The low-temperature thermoelectric properties of Ca3-xYbxCo4O9+delta systems (x = 0, 0.02, 0.05, and 0.10). It was determined that these systems produced positive thermopower, indicating that the dominant carriers were holes. The electrical resistivity and thermopower were found to increase with increasing Yb3+ content, and the thermal conductivity was found to decrease. The highest calculated thermoelectric figure of merit was 0.037, and this was calculated for the Ca2.95Yb0.05Co4O9+delta sample....
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 This study was conducted to determine if shotcrete in which sand has been replaced by perlite can potentially be used as thermal insulation for underground mines.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 ...
An investigation was conducted to determine the thermal properties of different types of gypsum boards from the USA and Japan. The thermal conductivity and specific heat were determined at room temperature using the transient plane source technique. Measurements were first performed with the paper backing still on the boards, and then once the backing had been removed. Removing the paper resulted in a change in the specific heat, but the ...
Carbon/liquid-crystal polymer composites were formulated. Composites containing one of three types of carbon filler, composites containing two types of carbon filler, and composites containing all three types of carbon filler were prepared to test not only the effect of each filler on the thermal conductivity of the composite, but also the effect of combining fillers. The anisotropic method on a TPS system was used for the thermal conductivity measurements. ...
Calcium is partially substituted by bismuth in the Ca3-xBixCoO9+delta (x=0.00, 0.05, 0.10, 0.15, 0.20, and 0.30) system in order to determine how this substitution affects the thermoelectric and magnetic properties of the system. It was determined that the system had a positive thermopower, and thus the main carriers were holes. A maximum thermoelectric figure of merit of 0.091 was achieved with the Ca2.7Bi0.3CoO9+delta sample. The magnetic property test results indicated that ...
