• Korean Journal of Food Science and Technology
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• v.46 no.1
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• pp.79-86
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• 2014

In previous work, we fermented coffee beans using solid-state culture with various fungal mycelia to enhance the physiological activity of the coffee. The coffee fermented with Monascus sp. showed a higher physiological activity than non-fermented coffee or other coffees fermented with mushroom mycelium. The aim of this study was to characterize the various fermented coffees with respect to their area of cultivation and their variety using Monascus purpureus (MP) mycelium solid-state culture. Thirty types of green coffee beans, which varied in terms of their cultivation area or variety, were purchased from different suppliers and fermented with MP under optimal conditions. Each MP-fermented coffee was medium roasted and extracted further using hot water (HW) under the same conditions. Of the HW extracts, those derived from MP-Mandheling coffees had the highest yield (13.6-15.5%), and MP-Robusta coffee showed a significantly higher polyphenolic content (3.03 mg gallic acid equivalent/100 mg) and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) free radical scavenging activity (27.11 mg ascorbic acid equivalent antioxidant capacity/100 mg). Furthermore, in comparison to other MP-fermented coffees at $1,000{\mu}g/mL$, MP-Robusta coffee showed not only the most effective inhibition of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) production in LPS-stimulated RAW 264.7 cells (67.1% of that in LPS-stimulated control cells), but also an effective inhibition of lipogenesis in 3T3-L1 adipose cells (22.2% of that in differentiated control cells). In conclusion, these results suggest that Vietnam Robusta coffee beans solid-state fermented with MP mycelium are amenable to industrial applications as a functional coffee beverage or material.

• Korean Journal of Plant Tissue Culture
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• v.22 no.5
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• pp.291-298
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• 1995

This study describes plant regeneration from leaf explant of Bupleurum falcatum through somatic embryogenesis, and the effect of 2,4-dichlorophenoxyacetic acid on somatic embryo abnormalities. The relationship between the cotyledon number of somatic embryo and its germinability is also described. Embryogenic calli were selected from calli formed on explants cultured on MS solid basal medium supplemented with 1 mg/L 2,4-D. Cotyledonary abnormalities were observed in somatic embryos which were developed from calli cultured on MS medium with 1 mg/L 2,4-D for 6-week and then subcultured on 2,4-D free MS medium for 3 weeks. The frequency of abnormalities was as follows: 7% of somatic embryos had one cotyledon, 65% of them had two cotyledons, 25% three cotyledons, 5% four cotyledons, 2% five cotyledons, and 3% trumpet-like cotyledons. The two cotyledon somatic embryos were germinated at a frequency of 80%. However the germination frequency of one cotyledon embryo and multicotyledonary embryo was lower than that of the two cotyledon somatic embryo. All of trumper-like somatic embryos did not germinate. Histological observations of multicotyledon embryo showed circular procambium in the root but pocambial strands in the cotyledonary node or upper hypocotyl. The number of the strands was equal to the cotyledon number.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.2
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• pp.140-145
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• 2002

The performances of a parallel current air driven type foam separator were evaluated in the pilot-scale recirculating aquaculture system. The system was stocked with Nile tilapia (Oreochromis niloticus) at an initial rearing densities of $2\%$, $5\%$ and $7\%$ of water volume of rearing tank and reared for 15, 30, 35 days, respectively. The condensated volume of effluent foam was increasing with increased rearing density. As increasing rearing density from $2\%$ to $7\%$, the protein concentration in rearing tank was increased from 16.6 g/$m^3$ to 21,9 g/$m^3$ and the removal amount of protein through foam separator as increased from 0.99 g/day to 2.5 g/day. But protein concentration ratio in the foam was decreased from 3.2 to 1.9. Changes of the removal amount and the concentration ratios of total suspended solid (TSS) and chemical oxygen demand (COD_cr.) were similar to proteins. The highest concentration ratios of TSS and COD_cr. were 10.2 and 8.4 at 2$2\%$ of rearing density.

• Journal of the Korean Ceramic Society
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• v.45 no.12
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• pp.772-776
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• 2008

The Korea Electric Power Research Institute (KEPRI) has been developing planar solid oxide fuel cells (SOFCs) and power systems for combined heat and power (CHP) units. The R&D work includes solid oxide fuel cell (SOFC) materials investigation, design and fabrication of single cells and stacks, and kW class SOFC CHP system development. Anode supported cells composed of Ni-YSZ/FL/YSZ/LSCF were enlarged up to $15{\times}15\;cm^2$ and stacks were manufactured using $10{\times}10\;cm^2$ cells and metallic interconnects such as ferritic stainless steel. The first-generation system had a 37-cell stack and an autothermal reformer for use with city gas. The system showed maximum stack power of about $1.3\;kW_{e,DC}$ and was able to recover heat of $0.57{\sim}1.2\;kW_{th}$ depending on loaded current by making hot water. The second-generation system was composed of an improved 48-cell stack and a prereformer (or steam reformer). The thermal management subsystem design including heat exchangers and insulators was also improved. The second-generation system was successfully operated without any external heat source. Under self-sustainable operation conditions, the stack power was about $1.3\;kW_{e,DC}$ with hydrogen and $1.2\;kW_{e,DC}$ with city. The system also recuperated heat of about $1.1\;kW_{th}$ by making hot water. Recently KEPRI manufactured a 2kW class SOFC stack and a system by scaling up the second-generation 1kW system and will develop a 5kW class CHP system by 2010.

• Journal of the Korean Electrochemical Society
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• v.12 no.2
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• pp.119-130
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• 2009

This article reviews recent R&D trends in SOFC development with an emphasis on industries that can produce the SOFC stack and power generation system. SOFC is an electrochemical device that can convert the chemical energy of fuel into the electrical energy with environment friendly system and high efficiency. SOFC power generation system could be classified as the portable power generation system, auxiliary power unit(APU), residential power generation(RPG) and large size distributed power generation. In the case of more than 10kW system, the major R&D trends are focused on the tubular type SOFC system with high efficient and long term stability to meet the commercialization of SOFC power generation system.

• Korean Journal of Materials Research
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• v.12 no.10
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• pp.825-830
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• 2002

The growth rate of solid grains in TiC-XC-2vol% and TiC-XC-30vo1% Ni cermets, where X=Zr, W or Mo, was fitted to an equation of the form $d^3$-$do^3$=Kt. The grain growth behavior during liquid phase sintering at 1673K decreased markedly with addition of $Mo_2$C or WC and increased with addition of ZrC. The contiguity ratio was greater in the alloys with smaller growth rate constant and decreased with increasing Ni content in the $TiC-Mo_2$C-Ni cermet. The grain growth mechanism could be explained by the effect of contiguous grain boundaries in restricting the overall grain growth.

• Journal of Ocean Engineering and Technology
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• v.11 no.2
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• pp.39-47
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• 1997

Creep rate the elevated temperature is known to be controller by the softening process of microstructure especially in the solid solution alloys such as 125 Cr rotor steel. The change of structure is a decreasing process of the free energy of the state including stress, diffusivity of the material, and tmeperature. This study shows that diffusion coefficient, D of 12% Cr rotor steel at 953K with 74.8 MPa is 1.084~3.140*$10^{15}mm^2sec^1$ compared to $1.658*10^{24}mm^2sec^1$at 963K without stress. During creep, the growth of martensite laths accelerates the diffusion coefficient under stress due to incoherency of interface between carbides and matrix.

• Journal of Microbiology and Biotechnology
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• v.17 no.10
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• pp.1717-1720
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• 2007

In the course of screening for nitric oxide inhibitors in activated microglial BV-2 cells, cyclo(dehydrohistidyl-L-tryptophyl) was isolated from solid-state fermentation cultures of an unidentified fungal strain, Fb956. Its structure was determined by spectroscopic methods including 2D NMR and chiral TLC analyses. Cyclo(dehydrohistidyl-L-tryptophyl) was found to have an inhibitory activity on nitric oxide production with an $IC_{50}$ of $6.5\;{\mu}M$ in activated BV-2 cells. The structure determination and biological activity of cyclo(dehydrohistidyl-L-tryptophyl) was reported for the first time in this study.

• Journal of the Korean Magnetic Resonance Society
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• v.3 no.2
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• pp.90-99
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• 1999

Doping of boron atoms in graphite has been well known method to increase the discharge capacity as the negative electrode material for lithium secondary battery. Herein, the boron-doped graphites are prepared by mixing 1, 2.5, 5, and 7 wt. % of boron carbide in carbon during the graphitizing process. The structural states of boron in boron-doped graphites are investigated by solid-state 11B NMR spectroscopy. The resonance lines for substitutional boron atoms are identified as the second order quadrupolar powder pattern with the quardrupole coupling constant, QCC = 3.36(2) MHz. The quantitative analysis of 11B NMR spectra with boron-doped graphite has also been performed via simulation.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1331-1333
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• 2005

A magnesium thiogallate phosphor doped with europium was prepared by solid-state method. This phosphor has green emission near 535 nm due to the allowed transition from $4f^65d$ at an excitation state $(T_{2g})$ to $4f^7 (^8S_{7/2}) at a ground state of $Eu^{2+}$ ion. This phosphor shows a wide excitation spectrum from ultra violet (300 nm) to bluish green (515 nm).