Thermal diffusivity measurements in organic liquids using transient thermal lens calorimetry

Abstract

Thermal diffusivity measurements are carried out in certain organic liquids using the pulsed dual beam thermal lens technique. The 532 nm pulses from a frequency doubled Q-switched Nd:YAG laser are used as the heating source and an intensity stabilized He-Ne laser serves as the probe beam. Experimental determination of the characteristic time constant of the transient thermal lens signal is verified theoretically. Measured thermal diffusivity values are in excellent agreement with literature values.

Photoacoustic Method for Measurement of Thermal Effusivity of Fe3O4 Nanofluid

“…Measured thermal conductivity values for Fe 3 O 4 nanofluid shows 20% enhancement. The measured effusivity and estimated diffusivity values for water and EG are in close agreement with values reported in the literature with an error of maximum ±5% [23,24]. Enhancement in thermal diffusivity can be explained due to Brownian motion, nanoconvection, and heat diffusion on addition of nanoparticles to the fluid [2,25].…”

Approach to the Assessment of Size-Dependent Thermal Properties of Disperse Solutions: Time-Resolved Photothermal Lensing of Aqueous Pristine Fullerenes C60 and C70

“…Such a difference in the time scale leads to an important distinction: the different information depending on the characteristic times of the process studies. Hence, relatively slow photothermal techniques like TLS are used for (i) estimating macroparameters of various liquids and (ii) assessing heat transfer between the phases of a disperse system and, thus, thermophysical parameters of such a system as a whole and with good precision. ,,− …”

Interferometry and thermal lens experimental method for studying the axial heat propagation in liquid samples

“…Preparando la muestra de esta forma, se supone entonces que lo que cambia ligeramente es la absorbancia de la solución pero no sus propiedades térmicas. Generalmente, se suele despreciar el cambio en la densidad de la solución y se supone que las propiedades térmo-ópticas de la solución (κ, dn/dT) son las del solvente [12,13], por lo que estas suposiciones no siempre son verificadas experimentalmente. Los resultados experimentales obtenidos en el presente trabajo, muestran que las propiedades térmicas de la solución acuosa de Tartracina son ligeramente mayores a los del agua pura, que es el solvente utilizado en este caso.…”