• Journal of the Korean Society of Food Culture
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• v.24 no.5
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• pp.540-551
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• 2009

This study was conducted to investigate the quality characteristics of mungbean starch gels containing various hydrocolloids (carrageenan, locust bean gum and xanthan gum) during room temperature storage ($25^{\circ}C$ for 24, 48 and 72 hours). Carrageenan and xanthan gum reduced the pasting viscosity of mungbean starch, whereas the locust bean gum increased the viscosity. The melting characteristics, as assessed by DSC, showed that carrageenan and xanthan gum delayed gelatinization of mungbean starch and the locust bean gum had no effect on this property. The lightness (L) of the gels with the locust bean gum was similar to that without the additive during storage, whereas that with carrageenan and xanthan gum was higher than that without the additive. Hardness, chewiness and gumminess of the gels with the locust bean gum was higher than that without the additive during storage, whereas that with carrageenan and xanthan gum was lower than that without the additive. The rupture stress, rupture strain and rupture energy of the gels with carrageenan and xanthan gum was lower than that without the additive during storage, whereas that with the locust bean gum was similar to that without the additive. In the sensory evaluation, springiness and cohesiveness of the gels with carrageenan and xanthan gum were lower than those without the additive, whereas springiness, brittleness and hardness of the gels with the locust bean gum were higher than those without the additive. In addition, the overall acceptability of the gels with the locust bean gum improved. The above results showed that carrageenan and xanthan gum lowered the quality characteristics of the mungbean starch gel and the locust bean gum improved them. Thus, the addition of 0.5% locust bean gum is an appropriate method for improving the quality characteristics of mungbean starch gel.

• Analytical Science and Technology
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• v.36 no.1
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• pp.32-43
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• 2023

This study reports for the first time about a stability indicating RP-HPLC method for qualitative and quantitative determination of acalabrutinib in bulk and dosage form and in presence its impurities 1, 2 and 3. The chromatographic separation was carried on Zorbax XDB-C18 (250×4.6 mm; 5 µ id) as stationary phase, Phosphate buffer pH 6.4 and methanol 80:20 (v/v) as mobile phase at a flow rate of 1.0 mL/min, UV detection was carried at wavelength of 238 nm and the analysis was completed with a run time of 15 min. In these conditions the retention time of acalabrutinib and its impurities 1, 2 and 3 was observed to be 3.50, 4.83, 8.40 and 9.93 min respectively. The method was validated for system suitability, range of analysis, precision, specificity, stability and robustness. Spiked recovery at 50 %, 100 % and 150 % was carried for both standard and impurities and the acceptable % recovery of 98-102 was observed for acalabrutinib and both impurities studied and the % RSD in each spiked level was found to be less than 2. Stability tests were done through exposure of the analyte solution to five different stress conditions i.e expose to 1N hydrochloric acid, 1 N sodium hydroxide, 3 % peroxide, 80 ℃ temperature and UV radiation at 254 nm. In all the degradation condition, standard drug acalabrutinib was detected along with both the impurities studied and the degradation products were successfully separated. In the formulation analysis there is no other chromatographic detection of other impurities and formulation excipients. Hence the developed method was found to be suitable for the quantification of acalabrutinib and can separate and analyse impurities 1 and 2.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.158-158
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• 2022

Ecological drought consequences have received a lot of attention in recent years. Thus, ecological drought was proposed as a new drought category to characterize the impact of drought on ecosystems. The current study used a unique drought index, the standardized supply-demand water index (SSDI), and a run theory to detect ecological drought occurrences and characteristics such as drought-affected area, drought severity, drought duration, drought frequency, and drought orientation in the Hwang River, an environmentally valuable region. Hence, to assess drought-prone areas, the bivariate probability and return period will be calculated using a two-dimensional joint copula. The core results show that (a) the Spatio-temporal characteristics of ecological drought were successfully recognized using the spatial and temporal identification approach; (b) in comparison to the SPEI meteorological drought index, the SSDI is more credible and can more readily and effectively capture the entire properties of ecological drought information; (c) the Hwang river had seen the most severe drought occurrences between the late 1990s and the mid-2020s, with 48.3 percent occurring before the twenty-first century; (d) Severe ecological drought occurrences occurred more frequently in most areas of the Hwang River (e) Only the drought duration and severity in the Hwang area were more responsive to temperature when temperatures rise around 1.1℃, the average drought duration and severity rise around 16 % and 26 %, respectively. This suggested that the Hwang River has been exposed to more severe heat stress in the twenty-first century. Thereupon droughts in the twenty-first century occurred with bigger affected regions, longer durations, higher frequency, and more intensity.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.08a
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• pp.63-63
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• 2020

This study investigated the growth of native ferns under indoor light intensities to identify the introduction possibility as in-door ornamental plants. Three evergreen perennial fern species used in this experiment were Coniogramme japonica (Thunb.) Diels, Woodwardia japonica (L. f.) Sm., and Cyclosorus acuminatus (Houtt.) Nakai ex H. Itô. The light intensities were adjusted to 10, 50, 100 and 200 PPFD (µmol·m^-2·s^-1) based on the measurement of the various indoor light quantities. The experiment was conducted for a total of 8 weeks, and the light period (12/12h), temperature (25±1℃), and humidity (55±3%) were maintained during the experiment. The control plant group was grown in glass greenhouse for the same period. As the result of the study, in door C. japonica showed better growth under light intensities of 100, 200 PPFD. However, withering of the plants were observed under all light intensities except the control, which causes an ornamental value decrease. This seems to be related to the increase of DIo/RC value in chlorophyll fluorescence parameters. In the W. japonica growth data, the plant height was not significantly different from the control but, the leaf number decreased more than a two-fold. Also, the formed leaves turned brown and showed a poor growth and SPAD value at 200 PPFD had decreased significantly. Growth data of C. acuminatus was not significantly different with the control at all light intensities however, withering was observed at 100 and 200 PPFD. In chlorophyll fluorescence parameters, significant decrease in Pi_Abs and increase in DIo/RC value at 200 PPFD impose that stress caused by the intense light might be the reason of the withering of the plants.

• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.3
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• pp.589-602
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• 2024

Thermoelectric generator (TEG) generally do not have high heat conversion efficiencies. The performance of a thermoelectric generator module depends on the shape of the legs as well as the properties of the material and the number of legs. In this study, the leg shapes of thermoelectric elements are modeled into various geometric structures such as cylinder and cube shaped to efficiently harvest waste heat, and the electrical characteristics are compared numerically. The temperature gradient and power generation according to the bridge shape are found to be highest at the existing Cube shape. As a result of comparing the power generation using the cooling effect, the Cone shape was the highest in natural convection and the Hourglass shape was highest in forced convection. Research results confirm that geometry can affect the efficiency of thermoelectric generators.

• Design & Manufacturing
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• v.17 no.3
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• pp.8-14
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• 2023

In this study, basic research was conducted on manufacturing technology of thick-walled light guide a component that controls the light source of automobile lamps. As a preliminary study for manufacturing the final injection molded parts, a model for analyzing the influence of micro patterns on light guides is presented. The optical characteristics of the light guide were analyzed according to the change of the curvature radius of the micro-optical pattern, and the injection molding characteristics of the light guide according to the change of injection molding conditions were analytically evaluated. It was confirmed that the luminance uniformity improves as the R value decreases for changes in the micro-pattern R value, but it was confirmed that there are technical limitations in actual injection mold core processing and high-replication injection molding. Injection molding analysis showed that cooling channel design is very important compared to general injection molding due to thick-wall characteristics and thickness variation. It was also confirmed that the cooling channel has a great influence on the cycle time and birefringence result due to residual stress. As a result of analyzing the influence of filling time, holding condition, and cooling on shrinkage, it was found that the cooling water temperature has a significant effect on the shrinkage of ultra-fine light guide parts, and the holding condition also has a significant effect.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.17 no.3
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• pp.146-154
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• 2024

In this paper, we present a convenient liquid crystal (LC) molecular alignment method using brush hairs as an alternative to the rubbing process in the LC display industry. Titanium strontium yttrium zirconium oxide (TiSrYZrO) solution was prepared using a sol-gel process, and the TiSrYZrO alignment film production and LC molecular alignment were integrated through a one-step brush coating process. As the curing temperature increased, the LC molecule alignment of the LC cell improved, and the formation of a physical surface anisotropic structure due to the shear stress caused by the movement of the brush hairs on the coating surface led to uniform alignment of the LC molecules. Uniform and homogeneous LC molecular alignment was confirmed through polarizing optical microscopy and pretilt angle measurement. Through thermal oxidation using X-ray photoelectron spectroscopy, the TiSrYZrO thin film well formed of metal oxide was confirmed and verified to have excellent optical transparency. From these results, it is expected that a convenient LC molecular alignment method using brush hairs as an alternative to the rubbing process will be a viable next-generation technology.

• Journal of Animal Environmental Science
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• v.2 no.1
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• pp.41-52
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• 1996

This experiment was carried out to study the effect of sprinkler and fan cooling system on the physiological parameter, milk production and milk composition for Holstein cows in hot, humid climates. Thirty cows were assigned to one of two sections of open-sided loose barn. Water nozzles of sprinkler system were spaced in line at 1.2m intervals. Forced air was provided by 85cm diameter fans at rate of 3.4㎥/sec. The results obtained from these experiments are as follows: 1. There was no significant difference in meteorological data between control and fan + sprinkler cooling system(treatment group). 2. Skin temperature and rectal temperature of the treatment group were significantly lower than those of the control group (32.96 : 39.53$^{\circ}C$ vs 34.02 : 41.21$^{\circ}C$ respectively) (P<0.05). 3. Serum cortisol concentration of the treatment group(0.90$\mu\textrm{g}$/dL) was lower than that of control group(1.44$\mu\textrm{g}$/dL)(P<0.05). 4. Milk production of cows cooled with a sprinkler and fan cooling system was significantly higher than that of no cooling system (P<0.0l). 5. Lactose, protein and solid-not-fat content of milk were not changed by the treatments. Milk fat content of the control(3.23%) was low compared with the treatment group(3.38%). Somatic cell count was reduced by 26.63% in the treatment. The results indicate that a sprinkler and fan cooling systems can provide an effective means to relieve heat stress and enhance productivity of lactating Holstein cows during hot and humid summer season.

• Journal of Korean Society of Forest Science
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• v.78 no.2
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• pp.151-159
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• 1989

The present study has been designed to define the effects of photosynthetically active radiation, leaf temperature, and water stress on photosynthesis and respiration of leaves of four oak species (Quercus mongolica, Quercus aliens, Quercus variabilis, and Quercus serrate). The results obtained are as follows : 1. The estimated light compensation points at which Pn approached zero were 38, 24, 20, and $18{\mu}Em^{-2}s^{-1}$ for Q. aliens, Q. variabilis, Q, mongolica, and Q. serrate, respectively. The light saturation points occurred at $500{\mu}Em^{-2}s^{-1}$ in three oak species except Q, aliens. 2. The maximum rates of Pn were 19.7, 15.2, 11.2, and 11.0 mg $CO_2$ $dm^{-2}h^{-1}$ for Q. variabilis, Q. serrate, Q. monglica, and Q. aliens leaves, respectively. 3. The transpiration rates of Q. variabilis and Q. serrate leaves were slightly higher than those of Q. mongolica and Q. aliens leaves at various photosynthetically active radiations(PAR), but cuticular transpiration rates at dark were similar in four oak species. 4. The optimum photosynthesis occurred at $25^{\circ}C$ in Q. aliens, Q. variabilis, and Q. serrate leaves, but $20^{\circ}C$ in Q. mongolica leaves. In four oak species, the net photosynthesis approached zero at about $40^{\circ}C$. 5. The dark respiration rates of leaves exhibited the following ranking of species : Q, variabilis > Q. mongolica > Q. aliens > Q. serrate. 6. The maximum productive efficiency (Pg/Rd) of leaves occurred highest in Q, serrate at $20^{\circ}C$, then in Q. mongolica at $20^{\circ}C$, then in Q, aliens at $25^{\circ}C$, and finally in Q. variabilis at $15^{\circ}C$. 7. The decrease of net photosynthesis in Q. serrate began at about -1.2 MPa, and then approached zero at -2.9 MPa of leaf water potential. The decrease of net photosynthesis began at 3% of water loss, and then approached zero at 17.5% of water loss. 8. As indicated by tissue-water relations parameters, it may be suggested that Q. aliens and Q. variabilis are more tolerant and favored on xeric forest soils than Q. mongolica and Q. serrate.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.4
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• pp.392-402
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• 2021

The present study investigated the effects of tillage practices (deep cultivation [DC] and conventional tillage [CT]) and extended planting dates (mid-June to July) for maize-onion rotation in paddy fields. The silage corn (Zea mays L.) cultivar 'Kwangpyeongok' and the waxy corn cultivar 'Ilmichal' were planted on June 14, July 3, and July 15 in 2019. In both maize, the plant height of June 14 planted was up to 100 cm greater than that of July 15 planted on August 16 and up to 40 cm on August 30. At 30 Days after planting, the leaf area index (LAI) of silage corn planted on July 3 and 15 greater than that of corn planted on June 14 due to high temperature in the early season; however, there were no differences in the LAI of waxy corn according to the planting date. Despite favorable temperature, plants sown on July 3 and 15 experienced high moisture stress during the seedling stage due to consistent rainfall, and waxy corn was highly sensitive to high moisture stress. The total yield of silage corn was 1,232 (845 in TDN), 860 (598 in TDN), and 765 (508 in TDN) DW kg·10a^-1 for plants sown on June 14, July 3, and July 15, respectively. The fresh marketable ear yield of waxy corn was 872, 814, and 525 FW kg·10a^-1 for plants sown on June 14, July 3, and July 15, respectively. After the completion of maize cultivation, onion seedlings (Allium cepa L.) were transplanted on November 12, 2019, and harvested on May 27, 2020. Neither summer tillage nor maize planting date affected onion growth or yield. The marketable onion yield was 8,305 and 7,848 kg·10a^-1 with DC and CT, respectively. In conclusion, DC did not improve maize growth or yield under paddy conditions. Mid-June to early July is a practical window for maize planting for growers in this region.