• Bulletin of the Korean Chemical Society
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• 제7권5호
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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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• 제45권3호
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• pp.219-225
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• 2007

비이온 계면활성제 $C_{12}E_8$ 수용액의 탄화수소 오일에 대한 가용화도(equilibrium solubilization capacity)를 $30^{\circ}C$에서 기체 크로마토그래피(GC)를 이용하여 측정하였다. 탄화수소 오일의 가용화도를 실험에 사용한 계면활성제의 농도로 나눈 값으로 표시한 molar solubilization ratio(MSR)는 순수한 단일 성분의 탄화수소 오일 경우, 탄화수소 오일의 탄소수(ACN)가 증가함에 따라 거의 선형적으로 감소함을 알 수 있었다. 한편 탄화수소 오일의 이성분 시스템은 사용한 두 탄화수소 오일의 탄소수(alkane carbon number, ACN) 차이에 따라 선택적 가용화 혹은 비선택적 가용화 경향을 나타내었다. 본 연구에서 가용화도 실험을 수행한 n-octane/n-nonane과 n-nonane/n-decane 혼합물 시스템의 경우, 비선택적 (non-selective) 가용화 경향을 나타내었으며, 반면에 n-octane/n-decane 혼합물 시스템의 경우에는 선택적(selective) 가용화 경향을 따르는 것을 GC 분석 결과로부터 확인할 수 있었다.

• 한국미생물·생명공학회지
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• 제10권2호
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• pp.109-115
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• 1982

토양으로 부터 diaminododecane 자화균 DAD2-2주를 분리하여 검토한 결과 Corynebacterium속으로 동정되었으며 DAD2-2주의 alkane 유도체에 대한 생육특성조사에서 putrescine dihydrochloride, dodecanethiol, dodecane. laurylamine등은 탄소원으로 이용될 수 있었으나 thioanisole, decanedithiol, dicyanooctane, 1aurylcyanide, dichlorodecane등은 이용되지 못하였다. Emulgen 25ppm을 DAD배지에 첨가하였을 경우 DAD2-2주에 의한 diaminododecane 자화가 현저하게 촉진되었으며 diaminododecane자화시 생성되는 중간생성물은 ethyl $\alpha$-ketoglutarate로 동정되었다. 그러나 diaminododecane을 탄소원 뿐만 아니라 질소원으로도 이용하였을 경우에 있어서는 ethyl $\alpha$-ketoglutarate와는 다른 생성물을 생성하였으며 diaminododecane 대신 glucose, putrescinc, n-dodecane을 생육기질로 이용하였을 때에도 ethyl $\alpha$-ketoglutarate와는 다른 생성물을 생성하였다. 또한 resting cell을 이용하여 alkane 유도체를 co-oxidation시키는 과정에서도 ethyl $\alpha$-ketoglutarate와는 상이한 생성물이 생성되었다.

• 한국대기환경학회지
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• 제34권1호
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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.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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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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• 제58권2호
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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.

• 한국환경과학회지
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• 제8권4호
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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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• 제15권11호
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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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• 제23권3호
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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.

• 생약학회지
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• 제21권1호
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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.