• Journal of the korean society of oceanography
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• v.37 no.1
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• pp.35-44
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• 2002

To assess the relative contribution of bacterial and phytoplankton biomasses to particulate organic matter (POM) in the water column, microbial abundance and biomass were from two transects in the western channel of the Korea Strait in 1996. Bacterial abundance had a mean value of $5.9{\times}10^5$ cells/ml and chlorophyll-a averaged 0.14 ${\mu}g/l$. Bacterial abundance in the Korea Strait showed a positive relationship with chlorophyll-a concentration, while the distribution of POM did not covary with chlorophyll-a. Particulate organic carbon (POC) and nitrogen (PON) concentrations were greater in August than in October. Bacterial carbon (POC) and nitrogen (PON) concentrations were greater in August than in October. Bacterial carbon and nitrogen biomasses were 7.29 ${\mu}gC/l$ and 1.24 ${\mu}gN/l$, respectively, during the study periods. Bacterial biomass was larger in October than in August due to the autumn phytoplankton bloom. Phytoplankton biomass based on chlorophyll-a was 7.67 ${\mu}gC/l$ for carbon and 1.10${\mu}gN/l$l for nitrogen. The ratio of bacterial carbon (BC) to phytoplankton carbon (Cp) averaged 0.95 in the Korea Strait in 1996. Bacteria may play a more significant role in the dynamics of POM than phytoplankton do in August, with BC/Cp ratio of 1.26. The ratio of BC to Cp increased with a decrease in chlorophyll-a concentration. Averaged over all the samples in both cruises, the contribution of microbial biomass to POC and PON was about 43% and 51%, respectively. Bacterial assemblage constituted a significant fraction of POC (21%) and PON (27%). Phytoplankton accounted for 22% of POC and 24% of PON. Microbial biomass played a more important role in the dynamics of POC and PON in October than in August due to a significant increase in microbial biomass in the southern transect (transect-B) in October by the autumn phytoplankton bloom. This study showed that marine microbes may constitute a significant part in the reservoir of POM in the Korea Strait.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.21 no.3
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• pp.99-110
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• 2018

Compared to yellow dust coming from China or particulate matter created naturally in spring due to Total Suspended Particulate(TSP), particulate matter in winter season have much more serious effect on human body as they penetrate cell membranes. Although such particulate matter are becoming a social issue, there are no concrete plans on how to reduce them. Air-purifying plants are limited in maintaining the indoor air quality of large area because it is usually difficult to quantify their performance. In order to improve this, a bio-filter that can be connected to air conditioner is suggested as an option. This study seeks to improve air conditioning model-based monitoring method for bio-filters from prior studies and objectify correlations between applied vegetation and growing environment into quantitative indicators. By doing so, this study seeks to provide criteria on plants applied to artificial soil-based vegetation bio-filters and basic information to set air-conditioning features. The study results confirmed significant tendency on the growing stability of each purifying plant in mechanical air-conditioning environment. Among three models selected for bio-filter vegetation models, epipremnum aureum showed high performance in quantitative indicators, including soil moisture, EC, and leaf temperature, etc., indicating that it would assure the highest growing stability in this test air-conditioning environment.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.1
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• pp.8-14
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• 2020

The human impact of particulate matter are revealed and demand for improved forecast accuracy is increasing. Recently, efforts is made to improve the accuracy of PM10 predictions by using machine learning, but prediction performance is decreasing due to the particulate matter data with a large rate of low concentration occurrence. In this paper, separation prediction model by concentration is proposed to improve the accuracy of PM10 particulate matter forecast. The low and high concentration prediction model was designed using the weather and air pollution factors in Cheonan, and the performance comparison with the prediction models was performed. As a result of experiments with RMSE, MAPE, correlation coefficient, and AQI accuracy, it was confirmed that the predictive performance was improved, and that 20.62% of the AQI high-concentration prediction performance was improved.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.802-806
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• 2001

Diesel particulate trap is the most reliable system to reduce the particulate matters from diesel engine. Filter is the core component of DPF and ceramic monolith type is dominantly used, which is expensive and fragile relatively at thermal shock. Porous metal filter, which has superior thermal characteristics and low cost, was tested in order to analyze the regeneration performance by using with ferrocene additive. This filter showed the 72% filtration efficiency, additives itself diminished 48% of PM from engine out emission, and final PM reduction ratio of 89% was achieved by DPF system with D-13 test mode.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.994-999
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• 2007

The particulate matters emitted by diesel locomotives cause serious air pollution in stations and railroad. There have been various attempt to reduce the air pollution from diesel bus or trucks. However, the air pollution from the diesel locomotives has been out of control because there has not any adaptable technology. In this study, a diesel particulate filter was developed and applied to the diesel locomotives. A 3,000 horsepower large-scale locomotive and a 1,500 horsepower middle-scale locomotive were used for the test of the filter. The particulate matter emissions before and after the treatment was monitored by a scanning mobility particle sizer and a dust monitor. As a result, it was observed that the particulate matters could be successfully removed from the emission gases by using the filter.

• Journal of the Korean Chemical Society
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• v.51 no.2
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• pp.213-222
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• 2007

In this study, science history program was developed to enhance student's concepts toward the particulate nature of matter and the understanding about the nature of science. And the effects of its application was investigated in the lesson of ‘Composition of Matter' in middle school science class. This science history program was based on genetic approach and included the contents from the old Greek natural philosophers to Avogadro. Before instruction, the test of understanding about nature of science was administered, and the science scores of the previous course were obtained, which were used as covariates. During 24 class hours, this study was conducted with two classes(experimental and comparison group) in a middle school in Seoul. The experimental group was received lessons by science history programs and the comparison group was received traditional lessons. After instruction, the scientific concept test, the test of understanding about nature of science were administered. The result of this study indicates that the scientific concept scores of experimental group were significantly higher than comparison group at p <.01 level of significance. It means that the students in experimental group has more sound conceptions about the particulate nature of matter and less mis conceptions about matter than the students in comparison group. However, there was no significant difference between two groups in the score of understanding about the nature of science.

• Tuberculosis and Respiratory Diseases
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• v.65 no.6
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• pp.504-511
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• 2008

Background: Particulate matter may be toxic to human tissue. Ambient air particulate matter ${\leq}10{\mu}m$ in aerodynamic size ($PM_{10}$), which changes under different environmental conditions, is a complex mixture of organic and inorganic compounds. The Asian dust event caused by meteorological phenomena can also spread unique particulate matter in affected areas. We evaluated production of ROS, $TGF-{\beta}$, fibronectin, and $NF{\kappa}B$ by exposing normal epithelial cells to Asian dust particulate matter. Methods: Bronchial epithelial cells were exposed to 0, 50, ${\leq}100{\mu}g/ml$ of a suspension of $PM_{10}$ for 24 h. ROS were detected by measurement of DCF release from DCF-DA by FACScan. $TGF-{\beta}$, fibronectin, and $NF{\kappa}B$ were detected by western blotting. Results: $PM_{10}$ exposure increased the expression of $TGF-{\beta}$, fibronectin, and $NF{\kappa}B$. ROS production and $TGF-{\beta}$ levels were significantly higher with 50 or ${\leq}100{\mu}g/ml$ $PM_{10}$. Fibronectin and $NF{\kappa}B$ production were significantly higher after ${\leq}100{\mu}g/ml$ of $PM_{10}$. Conclusion: $PM_{10}$ from Asian dust particles might have fibrotic potential in bronchial epithelial cells via ROS induction after $PM_{10}$ exposure.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2008.04a
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• pp.50-51
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• 2008

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2008.10a
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• pp.53-56
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• 2008

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2005.05a
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• pp.97-104
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• 2005