• Applied Biological Chemistry
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• v.50 no.3
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• pp.147-153
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• 2007

To search for a molecular design of a new breast cancerous inhibitory active compound, 2D-QSAR and HQSAR between the substituents of flavopiridol analogues as substrates and their breast cancerous inhibitory activities against MCF-7 cell were analyzed and discussed quantitatively. It was found that the dispersion with molecule and steric hindrance with substituents will have a tremendous impact on the inhibitory activities from the 2D-QSAR model (1). Also, MR constant is better than that of MS constant as animportant factor. The inhibitory activities from 2D-QSAR model (2) were dependent upon the optimum MR constant (MR = 126 $Cm^3/mol$). Optimized HQSAR model (V) exhibited the best predictability of the inhibitory activities based on the cross-validated $r^2_{cv}$($q^2$= 0.583) and non-cross-validated conventional coefficient ($r^2_{ncv}$= 0.982). From the contribution maps, the inhibitory activity by the imino group on $C_9$ atom was higher than that of the hydroxyl group of $C_8$ atom on the A ring in molecule. Therefore, we can confirm that the dispersion by substituents in molecule is the most important factor in inhibitory activities against MCF-7 cell.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.10
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• pp.743-748
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• 2013

The purposes of this study are to prepare Hanji fiber-filter sheets using replacement liquid in water-swollen fiber with non-polar solvent such as ethanol, methanol and pentane. The experiments were studied on the selection of optimal non-polar solvent and the optimal drying method for wetted fiber and then were to know physicochemical characteristics of prepared Hanji fiber-filter sheet. The Ethanol as liquid changer in water-swollen fiber was excellent solvent and the optimal drying method for them was freeze drying served with vacuum pump. The bulk density and porosity of prepared fiber sheet from freeze dryer were 0.11-0.13 g/mL, half of natural dried fiber sheet, and 90%, respectively. The results of SEM observation for the fiber sheet prepared with natural drying or heating drying were shown very close structure of fiber wall in dry state. However, the freeze drying sheet were shown the open structure. So, the head loss of freeze drying sheet was very lower than natural drying and heating drying sheets. From the results of BTEX removal experiments, the sheets dried at water wetted condition was shown more higher efficiency than the fiber sheets dried at solvent wetted condition.

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.2
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• pp.165-171
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• 2016

The objective of this study is to evaluate the compressive strength development and ecological characteristics of mortars using expanded vermiculite absorbing bacteria as a fundamental investigation to develop precast eco-concrete products. For bacterial growth under the high-alkalinity and high-dried environments within hardened mortars and for creating plant growth function to mortars, Bacillus alcalophilus and Rhodoblastus acidophilus were separated and cultured. The cultured bacteria were absorbed into expanded vermiculite selected for bacteria shelter. The expanded vermiculite absorbing bacteria was then added into mortar mixture as a volumetric replacement of fine aggregate. Test results showed that the developed technology is very effective in enhancing the plant growth onto the hardened mortars and reducing the COD and T-N concentration in raw water. The optimum replacement level of expanded vermiculite absorbing bacteria can be recommended to be less than 10% considering the compressive strength development and cost of mortars along with the ecological effectiveness.

• Journal of the Korean Ceramic Society
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• v.41 no.3
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• pp.221-228
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• 2004

Basic properties of artificial lightweight aggregate by using waste dusts and strength properties of LWA concrete were studied. Bulk specific gravity and water absorption of artificial lightweight aggregates varied from 1.4 to 1.7 and 13 to 16%, respectively. Crushing ratio of artificial lightweight aggregate was above 10% higher than that of crushed stone or gravel. As a result of TCLP leaching test, the leaching amount of tested heavy metal element was below the leaching standard of hazardous material. Slump, compressive strength and stress-strain properties of LWA concrete made of artificial lightweight aggregate were tested. Concrete samples derived from LWA substitution ratio of 30 vol% and W/C ratio of 45 wt% showed the best properties overall. Thermal insulation and sound insulation characteristics of light weight concrete panel with the optimum concrete proportion were tested. Average overall heat transmission of 3.293W/㎡$^{\circ}C$ was observed. It was higher by about 15% than those of normal concrete made by crushed stone. Sound transmission loss of 50.9 ㏈ in frequency of 500 ㎐ was observed. It was higher by about 13% than standard transmission loss.

• Explosives and Blasting
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• v.21 no.2
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• pp.21-30
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• 2003

Currently, the shotcrete used as basic support in the tunnel excavation, has the advantages of maintaining high-level strength in condition of early shooting with thin thickness based on the excavation characteristics of rock mass. Therefore supreme equipment and materials were developed and the great strides have continued. Also, the development of measurement technology and the rocks behaviors of undergound are evaluated in detail and the designs of strength and thickness are made. The reinforcement materials development of new material is carried on. Most of the coal fly ash produced in Korea fire power plant is fly ash and bottom mash. Fly ash has been producing to be applied in many fields such as cement, aggregate, construction, civil, agriculture and fisheries. Also a lot of experiments are actively on the way. Therefore in this experiment, in order to use the fly ash mixed with concrete as a material of shotcrete, the experiment was performed in the best content to reduce the compression strength and the shooting rebound ratio of the excavated surface to use fly ash as a substitute material of concrete. As a result, when 15%.wt substitution was made to the fly ash, about 10% of compression strength and 6% of rebound ratio was reduced.

• Journal of the Korean Ceramic Society
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• v.33 no.8
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• pp.895-900
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• 1996

Ba(Ti1-xSnx)4O9 powder was synthesized by oxalate method. With the substitution of Sn into Ti site the sintered BaTiO4 crystal phase was stabilized due to the formation of solid solution. The optimal amounts of Sn solutbility for formation of BaTi4O9 crystalline phase was 0.16mole and of Sn was substituted and sintering was done at 135$0^{\circ}C$ for 30 minutes long rod type crystal was well developed and the highest Q value was obtained. But dielectric constant wasnearly constant without regarding to the Sn addition and the sintering time.

• Korean Journal of Organic Agriculture
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• v.23 no.4
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• pp.813-827
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• 2015

This study was conducted to evaluate the effect of organic inputs on soil properties in a newly reclaimed organic soils. The soil of the experiment site was very low in soil fertility and the physico-chemical properties were poor. Several organic input treatments with different source of nutrient were placed, including compost in combination with green manures for organic agricultural practices, chemical fertilizers for conventional agricultural practices, and control without fertilizer. The experiment was conducted with continuous cropping system during 3 years. The chemical properties concentration in compost+green manure treatment was increased continually compare to control and chemical fertilizer treatment, and closed to the recommended rate of fertilizer. The organic matter value for compost+green manure treatment was increased from 0.86~0.96% to 2.00~2.29% by continuous nutrient supply of compost and green manure. However, further investigation on increasing of organic matter value for 3 years is necessary to monitor carefully during the long-term because it will help to clarify the all mechanisms of organic matter on organic input application way. The available phosphate value for compost+green manure treatment was generally increased from 21.9~27.1 mg/kg to 182.0~394.1 mg/kg. In case of exchange cation, the concentration for compost+green manure treatment was increased during 2 years within the range to the recommended rate of fertilizer, however, it is expected to cause a rather over supply for 3 years.

• Applied Chemistry for Engineering
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• v.2 no.3
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• pp.270-278
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• 1991

Carboxymethyl chitin(CM-chitin) was prepared by the reaction of alkali chitin with monochloroacetic acid in isopropyl alcohol. According to the pH variation, the adsorptivity of this chelating polymer to the alkali-earth metal ions such as $Ca^{2+},\;Mg^{2+}$, $Sr^{2+}$, $Ba^{2+}$ ions was determined by batch method. The adsorption tendency of this chelating polymer to most metal ions was increased with the increase of pH. The highest degree of adsorption was observed toward $Ca^{2+}$ ion among the alkali-earth metal ions. The selectivity adsorption property toward $Ca^{2+}$ ion was examined in the solution of $Ca^{2+}$ and $Mg^{2+}$ ions, and it was observed that CM-chitin showed excellent selectivity to $Ca^{2+}$ ion than $Mg^{2+}$ ion. $Mg^{2+}$ ion bound to CM-chitin molecule in the presence of $Ca^{2+}$ ion owing to low equilibrium constant. In the adsorption experiment of $Ca^{2+}$ and $Mg^{2+}$ ions to the CM-chitin under coexistence of $Na^+$ and $K^+$ ions, it observed that adsorptivity of only $Ca^{2+}$ ions was not affected by these monovalent cations.

• KSBB Journal
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• v.11 no.5
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• pp.606-612
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• 1996

A specific ammino auid in a mixture can be crystallized inside an ion exchange column when displacer concentration is high enough to concentrate the amino acid in a pure band beyond its solubility limit. Glutamic acid formpd a discrete crystal layer in a cation exchanger column by operating displacement development mode and using a high concentration of displacer NaOH. The glutamic acid crystal formed was eluded from the column with the effluent stream and collected in a fraction collector. When 1.0 M of NaOH was used as a displacer, more than 60% of the loaded glutamic acid was recovered as crystal. The continuous crystallization and dissolution of crystal occurred, resulting in apparent movement of the crystal along the column without clogging or pressure increase. NaOH was proved a better displacer than NaCl because hydroxide ions neutralized hydrogen ions released from the resin and thus reduced the number of hydrogen ion competing with sodium ion for re-adsorption. The displacement development process coupled with crystallization provided higher concentration and recovery of glutamic acrid than conventional chromatography.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.2B
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• pp.325-333
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• 2010

Most communication systems including Wibro use quasi-cyclic LDPC codes composed of circulants. However, it is very difficult to design quasi-cyclic(QC) LDPC codes with optimal degree distribution satisfying conditions on layered decoding and girth due to the restriction of the size of its base matrix. In this paper, we propose a good solution by introducing superposition matrices to QC LDPC codes. We derive the conditions on checking girth of QC LDPC codes with superposition matrices, and propose new decoder to support layered decoding both for original QC LDPC codes and their modifications with superposition matrices. Simulation results show considerable improvements to convergence speed and error-correcting performance of proposed scheme which adopts QC LDPC codes with superposition matrices.