• Journal of the Korean Chemical Society
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• v.51 no.1
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• pp.56-64
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• 2007

This study examined the influences of cognitive conflict and anxiety induced by a discrepant event and an alternative hypothesis, attention, and effort on conceptual change. Two hundred three students having misconceptions about density were selected from 462 seventh graders based on the results of a preconception test. Tests of cognitive responses and anxiety to a discrepant event were administered before and after presenting an alternative hypothesis. Computer-assisted instruction (CAI) was then provided to students as a conceptual change intervention. Tests assessing attention and effort allocated to the CAI, and conceptual understanding were administered as posttests. Cognitive conflict induced by a discrepant event was found to increase after presenting an alternative hypothesis. Pre-cognitive conflict induced by only a discrepant event exerted a direct effect on post-cognitive conflict induced by a discrepant event and an alternative hypothesis. Post-cognitive conflict had a direct effect on conceptual change. Pre-anxiety decreased after presenting an alternative hypothesis. Pre-anxiety influenced post-anxiety, and this influenced on conceptual change via effort negatively. Attention had a direct effect as well as an indirect effect on conceptual change via effort. These results suggest that the strategy presenting both a discrepant event and an alternative hypothesis to students in concept learning could facilitate conceptual change by inducing more cognitive conflict or active participation of students through the decrease of anxiety than that presenting a discrepant event only.

• Journal of the Korean Chemical Society
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• v.66 no.6
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• pp.493-508
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• 2022

Chemistry is the subject which includes properties, change, and composition of matter. Chemistry has the system which explains observable properties and change with microscopic level, it explains them using scientific theory and laws. In the national-level curriculum, the properties and changes of matter are continuously dealt with from elementary school to high school, and the curriculum are organized so that students could strengthen their understanding about matter. In other words, understanding of the properties and changes of matter is the base to explain everyday life with the view of chemistry, and these two are classified as domains of chemistry in the 2015 revised science curriculum. In this study, we confirmed students' understanding about properties of matter and change of matter, through the analysis about results of the National Assessment of Educational Achievement (NAEA). For that purpose, this study analyzed the 12 items about properties of matter, and 19 items about change of matter, which were used in the NAEA from 2015 to 2019. According to the results of classifying and analyzing questions according to the core concept, the understanding about the two domains significantly changed between the proficient achievement-level students and basic achievement-level students. Depending on the achievement-level, there was a difference in explaining the phenomenon by using the perspective of particles, and by associating scientific concepts and models, or there was a difference in understanding the inquiry related to these two domains. Based on this analysis, this study discussed some implications to be improved on teaching-learning for 'properties of matter', and 'change of matter'.

• Journal of the Korean Chemical Society
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• v.61 no.1
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• pp.34-44
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• 2017

The purpose of this study was to analyze the conception type change and to investigate the effect of understanding on concepts in electrochemistry after general chemistry lessons. The significant differences in concept understanding of electrochemistry were shown in both groups. Statistically significant gains in both groups were as shown in distinguishing the chemical cell, in identifying the anode and cathode, and in understanding current formation and flow, while, significant achievements in understanding the role of the salt bridge, and the need for a standard half-cell were not found. Taking elective chemistry II in high school had an effect on understanding related concepts of electrochemistry in general chemistry lessons. It was shown that many freshmen had difficulties in understanding exact related concepts in several kinds after general chemistry lessons. In order to solve these problems, it is necessary to teach contents of the basic concepts in electrochemistry exactly and to hold supplementary lessons.

• CELLMED
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• v.8 no.2
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• pp.7.1-7.12
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• 2018

Greying of hairs or Canities (Sheeb) is a hair disorder characterized by premature graying of scalp hair, beard, moustache etc. In Unani system of medicine (USM), the causes of premature greying of hairs, concept behind graying of hairs, principles of treatment, preparations that prevent premature greying of hairs, regimen, systemic and local treatment to stimulate pigmentation and the most interesting point is the use of different type of hair dyes (khizabat) is all illustrated. Classical texts described black, red, blond and white hair dye preparations with formulae and method of use. Initially for the hair graying management, utilizing simple and complex substances from plants, minerals, metals and mixture of these was the main method, which satisfied the desire to change the colour of the hair. With the advancement in chemical science, dyes formulaes, method of formation and application are changed. But due to the awareness about demerits of chemical dyes, people are looking back towards the natural ways to combat hair greying and herbal hair dye is an alternative. This paper is an overview of Unani drugs of local and internal use for hair greying with special attention towards herbal dyes. Most commonly used herbs in khizaab with their actions and constituents has been summarized. This is an effort to globalize the benefits of Unani herbs in hair greying problem. In short, International demand for hair dyes has been steadily growing and there is a wide scope for exploring different aspects of hair greying treatment and dyes in USM.

• Journal of the Korean Chemical Society
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• v.23 no.1
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• pp.20-29
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• 1979

The origin of barriers to internal rotation of hydrogen peroxide and ethane is investigated by using the concept of Bonding and Antibonding Regions. The strong bond formations between the axial and end atoms on the same side make the real charge densities in these molecules less dependent on conformations than those in the hypothetical molecules having no axial atoms. Thus, the existence of the axial atoms should induce the migration of the transition density from the Bonding region to the Antibonding region. Barrier to internal rotation can be understood in terms of this migration of the transition density to such an extent that the change in nuclear-nuclear repulsion energy becomes the dominating part of the total perturbation energy.

• Journal of the Korean Chemical Society
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• v.55 no.6
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• pp.1030-1041
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• 2011

We investigated the understanding of pre-service science teacher about the chemistry concept of middle school curriculum using some items in National Assessment of Educational Achievement and analyzed the result according to background variables of pre-service science teacher. The result was that there were some pre-service science teachers who select incorrect answer at all items, pre-service science teachers don't fully understand the concept needed to solve item. And the percentage of correct answer at some items was low regardless of selection of chemistry as an elective subject at CSAT(College Scholastic Ability Test). We found some facts through the depth interviews to find the cause of the result. First, the misconception acquired in middle school days is tend not to change until college student. Second, the formation of misconception is affected by the study habit with which solve problem by simple calculation and memory without essential understanding. Third, the study habit with which solve problem by simple calculation and memory without essential understanding could not replace misconceptions acquired in middle school days with scientific concept regardless of selection of chemistry as an elective subject at CSAT.

• Journal of the Korean Chemical Society
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• v.51 no.3
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• pp.279-286
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• 2007

In this study, we investigated the influences of cognitive conflict and situational interest induced by a discrepant event and an alternative hypothesis, attention and state learning strategies on conceptual change. A preconception test was administered to 486 seventh graders. They also completed the questionnaires of cognitive response and situational interest to a discrepant event before/after presenting an alternative hypothesis. After learning the concept of density with a CAI program as conceptual change intervention, the tests of attention, state learning strategies, and conceptual understanding were administered as posttests. Analyses of the results for 197 students having misconceptions about density revealed that post-cognitive conflict was significantly higher than pre-cognitive conflict. However, there was no statistically significant difference between the test scores of pre-situational interest and post-situational interest. Pre-cognitive conflict only exerted a direct effect on post-cognitive conflict, while post-cognitive conflict exerted a direct effect and Journal of the Korean Chemical Society an indirect effect via attention on conceptual understanding. Both pre- and post-situational interests were found to influence on conceptual understanding via attention. Attention had influences positively on deep learning strategy and negatively on surface learning strategy. There was a relatively small effect of state learning strategies on conceptual understanding.

• Fashion & Textile Research Journal
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• v.11 no.4
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• pp.527-536
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• 2009

The purpose of this study is to consider the characteristics of fashion paradigm on contemporary fashion in pursuit of social change towards 'slowness'. As for the research methodology, literature survey has been undertaken. The results of this study can be summarized as followings. First, eco-friendly ethics towards sustainability is in taking action. The concept of 'cradle-to-cradle' is realized through reuse, recycle, organic material, and no use of chemical. Second, local diversity is revolving quality and longevity. Good quality of fashion made by artisans and specificity in local area is to be kept last. Third, people are recast in roles from simple consumers to self-made producers of their clothes. Users of clothes are more active and skilled role in practice of handmade, reform, DIY, and open-source design. In Conclusion, the fashion paradigm of 'slowness' is about designing, producing, consuming and living better to combine ideas for sense of nature's time, culture's time and people's time.

• Journal of The Korean Association For Science Education
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• v.20 no.4
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• pp.527-541
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• 2000

The purpose of this study was to find out the characteristics of learning contents structure of K-12 science textbooks. The characteristics are related to 7 main concepts of matter properties; reaction rate, other reaction, density, solution, state change, absorption, and surface property. The contects are analyzed into 5 types of characteristics; type of concept extension, type of concept deepness, type of same level concept, type of confusion with other concepts, and type of concept interruption. First two types are positive content structures, but the others are negative structures. The findings are as follows. First, a lot of learning contents have the characteristic of 'type of same level concept'. There are few which have the characteristic of 'type of concept deepness'. Second, there are a lot of concepts related to 'properties of matter' which are not represented any more in middle and high school science textbooks. Those concepts are importantly taught in early childhood education and elementary school science. Most of the learning contents don't represent 'type of concept deepness'. Therefore the science textbooks needs to be restructuring.

• Journal of the Korean Chemical Society
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• v.60 no.1
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• pp.48-58
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• 2016

This study was to investigate the types of middle school students’ conceptual change on electrolyte and ion. Data were collected by pre- and post- exams of 9th grade students’ conceptions of electrolyte and ion, and by semi-structured interviews with nine students served as case representatives who participated in the study. All interviews were transcribed, analyzed and classified by conceptual change according to the responses of the students. The results are as follows: First, students’ ion conceptual change was classified into four types; simple conception to sophisticated conception, incomplete conception to scientific conception, misconception to confused conception, and misconception to misconception. Most students had difficulty in understanding of the concepts of ion in pre- and post-class, and they failed to distinguish between atom and subatomic particles precisely. Second, students’ conceptual change of electrolyte was also classified into the following four types; partially scientific conception to sophisticated conception, misconception to partial misconception, incomplete conception to incomplete conception and misconception to misconception. The study found that students had difficulty distinguishing the difference between electrolytes and nonelectrolytes. Third, students also had difficulty understanding the concepts on particles because they learned the ‘electrolyte and ion’ unit so quickly in the second semester of 9th grade in order to fill in the academic reports for applying high schools. Furthermore, some suggestions were made based on the results for understanding scientific concepts on particles.