• Title/Summary/Keyword: history of chemistry

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Taxonomic Position and Species Identity of the Cultivated Yeongji 'Ganoderma lucidum' in Korea

  • Kwon, O-Chul;Park, Young-Jin;Kim, Hong-Il;Kong, Won-Sik;Cho, Jae-Han;Lee, Chang-Soo
    • Mycobiology
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    • v.44 no.1
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    • pp.1-6
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    • 2016
  • Ganoderma lucidum has a long history of use as a traditional medicine in Asian countries. However, the taxonomy of Ganoderma species remains controversial, since they were initially classified on the basis of their morphological characteristics. Recently, it was proposed that G. lucidum from China be renamed as G. sichuanense or G. lingzhi. In the present study, phylogenetic analysis using the internal transcribed spacer region rDNA sequences of the Ganoderma species indicated that all strains of the Korean 'G. lucidum' clustered into one group together with G. sichuanense and G. lingzhi from China. However, strains from Europe and North American, which were regarded as true G. lucidum, were positioned in a clearly different group. In addition, the average size of the basidiospores from the Korean cultivated Yeongji strains was similar to that of G. lingzhi. Based on these results, we propose that the Korean cultivated Yeongji strains of 'G. lucidum' should be renamed as G. lingzhi.

The Effect of Science History Program Developed by Genetic Approach on Student's Conception toward Particulate Nature of Matter and Understanding about the Nature of Science (기원론적 접근법에 따라 개발한 과학사 프로그램이 학생들의 입자론적 물질관 및 과학의 본성에 대한 이해에 미치는 영향)

  • Yoo, Mi-Hyun;Yeo, Sang-Ihn;Hong, Hun-Gi
    • Journal of the Korean Chemical Society
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    • v.51 no.2
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    • pp.213-222
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    • 2007
  • In this study, science history program was developed to enhance student's concepts toward the particulate nature of matter and the understanding about the nature of science. And the effects of its application was investigated in the lesson of ‘Composition of Matter' in middle school science class. This science history program was based on genetic approach and included the contents from the old Greek natural philosophers to Avogadro. Before instruction, the test of understanding about nature of science was administered, and the science scores of the previous course were obtained, which were used as covariates. During 24 class hours, this study was conducted with two classes(experimental and comparison group) in a middle school in Seoul. The experimental group was received lessons by science history programs and the comparison group was received traditional lessons. After instruction, the scientific concept test, the test of understanding about nature of science were administered. The result of this study indicates that the scientific concept scores of experimental group were significantly higher than comparison group at p <.01 level of significance. It means that the students in experimental group has more sound conceptions about the particulate nature of matter and less mis conceptions about matter than the students in comparison group. However, there was no significant difference between two groups in the score of understanding about the nature of science.

Contamination Sources of Several Potentially Hazardous Compounds Found at the Gap Stream and the Miho Stream, Two Major Tributaries of the Geum River (금강 수계 주요지류인 갑천과 미호천에서 잠정유해물질 오염원 확인 연구)

  • Lee, Jun-Bae;Lee, Jay-Jung;Cho, Yoon-Hae;Yoon, Jo-Hee;Hong, Seoun-Hwa;Lee, Dae-Hee;Lee, Dae-Hee;Cho, Young-Hwan;Shin, Ho-Sang
    • Korean Journal of Environmental Agriculture
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    • v.35 no.1
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    • pp.15-23
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    • 2016
  • BACKGROUND: Water quality is of concern to water utility operators, public health officials, and populations using the water. If any contaminant is released from a point of entry, it could be spread rapidly throughout the water stream. So the identification of the location of the points of entry and its release history are critical informations to establish the management strategy.METHODS AND RESULTS: Aniline, nonylphenol, pentachlorophenol and formaldehyde in 39 surface water samples were analysed using Gas chromatography-mass spectrometry (GC-MS) methods. Formaldehyde, aniline and nonylphenol were mainly detected in the near sites where industrial waste water and domestic sewage were discharged into stream. But pentachlorophenol was detected in the downstream samples where pulp manufacturing plants were operated.CONCLUSION: Results indicate that pentachlorophenol found in main stream of Guem river was mainly introduced from pulp manufacture industries. Otherwise, formaldehyde, aniline and nonylphenol were mainly contaminated from the industrial waste water and domestic sewage.

About naked fluoride

  • Lee, Eunsung
    • Journal of Radiopharmaceuticals and Molecular Probes
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    • v.4 no.2
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    • pp.121-123
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    • 2018
  • Fluoride is one of most important atoms for both clinical and pharmaceutical usage. Associated with such a strong need, $^{18}F$-fluoride has been widely used as an essential radioisotope. The fluoride always suffers from strong solvation effects through strong hydrogen bonding, which reduce the reactivity of fluoride anion. To enhance the reactivity, the concept of naked fluoride was introduced in the fluorination field. In this essay, I will briefly describe the history of naked fluoride concept and development of naked fluoride sources.

Two Species of Bryoria (Lichenized Ascomycota, Parmeliaceae) from the Sino-Himalayas

  • Wang, Li-Song;Harada, Hiroshi;Koh, Young-Jin;Hur, Jae-Seoun
    • Mycobiology
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    • v.33 no.4
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    • pp.173-177
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    • 2005
  • We performed a taxonomic study on two species of the genus Bryoria from the Sino-Himalayas, SW-China. B, nadvornikiana is new to China and B. furcellata is new to Yunnan and Sichuan provinces in the Sino-Himalayas. Morphology, habitat, distributions and chemistry of the two species are discussed.

Oil and Fats Chemistry and Coatings (유지화학(油脂化學)과 도료(塗料))

  • Chung, Kyung-Taek
    • Journal of the Korean Applied Science and Technology
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    • v.11 no.2
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    • pp.17-38
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    • 1994
  • Oil and fats has been using as the important raw materials in the coating industry from ancient time to date. This article was prepared with the aim of helping to the forward development trend for coating uses of oil and fats, as understand together the history using oil and fats for coatings, composition and classification coatings, types and composition of oil and fats using for coatings nowaday, how to use oil and fats for coating, film for coatings, film forming mechanism.

A Study on the Research History of Stone Pagoda after Japanese Colonial (일제강점기 이후 석탑(石塔) 조사연구사)

  • Ji, Sung-Jin;Seo, Chi-Sang
    • Journal of architectural history
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    • v.20 no.1
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    • pp.61-75
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    • 2011
  • This study aims to investigate the changing aspects about research methodology of stone pagoda from the period of Japanese colonial to now. There were the differences in purpose, method and analysis of the research according to each period. In Japanese colonial period, the purpose of research was to make lists of almost stone pagodas in Korea. Following this, Japanese researchers conducted detailed research for academic purpose. They took measurements of stone pagodas and made drawings. After liberation the research was focused on the relics contained in pagodas. They proceeded to investigate the inner relics in order to attract the attention of the people. In the late 1900's, the repair works of cultural heritages were increased. Many reports of the repair works were released and sent to administration offices. The reports contained the change aspects of situation between before work and after with drawings or simple investigation documents. In the 1990's, the restoration works for important stone pagodas were started by the National Research Institute of Cultural Heritage. Since then, researches from various way - architectural and conservational researches about historical interpretation, shape, structure, proportion, technique, etc. - progressed for careful restoration and accurate study. In Recent years, various professional organizations(in the field of structure, physics, chemistry, biology, lithology, etc.) started to join the researches. Researches conducted studies directly with the stone pagodas, as well as conducting indirect studies with the stone pagodas, such as the structural stability of stone pagodas, the characteristics of rock, and conservation chemicals. Today the research project 'The preservation project of stone cultural property' is being conducted by the National Research Institute of Cultural Heritage. The purpose of this project is to gain more detailed and accurate investigation documents to be provided for the people. In conclusion, researches from various fields must be included in the research. Furthermore, a synthetic study should be done through comparing similar characteristics or different characteristics among many research results.

A Survey of Pesticide Residues of Citrus Fruits and Citrus Orchard Soil in Jeju Island - Part 1. Pesticide Residue of Citrus Fruits - (제주도(濟州道)의 감귤(柑橘)및 감귤원(柑橘園) 토양(土壤)에 관(關)한 잔류농약조사(殘留農藥調査) - 제1보(第一報), 감귤중(柑橘中)의 농약잔류(農藥殘留)에 관(關)하여 -)

  • Lee, Kyu-Seung
    • Applied Biological Chemistry
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    • v.23 no.3
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    • pp.178-183
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    • 1980
  • Citrus fruits harvested in 1979 were collected from markets scattered in Jeju and Seogwipo area on Jeju island and also from citrus orchards with five, ten, fifteen, twenty, and thirty years of cultivation history. Organophorous insecticides and organochloro acaricides in the pulp of fruits were analysed by gas liquid chromatograph. It was found that EPN and Kelthane were most significant residues found in the citrus fruits in terms of both level and frequency of occurrence. Among citrus fruits collected from various markets, EPN was detected in 28% of the fruits samples in the range of 0.009 to 0.025 ppm, while Kelthane, at lower level, was found in all citrus fruits in the range of trace to 0.007 ppm. Residue levels of citrus fruits from orchards of various cultivated periods, in general, confirmed those of the fruits collected from commercial markets. However, residues of Kelthane in the citrus fruits tended to increase with orchards having longer cultivation history.

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Analysis of Contents related to Models in the Chemistry Textbooks of the 2009 & 2015 Revised Curricula: Focusing on the Electrolysis of Aqueous Solutions (2009 및 2015 개정 교육과정의 화학 교과서에서 모델 관련 내용 분석: 수용액 전기 분해를 중심으로)

  • Kim, Kihyang;Chang, Hasok;Paik, Seoung-Hey
    • Journal of the Korean Chemical Society
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    • v.63 no.4
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    • pp.289-306
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    • 2019
  • The purpose of this study is to compare the contents of chemistry textbooks developed according to the 2015 revised curriculum with the contents of the 2009 revised curriculum to research the change in "the development and use of models". To do this, we analyzed 8 kinds of Chemistry I textbooks and 6 kinds of Chemistry II textbooks from the 2015 revised curriculum and compared them with 4 kinds of Chemistry I textbooks and 4 kinds of Chemistry II textbooks from the 2009 revised curriculum. The scope of the analysis was the explanations of the textbooks related to aqueous electrolysis experiments. In order to compare the contents regarding electrolytes when the same experiments are interpreted with different models, we analyzed contents of 4 kinds of middle school science textbooks from the 2015 revised curriculum and 9 kinds of middle school science textbooks from the 2009 revised curriculum. As a result of the analysis, the same experiment was explained by different models according to the grade level and unit, and all explanations were limited to a single model. Also, the tendency to limit the kinds of electrolytes for controlled experimental results is more pronounced in the 2015 revised curriculum than in the 2009 revised curriculum. From this results, we suggest that efforts are needed to reflect the "development and use of models" in chemistry textbooks developed according to the 2015 revised curriculum.

The Problems of Science Textbook Contents Related to Element and Atom in the Viewpoint of Science History (원소와 원자 개념에 대한 과학 교과서 진술의 문제점 분석. 과학 개념의 역사적 변천을 중심으로)

  • Paik, Seoung Hey;Ryu, Oh Hyeon;Kim, Dong Uk;Park, Kuk Tae
    • Journal of the Korean Chemical Society
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    • v.45 no.4
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    • pp.357-369
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    • 2001
  • This study aimed to analyze the evolution of general ideas concerning the element and the atom. In the scientific viewpoint, the modern idea of the element has been variously revised by the ancient Greeks, Boyle-Lavoisier, and Dalton. The definition of the atom was confused with that of the element from the ancient Greecian era to Lavoisier's era. The definition was also changed by Dalton and Rutherford. An analysis of the definitions of element and atom as presented in science textbooks for secondary school students and in general chemistry textbooks revealed that these definitions from diverse eras are confusing and inadequately explicated. The definition presented in one textbook was contradictory to the definitions in other textbooks. This tendency has been sustained in the textbooks from the 4th to 6th science curriculum. Therefore, we need to clarify the definitions of element and atom in order to help the students gain a better understanding of these scientific concepts.

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