• Bulletin of the Korean Chemical Society
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• v.7 no.5
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• pp.367-371
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• 1986

Dynamic and equilibrium properties of n-alkane chains immersed in solvent molecules have been investigated by a molecular dynamics method. The n-alkane chain is assumed to be a chain of elements (CH$_2$) interconnected by bonds having a fixed bond length and bond angle, but each bond of the chain is allowed to execute hindered internal rotation. We studied the effect of the number of the chain elements (N$_c$ = 10, 15 and 20) on the equilibrium properties of the system, e.g., the pair correlation functions between a chain element and solvent molecules, g$_{cs}$(r), and between the chain elements, g$_{cc}$(r), and the configurational properties such as the mean-square end-to-end distance < R$^2$ >, the mean-square radius of gyration < S$^2$ >, and the eigenvalues of the moment-of-inertia tensor < S$_i^2$ > / < S$^2$ > (i = 1, 2 and 3). We also studied the dynamic properties of the system, e.g., the autocorrelation function C(A;t) where A = R$^2$(t), = S$^2$(t), or = ${\vec{V}}(t)({\vec{V}}$ = velocity of the center of mass), and the diffusion coefficient D. The g$_{cs}$(r)'s are almost equal irrespective of the change of Nc while g$_{cc}$(r) becomes larger as N$_c$ increases; The MD computed configurational properties < R$^2$2 > and < S$^2$ > were found to be a little different from the values calculated from the statistical equations of < R$^2$ > and < S$^2$ >, it may be due to the fact that our model for the MD simulations includes a long-range volume effect. From the < S$_i^2$ > / < S$^2$ >, it is found that the chain molecule has a nearly spherical shape irrespective of the variation of N$_c$. For the dynamic properties we found that the C(R$^2$;t) and C(S$^2$;t) of lower N$_c$ decay faster than those of higher N$_c$, while the C($\vec V$;t) of the center of mass in the chain is weakly dependent on the N$_c$. The center of mass diffusion coefficient D$_c$ decreases as N$_c$ increases while the end point diffusion coefficient D$_e$ is nearly equal irrespective of the change of N$_c$.

• Korean Chemical Engineering Research
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• v.45 no.3
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• pp.219-225
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• 2007

The equilibrium solubilization capacity of pure hydrocarbon oils by 2.5 wt% $C_{12}E_8$ nonionic surfactant solution was measured at $30^{\circ}C$ by gas chromatography (GC) analysis. Experimental results indicated that the molar solubilization ratio (MSR) for pure alkanes was found to decrease almost linearly with the alkane carbon number (ACN) of the hydrocarbon oil. For the binary mixture systems of the hydrocarbon oils both selective and nonselective solubilization behaviors were observed depending on the difference in carbon number of the two hydrocarbon oils. Equilibrium solubilization tests for the two n-octane/n-nonane and n-nonane/n-decane mixture systems in $C_{12}E_8$ surfactant solutions suggest slightly selective solubilization in favor of n-octane, but the small difference in solubilization rates between two hydrocarbon oils does not allow ruling out non-selective solubilization for these particular systems. This is certainly not the case for the n-octane/n-decane mixture, for which selective solubilization was conclusively demonstrated by GC analysis data.

• Microbiology and Biotechnology Letters
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• v.10 no.2
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• pp.109-115
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• 1982

A Corynebacterium sp. capable of utilizing diaminododecane (DAD) were isolated from the soil by enrichment culture. Among 9 different kinds of substituted alkanes containing CN, NH$_2$, Cl, and SH groups (monoteminally or diterminally substituted) tested as carbon source, the isolate, designated as DAD 2-2. utilized DAD, putrescine dihydrochloride, dodecanethiol, dodecane and lautylamine. Thioanisole, decanedithiol, dicyanooctane, laurylcyanide, and dichlorodecane were not utilized. When emulgen 950 was added to the medium, the growth of DAD 2-2 was greatly accelerated. Isolated DAD 2-2 grown in the medium with DAD as carbon source formed ethyl $\alpha$-ketoglutarate. Metabolic product of DAD 2-2 grown in a medium without nitrogen source was different from that of grown in a medium with NH$_4$NO$_3$. When glucose, putrescine, n-dodecane and other alkane derivatives were tested in place of DAD, isolate DAD 2-2 yielded products different from those they formed with DAD suggesting specificity of DAD as a carbon source.

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.1
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• pp.166-176
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• 2018

The n-alkanes which are stable compounds in the atmosphere are emitted by anthropogenic sources and biological sources. The goal of this study is to understand characteristics of n-alkane distributions in $PM_{2.5}$ of the Anmyeon Island which is one of background site in Korea. The concentration of n-alkanes in $PM_{2.5}$ was measured at Anmyeon Island for one year from June 2015 to May 2016. The average concentration of total n-alkanes (${\sum}$ n-alkanes) from C20 to C34 was $14.02{\pm}10.26ng\;m^{-3}$ and ranged from 1.77 to $47.65ng\;m^{-3}$. Various diagnostic parameters were used to identify the source. As a result, it is considered that Anmyeon Island had a large influence of biological sources during non-heating period, while the influence of anthropogenic emission during the heating period was significant. Principle Component Analysis (PCA) was performed and yielded three components that accounted for 93.6% of the total variance in n-alkanes. Factor 1, which accounted for 42.3% of the total variance, indicated anthropogenic source including fossil fuel and biomass combustion, while, Factor 3 was interpreted as the biological sources such as plant wax.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.131-134
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• 2004

Several physical and chemical methods have been used for remediation contaminated by oils. However the cost was very high and secondary pollution rose during treating. The purpose of this study was to comprision TPH (total petroleum hydrocarbon) removal from artificially contaminated soil by diesel with and without seeding anaerobic digested sludge. After 120 days of overall at 35$^{\circ}C$, removal efficiency of TPH with seeding sludge was 2-3 times higher than blank. Also, the more amount seeding sludge, TPH removal efficiency and CH$_4$ content more obtained. It was sad that seeding of anaerobic digested sludge was a good method for enhancing TPH removal efficiency without increasing operating cost. Sulfate, nitrate-reducing, methanogenic condition were evaluated for alkane, isoprenoid as target contaminated soil.

• Korean Chemical Engineering Research
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• v.58 no.2
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• pp.257-265
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• 2020

Densities (ρ) for binary mixtures of ethanol (1) + diisopropyl ether (DIPE) or cyclohexane or alkane (C₆-C₉) (2) were measured at 298.15 K, 308.15 K and 318.15 K. The excess molar volume (V^E_m) of binary mixtures was calculated using ρ data and correlated with Redlich-Kister polynomial equation. The V^E_m values for binary mixtures of ethanol (1) + cyclohexane or n-alkane (C₆-C₉) (2) were positive, whereas for ethanol (1) + DIPE (2) these were negative. The magnitude of V^E_m values follows the order: cyclohexane > n-nonane > n-octane > n-heptane > n-hexane > DIPE. The V^E_m values have been interpreted qualitatively and also quantitatively in terms of Flory-Treszczanowicz-Benson (FTB) model and Prigogine-Flory-Patterson (PFP) theory. The values V^E_m predicted using FTB model agree well with experimental V^E_m values at all mole fractions. But the PFP theory describes well V^E_m data in ethanol-rich region (x₁ > 0.5) for all binary mixtures and is able to predict the sign of V^E_m vs x₁ curve for ethanol-lean region (x₁ < 0.5) except for ethanol (1) + nonane (2) mixtures.

• Journal of Environmental Science International
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• v.8 no.4
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• pp.451-456
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• 1999

Microorganisms utilizing petroleum as substrate were screened from the seawater in Pusan coastal area. Among them, fifty strains utilized bunker-A oil as a sole carbon and energy source. Five of these fifty strains were selected to experiment this study. According to the taxonomic characteristics of its morphological, cultural and biochemical properties, the selected stains were named Pseudomonas sp. EL-12, Flavobacterium sp. EL-15, Acinetobacter sp. EL-18, Enterobacter sp. EL-27 and Micrococcus sp. EL-43, respectively. The optimal medium compositions and cultural conditions for assimilation of bunker-A oil by the selected strains were 1.5-2% bunker-A oil, 0.1% $NH_4NO_3$, 1-1.5% $MgSO_4$.$7H_2O$, 0.05-0.15% KCl, 0.1-0.15% $CaCl_2$.$2H_2O$, 2.5-3.5% NaCl, initial pH 8-9, temperature 3$0^{\circ}C$ and aeration, respectively. The utilization and degradation characteristics on the various hydrocarbons by the selected stains were showed that bunker oil, n-alkane and branched alkane compounds were highly activity than cyclic alkane and aromatic hydrocarbon compounds.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.11
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• pp.1611-1616
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• 2002

The alkanes in plant materials can potentially be used as markers to estimate composition and digestibility of diet of deer for the development of feeding strategies, but the analysis of alkanes in plant materials and deer faeces is time-consuming and expensive. In this study, 242 faecal samples and 119 pasture samples were scanned using near infrared spectroscopy (NIR) and the concentrations of alkanes in these samples were analysed to develop calibrations for predicting alkane concentrations in pastures and deer faeces. The $R^2$ values for NIR calibrations were <0.6 for $C_{24}$, $C_{26}$, $C_{32}$ and $C_{36}$, but were >0.8 for other alkanes for faecal samples. The $R^2$ values were >0.87 for alkanes with chains from $C_{27}$ to C35 for pasture samples. However, NIR was unable to predict concentrations of alkanes with chains of $C_{24}$, $C_{26}$, $C_{32}$ and $C_{36}$ in faecal samples and $C_{24}$, C25, $C_{26}$ and $C_{36}$ in pasture samples. While the use of these NIR calibrations will accelerate the estimation of diet digestibility, dietary components and botanical composition of pastures, the influence of the type of pasture on NIR calibration will require further examination.

• Bulletin of the Korean Chemical Society
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• v.23 no.3
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• pp.459-468
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• 2002

Literature data measured by the author have been processed to report on the effect of solute structure on gas liquid partition coefficients of eleven normal, branched and cyclic alkanes ranging in carbon number from five to nine in sixty nine low molecular weight liquids. The alkane solutes are n-pentane(p), n-hexane(hx), n-heptane(hp), n-octane(o), n-nonane(n), 2-methylpentane(mp), 2,5-dimethylpentane(dp), 2,5-dimethylhexane(dh), 2,3,4-trimethylpentane(tp), cyclohexane(ch), and ethylcyclohexane(ec). The solvent set encompasses most of those studied by Rohrschneider as well as three homologous series of solvents (n-alkanes, 1-alcohols and 1-nitriles) and several perfluorinated alkanes and highly fluorinated alcohols. An excellent linear relationship was observed between lnK and the carbon number of n-alkanes. The effective carbon numbers of branched and cyclic alkanes were determined in a similar fashion to the method of Kovats index. We found that the logarithm of solute vapor pressure multiplied by solute molar volume was a perfect descriptor for the linear relationship with the median effective carbon number.

• Korean Journal of Pharmacognosy
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• v.21 no.1
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• pp.56-59
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• 1990

n-Alkanes (n-nonacosane and n-hentriacontane), phytosterols (campesterol and ${\beta}$-sitosterol) and phytosteryl glucosides (${\beta}$-sitosterol 3-O-${\beta}$-D-glucopyranoside and campesterol 3-O-${\beta}$-D-glucopyranoside) were isolated from the underground parts of Epimedium koreanum (Berberidaceae) and characterized by spectral data.