A method is proposed that allows threedimensional (3D) two-component measurements to be made by means of particle image velocimetry (PIV) in any volume illuminated over a finite thickness. The method is based on decomposing the cross-correlation function into various contributions at different depths. Because the technique is based on 3D decomposition of the correlation function and not reconst...

Einstein's theory of relativity establishes that the measurement speed light is constant and invariant in any frame reference. In this article, we will review postulate fulfilled by applying Einstein’s velocity addition for case one spatial dimension (1D). This work may be special usefulness physics students teachers pre-university first-year university levels to introduce relativistic theory.

Measurements of the mean and turbulent flow fields in undular and hydraulic jumps have been acquired with single-camera particle image velocimetry PIV . Three Froude numbers, ranging from 1.4 to 3.0, were studied, and in each case data were collected at numerous streamwise locations. The data from these streamwise locations were subsequently compiled into spatially dense 80,000 grid points “mos...

Two frequency planar Doppler Velocimetry (2ν-PDV) is a modification of the Planar Doppler Velocimetry (PDV) method that allows velocity measurements to be made, quickly and non intrusively, across a plane defined by a laser light sheet. In 2ν-PDV the flow is illuminated sequentially with two optical frequencies, separated by about 700MHz. A single CCD viewing through an iodine absorption cell i...

An unconventional type of electrostatic loudspeaker is presented in this paper. The loudspeaker made of thin, light, and flexible electret material lends itself well to the space-concerned applications. Electrical impedance measurement reveals that the coupling between the electrical system and the mechanical system is weak, which renders conventional parameter identification based on electrica...

Photoacoustic Doppler velocimetry provides a major opportunity to overcome limitations of existing blood flow measuring methods. By enabling measurements with high spatial resolution several millimetres deep in tissue, it could probe microvascular blood flow abnormalities characteristic of many different diseases. Although previous work has demonstrated feasibility in solid phantoms, measuremen...

seismic refraction and downhole survey were employed to study dynamic characteristics of subsurface materials in bam city, southeast of iran. the data acquisition was performed at 160 p and s-wave refraction stations and 15 boreholes in the city. to derive velocity depth sections along these profiles as well as to perform downhole diagrams, seisimager software was used. based on the obtained va...

conclusions large-scale studies on the healthy black african population could assess the relationship between diastolic dyssynchrony and changes in myocardial performance related to racial differences. results the frequency of some dyssynchrony markers was similar to that of other studies. the difference between maximal time-to-peak systolic velocity and minimal time-to-peak systolic velocity w...