• 전기학회논문지
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• 제67권3호
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• pp.474-478
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• 2018

The use of metals such as aluminum and titanium and the related industrial facilities have been continuously increasing to meet the requirements of the improvement of high-tech products due to the development of industry, and explosion of metal dust. Semiconductor process Metal dust is essential, but research is insufficient. The purpose of this study is to identify risk by analyzing the quantitative risk such as maximum explosion pressure and minimum explosion concentration applied international test standard in order to select the semiconductor process facilities handling dust and to predict possible risk of accidents.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2000년도 추계학술대회
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• pp.136-139
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• 2000

Fenton-like oxidation of para-nitrophenol(PNP) was studied using hydrogen peroxide iii combination with steeler's dust substituted for ferrous iron in Fenton's reaction. Various factors critical in the degradation of PNP were studied, including hydrogen peroxide dosage, concentration of steeler's dust. and initial pH. Experimental results showed that 1,000mg/L PNP and its oxidation intermediate could be mostly decomposed within 30m1n by 10g/L steeler's dust, 0.25% hydrogen peroxide, and initila pH of 3.0. The reaction rate constant (k) of CODcr concentration were calculated with the addition of steeler's dust(0.0059 min$^{-1}$ (g/L)$^{-1}$ ) and hydrogen peroxide(0.2965 min$^{-1}$ (%)$^{-1}$ ), respectively.

• 서비스연구
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• 제10권1호
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• pp.55-67
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• 2020

미세먼지 문제는 최근 우리나라 국민의 최대 관심사로 부상되었고 정부 및 지방자치단체에서도 상당한 노력을 기울이고 있다. 그간 미세먼지와 관련하여 다수의 학술적 연구가 진행되어왔지만 경제 분야의 연구는 상대적으로 미흡하였다. 본 연구에서는 미세먼지가 개별 주식에 어떠한 영향을 끼치는지에 대하여 빅데이터 분석을 통해 알아보고자 한다. 2013년부터 2017년까지 총 5개년을 대상으로 PM10농도 미세먼지 데이터와 미세먼지 테마주 데이터와의 관계를 분석하였다. 연구방법으로는 일반화최소제곱법을 사용한 선형회귀모형을 사용하여 회귀분석을 실시하였다. 연구 결과 미세먼지 농도가 전일에 비해서 증가했을 때 미세먼지 테마주의 주가가 상승하는 것으로 나타났다. 그리고, 2013년부터 2017년까지 주가변동 분석결과 회귀계수 값이 큰 기업은 매년 달라졌다. 5개년 동안 제일 큰 반응을 보인 기업은 오공, 웰크론, 동성제약, 삼일제약, 모나리자 순이었다. 그 중 연도별로 반복적으로 등장하는 기업으로는 모나리자가 2014년, 2015년, 2017년에, 삼일제약은 2015년, 2016년, 2017년에, 웰크론은 2016년, 2017년에 반복적으로 회귀계수가 크게 나타났으며 해당 기업은 미세먼지 농도에 주가가 민감하게 반응하는 기업이라고 사료된다. 향후 PM2.5 측정 데이터가 충분히 쌓이게 된다면 PM2.5의 농도를 독립변수로 한 연구와 비교·분석하는 것도 의미가 있을 것이다. 본 연구에서는 미세먼지 농도만을 독립변수로 하였는데 설명력을 높일 수 있는 변수를 추가한다면 좀 더 의미있는 연구결과를 기대할 수 있을 것이다.

• 한국대기환경학회지
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• 제24권3호
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• pp.300-309
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• 2008

Variations in PM10 concentration between 2000 and 2005 from 84 urban air monitoring stations operated by the government were analyzed. The K-means cluster analysis was attempted using annual average and the 99th percentile of daily averages as parameters. The results obtained by excluding Asian dust episode days were compared with those obtained by using all available data. In any cases, the cluster with the highest mean concentration was mostly composed of stations in Seoul and Gyeonggi. Annual average of the cluster with the highest mean concentration showed a distinct decreasing trend, but that excluding Asian dust episode days did not show such a trend. Without Asian dust episode days high concentrations of monthly averages in March and April were also not observed. The effect of Asian dust was more pronounced in the 99th percentile of daily averages. The 99th percentile of daily averages of the cluster with the highest mean concentration was the highest in June following downs in April and May.

• 한국산학기술학회논문지
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• 제20권6호
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• pp.587-591
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• 2019

미세먼지는 대기를 타고 호흡기를 거쳐 폐 혹은 혈관에 침투 한다. 최근 미세먼지 문제 때문에 국내에 공기청정기 수요도 급증하고 있다. 이끼는 가장 오래된 지상식물로 중금속과 미세먼지를 흡착하여 분해하는 성질을 가지고 있는 것으로 알려졌고 본 연구진은 이를 활용하여 화학적 필터를 대체 할 수 있는 시스템에 대해 연구하였다. 이끼와 기존 화학적 필터(Hepa)의 미세먼지 감소 효과를 비교하기 위하여 $1m^3$의 큐브를 제작하고 통제된 환경하에서 미세먼지의 감소량을 비교하였다. 미세먼지 상황 하에서 이끼, 헤파, 무필터를 탑재한 공기정화 시스템을 각 30회씩 총 90회 가동 하였고 각각의 미세먼지 감소량 및 감소율을 비교한 결과 감소량은 미세먼지 이끼필터를 사용한 평균이 138.93으로 헤파필터를 사용한 평균 76.57과 무필터 상태의 평균인 0.10보다 유의하게 높았으며 감소율의 평균 역시 이끼필터를 사용한 경우 0.2379로 헤파필터를 사용한 경우의 0.1298이나 무필터인 0.0063보다 유의하게 높았다. 이 결과를 통해 이끼의 미세먼지 감소효과를 확인하였고 향후 개선을 통해 기존 공기정화기의 화학필터를 대체하거나 보조할 것으로 기대된다.

• 대한안전경영과학회지
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• 제13권4호
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• pp.109-116
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• 2011

This study examined into property of flour dust explosion to get the basic data for safety of industry by protecting accident of dust explosion. The experiment was conducted to know the effect of distance between explodes in the experiment device, effect of flour dust concentration, effect of humidity, effect of explosion pressure to the dust concentration and effect of inactive substance additive. The study indicated that explosion was happened effectively at the optimum distance 100mm or less in inter-polar distance, and minimum ignition energy was measured at 6mm. The data of feed concentration to the probability of explosion showed that the smaller the particle diameter was, the larger probability of explosion was, and the higher the dust concentration was, the more increased the pressure of explosion was, but more than upper limit of dust concentration, then the explosion of pressure decreased. For the effect of humidity, the more it contained water, the more decreased the ignition energy of dust was, so increased minimum explosive concentration, and effective water content was minimum 10% or more. Inactive substance additive was effective in adding more than 15% CaCO3 and CaO as substance inhibiting dust explosion, in which CaCO3 was more effective than CaO. the analysis of the flame of dust explosion was performed by high-speed video camera, it showed the size of flame bacame smaller in order that sub feed, main feed, wheat powder. As a result, sub feed was expected to be less dangerous than others.

• 한국농공학회논문집
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• 제50권4호
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• pp.39-50
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• 2008

A study on fugitive dust dispersion was conducted at Saemanguem reclaimed area located at the west coastal area of Jeon-buk Province Total reclaimed area is 40,100ha developed by building a 33km long sea dike through Gunsan, Gimje, and Buan. (Land: 28,300ha, Fresh Water Lake: 11,800ha) After this area was completely reclaimed in 2006, there has been high possibility of dust generation and dispersion to the neighboring area. The dust generated at the reclaimed land was composed mainly of minerals with high salinity, and it could make harmful effect on crop production as well on to human's health such as eye irritation and respiratory disease. Especially, when those aerosol particles are reached on the leaves of farm crops, the photosynthesis and respiration of the plants can be under restraint resulting in the decrease of agricultural productivity of the nearby farm areas. Furthermore, highly concentrated salty particles can directly damage the leaf cells. In this study, field experiment has been conducted to regularly measure the locally suspended dust particles and analyze how they were dispersed to the neighboring areas. The collected dust particles were analyzed to examine theirs sizes, concentrations, and components. The SPSS statistical program was also used to separate the dust concentration generated by the reclaimed land from the total dust concentration measured at the measuring locations.

• Asian-Australasian Journal of Animal Sciences
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• 제18권4호
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• pp.574-579
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• 2005

Optimal management of indoor air quality in a confined pig house, especially in winter, is indispensable for preventing infectious respiratory disease to workers and animals. This study was performed to elucidate the correlation of aerial contaminants and climate factors in a confinement. It was observed that indoor air contaminants ion in the confinement was the highest at 2:00-5:00 pm in a day, followed by 8:00-11:00 pm and 8:00-11:00 am. This was attributed to the increase of pig activities in the afternoon. The concentration of total dust and total airborne bacteria was found to have a significant correlation with temperature and relative humidity (p<0.05). Correlation of total dust and total airborne bacteria, total dust and ammonia, and total dust and odor were shown statistically significant at 95% confidence level. In conclusion, temperature and total dust concentration correlated significantly with all the parameters except for hydrogen sulfide ($H_2S$). This could be explained by the fact the dryness of pig feces by increase of interior temperature and resuspension of feed deposited on the floor by the pig activity, resulted in high generation of dust which adsorbed and carried the airborne bacteria and odor compounds in a confined pig house. It was proved that the adsorptive capacity of dust with ammonia ($NH_3$) was higher than that with hydrogen sulfide ($H_2S$).

• 한국환경과학회지
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• 제25권5호
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• pp.705-713
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• 2016

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 mm/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.

• 한국지구과학회지
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• 제40권4호
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• pp.414-427
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• 2019

In East Asia, the long-range transport of dust storms originating from Mongolia and northern China affects airborne dust loadings over downwind areas in the southern Korean Peninsula. Since 1997, dust loading cases caused by dust storms have been observed using the thresholds of total suspended particles (TSP, ${\geq}250{\mu}g\;m^{-3}\;hr^{-1}$) and particulate matter less than $10{\mu}g$ ($PM_{10}$, ${\geq}190{\mu}g\;m^{-3}\;hr^{-1}$) in the central-southern Korean Peninsula. There were two dust loading cases that exceeded these thresholds in 2016 and three in 2017, which reflects the downward trend of the last twenty-one years in the central-southern Korean Peninsula. Furthermore, five other dust loading cases with mass concentrations lower than the thresholds were observed from 2016 to 2017. In the moderate dust loading cases exceeding the thresholds, a descending motion of cut-off lows below $45^{\circ}N$ and a southward trough at 500 hPa gpm isopleths intensified at the western ridge, and largely extended the surface high-pressure system over southeast China. Airborne dust loadings following pronounced north-westerlies in the forward side of the high-pressure system were transported to the surface of the central-southern Korean Peninsula. However, in slight dust loading cases lower than the thresholds, the restricted descending motion of cut-off lows over $45^{\circ}N$ and the southwestward trough at 500 hPa gpm isopleths intensified the zonal flow over the Korean Peninsula. Surface high- and low-pressure systems moved eastward from the source compared to moderate dust loading cases. Due to the zonal movement of dust storms traversing eastern China, slight dust loading cases were observed with relatively higher ratios of $PM_{2.5}/TSP$ and carbon monoxide (CO) in the central-southern Korean Peninsula.