Schematic diagram in which the lateral view of the photoacoustic system used for performing the experiments is presented.
Time evolution of the experimental photoacoustic amplitude measured for zirconia-based particles (50 μm) in water, 80% EG-water and citronella oil.
Time evolution of the amplitude of the photoacoustic signal obtained experimentally for zirconia-based particles (100 μm) in water, 80% EG-water and citronella oil.
Schematic diagram for the system in which (1) is the substrate layer, (2) is the concentration changing zirconia-based particles layer, and (3) is a semi-infinite fluid layer. The thickness of layers (1) and (2) are L 1 and L 2, respectively.
Two possible arrays of spheres were considered: (a) an odd-number of spheres accommodated along the diameter of a circle. (b) Spheres with half the diameter that the ones considered in (a). In this case, an even-number of spheres can be accommodated along the diameter of the circle. The area depicted in (b) corresponds to the dashed inner circle shown in (a).
Time evolution of the effective thermal effusivity for the zirconia particles of 50 and 100 μm sedimenting in deionized water. The first part of each graph corresponds to the measurement when there is only water, in the middle part we can observe the change in ETE during the sedimentation of particles, and in the final part, we can see the maximum ETE value when all the particles have sedimented.
Time evolution of the concentration of particles in water during the sedimentation process.
Time evolution of the effective thermal effusivity for 80% EG-water mixture with sedimenting zirconia particles of diameters 50 and 100 μm, as we can see the maximum ETE value reached is practically the same for both cases.
Time evolution of concentration of particles in 80% EG-water. Zirconia particles of 50 and 100 μm were used, notice that at the end the EVF maximum values converge to ≈0.50, which is the expected value.
ETE for citronella oil with sedimenting zirconia particles of 50 and 100 μm diameters.
Concentration of zirconia particles of 50 and 100 μm during the sedimentation in citronella oil. For both particle sizes, the maximum is reached at approximately 50% of the concentration of particles in the liquid.
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