In this work, we are concerned with the inverse scattering by interfaces for the linearized and isotropic elastic model at a fixed frequency. First, we derive complex geometrical optic solutions with linear or spherical phases having a computable dominant part and an H α-decaying remainder term with α < 3, where H α is the classical Sobolev space. Second, based on these properties, we estimate ...

Adhesive organs on the legs of arthropods and vertebrates are strongly direction dependent, making contact only when pulled towards the body but detaching when pushed away from it. Here we show that the two types of attachment pads found in cockroaches (Nauphoeta cinerea), tarsal euplantulae and pretarsal arolium, serve fundamentally different functions. Video recordings of vertical climbing re...

We have shown that leukocytes retract their pseudopods and detach from substrates after exposure to physiological fluid shear stresses ( approximately 1.5 dyn/cm(2)). In inflammation, however, pseudopod projection during spreading and firm adhesion on endothelium is observed even in microvessels with normal blood flow and fluid shear stresses. Thus, we examined mechanisms that may serve to regu...

The shear textures that develop in friction stir welds are reviewed and discussed. In all the materials examined, including face centred cubic (fcc), body centred cubic (bcc) and hexagonal close-packed (hcp) materials, friction stir welding produces a predominant shear texture with the close-packed directions aligned with the shear direction (SD) and the close-packed plane normal perpendicular ...

In the present study, plate impact pressure±shear friction experiments are conducted to provide insight into timeresolved dry sliding characteristics of metal on metal at normal pressures of approximately 1.5 GPa, slip speeds up to 60 m/s and interfacial temperatures as high as 8008C. The plate impact friction experiments represent a signi®cant improvement over conventional dynamic friction exp...

Stiffness matrix of the four-node quadrilateral plane stress element is decomposed into normal and shear components. A computer program is developed to obtain the straining modes using adequate and reduced integration. Then a solution for the problem of mixing straining modes is found. Accuracy of the computer program is validated by a closed-form stiffness matrix, derived for the plane rectang...

Left ventricular (LV) epicardial pacing acutely reduces wall thickening at the pacing site. Because LV epicardial pacing also reduces transverse shear deformation, which is related to myocardial sheet shear, we hypothesized that impaired end-systolic wall thickening at the pacing site is due to reduction in myocardial sheet shear deformation, resulting in a reduced contribution of sheet shear t...

In this work, the effect of rock bolt angle on the shear behavior of Rock Bridges is investigated using the particle flow code in two dimensions (PFC2D) for three different Rock Bridge lengths. Firstly, the calibration of PF2D is performed to reproduce the gypsum sample. Then the numerical models with the dimensions of 100 mm * 100 mm are prepared. The Rock Bridge is created in the middle of th...

We propose a fourth-order staggered-grid finite-difference method to study dynamic faulting in three dimensions. The method uses an implementation of the boundary conditions on the fault that allows the use of general friction models including slip weakening and rate dependence. Because the staggered-grid method defines stresses and particle velocities at different grid points, we preserve symm...