BACKGROUND The accuracy of vector flow mapping (VFM) was investigated in comparison to stereo particle image velocimetry (stereo-PIV) measurements using a left ventricular phantom. VFM is an echocardiographic approach to visualizing two-dimensional flow dynamics by estimating the azimuthal component of flow from the mass-conservation equation. VFM provides means of visualizing cardiac flow, but...

Controlling the interaction of a robot with a fluid, particularly when the desired behavior is intimately related to the dynamics of the fluid, is a difficult and important problem. Highperformance aircraft cannot ignore nonlinear stall effects, and robots hoping to fly and swim with performance matching that seen in birds and fish cannot treat fluid flows as quasisteady. If we wish to match th...

Digital Particle Imaging Velocimetry (DPIV) is a powerful nonintrusive measuring technique that has become popular in the last decade with the availability of commercial systems. In contrast to Particle Image Velocimetry (PIV), which utilizes analogue imaging and therefore time-consuming post processing, for DPIV digital video recording is encountered which is ideally suited for digital data pr...

A particle image velocimetry (PIV) system has been developed to measure velocity fields with order 1-lm spatial resolution. The technique uses 200 nm diameter flow-tracing particles, a pulsed Nd: YAG laser, an inverted epi-fluorescent microscope, and a cooled interline-transfer CCD camera to record high-resolution particle-image fields. The spatial resolution of the PIV technique is limited pri...

The neural network method uses ideas developed from the physiological modelling of the human brain in computational mechanics. The technique provides mechanisms analogous to biological processes such as learning from experience, generalizing from learning data to a wider set of stimuli and extraction of key attributes from excessively noisy data sets. It has found frequent application in optimi...

OBJECTIVE To examine the performance of screening for trisomies 21, 18 and 13 at 11-13 weeks' gestation using specific algorithms for these trisomies based on combinations of fetal nuchal translucency thickness (NT), fetal heart rate (FHR), ductus venosus pulsatility index for veins (DV PIV), and serum free β-human chorionic gonadotropin (β-hCG), pregnancy-associated plasma protein A (PAPP-A), ...

The viral etiologies of UTRIs and LTRIs in children in Jinan city were investigated between July 2009 and June 2010. Nasal and throat swabs were collected from 397 children with URTIs and bronchoalveolar lavage fluid specimens were collected from 323 children with LRTIs. RT-PCR/PCR was used to examine all samples for IFV, PIV, RSV, RV, hMPV, HBoV, CoV, ADV, RSV, and EV. Viral pathogens were det...

In this paper, a direct experimental comparison is made between scanning and tomo-PIV, on an unsteady wake flow behind a half-cylinder. Several seeding densities are used in order to demonstrate the capacities and limitations of both techniques. For the scanning technique, the effect of particles elongation is investigated and the influence of the seeding density on the volume reconstruction fo...

The size specifications for suitable tracer particles for particle image velocimetry (PIV), particularly with respect to their flow tracking capability, are discussed and quantified for several examples. A review of a wide variety of tracer materials used in recent PIV experiments in liquids and gases indicates that appropriately sized particles have normally been used. With emphasis on gas flo...

Using the CFD model, a new ventilation system design will be found later taking into consideration the ventilation efficiency such as uniformity, stability, and suitability of environmental factors in a naturally ventilated broiler house. Because conducting a field experiment for the ventilation study presented so many difficulties, a reliable 3-dimentional computational fluid dynamics (CFD) mo...