• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.507-510
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• 2000

The purpose of this study is to research and developV$_2$O$_{5}$-SP270 composite electrode for supercapacitor. Property of an electrical double layer capacitor depend both on the technique used to prepare the electrode and on the current collector structure. The study is to research that V$_2$O$_{5}$-carbon composite electrode for supercapacitor with different voltage range. Suprcapacitor cell of V$_2$O$_{5}$-SP270 composite electrode with 25PVDFLiC1O$_4$PC$_{10}$ polymer electrolyte bring out good capacitor performance below 3V. The discharge capacitance of SP270 in 1st cycles was 13F/g at 0.1mA/cm$^2$, 3V. We performed cycle voltammogram, charge/discharge property.y.rty.y.

• Computers and Concrete
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• v.1 no.1
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• pp.47-60
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• 2004

The influence of the fracture process zone (FPZ) on the fracture properties is one of the hottest topics in the field of fracture mechanics for cementitious materials. Within the FPZ in front of a traction free crack, cohesive forces are distributed in accordance with the softening stress-separation constitutive relation of the material. Therefore, further crack propagation necessitates energy dissipation, which is the work done by the cohesive forces. In this paper $g_f$, the local fracture energy characterizing the energy consumption due to the cohesive forces, is discussed. The computational expression of $g_f$ in the FPZ can be obtained for any stage during the material fracture process regarding the variation of FPZ, whether in terms of its length or width. $G_{fa}$, the average energy consumption along the crack extension region, has also been computed and discussed in this paper. The experimental results obtained from the wedge splitting tests on specimens with different initial notch ratios are employed to investigate the property of the local fracture energy $g_f$ and the average value $G_{fa}$ over the crack extension length. These results can be used to indicate the influence of the FPZ. Additionally, changes in the length of the FPZ during the fracture process are also studied.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.12
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• pp.1332-1339
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• 2005

The purpose of this study is to the distributive property of organic pollutants in effluents of domestic sewage treatment plants around Youngsan River using simultaneous analysis method of 310 chemicals. The numerous organic pollutants were detected in five sampling sites, and the major chemicals were pesticides, CH type chemicals such as benzenes and polycyclic compounds, ande CHO type chemicals such as phenols and phthalates. About 14 pesticides were detected in the effluent and most of them were found in summer. 1-Chlorobenzen and p-octylphenol were frequently detected in the concentration range of $0.52{\sim}0.61\;{\mu}g/L$ and $0.04{\sim}0.89\;{\mu}g/L$, respectively. Moreover, 18 kinds of endocrine disrupters include diethylphthalate were detected in effluents. From the results of this study, therefore, we confirmed that the pesticides, CH and CHO type chemicals in domestic effluents throughout Youngsan River are required specific regulation.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.1
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• pp.175-181
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• 2015

In this paper, we develop a 2.4GHz ISM band wireless communication platform prototype based on embedded linux which support can be u-Hospital service. The developed system is available connecting between ARM920T processor board and FPGA board and linking IEEE 802.11b PHY board, AD/DA(10Bit) and RF(2.4GHz) board for wireless access. It is also can be utilized for the embedded system design with IEEE 802.11b/g Access Point(Option: IEEE 802.11a/b/g) test due to the Embedded Linux. Also, the developed system is possible to test and verify the radio access technology, Modem(OFDM etc) and IP(Intellectual Property) circuit. And make the most use of the system, we search for a expansion to that home and mobile healthcare, wellness service application.

• Polymer(Korea)
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• v.28 no.6
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• pp.551-555
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• 2004

Cellulose diacetate (CDA) nanocomposite films were prepared by using various plasticizer and montmorillonite nanofiller in methylene chloride/ethanol (9:1 w/w) mixed solution. The thermal property (T$_{g}$) of prepared CDA films was observed by DSC and T$_{g}$ of the films was decreased with the increase in the plasticizer content. The degree of dispersion of MMT in the CDA film was observed by XRD and mechanical property of CDA film was measured by tensile strength and Young's modulus. When the plasticizer was added into the CDA film upto 30 wt%, the Young's modulus of film was decreased from 1930 MPa to 1131 MPa but was increased from 1731 MPa to 2272 MPa when the MMT was added into the film upto 7 wt%. The mechanical properties of CDA films were decreased by addition of plasticizer but strengthened by the incorporation of MMT.

• Applied Biological Chemistry
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• v.39 no.4
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• pp.274-281
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• 1996

To prepare edible skin gelatin of conger eel such as material fur quality improvement of surimi gel, the defatted skin was limed with 1% calcium hydroxide at $5^{\circ}C$ for 2 days, washed thoroughly with tap water, extracted with 8 volumes of distilled water to dehydrated skin for 2 hours at $50^{\circ}C$. The gelatin extract was centrifuged, filtered and then passed through anion(Amberlite 200C) and cation (Amberlite IR 900) resins. The purified gelatin solution was evaporated and dried by hot-air blast$(40^{\circ}C)$. The gelatin prepared by above condition had the highest quality as revealed by physical property values i.e. 240.5 g in gel strength, $28.0^{\circ}C$ in melting point and $28.0^{\circ}C$ in gelling point. Funtional property values were 56.8% in solubility, 1.8 ml/g in oil binding capacity, 55.0% in emulsifying capacity and 48.5% in emulsifying stability. jelly strength and senso교 evaluation of surimi gel from fish with red muscle were not improved by addition of emulsifying curd from conger eel skin gelatin as emulsifier. Therefore, the conger eel skin gelatin requires a suitable modification of functional group and improvement of processing operation to utilize as a material for quality Improvement of surimi gel.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.4
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• pp.557-566
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• 2005

In preparation of steamed foam-cakes, effects of whipping time, amount of wheat flour, and amounts of emulsifier on physical properties of the steamed foam cakes were investigated using RSM (response surface methodology). The three independent variables selected for the RSM experiment were whipping time $(X_1)$, amount of wheat flour $(X_2)$, and amounts of wheat flour $(X_2)$, and concentration of emulsifier $(X_3)$ were set for single-stage mixing, respectively. A rotatable central composite design was used for treatment arrangement. The responses from the product for loaf volume, color values and textural properties were analysed. In the analysis of variance for the foam cakes prepared by single-stage method, significant interactions were observed between independent variables (experimental factors) and physical property like loaf volume (p<0.05); textural properties like hardness, gumminess, and chewiness (p<0.05). Among independent variables, concentration of emulsifier had the most effects on physical properties while whipping time. The ordinary points in surface response showed maximal points with physical property like colorimetric b value while other properties revealed saddle points. The 3-dimensional response surface graphs of the predicted regression models displayed decreasing loaf volumes with increasing whipping times and emulsifier concentrations beyond optimum levels. The optimum conditions for best loaf volume and textural property (hardness, gummimess and chewiness) of the products selected by extracting intersectional areas of the contour maps that commonly overlapped all characteristics were; $11\~13$ min whipping time, $470\~486\;g$ amount of wheat flour, and $19\~20\;g$ emulsifier concentration, in case of single-stage method. The median values extracted from the RSM experimental results for optimum manufacturing conditions for single-stage method, i.e., 12 min whipping time, 478 g amount of wheat flour, and 20 g emulsifier concentration were empirically proven to fit the predicted levels of physical properties from the final foam cakes.

• Analytical Science and Technology
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• v.20 no.1
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• pp.61-69
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• 2007

The geometrical parameters, total and relative energies, vibrational frequencies, the HOMO-LUMO energy gap, and reorganization energies for the neutral molecule, anion, and cation of $C_{16}H_{16}O_3$ have been determined using density functional method (DFT). The highest level of theory employed in this study is $B3LYP/6-311G^{**}$. Harmonic vibrational frequencies were determined at the $B3LYP/6-311G^{**}$ level of theory. All positive vibrational frequencies were obtained to confirm minimum structures. The HOMO-LUMO energy gap and reorganization energies were calculated to predict the charge transport property of liquid-crystal.

• Microbiology and Biotechnology Letters
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• v.31 no.2
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• pp.171-176
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• 2003

Productivity of biosurfactant (rhamnolipid) by Pseudomonas aeuginosa F722 was investigated in the several culture conditions and culture composition. Biosurfactant production by P. aeuginosa F722 was amounted to 0.78 g/l as the result of the nitrogen sources and carbon sources without investing of optimum conditions. As for that one was investigated, biosurfactant production by P. aeruginosa F722 was amounted to 1.66 g/l. Biosurfactant production increased twofold because the composition of a modified C-medium was investigated efficiently. $NE_4$Cl or $NaNO_2$ inorganic nitrogens and yeast extract or trypton organic nitrogens were effective, but others inorganic nitrogens and organic nitrogens tested were not efficient far biosurfactant production by P. aeruginosa F722. The optimum concentration of $NH_4$Cl; inorganic nitrogen and yeast extract; organic nitrogen were 0.05% and 0.1%, respectively. In various carbon sources, others with the exception of hydrophobic property substrate (n-alkane) and hydrophilic property substrate (glucose, glycol) were not found to be effective fur biosurfactant production, and 3.0% was better in yield than other concentration of glucose. This yielded C-to-N ratios between 17 and 20. In our experiment, the highest biosurfactant production by P. aeruginosa F722 were observed in 5 days cultivation, containing glucose 3.0%, $NH_4$Cl 0.05%, and yeast extract 0.1% and C-to-N ratio was 20. Optimal pH and temperature for biosurfactant production were 7.0 and $35^{\circ}C$, respectively. Under the optimal culture conditions with glucose, biosurfactant production was amounted to 1.66 g/l. Velocity of biosurfactant production and strain growth increased after nitrogen depletion. The average surface tension of 30 mN/m after the 3 days of incubation under optimal culture condition was measured by ring tensionmeter.

• Journal of Life Science
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• v.9 no.6
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• pp.737-742
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• 1999

The extremely halophilic archaebacterium Haloarcular sp. EH-1 was isolated from solar salts. Haloarcular sp. EH-1 accumulated poly(3-hydroxyalkanoate) (PHA) as intracellular granules. PHA production in batch culture have been studied. The PHA was identified as poly(3-hydroxybutyric acid-co-3-hydroxyvaleric acid) (PHB/HV) of 3-hydroxybutyric acid and 3-hydroxyvaleric acid by the analysis of GC, IR and NMR. The melting temperature of PHB/HV was 152.46$^{\circ}C$, viscosity was 1.25 ㎗/g, and molecular weight was $1.44 X 10^5.$