• Journal of Soil and Groundwater Environment
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• v.23 no.6
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• pp.82-89
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• 2018

The objective of this study is to evaluate efficiencies of chemical suppressants for control of fugitive dust in ash pond of thermal power plant. In this study, $MgCl_2$, PAM (polyacrylamide), and PVA (poly vinyl alcohol) that are generally applied to suppression of fugitive dust generated from unpaved road, coal mining, storage piles and etc, were employed as chemical dust suppressants. The coal ash (coal combustion residuals) were sampled from the ash pond of Yeongheung power division in Incheon, South Korea. The characterization of the sample including particle size distribution, pH, $pH_{PZC}$ and pore volume as well as XRF analysis were carried out. The suppressant treated-samples were investigated with the wind tunnel experiments to estimate and compare the effect of suppressants on stabilization of the surface of coal ash samples. According to the results, the stability of suppressant-treated samples were significantly improved compared to water-treated samples. Among the three kinds of suppressants, PAM and PVA showed higher efficiencies and cost saving than $MgCl_2$.

• Journal of Korean Society for Atmospheric Environment
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• v.22 no.4
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• pp.509-517
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• 2006

We investigated the change of symptoms and preventive behaviors before and after the Asian Dust events among indoor workers (teachers) and outdoor workers (taxi drivers and bus drivers). On February 2004, we recruited 195 taxi drivers, 135 bus drivers and 93 school teachers. Symptoms and behaviors related the Asian Dust events during 1 week were questioned by self administrated questionnaires. We surveyed pre-event and post-event. The symptom were not changed in bus drivers during the events. In taxi drivers and teachers,'Bad or smoky smell on the air' and 'eye congestion' symptoms were increased during the events. The preventive behaviors were decreased or not changed in taxi drivers and bus drivers. In teachers,'close the window','diminishing the outdoor activities', 'diminishing the going out', 'wearing the sunglasses', 'washing the eyes after going out'. This results suggest that the outdoor worker's guideline during the Asian dust eventsneeds to be developed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.6
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• pp.587-591
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• 2019

Fine dust aerated in the atomsphere penetrates our lungs and blood lines through respiratory. Recent fine dust problems in Korea leads to development of various air purifiers. The researchers used this to study systems that could replace chemical filters. In order to compare the effect of the reduction of moss and conventional chemical filter(Hepa), a 1 cubic meter cube was prepared and the amount of the concentration of fine dust reduction was compared under controlled environment. Under the high concentration of fine dust, a test was done to figure out the reduction rate of the fine dust concentration by using air purification system with moss, hepa, and no filter. The air purification system(moss, hepa, and no filter) were operated 90 times in total, 30 times each. The test explains that the reduction of the fine dust amount and the rate of fine dust concentration. The results illustrate that the reduction of the amount fine dust was 138.93 after using air purification system with moss filter. In contrast, the usage of air purification system with hepa filter reduced the amount of fine dust to 76.57. And the air purification with no filter shows that the slight reduction of fine dust amount at 0.10. In the rate of fine dust concentration, moss filter was significantly higher than that of hepa, no filter (0.2379, 0.1298 and 0.0063 each). The results have confirmed that moss is effective in reducing fine dust concentration, and it is expected that with further improvement it can be used as a means to replace or supplement existing chemical filters in air purifier.

• Journal of Korean Public Health Nursing
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• v.12 no.2
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• pp.136-148
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• 1998

This study was conducted to provide basic knowledge of effective environmental control of patients with allergic rhinitis during the period of July to December 1995. The subjects were consisted of 29 patients with allergic rhinitis. Each patient of nasal symptom scores assessed and dust samples drowned from their bedrooms twice for 1 month interval. The data. 58 samples were analyzed by using ANOVA. t-test and stepwise multiple regression. The results were as follows 1. Out of a total 52 dust samples $(89.7\%)$ were isolated house mites. Total 815mites/0.5gm dust were collected and identified the most prevalent house mites was Pyroglypidae mite with $81.1\%$ 2. The amount of house dust mites in the group of bedding laundry with hot water was significantly lower than that those of with cold water. 3. The nasal symptoms of the patients in the group of bedding laundry with hot water was significantly less than that those of with cold water. and also those of using large size bedroom was significantly lower than that those of using small size one. The nasal symptoms of the patients was closely associated with the washing water temperature. bedroom size. bedroom temperature. type of bedclothes, and frequency of cleanig room.

• Journal of Service Research and Studies
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• v.10 no.1
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• pp.55-67
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• 2020

Fine dust has recently become one of the greatest concerns of Korean people and has been a target of considerable efforts by governments and local governments. In the academic world, many researches have been carried out in relation to fine dust, but the research on the economic field has been relatively few. So we wanted to know how fine dust affects the economy. Big data of PM10 concentration for fine dust and fine dust theme stock price were collected for five years from 2013 to 2017. Regression analysis was performed using the linear regression model, the generalized least squares method. As a result, the change in the fine dust concentration was found to have a effect on the related theme stocks' price. When the fine dust concentration increased compared to the previous day, the fine dust theme stocks' price also showed a tendency to increase. Also, according to the analysis of stock price change from 2013 to 2017 based on fine dust theme stocks, companies with large regression coefficients were changed every year. Among them, the regression coefficients of Monalisa were repeatedly high in 2014, 2015, 2017, Samil Pharmaceutical in 2015, 2016 and 2017, and Welcron in 2016 and 2017, and the companies were judged to be sensitive to the concentration of fine dust. The companies that responded the most in the past 5 years were Wokong, Welcron, Dongsung Pharmaceutical, Samil Pharmaceutical, and Monalisa. If PM2.5 measurement data are accumulated enough, it would be meaningful to compare and analyze PM2.5 concentration with independent variables. In this study, only the fine dust concentration is used as an independent variable. However, it is expected that a more clear and well-explained result can be found by adding appropriate additional variables to increase the explanatory power.

• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.5
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• pp.512-517
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• 2014

This paper describes the development of new sweeping machine based on Cyclone Technology, which maintains constant suction power and uses it in a industrial applications as a method for dust removed from grinding work. The performance of a cyclone separator is determined by the turbulence characteristics and particle-particle interaction. To achieve this goal, we design cyclone technology based dust separator for sweeping machine has been proposed as a system which is suitable to work utilizing dust suction alternative to conventional manual system. and Numerical analysis with computational fluid dynamics(CFD) was carried out to investigate the working fluid that flow into cyclone dust separator in order to design optimal structure of the sweeping machine. The validation of cyclone model with CFD is carried out by comparing with experimental results.

• Journal of Power System Engineering
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• v.8 no.2
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• pp.31-38
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• 2004

The main purpose of this study is to investigate the characteristics of hybrid collection system combined with centrifugal force of cyclone and filtration of bag filter in one unit system. The experiment and numerical simulation are executed for the analysis of collection efficiency and pressure drop characteristics of hybrid system in comparison with those of a general fabric bag filter with the various experimental parameters such as inlet velocity(filtration velocity), dust concentration and dust type, etc.. In present system, dust particles tangentially coming into the system body are controlled by the centrifugal force effect, and the next collection is made out by the filtration mechanism in the fabric filter media. Therefore, the effective first collection causes the decrease of dust loading on the fabric filter, and it presents quite a lower pressure drop of fabric filter than that of a general fabric filter. At the inlet velocity, $21{\sim}27m/sec$ and inlet concentration(fly ash) $300mg/m^3$, pressure drops through the filter media of hybrid system are shown lower as $10{\sim}22mmH_2O$ comparing to those($17{\sim}33mmH_2O$) of a general fabric bag filter.

• Korean journal of applied entomology
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• v.10 no.2
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• pp.77-83
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• 1971

In order to find out the decomposing factors of Sumithion in mineral diluents, the physical and chemical properties of the diluents such as talcs, bentonites, diatomaceous earth and other clay minerals was studied in relation to the decomposition rate of Sumithion in dust formulations. The total base, moisture adsorption capacity, pH, specific surface, water contents, active $Fe^{++}$, ignition loss and cation exchange capacity were analysed as the properties of mineral diluents, and these properties were correlated with the stability of Sumithion in dust formulations. And in hope of finding out the main factors among those properties of diluents, the decomposed products of Sumithion in dust formulations prepared with standard Sumithion were separated by the methods of column chromatography and investigated by thin layer chromatography. The following results were otbained; 1. The total base, moisture adsorption capacity, specific surface, water contents, active $Fe^{++}$ and cation exchange capacity of mineral diluents were found to be highly effective on the rate of decomposition of Sumithion in dust formulations. 2. Decomposed products of Sumithion in dust formulations were found to be dimethylphosphorothionate, 3-methyl-4-nitro phenol and its derivatives. And one fraction was not dissolved in n-hexane and ethylether, but was soluble in methylalcohol and ethylalcohol. 3. The moat highly correlated properties of diluents with the decomposition rate of Sumithion in dust were found to be the total base and water contents. 4. In regard to the kind of diluents, it was found that the rate of decomposition of Sumithion in dust formulations was higher in order of bentonite, diatomaceous earth, kaolin and talc.

• Research in Community and Public Health Nursing
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• v.13 no.1
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• pp.79-88
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• 2002

Purpose: The purpose of this study was to identify the indoor environment i.e. house type and age, ventilation method, use of bed & sofa, cockroach, ants, etc. on HDM (House dust mites), especially Der fI allergen. Method: Samples of dust from mattresses, pillows and the floor were collected by using a vacuum cleaner from April. 2000. The amount of Group I allergen(Der. fI) of HDM (house dust mites) were measured by two-site ELISA. Indoor Environmental characteristics were accessed by using questionnaires on 178 house wives living in the Seoul area. Results: The amount of HDM allergen (Der fI) was higher in sofa using house. There were higher concentrations of HDM allergen (Der fI) in sofas made from quilt material than for those that were made from leather. Homes that had pets like dogs living in them had higher concentrations of HDM allergen (Der fI) than without dogs. Conclusion: The photophobic mites thrive in dark. warm and humid environments; Items such as pillows. mattresses, box springs, blankets. carpets. and upholstered furniture should be considered ideal environments for the mite. Therefore, an indoor environmental control program should be carried out to avoid the HDM allergen.

• Journal of the Mineralogical Society of Korea
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• v.23 no.2
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• pp.99-106
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• 2010

To evaluate a potential wash-out effect of rainfalls, a preliminary environmental magnetic test was attempted. Measurement of isothermal remanent magnetization (IRM) and intensive microscopic observations were carried out on the solid particles extracted from the rainfalls collected for the past year (2009) in Daejeon, Korea. Dust particles collected from the rain-free (daily dust) or dustheavy days (during the Asian dust storm event) were also used as a comparison. IRMs were unanimously low for the solid particles extracted from the rainfalls, indicating an efficient wash-out effect of rainfalls as long as the magnetic concentration is concerned. Electron microscopy identified carbonbearing material, (carbon-coated) magnetite, and quartz. It is highly likely that the carbon-containing particles were produced by anthropogenic fossil fuel combustion.