• Analytical Science and Technology
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• v.29 no.5
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• pp.209-218
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• 2016

PM₁₀ and PM_2.5 samples were collected at the 1100 site of Mt. Halla in Jeju Island during 2011~2012, and their ionic and elemental species were analyzed, in order to investigate the characteristics of emission sources as well as aerosol compositions. The mass concentrations of PM₁₀ and PM_2.5 were 22.0±13.1 µg/m³ and 11.3±6.1 µg/m³, respectively, showing 2.4~2.6 times lower than those of the capital city area of Korea. The composition ratios of major secondary pollutants (nss-SO₄²⁻, NH₄⁺, and NO₃⁻) were the highest as 85.5 % for PM₁₀ and 91.3 % for PM_2.5, and followed by the order of marine (Na⁺, Cl⁻, and Mg²⁺), organic acid (HCOO⁻ and CH₃COO⁻), and soil (nss-Ca²⁺) sources. Among the elemental species in PM₁₀, soil-originated components (Al, Fe, and Ca) were consisted of 50.9 %, which was higher proportion than marine and anthropogenic elements. The acidification of the fine particulate matters was found to be influenced mostly by sulfuric and nitric acids, and these acids were mainly neutralized by calcium carbonate in PM₁₀ and by ammonia in PM_2.5. The clustered back trajectories showed that 47 % of total air mass inflows was from the China, and the concentrations of NO₃⁻ and nss-Ca²⁺ were especially high corresponding to the inflows.

• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.6
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• pp.33-42
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• 2020

Emission factors for ammonia and particulate matters (PMs) from livestock buildings are of increasing importance in view of the environmental protection. While the existing emission factors were determined based on the emission inventory of other countries, in situ measurement of emission factors is required to construct an accurate emission inventory for Korea. This study is to report measurements of ammonia and PMs emissions from mechanically-ventilated pig houses, which are common types of pig barns in Korea. Ventilation rates and concentrations of ammonia and PMs were measured at the ventilation outlets of a weaner unit, a growing pig unit and a fattening pig unit to calculated the emission factors. The PMs emission was characterized with different aerodynamic diameters (PM_2.5, PM₁₀, and total suspended particulates (TSP)). The measured ammonia emission factors for weaners, growing pigs and fattening pigs were 0.225, 0.869 and 1.679 kg animal^-1 yr^-1, respectively, showing linear increase with pigs' age. The PMs emission factors for three growing stages were 0.023, 0.237 and 0.241 kg animal^-1 yr^-1, respectively for TSP, 0.017, 0.072 and 0.223 kg animal^-1 yr^-1, respectively for PM₁₀, and 0.011, 0.016 and 0.151 kg animal^-1 yr^-1, respectively for PM_2.5. PMs emissions were increased with pigs' age due to increasing feed supply and animal movement. The measured emission factors were smaller than those of the existing emission inventory indicating that the existing ones overestimate the emissions from pig buildings and also suggesting that long-term in situ monitoring at various livestock buildings is required to construct the accurate emission inventory.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.77-82
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• 2005

Recently, people's rising interests toward a 'well-being' lifestyle together with research contributions are accelerating the concerns regarding indoor air pollution making indoor air quality management an emerging environmental challenge of the era. The Ministry of Environment began to regulate the air quality of railway stations last year. The newly established 'Indoor Air Quality Act' covers 17 facilities whereas only underground subway stations and underground markets were regulated by previous 'Underground Air Quality Management Act' of 1996. In this study, we carried out the measurement of temperature, relative humidity, CO(carbon monooxide), $CO_2$(carbon dioxide), HCHO(formaldehyde), PM-10(particulate matters), and VOCs(volatile organic compounds) in underground subway stations. Based on the obtained results, we will suggest a way to improve the indoor air quality of the subway stations.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.989-993
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• 2007

It was intended in this study to seek for the measures to utilize the USN technique, which has high usability due to low price and low power consumption, in air quality monitoring. As a method, the sensors of temperature, humidity, particulate matters (PM10), and carbon dioxide ($CO_2$) were installed in the self-manufactured sensor nodes; the nodes were installed in the waiting rooms and platforms of a subway station and the measurements were collected at real time with use of a computer which micro gateway was built in. Collected data was to be processed by the statistics program installed in the computer; the collected data is to be used in managing the air quality of stations after transmission to the ventilation system of ventilation chambers.

• Journal of Korean Society for Atmospheric Environment
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• v.21 no.4
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• pp.439-458
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• 2005

An automated analysis system for water soluble constituents in $PM_{2.5}$ has been developed. The system consists of a high capacity multi tube diffusion scrubber (MTDS), a low temperature particle impactor (LTPI), and two ion (anion and cation) chromatography (IC) systems. Atmospheric particles have been collected by passing sample air through a thermostated MTDS followed by a LTPI. This system allows simultaneous measurements of soluble ions in $PM_{2.5}$ at 30 minutes interval. At the air sampling flow rate of 1.0L/min, the detection limits of the overall system are in the order of tens of $ng/m^3$. This system has been successfully used for the measurement of particulate components of Seoul air from April 2003 to January 2004. $SO_4^{2-},\;NO_3^-,\;NH_4^+,\;NO_2^-,\;Cl^-,\;Na^+,\;K^+,\;Ca^{2+},\;and\;Mg^{2+}$ are the major ionic species for $PM_{2.5}$ at Seoul. Among them, $SO_4^{2-},\;NO_3^-\;and\;NH_4^+$ are the most abundant ions, contributed up to $86\%$ of the total and the concentrations were higher than those in any other urban sites in the world except for Chinese cities. There are high pollutant episodes which contribute about $15\~20\%$ of annual average values of the major ions. During the episode, the all parcels were transported from the asian continent and $PM_{2.5}$ were significantly neutralized. This suggests that aged and long range transported pollutants caused the high pollutant episodes. They showed a distinct daily and seasonal variations:they showed a peak in the early morning caused by the night-time accumulation of particulate matters. Atmospheric reactions including gas-to-particle reactions and inter-particle reactions and meteorological parameters including relative humidity and ambient temperature were described with related to the $PM_{2.5}$ 5 concentrations. All of the ionic species showed higher concentrations during the spring than those for summer and winter.

• Journal of Korean Society for Atmospheric Environment
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• v.33 no.2
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• pp.139-158
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• 2017

CMAQ (Community Multiscale Air Quality Model) simulations were carried out to estimate the potential range of contributions on surface $PM_{2.5}$ concentrations over the Seoul Metropolitan Area (SMA) with the gaseous precursors and Primary Particulate Matters(PPM) available from a recent national emissions inventory. In detail, on top of a base simulation utilizing the 2013 Clean Air Policy Supporting System (CAPSS) emission inventory, a set of Brute Force Method (BFM) simulations after reducing anthropogenic $NO_x$, $SO_2$, $NH_3$, VOCs, and PPM emissions released from area, mobile, and point sources in SMA by 50% were performed in turn. Modeling results show that zero-out contributions(ZOC) of $NH_3$ and PPM emissions from SMA are as high as $4{\sim}5{\mu}g/m^3$ over the region during the modeling period. On the contrary, ZOC of local $NO_x$ and $SO_2$ emissions to SMA $PM_{2.5}$ are less than $1{\mu}g/m^3$. Moreover, model analyses indicate that a wintertime $NO_x$ reduction at least up to 50% increases SMA $PM_{2.5}$ concentrations, probably due to increased HNO3 formation and conversion to aerosols under more abundant ozone and radical conditions after the $NO_x$ reduction. However, a nation-wide $NO_x$ reduction decreased SMA $PM_{2.5}$ concentrations even during winter, which implies that nation-wide reductions would be more effective to curtail SMA $PM_{2.5}$ concentrations than localized efforts.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.4
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• pp.140-146
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• 2010

An experimental study was carried out to investigate the emission characteristics for various alternative fuels in a 2.0 liter 4-cylinder turbo-charged diesel engine. The conventional diesel fuel, neat GTL (Gas to Liquid), blends of diesel and biodiesel(BD20), and blends of GTL and biodiesel(G+BD20 and G+BD40) were applied, and their emission characteristics were compared at various steady-state engine operating conditions. A noticeable reduction of exhaust emissions compared to conventional diesel fuel, except for NOx emission, was observed for G+BD40, where there is a maximum 30% averaged reduction for gaseous emissions (THC and CO) and 70% for PM mass concentrations. When comparing PM size distributions for biodiesel blended fuels, the PM number concentration in accumulation mode, where the diameter of PM is greater than 50 nm, decreased due to additional oxygen content in the biodiesel fuel; in nucleation mode, where the diameter of PM is less than 50nm, there was a slight increase or decrease in the PM number concentration depending on the amount of oxygen available in the combustion chamber.

• Toxicological Research
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• v.27 no.3
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• pp.161-166
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• 2011

Carbon black, a particulate form of pure elemental carbon, is an industrial chemical with the high potential of occupational exposure. Although the relationship between exposure to particulate matters (PM) and cardiovascular diseases is well established, the cardiovascular risk of carbon black has not been characterized clearly. In this study, the cytotoxicity of carbon black to vascular smooth muscle and endothelial cells were examined to investigate the potential vascular toxicity of carbon black. Carbon black with distinct particle size, N330 (primary size, 28~36 nm) and N990 (250~350 nm) were treated to A-10, rat aortic smooth muscle cells and human umbilical vein endothelial cell line, ECV304, and cell viability was assessed by lactate dehydrogenase (LDH) leakage assay. Treatment of carbon black N990 resulted in the significant reduction of viability in A-10 cells at 100 ${\mu}g$/ml, the highest concentration tested, while N330 failed to cause cell death. Cytotoxicity to ECV304 cells was induced only by N330 at higher concentration, 200 ${\mu}g$/ml, suggesting that ECV304 cells were relatively resistant to carbon black. Treatment of 100 ${\mu}g$/ml N990 led to the elevation of reactive oxygen species (ROS) detected by dichlorodihydrofluorescein (DCF) in A-10 cells. Pretreatment of antioxidants, N-acetylcysteine (NAC) and sulforaphane restored decreased viability of N990-treated A-10 cells, and N-acetylcysteine, but not sulforaphane, attenuated N990-induced ROS generation in A-10 cells. Taken together, present study shows that carbon black is cytotoxic to vascular cells, and the generation of reactive oxygen contributes to the development of cytotoxicity. ROS scavenging antioxidant could be a potential strategy to attenuate the toxicity induced by carbon black exposure.

• Applied Chemistry for Engineering
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• v.31 no.1
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• pp.84-89
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• 2020

Particulate matters of PM_2.5, particularly focusing on 0.1~1 ㎛ decrease the efficiency of dust-collector due to the brownian-motion. This study is to verify the effect of coagulant on the particle size distributions of potassium and PM_2.5. The activated coagulant was spayed to the coal fired fluidized bed combustion boiler by the weight ratio of 1,200 : 1 = coal : coagulant, and the size distributions of captured particles at both the cyclone (FP) and electrostatic precipitator (EP) were measured. As the result of XRP analysis, the potassium content of FP increased to 13.33% (averagely from 1.65% to 1.87%) and, in EP at 17.68% (averagely from 1.65% to 2.03%). And it was confirmed by the particle size distribution analyzer and SEM image analysis that the distribution rates of PM_2.5 decreased at 89.53% on average in FP, and at 88.57% in EP. The total dust concentration (mg/㎥) confirmed by tele-monitering system (TMS) decreased during the primary test from 2.6 to 1.7~1.9 and also the secondary test from 2.9 to 1.7~1.9.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.613-618
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• 2011

More than 7 million persons use Seoul Metropolitan Subways (SMS) everyday and the number has been in increasing trend. With the increasing trend of concerns on indoor air quality(IAQ), the management of IAQ has become an important issue, especially in case of subway operators, because most of subway lines are placed underground with poor ventilation condition. The ultimate object of study develop independent cleaning device that reduce efficient fine particle and $CO_2$. Urban subway has characteristics about proper clean air flow, must be installed in narrow space and maintenance cycle has enough time. Two layered electrically pre-charged filters were used for removing particulate matters and gas absorbers are packed between two layer filters for removing gases pollutants such $CO_2$, VOCs and HCHO. Urban subway has characteristics about proper clean air flow, must be installed in narrow space and maintenance cycle has enough time. SCAP prototype is producted as all in one method which decrease fine dust, $CO_2$ and noxious gas. and basic test carry out with quantity of wind, a gap of pressure, sampling efficiency.