BACKGROUND Cross-sectional flow-velocity profiles from early mitral flow in 20 patients (10 with mitral regurgitation and 10 with mitral stenosis) were constructed from the velocity data from each point in sequentially delayed two-dimensional digital Doppler ultrasound maps. METHODS AND RESULTS The data suggested that the early mitral flow studied in an apical four-chamber view was variably s...

We present a technique to measure the velocity and flow profiles of a nanofluid in a microfluidic channel. Importantly, we extract the flow velocity from a series of standard brightfield images without employing particle tracking or laser-enhanced methods. Our analysis retrieves the flow information from the image structure function of sub-diffraction limited nanoparticles in suspension. We are...

The Study of heat transfer augmentation in micro scale and electronic packaging systems are some of the paramount areas of the impending universe. In such systems the cooling of the heat sinks are generally achieved through the impingement of air jet. Assuming the air jet to be continues & incompressible fluid, the heat dissipation rate over the target surface seems to either uniform or well ch...

High frequency oscillatory ventilation takes advantage of unique principles of gas flow when respiratory frequencies exceed 3 Hz (180 breaths per minute). These gas flow principles enable the alveolar gas turnover at volumes below or equal to physiologic deadspace. One of these principles is call asymmetrical velocity profile. As Froese and Bryan described in their “State of the Art” article on...

An approach to estimate blood flow cross-sectional velocity profiles in intravital microscopy videos of post-capillary venules is proposed. Given an image sequence, the cross-section upon which the velocity profile is to be estimated is manually chosen. The velocity of each streamline, assumed perpendicular to the chosen cross-section, is estimated separately from other streamlines, except for ...

The velocity profile and pressure gradient of an unsteady state unidirectional MHD flow of Voigt fluids moving between two parallel surfaces under magnetic field effects are solved by the Laplace transform method. The flow motion between parallel surfaces is induced by a prescribed inlet volume flow rate that varies with time. Four cases of different inlet volume flow rates are considered in th...

Mapping of blood velocities across the lumen of the ascending aorta was performed in eight patients during open-heart surgery. A Doppler ultrasound probe was constructed to measure velocities in 2 mm steps from the maximum convexity to the maximum concavity of aorta, 6 to 7 cm above the aortic valve. In five patients with angina and normal aortic valves, velocity profiles were very similar and ...

A theoretical solution is presented for the forced convection heat transfer of a viscoelastic fluid obeying the Giesekus constitutive equation in a concentric annulus under steady state, laminar, and purely tangential flow. A relative rotational motion exists between the inner and the outer cylinders, which induces the flow. A constant temperature was set in both cylinders, in this study. The f...

In this paper, a method by which the fluid velocity profile and the net flow rate in self-wiping co-rotating twin screw extruders can be estimated without determining the pressure gradient has been proposed. The method involves using analytical technique to determine the fluid velocity in the local zones of the extruder such as the down channel and axial velocity and subsequently, the net flow ...