This study investigates the effect changing the PH of a copper nanofluid and sodium dodecylbenzenesulfonate (SDBS) surfactant concentration has on the thermal conductivity of the nanofluid. The thermal conductivity was determined through the Hot Disk Transient Plane (TPS) method. As the PH is increased the thermal conductivity also increases because higher PH means more surface charges which increase conductivity. As the SDBS concentration is increased the thermal conductivity slightly increases ...
This study was conducted to determine if highly expanded open cell polycarbonate foams (PC) could be used as thermal insulation among other characteristics of the foam. This was accomplished through testing the PC foam with the Transient Plane Source (TPS) method. Multiple relative densities of foam were tested, and it was found that the higher the relative density the higher the thermal conductivity, and vice versa. The lower the relative ...
This paper investigates the effect sulphate exposure has on the thermal conductivity and mechanical strength of low density cement based foams, with and without microfiber reinforcement. This was done by exposing these cement foams to sulfphate over 90 days. The compressive strength and flexural toughness displayed a cyclic rise and fall for the plain sample, and the opposite for the reinforced sample. The thermal conductivity showed an initial rise, but then ...
Traditionally, white LED's are made by mixing phosphor with an epoxy resin. But, the phosphor is not always evenly distributed, and the epoxy resin has a low thermal conductivity resulting in accelerated thermal aging during operation. This article studies the effects of implementing a ceramic phosphor plate with varying concentrations of magnesium oxide, and silicon dioxide. It was found that as the magnesium oxide concentration increased so did the thermal ...
Thermoelectric (TE) generators have very important applications, such as emerging automotive waste heat recovery and cooling applications. This study investigates how thermal conductivity, seebeck coefficient, and resistivity of bismuth telluride changes with increasing isothermal aging. The thermal conductivity was tested with the Transient Plane Source (TPS) method. Both bismuth telluride n and p type were tested for 2 wk, 8 wk, 6 mo, 1 yr, and 2 yr of isothermal aging at 240 degrees Celsius. The ...