This study investigates a measurement method of thermal diffusivity for samples with arbitrary geometries and unknown material properties. The aim is to curve fit the use numerical simulation transient temperature inside object interest. approach designed assess bulk properties an that has composite structure such as underground soil. creates boundary conditions necessary apply analytical theor...

2014 A laser pulse method for diffusivity determination is analysed. The method which permits the measurement of the laser pulse energy distribution as well as its shape is developed. This method can be easily implanted into laser pulse diffusivity set-up and it allows to check periodically the pulse characteristics that is of primary importance for the accuracy of the diffusivity measurements....

Silver nanoparticles were successfully prepared in two different solvents using a microwave heating technique, with various irradiation times. The silver nanoparticles were dispersed in polar liquids (distilled water and ethylene glycol) without any other reducing agent, in the presence of the stabilizer polyvinylpyrrolidone (PVP). The optical properties, thermal properties, and morphology of t...

Particles moving along curved trajectories will diffuse if the curvature fluctuates sufficiently in either magnitude or orientation. We consider particles moving at a constant speed with either a fixed or a Gaussian distributed magnitude of curvature. At small speeds the diffusivity is independent of the speed. At larger particle speeds, the diffusivity depends on the speed through a novel expo...

We calculate the normal modes of vibration in jammed sphere packings to obtain the energy diffusivity, a spectral measure of transport. At the boson peak frequency, we find an Ioffe-Regel crossover from a diffusivity that drops rapidly with frequency to one that is nearly frequency independent. This crossover frequency shifts to zero as the system is decompressed towards the jamming transition,...