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Updated: Mar 17, 2026

High-speed Particle Image Velocimetry Near Surfaces
Published on: June 24, 2013
Terahertz correlation spectroscopy infers particle velocity and rheological properties
Abstract:
Correlation spectroscopy is an analytical technique that can identify the residence time of reflective or fluorescent particles in a measurement spot, allowing particle velocity or diffusion to be inferred. We show that the technique can be applied to data measured with a time-domain terahertz sensor. The speed of reflectors such as silica ballotini or bubbles can thus be measured in fluid samples. Time-domain terahertz sensors can therefore be used, for the first time, to measure rheological properties of optically opaque fluids that contain entrained reflectors, such as polyethylene beads.
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