• Journal of the Korean Chemical Society
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• v.24 no.3
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• pp.245-249
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• 1980

Uranium (Ⅵ) was extracted from dilute aqueous solutions of uranyl nitrate with acetylacetone and tri-n-butyl phosphate in n-dodecane. Synergistic effect was observed with the mixed reagents above pH 1. The species extracted are the 1:2:1 and the 1:2:2 uranyl-AA-TBP complexes. The extraction constants for these reactions have been determined.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.2
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• pp.211-217
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• 2016

The fuel cell based auxiliary power unit (APU) is promising for power source of armed vehicles due to its silence and high efficiency. Especially, the on board hydrogen generation and fed to fuel cell system was core technology of this power system. In this study, we analyzed the performance of the Auto thermal reactor (ATR) that produce the hydrogen from the fuel, integrated High temperature polymer electrolyte fuel cell (HT-PEFC) by Aspen plus software. The fuel was designed as a n-dodecane for analysis of military fuel (JP-8).

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2011.05a
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• pp.253-254
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• 2011

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2018.11a
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• pp.339-340
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• 2018

• 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.

• Applied Chemistry for Engineering
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• v.34 no.6
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• pp.619-625
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• 2023

In order to solve problems caused by the heat load of hypersonic aircraft, this study examined the optimization of the Si/Al ratio of the catalyst and nickel ion exchange to improve the performance of the hydrocarbon decomposition reaction (endothermic reaction). It was confirmed that the catalysts prepared through Si/Al ratio optimization and nickel ion exchange showed about 10% improvement in heat absorption performance compared to thermal cracking at 4 MPa and 550 ℃. FT-IR and NH₃-TPD analyses were found to identify factors affecting activity changes, and it was observed that the Si/Al ratio of the HZSM-5 catalyst was closely correlated with acid site development and catalytic activity. In addition, TGA and O₂-TPO analyses were conducted to observe the carbon deposition inhibition properties of the nickel-added catalyst.

• Korean Chemical Engineering Research
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• v.47 no.1
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• pp.24-30
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• 2009

In this study, solubilization experiments of n-decane, n-undecane and n-dodecane oil were performed by micellar solutions of polymeric nonionic surfactant Pluronic L64($EO_{13}PO_{30}EO_{13}$) at room temperature. A single spherical drop of hydrocarbon oil was injected into aqueous surfactant solution using an oil drop contacting technique and solubilization rate of hydrocarbon oil was measured by observing the size of oil drop with time. It was shown that solubilization rate decreased with the alkane carbon number(ACN) of the hydrocarbon oil. The solubilization rate was also found to be independent of initial oil dorp size and almost linearly proportional to the initial surfactant concentration. These results revealed that solubilization of n-decane, n-undecane and n-dodecane oils by L64 micellar solution is controlled by interface-controlled mechanism but not by diffusion-controlled mechanism. The equilibrium solubilization capacity(ESC) was measured by a turbidimeter and the result showed that EAC decreased with an increase in ACN but increased with both increases in surfactant concentration and solubilization rate. Dynamic interfacial tension measurements showed that interfacial tension and equilibrium time increased with an increase in ACN of hydrocarbon oil but decreased with an increase in surfactant concentration.

• Applied Chemistry for Engineering
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• v.8 no.6
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• pp.1006-1013
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• 1997

This study was carried out to elucidate the chemical characteristics of mutual separation for Am and Eu, which were selected as a stand-in from minor actinide and rare earth elements, by solvent extraction with di-(2-ethylhexyl)phosphoric acid containing zirconium at batch system. As results, 92.3% of Am and 99.1% of Eu were coextracted with 1M DEHPA/n-dodecane containing zirconium (Zr $concentration=8.7g/{\ell}$) at 0.5M $HNO_3$ in the extraction step. The extraction yields of Am and Eu were proportionally increased with the concentration of Zr in Zr salt of 1M DEHPA/n-dodecane having the synergistic effect. In the lst stripping step for the selective separation of Am, 38.1% of Am and 3% of Eu were stripped with the mixed solution of 0.05M DTPA and 1M lactic acid adjusted pH of 3.0. At that time, the separation factor calculated from the distribution coefficients of Am and Eu was 14.2. In the 2nd Stipping step to remove the Eu remained the organic phase after the lst stripping step, 94.4% 0f Eu was stripped into aqueous phase with 6M $HNO_3$.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.23 no.2
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• pp.71-96
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• 1997

We have used a novel liquid surface forces apparatus to determine the variation of disjoining pressure with film thickness for dodecane-water-dodecane emulsion films. The LSFA allows measurement of film thicknesses in the range 5-100 nm and disjoining pressure from 0-1500 Pa. Disjoining pressure isotherms are given for films stabilised by the nonionic surfactnat n-dodecyl pentaoxyethylene glycol ether$(C_{12}E_5)$ and n-decyl-$\beta$-D-glucopyranoside($C_{10}- $\beta$-Glu)$ and the anionic surfactant sodium bis(2-ethylhexyl) sulphosuccinate(AOT) in the presense of added electrolyte. For $C_{12}E_5$ and AOT, the emulsion films are indefinitely stable even for the highest concentration of NaCl tested (136.7 Nm) whereas the $C_{10}-{eta}-Glu$ film shows coalescence at this salt concentration. For film thicknesses greater than approximately 20 nm with all three surfactants, the disjoining pressure isotherms are reasonably well described in terms of electrostatic and van der Waals, forces. For the nonionic surfactant emulsion films, the charge properties of the monolayers are qualitatively similar to those seen for foam films. For AOT emulsion films, the monolayer surface potentials estimated by fitting the isotherms are similar to the values of the zeta potential measured for AOT stabilised emulsion droplets. For thin emulsion films certain systems showed isotherms which suggested the presence of an additional repulsive force with a range of approximately 20 nm.