• Journal of Biosystems Engineering
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• v.32 no.5
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• pp.316-323
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• 2007

This study was carried out to obtain the basic data for the development of the solid fuel with investigating the characteristics of mixtures of animal wastes and wasted coal and supply it as an energy resource to agricultural farms for heating of agricultural facilities. It was investigated for the characteristics of animal wastes (swine waste, swine waste with sawdust, cattle waste), wasted coal, the mixtures of animal wastes and wasted coal with or without mixing seawater. The characteristics of solid fuel according to the mixture ratio of animal wastes and wasted coal were analyzed. The effects of seawater affecting on calorific value and thermal pyrolysis of solid fuels were investigated. The results of this study are as follows: 1) The calorific value was improved with mixing seawater into wasted coal due to chemical reaction. 2) The diverse solid fuels of various calorific values can be made with adjusting the ratio of animal wastes and wasted coal. 3) Animal wastes and wasted coal had each different reaction temperature of thermal pyrolysis and the decreasing rate of weight. 4) The mixture of animal wastes and wasted coal would be ignited easily. Therefore, the solid fuel could be ignited more conveniently when seawater is mixed with it.

• Nuclear Engineering and Technology
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• v.38 no.3
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• pp.301-310
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• 2006

Destructive methods were used for the burnup determination of U-Zr alloy nuclear fuel irradiated in the High-flux Advanced Neutron Application Reactor (HANARO) at KAERI. The dissolution rate of unirradiated U-Zr alloy fuel in $HNO_3$/HF mixtures was investigated for the experimental conditions of a different temperature, and initial concentrations of HF and $HNO_3$. The irradiated U-Zr alloy fuel specimen was dissolved in a mixed acid condition of 3 M HNO3 and 1 M HF at $90^{\circ}C$ for 8 hours under reflux. The total burnup was determined from measurement of the Nd isotope burnup monitors. The method includes U, Pu, $^{148}Nd,\;^P{145}Nd+^{146}Nd,\;^{144}Nd+^{143}Nd$ and total Nd isotopes determination by the isotope dilution mass spectrometric method (IDMS) using triple spikes $(^{233}U,\;^{242}Pu\;and\;^{150}Nd)$. The effective fission yield was calculated from the weighted fission yields averaged over the irradiation period. The results are compared with that obtained by the destructive -spectrometric measurement of the $^{137}Cs$ monitor.

• Journal of the Korean Ceramic Society
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• v.44 no.12
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• pp.727-732
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• 2007

In order to fabricate a highly performing cathode for low-temperature type solid oxide fuel cells working at below $700^{\circ}C$, electrode microstructure control and electrode polarization measurement were performed with an electronic conductor, $La_{0.8}Sr_{0.2}MnO_3$ (LSM) and a mixed conductor, $La_{0.6}Sr_{0.4}Co_{0.2}Fe_{0.8}O_3$(LSCF). For both cathode materials, when $Sm_{0.2}Ce_{0.8}O_2$ (SDC) buffer layer was formed between the cathode and yttria-stabilized zirconia (YSZ) electrolyte, interfacial reaction products were effectively prevented at the high temperature of cathode sintering and the electrode polarization was also reduced. Moreover, cathode polarization was greatly reduced by applying the SDC sol-gel coating on the cathode pore surface, which can increase triple phase boundary from the electrolyte interface to the electrode surface. For the LSCF cathode with the SDC buffer layer and modified by the SDC sol-gel coating on the cathode pore surface, the cathode resistance was as low as 0.11 ${\Omega}{\cdot}cm^2$ measured at $700^{\circ}C$ in air atmosphere.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.800-805
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• 2001

Recently, our world is faced with very serious and hard problems related to the air pollution due to the exhaust emissions of the diesel engine. So, lots of researchers have studied to reduce the exhaust emissions which influenced the environment strong. In this paper, the effect of oxygen component in fuel on the exhaust emissions has been investigated for diesel engine. And, we tried to analysis the quantities of the low and high hydrocarbon among the exhaust emissions in diesel engine. It have been investigated by the quantitative analysis of the hydrocarbon $C_1\simC_6$ using the gas chromatography. This study carried out by comparing the chromatogram with diesel fuel and diesel fuel blended DGM(diethylene glycol dimethyl ether) 5%. The results of this study show that the hydrocarbon $C_1\simC_6$ among the exhaust emissions of the mixed fuels are exhausted lower than those of the diesel fuel at the all load and speed. In particular, high boiling point hydrocarbons such as $C_5$ and $C_6$ were reduced remarkably in high speed and load region.

• Journal of Hydrogen and New Energy
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• v.26 no.4
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• pp.363-368
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• 2015

Finding an alternative fuel and reducing environmental pollution are the main goals for future internal combustion engines. The purpose of this study is to obtain low-emission and high-efficiency by hydrogen enriched LPG fuel in a LPG engine. An experimental study was carried out to obtain fundamental data for the emit HC emission characteristics at cold start of pre-mixed LPG and hydrogen in a LPG engine with various fractions of hydrogen-LPG blends. To maintain equal volume ratio of fuel blend, the amount of HC was decreased as hydrogen was gradually added. The results showed that as hydrogen increases, in-cylinder pressure increased. Also emission of unburned hydrocarbon (HC) is sharply decreased.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.2
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• pp.110-115
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• 2012

This study describes the characteristics of combustion and exhaust emission in the special engine applying a fuel reactivity controlled compression ignition (RCCI) concept with two different energizing type (solenoid and piezoelectric) injectors for diesel injection. A diesel-gasoline mixed dual-fuel reactivity controlled compression ignition concept is demonstrated as a promising method to achieve high thermal efficiency and low emission in internal combustion engines for transportation vehicles. For investigating the combustion characteristics of RCCI, engine experiments were performed in a light-duty diesel engine over a range of injection timing and mixing rate of gasoline in mass. It was investigated that by increasing the nozzle hole diameter, increasing the combustion pressure and the net indicated mean effective pressure. $NO_x$ and soot can be reduced by advancing start of injection in 84 mixing rate of gasoline in mass. The resulting operation showed that light duty engine could achieve 48 percent net indicated efficiency and 191[g/kW-hr] net indicated specific fuel consumption with lower levels of nitrogen oxides and soot.

• Journal of ILASS-Korea
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• v.17 no.3
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• pp.121-127
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• 2012

The study is to investigate the mixing stability, fuel properties, and macroscopic spray characteristics of diesel-gasoline blended fuels in a common-rail injection system of a diesel engine. The test fuels were mixed diesel with gasoline fuel, which were based volume fraction of gasoline from 0 to 100% in 20% intervals. In order to analyze the blended effect of gasoline to diesel fuel, the properties of test fuels such as density, viscosity, and surface tension were measured. In addition, the spray behavior characteristics were studied by investigating the spray tip penetration and spray angle using a spray images through a spray visualization system. It was revealed that the density, kinematic viscosity and surface tension of diesel-gasoline blending fuels were decreased with the increase of gasoline fuel. The injection quantity of test fuels were almost similar level at short energizing duration condition. On the other hand, the increase of energizing duration shows the decrease of injection quantity compared to short energizing duration. The test blending fuels have similar growth in Spray tip penetration and Spray cone angle.

• Journal of the Korean Electrochemical Society
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• v.19 no.2
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• pp.45-49
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• 2016

In order to mitigate oxidative degradation of polymer membrane during fuel cell operation, an organic radical quencher was introduced. Rutin was selected as a radical quencher and mixed with sulfonated poly(arylene ether sulfone) to prepare composite membrane. Physicochemical properties of the composite membranes such as water uptake and proton conductivity were characterized. Hydrogen peroxide exposure experiment, which can mimic accelerated oxidative stability test during fuel cell operation, was adopted to evaluate the oxidative stability of the membranes. The composite membranes containing Rutin showed similar proton conductivity and enhanced oxidative stability compared to pristine ones.

• Nuclear Engineering and Technology
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• v.40 no.2
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• pp.147-154
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• 2008

The general corrosion behavior of austenitic and ferritic steels(316L, 304, N controlled 304L, and 410) in supercritical water is investigated in this paper. After exposure to deaerated supercritical water at $480^{\circ}C$/25 MPa for up to 500 h, the four steels studied were characterized using gravimetry, scanning electron microscopy/energy dispersive X-ray spectroscopy(SEM/EDS), X-ray photoelectron spectroscopy(XPS), and X-ray diffraction(XRD). The results show that the 316L steel with a higher Cr and Ni content has the best corrosion-resistance performance among the steels tested. In addition to the oxide layer mixed with $Fe_{3}O_{4}$ and $(Fe,Cr)_{3}O_{4}$ that formed on all the samples, a $Fe_{3}O_{4}$ loose outer layer was observed on the 410 steel. The corrosion mechanism of stainless steels in supercritical water is discussed based on the above results.

• Nuclear Engineering and Technology
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• v.50 no.5
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• pp.724-730
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• 2018

Chromium and chromium nitride were selected as potential barriers to prevent fuel-clad chemical interaction (FCCI) between the cladding and the fuel material. In this study, ferritic/martensitic HT-9 steel and misch metal were used to simulate the reaction between the cladding and fuel fission product, respectively. Radio frequency magnetron sputtering was used to deposit Cr and CrN films onto the cladding, and the gas flow rates of argon and nitrogen were fixed at certain values for each sample to control the deposition rate and the crystal structure of the films. The samples were heated for 24 h at 933 K through the diffusion couple test, and considerable amount of interdiffusion (max. thickness: $550{\mu}m$) occurred at the interface between HT-9 and misch metal when the argon and nitrogen were used individually. The elemental contents of misch metal were detected at the HT-9 through energy dispersive X-ray spectroscopy due to the interdiffusion. However, the specimens that were sputtered by mixed gases (Ar and $N_2$) exhibited excellent resistance to FCCI. The thickness of these CrN films were only $4{\mu}m$, but these films effectively prevented the FCCI due to their high adhesion strength (frictional force ${\geq}1,200{\mu}m$) and dense columnar microstructures.