Dihydro-1,4-oxathiin 유도체의 가수분해 Mechanism과 반응속도론적 연구

이광일,곽천근,장병만,김영주,한호규,남기달,이기창,Lee, Kwang Il,Kwak, Chun Geun,Jang, Byung Man,Kim, Young Ju,Hahn, Hoh Gyu,Nam, Kee Dal,Lee, Ki Chang 대한화학회 1996 대한화학회지 Vol.40 No.2

Dihydro-1, 4-oxathiin 유도체의 가수분해 반응속도를 25.deg.C의 수용액에서 자외선 분광기를 사용하여 측정하고 넓은 pH범위에서 적용될 수 있는 반응속도식을 유도하였다. 가수분해 반응속에에 미치는 치환기 효과를 검토하기 위하여 Hammett plot한 결과 전자 끄는기에 의하여 반응속도가 촉진됨을 확인할 수 있었다. 가수분해 최종 생성물은 2-(2-hydroxyethylthio)acetoacetanilide enol형이었다. 가수분해 반응속도상수 측정실험과 반응식 유도과장, 일반염기 효과, 치환기 효과 및 최종 생성물의 결과로부터 dihydro-1, 4-oxathiin 유도체의 기수분해 반응 메카니즘을 제안하였다. pH3.5이하에서는 양서자가 첨가된 dihydro-1, 4-oxathiin의 2번 탄소에 물분자의 공격에 의해 진행되며, pH3.5 이상에서는 2번 탄소에 히드록시이온의 첨가에 의하여 진행됨을 알 수 있었다. pH4.0-9.0사이에서는 dihydro-1, 4-oxathiin에 중성의 물분자가 첨가되는 것이 속도결정단계임을 알았다. The kinetics of the hydrolysis of dihydro-1, 4-oxathiin derivatives were investigated by ultraviolet spectrophotometry in H2O at $25^{\circ}C.$ A rate equation which can be applied over a wide pH range was obtained. The substituent effects on the hydrolysis of dihydro-1, 4-oxathiin derivatives were studied and the rate of hydrolysis was shown to be accelerated by electron accepting groups. Final product of the hydrolysis was 2-(2-hydroxyethylthio)acetoacet-anilide enol form. On the basis of rate equations derived and judging from hydrolysis products obtained and from general base effect and substituent effects, plausible mechanism of the hydrolysis in various pH range have been proposed. Below pH 3.5, the hydrolysis was initiated by the protonation and followed by the addition of water to 2-carbon. Above pH 10.0, the hydrolysis was proceeded by the addition of hydroxide to 2-carbon. In the range of pH 4.0∼10.0, the addition of water to dihydro-1,4-oxathiin is rate controlling step.

수용성 Chitosam 유도체를 이용한 중금속 이온 흡착에 관한 연구

이광일,곽천근,김영주,장병만,김상호,이기창 ( Kwang Il Lee,Chun Geun Kwak,Young Ju Kim,Buyng Man Jang,Sang ho Kim,Ki Chang Lee ) 한국유화학회 1996 한국응용과학기술학회지 Vol.13 No.2

Chitosan itself has been prepared using chitin, one of the most abundant compounds in nature, as a starting material. We have synthesized the water-soluble chitosan derivative, N-dithiocarboxy chitosan sodium salt, through the reaction of water-soluble chiotsan with carbon disulfide in the presence of alkali metal hydroxide. To elucidate this natural polymer capacity of adsorbing heavy metal ions, we have performed adsorption experiments using the water-soluble chitosan derivative various average molecular weight and of different percent contents of sulfur. The effect of pH, adsorption time and temperature on adsorption efficiency was also studied, The adsorbent derived from water-soluble chitosan of average molecular weight ranging 9,000~120,000 was shown to have the highest capacity of adsorbing heavy metal ions. On the whole, adsorbing efficiency was increased as the reaction time goes longer and also increased as the reaction temperature goes higer in temperature range of 15℃~45℃. The adsorption capacity at various pH, however, was appeared to vary depending on the heavy metal ions studied Judging from these finding, water-soluble N-dithiocarboxy chitosan sodium salt, a derivative of a biodegradable nature polymer, is believed to be a potential adsorbent for heavy metal ions since it not only is shown to lower the concentration of heavy metal ions to below the drainage quality standard, but also it would not cause acidification and hardening of soil which is one of the detrimental effects of synthetic macromolecular adsorbents present.

담지된 Pb 촉매에 의한 Ethylene Glycol 로부터 Oxalic Acid 의 합성

이광일,곽천근,장병만 ( Kwang Il Lee,Chun Geun Kwak,Byung Man Chang ) 한국공업화학회 1995 공업화학 Vol.6 No.6

Pd 금속을 활성탄에 담지 시킨 촉매를 제조하여 주 촉매로 사용하였고, 아울러 Pd와 Ni, Cu 및 Co와 같은 함금 촉매를 제조하여 ethylene glycol로부터 oxalic acid의 합성에 관하여 연구하였다. 본 연구에서 사용된 촉매는 함침법 중 흡착법과 초기 함침법으로 제조하였으며, 초기 함침법에서는 함침 과정이 끝난 촉매를 120℃에서 12시간 건조 시킨 후 430℃에서 수소 가스를 통과 시키면서 8시간 소성하여 환원 시킬 때 수율이 좋은 결과를 나타냈다. 값비싼 귀금속 촉매의 양을 줄이고 Ni, Cu 및 Co 등을 조촉매로 사용하여 활성도를 조사한 결과, Co를 사용한 촉매에서 활성이 우수하였다. 촉매의 특성을 조사하기 위하여 SEM-EDAX, X-ray diffraction 및 BET장치를 이용하였으며 촉매의 제조방법에 따라 촉매의 활성도가 다르게 나타남을 알 수 있었다. To investigate the optimum catalytic condition in the synthesis of oxalic acid from ethylene glycol, we empolyed palladium catalyst supported on activated carbon or bimetallic catalysts such as palladium-cobalt, palladium-nickel and palladium-copper supported on activated carbon. In this way, catalysts were prepared either by adsortion method or by incipient wetness method. The most effective catalyst was obtained when the catalyst was dried at 120℃ for 12hrs, followed by the reduction at 430℃ under the stream of hydrogen gas for 8hrs. In an attempt to reduce the amount of expensive noble metals to be used as a catalyst, we studied the effect of metallic promoters such as cobalt, nickel and copper as a co-catalyst. Cobalt was the only effective one when used along with palladium catalyst. In order to characterize the catalyst, we utilized scanning electron microscopy-energy dispersive X-ray spectrometer, X-ray diffraction and BET surface area. The activity of catalyst was shown to be changed depending upon how it was prepared.

재유화형 분말수지와 초속경 시멘트를 혼입한 모르타르의 압축강도 및 접착강도 특성

이광일,윤현섭,양근혁,Lee, Kwang-Il,Yoon, Hyun-Sub,Yang, Keun-Hyeok 한국건축시공학회 2018 한국건축시공학회지 Vol.18 No.4

본 연구의 목적은 기존 콘크리트 건물의 단면확대 내진보강 기술에서 필요한 고유동 고접착성의 보강 모르타르 배합의 개발이다. 보강 모르타르의 목표성능(플로우 220mm 이상, 압축강도 30MPa, 접착강도 1MPa 이상)을 위해 물-결합재비, 잔골재-결합재비, 폴리머-결합재비, 증점제 사용 및 초속경시멘트의 혼입 등을 변수로 단계적으로 배합실험을 수행하였다. 모르타르의 접착강도는 기존 콘크리트의 다양한 면 처리 상태에 따라 평가하였다. 실험결과로부터 단면증설용 보강 모르타르의 배합을 위해 폴리머-결합재비는 10%, 초속경시멘트의 치환율은 5%가 추천될 수 있었는데, 이 배합은 초기 플로우 220 mm, 높은 초기강도 발현, 압축강도 35 MPa 그리고 접착강도 1.2 MPa 이상의 성능을 보였다. The objective of this study is to develop a mortar mixture with high workability and adhesive strength for section jacketing in seismic strengthening technology of existing concrete structures. To achieve targeted requirements of the mortars (initial flow exceeding 200 mm, compressive strength of 30MPa, and adhesive strength exceeding 1MPa), step-by-step tests were conducted under the variation of the following mixture parameters: water-to-binder ratio, sand-to-binder ratio, polymer-to-binder ratio, dosage of viscosity agent, and content of ultra-rapid-hardening cement. The adhesive strength of the mortars was also estimated with respect to the various surface treatment states of existing concrete. Based on the test results, the mortar mixture with the polymer-to-binder ratio of 10% and the content of ultra-rapid-hardening cement of 5% can be recommended for the section jacketing materials. The recommended mortar mixture satisfied the targeted requirements as follows: initial flow of 220 mm, high-early strength gain, 28-day compressive strength of 35MPa, and adhesive strength exceeding 1.2MPa.

5축 공작기계에서 회전 테이블의 반경 오차 성능 평가

이광일(Kwang-Il Lee),양승한(Seung-Han Yang) 한국생산제조학회 2012 한국생산제조학회지 Vol.21 No.2

일반논문 : 자유주의 정치 기획의 반복, "정치 빈곤"의 자화상

이광일 ( Kwang Il Lee ) 민주사회정책연구원 2014 민주사회와 정책연구 Vol.26 No.-

이 글은 ‘정치영화 논란’의 중심에 서 있었던 <변호인>(양우석, 2013)이 어떤 정치적 기획을 소환하고자 하며 그것의 역사적 의미는 무엇인지, 그리고 그것이 지금‘포스트 민주주의시대’의 ‘정치 빈곤’에 대한 의미 있는 비판이 될 수 있는지 살펴보고자 한다. 이를 위해 이 글은 <변호인>과 1960년대 후반 정치적 억압이 고조되던 시기에 만들어진 <휴일>(이만희, 1968) 등을 비교·검토할 것이다. 그리고 그것을 통해 <변호인>이 자유주의 정치세력들의 명목뿐인 진보성을 계속 소환하면서<휴일>이 이미 그 주인공의 죽음을 통해 상징적으로 부정했던 ‘정상적 자유민주주의’의 실현에 집착하고 있음을 지적할 것이다. 이러한 의미에서 이 글은 <변호인>이 정치의 복원에 기여하기보다 오히려 그것의 빈곤을 조장하고 있음을 보일 것이다. This article deals with following questions on The Attorney(2013) that wasin the center of ‘political cinema dispute’; What political project does TheAttorney recall, and What historical meanings dose that political project hold,and Whether The Attorney would be a meaningful criticism on ‘the lack ofpolitics’ of the post-democratic era. To answer these questions, this article compares The Attorney to Holiday thatwere made in 1968 when political oppression was escalating. This article pointsout that The Attorney adheres to realization of ‘normal liberal democracy’ thatHoliday has already denied symbolically through its hero’s death, as recallingthe progressiveness in name only of liberal political forces. In this meaning,this article argues that The Attorney is rather aggravating the lack of politicsthan restoring.

민주노총의 ‘관료화·귀족화 논란’의 역사적 기원에 관한 연구

이광일(Kwang-il, Lee) 경상대학교 사회과학연구원(마르크스주의 연구) 2021 마르크스주의 연구 Vol.18 No.4

X-band용 4-비트 위상변위기의 설계 및 제작

이광일(Kwang-Il Lee),임인성(In-Sung Yim),전병휘(Byung-Hui Jeon),정영준(Jeong-Ki Ryoo),류정기(Young-Jun Chong),오승엽(Seung-Hyeub Oh) 한국통신학회 2001 한국통신학회 학술대회논문집 Vol.2001 No.11

‘민주화’ 전후 이데올로기 독점과 변형

이광일(Lee kwang-il) 경상대학교 사회과학연구원(마르크스주의 연구) 2007 마르크스주의 연구 Vol.4 No.2

멀티미디어 응용을 위한 멀티캐스트 라우팅 프로토콜

이광일(Lee Kwang il),조평동(Cho Pyoung Dong),김경일(Kim Kyoung il),김상하(Kim Sang ha) 한국정보처리학회 1998 정보처리학회논문지 Vol.5 No.5

Multicasting plays an important role in providing multimedia services like audio and video conferencing and has been actively studied for many years. The study of multicasting has been mainly focused on finding a low-cost tree on the assumption that every edge of the tree has enough link capacity to be allocated to the amound of bandwidth required by a service. In some cases, however, a multicasting tree whose some edges do not have enough bandwidth to be allocated may exist. A typical example of this case is to multicast among the group users located in the different sub-networks in the interconnected networks composed of the high bandwidth networks such as B-ISDN and the low bandwidth networks such as PSTN and PSDN. This paper proposes a novel multicasting protocol for providing multimedia services in a wide area network interconnected by multiple heterogeneous networks. First, the paper discusses the inherent limitation of present multicasting protocols for the case. Second, se introduce a new concept, multiple QoS's for a service, which extends the implicit assumption that only one QoS is assigned to a service in order to overcome this limitation. Third, our multicasting protocol is designed based on the current Internet protocol stacks. Last, we perform simulations for possible scenarios to provide multimedia services in the network and analyze their pros and cons.