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In its capacity as a refractory, it is useful in fiber form as a high-temperature thermal protection fabric. [52] Silica is used in the extraction of DNA and RNA due to its ability to bind to the nucleic acids under the presence of chaotropes. [53] Silica aerogel was used in the Stardust spacecraft to collect extraterrestrial particles. [54]
Beta cloth is a type of fireproof PTFE impregnated silica fiber cloth used in the manufacture of Apollo/Skylab A7L space suits, the Apollo Thermal Micrometeoroid Garment, the McDivitt Purse, [1] and in other specialized applications. Beta cloth consists of fine woven silica fiber, similar to glass fiber. The resulting fabric does not burn, and ...
30 varnished silicon steel foils each of thickness 0.0172 inches (0.4368 mm); density 7.51 g cm −3; measured near a temperature of 358.2 K under pressure in the range 0 — 128 psi: 0 psi 0.433 w m −1 K −1 20 psi 0.807 40 psi 0.965 60 psi 1.04 80 psi 1.10 100 psi 1.18 120 psi 1.24 128 psi 1.26 120 psi 1.26 100 psi 1.22 80 psi 1.18 60 psi ...
The simplest process to manufacture silicon carbide is to combine silica sand and carbon in an Acheson graphite electric resistance furnace at a high temperature, between 1,600 °C (2,910 °F) and 2,500 °C (4,530 °F).
The lowest-density silica nanofoam weighs 1,000 g/m 3, [59] which is the evacuated version of the record-aerogel of 1,900 g/m 3. [60] The density of air is 1,200 g/m 3 (at 20 °C and 1 atm). [61] The silica solidifies into three-dimensional, intertwined clusters that make up only 3% of the volume. Conduction through the solid is therefore very low.
The contribution of the muscle to the specific heat of the body is approximately 47%, and the contribution of the fat and skin is approximately 24%. The specific heat of tissues range from ~0.7 kJ · kg−1 · °C−1 for tooth (enamel) to 4.2 kJ · kg−1 · °C−1 for eye (sclera). [13]
Silica fibers are fibers made of sodium silicate (water glass). They are used in heat protection (including asbestos substitution) and in packings and compensators. They can be made such that they are substantially free from non- alkali metal compounds.
Fabrics of woven glass fibers are useful thermal insulators because of their high ratio of surface area to weight. However, the increased surface area makes them much more susceptible to chemical attack. By trapping air within them, blocks of glass fiber make good thermal insulation, with a thermal conductivity of the order of 0.05 W/(m·K). [12]