• Title/Summary/Keyword: steam

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Exergy Analysis on the System of Superheated Steam (700℃, 3 atm) Production for the Reversible Electrolysis: Based Hydrogen Production (양방향수전해 기반 수소제조용 초고온스팀 생산시스템의 엑서지 분석)

  • HAN, DANBEE;PARK, SENGRYONG;CHO, CHONGPYO;BAEK, YOUNGSOON
    • Journal of Hydrogen and New Energy
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    • v.29 no.3
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    • pp.235-242
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    • 2018
  • Hydrogen can be produced by reforming reaction of natural gas (NG) and biogas, or by water electrolysis. In this study, hydrogen production through water-electrolysis needs superheated steam above $700^{\circ}C$ for high efficiency. The production method of hydrogen like this was recommended for the 4-type processes for superheated steam ($700^{\circ}C$, 3 atm) by Bio-SRF combustion furnace. The 4-type processes to produce superheated steam at $700^{\circ}C$ from the heat source of SRF combustion furnace was simulated using PRO II. The optimum process was selected through exergy analysis. The difference of process 1 and 2 is to the order of depressure and heating process to change $180^{\circ}C$ and 7 atm to $700^{\circ}C$ and 3 atm. Process 3 and 4 is to utilize 25% of steam to generate superheated steam and remaining to use for the power generation by steam generator.

An Influence of Corium Composition Variations on a Spontaneous Steam Explosion in Severe Accidents in a Nuclear Reactor (원자로 노심용융물의 성분비 변화가 증기폭발에 미치는 영향)

  • Kim, Jong-Hwan;Park, Ik-Kyu;Hong, Seong-Wan;Min, Beong-Tae;Song, Jin-Ho;Kim, Hee-Dong
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.2041-2046
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    • 2004
  • Recently series of steam explosion experiments have been performed in the TROI facility to identify the influence of corium compositions on the occurrence of a spontaneous steam explosion varying corium melt composition. The compositions of the corium were 0 : 100, 50 : 50, 70 : 30, 80 : 20 and 87 : 13 at weight percent of $UO_2$ to $ZrO_2$, and the mass of the corium was about 10kg. Corium melt at 0 : 100 weight percent (pure zirconia) caused a strong spontaneous steam explosion, and melt at 70 : 30 weight percent(eutectic corium) led to a weak steam spike, while melts at other compositions did not result in spontaneous steam explosions, when they came into contact with 67cm deep water pool at room temperature. It seems that the explosivity of pure zirconia is stronger than that of corium at other compositions and a steam explosion is not likely to occur with corium melts at non-eutectic compositions which are included in mushy zone region.

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Low Temperature Methane Steam Reforming for Hydrogen Production for Fuel Cells

  • Roh, Hyun-Seog;Jun, Ki-Won
    • Bulletin of the Korean Chemical Society
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    • v.30 no.1
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    • pp.153-156
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    • 2009
  • Low temperature methane steam reforming to produce $H_2$ for fuel cells has been calculated thermodynamically considering both heat loss of the reformer and unreacted $H_2$ in fuel cell stack. According to the thermodynamic equilibrium analysis, it is possible to operate methane steam reforming at low temperatures. A scheme for the low temperature methane steam reforming to produce $H_2$ for fuel cells by burning both unconverted $CH_4$ and $H_2$ to supply the heat for steam methane reforming has been proposed. The calculated value of the heat balance temperature is strongly dependent upon the amount of unreacted $H_2$ and heat loss of the reformer. If unreacted $H_2$ increases, less methane is required because unreacted $H_2$ can be burned to supply the heat. As a consequence, it is suitable to increase the reaction temperature for getting higher $CH_4$ conversion and more $H_2$ for fuel cell stack. If heat loss increases from the reformer, it is necessary to supply more heat for the endothermic methane steam reforming reaction from burning unconverted $CH_4$, resulting in decreasing the reforming temperature. Experimentally, it has been confirmed that low temperature methane steam reforming is possible with stable activity.

Six Cases of Acne Vulgaris Treated by Sasang Constitutional Treatment with Herbal Steam Therapy (사상체질처방과 훈증요법을 병행한 여드름 치험 6례)

  • Kim, Ki-Bae;Kim, Tae-Wook;Choi, Sung-Hee
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.29 no.2
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    • pp.130-141
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    • 2016
  • Objectives : This study was to performed to investigate the effect of herbal steam therapy on acne vulgaris. Methods : 6 patients with acne vulgaris were treated with korean medicine therapy (herbal medicine and acupunture) including herbal steam therapy. We evaluated the effect by Korean Acne Grading System(KAGS) and Pictures. Results : After treatment, the KAGS Grade of all patients treated with korean medicine therapy including herbal steam therapy is 1. Based on this, we could find that korean medicine therapy including herbal steam therapy is effective and available to ameliorate for the symptoms of acne vulgaris. Conclusions : This clinical cases study shows us that korean medicine therapy including herbal steam therapy seem to be effective to improve symptoms of acne vulgaris. Further studies will be needed to identify herbal steam therapy is beneficial to acne vulgaris.

Unsteady Wet Steam Flow Measurements in a Low-Pressure Test Steam Turbine

  • Duan, Chongfei;Ishibashi, Koji;Senoo, Shigeki;Bosdas, Ilias;Mansour, Michel;Kalfas, Anestis I.;Abhari, Reza S.
    • International Journal of Fluid Machinery and Systems
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    • v.9 no.1
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    • pp.85-94
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    • 2016
  • An experimental study is conducted for unsteady wet steam flow in a four-stage low-pressure test steam turbine. The measurements are carried out at outlets of the last two stages by using a newly developed fast response aerodynamic probe. This FRAP-HTH probe (Fast Response Aerodynamic Probe - High Temperature Heated) has a miniature high-power cartridge heater with an active control system to heat the probe tip, allowing it to be applied to wet steam measurements. The phase-locked average results obtained with a sampling frequency of 200 kHz clarify the flow characteristics, such as the blade wakes and secondary vortexes, downstream from the individual rotational blades in the wet steam environment.

Research on the Emotional Expression of Synesthesia through STEAM Education Program (융합인재교육(STEAM) 프로그램을 통해 배우는 공감각의 감성적 표현 연구)

  • Lee, Jin;Lee, Seungyon-Seny
    • The Journal of the Korea Contents Association
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    • v.13 no.9
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    • pp.448-454
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    • 2013
  • This paper proposes a methodology of expanding the mind in multi-disciplinary ways through STEAM education program based on science and art. The paper aims at analyzing both the analog- an digital-based emotional expressions experienced by students. Students use digital visualization technology using linguistic tool as well as sense of vision, hearing and touching. This is a STEAM education program designed for high school students and called "Kandinsky, Drawing the Sound". Kandinsky was a prominent proponent of synesthesia and through his artwork, students can learn how to express and develop synesthetic senses. Through this STEAM program, students are empowered to express diverse emotions reconstructed through plays, stories and synesthesia.

The Effects of STEAM-Based Integrated Subject Study on Elementary School Students' Creative Personality (STEAM 기반 통합교과 학습이 초등학생의 창의적 인성에 미치는 영향)

  • Kwon, Soon-Beom;Nam, Dong-Soo;Lee, Tae-Wuk
    • Journal of the Korea Society of Computer and Information
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    • v.17 no.2
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    • pp.79-86
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    • 2012
  • The purpose of this study is to improve creative personality of elementary school students with integrated subject study program based STEAM education. On this study, I analyzed integrated subject study and STEAM, developed contents using educational robot applied integrated subject study program model. And analyzed result after applied to elementary school students. After dividing two groups-experimental group, comparison group-for this study, tested t-test. Finally I got a meaningful result statistically. There was an postive effect to improving elementary school students' creative personality by appling STEAM-based integrated subject study program.

The Development and Application Effects of STEAM Program Utilizing Animation Production about 'Structure and Function of the Our Body' ('우리 몸의 구조와 기능' 애니메이션 제작을 활용한 프로그램 개발 및 적용 효과)

  • Lee, Sang-Ho;Hong, Seung-Ho
    • Journal of Korean Elementary Science Education
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    • v.38 no.2
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    • pp.263-274
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    • 2019
  • The purpose of this study is to investigate the effect of STEAM program on students' academic achievement, creative problem-solving ability, scientific inquiry ability and scientific interests of elementary school students. For this, we developed a STEAM program to utilize animation production about 'structure and function of the our body' unit in 5th grade. The STEAM program was developed for a total of 9 sessions and was applied to the experimental group. The theoretical lesson of the 2009 revised curriculum was consisted of 11 sessions and was applied to the comparative group. The results of study showed significant differences of the students' academic achievement, creative problem-solving ability to the experimental group participating in the STEAM program and also showed significant effects in the domains of subject contents and teacher preference, which are the areas of scientific interests compared to the comparative group. This means that the STEAM program to utilize animation production about 'structure and function of the our body' developed in consideration of the characteristics of elementary students positively influenced the academic achievement, creative problem-solving ability and scientific interests of elementary school students. In the future we need to develop STEAM programs more variously that utilize animation production and that it needs to be applied to elementary schools.

The Development and Application of the SW-STEAM Program by Utilizing Ozobot Coding for Elementary Science Class (초등과학 수업에서 오조봇 코딩을 활용한 SW 융합교육프로그램의 개발과 적용)

  • Kim, Hye-Ran;Choi, Sun-Young
    • Journal of Korean Elementary Science Education
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    • v.38 no.2
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    • pp.234-243
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    • 2019
  • The purpose of this study is to investigate the effects of the SW-STEAM program by utilizing ozobot coding for elementary science class. The developed SW-STEAM program was applied to $5^{th}$ grade students of S elementary school located in B city. The participants were divided into an experimental group which is consisted of 22 students and a comparative group comprised 22 students. And they were engaged in different teaching and learning methods during 11 class hours. The experimental group participated in the SW-STEAM program, the comparative group was taught by using a traditional instruction. The main results of this study are like followings. The SW-STEAM program had a positive effect on elementary school students' basic science process skill, science learning motive, science achievement. Therefore, the SW-STEAM program by utilizing ozobot coding could be meaningful works to encourage students' basic science process skill, science learning motive and science achievement, and more studies on developing SW-STEAM program are needed.

Solar-driven steam flow for effective removal of particulate matters (PM) (태양열 기반 증기 유동을 이용한 미세먼지 제거 연구)

  • Kim, Jeongju;Kim, Jeong Jae
    • Journal of the Korean Society of Visualization
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    • v.19 no.3
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    • pp.130-135
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    • 2021
  • Water vapor has received worldwide large attention due to its broad technological implications ranged from resource production and environmental remediation. Especially, one of the typical areas where the water vapor is important is the removal of PM (particulate matter) which causes a critical hazard to human health. However, most vapor-based PM removal methods are limited in removing PM2.5 by using relatively large water droplets and consume large energy. Here, we propose a superhydrophilic thermally-insulated macroporous membrane to generate steam flow. The water vapor directly captures PM with steam flow and hygroscopic characteristic of PM. The steam, the cluster of water vapor, from the membrane gives rise to high removal efficiencies compared to those of the control case without light illumination. To reveal PM removal mechanism, the steam flow and PM were quantitatively analyzed using PIV measurement. The proposed steam generator could be utilized as an economical and ecofriendly platform for effective PM removal at a fairly low cost in a sustainable, energy-free, and harmless-to-human manner.