Two series of co-doped mifit-layered cobaltites were prepared with compositions of Ca3-xYbxCo4-yAgyO9+delta and Ca3-xEuxCo4-yAgyO9+delta. All of the samples exhibited an increasing thermopower as temperature was increased up to a temperature of 700 K. The sample with the highest power factor and figure of merit was Ca2.95Eu0.05Co3.95Ag0.05O9+delta....
This thesis presents a literature review of techniques for measuring the thermal conductivity of engineering materials. In addition to this, the cylindrical specimen apparatus developed at Arizona State University was improved upon, and this method was used to measure the thermal conductivity of five different materials. The results of this testing were compared with results obtained using the guarded hot-plate method, and the results were in good agreement with each ...
Graphite nano-platelets (GnPs) were dispersed in polyethylene glycol (PEG)/polymethyl methacrylate (PMMA) to form a PEG/PMMA/GnPs composite organic form-stable phase change material. The effects of the incorporation of the GnPs on the morphological, structural, thermal, and electrical properties of the composite were then assessed. The experimental results indicated that the incorporation of the GnPs into the polymer increased the thermal and electrical conductivities, and it was concluded that ...
Si-SiC composite foams were prepared using tannin-based foams as templates. The foams were prepared by four different methods for the determination of which method would best produce a foam with a pore size under 200 µm. The foam samples were characterized by SEM, XRD, and Raman spectroscopy, and the thermal conductivity of one of the foams was investigated by the transient plane source method. It was found that direct infiltration of ...
Ambient pressure dried hydrophobic silica aerogel monoliths were prepared via simultaneous solvent exchange and surface modification in order to minimize volume shrinkage and density. At room temperature, the obtained silica aerogels had a low density of 0.096 g/cm³, a high surface area and hydrophobicity, and a low thermal conductivity of 0.0217 W/m·K. The effect of heating on these properties was also determined. After the aerogel had been heated to 300°...
