• Analytical Science and Technology
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• v.19 no.1
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• pp.39-44
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• 2006

Puh-erh tea was extracted with water and then fractionated sequentially with n-hexane, ethyl acetate, n-butanol to find antioxidative compounds. The fractions were examined on the antioxidant activity using two different methods, free radical scavenging activity measurement and reductive potential. Those antioxidant activities were compared to standard antioxidants such as butylated hydroxyanisole(BHA), butylated hydroxytoluene (BHT), and ${\alpha}$-tocopherol. EA fraction of Pu-erh tea was showed excellent antioxidative activities over BHA and BHT.

• Journal of Korean Elementary Science Education
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• v.43 no.2
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• pp.252-268
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• 2024

This study developed a field trip program called "Planning a science exhibition" and explored elementary science-gifted students' perceptions of the program and learning experiences influencing them. To this end, 56 elementary science-gifted students in grades 4-6 from in an university-affiliated science-gifted education institute in metropolitan area were selected to participate in the field trip program. After the program, the students answered a survey regarding their perceptions of the program. Additionally, 19 students were selected for group interviews to further explore their survey responses. Results showed that many elementary science-gifted students perceived the program positively in various cognitive and affective aspects. Some students also pointed out certain limitations of the program. Five interconnected learning experiences were identified as influencing the students' perceptions: "experiences fostering creativity", "non-residential camp-type project-based learning experiences", "self-directed learning experiences", "experiences utilizing digital devices", and "collaborative experiences". Educational implications regarding these results were discussed.

• Membrane Journal
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• v.33 no.4
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• pp.149-157
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• 2023

Covalent organic frameworks (COFs) have shown promise in various applications, including molecular separation, dye separation, gas separation, filtration, and desalination. Integrating COFs into membranes enhances permeability, selectivity, and stability, improving separation processes. Combining COFs with single-walled carbon nanotubes (SWCNT) creates nanocomposite membranes with high permeability and stability, ideal for dye separation. Incorporating COFs into polyamide (PA) membranes improves permeability and selectivity through a synthetic interfacial strategy. Three-dimensional COF fillers in mixed-matrix membranes (MMMs) enhance CO₂/CH₄ separation, making them suitable for biogas upgrading. All-nanoporous composite (ANC) membranes, which combine COFs and metal-organic framework (MOF) membranes, overcome permeance-selectivity trade-offs, significantly improving gas permeance. Computational simulations using hypothetical COFs (hypoCOFs) demonstrate superior CO₂ selectivity and working capacity relevant for CO₂ separation and H₂ purification. COFs integrated into thin-film composite (TFC) and polysulfonamide (PSA) membranes enhance rejection performance for organic contaminants, salt contaminants, and heavy metal ions, improving separation capabilities. TpPa-SO₃H/PAN covalent organic framework membranes (COFMs) exhibited superior desalination performance compared to traditional polyamide membranes by utilizing charged groups to enable efficient desalination through electrostatic repulsion, suggesting their potential for ionic and molecular separations. These findings highlight COFs' potential in membrane technology for enhanced separation processes by improving permeability, selectivity, and stability. In this review, COF applied for the separation process is discussed.

• Journal of the Korean Society of Earth Science Education
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• v.14 no.2
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• pp.112-122
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• 2021

The goal of this study is to explore ways to restructure Convergence Elective Courses in science in preparation for the high school credit system, ahead of the 2022 revised science curriculum. This study started from the problem that the 2015 revised science curriculum has not guaranteed science subject choice for students with non-science/engineering career aptitudes. To this end, a survey was conducted by randomly sampling high schools across the country. A total of 1,738 students responded to the questionnaire of 3 science elective courses such as Science History, Life & Science, Convergence Science. In addition, in-depth interviews with 12 science teachers were conducted to examine the field operation of these three courses, which will be classified and revised as Convergence Elective subjects in the 2022 revised curriculum. According to the results of the study, high school students perceive these three courses as science literacy courses, and find these difficult to learn due to lack of personal interest, and difficulties in content itself. The reason students choose these three courses is mainly because they have aptitude for science, or these courses have connection with their desired career path. Teachers explained that students mainly choose Life & Science, and both teachers and students avoid Science History because the course content is difficult. Based on the research results, we suggested ways to restructure Convergence Electives for the 2022 revised curriculum including developing convergence electives composed of interdisciplinary convergence core concepts with high content accessibility, developing convergence electives with core concepts related to AI or advanced science, developing module-based courses, and supporting professional development of teachers who will teach interdisciplinary convergence electives.

• Journal of Science and Technology Studies
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• v.4 no.2 s.8
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• pp.67-101
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• 2004

Although the study of citation patterns is an important theme within the sociology of science, due to the fact that it is intimately related to the production, reproduction, and evaluation of knowledge, only sustained theoretical research outlining the differences of citation patterns between the hard and soft sciences has been conducted, and empirical studies nevertheless remain few and far between. The perspectives of institutionalism and constructivism have to attempted to explain different citation patterns between the hard and soft sciences as a contrast between 'what one says' and 'who one is'. Therefore, against this background this study examines the 'theoretical' controversy empirically by comparing the contrasting citation patterns of physics, as a representative of hard science, and sociology, as a representative of soft science. The results, in brief, are as follows: the citaton patterns in physics, as in sociology, vary according to the author's status within the hierarchical employment structure, i. e. whether s/he is a full-time lecturer or not, but diversity of citation patterns according to Ph. D. diploma area is unique to sociology. These results would suggest that the explanation of constructivism is more relevant in explaining variance according to the author's status in the employment hierarchy, but the approach of institutionalism is more appropriate to understanding variance due to Ph. D. diploma area. Furthermore, this implies the complex diversity of the citation patterns between the hard and soft sciences, pointing us to the more qualified conclusion that rather than having to choose between institutionalism and constructivism according to a mutually exclusive either/or logic, these two approaches can in fact be mutually complementary, and these approaches should also be applied piecemeal to different levels of phenomena. In conclusion, this comparative research enables us to assert the following two claims: firstly that physics, as a 'science in society', produces knowledge dependent on social context, and secondly that it also possesses a characteristic that transcends locality from the view of a sociology of knowledge.

• Journal of The Korean Association For Science Education
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• v.32 no.4
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• pp.775-788
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• 2012

This study was done at a scientific camp sponsored by Nara Women's University Secondary School, Japan. In this school, $10^{th}$ grade students from 4 East Asian countries: Korea, Japan, Taiwan, and Singapore, participated. We made a research on students' perceptions about nuclear energy. Sample populations include 77 students in total, with 12 Korean, 46 Japanese, 9 Taiwanese and 10 Singaporean students. Overall perceptions comparison about nuclear energy shows average values from the order of highest Korea, Taiwan, Singapore, and to lowest, Japan. We implemented a T-test to identify perception differences about nuclear energy, with one group that include 3 countries (Korea, Taiwan and Singapore) and another group that includes all the Japanese students. T-test results of perceptions about nuclear energy shows students from the 3 countries of Korea, Taiwan and Singapore having higher average than Japanese students. (p<.05). Korean average scores regarding overall perceptions about nuclear energy show as the highest in all 4 East Asian countries and also highest in all subcategories. On the contrary in Japan, they have lower and negative perceptions of nuclear energy. In spite of these facts, perceptions of Japanese students about nuclear energy seem lowest and negative mainly because of the recent Fukushima nuclear power plant disaster, caused by the tsunami and its subsequent damages and fears of radiation leaks, etc. This shows that negative information about future disasters and its resulting damages like the Chernobyl nuclear accident could influence more on people's risk perception than general information like nuclear energy-related technologies or the news that the plant is operating normally, etc. Even if the possibility of this kind of accident is very low, just one accident could bring abnormal risks to technology itself. This strong signal makes negative image and strengthens its perceptions to the people. This could bring a stigma about nuclear energy. This study shows that Government's policy about the highest priority for nuclear energy safety is most important. As long as such perception and decision are fixed, we found that it might not be easy to get changed again because they were already fortified and maintained.

• Journal of Apiculture
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• v.32 no.3
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• pp.139-146
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• 2017

Floral scent emitted from many plants is the critical factors for pollinator attraction and defense for adaptation in environments. The fragrance components of flowers are different in composition by geographical origins, climate factors and the development stages of flowers. In the present study, we investigated the volatile-floral compounds in flowers of Robinia pseudoacacia L. and defined the chemical contribution for flowering periods. The volatile compounds analysis was performed by gas chromatography with mass selective detector after solid phase microextraction (SPME). We reported different compositional features of fragrance compounds according to flowering periods. The abundant compounds identified in stage 1 were ${\alpha}$-pinene (66.80%) and ${\beta}$-pinene (26.53%). Those of the stage 2 were (Z)-${\beta}$-ocimene (37.57%), ${\alpha}$-pinene (15.16%), benzaldehyde (16.63%), linalool (12.13%). The volatiles of stage 3 comprised an abundance of (Z)-${\beta}$-ocimene (64.94%), ${\alpha}$-pinene (9.84%), linalool (8.92%), benzaldehyde (1.71%). Leaf volatiles were distinct from those in the reproductive plant parts by their high relative amount of (E)-${\beta}$-ocimene (23.50%) and (Z)-3-Hexenyl acetate (27.87%). Differences in flower scents of the different stages and leaves are discussed in light of biochemical constraints on volatile chemical synthesis and of the role of flower scent in evolutionary ecology of R. pseudoacacia.

• Journal of Environmental Impact Assessment
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• v.32 no.6
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• pp.450-462
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• 2023

This study suggested methodology of Citizen Science as a tool of ecosystem conservation and management to achieve Wetland Protected Area (WPA) Conservation Plan and examined whose applicability in 3 WPAs (Jangrok of Gwangju metropolitan city, Madongho of Goseong in South Gyeongsang Province, and Incheongang estuary of Gochang in North Jeolla Province). It consists of a) figuring out main interests and stakeholder or beneficiaries of WPA and their information demand based on conservation, utilization, and management target in the WPA Conservation Plan, b) conducting research activities to gain outcome to address stakeholder's demand, and c) returning the research outcome to citizen scientists and making diffusion to the society. Based on the suggested method and process, citizen scientists conducted ecosystem monitoring (plants including Invasive Alien Plants, terrestrial insects, traces of mammals, discovering unknown wetland). As a result, citizen scientists contributed to collecting species information of 16 plans, 43 species of terrestrial insects, 5 mammals including Lutra lutra (Endangered Species I) and Prionailurus bengalensis (Endangered Species II). The authors constructed and provided distribution map of Invasive Alien Plants, which included information of location and density which citizen scientists registered, for Environment Agencies and local governments who manage 3 WPAs to aid data-based ecosystem policy, In further studies, not only accumulating research data and outcomes acquired from citizen science to suffice the policy demands but also deliberate reviewing policy applicability and social·economic ripple effect should be processed for the suggested Citizen Science in WPA to be settled down as a tool of ecosystem conservation and management.

• Journal of the Korean earth science society
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• v.32 no.2
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• pp.225-238
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• 2011

The purpose of this study was to explore the factors that are critical for successful scientific inquiry activity in the classroom and to analyze the students' abilities of 'Doing' scientific inquiry. Two hundred and forty gifted science students in grades $7^{th}$ and $8^{th}$ participated in this study and demonstrated their abilities of framing questions and designing investigation through a survey questionnaire. The survey was developed for measuring factors in terms of personal and interactive variables that are needed for 'Doing' a successful scientific. Additionally, two other questionnaires were developed to measure students' abilities of framing testable questions and designing the investigation in a sequence. The results were as follows: Students' learning motivation factors as personal variable (self-confidence about group and inquiry activity, views about inquiry value) also considered as influential for students' group inquiry activity. Other four components of interactive variable (grouping, kinds of task, physical context, and teachers' role) were found to be influential in successful students' 'Doing' group inquiry activity. In students' evaluation of group inquiry activity, the grouping factor was the most critical one for a successful 'Doing' inquiry activity. Participating students showed some level of inability of in the process of framing inquiry question and designing investigation.

• Journal of The Korean Association For Science Education
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• v.23 no.3
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• pp.215-228
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• 2003

The present study is to analyze the arguments about the generation of declarative scientific-knowledge in the philosophy of science and invent a structured model of the process of scientific-knowledge generation with the types of the generated scientific-knowledge. The invented model shows that scientific-knowledge generation is a distinctive process with the processes of inductive, abductive, and deductive thinking. Furthermore, inductive process is included with observation, which is consisted of simple observation and operative observation, and rule-discovery which is involved with the processes of commonness discovery, classification, pattern discovery, and hierarchical relationship. Also, abductive process has two components. One component generates question and second component generates hypothesis in which the process consists of representing question situation, identifying experienced situation, identifying causal explicans, and generating hypothetical explicans. Finally, deductive process is involved with logical inventing test method and evaluation criteria, concrete inventing test method and evaluation criteria, evaluating hypothesis, and making conclusion.