• Journal of Korean Elementary Science Education
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• v.31 no.2
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• pp.154-163
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• 2012

In this study, we analyzed the proportions of STS content, components, topics, and types of the activities of STS content in the elementary science textbooks developed under the 2007 Revised National Curriculum. The analyses of the results revealed that the percentage of STS content included was 15.9% by the number of pages, and 13.5% by the lesson hour. By the components of the STS content, the proportion of 'application of science', 'science-technology and our life' and 'social problems and issues' were large. Most STS topics were related to the 'effects of technological developments' and 'environmental issue', and the topics of 'family and population' and 'human engineering' were few. By the types of the activities, reading was the most, and investigation and writing were also found. Compared with those of the science textbooks developed under the 7th National Curriculum, the variety of components of the STS content increased, but the proportion of STS content and the variety of activities of STS content decreased in the science textbooks developed under the 2007 Revised National Curriculum.

• Journal of the Korean earth science society
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• v.22 no.4
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• pp.259-267
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• 2001

The purpose of this study is to investigate the effects of the STS program on vocational high school students' science-related attitudes. In order to examine, we selected the content of instructions at the Earth Science content in the "Common Science" and applied the STS program for one year to the second grade students of six classes (N = 318) in a girls high school located in Kumi City, Kyungpook, Korea. For this study, we developed the instructional methods and then applied to the STS program. The result of this study revealed that the STS program on students' science achievement and attitudes were effective.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.6_2
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• pp.987-992
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• 2022

STS 410, a representative martensitic stainless steel, contains 13 % chromium and is used for building materials, automobile parts, office equipment, kitchen utensils, and tableware. In general, the strength of STS 410 changes by the carbon content, and STS 410 of low carbon has excellent toughness and high carbon has excellent abrasion resistance. In this study, a fatigue test was performed on the STS 410 material to evaluate the exact fatigue limit and to evaluate the behavior of the material against fatigue. In addition, the effect on burnishing, a kind of plastic processing that creates a smooth surface by pressing a ball or roller on the inner and outer surfaces of the material was evaluated. The fatigue limit was 509 MPa for the STS 410 material, and the result was 54.5 % of the tensile strength. The fatigue limit was 542 MPa for the specimen of diamind burnished STS 410 material, and it was 58.5 % of the tensile strength.

• Korean Journal of Metals and Materials
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• v.46 no.11
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• pp.708-712
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• 2008

The influence of high temperature gas nitriding (HTGN) in STS347 and STS310S steels was experimentally investigated. The HTGN was carried out at $1,050^{\circ}C{\sim}1,150^{\circ}C$ for 10 hrs in a gaseous atmosphere containing $1kg/mm^2$ of nitrogen. After HTGN, fine precipitates of $Cr_2N$ and NbN appeared in austenite on the surface of STS 347, while nitrogen pearlite, which was layeredof $Cr_2N$ and austenite alternatively, appeared in austenite on the surface of STS 310S. The surface hardness of HTGN-treated, STS 347 and STS 310S specimens was 250~360 Hv and 270~400 Hv, respectively, depending on the temperature of HTGN. The nitrogen content was analyzed 1.4 wt% and 1.6 wt% at the surface layer of STS 347 and STS 310S steels, respectively. In addition, an improvement in the corrosion resistance of HTGN treated specimens was observed.

• Journal of the Korean Society of Earth Science Education
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• v.5 no.1
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• pp.42-50
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• 2012

The Purpose of this study was to analyze STS contents in elementary school science textbooks according to 6th, 7th and revision 2007 national curriculum. The contents of STS were analyzed by the STS elements of Yager and the STS topics of Piel's standard. Major findings from the analyses are as follows: (1) The STS contents in the science textbooks of the 6th curriculum took up 13.7% and increased to 18.3% in the 7th and 19.0% in the revision 2007, which showed that the textbooks followed the goal of the national curriculum faithfully. (2) Based on the STS elements by Yager's standard, most of STS content is focused on 'Application of science', 'Social problems and issues' and 'Local and community relevance'. (3) Based on the STS topics by Piel's standard, most of STS contents are focused on 'Effect of technological development' and 'Society of science'. These results indicate that recent STS education trends are reflected on the 6th, 7th and revision 2007 textbooks well. However, it is suggested that some improvement is needed, such as diversification of topic.

• Journal of the Korean Chemical Society
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• v.49 no.2
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• pp.215-223
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• 2005

• Journal of The Korean Association For Science Education
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• v.25 no.3
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• pp.336-345
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• 2005

This study examined the efforts of both national and international science museums and centers to educate the public on recent developments in science, technology, social issues, and ethical issues by analyzing STS-related content exhibits. The results indicated that all science centers informed the public about recent science technology and relevant social and ethical issues by a variety of channels. However, science museums in Korea merely introduced new science and technology at the rudimentary level and used attractions to gather people's attention, which contributed in eliciting distorted thoughts on science and new technology. Science centers in Korea are in need of an upgrade. By analyzing science museums in foreign countries, a unique education on STS themes or scientific issues in Korea can be developed.

• Journal of the Korean Society for Heat Treatment
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• v.20 no.6
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• pp.311-317
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• 2007

This study examined the phase changes, nitride precipitation and variation in mechanical properties of STS 304, STS 321 and STS 316L austenitic stainless steels after high temperature gas nitriding (HTGN) at temperature ranges from $1050^{\circ}C\;to\;1150^{\circ}C$. Fine round type of $Cr_2N$ nitrides were observed in the surface layers of 304 and 316L steels, even more in STS 321. Additionally, square type of TiN was found in STS 321 austenitic matrix too. As a result of many precipitates in the surface layer of the STS 321, it was seen $370{\sim}470Hv$ hardness variation depending on the HTGN treatment conditions, and interior region of austenite represented 150Hv. The surface hardness value of STS 304 and STS 316L showed $255{\sim}320Hv$, respectively. The nitrogen content was shown 0.27, 1.7 and 0.4% respectively at the surface layers of the STS 304, STS 321 and STS 316L. After the HTGN it was shown the improvement of corrosion resistance of the STS 321 and STS 316L compared with solution annealed steels in the solution of 1N $H_2SO_4$ whereas the STS 304 was not.

• Journal of Korean Elementary Science Education
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• v.21 no.2
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• pp.289-296
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• 2002

The purpose of this study is to analyze STS contents in the elementary school science textbooks developed under the 7th national curriculum. Major findings from the analyses are as follows: (1) The Percentage of STS contents included is 26% by the number of pages, and 40% by the lesson hour, Higher proportions of the STS contents are found in the domains of ‘energy’ and ‘material’. By grade level, the coverage of 5th grade textbooks is relatively low. (2) Most STS topics are related to science rather than technology or society. (3) In many cases, STS contents are used in the whole processes of a lesson. (4) Most activities are 'group activity' or 'experiment.observation'. There are few activities of 'role playing', 'spot study' or 'interview'. These results indicate that recent STS education trends are reflected on the revised textbooks well. However, it is suggested that some improvement is needed, such as diversification of topic or activity.

• Journal of Korean Society for Atmospheric Environment
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• v.8 no.1
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• pp.7-12
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• 1992

This study was conducted to determine the effectiveness of silver thiosulfate(STS) in reducing $O_3$ injury to tomato plants(Lycopersicon esculentm Mill. 'Pink Glory'). Two days prior to $O_3$ fumigation, plants were given a foliar spray of STS solution at concentrations of 0, 0.2, 0.4, 0.6 mM contained with 0.05% Tween-20. STS concentrations below 0.6 mM were significantly effective in providing protection aginst $O_3$ exposure(16 h at 0.3 ppm). STS reduced leaf injury rate, defoliation of cotyledons, ethylene production and degree of epinasty induced by $O_3$ injury. STS slightly increased ethylene production in non-$O_3$-fumigated plants, but changes of chlorophyll content and transpiration rate on a whole plant basis were not observed. In $O_3$-fumigated plants, STS treatment reduced chlorophyll destruction but did not affect transpiration rate. STS treatment seemed not to affect peroxidase(POD) and superoxide dismutase (SOD) activity in non-fumigated plants but reduced increasing activity of POD by $O_3$ fumigation. However, such an effect as above was not found in SOD activity. Even though enzymatic protection effects were not confirmed, the fact that reduction of acute injury rate was attained for 16 h fumigation indicates that the phytoprotective effects of STS are not necessarily related to blocking the action of strees-induced-ethylene as an anti-ethylene agent.