• Journal of Korean Society for Atmospheric Environment
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• v.17 no.1
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• pp.85-96
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• 2001

The objective of this study is to develop the water spraying which can effectively by applied to the control or suppression of the fugitive dust generated from the scrap metal handling area at the Port of Inchon. As a first step toward this goal, we carried out some preliminary analyses on the chemical composition, physical shape, and particle size distribution of the sample dust. Next, to quantitatively investigate the effect of adding surfactants to the spraying water on the wettability of the sample dust, the Standard Sink Test was carried out for four different surfactants and at six different concentrations using the surfactants considered in this study. Results of from the preliminary analysis indicated that the main chemical component consisting of the sample dust is Goethite(FeO(OH)) and that the particles smaller than 10 ${\mu}{\textrm}{m}$ in geometric diameter occupy about 36% of the sample dust in mass. This result implies that the fugitive dust generated from the scrap metal handling area at the Port of Inchon should affect the environment nearby more than we have expected. This is because of relatively large mass percentage of the small metal particles less than 10${\mu}{\textrm}{m}$ in geometric diameter, what we may call respirable particles. As for the results of the Standard Sink Test, higher surfactant concentration tends to result in the higher wettability of the sample dust for the surfactants considered in this study, which in turn ensures the high particle collection efficiency of the droplets generated from the water spraying system. Based upon this preliminary results, studies to develop more sophisticated scaled model for dynamic test in underway and the effort to find the best surfactants as well as the optimum operating conditions are being made at the same time.

• Journal of the Korean Geotechnical Society
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• v.35 no.10
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• pp.67-78
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• 2019

The efficiency of suppressing fine dust was evaluated by conducting indoor and field experiments for the ground treated with EICP solution, which is an eco-friendly ground improvement method. In laboratory experiments, the EICP solution was prepared with inexpensive materials for the field applicability, and the optimal mixing ratio and optimal spraying volume of EICP solution were calculated. The optimum amount of calcium carbonate was shown when the ratio of urea/calcium chloride and white powder were 1.5 and 15 g/L, respectively. The optimum spraying amount of the EICP solution was $7L/m^2$ determined by fine dust suppression and cone tip resistance experiments. The spraying of water and EICP solution was conducted at the test-bed where dump trucks pass for the effect of suppressing fine dust of each method. The effective fine dust suppression method can be chosen depending on the situation of the site.

• Journal of the Korean Applied Science and Technology
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• v.27 no.4
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• pp.470-474
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• 2010

Various anti-scattering agents for suppression of dust scattering at waste depository were compared in this study. Based on the price, easy of usage, and no toxicity, 1% of $Al_2(SO_4)_3$ was selected as surface hardening agents. Only lower than 2% of total weight were flied when wind speed was monthly maximum velocity during 1 hr. These results were quite good with comparison of S anti-scattering agents which was made by C company in Korea. When $Al_2(SO_4)_3$ was spread, the surface waste became hard therefore the effect of suppression of scattering dust was long lasting. It was recommend that 2% of $Al_2(SO_4)_3$ was spread to keep suppression of scattering dust when sudden gust of wind such as natural disaster was occurred.

• Journal of Soil and Groundwater Environment
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• v.24 no.6
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• pp.9-15
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• 2019

Soil dust emitted from large scale construction sites in urban areas has posed a significant health threats to local residents by exacerbating air quality. Water-spraying (moistening) is commonly practiced to lower the dust emission in construction sites, but its long term effectiveness is highly questionable. In this study, the utility of starch and PVA(polyvinyl alcohol) was investigated in suppression of the soil dust emissions in construction sites in Seoul areas. The efficiency of the two suppressants was tested with test soil sample in a lab-scale wind tunnel box under different concentrations of suppressants and soil textures. Starch and PVA showed the superior ability to suppress soil dust emission as compared to moistening, resulting in PM₁₀ and PM_2.5 lower than the daily limit values of 30 and 15 ㎍/㎥ respectively. PVA showed higher suppression capability than starch for all conditions. The test soils mixed with suppressants also showed dramatically enhanced aggregate stability compared to the non-treated soil.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.4
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• pp.749-752
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• 2006

The house dust mites are well known to the most important causative allergens of major allergic diseases like pediatric asthma, allergic rhinitis or atopic dermatitis. This study was done for assessment of naphthalene effect against breeding suppression of the house dust mites. Twenty live adult house dust mites(Dermatophaogoides pteronyssinus) were each inoculated on mixed culture media containing 0 mg (control), 1mg, 2 mg, 3 mg, 5 mg, and 10 mg naphthalene and incubated at $25^{\circ}C$ with a relative humidity of 75%. After 4 weeks mean number of live house dust mites were 191.5, 24.3, 1.3, 1.3, 0, and 0, respectively. Above results showing that the naphthalene can suppress of breeding the house dust mites in vitro.

• 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 the Korean Recycled Construction Resources Institute
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• v.9 no.4
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• pp.405-412
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• 2021

The objective of this study is to investigate the environmental impact of fine dust generated at the construction waste intermediate treatment plants, and to propose engineering data and measures to suppress the generation of fine dust to cope with the expected strengthened environmental regulations of the government. The following study conclusions are drawn. 1) T he maximum concentration of fine dust in the workplace was measured as 160㎍/m³ from the crushing operation followed by the point of waste unloading, where focused suppression plan of the fine dust generation is needed in the future. 2) Fine dust concentrations of 113㎍/m³ in wet road conditions and 50㎍/m³ in dry conditions were measured, indicating that fine dust could be reduced by 50% with watering alone. 3) The effect of distancing from the dust source was studied. PM10 during operation of the workplace was measured as about 25㎍/m³ higher than those of the neighboring areas. Whereas there was no significant difference in case of PM2.5 between workplace and neighboring areas. 4) The measurement results of the heavy metal contents showed that these metals did not affect neighboring areas.

• Current Optics and Photonics
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• v.5 no.3
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• pp.220-228
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• 2021

To improve the measurement accuracy of a solar-radiation observer instrument, aiming at the problem of multiorder-stray-light interference caused by the diffraction of the flat-field concave grating in the spectroscopic system, straylight suppression methods for different forms of optical traps are studied. According to the grating surface-scattering distribution-function model, the bidirectional scattering distribution function (BSDF) of a dust-polluted surface and the flat-field concave grating's transition area of the spectroscopic system is calculated, and a Lyot stop with blade baffle is designed to suppress this kind of stray light. For diffraction multiorder stray light, based on the theory of light-energy transmission, a design for precise positioning of the trench optical trap is proposed. The superiority of the method is verified through simulation and actual measurement. The simulation results show that in a spectroscopic system approximately 160 mm × 140 mm × 80 mm in size, the energy of the stray light is reduced by one order of magnitude by means of the trench optical trap and Lyot stop, and the number of beams is reduced from 5664 to 1040. The actual measurements show that the stray-light-suppression efficiency is about 69.4%, which is effective reduction of the amount of stray light.

• Journal of Bio-Environment Control
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• v.31 no.2
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• pp.114-124
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• 2022

The Saemangeum has a dry surface characteristic with a low moisture content ratio due to the saline and silt soil, so the vegetation cover is low compared to other areas. In areas with low vegetation cover, wind erosion has a high probability of scattering dust. If the vegetation cover is increased by cultivating crops that can withstand the Saemangeum reclaimed environment, scattering dust can be reduced by reducing the flow rate at the bottom. Thus, the purpose of this study is to analyze the effect of suppressing the generation of fine dust and scattering dust by cultivating winter forage crops on the Saemangeum reclaimed land. While growing 0.5 ha of barley and 0.5 ha of triticale in Saemangeum reclaimed land, the concentration of fine dust was monitored according to agricultural work and growth stage. Changes in the concentrations of PM-10, PM-2.5, and PM-1.0 were monitored on the leeward, the windward and centering on the crop field. As a result of monitoring, PM-1.0 had little effect on crop cultivation. the concentration of PM-10 and PM-2.5 increased according to tillage and harvesting, and tillage had a higher increasing the concentration of PM-10 and PM-2.5 than that of harvesting. According to the growth stage of crops, the effect of suppressing scattering dust was shown, and the effect of suppressing scattering dust was higher in the heading stage than in the seedling stage. So, it was found that there was an effect of suppressing scattering dust other than the effect of land covering. Through this study, it was possible to know about the generation and suppression effect of scattering dust according to crop cultivation.

• Fire Science and Engineering
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• v.6 no.1
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• pp.55-64
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• 1992

대부분의 플라스틱 분진은 폭발 위험을 내포하고 있으며 이러한 분진 폭발위험은 공장의 설계와 운영시 고려하여야 할 요소이다. 이러한 위험을 평가하고 그에 따르는 적절한 대책을 세우기 위하여는 무엇보다도 분진의 폭발 특성을 파악하여야 한다. 일반적으로 사용되고 있는 분진 폭발대책은 폭발을 안전하게 방출시키는 것이며 쉽게 발화되넌 플라스틱의 건조 공정, 분쇄 공정등에 있어서는 Suppression이나 Inerting등의 방법을 사용하는 것이 효과적이다. 이러한 기본적인 방법 외에도 일반적인 예방 대책으로는 위험 지역의 분류, 관리 철저, 그리고 분진 발생과 발화원을 최소화하고 폭발이 발생할 경우 폭발 지역을 자동 차단하도록 공장을 설계하는 것이다.