• Journal of the Korean earth science society
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• v.43 no.1
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• pp.77-90
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• 2022

Despite the decreasing trend of anthropogenic emissions in East Asia in recent years, haze days still frequently occur in spring. Atmospheric blocking, which occurs frequently in the northeastern Pacific, leads to persistent changes in large-scale circulation and blocks westerly flow in the East Asian region. During March 2019, frequent warm and stagnant synoptic meteorological conditions over East Asia were accompanied 6-7 days later by the Alaskan atmospheric blocking. The Alaskan atmospheric blocking over the period of March 18-24, 2019 led to high particulate matter (PM₁₀) severe haze days exceeding a daily average of 50 ㎍ m^-3 over the period of March 25-28, 2019 in South Korea. Although the high-PM₁₀ severe haze days were caused by warm and stagnant meteorological conditions, the regional contribution of anthropogenic emissions in eastern China was calculated to be 30-40% using the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem). The major regional contributions of PM₁₀ aerosols in the period of high-PM₁₀ severe haze days were as follows: nitrates, 20-25%; sulphates, 10-15%; ammonium, 5-10%; and other inorganics, 15-20%. Ammonium nitrate generated via gas-to-aerosol conversion in a warm and stagnant atmosphere largely contributed to the regional transport of PM₁₀ aerosols in the high-PM₁₀ severe haze days in South Korea.

• Journal of Korean Society for Atmospheric Environment
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• v.21 no.1
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• pp.131-140
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• 2005

To investigate secondary carbonaceous species within PM$_{10}$ and PM$_{2.5}$ in Seoul urban Metropolitan Area (SMA), Korea. atmospheric particulate matters samples were collected at two sites of SMA at UOS (The University Of Seoul station) sites and IHU (InHa University of Incheon station) during the period of 4 to 14 January and 12 to 22 May, 11 to 15 August 2004, and their characteristics were qualitatively discussed. during January and May and August of 2004. Daily average mass concentration 0.095 mg/㎥ in PM$_{10}$ and 0.053 mg/㎥ in PM$_{2.5}$ for mass respectively. were observed in SMA. The concentrations of carbonaceous species contributed 18.4% and 16.4% of PM$_{2.5}$ and PM$_{10}$ during the sampling period, respectively, of which OC accounted for 68% and 52% more of the total carbon (TC). OC and EC concentrations and their mass percentages were higher in PM$_{2.5}$ than in PM$_{10}$ which could be attributed to generation process. Organic aerosols would constitute up to 38% of PM$_{2.5}$ based on the evaluation of 1.6 for the ratio of OC to organic particulate. Secondary organic carbon (SOC) were estimated to be more than 13% and up to 68% of total OC based on the minimum OC/EC ratio of 1.06/1.11 using least square method. Comparisons of OC and EC with trace elements. As results of carbonaceous species analysis, the dominant factor in view of fine particle (PM$_{10}$/PM$_{2.5}$) is primary emission source such as mobile, fossil fuel combustion etc. during winter time in SMA. But in summer periods, remarkable fine particle increasing factor was secondary organic carbon dependent to photochemical reaction. reaction.n. reaction.

• Journal of Veterinary Clinics
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• v.9 no.1
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• pp.273-276
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• 1992

Present study was undertaken in order to evaluate the lead contents of various feedstuffs produced in Chonbuk area. Fifty-five samples were collected from 5 regions. All of the samples were dry-ashed and analyzed for lead content using atomic absorption spectrophotometer. The results obtained were summarized as followed : 1. The lead content in $\mu\textrm{g}$/g of agriculture by-products were measured with the following mean values and ranges : soybean pod 7.01${\pm}$2.49(4.71∼10.66), rice bran 4.56${\pm}$0.90(3.17∼5.65), rice straw 3.89${\pm}$2.01(1.29∼6.33), rice hull 1.92${\pm}$1.77(0∼3.63). 2. The lead content in $\mu\textrm{g}$/g of pasture plants were measured with the following mean values and ranges : kudzu 20.29${\pm}$4.75(14.84∼25.34), clover 13.92${\pm}$2.68(10.17∼16.44), lespedeza 10.91${\pm}$9.00 (3.35∼23.54), sagebrush 10.75${\pm}$3.28(5.14∼13.18), Korean lawn grass 5.05${\pm}$2.29(2.57∼7.79), cornstalk 3.91${\pm}$2.55(0.50∼7.22), reed 2.92${\pm}$1.88(0.50∼5.73). 3. Seventeen samples (30.9%) out of 55 samples showed lead content of more than 10$\mu\textrm{g}$/g which are said to be the upper limit value for all animals. 4. The regional mean v짓ues for 리1 kinds of samples were Wanju-gun 10.02${\pm}$8.55$\mu\textrm{g}$/g, Mooju-gun 8.16${\pm}$4.91$\mu\textrm{g}$/g, Namwon-gun 7.09${\pm}$4.59$\mu\textrm{g}$/g, Okgu-gun 7.06${\pm}$7.11$\mu\textrm{g}$/g, Jeongup-gun 6.35${\pm}$6.50$\mu\textrm{g}$/g.

• Journal of Environmental Health Sciences
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• v.36 no.2
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• pp.108-117
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• 2010

In this study, ambient particulate matter ($PM_{2.5}$ and $PM_{10}$) levels were measured and their chemical and physical properties were characterized. Two sites in Gwangju were sampled once a month from December 2008 to November 2009. The annual mean concentrations of $PM_{2.5}$ and $PM_{10}$ were $26.9\;{\mu}g/m^3$ and $46.3\;{\mu}g/m^3$, respectively, in Nongseongdong and $26.1\;{\mu}g/m^3$ and $44.8\;{\mu}g/m^3$, respectively, in Duam-dong. $PM_{2.5}$ levels were 1.8 times higher than the USA Environmental Protection Agency (EPA) national ambient air quality standard for $PM_{2.5}$ ($15\;{\mu}g/m^3$). The average $PM_{2.5}/PM_{10}$ ratio of 0.58 suggested that $PM_{2.5}$ is a significant component of the ambient particle pollution. The order of concentration of metallic elements in $PM_{2.5}$ and $PM_{10}$ was Si > Al > Fe > Zn > Pb > Cu > Mn. Cd was not detected. The earth crustal enrichment factors for Cr, Cu, Pb and Zn in $PM_{2.5}$ were higher than those in $PM_{10}$. When the earth crustal enrichment factors for Cr, Cu, Pb and Zn were higher than 10, this suggested influence from anthropogenic sources. The soil contribution ratios for $PM_{2.5}$ and $PM_{10}$ were 11.3% and 16.4%, respectively, and were higher in the fall and winter. Anions (${SO_4}^{-2}$, ${NO_3}^-$, and $Cl^-$) comprise 28.7% of $PM_{2.5}$ and 21.4% of $PM_{10}$. The correlation coefficient of Zn-Fe, Mn-Cu, Fe-Cu and Fe-Mn in $PM_{2.5}$ was high in the sampling sites, and metallic elements were primarily from anthropogenic sources such as fuel combustion and vehicle emissions.

• Korean Journal of Microbiology
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• v.34 no.3
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• pp.144-148
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• 1998

Soil microorganisms including bacteria, fungi, and actinomycetes were seasonally isolated at depths (0.5~2, $10{\pm}1$, $50{\pm}1cm$) of field. The frequency of microbial isolates was employed for the determination of microbial population (CFU/g dry soil) and distribution ratio (%) in soil. Both bacteria (24-fold) and actinomycetes (7-fold) exhibited the biggest change at the depth of $50{\pm}1cm$, whereas fungi showed the maximum (13-fold) at $10{\pm}1cm$. On the whole, the bacterial population was high in spring soil, fungi in winter, and actinomycetes in autumn. Soil microorganisms also exhibited the seasonal variation on their distribution ratio (%). The maximum distribution ratio (85.7%) of bacteria was observed at the depth of $50{\pm}1cm$ in spring, whereas bacteria showed the minimum (35.2%) at the depth of $10{\pm}1cm$ in spring. The maximum distribution ratio (23.0%) of fungi was found at the depth of $50{\pm}1cm$ in spring, whereas its minimum (0.5%) at the depth of $10{\pm}1cm$ in spring. Actinomycetes exhibited the maximum distribution ratio (45.2%) at the depth of $10{\pm}1cm$ in spring, whereas its minimum (12.2%) was showed at the depth of $50{\pm}1cm$ in spring.

• Journal of the Korean Wood Science and Technology
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• v.15 no.2
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• pp.26-52
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• 1987

Among the diffuse-porous woods which arc dominant in Korea and used as construction materials due to their wood quality, ten species of six genus involving seven species of three genus in Betulaceae were studied on the radial variation of structural demenb. The species studied were Betula platyphylla var. japonica, B. ermanii, B. davurica, B. scstata, B. schmidtii, Carpinus laxifora, Alnus japonica, Prunus sargentii. Acer mono and Diospyros kaki. Wood fiber, vessel elements and ray increased rapidly in size from pith to a certain annual ring. After then the radial variation in size of the main structural elements seemed to be divided into three types; levelled off curve pattern indicating constant size(type I), continuously increasing curve pattern showing ever increase in size (type II) and parabolic curve pattern showing the gradual decrease after the maximum (type III), but the variation types by structural dements were different even in the same species. Based on the results from this study, it appears to be reasonable to consider the stabilized age of wood fiber, vessel elements and ray rather than considering wood fiber length in distinguishing mature woods from juvenile woods.

• Journal of Society of Preventive Korean Medicine
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• v.3 no.1
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• pp.36-36
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• 1999

From January 1994 to April 1997, there was 15 survivals who was admitted to the department of internal medicine, Wonkwang Oriental Medicine' Hospital in Cheun-ju, after ingestion of paraquat, and treated with Oriental and western medicine therapy. For the patients, I investigated clinical symptoms, gastroduodenoscopy, intake by oral and parenteral route, and output by urine and stool, serum ALP, AST. ALT, Bilirubin, BUN, Creatinine level and urine analysis. On admission day, the LFT level was as follows. The serum mean ALP, AST, ALT, Total Bilirubin and Direct Bilirubin was 10.05${\pm}$2.75 KAU, 66.67${\pm}$9.88 IU／L, 43.80${\pm}$7.74 IU／L, 1.89${\pm}$1.22 ㎎／dl and 1.10${\pm}$1.14 ㎎／dl respectively. After that day, administered Gamdutang and checked the mean LFT level regullary. Until the 3rd day, the mean ALP, AST, ALT, Total Bilirubin and Direct Bilirubin level was 11.0l${\pm}$3.16 KAU, 56.47${\pm}$7.19 IU／L, 59.00${\pm}$7.57 IU／L, 2.54${\pm}$1.78 ㎎／dl, 1.64${\pm}$1.59 ㎎／dl respectively. From 4th day to 7th day, the mean ALP; AST, ALT, Total Bilirubin and Direct Bilirubin level was 12.51${\pm}$3.49 KAU, 77.85${\pm}$7.17 IU／L, 58.00${\pm}$9.09 IU／L, 2.54${\pm}$1.97 ㎎／dl, and 1.80${\pm}$1.81 ㎎／dl respectively. From 8th day to 10th day, the mean ALP, AST, ALT, Total Bilirubin and Direct Bilirubin level was 12.43${\pm}$3.14 KAU, 41.13${\pm}$6.49 IU／L, 50.40${\pm}$7.17 IU／L, 1.66${\pm}$1.90 ㎎／dl and 1.14${\pm}$1.50 ㎎／dl respectively. From 11th day to 14th day, the mean ALP, AST, ALT, Total Bilirubin and Direct Bilirubin level was 12.30${\pm}$3.25 KAU, 31.07${\pm}$3.85 IU／L, 43.33${\pm}$5.49 IU／L, 1.62${\pm}$1.95 ㎎／dl, 1.17${\pm}$1.71 ㎎／dl respectvely. On admission day, the mean RFT level as follows. Serum BUN and Creatinine level was 28.73${\pm}$5.19 ㎎／dl and 1.82${\pm}$1.27 ㎎／dl respectively. After that day, administered Gamdutang and checked the mean RFT level regullary. Until the 3rd day, the mean BUN and Creatinine level was 32.12${\pm}$5.65 ㎎／dl and 2.31${\pm}$0.45 ㎎／dl respectively. From 4th day to 7th day, the mean BUN and Creatinine level was 31.07${\pm}$5.47 ㎎／dl and 1.92${\pm}$0.79 ㎎／dl respectively. From 7th day to 10th day, the mean BUN and Creatinine level was 17.47${\pm}$3.57 ㎎／dl and 1.33${\pm}$0.59 ㎎／dl respectively. From 11th day to 14th day, the mean BUN and Creatinine level was 11,93${\pm}$3.16 ㎎／dl, 1.27${\pm}$0.38 ㎎／dl respectively.

• Journal of Environmental Science International
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• v.26 no.1
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• pp.29-36
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• 2017

Aerosol mass size distributions were investigated at 865 m high the of Jirisan national park. A nanosampler cascade impactor was used to collect aerosols. The atmospheric aerosol particles had a unimodal mass size distribution, which peaked at $0.5-1.0{\mu}m$, and a mass aerodynamic diameter of $1.13{\mu}m$. The annual average concentrations of TSP, $PM_{10}$, $PM_{2.5}$, $PM_1$, $PM_{0.5}$ and $PM_{0.1}$ were $20.9{\mu}g/m^3$, $19.3{\mu}g/m^3$, $14.9{\mu}g/m^3$, $10.7{\mu}g/m^3$, $5.3{\mu}g/m^3$, $1.2{\mu}g/m^3$, respectively. TSP concentrations were below $30{\mu}g/m^3$ during the sampling period. On average $PM_{10}$, $PM_{2.5}$, $PM_1$, $PM_{0.5}$ and $PM_{0.1}$ made up 0.91, 0.70, 0.41, 0.19 and 0.07 of TSP, respectively. The annual average of PM2.5/PM10 ratio was 0.77.

• Journal of Environmental Science International
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• v.29 no.5
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• pp.495-506
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• 2020

This study investigated the nitrate formation process, and mass closure of Particulate Matter (PM) were calculated over the urbanized area of Jeju Island. The data for eight water-soluble inorganic ions and nineteen elements in PM_2.5 and PM₁₀ were used. The results show that the nitrate concentration increased as excess ammonium increased in ammonium-rich samples. Furthermore, nitrate formation was not as important in ammonium-poor samples as it was in previous studies. According to the sum of the measured species, approximately 45~53% of gravimetric mass of PM remained unidentified. To calculate the mass closure for both PM_2.5 and PM₁₀, PM chemical components were categorized into secondary inorganic aerosol, crustal matter, sea salt, trace matter and unidentified matter. The results by the mass reconstruction of PM components show that the portion of unidentified matter was decreased from 52.7% to 44.0% in PM_2.5 and from 45.1% to 29.1% in PM₁₀, despite the exclusion of organic matter and elemental carbon.

• Particle and aerosol research
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• v.14 no.4
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• pp.107-119
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• 2018

In this study, we have developed a real-time monitoring device for measuring PM10 and PM2.5 of ambient aerosol particles. The real-time PM monitor (SENTRY Dust Monitor) uses the optical scattering method and has 16 channels in particle size. The laboratory and field tests were carried out to evaluate the developed SENTRY Dust Monitor. Arizona Test Dust particles were used as test particles in the laboratory test and the field test was carried out at the Jongno-gu Observatory in Seoul. The measurements of PM10 and PM2.5 concentrations obtained by SENTTRY Dust Monitor were compared with Grimm Dust Monitor (Model 1.108) and a beta ray gauge. It was shown that the PM10 and PM2.5 concentrations obtained by SENTRY Dust Monitor agree well with that of the reference devices. Based on the results obtained in this study, it could be concluded that the SENTRY Dust Monitor can be used as a PM monitoring device for real-time monitoring of the ambient aerosols.