• Journal of the Korean Crystal Growth and Crystal Technology
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• v.22 no.2
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• pp.92-98
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• 2012

The co-precipitation technique has been applied to synthesize biphasic calcium phosphate (BCP). $Ca(NO_3)_2{\cdot}4H_2O$, $(NH_4)_2HPO_4$, TEOS and $Mg(NO_3)_2{\cdot}6H_2O$ as the starting materials was used. After the heat treatment of powder crystalline phases HAp and ${\beta}$-TCP analysis showed a mixed phase. The overall spectra appear to have mainly two modes corresponding to characteristic $PO^{3-}_4$ and $OH^-$ groups. After immersion in Hanks' Balanced Salt Solution (HBSS) for 1 week a precipitation started to be formed with individual small granules on the specimen surface. An MTT assay indicated that ionic substituted BCP powders had no cytotoxic effects on MG-63 cells, and that they have good biocompatibility.

• Journal of the Korean Chemical Society
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• v.45 no.5
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• pp.413-421
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• 2001

The carbon electrodes for fluorine electrolysis were prepared from petroleum cokes containing coal tar pitch as binder and the effects of binder contents on electrode properties were investigated. The evaluations were performed by cyclic voltammogram in the 0.5 M $K_2SO_4$ solution with 1 mM $[Fe$(CN)_6$]^{3-}$/$[Fe$(CN)_6$]^{4-}$redox couple, mechanical strength, and electrochemical behaviour in molten $KF{\cdot}2HF$ electrolyte. It was revealed that the carbon anode formed with 40wt% of coal tar pitch as binder has a better electrode properties compared to those of the other carbon anode, which led to the increase in the effective internal surface area due to proper size and distribution of pores on carbon anode.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.1
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• pp.115-120
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• 2006

To convert the soybean curd residue (SCR) to functional food ingredient, alkaline fermentation of SCR was performed by Bacillus firmus NA-1 and Bacillus subtilis GT-D for 22 hr at $42^{\circ}C$. The micronized full-fat soy flour (MFS) was fortified to reduce the moisture content as well as to supply protein source. The mucilage and flavor productions in the fermented SCR were enhanced by the fortification of $20\%$ MFS. The peptide production from the SCR fermented with B. subtilis GT-D substantially increased when judged by the detectable amount of tyrosine $(480\;mg\%)$. The production of fibrinolytic enzyme was increased by the fermentation for 22 hr, indicating the relative activity of $62\%$ (B. firmus NA-1) and $47\%$ (B. subtilis GT-D), respectively. The SCR fermented by B. firmus NA-1 and B. subtilis GT-D indicated the consistency of $1.95\;Pa{\cdot}s^n\;and\;0.21\;Pa{\cdot}s^n$, respectively. After freeze-drying, the protease activity (615 unit/g) and a-amylase activity (180 unit/g) were obtained from SCR fermented by Bacillus firmus NA-1 and Bacillus subtilis GT-D, respectively.

• Journal of the Korean Vacuum Society
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• v.15 no.5
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• pp.506-511
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• 2006

ZnO nanorods were prepared by the hydrothermal reaction of a solution containing $Zn(NO_3)_2{\cdot}6H_2O$, NaOH, cyclohexylamine, ethanol and water, and their $NO_2$ and CO sensing behaviors were investigated. By the control of water concentration in solution, the morphology and agglomeration of ZnO nanorods could be manipulated, which is associated with the variation of $[OH^-]$ resulted from an interaction between water and cyclohexylamine. Sea-urchin-like and well-dispersed ZnO nanorods were prepared at low and high water content, respectively. Well-dispersed ZnO nanorods showed 1.8 fold change in resistance at 1 ppm $NO_2$ while there was no significant change in resistance at 50 ppm CO. This selective detection of $NO_2$ in the presence of CO can be used in automated car ventilation systems.

• Clean Technology
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• v.6 no.1
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• pp.61-69
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• 2000

In this study, generation process and properties of inorganic industrial waste which can be used in cement industry were investigated. The scheme of recycling to use the selected waste as raw materials, mineralizer and flux, admixture and raw materials for special cement was decided and then various experiments were carried out. The experimental results were as follows ; In the use of industrial waste as raw materials, ferrous materials could be substituted by Cu-slag, Zn-slag, electric arc furnace or convertor furnace slag etc., and a siliceous material could be substituted by sand from cast-iron industry. By-products from sugar or fertilizer industry, which has $CaF_2$ as the main component, and jarosite from Zn refinery enabled clinker phases to be formed at lower temperature by $100{\sim}150^{\circ}C$. Adding Cu slag and STS sludge in proper proportion to cement improved properties of cement. Fly ash and limestone powder as admixture had the same effect on cement. As a raw material for special cement, aluminium waste sludge could be used in making ultra early strength cement, which had the compressive strength of $300kg/cm^2$ within 2hours. And two different ashes from municipal incinerator could be raw materials of the cement which was mainly composed of $C_3S$ and $C_{11}A_7{\cdot}CaCl_2$ as clinker phases.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.2
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• pp.87-92
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• 2000

This study was designed to investigate the effects og $10{\%},\;20{\%}\;and\;40{\%}$-addition of functional brown algae (FBA)-noodles on oxygen radicals and their scavenger enzymes in liver of Sprague-Dawley(SD) male rats. Hydroxyl radicals$({\cdot}OH)$ formations were significantly inhibited$(20{\~}35{\%}\;and\;12{\~}20{\%})$ in liver mitochondria and microsomes of rats administered $0{\%},\;20{\%}\;and\;40{\%}$ FBA-noodles compared with that of control group. Significant differences in $H_2O_2$ formations of liver microsome in these FBA-noodles fed groups could not be obtained, but superoxide-radical $(O_2^({\cdot}-))$ formations of liver cytosol resulted in a significant decrease about $10{\%}\;in\;20{\%}\;and\;40{\%}$ FBA-noodles compared with control group. Mn-SOD activities in liver mitochondria were significanlty increased $(10{\~}15{\%})$ in the groups fed $10{\%},\;20{\%}\;and\;40{\%}$ FBA-noodles, while a group administered $40{\%}$ FBA-noodle only resulted In a significant increases $(about 12{\%})$ in Mn-SOD activity of liver microsomes compared with control group. Cu, Zn-SOD activities in liver cytosol were significantly increased $(10{\~}20{\%})\;in\;10{\%},\;20{\%}\;and\;40{\%}$ FEA-noodles compared with control group. Administration of $10{\%},\;20{\%}\;and\;40{\%}$ FBA-noodles resulted in a marked increases$(20{\~}40{\%})$ in liver cytosolic glutathione peroxidase (GSHPx) compared with control group. Significant differences in lipid peroxide (LPO) levels of mitochondria and microsomes in $10{\%}$ FBA-noodle could not be obtained, while LPO levels of $20{\%} and 40{\%}$ FBA-noodles were significantly inhibited about $10{\%}$ in mitochondria and microsomes compared with control group. These results suggest that these FBA-noodles may play a desirable role in attenuating an oxygen radical formations and increasing a scavenger enzymes activity by some brown algae (Undaria pinnatifida) components.

• Korean Journal of Medicinal Crop Science
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• v.5 no.2
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• pp.102-107
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• 1997

This study was carried out to increase the rate of plant regeneration from embryogenic callus of A. keiskei on MS medium supplemented with ethylene inhibitors. When leaflet, petiolule, and petiole of A. keiskei were cultured on MS medium supplemented with 2, 4-D, callus was well induced from leaflet segments at 2.0 ppm 2, 4-D. Shoot elongation of plantlets and shooting from embryogenic callus of A. keiskei were best on 2, 4-D-free medium supplemented with 2 ppm $AgNO_3$ or 10 ppm $CoCl_2{\cdot}6H_2O$, but it was suppressed on the medium containing 1 ppm 2, 4-D with $AgNO_3$ or $CoCl_2{\cdot}6H_2O$. Root elongation of plantlets from embryogenic callus was best on 2, 4-D-free medium supplemented with 1 ppm $AgNO_3$ or 5 ppm $CoCl_2{\cdot}6H_2O$, but rooting from embryogenic callus was none on the medium containing 1 ppm 2, 4-D with $AgNO_3$ or $CoCl_2{\cdot}6H_2O$. Fresh weight of plantlets from embryogenic callus was heaviest on 2, 4-D-free medium supplemented with 2 ppm of $AgNO_3$ or $CoCl_2{\cdot}6H_2O$, while it was heaviest on the medium containing 1 ppm 2, 4-D with 1 ppm $AgNO_3$ or 2 ppm $CoCl_2{\cdot}6H_2O$.

• Korean Chemical Engineering Research
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• v.54 no.1
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• pp.135-139
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• 2016

We developed a liquid-liquid extraction method using an inorganic salt to dramatically improve the recovery efficiency of the anticancer agent paclitaxel from plant cell cultures. As a result of liquid-liquid extraction using a diverse types of inorganic salt (NaCl, KCl, $K_2HPO_4$, $NaH_2PO_4$, $NaH_2PO_4{\cdot}2H_2O$), NaCl gave the highest yield (~96%) and lowest partition coefficient (0.053) of paclitaxel. The optimal NaCl/solvent ratio, methylene chloride/MeOH ratio, and pure paclitaxel content for liquid-liquid extraction using NaCl were 1% (w/v), 26% (v/v), and 0.066% (w/v), respectively. Under the optimal conditions developed in the present method, most of the paclitaxel (~96%) was recovered from biomass by a single extraction step. In addition, this method facilitated 3-fold higher recovery efficiency of paclitaxel in a shorter extraction number than the conventional liquid-liquid extraction method.

• Applied Biological Chemistry
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• v.36 no.1
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• pp.11-16
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• 1993

A bacteria strain producing extracellular protein was isolated and identified from soil samples, and the optimum conditions of producing protein were investigated. Eleven strains of bacteria were isolated from soil samples. Among which WY-60 strain showed a very strong capability of producing protein and identified as a Bacillus sp. The optimum composition of nutrient medium for the production of the protein by WY-60 was fructose 4.0%, polypeptone 1.0%, $NH_4NO_3$ 0.1%, $K_2HPO_4$ 0.1%, $MgSO_4{\cdot}7H_2O$ 0.005%, $CaCO_3$ 1.0% and the optimum pH and temperature were 8.0 and $30^{\circ}C$, respectively. The penicillin G and lincomycin added to the above medium were effective for the protein production of the WY-60, but other antibiotics were non-effective. The maximum production of protein was obtained after 5 days culture.

• Journal of the Korean Electrochemical Society
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• v.4 no.1
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• pp.10-13
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• 2001

Effects of an anionic surfactant pentadecafluorooctanoic acid on the photoluminescence of porous silicon was investigated, which was prepared by photoelectrochemical etching at 4V of single crystalline n-type silicon (100) with the specific resistivity of $0.4\~0.8{\Omega}{\cdot}cm$. Photoluminescence shifted to shorter wavelength and its intensity decreased when the concentration of the surfactant increased. FT-IR and contact angle data supported the presence of the surfactant lying on the surface of porous silicon.