• Journal of Gifted/Talented Education
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• v.21 no.4
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• pp.801-828
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• 2011

In this study, we analyzed the characteristics of Pedagogical Content knowledge(PCK)'s components through actual course of teachers of science gifted students in the middle school. For this study, four middle school science teachers of gifted students belonging to the gifted education professional organizations in a metropolis were selected, each of them was physics, chemistry, biology, and earth science teacher. Two of them were full-time teachers to teach only gifted students and two were part-time teachers who had taught general students in ordinary time and specially had taught the gifted students once a week. Qualitative data were collected through classroom observations, interviews, and documents. As a result, some unique characteristics of PCK's components were identified. The teachers' orientations to teaching science were closely correlated with PCK's components. The teachers' knowledges of science curriculum were different individually. But the decisions about type of teaching(acceleration or enrichment) were connected with the objectives of gifted education and lesson objectives. Also, the teachers' knowledges of science curriculum were influenced by the knowledge of students' understanding. Teachers used different instructional strategies according to the knowledge of science curriculum and the knowledge of students' understanding. We found that PCK's components were so closely connected and could show the direction of relationships among those PCK's components. We suggested teachers' PCK model which was named "Tetrahedron Model of PCK", to explain the characteristics and relationships of PCK's components.

• Journal of Environmental Science International
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• v.13 no.3
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• pp.301-311
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• 2004

The purpose of this study was to examine teachers’ awareness of chemical waste produced in elementary school laboratory experimentation and how this awareness relates to collection and disposal of chemical waste. More specifically, the study looked at the correlation between the handling of chemical waste and factors such as years of teachers’ educational career, class size and amount of waste produced. The target population were 250 elementary school teachers in Gyeongnam area and 237 subjects were responded. Among the 237 responses, 37 cases that did not complete the questionnaire were eliminated. Therefore, 200 responses were analyzed in this study. The survey questionnaire consisted of 15 questions. The categories of the questionnaire were their skills of management and treatment of the chemical waste. The data collected were analyzed by SPSS 10.0, and the relations among variables such as class sizes and years of teaching experience were also analyzed by $x^2-test.$ The results in this study were as follows: First, there were no significant differences between the years of teaching and class sizes in the training experience of chemical waste disposal. Second, there was a significant difference between the science laboratory size and class sizes in the laboratory actual condition. In addition, in the relations between the number of times of experimentation and the years of teaching experience, there was a significant difference. Third, in terms of the discharge amount of chemical waste, there was a significant difference between the years of teaching and class sizes. Fourth, in the simple chemistry waste disposal process in the science laboratory, there also was a significant difference between the kinds of experimental equipments that used in the experimentation and the years of teaching. Based on this study, it was found that great amount of the chemical wastes produced in the science laboratory dumped into the drain and the treatment process of chemical waste was also inattentive. Even the importance of environmental education is emphasized in the elementary education, the basic problems occurred in the science laboratory is disregarded. Therefore, not only students but teachers have to pay attention to the disposal process of chemical waste in the laboratory in order to prevent environment pollution. Furthermore, the efforts of preventing environment pollution are needed such as opening the teacher training course about environment education, minimal use of chemicals, treatment of chemical waste, and so forth.

• Journal of Science Education
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• v.41 no.3
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• pp.297-317
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• 2017

The purpose of this study was to investigate the possibility of Science Social and Emotional Learning(SSEL). The factors of SSEL were suggested, and by utilizing them, the contents of middle school's science and Chemistry 1 textbook were analyzed. The factors are as follow: numeracy, information and communication technology, critical thinking, creative thinking, personal and social capability, ethical understanding, and intercultural understanding. The results showed that the 60~70% of textbooks put emphasis on numeracy, information and communication technology, critical thinking, creative thinking while some factors were limited in th contents, which were personal and social capability, ethical understanding, and intercultural understanding. Therefore, teacher should try to reconstruct the teaching and learning materials and fill in the deficiencies of SSEL factors through class activities. In addition, it is suggested to study specific application methods such as science activities or experiment activities in detail to meet social and emotional learning.

• Korean Journal of Environmental Agriculture
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• v.8 no.2
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• pp.142-147
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• 1989

In this report, we set up a simple device which enabled us to obtain data useful to estimate the relative capacity of thermal energy retention of greenhouse built with various plastic coverings. A box($20cm{\times}20cm{\times}30cm$) framed with flexiglass at the edges and covered with thin plastic films was made, in which were placed a thermostat-controlled nichrom wire heater and a thermal probe made of thermister to monitor temperature changes. A wheaston-bridge type transducer and a chart recorder were used to record the changes of temperature inside the box The data obtained by using the device showed that the relative rate of heat toss through plastic films with identical thickness decreased in the order of PE film>EVA film>PVC film and that IR additives such as fine silica gel improved the insulating power of plastic films. This observations are in well accord with general information, demostrating the feasibility of the device in usefulness for the purpose of screening of various commercial plastic coverings.

• Journal of The Korean Association For Science Education
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• v.22 no.3
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• pp.560-570
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• 2002

This study was focused on whether secondary science teachers have consistent, integrative scheme on the definition of atmospheric pressure and phenomena caused by air pressure. We had made questionnaire and let 94 science teachers answer. We sorted the responses according to their major, school and compared them with the description in textbooks. The result can be summarized into three findings. First of all, teachers whose major is chemistry have strong tendency to understand that atmospheric pressure is caused by molecular motion though it, in textbooks, is defined as the pressure by weight of air mass. The half of respondents believed that decreasing of atmospheric pressure in high altitude is due to molecular motions, while most textbook says decrease in the weight of air mass. Secondly, many science textbooks show that air mass expands, rises, becomes less dense and the pressure of atmosphere becomes low when it receives heat. So, most of respondents explained low pressure is formed by lower density. Thirdly, they answered that they just teach the phenomena of air pressure by using the textbooks which mainly deal with the present state rather than a principle. In conclusion, the science textbooks should present the exact description and consolidated structures of those concepts to prevent students from having misconceptions on air pressure. In addition, training program for science teachers would be necessary to reconsider and explore the natural phenomena in various viewpoints.

• Journal of the Korean Chemical Society
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• v.64 no.5
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• pp.304-317
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• 2020

This study was conducted on four 11^th grade students at a high school in a small town to determine the effectiveness of responsive teaching. The three phases of the responsive teaching method proposed in the previous study were subdivided into six stages; Step 1 is elicitation of students' thoughts related to macroscopic world, Step 2 is drawing of students' early thoughts related to microscopic world, Step 3 is disciplinary connections with ideas of the particle, Step 4 is to clarify the learner's thoughts on the particle by the teacher's involvement, Step 5 is deepening students' thoughts, and Step 6 is expanding ideas. In Step 4, students came to the recognition that the cause of mass was atoms and that the cause of volume was molecules. In Step 5, students led to a shift in thinking that could ignore the volume of the molecules themselves through the properties of protons and neutrons that affect mass from a particle perspective. In the Step 6 of expanding ideas, students explained molecular motion by the concept of material point which ignores the volume of particles. This steps gave students perspectives on the relationship between the mass and volume of particles required by Avogadro's law. The students recognized that some systems could be studied only indirectly because they were too small, too large, too fast, or too slow to observe directly.

• Journal of the Korean Chemical Society
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• v.33 no.1
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• pp.3-10
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• 1989

In order to obtain a clue in understanding enzymatic hydrolysis in which the His-Cys moieties of papain protease is involved, we prepared cationic peptide-sufactants bearing histidyl, cysteinyl, and both histydyl and cysteinyl residues. Their catalytic efficiency toward the hydrolysis of PNPL were investigated in comicellar phases formed with $N^{+}C_{2}CysC_{12}$, $N^{+}C_{2}HisC_{12}$, $N^{+}C_{2}HisCysC_{12}$ increased markedly in the same order compared with that of $N^{+}C_{2}AlaC_{12}$. The markedly increased catalytic effects are attributed to the imidazole groups of $N^{+}C_{2}HisC_{12}$ and the thiol groups of $N^{+}C_{2}CysC_{12}$, and the large catalytic efficiency of $N^{+}C_{2}HisCysC_{12}$, is considered due to the interaction of the imidazole and the thiol groups. In order to investigate catalytic activities, rate constants for the functional groups, km* and dissociation constants, pKa have been determined. The results showed that $k^{\ast}_m$ and pKa of the imidazole groups were $7.91{\times}10^{-4}S^{-1}$ and 6.49, and those of the thiol groups were $6.00{\times}10^{-4}S^{-1}$ and 10.50. The catalytic effects of comicellar systems on the hydrolysis of p-nitrophenyl esters has increased according to the increasing size of the alkyl carbon number. Therefore, the catalytic effects have been increasing by the interaction of micellar hydrophobic parts and substrates as well as action of the functional groups.

• Journal of The Korean Association For Science Education
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• v.41 no.4
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• pp.311-324
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• 2021

In this study, we analyzed the process of pre-service science teachers' designing and implementation of lessons in teaching practice from the perspective of CHAT. Five pre-service teachers attending the Department of Chemistry Education at the College of Education in Seoul participated in this study. We observed their teaching practice, collected documentary data, and conducted in-depth interviews. The data were analyzed using the constant comparative method based on grounded theory. The analyses of the results reveal that, due to the lack of authority to make decisions for lesson design, pre-service teachers faced difficulties and had direct conflict with teachers. In addition, it was difficult for them to obtain sufficient contextual information for lesson design even through subject orientation and classroom observation, which made it difficult for them to design lessons. When consecutive lessons were taken by several pre-service teachers, there were many problems such as poor continuity of lessons. Given limited authority to assess students, they conducted additional assessments. They showed a lack of professionalism when conducting assessments. The cause of this could be found in the curriculum of the College of Education. Some ways to provide better teaching practice based on the results are discussed.

• Journal of The Korean Association For Science Education
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• v.41 no.5
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• pp.391-400
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• 2021

This study investigated science education experts' perception of remote laboratory sessions (RLS) provoked by the COVID-19 pandemic. We conducted a total of 10 semi-structured interviews with experts in physics, chemistry, biology, and earth science education. As a result, science education experts primarily understood the RLS concerning pre-service teacher education and reconsidered the aim and goal of conventional laboratory education. On practices of RLS provoked by the COVID-19, they pointed out the learning loss due to deficiency of hands-on experience, decreased interactions between instructor and students, and instructors' increased burden. Meanwhile, they contemplated upon their adaptive implementation of RLS to suggest ways to improve RLS instruction and directions of post-COVID-19 science education. We recommend that RLS should be understood as a complemented version of minds-on teaching rather than a degraded version of hands-on teaching to elicit its full potentials. This study has its own significance providing an in-depth science educational perspective interpreting the RLS phenomena.

• Journal of The Korean Association For Science Education
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• v.29 no.4
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• pp.450-462
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• 2009

In this study, we investigated the influences of teaching practices upon pre-service secondary teachers' perceptions on the learning cycle by their understanding of it. Surveys on their understanding and perceptions of the learning cycle were administered to 37 seniors at the department of chemistry education in two colleges of education before teaching practices, and the survey for perceptions of the learning cycle was given to them after teaching practices. In addition, we selected seven pre-service teachers with decreased perceptions after teaching practices, and interviewed them thoroughly to investigate the factors influencing the decrease of their perceptions. The results revealed that the degree of pre-service secondary teachers' understanding of the learning cycle was not high, but their perceptions on the advantage/disadvantage of the learning cycle, their willingness to implement it, and the external aids influencing implementation were relatively positive before they practiced teaching. However, their positive perceptions more or less decreased after entering the teaching practice and the degree of decrease for those having a higher understanding of the learning cycle was larger than those having a lower understanding of it. The results of the interviews suggested the factors of pre-service teachers, students, curriculum and outside conditions as the causes of the decrease. Educational implications of these findings are discussed.