• Journal of Science Education
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• v.32 no.1
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• pp.47-60
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• 2008

The Ministry of Science and Technology has been planning various events and carrying them out as the effort for promotion and popularization of science. The ministry has made followings: i)Science culture year, 2004 ii) Physics year, 2006 iii)Chemistry year, 2007 iv)Biology year, 2008. Especially, in 2006 the ministry held various exhibitions and contests about chemistry. The science play "Oxygen" had been presented in the whole country, 2006. From 2006 to 2007 the moving science museum had been displayed many times in the whole country. The national broadcast media KBS made a special program and televised several times to commemorate the year of chemistry. Like that in 2006 the chemistry approached to general people. In these surroundings, we wondered how chemistry was expressed in daily newspaper and how the general public accepted chemistry in the year of chemistry, 2006. So we selected four daily newspaper and researched descriptions about chemistry then analyzed the image of chemistry in that descriptions. When we research, we first selected 5 words of high frequency. On the internet research engine we used these 5 words and searched descriptions. We read and sorted descriptions which were more connected to chemistry. Finally we analyzed the images of descriptions(affirmative or negative) and character. The chemistry's image on newspaper descriptions influences people greatly. Because that is the easiest channel.

• Journal of Food Hygiene and Safety
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• v.24 no.4
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• pp.338-347
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• 2009

The content of residual pesticides in commercial agricultural products in Gyeongsangbuk-Do area was investigated for 5 years extending the year 2004 through 2008. The detection rates of residual pesticides in agricultural products by year were similar in range of 11.6~16.4%. But the violation rates showed lower values in the last years from 4.5% of the year 2004 to 0% of the year 2007. The highest residual concentration of each pesticide detected in commercial agricultural products was investigated by year. That is, in the year 2004 and 2005, chlorpyrifos, chlorothalonil, diazinon, endosulfan, ethoprophos, fenarimol and procymidone were detected over the tolerance in kale, parsley, celery, chard and lettuce, and in the year 2006, permethrin in the soybean and peanut. The detection rate and violation rate of pesticides were highly increased in the order of the endosulfan, chlorpyrifos, procymidone, chlorfenapyr, fenitrothion, imazalil, isoprothiolane, methidathion and permethrin. The detection rate and violation rate of pesticides were increased after August every year.

• International Journal of Advanced Culture Technology
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• v.12 no.1
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• pp.209-219
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• 2024

We studied the effects of science high school students on the change of epistemological beliefs in chemistry and the academic achievement of chemistry by completing 'advanced chemistry'. For seven months from July 2023 to January 2024, 80 first-year students at G Science High School in Gyeongnam were surveyed and analyzed for epistemological beliefs about chemistry before and after classes in advanced chemistry. Chemistry academic achievement was classified by 'upper' and 'lower' levels based on the end-of-semester grades of 'advanced chemistry' in the second semester of the first year and analyzed with the SPSS 28 program. After completing advanced chemistry, the epistemological belief in chemistry increased in the proportion of favorable responses. After completing advanced chemistry, the proportion of favorable responses increased in detailed factors such as 'effort', 'math link', 'outcome', 'reality link', and 'concepts', while the 'visualization' factor decreased. Although completing 'advanced chemistry' positively changed students' epistemological beliefs about chemistry, visual expression showed little contribution to understanding chemical concepts. Based on the above results, we will have to focus on the design of instructors' teaching-learning, such as learner-centered inquiry experiments, creative visual expressions, etc., for successful chemistry teaching-learning.

• Applied Biological Chemistry
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• v.40 no.2
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• pp.152-156
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• 1997

Platycodon root contains abundant pharmaceutical substances and is widely used as a food and a medicinal herb. The three-year-old and the 24-year-old Platycodon roots cultivated in a local farm were analysed and compared with their pharmaceutical substances to identify the major components. Reverse column HPLC analysis of ethanol extracts from the 24-year-old roots showed some distintive peaks after the retention time of 50 min which were absent in the extracts from the three-year-old roots. This indicates that several pharmaceutical substances are present in the older roots. There were no differences in sterol composition and saponin content between the 24-year and three-year-old roots. The 15-year-old and the 23-year-old Platycodon roots, the 6-year-old Ginseng root, and the three-year-old Condonopsis root all did not show significant anticomplement activity.

• Applied Biological Chemistry
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• v.40 no.2
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• pp.148-151
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• 1997

Platycodon root contains abundant pharmaceutical substances and is widely used as a food and a medicinal herb. To identify the major components of the three-year-old and the 24-year-old platycodon roots cultivated in a local farm were analyzed and compared with their chemical compositions prior to their pharmaceutical substances, which were used as the fundamental data. There were no differences in chemical composition, inorganic compositions and fatty acid compositions between the 24-year-old and three-year-old roots. Total amino acid contents were 375.8 mg% and 891.6 mg% in the 24-year-old and three-year-old platycodcon roots, respectively. Sixteen species of amino acid were identified by amino acid autolyzer except cysteine both in the 24-year-old and three-year-old roots. Linoleic acid, which was the highest fatty acid contained both in the 24-year-old and three-year-old roots, was estimated to be 48.7% and 39.1% of total fatty acids, respectively.

• Journal of The Korean Association For Science Education
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• v.32 no.9
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• pp.1470-1488
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• 2012

This study examined changes in the quality of written arguments produced by freshman students in general chemistry laboratory classes using the SWH approach over a semester; difference in the quality of written argument between the original writing template (year I) and the extended writing template (year II); and any difference between Total Argument and Holistic Argument scores. 140 writing samples from 14 students on the year I and 228 samples from 19 students on the year II were collected. Results indicated that despite fluctuations, the students were producing stronger argument by the end of semester compared to the beginning of the semester. Original SWH template group received significantly higher argument scores than extended SWH template group. For the most of year I laboratory investigations, there was no significant difference in the quality of argument between Total Argument and Holistic Argument scores. An implication of this study would be to provide opportunities for students to practice constructing arguments using the original SWH writing template including questions, claims, evidence, and reflection.

• Journal of The Korean Association For Science Education
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• v.27 no.6
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• pp.477-487
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• 2007

Previous studies show that students have difficulties in understanding and using molecular visualization tools. This study focuses on the ways in which first year chemistry undergraduates use ball-and-stick molecular models to explain the concept of addition reaction and the difficulties that they face using the models. Video recordings of interviews with undergraduates manipulating ball-and-stick models to solve problems related to reaction mechanisms are analysed to determine if they are able to elucidate their understanding with use of models. The results showed that students have difficulties with viewing the ball-and-stick models from the proper perspective and understanding the relationship between the various structures that they have created using the models. They also find the use of ball-and-stick models tedious and prefer drawing molecular structures on paper to explain their ideas. Implications for the teaching using ball-and-stick molecular models are discussed.

• International Journal of Advanced Culture Technology
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• v.11 no.4
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• pp.263-272
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• 2023

We investigated and analyzed students' perceptions of their choice of science subjects in the high school credit system and the reasons for their choice. To achieve this, the selection of science subjects was investigated for the second year of S high school over the past three years. Students selected an average of 1.54 science subjects, and it was found that the rate of selection of science subjects was gradually increasing by year. Students chose high in the order of life science I, earth science I, chemistry I, physics I, etc. in the science subject group. Students who wish to enter the natural and engineering fields chose life science I, chemistry I, physics I, etc., while, students who wish to enter the humanities society chose society and culture, life science I, ethics and thought, etc. On the other hand, the reason for choosing science subjects was 'related to college admission', followed by 'aptitude and interest', 'career and real life help', etc. physics I, chemistry I, etc., were high in the subjects selected according to the 'related to college admission'. The subjects selected according to 'aptitude and interest' were high in life science I, earth science I, etc. Physics I, chemistry I, etc. are recognized as subjects necessary for college entrance, and life science I, earth science I, etc., are found to be related to their interests and aptitudes.

• Korean Journal of Agricultural Science
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• v.19 no.2
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• pp.187-193
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• 1992

The effects of continuous restoration of sludge into the reclamating paddy soil and leaching test of sludge components by soil column were investigated. 1. The contents of nitrogen, phosphorus, potassium, C.E.C. and organic matter(O.M.) were increased in/on the paddy soil treated with paper mill sludge than non-treated. 2. Humic layer depth recognized by color showed the non-treated(10 cm), second year(15 cm) and third year(20 cm), respectively. 3. The effects of sludge treatment showed in the contents of O.M. such as non-treatment(0.9 %) < second year(1.39 %) < third year(1.75 %) in 10 cm depth. 4. All components in soil tested with column were increased by holding capacity of sludge, and the contamination effects of soil and ground water were not found by leaching test.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1528-1528
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• 2001

Ginseng cultivated in different country or growing condition has generally different components such as saponin and protein, and it relates to efficacy and action. Protein content assumes by nitrogen content in ginseng radix. Nitrogen content could be determined by chemical analysis such as kjeldahl or extraction methods. However, these methods require long analysis time and result environmental pollution and sample damage. In this work we investigated possibility of non-destructive determination of nitrogen content in ginseng radix using near-infrared spectroscopy. Ginseng radix, root of Panax ginseng C. A. Meyer, was studied. Total 120 samples were used in this study and it was consisted of 6 sample sets, 4, 5 and 6-year-old Korea ginseng and 7, 8 and 9-year-old China ginseng, respectively. Each sample set has 20 sample. Nigrogen content was measured by electronic analysis. NIR reflectance spectra were collected over the 1100 to 2500 nm spectral region with a InfraAlyzer 500C (Bran+Luebbe, Germany) equipped with a halogen lapmp and PbS detector and data were collected every 2 nm data point intervals. The calibration models were carried out by multiple linear regression (MLR) and partial least squares (PLS) analysis using IDAS and SESAME software. Result of electronic analysis, Korean ginseng were different mean value in nitrogen content of China ginseng. Ginseng tend to generally decrease the nitrogen content according as cultivation year is over 6 years. The MLR calibration model with 8 wavelengths using IDAS software accurately predicted nitrogen contents with correlation coefficient (R) and standard error of prediction of 0.985 and 0.855%, respectively. In case of SESAME software, the MLR calibration with 9 wavelength was selected the best calibration, R and SEP were 0.972 and 0.596%, respectively. The PLSR calibration model result in 0.969 of R and 0.630 of RMSEP. This study shows the NIR spectroscopy could be applied to determine the nitrogen content in ginseng radix with high accuracy.