• Journal of the Korean Society of Clothing and Textiles
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• v.40 no.2
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• pp.305-314
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• 2016

This paper investigated the applicable possibility of PTT and wool staple fibers to the air vortex system as high quality yarns for a high emotional and comfort garment. It was found that the tactile hand of vortex yarn knitted fabrics was harsher than ring and compact yarns knitted fabrics. It was observed that formability and sewability of air vortex yarn knitted fabrics seemed worse than ring and compact yarns due to low tensile and compressional resilience and high bending and shear hysteresis of air vortex yarn knitted fabrics. It revealed that wicking and drying rates of air vortex yarn knitted fabric were better than ring and compact yarns; in addition, the heat keepability of vortex yarn knitted fabric was higher than ring and compact yarns due to low thermal conductivity and max heat flow rate ($Q_{max}$). Any difference of thermal shrinkage between air vortex and ring yarn knitted fabrics was not shown, but pilling characteristic of air vortex yarn knitted fabric was superior. However, it was shown that wicking, drying, thermal property and pilling characteristics of air vortex yarn knitted fabric were superior due to air vortex yarn structure with parallel fibers in the core part and periodical and fasciated twists in the sheath part of the yarns.

• Applied Chemistry for Engineering
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• v.23 no.6
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• pp.624-629
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• 2012

To capture and recover carbon dioxide ($CO_2$), we impregnated honeycomb made of ceramic paper with $K_2CO_3$ and its absorption characteristics of $CO_2$ were investigated. The absorption amount of $CO_2$ on the honeycomb absorbent impregnated with $K_2CO_3$ was 13.8 wt% at a constant temperature ($70^{\circ}C$) and relative humidity (66%) condition. Because the absorption amount of $CO_2$ achieved almost the same loading ratio of $K_2CO_3$ (17.6 wt%), the absorption reaction of $CO_2$ by $K_2CO_3$ on the honeycomb absorbent seems to be going smoothly. In addition, $CO_2$ absorption breakthrough characteristics of the honeycomb absorbent were analyzed at the temperature range of $50{\sim}80^{\circ}C$, and the water vapor was fed to an absorption column before the feeding of $CO_2$ or simultaneously with $CO_2$. As a result, the absorption capacity of $CO_2$ was more enhanced using the water vapor supplying before $CO_2$ than that of simultaneous supplying. It was confirmed by temperature programmed desorption analysis that the $KHCO_3$ produced by the absorption reaction of $K_2CO_3$ and $CO_2$ is regenerated by the desorption of $CO_2$ at a temperature of about $128^{\circ}C$.

• Journal of the Korean Magnetics Society
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• v.15 no.3
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• pp.202-206
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• 2005

The present investigation provides an electromagnetic radiation absorptive composition which comprises silver-coated ferrite microspheres dispersed in silicon rubber matrix for the aim of thin microwave absorber in GHz frequencies. Ni-Zn ferrite spheres with $50{\mu}m$ size in average were prepared by spray-drying and sintering at $1130^{\circ}C$. Conductive silver layer was plated on ferrite spheres by electroless plating. Conductive Ni-Zn ferrite sphere with uniform silver layer were obtained in the concentration of 10 g/L $AgNO_3$ per 20 g ferrite spheres. For this powder, electrical resistance is reduced as low as $10^{-2}\~10^{-3}\;\Omega$. The most sensitive material parameters with silver plating is real and imaginary parts of complex permittivity. The conductive Ni-Zn ferrite spheres have large values of dielectric constant. Due to this high dielectric constant of microspheres, matching thickness is reduced to as low as 2 mm at the frequency of 7 GHz, which is much thinner than conventional ferrite absorbers.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2003.05a
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• pp.45-48
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• 2003

Most concrete is recently made of an aggregate which is properly absorbed, and carried in it in order to do capability at every fields. We have been close to demand new capability of high flowing and enduring for specific concretes. That is difficult to cope with claiming the efficiency on deterioration from lack of a high quality aggregate. Therefore, For solving the problems we apply to a packing method for using dried materials. That is to say it is a kind of making into an instant. In this study, There is a purpose to present fundamental data, comparing and analyzing a phenomenon about aggregate's absorption following the rate of adding water, for using existing materials.

• Applied Biological Chemistry
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• v.33 no.4
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• pp.315-318
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• 1990

After technical pesticides and dispersants were dissolved in a volatile organic solvent, the wettable powders(WP's) were formulated by adsorbing the pesticide-dispersant solution to finely powdered porous synthetic silica without milling process. The median sizes of 11 WP'S were smaller than $8{\mu}m$, 9 of which had more than 80% suspensibility after 2 hours. It was possible In formulate 50% WP for liquid of fly technical pesticides. The pesticidal efficacies of WP's tested were comparable In commercial formulations regardless of suspensibilities of WP's.

• Korean Journal of Agricultural Science
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• v.19 no.1
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• pp.1-8
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• 1992

This experiment was conducted to improve the germination when we sowed Chinese milk vetch (Astragalus sinicus L. Local vas. Jinjoo) in the up-land.. The results are summerized as follows 1. There is no difference on the germination of Chinese milk vetch from $15^{\circ}C$ to $35^{\circ}C$. Germination ratio is 7l%, speed is 60% and mean of germinating day. is about 4. But at $10^{\circ}C$ germination ratio and speed are decreased as 65%, 8% but mean of germinating day is increased as 8. 2. Chemicals used for improve of germination $KNO_3$, $H_2SO_4$, HCl, NaOCl, NaOH and GA were increased about 6~8% of germination ratio. 3. Germination in response to soil covering up depth, surface sowing showed 68% of germination and not more than 4cm the seed is germinated 60% but not less than 6cm, germination ratio is not more than 50%. 4. Soil water content needed in the germination is proper about 70~80% of field water capacity and the ratio is 65% but not. more than 40% germination ratio is not more than 31%. 5. Germination in response to seed treatment (1 day sbsorption /1 day dry) germination ratio is not decreased when it treated 2 times but not less than 3 times it decreased seriously and not less that: 5 times it decreased not more than 31%. 6. Germination in response to seed largement, small seed is not good for germination, so seeds harvested after the majority of the seed is ripened.

• Journal of Conservation Science
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• v.9 no.1
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• pp.40-47
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• 2000

Dimension stability was examined after PEG pretreatment and post freeze-drying treatment in order to determine the PEG(#3350) concentration and solvent for pre-treatment of freeze-drying of highly-degraded waterlogged ash woods(Fraxinus spp.; ca. 5,700 BP) excavated from peat lands at Pyungtack, Kyounggi-do. At the low concentration (<30-40%) of PEG soaking in both water and t-butanol, the weight increases abruptly, but at high concentration (>50%) gradually, consequently, taking longer treatment time. PEG loading was higher in t-butanol solution than in water. However, the best dimesional stability was obtained from freeze-drying after lower PEG solution (40% in water) soaking. Low dimensional stability, found in the samples treated with higher PEG solutions (60%-70% in t-butanol), might come from incomplete freezing and excess PEG absorbing moisture. The samples air-dried after 70% PEG treatment had collapse defects. In conclusion, the use of low concentration (about 40% in water) PEG solution was the most suitable pretreatment for freeze drying of highly-degraded waterlogged ash woods.

• The Korean Journal of Ecology
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• v.3 no.1_2
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• pp.31-39
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• 1980

Light energy utilization was investigated in the fallen stems of Opuntia bigelovii. Threshold time for the decreasing steady state of acid accumulation in the palisade tissue of Opuntia stems was 4 hours under 1,000 $\mu Em^{-2}sec^{-1}$ of PAR at $75^{\circ}C$, while stomatal closing throughout the stem stage was illustrated by 256.0-310.4 sec $\textrm{cm}^{-1}$ of stem diffusive resistance and 0.20g $day^{-1}$ of the water loss rate as cuticular resistance. The acid loss rate in the stems per 4 hours was related to tissue water contents and a few acid loss rate could be recognized at the water content rage of 56.4%~46.8%. Endogenous oscillation of tissue acidity due to the diurnal rhythmic phenomena depended on the tissue water content was found in the Opuntia stems with stomatal closing during the normal day/night cycle. The survival rate of 1 segment to survive 2 years old cactus was 22.7% in desert environments. Such a compensation photosynthesis which utilizes light energy and maintains the reassimilation of endogenous gases was interpreted as conceptual model.

• Journal of the Korean Wood Science and Technology
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• v.39 no.6
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• pp.481-489
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• 2011

This study was conducted to evaluate the pressure treatment characteristics of Japanese red pine and Japanese larch skin timber with ACQ-2, CUAZ-2 and CuHDO-1. The effect of moisture content (MC) on preservative treatability was investigated for Japanese red pine sapwood and Japanese larch heartwood, and fixation characteristics of CCA alternatives was also evaluated. Japanese red pine sapwood, which was dried below 30 percent MC, was fully penetrated with preservatives, and minimum requirement of preservative retention for the hazard class H3 was achieved. Through measuring preservative retention gradient in Japanese red pine sapwood, it was confirmed that the retention gradient of CuHDO-1 was steeper than that of both ACQ-2 and CUAZ-2. In particular, it was intensified at a higher MCs of wood samples (25∼30%). Japanese larch heartwood did not meet the minimum requirement of penetration and retention for the hazard class H3 over the range of pretreatment MCs tested. With presteaming under $121^{\circ}C$ for 12 hours, the treatability of Japanese larch heartwood was enhanced to meet the minimum requirement for the hazard class H3. The fixation rate of copper was much more faster under drying condition compared with nondrying condition; more than 95% of copper were fixed in 3~6 days and 1 day under drying conditions in Japanese red pine sapwood and Japanese larch heartwood, respectively. After 3-week fixation period at ambient temperature, the amount of mobile copper in treated wood sample that remains available for leaching from treated wood was the highest in the wood samples treated with ACQ-2, followed by CuHDO-1 and CUAZ-2. It was proportional to the amount of copper in treating solution.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.2
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• pp.272-277
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• 1998

Filtering rates of two farming ascidians Styela clava and S. plicata, and of a farming mussel Mytilus edulis were experimentally investigated with reference to effects of water temperature and size. Absorptiometric determinations of filtering rates were carried out in a closed system with experimental animals being decreased indicate dyes neutral red. Optical density (OD) of 440 nm in path length 22 mm cell used as the indication of food particles absorption was appeared directly in proportion with the concentration of neutral red dyes. The filtering rate F is calculated by Kim's equation $F\;=\;V(1-e^{-z})$, where V is the water volume ($\ell$) in the experimental jar, and Z is the decreasing coefficient of OD as meaning of instantaneous removal speed as In $C_t\;=\;In\;C_{o}-Z{\cdot}t$, in this formula $C_t$ is OD at the time t. Filtering rate of S. clava increased as exponential function with increasing temperature while not over critical limit, and the critical temperature for filtering rate was assumed to be between $28^{\circ}C$ and $29^{\circ}C$. In case of S. plicata, the critical temperature was to be below $13^{\circ}C$, and through the temperature range $15\~25^{\circ}C$ appeared a little difference in level even though with significant. M. edulis was not appear any significant effects by water temperature less than $29^{\circ}C$. The model formula derived from the results is as below, where F is filtering rate (${\ell}/hr/animal$), T is water temperature ($^{\circ}C$), and DW is dry meat weight (g) of experimental animal. $$S.\;Clava;\;F\;=\;e xp\;(0.119\;T-4.540)\;(DW)^{0.6745},\;T<29^{\circ}C$$) $$S.\;plicata;\;F\;=\;e xp\;(A_t)\;(DW)^{0.5675},\;(13^{\circ}C $$[A_t =-8.56+0.6805\;T-0.0153\;T^2]$$ $$M.\;edulis;\;F\;=\;0.3844\;(DW)^{0.4952},\;<29^{\circ}C$$)