• Title/Summary/Keyword: 화학I

Search Result 3,761, Processing Time 0.023 seconds

Analysis of Reading Materials Presented in Chemistry and Science Textbooks and Survey on Utilization Reading Materials (화학 및 과학 교과서에 기술된 읽기자료 분석 및 활용도 조사)

  • Lim, Mi-Kyung;Yoo, Mi-Hyun;Nam, Seok-Hyun
    • Journal of Science Education
    • /
    • v.36 no.1
    • /
    • pp.69-83
    • /
    • 2012
  • The purpose of this study was to analyze the reading materials in 7th curriculum and 2009 revised high school chemistry I textbook for identifying the problems of reading material presented in science textbooks and to investigate science teachers' recognition about utilization reading materials in science textbook. For this purpose, each four 7th curriculum and 2009 revised high school chemistry I textbook were analyzed according to the number of reading materials, the type of contents and the type of students' activities. In addition, the secondary school science teachers' recognition about utilization reading materials in science textbook was investigated. The results were as follows: First, anylizing reading materials in chemistry I textbooks showed that and the rate of reading materials were presented from 7.9 to 17.1% in 7th curriculum and from 20.6 to 28.2% in 2009 revised curriculum textbook. It implies that the rate of reading materials in 2009 revised textbooks increases more than those in 7th curriculum textbook. The result of analyzing the type of contents, 'life sciences' was the largest proportion with 34.3 % in the 7th curriculum chemistry I, but 'enrichment and supplement of knowledge' was the largest proportion with 23.7% in 2009 revised curriculum. Analyzing the type of student activities, only 13% of the reading materials in 7th National Curriculum textbook was found to be inquiry type, but 35% of the reading materials in the 2009 revised curriculum. appears to be inquiry type. It suggested that the curriculum objectives was reflected in the textbook. Second, investigating recognition of teachers' perceptions of utilization science textbooks, 67% teachers responded that they used the reading materials in their science class, but teachers who didn't use the reading materials was almost 33%. A large number of teachers responded that the reading materials associated with the real-life needed for integrated education and thought that the reading materials about 'life and science' should be included in the science textbooks.

  • PDF

Studies of the Concept and Terminology of Heavy Metals Described in the Chemistry I Textbook (화학I 교과서에 나타난 중금속 용어와 개념의 고찰)

  • Moon, Kyung-Ah;Chae, Hee-K.
    • Journal of the Korean Chemical Society
    • /
    • v.51 no.6
    • /
    • pp.560-568
    • /
    • 2007
  • The aim of this study is to investigate the terminology of chemically unclear ‘heavy metals' which were expressed in the Korean secondary science textbook in terms of the definition, the type and the meaning. Initial results showed that six of ‘Chemistry I' textbooks among these texts defined a heavy metal with the density and described it as a metal which is hazardous and continuously accumulated in the human body. Specifically, cadmium, lead and mercury were presented as examples of the hazardous metal in all of the eight textbooks but non-metals such as arsenic and absolutely essential metals including chrome, manganese, iron, cobalt, nickel and copper were also given in the texts. Most of the texts described the hazardousness and toxicity of the metal too simple to understand the mechanism of its intoxication despite considering all of the factors including its oxidation state, residual amount and reactivity with biomolecules of the human body. Such an ambiguous definition and explanation may excluded in the textbook because the chemically undefined chemical vocabulary leads students to cause an alternative conception of the heavy metal, which means that the metal could be identical with toxins.

Study on the Safe use of the Chemical Extinguishing Agent (화학물질 소화약제 안전한 사용에 관한 연구)

  • Cho, Jung-Rae
    • Fire Science and Engineering
    • /
    • v.32 no.2
    • /
    • pp.118-129
    • /
    • 2018
  • This study analyzed the recent serious disaster cases of chemical extinguishing agent poisoning and suffocation investigated by KOSHA and proposed the safe use of chemical substances, including the chemical extinguishing agent. An analysis of the statistical figures an increase in the number and variations of chemical poisoning and suffocation cases in industry between 2011~2016 increased. Unlike other physical accidents, chemical accidents are very high in severity and it is difficult to identify the chemical hazard and risk. To prevent chemical disasters, it is essential to develop and use an easy chemical risk assessment tool. For the safe use of chemical substances, in which it is difficult to carry out hazard identification and risk assessments, this thesis presents the useful chemical recognition and risk assessment tools, CHEM-i and CHARM developed by KOSHA.

Adjuvant Chemotherapy after Surgical Resection for Small-Cell Carcinoma of Lung (소세포폐암에서 수술 후 복합화학요법의 성적)

  • Kim, Hak-Ryul;Jung, Jong-Hoon;Kim, Hwi-Jung;Yang, Sei-Hoon;Jeong, Eun-Taik
    • Tuberculosis and Respiratory Diseases
    • /
    • v.57 no.5
    • /
    • pp.443-448
    • /
    • 2004
  • Background : Small-cell carcinomas of lung have a tendency for rapid growth and early wide metastasis. Despite the high response rates of combination chemotherapy alone or with radiotherapy, the overall long-term survival rate is very disappointing. According to autopsy findings, the common cause of failure is local recurrence in the primary cancer site. Therefore, surgical resection with combined chemotherapy has recently been attempted for very early stage small-cell carcinomas of the lung. Methods : 10 patients (TNM I & II: 5 cases each) undergoing surgical resection for small-cell carcinomas of the lung were treated with adjuvant chemotherapy in an attempt to prolong survival. Of these, 9 patients received chemotherapy, and a retrospective study for survival undertaken (Kaplan-Meier analysis). Results : The median survival time was 26 months, and the 2- and 5-year survival rates were 68.6 and 46.7%, respectively. If the 1 patient not having undergone chemotherapy was excluded, the 2-, 5-year survival rates were 76.2 and 50.8%, respectively? No difference in the survival rate was seen between patients with TNM stages I and II. Conclusion : Adjuvant chemotherapy after surgical resection results in prolonged survival for patients with TNM stages I and II small-cell carcinomas of the lung.

Palladium(II) Complexes of Aminophosphines (I). Characterization and Synthesis of $[Pd(L)X_2] with X = Cl^-, Br^-, I^-, NCS^-$ (아미노포스핀류를 포함하는 팔라듐 (II) 착물 (제1보). $[Pd(L)X_2] (X = Cl^-, Br^-, I^-, NCS^-)$의 합성과 성질)

  • Myung-Ki Doh;Bong-Gon Kim
    • Journal of the Korean Chemical Society
    • /
    • v.27 no.4
    • /
    • pp.255-261
    • /
    • 1983
  • Several new $[Pd(L)X_2]$ complexes have been prepared with aminophosphines (L) such as trans-1,2-bis[diphenylphosphino)amino]cyclohexane and 1,2-bis[(diphenylphosphino) amino] propane that contain phosphorus atom as ${\pi}$-electron acceptor, and the bond character of complexes have been investigated by means of infrared and electronic spectroscopy. It was found that thiocyanate ions are N-coordinated possibly due to the steric and electronic influence of the phosphorus atom in aminophosphines that formed seven-membered chelate rings, and that spectrochemical series that is derived from the electronic spectra of the complexes is $NCS^- > Cl^- > Br^- > I^-$

  • PDF

Theoritical Studies on Structure of 4H-Pyran-4-one and Its Sulfur Analogues (4H-Pyran-4-one과 그의 황 유도체의 구조에 관한 이론적 연구)

  • Ikchoon Lee;Hyeong Yeoun Park;Young Ki Kim
    • Journal of the Korean Chemical Society
    • /
    • v.30 no.6
    • /
    • pp.495-499
    • /
    • 1986
  • Structures of 4H-pyran-4-one(I), 4H-pyran-4-thione(II), 4H-thiapyran-4-one (III), 4H-thiapyran-4-thione(IV) have been determined by MNDO and MINDO/3 methods. Geometries and physicochemical properties, especially the aromaticity, were found to agree well with the results of microwave experiments. The order of aromaticity was found to be (IV) > (III) > (II) > (I), which demonstrated inhibitory effect of strongly electronegative oxygen atom on the electron delocaligation, and the order of dipole moment, (II) > (IV) > (I) > (III), indicated the dominant contribution of the bond length of carbonyl group (C=O or C=S)

  • PDF