Differential phase-Doppler

Rheims, J., Wriedt, T., Bauckhage, K., Working Principle and Experimental Results for a Differential Phase-Doppler Technique, Part. Part./Syst. Charact, 1998, 15,219-224. 

Spray properties are mostly determined with optical measurement techniques. For the analysis of the droplet diameter Shadowgraphic methods, laser diffraction or Phase Doppler Anemometry (PDA) have been used elsewhere [1, 2, 11, 18]. Droplet velocities can be measured with Shadowgraphy, Particle Image Velocimetry (PIV), or PDA [1, 6, 19]. The determination of the spray temperature is possible with Global Rainbow Thermometry (GRT), Planar Laser Induced Fluorescence (PLIF), and Differential Infrared Thermography (DIT) [20-22]. 

By modulating the electric field and using phase-sensitive detection methods, Uehara et al. 8 ) were able to increase the sensitivity considerably and they could even detect Stark splittings of less than the doppler width of the components. Fig. 3 shows the Stark spectrum of HDCO for different electric field strengths. Because of the Stark modulation technique the absorption lines appear differentiated the zero points represent the center of each line. 

Assessment of vascularity can be useful in differentiating benign and malignant breast lesions using color Doppler examination. However, some neoplasms have low blood flow and Doppler may be suboptimal. In these cases, ultrasound contrast may be beneficial. In a phase II/III, multicenter, randomized study 220 patients... 

The temperature distribution in the loop is measured with chromel-alumel thermocouples and two Pt-100 temperature sensors for reference measurements. Absolute pressure is measured at the top of the riser and at the inlet of the core. The liquid level in the steam dome is measured with a differential pressure sensor. The differential pressure over the friction settings of the individual channels is a measure for the flow distribution over the coolant channels and bypass channels. The total flow in the loop is measured at 2 different positions with electromagnetic flow meters. The void fraction at a given height can be measured with gamma transmission techniques. At a fixed height at the top of the riser the radial void distribution is measured with a wire-mesh sensor, which measures the conduction of the two-phase mixture on a two-dimensional grid. Furthermore, laser doppler anemometry is used to study the local liquid velocity in the core or in the riser. 

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