기계적 합금화로 제조된 Fe_0.92Mn_0.08Si₂의 상변화 및 열전 특성

김영섭,조경원,김일호,어순철,이영근,Kim, Young-Seob,Cho, Kyung-Won,Kim, Il-Ho,Ur, Soon-Chul,Lee, Young-Geun 한국재료학회 2003 한국재료학회지 Vol.13 No.5

In an attempt to enhance phase transformation and homogenization of Mn-doped $FeSi_2$, mechanical alloying of elemental powders was applied. Cold pressing and sintering in vacuum were carried out to produce a dense microstructure, and then isothermal annealing was employed to induce a phase transformation to the $\beta$-$FeSi_2$semiconductor. Phase transitions in this alloy system during the process were investigated by using XRD, EDS and SEM. As-milled powders after 100 h of milling were shown to be metastable state. As-sintered iron silicides consisted of untransformed mixture of $\alpha$-$Fe_2$$Si_{5}$and $\varepsilon$-FeSi phases. $\beta$-$FeSi_2$phase transformation was induced by subsequent isothermal annealing at $830^{\circ}C$, and near single phase of $\beta$-$FeSi_2$was obtained after 24 h of annealing. Thermoelectric properties in terms of Seebeck coefficient, and electrical conductivity were evaluated and correlated with phase transformation. Seebeck coefficient electrical resistivity and hardness increased with increasing annealing time due to $\beta$ phase transformation.

수종 생약추출물의 muscarin성$(M_1\;type)$ acetylcholine 수용체$(mAChR-M_1)$에 대한 친화력 검색

김영섭,김정섭,김성기,허정희,이병의,유시용,Kim, Young-Sup,Kim, Jeoung-Seob,Kim, Seong-Kie,Heor, Jung-Hee,Lee, Byung-Eui,Ryu, Shi-Yong 한국생약학회 2001 생약학회지 Vol.32 No.3

The water extracts of 82 Korean medicinal herbs were examined for the binding affinity on the recombinant human muscarinic acetylcholine receptor subtype 1 $(mAChR-M_1)$ produced from the CHO (Chinese Hamster Ovary) cell line. Of those tested, the extracts of Coptidis Rhizoma, Phellodendri Cortex, Hedyotis Herba and of Terminariae Fructus were found to exhibit a significant competition with $[^3H]$ N-methyl-scopolamine for the specific binding to $mAChR-M_1$ in a dose dependent manner, respectively.

수종 생약추출물의 NMDA(N-Methyl-D-Aspartate) 수용체 glycine binding site에 대한 친화력 검색

김영섭,김정섭,김성기,허정희,이병의,유시용,Kim, Young-Sup,Kim, Jeoung-Seob,Kim, Seong-Kie,Heor, Jung-Hee,Lee, Byung-Eui,Ryu, Shi-Yong 한국생약학회 2001 생약학회지 Vol.32 No.3

The water extracts of 82 Korean medicinal herbs were prepared and were examined for the binding affinity on the glycine binding site of NMDA (N-methyl-D-aspartate) receptor prepared by the synaptic membranes from the forebrains of male Sprague-Dawley rats. Among the tested, the extracts of Dioscoreae Rhizoma, Hoveniae Semen cum Fructus, Astragali Radix, Armeniacae Semen, Huttuynia cordata Herba, Acanthopanacis Cortex, Aurantii nobilis Pericarpium, Phellinus linteus, Amomi Fructus, Artemisiae capillaris Herba, Polyporus, Agastachis Herba and of Galli Stomachichum Corium were found to exhibit significant competitions with $[^3H]-MDL$ 105,519 for the glycine specific binding site of NMDA receptor in a dose dependent manner, respectively.

혹고니(Cygnus olor)의 보툴리눔독소증

김영섭,김보숙,신남식,Kim, Young Seob,Kim, Bo Suk,Shin, Nam Shik 대한수의학회 2008 大韓獸醫學會誌 Vol.48 No.2

Many neurotoxigenic clostridia are found in soil. Among animals, birds are especially susceptible to botulism, perhaps because they feed on insects, invertebrate carcasses, and decayed feeds contaminated with spores of Clostridium (C.) botulinum. C. botulinum type C is mainly involved in avian botulism. In the summer of 2005, death of a mute swan (cygnus olor) living in the pond of large bird cage was found in Seoul Grand Park Zoo. The birds presented presumptive clinical signs of botulism, such as ruffled hackle feathers, abnormal posture of the head, weakness, and flaccid paralysis. At that time, pond water in the breeding facilities was drained for 7 days, but there were still remained water containing sediment of feed and feces. Therefore, botulism was suspected and an experimentation were made to detect C. botulinum in the dead mute swan. Gross post-mortem findings of a mute swan showed jelly-like hemorrhagic contents in the intestine, sands and vegetations in the stomach. C. botulinum was isolated from the liver, small intestine and large intestine samples. Botulism was also confirmed by mouse inoculation test with the organ samples. With PCR, a gene encoding C. botulinum type C toxin was detected for the several organs of the mute swan died. These results suggested that death of mute swan was caused by C. botulinum type C.

긴급제언 - 신재생에너지와 바이오가스

김영섭,Kim, Young-Seob 한국기술사회 2011 技術士 Vol.44 No.6

Many countries around the world have actively used biogas to reduce greenhouse gases in order to improve the environment. Recently, South Korea has invested a lot of money in technology development for organic waste and expanded the policy to supply renewable energy. The use of biogas would also increase our country's energy security. Therefore, I would suggest that our government adopt the relevant laws and systems regarding biogas in the near future.

Micro-Source의 모델링에 관한 연구

김영섭(Young-Seob Kim),손광명(Kwang-Myoung Son),이태기(Tae-Gi Lee) 동의대학교 정보통신연구소 2003 정보통신연구지 Vol.4 No.-

Micro-Source는 1KW~1MW사이의 전력을 공급하고, 친환경적이며, 에너지원의 소형화를 통해 실제적인 부하변화에 경제적으로 대처할 수 있어 유용하다. Micro-Turbine과 Fuel-Cell은 잠재적으로 성장 가능성이 높은Micro-Source이며 신뢰도가 높고, 적은 비용으로 효과적으로 부하변화에 대처 할 수 있다. 본 논문에서는 Micro-Turbine과 Fuel-Cell이 계통에 연계 되었을때의 동특성을 해석하기 위한 모델에 대하여 연구하였다. Micro-Sources anr emerging as a viable and economic solution for providing environ-mentally friendly and coping with the variation of loads. aong various options of Micro-Sources, Micro-turbine and Fuel-Cell are highlighted as they are reliable and effective.This paper considers the case Micro-Sources are connected to the grid. Dynamic models for studying the effect of Micor-Sources are developed.

CNG 용기용밸브의 압력방출장치 성능에 관한 연구

김영섭(Young Seob Kim),김래현(Lae Hyun Kim),이재훈(Jae Hun Lee) 한국가스학회 2009 한국가스학회지 Vol.13 No.4

이 연구는 천연가스버스에 장착된 용기가 국부화염에 집중적으로 노출되었을 때나 외기온도가 높은 여름철 충전과정에서 과 충전되었을 때 용기파열을 방지하기 위한 방안으로 압력방출장치의 성능을 확인하고 확대 적용할 목적으로 의도되었다. 열사이클링 실험결과, -40℃~82℃ 인증기준에서 가스누출요건을 모두 충족하였지만 -45℃~135℃의 가속조건에서는 3개사 시험편중 2개사 시험편의 오링이 손상되었다. 또한 온도감응형 PRD의 평균작동시간은 액체봉입식이 1분 39초가 걸렸고, 가용합금식이 2분 31초가 소요되어 액체봉입식이 가용합금식보다 약 1분 정도 빠름을 나타내었다. 또한 압력감응형 PRD의 작동압력은 가속조건에서 약 32.1 ㎫을 나타내었고 인증기준에서의 압력감응형 PRD의 파열압력은 30.7~32.1 ㎫를 기록하였다. 이상의 실험을 통해서 압력방출장치의 성능은 온도감응형 PRD의 경우, 액체봉입식이 가용합금식보다 화염에 더 효과적이며, 압력 감응형 PRD의 파열압력은 외부온도 및 반복가압이 파열판의 작동압력에 크게 영향을 미치지 않음을 확인할 수 있었다. This study is intended to experiment performance of pressure relief device and to extend the effective ways to prevent cylinders of NGV from bursting when they are exposed to local fire intensively or when they are overcharged under ambient temperature at fueling stations in summer. In the results of thermal cycling experiments, all products of three companies met the requirements for gas leakage in the qualification criteria between 82℃ and -40℃. But the o-rings of two companies’ specimens among the three companies’ specimens got damaged under the accelerated conditions between 135℃ and -45℃. It took one minute and thirty nine seconds for a glass bulb type of a thermal sensitive type PRD to activate and it took two minutes and thirty one seconds for a fusible plug type of a thermal sensitive type PRD to activate. These results indicated that a glass bulb type of a thermal sensitive type PRD was one minute faster than a fusible plug type of a thermal sensitive type PRD. Under the accelerated condition 135℃, the activation pressure of a pressure sensitive type PRD burst at 32.1 ㎫ and, under the condition of qualification criteria, it burst from 30.7 ㎫ to 32.1 ㎫.. As a result of the experiment for performance of pressure relief device, in the case of the thermal sensitive type PRD, a glass bulb type is more effective to flame than a fusible plug type. we confirmed that the rupture pressure of a pressure sensitive type PRD could not be affected by temperature and pressure cycling.

압축천연가스 자동차의 안전성 향상을 위한 제언

김영섭(Young-Seob Kim),박교식(Kyoshik Park),김태옥(Tae-Ok Kim) 한국가스학회 2012 한국가스학회지 Vol.16 No.4

지난 2010년 8월 9일 발생한 압축천연가스(compressed natural gas, CNG) 버스의 내압용기 파열사고 이후 정부는 CNG자동차의 안전관리 체계를 구축하기 위하여 다각적인 연구를 수행하였으며, 본 내용은 그 주요 내용을 정리한 것이다. CNG자동차의 안전성 향상을 위해 관련 법령, 검사·인증기준 등 안전관리제도를 검토하였고, 더불어 CNG자동차 관련 종사자(검사원, 정비원)에 대한 교육훈련 등도 검토하였다. 주요 검토내용으로는 CNG자동차용 용기형태, CNG용기의 설치위치, 압력방출배관의 재질 및 설치형태, 배관접속 및 접합방법, 가스누출 경보시스템, 긴급차단밸브 및 작동 스위치, CNG용기 보호커버, CNG 자동차 충전사업자의 공급자 의무사항, CNG자동차의 정기검사제도, CNG자동차의 일상점검 제도, CNG자동차 종사자의 교육훈련제도, CNG버스 운송사업체의 안전관리자 선임제도 등이다. 위의 주요 항목들을 중점적으로 검토하여 CNG자동차의 안전성 향상 방안을 제안하였다. Systematic safety research by Korea Government has been made to enhance the safety of CNG (compressed natural gas) vehicles since the burst of compressed cylinder of an urban bus in August 9, 2010. This article summarizes some major activities to ensure the safety of CNG vehicles, which covers review of regulation, safety management system including standard of inspection and certification, and training program of inspectors and car mechanics. Specifically, the followings were reviewed; type of CNG cylinder, location of CNG cylinder, material and type of fuel line and vent line, modification of pipeline connection, installation of gas detector, installation of emergency shutdown valve, installation of protecting cover for cylinder, obligations for CNG vehicle filling station. improving periodical inspection, routine test on gas vehicles, training program for engaged in gas vehicles, and designation of safety manager for CNG bus company. This paper suggests how to improve safety of CNG vehicles as a result of review of above mentioned check items.

천연가스자동차 사고사례 및 원인분석

김영섭(Young-Seob Kim),조은구(Eun-Goo Cho),김래현(Lae-Hyun Kim) 한국가스학회 2008 한국가스학회 학술대회논문집 Vol.2008 No.11

CNG 용기용밸브 압력방출장치 성능평가

김영섭(Young-Seob Kim),이재훈(Jae-Hun Lee),김래현(Lae-Hyun Kim) 한국가스학회 2009 한국가스학회 학술대회논문집 Vol.2009 No.4