soybean paste soup, while for broths, it was 0.6% for clear broth and 0.7% for other broths. The standards of salinity for stews were suggested to less than 0.8% for soybean paste stew, 0.6% for other stews, 0.9% for steamed and stir-fried fish dishes, 1.0% for braised dishes, 4.0% for stir-fried dried fishes, 1.3% for other braised dishes including vegetables, and 1.5% for pickled vegetables and kimchi. Conclusion: Standards for the sodium content and salinity were suggested to reduce the sodium level in fermented soybean sauces and representative Korean high sodium dishes by 20% from the current levels. Nevertheless, it will be necessary to adjust the standards properly to reduce the sodium content and salinity further by considering the future status of sodium intake.

• Korean Journal of Community Nutrition
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• v.23 no.4
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• pp.333-340
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• 2018

Objectives: This study was conducted to analyze the salinity of representative Korean foods high in sodium to generate data for use as a fundamental resource for setting salinity standards in foods. Methods: A total of 480 foods from 16 representative Korean foods high in sodium were collected from 10 households, 10 industry foodservice establishments, and 10 Korean restaurants in four regions (Capital area, Chungcheong Province, Gyeongsang Province, and Jeolla Province) and analyzed for salinity. Results: Among the foods, stir-fried anchovies (4.07~4.45%) showed the highest salinity, followed by pickled onion (1.86~2.62%), cabbage kimchi (1.83~2.2%), braised burdock and lotus root (1.79~2.17%), and sliced radish kimchi (1.78~1.89%) (p<0.001). The salinity of kimchi from home meals (2.2%) was significantly higher than that of foodservice (1.83%) and restaurant (1.93%) kimchi (p<0.05). Salinity in each group of food was highest in kimchi (1.83~2.04%), followed by braised dishes (1.54~1.78%), steamed dishes (1.0~1.22%), stir-fried dishes (1.02~1.18%), and soup or stew (0.74~1.02%) (p<0.001). The salinity of soup and stew from restaurants (1.02%) was significantly higher than that of home meal (0.84%) and foodservice (0.74%) soup and stew. Conclusions: Determination of the salinity of representative Korean foods known to be high in sodium by eating place is expected to be useful to establishing guidelines for reduction of salinity.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.3
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• pp.16-25
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• 2013

Now it's a trend to install a series of white fluorescent light and orange high pressure sodium lamps because tunnel lighting should be opaque to the safety of drivers from soot, dust, humidity, and fog. Also fluorescent lighting is replaced to LED due to the fact that it improves amenity and object recognition and LED lighting has gradually been improved its nature. In this paper, we have implemented the circuits of the yellow series of high-pressure sodium lamps and white series of LED lights at one board to improve the transparency and recognition of objects. It is possible for inductive high-pressure sodium lamps and the capacitive LED drivers to circuit without power factor compensation. Two circuit parts share only a small number of parts, so low cost LED drivers compared to conventional ones are possible. Therefore, the implementation of the hybrid lighting with high-pressure sodium lamps and LED lights that can be driven at the same time by one driving circuit is possible. The LED capacitive power factor was 0.91 while individually implemented the sodium lamp power factor was 0.98. It shows not only the 2% improvement of hybrid forms but also the efficiency and THD.

• Journal of Korean Tunnelling and Underground Space Association
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• v.23 no.4
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• pp.211-220
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• 2021

Low-pressure sodium lamps, high-pressure sodium lamps, and fluorescent lamps are mainly used for tunnel lighting in Rep. of Korea, which accounts for the highest percentage in the tunnel maintenance costs. Therefore, tunnel lights are being replaced by LED lamp that have advantages with respect to low power consumption and sustainability. To analyze the effect of replacement high pressure sodium lamp with LED lamp, illumination and monthly power usage per year have been investigated for 10 tunnels. The usage of LED lamp results in illumination improvement from 27.9% to 490% and power saving around average 47.1%.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.21 no.4
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• pp.269-275
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• 1988

Inhibitory effects on bacterial growth by using lysozyme and mixtures of it with other antibacterial substances (sodium hexametaphosphate and sodium pyrophosphate) were investigated against the 7 kinds of hacterial strains isolated from putrefied surumi products. The growth inhibitory concentrations of lysozyme and lysozyme + sodium hexametaphosphate + sodium pyrophosphate against the bacteria were added to kamaboko, imitation crab meat and fried surumi, then viable cell count, pH and VBN were examined during the storage at $30^{\circ}C$ for 7 days. Lysozyme showed growth inhibitions against 6 of 7 isolates and the inhibition effect of mixture of antibacterial substances was multiplied against all the isolates compare with those of its individual use. Growth inhibitory effect of the substances on the bacteria was high in order of lysozyme + sodium pyrophosphate + sodium hexametaphosphate, lysozyme + sodium hexametaphosphate, lysozyme + sodium pyrophosphate and lysozyme. The most effective inhibitory concentration of mixture of the antibacterial substances in kamaboko and imitation crab meat was $0.05\%$ of lysozyme, $0.5\%$ of sodium pyrophosphate and $0.1\%$ sodium hexametaphosphate. But the bacterial growth was slightly inhibited in fried surumi even if the same concentration of the dipped mixture and the effect of the mixture was less than that of $0.2\%$ sorbic acid.

• Korean Journal of Community Nutrition
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• v.17 no.6
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• pp.737-751
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• 2012

The purpose of this study was to assess sodium and potassium intakes and urinary excretion of adults in Busan and to evaluate the relationship of urinary sodium/potassium excretion (UNa/UK) to the status of anthropometric, blood pressure, urine analysis, and nutrient intake of subjects. Nutrient intake by 24-h recall, 24-h UNa/UK were measured with 87 adults aged 20-59 yrs (42 men and 45 women). The mean intakes of sodium and potassium were 3915.4 mg and 3093.9 mg, respectively. The mean 24-h UNa/UK was 3457.0/1680.4 mg. UNa showed significant positive correlations with sodium intake (p < 0.001, p < 0.001), sodium/potassium ratio (p < 0.001, p < 0.01), UK (p < 0.001, p < 0.001), and UNa/UK ratio (p < 0.05, p < 0.01) in men and women and with age, BMI, systolic blood pressure (SBP) and diastolic blood pressure in women (p < 0.05, p < 0.05, p < 0.05, p < 0.05). The UK showed significant positive correlations sodium intake (p < 0.001, p < 0.001), UNa (p < 0.001, p < 0.001) in men and women and with sodium density in men (p < 0.001) and with age, intakes of protein and potassium in women (p < 0.01, p < 0.05, p < 0.05). Mean SBP was lowest in the second quartile and highest in the fourth quartile of UNa. Mean UNa in the second, third, and fourth quartiles were 2821.1 mg, 3621.3 mg, and 5456.4 mg, respectively. Mean SBP in the second, third, and fourth quartiles were 115.8 mmHg, 120.7 mmHg, and 125.9 mmHg, respectively. Based on the results, UNa was related to sodium intake, UK, and SBP. We conclude that nutritional education for the reduction of high sodium intake is needed in the general population to prevent and control adverse blood pressure levels.

• Journal of the Korea Concrete Institute
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• v.27 no.4
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• pp.443-450
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• 2015

This paper presents an investigation of the mechanical and microstructural properties of Class F fly ash based geopolymer containing sodium sulfate as an additive. Sodium sulfate was used as an chemical additive at the dosage levels of 0, 2, 4, and 6wt% of fly ash. Sodium hydroxide and sodium silicate solutions were used to activate fly ash. The compressive strengths of geopolymer pastes were measured at the age of 28 days. The microstructures of the geopolymer pastes were examined using XRD, MIP and SEM tests. The additions of 2wt% and 4wt% sodium sulfate produced geopolymers with high strength, while increasing the dosage of levels to 6% resulted in almost no changes in strength, comparing with the control geopolymer. The optimum increase in strength was obtained with the addition of 4wt% sodium sulfate. As the amount of sodium sulfate is increased, no additional crystalline phase was detected and no change of amorphous phase indicated despite the change in the strength development. The increase in the strength was due to the change of pore size distribution in samples. As addition of sodium sulfate altered the morphologies of reactive productions and Si/Al ratios of the reaction products, the strengths were thus affected. It was found that the strengths of geopolymer were larger for lower Si/Al ratios of reaction products formed in samples. The optimal amount of sodium sulfate in the fly ash based geopolymer helps to improve mechanical properties of the geopolymer, on the other hand, the high percentage of sodium sulfate could exist as an impurity in the geopolymer and hinder the geopolymer reaction.