Autoclaved aerated concrete was studied because it has potential to be used in the design of energy-efficient buildings. Three different samples were tested, each with a unique density. Of particular interest to this work was the thermal conductivity of the samples, as this material would be used as a thermally insulating concrete. The thermal conductivities were measured at various percentages of moisture content, and it was found that increasing moisture ...
Author(s): Hong-Qing Jin, Li-Wu Fan, Xiao-Li Yao, Xu Xu, Zi-Tao Yu
Thermal properties of methane hydrate-bearing sediment samples taken from the Nankai Trough, Japan were investigated using the transient plane source method. It was determined that the thermal conductivity of these sediment samples decreased with increasing porosity, but increased with increasing methane hydrate saturation. The thermal diffusivity of the samples increased slightly with increasing porosity, but was almost independent of methane hydrate saturation. It was also found that the specific heat ...
Author(s): K. Suzuki, M. Muraoka, M. Ohtake, N. Susuki, T. Tsuji, Y. Yamamoto
The thermal conductivity, viscosity, and stability of nanofluids were evaluated to determine how varying experimental conditions can affect these properties. It was determined that increasing the concentration, temperature, and time spent sonicating the nanofluids can increase the thermal conductivity, while the addition of alcohol caused a decrease in thermal conductivity. Furthermore, it was found that the shape of the particles has an effect on the measured thermal conductivity. It was ...
Author(s): Mohammadreza Behi, Seyed Aliakbar Mirmohammadi
The laser floating zone method was used to prepare Pb doped Bi2-xPbxBa2Co2Oy thermoelectric materials with x=0, 0.2, 0.4, and 0.6. The highest power factor reported was obtained at 650oC for the 0.2 Pb doped samples. This value was higher than that for pure laser grown Bi2Ba2Co2Oy materials. The thermal conductivity was decreased, as is desired in thermoelectric materials....
Author(s): A. Sotelo, F. M. Costa, J. C. Diez, J. S. Amaral, M. A. Madre, M. A. Torres, N. M. Ferreira, S. I. R. Costa, Sh. Rasekh, V. S. Amaral
Three techniques were compared for the determination of thermal conductivity in poly-alpha-olefin (PAO)-based nanofluids. The three methods that were used were the transient hot wire, transient plane source, and laser flash techniques. The effects of temperature, nanoparticle concentration, and shape on the thermal conductivity were also examined, and these effects were compared to those predicted by a previously determined model. It was found that the transient hot wire technique ...
Author(s): Javier Artemio Narvaez