Thin solid shell contrast agents bubbles are expected to undergo different volume oscillating behaviors when the acoustic power is increased: small oscillations when the shell remains spherical, and large oscillations when the shell buckles. Contrary to bubbles covered with thin lipidic monolayers that buckle as soon as compressed: the solid shell bubbles resist compression, making the buckling...

We study the asymptotic behavior of one-dimensional functionals associated to the energy of a thin nonlinear elastic spherical shell in the limit of vanishing thickness (proportional to a small parameter) ε and under the assumption of radial deformations. The functionals are characterized by the presence of a nonlocal potential term and defined on suitable weighted functional spaces. The transi...

The main spectral property of a Sonic Crystal structure is a notable sound attenuation related to the Bragg band gaps. This effect is observed in air and makes Sonic Crystals effective noise barriers in a particular frequency range. This performance can be extended to a wider range of frequencies by introducing scatterers supporting multiple resonances of various types. In this paper the sonic ...

We study the asymptotic behavior of functionals associated to the energy of a thin nonlinear elastic spherical shell in the limit of vanishing thickness (proportional to a small parameter) ε and under the assumption of radial deformations. The functionals are characterized by the presence of a nonlocal potential term and defined on suitable weighted functional spaces. The transition shell-membr...

This paper presents the results of an investigation on the effect of a thin low-dielectric material (phantom shell) on measuring the Specific Absorption Rate (SAR) in the frequency range of 3 to 6 GHz. The International Electrotechnical Commission (IEC) has started to develop a SAR measurement procedure in order to cover such frequencies. In the procedure, the SAR is measured in a liquid phanto...

In the present research, free vibration and modal stress analyses of thin circular plates with arbitrary edge conditions, resting on two-parameter elastic foundations are investigated.  Both Pasternak and Winkler parameters are adopted to model the elastic foundation. The differential transform method (DTM) is used to solve the eigenvalue equation yielding the natural frequencies and mode shape...

The work described in this paper is concerned with providing a rational asymptotic analysis for the partial wrinkling bifurcation of thin elastic hemispherical segment which upper rim experiences in-plane circular shearing relative to other edge. mathematical structure associated complex-valued boundary eigenvalue problem revealed by using method matched expansions. Our key result three-term fo...

Using the techniques of linear and quadratic programming, it can be shown that the isostatic response function for the continental United States, computed by Lewis & Dorman (1970), is incompatible with any local compensation model that involves only negative density contrasts beneath topographic loads. We interpret the need for positive densities as indicating that compensation is regional rath...