Synthesis of Tris(silyl)methanes by Modified Direct Process

이창엽,한준수,유복렬,정일남,Lee, Chang Yeop,Han, Jun Su,Yu, Bok Ryeol,Jeong, Il Nam Korean Chemical Society 2000 Bulletin of the Korean Chemical Society Vol.21 No.10

Direct reaction of elemental silicon with a mixture of (dichloromethyl)silanes 1 $[Cl_3-nMenSiCHCl_2:$ n = 0 (a), n = 1(b), n = 2(c), n = 3(d)] and hydrogen chloride has been studied in the presence of copper catalyst using a stirred bed reactor equ ipped with a spiral band agitator at various temperatures from $240^{\circ}C$ to $340^{\circ}C.$ Tris(si-lyl) methanes with Si-H bonds, 3a-d $[Cl_3-nMenSiCH(SiHCl_2)_2]$, and 4a-d $[Cl_3-nMenSiCH(SiHCl_2)(SiCl_3)]$, were obtained as the major products and tris(silyl)methanes having no Si-H bond, 5a-d $[Cl_3-nMenSiCH(SiCl_3)_2]$, as the minor product along with byproducts of bis(chlorosilyl)methanes, derived from the reaction of silicon with chloromethylsilane formed by the decomposition of 1. In addition to those products, trichlorosilane and tetra-chlorosilane were produced by the reaction of elemental silicon with hydrogen chloride. The decomposition of 1 was suppressed and the production of polymeric carbosilanes reduced by adding hydrogen chloride to 1. Cad-mium was a good promoter for and the optimum temperature for this direct synthesis was $280^{\circ}C$.

무촉매 환원법이 적용된 응용 재연소 방법에 의한 NO_x와 CO의 저감 효과

이창엽,김동민,백승욱,Lee Chang-Yeop,Kim Dong-Min,Baek Seung-Wook 대한기계학회 2006 大韓機械學會論文集B Vol.30 No.8

From the view of the environmental protection against the use of fossil fuels, the great of efforts have been exerted to find an effective method which is not only pollutant reduction but also high thermal efficiency. Reburning is a useful technology in reducing nitric oxide through injection of a secondary hydrocarbon fuel. In this paper, an experimental study has been conducted to evaluate the hybrid effects of reburning and selective non-catalytic reaction (SNCR) on $NO_x/CO$ reduction from oxygen-enriched LPG flame. Experiments were performed in flames stabilized by a co-flow swirl burner, which was mounted at the bottom of the furnace. Tests were conducted using LPG gas as main fuel and also as reburn fuel. The paper reported data on flue gas emissions, temperature distribution in furnace and various heat fluxes at the wall for a wide range of experimental conditions. Overall temperature in the furnace, heat fluxes to the wall and $NO_x$ generation were observed to increase by oxygen-enriched combustion, but due to its hybrid effects of reburning and SNCR, $NOx/CO$ concentration in the downstream has considerably decreased.

이산화탄소가 수소 산소부화 화염의 열전달에 미치는 영향

이창엽(Chang Yeop Lee),최준원(Joon Won Choi),백승욱(Seung Wook Baek) 한국연소학회 2003 KOSCOSYMPOSIUM논문집 Vol.- No.-

연료 희박 재연소 과정에 의한 NOx 저감 및 CO 발생에 대한 실험적 연구

이창엽(Chang Yeop Lee),김학영(Hak Young Kim),백승욱(Seung Wook Baek),김세원(Se Won Kim) 대한기계학회 2008 大韓機械學會論文集B Vol.32 No.3

Reburning is a useful technology in reducing nitric oxide through injection of a secondary hydrocarbon fuel. In this paper, an experimental study has been conducted to evaluate the effect of fuel lean reburning on NOx/CO reduction in LPG flame. Experiments were performed in flames stabilized by a co-flow swirl burner, which was mounted at the bottom of the furnace. Tests were conducted using LPG gas as the reburn fuel as well as the main fuel. The effects of reburn fuel fraction and injection location of the reburn fuel were studied when the fuel lean reburning system was applied. The paper reports data on flue gas emissions and temperature distribution in the furnace for a wide range of experimental conditions. At steady state, temperature distribution and emission formation in the furnace have been measured and compared. This paper makes clear that in order to decrease both NOx and CO concentrations in the exhaust when the fuel lean reburning system was adapted, it is important that the control of some factors such as initial equivalence ratio, reburn fuel fraction and temperature of reburn fuel injection region. Also it shows the fuel lean reburning is also effective method to reduce NOx as much as reburning.

재연소가 열전달 특성과 NO<SUB>x</SUB> 감소에 미치는 영향

이창엽(Chang Yeop Lee),백승욱(Seung Wook Baek) 한국연소학회 2005 한국연소학회지 Vol.10 No.2

혼합형 재연소 기술의 열전달 특성 및 NOx 저감 효과

이창엽(Chang Yeop Lee),백승욱(Seung Wook Baek),김혁수(Hyuk Su Kim) 대한기계학회 2005 대한기계학회 춘추학술대회 Vol.2005 No.11

An experimental study has been conducted to evaluate the effects of advanced reburning and SNCR on NO<SUB>x</SUB> reduction and heat transfer characteristics. The paper reported data on flue gas emissions, temperature distribution in furnace and various heat fluxes at the wall for a wide range of experimental conditions. In a steady state, the Total as well as radiative heat flux from the flame to the wall of furnace has been measured. Temperature distribution and emission formation in furnace have been also measured and compared.

中西部地域 百濟漢城期 木棺墓 變化 - 烏山 水淸洞遺蹟을 中心으로

이창엽(Lee Chang-Yeop) 한국고대학회 2007 先史와 古代 Vol.27 No.-

서울과 경기남부, 충청지역에서 확인되는 원저단경호와 심발형토기가 조합되어 부장된 토광묘, 주구토광묘는 중서부지역 분묘 연구에 있어서 선구적인 역할을 담당했던 천안 청당동유적의 연대관에 근거하여 원삼국시대 대표적인 분묘로 인식되고 있다. 그런데 청당동유적의 연대는 당시 자료가 부족한 상황에서 부산 노포동유적과 같은 일부 영남지역 분묘와의 교차연대에 따라 설정된 것으로 이후 많은 자료가 축적되어 재고할 여건이 마련되어 가고 있다고 판단된다. 이에 본고에서는 중서부지역 원저단경호 출토 분묘에 대해 나름의 연대와 변화상을 제시하고자 하였다. 이를 위해 오산수청동유적을 중심으로 분묘의 구조와 유물조합상의 특징을 간략히 살펴보고, 소문단경호와 심발형토기의 형식분류를 중심으로 단계를 설정하였다. 이를 기반으로 교차편년을 행하고 그에 따른 중서부지역에 있어서 목관묘의 변화를 살폈다. 그 결과 기존에 원삼국시대에서 삼국시대 전기에 해당된다고 설정되었던 유물부장부를 가지는 토광묘는 목관묘이고, 그 연대는 3세기말 이후로 편년됨을 확인하였다. 백제의 중심으로 생각되는 서울지역에서의 유례가 없어 명확하지는 않으나, 서울을 제외한 경기 남부와 충청 북부 일대에 있어서는 대동소이한 흐름을 가지는 것으로 보아 서울 역시 예외는 아니었으리라 생각된다. 따라서 이 분묘들이 삼국시대 백제한성기 이른시기의 대표적인 분묘로 생각해도 좋을 것이다. 기존에 4세기대로 편년되어 한성기의 분묘로 생각되었던 백제토기가 출토되는 석촌동 분묘군은 백제토기의 편년 검토를 통해 그 연대는 재고되어야 할 것으로 생각된다. The pit tomb and the pit tomb with ditch in which buried together with combination of short necked round bottom jars and the deep bowl shaped potteries which have been discovered in Seoul as well as in the southern Gyeonggi and Chungcheong region are recognized as the prevailing forms of tomb representing the Proto-Three Kingdoms period based on the chronology of Cheonan Cheongdang-dong remains that has taken a trailblazing role in the research on tombs in mid-west region. However, it should be noted that the chronology of Cheongdang-dong remains had been established according to cross-dating in connection with the tombs found in some part of Yeongnam region, like Busan Nopodong remains, under a situation of lacking data and materials. Since then after, many data and resources have been cumulated, so then it is judged that conditions have been improved so much as to be able to reconsider the chronology thereof. In this research paper, researcher tried to present the chronology and the status of changes with regard to the tombs located in the mid-west region from which short necked round bottom jars were excavated. To do this, the distinctive features of structures of the tomb and of the status of relic combinations were briefly reviewed, and then the phases of change were established with a focus on the classification of type of short necked jar without a paddle pattern and the deep bowl shaped pottery. Cross dating was done based on these works, and according to this chronology, changes in wooden coffin tomb were investigated. As the results, it was confirmed that the pit tomb having the part of the interment of belonging with corpse, of which chronology was so regarded as to fall into the period, ranging from the Proto-Three Kingdoms period to the early Three Kingdoms period, was wooden coffin tomb, and that it was then chronologized after the end of third century. Though it is not so clear, for there were no examples found in Seoul region, which is considered the center of Baekje, it is thought that Seoul would have not been excepted, when judging it based on the fact that there are more or less same trend of the tomb in the southern Gyeonggi and a part of the northern Chungcheong, except Seoul. Therefore, it will be ok if these tombs are considered the tombs representing the early Baekje Hanseong Period. And it is thought that chronology of the group of tombs in Seokchon-dong where Baekje potteries have been excavated and which were regarded as the tombs from the Baekje Hanseong Period, for it was already chronologized as in four century should be reconsidered.

산소부화 LPG 화염에서 혼합형 재연소 방법에 의한 NOx 저감 효과

이창엽(Chang Yeop Lee),백승욱(Seung Wook Baek) 한국연소학회 2007 한국연소학회지 Vol.12 No.4

In order to enhance combustion efficiency, oxygen-enriched combustion is used by increasing the oxygen ratio in the oxidizer. However, since the flame temperature increases, NOx formation in the furnace seriously increases for low oxygen enrichment ratio. In this case, reburning is a useful technology for reducing nitric oxide. In this research, experimental studies have been conducted to evaluate the hybrid effects of reburning/selective non-catalytic reaction (SNCR) and reburning/air staging on NOx formation and also to examine heat transfer characteristics in various oxygen-enriched LPG flames. Experiments were performed in flames stabilized by a co-flow swirl burner, which were mounted at the bottom of the furnace. Tests were conducted using LPG gas as main fuel and also as reburn fuel. The paper reported data on flue gas emissions, temperature distribution in furnace and various heat fluxes at the wall for a wide range of experimental conditions. Overall temperature in the furnace, heat fluxes to the wall and NOx generation were observed to increase by low level oxygen-enriched combustion, but due to its hybrid effects of reburning, SNCR and Air staging, NOx concentration in the exhaust have decreased considerably.

전산화 단층촬영창치의 정도관리에 관한 연구

조평곤,이창엽,Cho Pyong Kon,Lee Chang Yeop 대한방사선사협회 2002 대한방사선사협회지 Vol.28 No.1

Purpose The quality assurance in a computed tomography gives a definition to be all the activity so as to optimize the performance of the device and keep an invariable quality of image, and it is to raise a high diagnostic efficiency to obtain a much info

재연소 과정을 적용한 연소로에서 공기 다단 연소기의 NO_x 발생 및 열전달에 대한 효과

김혁수,백승욱,이창엽,Kim, Hyuk-Su,Baek, Seung-Wook,Lee, Chang-Yeop 대한기계학회 2006 大韓機械學會論文集B Vol.30 No.9

An experimental study has been conducted to investigate the effects of a multi air-staged burner on NOx formation and heat transfer in a 15kW large-scale laboratory furnace adopted the reburning process. The reburn fuel as well as burnout air was injected from each nozzle attached at the wall of the cylindrical furnace. Fuel in both main burner and reburn nozzle was LPG (Liquefied Petroleum Gas). The paper reports the influences on NOx reduction of reburn fuel fraction in reburning zone. Temperature distribution inside the overall region as well as total heat flux at the wall of the furnace has been measured to examine the heat transfer characteristics due to the reburning process. For comparison, the reburning effects were examined for a combustor with two types of burner; a regular single staged burner and a multi-air staged burner. A gas analysis was also performed to evaluate an appropriate condition for NOx emission in a primary zone for the excess air ratio of 1.1. As a result, combustion efficiency expected to become more efficient due to the reduction of heat loss in burnout zone decrease when multi air-staged burner in furnace adopted reburning technology was used.