• 한국환경과학회지
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• 제28권7호
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• pp.581-594
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• 2019

This research investigated the characteristics of $PM_{10}$ and $PM_{2.5}$ concentrations at the main subway stations in Busan. Annual mean $PM_{10}$ concentrations at the Seomyeon 1- waiting room and platform were $51.3{\mu}g/m^3$ and $47.5{\mu}g/m^3$, respectively, and the annual $PM_{2.5}$ concentration at the Seomyeon 1- platform was $28.8{\mu}g/m^3$. $PM_{2.5}$/$PM_{10}$ ratio at Seomyeon 1-platform and Dongnae station were 0.58 and 0.53, respectively. Diurnal variation of $PM_{10}$ concentration at subway stations in Busan was categorized into four types, depending on the number of peaks and the times at which the peaks occurred. Unlike the areas outside of the subway stations which reported maximum $PM_{10}$ concentration mostly in spring across the entire locations, the interiors of the subway stations reported the maximum $PM_{10}$ concentration in spring, winter, and even summer, depending on their location. $PM_{10}$ concentration was highest on Saturday and lowest on Sunday. The numbers of days when $PM_{10}$ concentration exceeded $100{\mu}g/m^3$ and $80{\mu}g/m^3$ per day over the last three years at the subway stations in Busan were 36 and 239, respectively. The findings of this research are expected to enhace the understanding of the fine particle characteristics at subway stations in Busan and be useful for developing a strategy for controlling urban indoor air quality.

• 한국대기환경학회지
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• 제22권6호
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• pp.863-875
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• 2006

Intensive visibility monitoring was conducted to investigate physical and chemical characteristics of visibility impairment by airborne pollen. Light attenuation coefficients were optically measured by a transmissometer, a nephelometer, and an aethalometer. Elemental, ionic, and carbonaceous species were chemically analyzed on the filters collected by $PM_{2.5}$ and $PM_{10}$ samplers. Aerosol size distribution was analyzed using a cascade impactor during airborne pollen period. Airborne pollen count was calculated using a scanning electron microscope. Airborne pollen was emitted into the atmosphere in springtime and funker degraded visibility through its scattering and absorbing the light. Average light extinction coefficient was measured to be $211{\pm}36Mm^{-1}$ when airborne pollen was not observed. But it increased to $459{\pm}267Mm^{-1}$ during the airborne pollen period due to increase of average $PM_{2.5}$ and $PM_{10}$ mass concentration and relative humidity and airborne pollen count concentration for $PM_{10}$, which were measured to be $46.5{\pm}29.1{\mu}g\;m^{-3},\;97.0{\pm}41.7{\mu}g\;m^{-3},\;54.1{\pm}11.6%$, and $68.2{\pm}89.7m^{-3}$, respectively. Average light extinction efficiencies for $PM_{2.5}$ and $PM_{10}$ were calculated to be $5.9{\pm}0.9$ and $4.5{\pm}0.8m^2 g^{-1}$ during the airborne pollen period. Light extinction efficiency for $PM_{10}$ increased further than that for $PM_{2.5}$. The average light extinction budget by airborne pollen was estimated to be about 24% out of the average measured light extinction coefficient during the airborne pollen period.

• 한국대기환경학회지
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• 제24권3호
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• pp.367-375
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• 2008

To characterize atmospheric particles in Cheonan area, 5 monitoring sites representing highway area, commercial area, residential area, and industrial areas were selected, and the mass concentrations of PM10 and PM2.5 were monitored for 14 days at each site during 2007. The daily average PM10 and PM2.5 concentrations were in the range from 18.5 to $140.9{\mu}g/m^3$ and 8.2 to $116.6{\mu}g/m^3$, respectively, showing the highest mean concentrations at the commercial area site and the lowest concentration at the residential area site. The daily average PM 10 concentrations at Shinan (Commercial area) and Bakseok (Industrial area) sites were exceeded the current National Standard for 1 and 2 days during the monitoring periods. The fractions of PM2.5 in PM10 were above 70% for all sites, indicating fine particles are the major constituent of atmospheric particles in Cheonan. The results indicate that PM10 concentrations in Cheonan are at the concerning level, and the control strategy for fine particles is necessary to address this issue.

• Restorative Dentistry and Endodontics
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• 제37권2호
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• pp.96-103
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• 2012

Objectives: This study evaluated the effect of camphorquinone (CQ)-amine ratio on the C=C double bond conversion of resins with binary and ternary photoinitiation systems. Materials and Methods: Two monomer mixtures (37.5 Bis-GMA/37.5 Bis- EMA/25 TEGDMA) with binary systems (CQ/DMAEMA in weight ratio, group A [0.5/1.0] and B [1.0/0.5]) and four mixtures with ternary system (CQ/OPPI/DMAEMA, group C [0.1/1.0/0.1], D [0.1/1.0/ 0.2], E [0.2/1.0/0.1] and F [0.2/1.0/0.2]) were tested: 1 : 2 or 2 : 1 CQ-amine ratio in binary system, while 1 : 1 ratio was added in ternary system. The monomer mixture was cured for 5, 20, 40, and 300 sec with a Demetron 400 curing unit (Demetron). After each exposure time, degree of conversion (DC) was estimated using Fourier transform infrared (FTIR) spectrophotometer (Nicolet 520, Nicolet Instrument Corp.). The results were analyzed by ANOVA followed by Scheffe test, with p = 0.05 as the level of significance. Results: DC (%) was expressed in the order of curing time (5, 20, 40, and 300 sec). Group A ($14.63{\pm}10.42$, $25.23{\pm}6.32$, $51.62{\pm}2.69$, $68.52{\pm}2.77$); Group B ($4.04{\pm}6.23$, $16.56{\pm}3.38$, $37.95{\pm}2.79$, $64.48{\pm}1.21$); Group C ($16.87{\pm}5.72$, $55.47{\pm}2.75$, $60.83{\pm}2.07$, $68.32{\pm}3.31$); Group D ($23.77{\pm}1.64$, $61.05{\pm}1.82$, $65.13{\pm}2.09$, $71.87{\pm}1.17$); Group E ($28.66{\pm}2.92$, $56.68{\pm}1.33$, $60.66{\pm}1.17$, $68.78{\pm}1.30$); Group F ($39.74{\pm}6.31$, $61.07{\pm}2.58$, $64.22{\pm}2.29$, $69.94{\pm}2.15$). Conclusion: All the monomers with ternary photoinitiation system showed higher DC than the ones with binary system, until 40 sec. Concerning about the effect of CQ-amine ratio on the DC, group A converted into polymer more than group B in binary system. However, there was no significant difference among groups with ternary system, except group C when cured for 5 sec only.

• 대한예방한의학회지
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• 제3권1호
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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.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2001년도 추계학술대회 논문집
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• pp.329-330
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• 2001

대기오염물질은 입자상물질과 가스상물질로 구분되는데, 이 중 입자상물질은 시정을 감소시키고 인체 건강에 유해한 영향을 미친다. 일반적으로 입자크기가 큰 거대입자는 인체 호흡기관에서 대부분 차단되거나 다시 밖으로 나오게 되지만, 입자크기가 작은 미세입자의 경우 대부분 폐의 깊은 곳에 침착하여 인체에 매우 유해하다. 이러한 미세입자의 유해성 때문에 우리나라도 1995년부터 PM10에 대한 대기환경기준을 설정하여 그 양을 규제하고 있다. 최근에는 폐에 높은 침착률을 보이는 PM2.5에 대한 관심이 집중되고 있다. (중략)

• 한국대기환경학회지
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• 제26권2호
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• pp.151-160
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• 2010

Particles emitted from three coal-fired power plants burning bituminous and sub-bituminous coals were examined for PM and size fractions PM>2.5 and PM2.5. The ratio of PM2.5/PM was ranged from 10 to 62%, and PM emission increased with the amount of coal feed, which was 7.23~15.66 kg/h. The emission range of PM2.5 from three power plants was 1.24~4.48 kg/h (dry), which was function of the mixed rate of viscous sub-bituminous coal in feed. Of course such effect should be examined by further tests in details. Based on the consumed coal and thermal load, the emission factors averaged were shown as 59.03 g-PM/ton-coal, 14.79 g-PM2.5/ton-coal and 22.51 g-PM/MWh, 5.54 g-PM2.5/MWh, respectively.

• 한국임상수의학회지
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• 제9권1호
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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.

• 한국지구과학회지
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• 제33권6호
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• pp.469-480
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• 2012

본 연구는 3년(2005. 12. 1-2008. 11. 30) 동안 부산의 $PM_{2.5}$ 대기오염자동관측소(장림동: 공업지역, 좌동: 주거지역) 측정자료 중 고농도 $PM_{2.5}$(24시간 환경기준 $50{\mu}g/m^3$)에 대한 $PM_{2.5}$ 및 $PM_{2.5}/PM_{10}$ 농도비의 일변화 특성과 함께 시 공간적 풍계(풍향 및 풍속)에 따른 특성을 분석하고자 하였다. 고농도 $PM_{2.5}$는 장림동과 좌동 각각 182일 및 27일이었다. 장림동에서 고농도 $PM_{2.5}$의 시간평균농도 및 $PM_{2.5}/PM_{10}$ 농도비의 일변화는 모든 계절에서 오후에 비해 새벽과 오전 및 야간에 높은 비슷한 패턴을 나타내었다. 좌동의 여름 주간에 $PM_{2.5}/PM_{10}$ 농도비가 증가하는 것은 해양조건에서 광화학반응에 의해 생성되는 이차 입자상물질 중 $PM_{10}$의 거대입자 농도가 미세입자인 $PM_{2.5}$ 농도보다 더 감소하기 때문이다. 시간대별로 시 공간적 풍계(풍향 및 풍속등급) 특성을 분석하였다. 그 결과, 고농도 $PM_{2.5}$는 장림동에서 공업단지의 산업활동에 의한 오염물질 정체와 주변지역의 오염물질 이동에 의해 발생되었다. 좌동에서는 주로 주거와 상업활동으로 인한 지역적 오염물질 정체로 발생하는 것으로 나타났다.

• 한국대기환경학회지
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• 제21권1호
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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.