We show for the first time the dynamical relationship between the generation of magnetic field-aligned electric field (E||) and the temporal changes and spatial gradients of magnetic and velocity shears, and the plasma density in Earth's magnetosphere. We predict that the signatures of reconnection and auroral particle acceleration should have a correlation with low plasma density, and a locali...

A common problem in experimental mechanics is that when a sample is studied in, e.g. a tensile test machine, the sample is often simultaneously exposed to rigid body motions as small deformations occur. These two movements, the rigid body motion and the deformation, are often talked about as displacement fields. The sought deformation field is often in the micrometer range, while rigid body mot...

A new methodology is proposed to estimate displacement fields from pairs of images (reference and strained) that evaluates continuous displacement fields. This approach is specialized to a finite-element decomposition, therefore providing a natural interface with a numerical modeling of the mechanical behavior used for identification purposes. The method is illustrated with the analysis of Port...

Sensitive displacement detection has emerged as a significant technological challenge in mechanical resonators with nanometer-scale dimensions. A novel nanomechanical displacement detection scheme based upon the scattering of focused evanescent fields is proposed. The sensitivity of the proposed approach is studied using diffraction theory of evanescent waves. Diffraction theory results are com...

In this paper, synthetic aperture radar (SAR) data from ENVISAT ASAR ascending, descending and ALOS PALSAR ascending orbits are collected to investigate the coseismic displacements of the Mw 6.4 earthquake occurred in Gaize, Tibet on January 9, 2008 and the Mw 5.9 aftershock on January 16, 2008. Two interferometric phase analysis techniques, i.e., D-InSAR and multi-aperture InSAR, are employed ...

Optical methods that give displacement or strain fields are now emerging significantly in the mechanical sciences. In the Material Research laboratory at École des Mines d'Albi, we have developed a binocular stereovision system that can be used a) to measure the 3D shape of a static object or b) to measure the deformations of an object undergoing some 3D mechanical or thermal stress. In this pa...

In this paper, we develop the second-order two-scale (SOTS) analysis method and numerical algorithm for dynamic thermo-mechanical problems of composite materials with 3-D periodic configuration. In the problem considered, there exists a mutual interaction between the displacement and temperature fields. By the asymptotic expansion of temperature and displacement fields, the cell problems, effec...

Thermo-mechanical deformations of flip-chip interconnections on an organic substrate are investigated by microscopic moiré interferometry. A detailed experimental procedure for microscopic moiré experiments is described and the effect of specimen preparation is discussed. Two identical packages, one with and the other without underfill, are investigated. They are subjected to a uniform thermal ...

For an in-depth understanding of the failure of structural materials the study of deformation mechanisms in the material bulk is fundamental. In situ synchrotron computed laminography provides 3D images of sheet samples and digital volume correlation yields the displacement and strain fields between each step of experimental loading by using the natural contrast of the material. Difficulties ar...