• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.4 no.3
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• pp.185-193
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• 2000

A water treatment agent with antimicrobial activity(Ag-Os) was created by exchanging silver ion($Ag^{+}$) on calcined oyster shell powder. The desorption of the exchanged silver ion was negligible, thereby indicating a stable antimicrobial water treatment agent. The sterilization effect of Ag-Os on underwater microorganisms was then investigated. An MIC (Minimum Inhibitory Concentration) test result indicated that Ag-Os had an excellent sterilization effect on G-germs, such as Escherichia coli and Pseudomonas aeruginosa. Most germs were annihilated with an Ag-Os concentration of 200 ppm and contact time of 60 minutes. The sterilization effect was mainly dependent on the contact time. The zeta potential of the Ag-Os powder adsorbed on sand was measured relative to the concentration of exchanged silver ion. As the concentration of the exchanged silver ion increased, the surface charge density of the anions on the surface of the Ag-Os powder adsorbed on sand also increased. Accordingly, this result indicated that a higher silver ion than ion exchange capacity was present on the particle surface due to adsorption. Consequently, this increased concentration of exchanged silver ion would appear to significantly enhance the sterilization power.

• Textile Coloration and Finishing
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• v.24 no.3
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• pp.213-220
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• 2012

In this study, we investigated the effect of natural vegetable treatment agent on the bleaching and damage of human hair during permanent wave formation. The vegetable treatment agent was prepared by fermenting the mixture of tea leaves (10g), black rice (100g), black bean (100g), corn (100g), malt (50g), and water(500g) at room temperature for 1 week. The degree of bleaching and damage was checked by Munsell value 'L' and morphological changes of hair in FE-SEM. When the hair was bleached, the Munsell value 'L' was almost same regardless of adding the vegetable treatment to the bleaching solution. But when the hair was permanently waved, the curl formation ability was high and the damage was low in the case of adding the vegetable treatment. This means that the vegetable treatment covers the scale of hair and protects the hair from the chemicals.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1994.05a
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• pp.9-12
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• 1994

Epoxy-Ceramic Composite have good insulating, therma1 and mechanical properties, so it is studied actively on this material. In this thesis, we made a composite material b)\ulcorner filling Epoxy Resin with ceramics treated with Sillane Coupling Agent and studied dielectric and insulating characteristics according to treatment density of Sillane Coupling Agent and weight percent of filler. As a result, loss tangent increase and electrical breakdown voltage decrease according to increasing treatment density of sillane coupling agent because Interface matching between matrix and filler is not good. The best treatment density of sillane coupling agent is 0.5% water solution, in this density the best interface matching is achieved so good dielectric and insulation characteristics are shown. Dielectric and insulation characteristics according to weight percent of filler are best at 25wt.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.497-502
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• 2001

We examined the silicate-based material to develop the surface-treatment agent, which would be used to restore performance of the deteriorated concrete and to inhibit corrosion of the reinforcing bar. As a part of the study, we carried out experiments of the penetration and strengthening properties of concrete treated by the considering agent. The variables of experiment, were the type of silicates, the ratio of distilled water-silicate, the usage of surface-strengthening material, and the usage of biochemical material. The penetrating ability of concrete is assessed by viscosity and surface tension. Also assessments of strengthening effects of concrete are performed on compressive strength, absorption, and water permeability tests.

• Textile Coloration and Finishing
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• v.30 no.1
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• pp.51-61
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• 2018

In this study, effluent water was produced through Submerged Membrane Bio-Reactor(SMBR) process, which is a simple system and decomposes organic matter contained in wastewater with biological treatment process and performs solid-liquid separation, Especially, ozone oxidation treatment process is applied to effluent water containing fluorescent whitening agent, which is a trace pollutant which is not removed by biological treatment, and influences the quality of reused water. The concentration of $COD_{Cr}$ in the SMBR was $449.3mg/{\ell}-COD_{Cr}$, and the concentration of permeate water was $100.3mg/{\ell}-COD_{Cr}$. The removal efficiency was about 70.1%. The amount of ozone required for the removal of the fluorescent whitening agent in the permeated water in SMBR was $6.67g-O_3/min$, and the amount of ozone required to remove $COD_{Mn}$ relative to the permeate water was calculated to remove $0.997mg-COD_{Mn}$ for 1mg of $O_3$.

• Journal of Environmental Health Sciences
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• v.27 no.2
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• pp.17-21
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• 2001

The object of this study is to find out the characteristics of waste oyster shells and determine the proper dosage of powdered waster oyster shells as the conditioning agent for water treatment sludge dewatering process. The large amount of waste oyster shells which discharges from the oyster farming, occurs serious environmental hazards. However, oysters shell contain large amount(about 38% by weight) of alkaline minerals, such as calcium and magnesium and so on, this natural material is thought to have the petential ability as a good conditioning agent. The results of this study are as follows. The optimum condition for improvement of the water treatment sludge dewaterability is when 6 g of waste oyster shell powder added to 200$m\ell$ of water treatment sludge. At optimum condition, the solid contents can reach to 31.78% and the specific resistance of conditioned sludge is 0.16$\times$10$^{8}$ sec$^2$/g. However, exceeding the of powdered waste oyster shell is needed to get the effective result. Consequently, the waste oyster shell can be a recyclable material to improve the dewaterability of water treatment sludges.

• Journal of Life Science
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• v.7 no.4
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• pp.316-321
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• 1997

The effects of the silver ion-exchanged water treatment agent (Ag-Os) upon E. coli RB 797 and Bacillus sp. have been discussed in this study. Silver ion causes a number of toxic effects with no known biological function. Silver ion-exchanged water treatment agent (Ag-Os) using oyster shell here showed antimicrobial activities. the soluble form of silver ion in water is more toxic to the growth of Bacillus sp. than that of E. Coli RB 797. The minium amount of Ag-Os needed for growth inhibition is 0.2 mg/ml for E. Coli RB 797 and 0.02 mg/ml for Bacillus sp., which is consistant with the data of the survival cell fraction. Binding studies suggested that binding of silver to the cell surface was a rapid, metabolic-independent process and different from active transport. Bacillus sp. showed more binding than E. Coli RB 797. Reducing substances of the cell cultures in the presence of Ag-Os was detected using Methylen blue as an indicator. From these results, we suggest that Ag-Os is effective as an antimicrobial agent on E. Coli RB 797 and Bacillus sp. and silver binds to the cells through rapid, metabolic-independent process and might complex to sulfur group in the cells for its toxicity.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.998-1001
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• 2010

Most firming agent used in Korea is cement-firming agent. Cement-firming agent absorb water for combination, and then it makes ettringite. Through this chemical process, soft ground is firmed by cement-firming agent. Although most cement-firming agent used in Korea made from CSA, it relies on imports. Therefore, the development of soft ground firming agent using new materials is required. In this study, we suggested that EAF reduction slag not used for anything in the steel industry is available for material of soft ground firming agent. If EAF reduction slag is used in soft ground firming agent, it will be possible to solve the problem with treatment of slag and improvement of soft ground.

• Journal of the Korean Ceramic Society
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• v.27 no.7
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• pp.833-840
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• 1990

For the development of multi-functional materials which has water reducing power, air entraining power and waterproofing power as well as blending additive in cement mortar the coal ash was modified with asphalt-stearic acid or asphalt-boiled oil mixtures by mechanical treatment. And the physical properties of cement mortar blended with modified coal ashes were compared with those of the water-tightness-cement mortar and the ordinary-portland-cement mortar added with AE.water reducing agent. The mortar of coalash-blend-cement modified with asphalt-stearic mixture was increased acid about 20% in initial strengths and decreased about 20% in water absorption ratio than those of ordinary coalash-blend-cement. The mortar of coalash-blend-cement modified with asphalt-bolied oil mixture was similar to the cement mortar added with AE.water reducing agent in water reduction ratio, air entraining conents and the initial strengths, also was similar to the water-tightness-cement mortar in water absorption and water permeability ratios.

• Membrane and Water Treatment
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• v.9 no.5
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• pp.335-342
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• 2018

Micelle-Enhanced Ultrafiltration (MEUF) is a membrane separation processes that improving ultrafiltration process with the formation of micelles of the surface active agents. Surface active agents are widely used to improve membrane processes due to the ability to trap organic compounds and metals in the treatment of industrial waste water. In this study, surface active agents are used to improve micelle-enhanced ultrafiltration (MEUF) to reduce chemical oxygen demand (COD), total dissolved solid (TDS), turbidity and clogging the membrane in dairy wastewater treatment. Three important operational factors (anionic surface active agent concentration, pressure and pH) and these interactions were investigated by using response surface methodology (RSM) and Box-Behnken design. Results show that due to the concentration polarization layer and increase the number of Micelles; the anionic surface active agent concentration has a negative effect on the flux and has a positive effect on the elimination of contamination indices. pH, and the pressure have the greatest effect on flux. On the other hand, it could be stated that these percentages of separation are in the percentages range of Nano-filtration (NF). While MEUF process has higher flux than NF process. The results have been achieved at lower pressure while NF process needs high pressure, thus making MEUF is the replacement for the NF process.