Polymeric tannin/furanic foams fortified with polyurethane (PUR) and 4,4’ diphenylmethane diisocyanate (pMDI) were prepared. The thermo-physical and mechanical properties of the produced foams were investigated experimentally. It was found that since there were a number of active isocyanate groups on the PUR that was used, there was no difference in adding PUR or pMDI to the foams, and so only the results for pMDI were presented. It was found that ...
The effects of cooling time on the reproducibility and accuracy of thermal conductivity measurements made using a Thermal Constants Analyzer were evaluated. Selected metal alloys and silicone based electronic interface materials were used for the testing. Cooling times of 30, 15, 10, 5, and 1 minute between measurements were selected, and three measurements were made for each cooling time. These tests were also performed at temperatures of 25, 50, and 70ºC to determine if sample temperature had ...
This article describes the design, theory, advantages, and limitations of the TPS technique with a modified bridge. It also describes testing that has been done using the technique on a variety of solid materials from temperatures of 77 K to 1000 K. It was found that at any temperature, the testing was highly accurate, with a deviation of less than 2% when compared to recommended values....
The thermoelectric properties of the Ca1-xGdxMnO3-delta system where x= 0.00, 0.02, and 0.05 were evaluated. It was determined that the sample with the lowest electrical resistivity was the Ca0.95Gd0.05MnO3-delta sample. This result was attributed to the increase content of Mn3+ in the Mn4+ matrix resulting from doping of gadolinium. The dominant charge carriers in all samples were holes, as the thermopower was negative. The highest thermoelectric figure of ...
CdS nanoparticles were dispersed in varying quantities into a PVC matrix and the effective thermal conductivities of the produced nanocomposites were investigated at temperatures from 25 to 110C. It was determined that the dispersion of the nanoparticles in PVC caused an increase in thermal conductivity up to 2 wt. % filler concentration when compared to that of pure PVC. When more than 2 wt. % of filler was added to the PVC matrix, the thermal ...
