• Resources Recycling
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• v.26 no.3
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• pp.79-91
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• 2017

The core of Hydrogen Fuel Cell Vehicles (FCV) is polymer solid fuel cell (PEFC), and the core material that generates electrochemical electricity in the cell is platinum catalyst. Platinum is localized in South Africa and Russia, and the world production of Pt is about 178 tons per year, which is expensive and recycled. At present, the amount of Pt used in PEFC is $0.2{\sim}0.1mg/cm^2$. In order to reduce the price of the battery and increase the FCV supply, the target is to reduce the amount of Pt used to $0.05{\sim}0.03mg/cm^2$. $Pt-Pd/Al_2O_3$, Pt/C, Pt/GCB, Pt/Au/C, PtCo/C, PtPd/C, etc. by using polyol method using nano Pt, improved Cu-UPD/Pt substitution method and nano-capsule method, Have been researched and developed, and there have been reported techniques for improving the activity of Pt catalysts and stabilizing them. This paper investigates the production technology of nano-Pt and nano-Pt catalysts, recycling of spent Pt catalysts and application trends of Pt catalysts.

• Clean Technology
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• v.20 no.1
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• pp.57-63
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• 2014

In this work, we performed the methanation with steam and synthesis gas of a low $H_2/CO$ ratio to develop a process for producing SNG (synthetic natural gas). In this experiment conditions, the water gas shift reaction and the methanation reaction take place at the same time, and insufficient supply of steam might cause the deactivation of the catalyst. Therefore, the reaction characteristics with the amount of steam was performed, and the methanation on syngas containing $CO_2$ of the high concentration were studied. As a result, the temperature in the catalyst bed decreased by the supply of steam, and the methanation and the water gas shift reaction occurred at the same time. Although methane yield slightly decreased at the methanation using syngas containing $CO_2$ of the high concentration, the long-term operation (1,000 h) in the experimental conditions of this study indicates that this condition is suitable for the new commercial scale SNG process.

• Journal of the East Asian Society of Dietary Life
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• v.22 no.1
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• pp.88-94
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• 2012

Histamine is a kind of primary biogenic amine arising from the decarboxylation of the amino acid L-histidine. The toxicology of histamine and its occurrence and formation in foods are especially emphasized in fermented foods. In this study, the biosensor for detection of histamine with functionalized multi-walled carbon nanotubes (MWCNT) was developed. We also searched for an appropriate insoluble substrate to immobilize the enzyme. The developed biosensor showed a detection limit of $0.1{\mu}M$ hydrogen peroxide. The enzyme reactor was prepared with diamine oxidase immobilized on insoluble carriers including CNBr-activated sepharose 4B, calcium alginate, and controlled pore size glass beads. The coupling efficiency of CNBr-activated sepharose 4B, calcium alginate, and controlled pore size glass beads were 48.5%, 40.3%, and 51.0%, respectively. In addition, the response currents on histamine with each immobilized enzyme reactor prepared with CNBr-activated sepharose 4B, calcium alginate, and controlled pore size glass beads were 120 nA, 110 nA, and 140 nA at $100{\mu}M$ of histamine concentration, respectively. Therefore, it is suggested that controlled pore size glass beads are the best carriers for immobilizing diamine oxidase to detect histamine in this biosensor.

• Journal of Digital Convergence
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• v.10 no.7
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• pp.201-206
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• 2012

Benzo(a)pyrene is a polycyclic aromatic hydrocarbons (PAHs) whose metabolites are mutagenic and highly carcinogenic and is listed as a Group 1 carcinogen by the IARC. It has been found at variable concentrations in several foods and is associated with several factors during the process including contaminated raw materials, exposure of environment, and procedure of process or cooking. In this study, benzo(a)pyrene in 45 oriental medicines were determined by HPLC/FLD. The calibration curves of benzo(a)pyrene was linear over the concentration range of 0.5~40 ng/mL with correlation coefficient of above 0.999. The limit of detection (LOD) and limit of quantitation (LOQ) of benzo(a)pyrene were 0.04 and 0.10 ${\mu}g/kg$. Benzo(a)pyrene in 3 samples out of 45 samples was not detected. The level of benzo(a)pyrene in 26 (57.7%), 8 (17.8%) and 7 (15.6%) samples was 0.1~0.5, 0.5~1.0 and 1.0~5.0 ${\mu}g/kg$, respectively. Especially, content of benzo(a)pyrene in Coptis Rhizome is the highest (5.97 ${\mu}g/kg$). In conclusion, these results suggest that could be applied to fundamental study and guideline on drying condition to decrease content of benzo(a)pyrene in oriental medicine.

• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1447-1452
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• 1999

Lipid-related components were comparatively investigated for white ginseng when exposed to both phosphine fumigation and gamma irradiation at 5 kGy or less, which were found effective for improving its biological quality. Fumigation resulted in the increase in pH of the sample, and thereafter it showed a decreasing tendency in all samples during storage for 6 months at ambient $(20^{circ}C/70%\;RH)$ and accelerated $(40^{\circ}C/90%\;RH)$ conditions. The severe conditions led to an apparent browning of the stored samples without significant differences among them, while the sample stored at ambient condition showed negligible changes in its color up to 6 months. The development of browning in the stored sample was in proportional to hydrogen donating ability of the corresponding sample extract. TBA value increased by gamma irradiation gradually decreased with storage time, showing similar values to that of other samples, whereas carbonyl value gradually increased in all samples. Both fumigation and gamma irradiation caused negligible changes in fatty acid composition; however, a partial increase in saturated fatty acid composition and some decrease in polyunsaturated ones were observed with the storage time.

• Journal of Life Science
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• v.21 no.9
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• pp.1315-1322
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• 2011

This study was conducted to investigate the effects of several herbal extracts (obtusifolia, cinnamon, chinese pepper, licorice root) on the characteristics of rumen fermentation in vitro. Soybean meal was used as a substrate for fermentation in vitro. Herbal extracts were supplemented to media by 10% of the substrate. The substrates supplemented to Dehority artificial media with herbal extracts were fermented in 30ml serum bottles for 0, 3, 6, 9, 12 and 24 hr at $39^{\circ}C$. Cumulative gas production was significantly (p<0.05) greater in the herbal extract supplements than in the control, in the order of licorice root, chinese pepper, cinnamon and obtusifolia. Methane proportions of the herbal extracts were significantly (p<0.05) higher than that of the control. Licorice root extract supplementation resulted in the lowest methane proportion at 3 hr fermentation. Proportion of hydrogen was significantly (p<0.05) higher in the herbal extract supplements than in the control at 12 hr fermentation. Compared to the control, ammonia concentration in the licorice root was significantly higher at 3 hr fermentation, but lower at 12 hr fermentation (p<0.05). Based on these results, supplementation of the herbal extracts used in this experiment resulted in increased cumulative gas production and stimulating methane production in vitro rumen fermentation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.11
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• pp.1571-1579
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• 2016

We investigated the effect of peanut sprout extract (PSE) on andropause symptoms. PSE was evaluated for impotency and benign prostatic hyperplasia via phosphodiesterase (PDE) or 5-alpha reductase II inhibition assay. Inhibition of PDE and 5-alpha reductase II activities in PSE was significantly higher than that of the non-treated control. To investigate the effects of testosterone levels by PSE, we performed cell media test using TM3 cells. Production of testosterone in TM3 cells was elevated by PSE. These results indicate that PSE was able to alleviate andropause symptoms.

• Journal of Animal Science and Technology
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• v.50 no.3
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• pp.321-330
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• 2008

본 연구는 흑운모 분말 급여시 육성돈에 생산성, 면역관련 혈액학적 지표, 혈청 내 스트레스 농도 및 분내 유해가스 발생에 미치는 영향을 구명하고자 실시하였다. 시험 동물은 [(Landrace ×Yorkshire)×Duroc] 3원 교잡종 육성돈 96두를 공시하였으며, 시험 개시시의 체중은 29.45±1.35kg으로 사양시험을 42일간 실시하였다. 시험설계에서 공시돈은 돈방당 4두씩 1) CON(Basal diet), 2) Solt2(Basal diet+Solto-B 0.2%), 3) Solt4(Basal diet+Solto-B 0.4%) 및 4) Solt6 (Basal diet+Solto-B 0.6%)로 4처리구에 각각 6돈방씩 완전 임의배치 하였다. 질소 소화율에서는 solt4 처리구가 CON과 solt2 처리구에 비해 유의적으로 높게 나타내었다(Linear effect = 0.016). 총 에너지에서는 Solt4와 Solt6 처리구가 CON 처리구에 비해 유의적으로 높게 나타내었다(Linear effect=0.008, Quadratic effect=0.019). 면역 및 스트레스 관련 혈액성상에서는 처리간의 차이가 없었다. 황화수소는 5 day와 10 day에서 대조구에 비해 Solt 처리구가 유의적으로 감소를 하였다(5 day, Linear effect=0.009, Quadractic effect=0.037; 10 day, Linear effect = 0.009). 아세트산는 5 day에서 대조구에 비해 Solt 처리구가 유의적으로 감소를 하였다(Linear effect <0.001, Quadractic effect < 0.001). 15 day에서도 CON과 Solt6 처리구가 Solt2와 Solt4 처리구에 비해 유의적으로 감소를 하였다(Quadractic effect=0.023). 메캅탄은 5 day와 10 day에서 CON 처리구에 비해 Solt 처리구가 유의적으로 감소를 하였다(5 day, Linear effec= 0.029, Quadractic effect=0.037; 10 day, Linear effect=0.029). 암모니아는 5 day, 10 day 및 15 day에서 Solt2와 Solt4 처리구가 CON과 Solt6 처리구에 비해 유의적으로 감소하였다(5 day, Quadractic effect=0.038; 10day, Quadractic effect = 0.045; 15day, Quadractic effect = 0.038). 결론적으로, 육성돈에 흑운모 분말 급여시 분내 유해가스 함량에 유의적인 감소를 나타내었다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.7
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• pp.1393-1398
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• 2009

Conventionally, etching is first considered for microelectronics fabrication process and is specially important in process of a-Si:H thin film transistor for LCD. In this paper, we stabilize properties of device by development of wet and dry etching process. The a-Si:H TFTs of this paper is inverted staggered type. The gate electrode is lower part. The gate electrode is formed by patterning with length of 8 ${\mu}$m${\sim}$16 ${\mu}$m and width of 80${\sim}$200 ${\mu}$m after depositing with gate electrode (Cr) 1500 ${\AA}$under coming 7059 glass substrate. We have fabricated a-SiN:H, conductor, etch-stopper and photo resistor on gate electrode in sequence, respectively. The thickness of these thin films is formed with a-SiN:H (2000 ${\mu}$m), a-Si:H(2000 ${\mu}$m) and n+a-Si:H (500 ${\mu}$m), We have deposited n-a-Si:H, NPR(Negative Photo Resister) layer after forming pattern of Cr gate electrode by etch-stopper pattern. The NPR layer by inverting pattern of upper gate electrode is patterned and the n+a-Si:H layer is etched by the NPR pattern. The NPR layer is removed. After Cr layer is deposited and patterned, the source-drain electrode is formed. In the fabricated TFT, the most frequent problems are over and under etching in etching process. We were able to improve properties of device by strict criterion on wet, dry etching and cleaning process.

• Journal of Soil and Groundwater Environment
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• v.9 no.3
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• pp.33-37
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• 2004

Soil samples used in this study were taken from the site at which diesel spill accident had occurred in 1995. It was confirmed that all of soil samples were contaminated with diesel which was going on weathering. The concentrations of diesel in soils were determined by Korea standard method revised in July 1999 (Method 1) and US EPA method 8015b (Method 2). Some additional soil samples were analyzed with Korea standard method revised in July 2002 (Method 3) to compare the accuracy and reproducibility with Method 2. The only four of forty-six samples were determined when the analysis carried out according to Method 1 while forty-three of forty-six samples had the value above criterion (2000mg kg$^{-1}$ ) according to Method 2. There were no significant differences between the results of the analysis by Method 2 and Method 3. Based on these results, Method 2 and 3 were more appropriate than Method 1 for the determination of weathered diesel in soil. Method 2 had almost equivalent accuracy and reproducibility to Method 3.