• Korean Journal of Organic Agriculture
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• v.32 no.1
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• pp.107-125
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• 2024

Three types of veterinary antibiotics, including oxytetracycline (OTC) and chlortetracycline (CTC) of tetracycline class and amoxicillin (AMX) of penicilline class, were artificially introduced into the irrigation water. The residue of veterinary antibiotics in the soil, the absorption-translocation of veterinary antibiotics into the red lettuce and young radish plant, and crops yield were investigated according to the agricultural water irrigation method (surface drip irrigation, underground drip irrigation, and sprinkler irrigation). There was no significant difference in the residue and translocation of veterinary antibiotics in the soils and crops according to the irrigation method and type of veterinary antibiotics (p>0.05). For the edible parts of red lettuce and young radish, all three types of veterinary antibiotics were found to be below the detection limit, indicating that the safety of the crops was secured. The translocation factor of red lettuce and young radish were found to be less than 0.3 and 0.2, respectively. However, continuous introduction of veterinary antibiotics in agricultural arable lands may have negative effects by affecting soil microbial activity and soil microbe species diversity, so continuous management is deemed necessary.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.11
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• pp.1524-1528
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• 2005

Molecular genetic markers were used to detect chromosomal regions which contain economically important traits such as growth, carcass, and meat quality traits in pigs. A three generation resource population was constructed from a cross between Korean native boars and Landrace sows. A total of 240 F2 animals from intercross of F1 was produced. Phenotypic data on 17 traits, birth weight, body weights at 3, 5, 12, and 30 weeks of age, teat number, carcass weight, backfat thickness, body fat, backbone number, muscle pH, meat color, drip loss, cooking loss, water holding capacity, shear force, and intramuscular fat content were collected for F2 animals. Animals including grandparents (F0), parents (F1), and offspring (F2) were genotyped for 80 microsatellite markers covering from chromosome 1 to 10. Least squares regression interval mapping was used for quantitative trait loci (QTL) identification. Significance thresholds were determined by permutation tests. A total of 10 QTL were detected at 5% chromosome-wide significance levels for growth traits on SSCs 2, 4, 5, 6, and 8.

• Food Science of Animal Resources
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• v.37 no.2
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• pp.153-161
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• 2017

Fatty acid profiles in relation to meat quality traits and sensory palatability of grain-fed and grass-fed beef from Hanwoo, American, and Australian crossbred cattle were examined in this study. There were significant (p<0.001) differences in fat content and fatty acid compositions between grain-fed and grass-fed beef. Grain-fed Hanwoo had significantly (p<0.001) lower saturated fatty acid (SFA) proportion but higher monounsaturated fatty acid (MUFA) proportion compared to grass-fed cattle. The proportion of oleic acid in grain-fed Hanwoo was significantly (p<0.001) higher than that in grass-fed Hanwoo, Australian crossbred, or American crossbred cattle. Grain-fed Hanwoo had significantly (p<0.001) lower percentages of drip loss and cooking loss compared to other cattle. Overall palatability panel scores of grain-fed cattle were significantly (p<0.001) higher than those of grass-fed cattle. Consequently, sensory overall palatability was negatively correlated with proportions of SFA and polyunsaturated fatty acid (PUFA), but positively correlated with the proportion of MUFA. In particular, the proportion of oleic acid was strongly and positively correlated with fat content (r=0.91, p<0.001) and overall palatability (r=0.92, p<0.001). These results implied that high-concentrate grain-fed could increase intramuscular fat (IMF) content and the proportion of oleic acid, thus increasing the sensory palatability of Hanwoo beef.

• Journal of Animal Science and Technology
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• v.60 no.7
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• pp.19.1-19.10
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• 2018

Background: A mold strain thought to be suitable for dry-aging process was isolated. The information about the scientific aspects of molds related to dry-aging beef is scarce. We, therefore, conducted aging trials to determine the characteristics of the isolated mold strain associated with dry-aging process. Specifically, during the dry-aging of beef with the mold strain, the changes in the free amino acid content, hardness, productive loss, drip and cooking loss were analyzed. These characteristics were compared with those obtained while dry-aging in the absence of a mold. Results: The isolated mold strain was identified as Mucor flavus. The free amino acid content in the mold-aging beef decreased or remained constant during the aging process. However, that in the trimming sections of the beef dramatically increased in the presence of mold. In addition, hardness of mold-aging beef gradually decreased during the aging process and finally decreased significantly. Conclusion: Amino acids such as GABA (gamma-aminobutyric acid), proline, and aspartic acid were produced by our mold strain, M. flavus during its growth on beef meat, and the mold conferred savory odors to the dry-aged beef.

• Food Science of Animal Resources
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• v.35 no.4
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• pp.524-532
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• 2015

The objective of this study was to investigate the effects of high post-mortem temperature application on development of pale, soft, exudative (PSE) turkey meat characteristics in terms of local slaughter conditions. Within this scope, it was targeted to obtain PSE-like muscles benefiting from different post-mortem temperature applications. Immediately after slaughter, turkey Pectoralis major (n=15) muscles were kept at various post-mortem temperatures (0, 10, 20, 30, and 40℃) for 5 h. pH values of 40°C treatment were lower than four other treatments (p<0.05). L* values, drip loss, cook loss, and thawing loss of 40℃ group were higher than the other groups (p< 0.05). Napole yield of 40℃ treatment indicated that high post-mortem temperature decreases brine uptake. Protein solubility of 40℃ group was lower than 0℃ group (p<0.05). Expressible moisture did not differ between 0 and 40℃ treatments. Hardness, gumminess and chewiness of 40℃ treatment were higher than 0℃ treatment. The results of this research showed that high post-mortem temperature treatment induced development of PSE-like turkey meat, with lower pH, paler color, higher technological and storage losses, and reduced protein solubility and texture.

• The Korean Journal of Food And Nutrition
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• v.11 no.4
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• pp.409-415
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• 1998

This study was carried out to investigate the effects of freezing temperature on quality of vacuum packaging freezed beef. In case of thaw drip loss, the freezing of -3$^{\circ}C$ and -20$^{\circ}C$ were 5.23% and 5.17% to 60 days respectively, were increased significantly during freezing. The cooking loss of water bath and pan were increased significantly during freezing than the beginning of freezing, but were no different between -3$^{\circ}C$ and -20$^{\circ}C$. The salt soluble protein extractability was decreased during freezing, the -20$^{\circ}C$ freezing was higher than -3$^{\circ}C$freezing. The water soluble protein extractability was increased during freezing higher than during freezing. The myoglobin denatured percentage of the -3$^{\circ}C$ freezing was higher than -20$^{\circ}C$ freezing, the 15 days storage of -3$^{\circ}C$ freezing was highest to 96%. The shear force value was not change during freezing, the myofibrillar fragmentation index during freezing was higher than the beginning of freezing, but was not change during freezing. The pH was decreased to freezing 45 days, after that increased.

• Journal of The Korean Society of Agricultural Engineers
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• v.49 no.2
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• pp.87-97
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• 2007

The aim of this study was to compare crop contamination between two irrigation methods using microbial-contaminated water. The effect of relative humidity on microbial survival of the three indicator microorganisms was also investigated. Escherichia coli ATCC 25922, Clostridium perfringens ATCC 3624, and coliphage PRD1 were applied to irrigation water to grow cantaloupe, lettuce, and bell pepper. Half of the sixteen plots were subsurface drip irrigated (SDI) and the other half were furrow irrigated (FI). Two relative humidity levels were controlled at 15-65 % and 55-80 % for the dry and humid condition experiments, respectively. Samples of produce, surface soil, and subsurface soil at a depth of 10 cm were collected over a two-week period following the application of the study microorganisms. Overall, greater contamination of both produce and soil occurred in the FI plots. For the SDI plots, preferential water paths and resulting water appearance on the seed beds seemed to be responsible for produce contamination. Relative humidity levels did not appear to affect microbial survival in soil. PRD 1 showed lower inactivation rates than 5. coli in both dry and humid conditions. C. perfringens did not experience significant inactivation over the experimental period, suggesting this microorganism can be an effective indicator of fecal contamination.

• Journal of Environmental Science International
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• v.10 no.5
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• pp.351-358
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• 2001

The main purpose of this study was to investigate the characteristics of cylindrical electrostatic precipitator with centrifugal effect in viewpoints of pressure drip and collection efficiency, experimentally. The experiment was carried out for the analysis of current-voltage, pressure drop and collection efficiency with various experimental parameters such as the applied voltage, inlet velocity, inlet size and inlet type(upper and bottom), etc. In the results, the pressure drops were estimated as 27~54, $34~63mmH_2O$ for inlet size $15mm{\tiems}30mm$ and $30mm{\tiems}60mm$, respectively. The collection effeciencies were shown over 90% with the small inlet size($15mm{\tiems}30mm$) for the applied voltage 40kV, inlet velocity(15~21m/s), and 51~89% with the large inlet size ($30mm{\tiems}60mm$). Moreover, in the applied voltage 0kV and inlet size $15mm{\tiems}30mm$, the collection efficiency induced by centrifugal force was represented as about 35% with inlet velocity 15 - 21m/s.

• Journal of Biosystems Engineering
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• v.14 no.2
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• pp.128-136
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• 1989

The purpose of this study was to develop a computer operated automatic drip irrigation system for application in vinyl-house cultivation. The results can be summarized as follows: 1) The T-type ice compensation wire was used to measure the temperature. The voltage level measured up to 0.02 volt was used as input to an 8-bit A/D converter. 2) A specially devised tensiometer was used to content the watering system. When the needle of the pressure gauge reaches the lower threshold position it turns on the pumping system and turns off when it reaches higher threshold position. 3) In order to use the multiple gypsum blocks for one transducer, reed relays and a D/O board were used to make the sequential switching possible. 4) It was possible to automate the trickle irrigation system for the whole growth period of vinyl-house crops with the help of microcomputer. 5) In terms of furrow irrigation, the irrigation water consumption was the smallest, 2.8 times less than conventional method of surface trickle irrigation, 3.4 times less than subsurface trickle irrigation method. 6) In terms of productivity of cucumber, there was a drop in productivity when compared to furrow irrigation method, 7.2% for surface trickle irrigation, 27.4% for subsurface irrigation method.

• Journal of the Korean Society of Safety
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• v.25 no.3
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• pp.45-52
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• 2010

The purpose of this study is application to flame retardant powder coating(FRPC) material consisting of ammonium polyphosphate(APP) and magnesium hydroxide($Mg(OH)_2$) as a halogen free flame retardant into thermoplastic resin(LDPE-g-MAH). For improvement of adhesion, LDPE-g-MAH was synthesized from low density polyethylene(LDPE) and maleic anhydride(MAH). The mechanical properties as melt flow index, pencil hardness, cross-hatch adhesion and impact resistance of FRPC were measured. Also, the limited oxygen index(LOI) values were measured 17.3vol%, 31.1vol% and 33.7vol% for LDPE-g-MAH, FRPC-3(APP 15wt%, $Mg(OH)_2$ 15wt%) and FRPC-5(APP 30 wt%), respectively. The thermo gravimetry/differential thermal analysis(TG/DTA) of FPRC-3 was observed endothermic peak at $340^{\circ}C$ and $450^{\circ}C$, it was confirmed predominant thermal stability though the wide temperature range by APP and $Mg(OH)_2$. It was showed V-0 grade for FRPC-3 and FRPC-4(APP 20wt%, $Mg(OH)_2$ 10wt%) that a char formation and drip suppressing effect, and combustion time reduced by UL94(vertical burning test). It was confirmed that flame retardancy was improved with the synergy effect because of char formation by APP and $Mg(OH)_2$.