Heat dissipation per unit volume has grown rapidly, as the size of modern electronic devices has continued to decrease. The air flow induced by an oscillating cantilever blade enhances the heat transfer performance of high heat density devices. The heat transfer improvement mainly depends on the velocity magnitude and distribution of air streams induced by the vibrating blade. Accordingly, this...

We present experimental demonstrations of negative refraction and focusing of ultrasonic waves in twodimensional phononic crystals made of stainless steel rods assembled in a triangular lattice and immersed in a liquid. Negative refraction is achieved for the range of frequencies in the second band, where the directions of the wave vector and group velocity are antiparallel to each other due to...

Methods In 88 consecutive patients (66.9 ± 9.59 years, 63% men) with varying degrees of aortic valve stenosis, high-resolution 3D SSFP images (3D planimetry; 2.0 mm slice thickness, 20 contiguous slices; image matrix, 256 ‘ 209) were acquired with single breath-hold during mid systole and mid diastole. SSFP cine MR imaging (2D planimetry) and velocity-encoded cine MRI (slice thickness, 4.5 mm) ...

Methods Vascular ejection efficiency (VEE) is proportional to the dimensionless ratio of aortic diameter to wavelength of the transmitted blood pulse. The wavelength of ejected blood is proportional to blood wave velocity divided by blood wave frequency measured using phase velocity mapping (PVM) applied to the ascending aorta. Left ventricular function and aortic PVM data were retrospectively ...

Automated eddy detection methods are fundamental tools to analyze eddy activity from the large datasets derived from satellite measurements and numerical model simulations. Existing methods are either based on the distribution of physical parameters usually computed from velocity derivatives or on the geometry of velocity streamlines around minima or maxima of sea level anomaly. A new algorithm...

In this article we analyze the motion of 3-D objects either in terms of image contours or intensity gradients. We make the assumption that the objects viewed are locally rigid and planar. We suppose that the projection is perspective and use the "perspective" velocity vector, which has been introduced by G.L.Scott. We give spatial relations on the "perspective" velocity field both in the case o...

Abstract We use the AREPO numerical code to model structure of a Milky Way like galaxy (MW) via suite simulations composed stellar disc and bulge, dark matter halo, gaseous under isothermal conditions. For each model, we produce longitude velocity ( l-v ) maps gas surface densities extract skeletons main features (arms, bar), contours defining terminal velocities gas. compare these with observa...