• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1995.05a
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• pp.145-149
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• 1995

The metallization is the key to determining cell costs, call performance, and cell and system reliabiltiy. The Burled Contact Solar Cell (BCSC) was specifical1y desinged to be compatible tilth low cost, mass production techniques and avoid the conventional metallization problem. By using electroless plating trchniqeu, we performed this metallization inexpensively and reliabley, This paper presents the details of the optimization procedure of metallization schemes on laser grooved cell surface Commercially available Ni ,Cu, and Ag plating solutions were applied for the cell metallization. The application of those solutions on the buried contact front metalization has resulted in an cell efficiency of 18.5% The cell parameters are an open circuit voltage of 651 mV, short circuit current density of 38.6 mA/$\textrm{cm}^2$, and fill factor of 73.5%.

• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.5
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• pp.350-354
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• 2000

The growth promotion of a Taxus brevifolia cell suspension culture was investigated using conditioning factors. The conditioning factors produced and secreted from cultured cells usually stimulate cell division and the production of secondary metabolites. Therefore, the effective incubation time for the optimal secretion of conditioning factors was firstly determined for the promotion of cell growth. Conditioned media obtained by cultivating for 2 and 5 days showed the promotion of initial cell growth during the early cell growth period. However, the positive effect of the conditioning factors on the initial cell growth did not continue because of the depletion of the medium nutrients. Accordingly, the addition of a carbon source to the conditioned medium prolonged the positive effect on the cell growth. The addition of sucrose to the conditioned medium resulted in the maximum cell density being reached 4 days earlier compared to the control group and an increased substrate yield.

• Transactions on Electrical and Electronic Materials
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• v.8 no.6
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• pp.286-288
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• 2007

The research and development for the solid oxide fuel cell have been promoted rapidly and extensively in recent years, because of their high efficiency and future potential. Therefore this paper describes the manufacturing method and characteristics of anode electrode for solid oxide fuel cell, by the way, Ni-YSZ materials are used as anode of solid oxide fuel cell widely. In order to reduce production costs, we have fabricated single solid oxide fuel cell by doctor blade and screen printing method. Disk-type planar solid oxide fuel cell with an effective electrode area of about $7cm^2$ were fabricated and run for 500 h to investigate cell performance. The current density at a voltage of 0.7 V was $850mA/cm^2$.

• Journal of the Korean Society of Visualization
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• v.20 no.3
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• pp.117-127
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• 2022

The present study has investigated the performance of hydrogen gas generators for inhalation purposes based on polyelectrolyte membrane water electrolysis (PEMWE). The system applied two watering methods. One is pumped water (pumping system) and the other is gravity-fed water without a pump (non-pumping system). The cell efficiencies were compared by measuring the cell voltage and temperature in the hydrogen gas generator, respectively. The results show that the cell voltage and temperature increase with the cell current. The cell temperature is lower in the pumping system than that in the non-pumping system at a given cell current. Even though the amount of hydrogen production is the same regardless of the pumping system, the cell efficiency of the hydrogen gas generator in the non-pumping system is better than that in the pumping system.

• Microbiology and Biotechnology Letters
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• v.26 no.3
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• pp.213-220
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• 1998

An ATP regeneration system was used for the production of glutathione which was synthesized by a sequential action of ${\gamma}$-glutamyl-cysteine synthetase and glutathione synthetase. The synthetases above were produced in the recombinant E. coli (TG1/pDG7) with the highest specific production yield of 31 mg glutathione/g wet cell. Bakers yeast was considered to have economically a better ATP regeneration system although the glutathione production yield was lower than that of acetate kinase. It was also observed that the ATP regeneration system of bakers yeast was superior to that of Saccharomyces cerevisiae ATCC24858. The yield of glutathione production with bakers yeast was 36% with the ATP concentration of 5 mM. To avoid the cysteine limitation during the early phase of glutatione production, an extra cysteine was added at 2 hours after reaction and the production yield increased 1.91 times. The effectiveness of bakers yeast as an ATP regeneration system was proved by several sets of extra feeding experiments. The product inhibition by glutathione above 14 mM was also observed.

• Microbiology and Biotechnology Letters
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• v.27 no.5
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• pp.378-384
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• 1999

Protopectinase (PPases) are heterologous group of enzymes that degrade pectin from the insoluble protopection which is constituent of the middle lamella and primary cell wall of higher plants by restricted depolymerization. From the previous report[6], enzymatically separated plant cells, which are produced from plant tissues by PPases treatment, showed well-conserved cellular components with their rigid cell wall and this characteristic is applicable to preparation of novel food material. The purpose of this study is to investigate the effect of medium composition of PPase production from Bacillus subtilis EK11 which was selected as a PPase producer. Various carbon sources and concentrations on PPase production were studied and corn starch at 0.7% was the most effective for production of PPase. Among the nitrogen sources, yeast extract was the most effective for PPase production and the effect of (NH4)2SO4 was notable as inotganic nitrogen source. Inorganic compounds such as KH2PO4, K2HPO4, Na3-citrate.2H2O and MgSO4 were optimized for PPase production. PPase activity was inhibited by the adition of Ba2+ or Zn2+. The optimal medium for PPase production was devised: 0.7% corn starch, 0.3% yeast extract, 1.4% KH2PO4, 0.6% K2HPO4, 0.1% Na3-citrate.2H2O and 0.02% MgSO4. PPase production by using the optimum medium was carried out with shaking cultivation at 37$^{\circ}C$. The maximum PPase activity of 256unit/ml could be obtained after the cultivation for 48hrs. The activity was increased about 2.2timesthan the activity, 112 unit/ml, in basal medium.

• KSBB Journal
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• v.25 no.6
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• pp.539-546
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• 2010

In this work, mass production of Bacillus licheniformis SCD121067 through medium optimization by statistical experimental method was studied. First, galactose, yeast extract and potassium phosphate dibasic were selected as carbon, nitrogen and phosphate sources for mass production of B. licheniformis SCD121067 by using one factor at a time method. Second, according to the result of Plackett-Burman experimental design, key factors was yeast extract and $K_2HPO$. Finally, the response surface methodology was performed to obtain the optimum concentrations of two selected variables. The optimized medium composition consisted of 20 g/L galactose, 36 g/L yeast extract, 0.41 g/L $K_2HPO4$, 0.25 g/L $Na_2CO_3$, 0.4g/L $MgSO_4$ and 0.01g/L $CaCl_2$. Dry cell weight (15.4 g/L) by optimum production medium were increased 10 times, as compared to that determined with basic production medium (1.5 g/L). Fermentation conditions were examined for the mass production of B. licheniformis. The effect of temperature, agitation speed, pH and aeration rate on the mass production of B. licheniformis were also studied in a batch fermenter which was carried out in a 2.5 L bioreactor with a working volume of 1.5 L containing optimized production medium. As a result, dry cell weight of batch culture was 30.7 g/L at $42^{\circ}C$, 300 rpm, pH 8.0 and 2 vvm.

• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.2
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• pp.294-299
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• 2011

The purpose of this study is to investigate effects of Red Ginseng-Ejung-tang (RE) on nitric oxide (NO) and hydrogen peroxide production in RAW 264.7 mouse macrophages induced by lipopolysaccharide (LPS). Cell viability was measured by modified MTT assay. NO production was measured by Griess reagent assay. Hydrogen peroxide production was measured by dihydrorhodamine 123 (DHR) assay. RE did not show cell toxicity against RAW 264.7 for 24 hr incubation at the concentrations of 10, 25, 50, 100, and $200{\mu}g/mL$ in RAW 264.7. RE significantly inhibited NO production for 24 hr incubation at the concentrations of 10, 25, 50, and $100{\mu}g/mL$ in RAW 264.7 (P < 0.05). RE significantly inhibited the LPS-induced production of NO for 24 hr incubation at the concentrations of 10, 25, 50, and $100{\mu}g/mL$ in RAW 264.7 (P < 0.05). RE significantly inhibited the LPS-induced production of hydrogen peroxide for 16, 24, 40, 48, 64, and 72 hr incubation at the concentrations of 50, 100, and $200{\mu}g/mL$ in RAW 264.7 (P < 0.05). These results suggest that RE has anti-inflammatory property related with its inhibition of NO and hydrogen peroxide production in LPS-induced macrophages.

• YAKHAK HOEJI
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• v.42 no.1
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• pp.82-88
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• 1998

The effect of hepatoprotective agents and bile acids on tumor necrosis factor-alpha, (TNF-${\alpha}$) production in murine and human macrophage cell line (RAW264.7 and U937) was inve stigated. The hepatoprotective agents including silymarin and its major component, silybin, significantly inhibited TNF-alpha production in a concentration dependent manner ($IC_50$ of silybin=67.7${\mu}g$/ml (140.3${\mu}g$M)). In differentiated U937 cells, especially, silybin showed more effective inbitory activity ($IC_50$=35.1${\mu}g$g/ml (72.7${\mu}g$M)). These results suggest that silymarin and silybin may inhibit TNF-alpha production in the process of hepatic diseases in human. However, biphenyldimethyl dicarboxylate (DDB) was not effective. In the case of bile acids, chenodeoxycholic acid (CDCA) showed a concentration dependent inhibitory effect on TNF-alpha production ($IC_50$ of CDCA= 71.5${\mu}g$g/ml (182.1${\mu}g$M)). In contrast, glycine or taurine conjugated form (G-CDCA or T-CDCA) restored to the control level or significantly increased TNF-${\alpha}$ production. And also ursodeoxycholic acid (UDCA) and its conjugated forms (G-UDCA and T-UDCA) showed a variety of patterns on TNF-${\alpha}$ production by changes of functional groups and concentration. These results also indicate that bile acids may regulate TNF-${\alpha}$ production in normal hepatic function or disease conditions.

• The Korea Journal of Herbology
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• v.29 no.5
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• pp.83-90
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• 2014

Objectives : This research has been done to investigate the anti-inflammatory effect of Coptidis Rhizoma extracts. Method : Coptidis Rhizoma was extracted by $100^{\circ}C$ water. The extract (CC : Extract of Coptis chinensis rhizome) was used to examine its effects on the cell viability of mouse macrophage Raw 264.7 cell line. Also the production of nitric oxide (NO), the c-jun N-terminalkinase (JNK) activation and the production of cytokines such as (IL)-5 were evaluated in lipopolysaccharide (LPS)-stimulated Raw 264.7 cells. After the CC and LPS were applied to Raw 264.7 cells which were cultured for 24 hours, the MTT assay was performed. Result : The CC extracts didn't affect the viability of macrophage cells. However, the extracts inhibited the NO production and the JNK activation significantly in LPS-stimulated macrophage cells treated with 100 and $200{\mu}g/mL$ concentrations. The CC extract, also, impeded the production of inflammation-related factors and cytokines such as KC, VEGF, MCP-1, GM-CSF, IL-$1{\alpha}$, IL-5, IL-6, and IL-12p40 in LPS-stimulated macrophage cells at the concentration higher than $25{\mu}g/mL$. The production of basic-FGF concentration of 50 and $100{\mu}g/mL$, the production of IP-10 at $100{\mu}g/mL$, and the production of IFN-${\gamma}$ at $25{\mu}g/mL$, respectively. Conclusion : The CC prepared using $100^{\circ}C$ water showed the significant anti-inflammatory effect such as the inhibition not only on the production of NO, KC, VEGF, MCP-1, GM-CSF, IL-$1{\alpha}$, IL-5, IL-6, and IL-12p40 in LPS-stimulated macrophage cells at or higher than the concentration of $25{\mu}g/mL$, but also on the JNK activation at 100 and $200{\mu}g/mL$.