• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.1
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• pp.23-30
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• 2015

The scanning quality can be influenced by reflective abilities of a surface. Transparency and glossiness of a surface can highly limit the scanning results. Various techniques have been developed to solve problems of reflective and transparent surfaces. As one of the most feasible and convenient solutions, a thin layer of coating with proper specifications is sprayed on surface for eliminating the problems of the surfaces. As the main goal is to keep the object geometry unchanged, then it is important to coat the surface with layers less than one micrometer in thickness. For this purpose, a newly designed atomization-based spray system has been developed and tested in sets of experiments to study its efficiency on scanning results while objects with the surface are in use. This paper presents the spray design process and then studies and compares the 3D scanning results of the surfaces coated with atomization-based and aerosol sprays.

• Journal of Korean Society for Atmospheric Environment
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• v.11 no.3
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• pp.263-272
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• 1995

Characteristics of anbient at Korean, Cheju Island have been studied during the intensive field study period on March 11 .sim. 17, 1994 in collaboration with other research organizations from Korea and abroad. The particle size distribution was measured using an Electrical Aerosol Analyzer(EAA) and an Optical particle Counter(OPC). Fine particles(PM1 and PM3) have been collected by filter pack samplers and their ionic compositions have been analyzed. sampling errors inherent to the filter pack sampling method are discussed and the method to analyze those errors are presented. The rine mass concentrations of this study show very similar mass concentrations when Seoul is clear. This is somewhat surprising result, because the most of researchers believe that Kosan is one of the cleanest area in Korea. Bimodal volume size distributions with peak values around 0.1 .sim. 0.2.mu.m and 3.mu.m in particle dimeter were observed for most of the measurement period, particle mass loadings and ionic composition data show a large fraction of particles are from non-sea salt origins. Estimation of water content and acidity of particles based on measurement by a gas/particle equilibrium model, SCAPE, reveals that the pH values of particles are comparable to or lower than those estimated based on measurements in Los Angeles, U.S.A. during the SCAQS study. These findings with the meteorological conditions during the study period suggest that the particles collected during the period have originated from outside Cheju Island.

• Toxicological Research
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• v.30 no.1
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• pp.13-18
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• 2014

Electronic cigarettes (e-cigarettes) are becoming increasingly popular worldwide and their cellular effects warrant further evaluation. In this study, we investigated the effects of an e-cigarette cartridge solution on allergen related asthmatic airway inflammation (AI) and airway hyperresponsiveness (AHR), when it is delivered by intratracheal route in mice. Asthmatic AI and AHR were induced by systemic sensitization to ovalbumin (OVA) followed by intratracheal, intraperitoneal, and aerosol allergen challenges in BALB/c mice. The cartridge solution of e-cigarette (containing 16 mg/ml nicotine) was diluted 50 times and $100{\mu}l$ of the diluted solution was intratracheally instilled to OVA-sensitized (OVA-S) mice two times a week for 10 weeks. Long-term e-cigarette inhalation elicited no remarkable changes in the activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase enzymes in serum, however, increased infiltration of inflammatory cells including eosinophils, into airways from blood, aggravated the asthmatic AI and AHR, and stimulated the production of cytokines such as interleukin (IL)-4, IL-5 and IL-13, and OVA-specific IgE production. Our data suggest that the inhalation of e-cigarette solutions can function as an important factor to exacerbate the allergy-induced asthma symptoms. Further studies are needed to address the effects of e-cigarette solutions on human health.

• Advances in Traditional Medicine
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• v.8 no.1
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• pp.24-31
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• 2008

In the present investigation, we studied the effect of alcoholic extract of Moringa oleifera (M. oleifera) seed kernels on various experimental models of bronchial asthma. Significant (P < 0. 05) increase in preconvulsion time was observed due to pretreatment with M. oleifera when the guinea pigs were exposed to either acetylcholine (Ach) or histamine aerosol. This bronchodilating effect of M. oleifera was comparable to ketotifen fumarate. Spasmolytic effect of M. oleifera was also observed by dose dependent inhibition of ideal contractions induced by Ach, 5HT, histamine and $BaCl_2$. Alcoholic extract of M. oleifera produced significant dose dependent protection by egg albumin and compound 48/80 induced mast cell degranulation. Pretreatment with alcoholic extract of M. oleifera also decreased carrageenan induced rat paw edema, which was comparable to that of standard diclofenac sodium. Minimum inhibitory concentration for alcoholic extract of M. oleifera was low as compared to cold-water extract and hot water extract when antimicrobial activity was tested against various respiratory pathogens like Escherichia coli (E. coli), Staphylococus aureus (S. aureus) and pseudomonas aeruginosa (P. aeruginosa). Our data suggest that antiasthmatic activity of M. oleifera seed kernels may be due to its bronchodilator, anti-inflammatory, mast cell stabilization and antimicrobial activity.

• The Korea Journal of Herbology
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• v.26 no.4
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• pp.49-57
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• 2011

Objective : Allergic asthma is a chronic airway disease that affects millions of people in the developed world. The disease is characterized by concurring airway inflammation, Th2 cytokine production, increased mucus secretion, airway hyperresponsiveness (AHR) to inhaled antigen, and pulmonary fibrosis. To investigate the therapeutic and anti-asthmatic effects of Drynariae Rhizoma (DR), we examined the influence of DR on the development of pulmonary eosinophilic inflammation and airway hyperresponsiveness in a mouse model of allergic asthma. Methods : In this study, BALB/c mice were systemically sensitized to ovalbumin (OVA) followed intratracheally, intraperitoneally, and by aerosol allergen challenges. We investigated the effect of DR on airway hyperresponsiveness, pulmonary eosinophilic infiltration, various immune cell phenotypes, Th2 cytokine production and OVA specific IgE production in a mouse model of asthma. Results : In asthmatic mice, we found that DR.treated groups had suppressed eosinophil infiltration, allergic airway inflammation and AHR by suppressing the production of IL-5, IL-13 and OVA specific IgE. Conclusions : Our data suggest that the therapeutic mechanism by which DR effectively treats asthma is based on reductions of Th2 cytokines (IL-5), eotaxin, OVA-specific IgE production and eosinophil infiltration.

• Bulletin of the Korean Chemical Society
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• v.35 no.4
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• pp.1191-1194
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• 2014

Imaging Differential Optical Absorption Spectroscopy (Imaging-DOAS) has been utilized in recent years to provide slant column density (SCD) distributions of several trace gas species in the plume. The present study introduces a new method using Imaging-DOAS data to determine two-dimensional plume structure from the plume emissions of power plant in conditions of negligible aerosol effects on radiative transfer within the plume. We demonstrates for the first time that two-dimensional distributions of sulfur dioxide ($SO_2$) and nitrogen dioxide ($NO_2$) in power plant emissions can be determined simultaneously in terms of SCD distribution. The $SO_2$ SCD values generally decreased with increasing distance from the stack and with distance from the center of the plume. Meanwhile, high $NO_2$ SCD was observed at locations several hundred meters away from the first stack due to the ratio change of NO to $NO_2$ in NOx concentration, attributed to the NO oxidation by $O_3$. The results of this study show the capability of the Imaging-DOAS technique as a tool to estimate plume dimensions in power plant emissions.

• Advances in environmental research
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• v.1 no.1
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• pp.69-82
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• 2012

Based on the measurement data of the particulate matter with an aerodynamic diameter of less than or equal to a nominal 10 ${\mu}m$ (PM10) by the ${\beta}$-ray absorption method (BAM) equipped with an inlet heater and the gravimetric method (GMM) at two coastal sites in Korea, the optimal inlet heater temperature was estimated. By using a gas/particle equilibrium model, Simulating Composition of Atmospheric Particles at Equilibrium 2 (SCAPE2), water content in aerosols was estimated with varying temperature to find the optimal temperature increase to make the PM10 concentration by BAM comparable to that by GMM. It was estimated that the heated air temperature inside the BAM should be increased up to $35{\sim}45^{\circ}C$ at both sites. At this temperature range, evaporation of volatile aerosol components was minor. Similar ($30{\sim}50^{\circ}C$) temperature range was also obtained from the calculation based on the absolute humidity which changed with ambient absolute humidity and chemical composition of hygroscopic species.

• Environmental Engineering Research
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• v.17 no.4
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• pp.211-216
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• 2012

Quantification of the airborne microorganisms (bacteria and fungi) at a swine wastewater treatment plant was performed. Microbial samples were collected at three different phases of the treatment process over a 1-yr period. Cultivation methods based on the viable counts of mesophilic heterotrophic bacteria and fungi were performed. The concentrations of airborne bacteria ranged up to about $5{\times}10^3$ colony-forming unit (CFU)/$m^3$, and those of airborne fungi ranged up to about $9{\times}10^2CFU/m^3$. The primary treatment (e.g., screen, grit removal, and primary sedimentation) was found to be the major source of airborne microorganisms at the site studied, and higher levels of airborne bacteria and fungi were observed in summer. High levels of the respirable bioaerosol (0.65 to $4.7{\mu}m$ in size) were detected in the aeration phase. Among the environmental factors studied, temperature was strongly associated with fungal aerosol generation (with a Spearman correlation coefficient of 0.90 and p-value <0.01). Occupational biorisks are discussed based on the observed field data.

• Safety and Health at Work
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• v.12 no.2
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• pp.209-216
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• 2021

Background: The article presents the results of studies performed in order to develop a new method of airborne potassium bromate(V) determination at workplaces. Methods: The method is based on a collection of the inhalable fraction of potassium bromate(V) using the IOM Sampler, then extraction of bromates with deionized water and chromatographic analysis of the obtained solution. The analysis was performed using ion chromatography with conductometric detection. The tests were performed on a Dionex IonPac®AS22 analytic column (250 × 4 mm, 6 ㎛) with AG22 precolumn (50 × 4 mm 11 ㎛). Results: The method provides for potassium bromate(V) determination within the concentration range of 0.043 ÷ 0.88 mg/m³ for an air sample of 0.72 m³ in volume, i.e., 0.1-2 times the exposure limit value as proposed in Poland. The method was validated in accordance with PN-EN 482. The obtained validation data are as follows: measuring range: 3.1-63.4 ㎍/mL, limit of detection (LOD) = 0.018 ㎍/mL and limit of quantification (LOQ) = 0.053 ㎍/mL. The developed method has been tested in the work environment, on laboratory employees having contact with potassium bromate(V). Conclusion: The analytical method allowed the determination of the inhalable fraction of airborne potassium bromate(V) at workplaces and can be used to assess occupational exposure.

• Korean Journal of Remote Sensing
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• v.35 no.6_1
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• pp.919-932
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• 2019

Fine particulate matter (PM2.5) is not only affected by anthropogenic emissions, but also intensifies, migrates, decreases by hydrometeorological factors. Therefore, it is essential to understand relationships between the hydrometeorological factors and PM2.5 concentration. In Korea, PM2.5 concentration is measured at the ground observatories and estimated data are given to locations where observatories are not present. In this way, the data is not suitable to represent an area, hence it is impossible to know accurate concentration at such locations. In addition, it is hard to trace migration, intensification, reduction of PM2.5. In this study, we analyzed the relationships between hydrometeorological factors, acquired from Global Land Data Assimilation System (GLDAS), and PM2.5 by means of Bayesian Model Averaging (BMA). By BMA, we also selected factors that have meaningful relationship with the variation of PM2.5 concentration. 4 PM2.5 concentration models for different seasons were developed using those selected factors, with Aerosol Optical Depth (AOD) from MODerate resolution Imaging Spectroradiometer (MODIS). Finally, we mapped the result of the model, to show spatial distribution of PM2.5. The model correlated well with the observed PM2.5 concentration (R ~0.7; IOA ~0.78; RMSE ~7.66 ㎍/㎥). When the models were compared with the observed PM2.5 concentrations at different locations, the correlation coefficients differed (R: 0.32-0.82), although there were similarities in data distribution. The developed concentration map using the models showed its capability in representing temporal, spatial variation of PM2.5 concentration. The result of this study is expected to be able to facilitate researches that aim to analyze sources and movements of PM2.5, if the study area is extended to East Asia.