• Title/Summary/Keyword: 퇴수시간

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Improvement of sampling method for bacteriological test in tap water (수도꼭지에서 미생물 검사 목적의 샘플링 방법 개선 연구)

  • Lee, Eun-Sook;Lee, Dong-Sik;Lee, Mok-Young;Lee, Man-Ho;Han, Sun-Hee
    • Journal of Korean Society of Water and Wastewater
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    • v.25 no.4
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    • pp.519-525
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    • 2011
  • We studied on the effect of faucet cleanliness, faucet conditions (screen, mixing faucet), and flushing time for bacterial detection in tap water. As results, tap water should be left to run to waste for 2 to 3 minutes and if a questionable cleanliness is questionable, disinfect the faucet by using flaming or other methods before sampling. We proposed sampling method to decrease effect of factors associated with bacterial detection in tap water and contributed to be evaluated more accurate water quality.

Effect of Overhead Flooding Stress on Photosynthesis and Growth in Rice (벼의 관수기간 및 수질이 광합성과 생육에 미치는 영향)

  • 이상각;강병화
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.46 no.3
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    • pp.209-214
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    • 2001
  • Physiological responses of rice to the flooding time of different water turbidity (clear water, sub-muddy water, muddy water) were analyzed as photosynthesis, chlorophyll fluorescence, transpiration, and physiological recovery. Photosynthetic rate was higher as turbidity increased and decreased as flooding time was extended. Floodings of 36 hrs and 42 hrs were resulted in 25% and 50% decrease of photosynthetic rate, respectively. Transpiration rate was higher in high turbidity (increased 30%, 25%, and 20% in clear, sub-muddy, and muddy water, respectively) and in increased floodings. Fv/Fm decreased as increased turbidity and flooding time. About 20% decrease of Fv/Fm was recorded in 48 hrs and 36 hrs after flooding with clear water and sub-muddy water(including muddy water), respectively. Total nitrogen was decreased with flooding treatment. Significant decrease of total nitrogen was occurred 36 hrs after flooding with muddy water, Dry weight measured 2 weeks after flooding treatment as an indication of recovery of flooding stress didn't show significant difference with turbidity, but significantly decreased as flooding time was prolonged. About 25% and 50% decreases were found in 24 hrs and 42 hrs flooding time, respectively. furthermore, 48 hrs of flooding with sub-muddy and muddy water resulted in no physiological recovery. Photosynthetic rate was decreased 15% and 10% with clear water and muddy water(including sub-muddy water), respectively. The rate was dramatically decreased 42 hrs after flooding. Transpiration rate increased about 20% regardless of turbidity and flooding time. We found transitory decrease of photosynthetic and transpiration rate at the point of 24 hrs after flooding and right after do-flooding.

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