Microcellular (methylmethacrylate)-(butyl acrylate)-(Methylmethacrylate) triblock copolymer foams were prepared by a foaming process using CO2. CO2 was first dissolved into sheets of the polymer, and then the pressure was released over different time periods, from 2 to 30 minutes. The density, cellular structure, and thermal conductivity of these foams were then investigated. It was determined that the density decreased with increasing depressurization time; however, the density did not change ...
The transient plane source (TPS) technique was used to determine the anisotropy of titanium aluminide bars with different microstructures. The thermal conductivity of the bars was measured at temperatures up to 700oC. It was determined that the anisotropy in the bars was approximately 15% at all temperatures....
A porous matrix was prepared using low-density sawdust and a metakaolin-based geopolymer paste. The matrix was prepared in order to evaluate its performance as a thermally insulating building envelope. The matrices that had approximately 4 MPa of bi-axial four points flexural strength were prepared in a ratio of geopolymer paste:sawdust of between 1:1 and 1:1.5, and the thermal conductivity of these matrices was between 0.2-0.3 W/m·K....
Thermal conductivity, thermal diffusivity and specific heat are investigated for a granite rock sample from a deep borehole in central Portugal. Thirty-three samples were divided into two groups based on the degree of metasomatic alteration. It was found that the average thermal conductivity for the samples in the group comprising the less altered samples was 2.90 ± 0.26 W/m K, and for the more altered samples, the average value was 2.95 ± 0.19 W/m ...
The effective thermal conductivity of a commercial silica aerogel is determined at various gas pressures ranging from 0.001 Pa to 1 MPa in order to determine the contribution of gaseous heat conduction to the effective thermal conductivity of nano-porous materials. It was determined that the gas pressure had a significant effect on the effective thermal conductivity of the aerogel and that the contribution of gaseous heat conduction was greater than the gas ...
