• Fire Science and Engineering
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• v.31 no.4
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• pp.43-51
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• 2017

In this study, new design fire curves were suggested for the utilization in fire simulations. Numerical simulations with the Fire Dynamics Simulator (FDS) were performed for the n-octane and n-heptane pool fires in the ISO 9705 compartment to evaluate the prediction performance of the previous quadratic, exponential design fire curves and newly suggested ones. The numerical results were compared with the experimental temperature and concentrations of $O_2$ and $CO_2$. The numerical results with the previous quadratic and exponential curves showed slow increase and decrease trend than experiments. However, the numerical results with the newly suggested 2 design fire curves showed more similar variation trend in temperature, $O_2$ and $CO_2$ concentrations than the quadratic and exponential curves. It was found that the newly suggested design fire curves can be possibly used in the numerical simulation of fires in a practical respect.

• Journal of Radiation Industry
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• v.5 no.2
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• pp.179-184
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• 2011

In this study, several anion exchange membranes were successfully prepared by radiation grafting of vinylbenzyl chloride (VBC) monomer onto a polyethylene-co-tetrafluoroethylene (ETFE) film and subsequent quaternarization with diamins such as 1,4-diazbicyclo[2,2,2]octane, N,N,N',N'-tetramethyl-1,3-diaminopropane, N,N,N',N'-tetramethyl-1,6-diaminohexane, and trimethylamine. The anion exchange capacities of the prepared membranes were determined by using acid-base titration method. The cross-sectional morphology of the membranes was studied by using SEM instrument. The cross-sectional distribution patterns of the grafted polymers with anion exchange functional groups were also studied by EDX analysis.

• Korean Chemical Engineering Research
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• v.52 no.2
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• pp.219-225
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• 2014

In this study, effect of cosurfactant on the solubilization rate of n-octane, n-decane and n-dodecane oil was performed by micellar solutions of polymeric nonionic surfactant Pluronic L64($EO_{13}PO_{30}EO_{13}$) at room temperature. It has been found that the solubilization rate of a hydrocarbon oil was enhanced with an increase in both chain length and amount of alcohol added. In case of addition of a short chain alcohol such as 1-butanol, the solubilization rate of a hydrocarbon oil was slightly increased since most of alcohol molecules remained in an aqueous surfactant solution. On the other hand, the addition of a relatively long chain alcohol such as 1-hexanol and 1-octanol produced a big increase in solubilization rate of a hydrocarbon oil mainly due to incorporation of alcohol molecules into micelles and thus producing more flexible micellar packing density. Dynamic interfacial tension measurements showed the same trend found in solubilization rate measurement. Both interfacial tension value at equilibrium and time required to reach equilibrium decreased with an increase in chain length of an alcohol.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.4
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• pp.44-49
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• 2001

Reduced chemical kinetics mechanism has been derived, which can be applicable for autoignition model of hydrocarbon fuels, and contains 23 reactions and 18 species. The present model is validated with the experimental data, where the ignition delays of several hydrocarbon fuels, such as n-heptane, i-octane, n-decane and DME(dimethylether) are measured as equivalence ratios are varied. Especially, the effects of different fuels on ignition delays can be explained by changing the rate constants of three reactions among the present model. As a result, the proposed model can be applicable to two stage ignition model of Diesel combustion.

• Proceedings of the Membrane Society of Korea Conference
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• 2004.05a
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• pp.179-182
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• 2004

This study reports the extraction behavior of $\alpha$-lactalbumin using bis(2-ethylhexyl) sulfosuccinate sodium (AOT) reverse micelles. Forward extraction of $\alpha$-lactalbumin in the reverse micellar organic phase from aqueous feed solutions was strongly dependent on the AOT concentration and the complete forward extraction of 0.03 mM $\alpha$-lactalbumin was successfully achieved at an AOT concentration of ca. 100 mM. A similar dependency of the forward extraction on the AOT concentration was obtained in isooctane, n-hexane, and n-octane systems. In the backward extraction from the micellar organic phase, the recovery of the protein as high as ca. 90% was obtained with pH control and/or salt addition.

• Bulletin of the Korean Chemical Society
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• v.17 no.10
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• pp.909-918
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• 1996

Syntheses of carbapenam skeletons were achieved from 1,3-propanediol through 1,3-dipolar cycloaddition. 3-(Tetrahydropyran-2-yloxy)-(10) and 3-(t-butyldimethylsilyloxy) propanal (13) were obtained from 1,3-propanediol. 3-Hydroxypropanals (10, 13, 14) were reacted with N-hydroxyglycine esters to give C-(2-hydroxyethyl)-N-alkoxycarbonylmethylnitrones (15a-15d). 1,3-Dipolar cycloaddition of the nitrones with methyl acrylate or ethyl crotonate gave 3-(2-hydroxyethyl)isoxazolidines (16a-16b, 17a-17b, 18, 19a-19b). 3-(2-Hydroxyethyl)isoxazolidines (17a, 17c, 19a, 19b) were converted to 3-(2-iodoethyl)isoxazolidines (21a-21d) or 3-phenylthiocarbonylmethylisoxazolidines (25a-25d) which were cyclized to give 2-oxa-1-azabicyclo[3.3.0]octanedicarboxylates (22a-22d, 26a-26d). 2-Oxa-1-azabicyclo[3.3.0]octane-4,8-dicarboxylates (22c-22d, 26c-26d) were transformed to 6-(l-hydroxyethyl)carbapenam-3-carboxylates (30a-30b, 31a-31b).

• Journal of the Korean Chemical Society
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• v.32 no.4
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• pp.390-405
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• 1988

The chlorination of $C_7H_16,\;C_8H_18,\;C_10H_22,\;and\;(Me_2CH)_2$ with N-Chlorosuccinimide, tert-BuOCl, $CCl_3SO_2Cl,\;CCl_4,\;CCl_3SCl,\; PCl_5,\;and\;Cl_2\;in\;C_6H_6\;or\;CS_2$ which both form loose complexes with $Cl_2$ atoms yielded mixtures of isomeric monochloroalkanes which were analyzed quantitatively. An isomer ratio differing from that known for the substitution of paraffinic hydrocarbons was observed. The isomer distribution observed is the result of the combined effects of the differing C-H dissociation energies of the different types of H atoms of the alkane and of the free energy of the attacking radical with polar effects of the attacking radical as well as of the hydrocarbon.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.2
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• pp.37-44
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• 2013

Generally, a reduced chemical mechanism of n-heptane is used as chemical fuel of a 3-D diesel engine simulation because diesel fuel consists of hundreds of chemical components and various chemical classes so that it is very complex and large to use for the calculation. However, the importance of fuel in a 3-D simulation increases because detailed fuel characteristics are the key factor in the recent engine research such as homogeneous charged compression ignition engine. In this study, normal paraffin, iso paraffin and aromatics were selected to represent diesel characteristics and n-dodecane was used as a representative normal paraffin to describe the heavy molecular weight of diesel oil (C10~C20). Reduced kinetics of iso-octane and toluene which are representative species of iso paraffin and aromatics respectively were developed in the previous study. Some species were selected based on the sensitivity analysis and a mechanism was developed based on the general oxidation scheme. The ignition delay times, maximum pressure and temperature of the new reduced n-dodecane chemical mechanisms were well matched to the detailed mechanism data.

• Bulletin of the Korean Chemical Society
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• v.13 no.3
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• pp.296-306
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• 1992

$^{13}C$ spin-lattice relaxation times were measured for n-alkanes of moderate chain length, ranging from n-octane to n-dodecane, under the condition of proton broad-band decoupling within the temperature range of 248-318 K in order to gain some insight into basic features of segmental motions occurring in long chain ploymeric molecules. The NOE data showed that except for methyl carbon-13 dipole-dipole interactions between $^{13}C$ and directly bonded $^1H$ provide the major relaxation pathway, and we have analyzed the observed $T_1data$ on the basis of the internal rotational diffusion theory by Wallach and the conformational jump theory by London and Avitabile. The results show that the internal rotational diffusion constants about C-C bonds in the alkane backbone are all within the range of $10^9\;-10^10\;sec^{-1}$ in magnitude while the mean lifetimes for rotational isomers are all of the order of $10^{-11}\;-10^{-10}$ sec. Analysis by the L-A theory predicts that activation energies for conformational interconversion between gauche and trans form gradually increase as we move from the chain end toward the central C-C bond and they are within the range of 2-4 kcal/mol for all the compounds investigated.

• Transactions of the Korean hydrogen and new energy society
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• v.15 no.4
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• pp.274-282
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• 2004

This study focused on the development of high performance catalyst for autothermal reforming (ATR) of gasoline to produce hydrogen. The ATR was carried out over MgO/Al2O3 supported metal catalysts prepared under various experimental conditions. The catalysts before and after reaction were characterized by N2-physisorption, CO-chemisorption, SEM and XRD. The performance of supported multi-metal catalysts were better than that of supported mono-metal catalysts. Especially, it was observed that the conversion of iso-octane over prepared Ni/Fe/MgO/Al2O3 catalyst was 99.9 % comparable with commercial catalyst (ICI) and the selectivity of hydrogen over the prepared catalyst was 65% higher than ICI catalyst. Furthermore, it was identified that the sulfur tolerance of prepared catalyst was much better than ICI catalyst based on the ATR reaction of iso-octane containing sulfur of 100 ppm. Therefore, Ni/Fe/MgO/Al2O3 catalyst can be applied for a fuel reformer, hydrogen station and on-board reformer in furl cell powered vehicles.