• Transactions on Electrical and Electronic Materials
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• v.6 no.5
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• pp.233-237
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• 2005

In the device structure of ITO/hole injection layer/N, N'-biphenyl-N, N'-bis-(1-naphenyl)-[1,1'-biphenyl]4,4'-diamine(NPB)/tris(8-hydroxyquinoline) aluminum$(Alq_3)/Al$, we investigated an effect of hole-injection materials (PTFE, PVK) on the electrical characteristics and efficiency of organic light-emitting diodes. A thermal evaporation was performed to make a thickness of NPB layer with a evaporation rate of $0.5\~1.0\;\AA/s$ in a base pressure of $5\times10^{-6}$ Torr. We measured current-voltage characteristics and efficiency with a thickness variation of hole-injection layer. The PTFE and PVK hole-injection layer improve a performance of the device in several aspects, such as good mechanical junction, reducing the operating voltage and energy band adjustment. Compared with the devices without a hole-injection layer, we have obtained that an optimal thickness of NPB was 20 nm in the device structure of $ITO/NPB/Alq_3/Al$. And using the PTFE or PVK hole-injection layer, the external quantum efficiencies of the devices were improved by $24.5\%\;and\;51.3\%$, respectively.

• Journal of the Korean Chemical Society
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• v.41 no.3
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• pp.144-149
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• 1997

Organic electroluminescence devices(ELD) were fabricated using by molecularly doped method with N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine(TPD) as a hole transport agent, squarylium dye as an emitting agent, and side chain liquid crystalline polymer(MCH) as matrix for TPD. An indium-tin-oxide(ITO) coated glass and an Mg electrode were used as the hole and the electron injecting electrode, respectively. The highest stability of ELD was obtained by spin coating method using dichloroethane as a solvent at a polymer/TPD concentration of 0.005 wt%. For the EL cell with ITO/polymer-TPD/SQ dye/Mg structure, we achieved light red luminescence at a current of 102 mA/$cm^2$ with an applied voltage of 23 V.

• Journal of Environmental Health Sciences
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• v.40 no.2
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• pp.147-156
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• 2014

Objectives: This study was carried out to examine whether the apparent photolysis with or without sensitizers [NaOH and humic acid (HA)] was prompted photodegradation of polychlorinated biphenyl (PCB) in aqueous solution. Methods: PCBs photodegradation occurred using fluorescence black lamps at ${\lambda}_{max}=300nm$. PCB congeners were exposed in 10 ppm HA or 0.05N NaOH solutions, to investigate the decreasing profile of PCB concentration with time. The PCBs were then analyzed by gas chromatography/mass spectrometry (GC-MS). Reductive degradation profile of PCB congeners in the presence of both sensitizers under oxygen-saturated protic conditions was described using the wind-rose diagrams. Results: Use of HA or NaOH decreased PCB concentration with time in the dark and on irradiation, indicating that photolysis underwent through reductive dechlorination through energy transfer and possibly with reactive oxygens. The dechlorination was marked by a chromatographic shift, observed in the GC-MS plots. Therefore it is logical to assume that increasing the dose of sensitizers would increase the photodegradation rates of PCBs. The half-lives of pentachloro-PCB (penta-3) in 0.05N NaOH and 10 ppm HA were estimated at about 47 hours and 39 hours, respectively, under the same experimental conditions of photolysis. It was found that the rate of photolysis of pentachloro-PCB in aqueous solution followed apparent first-order kinetics compared to other congeners. Conclusion: Photochemical degradation (using 328 nm UV light) of penta- and hexa-PCBs in HA or alkaline solution is a viable method for pretreatment method. The results are helpful for the further comprehension of the reaction mechanism for photolytic dechlorination of PCBs in aquatic system.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.2
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• pp.130-138
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• 2017

This study examined chemical characterization in commercial dark-fleshed fish (mackerel Scomber japonicus, Japanese Spanish mackerel Scomberomorus niphonius, and Pacific herring Clupea pallasii) to determine their suitability for use as raw materials for seafood products. The volatile basic nitrogen (VBN), heavy metal, radioactivity, polychlorinated biphenyl (PCBs), benzo[a]pyrene, and histamine concentrations were measured. The VBN in all of the dark-fleshed fish was less than 20 mg/100 g, which is the limit for raw materials for seafood processing. Except for mackerel based on the lead (Pb) standards of the European Union (EU), Taiwan, and CODEX, and all fish based on the cadmium (Cd) standards for China and the EU, the commercial dark-fleshed fish were free from total mercury (Hg), Pb, and Cd based on domestic and foreign standards. The radioactivity, polychlorinated biphenyl (PCB), benzo[a]pyrene, and histamine concentrations of the commercial dark-fleshed fish all adhered to the domestic and foreign standards. The commercial dark-fleshed fish tested could all be used as raw materials for seafood products, except for some exported products.

• Applied Chemistry for Engineering
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• v.18 no.2
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• pp.168-172
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• 2007

The separation of indole from a model mixture comprising four kinds of nitrogen heterocyclic compounds [indole (In), quinoline (Q), iso-quinoline (iQ), quinaldine (Qu)], three kinds of bicyclic aromatic compounds [1-methylnaphthalene (1MN), 2-methylnaphthalene (2MN), dimethylnaphthalene (DMN)], biphenyl (Bp) and phenyl ether (Pe) was examined by batch cocurrent 4 stages equilibrium extraction. The model mixture used as a raw material in this work was prepared according to the components and compositions contained in coal tar fraction (the temperature ranges of fraction: $240{\sim}265^{\circ}C$). An aqueous solution of formamide was used as a solvent. Indole was recovered more than 99% through 4 stages of the equilibrium extraction. The range of selectivity of indole in reference to DMN obtained through the 5 stages equilibrium extraction was found to be 63~118. The process for separation and recovery of indole contained in coal tar was studied by using the experimental results obtained from this work and the previous work.

• Journal of Microbiology and Biotechnology
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• v.9 no.6
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• pp.804-810
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• 1999

There is a possibility that carvone, a monoterpene from spearmint (Mentha spicata), could induce the bph degradative pathway and genes in Alcaligenes eutrophus H850, which is a known Gram-negative PCB degrader with a broad substrate specificity that was thoroughly investigated with Arthrobacter sp. BIB, a Gram-positive PCB degrader. The strains BIB and H850 were unable to utilize and grow on the plant terpene [(R)-(-)-carvone] (50ppm) to be recognized as a sole carbon source. Nevertheless, the carvone did induce 2,3-dihydroxybiphenyl 1,2-dioxygenase (encoded by bphC) in the strain B lB, as observed by a resting cell assay that monitors accumulation of a yellow meta ring fission product from 4,4'-dichlorobiphenyl (DCBp). The monoterpene, however, did not appear to induce the meta cleavage pathway in the strain H850. Instead, an assumption was made that the strain might be using an alternative pathway, probably the ortho-cleavage pathway. A reverse transcription (RT)-PCR system, utilizing primers designed from a conserved region of the bphC gene of Arthrobacter sp. M5, was employed to verify the occurrence of the alternative pathway. A successful amplification (182bp) of mRNA transcribed from the N-terminal region of the bphC gene was accomplished in H850 cells induced by carvone (50ppm) as well as in biphenyl-growth cells. It is, therefore, likely that H850 possesses a specific PCB degradation pathway and hence a different substrate specificity compared with B1B. This study will contribute to an elucidation of the dynamic aspects of PCB bioremediation in terms of roles played by PCB degraders and plant terpenes as natural inducer substrates that are ubiquitous and environmentally compatible.

• Polymer(Korea)
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• v.29 no.4
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• pp.331-337
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• 2005

In general, alkanethiolates having carboxylic acid in the tail group have been used as biorecepton. In this study, we have immobilized a cytochrome c protein using conjugated aromaticthiolates in order to improve the electrical property and physical stability of alkanethilolates. The pattern formation of self-assembled aromaticthiolate monolayers was as follow. Aromatic thiolates bound on the gold surface by the adsorption of 4'-mercapto-biphenyl-4-carboxylic acid and 4-mercapto-[1,1';4',1']terphenyl-4'-carboxylic acid were oxidized by the irradiation of deep UV light through a negative mask. The negative type pattern of the self-assembled monolayer (SAM) was obtained by developing with a deionized water. The pattern formation and electrical conductivity of aromaticthiolate SAMs was investigated by the measurements of STM and AFM. In addition, cytochrome c or ferrocene amide was immobilized onto the patterned substrate. We also studied on the effect of conjugated aromatic thiolates on the electrical activity of cytochrome c or ferrocene amide by cyclic voltammetry.

• Journal of Veterinary Clinics
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• v.28 no.2
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• pp.249-253
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• 2011

A 4-year-old intact female American Cocker Spaniel presented with lack of appetite, shivering, and abdominal distension. It was initially diagnosed with chronic hepatitis with cirrhosis, by serum chemistry, radiography, ultrasonography, and histopathologic examination following liver biopsy. Abundant copper granules were detected in most hepatocytes with rhodanine stain, with hepatic copper concentration at 1460 ppm (reference range: <400 ppm). Based on these findings, copper-associated hepatitis with cirrhosis was diagnosed and successfully managed with long-term D-penicillamine, s-adenosylmethionine, biphenyl-dimethyl-dicarboxylate and supportive care. The spaniel died 35 months after diagnosis.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.272-273
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• 2011

유기발광소자는 차세대 디스플레이 소자로서 빠른 응답 속도, 높은 색 재현성 및 매우 얇은 두께로 제작이 가능한 장점을 가지고 있어서 차세대 디스플레이 소자로서 많은 응용 가능성을 가지고 있다. 청색 유기발광소자는 적색 및 녹색의 유기발광소자의 발광 효율 특성보다 상대적으로 효율이 떨어지고, 색 순도가 낮으며 수명이 짧은 단점을 가지고 있어 소자 특성을 개선해야 한다. 본 논문에서는 청색 유기발광소자의 색 순도와 색 안정성 증진을 위하여 발광층을 2개의 층으로 나누어 15 nm 두께의 4,4'-Bis(2,2-diphenyl-ethen-1-yl)diphenyl (DPVBi) 형광 청색 호스트 물질에 4,4 '-Bis[4-(diphenylamino)stylyl]biphenyl (BDAVBi) 형광 청색 게스트 물질을 첨가하여 제 1 형광 발광층을 형성하고 15 nm 두께의 4,4'-Bis(carbazol-9-yl)biphenyl (CBP) 인광 호스트 물질에 bis(3,5-difluoro-2-(2-pyridyl)phenyl-(2-carboxypyridyl)iridium III (FIrpic) 인광 게스트 물질을 첨가한 제 2 인광 발광층으로 구성된 30 nm 두께의 하이브리드 발광층을 사용하여 청색 유기 발광소자를 제작하고 전기적 특성과 광학적 성질을 조사하였다. 하이브리드 발광층을 사용하여 제작된 유기발광소자는 20 mA/cm2의 전류 밀도에서 6.2 cd/A의 발광 효율을 나타내었고, 최대 밝기는 약 16,200 cd/m2로 측정 되었다. 하이브리드 발광층을 사용한 청색 유기발광소자는 전류의 흐름이 단일 발광층 유기발광소자에 비교하여 상대적으로 안정적인 전류 흐름을 가지며 발광층 내부에 더 많은 정공과 전자를 포획하여 엑시톤 형성 확률이 증가하여 발광효율과 밝기가 향상되었다. 하이브리드 발광층을 적용한 유기발광소자는 469 nm파장에서 형광 발광층의 주 전계발광 피크가 나타났고 그와 함께 인광 발광층의 부 전계발광 피크가 491 nm의 파장에서 관측되었다. 또한 전계발광 스펙트럼의 반치폭이 10 nm 감소하여 청색의 색 순도 증가에도 기여하였다. 하이브리드 발광층을 가진 청색 유기발광소자의 색 좌표는 전압 변화에 관계없이 일정한 값을 나타내었다. 이러한 결과는 형광과 인광 발광층으로 구성된 하이브리드 발광층 유기발광소자가 전기적으로 안정성을 가지며 발광 특성을 개선하고 안정적인 청색 유기 발광 디스플레이 소자로 사용 가능함을 나타내고 있다.

• Analytical Science and Technology
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• v.13 no.6
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• pp.802-809
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• 2000

Concentrations of polychlorinated biphenyl congeners (PCBs) in samples collected from 43 kindss of water, 35 kinds of soil and 11 kinds of sediment in various place of Korea have been monitored using GC/MS/SIM analytical method. In our investigation, mean recoveries were $83.8{\pm}10.4%$ for water, $94.9{\pm}12.2%$ for soil and sediment samples and $80.2{\pm}8.7%$ for the spiked $^{13}C{_{12}}$-PCBs. Detection limits of PCBs for water, soil and sediment samples are 0.01 ng/ml and 0.05 ng/g. PCB congeners in water samples were not detected within quantitation limit, but trace amounts were detected in most of soil and sediment samples. The contamination level of PCBs in Korea was evaluated to be lower than in advanced countries like USA, Europe and Japan.