• Atmosphere
• /
• v.31 no.3
• /
• pp.267-282
• /
• 2021

Characteristics of carbonaceous components and organic compounds in PM_2.5 over the atmosphere of the Yellow Sea were investigated. PM_2.5 samples were collected onboard the meteorological research vessel, GISANG 1, over the Yellow Sea during the YES-AQ campaign in 2018 and 2019, respectively. The average concentrations of carbonaceous components in this region were 2.59 ± 1.59 ㎍ m^-3 for the OC, 0.24 ± 0.10 ㎍ m^-3 for the EC, 2.14 ± 1.30 ㎍ m^-3 for the WSOC and 1.17 ± 0.94 ㎍ m^-3 for the HULIS-C, respectively. The total concentration of 56 organic compounds (ΣOCs) accounts for 10% of OC. The main group among organic compounds were dicarboxylic acids which account for 57% of ΣOCs, followed by n-alkanoic acids accounting for 34% of ΣOCs. In n-alkanoic acid distribution, hexanoic (C_6:0) and octanoic (C_8:0) acids which are low molecular weight n-alkanoic acids and known as emitted from marine biogenic activities were dominant in this region. Furthermore, non-HULIS-C fraction increased when the air mass originated from the marine region rather than the continental region. When the Asian dust episode was observed, the WISOC concentrations along with the levoglucosan were increased, while the haze episodes caused the increase of WSOC, HULIC-S and DCAs. In this study, we found that the components of carbonaceous and organic aerosols in PM_2.5 over the Yellow Sea were changed with the specific air pollution episodes. It indicates that the physicochemical properties of PM_2.5 can be changed by the air pollution episodes in this region.

• Clean Technology
• /
• v.27 no.2
• /
• pp.190-197
• /
• 2021

Kraft lignin is a by-product of the pulp and paper industry, obtained as a black liquor after the extraction of cellulose from wood through the Kraft pulping process. Right now, kraft lignin is utilized as a low-grade boiler fuel to provide heat and power but can be converted into high-calorific biofuels or high-value chemicals once the efficient catalytic depolymerization process is developed. In this work, the multi-functional catalyst of Ru-Mg-Al-oxide, which contains hydrogenation metals, acid, and base sites for the effective depolymerization of kraft lignin are prepared, and its lignin depolymerization efficiency is evaluated. In order to understand the role of different active sites in the lignin depolymerization, the three different catalysts of MgO, Mg-Al-oxide, and Ru-Mg-Al-oxide were synthesized, and their lignin depolymerization activity was compared in terms of the yield and the average molecular weight of bio-oil, as well as the yield of phenolic monomers contained in the bio-oil. Among the catalysts tested, the Ru-Mg-Al-oxide catalyst exhibited the highest yield of bio-oil and phenolic monomers due to the synergy between active sites. Furthermore, in order to maximize the extent of lignin depolymerization over the Ru-Mg-Al-oxide, the effects of reaction conditions (i.e., temperature, time, and catalyst loading amount) on the lignin depolymerization were investigated. Overall, the highest bio-oil yield of 72% and the 3.5 times higher yield of phenolic monomers than that without a catalyst were successfully achieved at 350 ℃ and 10% catalyst loading after 4 h reaction time.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.16 no.5
• /
• pp.217-222
• /
• 2023

The purpose of this paper was to synthesize a polymer organic hard mask that simplifies the manufacturing process, reduces process time significantly, and thereby lowers manufacturing costs. The results of measuring residual metals through vapor refining showed that 9-Naphthalen-1-ylcarbazole(9-NC) measured 101.75ppb in the 4th zone, 2-Naphthol (2-NA) measured 306.98ppb in the 5th zone, and 9-Fluorenone(9-F) measured between 129.05ppb across the 4th and 5th zones. After passing through a filtration system, the synthesized organic hard mask measured residual metals in the range of 9 to 7ppb. Additionally, the thermal analysis indicated a decrease of 2.78%, a molecular weight of 942, carbon content of 89.74%, and a yield of 72.4%. The etching rate was measured at an average of 18.22Å/s, and the coating thickness deviation was averaged at 1.19. For particle sizes below 0.2㎛ in the organic hard mask, no particles were observed. By varying the coating speed at 1,000, 1,500, and 1,800rpm and measuring the resulting coating thickness, the shrinkage rate ranged from 17.9% to 20.8%. The coating results demonstrated excellent adhesion to SiON, and it was evident that the organic hard mask was uniformly applied.

• Korean Journal of Radiology
• /
• v.20 no.5
• /
• pp.830-843
• /
• 2019

Objective: To examine the potential of intravoxel incoherent motion (IVIM) and blood oxygen level-dependent (BOLD) magnetic resonance imaging for detecting renal changes after iodinated contrast-induced acute kidney injury (CI-AKI) development in a diabetic rabbit model. Materials and Methods: Sixty-two rabbits were randomized into 2 groups: diabetic rabbits with the contrast agent (DCA) and healthy rabbits with the contrast agent (NCA). In each group, 6 rabbits underwent IVIM and BOLD imaging at 1 hour, 1 day, 2 days, 3 days, and 4 days after an iohexol injection while 5 rabbits were selected to undergo blood and histological examinations at these specific time points. Iohexol was administrated at a dose of 2.5 g I/kg of body weight. Further, the apparent transverse relaxation rate (R2^*), average pure molecular diffusion coefficient (D), pseudo-diffusion coefficient (D^*), perfusion fraction (f) were calculated. Results: The D and f values of the renal cortex (CO) and outer medulla (OM) were significantly decreased compared to baseline values in the 2 groups 1 day after the iohexol injection (p < 0.05). A marked reduction in the D^* values for both the CO and OM was also observed after 1 hour in each group (p < 0.05). In the OM, a persistent elevation of the R2^* was detected for 4 days in the DCA group (p < 0.05). Histopathological changes were prominent, and the pathological features of CI-AKI aggravated in the DCA group until day 4. The D, f, and R2^* values significantly correlated with the histological damage scores, hypoxia-inducible transcription factor-1α expression scores, and serum creatinine levels. Conclusion: A combination of IVIM and BOLD imaging may serve as a noninvasive method for detecting and monitoring CI-AKI in the early stages in the diabetic kidney.

• Korean Journal of Breeding Science
• /
• v.41 no.2
• /
• pp.115-125
• /
• 2009

This study was undertaken to investigate the genetic diversity and to develop a technique for cultivar discrimination using SSR markers in rice. Sixty-seven recently distributed rice cultivars in Korea from 1998 to 2005 were evaluated by 20 SSR markers. A total of 149 alleles were produced ranging from 4 to 14 alleles with an average of 7.5 alleles per locus. The molecular weight of alleles per locus varied from 4 bp (RM253) to 51 bp (RM335), and PIC values ranged from 0.45 (RM202) to 0.87 (RM204) with an average of 0.67. Of them, seven markers, RM204, RM257, RM21, RM224, RM249, RM253, and RM264, were selected as key markers for differentiating rice varieties. The seven markers produced a total of 67 alleles with an average of 9.6 alleles per marker. PIC values ranged from 0.48 (RM253) to 0.87 (RM204) with an average of 0.72. The 63 cultivars (94%) out of 67 cultivars could be individually identified by the genotype using the seven SSR markers, which will be applicable to discriminating rice cultivars.

• Korean Journal of Poultry Science
• /
• v.40 no.2
• /
• pp.83-89
• /
• 2013

iNOS (Inducible nitric oxide synthase) and TLR-4 (Toll-like Receptor-4) play crucial roles in innate immunity of poultry. iNOS has been mapped to chicken chromosome 14 and implicated in a variety of chicken diseases. iNOS possesses potent antimicrobial activity, including the inhibition of microbes replication in vitro. TLR-4 is a pathogen associated molecular-pattern receptor for bacterial product, such as LPS (lipopolysaccharides) found in Gram negative bacteria, that triggers pro-inflammatory cytokine expression after engagement with ligands. In the previous studies, genetic analysis of iNOS and TLR-4 revealed the possible association of mutation in these genes with the intestinal microflora of cecum when infected with Salmonella spp. This study was aimed to augment previous findings, which show the association of iNOS (C14513T) and TLR-4 (G4409T) polymorphisms with economic traits in Korean Native Black (KNB), Rhode Island Red (RIR) and Cornish chickens. Investigation in the effect of SNPs on economic traits (layday, layw, layno, bw150, bw270, layw270) was conducted. iNOS (C14513T) had a significant effect on the average body weight at 270 days of age (p<0.05) in both KNB and RIR, whereas TLR-4 (G4409T) showed no significant correlation with all traits (p>0.05). The results obtained from using the candidate genes can be useful for the genetic improvement of body weight in both KNB and RIR breeds.

• Asian-Australasian Journal of Animal Sciences
• /
• v.18 no.10
• /
• pp.1485-1491
• /
• 2005

This experiment was conducted to investigate the effects of iron from an amino acid complex (Availa-$Fe^{\circledR}$) on the iron status of neonatal and suckling piglets. A total of 24 gestating sows (Landrace${\times}$Large White) were randomly allocated to three dietary treatments. The control diet contained 80 mg $kg^{-1}$ Fe from ferrous sulfate heptahydrate ($FeSO_4$.$7H_2O$), while the two experimental diets were supplemented with an additional 120 mg $kg^{-1}$ Fe from Availa-$Fe^{(R)}$ or $FeSO_4$.$7H_2O$, respectively. The lactating sows remained the same iron treatments as gestating sows, while neonatal piglets of 24 litters born from the above sows were allotted to another three treatments. Piglets from the sows of the control treatment were fed basal diet with no supplemental Fe as control treatment, but were injected with 100 mg Fe as Fe dextran at birth. Piglets from the sows of Availa-$Fe^{(R)}$ or $FeSO_4$.$7H_2O$ treatments were supplemented with 120 mg $kg^{-1}$ iron from Availa-$Fe^{(R)}$ or $FeSO_4$.$7H_2O$, respectively. The total born alive and weaned, and the average piglets weight at birth and at weaning were not significantly affected by the sow' dietary treatments (p>0.05). Iron from Availa-$Fe^{(R)}$ did not demonstrate a statistically significant improvement in hemoglobin concentration, hematocrit and plasma iron of sows on day 90 and 105 of pregnancy and the milk iron of sows during lactation (p>0.05). Neonatal piglets in the Availa-$Fe^{(R)}$ treatment had a significantly higher hemoglobin concentration (p<0.05) and higher hematocrit and plasma iron (p>0.05) than those in the other two treatments, respectively. The hemoglobin of suckling piglets in the Availa-$Fe^{(R)}$ treatment was higher than that of piglets in $FeSO_4$.$7H_2O$ treatment on day 28 (p<0.05). The total iron binding capacity of piglets in Availa-$Fe^{(R)}$ treatment was lower than that of piglets in the control and $FeSO_4$.$7H_2O$ treatment on day 14 (p<0.05), but there was not a statistically significant difference among three treatments on day 28 (p>0.05). However, the hemoglobin and hematocrit of suckling piglets injected with Fe were higher than those of piglets in the other two treatments (p<0.05). This study indicated that the addition of 120 mg $kg^{-1}$ iron from amino acid complex into the diets improved iron status of neonatal and nursing piglets more effectively than the addition of 120 mg $kg^{-1}$ iron from $FeSO_4$.$7H_2O$, however, this improvement of the organic Fe was not sufficient to replace the Fe injection for prevention of iron-deficiency anemia.

• Journal of environmental and Sanitary engineering
• /
• v.3 no.2 s.5
• /
• pp.23-41
• /
• 1988

Two hundred and eighty-six strains of Salmonella species were isolated from the twelve provincial institutes of health and 19 general hospitals of urban and rural areas in Korea from January to December in 1986. The antimicrobial susceptibility test of these cultures was done by the method of agar diluton. The resistance frequency of Salmonella cultures was $29.7\%$. Among these resistant cultures, the most provalent resistance pattern of Salmonella was ampicillin, carbenicillin, chloramphenicol, tetracycline, streptomycin, and its resistance frequency was $15\%$. In plasmid profile of resistance strains, average number of plasmid harboring in Salmonella was 1-4 and molecular weight of plasmid ranged 1.6 to 70 megadalton (Md.). Plasmid pattern of strains isolated from Seoul and Kang-won showed the same or similar profiles. Plasmid pattern was identical in the same resistance pattern.

• The Korean Journal of Pesticide Science
• /
• v.18 no.4
• /
• pp.247-257
• /
• 2014

Assessment for operator's dermal and inhalation exposure to acetamiprid during cultivation of water melon in greenhouse was carried out. For dermal exposure measurement, whole body dosimetry (WBD) was performed as the first trial in Korea. WBD consists of cotton/polyester outer clothes and cotton inner clothes. Hand exposure was measured by washing of nitrile gloves and hands while head exposure was monitored by face/neck wipe technique. Inhalation exposure was monitored with personal air sampling pumps and IOM sampler (glass fiber filter). Analytical limit of quantitation was 2.5 ng/mL. Good reproducibility (C.V < 8.7%), linearity ($R^2$ > 0.99) and recovery (70~119%) were obtained. Field recovery of acetamiprid was 77~95%. During mixing/loading, hand exposure of acetamiprid was about 10 times ($229.7{\mu}g$) more than that of application case ($20.9{\mu}g$). During application, total dermal exposure was $1207.4{\mu}g$. Exposure of lower legs was $1132.1{\mu}g$, which is 93.8% of the total dermal exposure. Inhalation exposure during mixing/loading and application was not detected. Margin of safety (MOS) was calculated for risk assessment using male Korean average body weight (70 kg) and acceptable operator exposure level ($124{\mu}g/kg/day$) to give 140, suggesting that health risk of operator during treatment of acetamiprid for water melon in greenhouse could be safe.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.27 no.2
• /
• pp.107-113
• /
• 1994

Among the currently recognized pathogenic vibrios, V. vulnificus and V. cholerae non O1 are the most serious bacteria from the point of view of sea food hygiene in Korea. In this paper, the authors compared the hemolytic activities of the crude hemolysin produced by V. vulnificus and V. cholerae non O1 isolated from shellfish collected in Chungmoo, Korea. The authors also attempted to improve the purification method of V. vulnificus hemolysin(VVH) and tried to make antiserum with the purified hemolysin. VVH was produced in abundance in heart infusion broth containing $2\%$ NaCl in a shaking cultivation process(140rpm) at $37^{\circ}C$ for 15 hours. While hemolysin production patterns of V. cholerae non O1 were quite different by the strain during the culture times compared with the V. vulnificus. Hemolytic activity of the VVH on sheep erythrocytes was stronger than those of rabbit, but hemolytic activities of the hemolysin produced by V. cholerae non O1 on rabbit erythrocytes were as much as twice as strong as on those of sheep and horse. VVH was purified by two steps of hydrophobic column chromatography on Phenyl-Sepharose HP with Fast Protein Liquid Chromatography(FPLC). Purification fold and yield of VVH was much improved by changing the elution buffer's pH from 6.0 to 9.8 and adding $1\%$ CHAPS(a zwitter ionic detergent) and $50\%$ ethylene glycol to the 10mM glycine buffer during the repeated hydrophobic column chromatography. Homogeneity of the purified hemolysin was shown by polyacrylamide gel electrophoresis. According to the five times repeated purification results, the specific activity was increased 27500 times and the yield was improved by $23.4\%$ on average. About $250{\mu}g$ of purified hemolysin was harvested from the 2400ml of culture supernatant of V. vulnificus. Molecular weight of VVH was estimated to be 50KDa by the SDS-PAGE and the neutralization scores of the obtained antiserum acting against VVH were $2000{\sim}8500$.