• Nuclear Engineering and Technology
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• v.52 no.12
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• pp.2771-2788
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• 2020

Experiments are conducted to study bubble flow behavior during the instability of subcooled boiling under uniform and non-uniform transverse heating. The non-uniform heat distribution introduces nonuniform bubble generation and condensation rates on the heated surface, which is different from the uniform heating. These bubble generation and condensation characteristics introduce a non-uniform local pressure distribution in the transverse direction, which creates an extra non-uniform pressure on the flowing bubbles. Therefore, different bubble flow behavior can be observed between uniform and non-uniform heating conditions. In the uniform heating, bubble velocity fluctuations are low, and the bubbles travel straight along the axial direction. In the non-uniform heating, more fluctuation in the bubble velocity occurs at low mass flow rate and high subcooled inlet temperatures, and reverse flow is observed. Additionally, the bubbles show a zigzag trajectory when they pass through the channel, which indicates the existence of cross flow in the transverse direction.

• Journal of Digital Convergence
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• v.19 no.5
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• pp.81-92
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• 2021

The purpose of this study is to present an approach to the "Digital Health Passport" (DHP), which will be the most important in the change of the travel industry among the sudden environmental changes brought about by COVID-19. To this end, this study reviewed a variety of empirical literature on DHP, and proposed a framework for DHP based on literature review. The framework is composed of travel intention, health information provision intention, and new technology acceptance/adoption of tourists. First, in terms of travel intention, providing information to DHP should not undermine the travel intention of the travelers. It should be possible to facilitate the travelers' enjoyment by using the information provided by the traveler. In addition, there is a need to assure that the data provided by travelers is managed in a reliable way. Second, it is necessary to understand why the travelers want to provide additional personal information (information disclosure), rather than seeing healthcare information only in terms of mandatory information provision. Finally, from the perspective of new technology, it is necessary to understand the intention of travelers to use/adopt DHP. The key implication of this work is that it proposed a DHP framework for realizing the travel bubble to predict and respond to foreign travelers' behaviors.