• Journal of the korean society of oceanography
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• 제39권1호
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• pp.14-19
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• 2004

Difference of Dissolved Inorganic Phosphorus (DIP), Dissolved Inorganic Nitrogen (DIN) and Dissolved Silicate (DSi) budgets in the Bohai Sea between 1982 and 1992 related the decrease of the Yellow River discharge is discussed on the basis of observed data. The estuarine circulation in the Bohai Sea had been weakened from 1982 to 1992 due to the decrease of the Yellow River discharge and the average residence time of fresh water had become longer. DIN concentration increased but DIP and DSi concentrations decreased from 1982 to 1992 in the Bohai Sea. Primary production was regulated mainly by water temperature and DIN concentration in 1982 but it was regulated mainly by DIP concentration in 1992. Primary production was larger than decomposition plus bottom release and nitrogen fixation was larger than denitrification in 1982. However, decomposition plus bottom release was larger than primary production and denitrification was larger than nitrogen fixation in 1992 in the Bohai Sea.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 추계학술발표회
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• pp.355-358
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• 2002

A sediments are Integral called as gravel, sand, clay, mineral materials which are settling in bottom layer of reservoir, stream, and oceans from land. In practical problems relations of sediments are flood by decreed of flow capacity and down of water quality. Dredged sediments are composed with constructed material and variety of pollutant compounds. Therefore, it is very much of cost effects in nationally, if development for use of constructed material separated only constructed material within sediments. And it will be continue to the dredge operation of stream sediment for retrofit of water environment and sustainable's after the years. The following results could be obtained : In case of high concentration sediments, sample for design of CDF was shown property of flocculent settling. Assuming that average inflow rate is 1, 000㎥/hr, mean residence time( $T_{d}$), average ponding depth( $H_{pd}$ ), and design surface area for flocculent settling( $A_{df}$ ) were 5 hr, 0.6m, and 15, 750 $m^2$ respectivelyrespectivelyy

• 물과 미래
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• 제20권3호
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• pp.247-252
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• 1987

조정지로 유입되는 음부력흐름에 대한 거동이 수치적 방법으로 해석되었다. 조정지의 밀도류를 지배하는 매개변수는 유입밀도 Froude수, $Fr_e$이고, 조정지에서 오른쪽 낮은 구석과 가라앉은 유체의 흐름위에 와는 형성된다. 유입유체의 특성이 주어진다면 유출구에서의 온도, 조정지의 규모 및 유입유체의 체류시간을 알 수 있다.

• 한국안전학회지
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• 제8권2호
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• pp.44-50
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• 1993

The objective of this study was to investigate the extraction of chromium(Vl) ion in waste water through the liquid surfactant membrane with open-type Perforated Reciprocating-Plate Column. Extraction experiments were conducted to measure the effect of flow characteristics of continuous and dispersed phase and stroke velocity, sodium hydroxide concentraction in internal aqueous phase, sulfuric acid concentraction in outer phase, and residence time distribution and measured extraction velocity. The result of experiments showed that extraction velocity of chromium ion was maximum when stroke velocity was 180 1/min and dispersion phase velocity was 30m11min, continuous phase velocity was 20m1/min. Extraction velocity of chromium ion increased with increasing difference of hydrogen ion concentraction of dispersion and continuous phase and column stage decreased.

• Journal of the korean society of oceanography
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• 제36권3호
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• pp.59-71
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• 2001

In order to investigate the temporal variability of dissolved and particulate trace metals in the Han River, water samples were collected intermittently at two sites for 3 years (August 91 to December 94). Surface seawaters covering the range of salinity were also collected at the estuarine region to evaluate the role of estuary for the riverine fluxes of trace metals within the estuary during October 95 and 96. During the study period, dissolved metal concentrations in riverwaters varied by a factor of 5-10 for Fe, Ni, Co and Cu and 50-100 for Mn, Cd and Pb depending upon the water level; high concentration during the low water and low concentration in high water period except for Fe. The concentration of dissolved Fe increased with increasing water discharge. These concentration-discharge relationships of the studied trace metals are explained by the successive dilution of waters from two different origins, which can be presumably identified as anthropogenic discharges and watershed flushing. Although estuarine waters at early mixing region were not collected due to the difficulty of sampling, mixing behaviors of metals were inferred from the concentration-salinity relationships through the laboratory mixing experiment and field sampling, and distribution coefficients between dissolved and labile particulate phases. It is suggested that the Han River estuary plays a role of accumulating Fe, Mn, Co and Pb from riverine sources due to high turbidity caused by strong tidal current, whereas this system serves as a source of dissolved Cd due to release caused by extended residence time of riverine particles.

• 한국수산과학회지
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• 제33권3호
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• pp.205-212
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• 2000

공기 구동식, 고속 폭기식 및 벤튜리식 포말분리 장치를 동일한 용량으로 제작하여 양어장 순환수 중의 단백질,총 부유 고형물 및 탁도를 제거하는데 있어 각 포말 분리장치의 운전 특성을 알아보고자 하였다. 공기구동식 포말분리기의 유략감소가 거의 없었으나 벤튜리식 포말분리기는 $66.1{\%}$정도의 유량감소가 발생하였으며 고속 폭기식 포말분리기는 $77.2{\%}$의 유량감소가 발생하였다. 공기 구동식, 고속 폭기식 및 벤튜리식 포말분리 장치의 단백질 제거속도는 수력학적 체류시간이 증가함에 따라 지수적으로 감소 하였다. 0.32 분 이상의 수력학적 체류시간에서는 공기 구동식 포말분리장치의 제거속도와 제거율이 가장 높게 나타났으며 그 이하의 수력학적 체류시간에 대해서는 고속 폭기식 포말분리 장치의 제거속도와 제거율이 가장 높은 것으로 나타났다. 수력학적 체류시간의 변화에 따른 총 부유 고형물과 탁도의 제거속도와 제거율의 변화는 단백질 제거속도 및 제거율의 변화와 거의 비슷하였으며 벤튜리식 포말분리기는 짧은 수력학적 체류시간에서는 총 부유고형물의 제거 효율이 다른 두 포말분리기에 비해 떨어지는 것으로 나타났다. 탁도의 제거는 공기 구동식 포말 분리기가 가장 우수한 것으로 나타났다.

• 해양환경안전학회지
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• 제28권2호
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• pp.201-211
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• 2022

연구대상 해역은 노량수로를 중심으로 서측에 광양만 권역(여수해협 포함), 동측에 진주만 권역(강진만, 사천만 포함)이 위치하고, 연구대상 해역에 위치한 여러 하천에서 유출되는 유출수가 이들 만으로 유입되고 있으며, 특히 홍수시에는 광양만 권역은 섬진강의 하천유출수가, 진주만 권역은 가화천(남강댐 방류)의 하천유출수가 대량으로 유입되고 있다. 광양만 권역과 진주만 권역은 노량수로라는 협수로로 연결되어 있으며, 섬진강과 가화천의 하천유출수 또한 노량수로를 통해 서로 영향을 주고 있다. 연구대상 해역에 위치한 섬진강과 가화천을 포함한 51개 하천의 하천유출수로 인한 평수시와 50년빈도 홍수시의 해수교환율, 체류시간 특성을 입자추적 실험을 통해 파악하고자 하였다. 또한 홍수시 섬진강과 가화천의 하천유출수가 미치는 영향을 파악하기 위한 실험을 추가로 수행하였다. 수치실험 결과, 평수시와 홍수시 모두 광양만 권역에 투하한 입자는 노량수로를 통해 진주만 권역으로 이동하는 것으로 나타났고, 노량수로를 통해 진주만 권역에서 광양만 권역으로 이동하는 입자는 상대적으로 작은 것으로 나타났다. 30일 후 각 실험안별 해수교환율은 광양만 권역은 44.40~67.21%로 나타났고, 진주만 권역은 각각 50.37~73.10%로 나타났고, 각 실험안별 평균 체류시간은 광양만 권역은 7.07~15.36일로 나타났고, 진주만 권역은 6.45~12.75일로 나타났다. 그리고 홍수시에 해수교환을은 증가하고, 체류시간은 감소하는 것으로 나타났다. 광양만과 진주만 권역에서의 해수순환 구조를 살펴보기 위해 두 폐쇄성 해역에 대해서 7개 내부 영역과 5개 외부 영역에 대한 30일 동안의 단면유량 flux를 산정하였다. 그 결과, 평수시와 홍수시 모두 전반적으로 광양만 권역에서 진주만 권역으로 유량 flux가 이동하는 것으로 나타났다. 홍수시 유량을 적용할 경우 연구대상 해역의 유량 flux의 주 흐름 경로는 섬진강 하천유출수가 여수해협을 거쳐 외해로 이동하는 흐름과 가화천 하천유출수가 사천만, 진주만, 대방수로를 거쳐 외해로 이동하는 흐름으로 나타났다.

• 한국수산과학회지
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• 제32권2호
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• pp.180-185
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• 1999

본 연구에서는 양식장에서 많이 이용되고 있는 회전원판 반응기를 모의 순환 여과식 양어장에 적용하여 인공 양식수 처리 실험을 행하면서 어류의 최적 사육환경을 유지할 수 있는 운전인자를 도출하고자 하였다. 회전원판 반응기는 수리학적 체류시간이 감소하는 부하변동에대해 $5\~6$일 정도의 시간이 흐른 후 정상상태에 도달하였으며 수리학적 체류시간의 증가에 따라 모의 사육조의 암모니아 농도, 회전원판반응기의 암모니아성 질소 제거율 및 제거속도는 증가하였다. 14.6분의 수리학적 체류시간에서 암모니아성 질소의 제거율은 $82.5\%$로 실험조건 중 가장 낮았으나 사육조의 암모니아성 질소농도는 $1.28g/m^3$으로 가장 낮게 나타났다. 모의 사육조의 용존산소는 수리학적 체류시간의 변화와 무관하게 $5.0\~5.3g/m^3$의 범위로 유지되었으며 회전원판 반응기의 원판이 회전할 때 자체적으로 산소가 공급되어 암모니아 둥의 산화와 관련하여 별도의 용존산소 공급은 필요 없는 것으로 나타났다. 알칼리도 소모속도는 수리학적 체류시간의 증가에 따라 선형적으로 증가하였으며 알칼리도 소모속도와 암모니아제거속도의 비는 평균 7.73으로 암모니아성 질소 1 g의 질산화에 7.73g의 알칼리도가 소모되는 것으로 나타났다 회전원판반응기는 원판에 부착된 일부의 타가영양체 미생물에 의해 용존 유기물이 소모되어 COD가 감소되었으며 COD의 제거속도는 수리학적 체류시간의 감소에 따라 선형적으로 증가하여 14.6분의 수리학적 체류시간에서 $5.59\;g/m^3$의 가장 낮은 농도를 보였다.

• 한국농촌건축학회논문집
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• 제25권4호
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• pp.17-24
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• 2023

This study is about the traditional house of Kim Myeong-Gwan, the founder of Gwangsan Kim clan(光山金氏) and the 30th grandson of Heunggwang, the 49th king of the Unified Silla Dynasty. He sought a place to take refuge due to a plot and built a house in Jeongeup, adjacent to Yeonsan or Nonsan, Chungcheong-do, which is the home of the Gwangsan Kim clan. The location of old houses was analyzed through Hyeongselon(形勢論) and hyeongguklong(形局論) of Pungsu theory. The results of fengshui analysis of the house through fengshui literature that was presumed to have been used at the time are as follows.The dragon(龍) shows an auspicious condition in which the dragon vein is well connected from its roots in the Honam vein to Guksabong Mountain on Josan Mountain, Bibongsan Mountain on Sojo Mountain, and Mt. Changhasan reaching Jusan Mountain. Hyeol(穴) is a type of Wahyeol(窩穴) and is a Hwalwa(濶窩). Hyeolseong(穴星) is a Jeongche-Hyeolseong(正體穴星) and is a Suseong Hyeol(水星穴). HyeolJung(穴證) and Hyeolgi(穴忌) have the conditions to create hyeol. As for Sa(砂), the height of Hyeonmu(玄武) is not that high, but the Jujak(朱雀) is relatively high, the left blue dragon(左靑龍) is complemented by the outer blue dragon(外靑龍), and the right white tiger(右白虎) does not sufficiently surround the house. To compensate for this, Bibosu trees(裨補樹) were planted at the time of the construction of the house. As for the Water element, it appears to be auspicious as it approaches the old house in the form of a curve, but it has the disadvantage of not sufficiently surrounding the house, so an artificial pond is dug as a Bibo Pungsu(裨補風水). Through this study, it was found that Pungsu was applied as an important consideration factore in selecting the location of the house, and that Pungsu was not just a theory but had a practical effect in preserving the life and property of the family under the risky circumstances of the time.

• 상하수도학회지
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• 제31권2호
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• pp.177-186
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• 2017

This study concerned the analysis on the efficiency of the conversion of water tank type supply system to direct water supply system to examine the feasibility of the conversion, as well as the calculation of optimal conversion range that enables the supply of safe, high-quality water at stable pressure in accordance with the standards of water supply facility. The results of this research showed that when converting water supply system from water tank type supply system to direct water supply system, more nodal points could be properly converted and more reduction of electricity usage was expected in case water pressure rather than residence time was fixed. This means that higher efficacy can be obtained by fixing water pressure when converting water supply system. However, since the number of the locations that received on-spot inspection was small and the electricity usage measured was not exclusively by water supply facility, it is difficult to judge that such reduction of electricity usage accurately represents reduced electricity usage by water supply facility alone. therefore, after having secured on-spot information about a larger number of locations in apartment complexes that have converted water supply system, and utilizing information about electricity usage exclusively by water supply facility, the proposed method of this research could be applied to accurately deducing expected reduction of electricity usage by water supply facilities of various other apartment complexes. It is also considered possible to deduce an effective operation method of water supply system by finding out an area that shows low pressure or low residual chlorine concentration in the optimal conversion range of water supply, followed by estimating the proper location of pumping station or the proper chlorine dosage at the power purification plant that supply water to the target area.