The transient plane source technique was used to measure the thermal conductivity of construction materials at room temperatures. The samples were tested under both dry and partially wet conditions. It was found that the thermal conductivity increased significantly with increasing water content....
Calcium is partially substituted by bismuth in the Ca1-xBixMnO3-delta (x=0.00, 0.02, and 0.05) system in order to determine how this substitution affects the electrical resistivity, thermopower, and thermal conductivity. The experimental results were then used to calculate the thermoelectric figure of merit for each sample. The highest observed figure of merit was 0.047, which represented a 487% increase over the unsubstituted sample....
Thermoelectric materials are currently being researched as a source of energy in order to reduce carbon dioxide emissions. The efficiency of these materials depends on their Seebeck coefficient, electrical resistivity, and thermal conductivity, as well as the absolute temperature. Cobalt oxides (Ca3Co4O9+delta) have been researched extensively as potential thermoelectric materials because of their high Seebeck coefficient and low electrical resistivity and thermal conductivity. Systems have been studied ...
The low-temperature thermoelectric properties of Ca3-xDyxCo4O9+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 thermal conductivity were found to decrease with increasing Dy3+ content, and the thermopower was found to increase. The highest calculated thermoelectric figure of merit was 0.044, and this was calculated for the Ca2.9Dy0.1Co4O9+delta sample....
Coal fly ash was used as the base material for the formation of thermal insulation materials. The porosity of the produced materials ranged from 86.3-94.5 vol. %. The insulating materials were prepared by ball milling, followed by foaming assisted by the addition of K12, casting and drying, and finally sintering. No harmful chemicals were released to the environment during their preparation. It was found that the thermal conductivity of the samples ...
