A circuit was designed for use in the transient hot-strip method for the determination of thermal properties of thermal insulators and electrical properties of thin metal films. The article describes how the output of power in the strip source can be kept constant throughout a measurement, and how a low voltage can be used even for thin metal films with high resistances....
Composite silica aerogels were prepared using sodium silicate and ceramics fibers. The thermal conductivities of these composites were investigated to determine how effective they would be as thermal insulation. As temperature increased to 400oC, the thermal conductivity of these composites only increased from 0.0266 to 0.0572 W/(m·K). This indicates that these composites which have good structural and mechanical properties would be good thermal insulators during thermal processes....
This article focuses on creating a standard reference material and method for measuring the thermal conductivity of thermal insulation materials at a set temperature. The specific focus is in the temperature range above 100°C, where there are differences in values obtained using different techniques. The author performs a review on the influences of the guarded hot plate, cyclic heat and transient hot wire. The author developed three apparatuses that measure ...
Perlite was added to mortar in order to determine if the resulting composite was more thermally insulating than conventional shotcrete. This study was conducted to determine if shotcrete in which sand has been replaced by perlite can potentially be used as thermal insulation for underground mines. It was found that the addition of perlite decreased the weight of the shotcrete, as well as the thermal conductivity and diffusivity, but decreased ...
Ultralow density silica aerogels were formulated by sol-gel process using tetramethyl orthosilicate as the precursor. A supercritical drying step was performed using acetonitrile solvent extraction. These aerogels were found to have a high specific surface area (~812m2/g) and they were found to be excellent thermal insulators with thermal conductivities ranging from 0.024 to 0.043 W/m K at temperatures up to 400oC....
