• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.4
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• pp.53-60
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• 2017

Fly ash(FA) which is a byproduct in the coal combustion in thermal power plant contributes to pore structure densification due to pozzolanic reaction, and this leads to long-term strength development and excellent resistance to chloride penetration. In the work, compressive strength and chloride resistance in OPC(Ordinary Portland Cement) and FA-based concrete are evaluated, and the relationships are investigated considering ages. For the work, 3 different W/B (Water to Binder) ratios of 37%, 42%, and 47% are prepared, and 3 substitution ratio of fly ash(0%, 30%, and 50%) are considered as well. At the age of 28 days and 180 days, test results of compressive strength, diffusion coefficients based on Tang's method, and passed charges referred to ASTM C 1202 and KS F 2711 are obtained. With increasing replacement ratio of FA and decreasing W/B, the resistances to chlorides(diffusion coefficient and passed charge) are improved, and the results at the age of 180 days decrease to only 15% level at the age of 28 days due to pozzolanic reaction in FA 50 mixture, which shows that resistance to chloride is much dependent on age effect than strength development. After 180 days, more clear linear relationships are observed between strength and resistance to chloride.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.6
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• pp.779-783
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• 2006

The adiponectin gene is known to be involved in the regulation of energy homeostasis involving food intake, carbohydrate and lipid metabolism. Human adiponectin gene polymorphisms have been recently reported to be associated with obesity, insulin sensitivity and the risk of type 2 diabetes. The present study was carried out to investigate the porcine adiponectin gene as a candidate gene for fat deposition and carcass traits. A mutation of A178G of the porcine adiponectin gene that resulted in substitution of the amino acid Isoleucine to Valine was identified. AcyI PCR-RFLP was used to detect the polymorphism of the genotypes in five different pig populations (Large White, Landrace, Duroc, Chinese breeds Meishan and Qingping). The A allele frequency was significantly higher among subjects from Chinsese lard type breeds, while the G allele was the only one present in those from Western lean type breeds. To determine if there was an association of the polymorphism with phenotypic variation, the mutation was tested in 267 pigs of the "Large $White{\times}Meishan$" F2 resource population. The results of association analyses showed significant associations of the genotypes with fat deposition and carcass traits. Allele G was significantly associated with increase in loin eye height, loin eye area and lean meat percentage and bone percentage, and decrease in fat mean percentage, ratio of lean to fat, shoulder fat thickness, 6-7 rib fat thickness, thorax-waist fat thickness and buttock fat thickness. The substitution of A178G (Ile60Val) happened to be located at amino acid 60 in the collagenous domain of porcine adiponectin which might affect the association into higher-order structures, and accordingly affect the posttranslational modifications and optimal biological activity of the multimeric forms. The identified functional polymorphism provides new evidence of adiponectin as an important candidate gene affecting fat deposition and carcass traits in pigs.

• Journal of Animal Environmental Science
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• v.17 no.1
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• pp.1-10
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• 2011

This study was conducted to investigate the actual situation of animal medicine use in Hanwoo farms, which were a total of 114 farms. Items surveyed were preference of animal medicine, choice criterion, purchase route, purchase frequency, antibiotics substitution products, etc. Data were collected from May to June, 2010. The kinds of animal medicine which preferred in Hanwoo farms is probiotics (40.4%). Whereas the lowest preference is immunizing agent (12.3%). There was significant difference among regional group (p<0.05), and the significant difference was also found in different farm size group (p<0.05). The factor of choice for purchase of animal medicine was efficiency (31.6%), first of all. There was significant difference among regional group (p<0.05). The purchase route of animal medicine was mostly supplied with the help of government (41.6%). The significant difference were showed in regional group (p<0.05). But that was not found in farm size group (p>0.05). The highest frequency at purchasing antibiotics was less than 1 time per 1 year (38.6%). There was statistically significant difference among regional group (p<0.05). However, there was not significant difference among farm size group (p>0.05). Probiotics of antibiotics substitution products was mostly preferred (50.9%).

• Journal of Animal Science and Technology
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• v.46 no.5
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• pp.729-734
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• 2004

This study was performed to analyze the sequence variations of mtDNA D-loop and their effects on milk in Hanwoo(Korean cattle). The resulting sequences were compared with previously published sequences for other cattle breeds (GenBank JOI394). The Polymerase Chain Reaction was performed to amplify a total of 964 bp between nucleotide 15758 and 383 within D-loop region of mtDNA using specific primers. Twenty polymorphic sites by nucleotide substitution were found in mtDNA D-loop region of Hanwoo. The frequencies of positions at 8, 169, 16042, 16051, 16057, 16093, 16119, 16122, 16209, 16255 and 16302 nt with high levels of sequence polymorphism were 0.150, 0.950, 0.085, 0.138, 0.106, 0.085, 0.138, 0.212, 0.085, 0.148 and 0.180, respectively. The substitution effect at 16119(p<0.1) and 16185(p< 0.05) nt was found significant on milk production. Polymorphism of mtDNA sequence in D-Ioop region could be useful for the analysis of cytoplasmic genetic variation and associations with the other economically important traits and maternal lineage analysis in Hanwoo.

• Korean Journal of Food Science and Technology
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• v.33 no.5
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• pp.551-559
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• 2001

Sodium nitrite which is added in processing of meat process product to develope color and to keep bacteria from growing, produces toxic substance after reacting, bring about deterioration by oxidation and toxic substance. So natural material is needed to substitute this sodium nitrite for. Chitosan which is made of chitin by processing of deacetylase, has various function of antibiosis and antimutation. We studied about the substitution effect of chitosan against sodium nitrite in pork sausage. As a result, of storing the sausage, antimicrobial effect of sodium nitrite was detected by 0.35% of chitosan(M.W. 30 kDa). This chitosan had same color developing effect even though addition content of sodium nitrite reduced until 15 ppm which is less than 1/10 of standard level. And chitosan decreased fast a residual nitrite. This result shows that chitosan inhibited a formation of nitrosamine.

• Journal of the Korean Ceramic Society
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• v.41 no.3
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• pp.221-228
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• 2004

Basic properties of artificial lightweight aggregate by using waste dusts and strength properties of LWA concrete were studied. Bulk specific gravity and water absorption of artificial lightweight aggregates varied from 1.4 to 1.7 and 13 to 16%, respectively. Crushing ratio of artificial lightweight aggregate was above 10% higher than that of crushed stone or gravel. As a result of TCLP leaching test, the leaching amount of tested heavy metal element was below the leaching standard of hazardous material. Slump, compressive strength and stress-strain properties of LWA concrete made of artificial lightweight aggregate were tested. Concrete samples derived from LWA substitution ratio of 30 vol% and W/C ratio of 45 wt% showed the best properties overall. Thermal insulation and sound insulation characteristics of light weight concrete panel with the optimum concrete proportion were tested. Average overall heat transmission of 3.293W/㎡$^{\circ}C$ was observed. It was higher by about 15% than those of normal concrete made by crushed stone. Sound transmission loss of 50.9 ㏈ in frequency of 500 ㎐ was observed. It was higher by about 13% than standard transmission loss.

• Journal of Aerospace System Engineering
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• v.17 no.1
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• pp.42-50
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• 2023

In this study, hexagonal ferrite powder with chemical formula SrZn_2-xCo_xFe₁₆O₂₇ was synthesized by a solid-state reaction method and its electromagnetic (EM) wave absorption characteristics were evaluated in the frequency range of 0.1-18 GHz with absorber thickness range of 0 - 10 mm. Reflection loss (RL) affecting electromagnetic wave absorption performance was calculated based on the transmission line theory using measured complex permeabilities and permittivities. RL spectra were also directly measured for some samples. They were well matched with calculated results. High-frequency complex permeability characteristics were changed gradually according to the amount of Co substitution (x). The EM wave absorption frequency band could be tuned accordingly. Hexaferrite samples with x = 1.0, 1.25, and 1.5 exhibited remarkable maximum electromagnetic wave absorption performances with minimum RL (RL_min) lowered than -50 dB. They also showed a very broad frequency band (Δf > 10 GHz) in which more than 90% of the EM wave energy absorption occurred (RL ≤ -10 dB).

• Korean Journal of Mineralogy and Petrology
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• v.33 no.2
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• pp.115-127
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• 2020

The Unsang gold deposit has been one of the three largest deposits (Daeyudong and Kwangyang) in Korea. The deposit consists of Au-bearing quartz veins filling fractures along fault zones in Precambrian metasedimentary rock and Jurassic Porphyritic granite, which suggests that it might be an orogenic-type. Based on its mineral assemblages and quartz textures, quartz veins are classified into 1)galena-quartz, 2)pyrrhotite-quartz, 3)pyrite-quartz, 4)pegmatic quartz, 5)muscovite-quartz, and 6)simple quartz vein types. The pyrite-quartz vein type we studied shows the following alteration features: sericitization, chloritization, and silicification. The quartz vein contains minerals including white quartz, white mica, chlorite, pyrite, rutile, calcite, monazite, zircon, and apatite. Rutile with euhedral or medium aggregate occur at mafic part from laminated quartz vein. Two types of rutile are distinguishable in BSE image, light rutile is texturally later than dark rutile. Chemical composition of rutile has 89.69~98.71 wt.% (TiO₂), 0.25~7.04 wt.% (WO₃), 0.30~2.56 wt.% (FeO), 0.00~1.71 wt.% (Nb₂O₅), 0.17~0.35 wt.% (HfO₂), 0.00~0.30 wt.% (V₂O₃), 0.00~0.35 wt.% (Cr₂O₃) and 0.04~0.25 wt.% (Al₂O₃), and light rutile are higher WO₃, Nb₂O₅ and FeO compared to the dark rutile. It indicates that dark rutile and light rutile were formed at different stage. The substitution mechanisms of dark rutile and light rutile are suggested as followed : dark rutile [(V³⁺, Cr³⁺) + (Nb⁵⁺, Sb⁵⁺) ↔ 2Ti⁴⁺, 4Cr³⁺ (or 2W⁶⁺) ↔ 3Ti⁴⁺ (W⁶⁺ ↔ 2Cr³⁺), V⁴⁺ ↔ Ti⁴⁺], light rutile [2Fe³⁺ + W⁶⁺ ↔ 3Ti⁴⁺, 3Fe²⁺ + W⁶⁺ ↔ Ti⁴⁺ + (V³⁺, Al³⁺, Cr³⁺) +Nb⁵⁺], respectively. While the dark rutile was formed by cations including V³⁺, V⁴⁺, Cr³⁺, Nb⁵⁺, Sb⁵⁺ and W⁶⁺ by regional metamorphism of hostrock, the postdating light rutile was formed by redistribution of cations from predating dark rutile and addition of Fe²⁺ and W⁶⁺ from Au-bearing hydrothermal fluid during ductile shear.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.11
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• pp.1651-1654
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• 2007

The mouse myxovirus resistance protein 1 (Mx1) is known to be sufficient to confer resistance to influenza viruses, and the gene encoding Mx1 is, therefore, an interesting candidate gene for disease resistance in farm animals. The porcine Mx1 gene has already been identified and characterized based on its homology with mouse Mx1; the full-length coding region of the pig Mx1 gene spans 2,545 bp (M65087) and is organized into 17 exons compared with the human ortholog mRNA. In this study, the exons 9, 10 and 11 and introns 6 and 9 of the porcine Mx1 gene were cloned and sequenced. Two SNPs were identified in exons 9, 10 and 11 but none of the SNPs led to an amino acid exchange, and the other eleven variants were detected in introns 6 and 9, respectively. Differences in allele frequency between Meishan and other pig breeds were observed within intron 6, of which an $A{\rightarrow}G$ substitution at position 371 was detected as an SnaBI PCR-RFLP. The association analysis using the Large White${\times}$Meishan $F_2$ offspring suggested that the Mx1 genotype was associated with variation in several immunity traits that are of interest in pig breeding. However, further investigations in more populations are needed to confirm the above result.

• Journal of Animal Science and Technology
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• v.62 no.5
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• pp.702-712
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• 2020

Synthetic nitrite imparts a reddish-pink color to meat and a distinct flavor to meat products, delays lipid oxidation, and inhibits microbial growth and pathogens. However, excessive intake of nitrite might result in the production of carcinogenic nitrosamine, which might increase the risk of cancer in humans. Therefore, we aimed to find an alternative natural colorant for pork sausages. Pork sausages were mixed with 0.014% sodium nitrite (NaNO₂) alone (CON), without either NaNO₂ or purple-fleshed sweet potato powder (PP; CON1), 0.5% PP alone (PP1), 1% PP (PP2) alone, 0.011% NaNO₂ and 0.5% PP (SP1), and 0.011% NaNO₂ and 1% PP (SP2). The sausages were then cooked and stored for physicochemical analysis on days 0, 5, 10, 15, and 20. The a* and W* values were the greatest and lowest in the SP2 and CON1 treatments, respectively (p < 0.05). The concentrations of residual nitrite in the sausages at 20 days decreased in the order of CON > SP1, SP2 > PP2 > PP1, CON1. The fatty acid content was higher, and flavorous amino acids were more in PP2 (p < 0.05). The fatty acid composition was comparable between the SP2 and CON groups, but the contents of glutamic acid and alanine were greater in the SP2 group. In conclusion, SP2 (0.011% NaNO₂ with 1% PP) could be added as a natural colorant for pork sausage production, and NaNO₂ could be substituted with up to 20% PP without detrimental effects on sausage appearance and/or quality.