• Food Science and Preservation
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• v.16 no.1
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• pp.109-114
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• 2009

To develop Salicornia herbacea as a functional food material, crude polysaccharides and saponins were isolated from 80% ethanolic extracts of Salicornia herbacea using Diaion HP-20 column chromatography, and biological activities including anti-oxidation, anti-proliferation of cancer cells, and immune activities were investigated. The hydrogen-donating properties of crude polysaccharides and saponins were above 20% at $500{\mu}g/mL$ concentration. The reducing power of fractions increased in a dose-dependent manner. Crude polysaccharides and saponins at $500{\mu}g/mL$ inhibited more than 20% and 50% of proliferation by PC-3 and HT-29 human cancer cells, respectively. The anti-oxidative and anti-cancer properties of crude saponins were higher than those of crude polysaccharides. Also, proliferation in spleen cells and (nitric oxide) NO production in RAW264.7 macrophages treated with crude polysaccharides increased in a dose-dependent manner compared with the untreated control cells. However, crude saponins at concentration greater than $500{\mu}g/mL$ resulted in decreases in immune activities. Immune activities of crude polysaccharide were greater than those of crude saponins. These results indicate that Salicornia herbacea may be used as functional food materials.

• Clean Technology
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• v.14 no.1
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• pp.61-68
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• 2008

There have been great attentions on polymer electrolyte membrane fuel cell (PEMFC) due to their advantageous characteristics such as zero emission of hazardous pollutant and high energy density. In this work, we evaluated degradation phenomena and stability of single cell performance via one dimensional single cell modeling. Here, CO poisoning on anode on anode was considered for cell performance degradation. Modeling results showed that the performance and stability were highly degraded with CO concentration in fuel gas. In addition, cell performance was reduced by slow oxygen reduction on cathode in long term operation. In order to overcome, it is required to increase ratio o#hydrogen in the fuel gas of anode and high Pt loading contained in the cathodic catalyst layer.

• Nuclear Engineering and Technology
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• v.13 no.3
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• pp.145-152
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• 1981

Even though a lately reported method of high temperature exchange labelling of o-iodo-hippuric acid (Hippuran) in the absence of oxidizing agent was considered to be an attractive one, the exchange mechanism was somewhat unclear. In this study iodine isotope exchanges between o-iodohippuric acid (OIH) and radioiodide ($^{125}$ $I^{ }$) or between OIH and molecular radioiodine ($^{125}$ $I_2$) were carried out at two different temperatures. Rate constants and activation parameters were measured by applying a radio-paper chromatography technique. Since o-iodobenzoic acid is known as a by-product in the exchange labelling of OIH, data were also obtained for the OIB-iodide systems for comparison. The rate constant was increased in the order of OIB...$^{125}$ $I^{[-10]}$ >OIB...$^{125}$ $I_2$>OIH..$^{125}$ $I^{[-10]}$ >OIH...$^{125}$ $I_2$ and the activation parameters for OIH were generally larger than those for OIB :$\Delta$H$\neq$$_{OIH}$>$\Delta$H$\neq$$_{OIB}$, $\Delta$S$\neq$$_{OIH}$>$\Delta$S$\neq$$_{OIB}$. These results suggest that the mechanism of the high temperature exchange is predominantly nucleophilic even though some electrophilic character can also be involved depending upon reaction conditions. Such a fact may well be caused by a feasible formation of hydrogen bonding type transition state due probably to the ortho substituent effect of-CONHC $H_2$COOH. Thus, the high temperature exchange method is estimated to be quite effective for labelling Hippuran especially at a small research center where reducing agent-free $^{131}$ I is unavailable.ailable..

• Journal of the Korean Electrochemical Society
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• v.8 no.2
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• pp.88-93
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• 2005

Anode-supported solid oxide fuel cell (SOFC) was investigated to increase the cell power density at intermediate temperature through control of the cathode structure. The anode-supported SOFC cell were fabricated by wet process, in which the electrolyte of $8mol\%\;Y_2O_3-stabilized\;ZrO_2 (YSZ)$ was coated on the surface of anode support of Ni/YSA and then the cathode was coated. The cathode has two- or three- layered structure composed of $(La_{0.85}Sr_{0.15})_{0.9}MnO_{3-x}(LSM),\;LSM/YS$ composite (LY), and $La_{0.6}Sr_{0.4}Co_{0.2}Fe_{0.8}O_3{LSCF)$ with different thickness. Their single cells with different cathode structures were characterized by measuring the cell performance and ac impedance in the temperature range of 600 to $800^{\circ}C$ in humidified hydrogen with $3\%$ water and air. The cell with $LY\;9{\mu}m/LSM\;9{\mu}m/LSCF\;17{\mu}m$ showed best performance of $590mW/cm^2$, which was attributed to low polarization resistance due to LY and to low interfacial resistance due to LSCF.

• Economic and Environmental Geology
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• v.49 no.3
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• pp.167-179
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• 2016

Water quality of Oseepchun, Dogye area, was investigated quantitatively for its origin and hydrogeochemistry in relation to the influence of groundwater. Groundwater appears to be the principal source of Oseepchun from the water-quality monitoring data including redox potentials, composition of dissolved ions and their correlations, hydrogen and oxygen stable isotopic ratios, and the distribution and occurrence of contaminants. Water-quality type of the surface water was grouped by the water-rock interactions as $Ca-HCO_3$ type originated from carbonated bed-rocks in the Joseon Supergroup, (Ca, Mg)-$SO_4$ type related with dissolution of surfide minerals in coal beds of Pyeongan Supergroup, and (Ca, Mg)-($HCO_3$, $SO_4$) type of the mixed one. Locally water pollution occurs by high $SO_4$ from mine drainage and $NO_3$ from waste-treatment facility. Intensive precipitation in summer has no effect on the water type of Oseepchun, but increases the inflow of nitrate and chloride originated from land surface. Results of this study direct that groundwater-surface water interaction is intimate, and thus surface-water resource management should begin with groundwater characterization.

• Applied Biological Chemistry
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• v.38 no.6
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• pp.590-595
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• 1995

To examine the characteristics of antioxidative compounds from Capsella bursa-pastoris, ethanol extracts were separated into five organic solvent fractions; hexane(Fr.H), diethyl ether (Fr.E), ethyl acetate(Fr.EA), butanol (Fr.B), and water(Fr.D) fractions. Fr.B showed the greatest electron donating ability and inhibitory effect on lipid peroxidation. Whereas Fr.E had the most excellent activity in the superoxide radical scavenging activity by xanthine/xanthine oxidase-cytochrome c reduction system. The inhibitory effect of each fraction on xanthine oxidase was also measured. Fr.E had the strongest inhibitory effect on xanthine oxidase and $IC_{50}$ was $5.65\;{\mu}g$. The results indicate that the superoxide radical scavenging activity of Fr.E is caused by the inhibitory effect on radical generating system of xanthine oxidase. Also the order of inhibitory effect on xanthine oxidase was Fr.B

• Journal of Life Science
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• v.26 no.7
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• pp.796-804
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• 2016

In the present study, we screened suitable yeasts for wine fermentation and evaluated the fermentative characteristics of Saccharomyces sp. BCNU 6006 and its anti-oxidant activities. Firstly, various yeasts were isolated from Makgeolli, fruits, and fermented foods. Then, the preliminary selections of suitable yeasts were made using an enzymatic activity assay of glucosidase, glycosidase, protease and tolerance to ethanol and SO₂. In addition, the production of biogenic amines and hydrogen sulfide was also monitored. The 9 yeast strains initially selected were determined to belong to the genera Saccharomyces and Kazachtania phylogenetically. We investigated the optimal conditions for wine fermented with black garlic juice (BGJ). The optimal conditions of alcohol fermentation using BGJ were 26 brix, 28℃, and 10 days. Finally, the fermentation products of black garlic wine (BGW) fermented with Saccharomyces sp. BCNU 6006 exhibited 15.03% ethanol, 12 brix of sugar, and pH 4.01. The contents of total polyphenol, total flavonoid, tannin, and 5-HMF compound of BGW were 3.85 mg/ml, 0.51mg/ml, 5.90 mg/ml, and 0.07 mg/ml respectively, lower than that of BGJ. DPPH radical scavenging activity, ABTS radical scavenging activity, and reducing power of BGW were 90.77%, 95.20% and 1.261 respectively, lower than that of BGJ. Superoxide anion (O²-) radical scavenging activity was 94.42%, higher than that of BGJ. Based on the above results, the industrial potential of Saccharomyces sp. BCNU 6006 as a wine-making yeast was confirmed in the present study.

• Applied Chemistry for Engineering
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• v.9 no.5
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• pp.639-647
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• 1998

Al-containing titanium silicalite-1 ([Al]-TS-1) catalyst was prepared hydrothermally, and the effects of synthesis parameters such as silica/alumina sources, $SiO_2/TiO_2$ ratio, and aging treatment were investigated. The structure, crystal size, and shape were examined by XRD and SEM, and the extent of titanium incorporation into the zeolite framework was examined using UV-vis DRS spectroscopy. For [Al]-TS-1 catalyst preparation, aging of ca. 24h was essential, and the faster crystallization rates were achieved with Cab-O-Sil than with Ludox or TEOS as a silica source. In addition, the higher crystallinity and faster crystallization rate were obtained using sodium aluminate as an aluminum source. 2-butanol oxidation using $H_2O_2$ as an oxidant was carried out to confirm the redox property of the [Al]-TS-1. Acid sites catalyzed toluene alkylation study indicated that lattice titanium species in [Al]-TS-1 weakened the acid strength, and the para-ethyltoluene selectivity was enhanced as a results.

• Journal of Chitin and Chitosan
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• v.22 no.4
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• pp.254-263
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• 2017

In order to improve the utilization of seaweeds, two kinds of mixed seasoning concentrates (KMS, MKS) were prepared with Kjellmaniella crassifolia and Mytilus coruscus as main ingredients. Fermentation experiments were carried out at $4^{\circ}C$ for 70 days with Kimchi. As a result, SK-A showed a decrease in pH and an increase in acidity. Salinity was not significantly different after 70th day. Reducing sugar content was higher in mixed seasoning group. Lactic acid bacteria Leuconostoc sp. and Lactobacillus sp. Increased in the control group after 20 days of fermentation. The lightness was higher in the control group from the early stage of dipping to 30 days, and the degree of yellowing was higher than that of SK-B group from 20 days. The hardness of the SK-A group was high at the early stage of immersion and at 10th day. The content of aspartic acid and glutamic acid in free amino acid SK-A group was significantly higher (p<0.05). The content of sweet amino acids was significantly higher in the SK-A group on the 0th, 10th, and 30th days of fermentation than the other groups (p<0.05). The sensory test results showed that SK-A showed the most favorable taste. As a result of reviewing the above results, it is expected that SK-A group immersed in 100 g of seasoning liquid KMS made from Kjellmaniella crassifolia and Mytilus coruscus as a subordinate material will provide taste and nutrition to consumers.

• Korean Journal of Metals and Materials
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• v.49 no.2
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• pp.167-173
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• 2011

Nickel cobalt ferrite($Ni_{0.5}Co_{0.5}Fe_2O_4$) powder was prepared through the ceramic route by the calcination of a stoichiometric mixture of NiO, CoO and $Fe_2O_3$ at $1100^{\circ}C$. The pressed pellets of $Ni_{0.5}Co_{0.5}Fe_2O_4$ were isothermally reduced in pure hydrogen at $800{\sim}1100^{\circ}C$. Based on the thermogravimetric analysis, the reduction behavior and the kinetic reaction mechanisms of the synthesized ferrite were studied. The initial ferrite powder and the various reduction products were characterized by X-ray diffraction, scanning electron microscopy, reflected light microscope and vibrating sample magnetometer to reveal the effect of hydrogen reduction on the composition, microstructure and magnetic properties of the produced Fe-Ni-Co alloy. The arrhenius equation with the approved mathematical formulations for the gas solid reaction was applied to calculate the activation energy($E_a$) and detect the controlling reaction mechanisms. In the initial stage of hydrogen reduction, the reduction rate was controlled by the gas diffusion and the interfacial chemical reaction. However, in later stages, the rate was controlled by the interfacial chemical reaction. The nature of the hydrogen reduction and the magnetic property changes for nickel cobalt ferrite were compared with the previous result for nickel ferrite. The microstructural development of the synthesized Fe-Ni-Co alloy with an increase in the reduction temperature improved its soft magnetic properties by increasing the saturation magnetization($M_s$) and by decreasing the coercivity($H_c$). The Fe-Ni-Co alloy showed higher saturation magnetization compared to Fe-Ni alloy.