Measurement of velocity in rotational flows using ultrasonic anemometry: the flowmeter

In this paper a previously developed theoretical model of the measurement process performed by a transit-time ultrasonic anemometer is applied to a fluid flowing through a circular section pipe. This model considers the influence of the shift of the acoustic pulse trajectory from straight propagation due to the flow on the measured speed. The aim of this work is to estimate the errors induced in the measured velocity by the shift of the acoustic pulse trajectory. Using different duct’s flow models, laminar and turbulent regimes have been analyzed. The results show that neglecting the effect of shift of the acoustic pulse trajectory leads to flow rate measurement underestimation.

Ultrasonic tagging of light: Theory

A theory is provided for the detection efficiency of diffuse light whose frequency is modulated by an acoustical wave. We derive expressions for the speckle pattern of the modulated light, as well as an expression for the signal-to-noise ratio for the detector. The aim is to develop a new imaging technology for detection of tumors in humans. The acoustic wave is focused into a small geometrical volume, which provides the spatial resolution for the imaging. The wavelength of the light wave can be selected to provide information regarding the kind of tumor.

Ultrasonic and X-ray computed tomography characterization of progressive fracture damage in low-porous carbonate rocks

This paper studies the fracturing process in low-porous rocks during uniaxial compressive tests considering the original defects and the new mechanical cracks in the material. For this purpose, five different kinds of rocks have been chosen with carbonate mineralogy and low porosity (lower than 2%). The characterization of the fracture damage is carried out using three different techniques: ultrasounds, mercury porosimetry and X-ray computed tomography. The proposed methodology allows quantifying the evolution of the porous system as well as studying the location of new cracks in the rock samples. Intercrystalline porosity (the smallest pores with pore radius < 1 μm) shows a limited development during loading, disappearing rapidly from the porosimetry curves and it is directly related to the initial plastic behaviour in the stress–strain patterns. However, the biggest pores (corresponding to the cracks) suffer a continuous enlargement until the unstable propagation of fractures. The measured crack initiation stress varies between 0.25 σp and 0.50 σp for marbles and between 0.50 σp and 0.85 σp for micrite limestone. The unstable propagation of cracks is assumed to occur very close to the peak strength. Crack propagation through the sample is completely independent of pre-existing defects (porous bands, stylolites, fractures and veins). The ultrasonic response in the time-domain is less sensitive to the fracture damage than the frequency-domain. P-wave velocity increases during loading test until the beginning of the unstable crack propagation. This increase is higher for marbles (between 15% and 30% from initial vp values) and lower for micrite limestones (between 5% and 10%). When the mechanical cracks propagate unstably, the velocity stops to increase and decreases only when rock damage is very high. Frequency analysis of the ultrasonic signals shows clear changes during the loading process. The spectrum of treated waveforms shows two main frequency peaks centred at low (~ 20 kHz) and high (~ 35 kHz) values. When new fractures appear and grow the amplitude of the high-frequency peak decreases, while that of the low-frequency peak increases. Besides, a slight frequency shift is observed towards higher frequencies.

Correlation between ultrasonic nondestructive inspection and wheel test of 34 retreaded tires. Interim report.

National Highway Traffic Safety Administration, Office of Research and Development, Washington, D.C.

Report of pre and post road test ultrasonic inspection results on 134 passenger tires: final report.

National Highway Traffic Safety Administration, Washington, D.C.

The development of an apparatus for cutting tooth structure by means of ultrasonic vibrations. research progress report.

"Project no. NM 008 015.08"

Guidelines for ultrasonic inspection of hanger pins /

"July 2004."

A semi-automated pulse-echo ultrasonic system for inspecting tires. Interim report.

National Highway Traffic Safety Administration, Office of Research and Development, Washington, D.C.

Ultrasonic inspection of ten retreaded tires and thirty-two casings. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Evaluation of a K. J. Law Model 8300 Ultrasonic Roughness Testing Device. Final report.

Federal Highway Administration, Washington, D.C.

Application study of ultrasonic nondestructive inspection for tire compliance testing. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Ultrasonic detection of overbuffing in retreaded tires. Interim report.

National Highway Traffic Safety Administration, Office of Research and Development, Washington, D.C.

The influence of ultrasonic vibrations upon the physical features of activated sludge.

Thesis (M.S.)--University of Illinois.

Operator, organizational, and intermediate (direct support and general support) maintenance manual (including repair parts and special tools list) : processor, passive signal ultrasonic MX-9443()/FSS-9(V), FSN 6350-228-2548; receiver, passive signal ultrasonic ....

"July 1974."