• Transactions of the Korean hydrogen and new energy society
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• 제24권2호
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• pp.113-120
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• 2013

A steam reformer is a chemical reactor to produce high purity hydrogen from fossil fuel. In the steam reformer, since endothermic steam reforming is heated by exothermic combustion of fossil fuel, the heat transfer between two reaction zones dominates conversion of fossil fuel to hydrogen. Steam Reforming is complex chemical reaction, mass and heat transfer due to the exothermic methane/air combustion reaction and the endothermic steam reforming reaction. Typically, a steam reformer employs burner to supply appropriate heat for endothermic steam reforming reaction which reduces system efficiency. In this study, the heat of steam reforming reaction is provided by anode-off gas combustion of stationary fuel cell. This paper presents a optimization of heat transfer effect and average temperature of cross-section using two-dimensional models of a coaxial cylindrical reactor, and analysis three-dimensional models of a coaxial cylindrical steam reformer with chemical reaction. Numerical analysis needs to dominant chemical reaction that are assumed as a Steam Reforming (SR) reaction, a Water-Gas Shift (WGS) reaction, and a Direct Steam Reforming(DSR) reaction. The major parameters of analysis are temperature, fuel conversion and heat flux in the coaxial reactor.

• Journal of the Korean Institute of Gas
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• 제17권2호
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• pp.70-77
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• 2013

The present study has been carried out to analyze the effect of steam hammering on the steam piping system including the final superheater, the high pressure turbine, check valve and the first reheater by sudden stoping of main stop valve in a power plant. For the present steam hammering analysis, the well known Flowmaster software has been used to model the steam piping system and the time dependent characteristics of pressure and steam mass flow rate has been conducted. Using the result of the unsteady pressure and steam mass flow rate, the forces acting on the elbows in the piping system has been derived. From the present analysis, it has been elucidated that the elbow just before the main stop valve and the elbow near the connection pipe between bypass pipe and check valve had the largest force among the elbows in the steam piping system. The structural safety diagnostics study on the elbow and the supporting structures of the steam piping system of a power plant will be conducted in the future by the present results of the forces acting on the elbow.

• Journal of Digital Convergence
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• 제13권2호
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• pp.333-341
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• 2015

The purpose of this research is to study possibilities of animation education in art centered STEAM. We suggest not the animation education contents model of a functional skills of the past but the one for STEAM. In order to suggest the role of animation education, we should first study the convergence values of animation. And this study make a curriculum of animation for the creativity by convergence thinking. Finally, this study build the animation class model applied in STEAM by Fogarty's integrated education method. By studying, we can get the result that animation has the convergence characteristics and it has the effective role of art centered STEAM education for the convergence thinking. Also, it is expected that the results of this study will contribute to education and training of convergence of the global talent with creativity in STEAM.

• Education of Primary School Mathematics
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• 제18권2호
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• pp.91-106
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• 2015

The purpose of this study were to develop a M-STEAM program for first grades in elementary school and investigate the effects of the program on their learning motivation for the math subject and creative personality. For those purpose, this study set the following research questions. Research Question 1 : How will a M-STEAM program be devised applicable to first grades in elementary school? Research Question 2 : What kind of effect does a M-STEAM program have on the learning motivation and creative personality of students? The findings were as follows: First, lesson contents were reorganized by keeping the Unit 3 in the second semester of first grade in the current math curriculum under the convergence theme of "Build an environment friendly future city" to which the STEAM elements were added. Developed program promoted mathematical thinking ability for problem solving in the process of operating the number of blocks. Through the M-STEAM program, convergence thinking was created from a new perspective by exerting creativity in such process. Second, the STEAM program had effects on the learning motivation and creative personality of first graders in math subject. The t-test results show that the STEAM program developed in this study increased the fun and interest of students, helped with their concentration, and promoted their understanding of mathematical concepts. Therefore the M-STEAM program had positive impacts on the learning motivation and creative personality of first graders in math learning.

• Proceedings of the KSME Conference
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.3224-3229
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• 2007

This study aims to analyse the influence of steam injection on the performance of hybrid systems combining a solid oxide fuel cell and a gas turbine. The steam is generated by recovering heat from the exhaust gas. Two system configurations, with difference being the operating pressure of the SOFC, are examined and effects of steam injection on performances of the two systems are compared. Two representative gas turbine pressure ratios are simulated and a wide range of both the fuel cell temperature and the turbine inlet temperature is examined. Without steam injection, the pressurized system generally exhibits better system efficiency than the ambient pressure system. Steam injection increases system power capacity for all design cases. However, its effect on system efficiency varies much depending on design conditions. The pressurized system hardly takes advantage of the steam injection in terms of the system efficiency. On the other hand, steam injection contributes to the efficiency improvement of the ambient pressure system in some design conditions. A higher pressure ratio provides a better chance of efficiency increase due to steam injection.

• Proceedings of the KSME Conference
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• 대한기계학회 2001년도 춘계학술대회논문집D
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• pp.240-245
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• 2001

Phenomena of direct contact condensation (DCC) heat transfer between steam and water are characterized by the transport of heat and mass through a moving steam/water interface. Application of the phenomena of DCC heat transfer to the engineering industries provides some advantageous features in the viewpoint of enhanced heat transfer. This study proposes a simple condensation model on the steam jets discharging into subcooled water from a single horizontal pipe for the prediction of the steam jet shapes. The analysis model was derived from the mass, momentum and energy equations as well as a thermal balance equation with condensing characteristics at the steam/water interface for the axi-symmetric coordinates. The extremely large heat transfer rate at the steam/water interface was reflected in the effective thermal conductivity estimated from the previous experimental results. The analysis results were compared with the experimental ones. The analysis model predicted that the steam jet shape (i. e. radius and length) was increasing as the steam mass flux and the pool temperature were increasing, which was similar in trend to that observed in the experiment.

• Journal of The Korean Association of Information Education
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• 제17권2호
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• pp.167-175
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• 2013

This paper examined various study case about smart grid and STEAM education. We develop this STEAM education of IT subject using smart grid for 3rd and 4th graders in elementary school. We make this program and teaching materials by considering about student's intellectual level and interests. We offered this program to 10 elementary 4th graders in Jeju island step by step for 6 period to evaluate the effectiveness of the developed program and teaching materials. Future work will include the follow-up and extended study. It will be expected that students will be able to develop their abilities by this STEAM education using IT.

• Journal of computational fluids engineering
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• 제20권3호
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• pp.1-7
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• 2015

When the steam is used as working fluid in fluid machinery, different from other gases as air, phase transition (steam condensation) can occur and it affects not only the flow fields, but also machine performance & efficiency. Therefore, considering phase transition phenomena in CFD calculation is required to achieve accurate prediction of steam flow and non-equilibrium wet-steam model is needed to simulate realistic steam condensing flow. In this research, non-equilibrium wet-steam model is implemented on in-house code(T-Flow), the flow fields including phase transition phenomena in convergent-divergent nozzle are studied and compared to results of advance researches.

• Journal of The Korean Association of Information Education
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• 제17권3호
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• pp.339-346
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• 2013

For this study, we searched recent trend of STEAM education and developed 'STEAM education program by producing UCC'. We developed and applied this program which is designed for 'wise of life' of 2nd graders in elementary school for the real class. As a result, the creativity index of the students who went through the researched program increased with meaningful difference compared to that of sample population. And positive response increased in both of interest and attitude among affective region related to science. The result of this study shows that 'STEAM education program by producing UC' can bring positive change for the expansion of creativities and scientific attitude.

• Journal of Korean Medical classics
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• 제24권5호
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• pp.119-129
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• 2011

The Chapter of "Records on Steam Room(蒸室記)" in "Shandangjip(山堂集)" by CHOI Chungsung is a rare and notable one in that it contains the first concrete and detailed description and view of steam shower in the early Joseon Dynasty. It is known that Choi's Wind stroke(brain stroke) deteriorated due to excessive steam shower. He unreasonably entered the steam room 4 or 5 times a day for 9 consecutive days even though external pathogens had intruded into visceral organs and his energizing chi got less and weaker. By this excessive steam showering, his righteous chi was exhausted and eventually burned out. Given some records in the Annals of the Joseon Dynasty writing that people died due to excessive steam shower, there was no established medical theory on the effect of steam shower before the publication of "Donguibogam(東醫寶鑑)".