• Particle and aerosol research
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• v.20 no.1
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• pp.13-24
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• 2024

The concentrations of polycyclic aromatic hydrocarbons (PAHs) and elemental carbon (EC) in particulate matter, typical primary aerosols have decreased in Seoul between 2003 and 2018 (80% for PAHs and 85% for EC). The yearly mean benzo[a]pyrene (BaP) concentration has been lower than 1 ng/m3 since 2010-2011, the target value set by the European Union (EU) and China. A series of policies related to solid fuel and vehicle in South Korea and China should be effective in the reduction of the ambient PAHs and EC concentrations. But the emission data of PAHs and EC at both countries did not support that hypothesis. Possible causes are uncertainties in the emission inventories of primary carbonaceous aerosols in South Korea and China, although there may be a minor effect of the emissions from North Korea on the concentrations in Seoul. Thus the further policy directions against PAHs and EC such as improvements of emissions inventories and measurements, intensive regulation of non-road mobile sources and control of PAHs derivatives are discussed.

• Journal of Environmental Science International
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• v.23 no.9
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• pp.1643-1654
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• 2014

The university is one of the main energy consumption facilities and thereby releases a large amount of greenhouse gas (GHG). Accordingly, efforts for reducing energy consumption and GHG have been established in many local as well as international universities. However, it has been limited to energy consumption and GHG, and has not included air pollution (AP). Therefore, we estimated GHG and AP integrated emissions from the energy consumed by Seoul National University of Science and Technology during the years between 2010 and 2012. In addition, the effect of alternative energy use scenario was analysed. We estimated GHG using IPCC guideline and Guidelines for Local Government Greenhouse Inventories, and AP using APEMEP/EEA Emission Inventory Guidebook 2013 and Air Pollutants Calculation Manual. The estimated annual average GHG emission was $11,420tonCO_{2eq}$, of which 27% was direct emissions from fuel combustion sectors, including stationary and mobile source, and the remaining 73% was indirect emissions from purchased electricity and purchased water supply. The estimated annual average AP emission was 7,757 kgAP, of which the total amount was from direct emissions only. The annual GHG emissions from city gas and purchased electricity usage per unit area ($m^2$) of the university buildings were estimated as $15.4kgCO_{2eq}/m^2$ and $42.4tonCO_{2eq}/m^2$ and those per person enrolled in the university were $210kgCO_{2eq}$/capita and $577kgCO_{2eq}$/capita. Alternative energy use scenarios revealed that the use of all alternative energy sources including solar energy, electric car and rain water reuse applicable to the university could reduce as much as 9.4% of the annual GHG and 34% of AP integrated emissions, saving approximately 400 million won per year, corresponding to 14% of the university energy budget.

• Journal of Korean Society for Atmospheric Environment
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• v.22 no.3
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• pp.287-295
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• 2006

PAHs (Polycyclic Aromatic Hydrocarbons), one of the carcinogenic materials in environment, were investigated in this study. The standardized analysis conditions were tested, and then various factors which affect to the ambient PAHs concentration in Seoul were estimated. Moreover, the emissions of PAHs from major stationary sources were investigated to determine the quantitative relationships between ambient PAHs concentrations and emission sources. From the factor analysis, three factors relevant to the ambient PAHs in Seoul were found. Factor 1 was related to the concentrations of chrysene, pyrene, indeno (1, 2, 3-cd)pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene, and benzo prerylene which were mainly emitted from gasoline and diesel fueled cars. Factor 2 showed higher loadings in phenanthrene and anthracene which were due to LNG and BC oil combustion in industry and home. And factor 3 included dibenz(a, h)anthracene and acenaphthene which were emitted from open burning and municipal solid waste incineration. Conclusively, all of three factors were consisted in 82% of total variance. The contribution of mobile sources in ambient air in Seoul was estimated at 64%, that of industrial and home sources at 17%, and that of open burning and municipal incineration at 1%.

• Journal of Advanced Navigation Technology
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• v.18 no.5
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• pp.513-517
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• 2014

In this study, we implemented and designed an RF monitoring system to manage a dust collector wirelessly, which is manually operated. The dust collector prevents the emission of air pollutants and improves air condition. It is possible to implement a high-value monitoring system of a dust collector, the system will wirelessly monitor many important data such as the operating time, the amount of electricity consumption, and the differential pressure value of a large number of the dust collectors in an industrial site, the system also displays and saves these data on a manager's PC, and when an error occurs, the system sends the error message to a manager's mobile phone. Therefore, through the RF monitoring system implemented in this paper, it is possible to reduce unnecessary loss for recording information of each dust collector to stack emission management system (SEMS).

• Journal of ILASS-Korea
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• v.23 no.2
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• pp.81-89
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• 2018

The objective of this study is to estimate the level of exposure of traffic-related air pollutants (TRAPs) on the pedestrians in Seoul area. The road network's link-based pollutant emission was calculated by using a set of mobile source emission factor package and associated activity information. The population information, which is the number of pedestrian, was analyzed in conjunction with the link-based traffic emissions in order to quantify exposure level by selected 23 spots. We proposed the Exposure Intensity, which is defined by the amount of traffic emission and the population, to quantify the probability of exposure of pedestrian. Link-based traffic NOx and PM emissions vary by up to four times depending on the location of each spot. The Hot-spots is estimated to be around 1.8 times higher Exposure Intensity than the average of the 23 selected spots. The information of Exposure Intensity of each spot allows us to develop localized policies for air quality and health. Even in the same area, the Exposure Intensity over time also shows a large fluctuation, which gives suggestions for establishing site-specific counter-measures.

• Journal of Climate Change Research
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• v.3 no.4
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• pp.259-270
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• 2012

Mobile air conditioning(MAC) systems of light-duty vehicles consume the most energy among auxiliary parts. Vehicle $CO_2$ reduction policies in Korea, US EPA and EU include the strategies to reduce additional $CO_2$ by MAC operation with providing incentive for the high-efficient MAC technologies. It is under development how to estimate MAC $CO_2$ and to differentiate advanced or high-efficient MAC system in US EPA and EU. The additional energy by MAC operation would beaffected by not only driving patterns but also environmental conditions such as temperature and humidity. In this study, we estimated MAC $CO_2$ of Korean light-duty vehicles with various driving cycles and environmental conditions. Test results were corrected to reference conditions for varied temperature and humidity during tests to get the comparable data for test vehicles. The test results showed that high-efficient MAC technologies have potential to reduce MAC $CO_2$ approximately by 50%. Considering the rate of MAC $CO_2$ to vehicle $CO_2$, it is expected that the introduction of high-efficient MAC technologies would considerably reduce vehicle $CO_2$ emission in MAC operation.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.609-613
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• 2005

Advanced mobile communication devices require a bright, high information content display in a small, light-weight, low power consumption package. In this paper we will outline our progress towards developing such a low power consumption active-matrix flexible OLED ($FOLED^{TM}$) display. Our work in this area is focused on three critical enabling technologies. The first is the development of a high efficiency long-lived phosphorescent OLED ($PHOLED{TM}$) device technology, which has now proven itself to be capable of meeting the low power consumption performance requirements for mobile display applications. Secondly, is the development of flexible active matrix backplanes, and for this our team are employing poly-Si TFTs formed on metal foil substrates as this approach represents an attractive alternative to fabricating poly-Si TFTs on plastic for the realization of first generation flexible active matrix OLED displays. Unlike most plastics, metal foil substrates can withstand a large thermal load and do not require a moisture and oxygen permeation barrier. Thirdly, the key to reliable operation is to ensure that the organic materials are fully encapsulated in a package designed for repetitive flexing. We also present progress in operational lifetime of encapsulated T-PHOLED pixels on planarized metal foil and discuss PHOLED encapsulation strategy.

• Archives of Pharmacal Research
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• v.26 no.9
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• pp.763-767
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• 2003

The differences in pharmacokinetic behavior and tissue distribution of verapamil and its enantiomers were investigated in rats. In high-performance liquid chromatographic method, an achiral ODS column (150 mm $\times$ 4.6 mm i.d.) with the mobile phase consisting of methanol-water (73:30, v/v) was used for the determination of the concentration for racemic verapamil, and a Chiralcel OJ column (250 mm$\times$4.6 mm i.d.) with the mixture of n-haxane-ethanol-triethylamine (85:15:0.2, v/v/v) as mobile phase was used to determine the concentrations of verapamil enantiomers. A fluorescence detector in the analytical system was set at excitation and emission wavelengths of 275 nm and 315 nm. The differences between enantiomers were apparent in the pharmacokinetics in rats. The area under the concentration-time curve (AUC) of S-(-) verapamil was higher than that of R-(+) verapamil. The half-distribution time ($T_{1/2(\alpha)}$) of S-(-) verapamil which distributing to tissue from blood was shorter than that of R-(+) verapamil, but the elimination half-time ($T_{1/2(\beta)}$) was longer in rat following oral administration of racemic verapamil. At 1.3 h after oral administration of racemic verapamil, however, there were no significant differences between enantiomers for the distributions in major tissues such as heart, cerebrum, cerebellum, liver, spleen and kidney.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.5
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• pp.361-368
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• 2000

This study was carried out to investigate the influence of artificial zeolite on the change of temperature, gas emission, water content and chemical properties during the composting process with the mixture of animal feces, broken bark and extruded rice hull. Artificial zeolite was added 0, 0.5, 1, 3 and 5% volume of the raw composting material, and proceeded 1.2m every day with mobile stacking escalator. Temperature was increased, and water content was decreased in the composting pile by addition of artificial zeolite. This caused to accelerate decomposition of organic matter during composting. $NH_3$ was emitted the highest at 6th day after stacking, then decreased gradually. And addition of artificial zeolite caused to decrease greatly in $NH_3$ emission from composting pile. As result of this, content of nitrogen in the compost was increased by addition of artificial zeolite. Emission of $CH_4$ was the highest at early stacking stage, and that was decreased drastically at 8th day. Emission of $CH_4$ was also decreased greatly by addition of artificial zeolite at 5th days after stacking. It may be resulted from adsorption of $CH_4$ into the molecular sieve structure of artificial zeolite and low water content by high temperature fermentation.

• Journal of Korean Society for Atmospheric Environment
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• v.33 no.4
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• pp.377-392
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• 2017

A set of BFM (Brute Force Method) simulations with the CMAQ (Community Multiscale Air Quality) model were conducted in order to estimate self-contributions and conversion rates of PPM (Primary $PM_{2.5}$), $NO_x$, $SO_2$, $NH_3$, and VOC emissions to $PM_{2.5}$ concentrations over the SMA (Seoul Metropolitan Area). CAPSS (Clean Air Policy Support System) 2013 EI (emissions inventory) from the NIER (National Institute of Environmental Research) was used for the base and sensitivity simulations. SCCs (Source Classification Codes) in the EI were utilized to group the emissions into area, mobile, and point source categories. PPM and $PM_{2.5}$ precursor emissions from each source category were reduced by 50%. In turn, air quality was simulated with CMAQ during January, April, July, and October in 2014 for the BFM runs. In this study, seasonal variations of SMA $PM_{2.5}$ self-sensitivities to PPM, $SO_2$, and $NH_3$ emissions can be observed even when the seasonal emission rates are almost identical. For example, when the mobile PPM emissions from the SMA were 634 TPM (Tons Per Month) and 603 TPM in January and July, self-contributions of the emissions to monthly mean $PM_{2.5}$ were $2.7{\mu}g/m^3$ and $1.3{\mu}g/m^3$ for the months, respectively. Similarly, while $NH_3$ emissions from area sources were 4,169 TPM and 3,951 TPM in January and July, the self-contributions to monthly mean $PM_{2.5}$ for the months were $2.0{\mu}g/m^3$ and $4.4{\mu}g/m^3$, respectively. Meanwhile, emission-to-$PM_{2.5}$ conversion rates of precursors vary among source categories. For instance, the annual mean conversion rates of the SMA mobile, area, and point sources were 19.3, 10.8, and $6.6{\mu}g/m^3/10^6TPY$ for $SO_2$ emissions while those rates for PPM emissions were 268.6, 207.7, and 181.5 (${\mu}g/m^3/10^6TPY$), respectively, over the region. The results demonstrate that SMA $PM_{2.5}$ responses to the same amount of reduction in precursor emissions differ for source categories and in time (e.g. seasons), which is important when the cost-benefit analysis is conducted during air quality improvement planning. On the other hand, annual mean $PM_{2.5}$ sensitivities to the SMA $NO_x$ emissions remains still negative even after a 50% reduction in emission category which implies that more aggressive $NO_x$ reductions are required for the SMA to overcome '$NO_x$ disbenefit' under the base condition.