• 자원ㆍ환경경제연구
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• 제9권2호
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• pp.311-332
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• 2000

The main aim of this paper is to estimate the change in the quantity demanded of public water when the economic factors such as income and water price are changed. The privious methods to estimate the quantity of public water demanded has been usually based on the LPCD(liter per capita per day). Implicitly, this method regards the price of water as given. If the water price and income elasticities of water demand are estimated using the time-series and pooled data analysis. In the second step, the quantity demanded of public water are forecasted using the estimated elasticities. The results show that we can reduce the quantity demanded of residential water considerably when the water price is changed.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2006년 제4회 한국유체공학학술대회 논문집
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• pp.61-64
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• 2006

Recently the development of small hydropower generation with using water pipes is revitalized by the water works facilities. However, when the tubine generator is in case of emergency stop by the internal and external accidents, it causes water hammer in water pipes and suspension of water supply. To prevent these problems of small hydropower generator, we has analyzed water supply patterns, installation position and water pipe systems.

• 대한토목학회논문집
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• 제31권6B호
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• pp.551-563
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• 2011

수자원사업은 대규모의 예산이 투입된다. 따라서 수자원사업은 합리적이고 신뢰성 있는 의사결정이 필요한데 그동안 주로 경제성분석에 의존하여 왔다. 본 연구목적은 경제성분석위주의 기존 의사결정이 아닌, 사업의 필요성과 투자의 타당성을 다양한 각도로 평가할 수 있는 수자원사업 대안선정과 투자우선순위결정을 위한 다기준의사결정방법을 도출하는 것이다. 본 논문은 경제성 분석, 정책적 분석, 취약성 분석과 각각의 하위평가항목으로 평가기준을 구성하였다. 또한, 전문가 설문을 통한 사전 가중치를 제시함으로써, 일관성 있는 평가가 이루어지도록 하였다. 그리고 전문가 설문을 통해 평가항목의 속성별로 위험성향을 고려한 효용함수를 도출하였다. 종합평가점수는 평가항목별 가중치와 속성별 효용점수로 산정된다. 적용결과, 평가기준은 취약성 기준에 큰 영향을 받는 것으로 나타났다. 본 연구는 수자원사업에 대한 효율성과 취약지역에 대한 형평성을 제고하는데 기여할 수 있을 것으로 판단된다.

• Geomechanics and Engineering
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• 제8권5호
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• pp.727-739
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• 2015

Reclamation of closed dumping grounds is a potential solution to solve land scarce problems. Traditional geotechnical investigations of closed dumping grounds face some problems, such as the emission of hazardous liquids and gases, and the lack of ground information due to the discontinuity between two boreholes. Thus, noninvasive and continuous investigation methods are needed to supplement traditional geotechnical investigations. In this paper, two types of geophysical investigation methods, Seismic Analysis of Surface Waves (SASW) and 2D Resistivity, were carried out to study noninvasive and continuous site investigations for dumping grounds. The two geophysical methods are able to profile the distribution of physical properties of the fill and original materials, by which the extent of the dumping ground can be found and some anomalies in the subsurface can be located. Boreholes were used to assist in locating the dumping material-ground interfaces. The results show that dumping material-ground interfaces obtained from the two geophysical methods are roughly consistent. Moreover, attempt is made in the paper to use the geophysical methods to classify the types of dumping materials. The results show that the classification of dumping materials using the geophysical methods follows the results of the manual sorting of the dumping materials from a borehole.

• 분석과학
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• 제9권4호
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• pp.392-398
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• 1996

광주천 유역내에 분포된 8개 업종 26개 배출원의 원폐수로부터 인간에게 유해한 11개의 유기화학물질 tetrachloroethylene, ethyl benzene, p-xylene, o-xylene, isopropyl benzene, n-propyl benzene, 1,2,4-trimethyl benzene, 1,3,5-trimethyl benzene, p-isopropyl toluene, see-butyl benzene, naphthalene을 액체-액체 추출법으로 분리하였다. 추출물 중 각 화합물들의 구조는 기체 크로마토그래피/질량분석계(GC/MS)를 사용하여 확인하였고, 표준시료와 비교함으로써 밝혔다.

• Journal of Microbiology and Biotechnology
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• 제22권5호
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• pp.668-673
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• 2012

Biohydrogen production from organic wastewater by anaerobically activated sludge fermentation has already been extensively investigated, and it is known that hydrogen can be produced by glucose fermentation through three metabolic pathways, including the oxidative decarboxylation of pyruvic acid to acetyl-CoA, oxidation of NADH to $NAD^+$, and acetogenesis by hydrogen-producing acetogens. However, the exact or dominant pathways of hydrogen production in the anaerobically activated sludge fermentation process have not yet been identified. Thus, a continuous stirred-tank reactor (CSTR) was introduced and a specifically acclimated acidogenic fermentative microflora obtained under certain operation conditions. The hydrogen production activity and potential hydrogen-producing pathways in the acidogenic fermentative microflora were then investigated using batch cultures in Erlenmeyer flasks with a working volume of 500 ml. Based on an initial glucose concentration of 10 g/l, pH 6.0, and a biomass of 1.01 g/l of a mixed liquid volatile suspended solid (MLVSS), 247.7 ml of hydrogen was obtained after a 68 h cultivation period at $35{\pm}1^{\circ}C$. Further tests indicated that 69% of the hydrogen was produced from the oxidative decarboxylation of pyruvic acid, whereas the remaining 31% was from the oxidation of NADH to $NAD^+$. There were no hydrogen-producing acetogens or they were unable to work effectively in the anaerobically activated sludge with a hydraulic retention time (HRT) of less than 8 h.

• Journal of Microbiology and Biotechnology
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• 제23권2호
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• pp.137-143
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• 2013

The diversity and distribution of methanogenic archaea in a four-compartment anaerobic baffled reactor (ABR) treating sugar refinery wastewater were investigated by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). At an organic loading rate of 5.33 kg $COD/m^3{\cdot}day$, the ABR could perform steadily with the mean chemical oxygen demand (COD) removal of 94.8% and the specific $CH_4$ yield of 0.21 l/g $COD_{removed}$. The $CH_4$ content in the biogas was increased along the compartments, whereas the percentage of $H_2$ was decreased, indicating the distribution characteristics of the methanogens occurred longitudinally down the ABR. A high phylogenetic and ecological diversity of methanogens was found in the ABR, and all the detected methanogens were classified into six groups, including Methanomicrobiales, Methanosarcinales, Methanobacteriales, Crenarchaeota, Arc I, and Unidentified. Among the methanogenic population, the acid-tolerant hydrogenotrophic methanogens including Methanoregula and Methanosphaerula dominated the first two compartments. In the last two compartments, the dominant methanogenic population was Methanosaeta, which was the major acetate oxidizer under methanogenic conditions and could promote the formation of granular sludge. The distribution of the hydrogenotrophic (acid-tolerant) and acetotrophic methanogens in sequence along the compartments allowed the ABR to perform more efficiently and steadily.

• Nano
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• 제13권11호
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• pp.1850134.1-1850134.10
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• 2018

Increasing active sites and enhancing electric conductivity are critical factors to improve sensing performance toward phenol. Herein, Ni nanoparticle was successfully anchored on acidified multiwalled carbon nanotube (a-MWCNT) surface by electroless plating technique to avoid Ni nanoparticle agglomeration and guarantee high conductivity. The crystal structure, phase composition and surface morphology were characterized by XRD, SEM and TEM measurement. The as-prepared Ni/a-MWCNT nanohybrid was immobilized onto glassy carbon electrode (GCE) surface for constructing phenol sensor. The phenol sensing performance indicated that Ni/a-MWCNT/GCE exhibited an amazing detection performance with rapid response time of 4 s, a relatively wide detection range from 0.01 mM to 0.48 mM, a detection limit of $7.07{\mu}M$ and high sensitivity of $566.2{\mu}A\;mM^{-1}\;cm^{-2}$. The superior selectivity, reproducibility, stability and applicability in real sample of Ni/a-MWCNT/GCE endowed it with potential application in discharged wastewater.

• Water Engineering Research
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• 제3권1호
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• pp.63-74
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• 2002

• 물과 미래
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• 제30권1호
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• pp.7-18
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• 1997