• Molecular & Cellular Toxicology
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• v.5 no.4
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• pp.283-290
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• 2009

Differential gene expression profiling was performed in the hepatic tissue of marine medaka fish (Oryzias javanicus) after exposure to benzo[a]pyrene (BaP), a polycyclic aromatic hydrocarbon (PAH), by heterologous hybridization using a medaka cDNA microarray. Thirty-eight differentially expressed candidate genes, of which 23 were induced and 15 repressed (P<0.01), were identified and found to be associated with cell cycle, development, endocrine/reproduction, immune, metabolism, nucleic acid/protein binding, signal transduction, or non-categorized. The presumptive physiological changes induced by BaP exposure were identified after considering the biological function of each gene candidate. The results obtained in this study will allow future studies to assess the molecular mechanisms of BaP toxicity and the development of a systems biology approach to the stress biology of organic chemicals.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.266-268
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• 2004

대부분의 유기물은 토양의 특성에 따라 그 흡착 및 탈착 양상이 다르며 이는 오염물질의 토양에서의 지속성 및 이동성에 영향을 미치게 된다. 본 연구에서는 대표적인 유기오염물인 PAH(Polycyclic Aromatic Hydrocarbon)에 대하여 흡착 및 탈착과 오염물질의 미생물 분해 등을 통한 제거 기작과의 연관성을 연구하고자 한다. PAH의 이론적인 미생물분해반응식은 열역학적 이론을 바탕으로 하는 반쪽반응방법을 사용하여 예측할 수 있다. 오염물과 토양의 특성에 따른 흡착 및 탈착 양상을 파악하고, 앞에서 구한 미생물 분해반응식을 이용하여 이론적 분해량을 예측하면 오염물의 생물학적 이용성과 노출량을 결정할 수 있다 이를 위하여 본 연구에서는 토양의 여러 특성을 분석한 후, PAH의 미생물 분해량 및 분해율을 측정하고자 한다. 실험을 통하여 실제 토양에서 측정된 PAH 분해량과 위의 이론적 분해량 예측 결과 사이의 관계를 토양의 특성을 이용하여 설명할 수 있으며 나아가 오염물질의 생물학적이용성에 관하여 개략적으로 일반화된 예측 모형을 얻을 수 있을 것이다. 본 연구를 통하여 토양과 유기오염물질, 미생물간의 상호 작용에 대한 이해를 높이고 보다 실질적인 유기오염물의 생물학적 이용성을 예측할 수 있는 방안을 마련할 수 있을 것이다.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.2
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• pp.40.2-40.2
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• 2010

Polycyclic aromatic hydrocarbon (PAH) features have emerged as one of the most important infrared (IR) features since these PAH features dominate mid-IR spectra of galaxies and are ubiquitous within galactic and extragalactic objects. These PAH features have the potentials to become reliable star formation rate (SFR) proxies and diagnostics of physical conditions of interstellar medium, such as ionization states of dust grains and grain sizes. While constructing an unbiased library of 44 sample galaxies selected from 5MUSES sample, AKARI mJY Unbiased Survey of Extragalactic Sources in 5MUSES (AMUSES) intends to measure and to calibrate the PAH 3.3 mm emission feature which has not been studied extensively due to its weak strength and dearth of capable instruments. Out of 20 target galaxies, we detected the 3.3mm feature from eight galaxies and measured their line strengths, line widths and line ratios with other PAH emission features. Sample galaxies whose spectral energy distributions (SEDs) are classified as starburst-type have clearly stronger 3.3mm emission features than ones with AGN-type SEDs. We also found that there is a correlation between the PAH 3.3mm luminosity and total IR luminosity within our sample galaxies, albeit a large scatter. We further discuss implications of our results.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.163-166
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• 2005

[ $TiO_2$ ] 광촉매에 의한 분해 반응의 활성을 높이기 위한 다양한 연구가 진행되었다. 광촉매 반응은 1차 반응을 따랐으며 초기농도가 높을수록 분해효율이 감소하는 경향을 보였다. 본 연구에서는 산화제로 과산화수소가 주입되었을 경우 분해효율을 조사하였으며, 과산화수소를 주입하였을 경우가 그렇지 않은 경우보다 더 높은 분해효율을 보였다. 또한 과산화수소 주입량을 달리했을 때, 주입량이 증가할수록 효율이 높아지다가 일정량 이상에서는 오히려 효율이 감소하는 것으로 나타났다. 따라서 과산화수소 최적첨가량이 존재함을 알 수 있었다. 한편 $TiO_2$에 전이금속을 첨가하여 전이금속이 $TiO_2$ 촉매의 분해효율에 미치는 영향을 알아보았다. Pt(0.5%)-$TiO_2$가 가장 높은 분해효을을 보였으며, Pt첨가함량이 더 큰 Pt(2%)-$TiO_2$는 함량이 증가했음에도 불구하고 큰 차이는 아니지만 오히려 효율이 감소하였다. 따라서 촉매표면에서 전자와 정공이 생성되었을 때, Pt가 전자를 포획함으로써 전자와 정공의 재결합율을 감소시켜 OH라디칼을 생성할 수 있는 정공이 많아져 반응효율을 증가되는 것을 알 수 있었고, 금속에 따른 최적 첨가함량이 존재함을 알 수 있다. 반면에 Pd를 첨가했을 경우는 첨가 함량에 관계없이 모두 분해효율이 오히려 감소하는 경향을 나타냈으며 이는 전이금속 고유의 성질이나, 또는 대상물질에 따라 각기 다른 경향이 존재함을 나타내며 추가적인 연구가 필요하다고 사료된다.

• International Journal of Automotive Technology
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• v.7 no.6
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• pp.653-658
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• 2006

The enormous increase in the use of fossil energy sources throughout the world has caused severe air pollution and a depletion of energy. Besides, it seems very difficult to comply with the upcoming stringent emission standards in vehicles. In order to develop low emission engines, research on better qualified fuels as alternative fuels to secure high engine performance becomes a more important issue than ever. Since sulfur contained in diesel fuel is transformed in sulfate-laden particulate matters when a catalyst is applied, it is necessary to provide low sulfur fuels before any Pt-based oxidation catalysts are applied. But the excessive reduction of sulfur levels may cause the lubricity of fuel and engine performance to degrade. In this aspect, biodiesel fuel derived from rice bran is applied to compensate viscosity lost in the desulfurization treatment. This research is focused on the performance of an 11,000cc diesel engine and the emission characteristics by the introduction of ULSD(Ultra Low Sulfur Diesel), BD20(Diesel 80%+Biodiesel 20%) and a diesel oxidation catalyst, where BD20 is used to improve the lubricity of fuel in fuel injection systems as fuel additives or alternative fuels.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.2
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• pp.110-118
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• 2002

Organic thin film transitors(OTFT) are of interest for use in broad area electronic applications. And recently organic electroluminescent devices(OELD) have been intensively investigated for using in full-color flat-panel display. We have fabricated inverted-staggered structure OTFTs at lower temperature using the fused-ring polycyclic aromatic hydrocarbon pentacene as the active eletronic material and photoacryl as the organic gate insulator. The field effect mobility is 0.039∼0.17 ㎠/Vs, on-off current ratio is 10$\^$6/, and threshold voltage is -7V. And here we report the study of driving emitting, Ir(ppy)$_3$, phosphorescent OELD with all organic thin film transistor and investigated its electrical characteristics. The OELD with a structure of ITO/TPD/8% Ir(ooy)$_3$ doped in BCP/BCP/Alq$_3$/Li:Al/Al and OTFT with a structure of inverted-stagged Al(gate electrode)/photoacry(gate insulator)/pentacene(p-type organic semiconductor)/ Au(source-drain electrode) were fabricated on the ITP patterned glass substrate. The electrical characteristics are turn-on voltage of -10V, and maximum luminance of about 90 cd/㎡. Device characteristics were quite different with that of only OELD.

• Proceedings of the KIEE Conference
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• 2000.11c
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• pp.446-448
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• 2000

Organic semiconductors based on vacuum-deposited films of fused-ring polycyclic aromatic hydrocarbon have great potential to be utilized as an active layer for electronic and optoelectronic devices. In this study, pentacene thin films and electrode materials were deposited by Organic Molecular Beam Deposition (OMBD) and vacuum evaporation respectively. For the gate dielectric layer, OPTMER PC403 photo acryl (JSR Coporation.) was spin-coated and cured at $220^{\circ}C$. Electrical characteristics of the devices were investigated, where the channel length and width was $50{\mu}m$ and 5 mm. It was found that field effect mobility was $0.039\;cm^2V^{-1}s^{-1}$, threshold voltage was -7 V, and on/off current ratio was $10^6$.

• Journal of the Korean Applied Science and Technology
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• v.2 no.2
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• pp.47-53
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• 1985

Correlation among the wax-pigment composites which is base vehicles for the crepas was investigated in terms of fadeness. The base wax synthesized and pigments are compounded with petroleum lubricant and exposed under carbon arc individually. The yellowing phenomenon was appeared on the reference papers coated with the spindle oil which was then exposed. The papers were again extracted with distilled water and pH of them were ranged between 6.2-6.5. Color difference from Adam-Nickerson equation, ${\vartriangle}E$ of base wax is 0.15 and that of spindle oil are varied from 0.66 to 15.62. Since the main components of the petroleum lubricant are aromatic hydrocarbons which have absorptions characteric of UV ranging from 240 to 280 nm, fadeness characteristics of the composites are largely depend upon the change of molecular structure of spindle oil by absorbing UV. Thus the spindle oil having the following physical properties has the better resistance of fadness and is recommended to use in compounding the base wax-pigment composites: ${\cdot}$ main component: paraffinic hydrocarbon ${\cdot}$ pour point: below - $15^{\circ}C$ ${\cdot}$ UV absorption characteristics: ${\lambda}max.$ : 268-290nm ${\cdot}$ absorbancy: below 0.1(0.03ml of sample/50ml of $CHCl_3$)

• Journal of the Korean Applied Science and Technology
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• v.18 no.3
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• pp.191-196
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• 2001

Organic semiconductors based on vacuum-deposited films of fused-ring polycyclic aromatic hydrocarbon have great potential to be utilized as an active layer for electronic and optoelectronic devices. In this study, pentacene thin films and electrode materials were deposited by Organic Molecular Beam Deposition (OMBD) and vacuum evaporation respectively. For the gate dielectric layer, photoacryl (OPTMER PC403 from JSR Co.) was spin-coated and cured at $220^{\circ}C$. Electrical characteristics of the device were investigated, where the channel length and width was 50 ${\mu}m$ and 5 mm. It was found that field effect mobility was 0.039 $cm^{2}V^{-1}s^{-1}$, threshold voltage was -8 V, and on/off current ratio was $10^{6}$. Further details will be discussed.

• Journal of the Korean Applied Science and Technology
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• v.24 no.1
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• pp.47-53
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• 2007

The acenaphthene(ACE) or acenaphthylene(ACEL) is one of the most frequently found compound in polycyclic aromatic hydrocarbon (PAH)-contaminated soil. In this study, we make 10mg/L ACE or ACEL in ethanol which is the model washing solvent for contaminated soil. This was followed by Fenton treatment in which 0.2 or 0.3mL of 30% $H_2O_2$ and 0.2 ml of 0.5 M $Fe^{2+}$ were added. The results showed more than 88 or 99% of ACE or ACEL removal efficiency, respectively. Additionally, we employed GC-MS to identify the main oxidation product generated by the optimized Fenton oxidation [i.e., ACE or ACEL degraded in to 21, 34 % 1,8-naphthalic anhydride(NAPAN), repectively]. It is expected that biodegradability of NAPAN is enhanced because NAPAN has three oxygens compared with ACE and ACEL. Therefore the results suggest that the hybrid treatment system (i.e., ethanol washing -Fenton oxidation treatment) can be effectively applied to remove ACE or ACEL from soil..