급냉응고/분말야금법으로 제조된 Al-Fe-V-Si 합금의 기계적 성질 (2) : 파괴기구에 관한 연구 Micromechanism of Fracture

이종철,이두영,이성학,김낙준 대한금속재료학회(대한금속학회) 1990 대한금속·재료학회지 Vol.28 No.4

This study is concerned with a correlation between the microstructure and the micromechanism of fracture processes in an RSP/PM Al-8.5Fe-1.3V-1.7Si alloy. The specimens were exposed to the temperatures ranging from 150℃ to 480℃ for 100 hours, followed by room temperature tensile tests, fracture toughness tests and void initiation tests. This RSP/PM Al alloy did not show any significant change in room temperature tensile strength, tensile elongation and fracture toughness even after exposure up to 425℃ for 100 hours. However, tensile elongation and fracture toughness decreased significantly after exposed to 480℃ for 100 hours. Detailed microstructructural analyses showed that the alloy ahs a band structure due to non-uniform distribution of the silicide dispersoids. After exposure to 480℃, the formation of θ-Al₃Fe phases occurs at band structure boundaries by the dissolution of coarse silicide dispersoids, resulting in a loss of ductility and fracture toughness. The micromechanical processes involved in void and microcrack formation were identified and quantified. The results are interpreted using a simplified ductile fracture initiation model based on the basic assumption that crack extention starts to occur at a certain critical strain over a microsturcturally significant critical distance. This model enables us to correlate fracture toughness and microstructure, confirming that the formation of θ-Al₃Fe phases is the main metallurgical factor which contributes to the embrittlement phenomenon after exposure to 480℃ for 100 hours.

Changes of Electrical Conductivity and Temperature Caused by Electrode Erosion for Atmospheric Plasma Systems

이종철,김윤제,부진효 한국물리학회 2007 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.51 No.3

Electrode erosion is indispensable for atmospheric plasma systems, as well as for switching devices, due to the high heat flux transferred from arc plasmas to contacts, but experimental and theoretical works have not identified the characteristic phenomena because of the complex physical processes. In this study, we analyzed the electrical conductivity and the temperature of arc plasmas using the field-coupled computational techniques to consider the electrode erosion in a thermal puffer plasma chamber. Based on the results from the arcing history with metallic vapors, the thermal and electromagnetic characteristics near current zero were investigated using the electrical conductivity and the temperature of the arcing zone. Numerical results showed that the existence of electrode vapors made the arc temperature down during the high-current period and a negative effect with high electrical conductivity on the current interruption.

NK2-specific domain is responsible for cell death upon ectopic expression of VND in various Drosophila tissues

이종철,유시욱,김건희,이윤정 한국유전학회 2014 Genes & Genomics Vol.36 No.1

Drosophila ventral nervous system defective(VND) is a transcription factor containing tinman domain,homeodomain, and NK2-specific domain. The VND playsan essential role during the development of embryonicnervous system, however, little is known about its rolesbeyond embryonic stage. In this study, the expressionpatterns and levels of the VND during larval and adultstages were examined by using GAL4/UAS binaryexpression system and real-time PCR. The VND proteinwas expressed in larval brain, eye, and wing imaginal discs,implying possible roles of this protein in the larval tissuesother than embryonic nervous system. Gain-of-functionphenotypes of vnd were analyzed by crossing variousGAL4 drivers with UAS-vnd transgenic line. Interestingly,we observed the massive cell death in the tissues includingeye and wing discs where GAL4 is expressed. To downregulateendogenous vnd transcripts in the eye disc, UASvnd-IR (inverted repeat) was crossed with ey3.5-GAL4 line. Loss-of-function phenotypes of vnd also revealed the blackommatidial spots indicating apoptotic cell death in thetransgenic eye tissues. To identify a domain within theVND involved in apoptosis, VND mutant proteins wereectopically expressed in the eye disc. In contrast to VNDDtinmanand VND-Y54M mutant proteins, overexpressionof VND-DNK2 did not lead to cell death, indicating thatNK2-specific domain is responsible for apoptosis. Takentogether, our results suggest that VND might be involved inthe development of the various tissues after embryonicstages and in apoptosis via NK2-specific domain.

국내.외 토너 카트리지 재제조 산업의 현황 및 전망

이종철 대한산업공학회 2009 대한산업공학회 춘계학술대회논문집 Vol.2009 No.5

헬싱키 프로세스의 북한 인권 적용 가능성과 함의 -소련 및 동구 변화의 동학으로부터-

이종철 대한정치학회 2010 大韓政治學會報 Vol.17 No.3

심각한 북한의 인권 상황에 접하여 “헬싱키 프로세스”를 북한 인권에 적용하고자 하는 관심이 높다. 헬싱키 프로세스는 소련 및 동구의 인권 운동에 주요한 영향을 미쳤으며 궁극적으로 소련 및 동구의 체제 변화를 유인하는 외부 압력 기제로 작동하였다. 헬싱키 프로세스가 북한 인권에 주는 함의는 북한 인권 개선을 위한 꾸준한 문제제기와 국제적 공동노력의 강화 필요성이다. 구체적으로 헬싱키 체제의 북한 인권에의 적용 가능성과 효과적 방도는 다각도로 검토될 수 있다. “나선형 5단계론”에서 보듯이 북한 인권을 위한 외부의 노력은 장기적으로 북한 내 인권 운동을 촉발시키고 북한을 변화로 이끄는 데 중대한 기여를 할 것이다.

RFID 서비스 인프라 환경에 따른 상거래 비즈니스 모델 제안

이종철,이경전 한국경영과학회 2007 한국경영과학회 학술대회논문집 Vol.2007 No.11

본 연구에서는 상거래 분야에서의 RFID를 이용한 비즈니스 모델과 함께 사업 참여자의 서비스 도입 가치를 탐색하였다. 제안하는 세 가지 비즈니스 모델은 RFID 서비스 인프라 환경을 고려하여 설계하였으며, 상거래 사업자에게는 기존에 수행하던 상거래 서비스의 효율화와 상거래 기능이 없었던 공간에서의 상거래 기능 부여, 모든 생활 공간의 상거래 가능 공간으로의 변화라는 가치를 제공한다.

Toxicity of Eun-bi San Pharmacopuncture Injection in the Muscle of Rats

이종철,정호현,차은혜,박만용,최성열,육태한,송인자,김성철 대한약침학회 2015 Journal of pharmacopuncture Vol.18 No.1

Objectives: This study was carried out to analyze the single-dose toxicity of Eun-Bi San pharmacopuncture injected into the muscle of Sprague-Dawley (SD) rats. Methods: All experiments were performed at Biotoxtech, an institution certified to conduct non-clinical studies under the Good Laboratory Practice (GLP) regulations. Six week old SD rats reared by ORIENTBIO were chosen for this pilot study. The reason SD rats were chosen is that they have been widely used in safety tests in the field of medicine, so the results can be easily compared with many other databases. The Eun-Bi San pharmacopuncture was made in a clean room at the Korean Pharmacopuncture Institute (KPI, K-GMP). The constituents of the Eun-Bi San pharmacopuncture are Angelicae gigantis radix, Strychni semen and Glycyrrhizae radix. These were extracted at low temperature and low pressure in an aseptic room at the KPI. Doses of Eun-Bi San pharmacopuncture, 0.25, 0.5 and 1.0 mL, were administered to the experimental groups, and a dose of normal saline solution, 1.0 mL, was administered to the control group. This study was performed under the apapproval of the Institutional Animal Ethics Committee of Biotoxtech Co., Ltd. Results: No deaths or abnormalities occurred in any of the four groups. No significant changes in weight, hematological parameters or clinical chemistry between the control group and the experimental groups were observed. To determine if abnormalities existed in any organs and tissues, we used microscopy to examine representative histological sections of each specified organ; the results showed no significant differences in any of the organs or tissues. Conclusion: The results of this study suggest that treatment with Eun-Bi San pharmacopuncture is relatively safe and that its clinical use may be beneficial. Further evaluations and studies on this subject will be needed to provide more concrete evidence in support of these conclusions.

고무압착식 하수관거 분기관의 특성

이종철,구도훈,이병헌 대한환경공학회 2008 대한환경공학회 학술발표논문집 Vol.2008 No.12

일측성 메니에르병에서의 전정 유발 근전위의 진단적 가치

이종철,윤태현,정종우,안중호,김종양,김윤경 대한이비인후과학회 2007 대한이비인후과학회지 두경부외과학 Vol.50 No.6

Background and Objectives:Because the saccule, next to the cochlea, is the second most frequent site of hydrops formation, (VEMP) responses can reflect the diagnosis and the stage of Meni-eres disease. Subjects and Method:Retrospectively, we analyzed the results of VEMP in 40 patients (11 men and 29 women) with unilateral definite Menieres disease. Al subjects underwent VEMP testing using ipsilateral 500 Hz-tone burst sound with 90 dBnHL (rise/fal time= 2 msec, plateau time= 3 msec). Results: (37/40). The latency of p13 of afected ears in patients with Menieres disease was significantly prolonged than that of normal ears in the control group (p= 0.05). However, no relationship was found in latencies of p13, n23, and interpeak latency among groups classified by the stage of Menieres disease. In the patients with Menieres disease, the mean interaural amplitude diference (IAD) ratio was 23.9± significant (p=0.13 ). Conclusion:Prolonged p13 latency of VEMP was a pathognomic finding for Menieres disease in this study.(Korean J Otolaryngol 2007 ;50 :486-90)

주류경제학에서 윤리성 논제 실종 문제의 근원

이종철 기독교학문연구회 2013 신앙과 학문 Vol.18 No.2

In the wake of recent financial crisis, it's recognized again that there exists an incongruence between the theories of mainstream economics and the real world. This disparity is mainly due to the fact that the main stream economics fundamentally tends not to focus on describing and explaining actual economies, but instead on describing an ideal type world. This ideal type world is composed of ‘Economic Man’, ‘Perfect Rationality’, ‘Perfectly Competitive Market.’ In this world, a unique norm is derived and exits, that is, economic efficiency (in Pareto sense, allocative efficiency or Pareto optimality). The ideal type world, if it is not formed based on the actual world, epistemically turns into ideal world which itself manifests a unique norm. So, it is not ironical that the pursuit of ideal world leads to a disconnection from the real world, and result in missing ethical issues as well in mainstream economics. As a matter of fact, missing ethical issues reflects the nature of mainstream economics that is far from the real world which sometimes becomes the world of the madding crowd partly and indirectly supported by the economists. The purpose of the study is to figure out the root cause of the phenomena of dominating efficiency issues and missing ethical issues in the field of mainstream economics. Idealogically, the main economics has rooted in utilitarianism which took over the ideology from ontological naturalism. In fact, ideal type of ‘Economic Man’ came from utilitarianism and the core theoretical model of economics, the utility maximization model, is associated with the Principle of Utility, the core of thoughts of utilitarianism. In this paper, I demonstrated that economics associated utilitarianism did necessarily reduce ethical behavior to economic rationality, and adopt efficiency as the ultimate value and social norm. This necessity follows from the nature of the ‘Economic Man’ and the framework of the ideal type world. And the fundamental source for this necessity is the oneness proposition in utilitarianism:“pleasure is in itself a good… the only good”, which is written by Jeremy Bentham. 근년에 세계경제를 위기 상황까지 가게 한 미국발 금융위기를 계기로 경제학의 현실성 문제와 윤리성 논제 실종 문제가 다시금 제기되었다. 주류경제학에서는 합리성과 효율성만을 경제 분석의 근간으로 하는데, 문제의 근원은 주류경제학의 패러다임을 대변하는 ‘경제인’의 인간상에서부터 찾아나갈 수 있다. 경제 분석은 경제주체로서의 ‘경제인’을 전제로 하는데, 윤리성 논제 부재의 경제학은 근원적으로 ‘경제인’의 무윤리성에서 비롯된 것이다. ‘경제인’은 공리주의적 인간상의 전형이다. 주류경제학과 공리주의의 불가분리적 관계는 ‘경제인’의 인간상에 명료하게 드러나 있다. 본 논문에서는 공리주의와 결합된 경제학에서는 필연적으로 윤리성이 합리성으로 환원되고, 효율성으로 치환됨을 논증하였고, 효율성을 최고의 가치 규범으로 삼게 됨을 보였다. 이와 같이 된 근원은 존재론적 자연주의에 뿌리를 둔 공리주의적 인간관과 이에 근거한 ‘선(good)’ 개념의 정립에 있다. ‘오직 쾌락(행복)만이 선이고, 선이란다른 무엇이 아니라 바로 쾌락(행복)이다‘라고 하는 공리주의의 동일성 명제는 존재론적 자연주의에 뿌리를 둔, 공리주의 윤리사상의 근간인 것이다. 이것이 행위 규범이 없는 ’경제인 ‘의 근원이다. ’공리의 원리‘로 대표되는 공리주의 윤리사상은 결과주의를 행위 판단의 기준으로 삼는다. 행위의 동기나 의도는 윤리 판단의 대상이 아닌 것이다. 공리주의 인간관에 의하면 사람들은 본성대로 각자 자기 쾌락(행복)의 증진을 추구하는 행위를 하는 것이므로, 그본성대로 하고자 함이 바로 행위의 동기요 의도인 것이기 때문이다. 이와 같은 본성을 지닌 공리주의적 인간은 선과 악을 규정하는 주체요 선과 악을 판단하는 주체로 서 있는 것이다.