• Title/Summary/Keyword: outflow

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Nutrient Behavior at Paddy Field Area with Large-Scaled Plots during Irrigation Periods (관개기 대구획 광역논에서의 영양물질 거동)

  • Oh, Seung-Young;Kim, Jin-Soo;Jung, Gu-Young
    • Proceedings of the Korea Water Resources Association Conference
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    • 2005.05b
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    • pp.1254-1258
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    • 2005
  • Net outflow flux and unit load of pollutants were investigated at a paddy fields area(Soro-ri) with large-scaled plots on loam soil during irrigation seasons of $2001\~2003$. Water samples were collected, and inflow and outflow were .measured at $5\~10$ day intervals during non-storm periods and at $2\~6$ hours intervals during storm events. The average concentration of TP in percolated water was much smaller than that in irrigation and surface outflow water likely due to phosphorus absorption capacity of paddy soils. Net outflow flux in study area was significantly correlated with rainfall and surface outflow discharge. Nutrient flux from Paddy fields can be abated by reduction in outflow surface discharge.

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Changes of Outflow with Time Varied Monthly Rainfall Data (월강우의 시간분포에 따른 유출량 변화)

  • Hwang, Man-Ha;Kang, Shin-Uk
    • Proceedings of the Korea Water Resources Association Conference
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    • 2007.05a
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    • pp.1967-1971
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    • 2007
  • In general, outflow is larger with rainfall but it is various in the initial moisture condition of basin and condition of rainfall distribution in both time and space. In this study, changes of outflow with time varied rainfall data were analyzed in the basin in which the moisture distribution is constant. Outflow differences with rainfall intensive of first period, middle period, and last period of month are 6.1% in January, 7.8% in February, 9.8% in March, 22.6% in April, 15.7% in May, 19.1% in June, 22.6% in July, 22.4% in August, and 16.8% in september respectably. The results show that 10 days outflow differences are ranged from 6.1% to 22.6% under the constant moisture condition, Outflow differences in the flood seasons are larger than them in the drought seasons.

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The characteristics of radial consolidation & permeability on the inflow & outflow condition (내.외향류 방사형 압밀/투수 특성에 관한 연구)

  • 천홍래;김지용;김수삼
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.10a
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    • pp.109-116
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    • 1999
  • This study is to make clear for the characteristics of radial drainage consolidation/permeability At the result of the radial drainage consolidation / permeability test, the permeability of outflow drainage condition is higher than Inflow drainage condition and the time for the end of consolidation, outflow drainage condition is shorter than inflow drainage condition. So drainage area ratio test and control of hydraulic gradient test are carry out to analysis this result. Finally, compared with the characteristics on the condition of inflow and outflow permeability and consolidation.

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A Study on Outflow and Pollutant Loading in Nam River Dam Basins (남강댐 유역의 유출량과 오염부하량 연구)

  • Kim, Jong-Oh;Kim, Ok-Sun;Kim, Hong-Chul
    • Journal of Wetlands Research
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    • v.2 no.1
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    • pp.87-94
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    • 2000
  • The purpose of this study was to analysis the pollutant loading of Chin yang Reservoir according to the variation of outflow. Regression equation of the pollutant loading and outflow was represented as $L=a\;Q^b$ in which L = pollutant loading(kg/day), a and b = regression coefficient, and Q = outflow($m^3/day$). Regression coefficients ($R^2$) of Sanchung, Sinan and Changchon site was in range of 0.8376 to 0.9818. Therefore the pollutant loading was good correlated with outflow. Changchon site had minimum b value because outflow of pollutant was little compared with rainfall. The SS was the highest b value 1.621~1.7834 among water quality parameters because the pollutant loading of SS was much affected by outflow. Also, the pollutant loadings per area could be calculated and compared in case of the dry season, normal season and flood season. The pollutant loading in the normal and flood season except the dry season were higher in order of Sanchung, Sinan and Changchon site. Pollutant loading per area were higher in order of Sinan, Sanchung and Changchon site. When it compared with pollutant loading per area calculated using pollutant unit loading, T-N was much different each other.

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A Study on the Prediction of Outflow of Groundwater in Tunnel Construction Areas (터널 굴착시 발생하는 지하수의 유출량 예측에 관한 연구)

  • Park, Sun Hwan;Chang, Yoon Young;Kang, Hyung Sik;Choi, Joon Gyu;Yang, Keun Ho
    • Journal of Environmental Impact Assessment
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    • v.16 no.6
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    • pp.407-419
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    • 2007
  • This study investigated the predicted and abserved outflow of groundwater which occurred during tunnel constructions. Among the 586 road construction projects from 1986 to 2006, 4 route 25 tunnel construction areas and 26 waste water treatment facilities under construction were studied. Most of the tunnel outflow prediction in EIA (Environmental Impact Assessment) process have been classified into the 17 types of units depending on the assessor's options, which have not conformed to the request of the residents and non government organizations. The investigation results showed that the outflow of underground water in tunnel construction areas averaged about $0.133m^3/km{\cdot}min$ with the maximum $0.386m^3/km{\cdot}min$, and that the outflow mostly occurred in the early stage of tunnel excavation and diminished gradually. The prediction of outflow of underground water in the EIA process showed excessive results compared to observed outflow, the even 51.7 times. Consequently for more realistic prediction, current EIA method for prediction of outflow of underground water in tunnel construction areas has to adopt numerical methods coupled with hydraulics and geologic informations from unit methods of present time.

Sap Outflow Characteristics of Walnut Tree (Juglans sinensis Dode) (호두나무 수액의 유출특성)

  • Kim, Chul-Woo;Kim, Mahn-Jo;Park, Youngki
    • Korean Journal of Plant Resources
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    • v.27 no.2
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    • pp.188-193
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    • 2014
  • The sap outflow characteristics of Juglans sinensis and J. mandshurica were investigated to evaluate the optimum pruning period of walnut tree that there is a sap spill on dormant. The total period of sap outflow were 34 days for both J. sinensis and J. mandshurica. Total amount of sap outflow per tree in J. sinensis and J. mandshurica were 2,922 mL/tree and 3,135 mL/tree, respectively and the period of sap outflow and non sap outflow between two species were similar. ANOVA analysis showed that the amount of sap outflow was significant differences with day of sap outflow but there were no significant differences between species. From the correlation analysis between air-temperature and sap outflow, daily minimum temperature showed a positive correlation at the 1% level of significance (r=0.56 and r=0.46) for both J. sinensis and J. mandshurica. When branch of walnut tree that diameter is 5 cm cut on the period of sap outflow, the sap flowed down the longest period (48 days) but the sap outflow was not observed after budburst. Therefore, our study supported that the pruning have to avoid the period of sap outflow to reduce sap outflow of walnut tree.

Runoff of Pollutant Loads from Paddy Field Area in a Dry Year (갈수년 광역논에서의 오염부하의 유출 특성)

  • Oh, Seung-Young;Kim, Jin-Soo
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2002.10a
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    • pp.385-388
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    • 2002
  • We investigated net outflow load and unit load of pollutants from a paddy fields area in dry year 2001. Amount of irrigation water in 2001 was about 61-63% of that in previous years 1999 and 2000 due to drought. The net outflow load and unit load of pollutants in 2001 were negative, showing that paddy fields acts as sink of pollutants due to function of water quality purification. The relationship between unit load of pollutants and net surface outflow (= surface outflow - irrigation water) showed positive correlation. The results showed that abatement of surface outflow by appropriate water management contribute to reduce surface outflow load from paddy fields.

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Gas outflow in BLR of low-redshift AGNs

  • Shin, Jaejin;Woo, Jong-Hak;Nagao, Tohru
    • The Bulletin of The Korean Astronomical Society
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    • v.39 no.2
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    • pp.59.1-59.1
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    • 2014
  • AGN feedback has been believed as playing an important role in the galaxy-super massive black hole (SMBH) co-evolution. AGN gas outflow can lead to AGN feedback. We investigate gas outflow of low-redshift AGNs by using blue shift/asymmetric index (BAI), and velocity offset of CIV line. By comparing these gas outflow indicators (BAI and velocity offset) to AGN properties (i.e., SMBH mass, bolometric luminosity, and Eddington ratio) and BLR gas metallicity, we find positive correlations among outflow, Eddington ratio, and metallicity. These relations are consistent with those observed at high-redshift. We discuss the possibility of the connection between previous star formation with current AGN accretion and outflow.

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A Note on the Outflow Boundary Conditions in Modeling the East Sea Circulation

  • Seung, Young-Ho;Cho, Kyoung-Ho
    • Journal of the korean society of oceanography
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    • v.33 no.4
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    • pp.212-218
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    • 1998
  • Three different outflow boundary conditions are considered in modeling the East Sea circulation. The first one is that of the conventional constant volume transport (CT). The second one is the Orlanski radiation boundary condition (OR). The third one is that of the constant sea level just outside the outflow boundary (SL). In the third condition, the outflow current is set to be driven by the sea level differences across the outflow open-boundary lines, based on the recent knowledge that the Tsushima Current is driven by the sea level differences across the inflow and outflow boundaries. In case of OR it takes too much time to reach the steady state, resulting in a large increase of Tsushima Current Water in the basin and low level of kinetic energy. Both CT and SL reach the steady state in a relatively short time. However, SL is more recommendable, because it is based on physical background and generates less numerical noises than CT.

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Physical modelling of a downdraft outflow with a slot jet

  • Lin, W.E.;Savory, E.
    • Wind and Structures
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    • v.13 no.5
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    • pp.385-412
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    • 2010
  • This article provides a time-resolved characterisation of the wind field in a recently-commissioned, downdraft outflow simulator at The University of Western Ontario. A large slot jet approach to physical simulation was used. The simulator performance was assessed against field observations from a 2002 downdraft outflow near Lubbock, Texas. Outflow wind speed records were decomposed according to classical time series analysis. Length scales, characterising the coarse and fine flow structure, were determined from the time-varying mean and residual components, respectively. The simulated downdraft outflow was approximately 1200 times smaller in spatial extent than the 2002 Lubbock event.