• The Korean Journal of Food And Nutrition
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• v.36 no.4
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• pp.334-339
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• 2023

To suppress mold generation of yujacheong, Penicillium chrysogenum LB31 was cultured, and spores were harvested and put into yujacheong. Antioxidant activity, useful ingredients, mold size and incidence were investigated while storing yujacheong for 30 days, after sterilization with different methods (nontreatment, ozone gas emission, heating after ozone gas emission and heating). The results showed that the content of narirutin, naringin, hesperidin, or neohesperidin, which are functional components of yuzu, increased as the storage period increased in all the treatment units. In addition, mold generation was not observed until the 15th day in the heat treatment group after ozone gas emission. As the treatment group emitted ozone gas. molds of 34.8 and 112 mm2 in size were observed on the 30th day. These results suggested that ozone sterilization can prevent microbial contamination, further extending the shelf life of yuzacheong and maintaining a fresh state.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.10 no.4
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• pp.304-315
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• 1981

This paper presents, the result of the study for the fluctuant temperature of the out-side air adopting the heat pump system in seoul, Taejean, Taegu, Busan and Jejeu among principle cities in korea for the purpose of checking the heating capacity, Heat pump capacity (outlet capacity), Coefficient of performance and running cost in comparison with the supporting the energy for the boiler's operation. According to the supply temperature changes of the out door coil by the out side air-return air mixing ratio, the Coefficient of performance is increased from 3. 1 to 5.0. Particularly, in Taegu, it is necessary to adopt the heat pump system against the supplement heat supply on the full outside air intake in January of the heating period, and it was recognized that the running cost is cheaper than that of the Boiler use. At the same time, if it is able to get $25\%$ of return air of the inside in the Seoul, it could be saved its costs when we use the supplementary boiler. And I think it is necessary to the development.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.295-303
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• 2022

Residential heating systems in South Korea are largely based on the use of ondol pipelines. Heat is transferred to the floor by passing hot water through a metal or plastic pipe buried within the concrete of the floor. Consequently, it is difficult to clean the inside of these pipes after installation. Over time, foreign substances such as scale accumulate in the pipe when the ondol heating method is used for an extended period. Therefore, in the past, pipes were cleaned by removing foreign substances attached to the inside surfaces of the pipes using high-pressure water or by disassembling the pipes and removing foreign substances with chemical agents. Recently, a method for removing foreign substances through the cavitation effect of ultrasound has been proposed. This idea might lead to the development of new technologies for cleaning pipe interiors. Consequently, this study investigated the use of ultrasound to clean pipes embedded in concrete. In this study, devices that generated ultrasonic waves with various frequencies and directions were prepared. After preparing arbitrarily contaminated pipes, the appropriate frequency, output strength, and output direction for each foreign substance were determined through repeated experiments. The results of this experiment could provide important information for future methods of cleaning the interior of ondol piping systems.

• Journal of the Korean Dietetic Association
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• v.19 no.3
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• pp.209-222
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• 2013

This study examined the hygiene practices of contract foodservice employees and investigated the influence of education and work environment on these hygienes practices. A questionnaire was distributed to 250 contract foodservice employees and a total of 232 responses were received and analyzed. The overall score for hygiene practices of contract foodservice employees was 3.89 based on a 5-point scale. Cross-contamination was prominent (highest score at 4.46) and the heating temperature was less prominent (lowest score at 3.49). The factors most affecting contract foodservice employees were their work period, the size of the contract foodservice management company, the number of meals served daily, the frequency of meal service per day and the frequency of hygiene education. Compared to small and medium-sized contract foodservice management companies, the major contract foodservice management companies showed higher scores for refrigerator/freezer control (P<0.001), vegetable/fruit disinfection (P<0.001), thawing (P<0.001), heating temperature (P<0.001), cleaning/disinfection (P<0.01), and personal hygiene (P<0.05). The frequency of hygiene education had a significant effect on the performance levels for refrigerator/freezer control (P<0.001), vegetable/fruit disinfection (P<0.001), thawing (P<0.001), heating temperature (P<0.001), cleaning/disinfection control (P<0.001), food supply control (P<0.05), and personal hygiene (P<0.05). From these results, to increase the sanitation quality of contract foodservice operations, hygiene practice levels need to increase and hygiene education systematically should be enforced for foodservice employees.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.29 no.11
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• pp.605-611
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• 2017

The purpose of this study is to calculate the energy consumption rate based on data regarding energy use in office buildings, and to confirm the general characteristics of energy consumption. The energy consumption rate of the building is calculated by dividing the energy consumption by the floor area. The energy consumption rate of small-sized office buildings was calculated as $101.48{\sim}201.55kWh/m^2{\cdot}year$ and in the case of medium-sized buildings, the range was $92.77{\sim}177.89kWh/m^2{\cdot}year$. In the case of small buildings, it was found that the energy consumption was $73.24kWh/m^2{\cdot}year$ in electronic device, $34.31kWh/m^2{\cdot}year$ in hot water supply, and $18.37kWh/m^2{\cdot}year$ in heating. In the case of medium-sized buildings, electronic devices was $73.08kWh/m^2{\cdot}year$, lighting was $18.35kWh/m^2{\cdot}year$ and heating, $15.37kWh/m^2{\cdot}year$. In all of the study buildings, the peak heating energy use was observed from 8:00 a.m. to 10:00 a.m during the winter, and the peak power management was required. Energy use at and around the midnight hour is confirmed to be 40~60% of weekly working hours, so it is necessary to manage power use at night time as well as during the day. In order to improve the accuracy of future studies, it is necessary to make efforts to secure the data with standardized energy measuring units for the various type of buildings.

• Journal of the Korean Society of Food Culture
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• v.17 no.4
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• pp.363-376
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• 2002

In order to establish the processing conditions for salt-fermented liquefaction of anchovy(Engrulis japonica), changes in the amino acid composition from oligopeptides during fermentation periods were analyzed. Experimental sample A: chopped whole anchovy, adding 20% water, heating at $50^{\circ}C$ for 9 hrs and then adding 10% NaCl. Sample B: chopped whole anchovy, adding 20% water, heating at $50^{\circ}C$ for 9 hrs and then adding 13% NaCl. Sample C: chopped whole anchovy adding 13% NaCl. Sample D: whole anchovy adding 17% NaCl. The total amino acids from oligopeptides in fermented liquefaction of anchovy increased in early fermentation period and reached highest level, and then they declined irregularly during fermentation. Their maximum amounts were just after heating at $50^{\circ}C$ for 9 hrs in sample A, after 15 days in sample B, and after 60 days in samples C and D. The fermented liquefaction of anchovy extracts were rich in glutamic acid, aspartic acid, proline, glycine, alanine, lysine and valine. However, the contents of most amino acids fluctuated by the experimental specimens and fermenting periods. Among them glutamic acid was the most abundant amino acid which was occupied $0.6{\sim}27.7%$(average 24.0%) in the content of total amino acids from oligopeptides. The contribution of the amino acid composition from oligopeptides to extractive nitrogen was occupying average 20.8 and 17.5% in rapid- and low salt-fermented liquefaction(sample A, B and C) and traditional fermented liquefaction(sample D), respectively.

• Environmental and Resource Economics Review
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• v.17 no.3
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• pp.91-134
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• 2008

Korean district heating companies levy comprehensive construction fee on consumers in the beginning of construction period and the consumers' burden is much higher than those in any other network industries in Korea. It has also many problems such as inappropriate fee calculation method, cross subsidization, property right dispute, etc.. I show that the cut of construction fee by 30% and at the same time, the upward adjustment of tariff rates by 4~6% for 20 years on average will maintain current profitability based on the standard model simulation, I also suggest that fixed charge part of double tariff should be increased to 25% of total tariff and the cut of construction fee should be levied on fixed charge, directly to improve efficiency.

• Journal of the Korean Solar Energy Society
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• v.35 no.5
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• pp.39-48
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• 2015

In this study, the solar chimney, one of the passive solar systems, is proposed as a method to improve the thermal environment of northern zones in buildings. As this well-known system has rarely been used in building projects, an adequate application of the system is proposed in this paper: the solar chimney system is designed to meet the required ventilation rate and consequently to reduce the ventilation load in the northern part of a building. To investigate such a possibility, a numerical model for the system is developed, and results of numerical tests are used for energy simulations. The results were taken into account for test simulations in EnergyPlus. As a result, approximately 75% of the volumetric ventilation rate required in the north zone could be supplied with the air volume acquired through the system and the monthly mean load was reduced by 29.5%, from 1.584 kWh to 1.117 kWh. The analyses of hourly mean heating and ventilation load over the heating period indicated that the system was very effective at around 13:00. Results show that 33% reduction in the ventilation load and 17% in the heating load for the north zone could be acquired through this system.

• Textile Coloration and Finishing
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• v.30 no.3
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• pp.216-226
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• 2018

The combination dyeing have been attempted to get the various color. The objective of this research was to study the color developing effects on cotton fabrics dyed with persimmon, catechu and combination of the both by heat treatment process. These dye were applied on bleached cotton fabrics for the dyeing before post mordanting with aluminium potassium sulfate, copper sulfate, and iron sulfate. The various color changes on cotton fabric were measured by color spectrophotometer. The heat treatment of temperature around $150^{\circ}C$ for an hour can reach the highest color developing. The dyed fabrics with mordanting were heated for specific time period, which was compared without the mordanting. The post mordanted fabrics showed that more various colors can be obtained using combination dyeing. K/S values of dyed fabrics with Al, Fe, and Cu mordants were higher than the cases without mordants. The Cu mordanted fabric showed very effective color developing by the heating process. The fabrics dyed with catechu lowered L* value with little changes in a* and b* values, while the a* and b* values became higher with heat treatment. The fabrics dyed with persimmon has the lowest L* value and more changes in a*, b* value with heating process. Therefore, K/S values can be increased effectively by the combination dyeing of persimmon and catechu. Colorfastness to washing in color change was grade 2-3 in non-mordanted fabric, and grade 3 in mordanted fabric. Lightfastness of the dyed fabrics was above grade 4.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.3
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• pp.221-229
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• 2018

Various types of dried laver Pyropia yezoensis have been produced in response to increasing demand and other laver goods manufactured using different processing methods are continuously being developed. The dried laver used in this experiment was initially heated at $165^{\circ}C$ for 3 seconds, followed by second heating at a high temperature ($340-350^{\circ}C$) to increase the storage period and enhance taste and flavor. Nutrient analysis of each sample heated under three conditions revealed that the protein and lipid contents were highest in samples from D company, while the carbohydrate contents remained relatively stable. After storage for 10 weeks at room temperature, changes in the composition were evaluated. The results showed decrease in protein (30%-49%) and essential amino acid contents. During storage, the major unsaturated fatty acids contained in dried laver slightly changed to 53.4%-56.0% in the form of EPA, while saturated fatty acids slightly increased to 18.4%-22.6% in the form of palmitic acid. The variables derived from fatty acid composition, such as atherogenic and thrombogenic, and hypocholesterolemic/hypercholesterolemic dietary indices, and polyunsaturated fatty acids/saturated fatty acids ratio, also indicated reasonable levels of stability. However, the laver should be consumed within 2 months.