AIM To study continuously cerebral blood flow velocity in the middle cerebral artery before, during, and after tube feeding in neonates. METHOD Cerebral blood flow velocity was measured in 14 neonates using a Doppler ultrasound device. Blood pressure, respiration, and oxygen saturation were monitored. RESULTS Mean blood flow velocity decreased from 37 cm/s before feeding to 33 cm/s (P < 0.0...

We present a family of conforming finite elements for the Stokes problem on general triangular meshes in two dimensions. The lowest order case consists of enriched piecewise linear polynomials for the velocity and piecewise constant polynomials for the pressure. We show that the elements satisfy the inf-sup condition and converges optimally for both the velocity and pressure. Moreover, the pres...

Simultaneous effects of slip and heat transfer on peristaltic transport of an incompressible electrically conducting viscous fluid  in an  asymmetric channel is studied under the assumptions of long wavelength and low Reynold number .The  asymmetry is produced by choosing the peristaltic wave train on the walls to have different amplitudes and phase.Exect solutions for stream function,velocity ...

A new scalar projection method presented for simulating incompressible flows with variable density is proposed. It reverses conventional projection algorithm by computing first the irrotational component of the velocity and then the pressure. The first phase of the projection is purely kinematics. The predicted velocity field is subjected to a discrete Hodge-Helmholtz decomposition. The second ...

This paper proposes a numerical simulation of the incompressible viscous flows with hyper dissipation using Femlab. We propose two variational formulations to solve this problem: the primal and the mixed formulations. For the first one, a biharmonic formulation for the velocity and the pressure is used. The second one uses a mixed formulation where the laplacian of the velocity, the velocity an...

Marques, Koen M. J., Machiel J. van Eenige, Hugo J. Spruijt, Nico Westerhof, Jos Twisk, Cees A. Visser, and Frans C. Visser. The diastolic flow velocity-pressure gradient relation and dpv50 to assess the hemodynamic significance of coronary stenoses. Am J Physiol Heart Circ Physiol 291: H2630–H2635, 2006. First published August 18, 2006; doi:10.1152/ajpheart.00030.2006.—To evaluate the hemodyna...

An experimental investigation is conducted to calculate the shock standoff (SSO) distance in front of an acute-angled wedge. For this experimentation, simple water flows channel analysis is carried out. The flow velocity is varied from 13.2 cm/s to 25.5 cm/s increasing in steps of 1 cm/s. A velocity of 13.2 cm/s corresponds to Froude number 1.13 and velocity of 25.5 cm/s to Froude number 1.41. ...

BACKGROUND While flow convergence methods have been promising for calculating volume flows from color Doppler images, it appears that the velocity threshold used and the transorifice pressure gradient dramatically influence the accuracy of application of the simple hemispheric flow convergence equation for calculation of flow rate. The present in vitro study was performed to determine whether t...

Direct impedance control (DIC) technique used for an electroacoustic absorber in this paper requires a pair of pressure and velocity sensor. However, it can be quite costly to develop array system of this electrostatic absorber for acoustically large space. To overcome this problem, in this paper instead of using velocity sensor, disturbance-observer-type velocity estimator is applied to DIC te...

This paper presents a modified form of the Walker-Anderson (W-A) model for analyzing high velocity penetration of an eroding projectile into a concrete target in which the W-A model is improved by incorporating calculations for the plastic flow field of concrete in terms of its compressibility and strain rate sensitivity under severe pressure. With the changes to and calculations of plastic fie...