• Title/Summary/Keyword: 화학 영역

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Analysis of Selection Items Test for Selecting Scientifically Gifted Students in Chemistry Class (과학영재 선발을 위한 선발문항 분석: 서울대학교 과학영재센터 중학교 심화과정의 화학영역 중심)

  • Choi, Chui-Im;Jung, Min-Soo;Hong, Hun-Gi;Chae, Hee K;Jeong, Dae-Hong
    • Journal of the Korean Chemical Society
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    • v.52 no.3
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    • pp.295-302
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    • 2008
  • In this study, the test that were used in entrance examination for chemistry class in a Science-Gifted Education Center for middle school students were analyzed by using criteria for identification and measurement of scientific giftedness and a classical test theory. The result of analysis exhibited that most of problems measured more than two elements of scientific giftedness and required applications of scientific knowledge of middle school level to solve problems. In the analysis of sub-elements of scientific giftedness, originality, fluency in creativity and finding problems/formulating hypothesis, planning inquiry, interpreting data in science process skills were dominant while drawing conclusion and generalization processes were lacking. In correlation analysis between total score and each type of problems, total score was most influenced by the problems measuring science inquiry linked with scientific knowledge. Item difficulty is moderately high and item discrimination is moderate.

Evaluation of Stated Models for the Floating and Sinking Phenomena in the Chemical Domain (화학영역에서 뜨고 가라앉는 현상에 대해 진술된 모델의 평가)

  • Kim, Sung-Ki;Park, Chul-Yong;Choi, Hee;Paik, Seoung-Hey
    • Journal of the Korean Chemical Society
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    • v.62 no.3
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    • pp.226-234
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    • 2018
  • In this study, the models described in the textbooks related to floating and sinking phenomena in the chemical domain were evaluated based on the aspect of nature related to the generation of models. To achieve this, we were targeting statement of textbooks from 7th curriculum to 2009 revised curriculum. Analysis of textbooks was performed for science of elementary school (total 2 textbooks) and science of middle school (total 21 textbooks) which dealt with these phenomena. According to the textbooks analysis, characteristics of statement way were (1) No description of the model's prerequisites, (2) Statement based matter viewpoint, (3) Lack of pattern principle, (4) Inadequacy of the case covered. Although the education about the model for the students should be preceded by the education related to the process of model creation rather than the activity using the model, the education about the nature of the model is insufficient. In order to solve this problem, we propose the model statement in textbooks and the development of the model evaluation tool related to model creation.

An Analysis of Analogies in the Chemistry Domain of Middle School Science Textbooks Developed under the 2007 Revised National Curriculum (2007 개정 중학교 과학 교과서의 화학 영역에 사용된 비유의 분석)

  • Noh, Taehee;Ahn, Inyoung;Kang, Sukjin
    • Journal of the Korean Chemical Society
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    • v.57 no.3
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    • pp.398-404
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    • 2013
  • In this study, the analogies in the chemistry domain of middle school science textbooks developed under the 2007 revised National Curriculum were analyzed. A total of 235 analogies were found in 27 middle school science textbooks analysed, which means that one analogy per 10 pages was used on average. The number of analogies found in each textbook considerably varied depending on both publishing company and chemistry domain. Functional analogies, verbal and pictorial analogies, analogies with abstract target and concrete analog, enriched analogies, everyday contexts analogies, student-centered analogies, and analogies with low systematicity were frequently used. On presenting the analogies in the textbooks, the term analogy and description about the limitations of the analogies were rarely mentioned. In comparison with the analogies in the science textbooks developed under the 7th National Curriculum, the frequency of analogies per page was increased. There were positive changes in the aspects of representation, extent of mapping and artificiality. No differences, however, were found in the patterns of the other aspects.

A study on the ECMP process improvement with optimization of $NaNO_3$ Electrolyte ($NaNO_3$ 전해액의 최적화로 인한 ECMP 공정 개선에 관한 연구)

  • Lee, Young-Kyun;Park, Sung-Woo;Han, Sang-Jun;Lee, Sung-Il;Jung, Pan-Geom;Choi, Gwon-Woo;Seo, Yong-Jin;Lee, Woo-Sun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.11a
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    • pp.53-53
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    • 2007
  • 반도체 소자의 고집적화, 미세화 화로 인해 반도체의 동작속도를 증가시키기 위하여 Cu를 이용한 금속배선이 주목받게 되었으나, 높은 압력으로 인한 보은 Cu 영역에서 과잉 디슁 현상과 에로젼을 유도하고 반도체 웨이퍼위의 low-k 물질에 손상을 줌에 따라 메탈라인 브리징과 단락을 초래할 있어, Cu의 단락인 islands를 남김으로서 표면 결항을 제거하지 못한다는 단점을 가지고 있었다. 그래서 이러한 문제점을 해결하기 위하여 기존의 CMP에 전기화학을 결합시킴으로서 낮은 하력에서의 Cu평탄화를 달성할 수 있는 ECMP (electrochemical mechanical polishing)기술이 필요하게 되었다. 따라서 본 논문에서는 전기화학적 기계적 연마(ECMP)작용을 위해, I-V 특성 곡선을 이용하여 패시베이션 막의 active, passive, transient, trans-passive영역의 전기화학적 특성을 비교 분석하였으며, Cu막의 표면 형상을 알아보기 위해 scanning electron microscopy (SEM) 측정과 energy dispersive spectroscopy (EDS)와 X-ray Diffraction (XRD) 분석을 통해 금속 화학적 조성을 조사하였다.

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Risk Assessment Based on Highway Hydrogen Chloride Gas Leakage Scenario Using GIS (GIS를 활용한 고속도로 염화수소 가스 누출 시나리오 기반 리스크 평가)

  • Kim, Kuyoon;Lee, Jaejoon;Yun, Hongsik
    • Korean Journal of Remote Sensing
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    • v.37 no.3
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    • pp.591-601
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    • 2021
  • As the domestic chemical industry continues to develop, handling and transportation of chemicals increases every year. Road freight in Korea accounts for more than 90%, and most of the chemical transportation is done through roads. These chemical vehicles can lead to major accidents if accidents occur. Transportation vehicles are likely to cause water pollution and soil pollution, which are factors of environmental damage, as well as traffic accidents that are the primary damage. In this work, we write a scenario for hydrogen chloride gas leakage by setting Banpo IC and Seocho IC sections as research areas, and use the ALOHA program to measure the predicted distance and analyze the time when hydrogen chloride gas reached according to the distance. In addition, risk assessment using population density was carried out for areas of damage caused by time using GIS. This suggests the need for prevention and countermeasures in areas of damage.

Automated Bacterial Cell Counting Method in a Droplet Using ImageJ (이미지 분석 프로그램을 이용한 액적 내 세포 계수 방법)

  • Jingyeong Kim;Jae Seong Kim;Chang-Soo Lee
    • Korean Chemical Engineering Research
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    • v.61 no.2
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    • pp.247-257
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    • 2023
  • Precise counting of cell number stands in important position within clinical and research laboratories. Conventional methods such as hemocytometer, migration/invasion assay, or automated cell counters have limited in analytical time, cost, and accuracy., which needs an alternative way with time-efficient in-situ approach to broaden the application avenue. Here, we present simple coding-based cell counting method using image analysis tool, freely available image software (ImageJ). Firstly, we encapsulated RFP-expressing bacteria in a droplet using microfluidic device and automatically performed fluorescence image-based analysis for the quantification of cell numbers. Also, time-lapse images were captured for tracking the change of cell numbers in a droplet containing different concentrations of antibiotics. This study confirms that our approach is approximately 15 times faster and provides more accurate number of cells in a droplet than the external analysis program method. We envision that it can be used to the development of high-throughput image-based cell counting analysis.

Visualization of Geometric Features in the Contact Region of Proteins (단백질 접촉 영역의 기하학적 특성 가시화)

  • Kim, Ku-Jin
    • KIPS Transactions on Software and Data Engineering
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    • v.8 no.10
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    • pp.421-426
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    • 2019
  • In this paper, we propose a method to visualize the geometric features of the contact region between proteins in a protein complex. When proteins or ligands are represented as curved surfaces with irregularities, the property that the two surfaces contact each other without intersections is called shape compatibility. Protein-Protein or Protein-Ligand docking researches have shown that shape complementarity, chemical properties, and entropy play an important role in finding contact regions. Usually, after finding a region with high shape complementarity, we can predict the contact region by using residual polarity and hydrophobicity of amino acids belonging to this region. In the research for predicting the contact region, it is necessary to investigate the geometrical features of the contact region in known protein complexes. For this purpose, it is essential to visualize the geometric features of the molecular surface. In this paper, we propose a method to find the contact region, and visualize the geometric features of it as normal vectors and mean curvatures of the protein complex.

Study on the Effects of Corrosion Inhibitor According to the Functional Groups for Cu Chemical Mechanical Polishing in Neutral Environment (중성 영역 구리 화학적 기계적 평탄화 공정에서의 작용기에 따른 부식방지제의 영향성 연구)

  • Lee, Sang Won;Kim, Jae Jeong
    • Korean Chemical Engineering Research
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    • v.53 no.4
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    • pp.517-523
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    • 2015
  • As the aluminum (Al) metallization process was replaced with copper (Cu), the damascene process was introduced, which required the planarization step to eliminate over-deposited Cu with Chemical Mechanical Polishing (CMP) process. In this study, the verification of the corrosion inhibitors, one of the Cu CMP slurry components, was conducted to find out the tendency regarding the carboxyl and amino functional group in neutral environment. Through the results of etch rate, removal rate, and chemical ability of corrosion inhibitors based on 1H-1,2,4-triazole as the base-corrosion inhibitor, while the amine functional group presents high Cu etching ability, carboxyl functional group shows lower Cu etching ability than base-corrosion inhibitor which means that it increases passivation effect by making strong passivation layer. It implies that the corrosion inhibitor with amine functional group was proper to apply for 1st Cu CMP slurry owing to the high etch rate and with carboxyl functional group was favorable for the 2nd Cu CMP slurry due to the high Cu removal rate/dissolution rate ratio.

A Linear Stability Analysis of Unsteady Combustion of Solid Propellants (고체추진제 비-정상연소의 선형 안정성해석)

  • 이창진;김성인;변영환
    • Journal of the Korean Society of Propulsion Engineers
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    • v.2 no.1
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    • pp.59-66
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    • 1998
  • The combustion instability analysis of solid propellants is generally done by the simplified governing equations for chemically inert condensed phase region with QSHOD assumption. Since the gas phase and surface reaction layer can be more rapidly relaxed to the external perturbations than the condensed phase, these regions are treated as quasi-steady manner in the analysis. In this paper, the classical ZN(Zeldovic-Novozhilov)approach was re-examined with the presence of radiation augmented burning enhancement in the combustion. Also, the surface reaction was assumed to partially absorb the incident radiant heat fluxes and pass the remaining to the chemically inert condensed phase. As a result of the analysis, the burning rate response function was obtained which consists of a pressure response function and a radiation response function. The response function was shown to be able to predict the results of T-burner tests.

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An Interdisciplinarity Identification based upon the Mapping Between Authors' Affiliations and Research Areas (연구자 소속과 연구영역 매핑에 의한 학제성 규명에 관한 연구)

  • Chung, Eun-Kyung;Chung, Yeon-Kyoung;Lee, Jeong-Yeon
    • Journal of the Korean Society for information Management
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    • v.26 no.1
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    • pp.147-161
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    • 2009
  • The purpose of this study is to identify interdisciplinarity among eight research areas based upon the correlations between researchers' department affiliations and research areas. More specifically, eight research areas and their sub-areas, 153 sub-areas with researchers' department affiliations were analyzed in terms of Pearson correlation analyses. The findings demonstrated that there was interdisciplinarity between Social Science and Multiple Science Areas, Social Science and Medical & Pharmaceutical Area, Natural Science and Medical & Pharmaceutical Area, and Medical & Pharmaceutical Area and Agricultural Science.