• Applied Chemistry for Engineering
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• v.4 no.3
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• pp.564-568
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• 1993

By measuring the COD (chemical oxygen demend) of dish washing detergents being sold at market and pollutants connected with domestic sewage, we compared the amounts of water pollutants of one with other and carried out the experiments of ultimate biodegradation as against these samples. Also we combined our experimental results and circumstances of water pollution and wastewater treatments to the sewage system, compared the effects of synthetic detergent on water pollution with soap and the other pollutants and investigated results of our research.

• Applied Chemistry for Engineering
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• v.4 no.3
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• pp.558-563
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• 1993

To reveal the effect of synthetic detergent on the water pollution as a preliminary step, we measured the primary biodegradation and ultimate biodegradation with three kinds of dishwashing detergents being sold at market. Consequently, the primary biodegradation of above mentioned samples were suited to Korean Standards. Above all, the goods that has fast primary biodegradation shows the tendency to fast ultimate biodegradation.

• Microbiology and Biotechnology Letters
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• v.37 no.1
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• pp.85-89
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• 2009

For the purpose of the methodological development to convert the food wastes into resources, we have attempted to culture the mushroom hypha, Pleurotus ostreatus. The food-wastes were mixed with distilled water, and the mixture was autoclaved to produce fluid, which was centrifugated and used as the growth media. Concentrations of the food wastes extracts were prepared with 10, 20, 30, 40, and 50%(W/V), and the initial pH were set variously with 4, 5, 6, and 7. These were cultured for 9 days at the temperature of $25^{\circ}C$ and the rotation rate of 120 rpm. The result is that the fluid form of the mushroom hypha have been grown best at the concentration of 30% and the optimal pH was 5 and 6.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.1384-1389
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• 2005

A real-time monitoring system for in-situ soil remediation technologies is developed and then applied to electrokinetic remediation technique in the field trial tests during 150days. The developed system is consisted the controlled program based on internet web page, data logger, measurement instruments and so on. In the measured items there are pH, temperature, electrical current and potential, vacuum pressure. The results indicated that the system is successively applied to electrokinetic remediation technique, and further research considering economic view and multi purpose system for in-situ soil remediation technologies is needed.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1512-1517
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• 2008

Laboratory column tests were conducted in this study using $Cl^-$ tracers on Jumunjin sand to analyze contaminant transport in mixed contaminated soils. Results obtained from clean soils and soils containing residual diesel verified heterogeneous distribution of residual diesel, and clear acceleration of solute movement. In addition, asymmetric breakthrough curves indicated development of immobile region where solute movement becomes stagnant and creates tailing phenomenon.

• Water Engineering Research
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• v.3 no.3
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• pp.177-193
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• 2002

Experiments were conducted in an initially straight laboratory alluvial channel to investigate channel meandering characteristics. The experimental observations revealed an empirical relation between three types of tortuosity ratios used for describing meandering characteristics. Furthermore, the Strauhal number was found to be higher for bed material with greater resistance to erosion than with lower resistance to erosion. The meandering characteristics were also investigated using the concept of buckling employed in solid mechanics and the concept of siphoning of fluid mechanics. The buckling of flow, attributable to the flow nonuniformity across the channel cross-section, was found to follow the same pattern as did meandering observed experimentally. The processes of expansion of meanders and cut-off can be explained using the concept of siphoning. The results of expanding meander planforms observed in four experimental tests supported the viability of these concepts.

• Journal of the Korean Geosynthetics Society
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• v.5 no.4
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• pp.43-47
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• 2006

Installation damage of 3 types of geogrids were evaluated with compaction condition. This experimental test was in accordance with ENV ISO 10722-1. Tensile strength of geogrids were decreased with number of cyclic compaction loading without regard to kind of filled material and it was seen that strength decrease tendency showed the dependence on geogrid type. Woven and warp-knitted type geogrids showed the bigger decrease of tensile strength than welded type geogrids.

• Proceedings of the KSEEG Conference
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• 2003.04a
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• pp.180-183
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• 2003

Epithermal deposits are an important class of hydrothermal deposits, that have recently seen an surge of exploration and research, principally as significant resources of gold and silver. Epithermal deposits form at shallow depths (surface to 1-2km) and temperatures less than 30$0^{\circ}C$ (Hayba et al., 1985), and encompass a variety of low-sulfidation (near-neutral pH, reduced fluid; LS) and high-sulfidation (acidic and oxidized fluid; HS) deposits (Sillitoe, 1993; White and Hedenquist, 1995). (omitted)

• Proceedings of the KAIS Fall Conference
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• 2011.12a
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• pp.277-279
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• 2011

Red mud는 Bauxite 광물을 정제하여 알루미나를 생산하는 과정에서 발생하는 산업 고형 폐기물이다. Red mud 내에는 경제적으로 가치 있는 다양한 금속 성분과 희토류 등이 함유되어 있다. 하지만 적절한 처리법이 없어 현재 산업폐기물로 방치되고 있는 실정이며, 방치되고 있는 red mud 내에 함유되어 있는 독성물질은 수질 및 토양 등의 환경오염을 유발의 원인이 되고 있다. 이로 인해 본 논문에서는 보다 효율적으로 처리하기 위해 유가 금속을 회수 하는 방법을 알아보았다.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.48 no.2
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• pp.34-45
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• 2016

Global warming and climate change have been caused by combustion of fossil fuels. The greenhouse gases contributed to the rise of temperature between $0.6^{\circ}C$ and $0.9^{\circ}C$ over the past century. Presently, fossil fuels account for about 88% of the commercial energy sources used. In developing countries, fossil fuels are a very attractive energy source because they are available and relatively inexpensive. The environmental problems with fossil fuels have been aggravating stress from already existing factors including acid deposition, urban air pollution, and climate change. In order to control greenhouse gas emissions, particularly CO2, fossil fuels must be replaced by eco-friendly fuels such as biomass. The use of renewable energy sources is becoming increasingly necessary. The biomass resources are the most common form of renewable energy. The conversion of biomass into energy can be achieved in a number of ways. The most common form of converted biomass is pellet fuels as biofuels made from compressed organic matter or biomass. Pellets from lignocellulosic biomass has compared to conventional fuels with a relatively low bulk and energy density and a low degree of homogeneity. Thermal pretreatment technology like torrefaction is applied to improve fuel efficiency of lignocellulosic biomass, i.e., less moisture and oxygen in the product, preferrable grinding properties, storage properties, etc.. During torrefacton, lignocelluosic biomass such as palm kernell shell (PKS) and empty fruit bunch (EFB) was roasted under an oxygen-depleted enviroment at temperature between 200 and $300^{\circ}C$. Low degree of thermal treatment led to the removal of moisture and low molecular volatile matters with low O/C and H/C elemental ratios. The mechanical characteristics of torrefied biomass have also been altered to a brittle and partly hydrophobic materials. Unfortunately, it was much harder to form pellets from torrefied PKS and EFB due to thermal degradation of lignin as a natural binder during torrefaction compared to non-torrefied ones. For easy pelletization of biomass with torrefaction, pellets from PKS and EFB were manufactured before torrefaction, and thereafter they were torrefied at different temperature. Even after torrefaction of pellets from PKS and EFB, their appearance was well preserved with better fuel efficiency than non-torrefied ones. The physical properties of the torrefied pellets largely depended on the torrefaction condition such as reaction time and reaction temperature. Temperature over $250^{\circ}C$ during torrefaction gave a significant impact on the fuel properties of the pellets. In particular, torrefied EFB pellets displayed much faster development of the fuel properties than did torrefied PKS pellets. During torrefaction, extensive carbonization with the increase of fixed carbons, the behavior of thermal degradation of torrefied biomass became significantly different according to the increase of torrefaction temperature. In conclusion, pelletization of PKS and EFB before torrefaction made it much easier to proceed with torrefaction of pellets from PKS and EFB, leading to excellent eco-friendly fuels.