• 한국응용곤충학회지
• /
• 제30권4호
• /
• pp.227-232
• /
• 1991

식엽성 삼림해충인 오리나무잎벌레와 사철나무알락명나방, 회양목명나방에 대한 곤충병원성 선충, Steinernema carpocapsae와 Heterorhabditis bacteriophora의 살충력을 알아보기 위하여 실내 검정한 결과 선충의 조유, 농도, 기주에 따라 차이는 있었으나 높은 치사력을 보았다. 오리나무잎벌레인 경우 S.carpocapsae를 유충 한 마리당 25~100마리/ml 농도로 엽상에 처리했을 때 1령충 85.0$\pm$4.1~100%, 2령충 80.0$\pm$5.8~100%, 3령충 65.0$\pm$10.8~100%의 치사율을 보였으며, H. bacteriophora 10~40마리/ml 처리에서는 1령충 82.5$\pm$6.9~100%, 2령충 77.5$\pm$4.7~100%의 치사율을 나타내었다. 사철나무 알락명나방은 유충 gs마리당 S. carpocapsae 5~80마리/ml 처리에서 98.9$\pm$1.1~100%, H. bacteriophora 2~40마리/ml 처리에서는 26.7$\pm$5.1~74.5$\pm$6.2%의 치사율을 나타내었으며, 회양목명나방은 유충한마리당 S. carpocapsae 20~80마리/ml 처리구에서 97.8$\pm$1.5~100%, H. bacteriophora 10~40마리/ml 처리구에서 92.0$\pm$6.2~98.9$\pm$1.1%의 살충력을 보였다.

• 환경위생공학
• /
• 제23권1호
• /
• pp.33-48
• /
• 2008

The purpose of this study was to characterize background mass concentration of $PM_{10},\;PM_{2.5}$ and metallic composition from June 2004 to June 2005 in comparison with Seoul and Asan city. The results were as follows: 1. Annual mean of $PM_{10}$ concentrations in Seoul and Asan were $56.95({\pm}25.63){\mu}g/m^3,\;57.02({\pm}27.22){\mu}g/m^3$ respectly. 2. Annual mean of $PM_{2.5}$ concentrations in Seoul and Asan were $46.97({\pm}40.36){\mu}g/m^3,\;42.16({\pm}21.79){\mu}g/m^3$ respectly. 3. The average $PM_{2.5}/PM_{10}$ ratio was 0.82 in Seoul and 0.74 in Asan city. 4. The concentration of $PM_{10},\;PM_{2.5}$ were the highest in spring and the lowest in summer. Asan was higher than Seoul in spring and summer. 5. The results showed that average $PM_{10}$ composition order as Si>Fe>Pb>Zn>Mn in Seoul and Si>Fe>Zn>Pb>Mn in Asan. The concentration of metals in $PM_{10}$ of Seoul that Cr, Cu, Fe, Mn were high in spring and Zn was low in Fall. Fe, Mn were high in spring of Asan. 6. The results showed that average $PM_{2.5}$ composition order as Si>Pb>Fe>Zn>Mn in Seoul and Si>Fe>Pb>Zn>Cr in Asan. The concentration of metals in $PM_{2.5}$ of Seoul that Cr was high in spring. 7. The result showed that relation between Cr and Cu, Cu and Fe, Fe and Mn, Mn and Zn, Zn and Si in Seoul, Cr and Zn, Cu and Pb, Zn and Pb, Pb and Mn in Asan. The result showed that $PM_{10}$ concentration exceeding $50{\mu}g/m^3$(US-EPA Standard) and $PM_{2.5}$ concentration exceeding $15{\mu}g/m^3$(US-EPA Standard). In urban area, the monitoring of $PM_{2.5}$ permits the anthropogenic sources and the interference of natural sources with respect to $PM_{10}$ measurements.

• 한국환경과학회지
• /
• 제31권12호
• /
• pp.1079-1087
• /
• 2022

This study investigated the effect of volcanic materials that erupted from the Nishinoshima volcano, Japan, 1,300 km southeast of the Busan area at the end of July 2020, on the fine particle concentration in the Busan area. Backward trajectory analysis from the HYSPLIT model showed that the air parcel from the Nishinoshima volcano turned clockwise along the edge of the North Pacific high pressure and reached the Busan area. From August 4 to August 5, 2020, the concentration of PM₁₀ and PM_2.5 in Busan started to increase rapidly from 1000 LST on August 4, and showed a high concentration for approximately 13 hours until 2400 LST. The PM_2.5/PM₁₀ ratio showed a relatively high value of 0.7 or more, and the SO₂ concentration also showed a high value at the time when the PM₁₀ and PM_2.5 concentrations were relatively high. The SO₄^2- concentration in PM_2.5 in Busan showed a similar trend to the change in PM₁₀ and PM_2.5 concentrations. It rose sharply from 1300 LST on August 4, at the time where it was expected to have been affected by the Nishinoshima Volcano. This study has shown that the occurrence of high concentration fine particle in Busan in summer has the potential to affect Korea not only due to anthropogenic factors but also from natural causes such as volcanic eruptions in Japan.

• 한국환경과학회지
• /
• 제23권7호
• /
• pp.1241-1251
• /
• 2014

The study investigates weekday/weekend characteristics of $PM_{10}$ and $PM_{2.5}$ concentrations and meteorological elements in Busan. The $PM_{10}$ concentration is highest on Wednesday and Thursday, and lowest on Sunday. On the other hand, the $PM_{2.5}$ concentration is highest on Wednesday and lowest on Sunday. The location where concentrations of weekdays and weekend differ the most is Hwakjang-dong, the industrial area, and where they differ the least is Gijang-up and Joa-dong, the residential area. Fine particle concentration in the industrial area was consistent at dawn and in the morning, but varied in the afternoon and at night. The visibility of Sunday was 0.49 km higher than that of weekdays, and the solar radiation of Sunday was $0.11MJ/m^2$ higher than that of weekdays. These results indicate that the concentration of fine particles had influence on the change of visibility and solar radiation.

• 한국환경보건학회지
• /
• 제40권1호
• /
• pp.10-16
• /
• 2014

Objectives: This pilot study assessed secondhand smoke (SHS) exposure in smoking and non-smoking nightclubs in Seoul, Korea by measuring the concentration of particulate matter smaller than $2.5{\mu}m$ ($PM_{2.5}$). Methods: This comparative study was conducted in three nightclubs in Seoul. While one non-smoking nightclub was measured on weekdays and weekends, different smoking nightclubs were measured on weekdays and weekends. The concentration of $PM_{2.5}$ was observed using a real-time monitor over an average of three hours. The number of people in the clubs was also estimated. Settled dust was collected in a smoking and a non-smoking nightclub and analyzed for NNK concentration. Results: The $PM_{2.5}$ concentration in the smoking nightclubs was higher than those found in the non-smoking nightclub by 26 times on weekdays and three times on weekends. Indoor $PM_{2.5}$ concentration was correlated with the number of people in the smoking nightclubs. Relatively high $PM_{2.5}$ concentration was observed in the non-smoking nightclub on weekends. NNK concentration in the smoking nightclub was 7 times higer than in the non-smoking nightclub. Conclusion: Smoking in nightclubs caused high $PM_{2.5}$ concentration. Although the non-smoking nightclub had a lower $PM_{2.5}$ concentration, $PM_{2.5}$ concentration on weekends was higher due to the smoking room. Complete prohibition of smoking in nightclubs can protect patrons from secondhand smoke exposure.

• Reproductive and Developmental Biology
• /
• 제34권3호
• /
• pp.271-274
• /
• 2010

This study was conducted to investigate the survival rate of frozen-thawed spermatozoa in equine by glycerol concentration and freezing speed Two stallions (1 Thoroughbred-13 year old and 1 Arab-7 year old) bred in Korea Racing authority was examined for 1 times in a couple of weeks. Semen was collected by condom method standing heated mare and were centrifuged 650 g for 15 min. and isolated the seminal plasma. Thick fraction of semen was diluted EDTA-Lactose-egg yolk diluents to 1:1 and contained in 0.5 ml straw as $6{\sim}14{\times}10^7\;cells/ml$. Final concentrations of glycerol were 3, 5 and 7% in cryopreseved diluents and added 4 times for 2 hours equilibration. For the freezing, equilibrated straws were located 3 or 5 em above $LN_2$ gas for 5 or 10 min. Survival rates of pre-frozen sperm were $65.0{\pm}13.2%$, $68.3{\pm}10.4%$, $66.7{\pm}11.5%$ and post-frozen were $53.3{\pm}23.1%$, $45.0{\pm}15.0%$, $50.0{\pm}18.0%$ in 3, 5, 7% glycerol concentration, respectively. There was no difference between glycerol concentrations. Survival rates of frozen-thawed sperm on freezing speed were $36.7{\pm}10.4%$, $40.0{\pm}7.1%$, $30.0{\pm}13.2%$ at 3 cm-5 min and $33.3{\pm}11.5%$, $31.7{\pm}2.9%$, $21.7{\pm}10.4%$ at 3 cm-10 min in 3, 5, 7% glycerol concentration, respectively. Survival rates of frozen-thawed sperm on freezing speed were $43.3{\pm}15.3%$, $32.0{\pm}17.9%$, $22.3{\pm}15.7%$ at 5cm-5 min and were $47.5{\pm}15.0%$, $43.3{\pm}12.6%$, $48.3{\pm}15.3%$ at 5cm-10 min in 3, 5, 7% glycerol concentration, respectively. There were significantly different between groups (p<0.05). These results suggest that glycerol concentration did not affect cryopreservation of stallion semen within 3~7% but freezing speed affects. In our experiment, the best cryopreservation condition was at 5 cm above $LN_2$ gas for 10 min for pre-freezing and 7% of glycerol concentration. These results lead to commercial AI with frozen-thawed stallion semen.

• 한국지구과학회지
• /
• 제31권3호
• /
• pp.234-245
• /
• 2010

본 연구에서는 2006년부터 2008년까지 3년간 봄철에 $PM_{10}$과 $PM_{2.5}$를 채취하여 질량농도와 금속원소의 화학적 특성, 기상인자와의 관계 분석, 황사 및 비황사시의 미세먼지 특성 그리고 이동경로에 따른 농도의 특성을 고찰하였다. 연구기간동안의 $PM_{10}$, $PM_{2.5}$, $PM_{10-2.5}$평균농도는 각각 $126.2{\pm}89.8$, $85.5{\pm}41.6$, $40.7{\pm}54.9{\mu}g/m^3$이었으며 $PM_{2.5}/PM_{10}$ 및 $PM_{10-2.5}/PM_{2.5}$ 비는 각각 0.70, 0.48이었다. 우리나라의 북서쪽인 북경을 포함한 지역과 서쪽인 상해를 포함한 지역에서 공기덩어리가 이류 할 때 가장 높은 미세먼지농도를 나타내었다.

• Communications for Statistical Applications and Methods
• /
• 제25권2호
• /
• pp.199-215
• /
• 2018

Interest in $PM_{10}$ concentrations have increased greatly in Korea due to recent increases in air pollution levels. Therefore, we consider a forecasting model for next day $PM_{10}$ concentration based on the principal elements of air pollution, weather information and Beijing $PM_{2.5}$. If we can forecast the next day $PM_{10}$ concentration level accurately, we believe that this forecasting can be useful for policy makers and public. This paper is intended to help forecast a daily mean $PM_{10}$, a daily max $PM_{10}$ and four stages of $PM_{10}$ provided by the Ministry of Environment using various data mining techniques. We use seven models to forecast the daily $PM_{10}$, which include five regression models (linear regression, Randomforest, gradient boosting, support vector machine, neural network), and two time series models (ARIMA, ARFIMA). As a result, the linear regression model performs the best in the $PM_{10}$ concentration forecast and the linear regression and Randomforest model performs the best in the $PM_{10}$ class forecast. The results also indicate that the $PM_{10}$ in Seoul is influenced by Beijing $PM_{2.5}$ and air pollution from power stations in the west coast.

• 대한원격탐사학회지
• /
• 제37권6_2호
• /
• pp.1793-1801
• /
• 2021

2015년 1월부터 2020년 6월까지 라이다를 이용하여 측정된 532와 1064 nm의 후방산란계수와 532 nm의 편광소멸도를 이용하여 532 nm의 후방산란계수를 PM₁₀, PM_2.5-10, PM_2.5에 해당하는 세 유형으로 구분하고 지상에서 측정된 질량 농도를 이용하여 각각의 질량소산효율을 산출하였다. 산출된 질량소산효율의 전체 평균값은 PM₁₀, PM_2.5-10, PM_2.5에서 각각 5.1±2.5, 1.7±3.7, 9.3±6.3 m²/g으로 PM_2.5가 가장 높은 값을 보였다. PM₁₀과 PM_2.5의 질량 농도가 낮을 때 평균 이상의 높은 질량소산효율이 산출되었으며 질량 농도가 높아질수록 질량소산효율이 감소되는 경향을 확인하였다. 황사의 혼합 정도에 따른 유형별로 질량소산효율을 산출하였을 때, PM_2.5-10는 황사의 영향으로 오염입자(pollution aerosol, PA)가 2.1±2.8 m²/g으로 오염입자가 주요한 혼합입자(pollution-dominated mixture, PDM), 황사가 주요한 혼합입자 (dust-dominated mixture, DDM), 순수황사 (pure dust, PD)의 1.1±1.8, 1.4±3.3, 1.1±1.5 m²/g보다 두 배 정도 높은 값을 보였다. 하지만, PM_2.5는 9.4±6.5, 9.0±5.8, 10.3±7.5, 9.1±9.0 m²/g으로 유형 구분 없이 비슷한 값을 보였다. PM₁₀의 질량소산효율은 PA, PDM, DDM, PD 에서 각각 5.6±2.9, 4.4±2.0, 3.6±2.9, 2.8±2.4 m²/g으로 황사의 비율이 감소할수록 증가하는 경향을 보였다. 동일한 질량 농도 또는 황사 혼합에 따른 동일한 유형을 보이더라도 PM_2.5/PM₁₀ 값이 낮아질수록 PM_2.5-10의 질량소산효율은 감소하고, PM_2.5의 질량소산효율은 증가하는 경향을 보였다.

• 한국환경과학회지
• /
• 제26권6호
• /
• pp.751-765
• /
• 2017

This research investigates the characteristics of meteorological variation and fine particles ($PM_{10}$ and $PM_{2.5}$) for case related to the haze occurrence (Asian dust, long range transport, stationary) in Busan. Haze occurrence day was 559 days for 20 years (from 1996 to 2015), haze occurrence frequency was 82 days (14.7%) in March, followed by 67 days (12.0%) in February and 56 days (10.0%) in May. Asian dust occurred most frequently in spring and least in winter, whereas haze occurrence frequency was 31.5% in spring, 29.7% in winter, 21.1% in fall, and 17.7% in summer. $PM_{10}$ concentration was highest in the occurrence of Asian dust, followed by haze and haze + mist, whereas $PM_{2.5}$ concentration was highest in the occurrence of haze. These results indicate that understanding the relation between meteorological phenomena and fine particle concentration can provide insight into establishing a strategy to control urban air quality.