• Journal of the Korean Chemical Society
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• v.56 no.5
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• pp.617-627
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• 2012

We investigated pre-service science teachers' understanding of and problem-solving ability with regard to chemistry concepts in the high school curriculum. For this purpose, we used related certain items and analyzed the results. We found that in the case of all items, some pre-service science teachers, who do not have clear concepts, selected incorrect answers. The in-depth interviews we conducted with the participants revealed some of the causes for the results obtained. First, although pre-service science teachers have better concepts as compared to high school students, they have the same misconceptions as students with regard to some concepts. Second, although they are familiar with the general definitions or meanings of scientific concepts, they do not understand the specific content that is emphasized in the curriculum. Moreover, they tend to solve problems by the information visually conceived. Third, although they know the necessity of general concepts related to problem solving, they sometimes fail to apply inquiry skills and tend to suggest concepts from the higher education curriculum that are not helpful for solving problems.

• Journal of the Korean Chemical Society
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• v.22 no.1
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• pp.19-24
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• 1978

Novel nickel(II) complexes of the type Ni(IBA-NH)(IBA-NR), where IBA-NH and IBA-NR (R=H, methyl, ethyl, n-propyl, iso-propyl, n-butyl or benzyl) represent isonitrosobenzoylacetone imine and its N-alkyl derivative respectively, have been prepared. The ir, nmr, and electronic spectra and magnetic moment of the nickel(II) complexes have been studied. It has been determined that the isonitroso group of IBA-NH coordinates to nickel through the oxygen to form 6-membered chelate ring and that of IBA-NR coordinates to nickel through the nitrogen to form 5-membered ring in square-planar Ni(IBA-NH) (IBA-NR). The coordination manner of the ligands is similar to that of isonitrosoacetylacetone imines obtained by Bose, et al.

• Journal of the Korean Chemical Society
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• v.33 no.5
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• pp.551-557
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• 1989

7-Alkyl-1,3-dihydroxyphenazine-5,10-dioxides were synthesized by the reaction of 1,3,5-trihydroxybenzene with 6-alkylbenzofuroxans which had been obtained from aniline and n-alkyl alcohols bearing butyl, hexyl and octyl group. 1,3-Dihydroxyphenazine-5,10-dioxide was also prepared by the reaction of 1,3,5-trihydroxybenzene with benzofuroxan. The surface tension of aqueous solutions of these phenazine dioxide derivatives was determined by surface tensiometer and it was found out that the surface tension decreased with an increase of the number of carbon in the alkyl group. The antimicrobial activities of these phenazine dioxide derivatives were investigated in terms of minimum inhibitory concentration by the common twofold dilution technique. The derivative bearing butyl group showed the highest activity among these derivatives examined. It was observed that the antimicrobial activity of these alkyl substituted phenazine dioxide derivatives was stronger than that of the unsubstituted phenazine dioxide derivative.

• Journal of the Korean Chemical Society
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• v.54 no.5
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• pp.633-642
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• 2010

In this study, science teachers' perception and attitude toward nanotechnology are examined through questionnaires gathered from 134 secondary science teachers. As a result, the study shows that science teachers have high perceptiveness. However, they do not understand specific information on nanotechnology correctly. Science teachers have positive attitudes toward nanotechnology and they have perceived risks of nanotechnology as well as benefits of nanotechnology. Science teachers show positive attitudes toward the application of nanotechnology, whereas they show negative attitudes toward personal information chip and nano-taste enhancer. Science teachers are exposed to nanotechnology via various sources such as TV and internet, whereas teachers rarely get information on nanotechnology-related concepts in textbooks and teaching resources. Science teachers have perceived many textbooks do not introduce enough nanotechnology-related concepts. Many teachers try to explain the nanotechnology when textbooks include nanotechnology-related concepts, whereas quite a few of teachers do not introduce the nanotechnology-related concepts in class.

• Journal of the Korean Chemical Society
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• v.59 no.4
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• pp.289-295
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• 2015

The purpose of this study was to survey the elementary school teachers' thoughts of the classification criteria for evaporation and boiling concept in the heating and non-heating conditions. For this purpose, we conducted a survey and interviews with 37 elementary school teachers. When the heating conditions were presented, many teachers thought evaporation phenomena as boiling. In opposite condition, many teachers thought boiling phenomena as evaporation. This means that teachers‘ thought of boiling phenomena was connected with heating conditions and evaporation phenomena with non-heating conditions. In addition, the classification criteria to distinguish evaporation and boiling phenomena depending on the heating and non-heating conditions were not coherent. In this study, we suggested that a various cases beyond the typical case must be presented in the textbooks and teaching in order to avoid confusion of thoughts related to evaporation and boiling concepts.

• Bulletin of the Korean Chemical Society
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• v.8 no.1
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• pp.31-39
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• 1987

By using a complete rate constant($k_e$) which treats a solvent (water) as a reactant, and a conventional rate constant($k_c$), which ignores the solvent in describing the rate, the parameters ${\Delta}V^{\neq}_s,\;{\Delta}H^{\neq}_s\;and\;{\Delta}S^{\neq}_s$ were introduced. These quantities represent the volume change, the enthalpy change, and the entropy change accompanying the electrostriction which occurs when solvent molecules condense on the activated complex. The authors measured the rates of the solvolysis of benzoyl chloride in water-acetone mixtures at $15^{\circ}$ to $30^{\circ}C$ and 1 bar to 2500 bars. Applying the authors' theory to the experimental results, the parameters, ${\Delta}V^{\neq}_s,\;{\Delta}H^{\neq}_s\;and\;{\Delta}S^{\neq}_s$ were evaluated, and it was found that they are all negative, indicating that water dipoles condense on the activated complex. They also proposed the following equations: ${\Delta}H^{\neq}_c\;=\;{\Delta}H^{\neq}_e\;+\;{\Delta}H^{\neq}_s\;and\; {\Delta}S^{\neq}_c\;=\;{\Delta}S^{\neq}_e\;+{\Delta}S^{\neq}_s\;,\;where\;{\Delta}H^{\neq}_c\;and\;{\Delta}H^{\neq}_c\;and\;{\Delta}S^{\neq}_s $are the activation enthalpy change and the activation entropy change for the conventional reaction rate, respectively, and ${\Delta}H^{\neq}_e$ and ${\Delta}S^{\neq}_e$ are the corresponding quantities for the complete reaction rate. The authors proposed that for the $SN_1$ type, all the quantities, ${\Delta}V^{\neq}_s,\;{\Delta}S^{\neq}_s\;,{\Delta}H^{\neq}_s\;and\;{\Delta}S^{\neq}_s$ are comparatively large, and for the $SN_2$ type, these quantities are smaller than for the $SN_1$ type, and occasionally the case ${\Delta}S^{\neq}_e$ < 0 occurs. Using these criteria, the authors concluded that at high temperature, high pressure and for a high water content solvent, the SN_1$ type mechanism predominates whereas in the reversed case the $SN_2$M type predominates.

• Nutrition Research and Practice
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• v.17 no.4
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• pp.803-811
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• 2023

BACKGROUND/OBJECTIVES: Nutrition knowledge has been reported to have a weak positive effect on healthy eating behavior. This study aimed to determine if there was a difference in nutrition knowledge depending on the choice of science subject in high school and whether that affected the actual eating habits of college students in Japan. SUBJECTS/METHODS: The subjects were 514 college students, the majority first-year students, in 3 cities in Japan. A questionnaire survey was conducted on elective subjects in science in high school, diet (11 items), lifestyle (5 items), and nutrition knowledge (34 questions). The preliminary survey was conducted on 47 students in the fall of 2019, and the full-scale survey was conducted in May-June and October-November 2021 at the end of lectures for the first-year students. RESULTS: The students in the high-score group (24-31 points, n = 180) had a higher intake of vegetables (odds ratio [OR], 1.78; 95% confidence interval [CI], 1.12-2.82; P = 0.015) and breakfast (OR, 1.64; 95% CI, 1.03-2.60; P = 0.035), and a reduced intake of fast food (OR, 0.27; 95% CI, 0.14-0.51; P < 0.001) than those in the low-score group (6-19 points, n = 150). Only the biology and chemistry students had significantly higher nutrition scores than the other groups (all: P < 0.001), but no significant difference was found between the other groups. Understanding nutrition learned in elementary and junior high school is appropriate, while molecular structure, recommended amount, and food poisoning were insufficient. CONCLUSIONS: Knowledge of nutrition appears to have a positive effect on the actual eating habits of college students. Although biology and chemistry in high school may help students understand the foundations of good nutrition, specialized food education may be required to make informed dietary choices.

• Journal of The Korean Association For Science Education
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• v.37 no.3
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• pp.429-440
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• 2017

This study investigated the influence of paired think-aloud problem solving on interactions among the pedagogical content knowledge (PCK) components considered in the processes of making written test items by pre-service chemistry teachers. The processes of making written test items using paired think-aloud problem solving in four small groups consisting of two pre-service chemistry teachers were recorded and transcribed. The analysis of the results revealed that the 'assessment in science education' of the five PCK components, regardless of the roles (solver or listener), was most frequently used in making written test items. 'Subject matter knowledge' and 'students' were also frequently used although less than the previous component. However, 'curriculum for science education' and 'instructional strategies and instruction for science education' was a little used. In the aspects of integration, the integrations between two or three components of various types were frequently found. The integrations among four or five components were also slightly found. However, the integrations of 'curriculum for science education' with the other components were less frequently found. The integrations of 'instructional strategies and instruction for science education' with other components were hardly found. The usefulness, limitations, and effective use of paired think-aloud problem solving as a strategy improving competency to make written test items and the PCK of pre-service teachers were discussed on the basis of the results.

• Journal of The Korean Association For Science Education
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• v.19 no.4
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• pp.507-515
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• 1999

This study is to develope the performance scoring rubrics for the inquiry-based experiments of general chemistry course in the college of education. Two types of analytic scoring rubrics have been developed for nine different experiments. The first one is to assess scientific process skills from the written experimental reports. These analytic scoring rubrics include seven process skills selected from the Lawson's 'creative and critical thinking skills' and other known process skills. The second one is to assess the individual manipulative skills and experimental attitudes through direct observations by the teacher. The content validity of all scoring rubrics was testified by six science educators. Also the inter-scorer reliability of analytic scoring rubrics administered on the students' experimental reports was examined. The correlation coefficient between the scores obtained from the experiments and those of the written test for theoretical knowledges was found to be r=.663(p <.01). From the variance($r^2$=.440), we would say indirectly that the 56% of this experimental assessment does not overlap with the theoretical knowledges test and assesses students' science process skills, manipulative skills, and attitudes.

• Journal of the Korean Chemical Society
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• v.29 no.2
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• pp.144-150
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• 1985

For the separation of boron isotopes, aminated polystyrenedivinylbenzene ion-exchange resins were prepared by chloromethylation of styrene-divinylbenzene copolymer (DVB 10%), followed by the reaction of methylamine. During the preparation of styrene-divinylbenzene copolymer, heptane for the porous resin and toluene for the non-porous resin were used as diluent, and the pore volume of the resins was determined by mercury porosimeter. In both water and aqueous alcohol solutions, the distribution coefficient of boric acid was decreased in accordance with increasing the alcohol concentration and the number of carbon atoms in the alcohol molecules. As a result of separatioin of boron isotope with nonporous and porous resin in water solvent, the separation efficiency of porous resin is better than that of the nonporous, and the result in both water and 50% methyl alcohol solvent relevant to nonporous resin indicated that the latter was better than the former.