• Resources Recycling
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• v.16 no.6
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• pp.28-33
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• 2007

Coal is the most abundant energy source and deposited in every area of world. Combustion process with lower efficiency has been mainly used. Therefore, implementation of more efficient technologies, involving gasification, combined cycles and fuel cells, would be a key issue in the plans for more efficient power generation. In these technologies, gasification has been studied for decades. However, coal gasification to high value combustible gas such as hydrogen and carbon monoxide is focused again due to high oil price. The gaseous product, called syngas, can be effectively utilized in a variety of ways ranging from electricity production to chemical industry (as feedstock). In this study, coal gasification with ultra high temperature steam has been performed. The effect of steam/carbon ratio on the produced gas concentrations, gasification rate and additional products like tar, ammonia and cyan compounds has been determined.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.9
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• pp.991-997
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• 2011

This paper deals with the basic principles and procedures involved in the steam-chest molding process used for manufacturing expanded polypropylene (EPP) bead foam. Steam-chest molding is an integral process for EPP technology. However, little research has been carried out on the processing conditions for steam-chest molding this process. The characteristics of EPP foam are energy absorption, multiple-impact protection, low weight, structural strength, and durability. In this study, the steam pressure in steam-chest molding was varied to determine the optimum conditions for manufacturing EPP foam. Moreover, annealing was performed after EPP-foam molding to prevent the shrinkage of the steam-molded product. It was possible to verify the mechanism of foam shrinkage by observing the change in weight with time at different annealing temperatures. Moreover, a tensile test and scanning electron microscopy (SEM) analysis were performed to support these experimental results. The dimensional stability of each molded product was investigated at different steam pressures.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.9
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• pp.1083-1090
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• 2011

A steam generator poses many difficulties during the development of a sodium-cooled fast reactor because of the sodium-water-reaction problems. Until now, several types of steam generators have been developed, but the specifications of these generators differed in each country. Moreover, even if a country had developed a steam generator, it was not used in the subsequent reactor because the current techniques were not stabilized to select the proper steam generator. As a common development, the Benson steam cycle with few welding locations and high economical efficiency may be adopted. Moreover, the design is dwelled on the convenience of inspection, detection, control, and maintenance for the wear caused by sodiumwater reactions. The specifications of the designed steam generators were reviewed and the current technical problems for steam generators were analyzed. Concepts were proposed to overcome the current technical problems for steam generators.

• Journal of the Korean Wood Science and Technology
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• v.47 no.2
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• pp.189-199
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• 2019

This study addresses the biorefinery feedstock from Pinus densiflora. This raw material is a major tree species in the Republic of Korea; it is renewable, has cost-effective, and is readily available. In this study, steam explosion of P. densiflora was performed in a reactor at $225^{\circ}C$ and with 1 to 13 min reaction times with or without previous water impregnation. The combined severity factor (Ro), which is an expression relating the reaction temperature and reaction time used in the steam explosion treatment, ranged from 3.68 to 4.79. The influence of both impregnation and steam explosion conditions were investigated by examining color variations, chemical composition, and mass balance on the pretreated solids. The results showed that steam-exploded P. densiflora that was not impregnated with water exhibited significantly darker color (chroma 28.8-41.4) than water-impregnated and steam-exploded P. densiflora (chroma 18.8-37.3). The increased ${\alpha}$-cellulose and lignin contents were detected as the severity factor increased. Furthermore, the ${\alpha}$-cellulose and lignin contents in the non-impregnated/steam-exploded P. densiflora were higher than those in the water-impregnated/steam-exploded P. densiflora. However, the decreased holocellulose content was detected as the severity factor increased. In mass balance, the holocellulose yield from water-impregnated/steam-exploded P. densiflora was higher than that from the non-impregnated P. densiflora.

• Journal of the Korean Society of Earth Science Education
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• v.13 no.3
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• pp.330-343
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• 2020

In this study, STEAM program on the subject of 'atmospheric circulation and surface current' was produced based on data and applied to 106 first-year high school students to analyze its effect and problem-solving processes. This program was organized to collect, refine, visualize, and analyze data and to allow communication processes to proceed based on these results. Using this, the concept of circulation in daily life was expanded from a global perspective to identify problems about circulation around the world. As a result of the application of the program, significant changes were identified in knowledge information processing competency. Also, significant changes were made in terms of convergence and creativity, which are sub categories among STEAM core competencies. It also sought to obtain suggestions for data-based STEAM education by analyzing students' responses in the form of a Text network.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.18 no.4
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• pp.12-21
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• 2022

Steam assisted gravity drainage(SAGD) is a process that drills well in the underground oil sands layer, injects hightemperature steam, lowers the viscosity of buried bitumen, and recovers it to the ground. Recently, direct contact steam generator(DCSG) is being developed to maximize steam efficiency for SAGD process. The DCSG requires high technology to achieve pressurized combustion and steam generation in accordance with underground pressurized conditions. Therefore, it is necessary to develop a combustion technology that can control the heat load and exhaust gas composition. In this study, process analysis of high-pressurized DCSG was conducted to apply oxygen enrichment technology in which nitrogen of the air was partially removed for increasing steam production and reducing fuel consumption. As the process analysis conditions, methane as the fuel and normal air or oxygen enriched air as the oxidizing agent were applied to high-pressurized DCSG process model. A simple combustion reaction program was used to calculate the property variations for combustion temperature, steam ratio and residual heat in exhaust gas. As a major results, the steam production efficiency of DCSG using the pure oxygen was about 6% higher than that of the normal air due to the reducing nitrogen in the air. The results of this study will be used as operating data to test the demonstration device.

• Journal of the Korean earth science society
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• v.35 no.7
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• pp.572-584
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• 2014

The purpose of this study was to find out the effects of astronomical STEAM program using co-teaching on self-directed learning attitude. For this purpose, we developed an astronomical STEAM program and applied it to elementary science gifted students. Thirty six, $5^{th}$ and $6^{th}$ grade elementary science gifted students were participated in this study in total having 16 students in experimental group and 20 students in control group. The results were described as follows. First, astronomical STEAM program using co-teaching was effective in improving self-directed learning attitude. Second, the program was effective in improving participants' openness to learning opportunities and problem-solving. Third, students were satisfied with the co-teaching that provided ample feedbacks and detailed explanations, and teachers perceived that co-teaching was helpful to overcome a lack of professional knowledge, and to solve difficulties of evaluation and preparing teaching materials for STEAM classes. With findings, we discussed implications for co-teaching of STEAM lessons to improve students' self-directed learning attitude at the end of paper.

• Journal of The Korean Association For Science Education
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• v.37 no.2
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• pp.313-322
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• 2017

This study aims to analyze the content and methodological aspects of converging scientific technology and humanities in 233 elementary school STEAM programs developed and publicized from 2012 to 2015, to provide the basic materials and implications for editing and supplementing the development of future STEAM programs or policies, or on-site applications of developed programs. The analysis results show that among the Liberal Arts courses of the STEAM program, including Korean, Social Studies, and Ethics, the level of convergence was lowest in Ethics. This seems to be due to the fact that convergence between scientific technology and humanities tended to emphasize a cross-studies convergence over a content convergence done with a specific purpose. In terms of methodological convergence between scientific technology and humanities, the level of convergence of humanities at a normative level was relatively lower than that at a descriptive level. Although a quantitative comparison of the two methods was not significant, it is rather concerning that due to simply converging descriptive humanities, students may not be so aware of the double-sidedness of scientific technology, despite the discovery of some programs that need re-evaluations of their ethical or normative directions. Moreover, the results showed that the cases of converging scientific technology and humanities at a normative level that were analyzed in the STEAM program can be divided into 'complementation of humanities to utilizing scientific technology' and 'complementation of humanities to research in scientific technology and development.' Based on such research results, the study discusses the development of STEAM programs and policies and directions for editing and supplementing programs on-site.

• 대한공업교육학회지
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• v.38 no.2
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• pp.68-88
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• 2013

This study is to analyze teacher's recognition and needs of STEAM education in specialized high schools for technical fields. For this study, survey using questionnaire was applied to teachers in specialized high schools for technical fields. This study includes the recognition and the needs on STEAM education of general and industrial subject teachers in specialized high schools for technical fields. In order to carry on this study, 655 questionnaires were collected from teachers of 16 specialized high schools for technical fields in the whole country. Practically, 611 questionnaires (257 of normal subject teachers and 398 of industrial subject teachers) were used for this study. As a result, it is known that the needs of STEAM education is larger to industrial subject teachers than general subject teachers. But it is disclosed that STEAM education is more difficult to general subject teachers than industrial subject teachers. In requirements of teaching-learning, general subject teachers only required reference materials, but industrial subject teachers needed STEAM lesson under the same subjects and data sharing system as a priority. General and industrial subject teachers also considered education program development for creative thinking skills and problem solving abilities as a priority. Finally, in the administrative and financial requirement, both of them demand to reduce administrative tasks as a priority.

• The Journal of the Korea Contents Association
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• v.19 no.11
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• pp.211-225
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• 2019

The purpose of this study was to develop the E-STEAM program emphasizing the engineering design process and apply them to young children to examine their effects on scientific problem-solving ability and communication ability. In order to develop the E-STEAM program, activities were organized by reviewing previous studies and websites related to STEAM and engineering education. The organized activities were selected as final activities after consulting with experts. To examine the effectiveness of the program, 50 subjects(experimental group: 25, control group:25) participated in K kindergarten in G city. The experimental group took part in the E-STEAM activities during 7 weeks, while the control group took part in the traditional science activities. The procedure for this study consisted of a pre-study, a pre-test, the treatment, and a post-test schedule. The results of this study were as follows: First, the experimental group showed significantly higher score than the control group in total problem-solving ability. Second, the experimental group showed significantly higher score than the control group in total communication ability. These findings suggest that the experience of E-STEAM activities for young children can be effective teaching-learning methods for young children's problem solving ability and communication ability.