지속적으로 관찰되어 온 백두산 화산폭발 전조 현상들이 사회적 이슈가 되고 있으며 주변국인 일본의 화산활동 또한 활발한 추세이다. 국내와 500km 이상 떨어진 위 화산들은 국내에 직접적인 피해를 주기 어렵지만 화산 분화와 함께 분출되는 화산재의 경우 국내에 직간접적인 피해를 미칠 수 있다. 화산재 확산대응의 일환으로 수치해석 모델이 국내외로 사용되고 있으며 각 수치해석 모델 은 사용된 수치해석 방법에 따라 한계가 있다. 본 논문에서는 라그랑지안 방법을 기반으로 한 PUFF-UAF 모델을 분석하였으며, 초기 입자의 수에 대한 의존성의 문제점과 많은 입자개수를 사용함에도 불구하고 나타나는 화산재 농도 예측의 부정확성에 대한 문제점을 제기하였다. 이에 본 논문 연구를 통하여 라그랑지안 기법의 전산효용성을 이용하고 나타난 문제점을 해결하기 위하여 PUFF-UAF 모 델의 결과에 가우시안 확산 모델을 적용하여 결과를 보완하는 PUFF-Gaussian 모델을 개발하였다. 실제 화산분화로 부터 관측된 결과 와 본 연구로 예측된 결과를 비교한 결과 본 연구에서 제안한 방법의 효용성을 보였다.

Melamine has been reported to be responsible for kidney stones and renal failure among infants and children. Con-ventional detection methods, High-Performance Liquid Chromatography (HPLC) and Gas Chromatography (GC), aresensitive enough to detect trace amounts of the contaminant, but they are time consuming, expensive, and labor-intensive. Hyperspectral imaging methods, which combine spectroscopy and imaging, can provide rapid and non-destructive means to assess the quality and safety of agricultural products. In this study, near-infrared hyperspectralreflectance imaging combined with partial least square regression analysis was used to predict melamine particleconcentration in dry milk powder. Melamine particles, with concentration levels ranging from 0.02% to 1% byweight ratio (g/g), were mixed with dry milk powder and used for the experiment. Hyperspectral reflectance imagesin the wavelength range from 992.0nm to 1682.1nm were acquired for the mixtures. Then PLSR models weredeveloped with several preprocessing methods. Optimal wavelength bands were selected from 1454.5nm to 1555.6nm using beta-coefficients from the PLSR model. The best PLSR result for predicting melamine concentration inmilk powder was obtained using a 1st order derivative pretreatment with Rv=0.974, SEP=±0.055%, and F=6.

본 연구는 고속도로 강우 유출수에서 입도 크기 분포 특성(PSD)을 이해하기 위하여 수행하였다. 경기도내 4곳의 포장도로 지역에서 2번의 강우사상동안 강우유출수 샘플 모니터링을 수행하였고, 시료내 입자의 크기분포를 분석하였다. 또한, 강우량, 유량 및 각 오염물질들을 분석하였다. 시료내 입자의 시간별 변화농도는 강우유출수의 시작 시 높은 값을 보였다가 급속히 감소하였으며 탁도, 총부유물질, BOD, 총질소 및 총인과 같은 오염물질과 유사한 유출경향을 보여주었다. 특히 총부유물질과 탁도와의 높은 상관성을 보여주었다. 강우유출수와 퇴적물내에 포함된 중금속에 있어서 구리, 납, 아연은 높은 농도를 보였으며 대부분의 중금속은 넓이에 대한 부피의 비율이 큰 세립입자에 강하게 결합된 형태로 존재한다.

This study investigated the effect of May 31, 2022 Miryang wildfire on fine particle concentrations in Busan and Gimhae, which are neighboring urban areas. In addition, fine particle characteristics and air pollution concentrations were investigated in Miryang, where haze occurred. The Miryang city wildfire that occurred on May 31, 2022, at 0925 LST, was driven by strong north winds and increased fine particle concentrations in Dongsangdong and Jangyoodong, Gimhae City, which are approximately 35 km to the southeast and south, respectively, of the wildfire occurrence site. Furthermore, the fine particle concentration in Myeongjidong, which is approximately 50 km south-southeast of the wildfire site, exhibited a temporary increase at 1400 LST owing to the effects of wildfire smoke. On the morning of June 1, the day after the fire, the Miryang area had very bad visibility because of the smoke from the fire. Therefore the PM10 and PM2.5 concentrations in Naeildong, 3 km south of the wildfire site, were 276 μg/㎥ and 222 μg/㎥, respectively, at 1200 LST. In addition, the gases O3, CO, and SO2 showed high concentrations at the time of haze generation. This study provides insights into policy making in response to the rapid increase in fine dust when wildfire occurs near cities.

This study investigated the weather conditions, fine particle concentration, and ion components in PM2.5 when two cold fronts passed through Busan in succession on February 1 and 2, 2021. A analysis of the surface weather chart, AWS, and backward trajectory revealed that the first cold front passed through the Busan at 0900 LST on February 1, 2021, with the second cold front arriving at 0100 LST on February 2, 2021. According to the PM10 concentration of the KMA, the timing of the cold front passage had a close relationship with the occurrence of the highest concentration of fine particles. The transport time of the cold front from Baengnyeongdo to Mt. Gudeok was approximately 11 hours . The PM10 and PM2.5 concentrations in Busan started to increase after the first cold front had passed, and the maximum concentration occurred two hours after the second cold front passed. The SO4 2-, NO3 -, and NH4 + concentration in PM2.5 started to increase from 1100 to 1200 LST on February 1, after the first cold front passed, and peaked at 0100 LST to 0300 LST on February 2. However, the highest Ca2+ concentration was recorded 2-3 hours after the second cold front had passed.

This research investigated the characteristics of fine particle concentration and ionic elements of PM2.5 during sea breeze occurrences during summertime in Busan. The PM10 and PM2.5 concentrations of summertime sea breeze occurrence days in Busan were 46.5 ㎍/㎥ and 34.9 ㎍/㎥, respectively. The PM10 and PM2.5 concentrations of summertime non-sea breeze occurrence days in Busan were 25.3 ㎍/㎥ and 14.3 ㎍/㎥, respectively. The PM2.5/PM10 ratios of sea breeze occurrence days and non-sea breeze occurrence days were 0.74 and 0.55, respectively. The SO4 2-, NH4 +, and NO3 - concentrations in PM2.5 of sea breeze occurrence days were 9.20 ㎍/㎥, 4.26 ㎍/㎥, and 3.18 ㎍/㎥ respectively. The sulfur oxidation ratio (SOR) and nitrogen oxidation ratio (NOR) of sea breeze occurrence days were 0.33 and 0.05, respectively. These results indicated that understanding the fine particle concentration and ionic elements of PM2.5 during sea breeze summertime conditions can provide insights useful for establishing a control strategy of urban air quality.

This research investigates the characteristics of metallic and ionic elements in PM10 and PM2.5 on haze day and non-haze day in Busan. PM10 concentration on haze day and non-haze day were 85.75 and 33.52 ㎍/m³ , respectively, and PM2.5 on haze day and non-haze day were 68.24 and 23.86 ㎍/m³ , respectively. Contribution rate of total inorganic water-soluble ion to PM10 mass on haze day and non haze day were 58.2% and 61.5%, respectively, and contribution rate of total water-soluble ion to PM2.5 mass on haze day and non haze day were 58.7% and 64.7%, respectively. Also, contribution rate of secondary ion to PM10 mass on haze day and non haze day were 52.1% and 47.5%, respectively, and contribution rate of secondary ion to PM2.5 mass on haze day and non haze day were 54.4% and 53.6%, respectively. AC (anion equivalents)/CE (cation equivalents) ratio of PM10 mass on haze day and non haze day were 1.09 and 1.0, respectively, and AC/CE ratios of PM2.5 mass on haze day and non haze day were 1.12 and 1.04, respectively. Also, SOR (Sulfur Oxidation Ratio) of PM10 mass on haze day and non haze day were 0.32 and 0.17, respectively, and SOR of PM2.5 on haze day and non haze day were 0.30 and 0.15, respectively. Lastly, NOR (Nitrogen Oxidation Ratio) of PM10 on haze day and non haze day were 0.17 and 0.08, respectively, and NOR of PM2.5 on haze day and non haze day were 0.13 and 0.06, respectively.

This research investigates the characteristics of meteorological variation and fine particles (PM10 and PM2.5) 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. PM10 concentration was highest in the occurrence of Asian dust, followed by haze and haze + mist, whereas PM2.5 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.

This study investigates the concentration sudden rise in fine particle according to resuspended dust from paved roads after sudden heavy rain in Busan on August 25, 2015. The localized torrential rainfall in Busan area occurred as tropical airmass flow from the south and polar airmass flow from north merged. Orographic effect of Mt. Geumjeong enforced rainfall and it amounted to maximum 80 ㎜/hr at Dongrae and Geumjeong region in Busan. This heavy rain induced flood and landslide in Busan and the nearby areas. The sudden heavy rain moved soil and gravel from mountainous region, which deposited on paved roads and near roadside. These matters on road suspended by an automobile transit, and increased fine particle concentration of air. In addition outdoor fine particle of high concentration flowed in indoor by shoes, cloths and air circulation.

Using of the recycled aggregates is strongly promoted to use the national resources efficiently and enhance the recycling rate of construction wastes. However, the negative impact is expected by the alkalinity elution characteristic to the water quality and soil ecology in the region where could be contacted by water like ground water, river, area nearby coast, and etc. For this reason, we developed the pH test method to use the recycled aggregate in the drainage layer and analyse the pH concentration of the sort of time change and particle size. By the ‘Korean Standard Method for Waste’, the pH concentration was ranged from 10.78 to 11.72, by the ‘Korean Standard Method for Soil’, the pH concentration was ranged from 10.73 to 11.97, by the developed pH test in this study, the pH concentration was ranged from 10.82 to 11.71. There was no difference in the pH concentration in relation to the stirring time and the spread of particle size.

The versatile aerosol concentration enrichment system (VACES) have proven useful for providing elevated levels of atmospheric aerosol to human and animal exposures. In this study, we describe a VACES and tests conducted to both optimize the enhancement factor (EF) and characterize how it depends on experiment conditions. Particle number concentrations were measured from upstream and downstream of the system by scanning mobility particle sizer (SMPS) with a long differential mobility analyzer (DMA) in combination with a condensation particle counter (CPC). SMPS was used for to determine VACES particle EF. Particle EF tends to increase for higher the saturator temperature (TSat) and lower the condenser temperature (TCon). TCon higher than 0 °C and TSat lower than 50 °C was the best to obtain the most increase in particle concentration. Correlation analysis of EF with factor variables of TSat and TCon resulted in correlation 0.662 and 0.416, respectively. With all five predictor variables included in a multiple regression model, the EF had a liner correlation with R2 = 0.643.