• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.761-764
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• 2008

Most of ready-mixed concrete plants have the problem of construction waste sludge, which pollutes environment and causes economic loss due to the discard and increasing the cost of concrete. Thus, a recycling of the cement sludge has been strongly desired as one of their solution. This research is to the study on the recycling of the cement sludge, especially the study on the hydration control by the sodium gluconate as a set-retarder. The set-retarder can delay the hydration of the cement included in the sludge water, so that the sludge water can be substituted with some of new cement without the property of the cement. And it invests the effect of the sodium gluconate to the hydration of the cement in suspension. The degree of hydration of cement may be controlled by adding the sodium gliconate. The hydration delay time is observed that depends on the concentration of residual sodium gloconate, not how long the cement has been hydrated before the addition of the sodium gluconate.

• Journal of the Korean Geotechnical Society
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• v.15 no.5
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• pp.291-300
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• 1999

Surfactant flushing for enhancing the removal of BTEX from contaminated sand/clay mixtures was investigated. Eight soil columns packed with relatively undisturbed BTEX contaminated soils, were leached with water, methyl alcohol and then flushed with surfactant with or without several additives. Initial concentrations of BTEX mixture range from 278mg/kg to 1975mg/kg. Initial BTEX removal efficiency was 98% when the contaminated soil was flushed with water of 850 pore volumes. Because of tailing effect, water flushing could not remove below 8mg/kg concentrations during the experimental period. Eventually, the most effective surfactant for flushing was turned out to be 4% SOFTANOL(equation omitted)-90 with 3% ethyl alcohol and 3% SXS. In interrupted flow conditions, the removal efficiency was 99.5% with the flushed water of 95 pore volumes. The BTEX mixture removed from the soil columns during the surfactant flushing ranges from 84.5% to 99.5% of the initial amount for both water leaching(850 pore volumes) and surfactant flushing(95-165 pore volumes), respectively. Test results indicated that surfactant flushing could enhance the removal of BTEX mixture from contaminated soils and could reduce the aqueous phase BTEX mixture concentration in leachate.

• Journal of Environmental Science International
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• v.20 no.8
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• pp.977-986
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• 2011

This study analyzed the characteristics of stormwater runoff in the orchard areas and quantitatively estimated effluence of nonpoint source pollutants for the volume of runoff. Two target areas under vine cultivation were each $2,000m^2$ and $1,800m^2$, located in Gyeongju City. Since grape was the only crop on the target area, the characteristics of stormwater runoff at vineyard could be evaluated independently. A total of 51 rainfall events in the vineyard area during two years(2008-2009) was surveyed, and 19 of them became stormwater runoff, with rainfall ranging 16.5 - 79.7 mm and antecedent dry period of 1-13 days. The pollutant runoff loads by volume of stormwater runoff showed BOD ranging 19.5 - 45.3% in 30% of runoff volume. The average pollution discharge rate was 32.4%, indicating small first flush effect of BOD. The range of SS concentrations was 5 - 52.0% in 10% of runoff volume, showing the average 28.7% of discharge rate, about 3 times more than rainfall effluent. TOC and TN appeared to be similar to the results of BOD, the average discharge rate of 30.9% and 30.6% for TOC and TN, respectively, for 30% of stormwater runoff volume. Average discharge rate of COD and TP in the same runoff volume was 35.1% and 36%, respectively, showing comparatively high discharge ratio. As the targeted vineyard area was permeable land, the pollution load ratio against rainfall-runoff volume appeared to be 1:1, implying no strong first flush effect for all the survey items.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.3
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• pp.320-330
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• 2004

Most of domestic city is served combined sewer system among various sewer system like as separate sanitary, combined sewer system and storm sewers. During the wet weather, sewer and rainfall have been overflowed because it is over capacity of the combined sewer system; that is called combined sewer overflows(CSOs) This research was carried out to investigate runoff characteristics of combined sewer and to evaluate the effective CSOs volume in Hong-Chun gun. During wet weather, SS load of first rainfall at H-1, H-2, and H-3 were 600kg/event, 370kg/event, and 289kg/event, respectively. 55 load of second rainfall were 216kg/event, 113kg/event, and 37.2kg/event. When the first rainfall, event mean concentrations(EMCs) at each site were 702mg/L, 816mgjL and 861.5mg/L. The second rainfall's event mean concentrations(EMCs) were 99.9gm/L, 161.9mg/L, 103.6mg/L. Rrst flush coefficient b at each site were 0.237,0.166, and 0.151. When the first rainfall, the flow containing 80% of pollutant mass of CSOs at each site were 0.55, 0.23, 0.48 in first rainfall, respectively. The case of second rainfall were 0.79, 0.83, 0.81. Most of all, characteristics of rainfall like as analysis of first-flush, CSOs volume, pollutant loadings is investigated to decide intercepted volume for control of CSOs.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.6
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• pp.949-957
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• 2011

This aim of study was to investigate the characteristics of discharge of pollutants as well as the correlation between flow rate and water quality constituents in a combined sewer system according to the characteristics of rainfall. For the loading rates for each pollutant, the median concentrations of all pollutants except T-N was increased when a CSO took place. The loading rates of BOD, COD, SS, T-N, T-P, Cu and Zn at the CSOs were 328-1255, 25-129, 83-2009, 4-12, 14-51, 5-11 and 5-13 times higher than the DWF (Dry Whether Flow), respectively. Especially, SS loading rate was found to be highest in all pollutants. On the other hand, the range of the first flush coefficient, b for water quality constituents such as BOD, COD, SS, T-N, T-P, Cu and Zn were 0.537-0.878, 0.589-0.888, 0.516-1.062, 0.852-1.031, 0.649-0.954, 0.975-1.015 and 0.900-1.114, respectively. In term of correlation between flow rate and pollutant concentrations, SS concentration was highly correlated to flow rate. However, there was an inverse correlation between EC (Electrical Conductivity) and flow rate because of the high dilution of flow rate. In case of correlation between pollutants, there was a high correlation between SS and T-P.

• Journal of Wetlands Research
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• v.19 no.3
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• pp.296-302
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• 2017

Generally, a parking lot is constructed using asphalt or concrete. Such materials are impermeable, which means that a parking lot will directly release pollutants to any nearby water system during a rainfall event. An increased quantity of nonpoint source pollutants harms the ecohydrological system and causes further environmental damage leading to dysfunctional water circulation systems. Therefore, there is an urgent need for the design and application of Low Impact Development (LID) systems that allow more effective prevention of water circulation problems and management of nonpoint source pollution. This study aims to support such efforts by analyzing a permeable paver parking lot constructed using one of the LID techniques and comparing it to a conventional one in terms of the concentration of pollutants, nonpoint source pollution load and runoff rainfall lag effects during a rainfall event; it could serve as a reference for the construction of permeable paver parking lots in the future.

• Journal of Life Science
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• v.21 no.11
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• pp.1526-1531
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• 2011

Local protein synthesis in neuronal dendrites is important for site-specific regulation of synaptic plasticity. In this study, we investigated whether translation initiation factors (eIFs) are present at the postsynaptic sites. High resolution confocal microscopy showed that the eIF4E and eIF4G (which bind the 5'-terminal mRNA cap), eIF5 (which is important during the 3' direction scanning to find an initiation codon), eIF6 (which mediates upregulation of translation by external stimuli), and eIF5A (which mediate translation upregulation under adverse conditions) were localized to the post-synaptic sites. Immunoblot and detergent extraction experiments also indicated that these eIFs were present in the synapse in association with the postsynaptic density (PSD). Our data provide evidence for the strategic positioning of eIFs at the postsynaptic site for initiation of translation in diverse situations.

• Korean Journal of Plant Resources
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• v.26 no.5
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• pp.636-644
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• 2013

We examined the effects of soaking, saturation, and aging conditions of raw cowpea seeds, on the yield and growth responses of cowpea sprouts. The absorption caused rapid growth for the first two hours of soaking, then the growth slowed. The longer the soaking period (varied from 1 to 6 hours), the lower the germinability, yield ratio, and lateral root output became. A five-day saturation (moist $96{\pm}1%$, $20^{\circ}C$) treatment led to higher germinability, yield ratio, and lateral root output than no treatment and one- or three-day saturation treatment. High-temperature aging treatment led to lower germinability and yield ratio compared to no such treatment. Taking these findings into account, the optimal treatment conditions of raw cowpea seeds are a five-day saturation (moist $96{\pm}1%$, $20^{\circ}C$) treatment followed by cleaning and growing.

• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.4
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• pp.13-22
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• 2020

The Doam Lake watershed has a significant impact on the downstream water system due to nutrients and sediment outflow during rainfall caused by steep slopes, soil losses, and fertilization. These non-point sources are unclear in the discharge area and are affected by land use patterns, soil characteristics, and topographical features of the watershed. Therefore, this study conducted rainfall monitoring from July to October 2019 in Songcheon upstream of the Doam Lake watershed, one of the non-point pollution source management areas. Then, after analyzing rainfall runoff, Event Mean Concentration (EMC) and Mass First Flush ratio (MFFn) were calculated to compare and analyze the characteristics of rainfall and the non-point pollutant discharge. As a result of the analysis, it showed various non-point pollutant emission characteristics for each rainfall event. In addition, the concentration of EMC and the MFFn were affected by the average rainfall intensity and the maximum rainfall intensity, and were not significantly affected by the number of antecedent drying days. In the future, it is expected that effective non-point source reduction measures and management measures according to rainfall intensity through continuous monitoring and analysis will be needed.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.1
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• pp.14-22
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• 2015

In order to analyze the flow and pollutant runoff characteristics of industrial area, SWMM (Storm Water Management Model) was applied. The model was calibrated based on the measured data in the waterway of Sihwa industrial complex during six events, 2008-2009. The build-up process of pollutants is expressed as Power-linear form and washoff as Power-Exponential form. The validated model was used to analyze the change of the runoff characteristics in the industrial area. In the study area, runoff flow is decreased with an increase in impervious area, but there is no significant change in peak time. The results of this study will be used as basic information of impervious area reduction and watershed management in industrial areas.