http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
고분자 전해질형 연료전지(PEFC) 가스확산층의 이방성이 열 및 물관리에 미치는 영향에 대한 수치적 연구
이기용(Giyong Lee),최용준(Yongjun Choi),주현철(Hyunchul Ju) 한국자동차공학회 2009 한국자동차공학회 학술대회 및 전시회 Vol.2009 No.11
The goal of this paper is to numerically investigate the effects of gas-diffusion layer(GDL) anisotropy and the spatial variation of contact resistance between GDLs and catalyst layers(CLs) on water and heat transfer in polymer electrolyte fuel cells(PEFCs). A three-dimensional, two-phase, numerical PEFC model is employed to capture the transport phenomena inside the cell. The model is applied to a two-dimensional cross-sectional PEFC geometry with regard to the in-plane and through-plane directions. A parametric study is carried out to investigate the effects of various key parameters. The parameters include through-plane and in-plane GDL thermal conductivities, operating current densities, electronics and thermal contact resistance. The simulation results clearly demonstrate that GDL anisotropy and the spatial variation of GDL/CL contact resistance have a strong impact on thermal and two-phase transport characteristics in a PEFC by significantly altering the temperature, water and membrane current density distributes to the identification of optimum water and thermal management strategies of a PEFC based on realistic anisotropic GDL and contact resistance variation inside a cell.
실험동물 랫드를 이용한 미세먼지 기도노출에 따른 호흡기계 독성에 대한 마늘의 예방효과 탐색
이윤범(YoonBum Lee),김근우(GeunWoo Kim),송영민(YoungMin Song),한영훈(YoungHoon Han),하창수(ChangSu Ha),이지선(JiSun Lee),김민희(MinHee Kim),손혜영(HyeYoung Son),이기용(GiYong Lee),허 용(Yong Heo),김창열(ChangYul Kim) 한국환경보건학회 2020 한국환경보건학회지 Vol.46 No.6
Objectives: Exposure to fine dust (PM10) could contribute to the occurrence of cardiovascular disease or respiratory abnormalities. Since garlic is known to possess an anti-oxidative stress effect, the present study was performed to evaluate the effect of garlic intake on fine dust-mediated pulmonary toxicity. Methods: Rats were intratracheally instilled with fine dust at 15 mg/kg body weight (BW)/day for five days following five-day intragastric intubation of garlic at 0.7 or 1.4 g/kgBW/day, or 13.1 mg/kgBW/day S-allyl-cysteine (SAC) as a reference component in garlic. Blood and bronchoalveolar lavage fluid (BALF) were collected. Results: Deposit of fine dust was visually and histopathologically observed in the lungs. Body weight gain during the instillation period was significantly lowered in all the groups instilled with fine dust. Neutrophil numbers in blood were significantly elevated in the fine dust alone group, but this alteration was diminished in the groups administered with garlic. Levels of serum glutathione were lower in the rats instilled with fine dust alone, and this decrease in the glutathione level seems dose-dependently compensated among the groups administered with garlic. Similar findings were observed in the BALF with statistical significance. Typical pulmonary histopathological observation related with inflammation was demonstrated in the lungs of the rats exposed to fine dust alone, whereas such histopathologic findings were not improved in the groups administered with garlic. Conclusion: The present study suggests that garlic intake could alleviate fine dust-mediated pulmonary or systemic toxicities. Further investigation is necessary to delineate the mechanism of garlic-mediated effects on pulmonary function.
연료전지 모델을 이용한 분리판 분할 전류밀도분포 측정에 대한 연구
최용준(Yongjun Choi),이기용(Giyong Lee),남진무(Jinmoo Namg),주현철(Hyunchul Ju) 한국자동차공학회 2010 한국자동차공학회 부문종합 학술대회 Vol.2010 No.5
The goal of this paper is to numerically evaluate the accuracy of the measurement technique by applying a three-dimensional, two-phase fuel cell model to a 100㎠ area fuel cell geometry in which segmented bipolar plate(BP) and non-segmented membrane are combined together. The measurement method via segmented BP is generally used to be justified. The simulation results revealed a similarity of the current distribution between membrane and BP but not perfectly matched. The maximum relative error of 33% exited near the U-turn regions and the numerical study further illustrates that the erroneous result originates from the BP segmented non-symmetrically based on the flow channels that allows some currents by passing flow channels to flow into its neighboring segment. Finally, this paper suggested optimal way to minimize the error between bipolar plate and membrane.
강경문(Kang, Kyungmun),고요한(Ko, Johan),이기용(Lee, Giyong),주현철(Ju, Hyunchul) 한국신재생에너지학회 2010 한국신재생에너지학회 학술대회논문집 Vol.2010 No.06
In this paper, both theoretical and experimental investigations have been performed to examine the effects of key operating parameters on the cell performance of a DMFCs (i.e., methanol feed concentration and operating temperature). For experiment, the membrane electrode assemblies (MEAs) were prepared using a conventional MEA fabrication method based on a catalyst coated electrode (CCE) and tested under various cell temperatures and methanol feed concentrations. The polarization curve measurements were conducted using in-house-made 25cm² MEAs. The voltage-current density data were collected under three different cell temperatures (50?C, 60?C, and 70?C) and four different methanol feed concentrations (1 M, 2 M, 3 M, and 4 M). The experimental data indicate that the measured I-V curves are significantly altered, depending on these conditions. On the other hand, previously developed one-dimensional, two-phase DMFC model is simulated under the same operating conditions used in the experiments. The model predictions compare well with the experimental data over a wide range of these operating conditions, which demonstrates the validity and accuracy of the present DMFC model. Furthermore, both simulation and experimental results exhibit the strong influences of methanol and water crossover rates through the membrane on DMFC performance and I-V curve characteristics.
피부감작능 평가 대체시험법간 위양성 및 위음성 화학물질에 대한 인체 세포주 활성화방법의 전수에 따른 예측력 평가
조아랑 ( Ahrang Cho ),여경욱 ( Kyenguk Yeo ),정미숙 ( Misook Jung ),이재희 ( Jaehee Lee ),양수정 ( Sujeong Yang ),( Ravi Gautam ),이기용 ( Giyong Lee ),조지훈 ( Jihun Jo ),( Manju Acharya ),( Anju Maharjan ),김창열 ( Changyu 한국동물실험대체법학회 2020 동물실험대체법학회지 Vol.14 No.1
The in vitro alternative assay for evaluating skin sensitizing potentials (SSP) called human Cell Line Activation Test (h-CLAT) has been recently adopted as an international test guideline. The present study was proceeded to pursue the domestic establishment and expansion of h-CLAT. The standard operational procedure was prepared in detail by the lead laboratory (LL) and transferred to one participating laboratory (PL). The LL demonstrated technical proficiency for the 10 substances listed in OECD TG 442E. The PL also demonstrated a certain level of proficiency, in that 4-phenylenediamine and 4-aminobenzoic acid distributed with coded names were correctly classified as positive and negative on SSP, respectively, and other indices including 75% cell viability (CV75) and relative fluorescence intensity (RFI) % for CD54 and CD86 were fell within the reference range. Methyl methacrylate, nickel chloride, and resorcinol, which are inconsistent in predicting SSP through various alternative test methods, were unanimously predicted as negative, positive, and positive on SSP by the two laboratories for the first time through h-CLAT. Both chlorobenzene and sodium lauryl sulfate with the existing h-CLAT report as positive and negative, respectively, were predicted as negative by the PL, which could contribute toward overall categorization into non-skin sensitizer.