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The tuned mass damper (TMD) is a well acclaimed passive control device for vibration control of structures. However, the requirement of a higher mass ratio restricts its applicability for seismic vibration control of civil engineering structures. Improving the performance of TMDs has been attempted by supplementing them with nonlinear restoring devices. In this regard, the ability of shape memory alloy (SMA) in dissipating energy through a hysteretic phase transformation of its microstructure triggered by cyclic loading is notable. An improved version of TMD assisted by a nonlinear shape memory alloy (SMA) spring, referred as SMA-TMD, is studied here for seismic vibration mitigation. Extensive numerical simulations are conducted based on nonlinear random vibration analysis via stochastic linearization of the nonlinear force–deformation hysteresis of the SMA. A design optimization based on minimizing the root mean square displacement of the main structure is also carried out to postulate the optimal design parameters for the proposed system. The viability of the optimal design is verified with respect to its performance under recorded earthquake motions. Significant improvements of the control efficiency and a reduction of the TMD displacement at a much reduced mass ratio are shown to be achieved in the proposed SMA-TMD over those in the linear TMD.

The shape‐memory‐alloy supplemented rubber bearing (SMARB) has been recently proposed as a superior alternative to traditional elastomeric bearing, such as lead‐rubber bearing (LRB), because of the dubious performance of conventional bearings under near‐fault earthquakes. The present study establishes the significant improvement of performances in SMARB over the LRB in isolating multi‐storeyed building frame against earthquakes. The response of the isolated building is evaluated through nonlinear dynamic time‐history analysis under a set of recorded, near‐fault, fault‐normal component of ground motions. The optimal characteristic strengths for both the bearings are obtained through parametric study. The robustness of the improved performances are studied under varying characteristics of the superstructure, isolation bearing, as well as scenarios of seismic loading. It is demonstrated that the improvement of isolation efficiency, accompanied by considerable reduction of peak and residual bearing displacements can be attained by the SMARB over the LRB. The SMARB is also found to be more effective in suppressing transference of high‐frequency components of ground motions to the floor acceleration, which is expected to be beneficial for frequency‐sensitive equipment, mounted on the floors. Copyright © 2013 John Wiley & Sons, Ltd.

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A combination of the newly synthesized and structurally characterized compound, [MoO(O2)2(saloxH)](saloxH2= salicylaldoxime) as catalyst, H2O2 as terminal oxidant and NaHCO3 as co-catalyst when stirred in CH3CN (10 cm3) at room temperature (rt) shows a very pronounced efficiency epoxidation of olefinic compounds, the method being green and economical.

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