• Title/Summary/Keyword: Duration of hot water usage

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An Empirical Study of Hot Water Supply Patterns and Peak Time in Apartment Housing with District Heating System (공동주택의 급탕부하 지속시간 및 부하 패턴에 관한 실증연구)

  • Kim, Sung-Min;Chung, Kwang-Seop;Kim, Young-Il
    • Journal of Energy Engineering
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    • v.21 no.4
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    • pp.435-443
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    • 2012
  • The combination of space shortage and the high population density concentrated in urban areas of South Korea has resulted in the growth of large-scale high-rise residential complexes, naturally affecting water and hot water usage patterns as well. But the current designs for water and hot water supply in South Korea rely mostly on international design standards and data calculated on site due to the severe shortage of basic data in relation to actual use, which result in the frequent problem of the under-or over-design of water and hot water supply. The following study measures the hot water supplier's conditions and the user's heat usage to realize the amount of time required for hot water supply load generation and the pattern of actual use in order to create basic data for effective hot water supply facility design and maintenance.

Development of Mouthwash Products with Solid Fermented Oriental Medicinal Herb (고체발효 한약재 추출물을 함유한 구강세척제 개발)

  • Cho, Byung-Je;Hong, Jun Young;Kim, Mijeong;Song, Yeong Ok
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.43 no.9
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    • pp.1380-1387
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    • 2014
  • The purpose of this study was to develop a mouthwash product with solid fermented oriental medicinal herb (OMH). Solid fermentation of magnolia, liquorice, and cnidium by Phellinus linteus mycelium was carried out successfully when 30% water was added to the medium, whereas 10% brown rice powder was required as an extra nutrient for solid fermentation of mint besides water. The amount of total phenol compounds and DPPH radical scavenging activity of OMH increased significantly (P<0.05) upon solid fermentation. Anti-microbial activities of fermented OMH also increased and were approximately 100-fold greater than those of unfermented samples. Oral pathogens such as Staphylococcus epidermis, Streptococcus pyogenes, Candida albicans, or Streptococcus mutans were used for determination of anti-microbial effects of OMH. Formulation of the mouthwash was developed based on the results of the sensory evaluation. Among seven formulas, the best formula chosen by the sensory evaluation was as follows: mouthwash prepared with 0.075% ethanol extract of solid fermented OMH as a main ingredient, 83.64% hot water extract of mint and clove (100:15, v/v) as a mouthwash base component, and other miscellaneous ingredients, including sodium fluoride, menthol, and surfactants. Data from a consumer's preference test with 30 participants, overall acceptance, and willingness to buy the product developed in this study were all significantly higher for the tested mouthwash compared to mouthwash on the market manufactured with OMH but with a different formula. Duration of freshness of the mouthwash after usage as determined by Breath Checker was not significantly different between the two samples, although the duration of our product was slightly longer than that of the commercial product mentioned above.