A fluid-independent ultrasonic approach for flow determination in microchannels the harsh environment of an ultra high pressure liquid chromatography (UHPLC) system is presented. Ultrasonic waves fluid are excited by separate media surface acoustic (SAW) Rayleigh-Wave type. The LiNbO3 SAW chip being equipped with interdigitated transducers excitation also marks bottom channel and thus allows ve...

Gh. Amza, Z. Apostolescu, Faculty of Engineering and Management of Technological, Polytehnic University of Bucharest, Romania D. Dobrotă, Engineering Faculty, “Constantin Brâncuşi” University of Târgu-Jiu, Romania V. Petrescu, Engineering Faculty, Lucian Blaga University of Sibiu, Romania R. G. Albulescu, The Oil Company, Ploiesti, Romania Plating by welding in an ultrasonic field represents a ...

In this paper a non-destructive method for inspecting jet-engine turbine blades for root cracking is developed. This method utilises 2D ultrasonic arrays to enable the detection and characterisation of sub-surface cracks in three-dimensions. The majority of modern turbine blades are manufactured from single crystals of nickel based superalloys which exhibit high elastic anisotropy. This complic...

In this paper, an ultrasonic shear wave reflection method was adopted to mimic the microstructural evolution of hydrating Portland cement pastes with different water/cement-ratios (0.35, 0.5 and 0.6) cured under a constant temperature of 25°C. The reflection coefficient measured with this technique was correlated to microstructural parameters of the cement pastes. The application of numerical s...

Laser ultrasonic sources and guided wave sensing methods, using sub-wavelength miniature sensors, are utilized to nondestructively evaluate composite materials. These methods enable in-plane characterization of the ultrasonic signals directional velocities. Additionally, sensing of the guided wave modes changes, in the geometrically complex composite structures, enables detection of the materia...

The critical subject of transverse crack detection in a rail head is treated in this paper. Conventional bulk wave ultrasonic techniques often fail because of shelling and other surface imperfections that shield the defects that lie below the shelling. A guided wave inspection technique is introduced here that can send ultrasonic energy along the rail under the shelling with a capability of fin...

OBJECTIVE Estimates of ultrasonic attenuation (the loss of energy as an ultrasonic wave propagates through tissue) have been used to evaluate the structure and function of tissues in health and disease. The purpose of this research was to develop a method to estimate ultrasonic cervical attenuation during human pregnancy using a clinical ultrasound system. METHODS Forty women underwent a cerv...

The method of Acoustic Wavefield Imaging (AWI) offers many advantages over conventional ultrasonic techniques for nondestructive evaluation, and also provides a means of incorporating fixed ultrasonic sensors used for structural health monitoring into subsequent inspections. AWI utilizes these fixed sensors as wave sources and an externally scanned ultrasonic transducer (or laser interferometer...

Hepatic vein stenosis after liver transplantation is a relatively rare complication that could even result in graft loss. However, it is difficult to arrive at a definite diagnosis at the early stage of postoperation, and there are few researches on ultrasonic shear wave elastography in the diagnosis of hepatic vein stenosis. We report the case of an 11-year-old male patient with cirrhosis due ...

The market for process instruments generally requires low cost devices that are robust, small in size, portable, and usable in-plant. Ultrasonic torsional guided wave sensors have received much attention by researchers for measurement of viscosity and/or density of fluids in recent years. The supporting electronic systems for these sensors providing many different settings of sine-wave signals ...