• Food Science of Animal Resources
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• v.33 no.1
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• pp.119-124
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• 2013

This study was conducted to investigate meat quality and sensory characteristics between castrated and non-castrated dairy goats. Dairy goat of Saanen breeds was slaughtered at an age of 6 mon. Then, characteristics of dairy goat meat were analyzed to chemical compositions, collagen content, pH, meat color, cooking loss, water-holding capacity, shear force, protein solubility, and myofibrillar protein fractions by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Also, odor from dairy goat meats was analyzed by sensory evaluation and volatile substances by gas chromatography-mass spectrometry (GC-MS). As a result, the chemical compositions and physicochemical characteristics were not significantly different between castrated and non-castrated dairy goats meat. Also, there is no difference protein solubility (sarcoplasmic, myofibrillar and total protein) and protein fraction by SDS-PAGE. Sensory evaluation results in odour scores are highly (p<0.05) non-castration dairy goat meat better than castration. As a result, overall palatability was higher (p<0.05) in castrated goat meat when compared with non-castrated one. The indole and octadecanoic acid by GC-MS based on sensory evaluation results were only detected in non-castrated dairy goat meat. Therefore, distribution for goat meats castrated compared to non-castrated dairy goat meat is expected to be able to get a good response to the Korean consumer.

• Fire Science and Engineering
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• v.31 no.5
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• pp.53-62
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• 2017

Electric power which is the energy source of economy and industries requires long distance transportation due to regional difference between its production and consumption, and it is supplied through the multi-loop transmission and distribution system. Prior to its actual use, electric power flows through several transformations by voltage transformers in substations depending on the characteristics of each usage, and a transformer has the structure consisting of the main body, winding wire, insulating oil and bushings. A transformer fire that breaks out in substations entails the primary damage that interrupts the power supply to houses and commercial facilities and causes various safety accidents as well as the secondary economic losses. It is considered that causes of such fire include the leak of insulating oil resulting from the destruction of bottom part of bushings, and the chain reaction of fire due to insulating oil that reaches its ignition point within 1 second. The smoke detector and automatic fire extinguishing system are established in order to minimize fire damage, but a difficulty in securing golden time for extinguishing fire due to delay in the operation of detector and release of gas from the extinguishing system has become a problem. Accordingly, this study was carried out according to needs of active mechanism to prevent the spread of fire and block the leak of insulating oil, in accordance with the importance of securing golden time in extinguishing a fire in its early stage. A bushings fireproof structure was developed by applying the high temperature shape retention materials, which are expanded by flame, and mechanical flame cutoff devices. The bushings fireproof structure was installed on the transformer model produced by applying the actual standards of bushings and flange, and the full scale fire test was carried out. It was confirmed that the bushings fireproof structure operated at accurate position and height within 3 seconds from the flame initiation. It is considered that it could block the spread of flame effectively in the event of actual transformer fire.

• Journal of Korean Society of Forest Science
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• v.107 no.4
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• pp.351-360
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• 2018

This study was conducted to analyze the responses of chlorophyll contents and growth of Pinus densiflora and Quercus variabilis seedlings on distance from the well and $CO_2$ flux after the artificial $CO_2$ release. From June 1 to 30, 2016, $CO_2$ gas was injected at the rate of $6L\;min^{-1}$ at the study site in Eumseong. Chlorophyll content was analyzed in the middle of July, 2016, and root collar diameter (RCD), height (H), and biomass were measured in May and December, 2016 after planting 2-year-old P. densiflora and 1-year-old Q. variabilis seedlings in May, 2015. The chlorophyll content of P. densiflora seedlings did not show a significant correlation with $CO_2$ flux, whereas the chlorophyll content of Q. variabilis seedlings showed a significant negative correlation with increasing $CO_2$ flux (P<0.05). The RCD and H growth rates of both species showed the significant difference in the distance from the well of the $CO_2$ anthropogenic release treatment. In particular, the RCD and H growth rate of P. densiflora seedlings and the RCD growth rate of Q. variabilis seedlings increased significantly as the seedlings were closer to the well, but the H growth rate of Q. variabilis seedlings decreased significantly. In addition, as the $CO_2$ concentration in the ground increases, ${\Delta}R/S$ ratio increases in both species, suggesting that the high $CO_2$ concentration in the soil promotes carbon distribution relative to the root part. The results of this study can be used as data necessary to monitor the $CO_2$ leakage and physiological and growth responses of both species to leakage of stored $CO_2$ in the future.

• Analytical Science and Technology
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• v.34 no.6
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• pp.259-266
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• 2021

Cannabis (Marijuana) is one of the most widely used drugs in the world, and its distribution has been controlled in South Korea since 1976. Identification of 11-nor-Δ⁹-carboxy-tetrahydrocannabinol (THCCOOH) in urine can provide important proof of cannabis use, and it is considered scientific evidence in the forensic field. In this study, we describe a simultaneous quantitative method for identifying THCCOOH and THCCOOH-glucuronide in urine, using simple liquid-liquid extraction (LLE), and liquid chromatography-tandem mass spectrometry (LC-MS/MS). THCCOOH-D₃ and THCCOOH-glucuronide-D₃ were used as internal standards. Validation results of the matrix effect, as well as recovery, linearity, precision, accuracy, process efficiency, and stability were all satisfactory. No carryover, endogenous or exogenous interferences were observed. The limit of detection (LOD) of THCCOOH and THCCOOH-glucuronide were 0.3 and 0.2 ng/mL, respectively. The developed method was applied to 28 authentic human urine samples that tested positive in immunoassay screening and gas chromatography/mass spectrometry (GC/MS) tests. The ranges of concentrations of THCCOOH and THCCOOH-glucuronide in the samples were less than LOQ~266.90 ng/mL and 6.43~2133.03 ng/mL, respectively. The concentrations of THCCOOH-glucuronide were higher than those of THCCOOH in all samples. This method can be effectively and successfully applied for the confirmation of cannabinoid use in human urine samples in the forensic field.

• Journal of the Korea Organic Resources Recycling Association
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• v.31 no.1
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• pp.69-84
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• 2023

Despite the continuous installation and regular inspection of waste treatment facilities, complaints about excessive incineration and illegal dumping stench continue to occur at on-site treatment facilities. In addition, field surveys were conducted on the waste treatment facilities currently in operation (6 type) to understand the waste treatment process for each field, to grasp the main operating factors applied to the inspection. In addition, we calculated the material·energy balance for each main process and confirmed the proper operation of the waste disposal facility. As a result of the site survey, in the case of heat treatment facilities such as incineration, cement kilns, and incineration heat recovery facilities, the main factors are maintenance of the temperature of the incinerator required for incineration and treatment of the generated air pollutants, and in the case of landfill facilities Retaining wall stability, closed landfill leachate and emission control emerged as major factors. In the case of sterilization and crushing facilities, the most important factor is whether or not sterilization is possible (apobacterium inspection).In the case of food distribution waste treatment facilities, retention time and odor control during fermentation (digestion, decomposed) are major factors. Calculation results of material balance and energy resin for each waste treatment facility In the case of incineration facilities, it was confirmed that the amount of flooring materials generated is about 14 % and the amount of scattering materials is about 3 % of the amount of waste input, and that the facility is being operated properly. In addition, among foodwaste facilities, in the case of an anaerobic digestion facility, the amount of biogas generated relative to the amount of inflow is about 17 %, and the biogas conversion efficiency is about 81 %, in the case of composting facility, about 11 % composting of the inflow waste was produced, and it was comfirmend that all were properly operated. As a result, in order to improve the inspection method for waste treatment facilities, it is necessary not only to accumulate quantitative standards for detailed inspection methods, but also to collect operational data for one year at the time of regular inspections of each facility, Grasping the flow and judging whether or not the treatment facility is properly operated. It is then determined that the operation and management efficiency of the treatment facility will increase.

• Journal of the Korea Organic Resources Recycling Association
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• v.31 no.1
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• pp.85-100
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• 2023

In this study, in order to improve the installation periodical inspection method of waste treatment facilities, we conducted on-site surveys of waste treatment facilities classified into six fields, grasped the problems of inspection methods, and made improvements accordingly. And revised the inspection method for waste treatment facilities. As a result, in the field of incineration and incineration heat recovery, inspection methods such as total temperature measurement and one-year TMS data comparison using a thermal imaging camera were established. And for the safety of the inspected person, it was applied so that the waste can be replaced with a document without opening it. In the case of landfill facilities, the details regarding the use of video information processing equipment and the management of facilities covering the upper part of the landfill facility are presented in the law, but the items that do not have a inspection methods were applied to the inspection method. In the case of Food Waste Treatment Facility, inspection methods were put in place to ensure compliance with standards for foul-smelling fish in odor control, a major cause of complaints. As a result, 10 out of 18 improvement proposals were reflected in the incineration and sterilization grinding, cement kiln, and incineration heat recovery facilities, and 11 out of 12 improvement proposals were reflected in the landfill facility. In the case of food distribution waste treatment facilities, 10 out of 12 improvement proposals were reflected, and a total of 31 inspection methods were improved.

• Korean Journal of Environmental Biology
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• v.39 no.4
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• pp.526-535
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• 2021

Spatial sampling design plays an important role in GIS-based modeling studies because it increases modeling efficiency while reducing the cost of sampling. In the field of agricultural systems, research demand for high-resolution spatial databased modeling to predict and evaluate climate change impacts is growing rapidly. Accordingly, the need and importance of spatial sampling design are increasing. The purpose of this study was to design spatial sampling of paddy fields (11,386 grids with 1 km spatial resolution) in Korea for use in agricultural spatial modeling. A stratified random sampling design was developed and applied in 2030s, 2050s, and 2080s under two RCP scenarios of 4.5 and 8.5. Twenty-five weather and four soil characteristics were used as stratification variables. Stratification and sample allocation were optimized to ensure minimum sample size under given precision constraints for 16 target variables such as crop yield, greenhouse gas emission, and pest distribution. Precision and accuracy of the sampling were evaluated through sampling simulations based on coefficient of variation (CV) and relative bias, respectively. As a result, the paddy field could be optimized in the range of 5 to 21 strata and 46 to 69 samples. Evaluation results showed that target variables were within precision constraints (CV<0.05 except for crop yield) with low bias values (below 3%). These results can contribute to reducing sampling cost and computation time while having high predictive power. It is expected to be widely used as a representative sample grid in various agriculture spatial modeling studies.

• The Journal of Engineering Geology
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• v.33 no.4
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• pp.543-553
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• 2023

The current status of domestic a agalmatolite mines in South Korea was investigated with a view to establishing a stable supply of agalmatolite and managing its demand. Most mined agalmatolite deposits were formed through hydrothermal alteration of Mesozoic volcanic rocks. The physical characteristics of pyrophyllite, the main constituent mineral of agalmatolite, are as follows: specific gravity 2.65~2.90, hardness 1~2, density 1.60~1.80 g/cm³, refractoriness ≥29, and color white, gray, grayish white, grayish green, yellow, or yellowish green. Among the chemical components of domestic agalmatolite, SiO₂ and Al₂O₃ contents are respectively 58.2~67.2 and 23.1~28.8 wt.% for pyrophyllite, 49.2~72.6 and 16.5~31.0 wt.% for pyrophyllite + dickite, 45.1 and 23.3 wt.% for pyrophyllite + illite, 43.1~82.3 and 11.4~35.8 wt.% for illite, and 37.6~69.0 and 19.6~35.3 wt.% for dickite. Domestic agalmatolite mines are concentrated mainly in the southwest and southeast of the Korean Peninsula, with some occurring in the northeast. Twenty-one mines currently produce agalmatolite in South Korea, with reserves in the order of Jeonnam (45.6%) > Chungbuk (30.8%) > Gyeongnam (13.0%) > Gangwon (4.8%), and Gyeongbuk (4.8%). The top 10 agalmatolite-producing mines are in the order of the Central Resources Mine (37.9%) > Wando Mine (25.6%) > Naju Ceramic Mine (13.4%) > Cheongseok-Sajiwon Mine (5.4%) > Gyeongju Mine (5.0%) > Baekam Mine (5.0%) > Minkyung-Nohwado Mine (3.3%) > Bugok Mine (2.3%) > Jinhae Pylphin Mine (2.2%) > Bohae Mine. Agalmatolite has low thermal conductivity, thermal expansion, thermal deformation, and expansion coefficients, low bulk density, high heat and corrosion resistance, and high sterilization and insecticidal efficiency. Accordingly, it is used in fields such as refractory, ceramic, cement additive, sterilization, and insecticide manufacturing and in filling materials. Its scope of use is expanding to high-tech industries, such as water treatment ceramic membranes, diesel exhaust gas-reduction ceramic filters, glass fibers, and LCD panels.

• Resources Recycling
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• v.33 no.4
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• pp.47-61
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• 2024

As a recycling technology for recovering zinc contained in large amounts in electric arc furnace dust (EAFD), the most commercialized technology in the world is the Wealz Kiln Process. The Wealz Kiln Process is a process in which components such as Zn and Pb in EAFD are reduced/volatile (endothermic reaction) in high-temperature Kiln and then re-oxidized (exothermic reaction) in the gas phase and recovered in the form of Crude zinc oxide (60wt%Zn) in the Bag Filter installed at the rear end of Kiln. In this study, an experimental Wealz kiln was produced to investigate the optimal process variable value for practical application to the recycling process of large-scale kiln on a commercial scale. Additionally, Pellets containing EAFD, reducing agents, and limestone were continuously loaded into Kiln, and the amount of input, heating temperature, and residence time were examined to obtain the optimal crude zinc oxide recovery rate. In addition, the optimal manufacturing conditions of Pellets (drum tilt angle, moisture addition, mixing time, etc.) were also investigated. In addition, referring to the SiO₂-CaO-FeO ternary system diagram, the formation behavior of a low melting point compound, a reaction product inside Kiln according to the change in the basicity of Pellet, and the reactivity (adhesion) with the castable constructed on the inner wall of Kiln were investigated. In addition, in order to quantitatively investigate the possibility of using anthracite as a substitute for Coke, a reducing agent, changes in the temperature distribution inside Kiln, where oxidation/reduction reactions occur due to an increase in the amount of anthracite, the quality of Crude zinc oxide, and the behavior of tar in anthracite were also investigated.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.4
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• pp.333-343
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• 1984

This study was designed to elucidate the lipid and its fatty acid composition in various tissues of fresh water fishes. The free and bound lipids in meat, skin and viscera of crucian carp (Carassius carassius) were extracted with ethyl ether and the mixed solvent of chloroform-methanol-water (10/9/1, v/v). The free and bound lipids were fractionated into neutral lipid, glycolipid and phospholipid by a silicic acid column chromatography using chloroform, acetone and methanol, respectively, and quantitatively analyzed by thin layer chromatography (TLC) and TLC scanner. The fatty acid compositions of polar ana nonpolar lipids in meat, and these of neutral lipid in various tissues were analyzed by gas liquid chromatography(GLC). The free lipid content in meat, skin and viscera was $6.22\%,\;9.95\%\;and\;9.76\%$, whereas the bound lipid content in those tissues was $10.01\%,\;3.56\%\;and\;7.36\%$, respectively. The neutral lipid contents in free lipid were ranged from $71.7\%$ to $89.4\%$, and $3{\sim}9$ times higher than those in bound lipid, while the phospholipid contents in bound lipid were ranged from $42.3\%$ to $63.2\%$, and $5{\sim}10$ times higher than those in free lipid. The neutral lipid was mainly consisted of triglyceride ($81.91{\sim}88.34\%$) in free lipid, and esterified sterol & hydrocarbon ($41.00{\sim}59.43\%$) in bound lipid. The phospholipid was mainly consisted of phosphatidyl ethanolamine($54.56{\sim}66.79\%$) and phosphatidyl choline ($21.88{\sim}34.28\%$) in free lipid, and phosphatidyl choline ($50.49{\sim}70.57\%$) and phosphatidyl ethanolamine ($15.74{\sim}24.92\%$) in bound lipid. The major fatty acids of polar lipid in free and bound lipids were $C_{16:0}\;(17.53\%,\;19.29\%)$, $C_{18:1}\;(24.57\%,\;16.08\%)$, $C_{18:2}\;(8.39\%,\;4.03\%)$, $C_{22:5}\;(1.68\%,\;8.08\%)$, and $C_{22:6}\;(6.22\%,\;13.60\%)$ and these of neutral lipid in free and bound lipids were $C_{16:0}\;(17.67\%,\;24.15\%)$, $C_{16:1}\;(12.81\%,\;5.52\%)$, $C_{18:1}\;(24.13\%,\;13.02\%)$, $C_{18:2}\;(15.47\%,\;8.68\%)$, $C_{22:5}\;(0.88\%,\;4.14\%)$ and $C_{22:6}\;(1.17\%,\;5.04\%)$, respectively. The unsaturations (TUFA/TSFA) of polar lipid in free and bound lipids were 2.02 and 2.74, and $1.5{\sim}2.0$ times higher than 1.51 and 1.23 of nonpolar lipid. In both polar and nonpolar lipids, w3 highly unsaturated fatty acid (w3HUFA) content of bound lipid was $2{\sim}5$ times higher than that of free lipid. The polyenoic acid contents such as $C_{20:5},\;C_{22:5}\;and\;C_{22:6}$ in bound lipid were $2{\sim}5$ times higher than these in free lipid. Consequently, there were significant difference between the lipid and its fatty acid composition in free and bound lipids and/or in various tissues.