• Progress in Superconductivity
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• v.11 no.1
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• pp.42-46
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• 2009

With an aim of comparison, single grain Y-Ba-Cu-O (YBCO) bulk superconductors were fabricated using a liquid infiltration growth (LIG) process and a conventional melt growth (MTG) process with top seeding. The MTG process uses an $YBa_2Cu_3O_{7-x}$(Y123) powder as a precursor, while the LIG process uses $Y_2BaCuO_5(Y211)/Ba_3Cu_5O_8(Y035)$ pre-forms. The growth of a single Y123 domain on the top seed was successful in the both processes. Different feature between the two processes is the interior microstructure regarding the critical current density ($J_c$). The LIG-processed YBCO sample showed a lower porosity, more uniform distribution of Y211 particles and the enhanced Y211 refinement compared to the conventional MTG process. The $J_c$ improvement in the LIG process is attributed to the dispersion of finer Y211 particles as well as lower porosity within the Y123 superconducting matrix.

• Journal of the Korean Society of Safety
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• v.33 no.1
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• pp.1-6
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• 2018

The effects of the fiber direction, specimen size and temperature on the compressive strength of carbon fiber reinforced silicon carbide composite (C/SiC composite) manufactured by liquid silicon infiltration(LSI) is investigated. Tests were conducted in accordance with ASTM C 695 at room temperature and elevated temperatures. Experiments are conducted with two different specimens considering grain direction. With grain (W/G) specimens have a carbon fibers parallel to the load direction, but across grain (A/G) specimens have a perpendicular carbon fibers. To verify the specimen size effect of C/SiC composite, two types of specimens are manufactured. One has a one to two ratio of diameter to height and the other has a one to one ratio. The compressive strength of C/SiC composite increased as temperature rise. As specimens are larger, compressive strength of A/G specimens increased, however compressive strength of W/G decreased.

• Journal of the Korea Institute of Building Construction
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• v.11 no.3
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• pp.256-264
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• 2011

By implementing an analysis on the liquid flame proof agent infiltration of microwave-heated wood under soaking conditions (room temperature soaking, heat soaking), its correlation with wood temperature, and the structure of wood and permeating components after soaking in flame proof agent, which was carried out as basic research in order to improve the fire resistance performance of the wood itself, it is found that the infiltration increases as the microwave heating time increases, while for heat soaking, it is found that high infiltration as well as the stable permeability of flame proof agent is achievable. Also, when the wood temperature is more than $80^{\circ}C$, the infiltration by the flame proof agent increased, and a very even infiltration of flame proof agent was observed, which implies that the liquid flame proof agent has a dependency on temperature change of the wood as a condition to penetrate into the wood. As a result of fine structure analysis, the flame proof agent transfer between cells through pits was considered as a cause to increase the infiltration of flame proof agent, and it is also shown that for heat soaking among the permeating component analysis, as the crystallized flame proof agent around the heartwood and sapwood inner pits increases, the flame proof agent can penetrate into the the heartwood part.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2003.10a
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• pp.50-53
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• 2003

Carbon nannofiber reinforced Cu matrix composite has potential applications for electrically conducting materials having high strength and electrical conductivity. In this study, we have developed fabrication technology of the nanocomposites using a liquid pressing process. The process is to use the low pressure for infiltration of Cu melt into carbon nanofiber mat as the Cu melt is pressurized directly. The minimum pressure required for infiltration was calculated from force balance equation, permeability measurement and compaction behavior of carbon nanofiber. Also, the melting temperature and the holding time have been optimized.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.6
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• pp.550-554
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• 2007

Large and single-grain Y-Ba-Cu-O(YBCO) bulk superconductors have been fabricated by using a seeded infiltration and growth method. $Y_2BaCuO_5$(Y211) precursor pellets and $YBa_2Cu_3O_x$(Y123) liquid source pellets were prepared using commercial powder and were processed by infiltration and growth method to achieve low pore and high trapped field property. The superconductor properties of the single crystal are measured and analyzed in relation with the density and size of the Y211 particle in the Y123 matrix. An optimum processing condition is suggested based on the analyzed results.

• Journal of the Korean GEO-environmental Society
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• v.16 no.11
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• pp.39-43
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• 2015

In this study, the infiltration quantity of fine-grained soil into coarse-grained soil or aggregate for methods to accelerate consolidation drainage is checked by laboratory tests under various conditions and those characteristics on infiltration are examined closely. Irrespectively of pressures to fine-grained soil corresponding to stresses in a soil mass or moisture contents of fine-grained soil, fine-grained soil does not infiltrate into standard sand and marine sand, so it is verified that drain-resistance into sand mass of drainage / pile does not occur entirely and its shear strength would increase highly by water compaction. It is known that the infiltration depth of fine-grained soil into aggregate increases according that those size is larger in case of aggregates and it increases according that the pressure or the moisture contents is higher in case of same size aggregate. It is thought that drain-resistance into aggregate mass of drainage / pile would occurs by infiltrated fine-grained soil in advance though the infiltration depth of fine-grained soi of lower moisture content than liquid limit into 13 mm aggregate is low quietly. So gravel drain method or gravel compaction pile method, etc. using aggregate of gravels or crushed stones, etc. larger than sand particle size should be not applied in very soft fine-grained soil mass of higher natural moisture contents than liquid limit, and it is thought that its applying is not nearly efficient also in soft fine-grained soil mass of lower natural moisture contents than liquid limit.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.190.1-190.1
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• 2015

Graphite has excellent mechanical and physical properties. It is known to advanced materials and is used to materials for molds, thermal treatment of furnace, sinter of diamond and cemented carbide tool etc. SiC materials are coated on the surface and holes of graphite to protect particles emitted from porous graphite with 5%~20% porosity and make graphite hard surface. SiC materials have high durability and thermal stability. Thermal CVD method is widely used to manufacture SiC thin films but high cost of machine investment and production are required. SiC thin films manufactured by Si reaction liquid and vapore with carbon are effective because of low cost of machine and production. SiC thin films made by vapor silicon infiltration into porous graphite can be obtained for shorter time than liquid silicon. Si materials are evaporated to the graphite surface in about $10^{-2}$ torr and high temperature. Si materials are melted in $1410^{\circ}C$. Si vapor is infiltrated into the surface hole of porous graphite and $Si_xC_y$ compound is made. $Si_x$ component is proportional to the Si vapor concentration. Si diffusion coefficient is estimated from quadratic equation obtained by Fick's second law. The steady stae is assumed. Si concentration variation for the depth from graphite surface is fitted to quadratic equation. Diffusion coefficient of Si vapor is estimated at about $10^{-8}cm^2s^{-1}$.

• 한국초전도학회:학술대회논문집
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• 2009.07a
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• pp.51-51
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• 2009

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1999.10c
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• pp.506-511
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• 1999

Three of the most important factors governing liquid transmission inunsaturated soils are field-saturated hydraulic conductivity, Kfs matric flux potential , ${\Phi}$m and sorptivity, S. The Guelph Permeameter is an in-hole constant-head permeameter, employing the Mariotte Principle. The study was carried out to investiate the characteristics of the water hsed average infiltration coefficient measured by the Guelph Permeameter at the Backokpo watershed in the Han river and at the Bandong watershed in the Keum river.

• Journal of Plant Biotechnology
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• v.31 no.4
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• pp.279-283
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• 2004

To lily (Lilium longflorum cv. Georgia) pollen, impacts by some physical, chemical and biological factors were examined in respects of its growth and transient gene expression via agro-infiltration. Rolling movement in liquid medium or vacuum pressure during Agro-infiltration was regarded as a impact that should be minimized for normal pollen growth. Pollen growth was maintained well in relatively broad range of temperature (19 to 27$^{\circ}C$) or pH (5.0 to 8.0). Chemical factors such as cefotaxime (up to 300mg/L), acetosyringone (up to 800 $\mu$M) and syringealdehyde (up to 800 $\mu$M) did not show any harmful effects but kanamycin severely did even at concentration as low as 25mg/L in some cases. For GUS gene expression, acetosyringone at 200 to 400 $\mu$M slightly improved the efficiency while syringealdehyde did not. Brief agro-infiltration followed by 18 hr of co-incubation of pollen along with Agrobacterium was suggested as a condition basically required for the transient expression system using lily pollen regardless of the presence of acetosyringone.