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
제28권 제9호 (2019년 9월) 8건
ORIGINAL ARTICLE
1.
2019.09
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In this study, the effect on the stability of Aerobic Granular Sludge (AGS) with different Carbon/Nitrogen (C/N) ratios was investigated. The C/N ratios were controlled to 10.0, 7.5, 5.0, and 2.5 using the sequencing batch reactor, and the results showed that the removal efficiency of organic matter and total nitrogen decreased simultaneously with the decrease of C/N ratio. The removal efficiency of organic matter and total nitrogen at C/N ratio of 2.5 was 70.7% and 52.3% respectively. In addition, the AGS/mixed liquor suspended solids (MLSS) ratio showed a tendency to decrease from 85.7% to 73.7%, while the sludge volume index showed a tendency to increase from 82 mL/g to 102 mL/g as the C/N ratio decreased. At the same time, the apparent deviation of polysaccharide (PS) content in extracellular polymeric substances was observed, and polysaccharides/protein (PS/PN) ratio decreased from 0.62 to 0.31 as the C/N ratio decreased. Optical microscope observations showed that the reduction in C/N ratio caused the growth of filamentous bacteria and significantly affected the stability of AGS.
2.
2019.09
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The aim of this study was to determine the effects of different compositions of environmental substrates on hydroponic tomato cultivation. Three different substrates were used in coir chip:dust (v/v=50:50; CP1), coir chip:dust (v/v=80:20; CP2), and rock wool cube with CP2 (CPR). The amount of irrigation during the cultivation period was 190 mL/(plant·time) in all substrates. The pH and EC were 5.8-6.2 and 2.6-2.9 dS/m, respectively. The drainage rate in CP1 was 31%, in CP2 was 36%, and in CPR was 29%. The growth of tomato plants in terms of height was higher in CP1 and CPR. The leaf area was greater in CP2. The fresh and dry weights were greater in CP2 and CPR treatments. The net photosynthesis in CP2 (19.31 μmol CO2/m2s) and root activity in CP2 were higher among all three treatments. The soluble solid content of fruit was not significantly different among treatments. The yield per plant in CP2 and CPR treatments was 17% greater than the yield per plant in CP1. Therefore, the most suitable substrate for hydroponic tomato cultivation is the substrate mixed with coir chip:dust (v:v=80:20; CP2), i.e., CPR.
3.
2019.09
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In this study, the sensitivity analysis of hydraulic conductivity and separation distance (distance between injection well and pumping well) was analyzed by establishing a conceptual model considering the hydrogeologic characteristics of facility agricultural complex in Korea. In the conceptual model, natural characteristics (topography and geology, precipitation, hydraulic conductivity, etc.) and artificial characteristics (separation distance from injection well to pumping well, injection rate and pumping rate, etc.) is entered, and sensitivity analysis was performed 12 scenarios using a combination of hydraulic conductivity (10-1 cm/sec, 10-2 cm/sec, 10-3 cm/sec, 10-4 cm/sec) and separation distance (10 m, 50 m, 100 m). Groundwater drawdown at the monitoring well was increased as the hydraulic conductivity decreased and the separation distance increased. From the regression analysis of groundwater drawdown as a hydraulic conductivity at the same separation distance, it was found that the groundwater level fluctuation of artificial recharge aquifer was dominantly influenced by hydraulic conductivity. In the condition that the hydraulic conductivity of artificial recharge aquifer was 10-2 cm/sec or more, the radius of influence of groundwater level was within 20 m, but In the condition that the hydraulic conductivity is 10-3 cm/sec or less, it is confirmed that the radius of influence of groundwater increases sharply as the separation distance increases.
4.
2019.09
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National parks, which are preserved areas of 6,726.298 km2(3,972.589 km2 on land and 2,753.709 km2, at sea), take up 6.71% of the national territory, and they are classified by type into 17 mountain parks, 4 maritime or coastal parks, and 1 historical site park. Of them all, the maritime or coastal national parks, which are preserved areas covering wide tracts of maritime, lately attract increasing numbers of visitors. In this light, this study identifies the issues with the maritime or coastal national parks such as the changes in the number of visitors and the unbalance involved in the budget execution, based on the visitors to the national parks and the specifics of budget executed for them. On this basis, the study has conducted the research with a view to suggesting improvements for more useful management and operation of the maritime or coastal national parks. As a result, the study has reached the following conclusions. First, to accommodate those who want to visit the maritime or coastal national parks, the tour infrastructure needs to be expanded to guide the visitors’ use of the facilities by focusing on their touring behavior and characteristics. Second, budget should be acquired through diversifying revenue structure to eliminate hugely unbalanced budget. Third, visitors nowadays come to national parks for recreational experience or to tour nature, but the maritime or coastal national parks focus on cultural facilities. To accommodate the visitors’ needs, the parks should get diversified visitor facilities that reflect the regional characteristics.
5.
2019.09
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The synoptic structural characteristics associated with heavy snowfall (Bukgangneung: 31.3 cm) that occurred in the Yeongdong area on 20 January 2017 was investigated using surface and upper-level weather charts, European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis data, radiosonde data, and Moderate Resolution Imaging Spectroradiometer (MODIS) cloud product. The cold dome and warm trough of approximately 500 hPa appeared with tropopause folding. As a result, cold and dry air penetrated into the middle and upper levels. At this time, the enhanced cyclonic potential vorticity caused strong baroclinicity, resulting in the sudden development of low pressure at the surface. Under the synoptic structure, localized heavy snowfall occurred in the Yeongdong area within a short time. These results can be confirmed from the vertical analysis of radiosonde data and the characteristics of the MODIS cloud product.
6.
2019.09
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In order to analyze the sensitivity of carbon dioxide flux by soil temperature in the grassplot, carbon dioxide flux and soil temperature were observed 24 times from March, 2010 to March, 2011 at nine sites in the grassplot. The average of CO2 in the grassplot is 2.2~36.7℃, the highest in August, the lowest in January, and the average of carbon dioxide flux is 12~1479 mgCO2·m-2·hr-1, and the carbon dioxide emission from the grassplot to the atmosphere was 10 times higher in summer than in winter. The temperature response coefficient estimated by the exponential function of carbon dioxide flux according to soil temperature was ranged from 0.1065 to 0.1274, and the increase tendency of CO2 flux with soil temperature was linear at 0~2 0℃and exponential at 20~40℃. The Q10 values for each of nine observation sites on the grassplot was in the range of 2.901 ~ 3.575, and the Q10 value using the total data observed in the lawn was estimated to be 3.374. In the homogeneous grassplot area, the average of Q10 values by observation point and the Q10 value by the total data were estimated similarly.
7.
2019.09
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The purposes of this study are to comprehend the importance of policy in improving the operation of the public arboretum and survey the program satisfaction of participants and operators based on the case of the Daegu arboretum. According to the order of policy priority regarding the Daegu arboretum, the expansion of the education program topped the list with 0.155 points, followed by the establishment of a vision and goal, and the reestablishment of function, which scored 0.135 and 0.135 points, respectively. Fostering citizens’ participation through volunteer work was in the upper ranks with 0.131 points. Building networks among public arboretums and constructing a research cooperation system with universities turned up with 0.09 and 0.075 points. As the result of program satisfaction, participants’ satisfaction was around 0.66 points higher than that of operators’ satisfaction. In the case of participants, comprehensive satisfaction, including that with the program operation method, was very high at 4.85 points. Out of the entire program, the operators were the most satisfied with the benefits. This study aims to share improvement plans for public arboretums constructed in urban areas, analyzing policy priorities and satisfaction related to the Daegu arboretum. The results of this study can be utilized as data for the improvement plans of public arboretums. If improvement plans for public arboretums are modeled with other follow-up case studies, it will help ensure that public arboretums become evolving rather than fixed areas for citizens.
SHORT COMMUNICATION
8.
2019.09
서비스 종료(열람 제한)
The present study aimed to examine the effects of dietary illite as a feed additive on the Haugh unit and fatty acid profiles of eggs. One hundred and twenty laying hens (48-week-old Hy-line Brown) were randomly assigned to one of the following two treatments: control or 2% illite powder. At 2 and 4 weeks, the Haugh unit values between the control and 2% illite powder groups were not significantly different (p>0.05). In addition, individual fatty acid content at 2 and 4 weeks did not differ between the treatments (p>0.05), except for palmitic (C16:0) and palmitoleic acid (C16:1) content. The addition of 2% illite powder caused no difference between the total saturated and total unsaturated fatty acids at 2 and 4 weeks (p>0.05). In conclusion, the addition of dietary illite at a rate of 2% did not improve the Haugh unit values or fatty acid profiles of eggs.
