고분자 전해질막 연료전지의 전기화학적 특성에 관한 연구

최경환,이승재,이태희 ( Kyoung Hwan Choi,Seung Jae Lee,Tae Hee Lee ) 한국화학공학회 1994 추계학술발표논문집 Vol.- No.-

고분자 전해질형 연료전지의 막 내에서 수분이동에 대한 모델링

최경환,이승재,설용건,이태희 ( Kyoung Hwan Choi,Seung Jae Lee,Yong Gun Shul,Tae Hee Lee ) 한국화학공학회 1996 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.34 No.2

When water and reactant gases keep steady-state flow in the membrane and electrode of polymer electrolyte membrane fuel cell, water distribution and membrane resistance in the membrane were calculated from one dimensional diffusion model equations. Water content in the membrane increased from anode to cathode and the difference of the water concentration gradient between anode and cathode increased at higher current density. The thinner membrane and the higher operating temperature, the water concentration increased and the membrane resistance decreased. The performance plot calculated by mathematical modeling approximately agreed with the performance plot measured by experiments in the range of membrane resistance overpotential.

인산형 단위연료전지의 연속운전에 관한 연구

최경환(Kyoung Hwan Choi),서동우(Dong Woo Sur),설용건(Yong Gun Shul),이태희(Tae Hee Lee) 한국화학공학회 1993 춘계학술발표논문집 Vol.- No.-

공업화학 촉매 / 반응공학 : 전착법을 이용한 PEMFC 용 전극제조

최경환(Choi Kyoung Hwan),박영준(Park Young Joon),김한성(Kim Han Sung),이태희(Lee Tae Hee) 한국화학공학회 2000 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.38 No.1

The low Pt loading electrodes for PEMFC were manufactured using electrodeposition and their cell performances were measured. Also an optimal electrode fabrication process was determined by comparing Pt dispersion, loading and electrodeposition efficiency in direct current and pulse electrodeposition. Electrodeposition could reduce Pt particle size about 15 Å, and enhance dispersion and specific surface area of Pt because of impregnating catalyst on the surface of electrode. Pulse electrodeposition was better than direct current one in electrodeposition efficiency and Pt dispersion, and it could increase cell performance due to higher Pt loading at same total passed charge. The electrode, which was made by growing Pt nuclei in direct current electrodeposition after creating Pt nuclei in pulse one at pulse charge of 3 C/㎠, showed the best performance of 300 ㎃/㎠(0.7 V). At 0.7 V the electrode that Pt dispersion was highest and pulse charge was 1.8 C/㎠ had the largest mass activity of 664 W/g Pt.

공적 신앙과 정치적 다원주의 -미로슬라브 볼프의 『광장에 선 기독교』와 『인간의 번영』을 중심으로

최경환(Choi Kyoung Hwan) 삼육대학교 신학연구소 2018 신학과 학문 Vol.23 No.-

이 연구는 다원주의 사회를 살아가는 그리스도인들이 공적 영역에서 어떻게 자신의 종교적 신념과 신학을 유지하면서 다른 가치를 가진 이들과 평화롭게 공존할 수 있는지를 볼프의 시각으로 설명한 것이다. 볼프는 기독교가 문화 전체와 관계를 맺으면서도 다른 종교 공동체와 평화를 유지하고 공동선을 실천하는 방법을 제시한다. 그가 제시하는 공적 신앙은 정의론과 관련하여 현대 사회에 유의미한 메시지를 던져준다. This article explains how Christians in a pluralist society can live peacefully with those of other values while maintaining their religious beliefs and theology in the public space. In his recently book “Public Faith” and “Flourishing,” Miroslav Volf suggests ways for Christianity to establish peace and practice common good with the other religious communities while forming relationships with the entire culture. In this article, I will try to connect Volf’s political theology with the various theory of justice being discussed in the American political philosophy today. I will critically supplement his theory by examining how the public faith he presents can be applied in modern society and whether there is any lack of explanation.

하버마스의 공론장 개념과 공공신학

최경환 ( Kyoung Hwan Choi ) 한국기독교철학회 2014 기독교철학 Vol.19 No.-

오늘날 공공신학에 관한 연구에 있어서 ‘공공성’이라는 말은 다양한 정의와 방법론으로 분화되었기 때문에, 이를 제대로 이해하기 위해서는 사회-정치학에서 다루고 있는 ‘공론장’ 개념과 연결해서 연구할 필요가 있다. 많은 공공신학자들이 하버마스의 ‘공론장’ 개념을 인용하면서 공공신학에 대한 중요한 이론들을 도출하고 있다. 하지만 하버마스의 ‘공론장’은 페미니스트들로부터 부르주아 남성들의 공론장을 이념화했다는 비판을 받고 있다. 프레이져와 영에 따르면, 진정한 공론장은 배제된 자들을 보다 넓은 실천적인 참여의 장으로 포함시켜야만 한다. 공론장과 관련된 다양한 논쟁들을 살펴 보는 것은 오늘날 공공신학의 이슈와 내용을 살펴보는데 큰 도움이 된다. 특별히 공론장에 대한 프레이져와 영의 비판은 공공신학이 보다 적극적으로 타자와 주변화된 이들을 수용하기 위한 대안적인 모델을 제시하도록 도와준다. 오늘날 남아공의 공공신학자들은 지나치게 추상적이고 보편적인 담론으로 공공신학을 이해하려는 서양의 이해에 맞서 보다 구체적이고 설전적인 공공신학을 제시한다. 따라서 본 논문은 배제된 자들을 수용하고 서로 다른 타자와 연대하는 것이야말로 진정한 공공신학의 과제라고 주장할 것이다. Because of many different definitions and methodologies in public theology suggested in history, the concept of ‘public’ in modern public theological study should be investigated to define the concept of ‘public sphere’ by the socio-political thoughts. Many public theologians quote his explanation on ‘public sphere’ of Habermas and it provides major methodological fundaments for public theology. However, current feminist criticize that Habermas’ theoretical framework represents the male bourgeois socieites and idealizes the bourgeois public sphere. According to Fraser and Young, the true public sphere has to include the broad mass of the practical participations within significant exclusions. To survey such a developing debate on the theoretical understanding of the concept of public sphere should help understanding the issues and contents of current public theology. In addition, studying Fraser and Young who established their own critics of the notion of ‘public sphere’ will help build up alternative approaches to public theology teaching which are more inclusive of the other and marginalized. The South African public theologians criticize the universality and abstractness of western public theology and suggest concrete and practical public theology. Therefore, I will suggest that the task of true public theology has to accept the exclusions and attain solidarity with the other in their difference.

활성탄소섬유 사용에 의한 인산형 연료전지 산소전극의 성능 향상

최경환(Kyoung Hwan Choi),유재현(Jae Hyun Liew),설용건(Yong Gun Shul),신창섭(Chang Sup Shin),유승곤(Seung Kon Ryu),이태희(Tae Hee Lee) 한국화학공학회 1997 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.35 No.3

The electrodes for phosphoric acid fuel cell were fabricated from the mixture of activated carbon fiber(ACF) and carbon black as an existing electrode constituent. The performance of the electrode was measured through a half cell at 190℃, 100% phosphoric acid electrolyte. Pt particles loaded on ACF were highly distributed below 30 Å, which increased reaction surface area. When the ratio of ACF to carbon black was 30 %, the electrode performance showed the value of 928 ㎃/㎠ at 700 ㎷ and the Tafel slope of 123 ㎷/decade, which proved the enhanced electrode characteristics in comparison with 145 ㎷/decade of the electrode composed of carbon black only.

조직신학연구 : 본회퍼의 타자 윤리에 대한 비판적 고찰

최경환 ( Kyoung Hwan Choi ) 한국복음주의조직신학회 2015 조직신학연구 Vol.22 No.-

이 논문은 본회퍼의 작품 속에 나타난 ‘타자’ 윤리를 비판적으로 소개하고, “성숙한 세상”에서 어떻게 ‘타자’를 발견할 수 있는지를 탐구한다. 특별히 본회퍼의 신학을 통해 세속화 시대에 ‘타자’에 대한 신학적 책임윤리가 서양철학 속에 나타난 자아중심주의와 주체성에 대한 대안이 될 수 있음을 밝힌다. 이를 위해 본 논문은 다음과 같은 순서로 전개된다. 첫째, 본회퍼의 초기 작품인 『성도의 교제』에 나타난 ‘타자’ 개념을 소개하고, 이것이 어떻게 자아와 ‘타자’의 절대화를 극복할 수 있는지 설명한다. 둘째, 본회퍼의 후기 저술인 『옥중서간(저항과 복종)』에서 ‘타자’ 개념이 어떻게 변화했으며, 세속화 시대에 우리는 어떻게 ‘타자’를 발견할 수 있는지 살펴본다. 마지막으로 본회퍼의 ‘타자’ 개념이 가지고 있는 의미와 한계를 지적하고, 이를 오늘날 탈식민주의 신학자들의 ‘타자’ 개념을 통해 수정 보완하고자 한다. The aim of this study is to provide an overview of Bonhoeffer’s ethics of ‘the other’ in his writings. Especially, I would like to study the way in which we can find ‘the other’ in “the come of age.” It will involve a critical examination of the above concept of selfness and subjectivity in Western philosophy, and I will suggest an alternative idea to theological responsibility for ‘the other’ in the secularized era through Bonhoeffer’s theology. The article is organized as follows. First, I will examine the development of Bonhoeffer’s concept of ‘the other’ in his early books, Sanctorum Communio. Especially, I will describe how Bonhoeffer can overcome absolutization of ‘the other.’ Second, I will investigate how he changed his opinion about the concept of ‘the other’ in his later book, Letter and Papers from Prison, particularly focusing upon where and how we can find ‘the other’ in a secularized era. Third and finally, weshall search for the significance and limits of Bonhoeffer’s ethics of ‘the other,’ andseek to provide indicators as to how we can establish an ethics of ‘the other’ and develop it in the future. I think that Bonhoeffer’s significance notion of “for others” does not seem to consider fully the potential power of others who struggle for their liberation by themselves. With this in mind, we suggest the notion of “of others” as an alternative to Bonhoeffer’s “for others.” In examining the concept of ‘the other’, I have relied heavily on the postcolonial theologian’s conception of ‘the other.’

고분자 전해질형 연료전지에서 Hot Pressing 조건의 영향

이승재,최경환,이태희,조원일,노용우,고영태 ( Seung Jae Lee,Kyoung Hwan Choi,Tae Hee Lee,Won Il Cho,Yong Woo Rho,Young Tai Kho ) 한국화학공학회 1996 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.34 No.1

For a proton exchange membrane fuel cell, membrane and electrode assemblies were fabricated by different hot pressing conditions and those performances were observed in a unit cell having 5 ㎠ active electrode area. The cell performance increased with lower hot pressing temperature in the range of temperature having intimate contact between membrane and electrodes and with higher hot pressing pressure. Namely, the performance of proton exchange membrane fuel cell could be raised with higher water content in the membrane, with lower contact resistance between membrane and electrodes and with lower ion resistance of the electrolyte using thinner membrane.

고분자 전해질형 연료전지에서 Nafion 함침량의 영향

이승재,최경환,이태희,조원일,노용우,고영태 ( Seung Jae Lee,Kyoung Hwan Choi,Tae Hee Lee,Won Il Cho,Yong Woo Rho,Young Tai Kho ) 한국화학공학회 1996 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.34 No.2

Membrane/electrode assemblies of proton exchange membrane fuel cell were prepared by impregnating Nafion solution in the electrodes and their performances were investigated in a single cell. The interfacial resistance of membrane/electrodes and the effective specific surface area of catalyst in the single cell were calculated from the AC impedance data and compared with the cell performance results. Experimental results showed that the electrode of 1.9 ㎎/㎠ Nafion loading gave the highest single cell performance, the largest effective specific surface area of catalyst and the lowest interfacial resistance of membrane/electrode. The increase of operating temperature and pressure also improved the single cell performance due to the increment of activity and concentration of reaction gases.