• Journal of Information Display
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• v.7 no.4
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• pp.9-12
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• 2006

This paper reports the synthesis and electroluminescent properties of new aromatic compounds as hole-transporting materials based on phenothiazine, such as 1,4-diphenothiazyl-benzene [DPtzB], 1,4-diphenothiazyl-xylene [DPtzX] and 9,10-diphenothiazyl-anthracene [DPtzA]. DPtzB thin film exhibited photoluminescence (PL) maximum emission peak and emission shoulder at 450 and 475 nm, and a maximum emission at 447 nm without emission shoulder was obtained in DPtzX thin film. When DPtzA was excited by incident light of 359 nm, DPtzA showed strong PL emission at 417 nm and weak emission at 600 nm. Luminance efficiency of DPtzB, DPtzX and DPtzA-based electroluminescence (EL) devices was 3.57, 3.46 and 0.47 cd/A, and power efficiency of DPtzB, DPtzX and DPtzA-based EL devices was 1.48, 1.26 and 0.201 m/W.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1054-1058
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• 2006

We report the synthesis and electroluminescent properties of new aromatic compounds as hole-transporting materials based on phenothiazine, such as 1,4-diphenothiazyl-benzene [DPtzB], 1,4-diphenothiazyl-xylene [DPtzX] and 9,10-diphenothiazyl-anthracene [DPtzA]. DPtzB thin film exhibited photoluminescence (PL) maximum emission peak and emission shoulder at 450 and 475nm, and maximum emission at 447nm without emission shoulder was found in DPtzX thin film. When DPtzA was excited by incident light of 359nm, DPtzA showed strong PL emission at 417nm and weak emission at 600nm. Luminance efficiency of DPtzB, DPtzX and DPtzA-based electroluminescence (EL) devices was 3.57, 3.46 and 0.47cd/A, and power efficiency of DPtzB, DPtzX and DPtzA-based EL devices was 1.48, 1.26 and 0.20lm/W.

• Plant Biotechnology Reports
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• v.3 no.1
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• pp.57-65
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• 2009

Cultured Cupressus lusitanica cells induced by various stresses are thought to produce different complexes of defense chemicals to optimize defense. To compare the induced products of two stimulations, we investigated the emission of monoterpenes, biosynthesis of ${\beta}-thujaplicin$, and accumulation of lignin in mechanically stressed and fungal elicited cultured C. lusitanica cells. Both mechanical stress and fungal elicitor caused emission of qualitatively similar monoterpene blends indicating de novo biosynthesis of these compounds after stimulation, while mechanical stress alone is sufficient to induce fungal elicitor-related monoterpene emission. Sabinene and limonene were the dominant compounds over the time course in both volatile blends. Although the emitted volatile blends were qualitatively similar, the time course and the relative ratios of the constituents of the volatile blends differed with the type of stimulation. While fungal elicited cells produced significant amounts of ${\beta}-thujaplicin$ over the 5-day time course, no ${\beta}-thujaplicin$ was observed in the mechanically stressed cells. The production of ${\beta}-thujaplicin$ was the main dissimilarity of the induced products of these two treatments, suggesting that synthesis of ${\beta}-thujaplicin$ is not a general response to all types of stresses, but is a specific response and serves as a strong toxic compound against already invaded fungus. Significantly higher amounts of lignin accumulations were observed in the fungal elicited and mechanically stressed cells on the 5th day after induction. Based on these results, we suggest the composition of induced products was dependent on the method of stimulation.

• Environmental Engineering Research
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• v.14 no.4
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• pp.212-219
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• 2009

Emission characteristics of air pollutants from three commercially operating cement kilns co-burning waste were investigated. The major heavy metals emitted were mercury (Hg), zinc (Zn), nickel (Ni), chromium (Cr), lead (Pb), cadmium (Cd), and arsenic (As) Removal efficiency of the bag filter was above 98.5% for heavy metals (except Hg), and above 60% for Hg. Higher fractions of heavy metals entering the bag filter were speciated to cement kiln dust. On average, 3.3% of the -heavy metals of medium and low toxicity (Pb, Ni, and Cr) entering the bag filter were released into the atmosphere. Among highly toxic heavy metals, 0.14% of Cd, 0.01% of As, and 40% of Hg entering the bag filter were released into the atmosphere. In passing through the bag filter, the proportion of oxidized Hg in all cases increased. Emission variations of hazardous air pollutants in cement kilns tested were related to raw materials, fuel, waste feed and operating conditions. Volatile organic compounds detected in gas emissions were toluene, acrylonitrile benzene, styrene, 1,3-butadiene, and methylene chloride. Although hazardous air pollutants in emissions from cement kilns co-burning waste were within the existing emission limit, efforts are required to minimize their levels.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.E1
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• pp.1-11
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• 2008

Mercury (Hg), which is mainly emitted from coal-fired power plants, remains one of the most toxic compounds to both humans and ecosystems. Hg pollution is not a local or regional issue, but a global issue. Hg compounds emitted from anthropogenic sources such as coal-fired power plants, incinerators, and boilers, can be transported over long distances. Since the last decade, many European countries, Canada, and especially the United States, have focused on technology to control Hg emissions. Korea has also recently showed an interest in managing Hg pollution from various combustion sources. Previous studies indicate that coal-fired power plants are one of the major sources of Hg in Korea. However, lack of Hg emission data and feasible emission controls have been major obstacles in Hg study. In order to achieve effective Hg control, understanding the characteristics of current Hg sampling methods and control technologies is essential. There is no one proven technology that fits all Hg emission sources, because Hg emission and control efficiency depend on fuel type, configuration of air pollution control devices, flue gas composition, among others. Therefore, a broad knowledge of Hg sampling and control technologies is necessary to select the most suitable method for each Hg-emitting source. In this paper, various Hg sampling methods, including wet chemistry, dry sorbents trap, field, and laboratory demonstrated control technologies, and international regulations, are introduced, with a focus on coal-fired power plants.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.742-747
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• 2008

Formaldehyde(HCHO) and total volatile organic compounds(VOCs) can cause adverse health effects to the building occupants and may contribute to symptoms of 'Sick Building Syndrome'. These chemical contaminants are emitted from furnishings and electronic equipments as well as building materials. The purpose of this study is to measure and analyze VOCs and HCHO emission concentration from furnitures composed of wood materials including various chemicals by the large chamber method. This paper presents experiment results on the emission concentration of TVOCs and HCHO released from furnitures, such as bed, kitchen, sofa and table by a large chamber($24m^3$). The temperature and air humidity in the chamber are controlled to $25{\pm}1{\circ}C$ and $50{\pm}5%$ for this experiment. When the air change rate is $0.5hr^{-1}$, the background concentrations within the large chamber are below $50{\mu}g/m^3$ for TVOC, $5{\mu}g/m^3$ for HCHO and individual VOCs. The study is investigated the characterization of the chemical emission TVOC and HCHO concentrations and unknown VOCs from 6 furnitures.

• Journal of the Korean Wood Science and Technology
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• v.36 no.2
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• pp.39-45
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• 2008

Formaldehyde and volatile organic compounds (VOCs) are emitted from wood-based panels that have been made using wood particles, wood fiber, wood chips, formaldehyde-based resins and so on. In this study, we examined formaldehyde and total VOCs (TVOC) emission behaviors for plywood overlaid with water-soluble phenolic resin impregnated linerboard (PL), and two kinds of surface materials (decorative veneer and pre-impregnated finishing foil) that were adhered onto the PL that named DPL and PPL. EVA (ethyl vinyl acetate) was used to overlay the decorative veneer and pre-impregnated finishing foil on the plywood with water-soluble phenolic resin impregnated linerboard by a hot press instrument. The debonding test and accelerated aging test were conducted to assess their mechanical properties. Formaldehyde and TVOC emission concentrations were measured using the FLEC method and a VOC Analyzer, respectively. The debonding test results of PL, DPL and PPL were 1.2, 1.5, and $0.5N/mm^2$, respectively. The surface appearance of the samples were not changed after the accelerated aging test. The PL and DPL exhibited reduced formaldehyde and TVOC emission levels, respectively. In the case of PPL, the VOC value was relatively higher than those of PL and DPL.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.3
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• pp.183-190
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• 2011

This study investigated the emissions characteristics of air freshener using small emission chamber method. The emission of VOCs from air freshener were determined in the small chambers in the temperature (25, $30({\pm}1)^{\circ}C$), relative humidity ($50{\pm}5%$), ventilation rate (0.3, 0.5, ($0.8({\pm}0.005)/hr$), and sample loading factor ($1.4{\sim}551.0g/m^2$) in this study. The emission tests from air freshener for sample loading factor resulted in TVOC emission rates of $0.7{\sim}64.4mg/m^2{\cdot}h$ after 5 hours. For most target VOCs such as limonene, ${\alpha}$-pinene and linalool, higher temperature and ventilation rate levels exhibited increased emission rates.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.8
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• pp.541-548
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• 2012

The objective of this study was to investigate emission characteristics of odorous compounds from the pneumatic waste collection plants (namely, A and B sites). The air samples were collected from each site, at a carrier gas inside the plant and an exhaust gas, to analyze complex odor and 22 odorous compounds. Ammonia, sulfur compounds, and acetaldehyde were the critical odorous components generated in the plants studied. Characteristics of odor at exhaust outlet varied according to the type of odor control engineering. In the analysis of the odor contribution degree of odor components based on odor threshold, site A shows that the odor contribution of dimethyl sulfide was found to be 26%, acetaldehyde 18%, and methyl mercaptan 14%. For site B, methyl mercaptan was 56% and both hydrogen sulfide and dimethyl sulfide were 15%.

• Journal of Korean Society for Atmospheric Environment
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• v.29 no.5
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• pp.615-624
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• 2013

In this study, the emission patterns of reduced sulfur compounds (RSC) were investigated using four different types of food samples (boiled egg, milk, canned meat and strawberry) between fresh and decaying stages. To this end, the concentrations of RSCs were measured at storage days of 0, 1, 3, 6, and 9 under room temperature. Four sulfur compounds ($H_2S$, $CH_3SH$, DMS and DMDS) were selected as target compounds along with two reference compounds ($CS_2$ and $SO_2$). Their concentrations were quantified using GC-PFPD equipped with thermal desorption (TD) system. The boiled egg showed the highest concentration of $H_2S$ (3,655 ppb) at D-1, while $CH_3SH$ reached its maximum value of 64.4~78.5 ppb after 3 days. In milk samples, concentration of $CH_3SH$, DMS, and DMDS went up to 487, 16.3, and 578 ppb, respectively with the progress of decay (D-9). In case of canned meat, concentration of $H_2S$ and $CH_3SH$ peaked in the beginning (D-0) such as 345 and 66.6 ppb. In case of strawberry, $CH_3SH$ and DMDS showed the maximum concentrations 135 and 50.5 ppb at D-1, respectively. The olfactometry dilution-to-threshold (D/T) ratio by air dilution sensory (ADS) test showed similar patterns when sum of odor intensity (SOI) was derived via conversion of odorant concentration data. The results of this study confirm that the time of strong RSC emissions is distinguished for each food type between fresh (e.g., strawberries) and decaying conditions (e.g., milk).