Ricerc@Sapienza

Photoacoustic spectroscopy investigation was carried out on ZnO nanoparticles grown at 80 °C on porous surface of diatomite (DE) by sol–gel technique, using zinc acetate dihydrate as ceramic precursor and triethanolamine to mediate the surface growth of the nanoparticles. Absorption and scattering characteristics of hybrid ZnO/DE powder in the UV–Vis range were inferred by photoacoustic spectroscopy, and results were analyzed based on Helander’s theory.

Quality control of the performance of mechanical components subjected to hardness processing is a topic of fundamental importance in the field of automotive. The lack of hardening, may cause failures with serious repercussions. The industry and the companies responsible for the hardening processes as well as for the quality control of the mechanical components are continuously seeking for improvements in the standard destructive tests performed by Vicker or Brinell durometers.

Compact samples of nano-helices built by means of a focused ion beam technology with large
bandwidth and high dichroism for circular polarization are promising for the construction of built-in-chip
sensors, where the ideal transducer must be sufficiently confined without compromising its filtering
ability. Direct all-optical measurements revealed the sample’s dichroic character with insufficient details
because of scattering and diffraction interference. On the other hand, photoacoustic measurements