• Journal of Aquaculture
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• v.21 no.1
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• pp.41-46
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• 2008

The purpose of the study was to suggest the optimal lipid enrichment conditions used digestive enzyme activity of rotifer changing due to water temperature and salinity. The high population growth appeared at the experiment temperature more than 28 degrees highly on the culture temperature(maximum 32 degrees, 1,453 individual/mL). The fecundity was low at high temperature, and the egg ratio was high at low temperature. Population growth of 10 and 15 ppt appeared in most highly, but the fecundity and the egg ratio were high most significantly appeared in natural seawater(32 psu). The digestive enzyme activity by the culture environment mainly showed high activity in natural seawater(amylase exclusion, 15 psu). However, the TAP activity by the water temperature showed highly at the more high temperature, but the amylase and the lipase appeared at low temperature. We carried out the lipid enrichment at 20 degrees and 26 degrees in a condition of the natural seawater. Total protein, the total essential amino acids differed not significantly. The methionine content that was essential amino acids, a total lipid content, unsaturated index of fatty acids, DHA and the DHA/EPA ratio were high significantly each in $20^{\circ}C$ enrichment trial. Therefore, we could suggest the $20^{\circ}C$ and natural seawater for the optimal lipid enrichment condition in aquaculture, because methionine contents, several indexes by the lipid, TG-lipase activity, fecundity and egg ratio are high.

• Korean Journal of Food Science and Technology
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• v.42 no.3
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• pp.329-334
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• 2010

Escherichia coli O157:H7 causes hemolytic uremic syndrome and hemorrhagic colitis in humans. The objectives of this study were to produce monoclonal antibody(MAb) against E. coli O157:H7 and to develop an enzyme linked immunosorbent assay(ELISA) for the rapid detection of E. coli O157:H7 in agri-stockbreeding. The characterization of MAb produced from hybridoma cell (HKEC 4G8-5) was validated by ELISA and Western blot. The produced MAb was specific to E. coli O157:H7 and showed weak cross-reaction to Staphylococcus aureus. The detection limit of ELISA based on 4G8-5 MAb was $10^5\;cell/mL$. Although the ELISA could not detect E. coli O157:H7 in the meat and sprout samples inoculated with $1{\times}10^1\;cell$/10 g without enrichment, the same samples after enrichment for 6 hr were confirmed to be positive by ELISA. These results indicated that the ELISA combined with short enrichment (6 hr) is useful tool for rapid screening of E. coli O157:H7 in various samples.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.4
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• pp.367-371
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• 2005

About 3,000 bacterial colonies with esterase activities were isolated from soil samples by enrichment culture and halo-size on Luria broth-tributyrin (LT) plates. The colonies were assayed for esterase activity in microtiter plates using enantiomerically pure (R)- and (S)-2-phenylbutyric acid resorufin ester (2PB-O-res) as substrates. Two enantioselective strains (JH2 and JH13) were selected by the ratio of initial rate of hydrolysis of enantiomerically pure (R)- and (S)-2-PB-O-res. When cell pellets were used, both strains showed high apparent enantioselectivity ($E_{app}>100$) for (R)-2PB-O-res and were identified as Exiguobacterium acetylicum. The JH13 strain showed high esterase activity on p-nitrophenyl acetate (pNPA), but showed low lipase activity on p-nitrophenyl palmitate (pNPP). The esterase was located in the soluble fraction of the cell extract. The crude intracellular enzyme preparation was stable at a pH range from 6.0 to 11.0.

• Nuclear Engineering and Technology
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• v.20 no.3
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• pp.165-169
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• 1988

As a part of tandem fuel cycle feasibility study, the residual U and Pu nuclide contents of PWR spent fuels are computed using ORICEN2 code for each Korea Nuclear Unit and batch to investigate the potential of utilizing them as CANDU fuels. The annual and accumulated discharged amounts of U and Pu nuclides are computed for the PWRs from KNU 1 through KNU 10. The results of computation show that the spent fuels having 0.7-0.8 w/o U-235 are dominant and considerable amounts of fissile Pu are produced. The enrichment of U-235 is less than the expected 0.8-0.9 w/o U-235 since the burnups offered by KEPCO are higher than those of other PWRs.

• Journal of Environmental Science International
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• v.6 no.2
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• pp.173-182
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• 1997

The bacterial strains, which utilizes 2,4,4'-trichloro-2'-hydroxydiphenyl ether(TCHDPE) as a sole carbon source, were isolated by selective enrichment culture from soil samples of industrial waste deposits. The bacterium that showed the highestt biodegradation activity was designated as EL-O47R The isolated strain EL-O47R was Identified as the genus Pseudomonas from the results of morphological, cultural, and biochemical tests. The optimum conditions of medium for the growth and the degradation of TCHDPE were TCHDPE 500 ppm, (NH4)2SO4 0.1% as the nitrogen source, initial pH 7.0±0.1, and 37℃, respectively. In this conditions, the regradation rate of TCHDPE was about 97%. Pseudomonas sp. EL-O47R was tested for resistance to several metal compounds and antibiotics. Pseudomonas sp. EL-O47R was moderately grown to Cd(NO3)2, ZnCl2, AgSO4, CuSO4 and HgCl2. This strain was sensitive to rifampicin and kanamycln but resistant to ampicillin, penicillin, tetracyclin and chloramphenlcol. Pseudomonas sp. EL-O47R was grown structurally related com- pounds and potential metabolites of TCHDPE, and has the stability on TCHDPE biodegradation.

• The Journal of Engineering Geology
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• v.15 no.3
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• pp.349-363
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• 2005

Many Quaternary faults are recognized as thin gouge and narrow cataclastic zone juxtaposing the Bulguksa granite and Quaternary deposit bed in the eastern block of the Using Fault, Korea: Gaegok 1, Caegok 2, Singye, Madong Wonwonsa and Jinhyeon faults. This study was performed to calculate chemical change, volume change, silica loss and fluid-rock ratio taken place in gouge zones of these Quaternary faults using XRF, XRD, EPMA. The chemical compositions of fault rocks reveal that the fault gouges are depleted in $SiO_2,\;Na_2\;O,and\;K_2O$ and enriched in $Al_2O_3,\;Fe_2O_3,\;P_2O_5,\;MgO,\;MnO,\;CaO,\;and\;LOI(H_2O+CO_2)$ relative to protoliths. The fact that there is enrichment of relatively immobile elements and depletion of the more soluble elements in the fault gouges relative to protoliths can be explained by fluid-assisted volume loss of $56\%$ for Caegok 1 fault, $22\%$ for Caegok 2 fault,$34\%$, for Singye fault, $8\%$ for Madong fault, $2\%$ for the Wonwonsa fault and $53\%$ for the linhyeon fault. Madong fault and Wonwonsa fault where ratios of the volume change, silica loss and fluid-rock are low might have acted as a closed system for fluid activity, whereas Caegok 1 fault and Jinhyeon fault with high ratios in those factors be an open system. The volumetric fluid-rock ratios range $10^2\sim10^4$ for all faults, being highest in Caegok 1 fault and Jinhyeon fault whose fluid activity was most significant.

• Proceedings of the Korean Nuclear Society Conference
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• 1995.10a
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• pp.35-40
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• 1995

Considering the higher discharge burnup, lower channel refuelling rate, lower linear element rating(LER), lower coolant void reactivity and axial power shape, CANFLEX-RU fuel bundle is optimized for CANDU-6 by grading the fissile composition in the ring-wise of the bundle and by applying fuel management scheme appropriately. The fissile composition of the fuel bundle is graded as the recovered uranium (0.9 w/o U-235) in the outer and intermediate elements, depleted Uranium (0.2 w/o U-235) in the center element, natural uranium (0.71 w/o U-235) in the inner elements. Enrichment is not required for these fuel. The fissile composition is optimized by lattice calculation and by time-averaged reactor simulation. CANFLEX-RU optimized for CANDU-6 resulted to be the 15% lower channel refuelling rate, acceptable axial power profile and power envelope, 70% higher discharge burnup, 15% lower LER and not increase coolant void reactivity compared with the 37-element natural uranium bundle for CANDU-6.

• The Journal of the Petrological Society of Korea
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• v.15 no.2 s.44
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• pp.90-105
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• 2006

The Cretaceous volcanic rocks in the study area represented by andesitic rocks occupy eastern part of the Kyeongsan Caldera. The volcanic rocks comprise andesite I, andesitic tuff, andesite II, and andesitic tuff breccia in their stratigraphic succession, and andesitic porphyry. Andesite I is distinguished from andesite II in their color, texture, phenocryst mineralogy and petrochemisty. In outcrops, andesite I is compact and dark-green, and andesite II is brick red in color and porphyritic in texture. In their phenocryst mineralogy, andesite I contains olivine phenocryst in addition to plagioclase and pyroxene which occur in both of andesites. Compared to andesite II, andesite I is higher in $SiO_2$ and $K_2O$ contents and lower in CaO, MgO, MnO, $TiO_2,\;Fe_2O_3$, and $P_2O_5$. Major elements petrochemistry shows that magma series of the volcanic rocks spread widely from calc-alkaline to alkaline series. On the other hand, immobile trace elements petrochemistry shows that the magma series is calc-alkaline without exception, suggesting that the volcanics has experienced more or less alkali enrichment after their eruption. Trace element diagrams for discrimination of tectonic setting show that the volcanics of the study area might be originated from calc-alkaline continental volcanic arc.

• The Journal of the Petrological Society of Korea
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• v.12 no.3
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• pp.135-153
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• 2003

In order to understand its origin and petrogenesis, petrochemical studies of major, trace elements, REE, and stable isotopes of oxygen and carbon from the Hongcheon Fe-REE deposits have been investigated. The Hongcheon Fe-REE deposit intruding into Precambrian metasedimentary rocks consists of magnetite, various carbonates such as ankerite, siderite, magnesite and strontianite, monazite, aegirine-augite, Na-amphibole, and sulfides. Compared with major elements abundances of typical ferro-carbonatites, the Hongcheon Fe-REE deposit is enriched in FeO and depleted in CaO with increasing of $SiO_2$, where $TiO_2$and $A1_2O_3$increased and CaO, FeO, MgO and $P_2O_5$ are slightly decreased, but those are rather scattered and their trends are somewhat ambiguous. V Ni, U and Rb slightly increasing with of $SiO_2$increase and scattering or no trends of other detected elements. Nb, Zr and Zn are depleted then the abundances of typical ferro-carbonatites (Woolley and Kempe, 1989). In rare earth elements a large enrichment of total REE (maximum 14.8 wt%) and LREE relative to chondrites and HREE depleted more then the values of ferro-carbontites therefore La/Lu ratios shows large abundances (max. 16,197). The results of stable isotopes of O and C from minerals of ankerite and strontianite and whole rocks represent studied rocks are from igneous carbonatitic melts. Although petrochemical characteristics of the Hongcheon Fe-REE deposits are somewhat different from normal ferro-carbonatites from the world, this discrepancy suggests another conclusion that petrochemical characteristic of the studied Fe-REE mineralized rocks are similar to those of phoscorites from Kovdor, Russia and Sokli, Finland showing the same petrochemical compositions described above.

• Progress in Superconductivity and Cryogenics
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• v.20 no.2
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• pp.16-19
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• 2018

Comprehensive utilization of zinc smelting iron slag not only solves environmental problems but also creates huge economic benefits. This study was conducted on the enrichment and recovery of ${\alpha}-Fe_2O_3$ from zinc smelting iron slag by superconducting HGMS technology. Several variables such as slurry flow velocity, slag concentration, magnetic field intensity and the amount of dispersing agent were tested in magnetic separation. In the experiments, obtained optimal magnetic separation parameters were 1.60 T of magnetic flux intensity, 600 mL/min of slurry flow velocity of, 15 g/L of slag concentration of, 0.10 g/L of dispersing agent. Under this condition, the content of ${\alpha}-Fe_2O_3$ was increased from 86.22% to 94.39% that can approach the Chinese national standard requirements (A level) of iron oxide red. It was concluded that using superconducting HGMS technology was an effective method for the purification of ${\alpha}-Fe_2O_3$ from zinc smelting iron slag.