• 한국초전도학회:학술대회논문집
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• v.15
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• pp.68-68
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• 2005

• Applied Chemistry for Engineering
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• v.28 no.6
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• pp.720-725
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• 2017

M(10)-Ni(5)/SBA-15(M=Ce, Nd, Sm) catalysts were prepared for the partial oxidation of methane (POM) to syngas. The catalysts were characterized by BET, TEM, and XPS. The BET-specific surface area and average pore size for M(10)-Ni(5)/SBA-15(M=Ce, Nd, Sm) were 538.8, 504.3, and $447.3m^2/g$ and 6.4, 6.8, and 7.1 nm, respectively. TEM results showed that the mesoporous hexagonol structure was formed for SBA-15, while the homogeneous dispersion of Ni and Ce particles on the surface was formed for Ce(10)-Ni(5)/SBA-15 caused by the confinment effect of SBA-15. XPS data confirmed that $Ce^{4+}$ and $Ce^{3+}$ on the surface catalyst have two oxidation states due to the lattice oxygen species ($O^{2-}$, $O^-$). The yields of POM to syngas over Ce(10)-Ni(5)/SBA-15 were 52.9% $H_2$ and 21.7% CO at 1 atm, 973 K, $CH_4/O_2=2$, $GHSV=1.08{\times}10^5mL/g_{cat.}{\cdot}h$, and these values were kept constant even after 75 h on streams. The same tendency of syngas yields was observed for M(10)-Ni(5)/SBA-15(M=Ce, Nd, Sm). These results confirm that the redox reaction of promoters including Ce, Nd, and Sm enhanced the stability and yield of catalysts.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.4
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• pp.414-420
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• 2006

Effluent from an anaerobic digestion system with an elutriated phased treatment(ADEPT, Anaeorbic Digestion Elutriated Phase Treatment) for piggery waste treatment using anaerobic ammonium oxidation(ANAMMOX) process was used as a substrate of partial nitrification reactor. In mesophilic condition($35^{\circ}C$), controlling parameters of nitrite accumulation were HRT, pH, free ammonia(FA) and hydroxylamine rather than dissolved oxygen. Bicarbonate alkalinity consumption ratio including bicarbonate stripping and buffering was 8.78 g $Alk._{comsumed}/g\;NH_4-N_{converted}$. In steady state for 1 day of HRT and $2.7{\sim}4.4mg/L$ of DO, $NO_2-N/NH_4-N$ ratio of partial nitrification effluent was about $1{\sim}3$, which was applicable to ANAMMOX reactor influent for the combined partial nitrification-ANAMMOX process.

• Toxicological Research
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• v.14 no.3
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• pp.285-291
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• 1998

This study was designed to examine the effects of polyundaturated fatty acid(PUFA) from different sourecs on hepatic lipogenic enzyme and peroxisomal ${\beta}$-oxidation in murine hepatocarcinogenesis initiated by diethylnitrodamine (DEN). Male Sprague-Dawley rats were fed one of three diets containing 10%(w/w)fat; fish oil-corn oil blended(FO), corn oil-beef tallow-fish oil blended(CF), or corn oil-beef tallow-perilla oil blended (CP), from the gestation period. At 10 weeks, animals were received a single inraperitoneal injection of DEN (200mg/kg body weight), were subjected to two-thirds partial hepatectomy 3 weeks later and were sacrificed 8 weeks after DEN initiation. The areas of placental glutathione S-transferase (GST-P) positive foci were significantly smaller in rats fed fish oil containing diets (FO and CF) than those fed CP diet. Fish oil feeding significantly decreased th activities of lipogenic enzyme. Rats fed fish oil containing diets (FO, CF) exhibited the lower fatty acid synthase (FAS) activity than those fed CP diet and FAS activity was positively correlated with areas of GSP-P positivie foci. Glucose-6-phophate dehydrogenase activity was the lowest and peroxisomal ${\beta}$-oxidation was stimulated in rats fed FO diet compared to other groups. It was also found that serum cholesterol was decreased in FO group. Therefore, the preventive effect against hepatocarcinogenesis and hypolipidemic effect of fish oil can be explained partly by suppression of the hepatic lipogenesis and by increase of peroxisomal ${\beta}$-oxidation.

• Transactions of the Korean hydrogen and new energy society
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• v.17 no.3
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• pp.293-300
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• 2006

KIER has been developing a Ru-based preferential oxidation catalysts and a novel fuel processing system to provide hydrogen rich gas to residential PEMFCs system. The catalytic activity of Ru-based catalysts was investigated at different Ru loading amount and different support structure. The obtained result indicated that 2 wt% loaded Ru-based catalyst supported on ${\alpha}-Al_2O_3$ showed high activity in low temperature range and suppressed the methanation reaction. The developed prototype fuel processor showed thermal efficiency of 78% as a HHV basis with methane conversion of 92%. CO concentration below 10 ppm in the produced gas is achieved with separate preferential oxidation unit under the condition of $[O_2]/[CO]=2.0$. The partial load operation have been carried out to test the performance of fuel processor from 40% to 80% load, showing stable methane conversion and CO concentration below 10 ppm. The durability test for the daily start-stop and 8 h operation procedure is under investigation and shows no deterioration of its performance after 50 start-stop cycles. In addition to the system design and development.

• Journal of Life Science
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• v.15 no.1 s.68
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• pp.94-99
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• 2005

Sixty four bacterial colonies which were able to oxidize the manganese were isolated from soil samples in Mokcheon and Ochang area. Among them, one bacterial strain was selected for this study based on its higher manganese oxidation, and this selected bacterial strain was identified as Aeromonas sp. MN44 through physiological-biochemical test and analysis of its 16s rRNA sequence. Aeromonas sp. MN44 was able to utilize lactose but did not utilize various carbohydrates as a sole carbon source. Aeromonas sp. MN44 showed a very sensitive to antibiotics such as kanamycin, chloramphenicol, ampicillin, tetracycline and spectinomycin, and heavy metal such as cadmium. But this strain showed a high resistance up to mg/ml unit to heavy metals such as lithium and manganese. Optimal manganese oxidation condition of Aeromonas sp. MN44 was pH 7.4 and manganese oxidation activity was inhibited by proteinase K and boiling treatment. So, we concluded that this factor was protein. The manganese oxidizing factor produced by Aeromonas sp. MN44 was partial purified by ammonium sulfate precipitation, DEAE-Toyopearl 650M ion exchange chromatography and Sephadex gel filtration chromatography. Its molecular mass was about 113 kDa.

• Transactions of the Korean hydrogen and new energy society
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• v.23 no.4
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• pp.346-352
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• 2012

The properties of methane oxidation were studied in this research over transition metal containing $CeO_2$ (TM/$CeO_2$, TM=Ni, Co, Cu, Fe) with TM content of 5 wt. % at atmospheric pressure. The characteristics of catalysts were investigated by various characterization techniques, including XRD, GC, SEM and EPMA analyses. The catalytic tests were carried out in a fixed Rmix ratio of 1.5 ($CH_4/O_2$) in a fixed-bed reactor operating isothermally at atmospheric pressure. Only the Ni/$CeO_2$ catalysts showed syngas production above $400^{\circ}C$ via typical partial oxidation reaction whereas other catalysts induced complete oxidation resulting in the production of $CO_2$ and $H_2O$ in whole reaction temperature range. From the quantitative analysis on carbon deposition after catalytic tests, Cu/$CeO_2$ was found to show the highest resistance on carbon deposition. Therefore Cu can be proposed as an efficient catalyst element which can be combined with a conventional Ni-based SOFC anode to enhance the carbon tolerance.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.6
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• pp.529-537
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• 1985

The present study was carried out to investigate the effect of the partial freezing as a means of keeping freshness of mullet (Mugil cephlus). Living samples were killed and stored by icing, partial freezing at $-3^{\circ}C$ and freezing at $-30^{\circ}C$, respectively, Changes in the freshness of the mullet muscle and the phys cal properties of its meat paste product were examined during storage. The results obtained are summarized as follows: The period that k value reached to $20\%$ during storage was the longest in the frozen storage, followed by the partial frozen storage and the ice storage, which was 4 days in the mullet muscle stored by partial freezing. In the case of VBN content, it was below 20 mg/100g in the mullet muscle stored by icing and partial freezing. The oxidation of lipids in the mullet muscle was greater in the ice storage than in the partial frozen storage. The myofibrillar protein of the mullet muscle was appeared to decrease during storage, which the decreasing ratios during storage for 9 days were below $3\%$ in the frozen storage, $17\%$ in the ice storage and $10\%$ in the partial frozen storage. While, the alkali-soluble protein showed to increase and in non-protein nitrgenous compounds, sarcoplasmic protein and stroma was not a great change during storage. The decrease of gel strength, folding strength and texture of meat paste products prepared under different storage conditions was the greatest in the ice storage, the next in the partial frozen storage and such changes in the frozen storage were not so much. In gel strength of the product prepared with sample fishes stored for 10 days, the gel strength in the ice storage, partial frozen storage and frozen storage was about $30\%,\;60\%\;and\;97\%$ of the control. respectively. The expressible drip of the products increased with storage time of raw fishes, which that of the products prepared with sample fishes stored for 15 days was about 2.1 times in the ics storage, about 1.5 times in the partial frozen storage and about 1.1 times in frozen storage as much as that of the control, respectively.

• Journal of the Korean Institute of Gas
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• v.13 no.4
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• pp.46-52
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• 2009

Hydrogen can extend the lean misfire limit to a large extent when it is mixed with conventional fuels for an internal combustion engine. This study is about fuel reforming to produce hydrogen enriched gas as a fuel for engine. Especially gasoline, which consists of numerous hydrocarbon fuels, considered as source of reformed gas. Various hydrocarbons, including commercial fuel were reformed and potentialities of reformed gas on vehicles were accessed. The reforming efficiency and hydrogen yield were observed. Maximum hydrogen yield were found with different gas hourly space velocity(GHSV) and O2/C ratio of reforming conditions.

• Journal of the Korean Applied Science and Technology
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• v.20 no.3
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• pp.230-236
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• 2003

Synthesis gas is commercially produced by a steam reforming process. However, the process is highly endothermic and energy-consuming. Thus, this study was conducted to produce synthesis gas by the partial oxidation of methane to decrease the energy cost. Supported Ni catalysts were prepared by the impregnation method. To examine the activity of the catalysts, a differential fixed bed reactor was used, and the reaction was carried out at $750{\sim}850^{\circ}C$ and 1 atm. The fresh and used catalysts were characterized by XRD, XPS, TGA and AAS. The highest catalytic activity was obtained with the 13wt% Ni/MgO catalyst, with which methane conversion was 81%, and $H_2$ and CO selectivities were 94% and 93%, respectively. 13wt% Ni/MgO catalyst showed the best $MgNiO_2$ solid solution state, which can explain the highest catalytic activity of the 13wt% Ni/MgO catalyst.