• Bulletin of the Korean Chemical Society
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• v.35 no.11
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• pp.3331-3335
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• 2014

We examine the potential use of disordered mesoporous carbon as a functional additive for confining dissolved Li-polysulfides and improving the cycling performance of Li-S batteries. To promote a better understanding of the correlation between the total pore volume of disordered mesoporous carbon and the cycling performance of Li-S batteries, a series of disordered mesoporous carbons with different total pore volumes are successfully synthesized using a commercial silica template. Based on the electrochemical and structural analyses, we suggest that the total pore volume of disordered mesoporous carbon is a predominant factor in determining its capability for either the absorption or adsorption of Li-polysulfides, which is primarily responsible for enhancing the cycling performance. The addition of disordered mesoporous carbon is also effective in enhancing the homogeneous distribution of active sulfur in the cathode, thereby affecting the cycling performance.

• KSBB Journal
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• v.22 no.5
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• pp.351-355
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• 2007

Resveratrol, a polyphenolic compound with antioxidative property, was purified from the grape's twig to be used as functional additives of food and/or cosmetics. Extraction of the grape's twig was performed using 80% ethanol in ultrasonic extractor for 60 min. The crude extract was purified up to 99% after elution through silica gel open column chromatography. The stability of the purified resveratrol was as follows: a half life of 90 days at 40$^{\circ}C$ and 60 days at 25$^{\circ}C$. A sensory test of the commercial grape juice including the 1-10 ppm of purified resveratrol showed better preference than the grape juice without purified resveratrol additive. Color and smell test showed no difference between the samples. The grape twig can be used as a valuable resource for the extraction of resveratrol, which would be added to nutraceutical and cosmetic products.

• Proceedings of the SAREK Conference
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• 2008.11a
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• pp.369-374
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• 2008

This study is an inorganic foaming ceramic by sol-gel reaction in order to overcome weak point of insulator using in construction equipment. We shall be able to confirm as the existing product substitute is possible result of this study. The solution where the silicate, the ceramic powder and the additive are included which makes foaming ceramic slurry, then the insulator made by used $CO_2$ Sol-Gel reaction. There being will be able to manufacture the insulator where the economical efficiency is excellent confirmed at the start product which is completed. The recording gel time decreases when the silicate will increase. Uses the hydrogen peroxide and fe make foam, when additionally surface preparation the fluorine resin, the water tolerance increases and will be able to complement the weak point of the silicate which omits in the water. The case which will use the loess powder with the research method which sees specially was environment-friendly product and according to appearing, the physical properties of nonflammability.

• Journal of the Korean GEO-environmental Society
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• v.24 no.1
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• pp.15-23
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• 2023

The grouting method is a method of construction for the purpose of waterproofing and reinforcing soft ground. When grout is injected into the ground, there are various types of penetration and diffusion of grout depending on the shape of the ground, the size of soil, the porosity, and the presence or absence of groundwater. the current situation. Therefore, in this study, to investigate the penetration performance of the grouting to conductive material, laboratory tests were performed on the addition of the conductive material. In the injection test, 0%, 3%, and 5% of the mixed water were added as conductive materials to the grout, and the original ground condition was composed of various types of ground composed of gravel and silica sand. Conductive grout is injected by pressure into the model ground using a dedicated injection device, and the injection time (t), pressure (p), flow rate (v) and injection amount (q) are measured, and the hardened body injected in the model ground is collected. Penetration performance was evaluated. In the results of the grout injection experiment, the amount of conductive material used and the grout injection rate showed an inverse relationship, and it was confirmed that the penetration pattern was changed according to the size of the soil particles in the model ground. The grout containing the conductive material has relatively good penetration into the ground and excellent strength and durability of the hardened body, so it was judged that it could be used as an additive for measuring the penetration range of the grout.

• Journal of the Korean Geotechnical Society
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• v.26 no.12
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• pp.19-30
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• 2010

Bentonite-based grout has been widely used to seal a borehole constructed for a closed-loop vertical ground heat exchanger in a geothermal heat pump system (GHP) because of its high swelling potential and low hydraulic conductivity. Three types of bentonites were compared one another in terms of viscosity and thermal conductivity in this paper. The viscosity and thermal conductivity of the grouts with bentonite contents of 5%, 10%, 15%, 20% and 25% by weight were examined to take into account a variable water content of bentonite grout depending on field conditions. To evaluate the effect of salinity (i.e., concentration of NaCl : 0.1M, 0.25M, and 0.5M) on swelling potential of the bentonite-based grouts, a series of volume reduction tests were performed. In addition, if the viscosity of bentonite-water mixture is relatively low, particle segregation can occur. To examine the segregation phenomenon, the degree of segregation has been evaluated for the bentonite grouts especially in case of relatively low viscosity. From the experimental results, it is found that (1) the viscosity of the bentonite mixture increased with time and/or with increasing the mixing ratio. However, the thermal conductivity of the bentonite mixture did not increase with time but increased with increasing the mixing ratio; (2) If bentonite grout has a relatively high swelling index, the volume reduction ratio in the saline condition will be low; (3) The additive, such as a silica sand, can settle down on the bottom of the borehole if the bentonite has a very low viscosity. Consequently, the thermal conductivity of the upper portion of the ground heat exchanger will be much smaller than that of the lower portion.