Showing papers in "Ultrasonics in 2003"

TL;DR: Theoretical and experimental issues of acquiring dispersion curves for bars of arbitrary cross-section for guided waves have great potential for being applied to the rapid non-destructive evaluation of large structures such as rails in the railroad industry.

TL;DR: Observations show that the primary and secondary nucleation of ice are both possible during the sonocrystallisation of ice.

TL;DR: It was found that 28 kHz frequency US could enhance formation of the fouled layer in both filtration systems of peptone and milk solution, and US-enhanced permeability of membranes was discussed in both membrane systems.

TL;DR: It was found that the high power technique showed the greatest sensitivity to these kissing bonds at low contact pressures, however at high loads conventional longitudinal wave testing was more sensitive.

TL;DR: A novel, noninvasive method for measurement of liquid level in closed metal tanks that are under high pressure, based on the use of ultrasonic Lamb waves propagating along the tank wall, which has been described.

TL;DR: Experiments have been conducted on buried water mains at test sites in the UK to verify the attenuation and velocity dispersion predictions of the fundamental non-torsional modes that propagate down buried iron water pipes.

TL;DR: Preliminary results of hidden corrosion detection in aircraft aluminum structures using a noncontact laser based ultrasonic technique are presented.

TL;DR: T theoretical analysis of Bleustein-Gulyaev surface acoustic wave propagation in a prestressed layered piezoelectric structure finds an almost linear behavior of the relative change in phase velocity versus the initial stress for both surface electrically free and shorted cases.

TL;DR: This paper will analyze the inadequacy of the traditional characterization methods and provide some basic guidelines for properly characterizing piezoelectric materials with extremely high piezOElectric and electromechanical coupling coefficients.

TL;DR: Study of the effect of humidity on the acoustic agglomeration of diesel exhausts particles in the nanometer size range at 21 kHz confirms the benefit of using high-power ultrasound together with humidity to enhance the agglomersation of particles much smaller than 1 micro m.

TL;DR: This paper describes the method and presents examples to illustrate its interests and its efficiency where other techniques fail, for instance in the case of modes possessing energy in layers embedded in the structure.

TL;DR: Quantitative analysis of simulated B-mode images shows that the new method of imaging efficiently improves visibility, detectability, and lateral resolution of low contrast regions.

TL;DR: In this article, a SAFT imaging algorithm is presented which fully accounts for the nature of wave radiation and propagation within anisotropic materials.

TL;DR: The test results indicated that the rate of contaminant extraction increased considerably with increasing sonication power up to the level where cavitation occurred.

TL;DR: It was concluded that absorption in polymer gel dosimeters is due to a number of relaxation processes which may include polymer-solvent interactions as well as relaxation due to motion of polymer side groups.

TL;DR: A KLM model has been developed using equivalent circuits to analyze the effects of different loss mechanisms on the transducer performance in the time and frequency domain and results are in good agreement with the theoretical simulation.

TL;DR: In the high crack depth to wavelength ratio (a/lambda(R)) regime, the finite element and experimental results close to the crack approach the limiting value of the reflection coefficient from a 90 degrees corner.

TL;DR: The results obtained using infrared spectroscopy for both the systems also support the occurrence of complex formation through intermolecular hydrogen bonding in these ternary liquid mixtures.

TL;DR: A novel approach termed time gating frequency analysis (TGFA) is described that provides the transduction factor of the hydrophone probes in the frequency domain and significantly extends the quasi-continuous calibration of the probes up to 60 MHz.

TL;DR: The edge resonance is linked to the strong increase in amplitude of two complex Lamb waves, and the edge mode is proved to radiate into the plate as the first symmetrical Lamb mode S(0).

TL;DR: Experiments indicate a potential improvement of the concentration limit of detection of 10(4) compared to current CE systems, andoretical calculations show room for further improvement.

TL;DR: The present paper deals with the detailed description of the signal processing that is used in the spectroscopy method that allows measurement over a broadband frequency spectrum in a strong absorbing and high dispersive medium.

TL;DR: Viscous frequencies in bone are found to be several orders of magnitude greater than calculated critical frequencies, and it is probable megahertz frequencies would be needed for observation of two waves in vivo.

TL;DR: ZnO/90 degrees rotated ST-cut quartz structure of Love wave sensors with high sensitivity of viscosity and conductivity in liquid circumstance and TCF of quartz is compensated by ZnO film is reported.

TL;DR: Simulation and ex vivo experimental results indicate that the USAE frequency shift method can help decouple the mechanical from the acoustical parameter dependence as well as detect the onset of thermal coagulative necrosis.

TL;DR: How a spatial light modulator may be used to adapt the generating optical distribution to compensate for the material properties is demonstrated, which facilitates simpler alignment and velocity matching and will allow real-time adjustment of the generating source to enable imaging on anisotropic materials.

TL;DR: The effects of two different sonic exposures on two vegetables at two growth stages, including seedlings and mature plants were investigated, with significant elevations in the level of polyamines (PAs) and increased uptake of oxygen O(2) in comparison with the controls.

TL;DR: A nondestructive method for estimating the fracture toughness of CrMoV steels used as the rotor material of steam turbines in power plants was developed, and the fracture appearance transition temperature (FATT) was determined as a function of aging time.

TL;DR: An experimental method was developed to determine effective diameter of circular aperture hydrophones to be determined as a quasi-continuous function of frequency up to 40 MHz, successfully employed in the development of spatial averaging correction algorithms.

TL;DR: This paper describes a novel approach to estimate broadband ultrasound attenuation (BUA) in a bone structure in human in vivo using coded excitation, an accepted indicator for assessment of osteoporosis and examines the properties of three different transmission schemes, based on Barker code, chirp and Golay code.