• Economic and Environmental Geology
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• v.51 no.2
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• pp.99-111
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• 2018

In this study three target radionuclides ($^{60}Co$, $^{137}Cs$, and $^{125}Sb$) were reacted with solid samples collected from the nuclear facility sites to investigate their sorption and mobility behaviors for preparing unexpected nuclear accidents. The highest sorption distribution coefficients ($K_{ds}$) of target radionuclides ($^{60}Co=947mL/g$, $^{137}Cs=2105mL/g$, $^{125}Sb=81.3mL/g$) were found in topsoil layer under groundwater condition, and the $K_d$ values of three radionuclides decreased in the order of fractured rock and bedrock samples under the same groundwater condition. High $K_d$ values of $^{60}Co$ in topsoil layer and fracture rock resulted from the clay minerals present, and the $K_d$ values decreased 58-69 % under seawater condition due to high ionic strength. $^{137}Cs$ sorption was controlled by the ion exchange reaction with $K^+$ on flayed edge sites (FES) of mica. The $^{137}Cs$ sorption was the most affected by seawater (89-97 % decrease), while $^{125}Sb$ sorption was not much affected by seawater. As the results of column and batch experiments, the retardation factors (R) of $^{137}Cs$, $^{60}Co$, and $^{125}Sb$ were determined about 5400-7400, 2000-2500, and 250-415, respectively, indicating no significant transport for these radionuclides even in fractured zone with groundwater. These results suggest that even in the case of severe nuclear accident at the nuclear facilities the mobility of released radionuclides ($^{60}Co$, $^{137}Cs$, and $^{125}Sb$) can be significantly retarded by the topsoil layer and fractured rock. In addition, the results of this study will be used for the safety and environmental performance assessment of nuclear facilities.

• Pediatric Infection and Vaccine
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• v.8 no.2
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• pp.175-180
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• 2001

Purpose : Recently in Korea since 1998, 2TU has been used instead of 5TU, which caused a confusion in interpreting tuberculin skin tests. We compared the tuberculin skin reaction to PPD(purified protein derivatives) 1TU, 2TU and 5TU. Methods : We studied tuberculin skin reaction to PPD 1TU, 2TU and 5TU on 92 infants who were vaccinated with percutaneous multiple puncture BCG vaccine(Tokyo 172 strain, Japan BCG Laboratory Co.) in neonatal period. Diameters of indurations were measured in millimeters 48~72 hours after the intradermal injection of PPD 1TU, 2TU and 5TU. Results : Among 92 infants(male : 56, female : 36), 1TU was used on 31 infants, 2TU on 31 infants and 5TU on 30 infants for tuberculin skin test. The mean diameter of induration for PPD 1TU, 2TU and 5TU were $5.7{\pm}4.2mm$, $7.1{\pm}3.7mm$, and $9.2{\pm}4.2mm$, respectively. There was no statistical difference in mean diameter of induration between 1TU and 2TU. However, when tested with 5TU, the diameter of induration was significantly larger than those of PPD 1TU and 2TU(P<0.05). Six subjects(19.4%) tested with 1TU, 9 subjects(29%) tested with 2TU and 16 subjects(53.3%) tested with 5TU had diameter of 10 mm or more. There was no statistical difference between 1TU and 2TU but for 5TU, number of subjects with diameter of 10 mm or more was significantly higher than PPD 1TU and 2TU(P<0.05). Number of subjects with induration diameter of 5 mm or more for 1TU, 2TU and 5TU was 19(61.3%), 22(71.0%) and 26(86.7%), respectively. However, there was no statistical difference. Conclusion : A new standard criteria for interpreting the tuberculin skin test with PPD 2TU should be established for clinical diagnosis of tuberculosis.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.7
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• pp.523-529
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• 2011

This study has been performed to examine the influence of the size of particles on the stabilization in the aerobic stabilization equipment connected with MBT system. The biodegradable waste inside the reactor (60% of food waste, 25% of paper waste, 2% of wood waste and 5% of compost) has been charged in same composition. The degree of stabilization was compared and analyzed after charging with adjustment of particle size in 5 mm, 10 mm, 20 mm, 50 mm, 100 mm and state of no separation. The experiment revealed that highest temperature beyond $65^{\circ}C$ was shown in the particle size of less than 50 mm in change of temperature and the highest temperature was about $50^{\circ}C$ in reactor of 100 mm and no separation. The proportionality between generated quantity of $CO_2$ and particle size was not observed, even the highest in generated quantity was shown in over 100 mm. The weight changes based on wet and dry conditions in the reaction process showed the 30% and 46% of reduction in the smallest particle size of 5 mm and it showed the trend of the lower reduction rate at the bigger particle size. The water soluble $COD_{Cr}$ and TOC showed the reduction rate of 60% in reactor of particle size in 100 mm and no separation while the reduction rate comparing to the initial stage of reaction in the reactor of less than 50 mm was 80%. Such result derived the conclusion of acceleration in the decomposing stabilization of biodegradable material due to the decomposing rate of organic substance as the particle size of biodegradable waste gets smaller. It is concluded as necessary to react in adjustment under 50 mm of particle size as much as possible.

• Clean Technology
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• v.28 no.2
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• pp.131-137
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• 2022

The semiconductor process currently emits various by-products and unused gases. Emissions containing pollutants are generally classified into categories such as organic, acid, alkali, thermal, and cabinet exhaust. They are discharged after treatment in an atmospheric prevention facility suitable for each exhaust type. The main components of organic exhaust are volatile organic compounds (VOC), which is a generic term for oxygen-containing hydrocarbons, sulfur-containing hydrocarbons, and volatile hydrocarbons, while the main components of alkali exhaust include ammonia and tetramethylammonium hydroxide. The purpose of this study was to determine the combustion characteristics and analyze the NO_X reduction rate by maintaining a direct combustion and temperature to process organic and alkaline exhaust gases simultaneously. Acetone, isopropyl alcohol (IPA), and propylene glycol methyl ether acetate (PGMEA) were used as VOCs and ammonia was used as an alkali exhaust material. Independent and VOC-ammonia mixture combustion tests were conducted for each material. The combustion tests for the VOCs confirmed that complete combustion occurred at an equivalence ratio of 1.4. In the ammonia combustion test, the NO_X concentration decreased at a lower equivalence ratio. In the co-combustion of VOC and ammonia, NO was dominant in the NO_X emission while NO₂ was detected at approximately 10 ppm. Overall, the concentration of nitrogen oxide decreased due to the activation of the oxidation reaction as the reaction temperature increased. On the other hand, the concentration of carbon dioxide increased. Flameless combustion with an electric heat source achieved successful combustion of VOC and ammonia. This technology is expected to have advantages in cost and compactness compared to existing organic and alkaline treatment systems applied separately.

• Korean Journal of Animal Reproduction
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• v.10 no.2
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• pp.192-203
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• 1986

Two experiments in this study were designed to compare the potential for in vitro capacitation and in vitro fertilization of ejaculated sperm among individual rabbit bucks. In experiment 1, for in vitro capacitation, the ejaculated sperm were preincubated in DM for 12 hr or 18 hr after HIS treatment, then 12 hr -or 18 hr- preincubated sperm were incubated with superovulated rabbit ova in a 5% CO2 incubator for 36 hr at 38$^{\circ}C$, and a part of cleaved ova was transferred to the recipient does for implantation of embryo. In experiment 2, effect of lysolecithin addition to preincubation medium on induction of accelerated in vitro capacitation and in vitro fertilization of individual rabbit sperm was studied. Experiment 1; 1. Percent acrosome reaction of sperm, noted after staining, after 12 hr or 18 hr preincubation ranged from 52.5 to 76.0% and from 67.5 to 90.0%, respectively and sperm motility index of these sperm ranged from 20.0 to 47.5 for 12 hr-preincubated sperm and from 15.0 to 37.5 for 18 hr- preincubated sperm. There was no a certain relation between percent acrosome reaction and sperm motility index. 2. In vitro fertilization rate (cleavage rate) of in vitro capacitated sperm varied widely among individual bucks, ranging from 0 to 47.8% for 12 hr - preincubated sperm and from 0 to 60.9% for 18 hr -prein- cubated sperm. Cleavage rate of 18 hr - preincubated sperm was higher and faster than that of 12 hr - preincubated sperm. 3. Eight of 44 in vitro fertilized embryos transferred into 6 recipients were implanted in 4 recipients (66.7%) up to day 15 and implnatation rate was 18.2%. Experiment 2; 1. The percent acrosome reaction of sperm before and after 4 hr preincubation in DM without lysolecithin varied significantly among individual bucks, ranging from 0.4 to 18.4% and from 1.7 to 37.4%, respectively and percent acrosome reaction of sperm at 30 min after addition of 60${\mu}$g/ml lysolecithin also was significantly different among bucks, ranging from 19.2 to 67.1%. 2. Effect of accelerated acrosome reaction following lysolecithin addition was more considerable in the individuals showed less percent acrosome reaction before and after 4 hr preincubation. Percentage of motile sperm and motility score showed a trendency towards a decrease with increase of preincubation time and time after lysolecithin addition. 3. In vitro fertilization rate (cleavage rate) at 24 hr postinesmination with pooled sperm were treated to 60 $\mu\textrm{g}$/ml lysolecithin for 30 min after 4 hr preincubation was 24.6%, a higher rate than 13.2% for control. While 80 $\mu\textrm{g}$/ml lysolecithin-added sperm showed a lower cleavage than control and 60$\mu\textrm{g}$/ml-added sperm at both 24 hr and 48 hr postinsemination. These results from 2 experiments suggest that more useful preincubation time for the in vitro capacitation of ejaculated rabbit sperm is 18 hr in DM after HIS treatment, although there is wide variation in vitro capacitation and in vitro fertilization rate among individual bucks, and lysolecithin addition to at least 4 hr - preincubated sperm in DM can result in almost same in vitro fertilization rate as that of 18 hr - preincubated sperm in the experiment 1.

• Horticultural Science & Technology
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• v.16 no.1
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• pp.21-24
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• 1998

RAPD markers were analyzed in order to detect the genetic variation and diversity of the fifty-two melon lines. SDS extraction method produced more and purer DNA than CTAB method. RAPD reaction conditions were optimized as follows ; 10ng template DNA, 270nM primer, $200{\mu}M$ each of dATP, dCTP, dGTP and dTTP, $0.3{\mu}unit$ dynazyme and 10x buffer brought to $15{\mu}l$ final volume with distilled water. The adequate annealing temperature was $39^{\circ}C$ and forty cycles of amplification produced the best RAPD band patterns. Among a total of 123 bands from 12 random primers, 25 polymorphic bands(20%) were selected as reliable markers. The average number of polymorphic bands per primer was 2.1 among the 52 lines. Intragroup genetic relationship based on the marker difference was closer than intergroup genetic relationship. The 52 lines could be grouped into two major group (Korean landraces and melon lines) and then melon group subdivided into two subgroups (net melon lines and no-net melon). This result corresponded to morphological grouping. Eight RAPD markers separated the Korean landraces and melon groups and four RAPD markers separated net melon and no-net melon groups.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.11
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• pp.1065-1072
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• 2012

Due to its oxygen (O) content, biodiesel (BD) is advantageous in that it lowers PM emissions in CI engines. Therefore, BD is considered one of the best candidates for low temperature combustion (LTC) operation because its use can extend the regime for simultaneous reduction of PM and $NO_x$. Thus, in this study, LTC operation was realized using BD and diesel with a 5~7% $O_2$ fraction. Engine test results show that the use of BD increased the efficiency and reduced emissions such as PM, THC, and CO; furthermore, IMEP reduced by 10~12% owing to the lower LHV of the fuel. In particular, smoke was suppressed by up to 90% because O atoms in the BD enhanced the soot oxidation reaction. To compensate the IMEP loss, turbocharging (TC) was then tested, and the results showed that the power output increased and PM was reduced further. Moreover, TC in BD engine operation allowed a similar level of reduction in both $NO_x$ and PM at 11~12% $O_2$ fraction, suggesting that there is a potential to widen the operating range by the combination of TC and BD.

• Journal of Life Science
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• v.24 no.6
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• pp.603-611
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• 2014

The lectins were separated from Korean and Chinese mung bean seeds finally via chromatography using Sephadex G-100 and their biochemical features were studied and compared. They showed no hemagglutination with human red blood cells regardless of trypsin treatment and showed hemagglutination with only trypsin treated rabbit red blood cells. The molecular weights of two lectins were identified as 54 kDa and 28 kDa by SDS-PAGE. It was found that while the optimal reaction temperature of the lectin from Korean mung bean was $60^{\circ}C$, that of the lectin from Chinese mung bean seeds was $50^{\circ}C$. It was found also that the most thermal stable temperature of the seed lectin from Korean mung bean seeds was $50^{\circ}C$ and the lectin from Chinese mung bean was $40-50^{\circ}C$. The lectin from Korean mung bean seeds showed the highest activity at pH 3.2 and the lectin from Chinese mung bean showed the highest activity at pH 6.2. It was identified that when treating a denaturant, thiourea and guanidine-HCl resulted in no hemagglutination, so they induced denaturalization. It was identified also that there was no hemagglutination with urea, so it did not induced denaturalization. They showed no septicity to 6 types of carbohydrates including D-glucose. In addition, the lectins from the two mung bean seed had specificity to metal ions.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.2
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• pp.158-167
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• 2015

A lateral flow immunoassay kit based on antigen-antibody interactions was developed to detect residues of beta-lactams, quinolones, tetracyclines, and sulfonamides in farmed fish. Group-specific antibodies showing cross-reactivity with other antibiotics in the same group were produced in rabbits. The rabbits were immunized eight times to obtain the maximum titers. Antibodies were extracted from the antisera collected from the immunized rabbits and produced group-specific reactions with antibiotics from the four groups. A kit was prepared that optimize conditions for the antigen-antibody reaction, using colloidal gold conjugated antibodies, and was designed to detect the four groups of antibiotics simultaneously. The kit enabled the detection of antibiotics in the four groups at below maximum residue limits (MRLs), which were $200{\mu}g/kg$ for tetracyclines, $100{\mu}g/kg$ for sulfonamides, $50{\mu}g/kg$ for beta-lactams, and $100{\mu}g/kg$ for quinolones. The cross-reactivity of the antibodies ranged from 10-80% for the sulfonamides, 20-100% for tetracyclines, 38-100% for quinolones, and 20-100% for the beta-lactams, confirming that the antibodies were group specific. The test kit was used 30 times to examine spiked antibiotics at the limits of detection (LODs) and all produced positive results, indicating high sensitivity. The LODs for the assay ranged from 4-20 ng/mL for beta-lactams, 25-50 ng/mL for sulfonamides, 20-100 ng/mL for tetracyclines, and 30-80 ng/mL for quinolones, and there were no false negative reactions at above these LODs. In addition, all of the LODs of the developed kit were correlated with high-performance liquid chromatography (HPLC) data. Our lateral flow immunoassay kit can simultaneously detect antibiotic residues from a large number of fish samples rapidly, strengthening the safety of domestic farmed and imported fish.

• Clean Technology
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• v.13 no.4
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• pp.266-273
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• 2007

The adsorption properties of the activated carbon-based adsorbents were studied to remove COS emitted from $SO_2$ catalytic reduction process on the integrated gasification combined cycle (IGCC) system in this work. Transition metal supported catalysts and mixed metal oxide catalysts were used for the $SO_2$ catalytic reduction. The mechanism of COS produced from the $SO_2$ reduction and the COS concentration s according to the reaction temperature were investigated. In this study, an activated carbon and a modified activated carbon doped with KOH were used to remove the very low concentration of COS effectively. The adsorption rate and the breakthrough time of COS were measured by a thermo gravity analyzer (TGA, Cahn Balance) and a fixed bed flow reactor equipped with GC-pulsed flammable photometric detector (PFPD), respectively. It was confirmed that the COS breakthrough time of the activated carbon doped with KOH was longer than that of an activated carbon. In conclusion, the modified-activated carbon having a high surface area showed a high adsorption rate of COS produced from the $SO_2$ reduction.