• Journal of Animal Environmental Science
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• v.6 no.3
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• pp.185-190
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• 2000

TAO system and solid-liquid separation (28mesh filter and 200mesh filter) were applied in processing piggery slurry to see the reduction of N and P and to draw the efficiency in reducing manure application area. The results are as follows; 1. The amount of N and P in slurry of $4.6m^3/day$ was 22.5kg/day ($4,893mg/{\ell}$) and 7.32kg/day ($1,592mg/{\ell}$). 2. Reduction rate of N and P by TAO reactor was 9.9 kg/day (46.0%) and 3.47kg/day(34.0%). 3. Reduction rate of N and P by Solid-liquid separation was 10.5kg/day (46.6%) and 5.12kg/day (69.8%). 4. One the basis of the amount of nitrogen composting, the square size of liquid manure sprinkled area was reduced from 74.6ha/y to 39.0ha/y in rice paddy, and from 63.2ha/y to 33.0ha/y by the treatment.

• Korean Journal of Medicinal Crop Science
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• v.17 no.4
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• pp.233-237
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• 2009

Astragalus membranaceus has a long history of medicinal use in Chinese herbal medicine. It has been shown to have immunostimulant, tonic, antioxidant, antiperspirant, diuretic, anti-diabetic, expectorant properties, and a supplementary medicine during cancer therapy. In this study, we investigated the effect of anti-oxidation of Astragalus membranaceus root extract. The anti-oxidative activities of water, 80% methanol, and 100% methanol extracts from Astragalus membranaceus were analyzed by DPPH free radical scavenging activity, Superoxide dismutase-like activity, reducing power, and crude ash. The water extract demonstrated to be more effective than methanol extract for a DPPH radicals scavenging activities and reducing power. Superoxide dismutase-like activity showed higher efficiency in 80% methanol extract. Our results indicate that Astragalus membranaceus extracts could be used as a source of antioxidant ingredients in the food industry.

• Journal of environmental and Sanitary engineering
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• v.14 no.3
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• pp.123-129
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• 1999

The utilization methods of algae biomass have been studied constantly in whole world. These are $\circled1$the wastewater treatment if waste stabilization pond and oxidation ditch etc. and $\circled2$the biosorption of heavy metals and recovery of strategic' precious metals and $\circled3$the single-celled protein production and the production of chemicals like coloring agent and $\circled4$the production of electric energy through methane gasification. The culture system also has been developed constantly in relation with such utilization method developments. In the result of experimental operation under continuous and cyclic irradiation of light, using high rate algae biomass culture pond(HRABCP), which had been made so as to be an association system with the various items which had been managed to have high efficiency for algae culture, the algae production of the 12 hours-irradiance pond was 41.48 Chlorophyll-a ${\mu}g/L$ only in spite of having the more chance of $CO_2$ synthesis to algae cell than the 24 hours-irradiance pond. This means that the energy supply required for dark-reaction of photosynthesis is very important like this. The difference of algae production between continuous and cyclc irradiation explains that the dark-reaction of photosynthesis acts on algae production as the biggest primary factor. The continuous irradiance on HRABCP made the good algae-production($1403.97{\;}{\mu}g$ Chlorophyll-a/mg) and the good oxygen-production(5.8 mg $O_2/L$) and the good solid-liquid seperation. especially, DO concentration through the oxygen-production was enough to fishes' survival.

• Journal of the Korean Ceramic Society
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• v.39 no.1
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• pp.86-91
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• 2002

Solid Oxide Fuel Cells (SOFC) are of great interest of next generation energy conversion system due to their high energy efficiency and environmental friendliness. The basic SOFC unit consists of anode, cathode and solid electrolyte. Among these components, anode plays the most important role for the oxidation of fuel to generate electricity and also behaves as a substrate of the whole cell. It is normally requested that the anode materials should have the high electrical conductivity and gas permeability to reduce the polarization loss of the cell. In this study, the effect of pore former on the microstructure of anode substrate was investigated and thus on the electrical conductivity and the gas permeability. According to the results, microstructure and electrical conductivity of anode substrate were greatly influenced by the shape of pore former and especially by the anisotrpy of the pore former. The use of anisotropic pore former is supposed to deteriorate the cell performance by which the electrical conduction path is disconnected but also the effective gas diffusion path for the fuel is reduced.

• Bulletin of the Korean Chemical Society
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• v.23 no.2
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• pp.281-285
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• 2002

The photophysical properties and the singlet oxygen generation efficiencies of meso-tetraphenyl-trithiasapphyrin $(S_3TPS)$ and meso-tetmkis(p-methoxy phenyl)-trithiasapphy rin ((p-MeO)-$S_3TPS$) have been investigated, utilizing steady-state and time-resolved spectroscopic methods to elucidate the possibility of their use as photosensitizers for photodynamic therapy (PDT). The observed photophysical properties were compared with those of other porphyrin-like photosensitizers in geometrical and electronic structural aspects, such as extended ${\pi}$ conjugation, structural distortion, and internal heavy atoms. The steady-state electronic absorption and fluorescence spectra were both red-shifted due to the extended ${\pi}$-conjugation. The fluorescence quantum yields were measured as very small. Even though intersystem crossing rates were expected to increase due to the increment of spin orbital coupling, the triplet quantum yields were measured as less than 0.15. Such characteristics can be ascribed to the more enhanced internal conversion rates compared with the intersystem crossing rates. Furthermore, the triplet state lifetimes were shortened to -1.0 ${\mu}s$ as expected. Therefore, the singlet oxygen quantum yields were estimated to be near zero due to the fast triplet state decay rates and the inefficient energy transfer to the oxygen molecule as well as the low triplet quantum yields. The low efficiencies of energy transfer to the oxygen molecule can be attributed to the lower oxidation potential and/or the energetically low lying triplet state. Such photophysical factors should be carefully evaluated as potential photosensitizers that have extended ${\pi}$-conjugation and heavy core atoms synthesized for red-shifted absorption and high triplet state quantum yields.

• Transactions of the Korean hydrogen and new energy society
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• v.17 no.1
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• pp.62-68
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• 2006

High temperature electrolysis is a promising technology to produce massively hydrogen using renewable and nuclear energy. Solid oxide fuel cell materials are candidates as the components of steam electrolysers. However, the polarization characteristics of the typical electrode materials during the electrolysis have not been intensively investigated. In this study, NiO electrode was deposited on YSZ electrolyte by spin coat process and firing at $1300^{\circ}C$. Pt electrode was applied on the other side of the electrolyte to compare the polarization characteristics with those by NiO during electrolysis. The $H_2$ evolution rate was also monitored by measuring the electromotive force of Lambda probe and calculated by thermodynamic consideration. At low current density, Pt showed lower cathodic polarization and thus higher current efficiency than Ni, but the oxidation of Ni into NiO caused the increase of anodic resistance with increasing current density. High overpotential induced high power consumption to produce hydrogen by electrolysis.

• KSBB Journal
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• v.15 no.4
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• pp.375-379
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• 2000

Alginate derivatives possessing various lengths of alkyl amine (C8, C12, C16) chain were prepared by oxidation followed by reductive amination of alginate and the products were characterized by spectral analysis. The surface tension critical micelle concentration (c. m. c) and solubility of a hydrophobic compound azobenzene were examined. Series of synthesized alginate-derived polymeric surfactants(APSs) reduced the surface tension. The dissolving capacity of APSs toward azobenzene was about half that of SDS. In order to investigate the capacity of metal adsorption Co and Pb were selected as a representative metal. The overall removal efficiency of APSs were high compared with that of alginate at pH 3.5 and 7 respectively. Major mechanism of the heavy metal removal is the complex of metal with carboxyl group.

• Food Science of Animal Resources
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• v.40 no.4
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• pp.636-648
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• 2020

This study investigated the effects of the addition levels of white kimchi powder and acerola juice powder, as natural sources of sodium nitrite and sodium ascorbate, on the quality of cooked ground pork products. Freeze-dried white kimchi powder was prepared and used after fermentation for 2 wk. Six treatments were included: control (100 ppm sodium nitrite and 500 ppm sodium ascorbate), treatment 1 (0.2% white kimchi powder, 0.02 % starter culture, and 0.1% acerola juice powder), treatment 2 (0.2% white kimchi powder, 0.02% starter culture, and 0.2% acerola juice powder), treatment 3 (0.4% white kimchi powder, 0.04% starter culture, and 0.1% acerola juice powder), treatment 4 (0.4% white kimchi powder, 0.04% starter culture, and 0.2% acerola juice powder), and treatment 5 (0.4% celery powder, 0.04% starter culture, and 0.2% acerola juice powder). The pH values were decreased (p<0.05) because of lower pH of acerola juice powder, resulting in lower cooking yields (p<0.05) in these treatments. CIE L* and CIE a* values of indirectly cured meat products were not different (p>0.05) from the sodium nitrite-added control. However, indirectly cured meat products showed lower (p<0.05) residual nitrite contents, but higher (p<0.05) nitrosyl hemochrome contents and cure efficiency than the control. Treatments 2 and 4 had higher (p<0.05) total pigment contents and lipid oxidation than the control. This study indicates that white kimchi powder coupled with acerola juice powder has substantial potential to substitute synthetic nitrite to naturally cured meat products, which could be favored by consumers seeking clean label products.

• Journal of Soil and Groundwater Environment
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• v.20 no.6
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• pp.117-126
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• 2015

Reductive degradation of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) by nanoscale zero-valent iron (nZVI) was investigated to evaluate the feasibility of using it for in-situ groundwater remediation. Batch experiments were conducted to quantify the kinetics and efficiency of RDX removal by nZVI, and to determine the effects of pH, dissolved oxygen (DO), and ionic strength on this process. Experimental results showed that the reduction of RDX by nZVI followed pseudo-first order kinetics with the observed rate constant (k_obs) in the range of 0.0056-0.0192 min⁻¹. Column tests were conducted to quantify the removal of RDX by nZVI under real groundwater conditions and evaluate the potential efficacy of nZVI for this purpose in real conditions. In column experiment, RDX removal capacity of nZVI was determined to be 82,500 mg/kg nZVI. pH, oxidation-reduction potential (ORP), and DO concentration varied significantly during the column experiments; the occurrence of these changes suggests that monitoring these quantities may be useful in evaluation of the reactivity of nZVI, because the most critical mechanisms for RDX removal are based on the chemical reduction reactions. These results revealed that nZVI can significantly degrade RDX and that use of nZVI could be an effective method for in-situ remediation of RDX-contaminated groundwater.

• Korean Journal of Materials Research
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• v.20 no.4
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• pp.228-234
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• 2010

In this paper, Fe-$TiO_2$ and Fe-fullerene/$TiO_2$ composite photocatalysts were prepared with titanium (IV) n-butoxide (TNB) by a sol-gel method. $TiO_2$, Fe-$TiO_2$ and Fe-fullerene/$TiO_2$ were characterized by scanning electron microscopy (SEM), Transmission electron microscope (TEM), specific surface area (BET), X-ray diffraction analysis (XRD) and energy dispersive X-ray spectroscopy (EDX). The photocatalytic activities were evaluated by the photocatalytic oxidation of methylene blue (MB) solution. XRD patterns of the composites showed that the photocatalyst composite contained a typical single and clear anatase phase. The surface properties shown by SEM presented a characterization of the texture on Fe-fullerene/$TiO_2$ composites and showed a homogenous composition in the particles for the titanium sources used. The EDX spectra for the elemental identification showed the presence of O, C and Ti elements. Moreover, peaks of the Fe element were observed in the Fe-$TiO_2$ and Fe-fullerene/$TiO_2$ composites. The degradation of MB solution by UV-light irradiation in the presence of photocatalyst compounds was investigated in complete darkness. The degradation of MB concentration in aqueous solution occurred via three kinds of physical phenomena: quantum efficiency of the fullerene; organo-metallic reaction of the Fe compound; and decomposition of $TiO_2$. The degradation rate of the methylene blue solution increased when using Fe-fullerene/$TiO_2$ compounds.