Abstract Background: Transcranial Doppler ultrasonography results have not been previously studied in among Iranian sickle cell anemia patients. The present study was performed to evaluate the pattern of intracranial flow velocities among Iranian children with sickle cell anemia and the hematological parameters that can affect the time-averaged mean of maximum velocity in major intracranial...

The traditional range/velocity limitation for blood velocity estimation systems using ultrasound is elucidated. It is stated that the equation is a property of the estimator used, not the actual physical measurement situation, as higher velocities can be estimated by the time domain cross-correlation approach. It is demonstrated that the time domain technique under certain measurement condition...

In this paper, using vortex blob method (VBM), turbulent flow in a channel is studied and physical concepts of turbulence are obtained and discussed. At first, time-averaged velocities,  and , and then their fluctuations are calculated. To clarify turbulence structures, velocity fluctuations and  are plotted. It is observed that turbulence structures occupy different positions and move with con...

background abnormalities in the velocity and pattern of myocardial shortening on tissue doppler imaging (tdi) have been proposed to aid in the noninvasive diagnosis of coronary artery disease (cad). objectives we investigated the diagnostic value of post-systolic shortening (pss), a delayed ejection velocity of the myocardium after the closure of the aortic valve, on tdi in the diagnosis of cad...

In this paper, an approximate solution of sensitivity matrix of required velocity with final velocity constraint is derived using a piecewise linear gravity assumption. The total flight time is also fixed for the problem. Simulation results show the accuracy of the method. Increasing the midway points for linearization, increases the accuracy of the solution, which this, in turn, depends on the...

the goal of this laboratory study is to investigate the effect of pore shapes on seismic wave velocities in carbonate rocks under reservoir conditions. in this research, 41 core plugs of carbonate rocks from oil fields of the southwest of iran were prepared. the compressional and shear wave velocities were measured in both dry and brine saturated samples under several pressures especially reser...

Dynamic compaction is a soil improvement method which has been widely used for the increase of bearing capacity through stress wave propagation during heavy tamping. The cost and time of project implementation can be effectively curtailed by developing a model that can be used in the design of dynamic compaction operations. The numerical models offered so far are mostly one or two-dimensional, ...