• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.41-44
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• 2007

Steam reforming reaction of natural gas is an important process for fuelcell commercialization. In this paper, steam reforming reaction is studied by numerical method. Pseudo-homogeneous model is incorporated for chemical reactions and one medium approach is used to take into account thermally equilibrium phenomena between catalyst and bulk gas. The model is validated with our experimental results under the same operating conditions. Because performance of reformer has relation to heat flux from wall, heat flux profiles was investigated by using Nusselt number. Value of Nusselt number in steam reformer is larger than one in channel, which does not have chemical reaction because steam reforming reaction is an endothermic reaction. When the difference of Nusselt number at the front and the rear is larger, performance is improved.

• Journal of the Korea Furniture Society
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• v.20 no.3
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• pp.222-231
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• 2009

At researching the history of furniture design, furniture based on the bentwood technique was often seen. There are different bending ways of wood. Among others the steam bending technique had been used since long time, but it's detailed method has been much less studied in Korea yet. The aim of the present study was to investigate the theoretical approach and making ways & process of the steam bending technique, and furthermore to utilize it for the works of the students majoring furniture design. This intends that the steam bending technique will be widely distributed by doing a mock up and it will be diversely used for development of more different furniture designs.

• Proceedings of the IEEK Conference
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• 2002.06d
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• pp.263-266
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• 2002

This paper describes extraction procedure for the center coordinates of steam generator tubes of Youngkwang NPP #6, which are arrayed in triangular patterns. Steam generator tube images taken with wide field-of-view lens and low-light lamp mounted on a ccd camera tend to have low contrast, because steam generator is sealed and poorly illuminated. The extraction procedures consists of two steps. The first step is to process the region with superior contrast in entire image of steam generator tubes and to extract the center points. Using the extracted coordinates in the first step and the geometrical array characteristics of tubes lined up in regular triangle forms, the central points of the rest region with low contrast are estimated. The straight lines from center point of a tube to neighbour points in horizontal and 60, 120$^{\circ}$ degree directions are derived. The intersections of straight line In horizontal direction and slant line in regular triangle direction are selected as the center coordinates of steam generator tubes. The Chi-square interpolation method is used to determine the line's coefficients in horizontal and regular triangle direction.

• 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 Association For Science Education
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• v.35 no.6
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• pp.949-959
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• 2015

In this case study, we analyzed the STEAM lessons conducted by secondary science teachers in the perspective of the CHAT. Two science teachers at high schools in Seoul participated in this study. All of the teaching-learning materials were collected before lessons, and their lessons were observed and videotaped. We also observed the atmospheres in both school offices and classrooms. Semi-structured interviews were conducted before and after their lessons. All the data collected were categorized according to the elements of the activity system and analyzed by using the constant comparative method. The analyses of the results revealed that both teachers did not consider the student-centered self-directed activities in their STEAM lessons, but that they differed in the subject element such as teacher's professionalism on STEAM. Various elements of the activity system such as environmental characteristics of the school and policies about the STEAM influenced the performance of their STEAM lessons. Contradictions in the elements of the activity system brought about various changes. Successful experiences of the STEAM lessons by complex effects of the elements positively influenced their performances on their STEAM lessons. Based on these results, we have made some suggestions for the establishment of the STEAM in secondary schools.

• Journal of the Korean Society of Earth Science Education
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• v.11 no.3
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• pp.224-236
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• 2018

The purpose of this study was to develop a reasoning-based HTE-STEAM program for the development of the cognitive capacity of middle school students and enhancement of their STEAM literacy, and to investigate the effectiveness of this study in the school setting. The subjects of this study were the students of two middle schools located in the central region of Korea. The students participated in the HTE-STEAM program during their free-learning semesters and 202 of them were selected by random sampling method. Main findings were as follows: First, pre- and post-HTE-STEAM program has shown a significant value in statistical verification (p<.05) and the level of logical thinking ability of the research participants improved after the class compared to before the class. Second, the paired samples t-test comparing the difference between the pre and post scores of the STEAM attitude test has shown a significant value in statistical verification (p<.05), and the HTE-STEAM program has turned out to have a positive effect on the STEAM literacy of the research participants. Third, in the HTE-STEAM satisfaction scale test, the mean value of the sub-construct stood at 3.27~4.12, showing a positive overall response. Therefore, the HTE-STEAM program under the topic of earth science of 'Disaster and Safety' developed at the final stage of this study has proven to have a positive influence on the research participants in terms of the development of cognitive capacity by reasoning and collaborative learning, an important quality of communication and consideration necessary for STEAM literacy.

• Korean Chemical Engineering Research
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• v.46 no.2
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• pp.258-273
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• 2008

For being recent high oil price age, the interest in superheated steam drying technology is increasing as the method to enhance the energy efficiency of drying process consuming a lot of energy. This technology uses the superheated steam as drying medium to dry the materials and has advantages that can save the energy by recycling the evaporated high-temperature steam, enhance the quality of dried products, and minimize the exhaust of environmental pollution materials. In this work, it has been introduced from general drying principle to the principle and related studies of drying technology using superheated steam, using examples of superheated steam with dryer types, and industrial applications.

• Journal of Fisheries and Marine Sciences Education
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• v.25 no.4
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• pp.915-927
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• 2013

This study aimed to discover the affective ability of students by applying a thematic project model concerning the marine field unit of science for third grade middle school students from among diverse methods of realizing STEAM education. Also, based on this, STEAM education is a new type of learning including the process of exploring by oneself, presenting, discussing and mutually evaluating by becoming an independent person in learning As the results of the study are as follows: First, the STEAM class applied with a thematic project model was discovered to promote a learning attitude toward science by learners. Second, the STEAM class applied with a thematic project model was shown to be effective in improving the self-directed learning characteristics of learners. Third, STEAM education applied with a thematic project model was found to promote learners' motivation for learning science. This may be an effective method for learners who have felt difficulty in the science curriculum or have not been interested in the curriculum by triggering voluntary motivation.

• 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.

• Explosives and Blasting
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• v.35 no.2
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• pp.1-8
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• 2017

In this study, the characteristics of a new rock cracking method using steam pressure are briefly presented. The rock cracking method was originally developed as a means to decrease the ground vibrations from underground rock excavations. The validation tests were also conducted by applying the method to an actual rock tunnel under construction. The ground vibrations were measured in the vicinity of the test site. The measured vibration results were compared with the values predicted by an attenuation equation, which had been proposed by a company in Japan. Also, a simple cost assessment for the method was conducted to demonstrate its cost effectiveness in underground tunnel excavations.