Recent studies on the image of the Turin Shroud (TS) lead to think it could have been formed through a not well-identified mechanism of energy radiation. In order to remove some lacunas about this imaging process, a reverse engineering method has been applied to it, arriving to exclude some possible mechanisms. The image formation of a human face wrapped on a cloth by using an ad-hoc developed software has been simulated. The results of different kinds of the radiation depending from different parameters have been simulated, each one connected with accredited hypotheses. On the basis of the comparison among the different images produced by the software and the TS Face, some useful information both about the kind of radiation and the cloth wrapping conditions have been obtained. The effect of image distortion of a cloth wrapped around a face has been discussed too by defining the best laws of radiation and of their attenuation with distance. A Lambertian law is not compatible with the TS image. A vertical radiation shows a problem in reproducing the requested resolution. A radiation perpendicular to the emitting surface, like that produced by an electric field appears promising to explain the TS Face.

Piezoelectric cantilever harvesters have a large power output at their natural frequency, but in some applications the frequency of ambient vibrations is different from the harvester’s frequency and/or ambient vibrations are periodic with some harmonic components. To cope with these operating conditions harvesters with integrated trimming devices (ITDs) are proposed. Some prototypes are developed with the aid of an analytical model and tested with an impulsive method. Results show that a small trimming device can lower the main resonance frequency of a piezoelectric harvester of the same extent as a larger tip mass and moreover generates at high frequency a second resonance peak. A multi-physics numerical FE model is developed for predicting the generated power and for performing stress-strain analysis of harvesters with ITDs. The numerical model is validated on the basis of experimental results. Several configurations of ITDs are conceived and studied. Numerical results show that harvesters with ITDs are able to generate relevant power at two frequencies owing to the particular shape of the modes of vibration. The stress in the harvesters with ITDs is smaller than the stress in the harvester with a tip mass trimmed to the same frequency.