• Environmental and Resource Economics Review
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• v.9 no.2
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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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• 2006.08a
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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.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.6B
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• pp.551-563
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• 2011

Water resource projects need an enormous national budget. Therefore, a reasonable and reliable decision making is required for the planning of water resource projects, but decision making has been mostly performed by economic analysis. The objective of this study is to develop a Multi-criteria Decision Making(MCDM) model which can assess the project in various aspects for the selection of preferable alternative and determination of investment priority in water resource projects. In this study, the criteria involves economic feasibility, policies, vulnerability, and sub-items which have weights obtained from the expert survey for the consistent evaluation. We also derived the utility function considering risk trend of each item based on the expert survey. Then, the total score was estimated by weights of each item and utility score of each attribute. The results show that vulnerability is a major contributor for the criteria. This study will contribute to the selection of proper water resource projects considering efficiency of project and fairness for vulnerable area.

• Geomechanics and Engineering
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• v.8 no.5
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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.

• Analytical Science and Technology
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• v.9 no.4
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• pp.392-398
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• 1996

Eleven organic chemical substances, 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, and naphthalene, which have hazardously influenced to human, were extracted from untreated wastewater collected at 26 companies of 8 types industry in the basin of Kwangju stream. Their structures were elucidated by Gas Chromatography/Mass Spectrometry(GC/MS) and in comparison with each standard reagents.

• Journal of Microbiology and Biotechnology
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• v.22 no.5
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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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• v.23 no.2
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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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• v.13 no.11
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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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• v.3 no.1
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• pp.63-74
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• 2002

• Water for future
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• v.30 no.1
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• pp.7-18
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• 1997