In this study, optical and thermal properties of normal grade and winter grade palm oil biodiesel were investigated. Surface Plasmon Resonance and Photopyroelectric technique were used to evaluate the samples. The dispersion curve and thermal diffusivity were obtained. Consequently, the variation of refractive index, as a function of wavelength in normal grade biodiesel is faster than winter gr...

In this study we applied thermal lens (TL) technique to study the effect of size on thermal diffusivity of cadmium sulphide (CdS) nanofluid prepared by using γ-radiation method containing particles with different sizes. In TL experimental set up a diode laser of wavelength 514 nm and intensity stabilized He-Ne laser were used as the excitation source and the probe beam respectively, respectivel...

Bismuth telluride nanowires are of interest for thermoelectric applications because of the predicted enhancement in the thermoelectric figure-of-merit in nanowire structures. In this letter, we carried out temperature-dependent thermal diffusivity characterization of a 40 nm diameter Bi2Te3 nanowires/alumina nanocomposite. Measured thermal diffusivity of the composite decreases from 9.2310−7 m2...

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,...

A method to measure thermal diffusivity around a single heated gold nanoparticle is presented. It is based on photothermal single particle microscopy and employs the phase delay of temperature modulation due to finite thermal diffusivity. The phase delay is detected optically averaging over the focal volume of a diffraction limited beam of light. Thermal diffusivity is extracted by comparison t...

Abstract In the present paper, results of a research focused on microstructure investigation steel welded joints by means non destructive thermographic technique are presented. particular, two rough obtained irregular manual welding analyzed. Active lock in thermography phase analysis is applied, basing evidence that thermal diffusivity related to diffusion length, using contrast trend as funct...

thin layer drying behavior of sweet lemon slice was experimentally investigated in a convective type dryer and the mathematical modeling performed, using thin layer drying models given in literature. drying experiments were conducted at inlet drying air temperatures of 40, 50, 60, 70 and 80 ?c; two slice thicknesses of 3 and 6 mm, and, at one drying air velocity of 0.5 m/s with three replicatio...

This paper reports solubility and diffusivity data for soy and rapeseed methyl esters in polyethylene together with comparisons with methyl oleate and linoleate. These data showed that there is no significant difference in diffusivity and solubility between all these penetrants. Data were used to discuss the reliability of predictive models for diffusion and solubility of additive type molecule...

We report results of molecular dynamics simulations to understand the role of solute and solute-solvent interaction on solute diffusivity in a solid solution within a body centered cubic solid when the solute size is significantly smaller than the size of the solvent atom. Results show that diffusivity is maximum for two specific sizes of the solute atom. This is the first time that twin maxima...

The aim is to investigate the relationship between microstructural white matter (WM) diffusivity indices and macrostructural WM volume (WMV) among healthy individuals (20-85 years). Whole-brain diffusion measures were calculated from diffusion tensor imaging using FMRIB software library while WMV was estimated through voxel-based morphometry, and voxel-based analysis was carried out using tract...