• 한국공작기계학회논문집
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• 제14권4호
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• pp.75-80
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• 2005

An experimental study is carried out to investigate the performance and the efficiency humidifying Membrane Electrolyte Assembly and having the double-tied catalyst layers in a fuel cell system which is taken into account the physical and thermal concept. Subsequently, an electric output produced by PEMFC(Polymer Electrolyte Membrane Fuel Cell) is measured to assess the performance of a stack, and the efficiency is also evaluated according to the different situation in which unit cell is placed with and without the humidification of the MEA. It is found that the measured values of stack voltage and current are influenced by the stack temperature, humidification, and the double-tied catalyst layers which give more enhanced values to be applied to electric units.

• 한국태양에너지학회 논문집
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• 제31권4호
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• pp.122-127
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• 2011

A bee venom is very useful and expensive medical resource. A bee venom collector has some difficulties and inconveniences because of its complex component. This is used normal battery as an electric power. However, using the solar cell of the bee venom collector reduces economic burden and guarantees high efficiency. We have performed comparative experiment between the bee venom collector to use battery and the one to use solar cell(polycrystalline silicon) by collecting the bee venom simultaneously. At the same electricity, the electric frequency(AC),312 Hz is more superior than 450Hz. This paper verified through the experiments that the bee venom collector to adopt solar cell is more effective than normal collector.

• 전력전자학회논문지
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• 제23권3호
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• pp.217-224
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• 2018

In this study, the optimal design methods of soft-switching cell for high-voltage DC-DC converter (HDC) of fuel cell electric vehicles (FCEVs) is proposed for high efficiency and high power density. The appropriate soft-switching cell for FCEVs is chosen by analyzing the losses of HDC which adopts soft-switching cell. The proposed optimal design methods for the soft-switching cell are divided into two purposes which are improvement of efficiency and power density. Two kinds of design methods enable to improve fuel efficiency and cost, respectively. The proposed design methods are validated with the experimental results based on the specification and hardware used in actual FCEVs.

• Journal of Electrochemical Science and Technology
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• 제10권2호
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• pp.104-114
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• 2019

Energy is an essential driving force for modern society. In particular, electricity has become the standard source of power for almost every aspect of life. Electric power runs lights, televisions, cell phones, laptops, etc. However, it has become apparent that the current methods of producing this most valuable commodity combustion of fossil fuels are of limited supply and has become detrimental for the Earth's environment. It is also self-evident, given the fact that these resources are non-renewable, that these sources of energy will eventually run out. One of the most promising alternatives to the burning of fossil fuel in the production of electric power is the proton exchange membrane (PEM) fuel cell. The PEM fuel cell is environmentally friendly and achieves much higher efficiencies than a combustion engine. Water management is an important issue of PEM fuel cell operation. Water is the product of the electrochemical reactions inside fuel cell. If liquid water accumulation becomes excessive in a fuel cell, water columns will clog the gas flow channel. This condition is referred to as flooding. A number of researchers have examined the water removal methods in order to improve the performance. In this paper, a new water removal method that investigates the use of vibro-acoustic methods is presented. Piezo-actuators are devices to generate the flexural wave and are attached at end of a cathode bipolar plate. The "flexural wave" is used to impart energy to resting droplets and thus cause movement of the droplets in the direction of the traveling wave.

• 동국한의학연구소논문집
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• 제9권
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• pp.51-71
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• 2000

본 실험은 월국환합보중익기탕(越鞠丸合補中益氣湯)의 항스트레스효과를 조사하기 위하여 시행되었다. 월국환합보중익기탕(越鞠丸合補中益氣湯)이 전기자극으로 스트레스 상황을 유발시킨 mouse에게 끼친 B 임파구 면역계 변화를 mouse 혈청의 면양적혈구(綿羊赤血球)에 대한 적혈구 응집소가와 비장세포에서 B 세포 및 T 세포가 차지하는 백분율의 변화를 통하여 측정하였으며 이를 대조군과 비교 분석하였다. 혈청 항체가의 측정에서 스트레스 자극하에서 월국환합보중익기탕(越鞠丸合補中益氣湯)을 투여받은 그룹에서 약제를 투여받지 않은 그룹에 비하여 유의성 있는 차이를 보여(p<0.01) 면역 기능을 정상군의 수준으로 유지하는 결과를 얻었다. T 세포와 B 세포의 백분율의 측정에서도 스트레스 자극하에서 월국환합보중익기탕(越鞠丸合補中益氣湯)을 투여 받은 그룹에서 약제를 투여 받지 않은 그룹에 비하여 유의성 있는 차이를 보여(p<0.01) 면역 기능을 정상군의 수준으로 유지하는 결과를 얻었다. 실험결과들로 보아 월국환합보중익기탕(越鞠丸合補中益氣湯)이 체액성 면역 반응과 비장 내 면역 세포의 백분율을 정상의 수준으로 유지하는 효과를 보여 면역 기능의 이상에 응용할 수 있는 가능성을 제시한다고 사료된다.

• 한국환경보건학회지
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• 제21권1호
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• pp.78-85
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• 1995

Ornithine decarboxylase(ODC) is an indicate enzyme in carcinogenesis. We divided Sprague Dawley rats into six groups: control, electric field exposure, X-ray only irradiation, X-ray irradiation with electric field exposure group, Sr-90 injected group and Sr-90 and electric field complex exposure group. The ODC activity was measured in rat's bone marrow cell every week. The results were summarized as follows: The ODC activitied was increased in X-ray irradiated, Sr-90 injected and Sr-90 and electric field complex exposed group as compared with that of control(p<0.05). The ODC activity was increased comparing that of control neither in X-ray and electric field complex exposed group nor electric field only exposed group. This result suggests that the electric field doesn't have myeloid carcinogenicity and myeloid cancer incidence caused by ionized radiation is suppressed by electric field exposure.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1086_1087
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• 2009

본 논문에서는 과도 응답 특성에 따른 고분자 전해질 연료전지(PEMFC)를 모델링하였다. 연료전지에 이러한 과도특성이 일어나는 것에 원인에 대하여 분석해보고, 실제 실험을 통해 과도특성이 일어나는 것을 확인하였다. 실험결과 파형을 분석하여 Matlab & Simulink를 이용하여 PEMFC의 과도 응답 특성을 모델링하였다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2007년도 추계학술발표대회 및
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• pp.37.1-37.1
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• 2007

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.3-4
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• 2007

Many electrochemical power devices such as solid state batteries and solid oxide fuel cell have been studied and developed for solving energy and environmental problems. Fuel cell is a modular, high efficient and environmentally energy conversion device, it has become a promising option to replace the conventional fossil fuel based electric power plants. This paper offers some new perspectives on fuel cell development and commercialization which come from the broad consideration of the commercialization efforts of the entire fuel cell industry.

• Transactions on Electrical and Electronic Materials
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• 제6권5호
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• pp.238-242
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• 2005

The Pt counter electrode of a dye-sensitized solar cell (DSSC) plays a role in helping redox reaction of iodine ions in electrolyte, also, transferring electrons into electrolyte. In this case, it is expected that characteristics of Pt electrodes strongly depend on fabrication process and its surface condition. In this study, Pt electrodes were prepared by a electro-deposition and a RF magnetron sputtering. Electrochemical behavior of Pt electrodes was compared using cyclic-voltammetry and impedance spectroscopy. Surface morphology of Pt electrodes was investigated by FE-SEM and AFM. I-V characteristics of DSSC were measured and discussed in association with the surface properties of counter electrode. As a result, electrochemical properties of electro-deposited Pt electrode were superior to that of sputtered Pt electrode. This is likely that enlarged area of surface in electro-deposited Pt electrode in comparison with the case of sputtered Pt electrode playa role in enhancing such electrochemical properties.