نتایج جستجو برای: and ultrasonic waves

تعداد نتایج: 16859911  

2017
Bin Zhang Yue-Juan Wei Wenyi Liu Yan-Jun Zhang Zong Yao Lihui Zhao Jijun Xiong

The proposed method for measuring the liquid level focuses on the ultrasonic impedance and echo energy inside a metal wall, to which the sensor is attached directly, not on ultrasonic waves that penetrate the gas-liquid medium of a container. Firstly, by analyzing the sound field distribution characteristics of the sensor in a metal wall, this paper proposes the concept of an "energy circle" an...

2012
A. Demčenko R. Akkerman P. B. Nagy

This work considers the characterization of linear PVC acoustic properties using a linear ultrasonic measurement technique and the non-collinear ultrasonic wave mixing technique for measurement of the physical ageing state in PVC. The immersion pulse-echo measurements were used to evaluate phase velocity dispersion and attenuation of longitudinal waves in PVC test specimens. The suggested nonco...

2011
Qin Shen

This study investigates the different types of ultrasonic inspection, when applied to assess the impact damage in Carbon Fiber Reinforced Plastic CFRP laminates. The study surveys the two most used ultrasonic testing approaches first; namely the pulse-echo and the through-transmission modes. Then, the manuscript discusses and analyzes the enhanced ultrasonic testing methods that use the polar s...

Journal: :Ultrasonics sonochemistry 2015
Mohammed Mohsin Mahmoud Meribout

This paper suggests a new ultrasonic-based enhanced oil recovery (EOR) model for application in oil field reservoirs. The model is modular and consists of an acoustic module and a heat transfer module, where the heat distribution is updated when the temperature rise exceeds 1 °C. The model also considers the main EOR parameters which includes both the geophysical (i.e., porosity, permeability, ...

2006
Jose L. Palacios Edward C. Smith Huidong Gao Joseph L. Rose Paul Morrow

A new conceptual non-thermal anti-icing system for helicopter rotor blades is introduced. Theoretical calculations predict that certain ultrasonic modes generated by horizontal shear waves produce sufficient interface stresses between a host structure and ice to remove the accreted ice layer. Experimentally obtained ultrasonic shear dispersion curves are compared to theoretical predictions for ...

2014
Qi Wu Yoji Okabe Kazuya Saito Fengming Yu

In this research, the sensitivity distribution properties of a phase-shifted fiber Bragg grating (PS-FBG) to ultrasonic waves were investigated employing the surface attachment method. A careful consideration was taken and examined by experimental results to explain that the distances and angles between the sensor and ultrasonic source influence not only the amplitudes, but also the initial pha...

2008
Zubin M. Master Thomas E. Michaels Jennifer E. Michaels

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...

2016
Markus RAHAMMER Igor SOLODOV Wolfgang BISLE Dieter SCHERLING Marc KREUTZBRUCK

Vibrothermography, is an established NDT method praised for its fullfield and defect-selective imaging. Especially for cracks and similar damage, defect signals are produced within seconds for a wide variety of materials. Usually high power sonotrodes that are applied with kN pressure are employed in order to maximize ultrasonic excitation of the specimens. An increase in excitation power is us...

2004
Jun Li Lihong V. Wang

An optical imaging technique called ultrasound-modulated optical computed tomography is demonstrated for tomographic imaging of biological tissues. Ultrasound-modulated optical signals are extracted from scattered light to provide projection data for the image reconstruction. A filtered back-projection algorithm is implemented to reconstruct an image reflecting optical tissue properties from an...

2003
A. ALIZAD D. H. WHALEY J. F. GREENLEAF

oscillation of newly coming bubble is between -90 to 90 degrees. Under this condition, the radius of the aggregated bubbles is determined by the ultrasonic wave frequency and the relative phase. Based on the model, numerical analysis is carried out. The Bjerknes force over (x,y) plane is evaluated for two or more bubbles cases. The stability of a couple of aggregated bubbles is also discussed. ...

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