• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.11a
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• pp.203-203
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• 2015

반도체 제조 공정 중에 CMP(Chemical Mechanical Planarization)는 디바이스의 집적도(degree of integration)에 크게 영향을 미치고 있으므로, 20nm급 이하의 디바이스에서 CMP 공정 안정화는 양질의 소자 특성을 확보하기 위해서는 시급한 문제가 되고 있다. CMP 공정 안정화를 위해서는 여러 가지 해결되어야 할 문제가 있는데, 그 중에서도 W plug 연마 공정 중에 관찰되고 있는 W missing은 전기 배선의 신뢰성에 직접 영향을 주고 있으므로 공정 엔지니어에게는 도전적인 과제이다. 본 연구에서는 W missing 현상을 전기화학적인 입장에서 해석하고 몇 가지 해결책을 제기하고자 한다.

• The Science & Technology
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• no.1 s.404
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• pp.88-90
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• 2003

이리 호에 대해 과학자들은 1960년대만 해도 확신에 차 있었다. 이리 호 오염의 원인이 단순했기 때문이다. 그러나 지금은 세 배, 혹은 그 이상으로 복잡하고 다층적이다. 외래 침입종에다 지구 온난화 문제, 거기에 인을 비롯한 독성 화학물질까지 가세해 이리 호 문제 해결을 더욱 어렵게 만들고 있다. 과학자들은 과연 죽어 가는 이리 호를 되살릴 수 있을까?

• KOREAN POULTRY JOURNAL
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• v.19 no.9 s.215
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• pp.39-41
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• 1987

화학비료에 의존한 경작으로 점차 토양은 산성화되고 지력의 저하가 경종농업분야에서 큰문제로 대두되고 있으며 한편에서는 계분의 처리문제로 양계농가의 어려움을 더해가고 있다. 계분을 효율적으로 발효처리한다면 양계농가의 골치거리를 해결할 뿐만 아니라 돈(금)으로 바꿔 경영에 보탬이 되고 국토의 지력상승면에서도 큰 기여를 할 수 있을 것이다. 계분발효의 원리와 방법을 제시한다.

• Information Display
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• v.20 no.1
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• pp.5-14
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• 2019

양자점 발광소자 기술은 지난 20여년 동안 급격한 발전이 이루어졌으며, 이는 양자점 발광체 및 소자기술 전반에 대한 집중적인 연구의 결과로 생각할 수 있다. 그러나 양자점 발광소자기술의 상용화를 위해서 해결해야 할 문제는 소재(예: 무중금속 양자점 구현, 대량생산 등) 및 소자(예: 수명문제, 대면적 프린팅문제, 효율저하문제)에 걸쳐 산적해 있다. 본 기고문에서는 이상의 다양한 문제 중 양자점 발광소자의 효율저하문제를 집중적으로 다루었다. 비록 양자점 나노구조체의 제어 및 발광소자 연구가 여전히 카드뮴 기반 양자점을 바탕으로 한 기초연구영역에 머물러 있지만, 향후 친환경 양자점 합성기술이 본격적으로 발전하게 된다면 우수한 효율과 안정성을 보이는 양자점 발광소자가 구현되리라 기대된다.

• The Journal of the Convergence on Culture Technology
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• v.7 no.4
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• pp.527-535
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• 2021

The STEAM education was applied to science high school students, and changes in perceptions of students and teachers were investigated after class treatment. By the results of the student's perception survey, very positive results were found in increasing problem-solving capabilities, educational satisfaction, etc. More than 98% of students said they would continue to participate in STEAM education classes. Meanwhile, the lack of time for class activities put a burden on students to complete the problems during class. Especially nanoscience content and activities were properly organized in consideration of the level of cognitive development of the students. In addition, as a result of a survey of teachers' perceptions for students, more than 80.0% of teachers responded very positively in 'self-directed learning ability' and 'problem-solving capability', etc.

• Journal of the Korean Chemical Society
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• v.66 no.4
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• pp.305-322
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• 2022

In this study, a practice-based teacher education program was developed and applied to improve the TPACK of pre-service chemistry teachers. Also the program effect and obstacles were confirmed by measuring the development of TPACK. The participants of this study were 20 pre-service chemistry teachers of 3rd grade and 2 pre-service chemistry teachers of 4th grade who took chemistry education courses at K University located in Chungcheongbuk Province. The developed teacher education program consisted of four stages: preparation, rehearsal, practice, and reflection. The feedbacks from researchers and colleagues pre-service teachers were provided in preparation, rehearsal, and reflection stages. As a result of the study, the program of this study did not show an educational effect in the "constructive learning activities" of preservice teachers, but it was found to have an educational effect in "problem solving". In other words, in "constructive learning activity", most pre-service teachers were at 0 level before and after the program. The pre-service teachers designed the class to unilaterally provide technology to simply use it as a tool to explain subject content or revise misconceptions, and learners can passively acquire knowledge. However, in the case of "problem solving", the pre-service teachers who were at level 0 before the educational program changed to level 1. Before the program, the pre-service teachers designed classes to solve problems by memory without using technology, but after the program they planned classes that provides opportunities to approach and solve various problems through the technology presented by the teacher. However, there were not many pre-service teachers corresponding to level 2, which constitutes voluntary learning in which learners use technology to solve various problems while selecting and variously manipulating technology. In addition, as obstacles to the TPACK development of pre-service chemistry teachers, there were external factors such as lack of classroom support environment for TPACK implementation, lack of time for education planning, and inadequate technology competency. And there were internal factors such as perspectives of traditional education and negative attitude toward technology. In particular, the proportion of pre-service teachers who preceived inappropriate technical competency as an external obstacles of TPACK development was high. Therefore, it was necessary to develop an education program corresponding to type 2 or type 3 that enables TPACK development through TK for pre-service teachers.

• Journal of the Korean Chemical Society
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• v.65 no.3
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• pp.209-218
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• 2021

This study investigated the condition of chemistry teacher's student competency assessment based on the inquiry report. To this end, an inquiry report was collected for chemistry teachers who took the training at two universities that conducted the 2020 first-class chemistry teacher training. The science subject competencies presented in NAEA analysis framework was used to analyze what kind of competencies teachers assess students through inquiry reports. A total of 63 chemistry teachers submitted inquiry reports, which were analyzed by competency, sub-element of each competency, and detail element to analyze the actual situation. As a result of the study, most chemistry teachers reflected their 'scientific inquiry and problem-solving ability' in their evaluation through inquiry reports. 'Ability to understand and apply scientific principles', which is mainly evaluated through paper-based evaluation, was partially used as confirmation of prerequisite learning at the beginning of the inquiry and the weight of evaluating 'scientific communication skill' was not large. In 'scientific inquiry and problem-solving ability' through inquiry report, 'design and conduct explorations', 'data analysis and interpretation' and 'drawing conclusion and suggesting solution' were mainly assessed. However, 'discover and recognize problems' and 'development and use of model' were hardly assessed.

• Journal of the Korean Chemical Society
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• v.64 no.1
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• pp.30-37
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• 2020

The purpose of this study was to identify the problems faced by students in sub-microscopic representation of acid-base reactions. Herein, we selected 30 students of 12^th grade science classes, who had studied various acid-base models. In order to investigate the sub-microscopic representation ability of the students, we developed nine items related to various contexts, such as one type of solute and solvent, two types of solutes and solvent, cases with water as solvent or with nonaqueous solvents. For all items, we consistently observed lack of concept of chemical change. In context of aqueous and nonaqueous solutions, the frequency of lack of concept of chemical bonding was high if ammonia was the solute or solvent. Moreover, the frequency of lack of concept related to the degree of electrolytic dissociation was high. Therefore, chemistry teachers should understand that students' ability to sub-microscopic representation of acid-base reactions can be enhanced by analyzing the difficulties faced by the students in solving diverse acid-base problems.

• Applied Chemistry for Engineering
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• v.33 no.4
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• pp.343-351
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• 2022

Lithium-ion batteries (LIBs) are considered promising energy storage devices with good performance such as high energy density, slow self-discharge rate, high rate charge capacity, and long battery life. However, the application of these LIBs in the high-energy density electric vehicle and large device industries poses a major safety problem. In order to solve this problem, developing a material having high thermal stability and intrinsic safety is the ultimate solution for improving the stability and electrochemical performance of LIBs. This review introduced a surface modification technology of a separator to overcome the stability problem of a commercial separator, and summarized and summarized the research trends using the modified separator for a lithium-ion battery. Based on this, the future prospects for the separator development by surface modification were discussed.

• Journal of the Korean Chemical Society
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• v.59 no.5
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• pp.434-444
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• 2015

Inquiry-based experiments provide opportunities to understand scientific knowledge and acquire nature of science. In this study, the difficulties which pre-service teachers experienced in inquiry-based experiment class were investigated and analyzed. Twenty-two pre-service teachers attended course designed as ‘ill-structured inquiry’ for 13 weeks, and researchers investigated their difficulties by questionnaires and interview. They showed difficulties mostly in designing experiment and interpretation and also in understanding inquiry purpose, lack of prior knowledge, confidence in inquiry performance, and understanding of experimental instruments and facilities. As a result, it is necessary to provide opportunities to engage in inquiries and environments to properly instruct pre-service teachers the inquiry ability in college of education.