• 제목/요약/키워드: Water transparency

검색결과 221건 처리시간 0.023초

시스템 다이나믹스를 이용한 투명성의 수도사업에 대한 영향 분석 (Analyzing Effects of Transparency on a Water Business Case Using System Dynamics)

  • 이상은;김현옥;박희경
    • 상하수도학회지
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    • 제20권4호
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    • pp.605-616
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    • 2006
  • This study focused on analyzing effects of transparency on the water system specifically and quantitatively. It was observed that transparency can give a water utility considerable motives for improving its performance and make the service price meet the production cost. System simulation made sure that these functions of transparency will eventually result in the better service for customers and the more favorable finance for a water utility. Results of this study can help some decision makers and utilities to sort out positive countermeasure for improving transparency.

The Relationship Between the Water Color and the Transparency in the Seas Around Korea

  • Hahn, Sangbok
    • 한국해양학회지
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    • 제3권2호
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    • pp.55-62
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    • 1968
  • The distributions of average water color and the transparency in the seas around Korea show two patterns: the one is the East Sea and the South Ses, the other is the Yellow Sea. In the East Sea and the South Sea, the water colors C$\sub$E/ in Forel scales change from green to greenish blue with distance x in miles from the seashore, an average color is bluish green, 3.7 in Forel scales, and the relationship is given by C$\sub$E/ = 5e$\^$-0.056.root.x; an average transparency is 15m and the transparency T$\sub$E/ shows following formula with distance x, E$\sub$E/=0.9.root.x+10. In the Yellow Sea, the water color C$\sub$Y/ changes from green yellow to bluish green with distance, an average color is light green, 5.6 in Forel scales, and the relationship is given by C$\sub$Y/= 8.5e$\^$-0.086.root.x; an average transparency is 7m, the farther it is from the seashore, the deeper transparency T$\sub$Y/ is as following, T$\sub$Y/=1.2 .root.x+1. Along the seashore, the transparency T$\sub$Y/ is only 10% that of the East Sea and the South Sea. The distributions of the water color and the transparency by depth change in values within the continental shelf. The water color in Forel scales decreases with the distance from the seashore and depth; the transparency increases with the distance and depth. They are caused by suspended particles, especially suspended clay, and it is the major factor in the change in color and transparency, particularly in the Yellow Sea. In September, the sea water is the clearest in the seas around Korea, transparency shows the maximum and water color the minimum in forel scales. The water color shows green yellow when transparency is 1m, green at 10m, and greenish blue at 20m. the relationship between the water color and the transparency shows an exponential distribution as following, C=9e$\^$-kT/, k=0.0625m$\^$-1/. This formula agrees with calculated formulas between the water color and the transparency from the emprircal formulas C$\sub$E/ and T$\sub$E/, C$\sub$Y/ and T$\sub$Y.

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득량만의 조석주기 및 계절변동에 따른 투명도의 변동특성 (The Transparency Variation According to Tidal and Seasonal Variation in Deukryang Bay , 1995 and 1996)

  • 이병걸;조규대;최용규
    • 수산해양기술연구
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    • 제32권4호
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    • pp.386-394
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    • 1996
  • The temporal variations of the transparency with water temperature, salinity and density during spring-neap tidal cycle of spring, summer, autumn and winter time were investigated at 34 stations using observation data in Deukryang Bay, Korea, in 1995. It was found that the transparency was depended on spread of tidal currents and vertical stratification of water. The depth of transparency during neap tide was deeper than that of spring tide. The value of transparency in summer was the largest among four seasons. We concluded that the vertical stratification intensity of water mass and vertical distribution of transparency.

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축열과 채광조절을 겸한 자연형 태양열 수벽시스템의 집열방식별 성능실험 (Experiment on measures of heat collection for passive solar water wall systems that provide heat storage and natural lighting control)

  • 오영훈;최지은;이철성;윤종호
    • KIEAE Journal
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    • 제16권4호
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    • pp.63-69
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    • 2016
  • Purpose: This preliminary study investigated a potential of the water wall systems that provide heat storage and natural lighting control simultaneously. Method: In order for transparency of the water wall to be controlled, the study first proposed two measures: to adjust transparency of the water wall; to control transparency of water wall surface. The performance of two measures then was verified and compared by experiments. In addition, a trade-off between heat collect and heat storage resulting from using additive for adjusting transparency was investigated. Result: The experiment showed that the two measures are similar in performance. The investigation of trade-off relation showed the additive should have the same heat storage as the water to prevent decrease in thermal performance of the water wall. As an economical measure to control transparency of the water wall, this study suggested a measure of secondary heat transfer systems using shading device that first absorbs solar radiation and then transfers heat to the water wall. The experiment show that performance of the proposed measure is similar to controlling transparency of water wall surface. In conclusion, it is expected that the performance of the water wall can be economically maximized by using the proposed mean in terms of heating, cooling and lighting energy saving.

Effect of Particle Size Distribution of Glass Frit on the Transparency of Transparent Dielectric Layer for Plasma Display Panel

  • Park, Ji-Su;Han, Sun-Mi;Hwang, Jong-Hee;Lim, Tae-Young;Kim, Kwang-Jin;Masaki, Takaki
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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    • pp.555-557
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    • 2004
  • We report the effect of the particle size (D50) and PSD (Particle Size Distribution) of glass frit on the transparency of transparent dielectric layer of PDP. The milling efficiency of wet milling with water was the best among the dry milling, wet milling with IPA and wet milling with water. The transparency increased with the reduction of particle size of glass frit as the milling time increased. Also the transparency changed by the PSD of glass frit. Glass frits of broad PSD showed high transparency compared with the glass frits of sharp PSD.

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수영만 해황의 계절적 변동 특성 (Seasonal Variation of Oceanic Conditions in Suyoung Bay)

  • 김동선;조규대;이병걸
    • 수산해양기술연구
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    • 제27권2호
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    • pp.105-119
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    • 1991
  • In order to study the seasonal variation in the physical properites in Suyoung Bay, we investigated the distributions of temperature, salinity, transparency and water color from May 1989 to April 1990. We also observed the tidal currents from February 27 to March 6 1990. There are conspicuous seasonal variation in water temperature and salinity. Water masses are characterized by two water types, i.e., one is influenced principally by river runoff and the other by the Tsushima Current. Transparency and water color increased gradually from the head of the bay to the mouth of the bay in all seasons. In winter, the transparency of water becomes minimum due to the enhanced vertical mixing.

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해수의 광학적 성질에 관한 연구 ( 1 ) - 부산근해의 하계 및 추계변화 (Optical Properties of Sea Water 1 Variation of the Coastal Sea Water Near Busan in Summer and Autumn)

  • 양용림
    • 수산해양기술연구
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    • 제11권1호
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    • pp.8-14
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    • 1975
  • The optical properties of the sea water were studied by use of underwater lux-meters in the coastal waters of Busan from May to November 1975. The absorption coefficient of the sea water in the area ranges from O. 169 to 1. 049 and the mean absorpflOn coefficient is 0.413. Maximum monthly mean absorption coefficient (0. 56) was observed in August, while the minimum was O. 338 in September. There was a distinct discontinuity layer of the absorption coefficient in accordance with the thermocline and the halocline in summer. The mean transparency of the area was 3. 8 meters, and transparency in autumn was higher than that in summer. The relation between absorption coefficient (m) and transparency (D) was deduced, m=1. 57/ D. The rate of light penetration at 5 m-layer of sea water was 2. 5 percent when the solar altitude was six degree in July 1975.

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마산만의 투명도 변동 (Variations of Secchi Depth in Coastal Water, Masan Bay in Korea)

  • 염말구;정연수
    • 수산해양기술연구
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    • 제39권1호
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    • pp.44-49
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    • 2003
  • 1995년부터 2002 년까지 마산만의 4개 정점에서 3-4개윌 간격으로 관측한 투명도 자료를 정리하여 다음과 같은 결과를 얻었다. 1) 4개 정점에서 각각 33회씩 관측한 자료에서 투명도의 범위는 0.2∼7.2m 이었고 , 평균은 2.4m이었으며 변동계수는 60%이었다. 평균은 만의 외해쪽으로 갈수록 증가하였고, 변동계수는 만의 안쪽으로 갈수록 큰 경향을 보였다. 2) 투명도의 월평균은 4월과 7 월에 비교적 낮고, 10 월 이후에 높게 나타났다. 3) 계절평균은 봄과 여름에 유사한 수준으로 낮고, 가을과 겨울에 높은 경향을 보였으며, 변동계수는 봄에 가장 크고 다음이 여름이며, 가을과 겨울은 같은 수준을 나타내었다. 4) 연평균은 4개의 정점에서 모두 1995년과 1998년에 낮은 값을 보였으며, 변동계수는 1996년과 1998년 및 2002년에 정점별 차이가 작게 나타났다. 5) 정점간의 상관성 검토에서 Sl 과 S4 정점의 투명도 변화가 다른 정점과 구별되었다. Sl 의 유별성은 지리적 특성에 기인하며, S4 의 유별성은 방류수와 관련이 있을 것으로 추정된다.

$TiO_2-SiO_2$ 이성분계 Aerogel의 광학적 투명성과 미세구조 (Optical Transparency and Microstructure of $TiO_2-SiO_2$ Binary Aerogels)

  • 이종혁;최수영;김창은;김구대;이해욱
    • 한국세라믹학회지
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    • 제32권3호
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    • pp.321-330
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    • 1995
  • Homogeneous and monolithic TiO2-SiO2 binary aerogels were prepared by supercritical drying. Optical transparency was increased with adding acid catalyst during two step hydrolysis and with decreasing water content. These differences in optical transparency were related to microstructures of gel network formed through polycondensation reaction during supercritical drying process, rather than the final composition of aerogel.

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황해 남동해역 투명도의 계절 변화 (Seasonal Variation of Transparency in the Southeastern Yellow Sea)

  • 최용규;권정노
    • 한국수산과학회지
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    • 제31권3호
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    • pp.323-329
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    • 1998
  • 황해 남동해역 투명도의 계절변화를 보기 위하여, 25개년 ($1966\~1990$)간의 해양조사 연보를 이용하여 우리나라 서해의 격월별, 정점별 자료를 정리하였다. 투명도의 분포는 계절에 관계없이 등수심선과 유사하게 뚜렷한 동서 대비를 보이고 있었다. 수심이 얕은 연안역에서는 3m(2월)$\~$8m (8월)로 낮고, 수심이 깊은 외양역에서는 10m (2월)$\~$17m (8월)로 높다. 겨울철 ($12\~2$월)은 투명도가 $\4m~10m$의 범위로, 여름철 ($6\~8$월)의 $6m\~17m$ 보다 낮다. 또한 부유 물질의 농도를 보면, 2월에는 $20\~120mg/\ell$이고 8월에는 $8\~20mg/\ell$의 범위였다. 성층과 투명도와의 관련성을 보면, TR(투명도)=0.61 DT(성층)+6.90, r=0.85로 양의 상관을 보이고, 정선 309에서 겨울의 보퍼트 풍력 계급은 약 3.5 내외로 여름보다도 약 1계급 이상 높은 값을 보였다. 이와 같은 사실들은 황해 남동해역에서의 투명도의 계절 변화는 겨울의 경우, 해수면 냉각과 바람에 의한 상하층 연직 혼합으로 저층 퇴적물의 재부유가 활발하여 투명도가 낮게 나타난다. 그리고 여름에는 해수면 가열에 의해서. 상하층 사이에 형성되는 수온 혹은 밀도 약층과 조석 혼합을 방해하는 태양 복사열의 증가로 인하여 저층 퇴적물의 재부유가 방해되어. 투명도가 높게 됨을 나타내고 있다.

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