• Fire Science and Engineering
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• v.27 no.2
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• pp.70-74
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• 2013

It is very important for the collected samples at fire scenes to be properly preserved for laboratory analysis. Preserving abilities of four type containers, metal cans, glass jars, zipper and heat sealed polymer bags, with the five ignitable liquids (toluene, n-octane, o-xylene, n-decane and n-hexadecane) were examined with gas chromatography-mass spectrometry. The glass jars with Teflon (PTFE) liner were the best ability to prevent the evaporation of the ignitable liquids.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.1
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• pp.35-42
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• 2009

In this study, a spark ignition engine operated with LPG and DME blended fuel was studied experimentally. The effect of n-butane and propane on performance and emissions of a SI engine fuelled by LPG/DME blended fuel were examined. Stable engine operation was achieved for a wide range of engine loads with propane containing LPG/DME blended fuel compare to butane containing LPG/DME blended fuel since octane number of propane was much higher than that of butane. Also, engine output operated with propane containing blended fuel was comparable to pure LPG fuel operation. Engine output power was decreased and break specific fuel consumption (BSFC) was increased with the blended fuel since the energy content of DME was much lower than that of LPG. Considering the results of engine output power, bsfc, and exhaust emissions, the propane containing LPG/DME blended fuel could be used as an alternative fuel for LPG.

• Proceedings of the Membrane Society of Korea Conference
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• 2004.05a
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• pp.207-210
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• 2004

The pore-filled anion-exchange membranes were prepared in this study with an asymmetric poly(vinylidene fluoride)(PVDF) membrane as a nascent membrane and poly(vinylbenzyl chloride)(PVBCl) as a polyelectrolyte. The solution of PVBCI having the chloromethylate aryl ring of 80 percents and 1,4-diaminobicyclo [2,2,2]octane(DABCO) was made with the solvent of tetrahydrofuran(THF) and N,N-Dimethylformamide(DMF), which is in the rotio of 8:2. A new preparation method in this study, i.e. in-situ crosslinking, enabled us to produce the pore-filled membranes without change of size, and to control the properties of final membrane with various degree of cross-linking. From the result of surface morphologies of SEM and AFM the polyelectrolyte exists in the pores of nascent membrane as a certain configuration. From the investigation of the solvent affecting much to the permeability and rejection, it was found. that the membranes using DMF and THF showed better performances than the membranes produced by THF only. The water permeability of the final membrane at low pressure(100㎪) showed a typical ultrafiltation membrane's permeability (8-10kg/㎡hr) and good values of rejection(55∼60 percent).

• Elastomers and Composites
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• v.39 no.4
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• pp.318-323
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• 2004

Cloud-point and bubble-point curves for poly(ethylene-co-13.8 mol% octene) ($PEO_{13.8}$) and Poly(ethylene-co-15.3 mol% octene) ($PEO_{15.3}$) were determined up to $150^{\circ}C$ and 450 bar in hydrocarbons which have different molecular size and structure. Whereas ($PEO_{15.3}$+ n-pentane) system has cloud-point and bubble-point type transitions, ($PEO_{15.3}$+ n-propane) and ($PEO_{15.3}$+ n-butane) systems do only cloud-point type transition. In cyclo-pentane, -hexane, -heptane, and -octane, $PEO_{15.3}$ has a bubble-point transition. ($PEO_{13.8}$+ n-butane) mixture has a critical mixture concentration at 5 wt% PEO. (PEO + hydrocarbon) mixtures exhibit LCST type behavior. Solubility of PEO increases with hydrocarbon size due to increasing dispersion interaction which is favorable to dissolve PEO.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.517-520
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• 2001

Fossil fuels such as coal and crude oil contain various organic sulfur compounds. Combustion of these fuels emit sulfur oxides which are considered as msjor air pollutants causing acid rain problem. Among various organic sulfur compounds, aromatic sulfur compounds of thiophenes which constitute major sulfur fractions of heavy oils are not easily removed by hydrodesulfurization. Many peroxidase and hemoproteins are known to oxidize dibenzothiophene (DBT) to dibenzothiophene-sulfoxide(DBT - sulfoxide) then dibenzothiophene- sulfone (DBT-sulfone). The oxidation of DBT by the immobilized hemoproteins in n-octane was increased significantly when the hemoproteins were deposited on celites of the particle size between 0.75 - 1.0 mm and a conventional substrates. such as t-butyl hydroperoxide and cumene hydroperoxide. In anhydrous organic solvents with log P values larger than 4.0 DBT was completely oxidized by cumene hydroperoxide catalyzed by cytochrome c deposited on celites.

• Journal of Microbiology and Biotechnology
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• v.14 no.5
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• pp.932-937
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• 2004

In situ extraction by organic solvent was studied in order to improve the recovery yield of hydrocarbon from the culture of Botryococcus braunii, a green colonial microalga. When the solvent mixture of octanol as an extractive solvent and n-octane as a biocompatible solvent was added to a two-phase column, the algal growth was seriously inhibited, even at a low concentration of polar octanol. Therefore, a two-stage cell-recycle extraction process was proposed to improve the contact area between the organic phase and the aqueous phase. The hydrocarbon recovery with in situ cell-recycle extraction showed a three-fold increase (57% of cell) in yield over that with two-phase extraction. In addition, over 60% of the hydrocarbon could be recovered without serious cell damage by downstream separation when this process was applied to the culture broth after batch fermentation.

• Archives of Pharmacal Research
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• v.28 no.9
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• pp.1023-1026
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• 2005

A new furofuran lignan (1) was isolated from the n-butanol fraction of the methanolic extract of the leaves of Petasites japonicus (Sieb. et Zucc.) Maxim. (Compositae). The structure of compound 1 was determined to be $2{\alpha}-(4'-hydroxy-3'-methoxyphenyl)-6{\alpha}-(4"-hydroxy-3"-methox­yphenyl)-8{\alpha}-hydroxy-3, 7-dioxabicyclo[3.3.0]octane\;4'-O-({\beta}-D-glucopyranoside)$ by spectroscopic methods including 2D-NMR. In further studies, it was found that the compound 1 expressed an antioxidant activity in DPPH radical scavenging assay, and moreover, ameliorated the seizure in kainic acid-treated mice.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.5
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• pp.172-180
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• 2006

This study was to analyze the effect of mixed fuel composition and mass fraction on the characteristics of evaporating diesel spray and combustion under the various ambient conditions. The characteristics of vaporization distribution and combustion were visualized by laser induced fluorescent method and direct photography. The experiments were conducted in the constant volume vessel and rapid compression expansion machine with optical access. Multi-component fuels mixed i-octane, n-dodecane and n-hexadecane were injected the vessel and rapid compression expansion machine with electronically controlled common rail injector. Experimental results show that fuel vapor formed stratified distribution. And vaporization and diffusion are become actively increasing in mass fraction of low boiling point component. Consequently multi-component fuels were expected to control the evaporating behavior according to their suitable mass fraction.

• Journal of ILASS-Korea
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• v.19 no.1
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• pp.1-8
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• 2014

Liquefied petroleum gas (LPG) is regarded as an alternative fuel for spark ignition engine due to similar or even higher octane number. In addition, LPG has better fuel characteristics including high vaporization characteristic and low carbon/hydrogen ratio leading to a reduction in carbon dioxide emission. Recently, development of LPG direct injection system started to improve performance of vehicles fuelled with LPG. However, spray characteristics of LPG were not well understood, which is should be known to develop injector for LPG direct injection engines. In this study, effects of operation condition including ambient pressure, temperature, and injection pressure on spray properties of n-butane were evaluated and compared to gasoline in a multi-hole injector. As general characteristics of both fuels, spray penetration becomes smaller with an increase of ambient pressure as well as a reduction in the injection pressure. However, it is found that evaporation of n-butane was faster compared to gasoline under all experimental condition. As a result, spray penetration of n-butane was shorter than that of gasoline. This result was due to higher vapor pressure and lower boiling point of n-butane. On the other hand, spray angle of both fuels do not vary much except under high ambient temperature conditions. Furthermore, spray shape of n-butane spray becomes completely different from that of gasoline at high ambient temperature conditions due to flash boiling of n-butane.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.27 no.1
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• pp.23-37
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• 2017

Objectives : This study was conducted to evaluate the level of exposure to volatile organic compounds (VOCs) among workers handling rust preventive oils. Methods : A total of 30 bulk samples and 54 personal air samples were collected using diffusive samplers at 22 workplaces handling rust preventive oils in Daegu and Gyongsangbuk-do Province from March to October 2013. We also investigated detailed information on the related work conditions, such as kinds of products, handling methods, local exhaustive ventilation systems, and the status of the wearing personal protective equipment. All bulk samples and air samples were analyzed using gas chromatography mass spectrometry (GC-MS) to identify components to which workers potentially were exposed. Quantitative airborne concentrations of VOCs were confirmed using gas chromatography with flame ionized detectors. Results : In terms of qualitative analyses for the 30 bulk samples, we found carcinogenic, mutagenic and reproductive toxic(CMR) substances such as butane(carcinogenic Group 1A, mutagenic Group 1B), butoxy ethanol(carcinogenic Group 2), cumene (carcinogenic Group 2), ethyl benzene(carcinogenic Group 2), methyl isobutyl ketone(carcinogenic Group 2) and toluene (reproductive toxic, Group 2). As a result of full-shift based personal air samples, eight substances such as n-hexane, n-heptane, octane, nonane, decane, toluene, ethyl benzene and xylene were detected. Among them, n-hexane and n-heptane were detected in all of 54 air samples with $13.13mg/m^3$ and $8.61mg/m^3$ of maximum concentration, respectively. The level of airborne concentration from all of samples were bellow the occupational exposure limit in Korea. Conclusions : Based on the results of this study, workers handling rust preventive oils could be exposed to CMR substances contained in rust preventive oils and n-hexane and n-heptane were found as the most frequent sources of VOC exposure.