• 한국환경과학회지
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• 제13권1호
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• pp.37-40
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• 2004

In this study, the decomposition of gas-phase TCE, Benzene and Toluene, in air streams by direct UV Photolysis and UV/TiO$_2$ process was studied. For direct UV Photolysis, by regressing with computer calculation to the experimental results the value of reaction rate constant k of TCE, Toluene and Benzene in this work were determined to be 0.00392s$\^$-l/, 0.00230s$\^$-1/ and 0.00126s$\^$-1/, respectively. And the adsorption constant K of TCE, Toluene and Benzene in this work were determined to be 0.0519 mol$\^$-l/ ,0.0313mo1$\^$-1/ and 0.0084mo1$\^$-1/, respectively. For UV/TiO$_2$ system by regressing with computer calculation to the experimental results the value of reaction rate constant k of TCE, Toluene, and Benzene in this work were determined to be 5.74g/$\ell$$.$min, 3.85g/$\ell$$.$min, and 1.18g/$\ell$$.$min, respectively. And the catalyst adsorption constant K of TCE, Toluene, and Benzene in this work were determined to be 0.0005㎥/mg, 0.0043㎥/mg and 0.0048㎥/mg, respectively.

• 한국환경과학회지
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• 제23권12호
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• pp.1971-1976
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• 2014

In this study, the photocatalytic decomposition characteristics of single toluene, toluene mixed with benzene, toluene mixed with acetone, and toluene mixed methyl mercaptan (MM) by UV reactor installed with $TiO_2$-coated perforated plate were studied. The photocatalytic decomposition rate of single toluene, toluene mixed with benzene, toluene mixed with acetone, and toluene mixed with MM fitted well on Langmuir-Hinshelwood (L-H) kinetics equation. The maximum elimination capacity was obtained to be $628g/m^3{\cdot}d$ for single toluene, $499g/m^3{\cdot}d$ for toluene mixed with benzene, $318g/m^3{\cdot}d$ for toluene mixed with acetone, and $513g/m^3{\cdot}d$ for toluene mixed with MM, respectively. The negative effect in photocatalytic decomposition of toluene are found to be in the order of acetone>benzene>MM.

• 한국전기전자재료학회논문지
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• 제18권6호
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• pp.510-514
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• 2005

We have investigated the excitation-light source dependence of photo-catalytic efficiency for the benzene removal. The photo-catalytic module for the benzene removal is fabricated by a combination of GaN-based ultraviolet light-emitting diode (UV GaN-LED) and $TiO_2$ thin film coated on an aluminum plate. The benzene reduction rates of 365 nm and 375 nm modules at 60 mA junction current are approximately $8.95\;\%/Hr$ and $9.2\;\%/Hr$, respectively, which indicates that 365 nm GaN-LED is more effective than 375 nm GaN-LED. The benzene reduction efficiency is also noticeably dependent on the excitation wavelength and excitation-light power, as well as it is increased with the shorter wavelength and higher excitation power. This result exhibits that UV GaN-LED is useful to remove the volatile organic compounds (VOCs) existing in the environment.

• 대한수의학회지
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• 제45권4호
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• pp.517-525
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• 2005

This study was performed to evaluate using wild-type (WT) and $C{\times}32$ knockout (KO) mice if lack of cell to cell communication by connexin 32 gap junction enhances the benzene-induced hematotoxicity and hemopoietic tumor development. The WT and $C{\times}32$ KO mice were exposed to 300 ppm of benzene for 6 hours/day, 5 days/week for a total of 26 weeks by inhalation, and then sacrificed to evaluate the toxicities of hemopoietic organs or allowed to live out their life span to evaluate the hemopoietic tumor incidence. The significant increase and decrease of organ weight were respectively noted in spleen and thymus of both WT and $C{\times}32$ KO mice without significant difference between the genotypes. Histopathologically, benzene exposure for 26 weeks induced the morphological changes in hemopoietic organs, characterized by fat cell accumulation in the bone marrow and extramedullary hemopoiesis in the spleen. The fat cell accumulation was, compared with that of WT mice, considerably exacerbated in the $C{\times}32$ KO mice. However, no significant difference was observed in the changes of hematological values and bone marrow cellularity as well as in the onset and incidence of hemopoietic tumors between WT and $C{\times}32$ KO mice. In conclusion, this study indicated little significant role of the cellular communication by $C{\times}32$ gap junction in the action mechanism of benzene hematotoxicity and leukemogenicity.

• 한국미생물·생명공학회지
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• 제22권4호
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• pp.415-422
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• 1994

The biodegradation of aromatic compounds by a mixed culture GE1 was investigated in an artificial wastewater containing 250 mg/l of benzene, toluene, and phenol in semicontinuous culture. In the control group (no strains) with an aeration rate of 75 ml/l/min, 37% of phenol and 83% of benzene were volatilized during early 24 hrs and toluene was disappeared from the medium within 12 hrs. The biodegradation of benzene and toluene was effective in SB (strains + biofilm) treatment, while phenol was degraded more quickly in SG (strains + glucose) treatment including glucose as an additional carbon source. aromatic compounds added at a concentration of 250 mg/l were completely removed by SG treatment after 16 hrs or 32 hrs, respectively. The removal rate of COD was high as much as 80 mg/l/h in SG treatment during early period, but COD revealed a stable value of 116~140 mg/l after 12 hrs caused by increased biomass. Therefore, it is concluded that the mixed GE1 could be used for the wastewater treatment including aromatic compounds such as benzene, toluene, and phenol.

• 보존과학연구
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• 통권15호
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• pp.21-32
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• 1994

Optimum conditions for benzene synthesis and liquid scintillation counting have been studied for the determination of radiocarbon age. In benzene synthesis the carbon dioxide converted to benzene with high efficiency of 91%. Yields of each step with 10L of carbon dioxide were $CO_2$ $\rightarrow$$C_2H_2$(94%), $C_2H_2$$\rightarrow$$C_6H_6$(96%) and$CO_2$$\rightarrow$$C_6H_6$(91%), respectively. Benzene synthesized from oxalate was measured with purity of 95% by GC /MS. $\delta^13$(C$^13$C/$^12$C) of oxalate was measured to $-24.7\{textperthousand}$ by massspectrometer. For liquid scintillation counting of benzene sample low background and highest FOM were measured in 0.5 ml cocktail and 3 ml standard solution with the range of 15.4∼74.9 KeV window setting. Oxalate and background samples weremeasured to $28.7\pm0.12$cpm and $3.92\pm0.04$ cpm in 15.4∼74.9 KeV

• 한국대기환경학회지
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• 제21권4호
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• pp.431-438
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• 2005

In order to apply the photocatalytic decomposition of aromatic VOCs, adsorbent prepared from MSWI fly ash was coated by $TiO_2$ solution to endow with photo-catalytic function. The effects of coating number, existence of light source and the type of $TiO_2$ solution used for coating were examined. Adsorbent coated with amorphous $TiO_2$ solution showed higher adsorptivity than adsorbent coated with crystal $TiO_2$ solution. Without light source, breakthrough curve of photo -catalyst absorbent for VOCs removal was similar to that of absorbent made from MSWI fly ash. On the other hand, breakthrough time was enlarged with light source and total removal efficiency of benzene and toluene was also increased. It can be explained as photo-decomposition effect of $TiO_2$ photo-catalyst. Total removal efficiency of benzene and toluene was increased according to the increase of coating number with light source. It was due to the effect of adsorption and photo reaction of photo-catalytic adsorbent. But total removal efficiency of benzene was lower than that of toluene. Because benzene was removed more effectively than toluene by adsorption, but photo - decomposition effect oi toluene was more high than benzene.

• Korean Chemical Engineering Research
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• 제53권4호
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• pp.450-456
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• 2015

본 연구에서는 압력변환 증류공정(Pressure-Swing Distillation, PSD)을 사용하여 에탄올-벤젠 공비혼합물의 분리공정에 대한 전산모사 및 공정 최적화를 수행하였다. 신뢰성 있는 공정 최적화 결과를 도출하기 위해 에탄올-벤젠 이성분계에 대한 기-액 상평형 실험을 수행한 후, 열역학 모델식의 회귀분석을 통해 이성분계 상호작용 매개변수를 도출하였다. 저압-고압 컬럼 배열, 고압-저압 컬럼 배열을 통한 압력변환 증류공정을 적용하여 고순도 에탄올과 고순도 벤젠을 얻기 위한 공정 최적화를 수행하였으며, 재비기의 heat duty량을 비교하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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• pp.1390-1391
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• 2006

본 연구에서는 전도성 분자로 잘 알려진 4,4-Di(ethynyl phenyl) -2'-nitro-1-(thioacetyl)-benzene(nitro - benzene) 분자를 Au (111) 표면에 자기조립하고, ultra high vacuum scanning tunneling microscopy (UHV-STM)을 사용하여 STM tip과 sample 사이의 거리를 변화시키면서 전기전도 특성을 측정하였다. Au 기판제작은 연증착시스템 (Thermal Evaporation System)으로 제작하였으며, piranha 용액 ($H_{2}SO_{4}\;:\;H_{2}O_{2}$=3:1)을 사용하여 전치리한 후, 자기조립 단분자막 (SAMs)을 형성하였다. 먼저 1-octanethiol을 ethanol solution용액 1 mM/L 농도에서 24시간 동안 자기조립한 후에, ethanol를 solution 용액으로 이용하여 nitro-benzene를 0.1 nM/L 농도로 암실에서 30분간 자기조립 하였다. 자기조림 후 solution을 제거하기 위해 에탄올로 세척하여 $N_2$로 건조시켰다. 이 조건하에서 UHV-STM을 사용하여 nitro-benzene SAMs의 실시간 모폴로지의 변화에 따른 nitro-benzene의 전기전도 특성을 STM tip - SAMs - Au 기판의 수직구조로 STM tip과 nitro-benzene의 거리를 변화시키면서, tunneling current을 조사하였다. 측정 결과 Z-position 변화에 대한 tunneling current와 resistance의 변화를 확인할 수 있었다.

• Safety and Health at Work
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• 제12권3호
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• pp.403-415
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• 2021

Background: This study aimed to assess the possibility of benzene exposure in workers of a Korean semiconductor manufacturing company by reviewing the issued patents. Methods: A systematic patent search was conducted with the Google "Advanced Patent Search" engine using the keywords "semiconductor" and "benzene" combined with all of the words accessed on January 24, 2016. Results: As a result of the search, we reviewed 75 patent documents filed by a Korean semiconductor manufacturing company from 1994 to 2010. From 22 patents, we found that benzene could have been used as one of the carbon sources in chemical vapor deposition for capacitor; as diamond-like carbon for solar cell, graphene formation, or etching for transition metal thin film; and as a solvent for dielectric film, silicon oxide layer, nanomaterials, photoresist, rise for immersion lithography, electrophotography, and quantum dot ink. Conclusion: Considering the date of patent filing, it is possible that workers in the chemical vapor deposition, immersion lithography, and graphene formation processes could be exposed to benzene from 1996 to 2010.