한국산 뱀독이 개구리 심실근육세포의 수축력과 활동전압에 미치는 영향

한형일,방효원,엄대용,이상돈 중앙대학교 의과대학 의과학연구소 1984 中央醫大誌 Vol.9 No.3

In order to observe the effects of freeze-dried saliva of Agkistrodon caliginosus and Agkistrodon saxatilis, the Korean poisonous snakes, on the contractility and action potential of frog ventricular muscle cells, the isometric tension in a vertical chamber and the action potential in horizontal chamber were recorded and analyzed. The following results were obtained; 1. ED_50, to reduce the contractility was 4-8ug/ml in the case of A. saxatilis and 8-16ug/ml in the case of A. caliginosus which all were higher than that of A. brevicaudus and the inhibitory effect on the contractility was greater in the case of A. saxatilis than that of A. caliginosus. 2. In the case of A. saxatilis, APD_50(time to repolarize 50% of action potential amplitude) decreased from 820±80 ms to 710±60 ms, the overshoot and the V max(Maximum depolarization rate) decreased from 34±8 mV to 18±4 mV, from 98±8 V/s to 89±4 V/s respectively. 3. In the case of A. caliginosus, ADP_50 decreased from 880±70 ms to 720±40 ms, the overshoot and the V max decreased from 28±6 mV to 20±4 mV, from 89±8V/s to 77±12V/s, respectively. 4. Inhibition of contractility and overshoot potential were more prominent in A. saxatilis and APD_50 was more decreased in A. caliginosus. The above result showed that Korean snake venoms would decrease the ionic current underlying the rapid upstroke phase and slow inward currents by calcium ions simultaneously in a frog ventricular muscle cells.

주물사를 이용한 건재제조

한상목,윤창호,신대용,김상진 강원대학교 석재복합신소재제품연구센터 1996 석재연 논문집 Vol.1 No.-

다량으로 폐기되는 주물사를 이용하여 반응인자인 열처리 온도, 열처리 시간 등을 변화하여 최적의 경량골재를 제조하여 반응인자에 따른 경량골재의 겉비중, 흡수율 및 강도 등을 측정하여 각종 제조 조건에 따른 영향을 검토하였다. The method of manufacture for the light-weight aggregate from casting sand is developed at this study. In order to find optimum manufacturing condition, firing time and firing temperature were varied and their effects on physical properties, such as density, water absorption, mechanical strength were measured.

Bi-계 고온 초전도 선재의 Jc향상에 관한 연구((II)

한일용,정대영,오영우 慶南大學校 附設 工業技術硏究所 1993 硏究論文集 Vol.11 No.-

Powder in tube 방법과 pressing 및 소결의 혼합공정의 반복법을 이용하여 Ag로 피복된 Bi(Pb)-Sr-Cu-O선재를 만드는데 있어서 2223상의 서로 다른 두가지 분말을 사용하였다. 보다 낮은 2223상을 함유하는 분말을 사용해서 만든 선재는 77.3K와 OT에서 Jc가 1*10⁴A/㎠임을 보여주었다. 두 선재의 XRD patterns의 비교, 미세구조, 전기적 성질에 의해서 얻어진 결과는 소량의 2212상의 존재와 최종 pressing후 소결 과정 동안 얻어진 Ca, Cu-rich액상을 형성하는 상은 잘 배열된 2223상의 입자들간의 향상된 결합과 pressing공정 중에 생긴 미세균열의 제거는 치밀한 미세조직과 높은 Jc를 나타내었다. Two powders different in the 2223 phase content were used to prepare Ag-sheathed Bi(Pb)-Sr-Ca-Cu-O tapes by using the power-in-tube method and a repitation of the combined process of pressing and sintering. The tapes prepared using the power with lower 2223 phase content showed a Jc of 1*10⁴A/㎠ at 77.3K and O T. The results obtained by comparing XRD patterns, micromorphology, electrical properties in both tapes, indicated that the presence of a little amount of 2212 phase and Ca, Cu-rich liquid forming phase during the sintering after the final pressing is critical in connecting and eliminating the well aligned 2223 phase grains and microcracks induced by the pressing process, respectively, resulting in a highly densified morphology and a high Jc.

점화시기 및 당량비 변화에 따른 CNG기관의 성능 및 배출가스에 관한 연구

한영출,오용석,박봉규,김대열,김미수 한국공작기계학회 2001 한국생산제조학회지 Vol.10 No.4

Research on the development of CNG dedicated en dine that has important meaning both as a clean fuel and an alterna-tive energy to reduce the exhaust emission horn diesel engine are actively going on these days. In this study, in order to present the direction and application of CNG engine, we tested the CNG engine performance experimented by changing the parameters such as ignition timing, equivalent ratio. The engine performance and exhaust emission were measured by engine performance mode at maximum load condition with increasing the rpm in the range of 1,000∼2,200rpm. Also, the testing engine was heavy-duty CNG dedicated engines with displacement of 11,050cc.

철원산 현무암을 이용한 결정화 유리 제조

한상목,신대용,이병민,木村邦夫 강원대학교 부설 석재복합신소재 제품연구센터 1999 석재연 논문집 Vol.4 No.-

철원산 현무암에 Al₂O₃와 CaO를 각각 첨가하여 결정화유리를 제조하고 그 물리적 특성을 조사하였다. SiO₂8.3wt%, CaO 20wt% 그리고 Al₂O₃8.3wt%를 현무암에 첨가하여 단일상의 Diopside 와 Anorthite를 제조할 수 있었으며, CaO를 첨가한 경우에는 첨가된 CaO가 결정핵으로 작용하여 anorthite와 diopside의 혼합 결정상이 얻어졌으며, Anothite는 CaO 첨가량이 증가함에 따라서 감소하는 경향을 나타내었다. Al₂O₃를 현무암에 첨가하면 hercynite(FeO·Al₂O₃)의 분해에 의해 anorthite가 생성되고 있음을 알 수 있었다. CaO 20wt% 첨가한 경우 900℃에서 2.93g/㎤의 부피 비중과 215MPa의 곡강도를 Al₂O₃ 8.3wt% 첨가한 경우에는 1000℃에서 2.83g/㎤과 210MPa의 곡강도를 나타내었다. 흡수율은 Al₂O₃8.3wt%, CaO 15wt% 그리고 Cao 20wt% 첨가한 경우 모두 900℃ 이상에서 1% 이하의 낮은 흡수율을 나타내었으며, 열팽창계수는 Diopside의 peak intensity가 증가함에 따라 증가하였다. Glass-ceramics were prepared by adding CaO 8.3wt%, 15wt%, 25wt% and Al₂O₃8.3wt% to SiO₂ 8.3wt% added Chulwon basalt and their effects of phase transition and firing temperature on the densification, microstructure development and thermal expansion coefficient were investigated by means of XRF. SEM and diletometer. It was one phase of diopside and anorthite respectively. The CaO added to Chulwon basalt played an role of crystal site of anorthite and diopside. However anorthite decreased and finally disappeared according as CaO addition increased by 20wt%. In case of decomposition. The flexural strength of CaO 20wt% added glass-ceramics fired at 900℃ and Al₂O₃ 8.3wt% added glass-ceramics fired at 1000℃ was 215MPa and 210MPa respectively. The thermal expansion coefficient varied from 6.554×??/℃ to 8.146×??/℃ depending on diopside peak intensity of CaO added glass-ceramics on XRD results.

유리폐기물과 하수슬러지 소각재의 고형화 처리연구

한상목,신대용,윤봉구,김승겸 강원대학교 부설 석재복합신소재 제품연구센터 2002 석재연 논문집 Vol.7 No.-

하수슬러지 소각재, 폐유리분말 및 고로슬래그의 고형화에 의하여 건자재를 제조하였다. 하수슬러지 소각재는 SiO_2와 Al_2O_3가 75 wt%, Fe_2O_3가 8.21 wt%, 폐유리분말은 SiO_2 71.4 wt%, Na_2O 14.43 wt% 및 CaO 9.32 wt%, 고로슬래그는 SiO_2 33.4 wt%, CaO 41 wt% 및 Al_2O_3 14.5 wt%를 함유하여 세라믹스 제조원료로 사용이 가능하였다. 하수슬러지를 800℃에서 2시간 하소한 무기질분말을 분쇄하여 하수슬러지 소각재를 제조하였다. 30∼70 wt%의 하수슬러지 소각재, 30∼70 wt%의 폐유리분말 및 10∼30 wt%의 고로슬래그를 혼함하여 950∼1,100℃에서 2시간 소성하여 시편을 제조하였다. 하수슬러지 소각재 첨가량이 감소하고 폐유리분말의 첨가량과 소성온도가 증가하면 부피비중과 압축강도는 증가하였으나 기공률과 흡수율은 감소하였다. 1,050℃에서 소성한 시편(No. 1, 3, 5 및 7)의 부피비중은 1.70∼1.83, 기공률과 흡수율은 0.3∼2.4% 및 0.1∼1.5%, 압축강도 272∼323 kgf/㎠을 나타내었다. 고로슬래그를 첨가하여 1,100℃로 소성한 시편(No. 8, 9, 및 10)의 부피비중은 1.82∼2.11 및 압축강도는 350∼671 kgf/㎠이었다. 하수슬러지 소각재, 고로슬래그 및 시편의 중금속출량은 매립지 침출수배출 허용기준치보다 낮아, 본 연구에서 제조한 시편은 주변 환경에 해가 없어 건자재로의 이용이 가능하였다. An experimental study for the constructional material by solidification using sewage sludge ash, waste glass powder and blast furnace slag was carried out in the senses of waste materials disposal and utilization. The reusability of sewage sludge ash, waste glass powder and blast furnace slag as a raw material in the manufacturing process of ceramics was highly expected because the chemical compositions of these waste materials were mostly SiO_2 and Al_2O_3. Sewage sludge ash was fabricated by calcined at 800℃ for 2 hours and obtained by the crushing. The mixture of 30∼70wt% of sewage sludge ash, 30∼70 wt% of waste glass powder and 10∼30 wt% of blast furnace slag were heated at 950∼1,100℃ for 2 hours. The density and the compressive strength of specimen increased with increasing the sintering temperature and decreasing the addition amount of sewage sludge ash, No. 1, 3, 5 and 7 specimens showed the bulk density of 1.70∼1.83, porosity of 0.3∼2.4%, water absorption of 0.1∼1.5% and compressive strength of 272∼323kgf/㎠. And, that of the No. 7 specimen heated at 1,100℃ increased with increasing the addition amount of blast furnace slag, and for No. 8, 9 and 10 specimens, bulk density was 1.82∼2.11 and compressive strength was 350∼671 kgf/㎠. An extraction test for specimen to detect toxic materials showed below the permitted standard of land-filling extractable heavy metal contents. It was founded that the specimen were useful for the constructional materials.

스위치드 릴럭턴스 전동기를 위한 구동시스템의 역률개선과 고효율에 관한 연구

한대희,최준혁,윤용호,정동효,김도군,원충연 성균관대학교 2003 학술회의지원논문목록집 Vol.2003 No.-

Switched Reluctance Motor (SRM) offers the advantages of simple and robust motor construction, high speeds and high efficiencies over a wide operating range of torque and speed, excellent controllability. However, SRM has the disadvantages of high current harmonics, and low power factor because of a capacitor filter is inserted in the power converter and inductance of SRM is high, it has pulse waveform of current. This paper deals with an energy efficient converter fed SRM system with the reduced harmonics and improved power factor and with higher efficiency. The validity of the proposed scheme is verified via experiment. We are implemented the proposed control system using 8OC196KC micro-controller.

수질정화용 실리케이트 다공질 담체 제조

한상목,신대용 강원대학교 부설 석재복합신소재 제품연구센터 2000 석재연 논문집 Vol.5 No.-

석탄회와 벤토나이트 혼합시료의 열분석 결과, 다공질체를 제조하기 위하여는 석탄회와 벤토나이트에 흡착되어 있는 흡착수의 이탈과 유기물의 연소가 완료되는 900℃이상의 열처리가 필요하였다. 벤토나이트의 첨가량과 열처리 온도가 증가함에 따라 다공질체의 미세구조가 치밀화되어 부피비중과 압축강도는 증가하였으며 흡수율과 기공률은 감소하였다. 900℃에서 2시간 열처리한 9FAIB시편의 부피비중은 1.23g/㎤, 기공률 47.5%, 흡수율 37.3% 및 압축강도 10.1MPa의 값을 나타내었으나, 1,100℃에서 2시간 열처리한 5FA5B 시편의 부피비중은 1.59g/㎤ 기공률 6.5%, 흡수율 4.5% 및 압축강도 19.3MPa의 값을 나타내었다. 본 연구에서는 아미노산의 첨가량이 증가할수록 부피비중과 압축강도는 증가하였으며 흡수율과 기공률은 감소하였다. Utilization of fly-ash by-product from coal fired power plants and classified as general waster became very important problem to solve in the environmental protection and recycling of waste materials. To investigate the possibility of large scale substitution of fly-ash as a raw materials for porous sintered materials for water-purifier, it was prepared with fly-ash and bentonite at 900-1100℃, and their physical properties were established by XRD, SEM, bulk density, porosity, water absorption and compressive strength test. The bulk density and compressive strength of the sintered bodies heat-treated at 900℃ made from 90wt% of fly-ash and 10wt% of bentonite was about 1.23g/㎤ and 15MPa. From the water absorption and porosity analysis of the sintered materials, a decrease of porosity and water absorption were observed with increasing the bentonite content in raw materials, water absorption and porosity were 37.3% and 47.5%. Pore with diameter of about 10㎛ were produced in porous sintered materials. In this study, it was shown that the porous sintered materials have a good performance of water-purifier with many pores and an adequate strength.

증산고령토를 이용한 경량건축자재 제조

한상목,윤창호,신대용,김상진 강원대학교 석재복합신소재제품연구센터 1997 석재연 논문집 Vol.2 No.-

저급의 점토질 원료인 증산 점토와 석탄폐석인 셰일를 이용하여 조성, 열처리 온도 및 열처리 시간 등의 반응인자를 변화하여 다공성의 경량건축자재를 제조하여 이들의 물리적 성질인 부피비중, 흡수율 및 기계적 강도를 측정하였다. 그 결과 증산점토 단일성분과 30wt%의 셰일을 첨가한 시편을 1200℃에서 30분간 급속가열하여 부피비중이 0.31g/cm³, 흡수율 1.0 % 및 압축강도가 69 kg/cm²인 다공성의 경량건축자재를 제조하였다. Suitability of low grade clay of Jungsan and shale as raw materials for light weight constructional material was examined. In order to find optimum manufacturing conditions with composition, heating temperature and heating time were varied and their effects on physical properties, such as bulk density, water absorption and mechanical strength were measured. The results obtained with a light weight constructional materials with one component of clay and 30wt% of shale added in clay heated at 1200℃ for 30 min, and the rapid-heating was more than the slow-heating for bloating. The light weight constructional material having bulk density of 0.31 g/cm³, water absorption of 1.03% and compressive fracture strength of 69 kg/cm² obtained.

재생 Al₂O₃분말을 이용한 Al₂O₃세라믹스의 소결 특성 연구

한상목,신대용 강원대학교 석재복합신소재제품연구센터 2001 석재연 논문집 Vol.6 No.-

Al2O3 세라믹스의 재활용을 위한 소결거동을 조사하기 위하여 재생 Al2O3 분말의 첨가량, 입자크기 및 소결온도에 따른 시편의 물리ㆍ기계적 특성을 측정하였다. 1,650℃에서 소결한 순수 Al2O3 시편을 급랭에 의하여 500㎛ 정도의 입자로 파쇄한 후, 자동유발을 이용하여 40㎛ 전ㆍ후로 분쇄하였다. 분쇄한 Al2O3 분말과 순수한 Al2O3 분말을 적정비로 혼합 후, 재소결에 의하여 제조한 Al2O3 세라믹스의 재생 Al2O3 분말의 첨가량, 입자 크기 및 소결온도에 따른 시편의 밀도 흡수율, 기공률, 3점곡강도 및 SEM 분석을 행하였다. 재생 Al2O3 분말의 첨가량이 증가함에 따라 시편 내에 존재한 기공에 의하여 밀도와 3점곡강도는 감소하였으나, 1,650℃에서 소결한 시편의 3점곡강도는 200 MPa 이상으로 구조용재료로 사용이 가능하였다. 또한, 재생 Al2O3 세라믹스 100wt%의 유리분말을 첨가하요 1,650℃에서 소결한 시편은 첨가한 유리분말의 고온용융에 의하여 생성한 액상에 의하여 물리ㆍ기계적 성질은 감소하였다. The sintering behavior of the Al2O3 composites for recycling Al2O3 powder was investigated as a function of the recycling Al2O3 powder and particle size with respect to physical and mechanical properties. Pure Al2O3 specimen was fabricated by sintering and was crushed into powder under 40㎛ in particle size by thermal shock treatment and automatic mortar crushing. Then, the crushed Al2O3 powder was mixed with pure Al2O3 powder, and the mixture was subjected to re-sintering to reuse Al2O3 composites. The reclaimed Al2O3 specimen were investigated by 3-point bending strength and SEM observation of microstructure. Density and 3-point bending strength of the reclaimed Al2O3 composites decreased as the addition amounts of recycled Al2O3 powder increased. The average 3-point bending strength of specimens heated at 1,650℃ were over 200 MPa. SEM observation indicated that pore distribution was inhomogeneous and pores were still resided in specimen, Pores, consequently, formed cracks which markedly decreased bending strength. Futhermore, 10wt% glass containing reused Al2O3 specimens were decreased physical and mechanical properties, so called over-sintering behavior.