Changes In Ultrasonic Velocity Research Articles

S0302-3-2 塑性変形と熱処理による純銅圧延板の超音波速度変化([S0302-3]超音波非破壊評価の高精度化(3))

S0302-3-2 塑性変形と熱処理による純銅圧延板の超音波速度変化([S0302-3]超音波非破壊評価の高精度化(3))

3P-50 Application of Ultrasonic Velocity-Change Imaging for Diagnosis of Visceral Fat(Poster Session)

3P-50 Application of Ultrasonic Velocity-Change Imaging for Diagnosis of Visceral Fat(Poster Session)

Use of ultrasound spectroscopy to examine the effect of cysteine on β-lactoglobulin interactions

We investigated the effects of cysteine on β-lactoglobulin interactions using ultrasound spectroscopy, rheological measurements, and differential scanning calorimetry. Changes in ultrasonic velocity and attenuation were monitored using ultrasound spectroscopy, and we discuss the effects of cysteine on gel formation together with the results obtained using other methods. A decrease in ultrasonic velocity occurred around 54 °C, suggesting that the compressibility of the system increases at approximately this temperature. An increase in ultrasonic attenuation was observed at approximately 54 °C, which is much lower than the commonly observed denaturation temperature of 75–80 °C. The temperature coincided with the onset of phase transition by differential scanning calorimetry and the initial rise in temperature of dynamic modulus for rheological measurements under heat treatment. We conclude that cysteine promotes the polymerization processes of denatured proteins during the initial stage of gelation. The ultrasonic spectroscopic analysis is a useful tool to monitor protein molecule interactions prior to gelation.

Low Temperature Curing of Metakaolin Concrete

The influence of low temperature curing on the performance of concrete containing metakaolin (MK) is investigated. Portland cement was partially replaced with 0–30% MK. The water to binder ratio was maintained at 0.5 for all mixes. Concretes were subjected to water and air curing at 5°C. Compressive strength was conducted on water cured specimens whereas, ultrasonic pulse velocity and length change were conducted on water and air cured specimens. During the first day of hydration, the concrete strength is substantially reduced especially at high MK content. However, the incorporation of up to 20% MK causes an enhancement in concrete strength beyond 7 days of curing. This increase could be up to 50% depending upon the age of curing and the MK content. After 28 days of curing the relative strength continues to increase. This finding is compared with results obtained in a previous investigation for MK concrete cured at 20°C and analyzed using the maturity method. The incorporation of up to 15% MK causes an increase in linear shrinkage. Beyond 20% MK, the shrinkage is reduced.

20907 Hysteresis change of ultrasonic wave velocity in MR fluid caused by the magnetic field

20907 Hysteresis change of ultrasonic wave velocity in MR fluid caused by the magnetic field

Microstructure and ultrasonic behaviour on thermal heat-treated Al–Li 8090 alloy

Ultrasonic velocity and attenuation measurements have been carried out on the as-received and thermally treated 8090 Al–Li alloys (T8771). Ultrasonic velocities, density and elastic moduli show a maximum at the thermally treated temperature of 463 K due to the influence of δ′ phase precipitation. The decrease in velocity beyond 463 K is associated with the initiation of dissolution of δ′ and δ phases and also the presence of small fraction of S′ phase. Overaging could be identified at 673 K from the changes in ultrasonic velocities and attenuation. The observed pronounced maxima in ultrasonic velocities and minima in attenuation at 470 and 593 K are associated with precipitation of δ′ and S′ phases, respectively.

Lignite humic acids aggregates studied by high resolution ultrasonic spectroscopy

The thermodynamic stability of lignite humic acids (sodium salt) aggregates was studied by high resolution ultrasonic spectroscopy within the temperature interval from 5 to 90°C. The changes in differential ultrasonic velocity (U12) showed strong differences among humic solutions within the concentration range from 0.005 to 10 g L−1. Measurement revealed several transitions which were attributed to the weakening of humic secondary structure. Concentration around 1 g L−1 seemed to be a limit under which the change of the prevalence and importance of hydration occurred. Above this concentration the difference in U12 decreased following the temperature increase which was explained as a dominance of hydrophilic hydration. In contrast, below this concentration, the temperature dependence of U12 resulted in increasing tendency which was attributed to the prevalence of hydrophobic hydration, i.e. uncovering of apolar groups towards surrounding water. Additional experiments in which the humic sample was modified by hydrochloric acid resulted in a slight structural stabilization which lead to the conclusion that humic micelle-like subaggregates form an open-layer assemblies easily accessible for interaction with an extraneous molecule. That was partly verified by addition of propionic acid which brought about even larger reconformation of humic aggregates and exhibition of polar groups towards hydration water.

Non-destructive evaluation methods for degradation of IG-110 and IG-430 graphite

The lifetime extension of in-core graphite components is one of the key technologies for the VHTR. The residual stress in the graphite components caused by neutron irradiation at high temperatures affects their lifetime. Although oxidation damage in the components would not be significant in normal reactor operation, it should be checked as well. To evaluate the degradation of the graphite components directly by a non-destructive analysis, the applicability of the micro-indentation and ultrasonic wave methods were investigated. The fine-grained isotropic graphites of IG-110 and IG-430, the candidate grades for the VHTR, were used in this study. The following results were obtained. (1) The micro-indentation behavior was changed by applying the compressive strain on the graphite. It suggested that the residual stress would be measured directly. (2) The change of ultrasonic wave velocity with 1 MHz by the uniform oxidation could be evaluated by the wave–propagation analysis with wave–pore interaction model. (3) The trend of oxidation-induced strength degradation on IG-110 was expressed by using the proposed uniform oxidation model. The importance of the non-uniformity consideration was indicated.

Measurement of elastic nonlinearity using remote laser ultrasonics and CHeap Optical Transducers and dual frequency surface acoustic waves

A nonlinear ultrasonic technique for evaluating material elastic nonlinearity has been developed. It measures the phase modulation of a high frequency (82 MHz) surface acoustic wave interacting with a low frequency (1 MHz) high amplitude stress inducing surface acoustic wave. A new breed of optical transducers has been developed and used for the generation and detection of the high frequency wave. The CHeap Optical Transducer (CHOT) is an ultrasonic transducer system, optically activated and read by a laser. We show that CHOTs offer advantages over alternative transducers. CHOTs and nonlinear ultrasonics have great potential for aerospace applications. Results measuring changes in ultrasonic velocity corresponding to different stress states of the sample are presented on fused silica and aluminium.

Monitoring the setting of concrete containing blast-furnace slag by measuring the ultrasonic p-wave velocity

Ultrasonic transmission measurements allow the continuous monitoring of the setting of both mortar and concrete samples, which is important to determine for instance the formwork removal time. However, aspects such as the cause of the low initial velocity, the relation between the velocity and the setting times and the effect of cement type or cement replacing additives are still under discussion. Therefore, different concrete compositions with blast-furnace slag were tested by traditional as well as ultrasonic measurements. The ultrasonic method gives a more complete picture of the setting. The change of ultrasonic velocity in time is sensitive to the differences in setting behaviour of the tested mixtures. The initial setting seems to correspond with the inflection point of the velocity-vs.-time graphs and the final setting with the point at which the velocity increase levels off.

2P7a-14 Basic Investigation for Detection of Early Cancer by Optically Assisted Ultrasonic Velocity Change Imaging(Poster Session)

2P7a-14 Basic Investigation for Detection of Early Cancer by Optically Assisted Ultrasonic Velocity Change Imaging(Poster Session)

PROPERTIES OF ULTRASONIC PROPAGATION IN FUNCTIONAL FLUIDS UNDER MAGNETIC FIELDS

The properties of ultrasonic propagation velocity in water-based and kerosene-based magnetic fluids and an MR fluid are examined experimentally. The ultrasonic frequency used is 1 MHz and the measurement scheme is based on the pulse method. The external magnetic field intensity is varied from 0 mT to 550 mT and is swept at a constant rate dB/dt (sweep rate). The ultrasonic propagation velocity changes with applied magnetic field and hysteresis is observed. The properties of ultrasonic propagation seem to be highly influenced by the formation of chain-like clusters (in the magnetic fluids) and robust clusters (in the MR fluid).

Real-Time Determination of Structural Changes of Sodium Caseinate-Stabilized Emulsions Containing Pectin Using High Resolution Ultrasonic Spectroscopy

The interactions that lead to structure transitions in oil-in-water emulsions were investigated using high-resolution ultrasonic spectroscopy. High methoxyl pectin (HMP) was added to the emulsions at various concentrations and the dynamics of aggregation induced by changes in pH were observed. Two independent ultrasonic parameters, velocity and attenuation, were measured as a function of time or pH. At pH 6.8, both velocity and attenuation of sound changed as a function of HMP concentration. During acidification, caused by the addition of glucono-δ-lactone, there were small changes in the overall ultrasonic velocity, but it was possible to relate these changes to the structural changes in the emulsion. The values of ultrasonic attenuation decreased at high pH with increasing amount of HMP, indicating changes in the flocculation state of the oil droplets caused by depletion forces. During acidification at pH 5.4, emulsions containing HMP showed a steep increase in the ultrasonic attenuation, and this pH corresponds to the pH of association of HMP with the casein-covered oil droplets. The adsorption of HMP onto the interface causes a rearrangement of the oil droplets, and the emulsions containing sufficient amounts of HMP no longer gel at acid pH. This is well described by the ultrasonic attenuation changes in the various emulsions. This research demonstrated for the first time that ultrasonic spectroscopy can be employed for in situ monitoring and analysis of acid-induced destabilization of food emulsions.

Dependence of Localized Deformation on Point Defect Development Caused by Intersected Cross Slip among Dislocations

In this paper, via experimental results of ultrasonic wave velocity changes and FEPM simulations of slip system under the pure shear plastic deformation of a pure Aluminum single crystal, the authors verify that the ultrasonic longitudinal wave velocity depends upon the development of point defects caused by intersected cross slip among dislocations and also examine the correlation of the point defect dependence of the longitudinal wave velocity with the elastic stiffness degradation due to plastic deformation damage which is closely related to the deformation instability mechanism.

Laser-ultrasonic monitoring of ferrite recovery in ultra low carbon steel

The static recovery kinetics of warm deformed ferrite have been characterized by a combination of in situ laser ultrasonics and stress relaxation measurements. During recovery the ultrasonic velocity change decreased whilst the ultrasonic attenuation generally remained constant. The velocity change was explained in terms of dislocation damping, whilst for the attenuation the results were due to a combination of grain scattering and dislocation damping. From the ultrasonic velocity and attenuation measurements, the dislocation density and pinning point separation have been determined using a model in the literature. These values have been compared to those obtained from stress relaxation data for the same experimental conditions. The results showed that the difference in calculated dislocation densities differed by one or two orders of magnitude. The difference in the values of pinning point separation was about one order of magnitude. Finally possible reasons for these differences have been discussed with reference to the dislocation structure present during recovery.

Gold nanoparticle distribution monitor for drug delivery system based on optically assisted ultrasonic velocity-change imaging

Optical absorption images of the tissue mimic phantom including gold nanoparticles were obtained by detecting the ultrasonic velocity-change caused by light irradiation. A series of experimental results showed the possibility as a nanoparticle distribution monitor for the drug delivery system.

OS8-2-2 Ultrasonic analysis of clustering structures in magnetic fluid under magnetic field

Experimental results from studies on the properties of ultrasonic propagation velocity and attenuation in hydrocarbon-based magnetic fluid are reported. The ultrasonic frequency used is 2 MHz and the measurement scheme is based on the pulse method. The external magnetic field intensity is varied from 0 to 550 mT and the angle between the magnetic field direction and the direction of ultrasonic wave propagation is adjusted from 0 to 90°. The ultrasonic propagation velocity and attenuation changes are dependent upon the intensity of the magnetic field and the elapsed time of application. Characteristic properties of ultrasonic propagation in magnetic fluid are observed. These particular results seem to be caused by clustering structures in the magnetic fluid. Based on these results, the inner structure of the magnetic fluid is analyzed experimentally and the application of non-contact inspection in opaque fluids by ultrasonic techniques is discussed.

3-03-01 Monitoring Device of Au Nano-Particle Distribution in Living Body by Using Optically Assisted Ultrasonic Velocity-Change Imaging(Wave propagation, Imaging)

3-03-01 Monitoring Device of Au Nano-Particle Distribution in Living Body by Using Optically Assisted Ultrasonic Velocity-Change Imaging(Wave propagation, Imaging)

Comment on “Reappraisal of experimental values of third-order elastic constants of some cubic semiconductors and metals”

In a recent paper A. S. Johal and D. J. Dunstan [Phys. Rev. B 73, 024106 (2006)] have applied multivariate linear regression analysis to the published data of the change in ultrasonic velocity with applied stress. The aim is to obtain the best estimates for the third-order elastic constants in cubic materials. From such an analysis they conclude that uniaxial stress data on metals turns out to be nearly useless by itself. The purpose of this comment is to point out that by a proper analysis of uniaxial stress data it is possible to obtain reliable values of third-order elastic constants in cubic metals and alloys. Cu-based shape memory alloys are used as an illustrative example.

Evaluation of Stress Using Ultrasonic Technique Based on Hilbert-Huang Transform

Pressures vessel are widely used in the modern industry. It is important to measure pressure of vessels. It has been proved that the change of ultrasonic velocity can be used to detect the stress of the material, and the velocity change can be obtained by estimating the time delay of two ultrasonic pulses. In this paper, the Rayleigh wave is selected as the ultrasonic pulse. Because the Rayleigh wave usually contains noise which deteriorates the estimation precision of the time delay, a signal processing method has to be used. Compared with the continuous wavelet transform, the correlative time estimation method based on the Hilbert-Huang Transform is presented in order to calculate the transit time difference. The experiments results show that this method can improve the accuracy of the time estimation.