• Korean Journal of Plant Resources
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• v.28 no.5
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• pp.656-664
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• 2015

To produce high quality watermelon, three tetraploid watermelon breeding lines (‘SA03-1’, ‘SA06-1’ and ‘SB01-1’) were developed by treatment with different chromosome doubling reagents. To identify the optimal tetraploid inductive conditions, the three watermelon breeding lines were selected by counting the number of doubled chloroplasts in guard cells. Tetraploid induction rates differed depending on the genotypes and treatment with doubling reagents. However, the highest induction rate occurred with 1.0% colchicine (82.2%). These putative tetraploid lines were re-confirmed for ploidy using flow cytometric analysis and chromosome counting. The internode length of the tetraploid breeding lines was different when the leaf size was larger in all three tetraploid lines compared to their diploids. The fruit weight of the tetraploid fruits for ‘SA03-1’ and ‘SB01-1’ was lower than for their diploid, and the rind thickness and total sugar content (°Brix) of tetraploid SB01-1 were significantly different from those of its diploid. Tetraploid lines were sterile, yielded a lower number of seeds per fruit for ‘SA03-1’ (21), ‘SA06-1’ (62), and ‘SB01-1’ (34.7), and the seeds were larger and thicker than those of their diploids. These tetraploid breeding results will be useful for breeding new seedless watermelon cultivars.

• KSBB Journal
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• v.24 no.4
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• pp.367-376
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• 2009

In this study, two supercritical extraction systems of different scale, analytical-scale and lab-scale, were employed to investigate the extraction efficiency of canola oil from canola seeds using supercritical carbon dioxide ($SCCO_2$) as an extraction solvent. The effects of various parameters such as extraction temperature ($40{\sim}80^{\circ}C$), pressure (200~500 bar), particle size, and $SCCO_2$ flow direction on the extraction rate and yield were examined in detail. Triglycerides and fatty acids in the extracted canola oil were analyzed quantitatively by high-performance liquid chromatography and gas chromatography. The solubility values of canola oil in $SCCO_2$ could be calculated from the experimental results. Similar extraction yields were obtained from both analytical-scale and lab-scale extraction systems. The extraction rates obtained under solvent ($SCCO_2$ ) upflow conditions were found to be higher than those of solvent downflow extraction. However, the effect of $SCCO_2$ flow direction on the extraction yield was observed to be relatively insignificant.

• Elastomers and Composites
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• v.47 no.4
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• pp.355-363
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• 2012

A series of poly(hydroxyamide)s (PHAs) having trifluoromethyl group were prepared by direct polycondensation of aromatic diimide-dicarboxylic acids with 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane by thionyl chloride and triethyl amine in N-methyl-2-pyrrolidinone (NMP). The PHAs exhibited inherent viscosity in the range of 0.54-0.96 dL/g at $35^{\circ}C$ in DMAc solution. All PHAs were readily soluble in a variety of organic solvents, whereas the polybenzoxazoles (PBOs) were quite insoluble except partially soluble in sulfuric acid. PHAs were converted to PBOs by thermal cycling reaction with heat of endotherm. The maximum weight loss temperature of the PHAs occurred in the range of $559-567^{\circ}C$. The PBOs showed relatively high char yields in the range of 47-59%. Pyrolysis Combustion Flow Calorimeter (PCFC) results of the PBOs showed 12-19 W/g heat release rate (HRR), and 2.7-3.6 kJ/g total heat release (total HR). The HRR of PBO 1 showed the lowest value of 12 W/g, which was 37% lower than that of PBO 3 (19 W/g).

• KSBB Journal
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• v.20 no.1 s.90
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• pp.12-17
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• 2005

Despite a wide range of fatty acids in fish oil, its the usage are very limited owing to off-flavors and volatile compounds in the oil. A way to extract and remove volatile compounds was performed at a semi-flow extractor by using supercritical carbon dioxide $(SC-CO_2)$. Samples of the oil were treated at the conditions which ranged from $30\;to\;80^{\circ}C$ and from 80 to 200 bar with 10 mL/min flow rate of carbon dioxide. In the oil the volatile compounds were analyzed by gas chromatography. Before extraction with $SC-CO_2$ the oil sample was detected over 129 peaks but 99 compounds were identified. The results demonstrated that at $40^{\circ}C$ and 200 bar extraction condition the volatile compounds in the tuna fish oil were removed, except for 14 compounds identified after extraction and other $SC-CO_2$ extraction conditions reached to high reduction of the volatile compounds.

• Science of Emotion and Sensibility
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• v.15 no.1
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• pp.1-8
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• 2012

There have been many emotion researches to investigate physiological responses on specific emotions with physiological parameters such as heart rate, blood volume flow, and skin conductance. Very few researches, however, exists by detecting them with facial skin temperature. The purpose of present study was to observe the differences of facial skin temperature by using thermal camera, when participants stimulated by monitor scenes which could evoke fear or joy. There were totally 98 of participants; undergraduate students who were in their adult age and middle, high school students who were in their adolescence. We measured their facial temperature, before and after presenting emotional stimulus to see changes between both times. Temperature values were extracted in these regions; forehead, inner corners of the eyes, bridge of the nose, end of the nose, and cheeks. Temperature values in bridge and end of the nose were significantly decreased in fear emotion stimulated. There was also significant temperature increase in the area of forehead and the inner corners of the eyes, while the temperature value in end of the nose decreased. It showed decrease in both stimulated fear and joy. These results might be described as follows: When arousal level going up, sympathetic nervous activity increases, and in turn it makes blood flow in peripheral vessels under the nose decrease. Facial temperature changes by fear or joy in this study were the same as the previous studies which measured temperature of finger tip, when participants experiencing emotions. Our results may help to develop emotion-measuring techniques and establish computer system bases which are to detect human emotions.

• Journal of The Geomorphological Association of Korea
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• v.19 no.3
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• pp.51-69
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• 2012

Physical strength of the rock is the most important factor of resistance to erosion and has been measured through various way. Bedrock microforms, like potholes and grooves, are the forms sculpted by the erosional processes of flow and the location and morphology are strongly affected by the differential erosion. It also assumed that the physical strength of the rock controls the erosion rate and mode of erosion. The schmidt hammer has been used to measure the rock strength in the field for the geomorphological research. To find the relationship between the rock strength and microforms, Schmidt hammer's R(rebound) were measured in the Baeksuktan, middle reach of Gilancheon, Cheongsong, Gyungsangbuk do. The overall values of rebound of the local sandstone showed over 65 in most cases, so it can be regarded as 'very strong'. It is found that the rebound values of the rock surface decreased towards current water level. It also, however, found that there was no systematic differences in rebound values among the topographically high and lows in the bedrock surface. There was no statistically significant difference in rebound values of the area with well developed microforms and others. The values of R from the exposed faces and inside of the microforms are similar. In the case of conglomerate, the part with the gravel showed higher values that the parts with sands. The rebound values are decreased near of(<1cm) the geological discontinuities(including joint and faults), so this line of weakness could be the point of initiation of active erosion to form microforms. However there is large variations in rebound values within this part. It also should be mentioned that topological relation between the strike of the geologic discontinuities and flow direction looks control the mode of erosional processes.

• Journal of the Korean Institute of Gas
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• v.25 no.4
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• pp.10-18
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• 2021

CO₂ storage technology in an aquifer is one of the most effective way to decrease global warming due to a high storage capacity and economics. A demonstration-scale offshore CO₂ storage project was performed in a geological deep aquifer in the Pohang Basin, Korea for a technological development of large-scale CO₂ storage. A challenging issue in the early design stage of the project was to establish the proper injectivity during CO₂ injection. To solve this issue, injection conditions were calculated by calculating injection rate, pressure, temperature, CO₂ phase change, and thermodynamic properties. For this study, we simulated and numerically analyzed CO₂ phase change from gas to supercritical phase and flow behavior in transport piping and injection tubing using OLGA program. Our results provide the injectivity conditions of CO₂ injection system combined with a bottomhole pressure of an aquifer.

• Journal of the Korean Institute of Gas
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• v.27 no.3
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• pp.123-133
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• 2023

Commercial hydrogen fuel cell vehicles are charged by compressing gaseous hydrogen to high pressure and storing it in a storage tank in the vehicle. This process causes the temperature of the gas to rise, to ensure the safety to storage tanks, the temperature is limited. Therefore, a heat transfer model is needed to explain this temperature rise. The heat transfer model includes the convective heat transfer phenomenon, and accurate estimation is required. In this study, the convective heat transfer coefficient in the hydrogen fueling process was calculated and compared using various correlation equations considering physical phenomena. The hydrogen fueling process was classified into the fueling line from the dispenser to the tank inlet and the storage tank in the vehicle, and the convective heat transfer coefficients were estimated according to process parameters such as mass flow rate, diameter, temperature and pressure. As a result, in the case of the inside of the filling line, the convective heat transfer coefficient was about 1000 times larger than that of the inside of the storage tank, and in the case of the outside of the filling line, the convective heat transfer coefficient was about 3 times larger than that of the outside of the storage tank. Finally, as a result of a comprehensive analysis of convective heat transfer coefficients in each process, it was found that outside the storage tank was lowest in the entire hydrogen fueling process, thus dominated the heat transfer phenomenon.

• Journal of Korean Society of Water and Wastewater
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• v.37 no.4
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• pp.215-229
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• 2023

In this study, non-destructive technologies that can be applied to evaluate the integrity of valve materials, safety against internal pressure caused by corrosion, and the blocking function of large-diameter water valves during operation without requiring specimen collection or manpower entering the inside of the valve were tested to assess the reliability of the technologies and their suitability for field application. The results showed that the condition of the graphite structure inside the valve body can be evaluated directly through the optical microscope in the field without specimen collection for large-diameter water butterfly valves, and the depth of corrosion inside the valve body can be determined by array ultrasound and the tensile strength can be measured by instrumented indentation test. The reliability of each of these non-destructive techniques is high, and they can be widely used to evaluate the condition of steel or cast iron pipes that are significantly smaller in thickness than valves. Evaluation of blocking function of the valves with mixed gas showed that it can be detected even when a very low flow rate of mixed gas passes through the disk along with the water flow. Finally, as a result of evaluating the field applicability of non-destructive technologies for three old butterfly valves installed in the US industrial water pipeline, it was found that it is possible to check the material and determine the suitability of large-diameter water valves without taking samples, and to determine the corrosion state and mechanical strength. In addition, it was possible to evaluate safety through the measurement results, and it is judged that the evaluation of the blocking function using mixed gas will help strengthen preventive response in the event of an accident.

• Analytical Science and Technology
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• v.37 no.3
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• pp.143-154
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• 2024

In this study, we improved the vitamin C test method and reviewed data on the adjustable range of chromatography conditions for quantification. First, we adjusted the mobile phase conditions such as solvent composition, salt concentration, pH and column temperature and in particular, it was confirmed through an improved test method that the peak derived from the buffer solution could be clearly separated from the target component, vitamin C by adjusting the pH. The retention time of vitamin C was partially changed by adjusting the column diameter, length and particle size but the number of theoretical plates indicated similar values and did not affect the separation and quantitative analysis of the target component. The flow rate according to the column specifications was derived from the equation proposed by the U.S. FDA (Food and Drug administration) and the Korean MFDS (Ministry of Food and Drug Safety), and evaluation of the applicability to vitamin complexes showed high selectivity for vitamin C even with altered stationary phase conditions and flow rates. In conclusion, vitamin C can be optimally separated and detected by changing the chromatographic method conditions and it was confirmed that the mobile and stationary phase conditions of liquid chromatography can be slightly adjusted in case the assay method uses an isocratic elution.