• Proceedings of the Korean Vacuum Society Conference
• /
• 1996.06a
• /
• pp.151-151
• /
• 1996

• Journal of the Korean Society of Clothing and Textiles
• /
• v.22 no.4
• /
• pp.515-524
• /
• 1998

The purpose of this study was to evaluate the thermal properties of ceramics coated nylon fabrics by determining far infra-red emissive properties, heat storage/release and thermal insulation. Far IR emissivity and emissive power were measured for 7~ 140n at 50'C . Three types of ceramics such as cordierite with $\alpha$-alumina, a-alumina with titanium oxide and a-alumina were chosen as specimens. Cordierite with $\alpha$-alumina was chosen to treat on the fabrics due to the good emissive properties on the fabrics. Add-ons and contents of ceramics were analyzed for ceramics and/or polyurethane coated fabrics. For the physical properties, thickness and air permeability were measured. Results showed a difference in the emissive property between ceramics themselves and ceramics coated fabrics. In the ambient temperature, there was no diffenence in emissivity among the different ceramics contents. Thermography showed that when the fabric was heated with the light, surface mean temperatures of fabrics were increased as the contents of ceramics increased, and the heat storage property was confirmed. In case of same thickness and air permeability, the thermal insulation value increased as the contents of ceramics increased because of increasing heat storage and Far IR reflectivity. So there were absorption and heat storage of ceramics for Far IR from human and reflection to human between ceramics coated fabrics and human.

• Journal of the Korean Ceramic Society
• /
• v.48 no.5
• /
• pp.360-367
• /
• 2011

Macroporous silicon carbide (SiC) ceramics were fabricated by powder processing and polymer processing using carbon-filled polysiloxane as a precursor. The effects of the starting SiC polytype, template type, and template content on porosity and flexural strength of macroporous SiC ceramics were investigated. The ${\beta}$-SiC powder as a starting material or a filler led to higher porosity than ${\alpha}$-SiC powder, owing to the impingement of growing ${\alpha}$-SiC grains, which were transformed from ${\beta}$-SiC during sintering. Typical flexural strength of powder-processed macroporous SiC ceramics fabricated from ${\alpha}$-SiC starting powder and polymer microbeads was 127 MPa at 29% porosity. In contrast, that of polymer-processed macroporous SiC ceramics fabricated from carbon-filled polysiloxane, ${\beta}$-SiC fillers, and hollow microspheres was 116MPa at 29% porosity. The combination of ${\alpha}$-SiC starting powder and a fairly large amount (10 wt%) of $Al_2O_3-Y_2O_3$ additives led to macroporous SiC ceramics with excellent flexural strength.

• Proceedings of the Korean Vacuum Society Conference
• /
• 1995.02a
• /
• pp.071-72
• /
• 1995

• Proceedings of the Korean Vacuum Society Conference
• /
• 1997.02a
• /
• pp.69-69
• /
• 1997

• Proceedings of the Korean Vacuum Society Conference
• /
• 1996.02a
• /
• pp.133-133
• /
• 1996

• Proceedings of the Korean Vacuum Society Conference
• /
• 1996.06a
• /
• pp.150-150
• /
• 1996

• Journal of the Korean Society for Precision Engineering
• /
• v.21 no.1
• /
• pp.61-70
• /
• 2004

Generally, ceramics are very difficult-to-cut materials because of its high strength and hardness. The machining process of ceramics can be characterized by cracking and brittle fracture. In the machining of ceramics, edge chipping and crack propagation are the principal reasons to cause surface integrity deterioration. Such phenomenon can cause not only poor dimensional and geometric accuracy, but also possible failure of the ceramic parts. Ceramics can be machined with traditional method such as grinding and polishing. However, such processes are generally cost-expensive and have low material removal rate. Thus, in this paper, to overcome these problems. BN powder, which gives good cutting property, is added for the fabrication of machinable ceramics by volume of 5,10,15,20,25 and 30%. And, mechanical properties, R-curve behavior and machining tests are carried out to evaluate the machining properties of the manufactured machinable ceramics.

• Journal of the Korean Ceramic Society
• /
• v.29 no.6
• /
• pp.441-450
• /
• 1992

The microstructur and LPG sensing properties of maghemite (${\gamma}-Fe_2O_3$) ceramics have been studied. The acicular and fine spherical shaped iron oxide particles were sintered at below $900^{\circ}C$. The maghemite ceramics were prepared by reduction-oxidation of sintered iron oxide. With the microstructure of acicular and/or fine grains, the maghemite ceramics have good LPG sensing properties. Increased sintering temperature deteriorates the LPG sensitivity of maghemite ceramics due to the grain growth. The maghemite ceramics prepared from the mixed iron oxide, of a large amount of acicular particles and a small amount of spherical ones, have a lower LPG sensitivity than that of the acicular iron oxide ceramics. But, they seem to be of higher mechanical strength. The optimum working temperature for LPG sensing of the maghemite ceramics was found to be $300~350^{\circ}C$.

• Journal of Agricultural Extension & Community Development
• /
• v.7 no.1
• /
• pp.175-180
• /
• 2000

This experiment was conducts to find out the effects of ceramics mixing on mushrooms mycelial growth and density. It is better ceramics in $800^{\circ}C$ than $1000^{\circ}C$ to mycelial growth and density of Pleurotus astreatus, Flamulina velutepes, Lentinus edodes and Inonotus obliqua . Mycelial growth according to ceramics mixing contents with mushrooms media is good till 0.16% ceramics mixing, but if mycelial growth and density take into consideration, 0.12% ceramics mixing contents is best.