• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.6
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• pp.199-208
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• 2021

The extrudability of 3D printed concrete and its member strength can be highly influenced by water cement ratio (W/C) and printing time gap (PTG). In this study, mold cast specimens and 3D printed specimens were fabricated with variables of W/C ratio and PTG, and their shear bond strength and interlayer surface moisture content were measured and analyzed. The test results showed that the shear bond strength is greatly influenced by the amount of interlayer surface moisture. It is thus recommended that proper amount of interlayer surface moisture with respect to PTG needs to be maintained to have a required interlayer shear bond strength. In addition, further research is required to estimate the effect of many environmental factors that can influence the interlayer surface moisture content.

• Proceedings of the Korean Nuclear Society Conference
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• 2005.05a
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• pp.1092-1093
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• 2005

• Proceedings of the Korean Society of Crop Science Conference
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• 1993.10a
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• pp.62-63
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• 1993

• Proceedings of the PSK Conference
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• 2001.04a
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• pp.219.3-220
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• 2001

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.2
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• pp.288-295
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• 1998

Egg production of Acartia steueri was estimated in llkwang Bay, located in the southeastern coast of Korea. The equation, combining fecundity, temperature and chlorophyll a, obtained under the laboratory experiments, was applied to the in situ temperature and chlorophyll a for the estimation of field egg production. Mean egg size was $80.52{\mu}m$. Prosome length of adult females was not correlated with egg size. Egg production of field population ranged from 0.32 to $63.32{\mu}gC\;m^{-3}d^{-1}$ with a mean of $13.33{\mu}gC\;m^{-3}d^{-1}$, which were equivalent to $7.1\~1407.1\;eggs\;m^{-3}d^{-1}$ and $296.1\;eggs\;m^{-3}d^{-1}$, respectively. Fecundity of adult females ranged from 5.4 to $12.5\;eggs\;female^{-1}d{-1}$ with a mean of $8\;eggs\;female^{-1}d^{-1}$. Specific egg production rates ranged from 0.028 to 0.117 $d^{-1}$ with a mean of 0.064 $d^{-1}$. Considering the egg Production ($\%$ female body carbon) as a function of temperature and chlorophlrll a concentration, our results showed rather low fecundity, which might be underestimated. Probable cannibalism of egg by the adults were thought to be pan of the reason for this low estimated fecundity.

• Journal of Mushroom
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• v.21 no.4
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• pp.222-227
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• 2023

Mushrooms have a unique taste and aroma, so in the processing of mushroom products with other ingredients, a separate pre-processing step is often taken to eliminate the mushroom aroma. In this study, we analyzed the changes in the concentration of volatile compounds according to drying conditions to promote the activation of processing using the fruiting bodies of yellow oyster mushrooms(Pleurotus citrinopileatus) and pink oyster mushrooms(P. djamor). The caps and stipes of yellow oyster and pink oyster mushrooms were separated and freeze-dried at -70℃ for 120 hours. Subsequently, they were hot air-dried at temperatures of 40, 50, 60, and 70℃ for 24, 24, 16, and 12 hours, respectively. The dried samples were pulverized and quantitatively analyzed by SPME-GC-MS. In the case of yellow oyster mushrooms, the concentration of t-2-nonenal in caps and stipes during freeze-drying was 164.43 ㎍/g d.w. and 174.80 ㎍/g d.w., respectively, whereas during hot air-drying, it significantly decreased to 0.35~3.41 ㎍/g d.w. and 0.98~59.88 ㎍/g d.w. In a similar manner, for pink oyster mushrooms, the concentration of 1-octen-3-ol during freeze-drying in caps and stipes was 31.05 ㎍/g d.w. and 176.17 ㎍/g d.w., respectively, whereas during hot air-drying, it significantly decreased to 1.59~9.66 ㎍/g d.w. and 1.96~15.77 ㎍/g d.w. Furthermore, most volatile compounds showed a tendency to decrease in concentration as the temperature during hot air-drying increased.

• Mycobiology
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• v.32 no.2
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• pp.57-67
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• 2004

For investigation of the species diversity of the Genus Crepidotus in Korea and constructing a key to Korean Crepidotus species, a total of 65 specimens, collected from 18 locations from 1982 to 2002, were observed for morphological characters of carpophores and other features. All the specimens have been preserved in the herbarium of the National Institute of Agricultural Sciences and Technology, R.D.A., Suwon, Korea. The specimens were identified according to the classification systems given by Hesler and Smith(1965), Nordstein(1990), Orton(1960), Pilat(1948), Senn-Irlet(1991, 1992, 1993) and Singer(1951, 1973, 1986). In this study, a total of 10 Crepidotus species were confirmed. Among them, Korean common names were designated to six unrecorded species as follows: C. uber, "끈적귀버섯"; C. hygrophanus, "곤약귀버섯"; C. latifolius, "꼬마무리귀버섯"; C. obscurus, "먼지귀버섯"; C. subverrucisporus, "분홍주름귀버섯"; and C. circinatus, "노란고리귀버섯". A key to 10 Crepidotus species has been constructed.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.1
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• pp.76-81
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• 2015

The effects of temperature, photon irradiance, and photoperiod on the growth of Sargassum horneri embryos were examined for female plants collected at Chokpo in Tongyeoung, Gyeongnam Prefecture, Korea on 27 December 2011. Mature plant receptacles were detached, and fertilized eggs were cultured in the laboratory at temperatures of $5-25^{\circ}C$ with photon irradiances of $10-80{\mu}mol\;m^{-2}s^{-1}$ under 14L:10D and 10L:14D photoperiods. Germination and embryo growth were rapid at $20-25^{\circ}C$ and $40{\mu}mol\;m^{-2}s^{-1}$ under 14L:10D. The number of rhizoids in the germinated young thalli was high at high photon irradiances ($40-80{\mu}mol\;m^{-2}s^{-1}$) and $15-20^{\circ}C$. At $20^{\circ}C$ and 14L:10D, vigorous growth of main and lateral branches was observed; however, at $5^{\circ}C$ under both photoperiods, plant growth decreased markedly. In the present study, S. horneri grew well at high temperatures ($20-25^{\circ}C$) and high photon irradiances ($40-80{\mu}mol\;m^{-2}s^{-1}$) with a 14L:10D photoperiod.

• Journal of Powder Materials
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• v.29 no.1
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• pp.28-33
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• 2022

Aluminum-based powders have attracted attention as key materials for 3D printing owing to their low density, high specific strength, high corrosion resistance, and formability. This study describes the effects of TiC addition on the microstructure of the A6013 alloy. The alloy powder was successfully prepared by gas atomization and further densified using an extrusion process. We have carried out energy dispersive X-ray spectrometry (EDS) and electron backscatter diffraction (EBSD) using scanning electron microscopy (SEM) in order to investigate the effect of TiC addition on the microstructure and texture evolution of the A6013 alloy. The atomized A6013-xTiC alloy powder is fine and spherical, with an initial powder size distribution of approximately 73 ㎛ which decreases to 12.5, 13.9, 10.8, and 10.0 ㎛ with increments in the amount of TiC.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.10
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• pp.928-936
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• 2013

3D crosstalk is one of the disturbing things to recognize 3D images. This is caused by the phenomenon that input image for left eye is transferred at the right eye and right eye is transferred at the left eye because of the imperfect isolation by the device characteristics. In this paper, we review the 3D PDP (Plasma Display Panel) operation using active shutter glasses and crosstalk measurement method and investigate the major cause of 3D crosstalk and extend conventional 3D crosstalk using full white and full black image input to Gray-to-Gray (GtoG) 3D crosstalk. We suggest a specific method to reduce Gray-to-Gray 3D crosstalk by using Look up Table (LUT) and sub-field mapping in PDP. And then, we verify the method by measuring GtoG 3D crosstalk rate through specific test images and numerical results.