introduction: the resistance to fracture of endodontically treated teeth restored with esthetic post systems has not been extensively researched. this in vitro study compared the fracture patterns of endodontically treated teeth with esthetic post systems with different analysis methods. materials and methods: a total of 26 recently extracted human maxillary central incisors were decoronated an...

This paper describes the development and testing of a dynamic in vitro photo-elastic model for evaluating the effects of orthodontic mechanics on an entire arch of teeth. A model of a mandibular arch was made and the teeth were embedded in a gelatine material with a high level of mechanical creep which permitted tooth movement in response to orthodontic forces. The excellent photo-elastic prope...

In the study of developmental biology, the physical properties and constraints of the developing tissues are of great importance. In spite of this, not much is known about the elastic properties of biologically relevant tissues that are studied in biology labs. Here, we characterize properties of the wing imaginal disc of Drosophila, which is a precursor organ intensely studied in the framework...

The anisotropy of thermal lensing and the photo-elastic effect is characterized for diode-pumped Nd:KGd(WO4)2 crystals cut along the Np and Ng optical indicatrix axes and along its optical axis, O = Ng+43°, at a laser wavelength of 1067 nm. Distortions in the spatial profile of output laser beam are analyzed. The thermal lens is astigmatic; the orientation of its principal meridional planes, A ...

A study of using a single crystal photo-elastic modulator for active Q-switching of a fiber laser is presented. The modulator, which oscillates in a longitudinal eigenmode, was realized with LiTaO(3). This induces due to the photo-elastic effect a modulated artificial birefringence which modulates the polarization of passing light. When used together with a polarizer inside a laser cavity the l...

We demonstrate high-frequency Q-switching of a fiber rod laser with a Single-Crystal Photo-Elastic Modulator (SCPEM) made of a LiTaO₃₋ crystal. This type of photo-elastic modulator can be driven simultaneously with two different eigenmodes to achieve a shorter rise time, which is essential for high-power operation. When operated in the laser cavity, a pulse repetition frequency of 183.6 kHz wit...