• Water for future
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• v.35 no.3
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• pp.60-67
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• 2002

• Water for future
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• v.38 no.5 s.148
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• pp.73-80
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• 2005

• 열린충남
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• s.32
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• pp.84-103
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• 2005

• Environmental engineer
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• s.324
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• pp.16-16
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• 2013

• Water for future
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• v.37 no.1
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• pp.63-67
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• 2004

• Water for future
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• v.5 no.1
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• pp.62-66
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• 1972

• Clean Technology
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• v.12 no.1
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• pp.1-9
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• 2006

Aqueous cleaning agents which are considered to be environmental-friendly and promising alternative ones among various industrial cleaning agents were evaluated in this words. In order to formulate aqueous cleaning agents, primary alcohol ethoxylates with 3, 5 and 7 moles of ethylene oxides among nonionic surfactants were selected as main surfactants. And anionic surfactants and alcohols were chosen as their cosurfactants. Builders such as NaOH, KOH, $Na_2CO_3$ and $NaHCO_3$ were also evaluated as additives for improvement of cleaning efficiency of aqueous cleaning agents. The experimental results of cleaning ability tests show that introduction of anionic surfactant TLS as cosurfactant in alcohol ethoxylate-based aqueous solution gives the best cleaning efficiency for removing mixed soil of cutting oil and grease. NaOH and $Na_2CO_3$ are also shown to play an important role for improvement of cleaning efficiency in a aqueous cleaning agent.

• Clean Technology
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• v.3 no.2
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• pp.36-46
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• 1997

CFC and organic chlorine solvents has been used in the fine machinery and electronics industries for a long time since they have various excellent properties as cleaning agents. However, it is inevitable that alternative cleaning agents should be used since CFC and organic chlorine solvents were identified as ozone-depleting chemicals. There are various alternative cleaning agents. Among them, aqueous/semi-aqueous cleaning agents are environmentally friendly and promising in the long term. And their use and developement are on the increase in advanced countries, but few in our countries. In this paper, the charactistics and major components aqueous/semi-aqueous cleaning agents are analyzed and compared. And various cleaning equipments for aqueous/semi-aqueous cleaning agents such as immersion cleaner, ultronsonic cleaners, power spray cleaner, and vibration or rotational cleaners are compared and evaluated. Finally, important consideration points for selction of a cleaning system are analyzed and suggested in this paper.

• Journal of Korea Water Resources Association
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• v.33 no.6
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• pp.765-774
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• 2000

The purpose of this study are to develop a realistic methodology to estimate agricultural water supply for rice paddy fields from reservoirs, pumping stations, intake structures, and tube wells on river basin scale. Agricultural water supply from irrigation reservoirs are estimated using the daily or ten day's storage rate data and DIROMmaily Inigation Reservoir Operation Model) model. Estimation of daily water supply from pumping station are carried out from the annual water use with typical water supply patterns. The daily groundwater withdrawn are investigated from the gross water requirement for rice and the design capacity of tube well. And, the daily intake discharge are estimated the minimum amount from the gross water requirement, stream discharge, and the design capacity. During 1993 to 1997, the annual water supply for irrigation in the Han river basin ranged from 569 to 709 million $\textrm{m}^3/yr$, and the mean was estimated to be 640 million $\textrm{m}^3/yr$.

• Economic and Environmental Geology
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• v.40 no.3 s.184
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• pp.307-318
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• 2007

The occurrence of geothermal water has high correlates highly with fossil geothermal system. A fuzzy logic based data integration is applied for geothermal potential mapping in the Southern Gyeongsang Basin which is distributed in the regional fossil geothermal system. Several data sets are related with the origin and distribution of fossil geothermal system, such as the geological map, the density of lineaments, the aerial survey map of magnetic intensity, the map of hydrothermal alteration, the distribution density of hydrothermal mines, which were collected as thematic maps for the integration. Fuzzy membership functions for all thematic maps were compared to the locations of the spa hot springs, which were used as ground-truth control points. After integrating all thematic maps, the results of gamma operator (${\gamma}=0.1$) was showed the highest success rate, and new geothermal potential zone is prospected in some area.