• 한국농공학회논문집
• /
• 제55권5호
• /
• pp.25-35
• /
• 2013

In swine house, dust generation comes from various sources and is known to be harmful both for the animals and the farmers because the dust contains biological and gaseous matters. When farmers are constantly exposed to the dusts, they can suffer chronic or acute respiratory symptoms and have high probability of manifesting various diseases. To address this problem, understanding of the mechanism of dust generation is very important. In this paper, the dust concentration of inhalable, respirable, TSP and $PM_{10}$ were monitored and analyzed according to the pig-activity level, ventilation quantity and feeding method in fattening pig house. From the measured results, in case of the concentration of TSP, an inverse-linear relation with ventilation rate ($R^2=0.88$) and linear relation with the installation height of feed supply pipe ($R^2=0.73$) were determined. However in case of the concentration of $PM_{10}$, no particular relationship with the variables was observed. Using the concentration of inhalable and respirable dust based on the pig-activity level, multi-variate regression analysis was conducted and results have shown that the movement of pigs can contribute to the dust generation (p＜0.05, $R^2=0.71$, 0.61). The relationship determined between dust generation and environmental variables investigated in this study is very significant and useful in conducting dust-reduction researches.

• 한국대기환경학회지
• /
• 제20권1호
• /
• pp.69-76
• /
• 2004

Asian Dust samples were collected in the ambient air of Seosan, Western Korea, in spring of 2000∼2002. PM (Particulate Matter) concentrations were 199,8$\mu\textrm{g}$/㎥ in the first Asian Dust period (March, 23∼24) and 249.4$\mu\textrm{g}$/㎥ in the second period (April, 7∼9) of 2000. Compared with the concentrations in 2000, relatively low PM concentrations, 157.3$\mu\textrm{g}$/㎥ were measured in the periods of 2001 (April, 24∼26). Especially high PM concentration 953.1$\mu\textrm{g}$/㎥ were measured in the periods of 2002 (March, 21∼22). The variation in the PM concentration was observed according to the time for the formation of Asian dust. Considering the particle size distributions of Asian dust, a high concentration was also observed in coarse particle region. The results of backward trajectory model showed the route of the dust storms from northern area of Mongol and Gobi desert. Various mycelia grown from fungal spores were observed on the PM samples and identified at the genus level. All the genera from the three years (2000∼2002), Fusarium, Aspergillus, Penicillium, Basipetospora, Epicoccum and Monotospora are hyphomycetes in the division Fungi imperfecti (Deuteromycota). Fungal composition on the dust sample in March, 2000 was similar to the result of March, 2002. However, the result of April, 2001 was obviously different from the other dust periods. The variations of fungal compositions between the dust periods could be caused by the trajectories of the dust storms.

• Journal of Preventive Medicine and Public Health
• /
• 제20권2호
• /
• pp.255-260
• /
• 1987

The digital dust indicator (Sibata P-5), one of the direct·reading instruments was evaluated for the respirable dust in the underground coal mine environments. As a reference, respirable dust was determined using three cyclones and/or impactors. All the tests were performed on aerosol in twenty underground coal mines. The coefficients of mass-relative concentration were $0.067{\pm}0.054$ (Mean$\pm$Standard deviation) (range: 0.006-0.172). The relationship between relative concentration and temperature was not significant statistically. Also, the relationship of relative concentration and relative humidity was not significant. Mass concentration and relative concentration were $5.31{\pm}5.22mg/m^3$ and $162{\pm}163$ CPM ($Mean{\pm}Standard$ deviation) respectively. The range of mass concentration was $1.22-22.69mg/m^3$; relative concentration 16-628 CPM. The relationship of mass concentration and relative concentration was not significant in these ranges.

• 한국환경과학회지
• /
• 제23권5호
• /
• pp.819-827
• /
• 2014

This study analyzes the chemical composition of metallic elements and water-soluble ions in $PM_{10}$ and $PM_{2.5}$. $PM_{10}$ and $PM_{2.5}$ concentrations in Busan during 2010-2012 were $97.2{\pm}67.5$ and $67.5{\pm}32.8{\mu}g/m^3$, respectively, and the mean $PM_{2.5}/PM_{10}$ concentration ratio was 0.73. The contribution rate of water-soluble ions to $PM_{10}$ ranged from 29.0% to 58.6%(a mean of 38.6%) and that to $PM_{2.5}$ ranged from 33.9% to 58.4%(a mean of 43.1%). The contribution rate of sea salt to $PM_{10}$ was 13.9% for 2011 and 9.7% for 2012, while that to $PM_{2.5}$ was 17.4% for 2011 and 10.1% for 2012. $PM_{10}$ concentration during Asian dust events was $334.3{\mu}g/m^3$ and $113.3{\mu}g/m^3$ during non-Asian dust events, and the $PM_{10}$ concentration ratio of Asian Dust/Non Asian dust was 2.95. On the other hand, the $PM_{2.5}$ concentration in Asian dust was $157.4{\mu}g/m^3$ and $83.2{\mu}g/m^3$ in Non Asian dust, and the $PM_{2.5}$ concentration ratio of Asian Dust/Non Asian dust was 1.89, which was lower than that of $PM_{10}$.

• International journal of advanced smart convergence
• /
• 제11권2호
• /
• pp.30-37
• /
• 2022

Because fine dust (PM10) has a close effect on the environment, fine dust generated in the climate and living environment has a bad effect on the human body. In this study, the LSTM model was applied to predict and analyze the effect of fine dust on Gwangju Metropolitan City in Korea. This paper uses prediction values of input variables selected through correlation analysis to confirm fine dust prediction performance. In this paper, data from the Gwangju Metropolitan City area were collected to measure fine dust. The collection period is one year's worth of data was used from january to December of 2021, and the test data was conducted using three-month data from January to March of 2022. As a result of this study, in the as a result of predicting fine dust (PH10) and ultrafine dust (PH2.5) using the LSTM model, the RMSE was 4.61 and the test result value was as low as 4.37. This reason is judged to be the result of the contents of the one-year sample.

• 서비스연구
• /
• 제10권1호
• /
• pp.55-67
• /
• 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
• /
• 제20권3호
• /
• pp.371-380
• /
• 2004

In the dust separation by using porous filter media, the structure of dust layer deposited on the filter surface of filter medium directly affects the effective filtration. The present study has investigated the specific resistance (K$_2$') of the dust layer and its porosity ($\varepsilon$$_{c}$) for three different filters; FA composite filter, metal fiber filter and stainless filter. The specific resistance (K$_2$') increased and at the same time the cake porosity ($\varepsilon$$_{c}$) decreased with the increase of filtration velocity, possibly due to the compressible effect of dust layer. However, under the low dust concentration, subsequent dust particles would block the open channels through the layer resulting in high specific resistance of the layer. The FA composite filter among three filters was shown to be the most effective filter for dust cake filtration at low filtration velocities less than 0.1 m/s for an approximate dust concentration of 5 g/㎥.

• 대한치과기공학회지
• /
• 제33권1호
• /
• pp.93-102
• /
• 2011

Purpose: The study aimed to evaluate working environment for dental technician by measuring dust level, ventilation conditions and the use of personal protective equipment and to provide basic information required to improve working environment and develop health education programs for dental technician. Methods: A total of 240 dental technician who are registered with the Daegu Association of Dental technician and working at 34 dental laboratories participated in the study. And the dust level was measured at 21 different spots in 16 dental laboratories out of 34. Results: Of 34 dental laboratories, 31 (91.2%) were equipped with a ventilator, but the remaining 3 (8.8%) did not have a ventilator. By the number of ventilator, 1 to 3 ventilators were found in 22 dental laboratories (71.0%), 4 to 6 ventilators were in 7 laboratories (22.5%) and more than 7 ventilators in 2 laboratories(6.5%). According to the frequence of changing filters in dust collector, 20 dental laboratories (58.9%) changed filters every four weeks, 10 laboratories (29.4%) changed them every six weeks and 4 laboratories (11.7%) changed them every eight weeks. Of total respondents, 114 (61.3%) said they wore a mask all the time while working, 56 (29.6%) said they frequently wore a mask, 19 (10.1%) said they did not wear a mask. As for the type of masks, 159 (84.1%) used a disposable mask, 25 (13.2%) used a cotton mask and 5 (2.7%) used an anti-dust mask. For dust sat on their outfits while working, 102 (54.0%) shook their uniforms inside workplace to keep dust off the uniforms, 64 (33.9%) did not anything until they wash their uniforms and 23 (12.1%) shook their uniforms outside workplace to keep dust off the uniforms. Of total respondents, 182 (96.3%) had a particle in their eyes while carrying out grinding work. Based on the measurement of floating dust at workplace, 3 dental laboratories showed dust concentration exceeding the minimum level of 10 mg/$m^3$ allowed under the permit for environment. Of those, 1 laboratory had the dust concentration that was more than 1.5 times higher than the minimum level. Dust concentration was higher in laboratories that used a dust collector with 0.5 horse power and changed filters more than 3 weeks ago. Dust comprised of nickel (more than 70%), chrome (9%) and others. The mean chrome concentration was more than twice higher than the minimum permissible level of 0.5 mg/$m^3$. There were two laboratories that showed chrome concentration exceeding the level of 0.4 mg/$m^3$. Like dust concentration, chrome level was higher in laboratories that used a dust collector with 0.5 horse power and changed filters more than 3 weeks ago. There were six laboratories that had nickel concentration exceeding the minimum permissible level of 1 mg/$m^3$. Of those, one laboratory had nickel concentration that was more than three times higher than the minimum permissible level. Nickel concentration was also higher in laboratories that used a dust collector with 0.5 horse power and changed filters more than 3 weeks ago. Conclusion: It is not likely that heavy metal concentrations found in the study constitute respiratory dust. It is however necessary for health of dental technician to apply the Industrial Safety and Healthy Law to dental laboratories and make recommendations for the use of personal protective equipment, installation of a proper number of ventilators, more frequent change of filters in dust collector and improved ventilation for polishing work. At the same time, dental technician need education on how to use personal protective equipment and how to efficiently remove dust from their uniforms.

• 한국대기환경학회지
• /
• 제4권1호
• /
• pp.23-32
• /
• 1988

The exposure level of respirable dust and silica for the coal workers of underground coal mines in Taebaek area was evaluated. Personal air samplers were attached to the coal workers-drillers, coal cutters, their helpers, haulers, and separators. Normality and lognormality of respirable dust and silica concentrations were tested by Kolmogorov-Smirnov one-sample test, differences of means of respirable dust and silica concentration were tested by group-t-test and paired t-test, and relation between respirable dust and silica concentration were tested by regression test.

• 대한안전경영과학회:학술대회논문집
• /
• 대한안전경영과학회 2001년도 춘계학술대회
• /
• pp.301-310
• /
• 2001

A study for the dangerous properties measurment of dust explosion was attended by the various dust concentration on Anthraquinone, Sodiumbenzoic acid, Corn starch, soy sauce powder, and cheese powder. As the result, maximum explosion pressure, the maximum rate of pressure rise, autoigntion temperature, and the water content of dust on lower limit explosion concentration was obtained as follows 1. The lower limit explosion concentration on soy sauce powder with the humidity of 65 to 90% increased by increasing the con tent of moisture, and the effect of dry air and moisture air decreased better in make of dry air. 2. The effect of a various dust concentration on autoigntion temperatures is investigated, If the vessel of dust explosion is small size and the easiness of autoignition was controled by air within the vessel, because it was better decreased air with increasing of dust concentration 3. The maximum explosion pressures of Anthraguinone, sodiumbenzoic acid, com starch, soy sauce powder, and cheese powder were 1.0g/$\ell$, 1.0g/$\ell$, 1.5g/$\ell$, 1.5g/$\ell$, and 1.5g/$\ell$, respectively, and the maximum rate of pressure rise were 0.5g/$\ell$, 0.5g/$\ell$, 1.0g/$\ell$, 1.0g/$\ell$, and 1.0g/$\ell$, respectively.