• Applied Chemistry for Engineering
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• v.9 no.7
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• pp.1030-1035
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• 1998

The porous alumina membrane was prepared from aluminum metal(99.8%) by anodic oxidation using DC power supply of constant current mode in an aqueous solution of sulfuric acid. To prevent the chemical dissolution of alumina membrane, $Al_2(SO_4)_3$, $AlPO_4$ and $Al(NO_3)_3$ which could be considered to supply $Al^{3+}$ ions were added to electrolyte solution at a reaction temperature of $20^{\circ}C$ and cumulative charge of $150C/cm^2$. Effects of these additives on the formation of porous alumina membrane were evaluated under various electrolyte concentration(5~20 wt%) and current densities($10{\sim}50mA/cm^2$). The membrane surfaces which were prepared in electrolyte solution with all the additives except $Al_2(SO_4)_3$ were damaged. However, when $Al_2(SO_4)_3$ was added to the $H_2SO_4$ solution, an uniform surface of porous alumina was obtained. Also, it was shown that the pore size of membrane was nearly independent on the quantity of $Al_2(SO_4)_3$ added at same electrolyte concentration and current density.

• Applied Biological Chemistry
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• v.18 no.3
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• pp.177-182
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• 1975

The analysis of Jerusalem artichoke showed that it contains 12.09% of Inulin. The results obtained from the examination of the conditions for fructose production by cultivating Pencillum sp 1 in the Jerusalem articoke medium were as follows: 1. The optimum amount of water added to Jerusalem artichoke was 2.5 $\ell$ of distilled water per ㎏ of fresh Jerusalem artichoke. It this case, the concentration of Inulin was 4% (w/v). 2. The optimum temperature was $30^{\circ}C$, the initial optimum pH was 5.0 and the optimum cultural period was 72 hours. 3. Shaking culture with 50 ml of the medium and 120 oscills/min in 500 ml shaking flask was most effective as the culture method. 4. 0.1% of $NH_4H_2PO_4$ as a nitrogen source, 0.001 of $FeSO_47H_20$ and 0.001% of $MgSO_47H_2$ as metal salts were most effective. 5. Fructose production continued to increase for 72 hours under the optimum conditions for cultivation and the highest production rate to the Inulin was 95.25%.

• Journal of Applied Biological Chemistry
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• v.52 no.4
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• pp.157-162
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• 2009

An agar-liquefying bacteria (SC-22), which produces a diffusible agarase that caused agar softening around the colony was isolated from Daecheong lake in Korea. Chemotaxanomic and phylogenetic analyses based on 16S rRNA gene sequences revealed the strain was classified as Cellvibrio mixtus SC-22. The isolate SC-22 showed maximal extracellular agarase activity with 58.5 U/mL after 48 h cultivation in the presence of 0.2% agar. It was observed that the isolate produced two kinds of extracellular and three kinds of intracellular isoenzymes. The major agarase was purified from the culture filtrate of agarolytic bacteria by ammonium sulfate precipitation, anion exchange and gel filtration column chromatographic methods. The molecular mass of the purified enzyme was estimated to be 25 kDa by SDS-PAGE. The optimum pH and temperature of the purified enzyme were pH 7.0 and $50^{\circ}C$, respectively. The agarase activity was activated by $Fe^{2+}$, $Na^+$ and $Ca^{2+}$ ions while it was inhibited by $Hg^{2+}$, $Mn^{2+}$ and $Cu^{2+}$ at 1 mM concentration. The predominant hydrolysis product of agarose by the enzyme was galactose and disaccharide on TLC, indicating the cleavage of $\beta$-1,4 linkage in a random manner. The enzyme showed high substrate specificity for only agar and agarose among various polysaccharides.

• Journal of the Korean Applied Science and Technology
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• v.37 no.4
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• pp.723-732
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• 2020

The spent RHDS (Residue HydroDeSulfurization) catalyst is deactivated mainly by deposition of various contaminants such as coke, sulfur and vanadium on the surface of catalyst. To eliminate those contaminants, the following remanufacturing process was conducted. The first, heavy oil on the surface of the spent RHDS catalyst was removed by kerosene and dehydrated. The second, the high temperature incineration was carried out to eliminate coke and sulfur components deposited on the surface of spent RHDS catalyst. The third, the excessive quantity of Vanadium deposited on the surface of catalyst was removed by leaching process as follows: ultrasonic agitation was carried out at 50℃, for 10 seconds with 0.5% and 1% oxalic acid solution. The purpose of this process is to find out regenerated RHDS catalyst can be used as SCR catalyst for NOx reduction by controlling the vanadium residual content of the regenerated RHDS catalyst through leaching process. The composition of regenerated RHDS catalyst was analyzed by XRF and the NOx reduction efficiency was also measured by continuous catalytic fixed bed reactor. As the result, regenerated catalyst, with 0.5% oxalic acid, ultrasonic agitation in 10 seconds, showed the most stable NOx reduction efficiency. Also, in comparison with commercial SCR catalyst, the NOx reduction performance of regenerated catalyst was similar to that of commercial SCR catalyst at the temperature 375℃ and higher whereas was lower than commercial SCR catalyst at the temperature range between 200~250℃. Therefore, it was confirmed that the regenerated catalyst as powder form wash coated on the surface of metal corrugated substrate can be used for commercial SCR catalyst.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.15 no.4
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• pp.343-353
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• 2017

Processing and equipment were tailored for engineering scale fabrication of $UO_2$ porous pellets, a feed material for the electrolytic reduction process in the PRIDE (PyRoprocessing Integrated DEmonstration) facility at KAERI (Korea Atomic Energy Research Institute). The starting materials, $UO_2$ powder and pre-milled surrogate oxide powders, were proportioned to simulate the chemical composition of spent fuel (so-called Simfuel). The Simfuel powders were homogenized by mixing, compacted into a pellet shape, and finally heat treated using a tumbling mixer, rotary press, and sintering furnace. After sintering at $1450^{\circ}C$ for 24 h in $4%\;H_2-Ar$, the average bulk density of the $UO_2$ Simfuel pellets was $6.89g{\cdot}cm^{-3}$, which meets the standard of the following electrolytic reduction process. In addition, the results of a microstructural analysis demonstrated that the sintered Simfuel $UO_2$ porous pellets accurately simulate the properties of spent fuel in terms of the formation of second phases. These results provide essential information for the massive fabrication of $UO_2$ porous pellets for engineering scale pyroprocessing research.

• Applied Biological Chemistry
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• v.40 no.4
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• pp.342-346
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• 1997

Contents of heavy metals in paddy soils and brown rice of near the Kunsan industrial complex area were investigated. Average total heavy metal contents in paddy soils were Pb 34.33, Cd 0.50, Cu 35.49, and Zn 71.67 mg/kg respectively. There are no correlation between distances from industrial complex and contents of heavy metals in paddy soils. Average contents of heavy metals in brown rice grown above paddy soil were Pb 1.74, Cd 0.07, Cu 3.54, and Zn 16.53 mg/kg. Relationships between 0.1N HCl soluble heavy metals in paddy soils and contents of brown rice showed positive significant correlations for Pb at l% $level(r=0.6853^{**})$ and for Zn at 5% $level(r=0.5420^*)$. Relationships between total contents of heavy metals in paddy soils and contents of brown rice showed only positive significant correlation for Pb at 1% $level(r=0.7131^{**})$. Contents of heavy metals in paddy soils and brown rice of near the Kunsan industrial complex was polluted partly by the influence of smoke and dust out from industrial complex but not polluted anxious level

• Applied Biological Chemistry
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• v.42 no.4
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• pp.304-309
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• 1999

Two Lectins, designated FVL-1 and FVL-2, were isolated and purified from the fruiting bodies of edible mushroom Flammulina veluripes using ammonium sulfate fractionation, ethanol treatment, DEAE-TOYPEARL ion-exchange column chromatography, and TSK-Gel HW-55F column chromatography. Specific activity increased 18 folds for FVL-1 and 7.9 folds for FVL-2 from ethanol treated sample. SDS-PAGE of FVL-1 and FVL-2 gave apparent molecular mass of 10.6 kDa and 37 kDa, respectively. FVL-2 agglutinated all type of human erythrocytes (A, B, AB, and O). However, FVL-1 agglutinated more human erythrocyte type O than type A, B, and AB. The hemagglutination activities of the FVL-1 were effectively inhibited by bovine submaxillary and porcine stomach mucins(BSM and PSM), fetuin, asialofetuin and cations, such as $Cu^{2+}$, $Mg^{2+}$, $Ca^{2+}$, $Mn^{2+}$ and $Fe^{2+}$. However, FVL-2 was not inhibited by any cations. The hemagglutination activities of the two lectins were not inhibited by the sugar, such as lactose, galactose and sugar derivatives. FVL-1 and FVL-2 were stable at pH $5{\sim}11$ and pH $4{\sim}7$, respectively. FVL-1 was stable below $55^{\circ}C$ and FVL-2 was below $45^{\circ}C$.

• Journal of Nutrition and Health
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• v.14 no.1
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• pp.16-25
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• 1981

Commercially available duck-meat was subjected to proximate analysis. On a wet basis, the duck-meat contained 62.87, 17.05, 19.06 ana 1.02 percent of moisture, crude fat, crude protein and ash, respectively. Almost all the essential amino acids contained in the duck-meat protein, ana the tryptophan was the limiting one by amino acid analysis of GLC. An analysis of the fatty acid composition by GLC showed a relatively high concentration of oleic acid. There was also a considerable content of linoleic acid. The content of polyunsaturated fatty acids of duck-meat was 70.9% and the P/S ratio of fatty acids was 3.4. The cholesterol content in duck-meat was determined to be approximately 70. 5mg/100g ofm sample. According to blood analysis, it was understood that the content of phospholipids was relatively high, particulary in lecithin. ATP-phosphorus, at the higher temperature, was released faster than at the lower temperature, by two hours after postmortem. The ATPase activity of Myogibril was inhibited at the relatively high concentration of added EDTA and metallic ions, but the activity was very high in the lower concentrations. According to the cooking conditions, boiled duck-meat showed good digestion by pepsin. It was understood that the digestibility of duck meat was relatively high, so the duck-meat protein is good source of animal protein. Therefore, it is able to be recommended that duck-meat is good nitrogen source animal food.

• Resources Recycling
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• v.18 no.5
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• pp.26-36
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• 2009

A recovery process of Ruthenium from waste electronic scrap has been investigated by means of nitric acid leaching as a part of development for scrap pretreatment process to obtaining an optimum conditions for removal of removing various impurities such as Pb, Bi, Zn, Al, Bi, Ag Fe, Co, Zr, Si. From the experiments, 90% of Pb leached with 250 g/l pulp density in 10-15% nitric acid. Leaching behavior of Ba was also similar to that of the Pb, but those of other metal impurities, such as Zn, Al, Bi, Ag, Fe, Co, Zr, showed different behavior, in which the dissolution rate increased as the concentration of nitric acid in solution is increased up to the 10% $HNO_3$ in solution and then it was constant above 10% $HNO_3$ concentrations. Meanwhile, the dissolution of Ru in $HNO_3$ solution was less then 100ppm, and that the total content of Ru in undissolved residue scrap was resulted in an increment of 50%.

• Progress in Superconductivity
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• v.12 no.2
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• pp.118-123
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• 2011

The properties of $2^{nd}$ generation high temperature superconducting wire, coated conductor strongly depend on the quality of superconducting oxide layer and property of metal substrate is one of the most important factors affecting the quality of coated conductor. Good mechanical and chemical stability at high temperature are required to maintain the initial integrity during the various process steps required to deposit several layers consisting coated conductor. And substrate need to be nonmagnetic to reduce magnetization loss for ac application. Hastelloy and stainless steel are the most suitable alloys for metal substrate. One of the obstacles in using stainless steel as substrate for coated conductor is its difficulties in making smooth surface inevitable for depositing good IBAD layer. Conventional method involves several steps such as electro polishing, deposition of $Al_2O_3$ and $Y_2O_3$ before IBAD process. Chemical solution deposition method can simplify those steps into one step process having uniformity in large area. In this research, we tried to improve the surface roughness of stainless steel(SUS310). The precursor coating solution was synthesized by using yttrium complex. The viscosity of coating solution and heat treatment condition were optimized for smooth surface. A smooth amorphous $Y_2O_3$ thin film suitable for IBAD process was coated on SUS310 tape. The surface roughness was improved from 40nm to 1.8 nm by 4 coatings. The IBAD-MgO layer deposited on prepared substrate showed good in plane alignment(${\Delta}{\phi}$) of $6.2^{\circ}$.