• Title/Summary/Keyword: 지화학 분석

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Sedimentary type Non-Metallic Mineral Potential Analysis using GIS and Weight of Evidence Model in the Gangreung Area (지리정보시스템(GIS) 및 Weight of Evidence 기법을 이용한 강릉지역의 퇴적기원의 비금속 광상부존가능성 분석)

  • Lee Sa-Ro;Oh Hyun-Joo;Min Kyung-Duck
    • Spatial Information Research
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    • v.14 no.1 s.36
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    • pp.129-150
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    • 2006
  • Mineral potential mapping is an important procedure in mineral resource assessment. The purpose of this study is to analyze mineral potential using weight of evidence model and a Geographic Information System (GIS) environment to identify areas that have not been subjected to the same degree of exploration. For this, a variety of spatial geological data were compiled, evaluated and integrated to produce a map of potential mineral in the Gangreung area, Korea. for this, a spatial database considering mineral deposit, topographic, geologic, geophysical and geochemical data was constructed for the study area using a GIS. The used mineral deposits were non-metallic(Kaolin, Porcelainstone, Silicastone, Mica, Nephrite, Limestone and Pyrophyllite) deposits of sedimentary type. The factors relating to mineral deposits were the geological data such as lithology and fault structure, geochemical data, including the abundance of Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Si, Sr, V, Zn, $Cl^-,\;F^-,\;{PO_4}^{3-},\;{NO_2}^-,\;{NO_3}^-,\;SO_{42-}$, Eh, PH and conductivity and geophysical data, including the Bouguer and magnetic anomalies. These factors were used with weight of evidence model to analyze mineral potential. Probability models using the weight of evidence were applied to extract the relationship between mineral deposits and related factors, and the ratio were calculated. Then the potential indices were calculated by summation of the likelihood ratio and mineral potential maps were constructed from Geographic Information System (GIS). The mineral potential maps were then verified by comparison with the known mineral deposit areas. The result showed the 85.66% in prediction accuracy.

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Science High School Students' Understandings on Chemical Cells : In Relation to Chemical Equilibrium from the Microscopic Viewpoint at Molecular Level (과학고등학교 학생의 화학 전지에 대한 이해 분석: 분자적 수준의 미시적 관점에서 화학 평형과 연계하여)

  • Kim, Hyun-Jung;Hong, Hun-Gi
    • Journal of the Korean Chemical Society
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    • v.56 no.6
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    • pp.731-738
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    • 2012
  • The purpose of this study is to analyze the understandings of science high school students on the conception of chemical cell in relation to chemical equilibrium from the microscopic viewpoint at molecular level through questionnaires and follow-up interviews. The results show that they have high understandings on the chemical equilibrium states in the electrochemical cell and on the redox reaction taking place simultaneously when a metal electrode is immersed in the metal ion solution. However, they do not fully comprehend the development of electrical potential difference, electron movement, electrode potential measurement in the half-cells, and calculation of the net cell voltage between anode and cathode in the chemical cell because of difficulties in the microscopic understanding the interaction on the interface at the electrode and the electrolyte solution.

Hydrogeochemistry and Statistical Analysis for Low and Intermediate Level Radioactive Waste Disposal Site in Gyeongju (경주 중·저준위 방폐장의 수리지화학 및 통계 분석)

  • Soon-Il Ok;Sieun Kim;Seongyeon Jung;Chung-Mo Lee
    • Journal of the Korean earth science society
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    • v.44 no.6
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    • pp.629-642
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    • 2023
  • Currently, low and intermediate level radioactive waste is being disposed of at the Gyeongju disposal site for permanent isolation. Since 2006, the Korea Radioactive Waste Agency has been conducting site characteristics surveys continuously verifying changes in the site based on the site monitoring and investigation plan. The hydrogeochemical environment of the disposal site is considered for the evaluation of natural barriers. However, the seawater must be considered because of the regional characteristics of Gyeongju, which is near the East Sea. Therefore, this study, collected 30 samples for deriving the groundwater quality data from seven wells and compared with two seawater samples collected from October 2017 to June 2022. Additionally, the study explores the groundwater monitoring method using statistical tools such as clustering and background concentration analysis. The groundwater samples in the study area were classified into two to four clusters depending on their chemical constituents-especially, EC, HCO3, Na, and Cl-using statistical analysis, molar ratio, and K-means clustering.

Chemical Accident Response Plan: A Comparative Study between Regions in Korea (화학사고 대응계획: 국내 지역간 비교연구)

  • Min-Je Choi;Gyu-Sun Cho
    • Industry Promotion Research
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    • v.9 no.1
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    • pp.57-64
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    • 2024
  • In 2015, the paradigm of hazardous chemical substance management in Korea shifted from the workplace to the regional level due to the complete revision of the Chemicals Control Act. Although regional chemical accident response plans were established in 2020, there were slight differences in the scope and criteria of each local government. Therefore, this study compared and analyzed chemical accident response plans established in four different regions to provide insights into effective chemical accident response plans. Based on publicly available information, the current status of accident preparedness, chemical accident response systems, and resident evacuation response and education/training were compared and analyzed. The results showed that there were not significant differences in the accident preparedness and response systems between the regions. However, there was a lack of discussion on the preparedness system linked to the characteristics of each workplace in each region. Additionally, there were differences in education and training for residents between regions. In the future, each local government needs to establish a response organization that fits the characteristics of their region and develop strategies for agile and effective accident response through cooperation with relevant agencies.

Geochemistry and Petrogenesis of the Badwater Greenstones from Crystal Falls Terrane in Northeastern Wisconsin, U.S.A. (위스콘신주 북동부 지역에 분포하는 Badwater녹암에 대한 지화학적 연구)

  • Wee, Soo-Meen
    • Economic and Environmental Geology
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    • v.29 no.3
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    • pp.281-291
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    • 1996
  • Samples of Badwater greenstones from the Crystal Falls terrane in northeastern Wisconsin have been analyzed for major, trace and rare earth elements. Geochemical characteristics of the rocks provide clues to the petrologic character and paleotectonic environment of basaltic magma generation. They have chemical composition typical of continental tholeiites. The low Mg values and abundances of Ni and Cr indicate that the lavas were extensively fractionated prior to extrusion. The variations of incompatible elements suggest that the rocks were affected by interaction with crustal rocks. The samples least affected by contamination have trace element compositions similar to those of T-type mid-ocean ridge basalts. The parent was modified by crustal contamination process and this process shifted the rock compositions to that of continental tholeiites as the rock evolved. Interpretations of the chemical characteristics of the rocks, based on modem analogs, favor their emplacement in an extensional tectonic regime.

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Conception Analysis of Students, Pre-service Teachers and Chemistry Teachers on Boiling Point Elevation (끓는점 오름 현상에 대한 학생, 예비교사, 화학교사의 개념 분석)

  • Yoon, Hee-Sook;Jeong, Dae-Hong
    • Journal of The Korean Association For Science Education
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    • v.26 no.7
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    • pp.805-812
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    • 2006
  • In this study the description patterns of chemistry textbooks on the boiling point elevation phenomenon and the understanding patterns of high school students, pre-service teachers and chemistry teachers were investigated. High school chemistry II textbooks developed in the 6th and 7th national curricula were analyzed and the conception patterns of subjects on this phenomenon were categorized using a questionnaire developed for this study. The description patterns of science textbooks were classified into three: 'decreasing of surface solvent molecules', 'attraction force between solvent and solute molecules' and 'decreasing of surface solvent molecules and attraction force between solvent and solute molecules'. In the result of the conception analysis, the ratio of 'attraction force between solvent and solute molecules' was high among students, pre-service teachers, and chemistry teachers. There was a propensity that they would like to explain the boiling point elevation in terms of enthalpy rather than entropy, and in order to analyze this propensity, follow-up interviews were carried out.

Geochemical Approaches for Investigation and Assessment of Heavy Metal Contamination in Abandoned Mine Sites (폐광산지역의 오염특성 조사와 평가를 위한 지구화학적 접근방법)

  • 이평구;조호영;염승준
    • Economic and Environmental Geology
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    • v.37 no.1
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    • pp.35-48
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    • 2004
  • This paper provides a comprehensive overview of geochemical approaches for investigating and assessing heavy metal contamination in abandoned mine sites. Major sources of contaminants at the abandoned mine sites are mine water, waste rocks, tailings, and chemicals used in beneficiation and mineral processing. Soil, sediment, surface and ground water, and ecological system can be contaminated by heavy metals, which are transported due to erosion of mine waste piles, discharge of acid mine drainage and processed water, and dispersion of dust from waste rocks and tailings. The abandoned mine sites should be characterized using various methods including chemical analysis, mineralogical analysis, acid generation prediction tests, leaching/extraction tests, and field tests. Potential and practical environmental impacts from the abandoned mines should be assessed based on the site characterization.

Identification of High School Students' Understanding on the Reaction Rate Change During Chemical Equilibrium Shift (화학 평형 이동시 반응 속도 변화에 대한 고등학생들의 이해 조사)

  • Park, Jong-Yoon;Yu, Hyun-Hee
    • Journal of the Korean Chemical Society
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    • v.51 no.4
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    • pp.365-374
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    • 2007
  • The purpose of this study is to investigate the students' conceptions about the reaction rate changes during the chemical equilibrium shifts and also whether the questions about basic concepts of the reaction rate are helpful for the students' understanding of reaction rate changes during the chemical equilibrium shifts. The subjects were 100 students in the 12th grade. The questionnaires were composed of A, B, and A' set, which had to be answered sequentially. The A set consisted of questions asking the change of reaction rate when chemical equilibrium was shifted, the B set was to testify the basic concepts of the reaction rate, and the A' set was the same as the A set. The results showed that the students' understanding of the reverse reaction rate change was lower than that of the forward reaction rate change during the equilibrium shift. Also it was found that students' understanding of the reaction rate change caused by adding the reactant was fairly good while their understanding of the reaction rate change caused by temperature increment was very poor. Since the students marked very high scores in the B set questions, their poor understanding for the reaction rate changes during the equilibrium shifts was not seemed to be due to the lacks of the basic knowledge of reaction rate. Instead, it was due to the failure of applying the basic knowledge of reaction rate to the changes of reaction conditions. It was also found that the average scores of A' set were statistically higher than those of A set. It means the B set items were helpful for the students to solve the A' set items. These results evidenced the possibility of set questionnaires could help the students to connect the related concepts in solving the problems.

Analysis of Explanations and Examples of the Brønsted-Lowry Model Presented in Chemistry Textbooks Developed by 2009 Revised Curriculum (2009 개정교육과정의 화학교과서에 제시된 Brønsted-Lowry 모델에 관한 설명과 예시의 문제점 분석)

  • Choi, Hee;Park, Chul-Yong;Kim, Sungki;Paik, Seoung-Hey
    • Journal of the Korean Chemical Society
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    • v.62 no.4
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    • pp.279-287
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    • 2018
  • In this study, we analyzed the explanations and examples of Brønsted-Lowry model in Chemistry I and Chemistry II textbooks of the 2009 revised curriculum. In particular, the definition of the Brønsted-Lowry model, the examples, and the content of experiments were analyzed by the process perspective of chemical equilibrium, emergent process. The analyzed textbooks were 4 kinds of Chemistry I textbooks and 4 kinds of Chemistry II textbooks in 2009 revision curriculum. As a result, Chemical I textbooks did not adequately show the chemical equilibrium viewpoint when explaining the Brønsted-Lowry model. In the Chemistry II textbooks, the examples of Brønsted-Lowry model were not present emergent process viewpoint, and those were described as sequential viewpoint of Arrhenius model. In addition, examples of experiments to demonstrate the Brønsted-Lowry model of Chemistry II textbooks were insufficient. The experimental examples related to the definition of acid bases were at the level of classification by the color change of indicators. The experimental examples for explaining the strength of acid and base were to compare current intensity or amount of hydrogen gas generated from the reaction with metal. In addition, all textbooks presented the state of aqueous solution when describing the Brønsted-Lowry model, causing problems with differentiation from the Arrhenius model. Therefore, it is necessary to develop examples of experiments to help students understand Brønsted-Lowry model by presenting acid and base reaction in the non-aqueous solution state.