• The Korean Journal of Ceramics
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• v.4 no.2
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• pp.72-77
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• 1998

A defect model for UO$_2$ fuel containing soluble fission products was devised based on the defect structure of pure and doped uranias. Using the equilibrium between fuel solid-solution and fission-products and the material balance within the fuel, a tracing method to get the stoichiometry change of urania fuel with burnup was made. This tracing method was applied to high burnup urania fuel and DUPIC fuel. The oxygen potential of urania fuel turned out to increase slightly with burnup. The stoichiometry change was calculated to be negligible due to the buffering role f Mo. The oxygen potential of DUPIC fuel out to be sensitive to the initial chemical state of Mo in the fuel.

• Journal of the Korean Home Economics Association
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• v.40 no.8
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• pp.153-166
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• 2002

This study aims to reveal the influence of price increase in gasoline on household expenditure trade-off. The subjects were 651 households, acquired the first quarter of 1996 and 1997. This study shows the change of the auto fuel budget share in the same household and they were analyzed with the paired t-test, independent t-test. The results are as follows; 1) the price increase of auto gasoline resulted in the increase of its budget share, regardless of a household's true increase or decrease of income. 2) according to price increase in gasoline, the auto fuel budget share has been changed, therefore I divided these changes into three group on the base of it's degree of change. 3) In the group that had a decrease in auto fuel budget share compared to the degree of change, there was a trade-off between the increase in food and light & light water and the decrease of education and auto fuel budget share. Auto fuel in this group was used as discretionary good. 4) In the group that had a similar change in auto fuel budget share compared to the degree of change, there were no trade-off between expenditure items except auto fuel budget share and miscellaneous decrease. This group is the highest income group among the three groups. 5) In the group that had and increase of change in auto fuel budget share compared to the degree of change, there was a trade-off between the increase of eating-out and auto fuel, and the decrease of education and miscellaneous budget share. Auto fuel in this group was used as a discretionary good. 6) trade-off expenditure budget share showed a mixed effect between the influence of increase in gasoline price and influence of increase in true income.

• Journal of Institute of Convergence Technology
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• v.3 no.1
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• pp.25-29
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• 2013

The purpose of this paper is to determine the fuel change and weight change impact on the fuel economy and emission characteristic of ICE (Internal Combustion Engine) vehicle. According to fuel type, fuel consumption and emission characteristics were measured and fuel used in this paper was gasoline, diesel, and LPG. Four vehicles with different weight were tested and the fuel economy were compared and analyzed by using scatter graph. Test was carried out using chassis dynamometer, CVS (Constant Volume Sampler), and emission measurement system. Diesel vehicle less emited $CO_2$ compared to gasoline and LPG. Even if same $CO_2$ between gasoline and LPG, there are difference fuel economy depending on carbon proportion of specific fuel. The heavier weight of vehicle, the worse of fuel economy and Better fuel economy performance on highway driving mode.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.28 no.2
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• pp.29-35
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• 2020

In this paper, we established a prediction model of fuel consumption at the aircraft's taxi operation. To look for countermeasures to reduce fuel consumption and carbon emissions, Airbus A380's actual ground taxi data was used. As a result, the number of stops or turnings during the taxi operation was not related to fuel consumption. It was confirmed that the amount of fuel consumption in the taxi operation was the taxi time and the thrust change. It can be confirmed that ground control optimization, which is the result of close cooperation between the control organization and the airline, is absolutely necessary to reduce taxi time and minimize the occurrence of thrust change events.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.123.2-123.2
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• 2010

Fuel Cell cogeneration system is a promising technology for generating electricity and heat with high efficiency of low pollutant emission. We have been developed 5kW class fuel cell cogeneration system for commercial and residential application. The fuel processor is a crucial part of producing hydrogen from the fossil fuels such as LNG and LPG. The 5kW class high efficiency fuel processor consists of steam reformer, CO shift converter, CO preferential oxidation(PrOx) reactor, burner and heat exchanger. The one-stage CO shift converter process using a metal oxide catalyst was adopted. The efficiency of 5 kW class fuel processor shows 75% based on LHV. In addition, for the purpose of continuous operation with load fluctuations in the commercial system for residential use, load change of fuel processor was tested. Efficiency of 30%, 50%, 70% and 100% load shows 75%, 75%, 73% and 72%(LHV), respectively. Also, during the load change conditions, the product gas composition was stable and the outlet CO concentration was below 5 ppm. The Fuel processor operation was carried out in residential fuel cell cogeneration system with fuel cell stack under dynamic conditions. The 5kW class fuel processor have been evaluated for long-term durability and reliability test including with improvement in optimal operation logic.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2236-2241
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• 2008

The surface heat flux of nuclear fuel rod is the most important factor which can affect safety of reactor and fuel. If fuel rod surface heat flux exceeds the CHF(${\underline{C}}ritical$ ${\underline{H}}eat$ ${\underline{F}}lux$), fuel can be damaged. In case of double cooled annular fuel, which is under developing, contains two coolant channels. Therefore, a generated heat in the fuel pellet can move to inner or outer channel and heat flow direction is decided by both sides heat resistance which varied by dimension and material property change which caused by temperature and irradiation. The new program(called DUO) was developed. For the calculation of surface heat flux, a both sides convection by inner/outer coolant, s gap temperature jump and conduction in the fuel are modeled. Especially, temperature and time dependent fuel dimension and material property change are considered during the iteration. A sample calculation result shows that the DUO program has sufficient performance for annular fuel thermal hydraulics design.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.7 no.3
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• pp.353-358
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• 1995

The emission characteristics of a semi-Bunsen type burner for gas boilers were studied experimentally. The experimental results reveal that nitric oxide emission increases with fuel flow rate. It is linearly proportional to total fue flow rate at a small amount of fuel up to 0.4 liters per minute. It does not change significantly within the range of fuel flow rate from 0.4 to 1.2 liters per minute per nozzle and increases at large fuel flow rate. The carbon monoxide emission reveals to be dependent upon the fuel flow rate per each nozzle and the number of fuel injection nozzles. Diameter of an injection nozzle could have an effect on the emission characteristics of this type of burners. However, there is no marked change in the nitric oxide emission if the total fuel flow rate is same with different nozzle sizes.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.27 no.4
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• pp.96-104
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• 2019

The response to climate change of international air transport industry might be initiated by ICAO's CORSIA (Carbon Offsetting and Reduction Scheme for International Aviation) which will impact on international airlines' flight operation behavior in the future. Though the airlines' efforts to reduce fuel consumption has been a major issue in economics of aviation industry, the improvement of fuel efficiency in flight operation will have additional impact on their profitability by introducing carbon emission cost. The fuel consumption in flight operation will be somewhat influenced by pilots' technical action for maneuvering aircraft during flight operation. This study will investigate pilots' behavior on decision for tactical aircraft control for mission flight. The data will be collected by the survey through sample pilots asking about their intention and perception on fuel savings during flight operations. The data will be analyzed by AHP process and the study will find out the elements and factors influencing pilots' behavior on technical decision of flight and their weights on fuel saving effects.

• Transactions of the Korean hydrogen and new energy society
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• v.21 no.6
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• pp.526-532
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• 2010

The anode may inevitably undergo a number of reduction.oxidation (redox) cycles during solid oxide fuel cells (SOFCs) operation. The re-oxidation of Ni to NiO causes significant mechanical stress to be developed across the anode, which may destroy the integrity of the whole cell. In this study, the redox behavior of Ni-YSZ composite was examined at $800^{\circ}C$ using various characterization techniques.

• Journal of Climate Change Research
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• v.7 no.2
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• pp.177-184
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• 2016

Recently, the need for technology development of commercial vehicle fuel consumption has emerged. Fuel economy improvement of transport equipment and transportation efficiency, and increasing attention to the logistics cost reduction measures. Increasing attention to the logistics cost reduction measures by fuel economy improvement of transport equipment and transportation efficiency. In this study, we have installed aerodynamic reduction device (side skirt, boat tail) to 14.5 ton cargo trucks and 45 ft tractor-trailers. And the fuel consumption was compared installed before and after. Fuel economy assessment for the aerodynamic reduction value device was tested by modifying the SAE J1321 Joint TMC/SAE Fuel Consumption Test Procedure - Type II test in according domestic situation. Greenhouse gas reductions were calculated in accordance with the scenario, including fuel consumption test results. When the 14.5 ton cargo trucks has been equipped with side skirts and boat tail, it confirmed the improvement in fuel efficiency of 4.72%. One Heavy-duty truck's the annual greenhouse gas reductions value are $6.86ton\;CO_2\;eq$. And if applying the technology to more than 50% of registered 15 ton trucks, greenhouse gas reductions are calculated as $686,826ton\;CO_2\;eq./yr$.