• 한국미생물·생명공학회지
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• 제24권2호
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• pp.185-190
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• 1996

Some microorganisms including yeasts produce surface tension-decreasing biosurfactants. The strain G-1, the best producer of biosurfatants was isolated from the soil and identified as Rhodotorula sp., which was not discribed any report. The Rhodotorula sp. G-1 produced biosurfactant from vegetable oils, but failed to produce it from n-alkane or carbohydrate. Yeast extract was found to be more effective for the biosurfactant production as nitrogen source than any other inorganic nitrogen source. The composion of the optimal medium contained the following conponents: soybean oil 4%, glucose 2%, yeast extract 0.5%, KH$^{2}$PO$^{4}$ 0.1%, K$^{2}$HP0$^{4}$ 0.l%, MgSO$^{4}$ 5%, CaCl$^{2}$ 0.01%, NaCl 0.01%, pH 6.0. The surface tension activity was increased to 14% when, at first, the culture broth was fermented with only soybean oil as carbon sourse, and after 90 hours, feeded glucose, than that Of glucose and soybean oil added to it simultaneously. The maxium yield of the biosurfactant was about 15 g/l by after 90 hours, the feeding method of glucose.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2006년도 총회 및 춘계학술발표회
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• pp.115-118
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• 2006

The partitioning tracer method has been studied as an alternative method for characterizing aquifers contaminated by nonaqueous phase liquids (NAPLs). Accurate partition coefficients of tracers partitioning between NAPL and water are needed to improve the reliability of the partitioning tracer method. In this research, partition coefficients of alcohol tracers partitioning between benzene, toluene, ethylbenzene, and xylenes (BTEX) compounds and water are estimated from using the approach of equivalent alkane carbon number (EACN). General agreement was observed in between the measured and estimated partition coefficients. Based on these results we can verify that the EACN approach is suitable for estimating the partition coefficient.

• 생약학회지
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• 제9권2호
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• pp.73-75
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• 1978

We had previously reported that five compounds were obtained from fraction A of Aster divaricatus by using column chromatography and presumed them to be alkanes $CH_3\;(CH_2)n\;CH_3.$ In this investigation, compound (II) out of above five compounds was identified as hydrocarbon $C_{16}H_{34},$ m.w. 258 belonging to alkane, by using nmr spectra, mass spectra and the elementary analysis. It was also found that compound (IV) is the same compound as the campound (II).

• 한국응용과학기술학회지
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• 제31권1호
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• pp.151-158
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• 2014

Asphaltenes are generally defined by their solubility when a light alkane, such as n-heptane or n-pentane, is mixed with crude oils or oil sand bitumen. However, this definition is nowadays not enough to understand their behaviors during oil recovery, transport, storage, and even refinery operation. Interestingly, the researches regarding asphaltenes have been vastly presented within last decade. This is because the production of heavy oils is becoming larger and asphaltenes are known to play an important role in the property changes of heavy oils. In this paper, the researches regarding molecular weight, aggregation behavior of asphaltenes are introduced and discussed. It is expected that analytical studies will be appeared continuously in the form of global collaboration in order to describe asphaltene molecules as close as possible based on their origin.

• 대한화학회지
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• 제34권6호
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• pp.637-640
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• 1990

분자내에서의 전자에너지 전달시스템의 골격으로서 Bis (4,6-dichloropyrimidine-5-yl) alkanes류를 합성하였으며, 이화합물과 2-cyanomethylquinoline을 반응시켜 $\alpha$-(4-cyanomethylquinoline-6-chloropyrimidine-5-yl)-$\omega$-(4,6-dichloropyrimidine-5-yl) alkanes의 H-chelate를 합성하였다. 이들 화합물에 대한 구조는 분광학적인 방법으로 연구하였다.

• Bulletin of the Korean Chemical Society
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• 제17권7호
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• pp.625-630
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• 1996

The cobalt-substituted polyoxotungstate [(CoPW11O39)5-] has been used as a catalyst in olefin epoxidation and alkane hydroxylation reactions. The epoxidation of olefins by iodosylbenzene in CH3CN yielded epoxides predominantly with trace amounts of allylic oxidation products. cis-Stilbene was streoselectively oxidized to cis-stilbene oxide with small amounts of trans-stilbene oxide and benzaldehyde formation. The epoxidation of carbamazepine (CBZ) by potassium monopersulfate in aqueous solution gave the corresponding CBZ 10,11-oxide product. Other transition metal-substituted polyoxotungstates (M=Mn2+, Fe2+, Ni2+, and Cu2+) were inactive in the CBZ epoxidation reaction. The cobalt-substituted polyoxotungstate also catalyzed the oxidation of alkanes with m-chloroperbenzoic acid to give the corresponding alcohols and ketones. The presence of CH2Br2 in the hydroxylation of cyclohexane afforded the formation of bromocyclohexane, suggesting the participation of cyclohexyl radical. In the 18O-labeled water experiment, there was no incorporation of 18O into the cyclohexanol product when the hydroxylation of cyclohexane by MCPBA was carried out in the presence of H218O. Some mechanistic aspects are discussed as well.

• Bulletin of the Korean Chemical Society
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• 제17권3호
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• pp.269-273
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• 1996

Alkyl halides were reduced to the corresponding alkanes by the homonuclear bridging hydride, (μ-H)[(η5-MeCp)Mn(CO)2]2-PPN+ in THF at the elevated temperatures (40-60 ℃) under the pseudo first order reaction conditions where excess of alkyl halide was employed under nitrogen atmosphere. The reaction is of overall second order; first order with respect to [bridging hydride] and first order with respect to [alkyl halide] with the activation parameters, ΔH≠=28.93 kcal/mol and ΔS≠=17.95 e.u. The kinetic data, the ESR evidence and the reaction with cyclopropyl canbinyl bromide ensure that two possible reaction pathways are operable in this reaction: (1) concerted mechanism, and (2) single electron transfer pathway are in competition leading to the same product, the corresponding alkane.

• 한국응용곤충학회지
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• 제49권3호
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• pp.211-218
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• 2010

북방수염하늘소, 솔수염하늘소, 털두꺼비하늘소 성충 암·수의 표피탄화수소를 GC와 GC-MS로 분석하고 비교하였다. 북방수염하늘소와 솔수염하늘소는 소나무재선충병의 대표적 매개충이지만 같은 과에 속한 털두꺼비하늘소는 그렇지 않다. 이들은 표피탄화수소 사슬을 다르게 가지고 있는데, 북방수염하늘소의 표피탄화수소 사슬은 $C_{23-35}$, 솔수염하늘소는 $C_{25-32}$, 그리고 털두꺼비하늘소는 $C_{23-29}$로 종간 차이를 보였다. 주 구성성분의 암 수간 차이에서 함량에 대한 차이는 있었지만, 조성에 대한 차이는 없었다. 북방수염하늘소는 n-pentacosane > n-nonacosane > n-heptacosane, 솔수염하늘소는 n-nonacosene > n-pentacosane > n-nonacosane을 가장 많이 포함하고 있었으며, 털두꺼비하늘소는 n-heptacosane > 13-methylheptacosane > 3-methylheptacosane을 가장 많이 포함하고 있는데 반해 n-nonacosene, n-pentacosane의 함량은 적었다. 3종하늘소 표피의 대부분은 n-alkane인 포화탄화수소로 이루어져 있고(40.2 - 65.7%) 그 다음으로, 북방수염하늘소와 솔수염하늘소는 하나 또는 두 개의 이중결합을 갖는 olefins > monomethylalkanes 순이었다. 이와 달리, 털두꺼비하늘소는 monomethylalkanes > olefins 순으로 함량에 차이가 있었다.

• 한국미생물·생명공학회지
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• 제31권2호
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• pp.171-176
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• 2003

생물계면활성제 생성균주, Pseudomonas aeruginosa F722를 이용하여 다양한 배양조건과 배지조성에서 생물계면활성제 생산성을 검토하였다. 질소원과 탄소원을 검토하기 전에는 P. aeruginosa F722의 생물계면활성제 생산량은 0.78 g/l이었다. 하지만, 질소원과 탄소원을 검토한 후에는 생물계면활성제 생산량이 2배 증가한 1.66g/l이었다. 무기질소원으로 $_NH4$Cl 또는 $NaNO_2$를 첨가하였을 때 생물계면활성제 활성에 효과적이었으며 유기질소원으로는 yeast extract 또는 tryptone을 첨가하였을 때 생물계면활성제 활성이 높았다. 이중 무기 질소원으로 0.05% $NH_4$Cl , 유기 질소원으로 0.1% yeast extract를 질소원으로 첨가하였을 때 가장 최적이었다. 탄소원으로 소수성 기질(n-alkane) 또는 친수성 기질(glucose, glycol)을 첨가하여 생물계면활성제 생산량을 조사하였는데 소수성 기질보다는 친수성 기질인 3.0% glucose를 첨가하였을 때 생물계면활성제 생산량이 높았다. 이때의 탄소원/질소원 비율은 17~20이었다. P. aeruginosa F722는 배양조건 3.0% glucose, 0.05% $NH_4$Cl, 0.1% yeast extract, $35^{\circ}C$, pH 7.0, C/N ratio 20, 5 days에서 생물계면활성제 생산량은 1.66g/l이였다. 질소원이 결핍 후 탄소원을 첨가하여 배양하였을 때가 질소원과 탄소원을 함께 첨가하여 배양했을 때보다 생물계면활성제 생산속도 및 균체 생장속도가 높았다. 최적 배양조건하에서 얻어진 배양액의 표면장력은 30mN/m이었다.

• 한국식품과학회지
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• 제31권5호
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• pp.1221-1226
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• 1999

찹쌀로 담금한 찹쌀고오지 사용의 개량식고추장 숙성과정 중 휘발성향기성분을 purge and trap 장치로 포집하여 GC-MSD로 분석, 동정한 결과 alcohol 15종, ester 15종, acid 5종, aldehyde 5종, ketone 3종, alkane 1종, amine 1종, alkene 1종 등 46종의 향기성분이 동정되었다. 동정된 향기성분수는 담금 직후에 alcohol 6종, ester 6종, aldehyde 2종 등 21종이었으나 30일에 alcohol 3종, ester 5종을 비롯한 14종이 추가, 검출되어 34종으로 증가되었다. 150일에는 46종으로 향기성분수가 최대에 달하였다. 숙성 전 과정을 통하여 검출된 향기성분은 ethanol, 3-methyl-1-butanol, 2-methyl-1-propanol 등 alcohol류 5종, ethyl acetate, 2-methylpropylacetate, ethylbutanoate, phenylacetate 등 ester 6종, aldehyde류 2종, 기타 7종 등 20종이었다. 향기성분의 면적비율은 고추장 담금 직후 ethenone, $30{\sim}60$일에 ethylacetate, $90{\sim}120$일에 ethanol, 150일에 3-methyl-1-butanol 이 가장 높았고 숙성기간에 따라서는 2-methyl-1-propanol, 1-butanol, methylbenzene 등도 면적비율이 높아 이들 성분이 찹쌀고오지 개량식고추장의 주요 휘발성향기성분으로 여겨진다.