• Water Engineering Research
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• 제2권3호
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• pp.151-160
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• 2001

A two-dimensional flow model is newly developed. Two-dimensional shallow-water equations are discretized by the finite volume method. A nonorthogonal coordinate system is then employed. The developed model is applied to simulations of flows in a 180 degree curved bend flow. Numerical prediction are compared to available laboratory measurement. A good agreement is observed.

• 물과 미래
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• 제5권2호
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• pp.44-48
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• 1972

This article includes hydrometeorological analysis of evapotranspiration and precipitation, which are used available basic data for a certain basin water budget. Evapotranspiration on water surface, bare soil and rice fields is directly measured by Thornthwaite's type Lysimeter and on water surface and vegetables computed using the Penman's equation. Areal precipitation is analized through the Thiessen method and arithmatic mean method. It is interested fact that the correlation coefficient for Class A Pan's evaporation vs. the actual evapotranspiration is the highest value among the coefficients for different type evaporimeter and Penman equation, and evaporation ratio on rice field's evapotranspiration vs. Class A Pan's evaporation is 1. 5-2. 3.

• 한국해양학회지
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• 제8권1호
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• pp.46-52
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• 1973

From available data, the movement of the cold water in the Korea Strait was investigated. The cold water forms an undercurrent with a speed of 0.10knots near Ulgi in June. Sometimes it reaches a speed of 0.35knots. The cold water forms a sharp wdege in the western channel like a salt wedge in an estuary. The calculated volume transport of the cold water is 17,135 cubic meters per second in June. The external influences are also discussed.

• Applied Biological Chemistry
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• 제7권
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• pp.45-52
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• 1966

This study was carried out to determine how the water soluble, the available $P_2O_5$ and urea-N would change in the course of time, when the mixtures of calcium superphosphate and urea with lime for fertilizer which occurred in Korea and largely contained calcium carbonate were made. Three kinds of materials, i. e., calcium superphosphate, urea and lime for fertilizer were used in this study. Three kinds of mixed fertilizer, i. e., A, B and C were made up by mixing these materials to satisfy the following formula. $$1)\;Ca(H_2PO_4)_2+CaCO_3+CO(NH_2)_2{\rightarrow}$$$$Ca_2H_2(PO_4)+H_2CO_3+NH_3$$ $$2)\;Ca(H_2PO_4)_2+CaCO_3+CO(NH_2)_2{\rightarrow}$$$$Ca_3(PO_4)_2+H_2CO_3+NH_3$$ $$3)\;Ca(H_2PO_4)_2+CaCO_3+CO(NH_2)_2{\rightarrow}$$$$Ca_3(PO_4)_2+H_2CO_3+CaCO_3+NH_3$$ A,B and C were placed in desiccators respectively a six month period. During the time of storage, the water soluble, the available phosphoric acid and urea-N were measured once a month, seven times with the control measurement. The results may be summarized as follows. 1. None of A, B and C showed any change in the urea-N with the lapse of time. This fact indicated that the combination of calcium superphosphate and urea with lime for fertilizer was not unfavourable. 2. A, B and C decreased in the amount of water soluble $P_2O_5$ with the passage of time. This fact indicated that the mixing of calcium superphosphate and urea with lime for fertilizer was unfeasible. 3. The available $P_2O_5$ in any of A,B and C did not undergo a change as time went by. This fact suggested that the combination of calcium superphate and urea with lime for fertilizer was favourable.

• 상하수도학회지
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• 제26권2호
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• pp.285-294
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• 2012

Current urban stream conditions and their restoration projects were investigated by surveying the urban stream management experts in 29 cities with high population density (more than 1,000person/$km^{2}$). The survey results showed that the ratio of covered urban streams decreased by 1.4% (from 14% to 12.6%) in the last 5 years through steady river restoration projects promoted by governments. Nonetheless, 36.3% of 369 urban streams surveyed still report stream depletion problems; therefore, more efforts to alleviate the problems caused by distorted water circulation of urban streams are still necessary. Water depletion in many local urban streams, unlike national rivers, is accelerated due to negligence in stream management, budget shortage, and other reasons. To prevent stream depletion, the use of reclaimed water is suggested as one of the prevention plans. When available amounts of reused sewage are estimated through actual available nationwide sewage discharges of each watershed and instream flow of stream, annual instream flow supply of 780 million $m^{3}$ is expected; 4.8% reduction in the pollution load of public sewer treatment facilities is expected; and the creation of new value through water reuse service is expected. Thus, it is important for the reviews of feasibility and alternatives of water reuse projects for flow augmentation to consider not only investment budget reductions, but also environmental aspects. Also it is necessary to provide the financial support of unified government with strict water quality management policy.

• 한국화재소방학회논문지
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• 제26권4호
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• pp.10-17
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• 2012

본 연구에서는 목조 사찰 화재시 펌프(물탱크)차의 현장 도착 가능여부에 따라 사찰화재 유형별 진압대책을 4가지 유형으로 분류하고, 각 유형별 화재진압 전술 및 방법을 도출하였다. 연구결과, 펌프(물탱크)차의 접근 및 소방용수 확보가 가능한 사찰은 일반 건축물화재 진압전술을 적용하지만, 그렇지 않은 경우는 헬기, Water Bag, 연계급수 집중 진압전술, 무선통신을 이용한 소방차 수위 자동전송 System 및 급수낭을 활용하고, 사찰 인근 소방서에 화재진압 장비(동력펌프, 호스, 노즐, 급수낭 등)를 적재한 일반 4륜구동 차량 배치와 A자 사다리를 활용한 진압대책 등이 필요한 것으로 나타났다.

• 한국토양비료학회지
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• 제36권6호
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• pp.384-390
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• 2003

논토양의 환경기준 인산지표 예측기술개발을 위하여 논토양 35점을 $25{\pm}1^{\circ}C$ 에서 1, 2, 4주간 담수 항온한 결과 담수 항온 전 풍건 토양의 $0.01M\;CaCl_2$ 가용인산 함량과 유효인산 함량 및 인산흡수능의 관계는 습토로 분석할 경우 상관계수의 크기는 유효인산/인산흡수량>유효인산>유효인산/인산흡수계수>인산흡수량>총인산>인산흡수계수 순이었고, 항온기간별 상관계수 크기는 습토로 분석할 경우 항온이 길어질수록 상관계수는 점점 낮아 졌으나, 건토로 분석할 경우는 이와 반대 경향이었다. 토양의 유효인산 함량과 인산흡수량을 활용하여 $0.01M\;CaCl_2$ 가용인산 농도를 추정할 수 있는 관계식 $0.01M\;CaCl_2-P=0.0828$ (유효인산/인산흡수량) + 0.0374을 얻었으며, 이러한 관계식은 토양의 인산 함량과 인산흡수 특성을 고려하여 작물재배에 필요한 적정 유효인산 함량의 추정과 토양 인산의 유실 가능성 등을 예측하는데 활용될 수 있을 것이다.

• 한국막학회:학술대회논문집
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• 한국막학회 1991년도 추계 총회 및 학술발표회
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• pp.58-63
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• 1991

Membrane technology has been effectively used for many years in certain segments of industrial water treatment. Recent advances in combining sophisticated chemical pre-treatment technology with cross-flow membrane filtration technology have successfully demonstrated that highly efficient, low-cost methods for treating a large of industral streams are available.

• 한국환경보건학회지
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• 제19권2호
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• pp.55-60
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• 1993

This study was performed to investigate the effect of washing with water and detergent on the vitamin C content in strawberry and perilla leaf. Vitamin C was extracted with the solution of metaphosphoric acid and quantitated by high performance liquid chromatograph (HPLC). There was no significant difference of vitamin C content between the washing with distilled water and tap water. Three available detergents reduced the vitamin C content of samples to 92.5%, 92.2% and 78.5%, respectively. The content of vitamin C in samples was decreased by increasing the concentration of detergent and washing time.

• 미생물학회지
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• 제29권5호
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• pp.329-338
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• 1991

From July 1985 to December 1986, 28 variables of phycal-chemical factors, bacteria and heterotrophic activity were investigated 17 times at 3 stations in the estuary of Naktong River and the influences of environmental factors to bacterial population and heterotrophic activity were analyzed through multiple regression. The results of multiple regression were as follows. At station 1, total bacteria and heterotrophic bacteria(Z-25) could explain 57% of the variation of maximum uptake velocity for glucose and 54% of turnover time for glucose was explained by total coliform bacteria and MBOD, Sixty four percent of the variation of Kt+SN was accounted for salinity, MBOD-N and inorganic phosphate. Turnover rate for acetate was also accounted for the change of MBOD-P by 56%. At station 2 maximum uptake velocity for glucose depends on MBOD-N by 81%; turnover time on bacteria by 50%; Kt+Sn on avilable nutrient by 61%. More than 50% of maximum uptake velocity and turnover time for glucose were influenced by bacteria and that of Kt+Sn by the change of nutrient in the surface water of station 3. In the bottom water of station 3, the change of maximumuptake velocity, turnover time and Kt+Sn for glucose was controlled by total bacteria and available nutrient, bacteria, the change of nutrient salts respectively. On the whole, more than 50% of maximum uptake velocity and turnover time for glucose could be due to the change in the number of bacetria and the value of Kt+Sn was affected by the change of nutrient salts. Turnover rate for acetate was controlled by available phosphate at station 1 and by bacteria at station 2 and 3, which showed a distinct difference between the environmental factors which govern the rate of glucose and acetate uptake in the Naktong esturine ecosystem. And bacterial communities were controlled by available nutrients at station 1, by nutrient salts and salinity at station 2 and in the surface water of station 3 and by salinity in the bottom water of station 3.