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        촉매를 이용한 이산화탄소 고정화 및 고리형 카보네이트 합성반응에 대한 계산화학적 해석

        안혜영(Hye Young An),김민경(Min-Kyung Kim),정희철(Hui Cheol Jeong),엄기헌(Ki Heon Eom),원용선(Yong Sun Won) 한국청정기술학회 2016 청정기술 Vol.22 No.1

        본 연구에서는 이론화학 또는 분자모델링이라 불리는 계산화학을 기존에 연구된 촉매반응 실험결과를 해석하는 데 접목시켜 보았다. 온실효과의 주범인 이산화탄소를 에폭사이드와 반응을 통해 고정화하고 카보네이트를 생성하는 반응을 선택하였는데 이 반응은 활성화 에너지(55~59 kcal/mol)가 높아 촉매의 사용이 불가피하다. 많은 기존 연구들 중에 ZIF-90/ionic liquid immobilized ZIF-90 (IL-ZIF-90), polystyrene-supported quaternized ammonium salt, KI/KI-glycine, dimethylethanolamine (DMEA)를 촉매로 사용한 경우에 대해 반응의 각 단계를 계산하여 반응의 경로를 예측하고 단계별로 구한 에너지를 바탕으로 에너지도를 구성함으로써 실험결과를 열역학적으로 해석하였다. ZIF-90/IL-ZIF-90과 KI/KI-glycine의 경우는 실험적으로 후자들이 상대적으로 높은 수율을 얻었는데 계산 결과 활성화에너지가 낮아진 이유가 아니라 전자들의 경우 반응 중간체가 높은 에너지를 가져 반응물로 되돌아가는 역반응에 의해 정반응의 진행이 방해를 받은 것으로 밝혀졌다. DMEA를 촉매로 사용하였을 경우는 활성화 에너지를 ~42 kcal/mol로 낮춰줌으로써 금속이나 할로겐염 없이도 촉매의 활성이 잘 일어남을 증명하였다. 폴리스티렌(polystyrene)으로 지지된 quaternized 암모늄염 촉매의 경우 클러스터 가정을 사용하여 계산을 진행하였으며 암모늄염의 -NH기와 에폭사이드의 O 원자 사이의 상호작용의 가능성을 확인할 수 있는 반응경로를 제시하였다. In this study, a computational chemistry methodology called as molecular modeling was been applied to explain several experiment results mechanistically. The reaction chosen for this study was to remove carbon dioxide, known as a primary greenhouse gas, by an epoxide via the carbon dioxide fixation to produce carbonates. This reaction inherently needs the use of catalysts because it has a significantly high activation barrier (55~59 kcal/mol). Among various types of catalysts, we studied in zeolitic imidazolate framework 90 (ZIF-90)/ionic liquid immobilized ZIF-90 (IL-ZIF-90), polystyrene-supported quaternized ammonium salt, KI/KI-glycine, and dimethylethanolamine (DMEA). First, probable reaction pathways were proposed based on calculated energetics by computational chemistry. The energetics was then used for the thermodynamic interpretation on the activity of catalysts. In the case of ZIF-90/IL-ZIF-90 and KI/KI-glycine, IL-ZIF-90 and KI-glycine showed better yields compared to their counterparts. The calculation proposed interesting results that it is not from the lowering of activation energy but from the unstable intermediates of ZIF-90 and KI-glycine. For DMEA, the calculated activation energy was ~42 kcal/mol, much lower than that of the non-catalytic reaction. A possible reaction pathway was located to confirm the interaction between -NH group from ammonium and oxygen from epoxide for polystyrene-supported quaternized ammonium salt.

      • The fate of spinal schwannomas following subtotal resection: a retrospective multicenter study by the Korea spinal oncology research group.

        Sohn, Seil,Chung, Chun Kee,Park, Sung-Hye,Kim, Eun-Sang,Kim, Ki-Jeong,Kim, Chi Heon M. Nijhoff ; Kluwer Academic Publishers 2013 Journal of neuro-oncology Vol.114 No.3

        <P>The fate of residual spinal schwannomas needs to be estimated in order to plan further management after subtotal removal. Our aim was to evaluate the growth rate of residual spinal schwannomas and compare results in regrowth and no regrowth groups by using data collected from the Korea Spinal Oncology Research Group database. From January 1989 to August 2011, 27 patients with residual spinal schwannomas were selected. Patients with at least two follow-up magnetic resonance image (MRI) studies after subtotal resection were included. The mean period of MRI follow-up was 62.4 months. A tumor size increase of over 2 mm in the maximal diameter was considered indicative of regrowth. Age, sex, size at initial diagnosis, postoperative tumor size, and Ki-67 labeling index were compared between regrowth and no regrowth groups. Eight residual schwannomas regrew (29.6 %), and 19 (70.4 %) did not regrow. Average growth rate of the regrowing tumors was 1.0 4.4 mm/year. The mean percentage increase in tumor size during follow-up was 10.0 28.8 %. The Ki-67 labeling indices were significantly different between regrowth and no regrowth groups (P = 0.014). Two patients underwent a revision operation for significant tumor regrowth. Nineteen cases (70.4 %) among 27 residual spinal schwannomas did not regrow significantly, but further surgical treatments were necessary in 2 patients due to significant regrowth. The Ki-67 labeling index was higher in the regrowth group. Earlier follow-up MRI is recommended for patients whose tumors have higher Ki-67.</P>

      • B -NSF계 & 빈졸계 고분자로 변성된 인조석의 물성에 관한 기초 연구

        조헌영,서정목,박성기 공주대학교 방재연구센터 1998 공주대학교 방재연구센터 논문집 Vol.2 No.-

        In the recent years, artificial stone has been used as exterior finishing materials of bullding. Artificial stone is manufactured with mixture of cement, stone powder and light-weight aggregate. In this research, we tried to find a way of inceasing the properties needed for better quality artificial stone. So, we used β-NSF modifier and vinsol modifier to improve the physical properties of artifical stone. Through this research, we found that the optimum dosage of the β-NSF & the vinsol polymer is 0.1 wt% and 0.05wt% of cement.

      • 勞使關係와 勞動行政에 관한 硏究

        金憲起 대구보건대학 1991 대구보건대학 論文集 Vol.12 No.-

        The purpose of the Labor-Management Council System is to rise the productivity through the communication between the union and management, to promote the welfare of the laborer and to stabilize the Labor-Management Relations. But the present Labor-Management Council System has been successfully operating. Though the rise of the productivity, the target level of the manager and manage organization, has been achieved, the promotion of the welfare of the laborer and the stabilization of the Labor Management relations have not been achieved. In particular, the grievance handling which is closely connected with the promotion of the welfare and the stabilization of the Labor-management relations has not been ineffective due to the enervated grievance handling committee. partly because the antagonistic relations between employer and employee has been restricted conceiving the Labor-Management Council System in Korea, partly because the Collective Bargaining of the Union has been curbed partly because the conciliatory side in the Labor-Management Council System has been emphasized. To develop the Labor-Management Council System normally, not only the laborer, the Labor-Management Council, the enterprise and the Government should improve the Labor Management Council System systematically and administratively, but also, labor collective bargaining right being allowed, the Union and the Labor-Management Council System should be developed equally to induce re the mutual co-operative relation. In addition, to form the basis of it, the consciousness level of the Labor-Management relation and the managerial environment should be made better as well as the desirable Labor-Management and Administration must be taken a triangular position. In conclusion, I would like to present the following suggestions as to the directions in developing the Labor-Management Council System and achieving the prosperity of the Labor and Management. 1. The Labor-Management Council System should be improved systematically as well as the Union and the Labor-Management Council System should be developed equally to induce to the mutual co-operative relation. 2. It is quite necessary to recognize that the Labor-Management relation is neither only antagonistic nor only co-operative. For the relation should be compatible and commensal. 3. In the managerial and administrative environment, the humanism should be expanded to harmonize the efficiency and the humanism. 4. It is quite important that the unequal bargaining power should be recovered by the sublation of the exceeding governmental interference in the triple relations of the Labor, Management and Administration so that the equal dynamic relations might be realized. 5. The Labor-Management Administration should pursuit the democratic welfare administration which is the harmony of the laissez-faire administration 2nd the control administration and to do it, in the Labor-Management, Administration, the specialization, the individuality and the democracy should be guaranteed.

      • 自由놀이 活動에 관한 硏究

        金基玄 又石大學校 1983 論文集 Vol.5 No.-

        This study was aimed to find out the daily lesson period and located time for the free play activities, teacher's recognitions of values for the free play activities, teacher's role in various situations during the activities, and problem for the teacher's guidance for the activities, to get necessary information for the effective guidance for the free play activities. Questionnaire paper asked to the 80 teachers from 80 kindergartens in Jean Bug region, the recovery ratio of Questionnaires was 85%. Findings of the research are as follows : 1. In general 40-60 minutes a day are alocated for the free play activities, regardless to daily lesson period, and alocated time changes according to the seasons. 2. The teachers have revealed some tendency of putting first priority on the physical values of the free play activities, next on social values, on intellectual values. 3. The teachers pay attentions to trouble among infants during the activities to suggest for their solutions, but in other play parts they seldom pay any attentioks ons. 4. Imaginary play materials, creative play materials, rhythms materials, and printed materials are moderately provided. However natural play materials, science play materials are poorly ed. provid- 5. It is the Problems for the teacher's guidance for the free play activities that play materials are poorly provided, the teachers are not sufficient in number, space and time either.

      • 자가 면역성 간염에서 자가항체의 발현 양상과 스테로이드 치료의 효과

        박기오,채경훈,허원석,강윤세,정재훈,김연수,문희석,이엄석,김선문,이병석,김남재,이헌영 충남대학교 의과대학 의학연구소 2003 충남의대잡지 Vol.30 No.1

        목적 : 최근 8년간 본원에서 경험한 자기면역성 간염의 혈액학적 특징과 스테로이드의 치료효과를 알아보고자 본 연구를 시행하였다. 방법 : 1996년 이후부터 2002년까지 충남대학교 병원에서 1999년 International Autoimmune Hepatitis Group(LAHG)에서 제시한 수정 진단 기준안에 의거하여 총 진단점수가 probable 이상에 해당하는 환자들을 대상으로 임상적 특징, 검사실 및 조직 소견과 스테로이드와 azathioprine의 치료 효과를 후향적으로 조사하였다. 결과 : 9예의 환자들은 여성이 78%, 40대가 많았고, 급성 발병이 33.3%, 피로감, 식욕부진 및 황달 등이 나타났으며, 항핵항체가 55.6%에서 그리고 항평활근 항체가 77.8%에서 양성이었고, 동반 질환은 류마치스 관절염이 2예, 특발성 혈소판 감소증 1예, Henoch-Sch nlein 자반증 및 그레브스병이 각각 1예 씩이었다. 7예에 대해서 스테로이드와 azathioprine으로 치료하여 생화학적 임상적 완해가 이루어져서 유효한 치료 결과를 얻었다. 결론 : 자가면역성 간염은 우리 나라에서 원인을 찾을 수 없는 만성 간질환의 경우, 특히 중년여성에서 다른 자가면역성 질환이 동반되었을 때 자가면역성 간염을 의심하여 자가항체 선별검사를 시행해 보아야 할 것으로 생각된다. 향후 다기관 연구를 통하여 좀 더 많은 증례를 모으고 전향적인 연구를 시행하여야 할 필요가 있다. Although autoimmune hepatitis(AIH) is common in western contries, some studties have been reported in Korea. The aim of the study was to analyze the clinical and histological features and expression pattern of the autoantibody and to examine clinical course of AIH in Korea. For 9 patients diagnosed as having AIH in our hospital since 1996, we reviewed medical records and analyzed clinical and laboratory findings retrospectively. They had a probable or definite AIH according to the revised criteria of International AIH group. The mean age was 42.7(21∼68)years and 7(77.8%) were female. Three of them(33.3%) showed acute hepatitis and five of them showed cirrhosis. Fatigue and anorexia were the most frequently complained symptoms(55.6%). Four patients(44.4%) were accompanied with other autoimmune diseases. Antinuclear antibody was detected in 5(55.6%) and anti-smooth muscle antibody was detected in 7(77.8%). Three patients showed focal picemeal necrosis and four showed periportal fibrosis. Among 7 patients who received immunosuppressive therapy, six patients(85.7%) showed initial response. and biochemical and serologic remission were achived in 5(71.4%) and 3(42.8%) patients, AIH seems to be partly responsible for chronic liver disease of unknown etiology in Korea. AIH should be suspected in female patients with unknown chronic liver disease of unknown etiolgy, especially accompanied with other autoimmune disease. The clinical characteristics of AIH may not be quite different from those of Western countries.

      • β-NSF계와 빈졸계 계면활성제로 변성된 인조석의 물성

        조현영,박성기,김진만,서정목 공주대학교 자원재활용 신소재 연구센터 1999 1차년도 센터 성과집 Vol.1999 No.-

        건축용 외장재로 사용되는 인조석은 혼합수, 시멘트, 석분, 경량골재를 사용하여 만들어지는데 본 연구에서는 제조단가를 낮추고 물성을 향상시키기 위하여 β-NSF제 계면활성제와 빈졸계 계면활성제를 사용하였다. 본 연구를 통해 β-NSF제와 빈졸계 계면활성제의 최적 배합비가 1.0wt%와 0.1wt%됨을 도출하였고, 새로 개발된 인조석은 기존의 인조석에 비하여 물성이 약 20% 증가하고, 동결융해 저항성이 300% 증가하였다. 그러나, 제조가격은 기존의 제품에 비해 30% 이상 감소된다. Extrior finishing matcrials of artificial stones are manufactured with minture of water, cement, stone powder and light-weight aggregate. In this rescarch, we tried to find a way of increasing the physicl properties and decreasing the manufacturing cost of artificial stone. So we used β-NSF base surfactant and vinsol base surfactant to the artifical stone mixture instcad of light weight aggregatc. The optimum dosage of the β-NSF and the vinsol surfactants for artificial stone are found to be 1.0 wt % and 0.1 wt % of cement, respectively. The physical properties increased ca 20% and the durability for freezing &thawing of the new frtificial stone increased ca 300% while the manufacturing cost of the new artificial stone decreased as much as 30%.

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