The postperovskite transition in MgSiO(3) at conditions similar to those expected at the D'' discontinuity of Earth's lower mantle offers a paradigm for interpreting the properties of this region. Despite consistent experimental and theoretical predictions of this phase transformation, the complexity of the D'' region raises questions about its geophysical significance. Here we report the therm...

The present investigation was undertak en to obtain some knowledge about the submicroscopic structure of the cornea based on thermoelastic properties and polarization characteristics. Previous workers b have reported that the cornea exhibits a birefringence of uniaxial type. But as their observations were made in parallel polarized light only, it is desirable to make conoscopic observation as w...

The thermal expansion behavior of a metal-formate framework, Zn(HCOO)₂·2(H₂O) (1), has been systematically studied via variable temperature single-crystal X-ray diffraction. Our results demonstrate that this formate exhibits significant negative thermal expansion (NTE, -26(2) MK-1) along its c-axis. Detailed structural analyses reveal that the large NTE response is attributed to the 'hinge-stru...

We report stable systems which exhibit quasistatic stiffness that can be negative or tend to infinity without external constraint. They are based on coupled fields in the non-equilibrium presence of energy flux that is modulated by force. They evade thermodynamic restrictions by relaxing a restrictive assumption: equilibrium. Negative values of physical properties, including compressibility and...

Thermoelastic modeling at nanoscale is becoming more important as devices shrink and heat sources are widely used in modern industries, such nanoelectromechanical systems. However, the conventional thermoelastic theories no longer applicable high-temperature settings. This study provides an insight into thermomechanical features of a nonlocal viscous half-space exposed to cyclic source. Using n...

This work presents the first comprehensive investigation of phonon-electron interactions in bulk acoustic standing wave (BAW) resonators made from piezoelectric semiconductor (PS) materials. We show that these interactions constitute a significant energy loss mechanism and can set practical loss limits lower than anharmonic phonon scattering limits or thermoelastic damping limits. Secondly, we ...

The equations of coupled thermoelasticity are considered in the case of stationary vibrations. The dimensional and order-of-magnitude analysis of the parameters occurring within these equations prompts the introduction of the new non-dimensionalisation scheme, highlighting the nearly-adiabatic nature of the resulting motions. The departure from the purely adiabatic regime is characterised by a ...

In this article thermoelastic damping in nano-beam resonators is investigated based on nonlocal theory of elasticity and the Euler-Bernoulli beam assumptions. The governing equation of deflection of the beam is obtained from shear and moment resultants and stress–strain relationship of the nonlocal elasticity model and also the governing equations of thermoelastic damping are established by usi...

The purpose of this paper is to explain the thermodynamical and shape memory behaviour in comparison with structural parameters for Zr-based intermetallics a new class of potential shape memory alloys (SMA) for high-temperature applications [I]. Electrical resistivity, structural, shape memory and calorimetric measurements were carried out for the Zr2CuNi Zr,CuCo quasibinary cross-section. It w...