• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.1
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• pp.40-49
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• 2003

This study has been conducted to identify and quantify the emissions of Volatile Organic Compounds (VOCs) from a new carpet. The carpet sample consists of polypropylene cushion and latex backing. The VOCs have been sampled on sorbent tubes and analyzed by thermal desorption unit and GC/MSD. For over 240 hours, concentration of VOCs has been measured in a small chamber made of stainless steel. With the measured data, emission factor and mass balance have been considered. The experiments have been conducted in accordance with ASTM D5116-97. The carpet has emitted a variety of VOCs, but in this study, 7 VOCs compounds have been considered： chlorobenzene, ethylbenzene, styrene, isopropylbenzene, bromobenzene, 2-chlorotoluene, and 1,2,3-trimethylbenzene. The results show that the concentrations of VOCs and the emission factors have exponentially decayed from relatively high level to low level with time. The gradients of the concentration of VOCs and emission factors are different for various components. It is found that styrene, 2-chlorotoluene are emitted more than others with higher concentrations.

• Macromolecular Research
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• v.13 no.6
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• pp.491-498
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• 2005

Fluorene-containing, spiro-type, conjugated polymers were synthesized via the cyclopolymerization of dipropargylfluorenes (2-substituted, X=H, Br, Ac, $ NO_{2}$) with various transition metal catalysts. The polymerization of dipropargylfluorenes proceeded well using Mo-based catalysts to give a high polymer yield. The catalytic activities of the Mo-based catalysts were found to be more effective than those of W-based catalysts. The palladium (II) chloride also increased the polymer yield of the polymerization. The polymer structure of poly(dipropargylfluorene)s was characterized by such instrumental methods as NMR ($^{1}H_{-}$, $^{13}C_{-}$), IR, UV-visible spectroscopies, and elemental analysis as having the conjugated polymer backbone bearing fluorene moieties. The $^{13}C_{-}$NMR spectral data on the quaternary carbon atoms in polymers indicated that the conjugated cyclopolymers have the six-membered rings majorly. The poly(dipropargylfluorene) derivatives were completely soluble in halogenated and aromatic hydrocarbons such as methylene chloride, chloroform, benzene, toluene, and chlorobenzene. The poly(dipropargylfluorene) derivatives were thermally more stable than poly(dipropargylfluorene) itself, and X-ray diffraction analyses revealed that the polymers are mostly amorphous. The photoluminescence peaks of the polymers were observed at about 457-491 nm, depending on the substituents of fluorene moieties.

• Bulletin of the Korean Chemical Society
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• v.28 no.8
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• pp.1305-1310
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• 2007

A conjugated spirocyclic polymer was synthesized via the cyclopolymerization of 1,1-dipropargyl-1- silacyclohexane with various transition metal catalysts. The monomer, 1,1-dipropargyl-1-silacyclohexane was synthesized by Grignard reaction of 1,1-dichloro-1-silacyclohexane with propargyl magnesium bromide. This polymerization proceeded well to give the corresponding poly(1,1-dipropargyl-1-silacyclohexane). The catalytic activity of WCl6 was found to be similar with that of MoCl5. The structure of polymer having the conjugated backbone with silacyclohexane moieties was characterized by such instrumental methods as NMR (1H-, 13C-), IR, and UV-visible spectroscopies. The resulting polymers were mostly yellow or light-brown powders, depending on the catalyst systems used. This polymer was completely soluble in halogenated and aromatic hydrocarbons such as chloroform, 1,2-dichloromethane, benzene, toluene, and chlorobenzene, etc. The thermal and oxidative stabilities of polymer were also studied and discussed.

• Journal of the Korean Chemical Society
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• v.10 no.1
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• pp.46-49
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• 1966

The systems of bromobenzene with chlorine and iodine monobromide in carbon tetrachloride have been investigated at $25^{\circ}$ by means of ultraviolet spectrophotometric measurements. The results indicate the formation of one to one molecular complexes, $C_6H_5Br{\cdot}Cl_2$ and $C_6H_5Br{\cdot}IBr$, in solution. The equilibrium constants obtained at $25^{\circ}$ for the formation of these two complexes are 0.0485 and $0.183l{\cdot}mole^{-1}$, respectively. Comparison of these results with those reported in the literature on other complexes of similar type shows that the relative stabilities of the complexes decrease in the following orders: $ICl>IBr>I_2>Br_2>Cl_2$Benzene > bromobenzene > chlorobenzene.

• Bulletin of the Korean Chemical Society
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• v.30 no.2
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• pp.309-314
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• 2009

New poly(arylene-ethynylene)s with silicon-containing ferrocene moiety in the polymer main chain were synthesized via the C-C bond forming reactions of 1,1´-bis(ethynyldimethylsilyl)ferrocene and various aromatic dihalides in high yields. The aromatic dihalides include 1,4-dibromobenzene, 4,4´-dibromobiphenyl, 9,10-dibromoanthracene, 2,5-dibromopyridine, 2,5-dibromothiophene, and 2,6-diiodo-4-nitroaniline. The polymer structures and properties were characterized by such instrumental methods as NMR $(^1H-,\;^{13}C-,\;and\;^{29}Si-)$, IR, UV-visible spectroscopies and TGA/DSC. The spectral data indicated that the present polymers have the regular alternating structure of 1,1´-bis(ethynyldimethylsilyl)ferrocenylene and arylene units. The resulting polymers were completely soluble in such organic solvents as methylene chloride, chloroform, benzene, chlorobenzene, and THF. The thermal behaviors of the resulting polymers were examined.

• Journal of Microbiology and Biotechnology
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• v.18 no.10
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• pp.1701-1708
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• 2008

Previous investigations showed that three classes of haloaromatic compounds (HACs; chlorobenzoates, chlorophenols, and chlorobenzenes) enhanced the reductive dechlorination of Aroclor 1248, judging from the overall extent of reduction in CI atoms on the biphenyl. In the present study, we further investigated the kind of polychlorinated biphenyl (PCB) congeners involved in the enhanced dechlorination by four isomers belonging to each class (2,3-, 2,5-, 2,3,5-, and 2,4,6-chlorobenzoates; 2,3-, 3,4-, 2,5-, and 2,3,6-chlorophenols; and 1,2-, 1,2,3-, 1,2,4-, and penta-chlorobenzenes). Although the PCB congeners involved in the enhanced dechlorination varied with the HACs, the enhancement primarily involved para-dechlorination of the same congeners (2,3,4'-, 2,3,4,2'-plus 2,3,6,4'-, 2,5,3',4'- plus 2,4,5,2',6'-, and 2,3,6,2',4'-chlorobiphenyls), regardless of the HACs. These congeners are known to have low threshold concentrations for dechlorination. To a lesser extent, the enhancement also involved meta dechlorination of certain congeners with high threshold concentrations. There was no or less accumulation of 2,4,4'- and 2,5,4'-chlorobiphenyls as final products under HAC amendment. Although the dechlorination products varied, the accumulation of ortho-substituted congeners, 2-, 2,2'-, and 2,6-chlorobiphenyls, was significantly higher with the HACs, indicating a more complete dechlorination of the highly chlorinated congeners. Therefore, the present results suggest that the enhanced dechlorination under HAC enrichment is carried out through multiple pathways, some of which may be universal, regardless of the kind of HACs, whereas others may be HAC-specific.

• Proceedings of the KAIS Fall Conference
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• 2010.11a
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• pp.488-490
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• 2010

최근 심각한 환경오염 문제와 화석 에너지 고갈로 차세대 청정 에너지 개발에 대한 중요성이 증대되고 있다. 그중에서 태양정지는 공해가 적고, 자원이 무한적이며 반 영구적인 수명을 가지고 있어 미래에너지 문제를 해결할 수 있는 에너지원으로 기대되고 있다. 본 연구에서는 P3HT(regioregular poly(3-hexylthiophene))와 PCBM(fullerene derivative [6,6]-phenyl-C61-butyric acid methyl ester)을 전자 도너와 억셉터 물질을 하나의 브랜드로 광 활성층을 형성하는 BHJ(bulk hetero junction)구조를 갖는 고분자 유기 박막 태양전지를 각각 Toluene, Mono-Chlorobenzene, Dichlorobenzene에 $60^{\circ}C$, 200rpm으로 약 12시간동안 1wt%로 교반(Stirring)한 후에 중량비(1:1 wt%)로 혼합하여 스핀코팅(Spin-coating)으로 제작하였고, 완성된 소자의 광활성층 면적은 0.04cm2이며, $150^{\circ}C$에서 후속 열처리 공정을 통해 특성 향상이 측정 되었다. 태양전지 소자 구조는 Glass / ITO / PEDOT:PSS / P3HT : PCBM / Al이다. 전류-전압, FF(Fill Factor), 변환효율 측정을 위해 solar simulator를 AM1.5 조건(100 mW/cm2)으로 이용하였으며, 소자의 최대 전류밀도는 12mA/$cm^2$, 개방전압은 0.566V이고 F.F(Fill Factor)는 55.2%이고 변환효율은 3.7%이다. 후속 열처리후 더욱 좋은 성능을 갖게 되었고, 최대 효율은 Dichl orobenzene일 때 이다.

• Analytical Science and Technology
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• v.12 no.1
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• pp.61-67
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• 1999

Two of municipal waste incinerators were selected as surveying facilities to research on the emission of dioxin and precusors. The sampling of flue gas and analysis was performed in the selected facilities. From the result, the emission patterns of dioxin and precusors, their relatership were examined. The toxic equivalency quantity(TEQ) of dioxin concentration was evaluated in two municipal waste incinerators. The 76.24% and 60.84% of total dioxin concentration in A and B incinerator were made up of the penta-, hexa- and hepta-chlorinated dibenzo-p-dioxin, respectively. Therefore, to reduce the dioxins in flue gas have to control the formation of furans. The chlorobenzenes and chlorophenols were analyzed in two incinerators. The 1,2,4,5-tetrachlorobenzene, penta-, and hexachlorobenzene are discharged and 2,4,6-trichlorophenol, 2,3,4,6-tetrachlorophenol and pentachlorophenol are discharged mainly in A and B municipal waste incinerators.

• Journal of Environmental Science International
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• v.18 no.3
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• pp.345-353
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• 2009

The purpose of this study is to examine the health of beauty salon workers through the utilization of questionnaires concerning the extent of exposure to organic solvents found in the air of some beauty salons and any resultant symptoms in employees. The subjects were 36 employees from 10 beauty salons who agreed to participate in this study. The degree of exposure to organic solvents in the air of beauty salons was measured from September 1, 2008 to September 30, 2008. A survey of symptoms that occurred due to exposure to these solvents was also performed. The results were as follows: questionnaires were collected and analyzed from a total of 36 subjects. Of these, 28(77.8%) were female and 8(22.2%) were male. The mean age was 29.08. The mean working period was 7.13 years. Sixteen subjects attended programs at universities while 11 went to beauty schools for vocational education. When testing the concentration of organic solvents in the air of beauty salons, the highest value found was Isopropyl alcohol 511.85 ppb followed by butyl acetate, toluene, acetone, xylene, ethyl benzene, styrene, and chlorobenzene. A logistic regression analysis was performed as follows: the point of each factor was the dependent variable while sex, age, drinking, smoking, educational level, work experience, hairdresser's license, and organic solvents were the independent variables. Statistically significant difference (p<0.05) was shown in the hairdresser's license among Factor 1 and in Xylene among Factor 2; however, difference was not shown in the other variables.

• Journal of Microbiology and Biotechnology
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• v.18 no.1
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• pp.145-152
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• 2008

A cell-based in vitro exposure system was developed to determine whether oxidative stress plays a role in the cytotoxic effects of volatile organic compounds (VOCs) such as benzene, toluene, xylene, and chlorobenzene, using human epithelial HeLa cells. Thin films based on cysteine-terminated synthetic oligopeptides were fabricated for immobilization of the HeLa cells on a gold (Au) substrate. In addition, an immobilized cell-based sensor was applied to the electrochemical detection of the VOCs. Layer formation and immobilization of the cells were investigated with surface plasmon resonance (SPR), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The adhered living cells were exposed to VOCs; this caused a change in the SPR angle and the VOC-specific electrochemical signal. In addition, VOC toxicity was found to correlate with the degree of nitric oxide (NO) generation and EIS. The primary reason for the marked increase in impedance was the change of aqueous electrolyte composition as a result of cell responses. The p53 and NF-${\kappa}B $ downregulation were closely related to the magnitude of growth inhibition associated with increasing concentrations of each VOC. Therefore, the proposed cell immobilization method, using a self-assembly technique and VOC-specific electrochemical signals, can be applied to construct a cell microarray for onsite VOC monitoring.