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
제21권 제1호 (2012년 1월) 13건
1.
2012.01
서비스 종료(열람 제한)
A thermal-optical transmittance carbon analyzer has been developed to determine particulate organic (OC) and elemental (EC) carbon. Several analysis factors affecting the sensitivity of OC and EC determination were investigated for the carbon analyzer. Although total carbon (TC) is usually consistent in the determination, OC and EC split is sensitive to adopted analysis protocol. In this study the maximum temperature in oxygen-free He in the analysis was examined as a main cause of the uncertainty. Prior to the sensitivity analysis consistency in OC-EC determination of the carbon analyzer and the uniformity of carbonaceous aerosol loading on a sampled filter were checked to be in acceptable range. EC/TC ratios were slightly decreased with increasing the maximum temperature between 550-800oC. For the increase of maximum temperature from 500oC to 800oC, the EC/TC ratio was lowered by 4.65-5.61% for TC loading of 13-44 μg/cm2 with more decrease at higher loading. OC and EC determination was not influenced by trace amount of oxygen in pure He (>99.999%), which is typically used in OC and EC analysis. The facing of sample loaded surface to incident laser beam showed negligible influence in the OC-EC split, but it caused elevated PC fraction in OC for forward facing relative to backward facing.
2.
2012.01
서비스 종료(열람 제한)
This study investigated the characteristics of selected volatile organic compounds(VOCs) in newly-finished residential buildings, before the occupants moved in. This investigation was carried out by measuring the indoor and outdoor concentrations of selected VOCs before the occupants moved in and by utilizing an indoor mass balance model. Among 25 target VOCs, five aromatics(benzene, ethyl benzene, toluene, m,p-xylene, and o-xylene) were detected in all samples of both indoor and outdoor air. Toluene was most abundant VOC in the indoor air of new apartments, with a median value of 168 mg m-3. Unlike other VOCs, halogenated compounds would not be significantly emitted from building materials. The indoor air concentrations of all selected VOCs, except for 1,3,5-trimethyl benzene, exhibited significant correlations each other, while for outdoor air concentrations, five aromatics only were significantly correlated between them. The emission rate of toluene was higher for the current study(median value, 76.8 mg m-2 h-1) than for a previous study, while the emission rates of limonene, a-pinene and b-pinene(geometric means of 2.4, 13.8 and 9.6 mg m-2 h-1, respectively) were lower and the emission rates of m,p-xylene and 2-butanone(geometric means of 10.9 and 21.3 mg m-2 h-1, respectively) were similar. Although there were a few exceptions, the emission strengths are likely proportional to indoor temperature, and appear to reversely proportional to air exchange rate.
3.
2012.01
서비스 종료(열람 제한)
The aerosol number concentration have measured with an aerodynamic particle sizer spectrometer(APS) at Gosan site in Jeju, Korea, from March 2010 to March 2011. And then the atmospheric aerosol number concentration, the temporal variation and the size distribution of aerosol number concentration have been investigated.
The aerosol number concentration varies significantly from 748 particles/㎝3 to zero particles/㎝3. The average number concentration in small size ranges are very higher than those in large size ranges. The number concentrations in the size range 0.25∼0.28 ㎛, 0.40∼0.45 ㎛ and 2.0∼2.5 ㎛ are about 84 particles/㎝3, 2 particles/㎝3 and 0.4 particles/㎝3, respectively. The number concentrations in range of larger than 7.5 ㎛ are below 0.001 particles/㎝3.
The seasonal variations in the number concentration for smaller particle(<1.0 ㎛) are not much, but the variations for larger particle are very evident. And strong amplitudes of diurnal variations of entire averaged aerosol number concentration are not observed.
Size-fractioned aerosol number concentrations are dramatically decreased with increased particle size. The size-fractioned aerosol number concentrations in size range 0.8∼4.0 ㎛ during nighttime are evidently higher than during daytime, but similar levels are appeared in other size range. The seasonal differences in the size-fractioned number concentrations for smaller size range(<0.7 ㎛) are not observed, however, the remarkable seasonal differences are observed for larger size than 0.7 ㎛.
4.
2012.01
서비스 종료(열람 제한)
The objective of this study is to provide pollutant loads delivery ratio for flow duration in Oenam-cheon watershed, which is upstream watershed of Juam Lake. To calculate the delivery ratio by flow duration, rating curves and discharge-loads curves using measured data were established, then Flow Duration Curve(FDC) and pollutant loads delivery ratio curves were constructed. The results show that the delivery ratios for BOD5 for abundant flow(Q95), ordinary flow(Q185), low flow(Q275), and drought flow(Q355) were 23.9, 12.7, 7.1, and 2.9%, respectively. The delivery ratios of same flow regime for T-N were 58.4, 31.2, 17.2 and 7.1%, respectively. While, the delivery ratios T-P were 17.3, 7.5, 3.4, and 1.1% respectively. In general, delivery ratio of high flow condition showed higher value due to the influence of nonpoint source pollution. Based on the study results, generalized equations were developed for delivery ratio and discharge per unit area, which could be used for ungaged watershed with similar pollution sources.
5.
2012.01
서비스 종료(열람 제한)
This study was carried out to investigate the distribution and their change of Pinus densiflora forests by climate change in Mt. Hallasan. The results showed that the areas of P. densiflora forests of Mt. Hallasan varied by region, with a total area of 1,324.3 ha, concentrated mostly in the region 1,000 m - 1,400 m above sea level. The temperate coniferous forest zone are distributed in the upper part of temperate forest zone composed of deciduous broad-leaved trees. Most of the P. densiflora forests in the lower parts were found not to be spreading because they are located close to the deciduous broad-leaved trees. However, the P. densiflora forests in the Sajebi and Pyeonggwe regions composed of the grasslands and shrub forests were found to be spreading. In addition, the altitude of the P. densiflora forests distribution increased by about 50 m and 90 m in the Sajebi and Pyeonggwe regions, respectively. The spread rate is expected to become faster than in the past due to the rate of climate change. The structure of the vegetation in Mt. Hallasan and the changes in the vegetation due to various factors need to be investigated from a long-term point of view.
6.
2012.01
서비스 종료(열람 제한)
In this study, the characteristic of offensive major odorous compound from the Bon-San industrial complex in Gimhae were determined by analytical methods of Gas Chromatography, High Performance Liquid Chromatography and UV/VIS Spectrophotometer. The kind of major odorous compounds examined acetaldehyde, sulfur compounds, ammonia and styrene. The concentration of all odorous compounds at 3 sampling points of industrial complex were lower than those of regulation standard levels of the industrial complex in Korea. The mean concentration of hydrogen sulfide was 0.0235 ppm at sampling point 2, it was higher than other sampling point. Complex odors was lower than regulation standard levels of the industrial complex in Korea.
7.
2012.01
서비스 종료(열람 제한)
The midge samples were undertaken at three streams, representing different surrounding environments, to investigate the contaminant exposure of midge. The content of heavy metals in midge collected in Singil stream were generally higher as a result of input to the industrial effluents with respect to other streams.
Adsorption experiments were done to evaluate the possibility of removing contaminants from water with midge. Diazinon and heavy metals were contaminant target compounds in this study. The removal rate of diazinon in water by midge was 60-75%. In the case of Cu, the removal rate was reached around 90% at the lower initial concentration of 1.87 and 0.81 ppm rather than 4.25 ppm. The reduction of concentration of Cr and Cd according to the lapse of time was similar to the Cu, but their removal rates were shown 50% and 60-74%, respectively. The removal rate of Zn by midge represented relatively high level within the experimental condition. No change in concentration of Cr and As with time were occurred at all experimental conditions. It accounts for the fact that the reduction of Cr and As could not be achieved through the adsorption process, using midge.
8.
2012.01
서비스 종료(열람 제한)
This study forecasts changes in thermal environment and microclimate change per new building construction and assignment of green space in urban area using Computational Fluid Dynamics(CFD) simulation. The analysis studies temperature, humidity and wind speed changes in 4 different given conditions that each reflects; 1) new building construction; 2) no new building construction; 3) green spaces; and 4) no green spaces. Daily average wind speed change is studied to be; Case 2(2.3 m/s) ＞ Case 3. The result of daily average temperate change are; Case 3(26.5℃) ＞ Case 4(24. 6℃) ＞ Case 2(23.9℃). This result depicts average of 2.5℃ temperature rise post new building construction, and decrease of approximately 1.8℃ when green space is provided. Daily average absolute humidity change is analysed to be; Case 3(15.8 g/kg') ＞ Case 4(14.1 g/kg') ＞ Case 2(13.5 g/kg'). This also reveals that when no green spaces is provided, 2.3 g/kg' of humidity change occurs, and when green space is provided, 0.6 g/kg change occurnd 4(1.8 m/s), which leads to a conclusion that daily average wind velocity is reduced by 0.5 m/s per new building construction in a building complex.
9.
2012.01
서비스 종료(열람 제한)
This study was divided to three experiments for evaluating the effects of pre- or post-load 1-MCP on quality of ‘Fuji’ apples exposed to ethylene. The first experiment was compared for fruit quality at room temperature at 7, 14, 21, and 28 days between the control and 1-MCP-treated fruits followed storage of 130, 150, and 170 days. 1-MCP-treated fruits maintained higher fruit titratable acidity and firmness than those of control fruits. The second experiment was compared for fruit quality at room temperature at 7, 14, 21, and 28 days between fruits applied with pre-loaded-1-MCP on ethylene treatments (10 μL/L, 20 μL/L, and 40 μL/L) and control fruits. 1-MCP-treated fruits were not affected by ethylene concentrations, and had higher fruit weight and firmness than those of control. The third experiment was compared for fruit quality at room temperature at 7, 14, 21, and 28 days between fruits applied with pre-loading with ethylene (10 μL/L) followed by ventilation (8 h, or 32 h, or 56 h) and 1.0 μL/L 1-MCP treatment. As observed above experiments, 1-MCP-treated fruits had higher fruit weight and firmness than those of control fruits, regardless of the delayed applications of 1-MCP.
10.
2012.01
서비스 종료(열람 제한)
The rate of photosynthesis (A) of leaves from 10 plant species (6 evergreen and 4 deciduous) of the family Fagaceae was measured using a portable photosynthesis analyzer, to examine which species take up CO2 most efficiently. Of the evergreen species, the photosynthetic rate of Castanopsis cuspidata var. sieboldii was highest, and remained above 82.1～106.4 μmol kg-1s-1 from July to November. Of the deciduous species, the photosynthetic rate of Quercus acutissima was higher than that of the other three species, and remained high at 83.5～116.6 μmol kg-1s-1 from September to November. The photosynthetic rate of the 10 species was positively correlated with stomatal conductance (gs) and transpiration rate (E). However, there was no correlation between photosynthetic rate and intercellular CO2 concentration (Ci), although there was a positive correlation just in three species (Q. gilva, Q. acutissima and Q. glauca). These results suggest that the CO2 fixation capacity of C. cuspidata var. sieboldii, an evergreen species, and Q. acutissima, a deciduous species, is significantly higher than that of the other species examined, and that photosynthesis is regulated by both stomatal conductance and transpiration. Therefore, C. cuspidata var. sieboldii and Q. acutissima may be valuable for the evaluation of carbon uptake in urban green spaces as well as in afforested areas.
11.
2012.01
서비스 종료(열람 제한)
Suspended wood waste was being inflow into the dam and the problem of waste disposal has been occurred. In this study, ethanol production using woody floater wastes was performed to estimate value in use for raw material of renewable energy. To achieve the goal, experiments of acid hydrolysis and ethanol fermentation using dam woody floater as raw materials for bioethanol was carried out.
In the results of field survey in the chungju dam, kind of woody floater was mainly Japanese larch (Larix leptolepis) and hybrid poplar (Populus tomentiglandulosa). The results of sugar extraction showed that sugar content was higher in Larix leptolepis than Populus tomentiglandulosa. Extracted sugar from wood waste was effective consumed by yeast(P. Stipitis and S cerevisiae). In the experiment consumption of sugar including glucose, galactose and xylose, the consumption rate of S. cerevisiae is faster than that of P. stipitis. and efficiency for ethanol production is higer in S. cerevisiae than P. stipitis. Also it can be confirmed that resource as ethanol production using wood waste was available.
연구노트
12.
2012.01
서비스 종료(열람 제한)
The effects of substrate size on the growth of microphytobenthos Achnanthes sp., Amphora sp., Navicula sp. and Nitzschia sp. were examined using glass beads in order for phytoremediation in the benthic layer of coastal waters. The glass beads used in this study were 0.09～0.15 mm (G.B 1), 0.25～0.50 mm (G.B 2), 0.75～1.00 mm (G.B 3) and 1.25～1.65 mm (G.B 4). No addition of glass bead used as control. The specific growth rate and maximum cell density of four microphytobenthos species were increasing with decreasing size of glass beads. Moreover, the control experiment without added attachment substrates showed the lowest specific growth rate and maximum cell density. Therefore, the suitable attachment substrates for mass culture of microphytobenthos seems to be important in order for phytoremediation using microphytobenthos.
해설
13.
2012.01
서비스 종료(열람 제한)
A unit emission reduction of nitrous oxide (N2O) from anthropogenic sources is equivalent to a 310-unit CO2 emission reduction because the N2O has the global warming potential (GWP) of 310. This greatly promoted very active development and commercialization of catalysts to control N2O emissions from large-scale stationary sources, representatively nitric acid production plants, and numerous catalytic systems have been proposed for the N2O reduction to date and here designated to Options A to C with respect to in-duct-application scenarios. Whether or not these Options are suitable for N2O emissions control in nitric acid industries is primarily determined by positions of them being operated in nitric acid plants, which is mainly due to the difference in gas temperatures, compositions and pressures. The Option A being installed in the NH3 oxidation reactor requires catalysts that have very strong thermal stability and high selectivity, while the Option B technologies are operated between the NO2 absorption column and the gas expander and catalysts with medium thermal stability, good water tolerance and strong hydrothermal stability are applicable for this option. Catalysts for the Option C, that is positioned after the gas expander thereby having the lowest gas temperatures and pressure, should possess high deN2O performance and excellent water tolerance under such conditions. Consequently, each deN2O technology has different opportunities in nitric acid production plants and the best solution needs to be chosen considering the process requirements.
