• Title/Summary/Keyword: moderator

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Preliminary Thermal-Hydraulic Analysis of the CANDU Reactor Moderator Tank using the CUPID Code (CUPID 코드를 이용한 CANDU 원자로 칼란드리아 탱크 내부유동 열수력 예비 해석)

  • Choi, Su Ryong;Lee, Jae Ryong;Kim, Hyoung Tae;Yoon, Han Young;Jeong, Jae Jun
    • Journal of Energy Engineering
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    • v.23 no.4
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    • pp.95-105
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    • 2014

  • The CUPID code has been developed for a transient, three-dimensional, two-phase flow analysis at a component scale. It has been validated against a wide range of two-phase flow experiments. Especially, to assess its applicability to single- and two-phase flow analyses in the Calandria vessel of a CANDU nuclear reactor, it was validated using the experimental data of the 1/4-scaled facility of a Calandria vessel at the STERN laboratory. In this study, a preliminary thermal-hydraulic analysis of the CANDU reactor moderator tank using the CUPID code is carried out, which is based on the results of the previous studies. The complicated internal structure of the Calandria vessel and the inlet nozzle was modeled in a simplified manner by using a porous media approach. One of the most important factors in the analysis was found to be the modeling of the tank inlet nozzle. A calculation with a simple inlet nozzle modeling resulted in thermal stratification by buoyance, leading to a boiling from the top of the Calandria tank. This is not realistic at all and may occur due to the lack of inlet flow momentum. To improve this, a new nozzle modeling was used, which can preserve both mass flow and momentum flow at the inlet nozzle. This resulted in a realistic temperature distribution in the tank. In conclusion, it was shown that the CUPID code is applicable to thermal-hydraulic analysis of the CANDU reactor moderator tank using the cost-effective porous media approach and that the inlet nozzle modeling is very important for the flow analysis in the tank.

  • https://doi.org/10.5855/ENERGY.2014.23.4.095 인용 PDF KSCI

Social Viewing Motivations, Satisfaction, and Continuous Use Intention: Moderating Effects of Communication Behavior (동영상의 사회적 시청 동기와 만족도 및 지속의도에서 커뮤니케이션 행위의 조절효과 분석)

  • Cho, Eunyong;Lim, Sohye
    • Journal of Korea Multimedia Society
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    • v.23 no.10
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    • pp.1331-1338
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    • 2020

  • Social viewing has become an increasingly common viewing pattern by combining SNS use with video-watching. Accordingly, social viewing has attracted much scholarly attention, but a more comprehensive understanding of the process and effects of social viewing is warranted. For this, this study incorporated social viewing motivations, viewer satisfaction, and the continuous use intention, taking the viewer's communicative behavior into account as a possible moderator. This study conducted an online survey (N=334). Among four motivations, enjoyment, sharing and expression were significant predictors of program and communication satisfaction. Information, however, was only associated with program satisfaction but not with communication satisfaction. The moderating effects of three communication behaviors, production, sharing, and reception, were discussed in the relationship between user motivations and viewing satisfaction and continuous use intention. Production behaviors played a significant moderating role in between enjoyment, information, sharing, and communication satisfaction. Sharing moderatied information, sharing, and program satisfaction, whereas reception was not a significant moderator.

  • https://doi.org/10.9717/kmms.2020.23.10.1331 인용 PDF KSCI HTML