The study investigates the characteristics of PM10 concentration in Guducsan air quality observatory and in particular, analyzes the relationship between sudden increase of PM10 concentration in the morning of spring 2014 and meteorological parameters. PM10 concentration in April was 46.9 ㎍/㎥, the highest, followed by 45.5 ㎍/㎥ and 44.6 ㎍/㎥ in March and May, and 21.9 ㎍/㎥ in August. The low concentration in the early morning appeared on 0800 LST in spring, summer, and fall, whereas it emerged on 0900 LST in winter. High concentration in daytime lasted from 1200 LST to 1500 LST in spring and fall, whereas it continued from 1300 LST to 1600 LST in winter. The findings of PM10 concentration and change of meteorological parameters in Guducsan from April 20th to 27th in 2014 are as follows. The low concentration at dawn and in the morning decreased due to strong land breeze. Also, the sudden increase of PM10 concentration in the morning was attributable to low wind speed. Lastly, the sudden decrease of PM10 concentration in the afternoon was attributed to diffusion by strong sea breeze.

Atmospheric aerosol particles were investigated at GNTECH university in Jinju city. Samples were collected using the Nanosampler period from January to December 2014. The Nanosampler is a 6 stage cascade impactor(1 stage : > 10 μm, 2 stage : 2.5~10 μm, 3 stage : 1.0~2.5 μm, 4 stage : 0.5~1.0 μm, 5 stage : 0.1~0.5 μm, back-up : < 0.1 μm) with the stages having 50% cut-off ranging from 0.1 to 10 μm in aerodynamic diameter. The mass size distribution of Atmospheric aerosol particles was unimodal with peak at 1.0~2.5 μm or 0.5~1.0 μm. The annual average concentrations of TSP, PM10, PM2.5, PM1, PM0.5 and PM0.1 were 44.0 μg/m3, 40.3 μg/m3, 31.4 μg/m3, 18.0 μ g/m3, 8.2 μg/m3, 3.0 μg/m3, respectively. On average PM10, PM2.5, PM1, PM0.5 and PM0.1 make 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.

본 연구에서는 나노 입자와 시멘트로 보강된 조립토의 강도 특성에 관한 연구로서, 물과 시멘트의 수화 반응으로 발생하는 이산화칼슘과 나노 실리카 입자의 포졸란 반응을 통하여 강도 증진 효과 양상이 어떠하게 나타나는지 확인하였다. 실험은 상대밀도, 흙-시멘트비율, 시멘트-나노실리카비율, 물-시멘트 비율을 이용하여 배합하였다. 배합된 보강토는 직경과 높이가 50㎜×100㎜인 몰드를 이용하여 공시체로 제작하고 실내 일축압축시험을 진행하였다. 7일 양생 공시체의 일축압축강도의 경우 상대밀 도가 증가함에 따라 강도 증진 효과가 증가하는 것을 확인할 수 있었다. 이는 상대밀도가 증가하면서 첨가되는 나노 실리카의 양이 증가하여 초기 수화 반응을 촉진시켰기 때문이다. 반면 28일 양생 공시체의 일축압축강도의 경우 강도 증진 효과가 감소하는 것을 확인할 수 있었다. 장기간 양생의 경우 수화 반응에 의하여 모세관 공극이 형성되는데 공극 주변의 시멘트가 충분한 수분을 받지 못하여 완전한 수화가 이루어지지 않아 이와 같은 결과가 나타난다. 또한, 흙-시멘트비율이 일정할 때, 나노 실리카 함량의 최적값은 상대밀도 60% 이상에서는 3%임을 확인하였다.

국내 강원광산과 동해광산 주변 토양입자의 이화학적 광물학적 특성을 이용해 이들 광산주변내 토양 중금속 오염 원인을 규명하고자 하였다. 입도에 따른 중금속의 농도를 분석한 결과 강원광산의 경우 가장 큰 입경군인 10~18 mesh 구간에서 비소가 250.5 ppm, 가장 작은 325 mesh 이하 구간에서 445.7 ppm으로 나타났다. 동해광산의 경우에도 마찬가지로 10~18 mesh 구간에서 비소 70.4 ppm, 납 1,055 ppm, 아연 789.9 ppm으로 나타났으며 325 mesh 이하 구간에서 비소 117.7 ppm, 납 2,295 ppm, 아연 1,346 ppm으로 입도가 작아질수록 농집되는 경향을 보였다. 중금속과 토양 내 광물의 상호작용을 분석하기 위해 물리적 선별(자력, 부유선별) 후, 이들 시료에 대한 X-선 회절분석과 주사전자현미경 분석결과 강원광산 시료의 주 구성광물은 석영, 운모, 조장석, 녹니석, 자철석, 각섬석으로 확인되었으며 동해광산 시료에서는 석영, 운모, 고령석, 녹니석, 각섬석, 금홍석이 주 광물들로 나타났다. 강원광산의 자철석은 비소 농도와의 상관성이 매우 좋은 것으로 나타난 반면, 동해광산 시료에서는 티탄철석이 확인되었으며 미량의 비소를 포함하는 것으로 나타났다. 이 같은 결과들은 토양 내 광물의 이화학적 정보와 광물학적 특성 규명이 토양 오염원 형태와 이를 바탕으로 한 토양환경 오염처리에 매우 중요함을 시사하고 있다.

The feature of asthma are airway inflammation (AI), reversible airway obstruction, and an increased sensitivity to bronchoconstricting agents, elevated airway hyperresponsiveness (AHR), excess production of Th2 cytokines, and eosinophil accumulation in the lungs. This study was performed to investigate if oral administration of Scutellaria baicalensis Georgi water extracts (SBG) have the antiasthmatic potential for the treatment of asthma. Asthmatic HI and AHR were induced by systemic sensitization to ovalbumin (OVA) with intratracheal instillation with 0.1 mg/mL of diesel exhaust particles (DEP) suspension once a week for 10 weeks in BALB/c mice. SBG was orally administered with the concentraion of 200 mg/kg 5 days a week for 10 weeks. Long-term SBG treatment suppressed the eosinophil infiltration into airways from blood, the asthmatic AI and AHR by attenuating the production of cytokine IL-4, IL-5 and IL-13, histamine and OVA-specific IgE. Our data suggest that SBG has inhibitory effects on AI and AHR in a mouse model of asthma, may act as a potential Th2 cytokine antagonist, and may have a therapeutic effect on allergic asthma.

This research was done to clarify the cooling effect of water particles generated from a fountain. This effect is a one way to control the heat island effect of big cities. The result of this research was drawn by setting the jets of water in a certain height, and then studying the diffusion of water particles, which is affected by the size of the particles and the wind speed, and the cooling effect caused by the diffusion. 1) When a diameter of a water drop was 500 ㎛ and the wind speed was 2.0 to 6.0 m/sec, the water drop diffused 75 to 190m, and the water vapor spread over 175 to 440 m. As a result, there was more than 0.5℃ of cooling effect on the temperature in the atmosphere 130 to 330m around the water fountain. 2) When a diameter of a water drop was 750 ㎛ and the wind speed was 2.0 to 6.0 m/sec, the water drop diffused 65 to 150 m, and the water vapor spread over 160 to 405 m. Moreover, there was more than 0.5℃ of cooling effect on the temperature in the atmosphere 110 to 275 m around the water fountain. 3) After studying on the relationship between the diameter of water drop and the wind speed, and the diffusion of water particles and the range of the atmosphere that was cooled, a result could be drawn from the research that the smaller the diameter of the water vapor gets and the faster the wind speed becomes, the wider the water particles diffuse and the cooler the atmosphere around the fountain becomes. 4) This research further extrapolates that when the ordinary water(tap water, water from river and stream) is used in a fountain, the cooling effect of the air near the fountain can be approached similarly. If the seawater is used in a fountain, there is to be more to concern not only on cooling effect on the air, but also on other effects on surrounding environment generated by the salt in seawater.

This study examines the acquisition order and pattern of Korean particles in the interlanguage of migrant workers who were learning Korean as L2 in naturalistic settings with little exposure to formal instruction. Data collected from 48 Chinese and Indonesian workers through semi-structured interviews were analyzed, and the observed pattern was compared with that of instructed L2 learners reported in Hwang (2002). The results are the following: 1) A strong affinity was shown between the rank order of the particles in the workers' data and the frequency of particles in a native corpus presented in Se and Gu (2005), attesting the crucial role input plays in L2 acquisition. 2) The acquisition pattern of the workers was both similar and different from that of the instructed learners, the difference resulting from 'transfer of training'. 3) L1 influence was evidenced in the fact that the Japanese L1 learners passed through the developmental sequence faster than the other L2 groups.

This study was carried out to compare the toxicity of nano and micrometer particles with Cu and Zn on soil microbial community and metal uptake of buck wheat. In microcosm system, soil was incubated for 14 days after soil aliquots were artificially contaminated with 1,000 mg/kg Cu, Zn nano and micro particles, respectively. After then, buck wheat was planted in incubating soils and non incubating soils. After 14 days, we compared bioaccumulation of metal, and microbial carbon substrate utilization patterns between incubating soils and non-incubating soils. The enrichment factor (EF) values of incubating samples were greater than non-incubating soils. Dehydrogenase activity had been inhibited by Cu and Zn nanoparticles in non-incubating soil, as well as it had been inhibited by Zn micro particles in incubating soils. Results of biolog test, it was not significant different between nano particles and micro particles. It cannot be generalized that nanoparticles of metal are always more toxic to soil microbial activity and diversity than micrometer-sized particles and the toxicity needs to be assessed on a case-by-case basis.

The effects of meteorological and reclaiming conditions on the reduction of suspended particles are investigated using a computational fluid dynamics (CFD) model with the k-ε turbulence closure scheme based on the renormalization group (RNG) theory. Twelve numerical experiments with different meteorological and reclaiming conditions are performed. For identifying the meteorological characteristics of the target area and providing the inflow conditions of the CFD model, the observed data from the automatic weather station (AWS) near the target area is analyzed. Complicated flow patterns such as flow distortion, horse-shoe vortex, recirculation zone, and channeling flow appeared due to the topography and buildings in the domain. Specially, the flow characteristics around the reclamation area are affected by the reclaiming height, reclaiming size and windbreak height. Reclaiming height affected the wind speed above the reclaiming area. Windbreak induces more complicated flow patterns around the reclaiming area as well as within the reclaiming area. In front of the windbreak, flow is distorted as it impinges on the windbreak. As a result, upward flow is generated there. Behind the windbreak, a secondary circulation, so called, a recirculation zone is generated and flow is reattached at the end of the recirculation zone (reattachment point). At the lower part of the recirculation zone, there is a reverse flow toward the windbreak. Flow passing to the reattachment point starts to be recovered. Total amounts of suspended particles are calculated using the frictional and threshold frictional velocities, erosion potential function, and the number of surface disturbance. In the case of a 10 m-reclaiming and northerly wind, the amount of suspended particles is largest. In the presence of 5 m windbreak, the friction velocity above the reclaiming area is largely reduced. As a result, the total amount of the suspended particles largely decreases, compared to the case with the same reclaiming and meteorological conditions except for the windbreak The calculated suspended particle amounts are used as the emission rate of the dispersion model simulations and the dispersion characteristics of the suspended particles are analyzed.

금번 연구에서는 2009년 1월 1일부터 12월 31일 사이에 대전광역시 유성구 지역에서 확보한 강수 시료를 대상으로 강수에 의한 오염 희석 규명을 시도하였다. 강수여과물에 대해 등온잔류자화(Isothermal remanent magnetization) 측정과 현미경 분석 및 정성적인 화학 성분 분석을 실시하였다. 비강수일에 포집한 먼지 시료와 황사발생일에 채취한 먼지 시료도 비교를 위해 실험에 사용하였다. 자화특성 실험과 현미경 관찰 결과를 바탕으로 판단하면, 강수에서 여과된 고체 시료에 존재하는 자성 물질은 자철석이다. 관찰된 자성 물질의 특이한 형태(구형/타원체형)와 탄소 함유를 고려하면, 인위적인 연소에 의해 형성된 자철석이라 해석된다. 강수에서 여과된 고체 시료의 등온잔류자화는 일반 먼지보다도 낮고 황사에 비해서는 현저히 낮은데, 이는 강수에 의해 발생하는 상당한 양의 자성물질 희석 효과라 판단된다.

본 총설에서는 나노미터 크기의 고체 입자가 오일-물 계면에 흡착됨으로써 안정화된 에멀젼의 제조와 성질에 대하여 기술하였다. 이렇게 제조된 에멀젼을 Pickering 에멀젼이라 하며 이 에멀젼을 계면활성제로 안정화된 일반적인 에멀젼과 비교하였다. Pickering 에멀젼의 독특한 성질은 입자의 계면 흡착 에너지가 큰 점에 기인하며 일반 에멀젼과 주요한 차이점은 고체 입자가 비가역적으로 계면에 흡착한다는 사실이다. Pickering 에멀젼의 전상은 w/o (waterin-oil) 타입에서 o/w (oil-in-water)로 수상의 분율이 증가함에 따라 발생한다. 친수성의 입자는 o/w 에멀젼을 형성하는 경향을 보이고 친유성 입자는 w/o 에멀젼을 형성하는 경향을 보이며 이는 고체 입자의 오일-물 계면에서의 접촉각에 따른다. Pickering 에멀젼의 안정성은 많은 부분에서 일반적인 에멀젼과는 다른 거동을 보였다. 저자는 또한 Pickering 에멀젼의 화장품 응용 가능성에 대해서도 논의하였다.

The results of particulate matters level and heavy metal concentration, which surveyed in Gwang-Yang, Dang-Jin steel industry area, are as follows; The PM2.5, PM10 of exposure area are 22.3μg/m3, 40.4μg/m3 each in Kum-Ho dong, and 28.1μg/m3, 51.5 each in Jung dong. The PM2.5, PM10 of control area are 16.4μg/m3, 29.5μg/m3 each in Bonggang-myeon. The level is higher in exposure area than control area. In case of Dang Jin, the concentration of PM10 and PM2.5 is higher in exposure area than control area (PM2.5-20.4μg/m3, PM10-39.2μg/m3). The Pb level of Dang Jin area is higher in exposure area(0.13μg/m3) than control area(0.1μg/m3), and both Gwang-Yang and Dang-Jin area lower level than the Guideline level of Korea EPA.

The objective of this study was to investigate the effect of crude ginseng total saponins (CGS) against airway inflammation (AI) and airway hyperresponsiveness (AH) induced by diesel exhaust particles (DEP) in mice. AI and AH were induced by the intratracheal instillation with 0.1 mg/ml of DEP suspension once a week for 10 weeks combined with ovalbumin (OVA) sensitization. Mice were also treated orally with 75 mg/ml of CGS, 5 days a week for 10 weeks. Oral CGS treatment decreased in the level of serum immunoglobulin (IgE) and histamine increased by DEP and OVA, and declined respiratory resistance. It also dropped an enhanced infiltration of eosinophils in the bronchoalveolar lavage fluid (BALF) of mice, and an increased T helper type 2 cell derived cytokine levels such as of interleukin (IL)-4, IL-13 and IL-5 in the BALF. However, it did not influence T helper type 1 cytokine such as interferon-gamma in the BALF. These results indicate that CGS may alleviate allergen-related AI and AH in mice and may play an important role in the modulation of asthmatic inflammation.

본 연구는 점착성 퇴적물 예측에 가장 중요한 인자인 침강속도를 강 항만 저수지 그리고 호수에 녹아있는 이온 의 첨가 및 밀도의 변화 아래 실시되었다. 정수 중에 부유된 미립자(alumina와 quartz)의 침강 속도는 압력센서(최대 10 mbar)로 측정되었다. 초기 농도 20 g/l에서 alumina와 quartz의 평균 침강속도는 미립자의 응집현상 때문에 최고 값을 보였으며, 이때 각각 최대 평균 침강속도는 0.185 mm/s(alumina)와 0

During May of 2003, smoke from fires in the Yucatan Peninsula was transported across the Gulf of Mexico and into Texas where it caused significant enhancement in measured aerosol concentrations and reduced visibility. During this event, the formation and growth of aerosol particles has been observed by a differential mobility analyzer (DMA) / tandem differential mobility analyzer (TDMA) system to characterize the size distribution and size-resolved hygroscopicity of the aerosol. The most number concentration is by the particles smaller than 100 nm, but the integrated number concentrations for over 100 nm increased due to the aerosol growth. Hygroscopic growth factor increase from 1.2 to 1.4 for 25, 50, and 100 nm particles during the nucleating period. This distribution and the aerosol properties derived from the TDMA data were used to calculate the growth rate. Particle growth rates were in the range 1-12 nm/hr.

Deposited road particles (DRPs) were analysed for heavy metal concentrations at four different roads in a city, Korea. The samples were collected using a roadway surface vacuum cleaning vehicle which was commonly used in collecting roadway surface particles. Six particle size ranges were analyzed separately for twelve heavy metal elements (Cd, Cr, Pb, Ni, Al, As, Co, Cu, Fe, Mn, Zn and Hg). At all sampling sites, the high concentration of the heavy metals occurred in the <74um particle size range, which conventional roadway cleaning vehicles do not remove efficiently. The Pb concentration significantly increased with decreasing particle size of DRPs, and other toxic heavy metals (Cd, Cr and Ni) also showed similar results. The heavy metal concentrations in the smaller size fraction of DRPs is important because they are contaminants that are preferentially transported by road runoff during rainfall.

Vanoni가 1946년에 유사를 포함한 흐름에서는 Karman상수가 감소한다고 제안한 이후로 개수로 흐름에서 유사 입자가 평균 유속 분포를 변화시킨다는 것은 매우 잘 알려진 사실이다. 그러나 유사 입자가 어떤 역할을 하는지, 어떤 매개 변수가 변화할 것인지에 대해서는 현재까지도 논쟁이 계속되고 있다. 한편, 어떤 연구자들은 난류중에 유사입자가 투입되더라도 Karman 수는 변하지 않는다고 주장하였다. 본 연구에서는 Karman 수의 변화에 대한 기존의

Airborne particles collected from a heavily industrialized site were analyzed by chemical speciation of seven trace metals: Pb, Cd, Cr, Cu, Ni, Zn, and As. The average concentrations were as follows: Zn, 502.0 ± 230.7; Pb, 176.5 ± 310.9; Cu, 111.9 ± 82.7; As, 38.0 ± 31.0; Cr, 21.5 ± 24.4; Cd, 20.8 ± 17.4; and Ni, 11.4 ± 8.4 ng/m3. The median enrichment factor (EF) values of Cd (7,280), As (1,030), Cu (215), Zn (214), and Pb (143), with respect to iron, were much larger than 100. We observed that Cd was found in the soluble and exchangeable form (56.9%), and that Pb and Cr were found in carbonates, oxides and the reducible form (69.8% and 61.1%, respectively). These two forms, which are the most easily absorbed into human body tissue, predominated in most of the trace metals investigated in this study.