A tool for evaluating thin-film thermal conductivity to submicron spatial resolution has been developed. The micro-instrumentation utilizes the thermoreflectance (TR) technique to characterize thermal conductivity and material uniformity. The instrument consists of a heating element for creating temperature gradients and an Invar bar with in situ temperature monitoring for heat flux measurement...

experimental study of effective thermal conductivity of zno/eg nanofluid is presented in thisresearch. the nanofluid was prepared by dispersing zno nanoparticles in ethylene glycol using asonicator and adding surfactant. ethylene glycol based nanofluid containing zno nanoparticlewith a nominal diameter of 18 nm at different solid volume fractions (very low to high) atvarious temperatures was ex...

In order to study the effects of alkyl chain on the thermal properties of fullerene derivatives, we perform molecular dynamics (MD) simulations to predict the thermal conductivity of fullerene (C60) and its derivative phenyl-C61-butyric acid methyl ester (PCBM). The results of non-equilibrium MD simulations show a length-dependent thermal conductivity for C60 but not for PCBM. The thermal condu...

Using the phonon Boltzmann transport formalism and density functional theory based calculations, we show that stanene has a low thermal conductivity. For a sample size of 1 × 1 μm(2) (L × W), the lattice thermal conductivities along the zigzag and armchair directions are 10.83 W m(-1) K(-1) and 9.2 W m(-1) K(-1) respectively, at room temperature, indicating anisotropy in thermal transport. The ...

Light-emitting diode (LED) is an electronic device with high heat flux. The simulation and analysis of the heat dissipation play an important role in the improvement of performance and design of LEDmodule. In this paper, a thermal model was developed using ANSYS software to simulate the temperature distribution of LED module. The effect of thermal conductivity of MCPCB (metal-core printed circu...

Quasiparticle thermal conductivity in the vortex state of high-T c cuprates. Abstract We present the results of a microscopic calculation of the longitudinal thermal conductivity, κ xx , of a d-wave superconductor in the mixed state. Our results show an increase in the thermal conductivity with the applied field at low temperatures, and a decrease followed by a nearly field independent κ xx (H)...

The transport of heat and charge in the overdoped cuprate superconductor Tl(2)Ba2CuO(6+delta) was measured down to low temperature. In the normal state, obtained by applying a magnetic field greater than the upper critical field, the Wiedemann-Franz law is verified to hold perfectly. In the superconducting state, a large residual linear term is observed in the thermal conductivity, in quantitat...

Rate of heat transfer ∂u = (1) −K0 area ∂x where K0 is the thermal conductivity, units [K0] = MLT U . In other words, heat is transferred from areas of high temp to low temp. 3. Conservation of energy. Consider a uniform rod of length l with non-uniform temperature lying on the x-axis from x = 0 to x = l. By uniform rod, we mean the density ρ, specific heat c, thermal conductivity K0, cross-sec...

An improved thermal-needle approach for accurate and fast measurement of thermal conductivity of aqueous and soft biomaterials was developed using microfabricated thermal conductivity sensors. This microscopic measuring device was comprehensively characterized at temperatures from 0 °C to 40 °C. Despite the previous belief, system calibration constant was observed to be highly temperature-depen...

We report the first experimental results on the temperature dependent in-plane and cross-plane thermal conductivities of a symmetrically strained Si/Ge superlattice and a Ge quantum-dot superlattice measured by the two-wire 3 omega method. The measured thermal conductivity values are highly anisotropic and are significantly reduced compared to the bulk thermal conductivity of the structures. Th...