Production of Composite Zinc Oxide-Polylactic Acid Radiopaque Filaments for Fused Deposition Modeling: First Stage of a Feasibility Study.

Three-dimensional printing technologies are becoming increasingly attractive for their versatility; the geometrical customizability and manageability of the final product properties are the key points. This work aims to assess the feasibility of producing radiopaque filaments for fused deposition modeling (FDM), a 3D printing technology, starting with zinc oxide (ZnO) and polylactic acid (PLA) as the raw materials. Indeed, ZnO and PLA are promising materials due to their non-toxic and biocompatible nature.

Exact and linearized refractive index stress-dependence in anisotropic photoelastic crystals.

For the permittivity tensor of photoelastic anisotropic crystals, we obtain the exact nonlinear dependence on the Cauchy stress tensor. We obtain the same result for its square root, whose principal components, the crystal principal refractive index, are the starting point for any photoelastic analysis of transparent crystals. From these exact results we then obtain, in a totally general manner, the linearized expressions to within higher-order terms in the stress tensor for both the permittivity tensor and its square root.

Theoretical and experimental evaluation of piezo-optic parameters and photoelastic constant in tetragonal PWO.

The tetragonal PbWO (PWO) is one of the most important scintillating crystals, being used both in the Compact Muon Solenoid (CMS) experiment at the European Organization for Nuclear Research (CERN) and in the PANDA project at the Facility for Antiproton and Ion Research (FAIR). Light yield and other relevant scintillation properties depend, among many factors, also on the crystal mechanical quality. Accordingly, a detailed knowledge of crystal piezo-optic properties is a mandatory step toward understanding elasto-optic behavior and performing crystal quality control.

On the Bertin surfaces of photoelastic crystals.

Conoscopic analysis of interference fringes is one of the most useful tools for investigating the mechanical properties of a crystal. These fringes are generated by a surface of constant phase difference, called the Bertin surface, whose shape depends on the piezo-optic properties of the material and on the applied stress. Here we investigate systematically for the first time, to the best of our knowledge, these surfaces as algebraic surfaces.