Mg₈Ti_2-(10, 20 wt.%)Ni 수소저장합금의 제조 및 수소화 특성 평가

김경일,홍태환,Kim, Kyeong-Il,Hong, Tae-Whan 한국재료학회 2010 한국재료학회지 Vol.20 No.10

The hydrogen energy had recognized clean and high efficiency energy source. The research field of hydrogen energy was production, storage, application and transport. The commercial storage method was using high pressure tanks but it was not safety. However metal hydride was very safety due to high chemical stability. Mg and Mg alloys are attractive as hydrogen storage materials because of their lightweight and high absorption capacity (about 7.6 wt%). Their range of applications could be further extended if their hydrogenation properties and degradation behavior could be improved. The main emphasis of this study was to find an economical manufacturing method for Mg-Ti-Ni-H systems, and to investigate their hydrogenation properties. In order to examine their hydrogenation behavior, a Sievert's type automatic pressure-compositionisotherm (PCI) apparatus was used and experiments were performed at 423, 473, 523, 573, 623 and 673 K. The results of the thermogravimetric analysis (TGA) revealed that the absorbed hydrogen contents were around 2.5wt.% for (Mg8Ti2)-10 wt.%Ni. With an increasing Ni content, the absorbed hydrogen content decreased to 1.7 wt%, whereas the dehydriding starting temperatures were lowered by some 70-100 K. The results of PCI on (Mg8Ti2)-20 wt.%Ni showed that its hydrogen capacity was around 5.5 wt% and its reversible capacity and plateau pressure were also excellent at 623 K and 673 K.

기계적 합금화법으로 제조된 Mg-5wt.% TiCr10NbX (x=1,3,5) 복합재료의 수소화 특성 평가

김경일 ( Kyeong Il Kim ),홍태환 ( Tae Whan Hong ) 대한금속재료학회(구 대한금속학회) 2011 대한금속·재료학회지 Vol.49 No.3

Hydrogen and hydrogen energy have been recognized as clean energy sources and high energy carrier. Mg and Mg alloys are attractive hydrogen storage materials because of their lightweight and low cost materials with high hydrogen capacity (about 7.6wt.%). However, the commercial applications of the Mg hydrides are currently hinder by its high absorption/desorption temperature, and very slow reaction kinetics. However, Ti and Ti based hydrogen storage alloys have been thought to be the third generation of alloys with a high hydrogen capacity, which makes it difficult to handle because of high reactivity. One of the most methods to develope kinetics was addition of transition metal. Therefore, Mg-Ti-Cr-Nb alloy was fabricated to add TiCrNb by hydrogen induced mechanical alloying. TiCrNb systems have included transition metals, low operating temperatures and hydrogen storage materials. As-received specimens were characterized using X-ray Diffraction analysis (XRD), Scanning Electron Microscopy (SEM) and Thermo Gravimetric analysis/Differential Scanning Calorimetry (TG/DSC). Mg-TiCr10Nb systems were evaluated for hydrogen kinetics by Sievert`s type Pressure-Composition-Isotherm (PCI) equipment. The operating temperature range was 473, 523, 573 and 623 K.

단롤주조법에 의한 Ti-Nb-Cr 합금의 제조와 수소화 특성 평가

김경일 ( Kyeong Il Kim ),홍태환 ( Tae Whan Hong ) 대한금속재료학회 ( 구 대한금속학회 ) 2009 대한금속·재료학회지 Vol.47 No.7

Ti and Ti based hydrogen storage alloys have been thought to be the third generation of alloys with a high hydrogen capacity, which makes it difficult to handle because of high reactivity. In order to solve the problem, the activation of a wide range of hysteresis of hydriding/dehydriding and without degradation of hydrogen capacity due to the hydriding/dehydriding cycle have to be improved in order to be aplied. Ti-Cr alloys have a high capacity about 0.8 wt.% in an ambient atmosphere. When the Ti-Cr alloys are added to Nb and Ta elements, they formed a laves phase in the alloy system. The Nb element was expected to make easy diffuse hydrogen in the Ti-Cr storage alloy, which was a catalytic element. In this study, the Ti-Nb-Cr ternary alloy was prepared by melt spinning. As-received specimens were characterized using XRD (X-ray Diffraction), SEM (Scanning Electron Microscopy) with EDX (Energy Dispersive X-ray) and TG/DSC (Thermo Gravimetric Analysis/Differential Scanning Calorimetry). In order to examine hydrogenation behavior, the PCI (Pressure-Composition-Isotherm) was performed at 293, 323, 373 and 423 K.

요시노 사쿠조의 평화론에 대한 고찰

김경일(Kim, Kyeong Il) 동아시아일본학회 2014 일본문화연구 Vol.0 No.52

Yoshino Sakuzo was a famous Japanese democrat and pacifist who developed a peace theory based on democracy. His peace theory was based on relative cognizance. This is because he put national interests ahead of everything. Accordingly, his peace theory developed in various ways. For example, Yoshino designed a unilateral peace plan that connoted coercion for Korea, and he designed a ambilateral peace plan that connoted cooperation and invasion for China. It is certain that Yoshino’s peace theory had a limits. First, he overlooked the important roles of equality and reciprocity in international relations. In addition, he did not expand the consciousness of civil rights to international relations. It is clear that peace is a universal human value, but he applied this universal value arbitrarily. However, it is true that he propounded the need for peace, and suggested the methodology of peace. The focus of this study is the analysis of multiple cognizance in Yoshino’s peace theory. This research was done as part of the larger study of Japanese liberal democratic pacifism, and it is based on the liberalism of international politics and the theory of people’s rights.

石橋湛山의 日中關係 認識과 國益觀

김경일(金慶一)(Kim, Kyeong-Il) 일본어문학회 2011 일본어문학 Vol.55 No.-

本稿では、石橋湛山の日中関係に対する認識と国益観を分析し、その妥當性について評価した。これは、石橋湛山の平和論を構造的に把握することができ、その平和論に対する実証的究明という観点からも大きな意義のあることだと言える。本稿の内容は次のように構成されている。まず、日中関係に対する石橋湛山の認識体系を理解するために政策の不当性と安保的危険性という点から、当時の日本政府の対中国政策を批判したことを考察した。次に、対中国認識の転換と平和協力関係の構築という日中関係の正常化方案を検討してみた。そして日本の国益に関する石橋湛山の主張を、経済合理性と安保合理主義の側面から整理分析した。このような研究をするにあたり、石橋湛山の政策的提言を研究の重要な基礎資料として活用した。本研究が石橋湛山の平和論を理解し、彼が力說した政策的提言の真正な意味を把握することにより、今後東アジアの平和と安定に役に立つことを望みながら、特に彼の平和論の意味を新しい角度から見ることのできる機会になることも期待している。

연구논문 : 입체녹화를 위한 건축물 계획 및 자연에너지를 이용한 건축기법에 관한 연구

김경일 ( Kyeong Il Kim ),함정도 ( Zeong Do Herm ) 한국지역사회발전학회 ( 구- 한국지역사회개발학회 ) 2006 地域社會開發硏究 Vol.31 No.1

설계지향 구조 재해석 모델의 비교 평가

황진하,이재석,김경일,Hwang, Jin Ha,Lee, Jae Seok,Kim, Kyeong Il 한국강구조학회 2000 韓國鋼構造學會 論文集 Vol.12 No.1

본 연구는 반복되는 중간단계의 구조설계과정에 연동되는 근사 재해석 모델을 비교 평가하고, 특히 설계변수가 크게 변화할 때도 일정한 정확도를 유지하여 전체 설계과정에 효율성과 신뢰성을 함께 줄 수 있는 안정된 모델을 찾는다. 이를 위해 대형 프레임구조를 대상으로 설계변수 그룹의 갯수와 변화량을 달리하면서 최대 변위값을 정해와 비교하여 정확도 및 신뢰성을 검토하고, CPU 연산시간 비교를 통해 효율성을 시험한다. 예제를 통하여 부분근사화는 가장 간편하고 빠르기는 하나 설계의 면화가 극히 적은 특정한 경우에만 유용한 반면 전역근사화는 기저벡터를 효과적으로 취할 경우 설계 변화량이 클 때에도 비교적 높은 정확도를 유지하나 효율성이 떨어지는 취약점을 갖고 있다. 이들에 비해 전역-부분근사화는 어느 경우에나 높은 정확성과 효율성을 아울러 갖추고 있음을 보여준다. 이 방법들을 구조 재설계 과정에 연계할 때 설계정보에 따라 혼용하므로써 효율성을 증대시킬 수 있다. Design-oriented approximate structural reanalysis models are compared and assessed, particularly with focus on the case of large changes of design variables. The effectiveness and reliability are demonstrated by means of numerical examples. The results of the study suggest the following conclusions relative to the potential of the procedures. (A) local approximation is only appropriate for the case of small changes in design : (B) global approximation is exact for the case of large changes in a small number of design variables, but inefficient : (C) local-global approximation is most effective and reliable for the case of large changes with a large number of design variables. These methods can improve the total efficiency when they are appropriately used to the design information for the redesign process of large scale structures.

특수교육 저널: 이론과 실천 : 읽기부진학생과 일반학생의 초인지 읽기전략 사용 특성 비교 연구

김영걸 ( Young Gull Kim ),김남진 ( Nam Jin Kim ),김경일 ( Kyeong Il Kim ) 한국특수교육문제연구소 2015 특수교육저널 : 이론과 실천 Vol.16 No.3

글의 내용을 효과적으로 이해하고 의미를 구성하기 위해서는 초인지 읽기전략이 필요하다. 본 연구는 읽기부진학생과 일반학생의 초인지 읽기전략 사용 특성을 알아보고자 하였다. 구체적인 목적은 첫째, 읽기부진학생과 일반학생의 초인지 읽기전략 특성을 비교하고, 둘째, 읽기부진학생의 읽기과정별, 성별 및 학년에 따른 초인지 읽기전략 특성을 알아보며, 셋째, 일반학생의 읽기과정별, 성별 및 학년에 따른 초인지 읽기전략 특성을 알아보고자 하였다. 이를 위해 초등학교 4~6학년의 읽기부진학생(93명)과 일반학생(450명), 총 543명을 대상으로 ‘초인지 읽기전략 체크리스트’ 평가를 실시하였고, 자료의 처리를 위해 t-test와 이원변량분석을 실시하였다. 연구 결과 첫째, 읽기부진학생은 일반학생에 비해 읽기과정, 성별 및 학년에서 초인지 읽기전략의 사용 정도가 유의미하게 낮았다. 둘째, 읽기부진학생은 읽기과정에 따른 성별 및 학년 간에 유의미한 차이가 없었다. 셋째, 일반학생은 읽기과정에 따른 성별 및 학년간에 유의미한 차이가 있었다. 이와 같은 결과를 토대로 읽기부진학생의 읽기이해 지도를 위한 시사점을 제시하였다. The purpose of this study was to identify characteristics of metacognitive reading strategies of underachievers in reading and general students respectively. Concrete purposes of the study were as follows: First, to make a comparison of the features of reading strategies between underachievers in reading and general students. Second, to identify features of reading strategy of underachievers in reading based on gender and grade. Third, to identify features of reading strategy of general students based on gender and grade. For this study, 543 elementary school students from 4th to 6th grade(93 underachievers and 450 general students) were employed and tested by ``Metacognitive Reading Strategy Checklist``. The data analysis method were t-test and two-way ANOVA. Theresults of this study were as follows.First, the extent of using metacognitive reading strategies of underachievers in reading was lower with relevance than those of general students by regarding process, gender, and grade. Second, in comparisons of genders and grades, there was no difference in relevance among underachievers in reading. Third, in comparisons of genders and grades there was difference in relevance among general students. Based on this results, some suggestions were provided for teaching underachievers in reading.

모드시험을 이용한 구조손상추정 방법 분류체계

황진하 ( Jin Ha Hwang ),김경일 ( Kyeong Il Kim ),전소윤 ( So Yoon Joen ) 충북대학교 산업과학기술연구소 2003 산업과학기술연구 논문집 Vol.17 No.2

물질전과정평가(MLCA)를 통한 투명전극 ITO (Indium Tin Oxide)의 환경성 평가

이수선(Soo-Sun Lee),이나리(Na-Ri Lee),김경일(Kyeong-Il Kim),홍태환(Tae-Whan Hong) 한국청정기술학회 2012 청정기술 Vol.18 No.1

본 연구에서는 휴대용 기기의 터치스크린에 사용된 ITO (Indium Tin Oxide) 투명전극의 재활용에 대한 환경성 평가를 실시 하였다. ITO 전극의 경우 도전성과 함께 투명성을 가지는 재료로서 터치 패널이나 LCD (Liquid Crystal Display), ELD (Emitting Light Device), PDP (Plasma Display Panel) 등 각종 디스플레이 장치의 제조를 위한 투명전극으로 수요가 증가하는 추세이다. 특히 인듐과 같은 희소금속을 함유하고 있기 때문에 국가 전략적으로 반드시 재활용되어야 한다. 또한 매립이나 폐기시 발생하는 환경오염 및 인간에게 미치는 영향도 고려해야 한다. 이에 대해 Material Life Cycle Assessment (MLCA)를 이용하여 ITO를 재활용과 매립의 두 가지 처리방법에 따른 환경부하를 정량적으로 분석하고자 한다. 또한 이산화탄소 배출과 투입된 에너지량도 계산하였다. 재활용은 폐 디스플레이에 포함된 ITO의 10, 20, 30%를 회수했을 때를 기준으로 한다. In this study, we executed an environmental impact assessment about recycling of ITO (Indium Tin Oxide), used for touch panel. ITO is mainly used to make transparent conductive coatings for touch and flat screen LCD (Liquid Crystal Display), ELD (Emitting Light Device), PDP (Plasma Display Panel). This demand is increasing little by little. but form current status, ITO is discarded than recycling. It is important to recycling ITO for national strategies about resource conservation, and reduce environmental burden. Also Landfill or incineration of ITO cloud be harmful to the human health in the long-term. Material Life Cycle Assessment method (MLCA) was conducted for comparison landfill and recycling of ITO. MLCA would provide more information for environmental issues and potential environmental impacts of ITO. The study includes two scenarios, the basic scenario is recycling of ITO (10, 20, 30%) and the other scenario is landfill of ITO. In addition, amount of carbon dioxide and energy were calculated.