• Nuclear Engineering and Technology
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• v.29 no.1
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• pp.85-91
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• 1997

Cross-flow existing in a shell-and-tube steam generator can cause a tube to vibrate. There are four regions subjected to cross-flow in Yonggwang units 3 and 4 (YGN 3 and 4) steam generators, which are of the same design as the steam generators for Palo Verde nuclear power plant Palo Verde units 1 and 2 steam generators have experienced localized oar at the comers of the cold side recirculating fluid inlet regions. A number of design modifications were made to preclude tube failure in specific regions of YGN 3 and 4 steam generators. Therefore, flow induced vibration experiments were done to determine the vibration magnitude of tubes in the economizer tube free lane region. The objective of this experiment is to demonstrate that the tube displacement is less than 0.01 inch rms at 100% of full power flow and to quantify the remaining design margin at 120ft and 140% of full power flow.

• Hwankyungkyoyuk
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• v.25 no.1
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• pp.66-76
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• 2012

The purpose of this study was to investigate the effects of and development of the STEAM-based on environmental programs to enhance environmental literacy of elementary school students. Through the questionnaires and the analysis of students' outcomes, the effects on literacy in both quality and quantity were verified. By applying the STEAM-based to environmental programs for enhancing environmental literacy to elementary students, the results of this study was as follows: First, its application was meaningful in that the level of $p$<.05 in point view of environmental literacy was a result of the pre-post test in the experiment group, which was made up of the 6th graders in the elementary school. Second, analysis of students' reflective journals showed that the participants' understanding, actions, and attitudes were positively affected by the programs in terms of environmental literacy. In conclusion, the STEAM-based on environmental programs for environmental education was very effective in enhancing environmental literacy.

• Journal of the Korean Wood Science and Technology
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• v.25 no.4
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• pp.68-74
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• 1997

This research was studied dissolving pulp for rayon production, which is not KP, SP methods but steam explosion and oxygen alkali treatment. The variation of characterization in wood cellulose after steam explosion and oxygen alkali treatment this follows. In the oxygen alkali treatment of exploded pine wood, yield of dissolving pulp was lower than steam-exploded oak wood, and we have obtained dissolving pulp that high purity cellulose, but degree of polymerization was inclined to decrease less than 200. In the case of steam-exploded oak wood, degree of polymerization was higher than steam-exploded pine wood but purity of cellulose was lower than its.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.6_3
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• pp.1333-1339
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• 2023

To produce activated carbon fibers, the process is carried out through either physical activation method or chemical activation method. In this study, we present the results regarding the characteristics of activated carbon fibers manufactured under various conditions through the quantitative control of steam. The yield after activation indicates a decreasing trend with the increase in steam quantity and activation time. Additionally, specific surface area characteristics exhibit variations based on activation time and steam flow rate. The SEM analysis results reveal that higher steam flow rates lead to the presence of both mesopores and macropores on the surface of activated carbon fibers (ACF).

• Journal of Korean Elementary Science Education
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• v.40 no.2
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• pp.239-252
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• 2021

The purpose of this study is to develop an evolutionary STEAM education program based on the brain and to analyze its effects on scientific interest and scientific creativity of elementary school students. Four different topics based on four scientific fields (Physics, Chemistry, Biology and Earth Science) were derived from the science textbook under the 2015 revised curriculum to build a brain-based evolutionary STEAM education program. The research subjects were 90 fourth graders of S-elementary school located in Gyeonggi Province, Korea and they were divided into an experimental group of 45 students and a comparative group of 45 students. The main findings of this study are as follows. First, according to the independent samples t-test of scientific interest, no statistically significant difference were found between the two groups, but the brain-based evolutionary STEAM education had meaningful effect on improving 'interest in scientific learning' and 'anxiety about scientific learning'. Second, according to the paired samples t-test of scientific interest, the experimental group had significantly improved 'interest in science' but on the other hand, there was no effect on the comparative group. Third, scientific creativity and originality of the experimental group were significantly higher after the class than that of the comparative group. Fourth, although there were some significant differences between the two groups in scientific creativity after the class, both groups had improved scientific creativity between the results of pre and post test. Based on these results, we discuss implications for science education and STEAM education research.

• Journal of the Korean Society of Earth Science Education
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• v.16 no.2
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• pp.247-260
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• 2023

In this study, when applying the 'geological structure' content element of high school earth science I developed according to the 2015 curriculum to the STEAM program using a web-based expert system using 3D data of Google Earth and drones, the creative problem-solving ability of high school students, attitudes toward STEAM, and the results of this study are as follows. First, after applying the STEAM program, high school students' creative problem-solving ability showed meaningful results at the p<.001 level. Second, STEAM attitudes showed a significant value at the p<.001 level, confirming that they had a positive impact on high school students' attitudes towards STEAM. It was judged that web-based class activities using Google Earth and drones were useful for integrated thinking such as learners' sense of efficacy and value recognition for usefulness of knowledge. High school students' satisfaction with the STEAM program was 3.251, showing a slightly high average. It was confirmed that web-based class activities such as drones and Google Earth had a positive impact on learners' class satisfaction. However, it was interpreted that the lack of time for class activities limited the ability of the learners to increase their interest in class. The proposal of this research is as follows. First of all, in consideration of the production of presentation materials and practical training in the STEAM program, activities such as block time and advance instruction for class understanding before class are necessary. Secondly, in order to revitalize STEAM education in the high school curriculum, we judge that research on the development of various integrated education programs that can be applied to the high school grade system is necessary.

• Journal of The Korean Association of Information Education
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• v.18 no.1
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• pp.65-74
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• 2014

The STEAM education and the computer science education have become increasingly important with the advert of science technology that enhances the national competitiveness. The purpose of the research is to develop the STEAM education program focused on programming education. I introduced a programming activity utilizing a sensor that can trigger students' interest with relation to other school subject factors. I applied the education program to grade 4-5 students, then compared and analyzed effects of the education program by conducting pretest and posttest regarding the creativity, reasoning skills, and the affective domain in science learning. Overall, the analysis reveals that the STEAM education program developed in this study improved fluency, originality and creativity index of the students' creativity, reasoning skills and scientific attitudes.

• Journal of The Korean Association of Information Education
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• v.21 no.1
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• pp.67-76
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• 2017

Recently, the Ministry of Education is pursuing various educational reforms for the cultivation of creative talent in preparation for the fourth industrial revolution. In this study, we developed STEAM program using the info-graphic and 3D modeling. As a result of applying the developed STEAM program to 2 classes of 6 grade in ${\circ}{\circ}$ elementary school in Seoul, it showed that creative problem solving ability of all students participating in the program has improved. Particularly, Motivational component has shown the greatest improvement among the creative problem solving ability elements. Through the results of this study, it is expected that various STEAM programs using the infographic and 3D modeling will be developed and applied in the field of elementary school for the cultivation of creative talent with creative thinking ability in preparation for future society.

• The Korean Journal of Food And Nutrition
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• v.22 no.2
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• pp.199-204
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• 2009

For the purpose of developing a safe & hygienic manufacturing method to acquire low levels of benzo(a)pyrene in black and red ginseng products, this study investigated the effects of steam- and dry-processing temperatures on benzo(a)pyrene production in ginseng. By the red ginseng with a fix dry-process temperature of $50^{\circ}C$ and setting the steam-process temperature between $80{\sim}120^{\circ}C$, an extremely small amount(0.1 ppb) of benzo(a)pyrene was produced, indicating there was no relationship between the steam-temperature and benzo(a)pyrene production. On the other hand, when the red and black ginseng were steamed at the fixed temperature of $100^{\circ}C$ and dried at various temperatures between $50{\sim}120^{\circ}C$, the amount of benzo(a)pyrene produced was closely connected with the dry-temperature, and increased with higher drying temperatures. Upon repeating the steam and dry process nine times, in which the steam-temperature was set at $100^{\circ}C$ and the dry-temperature at $50^{\circ}C$, higher amount of benzo(a)pyrene were produced in red and black ginseng, respectively, with increasing steam- and dry-processing time. However, the level of benzo(a)pyrene still remained extremely small(below 0.12 ppb), showing a maximum amount in the black ginseng that was steamed and dried nine times. This suggests that the fine root of ginseng may be carbonized by increasing the number of times it is steam- and dry-processed. From the above results, this study determined that the optimum temperatures for manufacturing red and black ginseng products with safe levels of benzo(a)pyrene would be a temperature between 80 and $120^{\circ}C$ for steaming and a temperature less than $50^{\circ}C$ for drying.

• Journal of Energy Engineering
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• v.10 no.4
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• pp.349-356
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• 2001

Phenomenon of direct contact condensation (DCC) heat transfer between steam and water is characterized by the transport of heat and mass through a moving steam/water interface. Since the DCC heat transfer provides some advantageous features in the viewpoint of enhanced heat transfer, it is widely applied to the diversified industries. This study proposes a simple condensation model on the stable steam jets discharging into a quenching tank with subcooled water from a single horizontal pipe for the prediction of the steam jet shapes. The model was derived from the mass, momentum and energy equations as well as 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 results were compared with the experimental ones. The predicted steam jet shape(i. e. radius and length) by the model was increasing as the steam mass flux and the pool temperature were increasing, which was similar to the trend observed in the experiment.