This work describes the design, implementation and first results of a fatigue test rig capable of subjecting cylindrical specimens of different sizes and materials to complex real-life loading conditions. The resulting test rig can be used to combine a rotating bending load with a fluctuating torsional load. Due to a closed electromechanical loop, power consumption is limited and a maximum test...

Poly (methyl methacrylate) (PMMA) was used as a matrix for fabrication samples of polymer composites (PMCs). The reinforcement by (Al2O3) powder with volumetric ratio (20%) and an average grain size (40 ±5) μm. manufactured were treated after conducting the surface treatment operations thermally different temperatures (50,70 90 ⁰C) times (2,4,6,8, 10 hours). subjected to set mechanical microsco...

BACKGROUND Microwave postpolymerization has been suggested as a method to improve the flexural strength of an autopolymerizing denture reline resin. However, the effect of microwave postpolymerization on the residual monomer content and its influence on flexural strength have not been investigated. OBJECTIVES This study analyzed the effect of microwave postpolymerization on the residual monom...

We prove theoretically the possibility of electric-field controlled polaron formation involving flexural (bending) modes in suspended carbon nanotubes. Upon increasing the field, the ground state of the system with a single extra electron undergoes a first-order phase transition between an extended state and a localized polaron state. For a common experimental setup, the threshold electric fiel...

The aim of this study was to comparatively evaluate the bending resistance at 45º, the static and dynamic cyclic fatigue life, and the fracture type of the WaveOne (Dentsply Maillefer, Ballaigues, Switzerland) 25-08 and Reciproc (VDW, Munich, Germany) 25-08 instruments. A total of 60 nickel-titanium (NiTi) instruments (30 Reciproc and 30 WaveOne) from three different lots, each of which was 25 ...

This study evaluated the effect of grinding protocols and resintering on flexural fatigue limit and surface characterization of LavaTM Y-TZP. Bar-shaped specimens (20×4.0×1.2 mm, n=40; 20×4.0×1.5 mm, n=80) were obtained. Half of the thinner specimens (1.2 mm) constituted the as-sintered group (AS), while the thicker ones (1.5 mm) were ground with diamond burs under irrigation (WG) or not (G). T...

the joints between segmental rings can withstand a certain amount of bending moment as well as axial and shear forces. generally, in the structural analysis of tunnel segmental lining, the joints can be modeled as elastic hinges or rotational springs, and their rigidity should be demonstrated in terms of the rigidity of the joints or their rotational stiffness. therefore, the bending moment act...