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RISS 인기검색어
- 검색키워드
- 저자 : CHEN JINGWEN (검색결과 2 건)
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The effect of the anode porosity and fuel type on the performance of flat solid oxide fuel cells
Chen,JingWen 영남대학교 대학원 2021 국내석사
본 기사에서는 고체산화물 연료전지(플레이트형)의 성능을 분석한다. 먼저 수소 등 양극연료를 파악해 양극 전해질 물질의 공극비 효과를 비교·분석할 예정이다. 둘째, 고체연료전지는 수소에 최적이라는 것이 밝혀졌지만 온도 제한 때문에 수소 함량이 높고 다른 원소가 낮은 연료로 대체해 비교해본다. 연료 교환 시 연료 전지 전해액 소재의 다공성을 조절한다. 연료 점화 지점(및 반응 온도)의 차이가 배터리의 전반적인 성능에 영향을 미친다. 연료로 사용할 때의 시동 온도는 비교 및 분석에 사용된다. 시뮬레이션 분석에 COMSOL 5.5를 사용한 결과 전해액의 다공성이 SOFC에 영향을 주었지만 효과는 작았다. 성능은 일반적으로 사용되는 0.2 ~ 0.4 범위에 비례하며 이론적으로 가장 높은 SOFC 성능은 0.4이다. 이번 실험에서는 시작온도를 600℃로 설정해 수소 이외에는 프로판 성능이 가장 좋지만 에탄올 증기와의 간격이 그리 크지 않다. 단, 600 °C에서는 에탄올 증기와 프로판의 섬광점이 수소보다 낮으며, 저온에서 SOFC를 작동할 때 양극 연료를 교체할 수 있다. In this article, we will analyze the performance of solid oxide fuel cells (plate type). First, we will determine the anode fuel like hydrogen and compare and analyze the effect of the pore ratio of the anode electrolyte material. Second, solid fuel cells have been found to be optimal for hydrogen, but due to temperature limitations, try replacing them with fuels that are high in hydrogen and low in other elements for comparison. When changing fuel, adjust the porosity of the electrolyte material of the fuel cell. Differences in fuel ignition point (and reaction temperature) affect the overall performance of the battery. The starting temperature when used as fuel is used for comparison and analysis. After using COMSOL 5.5 for simulation analysis, we found that the porosity of the electrolyte affected SOFCs, but the effect was small. Performance is proportional to the commonly used range of 0.2 to 0.4, with a theoretically highest SOFC performance of 0.4. In this experiment, the starting temperature was set to 600 ° C, and propane has the best performance other than hydrogen, but the gap with ethanol vapor is not so large. However, at 600 ° C, the flashpoint of ethanol vapor and propane is lower than that of hydrogen, and the anode fuel can be replaced when operating SOFCs at low temperatures.
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Effect of Lycopus lucidus Turcz. leaves on matrix metalloproteinase activity and antioxidant
CHEN JINGWEN Graduate school of Korea Maritime & Ocean Universi 2021 국내석사
Lycopus lucidus Turcz. from Lamiaceae family, is a traditional eastern Asian medicinal plant, which is abundant in natural bioactive flavonoids, coumarins, terpenoids and tannins with potential antioxidant activity. In the present study, L. Turcz. leaves were extracted with acetone/methylene chloride and methanol solution, then sequentially partitioned with solvents (n-Hexane, 85% aqueous methanol, and water) in different polarities. Thus, two crude extracts (A+M and MeOH), as well as resulting four fractions (n-Hex, 85% aq. MeOH, n-BuOH and Water) was prepared to investigate the biological activities of L. Turcz. leaves. The effect of six samples on H2O2-induced injury in SH-SY5Y human neuroblastoma cells were evaluated by MTT assay at different doses (0.025 mg/L-0.25 mg/L). To study antioxidant effects of the crude extracts and fractions, reactive oxygen species (ROS) on SH-SY5Y human neuroblastoma cells and changes on intracellular glutathione (GSH) production were determined. In addition, nitric oxide (NO) as a mediator involved in the inflammation reaction, the inhibitory effects of NO production from samples were measured by using the in vitro lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cell line. Western blotting experiment was performed to compare the expression level of matrix metalloproteinases-2 and -9 (MMP-2 and MMP-9) in the phorbol 12-myristate 13-acetate (PMA)-induced HT-1080 cells. Finally, radical mediated DNA damage in HT-1080 cells were performed to investigate the protection ability from L. lucidus Turcz. leaves on DNA oxidative damage. In MTT assay, the pretreatment of MeOH extracts and four fractions from L. lucidus Turcz. leaves significantly increased the viability of H2O2 induced SH-SY5Y cells (p<0.05). But there was not any positive effect on SH-SY5Y cell viability after the treatment of A+M sample, which may be explained by the high cytotoxic effect from A+M sample. In western blotting experiment, these extracts and fractions led to a reduction of the secretion levels of MMP-2 and MMP-9 in HT-1080 cells. Due to the cell cytotoxicity of A+M extract, MMP-2 cannot be detected in this group, and only MMP-9 bands were found in control and Water fractions groups. In DNA oxidation analysis, the maximum inhibition of the genomic DNA damage caused by excessive oxidative stress was 80.89%, which is due to the present of A+M extracts. In antioxidant activity, intracellular ROS generation was significantly attenuated in two cells after treatment of crude extracts and fractions (p<0.05), 85% aq. MeOH and n-BuOH fractions showed a better scavenging ability than others. As for the effect of GSH production, A+M extract showed a more powerful ability in enhancing the GSH production by 15.81% than MeOH extract (13.53%) at the concentration of 1 mg/mL; meanwhile, among the fractions at the concentration of 0.5 mg/mL, 85% aq. MeOH fraction increased the GSH level most by 15.30% and followed by the n-BuOH fraction (11.80%). In regard to the effect of production of NO in RAW 264.7 cells, groups of treatment with samples all showed a significant decrease of NO level in comparison with control group (p<0.05). Both extracts efficiently decreased the NO production of cells at the inhibition of more than 80%. However, among the fractions, Water and n-Hex fractions showed better inhibitory effects in NO production than those of 85% aq. MeOH and n-BuOH fractions. Results obtained collectively indicate that the good biological activities from L. lucidus Turcz. leaves, which can be exploited for plant based anticancer and antioxidant agents in the pharmaceutical, cosmetic, nutraceutical and food industries.
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