• Title/Summary/Keyword: Research environment

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Comparative Analysis of ADCP Flow Measurement According to River Bed Material (하상재료에 따른 ADCP의 유량측정 비교 분석)

  • Choi, Jin-Woo;Hong, Chang-Su;Shin, Kyung-Yong;Lee, Jin Uk;Kim, Jeong-ae;Cho, Yong-Chul;Yu, Soon-Ju
    • Ecology and Resilient Infrastructure
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    • v.5 no.3
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    • pp.156-162
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    • 2018
  • This research aimed at analyzing comparison results between in gravel and sand bed with respect to the detailed Acoustic Doppler Current Profiler (ADCP) measurement in a velocity, depth, and flow rate data based on Acoustic Doppler Velocimeter (ADV) measurement result. Conclusionally, similar results were shown for gravel and sand bed in velocity, depth and flow rate data using ADV and ADCP measurement. The results of the flow rate show a relative error mean of 3.5 - 4.8% in the gravel bed and 0.02 - 3.2% in the sand bed, which is better performance than the mean error of 5% suggested by United States Geological Survey (USGS). The results can be used as a basis data for the measurement of ADCP and potentially able to be utilized for the more detailed uncertainty analysis of ADCP flow rate measurement.

Operational Hydrological Forecast for the Nakdong River Basin Using HSPF Watershed Model (HSPF 유역모델을 이용한 낙동강유역 실시간 수문 유출 예측)

  • Shin, Changmin;Na, Eunye;Lee, Eunjeong;Kim, Dukgil;Min, Joong-Hyuk
    • Journal of Korean Society on Water Environment
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    • v.29 no.2
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    • pp.212-222
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    • 2013
  • A watershed model was constructed using Hydrological Simulation Program Fortran to quantitatively predict the stream flows at major tributaries of Nakdong River basin, Korea. The entire basin was divided into 32 segments to effectively account for spatial variations in meteorological data and land segment parameter values of each tributary. The model was calibrated at ten tributaries including main stream of the river for a three-year period (2008 to 2010). The deviation values (Dv) of runoff volumes for operational stream flow forecasting for a six month period (2012.1.2 to 2012.6.29) at the ten tributaries ranged from -38.1 to 23.6%, which is on average 7.8% higher than those of runoff volumes for model calibration (-12.5 to 8.2%). The increased prediction errors were mainly from the uncertainties of numerical weather prediction modeling; nevertheless the stream flow forecasting results presented in this study were in a good agreement with the measured data.

Characterization of Poly(acrylic acid) Hydrogel Containing Zinc Oxide Particle Prepared by Radiation (방사선을 이용하여 제조한 zinc oxide 입자 함유 poly(acrylic acid) 하이드로젤의 특성)

  • Park, Jong-Seok;Jeong, Sung-In;Shin, Young Min;Choi, Jong-Bae;Gwon, Hui-Jeong;Lim, Youn-Mook;Jeun, Joon-Pyo;Kim, Hyin-Bin;Oh, Seung-Hwan;Kang, Phil Hyun;Nho, Young-Chang
    • Journal of Radiation Industry
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    • v.6 no.2
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    • pp.153-158
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    • 2012
  • In this research, poly(acrylic acid) (PAAc) hydrogels containing zinc oxide particle were prepared by gamma-ray irradiation. PAAc powder was completely dissolved in distilled water at room temperature. Water-insoluble zinc oxide powder were added into the PAAc solution and stirred until totally dissolved. Finally, the mixture was irradiated by gamma-ray irradiation to make crosslinking. The effects of various parameters such as zinc ions' concentration, irradiation doses were varied and investigated in detail. PAAc hydrogels containing zinc oxide particle were characterized by gel content and swelling ratio. Moreover, the antibacterial properties of this material were evaluated by paper diffusion test against the Gram positive and Gram negative bacteria.

Efficiency Study of Measurement Method by Flow Duration (유황별 유속측정 방법에 따른 유효성 연구)

  • Ham, Sang In;Lee, Jeong Hwan;Kim, Dae Young;Ha, Don Woo;Kim, Yoon Soo;Jung, Kang-Young;Lee, Yeong Jae;Kim, Gyeong Hyeon;Kim, Young Suk
    • Journal of Korean Society on Water Environment
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    • v.34 no.5
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    • pp.462-469
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    • 2018
  • There are differences in method and cycle of flow rate survey depending on purpose of the operating department. To verify and use results of flow data according to the purpose, flow data of the directly measured and tele monitoring system were compared to verify validity. Flow measurement in the Ministry of Environment is aimed at setting up a standard flow of target water quality for water quality management and securing flow data of low and normal water level seasons for water quality evaluation. In this study, correlation analysis result ($R^2$) of same time zone data by direct measurement and tele monitoring system (TMS) at Seombon D point, a unit watershed of Seomjin river, for six years ('10 ~ '15) according to implementation of Total Daily Maximum Load (TDML) was wading 0.716, boating 0.962 and on bridge 0.943, and effectiveness of measurement method was verified by characteristics of flow duration as a season of dry and low-water; normal and high water are appropriate for wading, boating, and on bridge respectively. Results revealed it is reasonable to use directly measured results using the wading and boating method for low water level and dry seasons, and TMS data for rainy seasons. It can be used important data for future policy decisions.

The Growth and Nutrient Removal Efficiency of Hydrophytes at an Artificial Vegetation Island, Lake Paldang (팔당호 인공 수초재배섬에서 수생식물의 생장 및 영양염류 제거 효율)

  • Choi, Myeong-Jae;Byeon, Myeong-Seop;Park, Hae-Kyung;Jeon, Nam-Hui;Yoon, Suk-Hwan;Kong, Dong-Soo
    • Journal of Korean Society on Water Environment
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    • v.23 no.3
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    • pp.348-355
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    • 2007
  • We investigated temporal changes of composition, habitat area, growth rate and elements content of hydrophytes at the artificial vegetation island (AVI) in Kyungan Stream within Lake Paldang. We also assessed nutrient removal rate through cutting off the emergent part of hydrophytes. The kinds of hydrophytes have increased from four species (P. australis, P. japonica, T. angustifolia and the Z. latifolia) at initial stage of installation to more than 29 species for 6-year operation. P. japonica was most dominant species at the AVI in 2006. The habitat area of have increased about 2.5 times compared to the initial planting area, occupying 63% of AVI's vegetation area. The incoming species of S. fluviatilis and B. frondosa have adapted successively and expanded habitat area in the AVI. The relative growth rate of P. japonica and P. australis was highest in spring sprouting period. Their hights and weights have increased until summer, by the time they were cutting off the emergent part. They started regrowth immediately after cutting and continued to grow until September and withered away in November. The carbon contents of P. japonica and P. australis have increased during growth phase, on the contrary, the nitrogen and phosphorus contents have decreased. By cutting off and removing the emergent part (leaves and branches) of hydrophytes twice from AVI, $17.6gN/m^2/y$ of nitrogen and $1.3gP/m^2/y$ of phosphorus was removed from AVI in 2006.