• 전기학회논문지P
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• 제58권4호
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• pp.563-567
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• 2009

The polymer electrolyte membrane fuel cell(PEMFC) with the advantages of low-operating temperature, high current density, low cost and volume, fast start-up ability, and suitability for discontinuous operation becomes the most reasonable and attractive power system for transportation vehicle and micro-grid power plant in a household. 200W PEM-type FCs system was integrated by this study, then the electrical characteristics and diagnosis of the fuel cell were analyzed with variations on mass flow rate and stack temperature. The ranges of the variations are 1~8L/min on $H_2$ volume and $20{\sim}70^{\circ}C$ on stack temperature.

• 설비공학논문집
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• 제14권4호
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• pp.278-284
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• 2002

The work presented here provides a control of the supply duct outlet air temperature in PEM (personal environment module) using fuzzy PID controller. In previous work, PID control systems were used, but the result shows that the outlet air temperature and electric heater regulating voltage were oscillated. Fuzzy PID control systems are designed to improve the system response obtained using PID control and implemented experimentally Also, PID controller and fuzzy controller without PID logic are provided to compare the result with that of the fuzzy PID controller. Data obtained shows that the fuzzy PID control system satisfies the design criteria and works proper1y in controlling the supply air temperature. Also it has bettor performance than the previous result obtained using PID control.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.285-285
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• 2006

The ionic layer-by-layer (LBL) assembled films can be formed by sequentially dipping of substrates to oppositely charged polyions solution in the multilayer, called polyelectrolytes multilayer (PEM) films. Easy way of these assemblies of charged polymers offer the ability to adjust important parameters such as controllability of thickness in the nanometer-scale level and functionality of most top layer of PEM films. Nevertheless, we do not know of any trials to fabricate PEM organic films into nanometer size. Herein, we show the integration of the LBL technique with DPN in fabricating nanometer size patterns of multilayered polyelectrolyte structures. Through the use of single and multiple cantilever AFM probes, we demonstrate the parallel writing capabilities of DPN.

• 한국수소및신에너지학회논문집
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• 제29권2호
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• pp.226-234
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• 2018

Even though the nuclear power plants has many advantages, safety issues of nuclear power plants are crucial factors of reliable operation. A tritium detector is a useful sensor to analyze amount of exposed radiation from the nuclear power plants. Currently, concentration of underwater tritium is measured precisely but it takes very long time. Since electrolysis is extracted hydrogen from the coolant of nuclear power plant, it can motivate to develop new type of real-time sensor. In this study, Proton Exchange Membrane (PEM) electrolyzer is studied for candidate as preprocessor of real-time tritium detector. Characteristics of the unit PEM electrolyzer were experimentally investigated. A simulation model is developed to understand physical behavior of unit PEM electrolyzer under dynamic operation.

• 전기화학회지
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• 제2권3호
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• pp.171-175
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• 1999

Novel process for high power catalyst electrode for PEM fuel cell has been developed. MEA having this catalyst electrode showed $0.5W/cm^2\;with\;0.2mg/cm^2$ of Pt loading at aunospheric humid hydrogen and oxygen condition. In this process, platinized carbon and plain carbon powders were coated with ionomer (Nafion) and hydrophobic polymer (PTFE), respectively and it could maximize two roles of catalyst electrode, l.e., reaction and gas supplying component. Those polarization characteristics proved the improved performance by reducing potential drop especially in the concentration polarization region.

• Journal of Electrochemical Science and Technology
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• 제9권2호
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• pp.99-108
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• 2018

Proton exchange membrane (PEM) water electrolysis systems offer several advantages over traditional technologies including higher energy efficiency, higher production rates, and more compact design. In this study, all the experiments were performed with a self-designed PEM electrolyser operated at 1 atm and $25^{\circ}C$. Two types of electrolyte were used: (i) potassium hydroxide (KOH), and (ii) sulfuric acid ($H_2SO_4$). In the experiments, the voltage, current, and time were measured. The concentration of the electrolyte significantly affected the electrolyser performance. Overall the best case was with 15 wt% $H_2SO_4$ at the anode channel and 20 wt% at the cathode channel with. In addition, increasing the difference in concentration of the sulfuric acid had an effect on the diffusion. The diffusion flux became larger when the difference in concentration became larger, increasing electrolyser efficiency without the addition of extra energy.

• 대한기계학회논문집B
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• 제30권11호
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• pp.1117-1122
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• 2006

The PEM type regenerative fuel cell(RFC) for the ground simulator of the regeneration electric power system has been designed, manufactured, and tested. In this paper, the designing and manufacturing procedures of the RFC were presented. Also, the performance test results were showed briefly. The RFC consists of PEM type stack, humidifier, pressure and flow control valve, storage tanks, pump and controller. The performance tests were carried out with stack and system performance tests. The performance targets are more than 50% stack efficiency, 1.5kW stack power, less 400W parasitic power in design condition. Most of the performances required are satisfied.

• 동아시아식생활학회지
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• 제7권1호
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• pp.65-70
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• 1997

To investigate the food preservative effects of leaf mustard Dolsan(Brassica juncea), the pretreated extract of leaf mustard Dolsan were added to Kimchi and the results are as following. pH of Kimchi added leaf mustard Dolsan extracts were lower than that of control at initial stage, but after 6 days of fermentation, pH was higher in order of Kimchi added the pretreated extract of leaf mustard Dolsan (hydrolyzed at 3$0^{\circ}C$ for 24 hours, PEM), the unpretreated extract of leaf mustard Dolsan(UEM) and control. The total number of bacteria and lactic acid bacteria increased rapidly at the initial stage of fermentation and reached plateau at 2 days of fermentation. The number of bacteria and lactic acid bacteria of Kimchi added leaf mustard Dolsan extracts were lower than that of control ,a and antimicrobial activity of PEM in Kimchi was higher than that of UEM. After 2 days fermentation, sensery value of Kimchi added PEM was more excellent than that of control.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.680-685
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• 2007

Power semiconductor which is adapted in the rolling stock has a high practicality for capacity of high voltage and high speed switching. but it has a trouble of fever cause of high speed On, Off switching loss and the operating junction temperature is limited to $150^{/circ}C$ because is made from the silicon for the foundation material. Therefore, it is important to find a way out of this trouble and must make the countermeasure. In this research, the caloric value of the integrated PEM is calculated to adapt the optimized heat pipe and the reliability of the heat pipe is demonstrated through the cooling performance test and vibration test.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 추계학술대회 논문집
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• pp.137-141
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• 2007

The startup behaviour of PEM fuel cells at subfreeze zero is one of the most challenging tasks to be solved before PEM fuel cell vehicle is commercialized. Automotive companies are trying to increase cold statup capability of fuel cell. In this study, we found out the design factor of the stack to increase cold startup capability using 4kW stack and then cold startup test was performed at the various shutdown condition and the various current. In order to test the cold startup possibility and capability in vehicle, we installed 80kW stack in the vehicle and this 80kW fuel cell vehicle was housed in an environmental chamber to investigate the characteristics of cold startup and driving. We found that it is possible for fuel cell vehicle with 80kW stack to self-heated cold startup and drive at $-15^{\circ}C$.