• Journal of Environmental Science International
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• v.13 no.2
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• pp.143-148
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• 2004

In this paper, the properties of inter - locking block using fly ash are discussed in order to provide economical advantages and improve quality, and protect environment and recycle resources. Fly ash is the by-product of coal in thermal power plant. The experimental parameters are fly ash content, the amount of AE water - reducing agent and mixing proportion of cement mortar. According to the experimental results, the improvement of quality in the side of strength, absorption ratio and freeze - thaw resistance for manufacturing inter -locking block and the curtailment of cost can be achieved in case of 15% of fly ash and 0.3% of AE water- reducing agent are mixed into mortar mixture of 1 :6(C:S).

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.9-18
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• 2008

The fundamental objects of the Korean Grand Canal (KGC) Project are the rehabilitation(or restoration) of river corridor ecology, improvement of river water quality, reduction of flood damages, countermeasure of the huge rise in energy price and the high discharge of $CO_2$ due to the vast use of energy for highway logistics. The other important objects, like an increase of water in the river channel, are to provide people with the pleasure of seeing the water and intimacy (touchiness) with it, an increase of flood controllability, effects of dilution of river pollutants, dredging out sedimentary pollutant from the river bottom, the function of infrastructure to pare down the logistics (distribution) costs, and the opportunity to expand tourism. These kinds of fundamental concepts must be evaluated as future values in Korea and elsewhere.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2000.10a
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• pp.550-556
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• 2000

Three floating islands were constructed on the surface of the reservoir, each consisting of 10 16-㎡ (4${\times}$4 m) segments, made of wood frames and floats. Three species of aquatic macrophytes were planted in each island on June, 1998. Phragmites australis was considered as the suitable aquatic macrophyte for the floating islands since it maintained the most efficient root and shoot balance among the macrophytes. The net primary productivity of P. Australis was 3,604 g/㎡ based on dry weight in 1999, with uptake rates of nitrogen and phosphorus estimated at 77.4 g/㎡/yr and 5.7 g/㎡/yr, respectively. The result of water quality simulation for the floating islands showed that, through adsorption of nutrients and light screening, they could reduce the amount of phytoplankton, thereby decreasing COD concentration.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.4
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• pp.535-543
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• 2006

The Ozone oxidation process was applied to increase the efficiency of reuse process when treating the secondary effluent by the membrane system. This paper focus on decreasing efficiency of membrane fouling, because of membrane fouling reduction by ozone and evaluation of application of the ozone oxidation. The feed water was secondary effluent from BNR process. The result shows that the ozone pretreatment can reduce membrane fouling effectively. Also, the improvement of treated water quality was obvious. The reduction of the membrane fouling led decrease of following pollutant and increase of lnner adsorptive ability of hydrophilic organic matter and decrease of molecular weight. MF membrane process alone can meet the domestic reuse water standards. And ozone pretreatment process also can increase the removal rates of turbidity, COD, nitrogen, and color.

• Journal of the Korean Applied Science and Technology
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• v.33 no.1
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• pp.75-82
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• 2016

The technology of fast pyrolysis is regarded as a promising route to convert lignocellulose biomass into bio-oil which can be upgraded to transportable fuels and high quality chemical products. Despite these promises, commercialization of bio-oil for fuels and chemicals production is limited due to its notoriously undesirable characteristics, such as high and changing viscosity, high water and oxygen contents, low heating value and high acidity. Therefore, in this study quality improvement of bio-oil through vaccum distillation had been targeted. A 600 g of cork oak(Quercus variabilis) which grounded 0.8~1.4 mm was processed into bio-oil via fast pyrolysis for 1.64 seconds at $465^{\circ}C$ and temperature of vaccum distillation(100hPa) was designed to control, $40^{\circ}C$, 50, 60, 70, and 80 for 30min. Bio-oil, biochar, and gas of pyrolytic product were produced to 62.6, 18.0 and 19.3 wt%, respectively. The water content, viscosity, HHV(Higher Heating Value) and pH of bio-oil were measured to 0.9~26.1 wt%, 4.2~11.0 cSt 3,893~5,230 kcal/kg and 2.6~3.0, respectively. Despite these quality improvement, production was still limited due to its notoriously undesirable characteristics, therefore continous quality improvement will be needed in order to use practical fuel of bio-oil.

• Journal of Korean Society for Quality Management
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• v.42 no.3
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• pp.301-310
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• 2014

Purpose: The purpose of this study is to improve a mechanism of expendable bathythermograph measurement by balancing wire resistances between plus wire part and minus wire part and by removing effects of sea water resistance between XBT(Expendable Bathythermograph) and temperature recorder. Methods: The problems are exactly found out through the analysis of XBT and temperature recorder circuit. A process of XBT manufacturing that balances wire resistances between plus wire part and minus wire part is added. Results: The results of this study are as follows; the complicated test process such as temperature accuracy test with a cistern is substituted with a simple process of XBT manufacturing such as balancing wire resistances between plus wire part and minus wire part. Then, the temperature accuracy tolerance of XBT is improved up to ${\pm}0.1^{\circ}C$. Conclusion: Consequently, balancing wire resistances and removing effects of sea water resistance improve temperature accuracy of XBT and reduce expensive and harassing process of XBT manufacturing.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1999.10c
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• pp.8-29
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• 1999

In this presentation I would like to introduce the Rural Sewerage Project, subsidized by the Ministry of Agriculture, Forestry and Fisheries $\alpha$UFF), for the purpose of water quality conservation and improvement onife in rural areas of Japan. Specifically, it will cover background information on the inauguration ofthe Project, its strong points, wastewater treatment technology and some of its problems, systems of t the Project, etc.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.3
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• pp.482-488
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• 1998

This study was carried out to determine the effect of treating with salt-fermented shrimp on quality of pig meat. The treated pig meats were stored at 4$^{\circ}C$, 1$0^{\circ}C$, 2$0^{\circ}C$ or 4$^{\circ}C$ after placing 2$0^{\circ}C$ for 35 hours, respectively. Meat tenderness was improved more at 2$0^{\circ}C$ storage than at 1$0^{\circ}C$ and 4$^{\circ}C$ storage. However, in water holding capacity, the meat stored at 4$^{\circ}C$ was increased more than them of 1$0^{\circ}C$ and 2$0^{\circ}C$. Cooking loss was decreased more at 4$^{\circ}C$ than the other storage temperatures. When meat color observed, it was good at the early stage of storage but went down to the worse gradually. According to the result of SDS-PAGE, myofibrillar proteins were degraded more after treated with salt-fermented shrimp than the control. Among them, titin-I was especially degraded after 2 days at 4$^{\circ}C$ storage even though it was degraded after 1 day at 1$0^{\circ}C$ and 2$0^{\circ}C$ storage. These results suggest that salt-fermented shrimps cause to improve the quality of pork meats by increasing the meat color, meat tenderness and water holding capacity at the early stage of storage.

• Journal of Environmental Health Sciences
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• v.19 no.2
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• pp.16-22
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• 1993

In recent years, great concern for the improvement of drinking water quality has been arising due to the contamination of the raw and treated water. So trihalomethanes (THMs) and some other volatile organic compounds (VOCs), potential carcinogenic substances, rendered the government to take some countermeasurements for clean water service in the dimension of public health. In this study, we used liquid-liquid extraction method as a rapid simple method for determination of VOCs through eluation with n-Pentane in water. The aim with the present study has been to determine the changes of recovery and reproducibility of the method under the various conditions in extraction solvents, solvent ratio and extraction time, and to observe the concentrations under the various temperature and pH during storage.

• Korean Journal of Ecology and Environment
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• v.33 no.3 s.91
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• pp.295-303
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• 2000

The water clarification efficiency was examined in a shallow wetland where dense vegetation was formed naturally in an abandoned paddy field. And, also two enclosure experiments were carried out to measure the effects of materials exchange between sediment and the overlying water with the existence of vegetation and accumulated litter. The hydraulic retention time of wetland was regulated in 1.2 day. The removal rates of SS (56%) and $NO_3-N$ (61%) were high, considering its short retention time. However, removal efficiencies of VSS (28%), COD (14%), DOC (1%),and TP (0.2%) were relatively lower. This low removal efficiencies were thought to be due to the release of dissolved form of organic matter and phosphorus from the sediment. Most of constituents except nitrate were higher in the enclosure at the beginning of enclosure installation than that of the outflowing water from wetland. And then, it has fluctuated and decreased with time. The wetland was in equilibrium state of settling, accumulation of organic debris, and regeneration of dissolved material from sediment. So ultimately high primary production by dense vegetation in the wetland may be the reason of unfavorable or low treatment efficiency of wetland after many years of operation for wastewater treatment. However, the water quality of effluent from the wetland showed smaller variation and better condition than that of inflow, especially during storm events. It can be concluded that this wetland is suitable for the improvement of water quality from nonpoint sources.