• 과학교육연구지
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• 제32권1호
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• pp.47-60
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• 2008

기초 과학 진흥과 과학의 대중화를 위한 노력의 일환으로 과학기술부는 2004년을 '과학문화의 해', 2005년을 '물리의 해', 2006년을 '화학의 해', 2007년을 '생물의 해' 그리고 2008년을 '지구의 해'로 정해 다양한 행사를 기획 시행하였고, 하고 있다. 2006년 '화학의 해'에는 화학을 소재로 한 각종 전시 행사 및 대회가 개최되었다. 과학연극 '산소'의 무료 전국순회공연이 있었고, 이동화학관은 2006년도뿐만 아니라 올해도 분주하게 전국투어를 하고 있다. 한국방송공사(KBS)에서는 '화학의 해'를 기념하여 특별기획 프로그램을 여러 차례 방영하였다. 이만큼 '화학의 해'에는 화학이 대중들에게 가까이 다가갔었다. 이 같은 환경 속에서 2006년 화학의 해에 대중매체 중 일간지에서는 화학이 어떻게 그려졌었는지, 그것은 대중들에게 어떻게 보여 졌는지 궁금하였다. 이에 국내 4대 일간지를 선정 '화학의 해'인 2006년에 보도된 화학 관련 기사를 여러 검색어를 이용 검색하여 기사에 나타난 화학의 이미지를 분석하였다. 검색어는 화학 관련 단어를 설문조사하여 빈도수가 가장 많은 5개의 단어 선정하였고, 이를 인터넷 신문사 검색 창에 입력하여 기사를 찾았다. 찾아진 기사는 연구자들이 읽어가면서 화학 관련된 것을 선별하였고, 선별된 기사들을 읽어 기사 속 화학의 이미지를 긍정과 부정 그리고 기사의 속성 등으로 분석하였다. 대중매체에 제시되는 화학의 이미지는 대중들에게 가장 쉽게 전달될 수 있는 경로이므로 대중매체에 나타나는 화학의 이미지는 음양으로 대중들에게 커다란 영향을 줄 수 있을 것이다.

• 한국식품위생안전성학회지
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• 제24권4호
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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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• 제12권1호
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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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• 제40권2호
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• pp.152-156
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• 1997

도라지는 약리성분을 많이 함유하고 있으며 식품 및 생약재료로 널리 사용되고 있다. 재배도라지 24년근 및 3년근의 주요성분을 동정하기 위하여 약리성분을 분석하고 비교하였다. 재배도라지의 에탄올 추출물에서는 24년근에서 역상column을 사용한 HPLC분석에서 retention time이 약 50분 이후부터 3년근에는 보이지 않았던 peak가 나타나고 있어 연수에 따라 다수의 약리성 물질이 생성되거나 미량물질이 생성되었다. 재배도라지의 sterol 조성비 및 saponin 함량에서는 24년근과 3년근간에는 별다른 차이가 없었다. 재배도라지 15년근및23년근, 인삼6년근, 더덕3년근 모두 유의성있는 항보체 활성효과는 없었다.

• Applied Biological Chemistry
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• 제40권2호
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• pp.148-151
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• 1997

도라지는 약리성분을 많이 함유하고 있으며 식품 및 생약재료로 널리 사용되고 있다. 재배도라지 24년근 및 3년근의 주요성분을 동정하기 위하여 약리성분 분석에 우선하여 일반성분을 분석하고 그것을 기초자료로 사용하였다. 재배도라지의 일반성분, 무기물과 지방산의 조성비는 24년근과 3년근 간에서 별 차이가 없었다. 재배도라지의 총 아미노산 함량은 24년근과 3년근에서 각각 375.8 mg%, 891.6 mg%였다. 재배도라지의 아미노산 종류는 24년근과 3년근 양쪽에서 cysteine를 제외한 총 16종의 아미노산을 자동아미노산 분석기로 확인하였다. 재배도라지의 지방산함량이 가장 높은 것은 24년근과 3년근 양쪽 모두에서 linoleic acid였고 그 함량은 24년근 및 3년근에서 48.7%, 39.1%였다.

• 한국과학교육학회지
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• 제32권9호
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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.

• 한국과학교육학회지
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• 제27권6호
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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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• 제11권4호
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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.

• 농업과학연구
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• 제19권2호
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• pp.187-193
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• 1992

신개간 논토양에 제지슬러지를 3년간 시용한 논토양의 개량효과와 토양 column에 처리한 슬러지의 용탈실험을 실시한 결과는 다음과 같다. 1) 제지슬러지 2년과 3년 연속시용으로 무시용 토양에 비하여 토양 심층의 성상에 차이가 나타났으며, 질소, 인산, 칼리, CEC 및 유기물함량이 다소 증가하였다. 2) 슬러지시용에따라 토양의 갈색층이 무처리(10cm), 2년시용(15cm) 그리고 3년시용(20cm)으로 토양의 부식화가 촉진되었다. 3) 슬러지시용 토양의 토심 10-20cm 층위에서 유기물함량은 3년시용(1.75%) 2년시용(1.39%) > 무시용(0.9%)의 순으로 슬러지 시용효과를 보여주었다. 4) 토양 column 용탈실험 결과 슬러지 시용으로 모든 양분의 보유능이 증가하였으며, 토양과 지하수의 오염가능성은 거의 없다고 본다.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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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.