• Bulletin of the Korean Chemical Society
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• 제23권3호
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• pp.503-506
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• 2002

• 생명과학회지
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• 제9권6호
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• pp.715-721
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• 1999

분리된 toluene내성세균 Pseudomonas sp. BCNU 154을 생물분해반응에 적용하고저 그 가능성을 조사하였다. 방향 족화합물 16개을 대상으로 저화능을 조사한 결과 cumene, cyclohexane, ethylbenzene, p-xylen, m-xylen, toluene 그리고 diphenylether가 공시균쥬에 의해 자화됨이 확인 되었다. Pseudomonas sp. BCNU 154는 toluene, ethylbenzene 그리고 p-xylen 그리고 cumene을 호기적으로 분해하였다. Touene은 12시간후에 완전히 분해되었고, p-xylene과 cumene은 12시간배양시 90% 분해되었으며, ethylbenzene은 12시간 배양시 75%가 분해되었다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.382-385
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• 2003

Organic solvent tolerant bacterium, designated as strain BCNU 106 is a gram negative, rod-shaped aerobe and grows on benzene, toluene, ethylbenzene, and xylenes (BTEX) as a sole carbon source. According to 16S rDNA analysis and fatty acid analysis, strain BCNU 106 showed highest similarity to Pseudomonas syringae var. savastanoi (Pseudomonas savastanoi). Strain BCNU 106 was able to utilize toluene, ethylbenzene, both o-, m-, p-xylene , m-cresol and o-cresol. The degradation of o-, m-, p-xylene by strain BCNU 106 is particularly important, since o-xylene is a compound of considerable environmental interest, owing to its recalcitrance; and very few microorganism have been reported to utilize both o-, m-, p-xylene as a sole carbon source.

• 한국환경과학회지
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• 제17권11호
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• pp.1195-1201
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• 2008

Enhancing with non-metallic elemental nitrogen(N) is one of several methods that have been proposed to modify the electronic properties of bulk titanium dioxide($TiO_2$), in order to make $TiO_2$ effective under visible-light irradiation. Accordingly, current study evaluated the feasibility of applying visible-light-induced $TiO_2$ enhanced with N element to cleanse aromatic compounds, focusing on xylene isomers at indoor air quality(IAQ) levels. The N-enhanced $TiO_2$ was prepared by applying two popular processes, and they were coated by applying two well-known methods. For three o-, m-, and p-xylene, the two coating methods exhibited different photocatalytic oxidation(PCO) efficiencies. Similarly, the two N-doping processes showed different PCO efficiencies. For all three stream flow rates(SFRs), the degradation efficiencies were similar between o-xylene and m,p-xylene. The degradation efficiencies of all target compounds increased as the SFR decreased. The degradation efficiencies determined via a PCO system with N-enhanced visible-light induced $TiO_2$ was somewhat lower than that with ultraviolet(UV)-light induced unmodified $TiO_2$, which was reported by previous studies. Nevertheless, it is noteworthy that PCO efficiencies increased up to 94% for o-xylene and 97% for the m,p-xylene under lower SFR(0.5 L $min^{-1}$). Consequently, it is suggested that with appropriate SFR conditions, the visible-light-assisted photocatalytic systems could also become important tools for improving IAQ.

• Bulletin of the Korean Chemical Society
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• 제23권3호
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• pp.369-373
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• 2002

The liquid phase oxidation of p-xylene has been carried out with oxygen-enriched gas, and the manganese component was precipitated probably via over-oxidation to $Mn^{4+}$. The precipitation increased with rising oxygen concentration in the reaction gas and occurred mainly in the later part of the oxidation. The activity of the reaction decreased, and the blackening of the product and side reactions to carbon dioxide increased with the degree of precipitation. Precipitation can be decreased with the addition of metal ions, such as cerium, chromium and iron.

• Journal of Microbiology
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• 제38권1호
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• pp.31-35
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• 2000

A suitable packing material for biofiltration of monoaromatic solvent vapors was selected among various types of packing materials such as peat, bark chips, vermiculite, and Hydroballs. A previously isolated strain, Pseudomonas pseudoalcaligenes BTXO2, which could utilize toluene, m-and p-xylene as carbon and energy sources was used as a biofilter inoculum. Four glass biofilters (6 cm dia. x 60 cm) were individually packed with each of the packing materials and solvent vapors were passed through the columns. During three weeks of peat biofilter operation, average removal efficiencies of toluene, m-and p-xylene were 90.4%, 95.3%, and 82.1%, respectively. With the other packings, the efficiencies were in the range of 10.1 to 58.6％ which were significantly lower than those of the peat biofilter. The peat biofilter was continually operated for approximately nine months and the biofilter sustained its degradation activity during the operation period with minimal maintenance. At steady state, average removal rates of toluene, m- and p-xylene vapors were estimated as 14.2, 5.5, and 8.1 g m$\^$-3/ packing h$\^$-1/, respectively.

• 대한의생명과학회지
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• 제9권2호
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• pp.93-98
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• 2003

To investigate the cyclohexane and xylene mixture treatment on the liver damage, the rats were treated by the mixture of cyclohexane and xylene (CH＋X) and then, liver damage was demonstrated by liver function findings based on liver weight/body weight, serum level of alanine aminotransferase (ALT), xanthine oxidase (XO) and then compared with cyclohexane treated group (CH group) and xylene-treated group (X). The CH＋X group showed merely severer liver damge than CH or X group. On the other hand, CH＋X group showed lower activity of hepatic cytochrome P-450 dependent aniline hydroxylase (CYPdAH) than CH or X group, but no statical differences were demonstrated among three experimental groups. Especially the hepatic GSH content was merely declined than CH or X group and the activity of hepatic GST was higher in CH＋X group than CH or X group. In conclusion, cyclohexane and xylene mixture treated animals showed merely severer liver damage than cyclohexane or xylene treated group and such a fact may be caused by inhibition of cyclohexane or xylene metabolism and oxygen free radical.

• 한국대기환경학회지
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• 제21권1호
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• pp.1-14
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• 2005

In this study, a Long Path Differential Optical Absorption Spectroscopy system (K-JIST LP-DOAS) has been used to simultaneously measure atmospheric monoaromatic hydrocarbons and other trace compounds. The validity of the K-JIST LP-DOAS for measuring atmospheric monoaromatic hydrocarbons was tested during a field campaign between 12 February and 14 March 2003 at an urban site in Seoul, Korea through inter-comparative measurements against a collocated on-line Gas Chromatography (GC) system. The concentrations of benzene, toluene, p-xylene, and m-xylene were measured with the K-JIST LP-DOAS system in the UV region (239～302 nm) over a 740 m beam path. For the other trace compounds, a longer spectral range (299～362 nm) was used. In order to remove the interference of atmospheric abundant species (such as oxygen, sulfur dioxide and ozone), two oxygen optical density spectra obtained at two pathlengths, 697 and 1133m, and reference spectra of sulfur dioxide and ozone were incorporated in the fitting procedure. The mean concentrations measured by our LP-DOAS during the measurement period were 0.77 ($\pm$0.38) ppbv for benzene, 3.68 ($\pm$1.90) ppbv for toluene, 0.41 ($\pm$0.19) ppbv for p-xylene, 0.54 ($\pm$0.24) ppbv for m-xylene. The concentration data of benzene, toluene, p-xylene and m-xylene obtained by our LP-DOAS were found to be in relatively good correlations with those of the online GC system. Pearson's coefficients in the observed concentrations between LP-DOAS and on-line GC were 0.84 for benzene, 0.83 for toluene and 0.65 for m,p-xylene. This study suggests that the LP-DOAS system can be used to provide reliable information on both the mixing ratios and temporal distribution characteristics of monoaromatic hydrocarbons in the urban air.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 춘계학술발표대회
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• pp.470-473
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• 2000

Indole은 미생물에 강한 독성을 가지고 있으므로 indole의 생물학적 전환이 어려우므로 단지 소수의 미생물들이 Indole이나 그것의 연관물질들로부터 Indigo와 Indirubin을 생산하는데 응용되어 왔다. 본 연구실에서 분리된 Pseudomonas savastanoi BCNU 106은 toluene에 강한 내성을 가졌으며 P. savastanoi BCNU 106의 Indole 내성 정도는 p-xylene이나 toluene이 배지 부피의 20% 로 첨가되었을 때 160 mg/ml로 매우 높은 내성 정도를 나타내었다. Indole (100 mg/ml) 과 p-xylene (0.2 ml/ml)을 포함한 two-phase culture system에서 자란 P. savastanoi BCNU 106은 indole로부터 푸른색 indigo나 보라색 indirubin의 미생물학적 전환을 보여주었다. indigo와 indirubin의 생산은 P. savastanoi BCNU 106가 적절한 농도의 유기용매가 중층된 two-phase system에서 자랐을 경우에만 형성되었다. 그러므로 본 연구는, 분리된 indole 내성 세균이 유기용매하에서 indirubin과 같은 산업적 가치를 가진 유용물질을 생산하는데 응용될 수 있을 것으로 사료된다.

• 한국화재소방학회논문지
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• 제24권2호
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• pp.172-177
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• 2010

가연성 혼합물의 최소자연발화온도 거동(MAITB, Minimum Autoignition Temperature Behavior)은 어떤 조성에서 두개의 순수물질 가운데 낮은 물질의 AIT보다 낮은 AIT를 갖는 현상을 말하며, 이는 위험물을 취급하는 공정에서 매우 관심있는 분야이다. 본 연구는 ASTM E659-78(Standard Test Method for Autoignition Temperature of Liquid Chemical)을 이용하여 toluene과 iso-propanol(IPA) 및 p-xylene과 n-butanol혼합물의 최소자연발화온도를 측정하였다. Toluene, IPA, p-xylene 그리고 n-butanol의 자연발화 온도는 각각 $547^{\circ}C,\;463^{\circ}C,\;557^{\circ}C,\;340^{\circ}C$였다. Toluene과 iso-propanol(IPA) 계의 경우는 3 : 7(Toluene :IPA) 비율의 혼합물 일 때는 IPA순수물질($464^{\circ}C$)보다 자연발화온도가 약 $3^{\circ}C$ 낮은 혼합물의 최소자연발화온도거동 MAITB(Minimum Autoignition Temperature Behavior)을 보였다.