• 제목/요약/키워드: Water accounting

검색결과 213건 처리시간 0.032초

능동적 신재생에너지 생산을 통한 하수처리장 에너지자립화 향상 (Improving Energy Self-sufficiency in Municipal Wastewater Treatment Plant using Renewable Energy Production)

  • 강지훈;채규정;김동수;양희정;안영섭;김원경;김정현;박동을
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2012년도 학술발표회
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    • pp.643-643
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    • 2012
  • Increasing energy prices and growing concerns about global warming address the need to improve energy self-sufficiency in many industrial and municipal sectors. Wastewater treatment plants (WWTPs) are representative of energy-consuming facilities in Korea, accounting for 5% of national energy consumption. We present renewable energy technologies and energy self-sufficiency scenarios in a municipal WWTP ($30,000m^3d^{-1}$) located in Yongin, South Korea. By employing photovoltaics (PV, 135 kW), small hydropower turbine (10 kW), and thermal energy from treated effluent (25 RT: refrigeration ton) within the WWTP, a total of 142 tonne of oil equivalent (toe) of energy was estimated to be generated, accounting for $365ton\;CO_2\;yr^{-1}$ of greenhouse gas emission reduction. Core renewable technologies under consideration include 1) hybrid solar PV system consisting of fixed PV, dual-axis PV, and building integrated PV, 2) low-head small hydropower plant specifically designed for treated effluent, 3) effluent heat recovery system for heating and air conditioning. In addition to these core technologies, smart operation and management scheme will be presented for enhancing overall energy savings and distribution within the WWTP.

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지자체 자산평가를 위한 GIS의 적용 (Application of GIS for Assessing Assets of Local Government)

  • 김동규;조은래;손덕재;유환희
    • 한국측량학회:학술대회논문집
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    • 한국측량학회 2007년도 춘계학술발표회 논문집
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    • pp.329-332
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    • 2007
  • Since enforcement of double entry book-keeping accounting system on 1 January 2007, local government should draw out financial statement for assets and liabilities possessed after due diligence. But, some social infrastructure including underground facilities are difficult to implement entire inspection actually. In this study, we proposed effective approach for assessing assets of local government's social infrastructure such as road, water and sewage, subsidiary facilities etc. using GIS built on local government by NGIS project. Through this, local government ensures correctness and effectiveness of asset inspection as a result of successive establishment of double entry book-keeping accounting system.

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북서태평양에서 난수성(Pleuromamma sp.)과 냉수성(Neocalanus plumchrus) 요각류의 지방 함량 및 구성 분석을 통한 생리/생태 비교 (The Physiological and Ecological Comparisons between Warm (Pleuromamma sp.) and Cold Water Copepod Species (Neocalanus plumchrus) in the Northwestern Pacific Ocean Using Lipid Contents and Compositions)

  • 고아라;주세종;이창래
    • Ocean and Polar Research
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    • 제31권1호
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    • pp.121-131
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    • 2009
  • In an effort to better understand the physiological and ecological differences between warm and cold water copepod species in Korean waters using lipid contents and compositions, two species of copepods (Pleuromamma sp. as a warm water species and Neocalanus plumchrus as a cold water species) were collected from the Northwest Pacific and East Sea/Sea of Japan, respectively. The cold water species showed two fold higher lipid contents than the warm water species (11% vs. 5% of dry weight). Wax esters, known as one of the major storage lipid classes, were found to be the dominant lipid class (accounting for 64% of total lipids) in the cold water species, whereas, in the warm water species, phospholipids, which are known as membrane components, were the dominant lipid class (accounting for 43% of total lipids),with a trace amount of the storage lipids as a form of triacylglycerols (${\leq}1%$ of total lipids). With regard to the fatty acid compositions, saturated fatty acids (SAFA), especially 16:0 (about 30% of total fatty acids), were most abundant in the warm water species, whereas the polyunsaturated fatty acids (PUFA), particularly eicosapentaenoic acid (EPA : 20:5(n-3)) (${\geq}16%$ of total fatty acids), were most abundant in the cold water species. Among the neutral fraction of lipids, phytol, originating from the side chain of chlorophyll and indicative of active feeding on phytoplankton, was detected only in the warm water species. Significant quantities of fatty alcohols were detected in cold water species, particularly long-chain monounsaturated fatty alcohols (i.e. 20:1(n-9) and 22:1(n-11)), which are well known to abound in cold water herbivorous copepods. However, only trace amounts of short-chain fatty alcohols were detected in the warm water species. Twelve different kinds of sterols were detected in these copepod species, with cholest-5-en-$3{\beta}$-ol (cholesterol) and cholesta-5, 24-dien-$3{\beta}$-ol (desmosterol) dominating in cold and warm water species, respectively. In addition, for the warm water species (Pleuromamma sp.), we assessed the latitudinal gradients of lipid contents and compositions using samples from three different latitudinal regions (Philippine EEZ, Japan EEZ, and the East China Sea). Although no latitudinal gradients of lipid contents were detected, the lipid compositions, particularly dietary fatty acid markers, varied significantly with the latitude. The findings of this study confirm that the distribution of lipid contents and compositions in copepods may not only indicate their nutritional condition and diet history, but may also provide insights into their living strategies under different environmental conditions (i.e., water temperature, food availability).

비정수압 자유수면 모형의 3차원 점성 흐름에의 적용 (Application of Non-hydrostatic Free Surface Model for Three-Dimensional Viscous Flows)

  • 최두용
    • 한국수자원학회논문집
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    • 제45권4호
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    • pp.349-360
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    • 2012
  • 본 연구에서는 3차원 점성 흐름에 적용될 수 있는 비정수압 자유수면 모형을 수평방향 직교 곡선좌표계에서 개발하였다. 개발된 수치모형은 엇갈린 격자를 사용함으로써 발생되는 자유수면에서의 경계조건 종결 문제를 수면층 방정식을 도입하여 해결하였으며, 난류의 유동 해석을 위한 폐합식으로 등방성의 k-${\varepsilon}$ 난류모형을 이용하였다. 본 연구에서 운동량방정식은 이송-확산항만으로 중간단계의 유속을 예측하고, 압력 및 중력을 포함하는 생성항과 연속방정식을 결합하여 다음 시간단계의 유동장을 결정하는 계산 단계 분리법을 이용하였다. 수치모형의 적용성 평가를 위하여 폐쇄된 2차원 수조에서의 취송류, 급경사를 가지는 2차원 수로에서의 흐름, 원심력에 의한 이차류 흐름특성 분석을 위한 3차원 급변 만곡류에 대한 모의를 실시하였다. 수치모의 예측치는 수리모형 실험값과 수위, 유속, 난류특성 등에서 일치하는 양상을 보이는 것이 확인되었다.

강우조건과 토양함수상태를 고려한 자연하천과 댐 방류량 조건에서의 도달시간 산정 (Estimation of Travel Time in Natural River and Dam Outflow Conditions Considering Rainfall Conditions and Soil Moisture Accounting)

  • 김동필;김경호
    • 대한토목학회논문집
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    • 제38권4호
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    • pp.537-545
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    • 2018
  • 설계홍수량 산정 시 도달시간과 같은 시간매개변수의 결정은 매우 중요한 요소이다. 도달시간은 주로 홍수 및 하천관리를 위해 이용되고 있으며, 평수기의 도달시간은 하천의 유지유량 및 이수관리를 위해 이용되고 있다. 자연하천에 대한 도달시간 산정은 주로 유역의 지형학적 인자를 기반으로 산정하고 있으며, 지형학적 인자 이외에 유출곡선지수, 유속, 강우강도의 인자를 고려하여 도달시간을 산정하고 있다. 그러나 재현기간별 강우조건과 토양함수상태를 함께 고려한 도달시간의 산정연구는 부재한 상황이다. 따라서 본 연구는 재현기간별 강우조건과 토양함수상태를 고려하여 임진강의 황강댐과 임진교 수위관측소 구간을 자연하천으로 설정한 경우와 황강댐의 방류량 조건에 따라 임진교 수위관측소에 도달하는 경우로 구분하여 도달시간을 산정하였다. 자연하천으로 설정한 구간에 대해서는 기 개발된 도달시간 산정방법과 비교 검토를 통해 결과를 입증하였으며, 이를 토대로 황강댐의 방류량 조건별 도달시간을 산정하였다. 본 연구에서 제시된 도달시간은 임진강 유역의 홍수관리와 황강댐 방류시 위험에 대비할 수 있는 시간을 확보할 수 있다.

Application of Model Based Predictive Control with Kalman Filter to Natural Circulation Water Tube Boiler

  • Kim, Tae-Shin;Kwon, Oh-Kyu
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2005년도 ICCAS
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    • pp.1146-1151
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    • 2005
  • This paper deals with the control problem of a natural circulation water tube boiler with constraint conditions. Some linearized models for the water tube boiler are proposed around some operating points, and the model based predictive control law is adopted to control the plant accounting for constraints. In this controller, the Kalman filter is used for the state estimation, and the controller is designed based on the linearized model. The control performance of the designed controller is exemplified via some nonlinear simulations around the operation point, which show it works well.

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월성 주변 해역의 부유성(浮游性) 난(卵)과 자치어(仔稚魚)의 분포(分布) (Distribution of Ichthyoplankton in the Adjacent Waters of Wolsong, Korea)

  • 차성식;박광재;유재명;김용억
    • 한국어류학회지
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    • 제3권1호
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    • pp.11-23
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    • 1991
  • 월성 주변 해역의 부유성 난 자치어 분포를 조사하기 위하여, 1989년 11월과 1990년 2월, 5월, 7월의 4회에 걸쳐 봉고네트로 부유성 난과 자치어를 표층채집 하였다. 본 해역에서 출현한 부유성 난은 멸치, 돛양태류, 앨퉁이, 전어와 기타로 분류되었는데, 조사기간 중 앨퉁이와 돛양태류는 전체 어란 출현량의 60.1%와 13.7%를 차지하여 우점종으로 나타났다. 자치어는 총 21개 분류군이 출현하였다. 조사기간 중 멸치는 전체 자치어 출현량의 61.2%를 차지하여 극우점종으로 나타났으며, 돛양태류가 11.9%를 차지하여 우점종으로 나타났다. 그 이외에도 앨퉁이, 망둑어류, 까나리, 볼락, 개볼락, Scartella cristata, 쏨뱅이가 주요 출현종을 이루었다. 이들 9개 분류군은 총출현량의 96.5%를 차지하였다. 본 해역은 용승이 자주 발생하는 지역으로 용승으로 인한 표층수의 이동은 부유성 난이나 자치어의 분포에 영향을 미치는 것으로 나타났다.

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Weightlessness in Water : Its Unexpected Mechanical Effects on Freestyle Swimming

  • Yanai, Toshimasa
    • 한국운동역학회지
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    • 제12권2호
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    • pp.393-405
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    • 2002
  • When our body is immersed in water, we experience weightlessness. The degree of weightlessness that we experience varies depending on the proportion of the body immersed in water, being governed by the relationship between the weight of body and the buoyant force acting on the body. Human body during the performance of swimming in no exception to these influences. Swimmers body is subject to a time and position dependent force system. Even the magnitude of the buoyant force acting on the swimmers body at every given instant and the corresponding position of the CB change continuously. The findings of this study support the following conclusions. The buoyancy torque was the primary source of bodyroll exhibited by front crawl swimmers performing at distance pace, accounting for 88 % of the bodyroll. Faster swimmers used buoyancy more effectively to generate bodyroll, partially supporting the postulation that an effective use of buoyancy for bodyroll may reduce the generated hydrodynamic forces to be wasted in non-propulsive directions and maximize forward propulsion.

수용성 단백질의 계면상 등온곡선의 모델과 실험적 규명 (Model and Experimental Isotherms of Soluble Proteins at water sur faces)

  • Cho, D.
    • 한국산학기술학회:학술대회논문집
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    • 한국산학기술학회 2003년도 춘계학술발표논문집
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    • pp.328-330
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    • 2003
  • A surface equation of state for globular proteins at air-water interface accounting for the molecular structure, segment-segment, segment-solvent, and electrostatic interactions was proposed and compared to C-14 isotope experiments. This lattice model comprised a simplifying assumption that all adsorbed segments are in the form of trains. The number of segment adsorbed per molecule in case of bovine serum albumin linearly depended on the surface concentration whereas the lysozyme segments adsorbed at the interface were independent of surface concentration. The segment-solvent(water) interaction for both of proteins were found to be unfavorable owing to the proteins unfolding. From comparison of model computation and experimental data, BSA unfolded more than lysozyne because of the larger surface area of contact.

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익산지역 대기에어로졸 중 수용성 이온성분의 계절별 침적 특성 (Seasonal Deposition Characteristics of Water-soluble Ion Species in Ambient Aerosol in Iksan City)

  • 강공언
    • 한국환경보건학회지
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    • 제39권1호
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    • pp.56-70
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    • 2013
  • Objectives: This paper aims to investigate the seasonal deposition characteristics of water-soluble ion species by comparing the deposition amount of two samples taken according to different sampling methods of deposition for ambient aerosol such as gases and particulate matters. Methods: Deposition samples were collected using two deposition gauges in the downtown area of Iksan City over approximately two weeks of each season in 2004. The type of deposition gauges consisted of two different sampling methods known as dry gauge and a wet gauge. The dry gauge was empty and used a dry PE bottle with an inlet diameter of 9.6 cm. Before the beginning of each deposition sampling, a volume of 30-50 ml distilled ionized water was added to the wet gauge to wet the bottom during the sampling period. Deposition samples were measured twice per day and analyzed for inorganic water-soluble ion species using ion chromatography. Results: The daily deposition amounts of all measured ions in the dry gauge and the wet gauge showed a significant increase when precipitation occurred, having no difference of deposition amount between in the wet gauge and in the dry gauge. By excluding two samples from rainy days during the sampling period, the mean daily deposition of all ions in dry gauge and wet gauge were $6.58mg/m^2/day$ and $18.16mg/m^2/day$, respectively. The mean deposition amounts of each ion species were higher in the wet gauge than in the dry gauge because of the surface difference of the sampling gauge, especially for $NH_4{^+}$ and ${SO_4}^{2-}$. The mean deposition amounts of $NH_4{^+}$ and ${SO_4}^{2-}$ in the wet gauge were found to be about 15.4 times and 5.2 times higher than that in dry gauge, with a pronounced difference between spring and summer, while the remaining ion species were 1.1-2.0 times higher in the wet gauge than in the dry gauge. Dominant species in the dry gauge were $Ca^{2+}$ and $NO_3{^-}$, accounting for 36.4% and 18.1% of the total ion deposition, whereas those in the wet gauge were $NH_4{^+}$ and ${SO_4}^{2-}$, accounting for 32.5% and 25.0% of the total ion deposition, respectively. Conclusion: The seasonal differences in deposition amounts of water-soluble ion species in ambient aerosol depending on the two types of different sampling methods were identified. This suggests that the removal of ambient aerosol is strongly influenced by the weather conditions of each season as well as the condition of earth's surface, such as dry ground and water.