• KSBB Journal
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• 제23권4호
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• pp.340-344
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• 2008

CiP를 이용한 유기합성은 주로 유기용매와 완충용액을 섞어서 반응을 한다. 하지만 단순히 유기용매 상에서 효소의 활성도를 측정한 것이 아니라, 과산화수소가 있을 경우에 효소의 활성도를 측정한 결과는 예상과는 다르게 순수한 완충용액에서 보다 유기용매를 포함하고 있는 것이 더 높게 나타났다. 또한 유기용매의 비율을 증가가 될수록 효소의 활성도가 더 높게 나타났으며, 특히 2-propanol이 33%가 포함이 된 경우에는 순수한 완충용액보다 효소의 활성도가 크게 증가가 되는 것을 관찰을 할 수가 있었다. 이러한 효소의 활성도가 유기용매가 포함이 된 조건에서 높게 나는 이유는 유기용매가 CiP에 의해 생성된 반응성이 높은 라디칼을 포집을 하여서, CiP의 활성 부위인 heme의 파괴를 막는 것에 크게 기여하는 것으로 판단이 되었다.

• 한국수소및신에너지학회논문집
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• 제26권6호
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• pp.547-553
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• 2015

For commercialization of fuel cell electric vehicles, one of the key objectives is to reduce cost of full stack assembly. Regarding Membrane Electrode Assembly, the major issue is to improve fuel cell activation process in the initial Hydrogen Oxidation Reaction and Oxygen Reduction Reaction. In this research, the VD (Vacuum Drying) process has been developed for improvement of activation process. The VD condition is developed by controlling the temperature and degree of vacuum to remove the remaining solvent of electrode. Consequently, the electrode applied to VD process showed the low characteristics such as 3.5% of remaining solvent content and the improved efficiency such as 15% of activation process speed.

• 한국가스학회지
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• 제24권5호
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• pp.65-73
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• 2020

본 연구에서는 재생에너지원의 에너지저장기술(Power to gas, P2G)로써 활용되는 수전해기의 가동률 향상과 산소 이용 극대화를 통해 경제성을 확보하기 위해서 수전해기에서 배출되는 산소를 바이오매스 가스화 공정에 공급하여 추가적인 수소 생산을 통해 수소 원가를 감소시키고, 재생에너지원의 출력 감소 시 수전해기를 바이오매스 가스화 공정의 산소 제조/공급 장치로 활용하는 공정을 제안하고, 이에 대한 정량적인 효율 분석과 경제성 분석을 수행하였다.

• Advances in Energy Research
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• 제5권2호
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• pp.147-177
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• 2017

This study aims to evaluate and prioritize ten different sites in Iran's Khorasan provinces for the construction of wind farm. After studying the geography of the sites, nine criteria; including wind power, topography, wind direction, population, distance from power grid, level of air pollution, land cost per square meter, rate of natural disasters, and distance from road network-are selected for the analysis. Prioritization is performed using data envelopment analysis (DEA). The developed DEA model is validated through value engineering based on the results of brainstorming sessions. The results show that the order of priority of ten assessed candidate sites for installing wind turbines is Khaf, Afriz, Ghadamgah, Fadashk, Sarakhs, Bojnoord, Nehbandan, Esfarayen, Davarzan, and Roudab. Additionally, the outcomes extracted from the value engineering method identify the city of Khaf as the best candidate site. Six different wind turbines (7.5 to 5,000 kW) are considered in this location to generate electricity. Regarding an approach to produce and store hydrogen from wind farm installed in the location, the AREVA M5000 wind turbine can produce approximately $337ton-H_2$ over a year. It is an enormous amount that can be used in transportation and other industries.

• KEPCO Journal on Electric Power and Energy
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• 제7권1호
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• pp.137-143
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• 2021

As an electrochemical water electrolysis for green hydrogen production, both polymer electrolyte membrane (PEM) and alkaline electrolyte are being developed extensively in various countries. The PEM electrolyzer with high current density (above 2 A/cm²) has the advantage of being able to design a simple structure. Also, it is known that it has high response to electrical output fluctuations. However, the cost problem of major components is the most important issue that a PEM electrolyzer must overcome. Instantly, there are platinum group metal (PGM)-based electrocatalysts, fluorine-based polyfluoro sulfuric acid (PFSA) membrane, Ti felt (porous transport layer, PTL) and so on. Another challenging issue is productivity. A securing outstanding productivity brings price benefits of the electrolytic cells. From this point of view, we conducted basic studies on manufacturing electrode and membrane electrode assembly (MEA) for PEM electrolyzer production.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 추계학술대회
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• pp.392-395
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• 2006

In this work, the reinforcing action of carbon blacks in rubber was investigated by SEM and UTM measurements which at low a testing of the surface and mechanical properties. In order to gain an insight into the different properties between carbon blacks before and after methane/propane decomposition, various composites were prepared with SBR synthetic rubber and different carbon blacks with four loading ratios. The results were analyzed with the aim of finding suitable conditions for decomposition reaction to cut down the net cost for hydrogen production through hydrocarbon decomposition.

• 한국수소및신에너지학회논문집
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• 제20권5호
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• pp.439-446
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• 2009

This paper investigates the dehydration and RDF (Refuse Derived Fuel) production of organic wastes, livestock manure and sewerage sludge with pressurized hydrothermal treatment process. The renewable technology for the organic wastes must involve short treatment time required, reusable energy source, anti-odor and viruses, low cost for the treatment, and well-fertilization. The pressurized hydrothermal treatment process promotes to evaporate moisture in the waste after being shortly treated in a reactor, which uses steam and heat supplied by an external boiler. By the pressurized steam, the cell walls of the waste break and effectively release the internal moisture. Then, the dried waste can be mixed with waste vinyls to produce RDF with a higher heating value as high as 6,700 kcal/kg.

• 한국수소및신에너지학회논문집
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• 제19권1호
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• pp.26-34
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• 2008

This study presents an aerodynamic design and an experimental performance test of a turbo air compressor consisted of mixed-flow impeller and curved diffuser for the PEM fuel cell vehicle application. Many studies compare the efficiency, cost or noise level of high-pressure and low-pressure operation of PEM fuel cell systems. Pressure ratio 2.2:1 is considered as design target The goal of compressor design is to enlarge the flow margin of compressor from surge to choke mass flow rate to cover the operational envelope of FCV. Large-scale rig test is performed to evaluate the compressor performance and to compare the effects of compressor exit pipe volume to stall or surge characteristics. The results show that the mixed-flow compressor designed has large flow margin, and the flow margin of compressor configuration with small exit volume is larger than that with large exit volume.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 추계학술대회 논문집
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• pp.71-74
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• 2007

We have concentrated on the performance improvement of each part for durability, safety and cost of high pressure storage system for fuel cell vehicle so far. But for the mass production of fuel cell vehicle, it is necessary to evaluate durability and safety in system module. We built the standard to evaluate vibration and collision safety of high pressure storage system for fuel cell vehicle, and could verify reliability of high pressure storage system.

• 한국전기전자재료학회논문지
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• 제16권10호
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• pp.853-858
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• 2003

In this study, a new simplified technology for fabricating high density trench gate DMOSFETs using only three mask layers and TEOS/nitride spacer is proposed. Due to the reduced masking steps and self-aligned process, this technique can afford to fabricate DMOSFETs with high cell density up to 100 Mcell/inch$^2$ and cost-effective production. The resulting unit cell pitch was 2.3∼2.4${\mu}$m. The fabricated device exhibited a excellent specific on-resistance characteristic of 0.36m$\Omega$. cm$^2$ with a breakdown voltage of 42V. Moreover, time to breakdown of gate oxide was remarkably increased by the hydrogen annealing after trench etching.