In a Distributed Thermal Response Test (DTRT) the ground thermal conductivity and borehole thermal resistance are determined at many instances along the borehole. Here, such a test is carried out at a 260 m deep water filled energy well, equipped with a U-pipe borehole heat exchanger, containing an aqueous solution of ethanol as working fluid. Distributed temperature measurements are carried ou...

The anisotropic thermal conductivity of passivated black phosphorus (BP), a reactive two-dimensional material with strong in-plane anisotropy, is ascertained. The room-temperature thermal conductivity for three crystalline axes of exfoliated BP is measured by time-domain thermo-reflectance. The thermal conductivity along the zigzag direction is ≈2.5 times higher than that of the armchair direct...

Suspended microdevices are employed to measure the in-plane electrical conductivity, thermal conductivity, and Seebeck coefficient of suspended poly(3,4-ethylenedioxythiophene) (PEDOT) thin films. The measured thermal conductivity is higher than previously reported for PEDOT and generally increases with the electrical conductivity. The increase exceeds that predicted by the Wiedemann-Franz law ...

In this paper, the non-Fourier heat conduction in a semi-infinite body was examined. The heat wave non-Fourier heat conduction model was used for thermal analysis. Thermal conductivity was assumed temperature-dependent which resulted in a non-linear equation. The heat source was also considered temperature-dependent which resulted in a non-homogeneous equation. The Mac-Cormack predictor-correct...

Thermal conductivity was dramatically increased after adding natural fiber into hexagonal boron nitride (hBN)/epoxy composites. Although natural fiber does not show high-thermal conductivity itself, this study found that the synergy of natural fiber with hBN could significantly improve thermal conductivity, compared with that solely using hBN. A design of mixtures approach using constant fibers...

In this paper natural convection heat transfer within a two-dimensional, horizontal, concentric cam shape cylinders that is partially filled with a fluid saturated porous medium has been investigated. both cylinder are kept at constant and uniform temperatures with the outer cylinder being subjected relatively lower than the inner one. In addition the forchheimer and brinkman effect are taken i...

The problem of phonon scattering by strain fields caused by Stone-Wales (SW) defects in graphene is studied in the framework of the deformation potential approach. An explicit form of the phonon mean free path due to phonon-SW scattering is obtained within the Born approximation. The mean free path demonstrates a specific q-dependence varying as q (-3) at low wavevectors and taking a constant v...

Yttria-stabilized hafnia (YSH) films of 90 nm thickness have been produced using sputter-deposition by varying the growth temperature (T(s)) from room-temperature (RT) to 400 °C. The effect of T(s) on the structure, morphology, and thermal conductivity of YSH films has been investigated. Structural studies indicate that YSH films crystallize in the cubic phase. The lattice constant decreases fr...

Polymer adhesives offer a viable method for mounting silicon dies for high temperature applications. Here a test vehicle for comparing the thermal conductivity of different die attach materials is presented. The setup can be used to determine the degree of degradation of polymers. It consists of a mock die that has an integrated thick film heater, which is mounted onto a substrate. In operation...