• 한국표면공학회지
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• 제22권2호
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• pp.55-61
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• 1989

A fuel cell which causes electrochemical ratio of conventional with oxygen consists of mainly there parts, such as electrolyte, fuel and oxidant electrode. IN this paper, most efforts were delivered to manufacturing PETE-bonded gas-diffusion electrode, and preparation methods of the porous electrodes has been discussd. A medio temperature, phosphoric acid fuel cell (PAFC) provided with fuel (hydrogen) and oxygen showed oxygen showed excellent performance characteristics with made electrodes. Performance data obtained from hydrgen-oxygen cell were presented to illustrate their properties. It was found that the optimum amounts of platinum in clectrode for hydrgen-oxygen PAFC were about 3mg/cm3 and the PTFE content of gas diffusion layer and catalyst layer were 25% and 15%, respectively.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1996년도 춘계학술발표회논문집(2)
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• pp.254-259
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• 1996

The hydraulic tests for 16$\times$16 JDFA were performed to obtain the pressure loss coefficients using the FACTS. The pressure loss coefficients are calculated by converting the each properties of experimental values for inlet region, mixing vane grid, outlet region and core region by performing a power fit of the pressure loss coefficient values to the corresponding Reynolds number. The test results are compared with the existing calculated values and evaluated by using the CALOPR code in terms of pressure drop. It is turned out that the differences between the test results and the calculated values are about by 3.8% for the pressure loss coefficients and by 8.5% for the pressure drop.

• 한국자동차공학회논문집
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• 제17권3호
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• pp.1-7
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• 2009

Ethanol has properties of a lower setting point, higher oxygen contents, lower cetane numbers, and also higher volatility compared to biodiesel. Thus, biodiesel fuel can be improved in the fluidity of and exhaust emissions by blended ethanol fuel. This research aims to understand combustion characteristics of biodiesel-ethanol blending fuel inside a constant volume chamber by obtaining some fundamental data in order to improve combustion atmosphere. To understand the physics of combustion, high speed camera was applied to visualize the development of combustion processes, and combustion pressure and exhaust emission were measured at several blending ratios of ethanol and biodiesel fuel. This information may contribute to improve the performance of biodiesel engine and reduce emissions in future.

• 방사선산업학회지
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• 제17권1호
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• pp.119-125
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• 2023

Burnup of spent nuclear fuel should be determined accurately for the safety storage of spent nuclear fuel. In this study, a gamma detection system was developed as a part of basic research to measure the burnup of spent nuclear fuel, and its performance was evaluated using a calibration source. The prototype of the gamma detection system was based on a semiconductor sensor using a CZT (Cadmium Zinc Telluride). For quantitative evaluation, tests were conducted using ¹³⁷Cs, ¹³⁴Cs and ²⁵²Cf calibration source. In the performance evaluation, Its field applicability was verified by assessing the energy resolution, the detection linearity and the shielding attenuation according to the nuclide.

• Applied Biological Chemistry
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• 제50권3호
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• pp.137-146
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• 2007

지구 온난화의 주 원인인 온실가스의 배출을 감소시키기 위해서 바이오연료에 대한 필요성 및 중요성이 제기되어 왔다. 이미 유럽을 중심으로 오래전부터 바이오디젤 연료에 대한 연구가 시작되어 왔으며 지금은 상용화 단계에 접어들고 있는 반면, 국내 바이오디젤 연료에 대한 연구 수준은 이제 시작단계에 불과한 실정이다. 바이오디젤 연료로 사용가능한 유지작물의 지방산 조성에 따라 자동차 엔진 성능이 저하될 수 있다는 문제가 제기되었고, 이를 해결하고자 표준화된 바이오디젤 품질 규격서가 마련되어졌다. 유럽에서 마련된 바이오디젤 규격에 의하면 올레인산 함량이 높은 기름이 바이오디젤 연료로 적합하며, 유채기름이 다른 유지작물의 기름에 비하여 바이오디젤 연료에 적합하다고 알려져 있다. 따라서 국내 유지작물의 바이오디젤 연료화를 위한 품질 개량과 생산량 증대를 위해 생명공학기술을 이용한 품종 개량에 관한 연구 전략에 대해 고찰하였다.

• Korean Chemical Engineering Research
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• 제47권2호
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• pp.237-242
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• 2009

화석연료의 고갈과 원유가격 폭등으로 인해 이를 대체할 수 있는 다양한 연료의 개발이 이루어지고 있다. 동물성 지방이나 식물성 기름의 주성분인 트리글리세라이드를 메탄올과 반응시켜 생산된 바이오디젤은 기존의 석유디젤을 대체할 수 있는 친환경적인 연료로 알려져 있다. 본 연구에서는 국내에서 유통중인 경유에 6종류의 원료별 바이오디젤을 일정 비율로 혼합한 뒤, 다양한 연료특성을 분석하였다. 바이오디젤의 농도가 높아질수록 밀도, 동점도, 인화점이 상승하였고, 저온특성은 악화되는 것을 확인하였다. 또한 경유의 중요한 연료특성인 세탄가를 IQT를 이용해 측정한 결과, 바이오디젤의 혼합비율이 높아질수록, 유도세탄가가 높게 측정되었으며, 특히 팜유로부터 생산된 바이오디젤의 경우, 71.26의 높은 유도세탄가가 측정되었다.

• 멤브레인
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• 제20권3호
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• pp.217-221
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• 2010

기존 고분자전해질연료전지(PEMFC)의 단점을 극복하기 위해 고체전해질 알카라인연료전지(SAMFC)가 근래에 많이 연구되고 있다. 본 논문에서는 술폰화 폴리벤지이미다졸(PBI) 유도체를 이용하여 SAMFC용 막을 제조하였다. 술폰화 폴리벤지이미다졸 유도체는 KOH에 의해 쉽게 도핑되고 도핑된 막은 높은 $OH^-$의 전도도와 기계적 강도를 보였다. 특히 sPBI-co-PBI (술폰화 PBI : 비술폰화 PBI = 75 : 25)의 경우, $90^{\circ}C$ 100% 상대습도 하에서 $2.98{\times}10^{-2}\;S/cm$의 높은 $OH^-$의 전도도를 보였다.

• 한국수소및신에너지학회논문집
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• 제30권6호
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• pp.567-577
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• 2019

Due to the depletion of fossil fuels and environmental pollution, demand for alternative energy is gradually increasing. Among the various methods, a method to convert biomass into alternative fuel has been proposed. The bio-fuel obtained from biomass through pyrolysis process is called pyrolysis oil (PO) or bio-oil. Because PO is difficult to use directly in conventional engines due to its poor fuel properties, various methods have been proposed to upgrade pyrolysis-oil. The simplest approach is to mix it with conventional fossil fuels. However, due to their different polarity of PO and fossil fuel, direct mixing is impossible. To resolve this problem, emulsification of two fuels with a proper surfactant was proposed, but it costs additional time and cost. Alternatively, the use of alcohol fuels as an organic solvent significantly improve the fuel properties such as fuel stability, calorific value and viscosity. In this study, blends of diesel, n-butanol, and coffee ground pyrolysis oil (CGPO) which is one of the promising PO, was applied to diesel generator. Combustion and emissions characteristics of blended fuels were investigated under the entire load range. Experimental results show that ignition delay is similar to that of diesel at high load. Although, hydrocarbon and carbon monoxide emissions are comparable to diesel, significant reduction of nitrogen oxides and particulate matter emissions were observed.

• Nuclear Engineering and Technology
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• 제46권2호
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• pp.169-182
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• 2014

High-performance research reactors require fuel that operates at high specific power to high fission density, but at relatively low temperatures. Research reactor fuels are designed for efficient heat rejection, and are composed of assemblies of thin-plates clad in aluminum alloy. The development of low-enriched fuels to replace high-enriched fuels for these reactors requires a substantially increased uranium density in the fuel to offset the decrease in enrichment. Very few fuel phases have been identified that have the required combination of very-high uranium density and stable fuel behavior at high burnup. U-Mo alloys represent the best known tradeoff in these properties. Testing of aluminum matrix U-Mo aluminum matrix dispersion fuel revealed a pattern of breakaway swelling behavior at intermediate burnup, related to the formation of a molybdenum stabilized high aluminum intermetallic phase that forms during irradiation. In the case of monolithic fuel, this issue was addressed by eliminating, as much as possible, the interfacial area between U-Mo and aluminum. Based on scoping irradiation test data, a fuel plate system composed of solid U-10Mo fuel meat, a zirconium diffusion barrier, and Al6061 cladding was selected for development. Developmental testing of this fuel system indicates that it meets core criteria for fuel qualification, including stable and predictable swelling behavior, mechanical integrity to high burnup, and geometric stability. In addition, the fuel exhibits robust behavior during power-cooling mismatch events under irradiation at high power.

• 대한기계학회논문집A
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• 제29권4호
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• pp.600-605
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• 2005

In this study, the ring tensile test at high temperature was suggested to evaluate the hoop tensile properties of small tube such as the cladding in the nuclear reactor Using the Arsene's ring model, the ring tensile test was performed and the test data were calibrated. From the result of the ring test with strain gauge and the numerical analysis with 1/8 model, LCRR(load-displacement conversion relationship of ring specimen) was determined. We could obtain the hoop tensile properties by means of applying the LCRR to the calibrated data of the ring tensile test. A few difference was observed in view of the shape of fractured surface and the fracture mechanism between at the high temperature and at the room temperature.