Cardiac magnetic resonance (MR) elastography noninvasively provides mechanics-based image contrast. The measurement of mechanical parameters is otherwise possible only by palpation or invasive pressure measurement. Measurement of parameters of myocardial shear stiffness is considered to be diagnostically beneficial especially in patients with diastolic dysfunction due to diffuse myocardial dise...

This paper considers the problem of shear building damage estimation subject to earthquake ground excitation using the Kalman filtering approach. The structural damage is assumed to take the form of reduced elemental stiffness. Two damage estimation algorithms are proposed: one is the multiple model approach via the optimal two-stage Kalman estimator (OTSKE), and the other is the robust two-sta...

The present study evaluates how the soft first story irregularity condition should be defined: (a) as a significant reduction of the lateral shear stiffness of all resisting frames within a given story, as established in the seismic provisions of Mexican building codes or, (b) as a substantial reduction of the lateral shear stiffness of one or more resisting frames within a given story, as prop...

The response of a steel moment resisting frame (MRF) depends on the specifications of its main components, namely the columns, beams and connections. One important connection element which can significantly affect frame behavior is the panel zone (PZ). The PZ is described to be an element mainly subjected to shear stresses and its failure mode is often governed by shear yielding. Several analyt...

The authors have recently demonstrated the shear wave interference patterns created by two coherent vibration sources imaged with the vibration sonoelastography technique. If the two sources vibrate at slightly different frequencies omega and omega+deltaomega, respectively, the interference patterns move at an apparent velocity of (deltaomega/2omega)upsilon(shear), where upsilon(shear) is the s...

The mechanical properties of cultured bovine aortic endothelial cells exposed to a fluid-imposed shear stress were studied using the micropipette technique. The cells, which were attached to a Thermanox plastic substrate, were exposed to a specific steady shear stress of either 10, 30, or 85 dynes/cm2 and for a duration ranging from 0.5 to 24 hours. Morphological changes in shape and orientatio...

We performed molecular dynamics simulations to study the equilibrium and flow properties of a liquid in a nano-channel with confining surfaces coated with a layer of grafted semiflexible polymers. The coverage spans a wide range of grafting densities from essentially isolated chains to dense brushes. The end-grafted polymers were described by a bead spring model with a harmonic potential to inc...

   This paper explores the mechanical properties and fracture analysis of C2N-h2D single-layer sheets using classical molecular dynamics (MD) simulations. Simulations are carried out based on the Tersoff potential energy function within Nose-Hoover thermostat algorithm at the constant room temperature in a canonical ensemble. The influences of boron (B) doping on the mechanical properties, ...

BACKGROUND AND PURPOSE Aneurysm progression and rupture is thought to be governed by progressive degradation and weakening of the wall in response to abnormal hemodynamics. Our goal was to investigate the relationship between the intra-aneurysmal hemodynamic conditions and wall mechanical properties in human aneurysms. MATERIALS AND METHODS A total of 8 unruptured aneurysms were analyzed. Com...