마늘의 Thiosulfinate 소장에 관한 연구

이명환,김주선 서울여자대학교 자연과학연구소 1990 자연과학연구논문집 Vol.1 No.-

마늘외 처리온도 및 시간에 따른 thiosulfinate 함량의 변화와 실온 및 고온추출시 황화합물의 성분 변화를 조사하기 위하여 N-ethylmaleimide 발색반응과 UV Spectrophotometer 및 gas chromatograph를 이용하여 분석한 결과 다음과 같은 결과를 얻었다. 처리온도 및 시간에 따른 thiosulfinate함량의 변화에 있어서 25℃, 50℃에서 5시간, 75℃에서 30분까지 존재하였으나, U.V spectrophotometer에 의한 검출에서는 75℃, 1시간과 100℃, 15분까지도 완전히 분해되지 않으며, 또한 diallyl disulfide의 양도 75℃, 15분보다 1시간에서 3배 정도 많았는데 이는 thiosulfinate가 분해되어 생성된 것으로 앞의 결과를 뒷받침해 주고 있다. 실온에서의 n-hexane 및 수증기 증류하여 얻은 추출물의 함량은 각각 0.10%, 0.12% 였으며 실온의 n-hexane추출물에서는 diallyl disulfide보다는 동정하지 못한 물질이 주물질이었으며 수증기 증류하여 얻은 정유에서는 diallyl disulfide가 주물질로 관찰되었다. The effects of heating time and temperature on the change of thiosulfinate content and the effects of n-hexane extraction and steam distillation on the change of sulfur compounds of garlic bulbs were investigated using N-ethylmaleimide color reaction, UV spectrophotometer and gas chromatograph. Thiosulfinate was detected in n-hexane extracts from garlic bulbs heated for 5 hours at 25℃ and 50℃ and for 30 minutes at 75℃ by the color reaction method. The UV spectrophotometer was more sensitive than the color reaction method to detect the thiosulfinate from even the extracts of samples heated for 1 hour at 75℃ and 15 minutes at l00℃.The quantity of diallyl disulfide which was formed from the decomposition of thiosulfinate increased to reach threefold values by 1 hour heating at 100℃ as compared with the samples heated for 15 minutes at 75℃, which well supported the above results. The steam distillation yielded extract of 0.12% which was mainly diallyl disulfide and the n-hexane extraction yielded extract of 0.10% at room temperature, however, the main compund was not diallyl disulfide but other unidentified compound.

스크러버형 EGR시스템 디젤기관의 배기 배출물에 미치는 재순환 배기온도의 영향

배명환,류창성 경상대학교 생산기술연구소 2002 工學硏究院論文集 Vol.2 No.-

The effects of intake mixture temperature on performance and exhaust emissions under four kinds of engine loads were experimentally investigated by using a four-cycle four-cylinder, swirl chamber type, water-cooled diesel engine with scrubber EGR system operating at three kinds of engine speeds. The purpose of this study is to develop the scrubber exhaust gas recirculation(EGR) control system for reducing NO_x and soot emissions simultaneously in diesel engines. The EGR system is used to reduce NO_x emissions. And a novel diesel soot-removal device with a cylinder-type scrubber which has five water injection nozzles is specially designed and manufactured to reduce soot contents in the recirculated exhaust gas to the intake system of the engine. The influences of cooled EGR and water injection, however, would be included within those of scrubber EGR system. In order to study the effect of intake mixture temperature, a intake mixture heating device which has five heating coils is made of a steel drum. It is found that the specific fuel consumption rate is considerably elevated by the increase of intake mixture temperature, and that NO_x emissions are markedly decreased as EGR rates are increased and intake mixture temperature is dropped, while soot emissions are increased with increasing EGR rates and intake mixture temperature.

Epichlorohydrin Polymer의 배합에 의한 성능변화 및 그 응용에 관한 연구

李明煥 서울여자대학교 1978 서울여자대학논문집 Vol.- No.7

The purpose of this study is to establish an effective way to utilize the application of Epichlorohydrin polymer compound. The results are shown as follow: 1. For the most effective heat-resisting compound of epichlorohydrin hose and tube either red lead or Dyphos/Dythal family is recommended to be used as acid acceptor, either NBC and Niclate as fire-fighting aid, and ethylene thiourea (NA-22, Thiate N or Pennac CRA) for crosslinking. Imidazol too appears to be the most effective for air aging, and especially the vulcanizer made under sufficient curing time turns out to have excellent heat-resisting effect. For the coulping agent Silane-189 was used, and when silica was charged in, long-range heat-proof quality was far better than that when in black compounding . 2. In long-range heat-proof air aging effect heat-resisting epichloro hydrin polymer compund was superior to CR, CSM or NBR, but in air aging effect was a little inferior heat-proof EPDM. In the meantime, epichlorohydrin only polymer compound shows a higher numerical value in long-range aging test than EPDM. The compound which showed the highest antioxidizing effect was ACM/ECO blend.

스크러버型 EGR 시스템 디젤機關의 NO_x 및 煤煙排出物에 미치는 酸素濃度의 影響에 관한 硏究

裵明煥 慶尙大學校 工科大學 自動化및컴퓨터應用技術硏究所 1999 自動化 및 컴퓨터應用技術 Vol.6 No.1

The effects of recirculated exhaust gas on the characteristics of NO_x and soot emissions under a wide range of engine load have been experimentally investigated by a water-cooled, four-cylinder, indirect injection, four cycle and marine diesel engine operating at two kinds of engine speeds. The purpose of the present study is to develop the EGR control system for reducing NO_x and soot emissions simultaneously in diesel engines. The EGR system is used to reduce NO_x emissions, and a novel diesel soot removal apparatus with a cylinder-type scrubber for the experiment system which has 6 water injector(A water injector is made up 144 nozzles with 1.0 mm in diameter) is specially designed and manufactured to reduce the soot contents in the recirculated exhaust gas to intake system of the engines. The intake oxygen concentration obtained by the intake air flow and the oxygen concentration in the recirculated exhaust gas, and the exhaust oxygen concentration measured in exhaust manifold are used to analyse and discuss the influences of EGR on NO_x and soot emissions. The experiments are performed at the fixed fuel injection timing of 15.3°BTDC regardless of experimental conditions. It is found that NO_x emissions are decreased and soot emissions are increased owing to the drop of intake oxygen concentration and exhaust oxygen concentration as the EGR rate rises.

유한요소법에 의한 헬리컬기어의 맞물림 강도특성에 관한 연구

박성환,유용석,김병석,최명진,오택열 慶熙大學校 大學院 1993 高凰論集 Vol.12 No.-

In this study, the mesh stiffness characteristics of helical gears are evaluated by applying the finite element method. The bending and shear deflections on the contact line are obtained by the finite element method, and the contact deflections are obtained using the equation of Weber and Banaschek. Finally, using the influence method, contact ratio and load sharing ratio, the mesh stiffness characteristics of helical gears are evaluated. The results obtained could be summarized as follows: 1) By increasing the facewidth and helix angle of helical gears, a more constant mesh stiffness and transmission errors are obtained. 2) m_p+m_f〈2.0 The characteristics of this class helical gear pair are similar to that of spur gear. 3) m_p+ 1.0m_f≥2.0 This class helical gear pair gives a good performance as expected from helical gears.

燃燒機關의 煤煙生成過程 모델링用 高溫·高壓 燃燒裝置의 開發

裵明煥 慶尙大學校生産技術硏究所 1997 生産技術硏究所論文集 Vol.13 No.-

A constant-volume combustion chamber with disk-type is developed to study the soot formation process under high temperatures and pressures. The premixed fuel rich propane-oxygen-inert gas mixture is simultaneously ignited by eight spark plugs located on the circumference of combus- tion chamber with 45 degree intervals. The eight converging flames compress the end gases to high pressures. The advantages of this experimental approach with symmetrically converging flames are as follows; first, the history of soot formation process with time during high tempe- ratures and pressures can be measured because the premixture in the observation field of combustion chamber is burned with a nearly constant pressure at the final stage of combustion process and the burnt gases of the observation region rarely flow in the chamber; and secondly, the combustion conditions during soot formation process can be arbitrarily changed because the combustion pressure and burnt gas temperature are easily varied by the initially charged pressure, and by the volume fraction of inert gas and oxygen concentration in the premixture, respectively.

Adriamycin-Induced Extravasation Necrosis에 관한 실험적 연구

김진환,이상열,김명석 대한성형외과학회 1992 Archives of Plastic Surgery Vol.19 No.3

Local extravasation during intravenous administration of adriamycin(doxorubicn HCI) can cause severe skin ulceration and necrosis. In order to investigate the mechanism of adriamycin-induced skin toxicity, the effects of adriamycin on reactive oxygen radical metabolism and its related lipid peroxidation were examined in vitro systems using cultured skin cells of fetal rats. Adriamycin produced a significant release of lactic dehydrogenase from cultured skin cell preparations, and varied on dosage and time. The production of superoxide anion in sonicated suspensions of cultured skin cells was significantly increased by adriamycin under the presence of NADPH and NADH. The drug also stimulated malondiadehyde(MDA) production, and index of lipid peroxidation, in NADPH-and NADH-supported cell preparations. The increased production of MDA was significantly inhibited by oxygen radical scavengers(superoxide dismutase, catalase, thiourea) and antioxidants(butylated hydroxytoluene, α-tocopherol). Treatment of cultured skin cells with 1, 3-bis(2-choroethyl)-1-nitrosourea(BCNU), an inhibitor of glutathione reductase, enhanced the lipid peroxidation induced by adriamycin, which was reduced by additions of the antioxidants. To conclude, the given data suggest that lipid peroxidation induced by oxidative insult, which resultd from stimulation on reactive oxygen radical formation and depression of antioxidative defense system, can cause cellular damage in adriamycin-treated skin cells of rats.

디젤機關의 피스톤 및 피스톤링 磨耗에 미치는 再循環 排氣의 影響에 관한 硏究

裵明煥 慶尙大學校生産技術硏究所 1999 生産技術硏究所論文集 Vol.15 No.-

The effects of recirculated exhaust gas on the wear of piston and piston rings were investigated by the experiment with a two-cylinder, four cycle, indirect injection diesel engine operating at an engine load of 75% and an engine speed of 1600 rpm. For the purpose of comparison between the wear rates of two cylinders with and without EGR, the recirculated exhaust gas was sucked into one of two cylinders after the soot contents in exhaust emissions were removed by an intentionally designed cylinder-type scrubber equipped with 6 water injectors(A water injector has 144 nozzles of 1.0 mm diameter), while only the fresh air was inhaled into the other cylinder. These experiments were carried out on the fuel injection timing fixed at 15.3˚ BTDC. It was found that the wear rate of piston skirt with EGR increased a little bit, but the piston head diameter increased, rather than decreased, owing to soot adhesion and erosion wear, and especially larger with EGR, and that the wear rates of the top and second piston ring(compression ring) thickness with EGR were more than twice the wear rate of top ring in case of no EGR, but the wear rate of oil rings thickness without EGR increased greater than that with EGR.

EGR시스템 디젤機關의 排氣 排出物 特性에 미치는 再循環 排氣의 影響에 관한 硏究

裵明煥 慶尙大學校 1997 論文集 Vol.36 No.-

The effects of recirculated exhaust gas on the characteristics of fuel economy, combustion and exhaust emissions have been experimentally investigated by a four-cylinder, four cycle., indirect injection, water-cooled and marine diesel engine operating at several loads and speeds. In order to reduce the soot contents in the recirculated exhaust gas to intake system of the engines, a novel diesel soot removal system with a cylinder-type scrubber which 6 water injectors(A water injector has 144 nozzles in 1.0 mm diameter) is specially designed and manufactured for the experiment system. The experiments in this study are performed at the fixed fuel injection timing of 15.3°BTDC regardless of experimental conditions. The brake specific fuel consumption rate is slightly fluctuated with EGR in the range of experimental conditions. The maximum value of premixed combustion for the rate of heat release is decreased with EGR at engine load 25% and the ignition is slightly delayed with EGR at engine load 100%. NOx emisons are markedly decreased with EGR, especially at high loads, while soot emissions are increased as the EGR rate rises

열분해 가스 크로마토그래피에 의한 EPDM-Polymer Blend 고무의 분석

이명환,황희선 서울여자대학교 자연과학연구소 1991 자연과학연구논문집 Vol.2 No.-

Pyrolytic analysis based on pyrolysis-gas chromatography(PGC) technique have been performaed for identification of NR, BR, SBR, CR, EPDM and their blends. The results each of characteristic peak of single rubber showed dipentene, 4-vinylcyclohexene, styrene, chloroprene, 2,4-dimethy1-1-heptene. Since the physicochemical properties of blends of NR/EPDM. BR/EPDM, SBR/EPEM, CR/EPDM,NR/EPDM, BR/SBR/EPDM were heavily affected by their blending ratio, it was found to be essential to confirm the blending ratio of the blends. Finally, the standard calibration curves for characterization of various blending ratio in each system were obtained on the basis of their pyrograms.