간행물
한국환경과학회지 KCI 등재 Journal of Environmental Science International
- 발행기관 한국환경과학회
- 자료유형 학술지
- 간기 월간
- ISSN 1225-4517 (Print)2287-3503 (Online)
- 수록기간 1992 ~ 2023
- 주제분류 자연과학 > 자연과학일반 자연과학 분류의 다른 간행물
- 십진분류KDC 539DDC 628
권호리스트/논문검색
제15권 제4호 (2006년 4월) 13건
1.
2006.04
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Sea water samples collected in August, 1994 from 20 stations in the Kwangyang Bay were analyzed by gas chromatography/mass spectrometry-selected ion monitoring (GC/MS-SIM) to investigate persistence and distribution pattern of four organophosphorus pesticides (DDVP, Diazinon, IBP, EDDP). Except for IBP, the contamination by DDVP, Diazinon, and EDDP in marine aquatic environment in Korea has not been reported previously. In this study, however, all these four pesticides were detected in all stations (except DDVP) and their concentrations were in ng/L level. The concentrations ranged from detection limit to 15.3ng/L for DDVP, 1.8-27.7ng/L for Diazinon, 7.3-63.5ng/L for IBP, and 22.2-1100.1ng/L for EDDP. It is noteworthy that the measured concentrations of IBP and EDDP in this study would be much lower than usual, since the use of IBP and EDDP was less than 50% of average annual consumption due to unusually dry and hot weather condition in the summer of 1994. It was very surprising to find that the highest concentrations of organophosphorus pesticides were observed at stations near Daesa Streamlet instead of Seomjin River, which has more point source of the pesticides. This result suggests that the small river discharge during heavy rain period in summer can give harmful effect on marine biota (both wild and aqua-cultured) with its organophosphorus pesticide residue, despite of their short residence time in aquatic environment. In order to protect the marine life properly from acute toxicity of the organophosphorus pesticides, it needs to be emphasized that monitoring the level of agricultural pesticides in river run-off should be done during active consumption period rather at regular intervals.
2.
2006.04
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The color and structure of urban constructions is a factor of urban landscape and shows their characteristics. Hence the modern buildings deal with their materials and external appearance as an important factor, making up the urban image. But it was nearby impossible to evaluate the value of visual landscape with objective measuring method. Most of all, it depends on the subjective estimation of a few talented or high educated experts with a sense of beauty. Such kinds of estimation can in some cases include arbitrary interpretations. In relation to this kind of problems, it is tried here in this study to analyse the human response of brain wave pattern (EEG) with use of SD method, while the tested persons watch the urban landscape scenery constructed in a visual reality.
The tested persons were 20 adult male and female with no color blindness and intact cognitive function. Light source with color filter was used for color environment in a dark soundproof chamber. The signal of EEG is analysed digitally and grouped into the α and β waves. The result showed that relative power of α wave ratio increased in the natural landscape scenery with blue and green color. From these results it was possible to evaluate the human response, which is affected by urban and natural color and structure stimulation and it might be useful as an indicator of visual cognition amenity toward the design of urban construction environment.
3.
2006.04
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The purpose of this study was to investigate Rn concentration and annual radiation exposure level in the basement and first floor. The Rn Cup monitors were placed in different environments such as shopping stage, office building, Apartment, Hospital , house in Seoul from March 1996 to April 1997 and CR-39 films were collected every two months.
The mean radon concentration in the basement of house(88.6 Bq/㎥) showed the highest level among the areas, while radon concentration on the first floor of house(50.5 Bq/㎥) showed the higher than other areas. The annual radiation exposure dose that person on the floor / in the basement of differential place in the seoul can be exposed during living was estimated from 24.11 to 87.64 mRem/yr. This radiation dose is significantly lower than 130mRem maximum radiation dosage from the radon nuclide prescribed by the ICRP, with respect to the overall average exposure of the working adult. this study indicated that possible radon sources on the first floor / in the basement areas are radon intrusion from soil gas, construction materials, or ground water leaking. Further study is needed to quantitatively assess major contributions of radon-222 and health effect to radon exposure.
4.
2006.04
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Release rate is one of the important items for the environmental impact assessment caused by radioactive materials in case of an accidental release from the nuclear facilities. In this study, the uncertainty of the estimated release rate is evaluated using Monte Carlo method. Gaussian plume model and linear programming are used for estimating the release rate of a source material. Tracer experiment is performed at the Yeoung-Kwang nuclear site to understand the dispersion characteristics. The optimized release rate was 1.56 times rather than the released source as a result of the linear programming to minimize the sum of square errors between the observed concentrations of the experiment and the calculated ones using Gaussian plume model. In the mean time, 95% confidence interval of the estimated release rate was from 1.41 to 2.53 times compared with the released rate as a result of the Monte Carlo simulation considering input variations of the Gaussian plume model. We confirm that this kind of the uncertainty evaluation for the source rate can support decision making appropriately in case of the radiological emergencies.
5.
2006.04
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The purpose of this paper is to suggest practical suggestions to mitigate Urban Heat Island(UHI) problems in Daegu regarding urban surface temperature.
Urban street trees's size and the relations between urban land use types and surface temperature are analysed using aerial photos, the numerical value map and Landsat TM image with special reference to Jung-gu.
Total urban street tree's crown size is 156,217.6㎡ and it is equal to 2.24% of study area. In addition, the size of 'city and residential area' is 6,681,870㎡(95.7% of study area), which causes UHI and the total size of 'river' shows the lowest surface temperature area and 'road' and 'business and service area' are the highest surface temperature zones. Therefore, it is probable that the network between urban street trees and the lowest surface temperature areas mitigate UHI effects.
6.
2006.04
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A (5 wt.%)Mn-(1 wt.%)V2O5/TiO2 catalyst were prepared by co-precipitation method and used for low-temperature selective catalytic reduction (SCR) of NOx with ammonia in the presence of oxygen. The properties of the catalysts were studied by X-ray diffraction (XRD), temperature programmed reduction (TPR) and scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDS).
The experimental results showed that (5 wt.%)Mn-(1 wt.%)V2O5/TiO2 catalyst yielded 81% NO conversion at temperature as low as 150℃ and a space velocity of 2,400 h-1. Crystalline phase of Mn2O3 was present at ≥15% Mn on V2O5/TiO2. XRD confirmed the presence of manganese oxide (Mn2O3) at 2θ=32.978°(222). The XRD patterns presented of (5 wt.%)Mn-(1 wt.%)V2O5/TiO2 did not show intense or sharp peaks for manganese oxides and vanadia oxides. The TPR profiles of (5 wt.%)Mn-(1 wt.%)V2O5/TiO2 catalyst showed main reduction peak of a maximum at 595℃.
7.
2006.04
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Adsorption characteristics of benzene by zeolite were investigated using irradiating microwave. Experimental apparatus was applied to a U-type fix-bed column equipped with microwave system. Zeolite, itself, seems to be inappropriated to remove benzene because of a hygroscopic property. Microwave irradiation to zeolite, however, brings about decreasing H2O adsorption and increasing benzene adsorption. This causes that the dipole material such as H2O was vibrated and heated by irradiation of microwave and desorbed from zeolite. And then, benzene starts to be absorbed by zeolite. In this study, the results showed that the selective adsorption of benzene was occurred by the microwave irradiation and the adsorption capacity of benzene was increased by increasing microwave energy. As a results, it was found that the zeolite could be used to adsorb benzene with microwave and this method make it feasible simultaneously to adsorb and desorb benzene.
8.
2006.04
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The purpose of this study is to evaluate the water pollution degree in the Mid-Nakdong River watershed regarding to landcover types using GIS method. As a result of landcover classification, rate of urban appeared highly on Daegu Metropolitan city. Also, rate of agriculture showed highly in the riparian zones of the Nakdong and Guemho River and rate of forest appeared highly in the borders of the study area. To identify the groups of watershed with similar landcover patterns using the Cluster Analysis.
According to the cluster analysis, the fifty sub-watersheds were grouped in three clusters, "Urban watershed", "Agriculture watershed", "Forest watershed". The proportion of urban area in each cluster had a positive correlation with water pollution degree.
Otherwise, the proportion of agriculture in the Agriculture watershed had a high positive correlation with water pollution degree. Therefore, it is necessary to estimate environmental capacity of water quality considering ecological and environmental characteristics of watershed ecosystem and expand water quality monitoring systems to small stream.
9.
2006.04
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Two sites with different average daily traffic volume at an intersection were selected in order to investigate water quality of the first flushes in the surface runoffs. The effects of rainfall intensities and accumulated non-rainy days before rainfall events on the water quality were also delineated. Samples were collected at every 2 min. interval from each first flush from February to May, 2004 for 4 major rainfall events. CODcr or SS concentrations at the site with an average daily traffic volume (ADTV) of 23,000 vehicles were 2-7 times higher than those at the site with an ADTV of 1,400 vehicles. The longer the accumulated non-rainy days were, the higher the concentration of heavy metals were than those of CODcr and SS in the first flushes.
10.
2006.04
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In this study investigated that topographical parametersestimate and calculated travel time, storage coefficient and lag time by watershed dividing 11, 8, 6 and 2. The results showed the more divide watershed, the more increase peak discharges. The results showed that Kraven-Clark-Kraven case is good simulated by compared observed data with calculated data. The sub-basin number are adequate 6~11 for wichun and travel times compare observed data with calculated data at the younggok, to take about 18~20hr by simulated results but observed data shorter 8~10hr. From this study results showed that it could be make narrow parameter estimate for observed hydrograph simulation, if more observed velocity and hydrograph. Also, as results of this study that is help to estimate parameters (arrival time, storage coefficient and lag time for Clark model.
11.
2006.04
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The western coast of South Korea is famous for its large and broad tidal lands. Nevertheless, land reclamation, which has been conducted on a large scale, such as Sihwa embankment construction project has accelerated coastal environmental changes in the embankment inland. For monitoring of environmental change, vegetation change detecting of the embankment inland were carried out and field survey data compared with Landsat TM, ETM+, IKONOS, and EOC satellite remotely sensed data. In order to utilize multi-temporal remotely sensed images effectively, all data set with pixel size were analyzed by same geometric correction method. To detect the tidal land vegetation change, the spectral characteristics and spatial resolution of Landsat TM and ETM+ images were analyzed by SMA(spectral mixture analysis).
We obtained the 78.96% classification accuracy and Kappa index 0.2376 using March 2000 Landsat data. The SMA(spectral mixture analysis) results were considered with comparing of vegetation seasonal change detection method.
12.
2006.04
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Eight USA soils were used for this study. The purpose of this study is to illustrate the characteristics of metals in the soil based on the sequential extraction with increasing pH. Extracts were analyzed for metals by ICP-MS and for dissolved organic carbon(DOC). As the pH increasing, the DOC extracted in each increment initially decreased and reached the minimum at pH 3 and then increased substantially at higher pH values. According to the pH increasing, the extraction of Ca, Cu, and Zn were illustrated as L type. It was found that there were strong correlation between the extracted Fe and DOC(r=0.64～0.97).
13.
2006.04
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In 2005, harmful dinoflagellate Cochlodinium polykrikoides was first occurred on July 18 and disappeared on September 12 in the Yeosu waters of the South Sea of Korea. During C. polykrikoides blooms, the species of Protoperidinium was isolated from Jabong Island in Yeosu in the middle of August, 2005. The surface water temperature at the sampling site was 25℃, and salinity was 33.1 psu. The specimen was somewhat large in size and was longer than its width. The shape was close to being ovoid, with an apical horn. This study discovered cells with colorless and transparent ingested chain-forming C. polykrikoides. However, this species was not abundant, implying low grazing impact on C. polykkoides.
