• Journal of Environmental Science International
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• v.20 no.1
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• pp.25-34
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• 2011

The new empirical static model was constructed on the basis of dimension analysis to predict the pressure drop according to the operating conditions. The empirical static model consists of the initial pressure drop term (${\Delta}P_{initial}$) and the dust mass number term($N_{dust}=\frac{{\omega}_0{\nu}_f}{P_{pulse}t}$), and two parameters (dust deposit resistance and exponent of dust mass number) have been estimated from experimental data. The optimum injection distance was identified in the 64 experimental data at the fixed filtration velocity and pulse pressure. The dust deposit resistance ($K_d$), one of the empirical static model parameters got the minimum value at d=0.11m, at which the total pressure drop was minimized. The exponent of dust mass number was interpreted as the elasticity of pressure drop to the dust mass number. The elasticity of the unimodal behavior had also a maximum value at d=0.11m, at which the pressure drop increased most rapidly with the dust mass number. Additionally, the correlation coefficient for the new empirical static model was 0.914.

• Journal of Korean Society for Atmospheric Environment
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• v.26 no.3
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• pp.298-304
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• 2010

In order to calculate the aerosol bulk densities of $PM_{1.0}$ and $PM_{10}$, aerosol mass and number concentrations were measured for the period of December 2008~April 2009. $PM_{1.0}$ and $PM_{10}$ mass concentrations were measured using a cascade impactor (Micro-Orifice Uniform Deposit Impactor, MOUDI) while their volume concentrations were calculated based on number concentrations from an environmental dust monitor (EDM). Normal aerosol size distribution fitting functions were retrieved for number size distribution since aerosols < $2.5{\mu}m$ were measured from the EDM. Strong correlation was found between $PM_{1.0}$ mass and volume concentrations obtained with a $R^2$ of 0.95. The calculated average bulk densities of $PM_{1.0}$ and $PM_{10}$ were $1.97{\pm}0.33g/cm^3$ and $2.15{\pm}0.18g/cm^3$, respectively.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2008.04a
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• pp.170-171
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• 2008

• Korean Chemical Engineering Research
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• v.48 no.5
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• pp.603-608
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• 2010

A study has been conducted experimentally to investigate behavior of ignition and flame spread over metal dust deposits with particle size using by a developed apparatus and thermogravimetric analysis(TGA). Zr, Ta and Mg-Al(90:10 wt%) alloy metal powders including Mg and Ti with different particle size were used. Also we used PMMA(Polymethylmethacrylate) powder to compare the combustion properties to those of metal powders. When dust layers were more than 5 mm in thickness, the dependency of deposit depth on flame spread rate over dust layer was not shown. With decreasing mean particle diameter, flame spread rate over Ti dust layer decreased, while the spread rate over Mg dust layer increased. For mean diameter of $51{\mu}m$, fire spread rate over pure Mg dust layer decreased to about 50 percent in Mg-Al(90:10 wt%) dust layer. The oxide thickness of metal dust used in this study tended to be inversely proportional with the spread rate, and it was quite small for influence with particle size. From the results of TGA for Ti and Mg, weight increasing curves(550 for Mg, 578 for Ta) were observed in the oxidation process, and they seems to be caused by ignition of upper dust layer.

• Journal of Environmental Health Sciences
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• v.46 no.6
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• pp.667-675
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• 2020

Objectives: Exposure to fine dust (PM10) could contribute to the occurrence of cardiovascular disease or respiratory abnormalities. Since garlic is known to possess an anti-oxidative stress effect, the present study was performed to evaluate the effect of garlic intake on fine dust-mediated pulmonary toxicity. Methods: Rats were intratracheally instilled with fine dust at 15 mg/kg body weight (BW)/day for five days following five-day intragastric intubation of garlic at 0.7 or 1.4 g/kgBW/day, or 13.1 mg/kgBW/day S-allyl-cysteine (SAC) as a reference component in garlic. Blood and bronchoalveolar lavage fluid (BALF) were collected. Results: Deposit of fine dust was visually and histopathologically observed in the lungs. Body weight gain during the instillation period was significantly lowered in all the groups instilled with fine dust. Neutrophil numbers in blood were significantly elevated in the fine dust alone group, but this alteration was diminished in the groups administered with garlic. Levels of serum glutathione were lower in the rats instilled with fine dust alone, and this decrease in the glutathione level seems dose-dependently compensated among the groups administered with garlic. Similar findings were observed in the BALF with statistical significance. Typical pulmonary histopathological observation related with inflammation was demonstrated in the lungs of the rats exposed to fine dust alone, whereas such histopathologic findings were not improved in the groups administered with garlic. Conclusion: The present study suggests that garlic intake could alleviate fine dust-mediated pulmonary or systemic toxicities. Further investigation is necessary to delineate the mechanism of garlic-mediated effects on pulmonary function.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1169_1170
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• 2009

This paper introduces insulator pollutant accumulate pattern in the tunnel of korea railroad. To accomplish this goal, effective sample collecting method was proposed for the first step. Dust at the surface was collected directly. Distilled water and brush was used while collecting. Through this method dust is easily and accurately collected. The second step is pollutant analysis. Several analyze item is selected such as quantity, conductivity, contact angle, Optical Microscope(OM), IR, Equivalent Salt Deposit Density(ESDD), and ICP-AES. The third step, best represent tunnel was selected considering location, length and natural surroundings. Also to consider the difference at inside the tunnel, several bracket insulators were selected along to the location. To make the result precise, above procedure was repeated several times at the same target. Finally relation among type of train, numbers of movement, surroundings, length will be considered in combination with the pollution. With this result pollute map for KORAIL could be accomplished and inspect period will be optimized case by case.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1651-1653
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• 1999

Room Temperature Vulcanizing (RTV) Silicone Rubber has been widely used to coat porcelain insulator to prevent formation water filming on insulator surface. and RTV silicone rubber has water repellency to suppress leakage current and consequent flashover. RTV silicone rubber's surface has been degradated by outdoor condition such as dust, salt, and water. etc. ESDD(Equivalent Salt Deposit Density) and leakage currents are increased by polymer surface toughness and degradation. In this paper, we investigated relations of surface toughness, ESDD, and leakage currents.

• Tuberculosis and Respiratory Diseases
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• v.57 no.5
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• pp.476-479
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• 2004

Pulmonary siderosis is one kind of pneumoconiosis, occurs from chronic inhalation of iron or iron oxide. Inhaled iron dust is deposited in the intra-alveolar spaces, which leads to radiological changes and respiratory symptoms. It is diagnosed by iron exposure history, radiological changes, and the evidence of intra-alveolar iron deposit. We have experienced a case of pulmonary siderosis which was confirmed by bronchoalveolar lavage and transbronchial lung biopsy, so report it with a review of literature.

• Journal of Environmental Health Sciences
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• v.22 no.2
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• pp.83-89
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• 1996

In order to evaluate the air quality, dry and wet deposition samples were collected by deposit containers during four months in Inchon area. The samples were analyzed for its solid composition and trace elements(Ca, Cd, Cu, Fe, Mn, Ni, Pb, Zn). The main results are summarized below 1. The amounts of dry and wet deposition in Inchon area were 1.06~3.14 ton/$km^2$/month, and affected by the rainfall and suspended yellow sand. 2. Through the analysis of solid balance, we found that 50% of total solids(TS) was fixed suspend ed solids(FSS), 25% was fixed dissolved solids(FDS), and each of volatile suspended solids(VSS) and volatile dissolved solids(VDS) accounted for 12.5%. 3. The amounts collected by sampler for trace elements were 938 ~ 2,765 $\mu g$ calcium/10days sampler, 0.2 ~ 90.4 $\mu g$ cadmium/10days/sampler, 26 ~ 298 $\mu g$ copper/10days/sampler, 928 ~ 3,939 $\mu g$ iron/10days/sampler, 50 ~ 202 $\mu g$ manganese/10days/sampler, 4 ~ 37 $\mu g$ nickel/10days/sampler, 52 ~ 406 $\mu g$ lead/10days/sampler, and 97 ~ 1,317 $\mu g$ zinc/10days/sampler, respectively. 4. Using the manganese analysis, it was found that 76.1% of TS was from soil.

• Journal of Korean Society for Atmospheric Environment
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• v.28 no.6
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• pp.644-655
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• 2012

As soon as a new air filter is applied to an air purification process, the filter gets loaded with dust particles. Thus, the study on the particle loading characteristics of air filter is very essential in order to understand the real filtration phenomena during filter use. In this study, we investigated the effect of particle and filter charge on the particle loading property of air filter. Charged filter and uncharged filter prepared by discharging the charged filter by isopropyl alcohol were used as test samples, and three types of particle having different charge states were supplied to filters tested. For neutralized particles there was a big difference in areal mass loading rates between charged and uncharged filters due to the very small amount of particle charge, on the other hand the difference was diminished for atomized particle and finally almost vanished for corona charged particles. The pressure drop of filter loaded with corona charged particles was only half of those for neutralized and atomized particles at the same areal mass loading because of the porous structure of particle deposit formed on filter fibers, caused by the space charge effect between particles.