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Conventional lead–rubber bearings (LRB) may have a problem of instability and unrecovered deformation with a strong ground motion. To improve the problems, this study proposed a new concept of an isolation device in which shape memory alloy wires were incorporated in an elastomeric bearing. This study illustrated the behavior of shape memory alloy in tension and discussed the variation of stiffness and stress on the hyteresis curves. A three-span continuous steel bridge was used for seismic analyses to compare the performance of lead–rubber bearings with the proposed bearings. This study showed that large residual deformation of LRB occurred even with a weak ground motion of peak ground acceleration (PGA) of 0.2g. The proposed bearings effectively limited the relative displacement of the deck when tested for the strong ground motions and almost recovered the original undeformed shape. However, the proposed bearing increases the demand on bridge columns compared with the LRB.Key words: shape memory alloy, lead–rubber bearings, seismic bridge analysis, isolation device, residual deformation.

The purpose of this study is to assess the confining effectiveness of shape memory alloy (SMA) wire jackets for concrete. The performance of SMA wire jackets was compared to that of steel jackets. A prestrained martensitic SMA wire was wrapped around a concrete cylinder and then heated by a heating jacket. In the process, a confining stress around the cylinder was developed in the SMA wire due to the shape memory effect; this jacketing method can increase the strength and ductility of the cylinder under an axial compressive load. In this study, NiTi and NiTiNb SMA wires of 1.0 mm in diameter were used for the confinement. Recovery tests were conducted on the wires to assess their recovery and residual stress.The confinement by SMA wire jackets increased the strength slightly and greatly increased the ductility compared to the strength and ductility of plain concrete cylinders. The NiTiNb SMA wire jacket showed better performance than that of the NiTi SMA wire jacket. The confining effectiveness of the SMA wire jackets of this study was estimated to be similar to that of the steel jackets. This study showed the potential of the SMA wire jacketing method to retrofit reinforced concrete columns and protect them from seismic risks.

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Intraoperative monitoring and adjustment of the cuff pressure can reduce POST in patients undergoing thyroidectomy.