• Elastomers and Composites
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• v.49 no.4
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• pp.284-292
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• 2014

Polymer has low mechanical strength than metal. In particular, the impact strength is very weak. Impact modifier reinforced polymers are frequently used. Impact strength of reinforced polymer is changed according to content and distribution of impact modifier. In this study, izod impact test has been simulated to analyze the mechanism of impact modifier reinforced Nylon 6. Computational results were compared for numbers and distributions of impact modifier. As the total volume of rubber particles decreased, the stress at the notch increased for the simulation model that the volume decreases as particle number increases. As the surface area of particle sphere increased, the stress and difference of principle stress increased for the simulation model that the total surface increases as particle number increases.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.2
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• pp.259-270
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• 2008

The regional air movement in a coastal area is generated by the different heat capacities of sea and land sides, which is called sea/land breeze. In the west coast area, the local air quality is significantly influenced by this sea/land breeze. In this study, the mathematical model is proposed to estimate the effective area of sea/land breeze. A commercial air model, that is suggested as an alternative air model by USEPA, is introduced to simulate the mechanism of sea/land breeze generation. From this study, it is confirmed that the numerical approach proposed in this study is reliable to predict the effective area of sea breeze in a coastal area. It implies that the current application of common air model needs to be carefully reviewed especially when dealing with a coastal air quality issue. It is also found that the sea breeze in Incheon area has the impact in the range of approximately 24 km in-land side, so-called penetration length.

• Journal of Environmental Impact Assessment
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• v.21 no.1
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• pp.1-13
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• 2012

We diagnosed on status and problems of environmental assessment regarding development of offshore wind power, and also on reasonable core assessment items. Most of the coastal wind power are located on the western coastline of Korea and Jeju Island. In the selections of the site for the offshore wind farms, a previous investigations should be conducted with regard to distances from the land, stabilities from external forces (tide, wave, etc.) and topographical changes, and characteristics of the surroundings (distributions of protected area, fishing ground, artificial seagrasses, and shipping traffic). It is needed to assess dispersion of suspended solids, changes of the sea bottom, and impacts on fisheries resources and fishing activities under construction of offshore wind power. Furthermore, the responses of marine organisms to noise and vibration, impacts by electromagnetic fields, impacts on sea birds, hindrances to sea lane routes, and damaged scenery and marine protection areas are thoroughly assessed during operation processes. The consultation criteria in case of development of offshore wind farm is adjusted by focusing marine environmental impact assessment.

• Journal of the Korean Solar Energy Society
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• v.31 no.5
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• pp.47-59
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• 2011

The purpose of this paper is to simulate the high ozone concentration in Shiwha Banwol indusrial complex. High pollution episodes (ozone alert) of this area are the results of geographical location and its air pollutants emission. This research has used meteorological model (RAMS) and photochemical air pollution Model (CIT model). As first step of the evaluate of this combined model system simulations are done in terms of meteorological characteristics like wind fields, PBL-height, etc.. Numerical simulations are carried out with real meteorological synoptic data on June. 24-25, 2010. In comparison with real measurement and another research the model reflects well local meteorological phenomena and shows the possibility to be utilized to analyse the pollutant dispersion over irregular terrain region. The high ozone concentration is deeply correlated to the ambient air temperature, wind speed and solar radiation. Local meteorological phenomena like sea-land breeze impact on horizontal dispersion of ozone. This analysis of meteorological characteristics can, in turn, help to predict their influences on air quality and to manage the high ozone episodes.

• Journal of Environmental Impact Assessment
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• v.32 no.4
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• pp.203-213
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• 2023

The AERMOD model was the most used, accounting for 89.0%, based on the analysis of the environmental impact assessment reports published in the Environmental Impact Assessment Information Support System (EIASS) between 2021 and 2022. The mismatch of versions between AERMET and AERMOD was found to be 25.3%. There was the operational time discrepancy of 50.6% from industrial complexes, urban development projects between used in the model and applied in estimating pollutant emissions. The results of applying various versions of the AERMET and AERMOD models to both area sources and point sources in both simple and complex terrain in the Gunsan area showed similar values after AERMOD version 12 (15181). Emissions are assessed as 24-hour operation, and the predicted concentration in both simple and complex terrain when using the variable emission coefficient option that applies an 8-hour daytime operation in the model is lowered by 37.42% ~ 74.27% for area sources and by 32.06% ~ 54.45% for point sources. Therefore, to prevent the error in using the variable emission coefficient, it is required to clearly present the emission calculation process and provide a detailed explanation of the composition of modeling input data in the environmental impact assessment reports. Also, thorough reviews by special institutions are essential.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.12
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• pp.1316-1322
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• 2006

The purpose of this study is to analyze the pattern distribution of the odorous compounds and air pollutants from the inventory sources in the Cheon-an second industrial complex. Twelve analysis including specified odor materials and air pollutants were concurrently measured during the month of August, 2005 to evalaute odor emission characterization in m3;or treatment facilities. Also, Concentration of air pollutants has been calculated by ISCST3 in ISC3 models. A Korean air diffusion modeling software, Air Master, was developed on a basis of diffusion theories adopted in U.S. EPA's ISC3 model to assess the air quality impact from the stacks. This investigation will be executed how large the complex pollutant sources such as industrial complex contribute to atmospheric environment and air quality of the surrounding the area as predicting by comparing and analyzing results of odorous compounds and air pollutants diffusion concentration model.

• Nuclear Engineering and Technology
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• v.55 no.12
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• pp.4543-4553
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• 2023

The dose from a possible accident at a microwave-based spent resin mixture treatment facility that was to be installed and operated at the Wolsong nuclear power plant was analyzed to evaluate the radiological safety prior to its installation and operation. The dose to which workers and nearby residents are likely to be exposed was calculated based on the atmospheric dispersion and deposition factors using the XOQDOQ code. The highest atmospheric dispersion factors were 1.349E-05 s/m³ (workers) and 1.534E-06 s/m³ (residents). The highest doses due to emissions from the mock-up tank before operation were 1.91E-06 mSv (workers) and 1.78E-07 mSv (residents). Even after 3 h of operation, emissions from the mock-up tank had the greatest impact ranging from 4.63E-08 to 1.24E-06 mSv (workers) and 2.74E-10 to 1.16E-07 mSv (residents), respectively. The doses were 7.09E-09-4.55E-07 mSv and 4.18E-11-4.25E-08 mSv at 4-5 h of operation, and the maximum doses after operation reached 5.69E-07 mSv and 5.31E-08 mSv for the workers and residents, respectively. Even at the exclusion area boundary (EAB), 4.76E-08-9.51E-07 mSv (annual dose:9.52E-05–1.90E-03 mSv/y) was below the dose limit of the EAB, and the safety of the facility installation inside the NPP was confirmed.

• Journal of Environmental Science International
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• v.23 no.12
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• pp.2089-2099
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• 2014

Emissions from aircraft have impacts on the air pollution of airport and the surrounding area. There are methods of emissions calculated as Tier 1, Tier2, Tier 3A and Tier 3B. Thus, this study investigated emissions from aircraft at the Gimhae International Airport using EDMS(Emissions & Dispersion Modeling System) program. Results of estimation from aviation emissions, Tier 3B considering all parts which can occur at the airport has the largest amount emissions. In order to understand the relation between aviation emissions and distribution of ozone concentration over airport area, numerical evaluation were carried out. Although the difference of surface ozone distribution between numerical assessment with and without aviation emissions was little, effects of air pollution at airport area from aviation emissions of NOx and VOCs.

• Journal of the Korean earth science society
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• v.36 no.4
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• pp.301-314
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• 2015

The purpose of this study was to investigate the impact of ground-based glaciogenic seeding on orographic clouds in the Daegwallyeong area on 13 March, 2013. The experiments was conducted by releasing silver iodide (AgI) under following conditions: surface temperature below $-4^{\circ}C$, wind direction between 45 and $130^{\circ}$, and wind speed less than $5ms^{-1}$. Two seeding rates, $38gh^{-1}$ (SR1) and $113gh^{-1}$ (SR2), were tested to obtain an appropriate AgI ratio for snowfall enhancement in the Daegwallyeong area. Numerical simulations were carried out by using the WRF (Weather Research and Forecast) model with AgI point-source module which predicted dispersion fields of AgI particles. The results indicated that the target orographic clouds contained adequate amount of supercooled liquid water and that the dispersion of AgI particles tended to move along the prevailing wind direction. To validate the seeding effects, the observation data from FM-120 and MPS as well as PARSIVEL disdrometer were analyzed. In this case study, glaciogenic seeding significantly increased the concentration of small ice particles below 1 mm in diameter. The observation results suggest that SR1 seeding be reasonable to use the ground-based seeding in the Daegwallyeong area.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.27 no.4
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• pp.15-27
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• 2024

Ecosystem-disturbing plant species pose a significant threat to native ecosystems due to their high reproductive capacity, making it essential to monitor their distribution and develop effective mitigation strategies. Consequently, it is crucial to enhance the evaluation of the impacts of these species in environmental impact assessments by incorporating scientific evidence alongside qualitative assessments. This study introduces a dispersal model into the species distribution model to simulate the potential spread of ecosystem-disturbing plant species, reflecting their ecological characteristics. Additionally, we developed mitigation scenarios and quantitatively calculated reduction rates to propose effective mitigation strategies. The species distribution model showed a reliable AUC (Area Under the Curve) of at least 0.890. The dispersal model's results were also credible, with 31 out of 34 validation coordinates falling within the predicted spread range. Simulating the impact of the spread of ecosystem-disturbing plant species over the next five years revealed that one project site had potential habitats for Ambrosia artemisiifolia, necessitating robust mitigation measures such as seed removal. Another project site, with potential habitats for Symphyotrichum pilosum, indicated that physical removal methods within the site were effective due to the species' relatively short dispersal distance. These findings can serve as fundamental data for project executors and reviewers in evaluating the impact of the spread of ecosystem-disturbing plant species during the planning stages of projects.