• Journal of the Korean Crystal Growth and Crystal Technology
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• v.21 no.3
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• pp.129-135
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• 2011

EAF dust from steel industry used as primary materials for the production of lightweight aggregates. Fe compounds in EAF dust plays an important role in the bloating reaction. This study was conducted to evaluate the feasibility of using bottom ash and dredged soil from coal power plant and EAF dust. The effect of different raw material compositions and sintering temperatures on the lightweight aggregate properties were evaluated. The characteristic of thermal bloating of bottom ash and dredged soil were mainly influenced by ferrous materials. The specific gravity of aggregate was decreased with the addition of EAF dust and kerosene was reduced sintering temperature on the bloating formation. Lightweight aggregate containing 10% EAF dust having apparent density under 1.0 g/$cm^3$ were produced at $1150{\sim}1200^{\circ}C$.

• Geomechanics and Engineering
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• v.20 no.3
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• pp.207-220
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• 2020

Clay soils have a big potential to become contaminated with the oil derivatives because they cover a vast area of the earth. The oil derivatives diffusion in the soil lead to soil contamination and changes the physical and mechanical properties of the soil specially clay soils. Soil stabilization by using new material is very important for geotechnical engineers in order to improve the engineering properties of the soil. The main subjects of this research are a- to investigate the effect of the cement and epoxy resin mixtures on the stabilization and on the mechanical parameters as well as the microstructural properties of clay soils contaminated with gasoline and kerosene, b- study on the phenomenon of clay concrete development. Practical engineering indexes such as Unconfined Compressive Strength (UCS), elastic modulus, toughness, elastic and plastic strains are all obtained during the course of experiments and are used to determine the optimum amount of additives (cement and epoxy resin) to reach a practical stabilization method. Microstructural tests were also conducted on the specimens to study the changes in the nature and texture of the soil. Results obtained indicated that by adding epoxy resin to the contaminated soil specimens, the strength and deformational properties are increased from 100 to 1500 times as that of original soils. Further, the UCS of some stabilized specimens reached 40 MPa which exceeded the strength of normal concrete. It is interesting to note that, in contrast to the normal concrete, the strength and deformational properties of such stabilized specimens (including UCS, toughness and strain at failure) are simultaneously increased which further indicate on suitability and applicability of the current stabilization method. It was also observed that increasing cement additive to the soil has negligible effect on the contaminated soils stabilized by epoxy resin. In addition, the epoxy resin showed a very good and satisfactory workability for the weakest and the most sensitive soils contaminated with oil derivatives.

• Journal of the Korean Ceramic Society
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• v.27 no.1
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• pp.13-22
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• 1990

The magnetite ferrofluids of which solvents are water or kerosene have been prepared by making surfactant absorbed on the surface of the magnetite which have been synthesized by air oxidation of Fe(OH)2 at pH 11 and 75$^{\circ}C$, and their basic properties have been measured by XRD, SEM, DTA, TG, viscometer, magnetometer and B-H tracer. The results are as follows ; 1) The shape of magnetite prepared by air oxidation is found to be sphere-like shape and its particle size is smaller than 200A. 2) The maximum amount of sodium oleate adsorbed on the surface of magnetite is about 20% in the weight of the magnetite including the adsorbed sodium oleate. And when magnetite is well dispersed into solvent, R(the weight ratio of the added sodium oleate to Fe3O4) is 0.40-0.48. 3) The dispersion ratio, the viscosity and the magnetization of magnetite ferrofluid are constant regardless of the added amount of sodium oleate above R=0.40-0.48. 4) The magnetic hysteresis curves of magnetite ferrofluid show superparamagnetism-like behavior.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.5
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• pp.31-39
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• 1999

A good atomization in uniform size brings the elevation of thermal efficiency in spray combustion, the beautiful painting on surfaces, and the economical sprinkling of chemicals. Ultrasonic atomization has been expected as a good uniform atomization mechanism due to its uniform size distribution. Influx, load, and physical properties of liquids are the effecting factors to atomize liquids. In this study, distilled water and city water are selected as reference liquids and gasoline, kerosene, and petroleum as fuel liquids. Characteristics and affinity to get the maximum effect for the ultrasonic atomization are observed by using the two ultrasonic transducers with 28kHz and 2MHz. Results show that the size distributions of liquid spray dorplet by the direct vibration method prevail over those by the aerosol method in uniform droplet size and as a whole, sizes of spray liquid droplets are increased slightly according to increasing influx in the direct vibration method and quantities of spray droplets in the aerosol method decreasing according to increasing liquid load h.

• Journal of the Korean Ceramic Society
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• v.29 no.10
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• pp.797-805
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• 1992

Al2O3-20 wt% ZrO2 composite powders to be used as the starting materials of the Al2O3/ZrO2-Spinel composite system were prepared by the use of the emulsion-hot kerosene drying method. The crystalline phase of ZrO2 in the synthesized Al2O3-ZrO2 composite powders was 100% tetragonal but the small amount of t-ZrO2 was transformed into m-ZrO2 after crushing. The hardness, fracture toughness, and flexural strength of the composite, which was sintered at 1650$^{\circ}C$ for 4 hrs after calcining at 1100$^{\circ}C$ for 2 hrs and had the relative density of 99%, were 15.7 GPa, 4.97 MN/m3/2, and 390 MPa, respectively. The fracture form in the sintered composites was found to be the intergranular fracture.

• Bulletin of the Korean Chemical Society
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• v.25 no.6
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• pp.806-808
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• 2004

A gas chromatography/mass spectrometric assay method has been developed for the simultaneous determination of icing inhibitors, ethylene glycol monomethyl ether and diethylene glycol monomethyl ether in ground water contaminated with JP-8. Ethylene glycol monobutyl ether and ethylene glycol monoethyl ether were used as the internal standard and surrogate, respectively. 100 mL of ground water was extracted twice with 20 mL of methylene chloride. The extract was concentrated to dryness, dissolved with 100 ${\mu}$L of methanol and analyzed by GC-MS (SIM). The use of an Innowax column gave the peaks good chromatographic properties, and the extraction of these compounds from samples gave recoveries of about 50% with small variations. The method detection limits of the target compounds were in a range of 0.5-0.8 ng/mL in ground water.

• Proceedings of the Korean Geotechical Society Conference
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• 1992.12a
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• pp.19-32
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• 1992

Objectives of this study are : 1) to utilize capillary theory and obtain pore-size distribution profiles from moisture-suction relationships using Laplace theory. 2) to investigate the behavior of Light Non-Aqueous Phase Liquids(LNAPLs) in the subsurface environment and to develop several predictive relationships which can be used to assess the effectiveness of various LNAPLs remediation technologies. The relationship to predict pore-size distribution function expressed in differencial equation is found by using capillary theory. Also, experiments are conducted to : the various LNAPLs subjected to vadose zone drainage, groundwater table drainage, waterflooding with surfactants. The experiments are performed with #2 heating oil, jet fuel. and kerosene. Several relationships have been derived describing the effect of various properties and process parameters on the LNAPL residual saturation.

• The Korean Journal of Ceramics
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• v.5 no.3
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• pp.250-254
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• 1999

Synthesis of the spinel $LiMn_2O_4$ by emulsion method was investigated. $LiOH.H_2O \;and \;Mn(NO_3)_2.6H_2O$ were used as starting materials to prepare mixed aqueous solution (0.5 mol/$\ell$ for the $LiMn_2O_4$). Kerosene, paraffin oil and span 80 were used for organic phase. The aqueous solutioin and organic phase were mixed in the ratio of 2:1 and emulsified at the speed of 4000 rpm for 5 min. The prepared emulsions were dropped into the petroleum heated at $170^{\circ}C$ to evaporate water in the silicon oil bath, dried at $120^{\circ}C$ in the oven the remove petroleum and calcined at temperature ranges from 600 to $900^{\circ}C$ for 48 hrs. The characteristics of powders were investigated by XRD, SEM, BET and electrochemical properties of synthesized cathode materials were measured with Galvanostatic system. $Li_{1.05}Mn_2O_4$ calcined at $800^{\circ}C$ for 48 hrs showed initial discharge capacity of 125.9mAH/g.

• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.5
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• pp.1-9
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• 2011

Researches on hypersonic aircraft technologies have been carried out to increase flight speeds. However, increase in flight speeds causes heat loads that could lead structural change of aircraft's component. Researches on cooling technologies using endothermic fuels are progressing in the USA, France and Russia to treat the heat loads. Endothermic fuels are liquid hydrocarbon aircraft fuels which are able to absorb the heat loads by undergoing endothermic reactions, such as thermal and catalytic cracking. In this study, methylcyclohexane, n-octane, and n-dodecane were selected as model endothermic fuels and experiments in endothermic properties were implemented. Experimental conditions were supercritical condition of each model fuels in which actual endothermic fuels were exposed. The object of this study is to identify endothermic properties of the model endothermic fuels and to predict endothermic properties of actual fuels such as kerosene fuels.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.279-286
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• 2010

Hypersonic aircraft technologies have been developed with increase in flight speeds. As hypersonic flight speeds increase, heat loads on an aircraft and it's engine increase. Researches on cooling technologies using endothermic fuels are progressing in the USA, France, and Russia to treat the heat loads. Endothermic fuels are liquid hydrocarbon aircraft fuels which are able to absorb the heat loads by undergoing endothermic reactions, such as thermal and catalytic cracking. In this study, methylcyclohexane, n-octane, and n-dodecane were selected as model endothermic fuels and experiments in endothermic properties were implemented. Experimental conditions were supercritical phase of each model fuels in which actual endothermic fuels were exposed. The object of this study is to identify endothermic properties of the model endothermic fuels and to predict endothermic properties of actual fuels such as kerosene fuels.