abstract：:This paper presents a study on the wave surfaces of anisotropic solids. In addition to the classical and real rays, which are defined by the normal to the slowness surfaces, it is obtained complex rays, which are associated to specific inhomogeneous plane waves. Referring to the complex Christoffel's equation and to t...

journal_title：Ultrasonics

authors： Deschamps M,Poncelet O

更新日期：2002-05-01 00:00:00

abstract：:In most of industries as aeronautics, aerospace and nuclear, the main part of the ultrasonic testing is carried out directly in touch with the inspected component. Among others, the cooling piping of French pressurized water reactor comprises many welding components with complex geometry: elbows, butt welds, nozzles. ...

journal_title：Ultrasonics

authors： Roy O,Mahaut S,Casula O

更新日期：2002-05-01 00:00:00

abstract：:Ultrasound has been used to non-destructively assess the quality of many foods such as meat, fish, vegetables and dairy products. This paper addresses the applications of low intensity ultrasonics in the cheese manufacturing processes and highlights the areas where ultrasonics could be successfully implemented in the ...

journal_title：Ultrasonics

authors： Benedito J,Carcel JA,Gonzalez R,Mulet A

更新日期：2002-05-01 00:00:00

abstract：:It is necessary to identify speckled regions in ultrasound images to control adaptive speckle suppression algorithms, for tissue characterisation, and to estimate the elevational separation of B-scans by speckle decorrelation. Previous authors have proposed classification techniques based on second order powers of the...

journal_title：Ultrasonics

authors： Prager RW,Gee AH,Treece GM,Berman LH

更新日期：2002-05-01 00:00:00

abstract：:Aluminium sheet thickness has been calculated from ultrasonic data obtained using a send-receive, radially polarised electromagnetic acoustic transducer (EMAT). Sheets in the thickness range between 0.1 and 0.5 mm have been measured using this non-contact approach at a stand-off of up to 1.5 mm. Normal incidence shear...

journal_title：Ultrasonics

authors： Dixon S,Edwards C,Palmer SB

更新日期：2001-10-01 00:00:00

abstract：:This paper presents a new method of measuring dispersion curves of leaky Lamb waves propagating in a thin plate. The measurement system is based on a lens-less line-focus transducer and its defocusing measurement technique. A new waveform processing method known as V(f, z) method is introduced for analyzing the measur...

journal_title：Ultrasonics

authors： Lee YC

更新日期：2001-06-01 00:00:00

abstract：:An ultrasonic method of acoustic parameter evaluation for porous materials saturated by air (or any other gas) is discussed. The method is based on the evolution of speed of sound and the attenuation inside the material when the static pressure of the gas saturating the material is changed. Asymptotic development of t...

journal_title：Ultrasonics

authors： Moussatov A,Ayrault C,Castagnède B

更新日期：2001-04-01 00:00:00

abstract：:This work is concerned with the reconstruction, from measured (synthetic or real) data, of a 2D penetrable fluid-like object of arbitrary cross-section embedded in a fluid of infinite extent and insonified by a plane acoustic wave. Green's theorem is used to provide a domain integral representation of the scattered fi...

journal_title：Ultrasonics

authors： Guillermin R,Lasaygues P,Sessarego JP,Wirgin A

更新日期：2001-03-01 00:00:00

abstract：:The matrix method for analyzing flexural vibration system is outlined. The displacement, stress and velocity gain of ultrasonic flexural vibration systems are investigated by transfer matrix method. A design method is given for flexural transducer and vibration system. ...

journal_title：Ultrasonics

authors： Zhou G

更新日期：2000-11-01 00:00:00

abstract：:The linear wave equation in a lossless medium is time reversible, i.e., every solution p(x, t) has a temporal mirror solution p(x, -t). Analysis shows that time reversal also holds for the lossless nonlinear wave equation. In both cases, time-reversal invariance is violated when losses are present. For nonlinear propa...

journal_title：Ultrasonics

authors： Hallaj IM,Cleveland R0,Barbone PE,Kargl SG,Roy RA

更新日期：2000-09-01 00:00:00

abstract：:The present investigation concerns the propagation of surface waves at the vacuum-solid interface of a solid which is isotropic and thermoviscoelastic, i.e., for which the effects of heat conductivity need to be taken into account. Calculations show that, in addition to the Rayleigh wave, a thermal surface wave propag...

journal_title：Ultrasonics

authors： Deschamps M,Poncelet O,Dilhaire S,Claeys W

更新日期：2000-07-01 00:00:00

abstract：:In this research, the use of powerful sonification is studied in making the extraction of tannins more efficient. A combined extraction-filtration system using sonification was designed and modelled. Preliminary extraction studies were carried out to show the effect of ultrasound in extraction. In these experiments hi...

journal_title：Ultrasonics

authors： Mantysalo M,Mantysalo E

更新日期：2000-03-01 00:00:00

abstract：:To understand the effect of the sound field on sonochemical luminescence, the exact sound pressure must be determined in each field. In this study it was determined by the Shlieren method, which measures the sound pressure without mixing the sound fields. We compared the efficiency of the sonochemical luminescence in ...

journal_title：Ultrasonics

authors： Yanagida H,Masubuchi Y,Minagawa K,Takimoto J,Ogata T,Koyama K

更新日期：2000-03-01 00:00:00

abstract：:Exposure of Petunia hybrida cell suspensions to ultrasound at a frequency of 2.43 MHz in a standing wave field at an energy density of 70 Jm-3 (pressure amplitude of 0.78 MPa) decreased their mean viability to 35% after 20 min of sonication. A comparison of propagating wave and standing wave treatments at equal freque...

journal_title：Ultrasonics

authors： Böhm H,Anthony P,Davey MR,Briarty LG,Power JB,Lowe KC,Benes E,Gröschl M

更新日期：2000-03-01 00:00:00

abstract：:A new type of optical fiber hydrophone is constructed with a fiber Bragg grating (FBG) based on the intensity modulation of laser light in an FBG under the influence of sound pressure. The FBG hydrophone shows linearity, with dynamic range about 70 dB. It can measure amplitude and phase of an acoustic field in real ti...

journal_title：Ultrasonics

authors： Takahashi N,Yoshimura K,Takahashi S,Imamura K

更新日期：2000-03-01 00:00:00

abstract：:The increasing number of concrete structures with symptoms of premature deterioration due to environmental action demands procedures to estimate the durability of this type of component. Concrete durability is related to porosity, which determines the intensity of interactions of the material with aggressive agents. T...

journal_title：Ultrasonics

authors： Hernandez MG,Izquierdo MA,Ibanez A,Anaya JJ,Ullate LG

更新日期：2000-03-01 00:00:00

abstract：:The film condensation of vapor on a cooled, downward-facing surface is a complex dynamic fluid phenomenon. This paper will describe the theoretical basis, instrumentation approach, and experimental results for a method for ultrasonic monitoring of film condensation. The ultrasound measurement system utilizes a 10 MHz ...

journal_title：Ultrasonics

authors： Pedersen PC,Cakareski Z,Hermanson JC

更新日期：2000-03-01 00:00:00

abstract：:This paper presents the influence of ultrasonic beam ray refraction effect on the internal object structure imaging using the ultrasound transmission tomography method (UTT), in parallel ray projection geometry, for ultrasonic pulse run-time measurements. Simulation calculations carried out using specially elaborated ...

journal_title：Ultrasonics

authors： Opielinski KJ,Gudra T

更新日期：2000-03-01 00:00:00

abstract：:Speckle tracking methods overcome the major limitations of current Doppler methods for flow imaging and quantification: angle dependence and aliasing. In this paper, we review the development of speckle tracking, with particular attention to the advantages and limitations of two-dimensional algorithms that use a singl...

journal_title：Ultrasonics

authors： Bohs LN,Geiman BJ,Anderson ME,Gebhart SC,Trahey GE

更新日期：2000-03-01 00:00:00

abstract：:The frequency dependence of H2O2 generation from H2O by a sonochemical reaction was detected experimentally. The results are in good agreement with previous experimental results, which indicate that in sonochemical reactions, frequencies higher than 90 kHz are more effective than frequencies of several tens of kiloher...

journal_title：Ultrasonics

authors： Sato M,Itoh H,Fujii T

更新日期：2000-03-01 00:00:00

abstract：:The propagation of ultrasound through an austenitic weld is investigated experimentally as well as in a numerical simulation. The weld is insonified at normal incidence to the fusion line with a longitudinal contact transducer. In order to experimentally trace the ultrasound through the weld, slices of different thick...

journal_title：Ultrasonics

authors： Halkjaer S,Sorensen MP,Kristensen WD

更新日期：2000-03-01 00:00:00

abstract：:Even though friction is one of the oldest problems in physics many aspects of friction processes are not clear today. We present an experimental setup, which permits the study of tribological systems by measuring the dissipated heat at the interface of two surfaces during a friction process with a time resolution of 1...

journal_title：Ultrasonics

authors： Schwaller P,Groning P,Schneuwly A,Boschung P,Muller E,Blanc M,Schlapbach L

更新日期：2000-03-01 00:00:00

abstract：:In this paper, an optimization method aimed at designing aperiodic linear sparse arrays is proposed that is based on the stochastic optimization methodology called simulated annealing. Such a method optimizes the positions and the weight coefficients of each element of a linear array in order to obtain a beam pattern ...

journal_title：Ultrasonics

authors： Trucco A

更新日期：2000-03-01 00:00:00

abstract：:An approximate formula has been developed to determine the electromechanical coupling coefficient of the piezoelectric film in a four-layer composite resonator, which includes two electrodes. In this formula, the coupling coefficient can be calculated from the distribution of the effective coupling coefficients, k2eff...

journal_title：Ultrasonics

authors： Zhang Y,Wang Z,Cheeke JD

更新日期：2000-03-01 00:00:00

abstract：:In the present paper, we report the first results concerning a centimetre cantilever driven through non-linear effects in thin magnetostrictive films. Bimorph centimetre beams (24 mm x 5 mm) were designed using 160 microns thick glass and 0.4 micron thick multilayer TbFe/Fe films deposited via RF sputtering, using sev...

journal_title：Ultrasonics

authors： Tiercelin N,Pernod P,Preobrazhensky V V,Le Gall H,Ben Youssef J

更新日期：2000-03-01 00:00:00

abstract：:Two merits of the surface acoustic wave (SAW) device are its high energy density and small size. However, the driving frequency is around 10 MHz or higher. In spite of the difficulties involved with high frequency, the high energy density is attractive for actuator applications. The SAW linear motor's no load speed an...

journal_title：Ultrasonics

authors： Kurosawa MK

更新日期：2000-03-01 00:00:00

abstract：:Acoustic scattering phenomena from complex immersed elastic shells are studied by high-speed Schlieren visualization for spark-generated spherical quasi-Dirac excitations. The situations considered are air-filled cylindrical shells under normal insonification and air-filled cylindrical shells soldered at one end with ...

journal_title：Ultrasonics

authors： Derbesse L,Pernod P,Latard V V,Merlen A,Decultot D,Touraine N,Maze G

更新日期：2000-03-01 00:00:00

abstract：:The location of continuous acoustic emission sources is a difficult problem of non-destructive testing. This article describes one-dimensional location of continuous acoustic emission sources by using an intelligent locator. The intelligent locator solves a location problem based on learning from examples. To verify w...

journal_title：Ultrasonics

authors： Kosel T,Grabec I I,Muzic P

更新日期：2000-03-01 00:00:00

abstract：:For medical high frequency acoustic imaging purposes the reduction in size of a single transducer element for one-dimensional and even more for two-dimensional arrays is more and more limited by fabrication and cabling technology. In the fields of industrial distance measurement and simple object recognition low cost ...

journal_title：Ultrasonics

authors： Eccardt PC,Niederer K

更新日期：2000-03-01 00:00:00

abstract：:The aim of this work was to show the applicability of light diffraction tomography on airborne ultrasound in the frequency range 40 kHz-2 MHz. Seven different air-coupled transducers were measured to show the method's performance regarding linearity, absolute pressure measurements, phase measurements, frequency respon...

journal_title：Ultrasonics

authors： Almqvist M,Holm A,Persson HW,Lindström K

更新日期：2000-01-01 00:00:00

abstract：:A split spectrum processing technique using a novel moving bandwidth minimization (MBM) method was developed to detect multiple specular targets having different spectral characteristics. Mathematical morphology (MM) algorithms were also implemented in order to compare the results. An experimental approach to optimal ...

journal_title：Ultrasonics

authors： Grevillot M,Cudel C,Meyer JJ,Jacquey S

更新日期：1999-09-01 00:00:00

abstract：:Ultrasonic standing wave chambers with acoustic pathlengths of 1.1 and 0.62 mm have been constructed. The chambers were driven at frequencies over the range 0.66-12.2 MHz. The behaviour of 2 microns diameter latex microparticles and 5 microns diameter yeast in the chambers has been elucidated. One (flow) chamber had a...

journal_title：Ultrasonics

authors： Hawkes JJ,Barrow D,Coakley WT

更新日期：1998-08-01 00:00:00

abstract：:The goal standard of contrast echocardiography is the absolute measure of myocardial perfusion using a contrast agent. Actually, several contrast agents are developed. All these agents show left ventricular opacification after intravenous injection. However, none of these agents shows an acceptable enhancement of the ...

journal_title：Ultrasonics

authors： Bouakaz A,de Jong N,Cachard C,Jouini K

更新日期：1998-02-01 00:00:00

abstract：:Ultrasonic techniques have been used to measure the elastic properties of bone. Eight human tibiae were used to determine and map the elastic properties of cortical and cancellous bone. The present study shows cortical bone to be at least orthotropic in its material symmetry. The mechanical properties of cortical bone...

journal_title：Ultrasonics

authors： Rho JY

更新日期：1996-12-01 00:00:00

abstract：:Reflections of 4 MHz ultrasound pulses from 60 sites on 15 human aorta specimens were analysed using the plane-wave Born approximation (PWBA) inverse scattering method. The recovered high-resolution acoustic impedance profile for each site was correlated with an analysis (by microscope) of sections taken from that sit...

journal_title：Ultrasonics

authors： Tobocman W,Santosh K,Carter JR,Haacke EM

更新日期：1995-07-01 00:00:00

abstract：:Human umbilical cords were exposed to high amplitude focussed ultrasonic pulses with focal energy densities 0.6 and 0.4 mJ mm-2. The endothelium of the exposed vessel (vein) was examined by means of confocal laser scanning microscopy and scanning electron microscopy. The degree of tissue change ranged from the inducti...

journal_title：Ultrasonics

authors： Seidl M,Steinbach P,Wörle K,Hofstädter F

更新日期：1994-09-01 00:00:00

abstract：:B-Scan images have been used as a means of detecting the onset of cavitation in tissues. New echoes appearing during simultaneous sonication with therapeutic ultrasound have often been attributed to bubble formation. In this study temperature rises up to 15 degrees C W-1 cm2 in guinea pig leg (post-mortem) were found,...

journal_title：Ultrasonics

authors： Watmough DJ,Davies HM,Quan KM,Wytch R,Williams AR

更新日期：1991-07-01 00:00:00

abstract：:An electrical sensory perception threshold technique has been developed for use with human volunteers. This technique has been used to reproducibly quantify the effects of three different commercially available topical anaesthetic preparations on superficial sensory cells (nociceptors) in the skin. Low intensities (0....

journal_title：Ultrasonics

authors： Williams AR

更新日期：1990-05-01 00:00:00

abstract：:Experimental results of ultrasound of varying frequency (0.8-5.0 MHz) propagating in cold drawn wires of stainless steel and aluminium ranging in diameter from 0.25 to 1.21 mm are in close agreement with theoretical predictions. This agreement is maintained when the coupling medium between the wire and the ultrasound ...

journal_title：Ultrasonics

authors： Nicholson NC,McDicken WN,Anderson T

更新日期：1989-03-01 00:00:00

abstract：:The attenuation of ultrasound in homogenates of bovine skeletal muscle and suspensions of myofibrils was measured over the frequency range 1.5-7 MHz, and found to be proportional to protein concentration in both. In the homogenates it varied with frequency and temperature in a similar way to the attenuation in post ri...

journal_title：Ultrasonics

authors： Shore D,Miles CA

更新日期：1988-07-01 00:00:00