Search

Perioperative pain control for hip arthroscopy procedures represents a significant challenge for both surgeons and anesthetists. In light of the opioid crisis, greater emphasis has been placed on multimodal pain control techniques. There is considerable debate regarding regional nerve blockade for hip arthroscopy. Although regional anesthesia has a significant role in perioperative pain management strategies, many of the most common techniques present their own risks and limitations. In particular, the less desirable effects of postoperative weakness in the lower extremity and difficulty with ambulation are commonly produced with standard regional blockades. We present a technique for performing a targeted, sensory nerve block that can be done efficiently and safely in the immediate preoperative period. This block can potentially lower the intraoperative and postoperative opioid requirements without the risks of muscle blockade and falls from other regional anesthesia modalities. [Display omitted] [ABSTRACT FROM AUTHOR]

Mechanical stress occurring during the manufacturing process of electrical machines detrimentally alters the magnetic properties (iron losses and magnetizability). This affects the efficiency and performance of the machine. Improvement of the manufacturing process in terms of reduced magnetic property deterioration enables the full potential of the magnetic materials to be exploited, and as a result, the performance of the machine to be improved. A high quantity of electrical machine components is needed, with shear cutting (punching, blanking) being the most efficient manufacturing technology. The cutting process leads to residual stresses inside the non-oriented electrical sheet metal, resulting in increased iron losses. This paper studies the residual stresses induced by punching with different shear cutting parameters, taking a qualitative approach using finite element analysis. In order to calibrate the finite element analysis, shear cutting experiments are performed. A single sheet tester analysis of the cut blanks allows the correlation between residual stresses, micro hardness measurements, cutting surface parameters and magnetic properties to be studied. [ABSTRACT FROM AUTHOR]

In this work the microstructure development during annealing of AZ31 sheets processed by equal channel angular pressing (ECAP) is presented. Samples with dimensions of 200 × 200 × 1.8 mm 3 were processed in a single ECAP pass at 225 °C using a channel angle of 130°. Subsequent isothermal and isochronal heat treatments were used to reveal the microstructure stability of the ECAPed sheets at temperatures between 180 and 300 °C. A systematic analysis of the microstructure development was conducted using optical microscopy and electron backscatter diffraction (EBSD). It was found that a texture modification produced by the profuse activation of 10 1 - 2 extension twinning during ECAP is lost during annealing as a result of thermal detwinning. Moreover, a bimodal microstructure composed by small and coarse grains was observed at 250 °C and 300 °C as a result of the fast growth of a few grains. The reason for the selective grain growth is related with the activation of strain induced grain boundary migration which was stimulated by the large stored strain contained in the as-ECAP processed sheets. The dissolution of Mg 17 Al 12 particles during annealing is also seen as a possible factor for the onset of rapid grain growth. [ABSTRACT FROM AUTHOR]