A new approach to correct yaw misalignment in the spinning ultrasonic anemometer

NASA Astrophysics Data System (ADS)

Ghaemi-Nasab, M.; Davari, Ali R.; Franchini, S.

2018-01-01

Single-axis ultrasonic anemometers are the modern instruments for accurate wind speed measurements. Despite their widespread and ever increasing applications, little attention has been paid up to now to spinning ultrasonic anemometers that can accurately measure both the wind speed and its direction in a single and robust apparatus. In this study, intensive wind-tunnel tests were conducted on a spinning single-axis ultrasonic anemometer to investigate the yaw misalignment in ultrasonic wind speed measurements during the yaw rotation. The anemometer was rotating inside the test section with various angular velocities, and the experiments were performed at several combinations of wind speed and anemometer angular velocity. The instantaneous angular position of the ultrasonic signal path with wind direction was measured using an angular position sensor. For a spinning anemometer, the circulatory wake and the associated flow distortion, along with the Doppler effect, impart a phase shift in the signals measured by the anemometer, which should be added to the position data for correcting the yaw misalignment. In this paper, the experimental data are used to construct a theoretical model, based on a response surface method, to correct the phase shift for various wind speeds and anemometer rotational velocities. This model is shown to successfully correct the velocity indicated by the spinning anemometer for the phase shift due to the rotation, and can easily be used in the calibration process for such anemometers.

In-plane ultrasonic velocity measurement of longitudinal and shear waves in the machine direction with transducers in rotating wheels

DOEpatents

Hall, M.S.; Jackson, T.G.; Knerr, C.

1998-02-17

An improved system for measuring the velocity of ultrasonic signals within the plane of moving web-like materials, such as paper, paperboard and the like. In addition to velocity measurements of ultrasonic signals in the plane of the web in the MD and CD, one embodiment of the system in accordance with the present invention is also adapted to provide on-line indication of the polar specific stiffness of the moving web. In another embodiment of the invention, the velocity of ultrasonic signals in the plane of the web are measured by way of a plurality of ultrasonic transducers carried by synchronously driven wheels or cylinders, thus eliminating undue transducer wear due to any speed differences between the transducers and the web. In order to provide relatively constant contact force between the transducers and the webs, the transducers are mounted in a sensor housings which include a spring for biasing the transducer radially outwardly. The sensor housings are adapted to be easily and conveniently mounted to the carrier to provide a relatively constant contact force between the transducers and the moving web. 37 figs.

In-plane ultrasonic velocity measurement of longitudinal and shear waves in the machine direction with transducers in rotating wheels

DOEpatents

Hall, Maclin S.; Jackson, Theodore G.; Knerr, Christopher

1998-02-17

An improved system for measuring the velocity of ultrasonic signals within the plane of moving web-like materials, such as paper, paperboard and the like. In addition to velocity measurements of ultrasonic signals in the plane of the web in the MD and CD, one embodiment of the system in accordance with the present invention is also adapted to provide on-line indication of the polar specific stiffness of the moving web. In another embodiment of the invention, the velocity of ultrasonic signals in the plane of the web are measured by way of a plurality of ultrasonic transducers carried by synchronously driven wheels or cylinders, thus eliminating undue transducer wear due to any speed differences between the transducers and the web. In order to provide relatively constant contact force between the transducers and the webs, the transducers are mounted in a sensor housings which include a spring for biasing the transducer radially outwardly. The sensor housings are adapted to be easily and conveniently mounted to the carrier to provide a relatively constant contact force between the transducers and the moving web.

Cavitation Bubble Streaming in Ultrasonic-Standing-Wave Field

NASA Astrophysics Data System (ADS)

Nomura, Shinfuku; Mukasa, Shinobu; Kuroiwa, Masaya; Okada, Yasuyuki; Murakami, Koichi

2005-05-01

The mechanism of cavitation bubble streaming by ultrasonic vibration in a water tank was experimentally investigated. A standard ultrasonic cleaner unit with a resonant frequency of 40 kHz was used as an ultrasonic generator. The behavior of the streaming was visualized by the schlieren method and sonochemical luminescence, and the velocity of the streaming was measured by laser Doppler velocity measurement equipment (LDV). The cavitation bubble streaming has two structures. A cavitation cloud, which consists of many cavitation bubbles, is shaped like a facing pair of bowls with a diameter of approximately 1/3 the wavelength of the standing wave, and moves inside the standing-wave field with a velocity of 30 to 60 mm/s. The cavitation bubbles move intensely in the cloud with a velocity of 5 m/s at an ultrasonic output power of 75 W. The streaming is completely different from conventional acoustic streaming. Also the cavitation bubble is generated neither at the pressure node nor at the antinode.

Ultrasonic surface measurements at the Porta Nigra, Trier, and the Neptungrotte, Park Sanssouci Potsdam

NASA Astrophysics Data System (ADS)

Meier, Thomas; Auras, Michael; Fehr, Moritz; Köhn, Daniel

2015-04-01

Ultrasonic measurements along profiles at the surface of an object are well suited to characterize non-destructively weathering of natural stone near the surface. Ultrasonic waveforms of surface measurements in the frequency range between 10 kHz and 300 kHz are often dominated by the Rayleigh wave - a surface wave that is mainly sensitive to the velocity and attenuation of S-waves in the upper 0.3 cm to 3 cm. The frequency dependence of the Rayleigh wave velocity may be used to analyze variations of the material properties with depth. Applications of ultrasonic surface measurements are shown for two buildings: the Roman Porta Nigra in Trier from the 3rd century AD and the Neptungrotte at Park Sanssouci in Potsdam designed by von Knobelsdorff in the 18th century. Both buildings belong to the world cultural heritage and restorations are planned for the near future. It is interesting to compare measurements at these two buildings because they show the applicability of ultrasonic surface measurements to different natural stones. The Porta Nigra is made of local sandstones whereas the facades of the Neptungrotte are made of Carrara and Kauffunger marble. 71 and 46 surface measurements have been carried out, respectively. At both buildings, Rayleigh-wave group velocities show huge variations. At the Porta Nigra they vary between ca. 0.4 km/s and 1.8 km/s and at the Neptungrotte between ca. 0.7 km/s and 3.0 km/s pointing to alterations in the Rayleigh- and S-wave velocities of more than 50 % due to weathering. Note that velocities of elastic waves may increase e.g. because of the formation of black crusts like at the Porta Nigra or they may be strongly reduced due to weathering. The accuracy of the ultrasonic surface measurements, its reproducibility, and the influence of varying water saturation are discussed. Options for the analysis of ultrasonic waveforms are presented ranging from dispersion analysis to full waveform inversions for one-dimensional and two-dimensional models of the outermost layers of the object under investigation. Furthermore, results of non-destructive ultrasonic surface measurements are compared to results of destructive investigation techniques.

Airborne ultrasonic inspection in carbon/carbon composite materials

NASA Astrophysics Data System (ADS)

Yang, In-Young; Kim, Young-Hun; Park, Je-Woong; Hsu, David K.; Song, Song-Jin; Cho, Hyun-Jun; Kim, Sun-Kyu; Im, Kwang-Hee

2007-07-01

In this work, a carbon/carbon (C/C) composite material was nondestructively characterized with non-contact ultrasonic methods using automated acquisition scanner as well as contact ultrasonic measurement because (C/C) composite materials have obvious high price over conventional materials. Because of permeation of coupling medium such as water, it is desirable to perform contact-less nondestructive evaluation to assess material properties and part homogeneity. Also through transmission mode was performed because of the main limitation for air-coupled transducers, which is the acoustic impedance mismatch between most materials and air. Especially ultrasonic images and velocities for C/C composite disk brake was measured and found to be consistent to some degree with the non-contact and contact ultrasonic measurement methods. Low frequency through-transmission scans based on both amplitude and time-of-flight of the ultrasonic pulse were used for mapping out the material property inhomogeneity. Measured results were compared with those obtained by the motorized system with using dry-coupling ultrasonics and through transmission method in immersion. Finally, results using a proposed peak-delay measurement method well corresponded to ultrasonic velocities of the pulse overlap method.

Investigation of magnetic transitions through ultrasonic measurements in double-layered CMR manganite La1.2Sr1.8Mn2O7

NASA Astrophysics Data System (ADS)

Reddy, Y. S.; Vishnuvardhan Reddy, C.

2014-03-01

A polycrystalline, double-layered, colossal magnetoresistive manganite La1.2Sr1.8Mn2O7 is synthesized by sol-gel process and its magnetic and ultrasonic properties were investigated in the temperature range 80-300 K. The sample has Curie temperature at 124 K, where the sample exhibits a transition from paramagnetic insulator to ferromagnetic metallic state. The longitudinal sound velocity measurements show a significant hardening of sound velocity below TC, which may be attributed to the coupling between ferromagnetic spins and longitudinal acoustic phonons. The magnetization and ultrasonic studies reveal the presence of secondary transition at ≈ 260 K in this sample. The present sound velocity measurement results confirm the reliability of ultrasonic investigations as an independent tool to probe magnetic transitions in manganites.

Use of Ultrasonic Technology for Soil Moisture Measurement

NASA Technical Reports Server (NTRS)

Choi, J.; Metzl, R.; Aggarwal, M. D.; Belisle, W.; Coleman, T.

1997-01-01

In an effort to improve existing soil moisture measurement techniques or find new techniques using physics principles, a new technique is presented in this paper using ultrasonic techniques. It has been found that ultrasonic velocity changes as the moisture content changes. Preliminary values of velocities are 676.1 m/s in dry soil and 356.8 m/s in 100% moist soils. Intermediate values can be calibrated to give exact values for the moisture content in an unknown sample.

Ultrasonic velocity profiling rheometry based on a widened circular Couette flow

NASA Astrophysics Data System (ADS)

Shiratori, Takahisa; Tasaka, Yuji; Oishi, Yoshihiko; Murai, Yuichi

2015-08-01

We propose a new rheometry for characterizing the rheological properties of fluids. The technique produces flow curves, which represent the relationship between the fluid shear rate and shear stress. Flow curves are obtained by measuring the circumferential velocity distribution of tested fluids in a circular Couette system, using an ultrasonic velocity profiling technique. By adopting a widened gap of concentric cylinders, a designed range of the shear rate is obtained so that velocity profile measurement along a single line directly acquires flow curves. To reduce the effect of ultrasonic noise on resultant flow curves, several fitting functions and variable transforms are examined to best approximate the velocity profile without introducing a priori rheological models. Silicone oil, polyacrylamide solution, and yogurt were used to evaluate the applicability of this technique. These substances are purposely targeted as examples of Newtonian fluids, shear thinning fluids, and opaque fluids with unknown rheological properties, respectively. We find that fourth-order Chebyshev polynomials provide the most accurate representation of flow curves in the context of model-free rheometry enabled by ultrasonic velocity profiling.

Numerical experiment for ultrasonic-measurement-integrated simulation of three-dimensional unsteady blood flow.

PubMed

Funamoto, Kenichi; Hayase, Toshiyuki; Saijo, Yoshifumi; Yambe, Tomoyuki

2008-08-01

Integration of ultrasonic measurement and numerical simulation is a possible way to break through limitations of existing methods for obtaining complete information on hemodynamics. We herein propose Ultrasonic-Measurement-Integrated (UMI) simulation, in which feedback signals based on the optimal estimation of errors in the velocity vector determined by measured and computed Doppler velocities at feedback points are added to the governing equations. With an eye towards practical implementation of UMI simulation with real measurement data, its efficiency for three-dimensional unsteady blood flow analysis and a method for treating low time resolution of ultrasonic measurement were investigated by a numerical experiment dealing with complicated blood flow in an aneurysm. Even when simplified boundary conditions were applied, the UMI simulation reduced the errors of velocity and pressure to 31% and 53% in the feedback domain which covered the aneurysm, respectively. Local maximum wall shear stress was estimated, showing both the proper position and the value with 1% deviance. A properly designed intermittent feedback applied only at the time when measurement data were obtained had the same computational accuracy as feedback applied at every computational time step. Hence, this feedback method is a possible solution to overcome the insufficient time resolution of ultrasonic measurement.

ULTRASONIC NEUTRON DOSIMETER

DOEpatents

Truell, R.; de Klerk, J.; Levy, P.W.

1960-02-23

A neutron dosimeter is described which utilizes ultrasonic waves in the megacycle region for determination of the extent of neutron damage in a borosilicate glass through ultrasonic wave velocity and attenuation measurements before and after damage.

An ultrasonic technique for measuring stress in fasteners

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stevens, K. J.; Day, P.; Byron, D.

1999-12-02

High temperature bolting alloys are extensively used in the thermal power generation industry as for example, reheat ESV and Governor valve studs. Remnant life assessment methodologies and plant maintenance procedures require the monitoring of the operational stress levels in these fasteners. Some conventional ultrasonic techniques require longitudinal wave measurements to be undertaken when the nut on the bolt is loosened and then re-tightened. Other techniques use a combination of shear waves and longitudinal waves. In this paper, the problems and pitfalls associated with various ultrasonic techniques for measuring stress in bolts, is discussed. An ultrasonic technique developed for measuring themore » stress in Durehete 1055 bolts is presented. Material from a textured rolled bar has been used as a test bed in the development work. The technique uses shear wave birefringence and compression waves at several frequencies to measure texture, fastener length and the average stress. The technique was developed by making ultrasonic measurements on bolts tensioned in universal testing machines and a hydraulic nut. The ultrasonic measurements of residual stress have been checked against strain gauge measurements. The Durehete bolts have a hollow cylinder geometry of restricted dimensions, which significantly alters compression and shear wave velocities from bulk values and introduces hoop stresses which can be measured by rotating the polarization of the shear wave probe. Modelling of the experimental results has been undertaken using theories for the elastic wave propagation through waveguides. The dispersion equations allow the velocity and length of the fastener to be measured ultrasonically in some situations where the length of the fastener can not be measured directly with a vernier caliper or micrometer and/or where it is undesirable to loosen nuts to take calibration readings of the shear and compression wave velocities.« less

Active ultrasonic cross-correlation flowmeters for mixed-phase pipe flows

NASA Astrophysics Data System (ADS)

Sheen, S. H.; Raptis, A. C.

Two ultrasonic flowmeters which employ the active cross-correlation technique and use a simple clamp-on transducer arrangement are discussed. The flowmeter for solid/liquid flows was tested over a wide range of coal concentration in water and oil. The measured velocity based on the peak position of the cross-correlation function is consistently higher by about 15% than the average velocity measured by flow diversion. The origin of the difference results mainly from the flow velocity profiles and the transit-time probability distribution. The flowmeter that can measure particle velocity in a solid/gas flow requires acoustic decoupling arrangement between two sensing stations. The measured velocity is mainly associated with the particles near the wall. Performance of both flowmeters is presented.

Method and system of measuring ultrasonic signals in the plane of a moving web

DOEpatents

Hall, Maclin S.; Jackson, Theodore G.; Wink, Wilmer A.; Knerr, Christopher

1996-01-01

An improved system for measuring the velocity of ultrasonic signals within the plane of moving web-like materials, such as paper, paperboard and the like. In addition to velocity measurements of ultrasonic signals in the plane of the web in the machine direction, MD, and a cross direction, CD, generally perpendicular to the direction of the traveling web, therefor, one embodiment of the system in accordance with the present invention is also adapted to provide on-line indication of the polar specific stiffness of the moving web. In another embodiment of the invention, the velocity of ultrasonic signals in the plane of the web are measured by way of a plurality of ultrasonic transducers carried by synchronously driven wheels or cylinders, thus eliminating undue transducer wear due to any speed differences between the transducers and the web. In order to provide relatively constant contact force between the transducers and the webs, the transducers are mounted in a sensor housings which include a spring for biasing the transducer radially outwardly. The sensor housings are adapted to be easily and conveniently mounted to the carrier to provide a relatively constant contact force between the transducers and the moving web.

Method and system of measuring ultrasonic signals in the plane of a moving web

DOEpatents

Hall, M.S.; Jackson, T.G.; Wink, W.A.; Knerr, C.

1996-02-27

An improved system for measuring the velocity of ultrasonic signals within the plane of moving web-like materials, such as paper, paperboard and the like is disclosed. In addition to velocity measurements of ultrasonic signals in the plane of the web in the machine direction, MD, and a cross direction, CD, generally perpendicular to the direction of the traveling web, therefore, one embodiment of the system in accordance with the present invention is also adapted to provide on-line indication of the polar specific stiffness of the moving web. In another embodiment of the invention, the velocity of ultrasonic signals in the plane of the web are measured by way of a plurality of ultrasonic transducers carried by synchronously driven wheels or cylinders, thus eliminating undue transducer wear due to any speed differences between the transducers and the web. In order to provide relatively constant contact force between the transducers and the webs, the transducers are mounted in a sensor housings which include a spring for biasing the transducer radially outwardly. The sensor housings are adapted to be easily and conveniently mounted to the carrier to provide a relatively constant contact force between the transducers and the moving web. 37 figs.

Ultrasonic liquid-level detector for varying temperature and pressure environments

DOEpatents

Anderson, R.L.; Miller, G.N.

1981-10-26

An ultrasonic liquid level detector for use in varying temperature and pressure environments, such as a pressurized water nuclear reactor vessel, is provided. The detector employs ultrasonic extensional and torsional waves launched in a multiplexed alternating sequence into a common sensor. The sensor is a rectangular cross section stainless steel rod which extends into the liquid medium whose level is to be detected. The sensor temperature derived from the extensional wave velocity measurements is used to compensate for the temperature dependence of the torsional wave velocity measurements which are also level dependent. The torsional wave velocity measurements of a multiple reflection sensor then provide a measurement of liquid level over a range of several meters with a small uncertainty over a temperature range of 20 to 250/sup 0/C and pressures up to 15 MPa.

Texture in steel plates revealed by laser ultrasonic surface acoustic waves velocity dispersion analysis.

PubMed

Yin, Anmin; Wang, Xiaochen; Glorieux, Christ; Yang, Quan; Dong, Feng; He, Fei; Wang, Yanlong; Sermeus, Jan; Van der Donck, Tom; Shu, Xuedao

2017-07-01

A photoacoustic, laser ultrasonics based approach in an Impulsive Stimulated Scattering (ISS) implementation was used to investigate the texture in polycrystalline metal plates. The angular dependence of the 'polycrystalline' surface acoustic wave (SAW) velocity measured along regions containing many grains was experimentally determined and compared with simulated results that were based on the angular dependence of the 'single grain' SAW velocity within single grains and the grain orientation distribution. The polycrystalline SAW velocities turn out to vary with texture. The SAW velocities and their angular variations for {110} texture were found to be larger than that the ones for {111} texture or the strong γ fiber texture. The SAW velocities for {001} texture were larger than for {111} texture, but with almost the same angular dependence. The results infer the feasibility to apply angular SAW angular dispersion measurements by laser ultrasonics for on-line texture monitoring. Copyright © 2017 Elsevier B.V. All rights reserved.

Feasibility on Ultrasonic Velocity using Contact and Non-Contact Nondestructive Techniques for Carbon/Carbon Composites

NASA Astrophysics Data System (ADS)

Im, K. H.; Chang, M.; Hsu, D. K.; Song, S. J.; Cho, H.; Park, J. W.; Kweon, Y. S.; Sim, J. K.; Yang, I. Y.

2007-03-01

Advanced materials are to be required to have specific functions associated with extremely environments. One of them is carbon/carbon(C/C) composite material, which has obvious advantages over conventional materials. The C/Cs have become to be utilized as parts of aerospace applications and its low density, high thermal conductivity and excellent mechanical properties at elevated temperatures make it an ideal material for aircraft brake disks. Because of permeation of coupling medium such as water, it is desirable to perform contact-less nondestructive evaluation to assess material properties and part homogeneity. In this work, a C/C composite material was characterized with non-contact and contact ultrasonic methods using a scanner with automatic-data acquisition function. Also through transmission mode was performed because of the main limitation for air-coupled transducers, which is the acoustic impedance mismatch between most materials and air. Especially ultrasonic images and velocities for C/C composite disk brake were compared and found to be consistent to some degree with the non-contact and contact ultrasonic measurement methods. Low frequency through-transmission scans based on both amplitude of the ultrasonic pulse was used for mapping out the material property inhomogeneity. Measured results were compared with those obtained by the dry-coupling ultrasonic UT system and through transmission method in immersion. Finally, feasibility has been found to measure and compare ultrasonic velocities of C/C composites with using the contact/noncontact peak-delay measurement method based on the pulse overlap method.

Continuous flow measurements using ultrasonic velocity meters - an update

USGS Publications Warehouse

Oltmann, Rick

1995-01-01

An article in the summer 1993 Newsletter described USGS work to continously monitor tidal flows in the delta using ultrasonic velocity meters.  This article updates progress since 1993, including new installations, results of data analysis, damage during this year's high flows, and the status of each site.

Measurement of airborne ultrasonic slow waves in calcaneal cancellous bone.

PubMed

Strelitzki, R; Paech, V; Nicholson, P H

1999-05-01

Measurements of an airborne ultrasonic wave were made in defatted cancellous bone from the human calcaneus using standard ultrasonic equipment. The wave propagating under these conditions was consistent with a decoupled Biot slow wave travelling in the air alone, as previously reported in gas-saturated foams. Reproducible measurements of phase velocity and attenuation coefficient were possible, and an estimate of the tortuosity of the trabecular framework was derived from the high frequency limit of the phase velocity. Thus the method offers a new approach to the acoustic characterisation of bone in vitro which, in contrast to existing techniques, has the potential to yield information directly characterising the trabecular structure.

Ultrasonic material property determinations

NASA Technical Reports Server (NTRS)

Serabian, S.

1986-01-01

The use and potential offered by ultrasonic velocity and attenuation measurements to determine and/or monitor material properties is explored. The basis for such unique measurements along with examples of materials from a variety of industries are presented.

The Effects of Flocculation on the Propagation of Ultrasound in Dilute Kaolin Slurries.

PubMed

Austin; Challis

1998-10-01

A broadband ultrasonic spectrometer has been used to measure ultrasonic attenuation and phase velocity dispersion as functions of frequency in kaolin suspensions over a range of solid volume fractions from phi = 0.01 to phi = 0.08 and over a pH range from 3 to 9. The Harker and Temple theory was used to simulate ultrasound propagation in the suspension, using measured slope viscosity, particle size, and size distribution. Simulated results for ultrasonic attenuation and phase velocity agree well with measured values. Both sets of results agree well and show that for volume fractions above phi approximately 0.05 attenuation and velocity dispersion increase for increasing floc size, whereas for volume fractions below phi approximately 0.05 attenuation and velocity dispersion both decrease. It is proposed that the mechanism for this change in behavior around phi approximately 0.05 involves changes in floc density and floc size distribution with phi and pH. Copyright 1998 Academic Press.

Method for measuring liquid viscosity and ultrasonic viscometer

DOEpatents

Sheen, Shuh-Haw; Lawrence, William P.; Chien, Hual-Te; Raptis, Apostolos C.

1994-01-01

An ultrasonic viscometer and method for measuring fluid viscosity are provided. Ultrasonic shear and longitudinal waves are generated and coupled to the fluid. Reflections from the generated ultrasonic shear and longitudinal waves are detected. Phase velocity of the fluid is determined responsive to the detected ultrasonic longitudinal waves reflections. Viscosity of the fluid is determined responsive to the detected ultrasonic shear waves reflections. Unique features of the ultrasonic viscometer include the use of a two-interface fluid and air transducer wedge to measure relative signal change and to enable self calibration and the use of a ratio of reflection coefficients for two different frequencies to compensate for environmental changes, such as temperature.

Intermolecular interaction studies of glyphosate with water

NASA Astrophysics Data System (ADS)

Manon, Priti; Juglan, K. C.; Kaur, Kirandeep; Sethi, Nidhi; Kaur, J. P.

2017-07-01

The density (ρ), viscosity (η) and ultrasonic velocity (U) of glyphosate with water have been measured on different ultrasonic frequency ranges from 1MHz, 2MHz, 3MHz & 5MHz by varying concentrations (0.05%, 0.10%, 0.15%, 0.20%, 0.25%, 0.30%, 0.35%, & 0.40%) at 30°C. The specific gravity bottle, Ostwald's viscometer and quartz crystal interferometer were used to determine density (ρ), viscosity (η) and ultrasonic velocity (U). These three factors contribute in evaluating the other parameters as acoustic impedance (Z), adiabatic compressibility (β), relaxation time (τ), intermolecular free length (Lf), free volume (Vf), ultrasonic attenuation (α/f2), Rao's constant (R), Wada's constant (W) and relative strength (R). Solute-solvent interaction is confirmed by ultrasonic velocity and viscosity values, which increases with increase in concentration indicates stronger association between solute and solvent molecules. With rise in ultrasonic frequency the interaction between the solute and solvent particles decreases. The linear variations in Rao's constant and Wada's constant suggest the absence of complex formation.

Ultrasonic monitoring of the setting of silicone elastomeric impression materials.

PubMed

Kanazawa, Tomoe; Murayama, Ryosuke; Furuichi, Tetsuya; Imai, Arisa; Suda, Shunichi; Kurokawa, Hiroyasu; Takamizawa, Toshiki; Miyazaki, Masashi

2017-01-31

This study used an ultrasonic measurement device to monitor the setting behavior of silicone elastomeric impression materials, and the influence of temperature on setting behavior was determined. The ultrasonic device consisted of a pulser-receiver, transducers, and an oscilloscope. The two-way transit time through the mixing material was divided by two to account for the down-and-back travel path; then it was multiplied by the sonic velocity. Analysis of variance and the Tukey honest significant difference test were used. In the early stages of the setting process, most of the ultrasonic energy was absorbed by the elastomers and the second echoes were relatively weak. As the elastomers hardened, the sonic velocities increased until they plateaued. The changes in sonic velocities varied among the elastomers tested, and were affected by temperature conditions. The ultrasonic method used in this study has considerable potential for determining the setting processes of elastomeric impression materials.

Determination of Residual Stress in Composite Materials Using Ultrasonic Waves

NASA Technical Reports Server (NTRS)

Rokhlin, S. I.

1997-01-01

The performance of high temperature composites can be significantly affected by the presence of residual stresses. These stresses arise during cooling processes from fabrication to room temperature due to mismatch of thermal expansion coefficients between matrix and fiber materials. This effect is especially pronounced in metal matrix and intermetallic composites. It can lead to plastic deformations, matrix cracking and fiber/matrix interface debonding. In this work the feasibility of ultrasonic techniques for residual stress assessment in composites is addressed. A novel technique for absolute stress determination in orthotropic materials from angular dependencies of ultrasonic velocities is described. The technique is applicable for determination of both applied and residual stresses and does not require calibration measurements on a reference sample. The important advantage of this method is that stress is determined simultaneously with stress-dependent elastic constants and is thus decoupled from the material texture. It is demonstrated that when the principal plane stress directions coincide with acoustical axes, the angular velocity data in the plane perpendicular to the stress plane may be used to determine both stress components. When the stress is off the acoustical axes, the shear and the difference of the normal stress components may be determined from the angular dependence of group velocities in the plane of stresses. Synthetic sets of experimental data corresponding to materials with different anisotropy and stress levels are used to check the applicability of the technique. The method is also verified experimentally. A high precision ultrasonic wave transmission technique is developed to measure angular dependence of ultrasonic velocities. Examples of stress determination from experimental velocity data are given. A method is presented for determination of velocities of ultrasonic waves propagating through the composite material with residual stresses. It is based on the generalized self-consistent multiple scattering model. Calculation results for longitudinal and shear ultrasonic wave velocities propagating perpendicular to the fibers direction in SCS-6/Ti composite with and without residual stresses are presented. They show that velocity changes due to presence of stresses are of order 1%.

Measurement of the degree of cure in epoxies with ultrasonic velocity

NASA Technical Reports Server (NTRS)

Winfree, W. P.; Parker, F. R.

1986-01-01

The use of ultrasonic longitudinal velocity values to measure the degree of cure (defined for an epoxide system as the concentration of epoxide/amine bonds divided by the initial epoxide concentration) in epoxy resins is investigated. The experimental setup used to measure the changes in longitudinal velocity with time is described, together with the technique used to calculate the degree of cure from the acoustic data, using the principle of additive module. Measurements were done with diglycidyl ether of bisphenol A epoxy resin cured with an amine adduct agent. Good qualitative agreement was shown between the time dependence of the acoustically measured degree of cure and the predicted rate of reaction.

Out-of-plane ultrasonic velocity measurement

DOEpatents

Hall, M.S.; Brodeur, P.H.; Jackson, T.G.

1998-07-14

A method for improving the accuracy of measuring the velocity and time of flight of ultrasonic signals through moving web-like materials such as paper, paperboard and the like, includes a pair of ultrasonic transducers disposed on opposing sides of a moving web-like material. In order to provide acoustical coupling between the transducers and the web-like material, the transducers are disposed in fluid-filled wheels. Errors due to variances in the wheel thicknesses about their circumference which can affect time of flight measurements and ultimately the mechanical property being tested are compensated by averaging the ultrasonic signals for a predetermined number of revolutions. The invention further includes a method for compensating for errors resulting from the digitization of the ultrasonic signals. More particularly, the invention includes a method for eliminating errors known as trigger jitter inherent with digitizing oscilloscopes used to digitize the signals for manipulation by a digital computer. In particular, rather than cross-correlate ultrasonic signals taken during different sample periods as is known in the art in order to determine the time of flight of the ultrasonic signal through the moving web, a pulse echo box is provided to enable cross-correlation of predetermined transmitted ultrasonic signals with predetermined reflected ultrasonic or echo signals during the sample period. By cross-correlating ultrasonic signals in the same sample period, the error associated with trigger jitter is eliminated. 20 figs.

Out-of-plane ultrasonic velocity measurement

DOEpatents

Hall, Maclin S.; Brodeur, Pierre H.; Jackson, Theodore G.

1998-01-01

A method for improving the accuracy of measuring the velocity and time of flight of ultrasonic signals through moving web-like materials such as paper, paperboard and the like, includes a pair of ultrasonic transducers disposed on opposing sides of a moving web-like material. In order to provide acoustical coupling between the transducers and the web-like material, the transducers are disposed in fluid-filled wheels. Errors due to variances in the wheel thicknesses about their circumference which can affect time of flight measurements and ultimately the mechanical property being tested are compensated by averaging the ultrasonic signals for a predetermined number of revolutions. The invention further includes a method for compensating for errors resulting from the digitization of the ultrasonic signals. More particularly, the invention includes a method for eliminating errors known as trigger jitter inherent with digitizing oscilloscopes used to digitize the signals for manipulation by a digital computer. In particular, rather than cross-correlate ultrasonic signals taken during different sample periods as is known in the art in order to determine the time of flight of the ultrasonic signal through the moving web, a pulse echo box is provided to enable cross-correlation of predetermined transmitted ultrasonic signals with predetermined reflected ultrasonic or echo signals during the sample period. By cross-correlating ultrasonic signals in the same sample period, the error associated with trigger jitter is eliminated.

Molecular studies on di-sodium tartrate molecule

NASA Astrophysics Data System (ADS)

Divya, P.; Jayakumar, S.; George, Preethamary; Shubashree, N. S.; Ahmed. M, Anees

2015-06-01

Structural characterization is important for the development of new material. The acoustical parameters such as Free Length, Internal Pressure have been measured from ultrasonic velocity, density for di sodium tartrate an optically active molecule at different temperatures using ultrasonic interferometer of frequency (2MHZ). The ultrasonic velocity increases with increase in concentration there is an increase in solute-solvent interaction. The stability constant had been calculated. SEM with EDAX studies has been done for Di-sodium tartrate an optically active molecule.

In-situ laser ultrasonic measurement of the hcp to bcc transformation in commercially pure titanium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shinbine, A., E-mail: alyssa.shinbine@gmail.com; Garcin, T.; Sinclair, C.

2016-07-15

Using a novel in-situ laser ultrasonic technique, the evolution of longitudinal velocity was used to measure the α − β transformation during cyclic heating and cooling in commercially pure titanium. In order to quantify the transformation kinetics, it is shown that changes in texture can not be ignored. This is particularly important in the case of titanium where significant grain growth occurs in the β-phase leading to the ultrasonic wave sampling a decreasing number of grains on each thermal treatment cycle. Electron backscatter diffraction measurements made postmortem in the region where the ultrasonic pulse traveled were used to obtain anmore » estimate of such local texture and grain size changes. An analysis technique for including the anisotropy of wave velocity depending on local texture is presented and shown to give self consistent results for the transformation kinetics. - Highlights: • Laser ultrasound and EBSD interpret the hcp/bcc phase transformation in cp-Ti. • Grain growth and texture produced variation in velocity during similar treatments. • Texture was deconvoluted from phase addition to obtain transformation kinetics.« less

Acoustic wave in a suspension of magnetic nanoparticle with sodium oleate coating

NASA Astrophysics Data System (ADS)

Józefczak, A.; Hornowski, T.; Závišová, V.; Skumiel, A.; Kubovčíková, M.; Timko, M.

2014-03-01

The ultrasonic propagation in the water-based magnetic fluid with doubled layered surfactant shell was studied. The measurements were carried out both in the presence as well as in the absence of the external magnetic field. The thickness of the surfactant shell was evaluated by comparing the mean size of magnetic grain extracted from magnetization curve with the mean hydrodynamic diameter obtained from differential centrifugal sedimentation method. The thickness of surfactant shell was used to estimate volume fraction of the particle aggregates consisted of magnetite grain and surfactant layer. From the ultrasonic velocity measurements in the absence of the applied magnetic field, the adiabatic compressibility of the particle aggregates was determined. In the external magnetic field, the magnetic fluid studied in this article becomes acoustically anisotropic, i.e., velocity and attenuation of the ultrasonic wave depend on the angle between the wave vector and the direction of the magnetic field. The results of the ultrasonic measurements in the external magnetic field were compared with the hydrodynamic theory of Ovchinnikov and Sokolov (velocity) and with the internal chain dynamics model of Shliomis, Mond and Morozov (attenuation).

Acoustic wave in a suspension of magnetic nanoparticle with sodium oleate coating.

PubMed

Józefczak, A; Hornowski, T; Závišová, V; Skumiel, A; Kubovčíková, M; Timko, M

2014-01-01

The ultrasonic propagation in the water-based magnetic fluid with doubled layered surfactant shell was studied. The measurements were carried out both in the presence as well as in the absence of the external magnetic field. The thickness of the surfactant shell was evaluated by comparing the mean size of magnetic grain extracted from magnetization curve with the mean hydrodynamic diameter obtained from differential centrifugal sedimentation method. The thickness of surfactant shell was used to estimate volume fraction of the particle aggregates consisted of magnetite grain and surfactant layer. From the ultrasonic velocity measurements in the absence of the applied magnetic field, the adiabatic compressibility of the particle aggregates was determined. In the external magnetic field, the magnetic fluid studied in this article becomes acoustically anisotropic, i.e., velocity and attenuation of the ultrasonic wave depend on the angle between the wave vector and the direction of the magnetic field. The results of the ultrasonic measurements in the external magnetic field were compared with the hydrodynamic theory of Ovchinnikov and Sokolov (velocity) and with the internal chain dynamics model of Shliomis, Mond and Morozov (attenuation).

In-situ ultrasonic inspection of submarine shaft seal housing for corrosion damage

NASA Astrophysics Data System (ADS)

Batra, Narendra K.; Chaskelis, Henry H.; Mignogna, Richard B.

1995-06-01

The interior of the housings of primary and backup shaft seals of 637 class submarines are exposed to sea water during service and become corroded during service. Corrosion damage evaluation requires disassembly of the housing and visual inspection. In this paper, we present quantitative results of in situ nondestructive ultrasonic technique developed for the inspection of the seal housings. Due to vast variations in velocity in the seal material, the velocity was determined at suitable sites not subjected to corrosion and of known thickness from the blueprints. Using this normalized velocity and measured time-of-flight, we determined the thickness of the seal housing at various locations on the circumference. Subsequent mechanical thickness measurements, made when the housings were removed from service, agreed within the predicted uncertainty of 1.5% of ultrasonic measurements. This technique for the assessment of corrosion damage saves time and money, by preventing premature disassembly and downtime for the submarine.

Zernike ultrasonic tomography for fluid velocity imaging based on pipeline intrusive time-of-flight measurements.

PubMed

Besic, Nikola; Vasile, Gabriel; Anghel, Andrei; Petrut, Teodor-Ion; Ioana, Cornel; Stankovic, Srdjan; Girard, Alexandre; d'Urso, Guy

2014-11-01

In this paper, we propose a novel ultrasonic tomography method for pipeline flow field imaging, based on the Zernike polynomial series. Having intrusive multipath time-offlight ultrasonic measurements (difference in flight time and speed of ultrasound) at the input, we provide at the output tomograms of the fluid velocity components (axial, radial, and orthoradial velocity). Principally, by representing these velocities as Zernike polynomial series, we reduce the tomography problem to an ill-posed problem of finding the coefficients of the series, relying on the acquired ultrasonic measurements. Thereupon, this problem is treated by applying and comparing Tikhonov regularization and quadratically constrained ℓ1 minimization. To enhance the comparative analysis, we additionally introduce sparsity, by employing SVD-based filtering in selecting Zernike polynomials which are to be included in the series. The first approach-Tikhonov regularization without filtering, is used because it is the most suitable method. The performances are quantitatively tested by considering a residual norm and by estimating the flow using the axial velocity tomogram. Finally, the obtained results show the relative residual norm and the error in flow estimation, respectively, ~0.3% and ~1.6% for the less turbulent flow and ~0.5% and ~1.8% for the turbulent flow. Additionally, a qualitative validation is performed by proximate matching of the derived tomograms with a flow physical model.

Analytical Ultrasonics in Materials Research and Testing

NASA Technical Reports Server (NTRS)

Vary, A.

1986-01-01

Research results in analytical ultrasonics for characterizing structural materials from metals and ceramics to composites are presented. General topics covered by the conference included: status and advances in analytical ultrasonics for characterizing material microstructures and mechanical properties; status and prospects for ultrasonic measurements of microdamage, degradation, and underlying morphological factors; status and problems in precision measurements of frequency-dependent velocity and attenuation for materials analysis; procedures and requirements for automated, digital signal acquisition, processing, analysis, and interpretation; incentives for analytical ultrasonics in materials research and materials processing, testing, and inspection; and examples of progress in ultrasonics for interrelating microstructure, mechanical properites, and dynamic response.

Structural investigations of bismuth lead borosilicate glasses under the influence of gamma irradiation through ultrasonic studies

NASA Astrophysics Data System (ADS)

Bootjomchai, Cherdsak; Laopaiboon, Jintana; Laopaiboon, Raewat

2012-04-01

The ultrasonic velocity measurements for different compositions of irradiated bismuth lead borosilicate glasses xBi2O3-(50-x)PbO-20B2O3-30SiO2 (x=2, 4, 6, 8, and 10 mol.%) were performed at room temperature using pulse-echo technique. Densities of glass samples were measured by Archimedes' principle using n-hexane as the immersion liquid. The results from the studies show that ultrasonic velocity, elastic moduli, Poisson's ratio, microhardness, and the Debye temperature increase with increasing bismuth oxide content and increasing gamma-radiation dose (3-12 Gy).

Novel Imaging Method of Continuous Shear Wave by Ultrasonic Color Flow Mapping

NASA Astrophysics Data System (ADS)

Yamakoshi, Yoshiki; Yamamoto, Atsushi; Yuminaka, Yasushi

Shear wave velocity measurement is a promising method in evaluation of tissue stiffness. Several methods have been developed to measure the shear wave velocity, however, it is difficult to obtain quantitative shear wave image in real-time by low cost system. In this paper, a novel shear wave imaging method for continuous shear wave is proposed. This method uses a color flow imaging which is used in ultrasonic imaging system to obtain shear wave's wavefront map. Two conditions, shear wave frequency condition and shear wave displacement amplitude condition, are required, however, these conditions are not severe restrictions in most applications. Using the proposed method, shear wave velocity of trapezius muscle is measured. The result is consistent with the velocity which is calculated from shear elastic modulus measured by ARFI method.

Turbulent slurry flow measurement using ultrasonic Doppler method in rectangular pipe

NASA Astrophysics Data System (ADS)

Bareš, V.; Krupička, J.; Picek, T.; Brabec, J.; Matoušek, V.

2014-03-01

Distribution of velocity and Reynolds stress was measured using ultrasonic velocimetry in flows of water and Newtonian water-ballotini slurries in a pressurized Plexiglas pipe. Profiles of the measured parameters were sensed in the vertical plane at the centreline of a rectangular cross section of the pipe. Reference measurements in clear water produced expected symmetrical velocity profiles the shape of which was affected by secondary currents developed in the rectangular pipe. Slurry-flow experiments provided information on an effect of the concentration of solid grains on the internal structure of the flow. Strong attenuation of velocity fluctuations caused by a presence of grains was identified. The attenuation increased with the increasing local concentration of the grains.

Monitoring of freeze-thaw cycles in concrete using embedded sensors and ultrasonic imaging.

PubMed

Ranz, Javier; Aparicio, Sofía; Romero, Héctor; Casati, María Jesús; Molero, Miguel; González, Margarita

2014-01-29

This paper deals with the study of damage produced during freeze-thaw (F-T) cycles using two non-destructive measurement approaches-the first approach devoted to continuous monitoring using embedded sensors during the cycles, and the second one, performing ultrasonic imaging before and after the cycles. Both methodologies have been tested in two different types of concrete specimens, with and without air-entraining agents. Using the first measurement approach, the size and distribution of pores were estimated using a thermoporometrical model and continuous measurements of temperature and ultrasonic velocity along cycles. These estimates have been compared with the results obtained using mercury porosimetry testing. In the second approach, the damage due to F-T cycles has been evaluated by automated ultrasonic transmission and pulse-echo inspections made before and after the cycles. With these inspections the variations in the dimensions, velocity and attenuation caused by the accelerated F-T cycles were determined.

Monitoring of Freeze-Thaw Cycles in Concrete Using Embedded Sensors and Ultrasonic Imaging

PubMed Central

Ranz, Javier; Aparicio, Sofía; Romero, Héctor; Casati, María Jesús; Molero, Miguel; González, Margarita

2014-01-01

This paper deals with the study of damage produced during freeze-thaw (F-T) cycles using two non-destructive measurement approaches—the first approach devoted to continuous monitoring using embedded sensors during the cycles, and the second one, performing ultrasonic imaging before and after the cycles. Both methodologies have been tested in two different types of concrete specimens, with and without air-entraining agents. Using the first measurement approach, the size and distribution of pores were estimated using a thermoporometrical model and continuous measurements of temperature and ultrasonic velocity along cycles. These estimates have been compared with the results obtained using mercury porosimetry testing. In the second approach, the damage due to F-T cycles has been evaluated by automated ultrasonic transmission and pulse-echo inspections made before and after the cycles. With these inspections the variations in the dimensions, velocity and attenuation caused by the accelerated F-T cycles were determined. PMID:24481231

Ultrasonic hydrometer. [Specific gravity of electrolyte

DOEpatents

Swoboda, C.A.

1982-03-09

The disclosed ultrasonic hydrometer determines the specific gravity (density) of the electrolyte of a wet battery, such as a lead-acid battery. The hydrometer utilizes a transducer that when excited emits an ultrasonic impulse that traverses through the electrolyte back and forth between spaced sonic surfaces. The transducer detects the returning impulse, and means measures the time t between the initial and returning impulses. Considering the distance d between the spaced sonic surfaces and the measured time t, the sonic velocity V is calculated with the equation V = 2d/t. The hydrometer also utilizes a thermocouple to measure the electrolyte temperature. A hydrometer database correlates three variable parameters including sonic velocity in and temperature and specific gravity of the electrolyte, for temperature values between 0 and 40/sup 0/C and for specific gravity values between 1.05 and 1.30. Upon knowing two parameters (the calculated sonic velocity and the measured temperature), the third parameter (specific gravity) can be uniquely found in the database. The hydrometer utilizes a microprocessor for data storage and manipulation.

Statistical analysis of ultrasonic measurements in concrete

NASA Astrophysics Data System (ADS)

Chiang, Chih-Hung; Chen, Po-Chih

2002-05-01

Stress wave techniques such as measurements of ultrasonic pulse velocity are often used to evaluate concrete quality in structures. For proper interpretation of measurement results, the dependence of pulse transit time on the average acoustic impedance and the material homogeneity along the sound path need to be examined. Semi-direct measurement of pulse velocity could be more convenient than through transmission measurement. It is not necessary to assess both sides of concrete floors or walls. A novel measurement scheme is proposed and verified based on statistical analysis. It is shown that Semi-direct measurements are very effective for gathering large amount of pulse velocity data from concrete reference specimens. The variability of measurements is comparable with that reported by American Concrete Institute using either break-off or pullout tests.

Evaluation of near-surface stress distributions in dissimilar welded joint by scanning acoustic microscopy.

PubMed

Kwak, Dong Ryul; Yoshida, Sanichiro; Sasaki, Tomohiro; Todd, Judith A; Park, Ik Keun

2016-04-01

This paper presents the results from a set of experiments designed to ultrasonically measure the near surface stresses distributed within a dissimilar metal welded plate. A scanning acoustic microscope (SAM), with a tone-burst ultrasonic wave frequency of 200 MHz, was used for the measurement of near surface stresses in the dissimilar welded plate between 304 stainless steel and low carbon steel. For quantitative data acquisition such as leaky surface acoustic wave (leaky SAW) velocity measurement, a point focus acoustic lens of frequency 200 MHz was used and the leaky SAW velocities within the specimen were precisely measured. The distributions of the surface acoustic wave velocities change according to the near-surface stresses within the joint. A three dimensional (3D) finite element simulation was carried out to predict numerically the stress distributions and compare with the experimental results. The experiment and FE simulation results for the dissimilar welded plate showed good agreement. This research demonstrates that a combination of FE simulation and ultrasonic stress measurements using SAW velocity distributions appear promising for determining welding residual stresses in dissimilar material joints. Copyright © 2016 Elsevier B.V. All rights reserved.

Velocity and attenuation of sound in arterial tissues

NASA Technical Reports Server (NTRS)

Rooney, J. A.; Gammell, P. M.; Hestenes, J. D.; Chin, H. P.; Blankenhorn, D. H.

1982-01-01

The velocity of sound in excised human and canine arterial tissues is measured in order to serve as a basis for the development and application of ultrasonic techniques for the diagnosis of atherosclerotic lesions. Measurements of sound velocity at different regions of 11 human and six canine aortas were made by a time delay spectrometer technique at frequencies from 2 to 10 MHz, and compared with ultrasonic attenuation parameters and the results of biochemical assays. Sound velocity is found to increase with increasing attenuation at all frequencies, and with increasing collagen content. A strong dependence of sound velocity on cholesterol content or low calcium contents is not observed, although velocities of up to 2000 m/sec are observed in highly organized calcified lesions. A decrease in velocity with decreasing temperature is also noted. It is thus concluded that it is principally the differences in tissue collagen levels that contribute to image formation according to sound velocity.

Improved formula for continuous-wave measurements of ultrasonic phase velocity

NASA Technical Reports Server (NTRS)

Chern, E. J.; Cantrell, J. H., Jr.; Heyman, J. S.

1981-01-01

An improved formula for continuous-wave ultrasonic phase velocity measurements using contact transducers is derived from the transmission line theory. The effect of transducer-sample coupling bonds is considered for measurements of solid samples even though it is often neglected because of the difficulty of accurately determining the bond thickness. Computer models show that the present formula is more accurate than previous expressions. Laboratory measurements using contacting transducers with the present formula are compared to measurements using noncontacting (hence effectively correction-free) capacitive transducers. The results of the experiments verify the validity and accuracy of the new formula.

Ultrasonic determination of the elastic constants of the stiffness matrix for unidirectional fiberglass epoxy composites

NASA Technical Reports Server (NTRS)

Marques, E. R. C.; Williams, J. H., Jr.

1986-01-01

The elastic constants of a fiberglass epoxy unidirectional composite are determined by measuring the phase velocities of longitudinal and shear stress waves via the through transmission ultrasonic technique. The waves introduced into the composite specimens were generated by piezoceramic transducers. Geometric lengths and the times required to travel those lengths were used to calculate the phase velocities. The model of the transversely isotropic medium was adopted to relate the velocities and elastic constants.

Acoustic phonon dispersion at hypersonic frequencies in Si and Ge

NASA Astrophysics Data System (ADS)

Kuok, M. H.; Ng, S. C.; Rang, Z. L.; Lockwood, D. J.

2000-11-01

Brillouin spectra of the longitudinal acoustic (LA) mode, traveling along the [001] direction, in silicon and germanium have been recorded in 180° backscattering using 457.9-514.5-nm laser lines. The wave velocity of the LA phonon propagating in the [001] direction was determined at hypersonic frequencies, from the measured acoustic phonon dispersion in silicon and germanium. The elastic modulus c11 of the two semiconductors has been calculated from the respective measured hypersonic wave velocities and the results are compared with values determined from lower-frequency ultrasonic and other measurements. Interestingly, the hypersonic velocities are consistently lower by ~1-2 % than the ultrasonic ones, but they generally agree within the present experimental accuracy.

Elastic Wave Velocity Measurements on Mantle Peridotite at High Pressure and Temperature

NASA Astrophysics Data System (ADS)

Mistler, G. W.; Ishikawa, M.; Li, B.

2002-12-01

With the success of conducting ultrasonic measurements at high pressure and high temperature in large volume high pressure apparatus with in-situ measurement of the sample length by X-ray imaging, it is now possible to measure elastic wave velocities on aggregate samples with candidate compositions of the mantle to the conditions of the Earth's transition zone in the laboratory. These data can be directly compared with seismic data to distinguish the compositional models in debate. In this work, we carried out velocity measurements on natural peridotite KLB-1 at the conditions of the Earth's upper mantle. Fine powered sample of natural KLB-1 was used as starting material. Specimens for ultrasonic measurements were hot-pressed and equilibrated at various pressure and temperature conditions along geotherm up to the transition zone. The recovered samples were characterized with density measurement, X-ray diffraction and microprobe analysis. Bench top P and S wave velocities of KLB-1 sample sintered at 3-4 GPa and 1400 degree centigrade showed a very good agreement with the VRH average of pyrolite. High pressure and high temperature measurements was conducted up to 7 GPa and 800 degree centigrade using ultrasonic interferometric method in a DIA-type high pressure apparatus in conjunction with X-ray diffraction and X-ray imaging. The utilization of X-ray imaging technique provides direct measurements of sample lengths at high pressure and high temperature, ensuring a precise determination of velocities. The results of P and S wave velocities at high pressure and high temperature as well as their comparison with calculated pyrolite model will be presented.

Ultrasonic evaluation of the physical and mechanical properties of granites.

PubMed

Vasconcelos, G; Lourenço, P B; Alves, C A S; Pamplona, J

2008-09-01

Masonry is the oldest building material that survived until today, being used all over the world and being present in the most impressive historical structures as an evidence of spirit of enterprise of ancient cultures. Conservation, rehabilitation and strengthening of the built heritage and protection of human lives are clear demands of modern societies. In this process, the use of nondestructive methods has become much common in the diagnosis of structural integrity of masonry elements. With respect to the evaluation of the stone condition, the ultrasonic pulse velocity is a simple and economical tool. Thus, the central issue of the present paper concerns the evaluation of the suitability of the ultrasonic pulse velocity method for describing the mechanical and physical properties of granites (range size between 0.1-4.0 mm and 0.3-16.5 mm) and for the assessment of its weathering state. The mechanical properties encompass the compressive and tensile strength and modulus of elasticity, and the physical properties include the density and porosity. For this purpose, measurements of the longitudinal ultrasonic pulse velocity with distinct natural frequency of the transducers were carried out on specimens with different size and shape. A discussion of the factors that induce variations on the ultrasonic velocity is also provided. Additionally, statistical correlations between ultrasonic pulse velocity and mechanical and physical properties of granites are presented and discussed. The major output of the work is the confirmation that ultrasonic pulse velocity can be effectively used as a simple and economical nondestructive method for a preliminary prediction of mechanical and physical properties, as well as a tool for the assessment of the weathering changes of granites that occur during the serviceable life. This is of much interest due to the usual difficulties in removing specimens for mechanical characterization.

Stress-dependent elastic properties of shales—laboratory experiments at seismic and ultrasonic frequencies

NASA Astrophysics Data System (ADS)

Szewczyk, Dawid; Bauer, Andreas; Holt, Rune M.

2018-01-01

Knowledge about the stress sensitivity of elastic properties and velocities of shales is important for the interpretation of seismic time-lapse data taken as part of reservoir and caprock surveillance of both unconventional and conventional oil and gas fields (e.g. during 4-D monitoring of CO2 storage). Rock physics models are often developed based on laboratory measurements at ultrasonic frequencies. However, as shown previously, shales exhibit large seismic dispersion, and it is possible that stress sensitivities of velocities are also frequency dependent. In this work, we report on a series of seismic and ultrasonic laboratory tests in which the stress sensitivity of elastic properties of Mancos shale and Pierre shale I were investigated. The shales were tested at different water saturations. Dynamic rock engineering parameters and elastic wave velocities were examined on core plugs exposed to isotropic loading. Experiments were carried out in an apparatus allowing for static-compaction and dynamic measurements at seismic and ultrasonic frequencies within single test. For both shale types, we present and discuss experimental results that demonstrate dispersion and stress sensitivity of the rock stiffness, as well as P- and S-wave velocities, and stiffness anisotropy. Our experimental results show that the stress-sensitivity of shales is different at seismic and ultrasonic frequencies, which can be linked with simultaneously occurring changes in the dispersion with applied stress. Measured stress sensitivity of elastic properties for relatively dry samples was higher at seismic frequencies however, the increasing saturation of shales decreases the difference between seismic and ultrasonic stress-sensitivities, and for moist samples stress-sensitivity is higher at ultrasonic frequencies. Simultaneously, the increased saturation highly increases the dispersion in shales. We have also found that the stress-sensitivity is highly anisotropic in both shales and that in some of the cases higher stress-sensitivity of elastic properties can be seen in the direction parallel to the bedding plane.

Semi-automatic system for ultrasonic measurement of texture

DOEpatents

Thompson, R. Bruce; Wormley, Samuel J.

1991-09-17

A means and method for ultrasonic measurement of texture non-destructively and efficiently. Texture characteristics are derived by transmitting ultrasound energy into the material, measuring the time it takes to be received by ultrasound receiving means, and calculating velocity of the ultrasound energy from the timed measurements. Textured characteristics can then be derived from the velocity calculations. One or more sets of ultrasound transmitters and receivers are utilized to derive velocity measurements in different angular orientations through the material and in different ultrasound modes. An ultrasound transmitter is utilized to direct ultrasound energy to the material and one or more ultrasound receivers are utilized to receive the same. The receivers are at a predetermined fixed distance from the transmitter. A control means is utilized to control transmission of the ultrasound, and a processing means derives timing, calculation of velocity and derivation of texture characteristics.

Semi-automatic system for ultrasonic measurement of texture

DOEpatents

Thompson, R.B.; Wormley, S.J.

1991-09-17

A means and method are disclosed for ultrasonic measurement of texture nondestructively and efficiently. Texture characteristics are derived by transmitting ultrasound energy into the material, measuring the time it takes to be received by ultrasound receiving means, and calculating velocity of the ultrasound energy from the timed measurements. Textured characteristics can then be derived from the velocity calculations. One or more sets of ultrasound transmitters and receivers are utilized to derive velocity measurements in different angular orientations through the material and in different ultrasound modes. An ultrasound transmitter is utilized to direct ultrasound energy to the material and one or more ultrasound receivers are utilized to receive the same. The receivers are at a predetermined fixed distance from the transmitter. A control means is utilized to control transmission of the ultrasound, and a processing means derives timing, calculation of velocity and derivation of texture characteristics. 5 figures.

Ultrasonic wave propagation in powders

NASA Astrophysics Data System (ADS)

Al-Lashi, R. S.; Povey, M. J. W.; Watson, N. J.

2018-05-01

Powder clumps (cakes) has a significant effect on the flowability and stability of powders. Powder caking is mainly caused by moisture migration due to wetting and environmental (temperature and humidity) changes. The process of moisture migration caking involves creating liquid bridges between the particles during condensation which subsequently harden to form solid bridges. Therefore, an effective and reliable technique is required to quantitatively and non-invasively monitor caking kinetics and effective stiffness. This paper describes two ultrasonic instruments (ultrasonic velocity pulse and airborne ultrasound systems) that have been used to monitor the caking phenomenon. Also, it discusses the relationship between the ultrasonic velocity and attenuation measurements and tracking caking kinetics and the effective stiffness of powders.

Subtle porosity variation in the YBa2Cu3O(7-x) high-temperature superconductor revealed by ultrasonic imaging

NASA Technical Reports Server (NTRS)

Roth, D. J.; Generazio, E. R.; Stang, D. B.; Hepp, A. F.

1990-01-01

The characterization of global porosity variation within a nominally 93-percent-dense specimen of YBa2Cu3O(7-x) high-temperature superconductor is reported. With a computer-controlled scanning system, precision ultrasonic velocity measurements were obtained at 100 micron increments over an 8- by 8-mm area of the YBa2Cu3O(7-x) specimen. The measurements were used to form a color map of velocity variation across the scanned region of the specimen. Subtle velocity variation on the order of 1 percent was observed. The specimen was shown by experimental methods to be single-phase, untextured, and free of nonuniform residual microstresses. From this knowledge and an established velocity-density relationship, a likely conclusion is that the observed velocity variations are solely due to porosity variations of similar magnitude. Locating these subtle porosity variations is critical since they can result in an order of magnitude variation in J(sub c) for dense YBCO specimens. Thus, mapping the global porosity distribution within YBa2Cu3O(7-x) may reveal regions that have poorer superconducting properties. Ultrasonic velocity results are translated into useful microstructural information for the material scientist.

Ultrasonic characterization of porosity using the Kramers-Kronig relations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rose, J.H.; Hsu, D.K.; Adler, L.

1985-01-01

A new algorithm is proposed to determine the volume fraction of pores in solids using the frequency dependent ultrasonic attenuation. The algorithm was developed by examining the Kramers-Kronig relation between the porosity induced ultrasonic attenuation and the change in sound velocity. The method is tested using data measured for several porous aluminum samples.

Monitoring the Cure State of Thermosetting Resins by Ultrasound.

PubMed

Lionetto, Francesca; Maffezzoli, Alfonso

2013-09-05

The propagation of low intensity ultrasound in a curing resin, acting as a high frequency oscillatory excitation, has been recently proposed as an ultrasonic dynamic mechanical analysis (UDMA) for cure monitoring. The technique measures sound velocity and attenuation, which are very sensitive to changes in the viscoelastic characteristics of the curing resin, since the velocity is related to the resin storage modulus and density, while the attenuation is related to the energy dissipation and scattering in the curing resin. The paper reviews the results obtained by the authors' research group in the last decade by means of in-house made ultrasonic set-ups for both contact and air-coupled ultrasonic experiments. The basics of the ultrasonic wave propagation in polymers and examples of measurements of the time-evolution of ultrasonic longitudinal modulus and chemical conversion of different thermosetting resins are presented. The effect of temperature on the cure kinetics, the comparison with rheological, low frequency dynamic mechanical and calorimetric results, and the correlation between ultrasonic modulus and crosslinking density will be also discussed. The paper highlights the reliability of ultrasonic wave propagation for monitoring the physical changes taking place during curing and the potential for online monitoring during polymer and polymer matrix composite processing.

Monitoring the Cure State of Thermosetting Resins by Ultrasound

PubMed Central

Lionetto, Francesca; Maffezzoli, Alfonso

2013-01-01

The propagation of low intensity ultrasound in a curing resin, acting as a high frequency oscillatory excitation, has been recently proposed as an ultrasonic dynamic mechanical analysis (UDMA) for cure monitoring. The technique measures sound velocity and attenuation, which are very sensitive to changes in the viscoelastic characteristics of the curing resin, since the velocity is related to the resin storage modulus and density, while the attenuation is related to the energy dissipation and scattering in the curing resin. The paper reviews the results obtained by the authors’ research group in the last decade by means of in-house made ultrasonic set-ups for both contact and air-coupled ultrasonic experiments. The basics of the ultrasonic wave propagation in polymers and examples of measurements of the time-evolution of ultrasonic longitudinal modulus and chemical conversion of different thermosetting resins are presented. The effect of temperature on the cure kinetics, the comparison with rheological, low frequency dynamic mechanical and calorimetric results, and the correlation between ultrasonic modulus and crosslinking density will be also discussed. The paper highlights the reliability of ultrasonic wave propagation for monitoring the physical changes taking place during curing and the potential for online monitoring during polymer and polymer matrix composite processing. PMID:28788306

Integrated ultrasonic and petrographical characterization of carbonate building materials

NASA Astrophysics Data System (ADS)

Ligas, Paola; Fais, Silvana; Cuccuru, Francesco

2014-05-01

This paper presents the application of non-destructive ultrasonic techniques in evaluating the conservation state and quality of monumental carbonate building materials. Ultrasonic methods are very effective in detecting the elastic characteristics of the materials and thus their mechanical behaviour. They are non-destructive and effective both for site and laboratory tests, though it should be pointed out that ultrasonic data interpretation is extremely complex, since elastic wave velocity heavily depends on moisture, heterogeneity, porosity and other physical properties of the materials. In our study, considering both the nature of the building materials and the constructive types of the investigated monuments, the ultrasonic investigation was carried out in low frequency ultrasonic range (24 kHz - 54 kHz) with the aim of detecting damages and degradation zones and assessing the alterability of the investigated stones by studying the propagation of the longitudinal ultrasonic pulses. In fact alterations in the materials generally cause a decrease in longitudinal pulse velocity values. Therefore starting from longitudinal velocity values the elasto-mechanical behaviour of the stone materials can be deduced. To this aim empirical and effective relations between longitudinal velocity and mechanical properties of the rocks can be used, by transferring the fundamental concepts of the studies of reservoir rocks in the framework of hydrocarbon research to the diagnostic process on stone materials. The ultrasonic measurements were performed both in laboratory and in situ using the Portable Ultrasonic Non-Destructive Digital Indicating Tester (PUNDIT) by C.N.S. Electronics LTD. A number of experimental sessions were carried out choosing different modalities of data acquisition. On the basis of the results of the laboratory measurements, an in situ ultrasonic survey on significant monuments, have been carried out. The ultrasonic measurements were integrated by a petrographical and petrophysical study of the investigated stone materials to correlate their petrographical-petrophysical features with the elastic ones. From this integrated study results that the modifications in the elasto-mechanical and petrographical-petrophysical features of the investigated carbonate materials are the main causes which reduce their quality as building materials. The use of the ultrasonic method integrated with information on petrography and petrophysics of the rocks has been successful to assess the rock quality and better understanding their alteration process. Acknowledgments: This work was financially supported by Sardinian Local Administration (RAS - LR 7 August 2007, n.7, Promotion of Scientific Research and Innovation in Sardinia - Italy, Responsible Scientist: S. Fais).

Stochastic simulation for the propagation of high-frequency acoustic waves through a random velocity field

NASA Astrophysics Data System (ADS)

Lu, B.; Darmon, M.; Leymarie, N.; Chatillon, S.; Potel, C.

2012-05-01

In-service inspection of Sodium-Cooled Fast Reactors (SFR) requires the development of non-destructive techniques adapted to the harsh environment conditions and the examination complexity. From past experiences, ultrasonic techniques are considered as suitable candidates. The ultrasonic telemetry is a technique used to constantly insure the safe functioning of reactor inner components by determining their exact position: it consists in measuring the time of flight of the ultrasonic response obtained after propagation of a pulse emitted by a transducer and its interaction with the targets. While in-service the sodium flow creates turbulences that lead to temperature inhomogeneities, which translates into ultrasonic velocity inhomogeneities. These velocity variations could directly impact the accuracy of the target locating by introducing time of flight variations. A stochastic simulation model has been developed to calculate the propagation of ultrasonic waves in such an inhomogeneous medium. Using this approach, the travel time is randomly generated by a stochastic process whose inputs are the statistical moments of travel times known analytically. The stochastic model predicts beam deviations due to velocity inhomogeneities, which are similar to those provided by a determinist method, such as the ray method.

The Effect of Non-Uniform Temperature and Velocity Fields on Long Range Ultrasonic Measurement Systems in MYRRHA

NASA Astrophysics Data System (ADS)

Van De Wyer, Nicolas; Schram, Christophe; Van Dyck, Dries; Dierckx, Marc

2017-02-01

SCK·CEN, the Belgian Nuclear Research Center, is developing MYRRHA, a generation IV liquid metal cooled nuclear research reactor. As the liquid metal coolant is opaque to light, normal visual feedback during fuel manipulations is not available and must therefore be replaced by a system that is not hindered by the opacity of the coolant. In this respect ultrasonic based instrumentation is under development at SCK·CEN to provide feedback during operations under liquid metal. One of the tasks that will be tackled using ultrasound is the detection and localization of a potentially lost fuel assembly. The development of this localization tool is detailed in this paper. In this application, the distance between ultrasonic sensor and target may be as large as 2.5m. At these distances, non uniform velocity and temperature fields in the liquid metal potentially influence the propagation of the ultrasonic signals, affecting the performance of the ultrasonic systems. In this paper, we investigate how relevant temperature and velocity gradients inside the liquid metal influence the propagation of ultrasonic waves. The effect of temperature and velocity gradients are simulated by means of a newly developed numerical raytracing model. The performance of the model is validated by dedicated water experiments. The setup is capable of creating velocity and temperature gradients representative for MYRRHA conditions. Once validated in water, the same model is used to make predictions for the effect of gradients in the MYRRHA liquid metal environment.

Continuous flow measurements using fixed ultrasonic meters

USGS Publications Warehouse

Oltmann, Rick

1993-01-01

USGS has or soon will be installing four continuous flow-monitoring stations in the delta that will use ultrasonic velocity meters (DVM). Funding for the stations has been provided by USGS, DWR, USBR, and Contra Costa Water District.

Single Transducer Ultrasonic Imaging Method that Eliminates the Effect of Plate Thickness Variation in the Image

NASA Technical Reports Server (NTRS)

Roth, Don J.

1996-01-01

This article describes a single transducer ultrasonic imaging method that eliminates the effect of plate thickness variation in the image. The method thus isolates ultrasonic variations due to material microstructure. The use of this method can result in significant cost savings because the ultrasonic image can be interpreted correctly without the need for machining to achieve precise thickness uniformity during nondestructive evaluations of material development. The method is based on measurement of ultrasonic velocity. Images obtained using the thickness-independent methodology are compared with conventional velocity and c-scan echo peak amplitude images for monolithic ceramic (silicon nitride), metal matrix composite and polymer matrix composite materials. It was found that the thickness-independent ultrasonic images reveal and quantify correctly areas of global microstructural (pore and fiber volume fraction) variation due to the elimination of thickness effects. The thickness-independent ultrasonic imaging method described in this article is currently being commercialized under a cooperative agreement between NASA Lewis Research Center and Sonix, Inc.

Laser ultrasonic investigations of vertical Bridgman crystal growth

NASA Astrophysics Data System (ADS)

Queheillalt, Douglas Ted

The many difficulties associated with the growth of premium quality CdTe and (Cd,Zn)Te alloys has stimulated an interest in the development of a non-invasive ultrasonic approach to monitor critical growth parameters such as the solid-liquid interface position and shape during vertical Bridgman growth. This sensor methodology is based upon the recognition that in most materials, the ultrasonic velocity (and the elastic stiffness constants that control it) of the solid and liquid phases are temperature dependent and an abrupt increase of the longitudinal wave velocity occurs upon solidification. The laser ultrasonic approach has also been used to measure the ultrasonic velocity of solid and liquid Cd0.96Zn0.04Te as a function of temperature up to 1140°C. Using longitudinal and shear wave velocity values together with data for the temperature dependent density allowed a complete evaluation of the temperature dependent single crystal elastic stiffness constants for solid and the adiabatic bulk modulus for liquid Cd0.96Zn0.04 Te. It was found that the ultrasonic velocities exhibited a strong monotonically decreasing function of temperature in the solid and liquid phases and the longitudinal wave indicated an abrupt almost 50% decrease upon melting. Because ray propagation in partially solidified bodies is complex and defines the sensing methodology, a ray tracing algorithm has been developed to analyze two-dimensional wave propagation in the diametral plane of cylindrical solid-liquid interfaces. Ray path, wavefront and time-of-flight (TOF) projections for rays that travel from a source to an arbitrarily positioned receiver on the diametral plane have been calculated and compared to experimentally measured data on a model liquid-solid interface. The simulations and the experimental results reveal that the interfacial region can be identified from transmission TOF data and when used in conjunction with a nonlinear least squares reconstruction algorithm, the interface geometry (i.e. axial location and shape) can be precisely recovered and the ultrasonic velocities of both solid and liquid phases obtained. To gain insight into the melting and solidification process, a single zone VB growth furnace was integrated with the laser ultrasonic sensor system and used to monitor the melting-solidification and directional solidification characteristics of Cd0.96Zn 0.04Te.

Transcutaneous measurement of volume blood flow

NASA Technical Reports Server (NTRS)

Daigle, R. E.; Mcleod, F. D.; Miller, C. W.; Histand, M. B.; Wells, M. K.

1974-01-01

Blood flow velocity measurements, using Doppler velocimeter, are described. The ability to measure blood velocity using ultrasound is derived from the Doppler effect; the change in frequency which occurs when sound is reflected or transmitted from a moving target. When ultrasound of the appropriate frequency is transmitted through a moving blood stream, the blood cells act as point scatterers of ultrasonic energy. If this scattered ultrasonic energy is detected, it is found to be shifted in frequency according to the velocity of the blood cells, nu, the frequency of the incident sound, f sub o, the speed of sound in the medium, c, and the angle between the sound beam and the velocity vector, o. The relation describing this effect is known as the Doppler equation. Delta f = 2 f sub o x nu x cos alpha/c. The theoretical and experimental methods are evaluated.

Elastic properties of transparent nano-polycrystalline diamond measured by GHz-ultrasonic interferometry and resonant sphere methods

NASA Astrophysics Data System (ADS)

Chang, Yun-Yuan; Jacobsen, Steven D.; Kimura, Masaki; Irifune, Tetsuo; Ohno, Ichiro

2014-03-01

The sound velocities and elastic moduli of transparent nano-polycrystalline diamond (NPD) have been determined by GHz-ultrasonic interferometry on three different bulk samples, and by resonant spectroscopy on a spherically fabricated NPD sample. We employ a newly-developed optical contact micrometer to measure the thickness of ultrasonic samples to ±0.05 μm with a spatial resolution of ∼50 μm in the same position of the GHz-ultrasonic measurements, resulting in acoustic-wave sound velocity measurements with uncertainties of 0.005-0.02%. The isotropic and adiabatic bulk and shear moduli of NPD measured by GHz-ultrasonic interferometry are KS0 = 442.5 (±0.5) GPa and G0 = 532.4 (±0.5) GPa. By rotating the shear-wave polarization direction, we observe no transverse anisotropy in this NPD. Using resonant sphere spectroscopy, we obtain KS0 = 440.3 (±0.5) GPa and G0 = 532.7 (±0.4) GPa. For comparison, we also measured by GHz-ultrasonic interferometry the elastic constants of a natural single-crystal type-IA diamond with about one-half the experimental uncertainty of previous measurements. The resulting Voigt-Reuss-Hill averaged bulk and shear moduli of natural diamond are KS0 = 441.8 (±0.8) GPa and G0 = 532.6 (±0.5) GPa, demonstrating that the bulk-elastic properties of transparent NPD are equivalent to natural single-crystal diamond as calculated from polycrystalline averaging of its elastic constants.

Study of the Earth's interior using measurements of sound velocities in minerals by ultrasonic interferometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Baosheng; Liebermann, Robert C.

2014-07-29

This paper reviews the progress of the technology of ultrasonic interferometry from the early 1950s to the present day. During this period of more than 60 years, sound wave velocity measurements have been increased from at pressures less than 1 GPa and temperatures less than 800 K to conditions above 25 GPa and temperatures of 1800 K. This is complimentary to other direct methods to measure sound velocities (such as Brillouin and impulsive stimulated scattering) as well as indirect methods (e.g., resonance ultrasound spectroscopy, static or shock compression, inelastic X-ray scattering). Newly-developed pressure calibration methods and data analysis procedures usingmore » a finite strain approach are described and applied to data for the major mantle minerals. The implications for the composition of the Earth’s mantle are discussed. The state-of-the-art ultrasonic experiments performed in conjunction with synchrotron X-radiation can provide simultaneous measurements of the elastic bulk and shear moduli and their pressure and temperature derivatives with direct determination of pressure. The current status and outlook/challenges for future experiments are summarized.« less

Ultrasonic Method for Measuring Internal Temperature Profile in Heated Materials

NASA Astrophysics Data System (ADS)

Ihara, I.; Takahashi, M.

2008-02-01

A new ultrasonic method for internal temperature measurement is presented. The principle of the method is based on temperature dependence of the velocity of the ultrasonic wave propagating through the material. An inverse analysis to determine the temperature profile in a heated material is developed and an experiment is carried out to verify the validity of the developed method. A single side of a silicone rubber plate of 30 mm thickness is heated and ultrasonic pulse-echo measurements are then performed during heating. A change in transit time of ultrasonic wave in the heated rubber plate is monitored and used to determine the transient variation in internal temperature distribution of the rubber. The internal temperature distribution determined ultrasonically agrees well with both obtained using commercial thermocouples installed in the rubber and estimated theoretically.

Development of ultrasonic methods for hemodynamic measurements

NASA Technical Reports Server (NTRS)

Histand, M. B.; Miller, C. W.; Wells, M. K.; Mcleod, F. D.; Greene, E. R.; Winter, D.

1975-01-01

A transcutanous method to measure instantaneous mean blood flow in peripheral arteries of the human body was defined. Transcutanous and implanted cuff ultrasound velocity measurements were evaluated, and the accuracies of velocity, flow, and diameter measurements were assessed for steady flow. Performance criteria were established for the pulsed Doppler velocity meter (PUDVM), and performance tests were conducted. Several improvements are suggested.

Multichannel analysis of surface-waves and integration of downhole acoustic televiewer imaging, ultrasonic Vs and Vp, and vertical seismic profiling in an NEHRP-standard classification, South of Concordia, Kansas, USA

NASA Astrophysics Data System (ADS)

Raef, Abdelmoneam; Gad, Sabreen; Tucker-Kulesza, Stacey

2015-10-01

Seismic site characteristics, as pertaining to earthquake hazard reduction, are a function of the subsurface elastic moduli and the geologic structures. This study explores how multiscale (surface, downhole, and laboratory) datasets can be utilized to improve "constrained" average Vs30 (shear-wave velocity to a 30-meter depth). We integrate borehole, surface and laboratory measurements for a seismic site classification based on the standards of the National Earthquake Hazard Reduction Program (NEHRP). The seismic shear-wave velocity (Vs30) was derived from a geophysical inversion workflow that utilized multichannel analysis of surface-waves (MASW) and downhole acoustic televiewer imaging (DATI). P-wave and S-wave velocities, based on laboratory measurements of arrival times of ultrasonic-frequency signals, supported the workflow by enabling us to calculate Poisson's ratio, which was incorporated in building an initial model for the geophysical inversion of MASW. Extraction of core samples from two boreholes provided lithology and thickness calibration of the amplitudes of the acoustic televiewer imaging for each layer. The MASW inversion, for calculating Vs sections, was constrained with both ultrasonic laboratory measurements (from first arrivals of Vs and Vp waveforms at simulated in situ overburden stress conditions) and the downhole acoustic televiewer (DATV) amplitude logs. The Vs30 calculations enabled categorizing the studied site as NEHRP-class "C" - very dense soil and soft rock. Unlike shallow fractured carbonates in the studied area, S-wave and P-wave velocities at ultrasonic frequency for the deeper intact shale core-samples from two boreholes were in better agreement with the corresponding velocities from both a zero-offset vertical seismic profiling (VSP) and inversion of Rayleigh-wave velocity dispersion curves.

Application of partial inversion pulse to ultrasonic time-domain correlation method to measure the flow rate in a pipe

NASA Astrophysics Data System (ADS)

Wada, Sanehiro; Furuichi, Noriyuki; Shimada, Takashi

2017-11-01

This paper proposes the application of a novel ultrasonic pulse, called a partial inversion pulse (PIP), to the measurement of the velocity profile and flow rate in a pipe using the ultrasound time-domain correlation (UTDC) method. In general, the measured flow rate depends on the velocity profile in the pipe; thus, on-site calibration is the only method of checking the accuracy of on-site flow rate measurements. Flow rate calculation using UTDC is based on the integration of the measured velocity profile. The advantages of this method compared with the ultrasonic pulse Doppler method include the possibility of the velocity range having no limitation and its applicability to flow fields without a sufficient amount of reflectors. However, it has been previously reported that the measurable velocity range for UTDC is limited by false detections. Considering the application of this method to on-site flow fields, the issue of velocity range is important. To reduce the effect of false detections, a PIP signal, which is an ultrasound signal that contains a partially inverted region, was developed in this study. The advantages of the PIP signal are that it requires little additional hardware cost and no additional software cost in comparison with conventional methods. The effects of inversion on the characteristics of the ultrasound transmission were estimated through numerical calculation. Then, experimental measurements were performed at a national standard calibration facility for water flow rate in Japan. The experimental results demonstrate that measurements made using a PIP signal are more accurate and yield a higher detection ratio than measurements using a normal pulse signal.

Ultrasonic Data Display and Analysis System Developed (Including Fuzzy Logic Analysis) for the Windows-Based PC

NASA Technical Reports Server (NTRS)

Lovelace, Jeffrey J.; Cios, Kryzsztof J.; Roth, Don J.; cAO, wEI n.

2001-01-01

Post-Scan Interactive Data Display (PSIDD) III is a user-oriented Windows-based system that facilitates the display and comparison of ultrasonic contact measurement data obtained at NASA Glenn Research Center's Ultrasonic Nondestructive Evaluation measurement facility. The system is optimized to compare ultrasonic measurements made at different locations within a material or at different stages of material degradation. PSIDD III provides complete analysis of the primary waveforms in the time and frequency domains along with the calculation of several frequency-dependent properties including phase velocity and attenuation coefficient and several frequency-independent properties, like the cross correlation velocity. The system allows image generation on all the frequency-dependent properties at any available frequency (limited by the bandwidth used in the scans) and on any of the frequency-independent properties. From ultrasonic contact scans, areas of interest on an image can be studied with regard to underlying raw waveforms and derived ultrasonic properties by simply selecting the point on the image. The system offers various modes of indepth comparison between scan points. Up to five scan points can be selected for comparative analysis at once. The system was developed with Borland Delphi software (Visual Pascal) and is based on an SQL data base. It is ideal for the classification of material properties or the location of microstructure variations in materials. Along with the ultrasonic contact measurement software that it is partnered with, this system is technology ready and can be transferred to users worldwide.

Prediction of Building Limestone Physical and Mechanical Properties by Means of Ultrasonic P-Wave Velocity

PubMed Central

Concu, Giovanna; De Nicolo, Barbara; Valdes, Monica

2014-01-01

The aim of this study was to evaluate ultrasonic P-wave velocity as a feature for predicting some physical and mechanical properties that describe the behavior of local building limestone. To this end, both ultrasonic testing and compressive tests were carried out on several limestone specimens and statistical correlation between ultrasonic velocity and density, compressive strength, and modulus of elasticity was studied. The effectiveness of ultrasonic velocity was evaluated by regression, with the aim of observing the coefficient of determination r 2 between ultrasonic velocity and the aforementioned parameters, and the mathematical expressions of the correlations were found and discussed. The strong relations that were established between ultrasonic velocity and limestone properties indicate that these parameters can be reasonably estimated by means of this nondestructive parameter. This may be of great value in a preliminary phase of the diagnosis and inspection of stone masonry conditions, especially when the possibility of sampling material cores is reduced. PMID:24511286

Prediction of building limestone physical and mechanical properties by means of ultrasonic P-wave velocity.

PubMed

Concu, Giovanna; De Nicolo, Barbara; Valdes, Monica

2014-01-01

The aim of this study was to evaluate ultrasonic P-wave velocity as a feature for predicting some physical and mechanical properties that describe the behavior of local building limestone. To this end, both ultrasonic testing and compressive tests were carried out on several limestone specimens and statistical correlation between ultrasonic velocity and density, compressive strength, and modulus of elasticity was studied. The effectiveness of ultrasonic velocity was evaluated by regression, with the aim of observing the coefficient of determination r(2) between ultrasonic velocity and the aforementioned parameters, and the mathematical expressions of the correlations were found and discussed. The strong relations that were established between ultrasonic velocity and limestone properties indicate that these parameters can be reasonably estimated by means of this nondestructive parameter. This may be of great value in a preliminary phase of the diagnosis and inspection of stone masonry conditions, especially when the possibility of sampling material cores is reduced.

Prediction of transverse shrinkages of young-growth Sitka spruce (Picea sitchensis) and western hemlock (Tsuga heterophylla) with ultrasonic measurements

Treesearch

Turker Dundar; Xiping Wang; Robert J. Ross

2013-01-01

The objective of this study was to examine the potential of acoustic measurement as a rapid and nondestructive method to predict the dimensional stability of young-growth Sitka spruce and western hemlock. Ultrasonic velocity, peak energy, specific gravity, and radial and tangential shrinkages were measured on twenty-four 25- x

Ultrasonic characterization of the nonlinear elastic properties of unidirectional graphite/epoxy composites

NASA Technical Reports Server (NTRS)

Prosser, William H.

1987-01-01

The theoretical treatment of linear and nonlinear elasticity in a unidirectionally fiber reinforced composite as well as measurements for a unidirectional graphite/epoxy composite (T300/5208) are presented. Linear elastic properties were measured by both ultrasonic and strain gage measurements. The nonlinear properties were determined by measuring changes in ultrasonic natural phase velocity with a pulsed phase locked loop interferometer as a function of stress and temperature. These measurements provide the basis for further investigations into the relationship between nonlinear elastic properties and other important properties such as strength and fiber-matrix interfacial stength in graphite/epoxy composites.

Ultrasonic evaluation of oxidation and reduction effects on the elastic behavior and global microstructure of YBa2Cu3O7-x

NASA Technical Reports Server (NTRS)

Roth, Don J.; Deguire, Mark R.; Dolhert, Leonard E.

1991-01-01

Ultrasonic velocity measurement techniques were used to evaluate the effects of oxidation and reduction on the elastic properties, global microstructure and oxygen content of the YBa2Cu3O(7-x) ceramic superconductor for samples ranging from 70 to 90 pct. of theoretical density. Bulk density, velocity, and elastic modulus generally increased with increasing oxygen content upon oxidation, and this behavior was reversible. Velocity image patterns were similar after oxidation and reduction treatments for a 90 pct. dense sample, although the velocity value at any given point on the sample was changed following the treatments. The unchanging pattern correlated with destructive measurements showing that the spatial pore distribution (fraction and size) was not measurably altered after the treatments. Changes in superconducting behavior, crystal structure, and grain structure were observed consistent with changes in oxygen content.

Ultrasonic Characterization of the Linear Elastic Properties of Myocardium and Other Anisotropic Soft Tissues

NASA Astrophysics Data System (ADS)

Hoffmeister, Brentley Keith

1995-01-01

This thesis seeks to contribute to a better understanding of the physics of interaction of ultrasonic waves with inhomogeneous and anisotropic media, one example of which is the human heart. The clinical success of echocardiography has generated a considerable interest in the development of ultrasonic techniques to measure the elastic properties of heart tissue. It is hypothesized that the elastic properties of myocardium are influenced by the interstitial content and organization of collagen. Collagen, which is the main component of tendon, interconnects the muscle cells of the heart to form locally unidirectional myofibers. This thesis therefore employs ultrasonic techniques to characterize the linear elastic properties of both heart and tendon. The linear elastic properties of tissues possessing a unidirectional arrangement of fibers may be described in terms of five independent elastic stiffness coefficients. Three of these coefficients were determined for formalin fixed specimens of bovine Achilles tendon and human myocardium by measuring the velocity of longitudinal mode ultrasonic pulses as a function of angle of propagation relative to the fiber axis of the tissue. The remaining two coefficients were determined by measuring the velocity of transverse mode ultrasonic waves through these tissues. To overcome technical difficulties associated with the extremely high attenuation of transverse mode waves at low megahertz frequencies, a novel measurement system was developed based on the sampled continuous wave technique. Results of these measurements were used to assess the influence of interstitial collagen, and to model the mechanical properties of heart wall.

Spatial variations in a.c. susceptibility and microstructure for the YBa2Cu3O(7-x) superconductor and their correlation with room-temperature ultrasonic measurements

NASA Technical Reports Server (NTRS)

Roth, Don J.; Hepp, Aloysius F.; Deguire, Mark R.; Dolhert, Leonard E.

1991-01-01

The spatial (within-sample) uniformity of superconducting behavior and microstructure in YBa2Cu30(7-x) specimens over the pore fraction range of 0.10 to 0.25 was examined. The viability of using a room-temperature, nondestructive characterization method (ultrasonic velocity imaging) to predict spatial variability was determined. Spatial variations in superconductor properties were observed for specimens containing 0.10 pore fraction. An ultrasonic velocity image constructed from measurements at 1 mm increments across one such specimen revealed microstructural variation between edge and center locations that correlated with variations in alternating-current shielding and loss behavior. Optical quantitative image analysis on sample cross-sections revealed pore fraction to be the varying microstructural feature.

Spatial variations in ac susceptibility and microstructure for the YBa2Cu3O(7-x) superconductor and their correlation with room-temperature ultrasonic measurements

NASA Technical Reports Server (NTRS)

Roth, Don J.; Deguire, Mark R.; Dolhert, Leonard E.; Hepp, Aloysius F.

1991-01-01

The spatial (within-sample) uniformity of superconducting behavior and microstructure in YBa2Cu3O(7-x) specimens over the pore fraction range of 0.10 to 0.25 was examined. The viability of using a room-temperature, nondestructive characterization method (ultrasonic velocity imaging) to predict spatial variability was determined. Spatial variations in superconductor properties were observed for specimens containing 0.10 pore fraction. An ultrasonic velocity image constructed from measurements at 1 mm increments across one such specimen revealed microstructural variation between edge and center locations that correlated with variations in alternating-current shielding and loss behavior. Optical quantitative image analysis on sample cross-sections revealed pore fraction to be the varying microstructural feature.

Correlation between compressive strength and ultrasonic pulse velocity of high strength concrete incorporating chopped basalt fibre

NASA Astrophysics Data System (ADS)

Shafiq, Nasir; Fadhilnuruddin, Muhd; Elshekh, Ali Elheber Ahmed; Fathi, Ahmed

2015-07-01

Ultrasonic pulse velocity (UPV), is considered as the most important test for non-destructive techniques that are used to evaluate the mechanical characteristics of high strength concrete (HSC). The relationship between the compressive strength of HSC containing chopped basalt fibre stands (CBSF) and UPV was investigated. The concrete specimens were prepared using a different ratio of CBSF as internal strengthening materials. The compressive strength measurements were conducted at the sample ages of 3, 7, 28, 56 and 90 days; whilst, the ultrasonic pulse velocity was measured at 28 days. The result of HSC's compressive strength with the chopped basalt fibre did not show any improvement; instead, it was decreased. The UPV of the chopped basalt fibre reinforced concrete has been found to be less than that of the control mix for each addition ratio of the basalt fibre. A relationship plot is gained between the cube compressive strength for HSC and UPV with various amounts of chopped basalt fibres.

Ultrasonic Guided Waves for Aging Wire Insulation Assessment

NASA Technical Reports Server (NTRS)

Anastasi, Robert F.; Madaras, Eric I.

2001-01-01

Environmentally aged wire insulation can become brittle and crack and thus expose the underlying conductive wire to the potential for short circuits and fire. The feasibility of using ultrasonic guided waves to measure insulation condition was examined. First a simple model to study guided wave propagation in a bare and thin plastic coated wire was examined and then some aviation grade wire samples that had been heat-damaged. Initial measurements indicate that ultrasonic guided wave velocity can be used to monitor insulation stiffness.

From the speed of sound to the speed of light: Ultrasonic Cherenkov refractometry

NASA Astrophysics Data System (ADS)

Hallewell, G. D.

2017-12-01

Despite its success in the SLD CRID at the SLAC Linear Collider, ultrasonic measurement of Cherenkov radiator refractive index has been less fully exploited in more recent Cherenkov detectors employing gaseous radiators. This is surprising, since it is ideally suited to monitoring hydrostatic variations in refractive index as well as its evolution during the replacement of a light radiator passivation gas (e.g. N2, CO2) with a heavier fluorocarbon (e.g. C4F10[CF4]; mol. wt. 188[88]). The technique exploits the dependence of sound velocity on the molar concentrations of the two components at known temperature and pressure. The SLD barrel CRID used an 87%C5F12/13%N2 blend, mixed before injection into the radiator vessel: blend control based on ultrasonic mixture analysis maintained the β=1 Cherenkov ring angle to a long term variation better than ±0.3%, with refractivity monitored ultrasonically at multiple points within the radiator vessel. Recent advances using microcontroller-based electronics have led to ultrasonic instruments capable of simultaneously measuring gas flow and binary mixture composition in the fluorocarbon evaporative cooling systems of the ATLAS Inner Detector. Sound transit times are measured with multi-MHz transit time clocks in opposite directions in flowing gas for simultaneous measurement of flow rate and sound velocity. Gas composition is evaluated in real-time by comparison with a sound velocity/composition database. Such instruments could be incorporated into new and upgraded gas Cherenkov detectors for radiator gas mixture (and corresponding refractive index) measurement to a precision better than 10-3. They have other applications in binary gas analysis - including in Xenon-based anaesthesia. These possibilities are discussed.

Ultrasonic Characterization of Microstructural Changes in Ti-10V-4.5Fe-1.5Al β-Titanium Alloy

NASA Astrophysics Data System (ADS)

Viswanath, A.; Kumar, Anish; Jayakumar, T.; Purnachandra Rao, B.

2015-08-01

Ultrasonic measurements have been carried out in Ti-10V-4.5Fe-1.5Al β-titanium alloy specimens subjected to β annealing at 1173 K (900 °C) for 1 hour followed by heat treatment in the temperature range of 823 K to 1173 K (550 °C to 900 °C) at an interval of 50 K (50 °C) for 1 hour, followed by water quenching. Ultrasonic parameters such as ultrasonic longitudinal wave velocity, ultrasonic shear wave velocity, shear anisotropy parameter, ultrasonic attenuation, and normalized nonlinear ultrasonic parameter have been correlated with various microstructural changes to understand the interaction of the propagating ultrasonic wave with microstructural features in the alloy. Simulation studies using JMatPro® software and X-ray diffraction measurements have been carried out to estimate the α-phase volume fraction in the specimens heat treated below the β-transus temperature (BTT). It is found that the α-phase (HCP) volume fraction increases from 0 to 52 pct, with decrease in the temperature from 1073 K to 823 K (800 °C to 550 °C). Ultrasonic longitudinal and shear wave velocities are found to increase with decrease in the heat treatment temperature below the BTT, and they exhibited linear relationships with the α-phase volume fraction. Thickness-independent ultrasonic parameters, Poisson's ratio, and the shear anisotropy parameter exhibited the opposite behavior, i.e., decrease with increase in the α-phase consequent to decrease in the heat treatment temperature from 1073 K to 823 K (800 °C to 550 °C). Ultrasonic attenuation is found to decrease from 0.7 dB/mm for the β-annealed specimen to 0.23 dB/mm in the specimen heat treated at 823 K (550 °C) due to the combined effect of the decrease in the β-phase (BCC) with higher damping characteristics and the reduction in scattering due to randomization of β grains with the precipitation of α-phase. Normalized nonlinear ultrasonic parameter is found to increase with increase in the α-phase volume fraction due to increased interfacial strain. For the first time, quantitative correlations established between various ultrasonic parameters and the volume fraction of α-phase in a β-titanium alloy are reported in the present paper. The established correlations are useful for estimation of volume fraction of α-phase in heat-treated β-titanium alloy, by nondestructive ultrasonic measurements.

Calculation of acoustic field based on laser-measured vibration velocities on ultrasonic transducer surface

NASA Astrophysics Data System (ADS)

Hu, Liang; Zhao, Nannan; Gao, Zhijian; Mao, Kai; Chen, Wenyu; Fu, Xin

2018-05-01

Determination of the distribution of a generated acoustic field is valuable for studying ultrasonic transducers, including providing the guidance for transducer design and the basis for analyzing their performance, etc. A method calculating the acoustic field based on laser-measured vibration velocities on the ultrasonic transducer surface is proposed in this paper. Without knowing the inner structure of the transducer, the acoustic field outside it can be calculated by solving the governing partial differential equation (PDE) of the field based on the specified boundary conditions (BCs). In our study, the BC on the transducer surface, i.e. the distribution of the vibration velocity on the surface, is accurately determined by laser scanning measurement of discrete points and follows a data fitting computation. In addition, to ensure the calculation accuracy for the whole field even in an inhomogeneous medium, a finite element method is used to solve the governing PDE based on the mixed BCs, including the discretely measured velocity data and other specified BCs. The method is firstly validated on numerical piezoelectric transducer models. The acoustic pressure distributions generated by a transducer operating in an homogeneous and inhomogeneous medium, respectively, are both calculated by the proposed method and compared with the results from other existing methods. Then, the method is further experimentally validated with two actual ultrasonic transducers used for flow measurement in our lab. The amplitude change of the output voltage signal from the receiver transducer due to changing the relative position of the two transducers is calculated by the proposed method and compared with the experimental data. This method can also provide the basis for complex multi-physical coupling computations where the effect of the acoustic field should be taken into account.

In vitro evaluation of forward and reverse volumetric flow across a regurgitant aortic valve using Doppler power-weighted mean velocities.

PubMed

Minich, L L; Tani, L Y; Pantalos, G M

1997-01-01

To determine the accuracy of using power-weighted mean velocities for quantitating volumetric flow across a cardiac valve, we equipped pulsatile flow-tank systems with a 25 mm porcine or a 27 mm mechanical valve with various sizes of regurgitant orifices. Forward and reverse volumetric flows were measured over a range of hemodynamic conditions using two insonating angles (0 and 45 degrees). Pulsed Doppler power-weighted mean velocity measurements were obtained simultaneously with electromagnetic or ultrasonic transit-time probe measurements. For the porcine valve, Doppler measurements correlated well with electromagnetic flow measurements for all (r = 0.75 to 0.97, p < 0.05) except the smallest (2.7 mm) orifice (r = 0.19). For the mechanical valve, power-weighted mean velocity measurements correlated well with ultrasonic transit-time measurements for each hemodynamic condition defined by pulse rate, mean arterial pressure, and insonating angle (r = 0.93 to 0.99, p < 0.01), but equations varied unpredictably. Thus, although power-weighted mean velocity volumetric flow measurements correlate well with flow probe measurements, equations vary widely as hemodynamic conditions change. Because of this variation, power-weighted mean velocity data are not useful for quantitation of volumetric flow across a cardiac valve at this time. Further investigation may show how different hemodynamic conditions affect power-weighted mean velocity measurements of volumetric flow.

Ultrasonic Technique for Predicting Grittiness of Salted Duck Egg

NASA Astrophysics Data System (ADS)

Erawan, S.; Budiastra, I. W.; Subrata, I. D. M.

2018-05-01

Grittiness of egg yolk is a major factor in consumer acceptance of salted duck egg product. Commonly, the grittiness level is determined by the destructive method. Salted egg industries need a grading system that can judge the grittiness accurately and nondestructively. The purpose of this study was to develop a method for determining grittiness of salted duck eggs nondestructively based on ultrasonic method. This study used 100 samples of salted duck eggs with 7,10,14 and 21 days of salting age. Velocity and attenuation were measured by an ultrasonic system at frequency 50 kHz, followed by physicochemical properties measurement (hardness of egg yolks and salt content), and organoleptic test. Ultrasonic wave velocity in salted duck eggs ranged from 620.6 m/s to 1334.6 m/s, while the coefficient of attenuation value ranged from – 0.76 dB/m to -0.51 dB/m. Yolk hardness was 2.68 N at 7 days to 5.54 N at 21 days of salting age. Salt content was 1.81 % at 7 days to 5.71 % at 21 days of salting age. Highest scores of organoleptic tests on salted duck eggs were 4.23 and 4.18 for 10 and 14 days of salting age, respectively. Discriminant function using ultrasonic velocity variables in minor and major diameter could predict grittiness with 95 % accuracy.

Ultrasonic sensor and method of use

DOEpatents

Condreva, Kenneth J.

2001-01-01

An ultrasonic sensor system and method of use for measuring transit time though a liquid sample, using one ultrasonic transducer coupled to a precision time interval counter. The timing circuit captures changes in transit time, representing small changes in the velocity of sound transmitted, over necessarily small time intervals (nanoseconds) and uses the transit time changes to identify the presence of non-conforming constituents in the sample.

Anisotropic determination and correction for ultrasonic flaw detection by spectral analysis

DOEpatents

Adler, Laszlo; Von Cook, K.; Simpson, Jr., William A.; Lewis, D. Kent

1978-01-01

The anisotropic nature of a material is determined by measuring the velocity of an ultrasonic longitudinal wave and a pair of perpendicular ultrasonic shear waves through a sample of the material each at a plurality of different angles in three planes orthogonal to each other. The determined anisotropic nature is used as a correction factor in a spectral analyzing system of flaw determination.

Estimation of two-dimensional motion velocity using ultrasonic signals beamformed in Cartesian coordinate for measurement of cardiac dynamics

NASA Astrophysics Data System (ADS)

Kaburaki, Kaori; Mozumi, Michiya; Hasegawa, Hideyuki

2018-07-01

Methods for the estimation of two-dimensional (2D) velocity and displacement of physiological tissues are necessary for quantitative diagnosis. In echocardiography with a phased array probe, the accuracy in the estimation of the lateral motion is lower than that of the axial motion. To improve the accuracy in the estimation of the lateral motion, in the present study, the coordinate system for ultrasonic beamforming was changed from the conventional polar coordinate to the Cartesian coordinate. In a basic experiment, the motion velocity of a phantom, which was moved at a constant speed, was estimated by the conventional and proposed methods. The proposed method reduced the bias error and standard deviation in the estimated motion velocities. In an in vivo measurement, intracardiac blood flow was analyzed by the proposed method.

Simultaneous Concentration and Velocity Maps in Particle Suspensions under Shear from Rheo-Ultrasonic Imaging

NASA Astrophysics Data System (ADS)

Saint-Michel, Brice; Bodiguel, Hugues; Meeker, Steven; Manneville, Sébastien

2017-07-01

We extend a previously developed ultrafast ultrasonic technique [T. Gallot et al., Rev. Sci. Instrum. 84, 045107 (2013), 10.1063/1.4801462] to concentration-field measurements in non-Brownian particle suspensions under shear. The technique provides access to time-resolved concentration maps within the gap of a Taylor-Couette cell simultaneously to local velocity measurements and standard rheological characterization. Benchmark experiments in homogeneous particle suspensions are used to calibrate the system. We then image heterogeneous concentration fields that result from centrifugation effects, from the classical Taylor-Couette instability, and from sedimentation or shear-induced resuspension.

A Simple Ultrasonic Experiment Using a Phase Shift Detection Technique.

ERIC Educational Resources Information Center

Yunus, W. Mahmood Mat; Ahmad, Maulana

1996-01-01

Describes a simple ultrasonic experiment that can be used to measure the purity of liquid samples by detecting variations in the velocity of sound. Uses a phase shift detection technique that incorporates the use of logic gates and a piezoelectric transducer. (JRH)

Two transducer formula for more precise determination of ultrasonic phase velocity from standing wave measurements

NASA Technical Reports Server (NTRS)

Ringermacher, H. I.; Moerner, W. E.; Miller, J. G.

1974-01-01

A two transducer correction formula valid for both solid and liquid specimens is presented. Using computer simulations of velocity measurements, the accuracy and range of validity of the results are discussed and are compared with previous approximations.

Ultrasonic Surface Measurements for the investigation of superficial alteration of natural stones

NASA Astrophysics Data System (ADS)

Meier, Thomas; Auras, Michael; Bilgili, Filiz; Christen, Sandra; Cristiano, Luigia; Krompholz, Rolf; Mosca, Ilaria; Rose, David

2013-04-01

Seismic waveform analysis is applicable also to the centimeter and decimeter scale for non-destructive testing of pavement, facades, plaster, sculptures, or load-bearing structures like pillars. Mostly transmission measurements are performed and travel-times of first arriving P-waves are considered that have limited resolution for the upper centimeters of an object. In contrast, surface measurements are well suited to quantify superficial alterations of material properties e.g. due to weathering. A number of surface measurements have been carried out in the laboratory as well as on real structures in order to study systematically the information content of ultrasonic waveforms and their variability under real conditions. As a preposition for ultrasonic waveform analysis, reproducible, broad-band measurements have to be carried out with a definite radiation pattern and an about 1 mm accuracy of the measurement geometry. We used special coupling devices for effective ultrasonic surface measurements in the laboratory as well as at real objects. Samples of concrete with varying composition and samples of natural stone - marble, tuff, and sandstone - were repeatedly weathered and tested by ultrasonic measurements. The resistance of the samples to weathering and the penetration depth of the weathering are analyzed. Furthermore, material specific calibration curves for changes in velocities of elastic waves due to weathering can be obtained by these tests. Tests on real structures have been carried out for marble (Schlossbrücke, Berlin) and sandstone (Porta Nigra, Trier). Altogether, these test measurements show clearly that despite of the internal inhomogeneity of many real objects, their surface roughness and topography especially ultrasonic Rayleigh waves are well suited to study material alterations in the upper centimeters. Dispersion of Rayleigh waves may be inverted for shear-wave velocity as a function of depth.

Effect of ultrasonication in synthesis of gold nano fluid for thermal applications

NASA Astrophysics Data System (ADS)

Nath, G.; Giri, R.

2018-02-01

Ultrasonically synthesized nanofluids are efficient coolant and heat exchanger material has demonstrated its potential in various fields and thermal engineering. The computation of different acoustical parameter using the ultrasonic velocity data of gold nanofluids are taken in estimation of thermal conductivity. The computational and experimental measured values of thermal conductivity are well agrees. The results execute ultrasonically synthesized gold nanofluids is an economic and efficient technology for explaining the increase of thermal conductivity of nanofluids in suitable optimum conditions.

PSIDD (2): A Prototype Post-Scan Interactive Data Display System for Detailed Analysis of Ultrasonic Scans

NASA Technical Reports Server (NTRS)

Cao, Wei; Roth, Don J.

1997-01-01

This article presents the description of PSIDD(2), a post-scan interactive data display system for ultrasonic contact scan and single measurement analysis. PSIDD(2) was developed in conjunction with ASTM standards for ultrasonic velocity and attenuation coefficient contact measurements. This system has been upgraded from its original version PSIDD(1) and improvements are described in this article. PSIDD(2) implements a comparison mode where the display of time domain waveforms and ultrasonic properties versus frequency can be shown for up to five scan points on one plot. This allows the rapid contrasting of sample areas exhibiting different ultrasonic properties as initially indicated by the ultrasonic contact scan image. This improvement plus additional features to be described in the article greatly facilitate material microstructural appraisal.

Welding induced residual stress evaluation using laser-generated Rayleigh waves

NASA Astrophysics Data System (ADS)

Ye, Chong; Zhou, Yuanlai; Reddy, Vishnu V. B.; Mebane, Aaron; Ume, I. Charles

2018-04-01

Welding induced residual stress could affect the dimensional stability, fatigue life, and chemical resistance of the weld joints. Ultrasonic method serves as an important non-destructive tool for the residual stress evaluation due to its easy implementation, low cost and wide application to different materials. Residual stress would result in the ultrasonic wave velocity variation, which is the so called acoustoelastic effect. In this paper, Laser/EMAT ultrasonic technique was proposed to experimentally study the relative velocity variation ΔV/V of Rayleigh wave, which has the potential to evaluate surface/subsurface longitudinal residual stress developed during the Gas Metal Arc Welding process. Broad band ultrasonic waves were excited by pulsed Q-Switched Nd: YAG laser. An electromagnetic acoustic transducer (EMAT) attached to the welded plates was used to capture the Rayleigh wave signals propagating along the weld seam direction. Different time of flight measurements were conducted by varying the distance between the weld seam and Rayleigh wave propagating path in the range of 0 to 45 mm. The maximum relative velocity difference was found on the weld seam. With the increasing distance away from the weld seam, the relative velocity difference sharply decreased to negative value. With further increase in distance, the relative velocity difference slowly increased and approached zero. The distribution of relative velocity variations indicates that tensile stress appears in the melted zone as it becomes compressive near the heat-affected zone.

Ultrasonic laboratory measurements of the seismic velocity changes due to CO2 injection

NASA Astrophysics Data System (ADS)

Park, K. G.; Choi, H.; Park, Y. C.; Hwang, S.

2009-04-01

Monitoring the behavior and movement of carbon dioxide (CO2) in the subsurface is a quite important in sequestration of CO2 in geological formation because such information provides a basis for demonstrating the safety of CO2 sequestration. Recent several applications in many commercial and pilot scale projects and researches show that 4D surface or borehole seismic methods are among the most promising techniques for this purpose. However, such information interpreted from the seismic velocity changes can be quite subjective and qualitative without petrophysical characterization for the effect of CO2 saturation on the seismic changes since seismic wave velocity depends on various factors and parameters like mineralogical composition, hydrogeological factors, in-situ conditions. In this respect, we have developed an ultrasonic laboratory measurement system and have carried out measurements for a porous sandstone sample to characterize the effects of CO2 injection to seismic velocity and amplitude. Measurements are done by ultrasonic piezoelectric transducer mounted on both ends of cylindrical core sample under various pressure, temperature, and saturation conditions. According to our fundamental experiments, injected CO2 introduces the decrease of seismic velocity and amplitude. We identified that the velocity decreases about 6% or more until fully saturated by CO2, but the attenuation of seismic amplitude is more drastically than the velocity decrease. We also identified that Vs/Vp or elastic modulus is more sensitive to CO2 saturation. We note that this means seismic amplitude and elastic modulus change can be an alternative target anomaly of seismic techniques in CO2 sequestration monitoring. Thus, we expect that we can estimate more quantitative petrophysical relationships between the changes of seismic attributes and CO2 concentration, which can provide basic relation for the quantitative assessment of CO2 sequestration by further researches.

Structural change and charge ordering correlated ultrasonic anomalies in La1-xCaxMnO3 (x=0.5,0.83) perovskite

NASA Astrophysics Data System (ADS)

Zheng, R. K.; Zhu, C. F.; Xie, J. Q.; Li, X. G.

2001-01-01

Ultrasonic sound velocity and attenuation have been measured in polycrystalline manganese oxide La1-xCaxMnO3 (x=0.5,0.83,1.0) at a frequency of 10 MHz. For x=0.5, on cooling down from high temperature, a slight softening of the sound velocity above the charge ordering transition temperature TCO and dramatic stiffening below TCO coincided with big attenuation peaks for both longitudinal and transverse waves were observed. It was found that these ultrasonic anomalies near TCO are correlated with the fine structure (i.e., the lattice parameters) change caused by the Jahn-Teller effect. For x=0.83, the sound velocity starts to soften dramatically with decreasing temperature from higher temperature to TS (180 K), and stiffens dramatically below TS. The large softening and stiffening of the sound velocity accompanied by a big attenuation peak are strongly correlated with a cubic-to-tetragonal structural phase transition at TS, which is confirmed by the low-temperature powder x-ray diffraction measurements. It is suggested that this structural phase transition be due to the Jahn-Teller distortion of the Mn3+O6 octahedra and related to the charge ordering transition. For CaMnO3, the anomaly in sound velocity is small.

Piston cylinder cell for high pressure ultrasonic pulse echo measurements.

PubMed

Kepa, M W; Ridley, C J; Kamenev, K V; Huxley, A D

2016-08-01

Ultrasonic techniques such as pulse echo, vibrating reed, or resonant ultrasound spectroscopy are powerful probes not only for studying elasticity but also for investigating electronic and magnetic properties. Here, we report on the design of a high pressure ultrasonic pulse echo apparatus, based on a piston cylinder cell, with a simplified electronic setup that operates with a single coaxial cable and requires sample lengths of mm only. The design allows simultaneous measurements of ultrasonic velocities and attenuation coefficients up to a pressure of 1.5 GPa. We illustrate the performance of the cell by probing the phase diagram of a single crystal of the ferromagnetic superconductor UGe2.

Piston cylinder cell for high pressure ultrasonic pulse echo measurements

NASA Astrophysics Data System (ADS)

Kepa, M. W.; Ridley, C. J.; Kamenev, K. V.; Huxley, A. D.

2016-08-01

Ultrasonic techniques such as pulse echo, vibrating reed, or resonant ultrasound spectroscopy are powerful probes not only for studying elasticity but also for investigating electronic and magnetic properties. Here, we report on the design of a high pressure ultrasonic pulse echo apparatus, based on a piston cylinder cell, with a simplified electronic setup that operates with a single coaxial cable and requires sample lengths of mm only. The design allows simultaneous measurements of ultrasonic velocities and attenuation coefficients up to a pressure of 1.5 GPa. We illustrate the performance of the cell by probing the phase diagram of a single crystal of the ferromagnetic superconductor UGe2.

Characterization of the Nonlinear Elastic Properties of Graphite/Epoxy Composites Using Ultrasound

NASA Technical Reports Server (NTRS)

Prosser, William H.; Green, Robert E., Jr.

1990-01-01

The normalized change in ultrasonic "natural" velocity as a function of stress and temperature was measured in a unidirectional laminate of T300/5208 graphite/epoxy composite using a pulsed phase locked loop ultrasonic interferometer. These measurements were used together with the linear (second order) elastic moduli to calculate some of the nonlinear (third order) moduli of this material.

Pulsed ultrasonic comb filtering effect and its applications in the measurement of sound velocity and thickness of thin plates.

PubMed

Liu, Jingfei; Declercq, Nico F

2017-03-01

An analytical and experimental study of the pulsed ultrasonic comb filtering effect is presented in this work intending to provide a fundamental tool for data analysis and phenomenon understanding in pulsed ultrasonics. The basic types of comb filter, feedforward and feedback filters, are numerically simulated and demonstrated. The characteristic features of comb filters, which include the formula for determining the locations of the spectral peaks or notches and the relationship between its temporal characteristics (relative time delay between constituent pulses) and its spectral characteristics (frequency interval between peaks or notches), are theoretically derived. To demonstrate the applicability of the comb filtering effect, it is applied to measuring the sound velocities and thickness of a thin plate sample. It is proven that the comb filtering effect based method not only is capable of accurate measurements, but also has advantages over the conventional time-of-flight based method in thin plate measurements. Furthermore, the principles developed in this study have potential applications in any pulsed ultrasonic cases where the output signal shows comb filter features. Copyright © 2016 Elsevier B.V. All rights reserved.

Influence of pressure on acoustic and rheologic parameters in water solutions of laury sodium sulfate

NASA Astrophysics Data System (ADS)

Khamidov, B. T.; Lezhnev, N. B.

1995-10-01

Ultrasonic velocity and density in water solutions of lauril sodium sulphate at frequency 36 MHz, within the range of pressures from 0.1 to 105 MPa at temperature T equals 293 K were measured. According to data of ultrasonic velocity and density under high pressures there was calculated adiabatic compressibility in objects studied from pressure. It was found out that the region of critical concentration of micelle formation has been shifted to the zone of much more low concentrations.

Modeling the interaction of ultrasound with pores

NASA Technical Reports Server (NTRS)

Lu, Yichi; Wadley, Haydn N. G.; Parthasarathi, Sanjai

1991-01-01

Factors that affect ultrasonic velocity sensing of density during consolidation of metal powders are examined. A comparison is made between experimental results obtained during the final stage of densification and the predictions of models that assume either a spherical or a spheroidal pore shape. It is found that for measurements made at low frequencies during the final stage of densification, relative density (pore fraction) and pore shape are the two most important factors determining the ultrasonic velocity, the effect of pore size is negligible.

Experimental investigation of the Multipoint Ultrasonic Flowmeter

NASA Astrophysics Data System (ADS)

Jakub, Filipský

2018-06-01

The Multipoint Ultrasonic Flowmeter is a vector tomographic device capable of reconstructing all three components of velocity field based solely on boundary ultrasonic measurements. Computer simulations have shown the feasibility of such a device and have been published previously. This paper describes an experimental investigation of achievable accuracy of such a method. Doubled acoustic tripoles used to obtain information of the solenoidal part of vector field show extremely short differences between the Time Of Flights (TOFs) of individual sensors and are therefore sensitive to parasitic effects of TOF measurements. Sampling at 40MHz and correlation method is used to measure the TOF.

Multiple temperature sensors embedded in an ultrasonic "spiral-like" waveguide

NASA Astrophysics Data System (ADS)

Periyannan, Suresh; Rajagopal, Prabhu; Balasubramaniam, Krishnan

2017-03-01

This paper studies the propagation of ultrasound in spiral waveguides, towards distributed temperature measurements on a plane. Finite Element (FE) approach was used for understanding the velocity behaviour and consequently designing the spiral waveguide. Temperature measurements were experimentally carried out on planar surface inside a hot chamber. Transduction was performed using a piezo-electric crystal that is attached to one end of the waveguide. Lower order axisymmetric guided ultrasonic modes L(0,1) and T(0,1) were employed. Notches were introduced along the waveguide to obtain ultrasonic wave reflections. Time of fight (TOF) differences between the pre-defined reflectors (notches) located on the waveguides were used to infer local temperatures. The ultrasonic temperature measurements were compared with commercially available thermocouples.

Understanding of Materials State and its Degradation using Non-Linear Ultrasound (NLU) Approaches

DTIC Science & Technology

2011-01-01

Traditional ultrasonic NDE is based on linear theory and normally relies on measuring some particular parameter (sound velocity , attenuation... velocity in the material. In most cases this technique is not considered to be very practical as very small changes in velocity has to be measured. Hence...nonlinear elasticity) of the material the input wave distorts as it propagates. This is attributed to the difference in the wave velocities of the

Density and Ultrasonic Characterization of Oil Palm Trunk Infected by Ganoderma Boninense Disease

NASA Astrophysics Data System (ADS)

Najmie, M. M. K.; Khalid, K.; Sidek, A. A.; Jusoh, M. A.

2011-01-01

Oil palm trunks infected by Ganoderma boninense disease have been studied using density and ultrasonic characterizations. The ultrasonic characterizations have been performed using a commercial ultrasonic instrument at the frequency of 54 kHz. The measurements have been done in 3 zones: inner zone, central zone and peripheral zone. It was found that the stem density of the oil palm infected by Ganoderma boninense disease was reduced by 50% in comparison to the original healthy trunk. From this effect the velocity of the ultrasonic wave propagated through the Longitudinal, Radial, and Tangential directions is lower for the trunk infected by Ganoderma boninense disease compared to a healthy trunk. For the 10 cm thickness of samples, the ultrasonic velocity for all transit directions was in range of 260 - 750 ms-1 for the infected sample, whereas for healthy samples was in the range of 460 - 900 ms-1. These results are very useful for the detection of the area which has been affected by the disease.

Physical interpretation and application of principles of ultrasonic nondestructive evaluation of high-performance materials

NASA Technical Reports Server (NTRS)

Miller, James G.

1990-01-01

An ultrasonic measurement system employed in the experimental interrogation of the anisotropic properties (through the measurement of the elastic stiffness constants) of the uniaxial graphite-epoxy composites is presented. The continuing effort for the development of improved visualization techniques for physical parameters is discussed. The background is set for the understanding and visualization of the relationship between the phase and energy/group velocity for propagation in high-performance anisotropic materials by investigating the general requirements imposed by the classical wave equation. The consequences are considered when the physical parameters of the anisotropic material are inserted into the classical wave equation by a linear elastic model. The relationship is described between the phase velocity and the energy/group velocity three dimensional surfaces through graphical techniques.

Ultrasonic Evaluation of Fatigue Damage

NASA Astrophysics Data System (ADS)

Bayer, P.; Singher, L.; Notea, A.

2004-02-01

Despite the fact that most engineers and designers are aware of fatigue, many severe breakdowns of industrial plant and machinery still occur due to fatigue. In effect, it's been estimated that fatigue causes at least 80% of the failures in modern engineering components. From an operational point of view, the detection of fatigue damage, preferably at a very early stage, is a critically important consideration in order to prevent possible catastrophic equipment failure and associated losses. This paper describes the investigation involving the use of ultrasonic waves as a potential tool for early detection of fatigue damage. The parameters investigated were the ultrasonic wave velocities (longitudinal and transverse waves) and attenuation coefficient before fatigue damage and after progressive stages of fatigue. Although comparatively small uncertainties were observed, the feasibility of utilizing the velocity of ultrasonic waves as a fatigue monitor was barely substantiated within actual research conditions. However, careful measurements of the ultrasonic attenuation parameter had demonstrated its potential to provide an early assessment of damage during fatigue.

Timelapse ultrasonic tomography for measuring damage localization in geomechanics laboratory tests.

PubMed

Tudisco, Erika; Roux, Philippe; Hall, Stephen A; Viggiani, Giulia M B; Viggiani, Gioacchino

2015-03-01

Variation of mechanical properties in materials can be detected non-destructively using ultrasonic measurements. In particular, changes in elastic wave velocity can occur due to damage, i.e., micro-cracking and particles debonding. Here the challenge of characterizing damage in geomaterials, i.e., rocks and soils, is addressed. Geomaterials are naturally heterogeneous media in which the deformation can localize, so that few measurements of acoustic velocity across the sample are not sufficient to capture the heterogeneities. Therefore, an ultrasonic tomography procedure has been implemented to map the spatial and temporal variations in propagation velocity, which provides information on the damage process. Moreover, double beamforming has been successfully applied to identify and isolate multiple arrivals that are caused by strong heterogeneities (natural or induced by the deformation process). The applicability of the developed experimental technique to laboratory geomechanics testing is illustrated using data acquired on a sample of natural rock before and after being deformed under triaxial compression. The approach is then validated and extended to time-lapse monitoring using data acquired during plane strain compression of a sample including a well defined layer with different mechanical properties than the matrix.

Evaluation method of TiO2-SiO2 ultra-low-expansion glasses with periodic striae using the LFB ultrasonic material characterization system.

PubMed

Kushibiki, Jun-ichi; Arakawa, Mototaka; Ohashi, Yuji; Suzuki, Kouji

2006-09-01

Experimental procedures and standard specimens for characterizing and evaluating TiO2-SiO2 ultra-low expansion glasses with periodic striae using the line-focus-beam (LFB) ultrasonic material characterization system are discussed. Two types of specimens were prepared, with specimen surfaces parallel and perpendicular to the striae plane using two different grades of glass ingots. The inhomogeneities of each of the specimens were evaluated at 225 MHz. It was clarified that parallel specimens are useful for accurately measuring velocity variations of leaky surface acoustic waves (LSAWs) excited on a water-loaded specimen surface associated with the striae. Perpendicular specimens are useful for obtaining periodicities in the striae for LSAW propagation perpendicular to the striae plane on a surface and for precisely measuring averaged velocities for LSAW propagation parallel to the striae plane. The standard velocity of Rayleigh-type LSAWs traveling parallel to the striae plane for the perpendicular specimens was numerically calculated using the measured velocities of longitudinal and shear waves and density. Consequently, a reliable standard specimen with an LSAW velocity of 3308.18 +/- 0.35 m/s at 23 degrees C and its temperature coefficient of 0.39 (m/s)/degrees C was obtained for a TiO2-SiO2 glass with a TiO2 concentration of 7.09 wt%. A basis for the striae analysis using this ultrasonic method was established.

Ultrasonic Cole-Cole diagram for solutions and application to alpha-chymotrypsin.

PubMed

Cerf, R; Salehi, S T; Rogez, D

1989-04-01

Deconvolution of ultrasonic data into single relaxations is rarely feasible when only the absorption or the velocity of the waves is measured. Here we use both series of data to construct a Cole-Cole diagram for a solution. When applied to alpha-chymotrypsin, this method shows two relaxations that are well separated on the time scale, a result that will help simplify analyses of the ultrasonic data for this enzyme.

Ultrasonic Cole-Cole diagram for solutions and application to alpha-chymotrypsin.

PubMed Central

Cerf, R; Salehi, S T; Rogez, D

1989-01-01

Deconvolution of ultrasonic data into single relaxations is rarely feasible when only the absorption or the velocity of the waves is measured. Here we use both series of data to construct a Cole-Cole diagram for a solution. When applied to alpha-chymotrypsin, this method shows two relaxations that are well separated on the time scale, a result that will help simplify analyses of the ultrasonic data for this enzyme. PMID:2720063

Silicon wafer temperature monitoring using all-fiber laser ultrasonics

NASA Astrophysics Data System (ADS)

Alcoz, Jorge J.; Duffer, Charles E.

1998-03-01

Laser-ultrasonics is a very attractive technique for in-line process control in the semiconductor industry as it is compatible with the clean room environment and offers the capability to inspect parts at high-temperature. We describe measurements of the velocity of laser-generated Lamb waves in silicon wafers as a function of temperature using fiber- optic laser delivery and all-fiber interferometric sensing. Fundamental anti-symmetric Lamb-wave modes were generated in 5 inches < 111 > silicon wafers using a Nd:YAG laser coupled to a large-core multimode fiber. Generation was also performed using an array of sources created with a diffraction grating. For detection a compact fiber-optic sensor was used which is well suited for industrial environments as it is compact, rugged, stable, and low-cost. The wafers were heated up to 1000 degrees C and the temperature correlated with ultrasonic velocity measurements.

Piston cylinder cell for high pressure ultrasonic pulse echo measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kepa, M. W., E-mail: mkepa@staffmail.ed.ac.uk; Huxley, A. D.; Ridley, C. J.

2016-08-15

Ultrasonic techniques such as pulse echo, vibrating reed, or resonant ultrasound spectroscopy are powerful probes not only for studying elasticity but also for investigating electronic and magnetic properties. Here, we report on the design of a high pressure ultrasonic pulse echo apparatus, based on a piston cylinder cell, with a simplified electronic setup that operates with a single coaxial cable and requires sample lengths of mm only. The design allows simultaneous measurements of ultrasonic velocities and attenuation coefficients up to a pressure of 1.5 GPa. We illustrate the performance of the cell by probing the phase diagram of a singlemore » crystal of the ferromagnetic superconductor UGe{sub 2}.« less

Ultrasonic and spectral studies on charge transfer complexes of anisole and certain aromatic amines

NASA Astrophysics Data System (ADS)

Rajesh, R.; Raj Muhamed, R.; Justin Adaikala Baskar, A.; Kannappan, V.

2016-10-01

Stability constants of two complexes of anisole with aniline and N-methylaniline (NMA) are determined from the measured ultrasonic velocity in n-hexane medium at four different temperatures. Acoustic and excess thermo acoustic parameters [excess ultrasonic velocity (uE), excess molar volume (VE), excess internal pressure (πiE)] are reported for these systems at four different temperatures. The trend in acoustic and excess parameters with concentration in the two systems establishes the formation of hydrogen bonded complexes between anisole and the two amines. Thermodynamic properties are computed for the two complexes from the variation in K with temperature. The formation of these complexes is also established by UV spectral method and their spectral characteristics and stability constants are determined. K values of these complexes obtained by ultrasonic and UV spectroscopic techniques agree well. Aniline forms more stable complex than N-methylaniline with anisole in n-hexane medium.

Development of coaxial ultrasonic probe for fatty liver diagnostic system using ultrasonic velocity change

NASA Astrophysics Data System (ADS)

Hori, Makoto; Yokota, Daiki; Aotani, Yuhei; Kumagai, Yuta; Wada, Kenji; Matsunaka, Toshiyuki; Morikawa, Hiroyasu; Horinaka, Hiromichi

2017-07-01

A diagnostic system for fatty liver at an early stage is needed because fatty liver is linked to metabolic syndrome. We have already proposed a fatty liver diagnosis method based on the temperature coefficient of ultrasonic velocity. In this study, we fabricated a coaxial ultrasonic probe by integrating two kinds of transducers for warming and signal detection. The diagnosis system equipped with the coaxial probe was applied to tissue-mimicking phantoms including the fat area. The fat content rates corresponding to the set rates of the phantoms were estimated by the ultrasonic velocity-change method.

Measurement of material nonlinearity using surface acoustic wave parametric interaction and laser ultrasonics.

PubMed

Stratoudaki, Theodosia; Ellwood, Robert; Sharples, Steve; Clark, Matthew; Somekh, Michael G; Collison, Ian J

2011-04-01

A dual frequency mixing technique has been developed for measuring velocity changes caused by material nonlinearity. The technique is based on the parametric interaction between two surface acoustic waves (SAWs): The low frequency pump SAW generated by a transducer and the high frequency probe SAW generated and detected using laser ultrasonics. The pump SAW stresses the material under the probe SAW. The stress (typically <5 MPa) is controlled by varying the timing between the pump and probe waves. The nonlinear interaction is measured as a phase modulation of the probe SAW and equated to a velocity change. The velocity-stress relationship is used as a measure of material nonlinearity. Experiments were conducted to observe the pump-probe interaction by changing the pump frequency and compare the nonlinear response of aluminum and fused silica. Experiments showed these two materials had opposite nonlinear responses, consistent with previously published data. The technique could be applied to life-time predictions of engineered components by measuring changes in nonlinear response caused by fatigue.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alhroob, M.; Boyd, G.; Hasib, A.

Precision ultrasonic measurements in binary gas systems provide continuous real-time monitoring of mixture composition and flow. Using custom micro-controller-based electronics, we have developed an ultrasonic instrument, with numerous potential applications, capable of making continuous high-precision sound velocity measurements. The instrument measures sound transit times along two opposite directions aligned parallel to - or obliquely crossing - the gas flow. The difference between the two measured times yields the gas flow rate while their average gives the sound velocity, which can be compared with a sound velocity vs. molar composition look-up table for the binary mixture at a given temperature andmore » pressure. The look-up table may be generated from prior measurements in known mixtures of the two components, from theoretical calculations, or from a combination of the two. We describe the instrument and its performance within numerous applications in the ATLAS experiment at the CERN Large Hadron Collider (LHC). The instrument can be of interest in other areas where continuous in-situ binary gas analysis and flowmetry are required. (authors)« less

Potential of ultrasonic pulse velocity for evaluating the dimensional stability of oak and chestnut wood

Treesearch

Turker Dundar; Xiping Wang; Nusret As; Erkan Avci

2016-01-01

The objective of this study was to examine the potential of ultrasonic velocity as a rapid and nondestructive method to predict the dimensional stability of oak (Quercus petraea (Mattuschka) Lieblein) and chestnut (Castanea sativa Mill.) that are commonly used in flooring industry. Ultrasonic velocity, specific gravity, and radial, tangential and volumetric shrinkages...

Modified Biot-Gassmann theory for calculating elastic velocities for unconsolidated and consolidated sediments

USGS Publications Warehouse

Lee, M.W.

2002-01-01

The classical Biot-Gassmann theory (BGT) generally overestimates shear-wave velocities of water-saturated sediments. To overcome this problem, a new theory is developed based on BGT and on the velocity ratio as a function of G(1 - ??)n, where ?? is porosity and n and G are constants. Based on laboratory data measured at ultrasonic frequencies, parameters for the new formulation are derived. This new theory is extended to include the effect of differential pressure and consolidation on the velocity ratio by making n a function of differential pressure and the rate of porosity reduction with respect to differential pressure. A scale G is introduced to compensate for discrepancies between measured and predicted velocities, mainly caused by the presence of clay in the matrix. As differential pressure increases and the rate of porosity reduction with respect to differential pressure decreases, the exponent n decreases and elastic velocities increase. Because velocity dispersion is not considered, this new formula is optimum for analyzing velocities measured at ultrasonic frequencies or for sediments having low dispersion characteristics such as clean sandstone with high permeability and lack of grain-scale local flow. The new formula is applied to predict velocities from porosity or from porosity and P-wave velocity and is in good agreement with laboratory and well log data. ?? 2004 Kluwer Academic Publishers. Printed in the Netherlands.

Monitoring of soluble starch hydrolysis induced by α-amylase from Aspergillus oryzae using ultrasonic spectroscopy

NASA Astrophysics Data System (ADS)

Sierra, Carlos; Resa, Pablo; Buckin, Vitaly; Elvira, Luis

2012-05-01

The online monitoring of enzymatic starch hydrolysis is an important issue for several industrial sectors, mainly in the alimentary industry. Ultrasonic non-invasive methods based on the detection of wave velocity and amplitude changes can be used to study this enzymatic reaction. These wave propagating changes are result of physicalchemical modifications produced in the media by the starch hydrolysis. In this work the starch hydrolysis induced by the enzyme α-amylase from Aspergillus oryzae is studied. This biochemical reaction has been monitored using a high-resolution ultrasonic spectroscopy (HR-US) which is non-invasive and nondestructive. The measured time profiles o of ultrasonic velocity are explained in terms of the starch hydrolysis and the subsequent production of oligosaccharides as a consequence of the enzymatic action. The obtained results have been compared to a conventional off-line technique used in biochemistry, the iodine-starch reaction, a spectrophotometric method to quantify the amount of starch remaining in the medium. The combination of these two types of measurement provides more complete information about the biochemical processes occurred during hydrolysis.

Ultrasonic Characterization of Superhard Material: Osmium Diboride

NASA Astrophysics Data System (ADS)

Yadawa, P. K.

2012-12-01

Higher order elastic constants have been calculated in hexagonal structured superhard material OsB2 at room temperature following the interaction potential model. The temperature variation of the ultrasonic velocities is evaluated along different angles with unique axis of the crystal using the second order elastic constants. The ultrasonic velocity decreases with the temperature along particular orientation with the unique axis. Temperature variation of the thermal relaxation time and Debye average velocities are also calculated along the same orientation. The temperature dependency of the ultrasonic properties is discussed in correlation with elastic, thermal and electrical properties. It has been found that the thermal conductivity is the main contributor to the behaviour of ultrasonic attenuation as a function of temperature and the responsible cause of attenuation is phonon-phonon interaction. The mechanical properties of OsB2 at low temperature are better than at high temperature, because at low temperature it has low ultrasonic velocity and ultrasonic attenuation. Superhard material OsB2 has many industrial applications, such as abrasives, cutting tools and hard coatings.

Effect of drug Piper nigrum on magnesium chloride at varying concentration and temperature through ultrasonic method: A thermoacoustic study

NASA Astrophysics Data System (ADS)

Nalle, Pallavi B.; Deshmukh, S. S.; Dorik, R. G.; Jadhav, K. M.

2016-12-01

The ultrasonic velocity (U), density (ρ), and viscosity (η) of an ethanolic extract of drug Piper nigrum with MgCl2 (metal ions) have been measured as a function of the number of moles n = (0.7009, 1.4018, 2.1027, 2.8036 and 3.5045) at 303.15, 308.15, 313.15 and 318.15 K temperature. Various thermoacoustic and their excess values such as adiabatic compressibilities (β), intermolecular free lengths (Lf), excess adiabatic compressibility (βE), excess intermolecular free length (?) have been computed using values of ultrasonic velocity (U), density (ρ), and viscosity (η). The excess values of ultrasonic velocity, specific acoustic impedance are positive, whereas isentropic compressibility and intermolecular free lengths are negative over the entire composition range of MgCl2 + P. nigrum which indicates the presence of specific interactions between unlike molecules. Molecular association is reflected by ultrasonic investigation. This may be interpreted due to the of complex formation. The chemical interaction may involve the association due to the solute-solvent and ion-solvent interaction and due to the formation of charge-transfer complexes, which is useful to understand the mechanism of their metabolism in living systems. The results obtained from these studies are helpful for pharmacological applications of drugs, transport of drugs across biological membranes.

Subsurface imaging of grain microstructure using picosecond ultrasonics

DOE PAGES

Khafizov, M.; Pakarinen, J.; He, L.; ...

2016-04-21

We report on imaging subsurface grain microstructure using picosecond ultrasonics. This approach relies on elastic anisotropy of crystalline materials where ultrasonic velocity depends on propagation direction relative to the crystal axes. Picosecond duration ultrasonic pulses are generated and detected using ultrashort light pulses. In materials that are transparent or semitransparent to the probe wavelength, the probe monitors GHz Brillouin oscillations. The frequency of these oscillations is related to the ultrasonic velocity and the optical index of refraction. Ultrasonic waves propagating across a grain boundary experience a change in velocity due to a change in crystallographic orientation relative to the ultrasonicmore » propagation direction. This change in velocity is manifested as a change in the Brillouin oscillation frequency. Using the ultrasonic propagation velocity, the depth of the interface can be determined from the location in time of the transition in oscillation frequency. An image of the grain boundary is obtained by scanning the beam along the surface. We demonstrate this volumetric imaging capability using a polycrystalline UO 2 sample. As a result, cross section liftout analysis of the grain boundaries using electron microscopy were used to verify our imaging results.« less

Correlation of field seismic refraction data with 3-D laboratory ultrasonic sounding data during exploration of a dimension stone deposit

NASA Astrophysics Data System (ADS)

Přikryl, Richard; Vilhelm, Jan; Lokajíček, Tomáš; Pros, Zdeněk; Klíma, Karel

2004-05-01

Multidirectional field seismic refraction data have been combined with 3-D laboratory ultrasonic sounding data in a preliminary exploration of a new dimension stone deposit in the Czech Republic. Rock fabric was interpreted from a detailed laboratory analysis of a 3-D P-wave velocity pattern and can be classified as pronounced orthorhombic due to a complex tectonometamorphic history of the rock. The P-wave velocity pattern recorded from laboratory measurements can be satisfactorily correlated with the anisotropy of P-wave velocity data acquired from field seismic refraction data. Rock fabric anisotropy also contributes to the observed anisotropy of strength and static deformational properties.

Doppler velocity measurements from large and small arteries of mice

PubMed Central

Reddy, Anilkumar K.; Madala, Sridhar; Entman, Mark L.; Michael, Lloyd H.; Taffet, George E.

2011-01-01

With the growth of genetic engineering, mice have become increasingly common as models of human diseases, and this has stimulated the development of techniques to assess the murine cardiovascular system. Our group has developed nonimaging and dedicated Doppler techniques for measuring blood velocity in the large and small peripheral arteries of anesthetized mice. We translated technology originally designed for human vessels for use in smaller mouse vessels at higher heart rates by using higher ultrasonic frequencies, smaller transducers, and higher-speed signal processing. With these methods one can measure cardiac filling and ejection velocities, velocity pulse arrival times for determining pulse wave velocity, peripheral blood velocity and vessel wall motion waveforms, jet velocities for the calculation of the pressure drop across stenoses, and left main coronary velocity for the estimation of coronary flow reserve. These noninvasive methods are convenient and easy to apply, but care must be taken in interpreting measurements due to Doppler sample volume size and angle of incidence. Doppler methods have been used to characterize and evaluate numerous cardiovascular phenotypes in mice and have been particularly useful in evaluating the cardiac and vascular remodeling that occur following transverse aortic constriction. Although duplex ultrasonic echo-Doppler instruments are being applied to mice, dedicated Doppler systems are more suitable for some applications. The magnitudes and waveforms of blood velocities from both cardiac and peripheral sites are similar in mice and humans, such that much of what is learned using Doppler technology in mice may be translated back to humans. PMID:21572013

Elasticity and wave velocity in fcc iron (austenite) at elevated temperatures - Experimental verification of ab-initio calculations.

PubMed

Hutchinson, Bevis; Malmström, Mikael; Lönnqvist, Johan; Bate, Pete; Ehteshami, Hossein; Korzhavyi, Pavel A

2018-07-01

High temperature crystal elasticity constants for face centred cubic austenite are important for interpreting the ultrasonic properties of iron and steels but cannot be determined by normal single crystal methods. Values of these constants have recently been calculated using an ab-initio approach and the present work was carried out to test their applicability using laser-ultrasonic measurements. Steel samples having a known texture were examined at temperatures between 800 °C and 1100 °C to measure the velocity of longitudinal P-waves which were found to be in good agreement with modelled values. Copyright © 2018 Elsevier B.V. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khafizov, M.; Pakarinen, J.; He, L.

We report on imaging subsurface grain microstructure using picosecond ultrasonics. This approach relies on elastic anisotropy of crystalline materials where ultrasonic velocity depends on propagation direction relative to the crystal axes. Picosecond duration ultrasonic pulses are generated and detected using ultrashort light pulses. In materials that are transparent or semitransparent to the probe wavelength, the probe monitors GHz Brillouin oscillations. The frequency of these oscillations is related to the ultrasonic velocity and the optical index of refraction. Ultrasonic waves propagating across a grain boundary experience a change in velocity due to a change in crystallographic orientation relative to the ultrasonicmore » propagation direction. This change in velocity is manifested as a change in the Brillouin oscillation frequency. Using the ultrasonic propagation velocity, the depth of the interface can be determined from the location in time of the transition in oscillation frequency. An image of the grain boundary is obtained by scanning the beam along the surface. We demonstrate this volumetric imaging capability using a polycrystalline UO 2 sample. As a result, cross section liftout analysis of the grain boundaries using electron microscopy were used to verify our imaging results.« less

Physical properties of fault zone rocks from SAFOD: Tying logging data to high-pressure measurements on drill core

NASA Astrophysics Data System (ADS)

Jeppson, T.; Tobin, H. J.

2013-12-01

In the summer of 2005, Phase 2 of the San Andreas Fault Observatory at Depth (SAFOD) borehole was completed and logged with wireline tools including a dipole sonic tool to measure P- and S-wave velocities. A zone of anomalously low velocity was detected from 3150 to 3414 m measured depth (MD), corresponding with the subsurface location of the San Andreas Fault Zone (SAFZ). This low velocity zone is 5-30% slower than the surrounding host rock. Within this broad low-velocity zone, several slip surfaces were identified as well as two actively deforming shear zones: the southwest deformation zone (SDZ) and the central deformation zone (CDZ), located at 3192 and 3302 m MD, respectively. The SAFZ had also previously been identified as a low velocity zone in seismic velocity inversion models. The anomalously low velocity was hypothesized to result from either (a) brittle deformation in the damage zone of the fault, (b) high fluid pressures with in the fault zone, or (c) lithological variation, or a combination of the above. We measured P- and S-wave velocities at ultrasonic frequencies on saturated 2.5 cm diameter core plug samples taken from SAFOD core obtained in 2007 from within the low velocity zone. The resulting values fall into two distinct groups: foliated fault gouge and non-gouge. Samples of the foliated fault gouge have P-wave velocities between 2.3-3.5 km/s while non-gouge samples lie between 4.1-5.4 km/s over a range of effective pressures from 5-70 MPa. There is a good correlation between the log measurements and laboratory values of P-and S wave velocity at in situ pressure conditions especially for the foliated fault gouge. For non-gouge samples the laboratory values are approximately 0.08-0.73 km/s faster than the log values. This difference places the non-gouge velocities within the Great Valley siltstone velocity range, as measured by logs and ultrasonic measurements performed on outcrop samples. As a high fluid pressure zone was not encountered during SAFOD drilling, we use the ultrasonic velocities of SAFOD core and analogous outcrop samples to determine if the velocity reduction is due to lithologic variations or the presence of deformational fabrics and alteration in the fault zone. Preliminary analysis indicates that while the decrease in velocity across the broad fault zone is heavily influenced by fractures, the extremely low velocities associated with the actively deforming zones are more likely caused by the development of scaly fabric with clay coatings on the fracture surfaces. Analysis of thin sections and well logs are used to support this interpretation.

Method and apparatus for measuring surface contour on parts with elevated temperatures

DOEpatents

Horvath, Mark S.; Nance, Roy A.; Cohen, George H.; Fodor, George

1991-01-01

The invention is directed to a method and apparatus for measuring the surface contour of a test piece, such as the bow of a radioactive fuel rod, which is completely immersed in water. The invention utilizes ultrasonic technology and is capable of measuring surface contours of test pieces which are at a higher temperature than the surrounding water. The presence of a test piece at a higher temperature adversely affects the distance measurements by causing thermal variations in the water near the surface of the test piece. The contour measurements depend upon a constant temperature of the water in the path of the ultrasonic wave to provide a constant acoustical velocity (the measurement is made by the time of flight measurement for an ultrasonic wave). Therefore, any variations of water temperature near the surface will introduce errors degrading the measurement. The present invention overcomes these problems by assuring that the supply of water through which the ultrasonic waves travel is at a predetermined and constant temperature.

Volumetric blood flow via time-domain correlation: experimental verification.

PubMed

Embree, P M; O'Brien, W R

1990-01-01

A novel ultrasonic volumetric flow measurement method using time-domain correlation of consecutive pairs of echoes has been developed. An ultrasonic data acquisition system determined the time shift between a pair of range gated echoes by searching for the time shift with the maximum correlation between the RF sampled waveforms. Experiments with a 5-MHz transducer indicate that the standard deviation of the estimate of steady fluid velocity through 6-mm-diameter tubes is less than 10% of the mean. Experimentally, Sephadex (G-50; 20-80 mum dia.) particles in water and fresh porcine blood have been used as ultrasound scattering fluids. Two-dimensional (2-D) flow velocity can be estimated by slowly sweeping the ultrasonic beam across the blood vessel phantom. Volumetric flow through the vessel is estimated by integrating the 2-D flow velocity field and then is compared to hydrodynamic flow measurements to assess the overall experimental accuracy of the time-domain method. Flow rates from 50-500 ml/min have been estimated with an accuracy better than 10% under the idealized characteristics used in this study, which include straight circular thin-walled tubes, laminar axially-symmetric steady flow, and no intervening tissues.

Ultrasonic hydrometer

DOEpatents

Swoboda, Carl A.

1984-01-01

The disclosed ultrasonic hydrometer determines the specific gravity (density) of the electrolyte of a wet battery, such as a lead-acid battery. The hydrometer utilizes a transducer that when excited emits an ultrasonic impulse that traverses through the electrolyte back and forth between spaced sonic surfaces. The transducer detects the returning impulse, and means measures the time "t" between the initial and returning impulses. Considering the distance "d" between the spaced sonic surfaces and the measured time "t", the sonic velocity "V" is calculated with the equation "V=2d/t". The hydrometer also utilizes a thermocouple to measure the electrolyte temperature. A hydrometer database correlates three variable parameters including sonic velocity in and temperature and specific gravity of the electrolyte, for temperature values between 0.degree. and 40.degree. C. and for specific gravity values between 1.05 and 1.30. Upon knowing two parameters (the calculated sonic velocity and the measured temperature), the third parameter (specific gravity) can be uniquely found in the database. The hydrometer utilizes a microprocessor for data storage and manipulation. The disclosed modified battery has a hollow spacer nub on the battery side wall, the sonic surfaces being on the inside of the nub and the electrolyte filling between the surfaces to the exclusion of intervening structure. An accessible pad exposed on the nub wall opposite one sonic surface allows the reliable placement thereagainst of the transducer.

Use of an ultrasonic device for the determination of elastic modulus of dentin.

PubMed

Miyazaki, Masashi; Inage, Hirohiko; Onose, Hideo

2002-03-01

The mechanical properties of dentin substrate are one of the important factors in determining bond strength of dentin bonding systems. The purpose of this study was to determine the elastic modulus of dentin substrate with the use of an ultrasonic device. The dentin disks of about 1 mm thickness were obtaining from freshly extracted human third molars, and the dentin disk was shaped in a rectangular form with a line diamond point. The size and weight of each specimen was measured to calculate the density of the specimen. The ultrasonic equipment employed in this study was composed of a Pulser-Receiver (Model 5900PR, Panametrics), transducers (V155, V156, Panametrics) and an oscilloscope. The measured two-way transit time through the dentin disk was divided by two to account for the down-and-back travel path, and then multiplied by the velocity of sound in the test material. Measuring the longitudinal and share wave sound velocity determine elastic modulus. The mean elastic modulus of horizontally sectioned specimens was 21.8 GPa and 18.5 GPa for the vertically sectioned specimens, and a significant difference was found between the two groups. The ultrasonic method used in this study shows considerable promise for determination of the elastic modulus of the tooth substrate.

Accuracy of coded excitation methods for measuring the time of flight: Application to ultrasonic characterization of wood samples.

PubMed

Lasaygues, Philippe; Arciniegas, Andres; Espinosa, Luis; Prieto, Flavio; Brancheriau, Loïc

2018-05-26

Ultrasound computed tomography (USCT) using the transmission mode is a way to detect and assess the extent of decay in wood structures. The resolution of the ultrasonic image is closely related to the different anatomical features of wood. The complexity of the wave propagation process generates complex signals consisting of several wave packets with different signatures. Wave paths, depth dependencies, wave velocities or attenuations are often difficult to interpret. For this kind of assessment, the focus is generally on signal pre-processing. Several approaches have been used so far including filtering, spectrum analysis and a method involving deconvolution using a characteristic transfer function of the experimental device. However, all these approaches may be too sophisticated and/or unstable. The alternative methods proposed in this work are based on coded excitation, which makes it possible to process both local and general information available such as frequency and time parameters. Coded excitation is based on the filtering of the transmitted signal using a suitable electric input signal. The aim of the present study was to compare two coded-excitation methods, a chirp- and a wavelet-coded excitation method, to determine the time of flight of the ultrasonic wave, and to investigate the feasibility, the robustness and the precision of the measurement of geometrical and acoustical properties in laboratory conditions. To obtain control experimental data, the two methods were compared with the conventional ultrasonic pulse method. Experiments were conducted on a polyurethane resin sample and two samples of different wood species using two 500 kHz-transducers. The relative errors in the measurement of thickness compared with the results of caliper measurements ranged from 0.13% minimum for the wavelet-coded excitation method to 2.3% maximum for the chirp-coded excitation method. For the relative errors in the measurement of ultrasonic wave velocity, the coded excitation methods showed differences ranging from 0.24% minimum for the wavelet-coded excitation method to 2.62% maximum for the chirp-coded excitation method. Methods based on coded excitation algorithms thus enable accurate measurements of thickness and ultrasonic wave velocity in samples of wood species. Copyright © 2018 Elsevier B.V. All rights reserved.

Ultrasonic attenuation and velocity in AS/3501-6 graphite/epoxy fiber composite

NASA Technical Reports Server (NTRS)

Williams, J. H., Jr.; Nayebhashemi, H.; Lee, S. S.

1979-01-01

The ultrasonic group velocity and attenuation were measured as a function of frequency for longitudinal and shear waves in the epoxy matrix (3501-6) and in the principal directions of the unidirectional graphite/epoxy composite (AS/3501-6). Tests were conducted in the frequency ranges 0.25 Mz to 14 MHz and 0.5 Mz to 3 MHz for longitudinal and shear wave modes, respectively. The attenuation increased with frequency for all wave modes, but the group velocity was independent of frequency for all wave modes. The effects of pressure and couplant at the transducer-specimen interface were studied and it was found that for each transducer type there exists a frequency dependent 'saturation pressure' corresponding to the maximum output signal amplitude.

Ultrasonic flow measurements for irrigation process monitoring

NASA Astrophysics Data System (ADS)

Ziani, Elmostafa; Bennouna, Mustapha; Boissier, Raymond

2004-02-01

This paper presents the state of the art of the general principle of liquid flow measurements by ultrasonic method, and problems of flow measurements. We present an ultrasonic flowmeter designed according to smart sensors concept, for the measurement of irrigation water flowing through pipelines or open channels, using the ultrasonic transit time approach. The new flowmeter works on the principle of measuring time delay differences between sound pulses transmitted upstream and downstream in the flowing liquid. The speed of sound in the flowing medium is eliminated as a variable because the flowrate calculations are based on the reciprocals of the transmission times. The transit time difference is digitally measured by means of a suitable, microprocessor controlled logic. This type of ultrasonic flowmeter will be widely used in industry and water management, it is well studied in this work, followed by some experimental results. For pressurized channels, we use one pair of ultrasonic transducer arranged in proper positions and directions of the pipe, in this case, to determine the liquid velocity, a real time on-line analysis taking account the geometries of the hydraulic system, is applied to the obtained ultrasonic data. In the open channels, we use a single or two pairs of ultrasonic emitter-receiver according to the desired performances. Finally, the goals of this work consist in integrating the smart sensor into irrigation systems monitoring in order to evaluate potential advantages and demonstrate their performance, on the other hand, to understand and use ultrasonic approach for determining flow characteristics and improving flow measurements by reducing errors caused by disturbances of the flow profiles.

Proceedings of the Second Annual Symposium for Nondestructive Evaluation of Bond Strength

NASA Technical Reports Server (NTRS)

Roberts, Mark J. (Compiler)

1999-01-01

Ultrasonics, microwaves, optically stimulated electron emission (OSEE), and computational chemistry approaches have shown relevance to bond strength determination. Nonlinear ultrasonic nondestructive evaluation methods, however, have shown the most effectiveness over other methods on adhesive bond analysis. Correlation to changes in higher order material properties due to microstructural changes using nonlinear ultrasonics has been shown related to bond strength. Nonlinear ultrasonic energy is an order of magnitude more sensitive than linear ultrasound to these material parameter changes and to acoustic velocity changes caused by the acoustoelastic effect when a bond is prestressed. Signal correlations between non-linear ultrasonic measurements and initialization of bond failures have been measured. This paper reviews bond strength research efforts presented by university and industry experts at the Second Annual Symposium for Nondestructive Evaluation of Bond Strength organized by the NDE Sciences Branch at NASA Langley in November 1998.

Ultrasonic technique for measuring porosity of plasma-sprayed alumina coatings

NASA Astrophysics Data System (ADS)

Parthasarathi, S.; Tittmann, B. R.; Onesto, E. J.

1997-12-01

Porosity is an important factor in plasma-sprayed coatings, especially ceramic coatings. Excessive poros-ity can adversely affect the performance of the coated component in various ways. An ultrasonic nonde-structive measurement technique has been developed to measure porosity in plasma-sprayed alumina coatings. The technique is generic and can be extended to other ceramic coating systems. To test the tech-nique, freestanding alumina coatings with varying levels of porosity were fabricated via plasma spray. Samples with varying porosity, obtained through innovative fabrication techniques, were used to gener-ate a calibration curve. The ultrasonic velocity in the low-frequency range was found to be dependent on the density of freestanding coatings (measured via Archimedian techniques). This dependence is the basis of the development of a technique to measure the density of coatings.

Compressional Wave Speed and Absorption Measurements in a Saturated Kaolinite-Water Artificial Sediment.

DTIC Science & Technology

OCEAN BOTTOM, ULTRASONIC PROPERTIES), (*UNDERWATER SOUND, SOUND TRANSMISSION), KAOLINITE , ABSORPTION, COMPRESSIVE PROPERTIES, POROSITY, VELOCITY, VISCOELASTICITY, MATHEMATICAL MODELS, THESES, SEDIMENTATION

Ultrasonic Acoustic Velocities During Partial Melting of a Mantle Peridotite KLB-1

NASA Astrophysics Data System (ADS)

Weidner, Donald J.; Li, Li; Whitaker, Matthew L.; Triplett, Richard

2018-02-01

Knowledge of the elastic properties of partially molten rocks is crucial for understanding low-velocity regions in the interior of the Earth. Models of fluid and solid mixtures have demonstrated that significant decreases in seismic velocity are possible with small amounts of melt, but there is very little available data for testing these models, particularly with both P and S waves for mantle compositions. We report ultrasonic measurements of P and S velocities on a partially molten KLB-1 sample at mantle conditions using a multi-anvil device at a synchrotron facility. The P, S, and bulk sound velocities decrease as melting occurs. We find that the quantity, ∂lnVS/∂lnVB (where VB is the bulk sound velocity) is lower than mechanical models estimate. Instead, our data, as well as previous data in the literature, are consistent with a dynamic melting model in which melting and solidification interact with the stress field of the acoustic wave.

Semi-continuous ultrasonic sounding and changes of ultrasonic signal characteristics as a sensitive tool for the evaluation of ongoing microstructural changes of experimental mortar bars tested for their ASR potential.

PubMed

Lokajíček, T; Kuchařová, A; Petružálek, M; Šachlová, Š; Svitek, T; Přikryl, R

2016-09-01

Semi-continuous ultrasonic sounding of experimental mortar bars used in the accelerated alkali silica reactivity laboratory test (ASTM C1260) is proposed as a supplementary measurement technique providing data that are highly sensitive to minor changes in the microstructure of hardening/deteriorating concrete mixture. A newly designed, patent pending, heating chamber was constructed allowing ultrasonic sounding of mortar bars, stored in accelerating solution without necessity to remove the test specimens from the bath during the measurement. Subsequent automatic data analysis of recorded ultrasonic signals proved their high correlation to the measured length changes (expansion) and their high sensitivity to microstructural changes. The changes of P-wave velocity, and of the energy, amplitude, and frequency of ultrasonic signal, were in the range of 10-80%, compared to 0.51% change of the length. Results presented in this study thus show that ultrasonic sounding seems to be more sensitive to microstructural changes due to ongoing deterioration of concrete microstructure by alkali-silica reaction than the dimensional changes. Copyright © 2016. Published by Elsevier B.V.

An ultrasonic investigation of the effect of voids on the mechanical properties of bread dough and the role of gas cells in determining the cellular structure of freeze- dried breadcrumb

NASA Astrophysics Data System (ADS)

Elmehdi, Hussein Mohamed

This thesis is an analysis of voids in the breadmaking process, more specifically the effect of gas cells entrapped in the dough during mixing, their expansion during fermentation, and their relationship to the breadcrumb structure in the final product. This is important to food scientists because the voids ultimately influence the structural integrity of bread and hence its quality. Understanding how voids affect the viscoelastic properties of dough is also a challenging problem in soft condensed matter physics. Longitudinal ultrasonic velocity and attenuation measurements, performed at 54 kHz, investigated changes in the mechanical properties of dough and bread as void concentration was varied. In the first part of the thesis, the effect of voids on the properties of unyeasted dough at the end of mixing was investigated. As φ is increased, the attenuation coefficient increased linearly with φ hence the change in attenuation is proportional to the number of voids, allowing the combined effects of scattering and absorption by single voids to be directly determined. By contrast, the ultrasonic velocity decreased dramatically with increasing φ in the range 0.0 12 < φ < 0.03, while at higher φ, the velocity decrease was less rapid. An effective medium model successfully modeled the viscoelastic behavior of the dough at all void fraction values, provided that the shear modulus of the matrix was permitted to vary. The same ultrasonic technique was also used to monitor the increase in gas cell size due to CO 2 production during fermentation of yeasted dough. A large decrease in velocity and an increase in the attenuation coefficient were observed as the gas cells grew. In addition, at early fermentation times, a substantial contribution to the velocity decrease arises from a reduction in the shear modulus of the dough matrix. This occurs because the pH drops as CO2 molecules dissolve in the matrix and intermolecular interactions are weakened due to protein chain charge repulsion effects. In the second part of the thesis, freeze-dried breadcrumb structure was investigated. To change the size of the air cells, the dough was proofed for various times. Ultrasonic velocity and amplitude decrease with increasing φ. The experimental data were found to be in reasonable agreement with theoretical models for the elasticity of isotropic cellular foams and tortuosity. The effects of anisotropy in breadcrumb structure were studied by compressing samples uniaxially, thereby transforming the shape of the air cells from approximately spherical to elongated ellipsoids. Ultrasonic measurements were taken in the directions parallel and perpendicular to the strain. These results indicated that the path by which sound propagates is critical. The data were interpreted using the same two theoretical models, taking into account anisotropy effects. The tortuosity model was able to interpret the void fraction dependence of the velocity along the two orthogonal directions, thus giving a way of relating changes in ultrasonic velocity to changes in breadcrumb structure. This thesis demonstrates the potential for using ultrasound as a non-destructive, cheap and accurate tool for studying the effect of voids (and their expansion) on dough properties. These ultrasonic techniques can also be used to investigate the effect of air cells on the structural integrity of breadcrumb and hence be a useful tool for quantitatively assessing bread quality.

Ultrasonic nondestructive materials characterization

NASA Technical Reports Server (NTRS)

Green, R. E., Jr.

1986-01-01

A brief review of ultrasonic wave propagation in solid materials is presented with consideration of the altered behavior in anisotropic and nonlinear elastic materials in comparison with isotropic and linear elastic materials. Some experimental results are described in which ultrasonic velocity and attenuation measurements give insight into materials microstructure and associated mechanical properties. Recent developments with laser beam non-contact generation and detection of ultrasound are presented. The results of several years of experimental measurements using high-power ultrasound are discussed, which provide substantial evidence of the inability of presently accepted theories to fully explain the interaction of ultrasound with solid materials. Finally, a special synchrotron X-ray topographic system is described which affords the possibility of observing direct interaction of ultrasonic waves with the microstructural features of real crystalline solid materials for the first time.

Assessment and Calibration of Ultrasonic Measurement Errors in Estimating Weathering Index of Stone Cultural Heritage

NASA Astrophysics Data System (ADS)

Lee, Y.; Keehm, Y.

2011-12-01

Estimating the degree of weathering in stone cultural heritage, such as pagodas and statues is very important to plan conservation and restoration. The ultrasonic measurement is one of commonly-used techniques to evaluate weathering index of stone cultual properties, since it is easy to use and non-destructive. Typically we use a portable ultrasonic device, PUNDIT with exponential sensors. However, there are many factors to cause errors in measurements such as operators, sensor layouts or measurement directions. In this study, we carried out variety of measurements with different operators (male and female), different sensor layouts (direct and indirect), and sensor directions (anisotropy). For operators bias, we found that there were not significant differences by the operator's sex, while the pressure an operator exerts can create larger error in measurements. Calibrating with a standard sample for each operator is very essential in this case. For the sensor layout, we found that the indirect measurement (commonly used for cultural properties, since the direct measurement is difficult in most cases) gives lower velocity than the real one. We found that the correction coefficient is slightly different for different types of rocks: 1.50 for granite and sandstone and 1.46 for marble. From the sensor directions, we found that many rocks have slight anisotropy in their ultrasonic velocity measurement, though they are considered isotropic in macroscopic scale. Thus averaging four different directional measurement (0°, 45°, 90°, 135°) gives much less errors in measurements (the variance is 2-3 times smaller). In conclusion, we reported the error in ultrasonic meaurement of stone cultural properties by various sources quantitatively and suggested the amount of correction and procedures to calibrate the measurements. Acknowledgement: This study, which forms a part of the project, has been achieved with the support of national R&D project, which has been hosted by National Research Institute of Cultural Heritage of Cultural Heritage Administration(No. NRICH-1107-B01F).

Simultaneous sound velocity and thickness measurement by the ultrasonic pitch-catch method for corrosion-layer-forming polymeric materials.

PubMed

Kusano, Masahiro; Takizawa, Shota; Sakai, Tetsuya; Arao, Yoshihiko; Kubouchi, Masatoshi

2018-01-01

Since thermosetting resins have excellent resistance to chemicals, fiber reinforced plastics composed of such resins and reinforcement fibers are widely used as construction materials for equipment in chemical plants. Such equipment is usually used for several decades under severe corrosive conditions so that failure due to degradation may result. One of the degradation behaviors in thermosetting resins under chemical solutions is "corrosion-layer-forming" degradation. In this type of degradation, surface resins in contact with a solution corrode, and some of them remain asa corrosion layer on the pristine part. It is difficult to precisely measure the thickness of the pristine part of such degradation type materials by conventional pulse-echo ultrasonic testing, because the sound velocity depends on the degree of corrosion of the polymeric material. In addition, the ultrasonic reflection interface between the pristine part and the corrosion layer is obscure. Thus, we propose a pitch-catch method using a pair of normal and angle probes to measure four parameters: the thicknesses of the pristine part and the corrosion layer, and their respective sound velocities. The validity of the proposed method was confirmed by measuring a two-layer sample and a sample including corroded parts. The results demonstrate that the pitch-catch method can successfully measure the four parameters and evaluate the residual thickness of the pristine part in the corrosion-layer-forming sample. Copyright © 2017 Elsevier B.V. All rights reserved.

Ultrasonic studies of intermolecular interactions in binary mixtures of 4-methoxy benzoin with various solvents: Excess molar functions of ultrasonic parameters at different concentrations and in different solvents.

PubMed

Thanuja, B; Nithya, G; Kanagam, Charles C

2012-11-01

Density (ρ), ultrasonic velocity (U), for the binary mixtures of 4-methoxy benzoin (4MB) with ethanol, chloroform, acetonitrile, benzene, and di-oxane were measured at 298K. The solute-solvent interactions and the effect of the polarity of the solvent on the type of intermolecular interactions are discussed here. From the above data, adiabatic compressibility (β), intermolecular free length (L(f)), acoustic impedance (Z), apparent molar volume (Ø), relative association (RA) have been calculated. Other useful parameters such as excess density, excess velocity and excess adiabatic compressibility have also been calculated. These parameters were used to study the nature and extent of intermolecular interactions between component molecules in the binary mixtures. Copyright © 2012 Elsevier B.V. All rights reserved.

Measurement of mechanical properties of homogeneous tissue with ultrasonically induced shear waves

NASA Astrophysics Data System (ADS)

Greenleaf, James F.; Chen, Shigao

2007-03-01

Fundamental mechanical properties of tissue are altered by many diseases. Regional and systemic diseases can cause changes in tissue properties. Liver stiffness is caused by cirrhosis and fibrosis. Vascular wall stiffness and tone are altered by smoking, diabetes and other diseases. Measurement of tissue mechanical properties has historically been done with palpation. However palpation is subjective, relative, and not quantitative or reproducible. Elastography in which strain is measured due to stress application gives a qualitative estimate of Young's modulus at low frequency. We have developed a method that takes advantage of the fact that the wave equation is local and shear wave propagation depends only on storage and loss moduli in addition to density, which does not vary much in soft tissues. Our method is called shearwave dispersion ultrasonic velocity measurement (SDUV). The method uses ultrasonic radiation force to produce repeated motion in tissue that induces shear waves to propagate. The shear wave propagation speed is measured with pulse echo ultrasound as a function of frequency of the shear wave. The resulting velocity dispersion curve is fit with a Voight model to determine the elastic and viscous moduli of the tissue. Results indicate accurate and precise measurements are possible using this "noninvasive biopsy" method. Measurements in beef along and across the fibers are consistent with the literature values.

Irrigant flow during photon-induced photoacoustic streaming (PIPS) using Particle Image Velocimetry (PIV).

PubMed

Koch, Jon D; Jaramillo, David E; DiVito, Enrico; Peters, Ove A

2016-03-01

This study aimed to compare fluid movements generated from photon-induced photoacoustic streaming (PIPS) and passive ultrasonic irrigation (PUI). Particle Image Velocimetry (PIV) was performed using 6-μm melamine spheres in water. Measurement areas were 3-mm-long sections of the canal in the coronal, midroot and apical regions for PIPS (erbium/yttrium-aluminium garnet (Er:YAG) laser set at 15 Hz with 20 mJ), or passive ultrasonic irrigation (PUI, non-cutting insert at 30% unit power) was performed in simulated root canals prepared to an apical size #30/0.04 taper. Fluid movement was analysed directly subjacent to the apical ends of ultrasonic insert or fiber optic tips as well as at midroot and apically. During PUI, measured average velocities were around 0.03 m/s in the immediate vicinity of the sides and tip of the ultrasonic file. Speeds decayed to non-measureable values at a distance of about 2 mm from the sides and tip. During PIPS, typical average speeds were about ten times higher than those measured for PUI, and they were measured throughout the length of the canal, at distances up to 20 mm away. PIPS caused higher average fluid speeds when compared to PUI, both close and distant from the instrument. The findings of this study could be relevant to the debriding and disinfecting stage of endodontic therapy. Irrigation enhancement beyond needle irrigation is relevant to more effectively eradicate microorganisms from root canal systems. PIPS may be an alternative approach due to its ability to create high streaming velocities further away from the activation source compared to ultrasonic activation.

Nondestructive ultrasonic characterization of engineering materials

NASA Technical Reports Server (NTRS)

Salama, K.

1985-01-01

The development of an ultrasonic method for the nondestructive characterization of mechanical properties of engineering material is described. The method utilizes the nonlinearity parameter measurement which describes the anharmonic behavior of the solid through measurements of amplitudes of the fundamental and of the generated second harmonic ultrasonic waves. The nonlinearity parameter is also directly related to the acoustoelastic constant of the solid which can be determined by measuring the linear dependence of ultrasonic velocity on stress. A major advantage of measurements of the nonlinearity parameter over that of the acoustoelastic constant is that it may be determined without the application of stress on the material, which makes it more applicable for in-service nondestructive characterization. The relationships between the nonlinearity parameter of second-harmonic generation and the percentage of solid solution phase in engineering materials such as heat treatable aluminum alloys was established. The acoustoelastic constants are measured on these alloys for comparison and confirmation. A linear relationship between the nonlinearity parameter and the volume fraction of second phase precipitates in the alloys is indicated.

Basic investigation on acoustic velocity change imaging method for quantitative assessment of fat content in human liver

NASA Astrophysics Data System (ADS)

Mano, Kazune; Tanigawa, Shohei; Hori, Makoto; Yokota, Daiki; Wada, Kenji; Matsunaka, Toshiyuki; Morikawa, Hiroyasu; Horinaka, Hiromichi

2016-07-01

Fatty liver is a disease caused by the excess accumulation of fat in the human liver. The early diagnosis of fatty liver is very important, because fatty liver is the major marker linked to metabolic syndrome. We already proposed the ultrasonic velocity change imaging method to diagnose fatty liver by using the fact that the temperature dependence of ultrasonic velocity is different in water and in fat. For the diagonosis of a fatty liver stage, we attempted a feasibility study of the quantitative assessment of the fat content in the human liver using our ultrasonic velocity change imaging method. Experimental results showed that the fat content in the tissue mimic phantom containing lard was determined by its ultrasonic velocity change in the flat temperature region formed by a circular warming ultrasonic transducer with an acoustic lens having an appropriate focal length. By considering the results of our simulation using a thermal diffusion equation, we determined whether this method could be applied to fatty liver assessment under the condition that the tissue had the thermal relaxation effect caused by blood flow.

Ultrasonic investigation of granular materials subjected to compression and crushing.

PubMed

Gheibi, Amin; Hedayat, Ahmadreza

2018-07-01

Ultrasonic wave propagation measurement has been used as a suitable technique for studying the granular materials and investigating the soil fabric structure, the grain contact stiffness, frictional strength, and inter-particle contact area. Previous studies have focused on the variations of shear and compressional wave velocities with effective stress and void ratio, and lesser effort has been made in understanding the variation of amplitude and dominant frequency of transmitted compressional waves with deformation of soil packing. In this study, continuous compressional wave transmission measurements during compaction of unconsolidated quartz sand are used to investigate the impact of soil layer deformation on ultrasonic wave properties. The test setup consisted of a loading machine to apply constant loading rate to a sand layer (granular quartz) of 6 mm thickness compressed between two forcing blocks, and an ultrasonic wave measurement system to continuously monitor the soil layer during compression up to 48 MPa normal stress. The variations in compressional wave attributes such as wave velocity, transmitted amplitude, and dominant frequency were studied as a function of the applied normal stress and the measured normal strain as well as void ratio and particle size. An increasing trend was observed for P-wave velocity, transmitted amplitude and dominant frequency with normal stress. In specimen with the largest particle size (D 50  = 0.32 mm), the wave velocity, amplitude and dominant frequency were found to increase about 230%, 4700% and 320% as the normal stress reached the value of 48 MPa. The absolute values of transmitted wave amplitude and dominant frequency were greater for specimens with smaller particle sizes while the normalized values indicate an opposite trend. The changes in the transmitted amplitude were linked to the changes in the true contact area between the particles with a transitional point in the slope of normalized amplitude, coinciding with the yield stress of the granular soil layer. The amount of grain crushing as a result of increase in the normal stress was experimentally measured and a linear correlation was found between the degree of grain crushing and the changes in the normalized dominant frequency of compressional waves. Copyright © 2018 Elsevier B.V. All rights reserved.

Measurement of the depth of narrow slotted sections in eddy current reference standards

NASA Astrophysics Data System (ADS)

Kim, Young-Joo; Kim, Young-gil; Ahn, Bongyoung; Yoon, Dong-Jin

2007-02-01

The dimensions of the slots in eddy current (EC) reference standards are too narrow to be measured by general depth measurement methods such as the optical (laser) or stylus methods. However, measurement of the dimensions of the machined slots is a prerequisite to using the blocks as references. The present paper suggests a measurement method for the slotted section using an ultrasonic test. The width and depth of the slots measured in our study are roughly 0.1 mm and 0.5 mm, respectively. The time of flight (TOF) of the ultrasonic wave was measured precisely. The ultrasonic velocity in the material of the EC reference standard was calculated with the measured values of the TOF and its thickness. Reflected waves from the tip of the slot and the bottom surface of the EC standard were successfully classified. Using this method we have successfully determined the depth of the slotted section.

Advanced ultrasonic measurement methodology for non-invasive interrogation and identification of fluids in sealed containers

NASA Astrophysics Data System (ADS)

Tucker, Brian J.; Diaz, Aaron A.; Eckenrode, Brian A.

2006-03-01

Government agencies and homeland security related organizations have identified the need to develop and establish a wide range of unprecedented capabilities for providing scientific and technical forensic services to investigations involving hazardous chemical, biological, and radiological materials, including extremely dangerous chemical and biological warfare agents. Pacific Northwest National Laboratory (PNNL) has developed a prototype portable, hand-held, hazardous materials acoustic inspection prototype that provides noninvasive container interrogation and material identification capabilities using nondestructive ultrasonic velocity and attenuation measurements. Due to the wide variety of fluids as well as container sizes and materials encountered in various law enforcement inspection activities, the need for high measurement sensitivity and advanced ultrasonic measurement techniques were identified. The prototype was developed using a versatile electronics platform, advanced ultrasonic wave propagation methods, and advanced signal processing techniques. This paper primarily focuses on the ultrasonic measurement methods and signal processing techniques incorporated into the prototype. High bandwidth ultrasonic transducers combined with an advanced pulse compression technique allowed researchers to 1) obtain high signal-to-noise ratios and 2) obtain accurate and consistent time-of-flight (TOF) measurements through a variety of highly attenuative containers and fluid media. Results of work conducted in the laboratory have demonstrated that the prototype experimental measurement technique also provided information regarding container properties, which will be utilized in future container-independent measurements of hidden liquids.

Experiment and numerical simulation for laser ultrasonic measurement of residual stress.

PubMed

Zhan, Yu; Liu, Changsheng; Kong, Xiangwei; Lin, Zhongya

2017-01-01

Laser ultrasonic is a most promising method for non-destructive evaluation of residual stress. The residual stress of thin steel plate is measured by laser ultrasonic technique. The pre-stress loading device is designed which can easily realize the condition of the specimen being laser ultrasonic tested at the same time in the known stress state. By the method of pre-stress loading, the acoustoelastic constants are obtained and the effect of different test directions on the results of surface wave velocity measurement is discussed. On the basis of known acoustoelastic constants, the longitudinal and transverse welding residual stresses are measured by the laser ultrasonic technique. The finite element method is used to simulate the process of surface wave detection of welding residual stress. The pulsed laser is equivalent to the surface load and the relationship between the physical parameters of the laser and the load is established by the correction coefficient. The welding residual stress of the specimen is realized by the ABAQUS function module of predefined field. The results of finite element analysis are in good agreement with the experimental method. The simple and effective numerical and experimental methods for laser ultrasonic measurement of residual stress are demonstrated. Copyright © 2016. Published by Elsevier B.V.

Measurement of physical characteristics of materials by ultrasonic methods

DOEpatents

Lu, Wei-yang; Min, Shermann

1998-01-01

A method is described for determining and evaluating physical characteristics of a material. In particular, the present invention provides for determining and evaluating the anisotropic characteristics of materials, especially those resulting from such manufacturing processes as rolling, forming, extruding, drawing, forging, etc. In operation, a complex ultrasonic wave is created in the material of interest by any method. The wave form may be any combination of wave types and modes and is not limited to fundamental plate modes. The velocity of propagation of selected components which make up the complex ultrasonic wave are measured and evaluated to determine the physical characteristics of the material including, texture, strain/stress, grain size, crystal structure, etc.

Measurement of physical characteristics of materials by ultrasonic methods

DOEpatents

Lu, W.Y.; Min, S.

1998-09-08

A method is described for determining and evaluating physical characteristics of a material. In particular, the present invention provides for determining and evaluating the anisotropic characteristics of materials, especially those resulting from such manufacturing processes as rolling, forming, extruding, drawing, forging, etc. In operation, a complex ultrasonic wave is created in the material of interest by any method. The wave form may be any combination of wave types and modes and is not limited to fundamental plate modes. The velocity of propagation of selected components which make up the complex ultrasonic wave are measured and evaluated to determine the physical characteristics of the material including, texture, strain/stress, grain size, crystal structure, etc. 14 figs.

New Experimental Setup for High-Pressure High-Temperature Gigahertz Ultrasonic Interferometry

NASA Astrophysics Data System (ADS)

Kantor, A. P.; Kantor, I. Y.; Dubrovinsky, L. S.; Jacobsen, S. D.

2005-12-01

The only direct information about Earth's interior comes from seismological observations of sound wave velocities. In order to create compositional and mineralogical model from seismological data knowledge of the elastic properties and crystal chemistry of minerals is necessary. Gigahertz ultrasonic interferometry (GUI) is a relatively new tool used to measure single-crystal compressional and shear-wave travel times, which are converted to sound velocities and elastic moduli for direct application to problems in geophysics. Although possibility of simultaneous high-pressure and high-temperature GUI measurements in diamond anvil cell was demonstrated before up to temperature of 250°C, in situ pressure measurements were not possible. We developed new experimental setup for simultaneous GUI and pressure determination using a ruby fluorescence gouge. A diamond anvil cell is equipped with a miniature internal resistive heater with thermocouple fixed at a very small distance from the sample chamber. DAC is mounted at the rotating stage with 5 degrees of freedom (XYZ and two tilting degrees), that can be fixed in three different positions: on top of a P-buffer rod for compressional wave velocities measurement, on top of S-buffer rod for shear wave velocities measurement and under the microscope, equipped with laser and portable high-resolution spectrometer for ruby fluorescence measurement. DAC under high temperature could be moved between these three positions, and independent pressure, temperature, S and P wave velocities measurements could be done simultaneously at each data point. In addition to single-crystal elasticity measurements, ability of GUI for elasticity measurements of liquids was demonstrated. Compressional wave velocities in liquid argon were measured at high pressures and temperatures, showing the ability of GUI for studies equation of state of a liquid.

Determination of plate wave velocities and diffuse field decay rates with braod-band acousto-ultrasonic signals

NASA Technical Reports Server (NTRS)

Kautz, Harold E.

1993-01-01

Lowest symmetric and lowest antisymmetric plate wave modes were excited and identified in broad-band acousto-ultrasonic (AU) signals collected from various high temperature composite materials. Group velocities have been determined for these nearly nondispersive modes. An algorithm has been developed and applied to determine phase velocities and hence dispersion curves for the frequency ranges of the broad-band pulses. It is demonstrated that these data are sensitive to changes in the various stiffness moduli of the materials, in agreement by analogy, with the theoretical and experimental results of Tang and Henneke on fiber reinforced polymers. Diffuse field decay rates have been determined in the same specimen geometries and AU configuration as for the plate wave measurements. These decay rates are of value in assessing degradation such as matrix cracking in ceramic matrix composites. In addition, we verify that diffuse field decay rates respond to fiber/matrix interfacial shear strength and density in ceramic matrix composites. This work shows that velocity/stiffness and decay rate measurements can be obtained in the same set of AU experiments for characterizing materials and in specimens with geometries useful for mechanical measurements.

Micro X-ray CT imaging of pore-scale changes in unconsolidated sediment under confining pressure

NASA Astrophysics Data System (ADS)

Schindler, M.; Prasad, M.

2017-12-01

Micro X-ray computed tomography was used to image confining-pressure induced changes in a dry, unconsolidated quartz sand pack while simultaneously recording ultrasonic P-wave velocities. The experiments were performed under in-situ pressure of up to 4000 psi. The majority of digital rock physics studies rely on micro CT images obtained under ambient pressure and temperature conditions although effective rock properties strongly depend on in situ conditions. Goal of this work is to be able to obtain micro CT images of rock samples while pore and confining pressure is applied. Simultaneously we recorded ultrasonic P-wave velocities. The combination of imaging and velocity measurements provides insight in pore-scale changes in the rock and their influence on elastic properties. We visually observed a reduction in porosity by more than a third of the initial value as well as extensive grain damage, changes in pore and grain size distribution and an increase in contact number and contact radius with increasing confining pressure. An increase in measured ultrasonic P-wave velocities with increasing pressure was observed. We used porosity, contact number and contact radius obtained from micro CT images to model P-wave velocity with the contact-radius model by Bachrach et al. (1998). Our observations showed that the frame of unconsolidated sediments is significantly altered starting at pressures of only 1000 psi. This finding indicates that common assumptions in rock physics models (the solid frame remains unchanged) are violated for unconsolidated sediments. The effects on the solid frame should be taken into account when modeling the pressure dependence of elastic rock properties.

Imaging subtle microstructural variations in ceramics with precision ultrasonic velocity and attenuation measurements

NASA Technical Reports Server (NTRS)

Generazio, Edward R.; Roth, Don J.; Baaklini, George Y.

1987-01-01

Acoustic images of a silicon carbide ceramic disk were obtained using a precision scanning contact pulse echo technique. Phase and cross-correlation velocity, and attenuation maps were used to form color images of microstructural variations. These acoustic images reveal microstructural variations not observable with X-ray radiography.

Dynamics of ultrasonic additive manufacturing.

PubMed

Hehr, Adam; Dapino, Marcelo J

2017-01-01

Ultrasonic additive manufacturing (UAM) is a solid-state technology for joining similar and dissimilar metal foils near room temperature by scrubbing them together with ultrasonic vibrations under pressure. Structural dynamics of the welding assembly and work piece influence how energy is transferred during the process and ultimately, part quality. To understand the effect of structural dynamics during UAM, a linear time-invariant model is proposed to relate the inputs of shear force and electric current to resultant welder velocity and voltage. Measured frequency response and operating performance of the welder under no load is used to identify model parameters. Using this model and in-situ measurements, shear force and welder efficiency are estimated to be near 2000N and 80% when welding Al 6061-H18 weld foil, respectively. Shear force and welder efficiency have never been estimated before in UAM. The influence of processing conditions, i.e., welder amplitude, normal force, and weld speed, on shear force and welder efficiency are investigated. Welder velocity was found to strongly influence the shear force magnitude and efficiency while normal force and weld speed showed little to no influence. The proposed model is used to describe high frequency harmonic content in the velocity response of the welder during welding operations and coupling of the UAM build with the welder. Copyright © 2016 Elsevier B.V. All rights reserved.

Evaluation of Early-Age Concrete Compressive Strength with Ultrasonic Sensors.

PubMed

Yoon, Hyejin; Kim, Young Jin; Kim, Hee Seok; Kang, Jun Won; Koh, Hyun-Moo

2017-08-07

Surface wave velocity measurement of concrete using ultrasonic sensors requires testing on only one side of a member. Thus, it is applicable to concrete cast inside a form and is often used to detect flaws and evaluate the compressive strength of hardened concrete. Predicting the in situ concrete strength at a very early stage inside the form helps with determining the appropriate form removal time and reducing construction time and costs. In this paper, the feasibility of using surface wave velocities to predict the strength of in situ concrete inside the form at a very early stage was evaluated. Ultrasonic sensors were used to measure a series of surface waves for concrete inside a form in the first 24 h after placement. A continuous wavelet transform was used to compute the travel time of the propagating surface waves. The cylindrical compressive strength and penetration resistance tests were also performed during the test period. Four mixtures and five curing temperatures were used for the specimens. The surface wave velocity was confirmed to be applicable to estimating the concrete strength at a very early age in wall-like elements. An empirical formula is proposed for evaluating the early-age compressive strength of concrete considering the 95% prediction intervals.

Evaluation of Early-Age Concrete Compressive Strength with Ultrasonic Sensors

PubMed Central

Yoon, Hyejin; Kim, Young Jin; Kim, Hee Seok; Kang, Jun Won; Koh, Hyun-Moo

2017-01-01

Surface wave velocity measurement of concrete using ultrasonic sensors requires testing on only one side of a member. Thus, it is applicable to concrete cast inside a form and is often used to detect flaws and evaluate the compressive strength of hardened concrete. Predicting the in situ concrete strength at a very early stage inside the form helps with determining the appropriate form removal time and reducing construction time and costs. In this paper, the feasibility of using surface wave velocities to predict the strength of in situ concrete inside the form at a very early stage was evaluated. Ultrasonic sensors were used to measure a series of surface waves for concrete inside a form in the first 24 h after placement. A continuous wavelet transform was used to compute the travel time of the propagating surface waves. The cylindrical compressive strength and penetration resistance tests were also performed during the test period. Four mixtures and five curing temperatures were used for the specimens. The surface wave velocity was confirmed to be applicable to estimating the concrete strength at a very early age in wall-like elements. An empirical formula is proposed for evaluating the early-age compressive strength of concrete considering the 95% prediction intervals. PMID:28783128

Ultrasonic velocity and absorption study of binary mixtures of cyclohexane with acrylonitrile by interferometric method at different frequencies

NASA Astrophysics Data System (ADS)

Pawar, N. R.; Chimankar, O. P.; Bhandakkar, V. D.; Padole, N. N.

2012-12-01

The ultrasonic velocity (u), absorption (α), density (ρ), and viscosity (η) has been measured at different frequencies (1MHz to 10MHz) in the binary mixtures of cyclohexane with acrylonitriile over the entire range of composition at temperature 303K. Vander Waal's constant (b), adiabatic compressibility (βa), acoustic impedance (Z), molar volume (V), free length (Lf), free volume, internal pressure, intermolecular radius and relative association have been also calculated. A special application for acrylonitrile is in the manufacture of carbon fibers. These are produced by paralysis of oriented poly acrylonitrile fibers and are used to reinforce composites for high-performance applications in the aircraft, defense and aerospace industries. Other applications of acrylonitrile are in the production of fatty amines, ion exchange resins and fatty amine amides used in cosmetics, adhesives, corrosion inhibitors and water-treatment resins. Cyclohexane derivatives can be used for the synthesis of pharmaceuticals, dyes, herbicides, plant growth regulator, plasticizers, rubber chemicals, nylon, cyclamens and other organic compounds. In the view of these extensive applications of acrylonitrile and cyclohexane in the engineering process, textile and pharmaceutical industries present study provides qualitative information regarding the nature and strength of interaction in the liquid mixtures through derive parameters from ultrasonic velocity and absorption measurement.

Liquid mercury sound velocity measurements under high pressure and high temperature by picosecond acoustics in a diamond anvils cell

NASA Astrophysics Data System (ADS)

Decremps, F.; Belliard, L.; Couzinet, B.; Vincent, S.; Munsch, P.; Le Marchand, G.; Perrin, B.

2009-07-01

Recent improvements to measure ultrasonic sound velocities of liquids under extreme conditions are described. Principle and feasibility of picosecond acoustics in liquids embedded in a diamond anvils cell are given. To illustrate the capability of these advances in the sound velocity measurement technique, original high pressure and high temperature results on the sound velocity of liquid mercury up to 5 GPa and 575 K are given. This high pressure technique will certainly be useful in several fundamental and applied problems in physics and many other fields such as geophysics, nonlinear acoustics, underwater sound, petrology or physical acoustics.

Measuring Ultrasonic Acoustic Velocity in a Thin Sheet of Graphite Epoxy Composite

NASA Technical Reports Server (NTRS)

2008-01-01

A method for measuring the acoustic velocity in a thin sheet of a graphite epoxy composite (GEC) material was investigated. This method uses two identical acoustic-emission (AE) sensors, one to transmit and one to receive. The delay time as a function of distance between sensors determines a bulk velocity. A lightweight fixture (balsa wood in the current implementation) provides a consistent method of positioning the sensors, thus providing multiple measurements of the time delay between sensors at different known distances. A linear fit to separation, x, versus delay time, t, will yield an estimate of the velocity from the slope of the line.

Ultrasonic transmission at solid-liquid interfaces

NASA Astrophysics Data System (ADS)

Wadley, Haydn N. G.; Queheillalt, Douglas T.; Lu, Yichi

1996-11-01

New non-invasive solid-liquid interface sensing technologies are a key element in the development of improved Bridman growth techniques for synthesizing single crystal semiconductor materials. Laser generated and optically detect ultrasonic techniques have the potential to satisfy this need. Using an anisotropic 3D ray tracing methodology combined with elastic constant data measured near the melting point, ultrasonic propagation in cylindrical single crystal bodies containing either a convex, flat, or concave solid-liquid interface has been simulated. Ray paths, wavefronts and the time-of-flight (TOF) of rays that travel from a source to an arbitrarily positioned receiver have all been calculated. Experimentally measured TOF data have been collected using laser generated, optically detected ultrasound on model systems with independently known interface shapes. Both numerically simulated and experimental data have shown that the solidification region can be easily identified from transmission TOF measurements because the velocity of the liquid is much smaller than that of the solid. Since convex and concave solid-liquid interfaces result in distinctively different TOF data profiles, the interface shape can also be readily determined from the TOF data. When TOF data collected in the diametral plane is used in conjunction with a nonlinear least squares algorithm, the interface geometry has been successfully reconstructed and ultrasonic velocities of both the solid and liquid obtained with reconstruction errors less than 5 percent.

Study of molecular interactions in binary mixtures of 2-chloro-4'methoxy benzoin with various solvents through ultrasonic speed measurements

NASA Astrophysics Data System (ADS)

Thanuja, B.; Kanakam, C.; Nithya, G.

2013-12-01

Density ( ρ) and ultrasonic velocity ( U), for binary mixtures of 2-chloro-4'-methoxy benzoin with ethanol, chloroform, acetonitrile, benzene and 1,4-dioxane of different compositions have been measured at 298 K and explanation of solute solvent interactions and effect of polarity of the solvent on type of interactions are presented in this paper. From the above data, adiabatic compressibility ( β), intermolecular free length ( L f ) and relative association ( R A ) have been calculated. Other useful parameters such as excess density, excess velocity, excess intermolecular freelength and excess adiabatic compressibility have also been calculated. These parameters have been used to study the nature and extent of intermolecular interactions between component molecules in present binary mixtures.

Prototype instrument for noninvasive ultrasonic inspection and identification of fluids in sealed containers

NASA Astrophysics Data System (ADS)

Tucker, Brian J.; Diaz, Aaron A.; Eckenrode, Brian A.

2006-05-01

Government agencies and homeland security related organizations have identified the need to develop and establish a wide range of unprecedented capabilities for providing scientific and technical forensic services to investigations involving hazardous chemical, biological, and radiological materials, including extremely dangerous chemical and biological warfare agents. Pacific Northwest National Laboratory (PNNL) has developed a prototype portable, handheld, hazardous materials acoustic inspection prototype that provides noninvasive container interrogation and material identification capabilities using nondestructive ultrasonic velocity and attenuation measurements. Due to the wide variety of fluids as well as container sizes and materials encountered in various law enforcement inspection activities, the need for high measurement sensitivity and advanced ultrasonic measurement techniques were identified. The prototype was developed using a versatile electronics platform, advanced ultrasonic wave propagation methods, and advanced signal processing techniques. This paper primarily focuses on the ultrasonic measurement methods and signal processing techniques incorporated into the prototype. High bandwidth ultrasonic transducers combined with an advanced pulse compression technique allowed researchers to 1) obtain high signal-to-noise ratios and 2) obtain accurate and consistent time-of-flight (TOF) measurements through a variety of highly attenuative containers and fluid media. Results of work conducted in the laboratory have demonstrated that the prototype experimental measurement technique also provided information regarding container properties, which will be utilized in future container-independent measurements of hidden liquids.

Frequency dispersion of longitudinal ultrasonic velocity and attenuation in [001]c-poled 0.24Pb(In₁/₂Nb₁/₂O₃- 0.45Pb(Mg₁/₃Nb₂/₃)O₃-0.31PbTiO₃ single crystal.

PubMed

Sun, Enwei; Cao, Wenwu; Han, Pengdi

2011-08-01

The frequency dispersion of ultrasonic velocity and attenuation in [001](c)-poled 0.24Pb(in(1/2)Nb(1/2))O(3)-0.45Pb(Mg(1/3)Nb(2/3))o(3)-0.31PbTio(3) (PIN-0.45PMN-0.31PT) ternary single crystal were measured by ultrasonic spectroscopy from 25 to 100 MHz for the longitudinal wave. It was found that the velocity has a linear relationship with the frequency f, but the attenuation has a quadratic relation with f. The attenuation and frequency dispersion of the ternary system are lower than that of the (1-x)Pb(Mg(1/3)Nb(2/3))O(3)-xPbTiO(3) (PMN-PT) binary system and the coercive field also increased by a factor of 2.5, hence, the ternary single system is superior to the corresponding binary single-crystal system for high-frequency and high-power transducer applications.

Characterization of Heat Treated Titanium-Based Implants by Nondestructive Eddy Current and Ultrasonic Tests

NASA Astrophysics Data System (ADS)

Mutlu, Ilven; Ekinci, Sinasi; Oktay, Enver

2014-06-01

This study presents nondestructive characterization of microstructure and mechanical properties of heat treated Ti, Ti-Cu, and Ti-6Al-4V titanium-based alloys and 17-4 PH stainless steel alloy for biomedical implant applications. Ti, Ti-Cu, and 17-4 PH stainless steel based implants were produced by powder metallurgy. Ti-6Al-4V alloy was investigated as bulk wrought specimens. Effects of sintering temperature, aging, and grain size on mechanical properties were investigated by nondestructive and destructive tests comparatively. Ultrasonic velocity in specimens was measured by using pulse-echo and transmission methods. Electrical conductivity of specimens was determined by eddy current tests. Determination of Young's modulus and strength is important in biomedical implants. Young's modulus of specimens was calculated by using ultrasonic velocities. Calculated Young's modulus values were compared and correlated with experimental values.

Shear wave mapping of skeletal muscle using shear wave wavefront reconstruction based on ultrasound color flow imaging

NASA Astrophysics Data System (ADS)

Yamakoshi, Yoshiki; Yamamoto, Atsushi; Kasahara, Toshihiro; Iijima, Tomohiro; Yuminaka, Yasushi

2015-07-01

We have proposed a quantitative shear wave imaging technique for continuous shear wave excitation. Shear wave wavefront is observed directly by color flow imaging using a general-purpose ultrasonic imaging system. In this study, the proposed method is applied to experiments in vivo, and shear wave maps, namely, the shear wave phase map, which shows the shear wave propagation inside the medium, and the shear wave velocity map, are observed for the skeletal muscle in the shoulder. To excite the shear wave inside the skeletal muscle of the shoulder, a hybrid ultrasonic wave transducer, which combines a small vibrator with an ultrasonic wave probe, is adopted. The shear wave velocity of supraspinatus muscle, which is measured by the proposed method, is 4.11 ± 0.06 m/s (N = 4). This value is consistent with those obtained by the acoustic radiation force impulse method.

Assessment of damage in ceramics and ceramic matrix composites using ultrasonic techniques

NASA Technical Reports Server (NTRS)

Chu, Y. C.; Baaklini, G. Y.; Rokhlin, S.I.

1993-01-01

This paper addresses the application of ultrasonic sensing to damage assessment in ceramics and ceramic matrix composites. It focuses on damage caused by thermal shock or oxidation at elevated temperatures, which often results in elastic anisotropy. This damaged-induced anisotropy is determined by measuring the velocities of ultrasonic waves in different propagation directions. Thermal shock damage is assessed in ceramic samples of reaction bonded silicon nitride (RBSN). Thermal shock treatment from different temperatures up to 1000 C is applied to produce the microcracks. Results indicate that most microcracks produced by thermal shock are located near sample surfaces. Ultrasonic measurements using the surface wave method are found to correlate well with measurements of degradation of mechanical properties obtained independently by other authors using destructive methods. Oxidation damage is assessed in silicon carbide fiber/reaction bonded silicon nitride matrix (SCS-6/RBSN) composites. The oxidation is done by exposing the samples in a flowing oxygen environment at elevated temperatures, up to 1400 C, for 100 hr. The Youngs' modulus in the fiber direction as obtained from ultrasonic measurements decreases significantly at 600 C but retains its original value at temperatures above 1200 C. This agrees well with the results of destructive tests by other authors. On the other hand, the transverse moduli obtained from ultrasonic measurements decrease continually until 1200 C. Measurements on the shear stiffnesses show behavior similar to the transverse moduli. The results of this work show that the damage-induced anisotropy in both ceramics and ceramic matrix composites can be determined successfully by ultrasonic methods. This suggests the possibility of assessing damage severity using ultrasonic techniques.

Quantitative Mapping of Pore Fraction Variations in Silicon Nitride Using an Ultrasonic Contact Scan Technique

NASA Technical Reports Server (NTRS)

Roth, Don J.; Kiser, James D.; Swickard, Suzanne M.; Szatmary, Steven A.; Kerwin, David P.

1993-01-01

An ultrasonic scan procedure using the pulse-echo contact configuration was employed to obtain maps of pore fraction variations in sintered silicon nitride samples in terms of ultrasonic material properties. Ultrasonic velocity, attenuation coefficient, and reflection coefficient images were obtained simultaneously over a broad band of frequencies (e.g., 30 to 110 MHz) by using spectroscopic analysis. Liquid and membrane (dry) coupling techniques and longitudinal and shear-wave energies were used. The major results include the following: Ultrasonic velocity (longitudinal and shear wave) images revealed and correlated with the extent of average through-thickness pore fraction variations in the silicon nitride disks. Attenuation coefficient images revealed pore fraction nonuniformity due to the scattering that occurred at boundaries between regions of high and low pore fraction. Velocity and attenuation coefficient images were each nearly identical for machined and polished disks, making the method readily applicable to machined materials. Velocity images were similar for wet and membrane coupling. Maps of apparent Poisson's ratio constructed from longitudinal and shear-wave velocities quantified Poisson's ratio variations across a silicon nitride disk. Thermal wave images of a disk indicated transient thermal behavior variations that correlated with observed variations in pore fraction and velocity and attenuation coefficients.

Exploring the relative contribution of mineralogy and CPO to the seismic velocity anisotropy of evaporites

NASA Astrophysics Data System (ADS)

Vargas-Meleza, Liliana; Healy, David; Alsop, G. Ian; Timms, Nicholas E.

2015-01-01

We present the influence of mineralogy and microstructure on the seismic velocity anisotropy of evaporites. Bulk elastic properties and seismic velocities are calculated for a suite of 20 natural evaporite samples, which consist mainly of halite, anhydrite, and gypsum. They exhibit strong fabrics as a result of tectonic and diagenetic processes. Sample mineralogy and crystallographic preferred orientation (CPO) were obtained with the electron backscatter diffraction (EBSD) technique and the data used for seismic velocity calculations. Bulk seismic properties for polymineralic evaporites were evaluated with a rock recipe approach. Ultrasonic velocity measurements were also taken on cube shaped samples to assess the contribution of grain-scale shape preferred orientation (SPO) to the total seismic anisotropy. The sample results suggest that CPO is responsible for a significant fraction of the bulk seismic properties, in agreement with observations from previous studies. Results from the rock recipe indicate that increasing modal proportion of anhydrite grains can lead to a greater seismic anisotropy of a halite-dominated rock. Conversely, it can lead to a smaller seismic anisotropy degree of a gypsum-dominated rock until an estimated threshold proportion after which anisotropy increases again. The difference between the predicted anisotropy due to CPO and the anisotropy measured with ultrasonic velocities is attributed to the SPO and grain boundary effects in these evaporites.

Characterization of Olive Oil by Ultrasonic and Physico-chemical Methods

NASA Astrophysics Data System (ADS)

Alouache, B.; Khechena, F. K.; Lecheb, F.; Boutkedjirt, T.

Olive oil excels by its nutritional and medicinal benefits. It can be consumed without any treatment. However, its quality can be altered by inadequate storage conditions or if it is mixed with other kinds of oils. The objective of this work is to demonstrate the ability of ultrasonic methods to characterize and control olive oil quality. By using of a transducer of 2.25 MHz nominal frequency, in pulse echo mode, ultrasonic parameters, such as propagation velocity and attenuation,have been measured for pure olive oil and for its mixtures with sunflower oil at different proportions. Mechanical properties, such as density and viscosity, have also been determined. The results of ultrasonic measurements are consistent with those obtained by physico-chemical methods, such as rancidity degree, acid index, UV specific extinction coefficient and viscosity. They show that the ultrasonic method allows to distinguish between mixtures at different proportions. The study allows concluding that ultrasound techniques can be considered as a useful complement to existing physico-chemical analysis techniques.

Experiments on Ultrasonic Lubrication Using a Piezoelectrically-assisted Tribometer and Optical Profilometer

PubMed Central

Dong, Sheng; Dapino, Marcelo

2015-01-01

Friction and wear are detrimental to engineered systems. Ultrasonic lubrication is achieved when the interface between two sliding surfaces is vibrated at a frequency above the acoustic range (20 kHz). As a solid-state technology, ultrasonic lubrication can be used where conventional lubricants are unfeasible or undesirable. Further, ultrasonic lubrication allows for electrical modulation of the effective friction coefficient between two sliding surfaces. This property enables adaptive systems that modify their frictional state and associated dynamic response as the operating conditions change. Surface wear can also be reduced through ultrasonic lubrication. We developed a protocol to investigate the dependence of friction force reduction and wear reduction on the linear sliding velocity between ultrasonically lubricated surfaces. A pin-on-disc tribometer was built which differs from commercial units in that a piezoelectric stack is used to vibrate the pin at 22 kHz normal to the rotating disc surface. Friction and wear metrics including effective friction force, volume loss, and surface roughness are measured without and with ultrasonic vibrations at a constant pressure of 1 to 4 MPa and three different sliding velocities: 20.3, 40.6, and 87 mm/sec. An optical profilometer is utilized to characterize the wear surfaces. The effective friction force is reduced by 62% at 20.3 mm/sec. Consistently with existing theories for ultrasonic lubrication, the percent reduction in friction force diminishes with increasing speed, down to 29% friction force reduction at 87 mm/sec. Wear reduction remains essentially constant (49%) at the three speeds considered. PMID:26436691

Ultrasonic Nondestructive Characterization of Porous Materials

NASA Astrophysics Data System (ADS)

Yang, Ningli

2011-12-01

Wave propagation in porous media is studied in a wide range of technological applications. In the manufacturing industry, determining porosity of materials in the manufacturing process is required for strict quality control. In the oil industry, acoustic signals and seismic surveys are used broadly to determine the physical properties of the reservoir rock which is a porous media filled with oil or gas. In porous noise control materials, a precise prediction of sound absorption with frequency and evaluation of tortuosity are necessary. Ultrasonic nondestructive methods are a very important tool for characterization of porous materials. The dissertation deals with two types of porous media: materials with relatively low and closed porosity and materials with comparatively high and open porosity. Numerical modeling, Finite Element simulations and experimental characterization are all discussed in this dissertation. First, ultrasonic scattering is used to determine the porosity in porous media with closed pores. In order get a relationship between the porosity in porous materials and ultrasonic scattering independently and to increase the sensitivity to obtain scattering information, ultrasonic imaging methods are applied and acoustic waves are focused by an acoustic lens. To verify the technique, engineered porous acrylic plates with varying porosity are measured by ultrasonic scanning and ultrasonic array sensors. Secondly, a laser based ultrasonic technique is explored for predicting the mechanical integrity and durability of cementitious materials. The technique used involves the measurement of the phase velocity of fast and slow longitudinal waves in water saturated cement paste. The slow wave velocity is related to the specimen's tortuosity. The fast wave speed is dependent on the elastic properties of porous solid. Experimental results detailing the generation and detection of fast and slow wave waves in freshly prepared and aged water-saturated cement samples with varying water-to-cement ratios are presented in the dissertation. The third part concerns the ultrasonic characterization of air-saturated porous materials. Using airborne reflected and transmitted ultrasonic experimental data, the open porosity and tortuosity value of a porous acrylic plate with graded void content and a polyimide foam are determined simultaneously. Experimental and numerical results of the method are presented.

High-pressure ultrasonic study of the commensurate-incommensurate spin-density-wave transition in an antiferromagnetic Cr-0.3 at. % Ru alloy single crystal

NASA Astrophysics Data System (ADS)

Cankurtaran, M.; Saunders, G. A.; Wang, Q.; Ford, P. J.; Alberts, H. L.

1992-12-01

A comprehensive experimental study has been made of the elastic and nonlinear acoustic behavior of a dilute Cr alloy as it undergoes a commensurate (C)-incommensurate (I) spin-density-wave transition. Simultaneous measurements of the temperature dependence of ultrasonic wave velocity and attenuation of longitudinal and shear 10-MHz ultrasonic waves propagated along both the [100] and the [110] direction of Cr-0.3 at. % Ru alloy single crystal have been made in the temperature range 200-300 K. The temperature dependence of ultrasonic attenuation for each mode is characterized by a spikelike peak centered at TCI (=238.6 K) (on cooling) and at TIC (=255.6 K) (on warming). The velocities of both longitudinal and shear ultrasonic waves exhibit a large and steep increase at TCI on cooling and a similar drop at TIC on warming with a pronounced hysteresis between TIC and TCI. These observations show that the transition between the commensurate and incommensurate phases is first order. Measurements of the effects of hydrostatic pressure (up to 0.15 GPa) on the velocities of ultrasonic waves, which were made at several fixed temperatures between 248 and 297 K, show similar features: a steep increase at PCI (increasing pressure) and a similar drop at PIC (decreasing pressure) with a well-defined hysteresis. Both TCI and TIC increase strongly and approximately linearly with pressure, the mean values of dTCI/dP and dTIC/dP being (333+/-3) K/GPa and (277+/-5) K/GPa, respectively. The pressure and temperature dependencies of the anomalies in the ultrasonic wave velocity have been used to locate both the C-I and I-C boundaries on the magnetic P-T phase diagram. There is a triple point (at about 315 K and 0.22 GPa) where the paramagnetic, commensurate, and incommensurate spin-density-wave phases coexist. Results for the complete sets of the elastic stiffness tensor components and their hydrostatic pressure derivatives have been used to evaluate the acoustic-mode Grüneisen parameters in both the commensurate and incommensurate phases. These quantify the vibrational anharmonicity of each acoustic phonon mode in the long-wavelength limit and establish which acoustic modes interact strongly with the spin-density waves. Pronounced longitudinal acoustic-mode softening under pressure results in negative Grüneisen parameters, a particularly marked feature of the commensurate phase.

Catalytic activity of acid and base with different concentration on sol-gel kinetics of silica by ultrasonic method.

PubMed

Das, R K; Das, M

2015-09-01

The effects of both acid (acetic acid) and base (ammonia) catalysts in varying on the sol-gel synthesis of SiO2 nanoparticles using tetra ethyl ortho silicate (TEOS) as a precursor was determined by ultrasonic method. The ultrasonic velocity was received by pulsar receiver. The ultrasonic velocity in the sol and the parameter ΔT (time difference between the original pulse and first back wall echo of the sol) was varied with time of gelation. The graphs of ln[ln1/ΔT] vs ln(t), indicate two region - nonlinear region and a linear region. The time corresponds to the point at which the non-linear region change to linear region is considered as gel time for the respective solutions. Gelation time is found to be dependent on the concentration and types of catalyst and is found from the graphs based on Avrami equation. The rate of condensation is found to be faster for base catalyst. The gelation process was also characterized by viscosity measurement. Normal sol-gel process was also carried out along with the ultrasonic one to compare the effectiveness of ultrasonic. The silica gel was calcined and the powdered sample was characterized with scanning electron microscopy, energy dispersive spectra, X-ray diffractogram, and FTIR spectroscopy. Copyright © 2014 Elsevier B.V. All rights reserved.

Prediction of ultrasonic pulse velocity for enhanced peat bricks using adaptive neuro-fuzzy methodology.

PubMed

Motamedi, Shervin; Roy, Chandrabhushan; Shamshirband, Shahaboddin; Hashim, Roslan; Petković, Dalibor; Song, Ki-Il

2015-08-01

Ultrasonic pulse velocity is affected by defects in material structure. This study applied soft computing techniques to predict the ultrasonic pulse velocity for various peats and cement content mixtures for several curing periods. First, this investigation constructed a process to simulate the ultrasonic pulse velocity with adaptive neuro-fuzzy inference system. Then, an ANFIS network with neurons was developed. The input and output layers consisted of four and one neurons, respectively. The four inputs were cement, peat, sand content (%) and curing period (days). The simulation results showed efficient performance of the proposed system. The ANFIS and experimental results were compared through the coefficient of determination and root-mean-square error. In conclusion, use of ANFIS network enhances prediction and generation of strength. The simulation results confirmed the effectiveness of the suggested strategies. Copyright © 2015 Elsevier B.V. All rights reserved.

Advanced Ultrasonic Measurement Methodology for Non-Invasive Interrogation and Identification of Fluids in Sealed Containers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tucker, Brian J.; Diaz, Aaron A.; Eckenrode, Brian A.

2006-03-16

The Hazardous Materials Response Unit (HMRU) and the Counterterrorism and Forensic Science Research Unit (CTFSRU), Laboratory Division, Federal Bureau of Investigation (FBI) have been mandated to develop and establish a wide range of unprecedented capabilities for providing scientific and technical forensic services to investigations involving hazardous chemical, biological, and radiological materials, including extremely dangerous chemical and biological warfare agents. Pacific Northwest National Laboratory (PNNL) has developed a portable, hand-held, hazardous materials acoustic inspection device (HAZAID) that provides noninvasive container interrogation and material identification capabilities using nondestructive ultrasonic velocity and attenuation measurements. Due to the wide variety of fluids as wellmore » as container sizes and materials, the need for high measurement sensitivity and advanced ultrasonic measurement techniques were identified. The HAZAID prototype was developed using a versatile electronics platform, advanced ultrasonic wave propagation methods, and advanced signal processing techniques. This paper primarily focuses on the ultrasonic measurement methods and signal processing techniques incorporated into the HAZAID prototype. High bandwidth ultrasonic transducers combined with the advanced pulse compression technique allowed researchers to 1) impart large amounts of energy, 2) obtain high signal-to-noise ratios, and 3) obtain accurate and consistent time-of-flight (TOF) measurements through a variety of highly attenuative containers and fluid media. Results of this feasibility study demonstrated that the HAZAID experimental measurement technique also provided information regarding container properties, which will be utilized in future container-independent measurements of hidden liquids.« less

On the feasibility of quantitative ultrasonic determination of fracture toughness: A literature review

NASA Technical Reports Server (NTRS)

Fu, L. S.

1980-01-01

The three main topics covered are: (1) fracture toughness and microstructure, (2) quantitative ultrasonic and microstructure; and (3) scattering and related mathematical methods. Literature in these areas is reviewed to give insight to the search of a theoretical foundation for quantitative ultrasonic measurement of fracture toughness. The literature review shows that fracture toughness is inherently related to the microstructure and in particular, it depends upon the spacing of inclusions or second particles and the aspect ratio of second phase particles. There are indications that ultrasonic velocity attenuation measurements can be used to determine fracture toughness. The leads to a review of the mathematical models available in solving boundary value problems related to microstructural factors that govern facture toughness and wave motion. A framework towards the theoretical study for the quantitative determination of fracture toughness is described and suggestions for future research are proposed.

Non-Intrusive Sensor for In-Situ Measurement of Recession Rate of Ablative and Eroding Materials

NASA Technical Reports Server (NTRS)

Papadopoulos, George (Inventor); Tiliakos, Nicholas (Inventor); Thomson, Clint (Inventor); Benel, Gabriel (Inventor)

2014-01-01

A non-intrusive sensor for in-situ measurement of recession rate of heat shield ablatives. An ultrasonic wave source is carried in the housing. A microphone is also carried in the housing, for collecting the reflected ultrasonic waves from an interface surface of the ablative material. A time phasing control circuit is also included for time-phasing the ultrasonic wave source so that the waves reflected from the interface surface of the ablative material focus on the microphone, to maximize the acoustic pressure detected by the microphone and to mitigate acoustic velocity variation effects through the material through a de-coupling process that involves a software algorithm. A software circuit for computing the location off of which the ultrasonic waves scattered to focus back at the microphone is also included, so that the recession rate of the heat shield ablative may be monitored in real-time through the scan-focus approach.

In-situ monitoring of ? phase transformation in Ti-6Al-6V-2Sn using laser ultrasonics

NASA Astrophysics Data System (ADS)

Hinterlechner, Irina; Barriobero-Vila, Pere; Reitinger, Bernhard; Fromherz, Thomas; Requena, Guillermo; Burgholzer, Peter

2018-04-01

Titanium is of great interest for metal processing industries due to its superior material properties, but it is also quite expensive. Therefore, a detailed knowledge of ? phase transformation and consequential the distribution of ? and ? phase in titanium alloys is crucial for their material properties and as a consequence for further processing steps. Measuring the ultrasonic velocity and attenuation by laser ultrasonics technology (LUS) as a non-destructive and non-contact technique, it is possible to qualitatively monitor in-situ the phase transformation during heating the sample from room temperature up to ?. We validate LUS methodology against high energy X-ray diffraction as well as against conventional metallurgic measurements and get excellent agreement between the results of these methods.

Thermo-acoustical molecular interaction study in binary mixtures of glycerol and ethylene glycol

NASA Astrophysics Data System (ADS)

Kaur, Kirandeep; Juglan, K. C.; Kumar, Harsh

2017-07-01

Ultrasonic velocity, density and viscosity are measured over the entire composition range for binary liquid mixtures of glycerol (CH2OH-CHOH-CH2OH) and ethylene glycol (HOCH2CH2OH) at different temperatures and constant frequency of 2MHz using ultrasonic interferometer, specific gravity bottle and viscometer respectively. Measured experimental values are used to obtained various acoustical parameters such as adiabatic compressibility, acoustic impedance, intermolecular free length, relaxation time, ultrasonic attenuation, effective molar weight, free volume, available volume, molar volume, Wada's constant, Rao's constant, Vander Waal's constant, internal pressure, Gibb's free energy and enthalpy. The variation in acoustical parameters are interpreted in terms of molecular interactions between the components of molecules of binary liquid mixtures.

The use of ultrasonic properties of CR-39 track detectors in neutron dosimetry

NASA Astrophysics Data System (ADS)

Afifi, H.; El-Sersy, A.; Khaled, N.

2004-01-01

The longitudinal and shear wave ultrasonic velocities have been measured before and after exposing 5-mm thick CR-39 solid state nuclear track detectors to both a mixed field of gamma-rays and fast neutrons from an Am-Be source in the ranges from 0 to 10 4 mSv. The change in the intermolecular structure as caused by the fast neutron exposure was studied by the ultrasonic pulse echo method at a frequency of 2 MHz and at room temperature. The elastic coefficients, Poisson's ratio, microhardness, ultrasonic absorption coefficient and internal friction have been determined. The study shows that the gamma-ray irradiation had no effect on the ultrasonic properties of CR-39 at least at the used doses. However, all the ultrasonic properties are influenced by the fast neutrons at doses up to 10 4 mSv. Our experimental results confirmed that the ultrasonic technique is useful for fast neutron detection, by exploiting the differences in mechanical properties of CR-39.

Laser ultrasonic evaluation of human dental enamel during remineralization treatment

PubMed Central

Wang, Hsiao-Chuan; Fleming, Simon; Lee, Yung-Chun; Swain, Michael; Law, Susan; Xue, Jing

2011-01-01

In this work a non-destructive laser ultrasonic technique is used to quantitatively evaluate the progressive change in the elastic response of human dental enamel during a remineralization treatment. The condition of the enamel was measured during two weeks treatment using laser generated and detected surface acoustic waves in sound and demineralized enamel. Analysis of the acoustic velocity dispersion confirms the efficacy, as well as illuminating the progress, of the treatment. PMID:21339879

Behavior of Two-Level Tunneling Systems in Disordered and Amorphous Mechanically Alloyed Palladium, Silicon, Copper and in the Crystalline High T

NASA Astrophysics Data System (ADS)

McKenna, Mark Joseph

Amorphous materials have different low temperature, T <=q 10K, properties than their crystalline counterparts. The "Two level Tunneling System", (TLS), model has been very successful in explaining many of these differences, for example: a specific heat term linearly dependent on temperature, a sound velocity which increases as lnT at low temperatures, and an amplitude dependent ultrasonic attenuation. We have studied several systems in this context with emphasis on the determination of the density of states of the TLS through measurements of sound velocity changes for 0.27 K < T < 5K in the 5-30 MHz frequency range. In conjunction with x-ray diffraction and differential scanning calorimetry, (DSC), measurements, we used this TLS density of states to measure solid state amorphization in the mechanical alloying process, where elemental crystalline powders are alloyed and amorphized by repeated deformation, fragmenting and cold welding. We find the low temperature ultrasonic characteristics of amorphous Pd_ {0.775}Si_{0.165} Cu_{0.060}, produced by mechanical alloying in an inert atmosphere, are comparable with those for the amorphous alloys prepared by rapid solidification. If the milling takes place in air, rather than in argon, we find that following amorphization in the early stages of mechanical alloying, recrystallization occurs in the amorphous powders with extended milling. We have used these three methods: ultrasonic velocity changes, DSC measurements, x-ray measurements, to study the crystallization of mechanically alloyed PdSiCu and have compared the results with those for rapidly solidified PdSiCu. We find the ultrasonic properties of the amorphous alloys produced by grinding the recrystallized PdSiCu alloy are similar to those of both the mechanically alloyed and the rapidly solidified metallic glass. We have discussed our results with regard to the various models for the amorphization mechanism. Ultrasonic velocity measurements were used to study the interactions of TLS with phonons and with electrons in the high T_{rm c} superconductor, YBa_2Cu _3O_{7-delta} , and in a niobium compact, a conventional BCS superconductor, at temperatures below 1K, i.e. for T << T_{rm c}. The high T_{rm c} superconductors exhibit TLS relaxation typically found in normal metallic glasses, whereas the TLS in the niobium compact relax through interactions with phonons. We also have studied the dependence of the density of states of the TLS on the oxygen content. We find an interesting dependence of the density of states with transition temperature and with oxygen content: a decreasing density of states of the TLS with decreasing transition temperature. We interpret these results in light of recent electron diffraction measurements on the increasing ordering of oxygen vacancies with decreasing oxygen content, increasing delta..

A nondestructive technique for predicting the strength remaining in filament wound composites subjected to low-level impact

NASA Technical Reports Server (NTRS)

Madaras, E. I.; Poe, C. C.; Heyman, J. S.

1987-01-01

A model for predicting the fracture strength of homogeneous materials is proposed. Impacted FWC samples were evaluated using ultrasonic testing and an X-ray dye penetration method. The ability of the model to measure fracture strength was also examined. The relation between attenuation and velocity measurements is studied. It is observed that the X-ray method is not useful for predicting fracture strength because the dye could not penetrate the matrix. It is noted that fracture strength predictions derived from the fracture mechanical model and the ultrasonic measurements correlate well with actual measured fracture strengths.

PSIDD3: Post-Scan Ultrasonic Data Display System for the Windows-Based PC Including Fuzzy Logic Analysis

NASA Technical Reports Server (NTRS)

Lovelace, Jeffrey J.; Cios, Krzysztof J.; Roth, Don J.; Cao, Wei

2000-01-01

Post-Scan Interactive Data Display (PSIDD) III is a user-oriented Windows-based system that facilitates the display and comparison of ultrasonic contact data. The system is optimized to compare ultrasonic measurements made at different locations within a material or at different stages of material degradation. PSIDD III provides complete analysis of the primary wave forms in the time and frequency domains along with the calculation of several frequency dependent properties including Phase Velocity and Attenuation Coefficient and several frequency independent properties, like the Cross Correlation Velocity. The system allows image generation on all of the frequency dependent properties at any available frequency (limited by the bandwidth used in the scans) and on any of the frequency independent properties. From ultrasonic contact scans, areas of interest on an image can be studied with regard to underlying raw waveforms and derived ultrasonic properties by simply selecting the point on the image. The system offers various modes of in-depth comparison between scan points. Up to five scan points can be selected for comparative analysis at once. The system was developed with Borland Delphi software (Visual Pascal) and is based on a SQL database. It is ideal for classification of material properties, or location of microstructure variations in materials.

Noncontact Measurement of Humidity and Temperature Using Airborne Ultrasound

NASA Astrophysics Data System (ADS)

Kon, Akihiko; Mizutani, Koichi; Wakatsuki, Naoto

2010-04-01

We describe a noncontact method for measuring humidity and dry-bulb temperature. Conventional humidity sensors are single-point measurement devices, so that a noncontact method for measuring the relative humidity is required. Ultrasonic temperature sensors are noncontact measurement sensors. Because water vapor in the air increases sound velocity, conventional ultrasonic temperature sensors measure virtual temperature, which is higher than dry-bulb temperature. We performed experiments using an ultrasonic delay line, an atmospheric pressure sensor, and either a thermometer or a relative humidity sensor to confirm the validity of our measurement method at relative humidities of 30, 50, 75, and 100% and at temperatures of 283.15, 293.15, 308.15, and 323.15 K. The results show that the proposed method measures relative humidity with an error rate of less than 16.4% and dry-bulb temperature with an error of less than 0.7 K. Adaptations of the measurement method for use in air-conditioning control systems are discussed.

In and ex-vivo Myocardial Tissue Temperature Monitoring by Combined Infrared and Ultrasonic Thermometries

NASA Astrophysics Data System (ADS)

Engrand, C.; Laux, D.; Ferrandis, J.-Y.; Sinquet, J.-C.; Demaria, R.; Le Clézio, E.

The success of cardiac surgery essentially depends on tissue preservation during intervention. Consequently a hypothermic cardio-plegia is applied in order to avoid ischemia. However, myocardial temperature is not monitored during operation. The aim of this study is then to find a relevant and simple method for myocardial global temperature estimation in real time using both ultrasounds and infra-red thermography. In order to quantify the sensitivity of ultrasonic velocity to temperature, a 2.25 MHz ultrasonic probe was used for ex-vivo tests. Pig myocards (n=25) were placed in a thermostatically-controlled water bath and measurements of the ultrasound velocity were realized from 10 to 30 ˚C. The results of this study indicate that the specificity and sensitivity of the ultrasonic echo delay induced by the modification of temperature can be exploited for in-depth thermometry. In parallel, for TIR experiments, a bolometer was used to detect the myocardium surface thermal evolution during in-vivo pig heart experiments. Hypothermic cardioplegic solutions were injected and infra-red surface imaging was performed during one hour. In the near futur, the correlation of the ultrasound and the infrared measurements should allow the real time estimation of the global temperature of the heart. The final objective being to realize in vivo measurements on human hearts, this information may have a very high importance in terms of per-operation inspection as well as decision making process during medical interventions.

An approach to improving transporting velocity in the long-range ultrasonic transportation of micro-particles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meng, Jianxin; Mei, Deqing, E-mail: meidq-127@zju.edu.cn; Yang, Keji

2014-08-14

In existing ultrasonic transportation methods, the long-range transportation of micro-particles is always realized in step-by-step way. Due to the substantial decrease of the driving force in each step, the transportation is lower-speed and stair-stepping. To improve the transporting velocity, a non-stepping ultrasonic transportation approach is proposed. By quantitatively analyzing the acoustic potential well, an optimal region is defined as the position, where the largest driving force is provided under the condition that the driving force is simultaneously the major component of an acoustic radiation force. To keep the micro-particle trapped in the optimal region during the whole transportation process, anmore » approach of optimizing the phase-shifting velocity and phase-shifting step is adopted. Due to the stable and large driving force, the displacement of the micro-particle is an approximately linear function of time, instead of a stair-stepping function of time as in the existing step-by-step methods. An experimental setup is also developed to validate this approach. Long-range ultrasonic transportations of zirconium beads with high transporting velocity were realized. The experimental results demonstrated that this approach is an effective way to improve transporting velocity in the long-range ultrasonic transportation of micro-particles.« less

Constant Group Velocity Ultrasonic Guided Wave Inspection for Corrosion and Erosion Monitoring in Pipes

NASA Astrophysics Data System (ADS)

Instanes, Geir; Pedersen, Audun; Toppe, Mads; Nagy, Peter B.

2009-03-01

This paper describes a novel ultrasonic guided wave inspection technique for the monitoring of internal corrosion and erosion in pipes, which exploits the fundamental flexural mode to measure the average wall thickness over the inspection path. The inspection frequency is chosen so that the group velocity of the fundamental flexural mode is essentially constant throughout the wall thickness range of interest, while the phase velocity is highly dispersive and changes in a systematic way with varying wall thickness in the pipe. Although this approach is somewhat less accurate than the often used transverse resonance methods, it smoothly integrates the wall thickness over the whole propagation length, therefore it is very robust and can tolerate large and uneven thickness variations from point to point. The constant group velocity (CGV) method is capable of monitoring the true average of the wall thickness over the inspection length with an accuracy of 1% even in the presence of one order of magnitude larger local variations. This method also eliminates spurious variations caused by changing temperature, which can cause fairly large velocity variations, but do not significantly influence the dispersion as measured by the true phase angle in the vicinity of the CGV point. The CGV guided wave CEM method was validated in both laboratory and field tests.

A program to calculate pulse transmission responses through transversely isotropic media

NASA Astrophysics Data System (ADS)

Li, Wei; Schmitt, Douglas R.; Zou, Changchun; Chen, Xiwei

2018-05-01

We provide a program (AOTI2D) to model responses of ultrasonic pulse transmission measurements through arbitrarily oriented transversely isotropic rocks. The program is built with the distributed point source method that treats the transducers as a series of point sources. The response of each point source is calculated according to the ray-tracing theory of elastic plane waves. The program could offer basic wave parameters including phase and group velocities, polarization, anisotropic reflection coefficients and directivity patterns, and model the wave fields, static wave beam, and the observed signals for pulse transmission measurements considering the material's elastic stiffnesses and orientations, sample dimensions, and the size and positions of the transmitters and the receivers. The program could be applied to exhibit the ultrasonic beam behaviors in anisotropic media, such as the skew and diffraction of ultrasonic beams, and analyze its effect on pulse transmission measurements. The program would be a useful tool to help design the experimental configuration and interpret the results of ultrasonic pulse transmission measurements through either isotropic or transversely isotropic rock samples.

Computerized Ultrasonic Testing System (CUTS) for in-process thickness determination

NASA Technical Reports Server (NTRS)

Frankel, J.; Doxbeck, M.; Schroeder, S. C.; Abbate, A.

1994-01-01

A Computerized Ultrasonic Testing System (CUTS) was developed to measure, in real-time, the rate of deposition and thickness of chromium plated on the inside of thick steel tubes. The measurements are made from the outside of the tubes with the ultrasonic pulse-echo technique. The resolution of the system is 2.5 micron. (0.0001 in.) and the accuracy is better than 10 micron (0.0004 in.). The thickness is measured using six transducers mounted at different locations on the tube. In addition, two transducers are mounted on two reference standards, thereby allowing the system to be continuously calibrated. The tube temperature varies during the process, thus the input from eight thermocouples, located at the measurement sites, is used to calculate and compensate for the change in return time of the ultrasonic echo due to the temperature dependence of the sound velocity. CUTS is applicable to any commercial process where real-time change of thickness of a sample has to be known, with the advantage of facilitating increased efficiency and of improving process control.

Ultrasonic-generated fluid velocity with Sovereign WhiteStar micropulse and continuous phacoemulsification.

PubMed

Steinert, Roger F; Schafer, Mark E

2006-02-01

To evaluate and compare ultrasonic turbulence created by conventional and micropulse ultrasound technology. Sonora Medical Systems, Longmont, Colorado, USA. A high-resolution digital ultrasound probe imaged the zone around a phacoemulsification tip. Doppler analysis allowed determination of flow. The fluid velocity was measured at 4 levels of ultrasound power at a constant flow, comparing the ultrasonic conditions of continuous energy to WhiteStar micropulses. In addition to the normal baseline irrigation and aspiration, fluid movement was detected directly below the phaco tip, produced by a nonlinear effect known as acoustic streaming. Acoustic streaming increased with increased phacoemulsification power for both conditions. At each of the 4 levels of power, fluid velocity away from the tip was less with micropulse technology than with continuous phacoemulsification. The demonstrated decrease in acoustic streaming flow away from the phaco tip with Sovereign WhiteStar micropulse technology compared to conventional ultrasound provides an objective explanation for clinical observations of increased stability of nuclear fragments at the tip and less turbulence in the anterior chamber during phacoemulsification. This methodology can be used to examine and compare fluid flow and turbulence under a variety of clinically relevant conditions.

High pressure system for 3-D study of elastic anisotropy

NASA Astrophysics Data System (ADS)

Lokajicek, T.; Pros, Z.; Klima, K.

2003-04-01

New high pressure system was designed for the study of elastic anisotropy of condensed matter under high confining pressure up to 700 MPa. Simultaneously could be measured dynamic and static parameters: a) dynamic parameters by ultrasonic sounding, b) static parameters by measuring of spherical sample deformation. The measurement is carried out on spherical samples diameter 50 +/- 0.01 mm. Higher value of confining pressure was reached due to the new construction of sample positioning unit. The positioning unit is equipped with two Portecap step motors, which are located inside the vessel and make possible to rotate with the sphere and couple of piezoceramic transducers. Sample deformation is measured in the same direction as ultrasonic signal travel time. Only electric leads connects inner part of high pressure vessel with surrounding environment. Experimental set up enables: - simultaneous P-wave ultrasonic sounding, - measurement of current sample deformation at sounding points, - measurement of current value of confining pressure and - measurement of current stress media temperature. Air driven high pressure pump Haskel is used to produce high value of confining pressure up to 700 MPa. Ultrasonic signals are recorded by digital scope Agilent 54562 with sampling frequency 100 MHz. Control and measuring software was developed under Agilent VEE software environment working under MS Win 2000 operating system. Measuring set up was tested by measurement of monomineral spherical samples of quartz and corundum. Both of them have trigonal symmetry. The measurement showed that the P-wave velocity range of quartz was between 5.7-7.0 km/sec. and velocity range of corundum was between 9.7-10.9 km/sec. High pressure resistant LVDT transducers Mesing together with Intronix electronic unit were used to monitor sample deformation. Sample deformation is monitored with the accuracy of 0.1 micron. All test measurements proved the good accuracy of the whole measuring set up. This project was supported by Grant Agency of the Czech Republic No.: 205/01/1430.

Ultrasonic Monitoring of CO2 Uptake and Release from Sand Packs*

NASA Astrophysics Data System (ADS)

Toffelmier, D. A.; Dufrane, W. L.; Bonner, B. P.; Viani, B. E.; Berge, P. A.

2002-12-01

Sequestration of atmospheric CO2 occurs naturally during the formation of calcite cement in sedimentary rock. Acceleration of this process has been proposed as a means of reducing the atmospheric concentration of CO2, which is a major cause of global warming. Calcite may also be precipitated when highly alkaline waste fluid is introduced into the vadose zone from leaking storage tanks. Seismic methods have potential for monitoring these processes. We devised an experiment, guided by geochemical modeling, to determine how the formation of calcite cement in unsaturated sand affects wave propagation. We used the ultrasonic pulse transmission method to measure compressional (P) and shear (S) wave velocities at ultrasonic frequencies (100-500 kHz) through packs of Ottawa sand containing chemically active pore fluids. The samples were saturated with water containing 0.1mol/L of Ca(OH)2 and 0.1mol/L of NaCl and then drained by flowing water saturated, CO2 free N2 gas, to a residual saturation of ~5%, so that the remaining pore fluid resides mainly in pendular spaces between the sand grains. Ambient air saturated with water and containing atmospheric concentration of CO2 was then passed through the sample to effect the precipitation of calcite. Finally, pure water saturated CO2, was flushed through the sample to dissolve most of the precipitated calcite. Over a three day period, measurable changes in Vp and Vs were observed following water saturation, desaturation, calcite precipitation, and calcite dissolution treatments. Changes in the contents of the pore space require waveforms to be recorded before and after each stage of the experiment so both the short and long range effects can be seen. Wave velocities were slow, as is typical for unconsolidated materials, for the dry sand, with values of 365m/s for Vp and 163m/s for Vs. Compressional velocities increased upon desaturation (443m/s), and again following calcite precipitation (460m/s). The compressional velocity measured following the CO2 flush to dissolve the calcite decreased (451m/s). The shear velocities varied similarly to the compressional velocities except that the dry sand shear velocity was faster than the other shear velocities. These preliminary results suggest that ultrasonics could provide a tool to locate the path of certain types of waste fluid in the vadose zone. *This work was performed under the auspices of the U.S. Department of Energy by the University of California, Lawrence Livermore National Laboratory under contract number W-7405-ENG-48 and was supported specifically by the Environmental Management Science Program of the Office of Environmental Management and the Office of Energy Research.

Thermal and ultrasonic evaluation of porosity in composite laminates

NASA Technical Reports Server (NTRS)

Johnston, Patrick H.; Winfree, William P.; Long, Edward R., Jr.; Kullerd, Susan M.; Nathan, N.; Partos, Richard D.

1992-01-01

The effects of porosity on damage incurred by low-velocity impact are investigated. Specimens of graphite/epoxy composite were fabricated with various volume fractions of voids. The void fraction was independently determined using optical examination and acid resin digestion methods. Thermal diffusivity and ultrasonic attenuation were measured, and these results were related to the void volume fraction. The relationship between diffusivity and fiber volume fraction was also considered. The slope of the ultrasonic attenuation coefficient was found to increase linearly with void content, and the diffusivity decreased linearly with void volume fraction, after compensation for an approximately linear dependence on the fiber volume fraction.

Optical and Radio Frequency Refractivity Fluctuations from High Resolution Point Sensors: Sea Breezes and Other Observations

DTIC Science & Technology

2007-03-01

velocity and direction along with vertical velocities are derived from the measured time of flight for the ultrasonic signals (manufacture’s...data set. To prevent aliasing a wave must be sample at least twice per period so the Nyquist frequency is sn ff 2 = . 3. Sampling Requirements...an order of magnitude or more. To refine models or conduct climatologically studies for Cn2 requires direct measurements to identify the underlying

Ultrasonic Evaluation of the Pull-Off Adhesion between Added Repair Layer and a Concrete Substrate

NASA Astrophysics Data System (ADS)

Czarnecki, Slawomir

2017-10-01

This paper concerns the evaluation of the pull-off adhesion between a concrete added repair layer with variable thickness and a concrete substrate, based on parameters assessed using ultrasonic pulse velocity (UPV) method. In construction practice, the experimental determination of pull-off adhesion f b, between added repair layer and a concrete substrate is necessary to assess the quality of repair. This is usually carried out with the use of pull-off method which results in local damage of the added concrete layer in all the testing areas. Bearing this in mind, it is important to describe the method without these disadvantages. The prediction of the pull-off adhesion of the two-layer concrete elements with variable thickness of each layer might be provided by means of UPV method with two-sided access to the investigated element. For this purpose, two-layered cylindrical specimens were obtained by drilling the borehole from a large size specially prepared concrete element. Those two-layer elements were made out of concrete substrate layer and Polymer Cement Concrete (PCC) mortar as an added repair layer. The values of pull-off adhesion f b of the elements were determined before obtaining the samples by using the semi-destructive pull-off method. The ultrasonic wave velocity was determined in samples with variable thickness of each layer and was then compared to theoretical ultrasonic wave velocity predicted for those specimens. The regression curve for the dependence of velocity and pull-off adhesion, determined by the pulloff method, was made. It has been proved that together with an increase of ratio of investigated ultrasonic wave velocity divided by theoretical ultrasonic wave velocity, the pull-off adhesion value f b between added repair layer with variable thickness and a substrate layer also increases.

Commercial Implementation of Ultrasonic Velocity Imaging Methods via Cooperative Agreement Between NASA Lewis Research Center and Sonix, Inc.

NASA Technical Reports Server (NTRS)

Roth, Don J.; Hendricks, J. Lynne; Whalen, Mike F.; Bodis, James R.; Martin, Katherine

1996-01-01

This article describes the commercial implementation of ultrasonic velocity imaging methods developed and refined at NASA Lewis Research Center on the Sonix c-scan inspection system. Two velocity imaging methods were implemented: thickness-based and non-thickness-based reflector plate methods. The article demonstrates capabilities of the commercial implementation and gives the detailed operating procedures required for Sonix customers to achieve optimum velocity imaging results. This commercial implementation of velocity imaging provides a 100x speed increase in scanning and processing over the lab-based methods developed at LeRC. The significance of this cooperative effort is that the aerospace and other materials development-intensive industries which use extensive ultrasonic inspection for process control and failure analysis will now have an alternative, highly accurate imaging method commercially available.

Non Destructive Analysis of Fsw Welds using Ultrasonic Signal Analysis

NASA Astrophysics Data System (ADS)

Pavan Kumar, T.; Prabhakar Reddy, P.

2017-08-01

Friction Stir Welding is an evolving metal joining technique and is mostly used in joining materials which cannot be easily joined by other available welding techniques. It is a technique which can be used for welding dissimilar materials also. The strength of the weld joint is determined by the way in which these material are mixing with each other, since we are not using any filler material for the welding process the intermixing has a significant importance. The complication with the friction stir welding process is that there are many process parameters which effect this intermixing process such as tool geometry, rotating speed of the tool, transverse speed etc., In this study an attempt is made to compare the material flow and weld quality of various weldments by changing the parameters. Ultrasonic signal Analysis is used to characterize the microstructure of the weldments. use of ultrasonic waves is a non destructive, accurate and fast way of characterization of microstructure. In this method the relationship between the ultrasonic measured parameters and microstructures are evaluated using background echo and backscattered signal process techniques. The ultrasonic velocity and attenuation measurements are dependent on the elastic modulus and any change in the microstructure is reflected in the ultrasonic velocity. An insight into material flow is essential to determine the quality of the weld. Hence an attempt is made in this study to know the relationship between tool geometry and the pattern of material flow and resulting weld quality the experiments are conducted to weld dissimilar aluminum alloys and the weldments are characterized using and ultra Sonic signal processing. Characterization is also done using Scanning Electron Microscopy. It is observed that there is a good correlation between the ultrasonic signal processing results and Scanning Electron Microscopy on the observed precipitates. Tensile tests and hardness tests are conducted on the weldments and compared for determining the weld quality.

Spatially resolved ultrasonic attenuation in resistance spot welds: implications for nondestructive testing.

PubMed

Mozurkewich, George; Ghaffari, Bita; Potter, Timothy J

2008-09-01

Spatial variation of ultrasonic attenuation and velocity has been measured in plane parallel specimens extracted from resistance spot welds. In a strong weld, attenuation is larger in the nugget than in the parent material, and the region of increased attenuation is surrounded by a ring of decreased attenuation. In the center of a stick weld, attenuation is even larger than in a strong weld, and the low-attenuation ring is absent. These spatial variations are interpreted in terms of differences in grain size and martensite formation. Measured frequency dependences indicate the presence of an additional attenuation mechanism besides grain scattering. The observed attenuations do not vary as commonly presumed with weld quality, suggesting that the common practice of using ultrasonic attenuation to indicate weld quality is not a reliable methodology.

A digital, constant-frequency pulsed phase-locked-loop instrument for real-time, absolute ultrasonic phase measurements

NASA Astrophysics Data System (ADS)

Haldren, H. A.; Perey, D. F.; Yost, W. T.; Cramer, K. E.; Gupta, M. C.

2018-05-01

A digitally controlled instrument for conducting single-frequency and swept-frequency ultrasonic phase measurements has been developed based on a constant-frequency pulsed phase-locked-loop (CFPPLL) design. This instrument uses a pair of direct digital synthesizers to generate an ultrasonically transceived tone-burst and an internal reference wave for phase comparison. Real-time, constant-frequency phase tracking in an interrogated specimen is possible with a resolution of 0.000 38 rad (0.022°), and swept-frequency phase measurements can be obtained. Using phase measurements, an absolute thickness in borosilicate glass is presented to show the instrument's efficacy, and these results are compared to conventional ultrasonic pulse-echo time-of-flight (ToF) measurements. The newly developed instrument predicted the thickness with a mean error of -0.04 μm and a standard deviation of error of 1.35 μm. Additionally, the CFPPLL instrument shows a lower measured phase error in the absence of changing temperature and couplant thickness than high-resolution cross-correlation ToF measurements at a similar signal-to-noise ratio. By showing higher accuracy and precision than conventional pulse-echo ToF measurements and lower phase errors than cross-correlation ToF measurements, the new digitally controlled CFPPLL instrument provides high-resolution absolute ultrasonic velocity or path-length measurements in solids or liquids, as well as tracking of material property changes with high sensitivity. The ability to obtain absolute phase measurements allows for many new applications than possible with previous ultrasonic pulsed phase-locked loop instruments. In addition to improved resolution, swept-frequency phase measurements add useful capability in measuring properties of layered structures, such as bonded joints, or materials which exhibit non-linear frequency-dependent behavior, such as dispersive media.

Influence of CeO2 on structural properties of glasses by using ultrasonic technique: comparison between the local sand and SiO2.

PubMed

Laopaiboon, Raewat; Bootjomchai, Cherdsak

2013-04-01

Comparison between the local sand and SiO2 with different compositions of CeO2 on the structural properties of glasses was carried out by using ultrasonic technique. The ultrasonic velocities were measured by the pulse echo technique with a frequency of 4 MHz and at room temperature. From these obtained velocities and densities, various elastic moduli, micro-hardness and Poisson's ratio were calculated. The interesting point of the bulk modulus (SiO2 glass system) decreases at x = 1.25 mol.% initially before it turns to increase between x = 3.75 and x = 5.00 mol.%. While the bulk modulus of the local sand glass system is near constant. FTIR spectra were used to study the structural properties of the prepared glass system. The results supported our discussion of the formation of non-bridging oxygens (NBO) and bridging oxygens (BO). Copyright © 2013 Elsevier B.V. All rights reserved.

Effects of the concentration of emulsion of oil-in-water on the propagation velocity and attenuation

NASA Astrophysics Data System (ADS)

Silva, L. S. F.; Bibiano, D. S.; Figueiredo, M. K. K.; Costa-Félix, R. P. B.

2015-01-01

Soybean oil is an important feedstock for production of biodiesel that generates about 20 % of oily effluents. This paper studied the effect of concentration of soybean oil-inwater emulsions, in the range from 6 000 to 14 000 ppm, on the propagation velocity and ultrasonic attenuation. The Emission-Reception method has shown that the propagation velocity depends linearly on the concentration. The behavior of attenuation is similar to the velocity. Thus, both parameters can be used to measure oils and greases content in water.

Implications of elastic wave velocities for Apollo 17 rock powders

NASA Technical Reports Server (NTRS)

Talwani, P.; Nur, A.; Kovach, R. L.

1974-01-01

Ultrasonic P- and S-wave velocities of lunar rock powders 172701, 172161, 170051, and 175081 were measured at room temperature and to 2.5 kb confining pressure. The results compare well with those of terrestrial volcanic ash and powdered basalt. P-wave velocity values up to pressures corresponding to a lunar depth of 1.4 km preclude cold compaction alone as an explanation for the observed seismic velocity structure at the Apollo 17 site. Application of small amounts of heat with simultaneous application of pressure causes rock powders to achieve equivalence of seismic velocities for competent rocks.

Interfacial Healing and Transport Phenomena Modeling ff Biopolymers

NASA Astrophysics Data System (ADS)

Lebron, Karla

This research focuses on the characterization of bioplastics joined using ultrasonic welding and modeling of temperature distributions and interfacial healing. Polylactic acid (PLA), which is typically derived from starch-rich crops such as corn, was studied. While the measurement of activation energy for interfacial healing at weld interfaces of PLA films has been reported, here, this information is used to predict the weld strength of rigid PLA samples welded by ultrasonics. A characterization of the mechanical properties was completed with a tensile test to determine the effects of amplitude, melt velocity and collapse distance on weld strength. From previous interfacial healing activation energy measurements based on an impulse welding method, it was also possible to predict weld strength. It was found that the most influential parameters were weld time, collapse distance and weld velocity. In general, the model predicted weld strength reasonably well with r2 values between 0.77 and 0.78.

Study of intermolecular interactions in binary mixtures of 2'-chloro-4-methoxy-3-nitro benzil in various solvents and at different concentrations by the measurement of acoustic properties.

PubMed

Nithya, G; Thanuja, B; Kanagam, Charles C

2013-01-01

Density (ρ), ultrasonic velocity (u), adiabatic compressibility (β), apparent molar volume (Ø), acoustic impedance (Z), intermolecular free length (L(f)), relative association (RA) of binary mixtures of 2'-chloro-4-methoxy-3-nitro benzil (abbreviated as 2CBe) in ethanol, acetonitrile, chloroform, dioxane and benzene were measured at different concentrations at 298 K. Several useful parameters such as excess density, excess ultrasonic velocity, excess adiabatic compressibility, excess apparent molar volume, excess acoustic impedance and excess intermolecular free length have been calculated. These parameters are used to explain the nature of intermolecular interactions taking place in the binary mixture. The above study is useful in understanding the solute--solvent interactions occurring in different concentrations at room temperature. Copyright © 2012 Elsevier B.V. All rights reserved.

Transparent electrodes made with ultrasonic spray coating technique for flexible heaters

NASA Astrophysics Data System (ADS)

Wroblewski, G.; Krzemiński, J.; Janczak, D.; Sowiński, J.; Jakubowska, M.

2017-08-01

Transparent electrodes are one of the basic elements of various electronic components. The paper presents the preliminary results related to novel method of ultrasonic spray coating used for fabrication of transparent flexible electrodes. Experiments were conducted by means of specially made laboratory setup composed of ultrasonic spray generator and XYZ plotter. In the first part of the paper diverse solvents were used to determine the crucial technological parameters such as atomization voltage and fluid flow velocity. Afterwards paint containing carbon nanotubes suspended in the two solvent system was prepared and deposited on the polyethylene terephthalate foil. Thickness, roughness and electrical measurements were performed to designate the relations of technological parameters of ultrasonic spray coating on thickness, roughness, sheet resistance and optical transmission of fabricated samples.

Ultrasound Analysis of Slurries

DOEpatents

Soong, Yee and Blackwell, Arthur G.

2005-11-01

An autoclave reactor allows for the ultrasonic analysis of slurry concentration and particle size distribution at elevated temperatures and pressures while maintaining the temperature- and pressure-sensitive ultrasonic transducers under ambient conditions. The reactor vessel is a hollow stainless steel cylinder containing the slurry which includes a stirrer and a N, gas source for directing gas bubbles through the slurry. Input and output transducers are connected to opposed lateral portions of the hollow cylinder for respectively directing sound waves through the slurry and receiving these sound waves after transmission through the slurry, where changes in sound wave velocity and amplitude can be used to measure slurry parameters. Ultrasonic adapters connect the transducers to the reactor vessel in a sealed manner and isolate the transducers from the hostile conditions within the vessel without ultrasonic signal distortion or losses.

Ultrasound Analysis Of Slurries

DOEpatents

Soong, Yee; Blackwell, Arthur G.

2005-11-01

An autoclave reactor allows for the ultrasonic analysis of slurry concentration and particle size distribution at elevated temperatures and pressures while maintaining the temperature- and pressure-sensitive ultrasonic transducers under ambient conditions. The reactor vessel is a hollow stainless steel cylinder containing the slurry which includes a stirrer and a N.sub.2 gas source for directing gas bubbles through the slurry. Input and output transducers are connected to opposed lateral portions of the hollow cylinder for respectively directing sound waves through the slurry and receiving these sound waves after transmission through the slurry, where changes in sound wave velocity and amplitude can be used to measure slurry parameters. Ultrasonic adapters connect the transducers to the reactor vessel in a sealed manner and isolate the transducers from the hostile conditions within the vessel without ultrasonic signal distortion or losses.

Laboratory ultrasonic pulse velocity logging for determination of elastic properties from rock core

NASA Astrophysics Data System (ADS)

Blacklock, Natalie Erin

During the development of deep underground excavations spalling and rockbursting have been recognized as significant mechanisms of violent brittle failure. In order to predict whether violent brittle failure will occur, it is important to identify the location of stiffness transitions that are associated with geologic structure. One approach to identify the effect of geologic structures is to apply borehole geophysical tools ahead of the tunnel advance. Stiffness transitions can be identified using mechanical property analysis surveys that combine acoustic velocity and density data to calculate acoustic estimates of elastic moduli. However, logistical concerns arise since the approach must be conducted at the advancing tunnel face. As a result, borehole mechanical property analyses are rarely used. Within this context, laboratory ultrasonic pulse velocity testing has been proposed as a potential alternative to borehole mechanical property analysis since moving the analysis to the laboratory would remove logistical constraints and improve safety for the evaluators. In addition to the traditional method of conducting velocity testing along the core axis, two new methodologies for point-focused testing were developed across the core diameter, and indirectly along intact lengths of drill core. The indirect test procedure was implemented in a continuous ultrasonic velocity test program along 573m of drill core to identify key geologic structures that generated transitions in ultrasonic elastic moduli. The test program was successful at identifying the location of geologic contacts, igneous intrusions, faults and shear structures. Ultrasonic values of Young's modulus and bulk modulus were determined at locations of significant velocity transitions to examine the potential for energy storage and energy release. Comparison of results from different ultrasonic velocity test configurations determined that the indirect test configuration provided underestimates for values of Young's modulus. This indicated that the test procedure will require modifications to improve coupling of the transducers to the core surface. In order to assess whether laboratory testing can be an alternative to borehole surveys, laboratory velocity testing must be directly assessed with results from acoustic borehole logging. There is also potential for the laboratory velocity program to be used to assess small scale stiffness changes, differences in mineral composition and the degree of fracturing of drill core.

Constant frequency pulsed phase-locked loop measuring device

NASA Technical Reports Server (NTRS)

Yost, William T. (Inventor); Kushnick, Peter W. (Inventor); Cantrell, John H. (Inventor)

1993-01-01

A measuring apparatus is presented that uses a fixed frequency oscillator to measure small changes in the phase velocity ultrasonic sound when a sample is exposed to environmental changes such as changes in pressure, temperature, etc. The invention automatically balances electrical phase shifts against the acoustical phase shifts in order to obtain an accurate measurement of electrical phase shifts.

Calculation for simulation of archery goal value using a web camera and ultrasonic sensor

NASA Astrophysics Data System (ADS)

Rusjdi, Darma; Abdurrasyid, Wulandari, Dewi Arianti

2017-08-01

Development of the device simulator digital indoor archery-based embedded systems as a solution to the limitations of the field or open space is adequate, especially in big cities. Development of the device requires simulations to calculate the value of achieving the target based on the approach defined by the parabolic motion variable initial velocity and direction of motion of the arrow reaches the target. The simulator device should be complemented with an initial velocity measuring device using ultrasonic sensors and measuring direction of the target using a digital camera. The methodology uses research and development of application software from modeling and simulation approach. The research objective to create simulation applications calculating the value of the achievement of the target arrows. Benefits as a preliminary stage for the development of the simulator device of archery. Implementation of calculating the value of the target arrows into the application program generates a simulation game of archery that can be used as a reference development of the digital archery simulator in a room with embedded systems using ultrasonic sensors and web cameras. Applications developed with the simulation calculation comparing the outer radius of the circle produced a camera from a distance of three meters.

Influence of power density and primer application on polymerization of dual-cured resin cements monitored by ultrasonic measurement.

PubMed

Takubo, Chikako; Yasuda, Genta; Murayama, Ryosuke; Ogura, Yukari; Tonegawa, Motoka; Kurokawa, Hiroyasu; Miyazaki, Masashi

2010-08-01

We used ultrasonic measurements to monitor the influence of power density and primer application on the polymerization reaction of dual-cured resin cements. The ultrasonic equipment comprised a pulser-receiver, transducers, and an oscilloscope. Resin cements were mixed and inserted into a transparent mould, and specimens were placed on the sample stage, onto which the primer, if used, was also applied. Power densities of 0 (no irradiation), 200, or 600 mW cm(-2) were used for curing. The transit time through the cement disk was divided by the specimen thickness to obtain the longitudinal sound velocity. When resin cements were light-irradiated, each curve displayed an initial plateau of approximately 1,500 m s(-1), which rapidly increased to a second plateau of 2,300-2,900 m s(-1). The rate of sound velocity increase was retarded when the cements were light-irradiated at lower power densities, and increased when the primer was applied. The polymerization behaviour of dual-cured resin cements was therefore shown to be affected by the power density of the curing unit and the application of self-etching primer. (c) 2010 The Authors. Journal compilation (c) 2010 Eur J Oral Sci.

Noninvasive measurement of central venous pressure

NASA Technical Reports Server (NTRS)

Webster, J. G.; Mastenbrook, S. M., Jr.

1972-01-01

A technique for the noninvasive measurement of CVP in man was developed. The method involves monitoring venous velocity at a point in the periphery with a transcutaneous Doppler ultrasonic velocity meter while the patient performs a forced expiratory maneuver. The idea is the CVP is related to the value of pressure measured at the mouth which just stops the flow in the vein. Two improvements were made over the original procedure. First, the site of venous velocity measurement was shifted from a vein at the antecubital fossa (elbow) to the right external jugular vein in the neck. This allows for sensing more readily events occurring in the central veins. Secondly, and perhaps most significantly, a procedure for obtaining a curve of relative mean venous velocity vs mouth pressure was developed.

Apparatus and techniques for measuring bedload

USGS Publications Warehouse

Hubbell, David Wellington

1964-01-01

The need for accurate determinations of the total sediment discharge of particles of bedload size has prompted this investigation of available and possible measuring apparatus and procedures. The accuracy of measurements of sediment discharge made with trap-type samplers is affected by the variability of sampler efficiency, by the oscillatory variation of bedload discharge, and by sampler placement. Equations that were developed for determining total discharge from measured bedioad discharge and measured suspended-sediment discharge are simplest if the bedload apparatus measures only the true bedload. Early bedload samplers are generally unsatisfactory. Recently developed or suggested apparatus include various improved samplers of the pressure-difference type, a pumping sampler, a magnetic sampler, acoustical instruments that measure the magnitude of the sound of particle collisions, an ultrasonic bedload sampler designed to measure and integrate electronically the concentration and velocity, and a tiltmeter designed to measure the total sediment discharge from the ground tilt that results from the passage of flow. All the pressure-difference samplers are improvements over early samplers, but none are void of the inherent shortcomings of trap-type apparatus; probably the Sphinx (Dutch) and VUV (Hungarian) samplers are the most satisfactory. The acoustical instruments are capable of measuring only the relative discharge. The ultrasonic sampler and the tiltmeter are not adequate without further development. Some new possible apparatus and means for measuring or aiding in measuring bedload discharge are small pit samplers, ultrasonic sounders, pressure transducers, and photography. A small pit sampler for measuring bedload discharge was designed to provide self-placement and portability ; however, its practicability and efficiency are undetermined. Exploratory films show that by using slowmotion photography the discharge of particles larger than about pea size can be determined provided the flow is clear; however, photography generally is not practical. Ultrasonic sounders provide continuous and accurate data on bed configuration and dune movement for use in equations that were developed for computing the bedload discharge. Computations with the equations indicate that the interpretation of the sounding data needs further study. Pressure transducers placed beneath the bed surface possibly can be used to provide information on dune movement; however, their installation would be difficult. The time required for collecting data on bed configuration and dune movement throughout a cross section could be substantially reduced by using several transducers simultaneously in conjunction with an ultrasonic sounder. A modified ultrasonic sounder that provides information on the shape and velocity of large particles and a method for determining the discharge of such particles were proposed; the method seems most feasible for particles of high sphericity.

Enhancement in Diffusion of Electrolyte through Membrane Using Ultrasonic Dialysis Equipment with Plane Membrane

NASA Astrophysics Data System (ADS)

Li, Hui; Ohdaira, Etsuzo; Ide, Masao

1995-05-01

Application of ultrasound to accelerate the dialysis separation of electrolytes through a membrane was studied with ultrasonic dialysis equipment. The experiments were conducted with cellophane membrane and KCl solution, CH3COONa solution, and a mixture of KCl and saponin solutions. It was found that the diffusion velocity of electrolyte through a membrane with ultrasonic irradiation is faster than that without ultrasonic irradiation, and it increases with acoustic pressure. It has become clear that the reasons for enhancement caused by ultrasound are increase in liquid particle velocity and diffusion coefficient due to ultrasonic vibration. It was confirmed that the permeability of the membrane was not degraded by ultrasound in the ranges of acoustic pressure and irradiation time in this study.

Method and apparatus for measuring stress

DOEpatents

Thompson, R.B.

1983-07-28

A method and apparatus for determining stress in a material independent of micro-structural variations and anisotropies. The method comprises comparing the velocities of two horizontally polarized and horizontally propagating ultrasonic shear waves with interchanged directions of propagation and polarization. The apparatus for carrying out the method comprises periodic permanent magnet-electromagnetic acoustic transducers for generating and detecting the shear waves and means for determining the wave velocities.

Method and apparatus for measuring stress

DOEpatents

Thompson, R. Bruce

1985-06-11

A method and apparatus for determining stress in a material independent of micro-structural variations and anisotropies. The method comprises comparing the velocities of two horizontally polarized and horizontally propagating ultrasonic shear waves with interchanged directions of propagation and polarization. The apparatus for carrying out the method comprises periodic permanent magnet-electromagnetic acoustic transducers for generating and detecting the shear waves and means for determining the wave velocities.

Review and statistical analysis of the use of ultrasonic velocity for estimating the porosity fraction in polycrystalline materials

NASA Technical Reports Server (NTRS)

Roth, D. J.; Swickard, S. M.; Stang, D. B.; Deguire, M. R.

1991-01-01

A review and statistical analysis of the ultrasonic velocity method for estimating the porosity fraction in polycrystalline materials is presented. Initially, a semiempirical model is developed showing the origin of the linear relationship between ultrasonic velocity and porosity fraction. Then, from a compilation of data produced by many researchers, scatter plots of velocity versus percent porosity data are shown for Al2O3, MgO, porcelain-based ceramics, PZT, SiC, Si3N4, steel, tungsten, UO2,(U0.30Pu0.70)C, and YBa2Cu3O(7-x). Linear regression analysis produces predicted slope, intercept, correlation coefficient, level of significance, and confidence interval statistics for the data. Velocity values predicted from regression analysis of fully-dense materials are in good agreement with those calculated from elastic properties.

Review and statistical analysis of the ultrasonic velocity method for estimating the porosity fraction in polycrystalline materials

NASA Technical Reports Server (NTRS)

Roth, D. J.; Swickard, S. M.; Stang, D. B.; Deguire, M. R.

1990-01-01

A review and statistical analysis of the ultrasonic velocity method for estimating the porosity fraction in polycrystalline materials is presented. Initially, a semi-empirical model is developed showing the origin of the linear relationship between ultrasonic velocity and porosity fraction. Then, from a compilation of data produced by many researchers, scatter plots of velocity versus percent porosity data are shown for Al2O3, MgO, porcelain-based ceramics, PZT, SiC, Si3N4, steel, tungsten, UO2,(U0.30Pu0.70)C, and YBa2Cu3O(7-x). Linear regression analysis produced predicted slope, intercept, correlation coefficient, level of significance, and confidence interval statistics for the data. Velocity values predicted from regression analysis for fully-dense materials are in good agreement with those calculated from elastic properties.

Experimental study on titanium wire drawing with ultrasonic vibration.

PubMed

Liu, Shen; Shan, Xiaobiao; Guo, Kai; Yang, Yuancai; Xie, Tao

2018-02-01

Titanium and its alloys have been widely used in aerospace and biomedical industries, however, they are classified as difficult-to-machine materials. In this paper, ultrasonic vibration is imposed on the die to overcome the difficulties during conventional titanium wire drawing processes at the room temperature. Numerical simulations were performed to investigate the variation of axial stress within the contacting region and study the change of the drawing stress with several factors in terms of the longitudinal amplitude and frequency of the applied ultrasonic vibration, the diameter reduction ratio, and the drawing force. An experimental testing equipment was established to measure the drawing torque and rotational velocity of the coiler drum during the wire drawing process. The result indicates the drawing force increases with the growth of the drawing velocity and the reduction ratio, whether with or without vibrations. Application of either form of ultrasonic vibrations contributes to the further decrease of the drawing force, especially the longitudinal vibration with larger amplitude. SEM was employed to detect the surface morphology of the processed wires drawn under the three circumstances. The surface quality of the drawn wires with ultrasonic vibrations was apparently improved compared with those using conventional method. In addition, the longitudinal and torsional composite vibration was more effective for surface quality improvement than pure longitudinal vibration, however, at the cost of weakened drawing force reduction effect. Copyright © 2017 Elsevier B.V. All rights reserved.

Ultrasonic characterization of granites obtained from industrial quarries of Extremadura (Spain).

PubMed

del Río, L M; López, F; Esteban, F J; Tejado, J J; Mota, M; González, I; San Emeterio, J L; Ramos, A

2006-12-22

The industry of ornamental rocks, such as granites, represents one of the most important industrial activities in the region of Extremadura, SW Spain. A detailed knowledge of the intrinsic properties of this natural stone and its environmental evolution is a required goal in order to fully characterize its quality. In this work, two independent NDT acoustic techniques have been used to measure the acoustic velocity of longitudinal waves in different prismatic granitic-samples of industrial quarries. A low-frequency transceiver set-up, based on a high-voltage BPV Steinkamp instrument and two 50 kHz probes, has been used to measure pulse travel times by ultrasonic through-transmission testing. In complementary fashion, an Erudite MK3 test equipment with an electromagnetic vibrator and two piezoelectric sensors has also been employed to measure ultrasonic velocity by means of a resonance-based method, using the same types of granite varieties. In addition, a comprehensive set of physical/mechanical properties have also been analyzed, according to Spanish regulations in force, by means of alternative methods including destructive techniques such as strength, porosity, absorption, etc. A large number of samples, representing the most important varieties of granites from quarries of Extremadura, have been analyzed using the above-mentioned procedures. Some results obtained by destructive techniques have been correlated with those found using ultrasonic techniques. Our experimental setting allowed a complementary characterization of granite samples and a thorough validation of the different techniques employed, thus providing the industry of ornamental rocks with a non-destructive tool that will facilitate a more detailed insight on the properties of the rocks under study.

Ultrasonic Sound Velocity of Diopside Liquid Under High Pressure and High Temperature Conditions

NASA Astrophysics Data System (ADS)

Xu, M.; Jing, Z.; Chantel, J.; Yu, T.; Wang, Y.; Jiang, P.

2017-12-01

The equation of state (EOS) of silicate liquids is of great significance to the understanding of the dynamics and differentiation of the magmatic systems in Earth and other terrestrial planets. Sound velocity of silicate liquids measured at high pressure can provide direct information on the bulk modulus and its pressure derivative and hence tightly constrain the EOS of silicate liquids. In addition, the sound velocity data can be directly compared to seismic observations to infer the presence of melts in the mantle. While the sound velocity for silicate liquids at ambient pressure has been well established, the high-pressure sound velocity data are still lacking due to experimental challenges. In this study, we successfully determined the sound velocities of diopside (CaMgSi2O6) liquid in a multi-anvil apparatus under high pressure-high temperature conditions from 1 to 4 GPa and 1973 to 2473 K by the ultrasonic interferometry in conjunction with synchrotron X-ray techniques. Diopside was chosen to study because it is not only one of the most important phases in the Earth's upper mantle, but also an end-member composition of model basalt. It is thus an ideal simplified melt composition in the upper mantle. Besides, diopside liquid has been studied by ambient-pressure ultrasonic measurements (e.g., Ai and Lange, 2008) and shock-wave experiments at much higher pressure (e.g., Asimow and Ahrens, 2010), which allows comparison with our results over a large pressure range. Our high-pressure results on the sound velocity of Di liquid are consistent with the ambient-pressure data and show an increase of velocity with pressure (from 3039 m/s at 0.1 GPa to 4215 m/s at 3.5 GPa). Fitting to the Murnaghan EOS gives an isentropic bulk modulus (Ks) of 24.8 GPa and its pressure dependence (K'S) of 7.8. These are consistent with the results from shock-wave experiments on Di liquid (Asimow and Ahrens, 2010), indicating that the technique used in this study is capable to accurately determine the sound velocity of silicate liquids at high pressures. We will use these results to better constrain the hard sphere EOS model for silicate liquids (Jing and Karato, 2011), with implications to the stability of melt layers in the deep mantle under gravity and the presence of partial melts in low velocity zones in the mantle.

Frictional response of simulated faults to normal stresses perturbations probed with ultrasonic waves

NASA Astrophysics Data System (ADS)

Shreedharan, S.; Riviere, J.; Marone, C.

2017-12-01

We report on a suite of laboratory friction experiments conducted on saw-cut Westerly Granite surfaces to probe frictional response to step changes in normal stress and loading rate. The experiments are conducted to illuminate the fundamental processes that yield friction rate and state dependence. We quantify the microphysical frictional response of the simulated fault surfaces to normal stress steps, in the range of 1% - 600% step increases and decreases from a nominal baseline normal stress. We measure directly the fault slip rate and account for changes in slip rate with changes in normal stress and complement mechanical data acquisition by continuously probing the faults with ultrasonic pulses. We conduct the experiments at room temperature and humidity conditions in a servo controlled biaxial testing apparatus in the double direct shear configuration. The samples are sheared over a range of velocities, from 0.02 - 100 μm/s. We report observations of a transient shear stress and friction evolution with step increases and decreases in normal stress. Specifically, we show that, at low shear velocities and small increases in normal stress (<5% increase), the shear stress on the fault does not increase instantaneously with the normal stress step while the ultrasonic wave amplitude and normal displacement do. In other words, the shear stress does not follow the load point stiffness curve. At high shear velocities and larger normal stress steps (> 5% increases), the shear stress evolves immediately with normal stress. We show that the excursions in slip rate resulting from the changes in normal stress must be accounted for in order to predict fault strength evolution. Ultrasonic wave amplitudes which first increase immediately in response to normal stress steps, then decrease approximately linearly to a new steady state value, in part due to changes in fault slip rate. Previous descriptions of frictional state evolution during normal stress perturbations have not adequately accounted for the effect of large slip velocity excursions. Here, we attempt to do so by using the measured ultrasonic amplitudes as a proxy for frictional state during transient shear stress evolution. Our work aims to improve understanding of induced and triggered seismicity with focus on simulating static triggering using rate and state friction.

Elastic Moduli of Pyrolytic Boron Nitride Measured Using 3-Point Bending and Ultrasonic Testing

NASA Technical Reports Server (NTRS)

Kaforey, M. L.; Deeb, C. W.; Matthiesen, D. H.; Roth, D. J.

1999-01-01

Three-point bending and ultrasonic testing were performed on a flat plate of PBN. In the bending experiment, the deformation mechanism was believed to be shear between the pyrolytic layers, which yielded a shear modulus, c (sub 44), of 2.60 plus or minus .31 GPa. Calculations based on the longitudinal and shear wave velocity measurements yielded values of 0.341 plus or minus 0.006 for Poisson's ratio, 10.34 plus or minus .30 GPa for the elastic modulus (c (sub 33)), and 3.85 plus or minus 0.02 GPa for the shear modulus (c (sub 44)). Since free basal dislocations have been reported to affect the value of c (sub 44) found using ultrasonic methods, the value from the bending experiment was assumed to be the more accurate value.

Soil quality as a factor of the distribution of damages at the meizoseismal area of the Kozani-Grevena 1995 earthquake, in Greece ( Ms = 6.6)

NASA Astrophysics Data System (ADS)

Christaras, B.; Dimitriou, An; Lemoni, Hel

The physical and mechanical properties of the soil formations were related to the damages observed in Kozani and Grevena area, in Northern Greece, after the earth-quake of 13th May 1995 ( Ms = 6.6). Properties such as grain size distribution, plasticity, shear strength, compression index, permeability and ultrasonic velocity were measured in order to classify the suitability of the soil formations, for urban planning, and correlate their mechanical behaviour with the damages observed in the construction. According to our observations, a great number of recent buildings were damaged also in areas far away from the seismotectonic zones, where silty and clayey soils dominate, presenting very low permeability, low ultrasonic velocity together with high plasticity and compressibility.

Ultrasonic characterization of pork fat crystallization during cold storage.

PubMed

Corona, Edith; García-Pérez, José V; Santacatalina, Juan V; Ventanas, Sonia; Benedito, José

2014-05-01

In this work, the feasibility of using ultrasonic velocity measurements for characterizing and differentiating the crystallization pattern in 2 pork backfats (Montanera and Cebo Iberian fats) during cold storage (0 °C, 2 °C, 5 °C, 7 °C, and 10 °C) was evaluated. The fatty acid profile, thermal behavior, and textural properties (hardness) of fat were also determined. Both fats became harder during cold storage (average hardness increase for both fats, 11.5 N, 8 N, and 1.8 N at 0, °C 2 °C, and 5 °C , respectively), showing a 2-step pattern related with the separate crystallization of the different existing triacylglycerols, which was well described using a modified Avrami equation (explained variance > 99%). Due to a greater content of saturated triacylglycerols, Cebo fat (45.1%) was harder than Montanera (41.8%). The ultrasonic velocity followed a similar 2-step pattern to hardness during cold storage, being found an average increase for both fats of 184, 161, and 150 m/s at 0 °C 2 °C, and 5 °C, respectively. Thus, ultrasonic measurements were useful both to characterize the textural changes taking place during cold storage and to differentiate between fats with different composition. The cold storage of dry-cured meat products during their distribution and retail sale exert an important effect on their textural properties and consumers' acceptance due to the crystallization of the fat fraction, which is greatly influenced by the type of fat. In this work, a nondestructive ultrasonic technique was used to identify the textural changes provoked by the crystallization during cold storage, and to differentiate between fats, which could be used for quality control purposes. © 2014 Institute of Food Technologists®

Inference of stress and texture from angular dependence of ultrasonic plate mode velocities

NASA Technical Reports Server (NTRS)

Thompson, R. B.; Smith, J. F.; Lee, S. S.

1986-01-01

The theory for the angular dependence of the ultrasonic wave velocity in a symmetry plane of an orthorhombic, stressed material is presented. The two waves having polarizations in this plane are shown to have velocities which can be estimated from measurements of the SH sub 0 and S sub 0 guided modes of a thin plate: the relationship being exact for the SH sub 0 mode and requiring a 10% correction for the S sub 0 mode at long wavelength. It is then shown how stress and texture can be independently inferred from various features of the angular dependence of these two velocities. From the SH sub 0 data, the ability to determine the directions and differences in magnitudes of principal stresses is described and supported by experimental data on several materials. From a combination of the SH sub 0 and S sub 0 data, a procedure is proposed for determining the coefficients W sub 400, W sub 420 and W sub 440 of an expansion of the crystallite orientation distribution function in terms of generalized Legendre functions. Possible applications in process control are indicated.

Evaluating Thermally Damaged Polyimide Insulated Wiring (MIL-W-81381) with Ultrasound

NASA Technical Reports Server (NTRS)

Madaras, Eric I.; Anastasi, Robert F.

2002-01-01

A series of experiments to investigate the use of ultrasound for measuring wire insulation have been conducted. Initial laboratory tests were performed on MIL-W-81381/7,/12, and /21 aviation wire, a wire that has polyimide (Kapton Registered Trademark) layers for insulation. Samples of this wiring were exposed to 370C temperatures for different periods of time to induce a range of thermal damage. For each exposure, 12 samples of each gauge (12, 16, and 20 gauges) were processed. The velocity of the lowest order axisymmetric ultrasonic guided mode, a mode that is sensitive to the geometry and stiffness of the wire conductor and insulation, was measured. The phase velocity for the 20-gauge MIL-W-81381/7 wire had a baseline value of 3023 +/- 78 m/s. After exposure to the high temperatures, the wire's phase velocity rapidly increased, and reached an asymptotic value of 3598 +/- 20 m/s after 100 hours exposure. Similar behavior was measured for the 16 gauge MIL-W-81381/21 wire and 12 gauge MIL-W-81381/12 wire which had baseline values of 3225 +/- 22 m/s and 3403 +/- 33 m/s respectively, and reached asymptotic values of 3668 +/- 19 m/s, and 3679 +/- 42 m/s respectively. These measured velocity changes represent changes of 19, 14, and 8 percent respectively for the 20, 16, and 12 gauge wires. Finally, some results for a wire with an ethylene tetrafluoroethylene insulation are reported. Qualitatively similar behaviors are noted ultrasonically.

Experimental study and theoretical interpretation of saturation effect on ultrasonic velocity in tight sandstones under different pressure conditions

NASA Astrophysics Data System (ADS)

Li, Dongqing; Wei, Jianxin; Di, Bangrang; Ding, Pinbo; Huang, Shiqi; Shuai, Da

2018-03-01

Understanding the influence of lithology, porosity, permeability, pore structure, fluid content and fluid distribution on the elastic wave properties of porous rocks is of great significance for seismic exploration. However, unlike conventional sandstones, the petrophysical characteristics of tight sandstones are more complex and less understood. To address this problem, we measured ultrasonic velocity in partially saturated tight sandstones under different effective pressures. A new model is proposed, combining the Mavko-Jizba-Gurevich relations and the White model. The proposed model can satisfactorily simulate and explain the saturation dependence and pressure dependence of velocity in tight sandstones. Under low effective pressure, the relationship of P-wave velocity to saturation is pre-dominantly attributed to local (pore scale) fluid flow and inhomogeneous pore-fluid distribution (large scale). At higher effective pressure, local fluid flow gradually decreases, and P-wave velocity gradually shifts from uniform saturation towards patchy saturation. We also find that shear modulus is more sensitive to saturation at low effective pressures. The new model includes wetting ratio, an adjustable parameter that is closely related to the relationship between shear modulus and saturation.

Velocity Profile measurements in two-phase flow using multi-wave sensors

NASA Astrophysics Data System (ADS)

Biddinika, M. K.; Ito, D.; Takahashi, H.; Kikura, H.; Aritomi, M.

2009-02-01

Two-phase flow has been recognized as one of the most important phenomena in fluid dynamics. In addition, gas-liquid two-phase flow appears in various industrial fields such as chemical industries and power generations. In order to clarify the flow structure, some flow parameters have been measured by using many effective measurement techniques. The velocity profile as one of the important flow parameter, has been measured by using ultrasonic velocity profile (UVP) technique. This technique can measure velocity distributions along a measuring line, which is a beam formed by pulse ultrasounds. Furthermore, a multi-wave sensor can measure the velocity profiles of both gas and liquid phase using UVP method. In this study, two types of multi-wave sensors are used. A sensor has cylindrical shape, and another one has square shape. The piezoelectric elements of each sensor have basic frequencies of 8 MHz for liquid phase and 2 MHz for gas phase, separately. The velocity profiles of air-water bubbly flow in a vertical rectangular channel were measured by using these multi-wave sensors, and the validation of the measuring accuracy was performed by the comparison between the velocity profiles measured by two multi-wave sensors.

Coherent transmission of an ultrasonic shock wave through a multiple scattering medium.

PubMed

Viard, Nicolas; Giammarinaro, Bruno; Derode, Arnaud; Barrière, Christophe

2013-08-01

We report measurements of the transmitted coherent (ensemble-averaged) wave resulting from the interaction of an ultrasonic shock wave with a two-dimensional random medium. Despite multiple scattering, the coherent waveform clearly shows the steepening that is typical of nonlinear harmonic generation. This is taken advantage of to measure the elastic mean free path and group velocity over a broad frequency range (2-15 MHz) in only one experiment. Experimental results are found to be in good agreement with a linear theoretical model taking into account spatial correlations between scatterers. These results show that nonlinearity and multiple scattering are both present, yet uncoupled.

Effect of intracrystalline water on longitudinal sound velocity in tetragonal hen-egg-white lysozyme crystals.

PubMed

Tachibana, M; Koizumi, H; Kojima, K

2004-05-01

Longitudinal sound velocity of tetragonal hen-egg-white (HEW) lysozyme crystals was measured during air drying by ultrasonic pulseecho method. The sound velocity increases with exposure to open air and approaches a constant value. The maximum value is approximately 2900 m/s that is about 1.6 times as much as that of original one before drying. In addition, the sound velocity clearly recovers to original one after immersing the dried crystal in solution. Therefore, the sound velocity in tetragonal HEW lysozyme crystals can be reversibly changed due to dehydration and rehydration. These changes in sound velocity are discussed in the light of water-mediated intramolecular and intermolecular interactions in the crystals.

Effect of intracrystalline water on longitudinal sound velocity in tetragonal hen-egg-white lysozyme crystals

NASA Astrophysics Data System (ADS)

Tachibana, M.; Koizumi, H.; Kojima, K.

2004-05-01

Longitudinal sound velocity of tetragonal hen-egg-white (HEW) lysozyme crystals was measured during air drying by ultrasonic pulseecho method. The sound velocity increases with exposure to open air and approaches a constant value. The maximum value is ˜2900 m/s that is about 1.6 times as much as that of original one before drying. In addition, the sound velocity clearly recovers to original one after immersing the dried crystal in solution. Therefore, the sound velocity in tetragonal HEW lysozyme crystals can be reversibly changed due to dehydration and rehydration. These changes in sound velocity are discussed in the light of water-mediated intramolecular and intermolecular interactions in the crystals.

Plate mode velocities in graphite/epoxy plates

NASA Technical Reports Server (NTRS)

Prosser, W. H.; Gorman, M. R.

1994-01-01

Measurements of the velocities of the extensional and flexural plate modes were made along three directions of propagation in four graphite/epoxy composite plates. The acoustic signals were generated by simulated acoustic emission events (pencil lead breaks or Hsu-Neilson sources) and detected by by broadband ultrasonic transducers. The first arrival of the extensional plate mode, which is nondispersive at low frequencies, was measured at a number of different distances from the source along the propagation direction of interest. The velocity was determined by plotting the distance versus arrival time and computing its slope. Because of the large dispersion of the flexural mode, a Fourier phase velocity technique was used to characterize this mode. The velocity was measured up to a frequency of 160 kHz. Theoretical predictions of the velocities of these modes were also made and compared with experimental observations. Classical plate theory yields good agreement with the measured extensional velocities. For predictions of the dispersion of the flexural mode, Mindlin plates theory, which includes the effects of shear deformation and rotatory inertia was shown to give better agreement with the experimental measurements.

Fuel spray data with LDV. [solar laser morphokinetomer capabilities in combustion research

NASA Technical Reports Server (NTRS)

Rohy, D. A.; Meier, J. G.

1979-01-01

Droplet size and two component velocities in the severe environment of an operating gas turbine combustor system can be measured simultaneously using the solar laser morphokinetomer (SLM) which incorporates the following capabilities: (1) measurement of a true two-dimensional velocity vector with a range of + or - (0.01-200 m/sec); (2) measurement of particle size (range 5 to 300 micron m) simultaneously with the measurement of velocity; (3) specification of probe volume position coordinates with a high degree of accuracy (+ or - 0.5 mm); (4) immediate on-line data checks; and (5) rapid computer storage of acquired data. The optical system of the SLM incorporates an ultrasonic beam splitter to allow the measurement of a two-dimensional velocity vector simultaneously with particle size. A microprocessor with a limited storage capability permits immediate analysis of test data in the test cell.

Ultrasonic wave velocity measurement in small polymeric and cortical bone specimens

NASA Technical Reports Server (NTRS)

Kohles, S. S.; Bowers, J. R.; Vailas, A. C.; Vanderby, R. Jr

1997-01-01

A system was refined for the determination of the bulk ultrasonic wave propagation velocity in small cortical bone specimens. Longitudinal and shear wave propagations were measured using ceramic, piezoelectric 20 and 5 MHz transducers, respectively. Results of the pulse transmission technique were refined via the measurement of the system delay time. The precision and accuracy of the system were quantified using small specimens of polyoxymethylene, polystyrene-butadiene, and high-density polyethylene. These polymeric materials had known acoustic properties, similarity of propagation velocities to cortical bone, and minimal sample inhomogeneity. Dependence of longitudinal and transverse specimen dimensions upon propagation times was quantified. To confirm the consistency of longitudinal wave propagation in small cortical bone specimens (< 1.0 mm), cut-down specimens were prepared from a normal rat femur. Finally, cortical samples were prepared from each of ten normal rat femora, and Young's moduli (Eii), shear moduli (Gij), and Poisson ratios (Vij) were measured. For all specimens (bone, polyoxymethylene, polystyrene-butadiene, and high-density polyethylene), strong linear correlations (R2 > 0.997) were maintained between propagation time and distance throughout the size ranges down to less than 0.4 mm. Results for polyoxymethylene, polystyrene-butadiene, and high-density polyethylene were accurate to within 5 percent of reported literature values. Measurement repeatability (precision) improved with an increase in the wave transmission distance (propagating dimension). No statistically significant effect due to the transverse dimension was detected.

Evaluation of nondestructive evaluation methods for application in early detection Of deterioration in concrete pavements

DOT National Transportation Integrated Search

2000-01-01

Three nondestructive evaluation (NDE) methods for concrete pavements - surface ultrasonic pulse velocity measurements (UPV), the impact-echo (IE) method, and the use of a seismic pavement analyzer (SPA) - were tested on six sections of two continuous...

Simulation and fabrication of 0-3 composite PZT films for ultrahigh frequency (100-300 MHz) ultrasonic transducers

NASA Astrophysics Data System (ADS)

Chen, Xiaoyang; Fei, Chunlong; Chen, Zeyu; Chen, Ruimin; Yu, Ping; Chen, Zhongping; Shung, K. Kirk; Zhou, Qifa

2016-03-01

This paper presents simulation, fabrication, and characterization of single-element ultrahigh frequency (100-300-MHz) needle ultrasonic transducers based on 0-3 composite Pb(Zr0.52Ti0.48)O3 (PZT) films prepared by using composite ceramic sol-gel film and sol-infiltration technique. The center frequency of the developed transducer at 300-MHz was the highest frequency of PbTiO3 ceramic-based ultrasonic transducers ever reported. Furthermore, a brief description of the composite model was followed by the development of a new expression for predicting the longitudinal velocity, the clamped dielectric constant, and the complex electromechanical coupling coefficient kt of these films, which is very important in ultrasonic transducer design. Moreover, these parameters are difficult to obtain by measuring the frequency dependence of impedance and phase angle because of the weak signal of the previous 0-3 composite films transducer (>100 MHz). The modeling results show that the Cubes model with a geometric factor n = 0.05 fits well with the measured data. This model will be helpful for developing the 0-3 composite systems for ultrahigh frequency ultrasonic transducer design.

Engineering studies of vectorcardiographs in blood pressure measuring systems, appendix 2

NASA Technical Reports Server (NTRS)

Mark, R. G.

1975-01-01

The development of a cardiovascular monitoring system to noninvasively monitor the blood pressure and heart rate using pulse wave velocity was described. The following topics were covered: (1) pulse wave velocity as a measure of arterial blood pressure, (2) diastolic blood pressure and pulse wave velocity in humans, (3) transducer development for blood pressure measuring device, and (4) cardiovascular monitoring system. It was found, in experiments on dogs, that the pulse wave velocity is linearly related to diastolic blood pressure over a wide range of blood pressure and in the presence of many physiological perturbations. A similar relationship was observed in normal, young human males over a moderate range of pressures. Past methods for monitoring blood pressure and a new method based on pulse wave velocity determination were described. Two systems were tested: a Doppler ultrasonic transducer and a photoelectric plethysmograph. A cardiovascular monitoring system was described, including operating instructions.

Prediction of ultrasonic properties from grain angle

Treesearch

M.F. Kabir

2001-01-01

The ultrasonic properties of rubber wood were evaluated in three main symmetry axes – longitudinal (L), radial (R) and tangential direction and also at an angle rotating from the symmetry axes at different moisture content. The ultrasonic velocity were determined with a commercial ultrasonic tester of 45 kHz pulsed longitudinal waves. The experimental results were...

Custom ultrasonic instrumentation for flow measurement and real-time binary gas analysis in the CERN ATLAS experiment

NASA Astrophysics Data System (ADS)

Alhroob, M.; Battistin, M.; Berry, S.; Bitadze, A.; Bonneau, P.; Boyd, G.; Crespo-Lopez, O.; Degeorge, C.; Deterre, C.; Di Girolamo, B.; Doubek, M.; Favre, G.; Hallewell, G.; Katunin, S.; Lombard, D.; Madsen, A.; McMahon, S.; Nagai, K.; O'Rourke, A.; Pearson, B.; Robinson, D.; Rossi, C.; Rozanov, A.; Stanecka, E.; Strauss, M.; Vacek, V.; Vaglio, R.; Young, J.; Zwalinski, L.

2017-01-01

The development of custom ultrasonic instrumentation was motivated by the need for continuous real-time monitoring of possible leaks and mass flow measurement in the evaporative cooling systems of the ATLAS silicon trackers. The instruments use pairs of ultrasonic transducers transmitting sound bursts and measuring transit times in opposite directions. The gas flow rate is calculated from the difference in transit times, while the sound velocity is deduced from their average. The gas composition is then evaluated by comparison with a molar composition vs. sound velocity database, based on the direct dependence between sound velocity and component molar concentration in a gas mixture at a known temperature and pressure. The instrumentation has been developed in several geometries, with five instruments now integrated and in continuous operation within the ATLAS Detector Control System (DCS) and its finite state machine. One instrument monitors C3F8 coolant leaks into the Pixel detector N2 envelope with a molar resolution better than 2ṡ 10-5, and has indicated a level of 0.14 % when all the cooling loops of the recently re-installed Pixel detector are operational. Another instrument monitors air ingress into the C3F8 condenser of the new C3F8 thermosiphon coolant recirculator, with sub-percent precision. The recent effect of the introduction of a small quantity of N2 volume into the 9.5 m3 total volume of the thermosiphon system was clearly seen with this instrument. Custom microcontroller-based readout has been developed for the instruments, allowing readout into the ATLAS DCS via Modbus TCP/IP on Ethernet. The instrumentation has many potential applications where continuous binary gas composition is required, including in hydrocarbon and anaesthetic gas mixtures.

Wave propagation in composite media and material characterization

NASA Technical Reports Server (NTRS)

Datta, Subhendu K.; Shah, A. H.; Karunasena, W.

1990-01-01

Characteristics of wave propagation in an undamaged composite medium are influenced by many factors, the most important of which are: microstructure, constituent properties, interfaces, residual stress fields, and ply lay-ups. Measurements of wave velocities, attenuation, and dispersion provide a powerful tool for nondestructive evaluation of these properties. Recent developments are reviewed for modeling ultrasonic wave propagation in fiber and particle-reinforced composite media. Additionally, some modeling studies are reviewed for the effects of interfaces and layering on attenuation and dispersion. These studies indicate possible ways of characterizing material properties by ultrasonic means.

Laboratory meter-scale seismic monitoring of varying water levels in granular media

NASA Astrophysics Data System (ADS)

Pasquet, S.; Bodet, L.; Bergamo, P.; Guérin, R.; Martin, R.; Mourgues, R.; Tournat, V.

2016-12-01

Laboratory physical modelling and non-contacting ultrasonic techniques are frequently proposed to tackle theoretical and methodological issues related to geophysical prospecting. Following recent developments illustrating the ability of seismic methods to image spatial and/or temporal variations of water content in the vadose zone, we developed laboratory experiments aimed at testing the sensitivity of seismic measurements (i.e., pressure-wave travel times and surface-wave phase velocities) to water saturation variations. Ultrasonic techniques were used to simulate typical seismic acquisitions on small-scale controlled granular media presenting different water levels. Travel times and phase velocity measurements obtained at the dry state were validated with both theoretical models and numerical simulations and serve as reference datasets. The increasing water level clearly affects the recorded wave field in both its phase and amplitude, but the collected data cannot yet be inverted in the absence of a comprehensive theoretical model for such partially saturated and unconsolidated granular media. The differences in travel time and phase velocity observed between the dry and wet models show patterns that are interestingly coincident with the observed water level and depth of the capillary fringe, thus offering attractive perspectives for studying soil water content variations in the field.

Electroacoustics modeling of piezoelectric welders for ultrasonic additive manufacturing processes

NASA Astrophysics Data System (ADS)

Hehr, Adam; Dapino, Marcelo J.

2016-04-01

Ultrasonic additive manufacturing (UAM) is a recent 3D metal printing technology which utilizes ultrasonic vibrations from high power piezoelectric transducers to additively weld similar and dissimilar metal foils. CNC machining is used intermittent of welding to create internal channels, embed temperature sensitive components, sensors, and materials, and for net shaping parts. Structural dynamics of the welder and work piece influence the performance of the welder and part quality. To understand the impact of structural dynamics on UAM, a linear time-invariant model is used to relate system shear force and electric current inputs to the system outputs of welder velocity and voltage. Frequency response measurements are combined with in-situ operating measurements of the welder to identify model parameters and to verify model assumptions. The proposed LTI model can enhance process consistency, performance, and guide the development of improved quality monitoring and control strategies.

Baseline UT Measurements for Armor Inspection

NASA Astrophysics Data System (ADS)

Margetan, Frank J.; Richter, Nate; Barnard, Dan; Hsu, David; Gray, Tim; Brasche, Lisa; Bruce Thompson, R.

2010-02-01

Some prototype armor panels are fabricated from several layers of dissimilar material bonded together. These may include ceramics, graphite composites, fiberglass composites and rubber. The ultrasonic properties of these layers influence inspections for armor defects. In this paper we describe measurements of ultrasonic velocity, attenuation, sound beam distortion and signal fluctuations for the individual layers comprising one armor prototype. We then discuss how knowledge of these properties can be used when choosing an optimum frequency for an ultrasonic pitch/catch immersion inspection. In our case an effective inspection frequency near 1.5 MHz affords: (1) adequate strength of through-transmitted signals in unflawed armor; (2) adequate lateral resolution for detecting small disbonds at interfaces; and (3) low levels of UT signal fluctuations due to the natural inhomogeneity of certain armor layers. The utility of this approach is demonstrated using armor panels containing artificial disbonds at selected interfaces.

Motion Estimation Using the Firefly Algorithm in Ultrasonic Image Sequence of Soft Tissue

PubMed Central

Chao, Chih-Feng; Horng, Ming-Huwi; Chen, Yu-Chan

2015-01-01

Ultrasonic image sequence of the soft tissue is widely used in disease diagnosis; however, the speckle noises usually influenced the image quality. These images usually have a low signal-to-noise ratio presentation. The phenomenon gives rise to traditional motion estimation algorithms that are not suitable to measure the motion vectors. In this paper, a new motion estimation algorithm is developed for assessing the velocity field of soft tissue in a sequence of ultrasonic B-mode images. The proposed iterative firefly algorithm (IFA) searches for few candidate points to obtain the optimal motion vector, and then compares it to the traditional iterative full search algorithm (IFSA) via a series of experiments of in vivo ultrasonic image sequences. The experimental results show that the IFA can assess the vector with better efficiency and almost equal estimation quality compared to the traditional IFSA method. PMID:25873987

Motion estimation using the firefly algorithm in ultrasonic image sequence of soft tissue.

PubMed

Chao, Chih-Feng; Horng, Ming-Huwi; Chen, Yu-Chan

2015-01-01

Ultrasonic image sequence of the soft tissue is widely used in disease diagnosis; however, the speckle noises usually influenced the image quality. These images usually have a low signal-to-noise ratio presentation. The phenomenon gives rise to traditional motion estimation algorithms that are not suitable to measure the motion vectors. In this paper, a new motion estimation algorithm is developed for assessing the velocity field of soft tissue in a sequence of ultrasonic B-mode images. The proposed iterative firefly algorithm (IFA) searches for few candidate points to obtain the optimal motion vector, and then compares it to the traditional iterative full search algorithm (IFSA) via a series of experiments of in vivo ultrasonic image sequences. The experimental results show that the IFA can assess the vector with better efficiency and almost equal estimation quality compared to the traditional IFSA method.

High precision UTDR measurements by sonic velocity compensation with reference transducer.

PubMed

Stade, Sam; Kallioinen, Mari; Mänttäri, Mika; Tuuva, Tuure

2014-07-02

An ultrasonic sensor design with sonic velocity compensation is developed to improve the accuracy of distance measurement in membrane modules. High accuracy real-time distance measurements are needed in membrane fouling and compaction studies. The benefits of the sonic velocity compensation with a reference transducer are compared to the sonic velocity calculated with the measured temperature and pressure using the model by Belogol'skii, Sekoyan et al. In the experiments the temperature was changed from 25 to 60 °C at pressures of 0.1, 0.3 and 0.5 MPa. The set measurement distance was 17.8 mm. Distance measurements with sonic velocity compensation were over ten times more accurate than the ones calculated based on the model. Using the reference transducer measured sonic velocity, the standard deviations for the distance measurements varied from 0.6 to 2.0 µm, while using the calculated sonic velocity the standard deviations were 21-39 µm. In industrial liquors, not only the temperature and the pressure, which were studied in this paper, but also the properties of the filtered solution, such as solute concentration, density, viscosity, etc., may vary greatly, leading to inaccuracy in the use of the Belogol'skii, Sekoyan et al. model. Therefore, calibration of the sonic velocity with reference transducers is needed for accurate distance measurements.

Local pulse wave velocity estimated from small vibrations measured ultrasonically at multiple points on the arterial wall

NASA Astrophysics Data System (ADS)

Ito, Mika; Arakawa, Mototaka; Kanai, Hiroshi

2018-07-01

Pulse wave velocity (PWV) is used as a diagnostic criterion for arteriosclerosis, a major cause of heart disease and cerebrovascular disease. However, there are several problems with conventional PWV measurement techniques. One is that a pulse wave is assumed to only have an incident component propagating at a constant speed from the heart to the femoral artery, and another is that PWV is only determined from a characteristic time such as the rise time of the blood pressure waveform. In this study, we noninvasively measured the velocity waveform of small vibrations at multiple points on the carotid arterial wall using ultrasound. Local PWV was determined by analyzing the phase component of the velocity waveform by the least squares method. This method allowed measurement of the time change of the PWV at approximately the arrival time of the pulse wave, which discriminates the period when the reflected component is not contaminated.

NDE application of ultrasonic tomography to a full-scale concrete structure.

PubMed

Choi, Hajin; Popovics, John S

2015-06-01

Newly developed ultrasonic imaging technology for large concrete elements, based on tomographic reconstruction, is presented. The developed 3-D internal images (velocity tomograms) are used to detect internal defects (polystyrene foam and pre-cracked concrete prisms) that represent structural damage within a large steel reinforced concrete element. A hybrid air-coupled/contact transducer system is deployed. Electrostatic air-coupled transducers are used to generate ultrasonic energy and contact accelerometers are attached on the opposing side of the concrete element to detect the ultrasonic pulses. The developed hybrid testing setup enables collection of a large amount of high-quality, through-thickness ultrasonic data without surface preparation to the concrete. The algebraic reconstruction technique is used to reconstruct p-wave velocity tomograms from the obtained time signal data. A comparison with a one-sided ultrasonic imaging method is presented for the same specimen. Through-thickness tomography shows some benefit over one-sided imaging for highly reinforced concrete elements. The results demonstrate that the proposed through-thickness ultrasonic technique shows great potential for evaluation of full-scale concrete structures in the field.

UHF RiverSonde observations of water surface velocity at Threemile Slough, California

USGS Publications Warehouse

Teague, C.C.; Barrick, D.E.; Lilleboe, P.M.; Cheng, R.T.; Ruhl, C.A.

2005-01-01

A UHF RiverSonde system, operating near 350 MHz, has been in operation at Threemile Slough in central California, USA since September 2004. The water in the slough is dominated by tidal effects, with flow reversals four times a day and a peak velocity of about 0.8 m/s in each direction. Water level and water velocity are continually measured by the U. S. Geological Survey at the experiment site. The velocity is measured every 15 minutes by an ultrasonic velocity meter (UVM) which determines the water velocity from two-way acoustic propagation time-difference measurements made across the channel. The RiverSonde also measures surface velocity every 15 minutes using radar resonant backscatter techniques. Velocity and water level data are retrieved through a radio data link and a wideband internet connection. Over a period of several months, the radar-derived mean surface velocity has been very highly correlated with the UVM index velocity several meters below the surface, with a coefficient of determination R2 of 0.976 and an RMS difference of less than 10 cm/s. The wind has a small but measurable effect on the velocities measured by both instruments. In addition to the mean surface velocity across the channel, the RiverSonde system provides an estimate of the cross-channel variation of the surface velocity. ?? 2005 IEEE.

Acousto-Ultrasonic analysis of failure in ceramic matrix composite tensile specimens

NASA Technical Reports Server (NTRS)

Kautz, Harold E.; Chulya, Abhisak

1993-01-01

Three types of acousto-ultrasonic (AU) measurements, stress-wave factor (SWF), lowest antisymmetric plate mode group velocity (VS), and lowest symmetric plate mode group velocity (VL), were performed on specimens before and after tensile failure. Three different Nicalon fiber architectures with ceramic matrices were tested. These composites were categorized as 1D (unidirectional fiber orientation) SiC/CAS glass ceramic, and 2D and 3D woven SiC/SiC ceramic matrix materials. SWF was found to be degraded after tensile failure in all three material categories. VS was found to be degraded only in the 1D SiC/CAS. VL was difficult to determine on the irregular specimen surfaces but appeared unchanged on all failed specimens. 3D woven specimens with heat-treatment at high temperature exhibited degradation only in SWF.

Design and performance testing of an ultrasonic linear motor with dual piezoelectric actuators.

PubMed

Smithmaitrie, Pruittikorn; Suybangdum, Panumas; Laoratanakul, Pitak; Muensit, Nantakan

2012-05-01

In this work, design and performance testing of an ultrasonic linear motor with dual piezoelectric actuator patches are studied. The motor system consists of a linear stator, a pre-load weight, and two piezoelectric actuator patches. The piezoelectric actuators are bonded with the linear elastic stator at specific locations. The stator generates propagating waves when the piezoelectric actuators are subjected to harmonic excitations. Vibration characteristics of the linear stator are analyzed and compared with finite element and experimental results. The analytical, finite element, and experimental results show agreement. In the experiments, performance of the ultrasonic linear motor is tested. Relationships between velocity and pre-load weight, velocity and applied voltage, driving force and applied voltage, and velocity and driving force are reported. The design of the dual piezoelectric actuators yields a simpler structure with a smaller number of actuators and lower stator stiffness compared with a conventional design of an ultrasonic linear motor with fully laminated piezoelectric actuators.

Elastic anisotropy of layered rocks: Ultrasonic measurements of plagioclase-biotite-muscovite (sillimanite) gneiss versus texture-based theoretical predictions (effective media modeling)

NASA Astrophysics Data System (ADS)

Ivankina, T. I.; Zel, I. Yu.; Lokajicek, T.; Kern, H.; Lobanov, K. V.; Zharikov, A. V.

2017-08-01

In this paper we present experimental and theoretical studies on a highly anisotropic layered rock sample characterized by alternating layers of biotite and muscovite (retrogressed from sillimanite) and plagioclase and quartz, respectively. We applied two different experimental methods to determine seismic anisotropy at pressures up to 400 MPa: (1) measurement of P- and S-wave phase velocities on a cube in three foliation-related orthogonal directions and (2) measurement of P-wave group velocities on a sphere in 132 directions The combination of the spatial distribution of P-wave velocities on the sphere (converted to phase velocities) with S-wave velocities of three orthogonal structural directions on the cube made it possible to calculate the bulk elastic moduli of the anisotropic rock sample. On the basis of the crystallographic preferred orientations (CPOs) of major minerals obtained by time-of-flight neutron diffraction, effective media modeling was performed using different inclusion methods and averaging procedures. The implementation of a nonlinear approximation of the P-wave velocity-pressure relation was applied to estimate the mineral matrix properties and the orientation distribution of microcracks. Comparison of theoretical calculations of elastic properties of the mineral matrix with those derived from the nonlinear approximation showed discrepancies in elastic moduli and P-wave velocities of about 10%. The observed discrepancies between the effective media modeling and ultrasonic velocity data are a consequence of the inhomogeneous structure of the sample and inability to perform long-wave approximation. Furthermore, small differences between elastic moduli predicted by the different theoretical models, including specific fabric characteristics such as crystallographic texture, grain shape and layering were observed. It is shown that the bulk elastic anisotropy of the sample is basically controlled by the CPO of biotite and muscovite and their volume proportions in the layers dominated by phyllosilicate minerals.

Noncontact measurement of vibration using airborne ultrasound.

PubMed

Mater, O B; Remenieras, J P; Bruneel, C; Roncin, A; Patat, F

1998-01-01

A noncontact ultrasonic method for measuring the surface normal vibration of objects was studied. The instrument consists of a pair of 420 kHz ultrasonic air transducers. One is used to emit ultrasounds toward the moving surface, and the other receives the ultrasound reflected from the object under test. Two effects induce a phase modulation on the received signal. The first effect results from the variation of the round trip time interval tau required for the wavefront to go from the emitter to the moving surface and back to the receiver. This is the Doppler effect directly proportional to the surface displacement. The second effect results from the nonlinear parametric interactions of the ultrasonic beams (forward and backward) with the low frequency sound field emitted in the air by the vibrating surface. This latter phenomenon, which is a volume effect, is proportional to the velocity of the vibrating surface and increases with the distance between the transducers and the surface under test. The relative contribution of the Doppler and parametric effects are evaluated, and both have to be taken into account for ultrasonic interferometry in air.

Thermal Cracking in Westerly Granite Monitored Using Direct Wave Velocity, Coda Wave Interferometry, and Acoustic Emissions

NASA Astrophysics Data System (ADS)

Griffiths, L.; Lengliné, O.; Heap, M. J.; Baud, P.; Schmittbuhl, J.

2018-03-01

To monitor both the permanent (thermal microcracking) and the nonpermanent (thermo-elastic) effects of temperature on Westerly Granite, we combine acoustic emission monitoring and ultrasonic velocity measurements at ambient pressure during three heating and cooling cycles to a maximum temperature of 450°C. For the velocity measurements we use both P wave direct traveltime and coda wave interferometry techniques, the latter being more sensitive to changes in S wave velocity. During the first cycle, we observe a high acoustic emission rate and large—and mostly permanent—apparent reductions in velocity with temperature (P wave velocity is reduced by 50% of the initial value at 450°C, and 40% upon cooling). Our measurements are indicative of extensive thermal microcracking during the first cycle, predominantly during the heating phase. During the second cycle we observe further—but reduced—microcracking, and less still during the third cycle, where the apparent decrease in velocity with temperature is near reversible (at 450°C, the P wave velocity is decreased by roughly 10% of the initial velocity). Our results, relevant for thermally dynamic environments such as geothermal reservoirs, highlight the value of performing measurements of rock properties under in situ temperature conditions.

Ultrasonic and elastic properties of Tl- and Hg-Based cuprate superconductors: a review

NASA Astrophysics Data System (ADS)

Abd-Shukor, R.

2018-01-01

This review is regarding the ultrasonic and elastic properties of Tl- and Hg-based cuprate superconductors. The objectives of this paper were to review the ultrasonic attenuation above the transition temperature ?, and sound velocity and elastic anomalies at ? in the Tl- and Hg-based cuprate superconductors. A discontinuity in the sound velocity and elastic moduli is observed near ? for the Hg-based and other cuprate high temperature superconductor but not the Tl-based superconductor. Ultrasonic attenuation peaks are observed between 200 and 250 K in almost all Tl- and Hg-based cuprate superconductors reported. These peaks were attributed to lattice stepping and oxygen ordering in the Tl-O and Hg-O layers. Some Tl- and Hg-based superconductors show attenuation peak near ?. However, this is not a common feature for the cuprate superconductors. The ultrasonic attenuation decrease rate below ? is slower than that expected from a Bardeen-Cooper-Schrieffer (BCS) and pseudo-gapped superconductor.

Ultrasonic investigation of the superconducting properties of the Nb-Mo system

NASA Technical Reports Server (NTRS)

Lacy, L. L.

1972-01-01

The superconducting properties of single crystals of Nb and two alloys of Nb with Mo were investigated by ultrasonic techniques. The results of measurements of the ultrasonic attenuation and velocities as a function of temperature, Mo composition, crystallographic direction, and ultrasonic frequency are reported. The attenuation and small velocity changes associated with the superconductivity of the samples are shown to be dependent on the sample resistivity ratio which varied from 4.3 for Nb-9% Mo to 6500 for pure Nb. The ultrasonic attenuation data are analyzed in terms of the superconducting energy gap term of the BCS theory. A new model is proposed for the analysis of ultrasonic attenuation in pure superconductors with two partially decoupled energy bands. To analyze the attenuation in pure superconducting Nb, the existence of two energy gaps was assumed to be associated with the two partially decoupled energy bands. One of the gaps was found to have the normal BCS value of 3.4 and the other gap was found to have the anomalously large value of 10. No experimental evidence was found to suggest that the second energy gap had a different transition temperature. The interpretation of the results for the Nb-Mo alloys is shown to be complicated by the possible existence of a second superconducting phase in Nb-Mo alloys with a transition temperature of 0.35 of the transition temperature of the first phase. The elastic constants of Nb and Nb-Mo alloys are shown to be approximately independent of Mo composition to nine atomic percent Mo. These results do not agree with the current microscopic theory of transition temperature for the transition elements.

Lamb Wave Assessment of Fatigue and Thermal Damage in Composites

NASA Technical Reports Server (NTRS)

Seale, Michael D.; Smith, Barry T.; Prosser, W. H.

2004-01-01

Among the various techniques available, ultrasonic Lamb waves offer a convenient method of evaluating composite materials. Since the Lamb wave velocity depends on the elastic properties of a structure, an effective tool exists to monitor damage in composites by measuring the velocity of these waves. Lamb wave measurements can propagate over long distances and are sensitive to the desired in-plane elastic properties of the material. This paper describes two studies which monitor fatigue damage and two studies which monitor thermal damage in composites using Lamb waves. In the fatigue studies, the Lamb wave velocity is compared to modulus measurements obtained using strain gage measurements in the first experiment and the velocity is monitored along with the crack density in the second. In the thermal damage studies, one examines samples which were exposed to varying temperatures for a three minute duration and the second includes rapid thermal damage in composites by intense laser beams. In all studies, the Lamb wave velocity is demonstrated to be an excellent method to monitor damage in composites.

High-pressure behavior of amorphous selenium from ultrasonic measurements and Raman spectroscopy

NASA Astrophysics Data System (ADS)

He, Z.; Wang, Z. G.; Zhu, H. Y.; Liu, X. R.; Peng, J. P.; Hong, S. M.

2014-07-01

The high-pressure behavior of melt-quenched amorphous selenium (a-Se) has been investigated via ultrasonic measurements and Raman scattering at room temperature. The ultrasonic measurements were conducted on a-Se in a multi-anvil apparatus with two different sample assemblies at pressures of up to 4.5 and 4.8 GPa. We discovered that similar kinks occur in the slopes of the pressure dependence characteristics of the travel time and the sound velocity in both shear and longitudinal waves in the 2.0-2.5 GPa range. These kinks are independent of the sample assemblies, indicating an intrinsic transformation of the a-Se. Additionally, we deduced the pressure-volume relationship of a-Se from the sound velocity characteristics using the Birch-Murnaghan equation of state, and the results agreed well with those of previous reports. In situ high-pressure Raman scattering measurements of a-Se were conducted in a diamond anvil cell with an 830 nm excitation line up to a pressure of 4.3 GPa. We found that the characteristic band of a-Se at ˜250 cm-1 experienced a smooth shift to a lower frequency with pressure, but a sharp slope change in the band intensity versus pressure occurred near 2.5 GPa. The results of X-ray diffraction and differential scanning calorimetry measurements indicate that the samples remain in their amorphous states after decompression. Thus, we proposed that the abnormal compression behavior of a-Se in the 2.0-2.5 GPa range can be attributed to pressure-induced local atomic reconfiguration, implying an amorphous-amorphous transition of the elementary selenium.

Digital core based transmitted ultrasonic wave simulation and velocity accuracy analysis

NASA Astrophysics Data System (ADS)

Zhu, Wei; Shan, Rui

2016-06-01

Transmitted ultrasonic wave simulation (TUWS) in a digital core is one of the important elements of digital rock physics and is used to study wave propagation in porous cores and calculate equivalent velocity. When simulating wave propagates in a 3D digital core, two additional layers are attached to its two surfaces vertical to the wave-direction and one planar wave source and two receiver-arrays are properly installed. After source excitation, the two receivers then record incident and transmitted waves of the digital rock. Wave propagating velocity, which is the velocity of the digital core, is computed by the picked peak-time difference between the two recorded waves. To evaluate the accuracy of TUWS, a digital core is fully saturated with gas, oil, and water to calculate the corresponding velocities. The velocities increase with decreasing wave frequencies in the simulation frequency band, and this is considered to be the result of scattering. When the pore fluids are varied from gas to oil and finally to water, the velocity-variation characteristics between the different frequencies are similar, thereby approximately following the variation law of velocities obtained from linear elastic statics simulation (LESS), although their absolute values are different. However, LESS has been widely used. The results of this paper show that the transmission ultrasonic simulation has high relative precision.

Ultrasonic measurement of the effects of light irradiation and presence of water on the polymerization of self-adhesive resin cement.

PubMed

Takenaka, Hirotaka; Ouchi, Hajime; Sai, Keiichi; Kawamoto, Ryo; Murayama, Ryosuke; Kurokawa, Hiroyasu; Miyazaki, Masashi

2015-08-14

Self-adhesive resin cements are useful in restorations because they reduce the number of clinical steps involved in the restoration process. This study evaluated, using ultrasonic measurements, the influence of light irradiation and the presence of water on the polymerization behavior and elastic modulus of a self-adhesive resin cement. A self-adhesive resin cement (RelyX Unicem 2 Automix) or a resin cement (RelyX ARC) was inserted into a transparent mold on a sample stage, and the presence of water and effect of light-irradiation were evaluated. The transit time of a sonic wave through the cement disk was divided by the specimen thickness to obtain the sonic velocity, and longitudinal and shear waves were used to determine the elastic modulus. When the resin cements were light-irradiated, the sonic velocity rapidly increased and plateaued at 2,500-2,700 m s -1 . When the cements were not irradiated, the rates of increase in the sonic velocity were reduced. When water was applied to the sample stage, the sonic velocity was reduced. The elastic modulus values of the specimens ranged from 9.9 to 15.9 GPa after 24 h. The polymerization behavior of self-adhesive resin cements is affected by the polymerization mode and the presence of water. © 2015 Eur J Oral Sci.

Standard-free Pressure Measurement by Ultrasonic Interferometry in a Multi-Anvil Device

NASA Astrophysics Data System (ADS)

Mueller, H. J.; Lathe, C.; Schilling, F. R.; Lauterjung, J.

2002-12-01

A key question to all high pressure research arises from the reliability of pressure standards. There is some indication and discussion of an uncertainty of 10-20% for higher pressures in all standards. Simultaneous and independent investigation of the dynamical (ultrasonic interferometry of elastic wave velocities) and static (XRD-measurement of the pressure-induced volume decline) compressibility on a sample reveal the possibility of a standard-free pressure calibration (see Getting, 1998) and, consequently an absolute pressure measurement. Ultrasonic interferometry is used to measure velocities of elastic compressional and shear waves in the multi-anvil high pressure device MAX80 at HASYLAB Hamburg enabling simultaneous XRD and ultrasonic experiments. Two of the six anvils were equipped with overtone polished lithium niobate transducers of 33.3 MHz natural frequency, for generation and detection of ultrasonic waves with a frequency sweep between 5 and 55 MHz. Different buffer - reflector combinations were tested to optimize the critical interference between both sample echoes. NaCl powder of 99.5 % purity (analytical grade by Merck) was used as starting material for manufacturing the samples used as pressure calibrant after Decker (1971). The medium grain size was 50 μm. The powder was pressed to a crude sample cylinder of 10 mm diameter and a length of 20 mm using a load of 6 tons resulting in an effective pressure of 0.25 to 0.3 GPa. The millimeter sized samples (diameter 2.4 mm and 1.6 mm length for 6 mm anvil truncation and diameter 3.1 mm and 1.1 mm length for 3.5 mm anvil truncation) for the high pressure experiments were shaped with a high-precision (+/- 0.5 μm) cylindrical grinding machine and polished at the front faces. From the ultrasonic wave velocity data we calculated the compressibility of NaCl. This requires in situ density data. Therefore the sample deformation during the high pressure experiments was analyzed in detail and the results were compared with models published by different authors. The experimental results measured with different set-ups under different pressure conditions were compared with EoS-data derived from static compression experiments up to 5 GPa (Bridgman, 1940) and up to 30 GPa (Holland and Ahrens, 1998; Birch, 1986) using experimental data from Boehler and Kennedy (1980) and Fritz et al. (1971). At 1.2 GPa and 5.3 GPa the results of static compression data exactly correspond to our velocity-based data, polynomial-fitted up to the power of 7. In the range between 2 and 4 GPa our dynamical data have 1.5 - 3 % higher values. Furthermore the pressure revealed according to Decker (1971) is in accordance to our standard-free pressure calibration within the uncertainty of the experiment. Birch, F., J., Geophys. Res., 91, 4,949-4,954, (1986).\\Boehler, R., Kennedy, G.C., J. Phys. Chem. Solids, 41, 517-523, (1980). Bridgman, P.W., Physical Review, 57, 237-239, (1940).\\Decker, D.L., J. Appl. Physics, 42, 3,239-3,244, (1971).\\Fritz, J.N., Marsh, S.P., Carter, W.J., McQueen, R.G., NBS Spec. Publ., E.C. Lloyd ed., 326, 201-208, (1971). Getting, I.C., Eos, 79, F830, (1998).\\Holland, K.G., Ahrens, T.H., Geophys. Mon. 101, Manghnani, M.H. and Yagi, T. eds., 335-355, (1998).

Prediction of reinforced concrete strength by ultrasonic velocities

NASA Astrophysics Data System (ADS)

Sabbağ, Nevbahar; Uyanık, Osman

2017-06-01

This study was aimed to determine the strength of the reinforced concrete and to reveal the reinforcement effect on the concrete strength by Ultrasonic P and S wave velocities. Studies were conducted with prepared 9 different concrete designs of showing low, medium and high strength features. 4 kinds of cubic samples which unreinforced and including 10, 14 or 20 mm diameter reinforcement were prepared for these designs. Studies were carried out on total 324 samples including 9 samples for each design of these 4 kinds. The prepared samples of these designs were subjected to water curing. On some days of the 90-day period, P and S wave measurements were repeated to reveal the changes in seismic velocities of samples depending on whether reinforced or unreinforced of samples and diameter of reinforcement. Besides, comparisons were done by performing uniaxial compressive strength test with crushing of 3 samples on 7th, 28th and 90th days. As a result of studies and evaluations, it was seen that values of seismic velocities and uniaxial compressive strength increased depending on reinforcement and diameter of reinforcement in low strength concretes. However, while the seismic velocities were not markedly affected from reinforcement or reinforcement diameter in high strength concrete, uniaxial compressive strength values were negatively affected.

Use of an ultrasonic reflectance technique to examine bubble size changes in dough

NASA Astrophysics Data System (ADS)

Strybulevych, A.; Leroy, V.; Shum, A. L.; Koksel, H. F.; Scanlon, M. G.; Page, J. H.

2012-12-01

Bread quality largely depends on the manner in which bubbles are created and manipulated in the dough during processing. We have developed an ultrasonic reflectance technique to monitor bubbles in dough, even at high volume fractions, where near the bubble resonances it is difficult to make measurements using transmission techniques. A broadband transducer centred at 3.5 MHz in a normal incidence wave reflection set-up is used to measure longitudinal velocity and attenuation from acoustic impedance measurements. The technique is illustrated by examining changes in bubbles in dough due to two very different physical effects. In dough made without yeast, a peak in attenuation due to bubble resonance is observed at approximately 2 MHz. This peak diminishes rapidly and shifts to lower frequencies, indicative of Ostwald ripening of bubbles within the dough. The second effect involves the growth of bubble sizes due to gas generated by yeast during fermentation. This process is experimentally challenging to investigate with ultrasound because of very high attenuation. The reflectance technique allows the changes of the velocity and attenuation during fermentation to be measured as a function of frequency and time, indicating bubble growth effects that can be monitored even at high volume fractions of bubbles.

Nonintrusive dynamic flowmeter

NASA Technical Reports Server (NTRS)

Pedersen, N. E.; Lynnworth, L. C.

1973-01-01

Description of some of the design and performance characteristics of an ultrasonic dynamic flowmeter which combines nonintrusiveness, fast response, high accuracy, and high resolution and is intended for use with cryogenic liquids and water. The flowmeter measures to 1% accuracy the dynamic as well as the steady flow velocity averaged over the pipe area.

Joint Measurements Of Acoustic And Mechanical Properties For Methane Hydrate-Bearing Unconsolidated Sediments Synthesized In Laboratory

NASA Astrophysics Data System (ADS)

Yang, Z.; He, T.

2017-12-01

To more accurately explain geophysical exploration data of natural gas hydrate reservoir and to better assess the formation stability for geological or engineering hazards, it is important to comprehensively understand the geophysical and mechanical properties of hydrate-bearing unconsolidated marine sediments, which are significantly different from sea-water saturated ones. Compared to hard-to-control in-situ measurement, laboratory methods are important and feasible to investigate the parameter effects. With the new designed experimental apparatus, we measured ultrasonic velocity, resistivity and stress-strain relation of methane hydrate-bearing unconsolidated sediments. The experimental mineral mixture is prepared as the composition of sample HY-3 of core SH-7 from Shenhu area, South China Sea. It composed of 0.4 wt. % kaolinite, 23.5 wt. % silt (4 - 63 μm), 32.1 wt. % fine sand (63 - 250 μm), 29.2 wt. % medium sand (250 - 500 μm) and 14.8 wt. % coarse sand (500 - 2000 μm). The pure methane enters into the brine (NaCl salinity of 3.5%) saturated sample all around to synthesis methane hydrate. The methane hydrate saturation was calculated by methane consumption amount, which was in turn calculated by gas state equation using the measured methane pressure drop in high pressure reactor. The ultrasonic velocities and resistivity were measured frequently during methane hydrate saturation increasing to examine the velocity varying pattern, especially for S-wave velocities, which may reflect different hydrate occurrence states in sediment pores: load-bearing or not. The stress - strain curves of methane hydrate - bearing sediments showed typical elastic - plastic characteristics and were used to obtain Young's modulus, Poisson's ratio, failure strength and other mechanical parameters. With these results, we can know better about the hydrate reservoir at Shenhu area.

MEMS based Doppler velocity measurement system

NASA Astrophysics Data System (ADS)

Shin, Minchul

The design, fabrication, modeling and characterization of a capacitive micromachined ultrasonic transducer (cMUT) based in-air Doppler velocity measurement system using a 1 cm2 planar array are described. Continuous wave operation in a narrowband was chosen in order to maximize range, as it allows for better rejection of broadband noise. The sensor array has a 160-185 kHz resonant frequency to achieve a 10 degree beamwidth. A model for the cMUT and the acoustic system which includes electrical, mechanical, and acoustic components is provided. Furthermore, characterization of the cMUT sensor with a variety of testing procedures is provided. Laser Doppler vibrometry (LDV), beampattern, reflection, and velocity testing characterize the performance of the sensors. The sensor is capable of measuring the velocity of a moving specular reflector with a resolution of 5 cm/s, an update rate of 0.016 second, and a range of 1.5 m.

Fourier Collocation Approach With Mesh Refinement Method for Simulating Transit-Time Ultrasonic Flowmeters Under Multiphase Flow Conditions.

PubMed

Simurda, Matej; Duggen, Lars; Basse, Nils T; Lassen, Benny

2018-02-01

A numerical model for transit-time ultrasonic flowmeters operating under multiphase flow conditions previously presented by us is extended by mesh refinement and grid point redistribution. The method solves modified first-order stress-velocity equations of elastodynamics with additional terms to account for the effect of the background flow. Spatial derivatives are calculated by a Fourier collocation scheme allowing the use of the fast Fourier transform, while the time integration is realized by the explicit third-order Runge-Kutta finite-difference scheme. The method is compared against analytical solutions and experimental measurements to verify the benefit of using mapped grids. Additionally, a study of clamp-on and in-line ultrasonic flowmeters operating under multiphase flow conditions is carried out.

[Bone quantitative ultrasound].

PubMed

Matsukawa, Mami

2016-01-01

The conventional ultrasonic bone densitometry system can give us information of bone as ultrasonic wave velocity and attenuation. However, the data reflect both structural and material properties of bone. In order to focus only on the bone matrix properties without the effect of bone structure, studies of microscopic Brillouin scattering technique are introduced. The wave velocity in a trabecula was anisotropic and depended on the position and structure of the cancellous bone. The glycation also affected on the wave velocities in bone. As a new bone quality, the piezoelectricity of bone is also discussed.

The propagation of Lamb waves in multilayered plates: phase-velocity measurement

NASA Astrophysics Data System (ADS)

Grondel, Sébastien; Assaad, Jamal; Delebarre, Christophe; Blanquet, Pierrick; Moulin, Emmanuel

1999-05-01

Owing to the dispersive nature and complexity of the Lamb waves generated in a composite plate, the measurement of the phase velocities by using classical methods is complicated. This paper describes a measurement method based upon the spectrum-analysis technique, which allows one to overcome these problems. The technique consists of using the fast Fourier transform to compute the spatial power-density spectrum. Additionally, weighted functions are used to increase the probability of detecting the various propagation modes. Experimental Lamb-wave dispersion curves of multilayered plates are successfully compared with the analytical ones. This technique is expected to be a useful way to design composite parts integrating ultrasonic transducers in the field of health monitoring. Indeed, Lamb waves and particularly their velocities are very sensitive to defects.

Measurements of acoustic surface waves on fluid-filled porous rocks

NASA Astrophysics Data System (ADS)

Adler, Laszlo; Nagy, Peter B.

1994-09-01

Novel experimental techniques to measure ultrasonic velocity and attenuation of surface waves on fluid-filled porous natural rocks are presented. Our experimental results are consistent with the theoretical predictions of Feng and Johnson (1983). Depending on the interface conditions, i.e., whether the surface pores are open or closed, pseudo-Rayleigh, pseudo-Stoneley, and/or Stoneley surface waves may exist on fluid-saturated rocks with closed 'slow' surface wave (true Stoneley mode) on fluid-filled porous rocks with closed surface pores. The velocity and attenuation of the 'slow' surface mode may be used to assess the dynamic permeabilty of porous formations.

Fast Lamb wave energy shift approach using fully contactless ultrasonic system to characterize concrete structures

NASA Astrophysics Data System (ADS)

Ham, Suyun; Popovics, John S.

2015-03-01

Ultrasonic techniques provide an effective non-destructive evaluation (NDE) method to monitor concrete structures, but the need to perform rapid and accurate structural assessment requires evaluation of hundreds, or even thousands, of measurement datasets. Use of a fully contactless ultrasonic system can save time and labor through rapid implementation, and can enable automated and controlled data acquisition, for example through robotic scanning. Here we present results using a fully contactless ultrasonic system. This paper describes our efforts to develop a contactless ultrasonic guided wave NDE approach to detect and characterize delamination defects in concrete structures. The developed contactless sensors, controlled scanning system, and employed Multi-channel Analysis of Surface Waves (MASW) signal processing scheme are reviewed. Then a guided wave interpretation approach for MASW data is described. The presence of delamination is interpreted by guided plate wave (Lamb wave) behavior, where a shift in excited Lamb mode phase velocity, is monitored. Numerically simulated and experimental ultrasonic data collected from a concrete sample with simulated delamination defects are presented, where the occurrence of delamination is shown to be associated with a mode shift in Lamb wave energy.

Discrimination of Mixed Taste Solutions using Ultrasonic Wave and Soft Computing

NASA Astrophysics Data System (ADS)

Kojima, Yohichiro; Kimura, Futoshi; Mikami, Tsuyoshi; Kitama, Masataka

In this study, ultrasonic wave acoustic properties of mixed taste solutions were investigated, and the possibility of taste sensing based on the acoustical properties obtained was examined. In previous studies, properties of solutions were discriminated based on sound velocity, amplitude and frequency characteristics of ultrasonic waves propagating through the five basic taste solutions and marketed beverages. However, to make this method applicable to beverages that contain many taste substances, further studies are required. In this paper, the waveform of an ultrasonic wave with frequency of approximately 5 MHz propagating through mixed solutions composed of sweet and salty substance was measured. As a result, differences among solutions were clearly observed as differences in their properties. Furthermore, these mixed solutions were discriminated by a self-organizing neural network. The ratio of volume in their mixed solutions was estimated by a distance-type fuzzy reasoning method. Therefore, the possibility of taste sensing was shown by using ultrasonic wave acoustic properties and the soft computing, such as the self-organizing neural network and the distance-type fuzzy reasoning method.

Gas-liquid two-phase flow pattern identification by ultrasonic echoes reflected from the inner wall of a pipe

NASA Astrophysics Data System (ADS)

Liang, Fachun; Zheng, Hongfeng; Yu, Hao; Sun, Yuan

2016-03-01

A novel ultrasonic pulse echo method is proposed for flow pattern identification in a horizontal pipe with gas-liquid two-phase flow. A trace of echoes reflected from the pipe’s internal wall rather than the gas-liquid interface is used for flow pattern identification. Experiments were conducted in a horizontal air-water two-phase flow loop. Two ultrasonic transducers with central frequency of 5 MHz were mounted at the top and bottom of the pipe respectively. The experimental results show that the ultrasonic reflection coefficient of the wall-gas interface is much larger than that of the wall-liquid interface due to the large difference in the acoustic impedance of gas and liquid. The stratified flow, annular flow and slug flow can be successfully recognized using the attenuation ratio of the echoes. Compared with the conventional ultrasonic echo measurement method, echoes reflected from the inner surface of a pipe wall are independent of gas-liquid interface fluctuation, sound speed, and gas and liquid superficial velocities, which makes the method presented a promising technique in field practice.

Evaluation of macrozone dimensions by ultrasound and EBSD techniques

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moreau, Andre, E-mail: Andre.Moreau@cnrc-nrc.gc.ca; Toubal, Lotfi; Ecole de technologie superieure, 1100, rue Notre-Dame Ouest, Montreal, QC, Canada H3C 1K3

2013-01-15

Titanium alloys are known to have texture heterogeneities, i.e. regions much larger than the grain dimensions, where the local orientation distribution of the grains differs from one region to the next. The electron backscattering diffraction (EBSD) technique is the method of choice to characterize these macro regions, which are called macrozones. Qualitatively, the images obtained by EBSD show that these macrozones may be larger or smaller, elongated or equiaxed. However, often no well-defined boundaries are observed between the macrozones and it is very hard to obtain objective and quantitative estimates of the macrozone dimensions from these data. In the presentmore » work, we present a novel, non-destructive ultrasonic technique that provides objective and quantitative characteristic dimensions of the macrozones. The obtained dimensions are based on the spatial autocorrelation function of fluctuations in the sound velocity. Thus, a pragmatic definition of macrozone dimensions naturally arises from the ultrasonic measurement. This paper has three objectives: 1) to disclose the novel, non-destructive ultrasonic technique to measure macrozone dimensions, 2) to propose a quantitative and objective definition of macrozone dimensions adapted to and arising from the ultrasonic measurement, and which is also applicable to the orientation data obtained by EBSD, and 3) to compare the macrozone dimensions obtained using the two techniques on two samples of the near-alpha titanium alloy IMI834. In addition, it was observed that macrozones may present a semi-periodical arrangement. - Highlights: Black-Right-Pointing-Pointer Discloses a novel, ultrasonic NDT technique to measure macrozone dimensions Black-Right-Pointing-Pointer Proposes a quantitative and objective definition of macrozone dimensions Black-Right-Pointing-Pointer Compares macrozone dimensions obtained using EBSD and ultrasonics on 2 Ti samples Black-Right-Pointing-Pointer Observes that macrozones may have a semi-periodical arrangement.« less

An experimental evaluation of two effective medium theories for ultrasonic wave propagation in concrete.

PubMed

Chaix, Jean-François; Rossat, Mathieu; Garnier, Vincent; Corneloup, Gilles

2012-06-01

This study compares ultrasonic wave propagation modeling and experimental data in concrete. As a consequence of its composition and manufacturing process, this material has a high elastic scattering (sand and aggregates) and air (microcracks and porosities) content. The behavior of the "Waterman-Truell" and "Generalized Self Consistent Method" dynamic homogenization models are analyzed in the context of an application for strong heterogeneous solid materials, in which the scatterers are of various concentrations and types. The experimental validations of results predicted by the models are carried out by making use of the phase velocity and the attenuation of longitudinal waves, as measured by an immersed transmission setup. The test specimen material has a cement-like matrix containing spherical inclusions of air or glass, with radius close to the ultrasonic wavelength. The models are adapted to the case of materials presenting several types of scattering particle, and allow the propagation of longitudinal waves to be described at the scale of materials such as concrete. The validity limits for frequency and for particle volume ratio can be approached through a comparison with experimental data. The potential of these homogenization models for the prediction of phase velocity and attenuation in strongly heterogeneous solids is demonstrated.

Durability of building stones against artificial salt crystallization

NASA Astrophysics Data System (ADS)

Min, K.; Park, J.; Han, D.

2005-12-01

Salts have been known as the most powerful weathering agents, especially when combined with frost action. Salt crystallization test along with freezing-thawing test and acid immersion test was carried out to assess the durability of building stones against weathering. Granite, limestone, marble and basalt were sampled from different quarries in south Korea for this study. One cycle of artificial salt crystallization test was composed of immersion of cored rock specimens in oversaturated solutions of CaCl2, KCl, NaCl and Na2SO4, respectively for 15 hours and successive drying in an oven of 105°C for 3 hours and cooling at room temperature. Tests were performed up to 30 cycles, and specific gravity and ultrasonic velocity were measured after experiencing every 10 cycles and uniaxial compressive strength was measured only after 30 cycles. During the repeated Na2SO4 salt crystallization, some rock samples were gradually deformed excessively and burst after 20 to 30 cycles of test. The variation patterns of physical properties during the salt crystallization tests are too variable to generalize the effect of salt weathering on physical properties but limestone, marble and basalt samples showed relatively greater change of physical properties than granite samples. The recrystallized salts were well observed in the cracks of rock samples through the scanning electron microscope. In the all salt crystallization tests, apparent specific gravities for all tested samples increased generally but not so significantly due to recrystallization of salts. It can be inferred that filling the pores with salt crystals cause the increase of ultrasonic velocity during the early stage of salt crystallization and then in later stages the repeated cycles of salt crystallization result in development of cracks leading decrease of ultrasonic velocity for some rock samples.

Determining the acoustic properties of the lens using a high-frequency ultrasonic needle transducer.

PubMed

Huang, Chih-Chung; Zhou, Qifa; Ameri, Hossein; Wu, Da Wei; Sun, Lei; Wang, Shyh-Hau; Humayun, Mark S; Shung, K Kirk

2007-12-01

Ultrasonic parameters including sound velocity and attenuation coefficient have recently been found to be useful in characterizing the cataract lens noninvasively. However, the regional changes of these acoustic parameters in the lens cannot be detected directly by those ultrasonic measurements. This prompted us to fabricate a 46-MHz needle transducer (lead magnesium niobate-lead titanate [PMN-PT] single crystal) with an aperture size of 0.4 mm and a diameter of 0.9 mm for directly measuring the sound velocity and frequency-dependent attenuation coefficient in lenses. These parameters have been shown to be related to the hardness of a cataract, and hence this technique may allow surgeons to detect the acoustic properties of the cataract via a small incision on the cornea before/during phacoemulsification surgery. To verify the performance of the needle transducer, experiments were performed on porcine lenses in which two types of cataracts (nucleus and cortical) were induced artificially. The needle transducer was mounted on a positioning system and its tip was inserted into the lens, allowing the anterior-to-posterior profiles of acoustic parameters along the lens axis to be obtained immediately. The experimental results show that the acoustic parameters are not constant within a single normal lens. The sound velocity and ultrasound attenuation coefficient (at 46 MHz) were 1701.2 +/- 8.4 m/s (mean +/- SD) and 9.42 +/- 0.57 dB/mm, respectively, at the nucleus, and 1597.2 +/- 9.6, 1589.3 +/- 6.1 m/s and 0.42 +/- 0.26 and 0.40 +/- 0.33 dB/mm close to the anterior and posterior capsules, respectively. Finally, the data obtained demonstrate that regional variations in the acoustic properties of lenses corresponding to the hardness of different types of cataract can be detected sensitively by a needle transducer.

Lamb Wave Assessment of Fiber Volume Fraction in Composites

NASA Technical Reports Server (NTRS)

Seale, Michael D.; Smith, Barry T.; Prosser, W. H.; Zalameda, Joseph N.

1998-01-01

Among the various techniques available, ultrasonic Lamb waves offer a convenient method of examining composite materials. Since the Lamb wave velocity depends on the elastic properties of a material, an effective tool exists to evaluate composites by measuring the velocity of these waves. Lamb waves can propagate over long distances and are sensitive to the desired in-plane elastic properties of the material. This paper discusses a study in which Lamb waves were used to examine fiber volume fraction variations of approximately 0.40-0.70 in composites. The Lamb wave measurements were compared to fiber volume fractions obtained from acid digestion tests. Additionally, a model to predict the fiber volume fraction from Lamb wave velocity values was evaluated.

Effect of shear strength on Hugoniot-compression curve and the equation of state of tungsten (W)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mashimo, Tsutomu, E-mail: mashimo@gpo.kumamoto-u.ac.jp; Liu, Xun; Kodama, Masao

2016-01-21

The Hugoniot data for highly dense polycrystalline tungsten were obtained for pressures above 200 GPa, and the equation of state (EOS) was determined taking into account shear strength effects. For this study, we have made some improvements in measurement system and analyses of the shock wave data. Symmetric-impact Hugoniot measurements were performed using the high-time resolution streak camera system equipped on a one-stage powder gun and two-stage light gas gun, where the effects of tilting and bowing of flyer plate on the Hugoniot data were carefully considered. The shock velocity–particle velocity (U{sub S}–U{sub P}) Hugoniot relation in the plastic regime wasmore » determined to be U{sub S} = 4.137 + 1.242U{sub P} km/s (U{sub P} < 2 km/s). Ultrasonic and Velocity Interferometer System for Any Reflector measurements were also performed in this study. The zero-intercept value of the U{sub S}–U{sub P} Hugoniot relation was found to be slightly larger than the ultrasonic bulk sound velocity (4.023 km/s). The hypothetical hydrostatic isothermal U{sub s}–U{sub p} Hugoniot curve, which corresponds to the hydrostatic isothermal compression curve derived from the Hugoniot data using the strength data, converged to the bulk sound velocity, clearly showing shear strength dependence in the Hugoniot data. The EOS for tungsten is derived from the hydrostatic isothermal compression curve using the strength data.« less

Experimental investigation of wave dispersion in hardened concrete and reference liquid media

NASA Astrophysics Data System (ADS)

Iliopoulos, Sokratis N.; Malm, Fabian; Grosse, Christian U.; Aggelis, Dimitrios G.

2017-04-01

Nowadays, more and more, the monitoring of concrete's setting and hardening as well as concrete's condition assessment and mechanical characterization is realized with the Ultrasonic Pulse Velocity technique. However, despite its increasing use, the high potential and the vast applicability over a wide range of materials and structures, the aforementioned nondestructive testing technique is only partially exploited since a) a default pulse usually not selected by the user is transmitted, b) a single frequency band dependent on the testing equipment (pulse generator and sensors) is excited and c) usually the first part of the signal is only considered. Moreover, the technique, as defined by its name, is based on pulse velocity measurements which strongly rely on a predefined threshold value for the calculation of the travel time between the transmitting and receiving sensor. To overcome all these issues, in the current experimental campaign, user-defined signals are generated, a broad range of ultrasonic frequencies is excited, while the full length of the signal is also taken into account. In addition, the pulse velocity measurements are replaced by the more advanced phase velocity calculations determined by reference phase points of the time domain signals or by phase differences of the signals transformed in the frequency domain. The experiments are mainly conducted in hardened concrete specimens but the aggregates are substituted by spherical glass beads of well-defined sizes and contents in order to better control the microstructure. Reference liquid media are also examined for comparison purposes. The results in both cases show strong dispersive trends indicated by significant changes in the phase velocity.

A Micro Ultrasonic Scalpel with Modified Stepped Horn

NASA Astrophysics Data System (ADS)

Kurosawa, Minoru; Umehara, Yuji

A transducer for a micro ultrasonic scalpel has been fabricated. The micro ultrasonic scalpel can be used with an endoscope for a non-abdominal operation or micro surgery, for example, through a microscope. The ultrasonic transducer was 9.8 mm long and 2.7 mm wide and has stepped horn to amplify vibration velocity; tip of the horn is 0.6 mm wide. The scalpel operated at the resonance frequency in longitudinal mode of 278 kHz. The piezoelectric material was lead zirconate titanate (PZT) that was deposited by the hydrothermal method. The vibration velocity at the tip of the horn in longitudinal direction was 4.0 m/s with 40Vp-p driving voltage in both side electrodes. To demonstrate a beneficial effect of the scalpel, a cutting test that the transducer was stuck into pork fat was carried out.

Active Ultrasonic Monitoring of High-Pressure Metamorphic Reactions Using a New Generation of Griggs-Type Apparatus

NASA Astrophysics Data System (ADS)

Fauconnier, J.; Gasc, J.; Petit, L.; Pinquier, Y.; Deldicque, D.; Renner, J.; Green, H. W., II; Schubnel, A.

2017-12-01

A new high pressure Griggs-type apparatus, equipped with ultrasonic transducers, was developed at the École Normale Supérieure (France). This press uses solid salt as confining medium and can reach 5 GPa confinement within a 20 mm borehole. Two piezoelectric transducers, with 5MHz center frequency, are installed above and below the sample, respectively in the deformation column and in the base plate. During the experiment, the top and bottom transducers are used as ultrasonic source and receiver, respectively, for pulse-through measurements. Full waveforms are digitized at 50MHz, and relative elastic waves travel times through the sample and part of the deformation column are calculated using cross-correlations.In order to calibrate our acoustic system, an alumina dummy was used to estimate the sensitivity of the setup (i.e. the minimum travel time difference between two measurements) and the acoustic `stiffness' of the apparatus (i.e. the relative change of travel time as a function of pressure, temperature and differential stress). We show that our resolution in relative travel time change is of the order of 10 ns, meaning that within a 7 mm long sample and given an average wave velocity of mineral assemblies of the order of 6-10 km/s, our theoretical resolution in velocity change in the sample is close to 1%.The aim of a second set of experiments is to study the kinetics of the quartz-coesite reaction under non-hydrostatic conditions. At our (P,T) conditions, P-wave velocities in coesite are roughly 25 % higher than in (metastable) quartz. Experiments were performed on 10-20 µm quartz powder, at 800°C and confining pressures ranging from 1 to 3 GPa. During each experiment, the maximum principal stress, σ1, was raised within the coesite field, at fixed σ3 and temperature conditions. Stress and temperature were then kept constant during 2 hours. Microstructures and phases distribution were characterized post-mortem using EBSD mapping. Preliminary results reveal that coesite was only observed when both σ3 and σ1 were in the coesite field. In this case, using our ultrasonic monitoring, the reaction was detected by a clear change of P-wave velocity in the sample, as approximately 20% of the quartz transformed to coesite.

High-pressure behavior of amorphous selenium from ultrasonic measurements and Raman spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

He, Z.; Liu, X. R.; Hong, S. M., E-mail: hpswjtu@gmail.com, E-mail: smhong@home.swjtu.edu.cn

2014-07-07

The high-pressure behavior of melt-quenched amorphous selenium (a-Se) has been investigated via ultrasonic measurements and Raman scattering at room temperature. The ultrasonic measurements were conducted on a-Se in a multi-anvil apparatus with two different sample assemblies at pressures of up to 4.5 and 4.8 GPa. We discovered that similar kinks occur in the slopes of the pressure dependence characteristics of the travel time and the sound velocity in both shear and longitudinal waves in the 2.0–2.5 GPa range. These kinks are independent of the sample assemblies, indicating an intrinsic transformation of the a-Se. Additionally, we deduced the pressure-volume relationship of a-Se frommore » the sound velocity characteristics using the Birch–Murnaghan equation of state, and the results agreed well with those of previous reports. In situ high-pressure Raman scattering measurements of a-Se were conducted in a diamond anvil cell with an 830 nm excitation line up to a pressure of 4.3 GPa. We found that the characteristic band of a-Se at ∼250 cm{sup −1} experienced a smooth shift to a lower frequency with pressure, but a sharp slope change in the band intensity versus pressure occurred near 2.5 GPa. The results of X-ray diffraction and differential scanning calorimetry measurements indicate that the samples remain in their amorphous states after decompression. Thus, we proposed that the abnormal compression behavior of a-Se in the 2.0–2.5 GPa range can be attributed to pressure-induced local atomic reconfiguration, implying an amorphous-amorphous transition of the elementary selenium.« less

Mapping of elasticity and damping in an α + β titanium alloy through atomic force acoustic microscopy

PubMed Central

Phani, M Kalyan; Kumar, Anish; Jayakumar, T; Samwer, Konrad

2015-01-01

Summary The distribution of elastic stiffness and damping of individual phases in an α + β titanium alloy (Ti-6Al-4V) measured by using atomic force acoustic microscopy (AFAM) is reported in the present study. The real and imaginary parts of the contact stiffness k * are obtained from the contact-resonance spectra and by using these two quantities, the maps of local elastic stiffness and the damping factor are derived. The evaluation of the data is based on the mass distribution of the cantilever with damped flexural modes. The cantilever dynamics model considering damping, which was proposed recently, has been used for mapping of indentation modulus and damping of different phases in a metallic structural material. The study indicated that in a Ti-6Al-4V alloy the metastable β phase has the minimum modulus and the maximum damping followed by α′- and α-phases. Volume fractions of the individual phases were determined by using a commercial material property evaluation software and were validated by using X-ray diffraction (XRD) and electron back-scatter diffraction (EBSD) studies on one of the heat-treated samples. The volume fractions of the phases and the modulus measured through AFAM are used to derive average modulus of the bulk sample which is correlated with the bulk elastic properties obtained by ultrasonic velocity measurements. The average modulus of the specimens estimated by AFAM technique is found to be within 5% of that obtained by ultrasonic velocity measurements. The effect of heat treatments on the ultrasonic attenuation in the bulk sample could also be understood based on the damping measurements on individual phases using AFAM. PMID:25977847

Mapping of elasticity and damping in an α + β titanium alloy through atomic force acoustic microscopy.

PubMed

Phani, M Kalyan; Kumar, Anish; Jayakumar, T; Arnold, Walter; Samwer, Konrad

2015-01-01

The distribution of elastic stiffness and damping of individual phases in an α + β titanium alloy (Ti-6Al-4V) measured by using atomic force acoustic microscopy (AFAM) is reported in the present study. The real and imaginary parts of the contact stiffness k (*) are obtained from the contact-resonance spectra and by using these two quantities, the maps of local elastic stiffness and the damping factor are derived. The evaluation of the data is based on the mass distribution of the cantilever with damped flexural modes. The cantilever dynamics model considering damping, which was proposed recently, has been used for mapping of indentation modulus and damping of different phases in a metallic structural material. The study indicated that in a Ti-6Al-4V alloy the metastable β phase has the minimum modulus and the maximum damping followed by α'- and α-phases. Volume fractions of the individual phases were determined by using a commercial material property evaluation software and were validated by using X-ray diffraction (XRD) and electron back-scatter diffraction (EBSD) studies on one of the heat-treated samples. The volume fractions of the phases and the modulus measured through AFAM are used to derive average modulus of the bulk sample which is correlated with the bulk elastic properties obtained by ultrasonic velocity measurements. The average modulus of the specimens estimated by AFAM technique is found to be within 5% of that obtained by ultrasonic velocity measurements. The effect of heat treatments on the ultrasonic attenuation in the bulk sample could also be understood based on the damping measurements on individual phases using AFAM.

Ultrasonic fluid flow measurement method and apparatus

DOEpatents

Kronberg, J.W.

1993-10-12

An apparatus for measuring the flow of a fluid in a pipe using ultrasonic waves. The apparatus comprises an ultrasonic generator, a lens for focusing the sound energy produced by the generator, and means for directing the focused energy into the side of the pipe through an opening and in a direction close to parallel to the long axis of the pipe. A cone carries the sound energy to the lens from the generator. Depending on the choice of materials, there may be a quarter-wave, acoustic impedance matching section between the generator and the cone to reduce the reflections of energy at the cone boundary. The lens material has an acoustic impedance similar to that of the cone material but a different sonic velocity so that the lens can converge the sound waves in the fluid. A transition section between the lens and the fluid helps to couple the energy to the fluid and assures it is directed as close to parallel to the fluid flow direction as possible. 3 figures.

Ultrasonic fluid flow measurement method and apparatus

DOEpatents

Kronberg, James W.

1993-01-01

An apparatus for measuring the flow of a fluid in a pipe using ultrasonic waves. The apparatus comprises an ultrasonic generator, a lens for focusing the sound energy produced by the generator, and means for directing the focused energy into the side of the pipe through an opening and in a direction close to parallel to the long axis of the pipe. A cone carries the sound energy to the lens from the generator. Depending on the choice of materials, there may be a quarter-wave, acoustic impedance matching section between the generator and the cone to reduce the reflections of energy at the cone boundary. The lens material has an acoustic impedance similar to that of the cone material but a different sonic velocity so that the lens can converge the sound waves in the fluid. A transition section between the lens and the fluid helps to couple the energy to the fluid and assures it is directed as close to parallel to the fluid flow direction as possible.

Effect of Decay on Ultrasonic Velocity and Attenuation Measurements in Wood

Treesearch

Megan McGovern; Adam Senalik; George Chen; Frank C. Beall; Henrique Reis

2013-01-01

The percentage mass loss of loblolly pine (pinus taeda) wood cube specimens exposed to Gloeophyllum fungus (Gloeophyllum trabeum) for increasing periods of time ranging from 1 to 12 weeks was recorded after being subjected to controlled decay following ASTM International standard ASTM D 1423-99. The specimens’ corresponding volume...

Volumetric and acoustical behaviour of sodium saccharin in aqueous system over temperature range (20.0-45.0)°C.

PubMed

Jamal, Muhammad Asghar; Rashad, Muhammad; Khosa, Muhammad Kaleem; Bhatti, Haq Nawaz

2015-04-15

Densities and ultrasonic velocity values for aqueous solutions of sodium saccharin (SS) has been measured as a function of concentration at 20.0-45.0 °C and atmospheric pressure using DSA-5000 M. The density and ultrasonic velocity values have been further used to calculate apparent molar volume, apparent specific volume, isentropic apparent molar compressibility and compressibility hydration numbers and reported. The values for apparent molar volume obtained at given temperatures showed negative deviations from Debye-Hückel limiting law and used as a direct measure of the ion-ion and ion-solvent interactions. The apparent specific volumes of the solute were calculated and it was found that these values of the investigated solutions lie on the borderline between the values reported for sweet substances. The sweetness response of the sweeteners is then explained in terms of their solution behaviours. Furthermore, the partial molar expansibility, its second derivative, (∂(2)V°/∂T(2)) as Hepler's constant and thermal expansion coefficient have been estimated. Copyright © 2014 Elsevier Ltd. All rights reserved.

Air-coupled ultrasound: a novel technique for monitoring the curing of thermosetting matrices.

PubMed

Lionetto, Francesca; Tarzia, Antonella; Maffezzoli, Alfonso

2007-07-01

A custom-made, air-coupled ultrasonic device was applied to cure monitoring of thick samples (7-10 mm) of unsaturated polyester resin at room temperature. A key point was the optimization of the experimental setup in order to propagate compression waves during the overall curing reaction by suitable placement of the noncontact transducers, placed on the same side of the test material, in the so-called pitch-catch configuration. The progress of polymerization was monitored through the variation of the time of flight of the propagating longitudinal waves. The exothermic character of the polymerization was taken into account by correcting the measured value of time of flight with that one in air, obtained by sampling the air velocity during the experiment. The air-coupled ultrasonic results were compared with those obtained from conventional contact ultrasonic measurements. The good agreement between the air-coupled ultrasonic results and those obtained by the rheological analysis demonstrated the reliability of air-coupled ultrasound in monitoring the changes of viscoelastic properties at gelation and vitrification. The position of the transducers on the same side of the sample makes this technique suitable for on-line cure monitoring during several composite manufacturing technologies.

Damage Characterization and Real-Time Health Monitoring of Aerospace Materials Using Innovative NDE Tools

NASA Astrophysics Data System (ADS)

Matikas, Theodore E.

2010-07-01

The objective of this work is to characterize the damage and monitor in real-time aging structural components used in aerospace applications by means of advanced nondestructive evaluation techniques. Two novel experimental methodologies are used in this study, based on ultrasonic microscopy and nonlinear acoustics. It is demonstrated in this work that ultrasonic microscopy can be successfully utilized for local elastic property measurement, crack-size determination as well as for interfacial damage evaluation in high-temperature materials, such as metal matrix composites. Nonlinear acoustics enables real-time monitoring of material degradation in aerospace structures. When a sinusoidal ultrasonic wave of a given frequency and of sufficient amplitude is introduced into a nonharmonic solid, the fundamental wave distorts as it propagates, and therefore the second and higher harmonics of the fundamental frequency are generated. Measurements of the amplitude of these harmonics provide information on the coefficient of second- and higher-order terms of the stress-strain relation for a nonlinear solid. It is shown in this article that the material bulk nonlinear parameter for metallic alloy samples at different fatigue levels exhibits large changes compared to linear ultrasonic parameters, such as velocity and attenuation.

Ultrasonic High-Temperature Sensors: Past Experiments and Prospects for Future Use

NASA Astrophysics Data System (ADS)

Laurie, M.; Magallon, D.; Rempe, J.; Wilkins, C.; Pierre, J.; Marquié, C.; Eymery, S.; Morice, R.

2010-09-01

Ultrasonic thermometry sensors (UTS) have been intensively studied in the past to measure temperatures from 2080 K to 3380 K. This sensor, which uses the temperature dependence of the acoustic velocity in materials, was developed for experiments in extreme environments. Its major advantages, which are (a) capability of measuring a temperature profile from multiple sensors on a single probe and (b) measurement near the sensor material melting point, can be of great interest when dealing with on-line monitoring of high-temperature safety tests. Ultrasonic techniques were successfully applied in several severe accident related experiments. With new developments of alternative materials, this instrument may be used in a wide range of experimental areas where robustness and compactness are required. Long-term irradiation experiments of nuclear fuel to extremely high burn-ups could benefit from this previous experience. After an overview of UTS technology, this article summarizes experimental work performed to improve the reliability of these sensors. The various designs, advantages, and drawbacks are outlined and future prospects for long-term high-temperature irradiation experiments are discussed.

Development and evaluation of an ultrasonic ground water seepage meter.

PubMed

Paulsen, R J; Smith, C F; O'Rourke, D; Wong, T F

2001-01-01

Submarine ground water discharge can influence significantly the near-shore transport and flux of chemicals into the oceans. Quantification of the sources and rates of such discharge requires a ground water seepage meter that provides continuous measurements at high resolution over an extended period of time. An ultrasonic flowmeter has been adapted for such measurements in the submarine environment. Connected to a steel collection funnel, the meter houses two piezoelectric transducers mounted at opposite ends of a cylindrical flow tube. By monitoring the perturbations of fluid flow on the propagation of sound waves inside the flow tube, the ultrasonic meter can measure both forward and reverse fluid flows in real time. Laboratory and field calibrations show that the ultrasonic meter can resolve ground water discharges on the order of 0.1 microm/sec, and it is sufficiently robust for deployment in the field for several days. Data from West Neck Bay, Shelter Island, New York, elucidate the temporal and spatial heterogeneity of submarine ground water discharge and its interplay with tidal loading. A negative correlation between the discharge and tidal elevation was generally observed. A methodology was also developed whereby data for the sound velocity as a function of temperature can be used to infer the salinity and source of the submarine discharge. Independent measurements of electrical conductance were performed to validate this methodology.

Optical vibration measurement of mechatronics devices

NASA Astrophysics Data System (ADS)

Yanabe, Shigeo

1993-09-01

An optical vibration measuring system which enables to detect both linear and angular displacement of 25 nm and 5 prad was developed. The system is mainly composed of a He-Ne laser, a displacement detecting photo-diode and lenses, and has linear and angular displacement magnification mechanism using two different principles of optical lever. The system was applied to measure vibrational characteristics of magnetic head slider of hard disk drives and to measure stator teeth driving velocities of ultrasonic motor.

Pressure Dependences of Elastic Constants of AMg6 Aluminum-Magnesium Alloy and n-AMg6/C60 Nanocomposite Alloy

NASA Astrophysics Data System (ADS)

Prokhorov, V. M.; Gromnitskaya, E. L.

2018-04-01

The ultrasonic study results for dependence of the elastic wave velocities and second-order elasticity coefficients of the polycrystalline aluminum alloy AMg6 and its nanocomposite n-AMg6/C60 on hydrostatic pressure up to 1.6 GPa have been described. The ultrasonic research has been carried out using a highpressure ultrasonic piezometer based on the piston-cylinder device. The pressure derivatives of the secondorder elastic constants of these materials established in the present study have been compared with the results of the third-order elastic constants measurements of the test alloys using the Thurston-Brugger method. Involving available literature data, we determined the relationships between the pressure derivatives of the second-order elastic constants of the AMg6 alloy and the Mg-content and nanostructuring.

Mechanics aspects of NDE by sound and ultrasound

NASA Technical Reports Server (NTRS)

Fu, L. S.

1982-01-01

Nondestructive evaluation (NDE) is considered as a means to detect the energy release mechanism of defects and the interaction of microstructures within materials with sound waves and/or ultrasonic waves. Ultrasonic inspection involves the frequency range 20 kHz-1 GHz with amplitudes depending on the sensitivity of the test instrumentation. Pulse echo systems are most frequently used in NDE. Information is extracted from the signals through measurements of the signal velocity, attenuation, the acoustic emission when stress is applied, and calculation of the acoustoelastic coefficients. Fracture properties, tensile and shear strengths, the interlaminar shear strength, the cohesive strength, yield and impact strengths, the hardness, and the residual stress can be assayed by ultrasonic methods. Finally, attention is given to analytical treatment of the derived data, with mention given to transition matrix, integral equation, and eigenstrain approaches.

Ultrasonic ranging for the oculometer

NASA Technical Reports Server (NTRS)

Guy, W. J.

1981-01-01

Ultrasonic tracking techniques are investigated for an oculometer. Two methods are reported in detail. The first is based on measurements of time from the start of a transmit burst to a received echo. Knowing the sound velocity, distance can be calculated. In the second method, a continuous signal is transmitted. Target movement causes phase shifting of the echo. By accumulating these phase shifts, tracking from a set point can be achieved. Both systems have problems with contoured targets, but work well on flat plates and the back of a human head. Also briefly reported is an evaluation of an ultrasonic ranging system. Interface circuits make this system compatible with the echo time design. While the system is consistently accurate, it has a beam too narrow for oculometer use. Finally, comments are provided on a tracking system using the Doppler frequency shift to give range data.

Porosity estimation of aged mortar using a micromechanical model.

PubMed

Hernández, M G; Anaya, J J; Sanchez, T; Segura, I

2006-12-22

Degradation of concrete structures located in high humidity atmospheres or under flowing water is a very important problem. In this study, a method for ultrasonic non-destructive characterization in aged mortar is presented. The proposed method makes a prediction of the behaviour of aged mortar accomplished with a three phase micromechanical model using ultrasonic measurements. Aging mortar was accelerated by immersing the probes in ammonium nitrate solution. Both destructive and non-destructive characterization of mortar was performed. Destructive tests of porosity were performed using a vacuum saturation method and non-destructive characterization was carried out using ultrasonic velocities. Aging experiments show that mortar degradation not only involves a porosity increase, but also microstructural changes in the cement matrix. Experimental results show that the estimated porosity using the proposed non-destructive methodology had a comparable performance to classical destructive techniques.

Novel Real-Time Temperature Diagnosis of Conventional Hot-Embossing Process Using an Ultrasonic Transducer

PubMed Central

Cheng, Chin-Chi; Yang, Sen-Yeu; Lee, Dasheng

2014-01-01

This paper presents an integrated high temperature ultrasonic transducer (HTUT) on a sensor insert and its application for real-time diagnostics of the conventional hot embossing process to fabricate V-cut patterns. The sensor was directly deposited onto the sensor insert of the hot embossing mold by using a sol-gel spray technique. It could operate at temperatures higher than 400 °C and uses an ultrasonic pulse-echo technique. The ultrasonic velocity could indicate the three statuses of the hot embossing process and also evaluate the replication of V-cut patterns on a plastic plate under various processing conditions. The progression of the process, including mold closure, plastic plate softening, cooling and plate detachment inside the mold, was clearly observed using ultrasound. For an ultrasonic velocity range from 2197.4 to 2435.9 m/s, the height of the V-cut pattern decreased from 23.0 to 3.2 μm linearly, with a ratio of −0.078 μm/(m/s). The incompleteness of the replication of the V-cut patterns could be indirectly observed by the ultrasonic signals. This study demonstrates the effectiveness of the ultrasonic sensors and technology for diagnosing the replicating condition of microstructures during the conventional hot embossing process. PMID:25330051

Application of the Pseudo Wigner-Ville Distribution to the Measurement of the Dispersion of Lamb Modes in Graphite/Epoxy Plates

NASA Technical Reports Server (NTRS)

Prosser, W. H.; Seale, M. D.; Smith, B. T.

1997-01-01

Acoustic waves propagate in thin plates as guided or Lamb modes. The velocities of these modes are dispersive in that they depend not only on the material elastic properties and density, but also on the frequency. Accurate characterization of Lamb wave dispersion is important in many acoustic based nondestructive evaluation techniques. It is necessary for ultrasonic measurements in thin plates to determine elastic properties and for flaw detection and localization. In acoustic emission (AE) testing, if not taken into account, highly dispersive Lamb mode propagation can lead to large errors in source location. In this study, the pseudo Wigner-Ville distribution (PWVD) was used for measurement of group velocity dispersion of Lamb waves in a unidirectional graphite/epoxy (AS4/3502) laminate. The PWVD is one of a number of transforms which provide a time-frequency representation of a digitized time series. Broad band acoustic waves were generated by a pencil lead fracture (Hsu-Neilsen source) and were detected with broad band ultrasonic transducers. The arrival times for the lowest order symmetric (S(sub 0)) and antisymmetric (A(sub 0)) Lamb modes were determined from measurements of the time at which the respective peak amplitudes occurred in the PWVD. Measurements were made at several source-to-detector distances and a least squares fit used to calculate the velocity. Results are presented for propagation along, and perpendicular to, the fiber direction. Theoretical dispersion curves were also calculated and a comparison between theory and experiment demonstrates good agreement.

Calibration of non-contact ultrasound as an online sensor for wood characterization: Effects of temperature, moisture, and scanning direction

NASA Astrophysics Data System (ADS)

Vun, R. Y.; Hoover, K.; Janowiak, J.; Bhardwaj, M.

2008-01-01

Numerous handheld moisture meters are available for measuring moisture levels of wood and building materials for a vast range of quality control and moisture diagnosis applications. However, many methods currently available require physical contact of a probe with the test material to operate. The contact requirement of such devices has limited applications for these purposes. There is a tremendous demand for dynamic online quality assessment of in-process materials for moisture content (MC) measurements. In this paper, a non-destructive non-contact ultrasound technology was used to evaluate the effects of increasing temperature in two MC levels and of increasing MC in lumber. The results show that the ultrasonic absolute transmittance and velocity parameters are directly correlated very well (R2≥0.87) with temperature for the two moisture levels in wood. At constant temperature, however, the velocity is inversely correlated with MC. It was also found that the distribution of MC along the length is marginally insignificant to both ultrasonic measurements. The transmittance measurement along the orthogonal thickness direction is insignificant above the fiber saturation MC; similarly, the velocity measurement is marginally insignificant. The study concludes a positive correlation and a good fit for this technology to advance into the development of an automated device for determining wood moisture levels, which will in turn be used to control the dynamics of wood drying/sterilization processes. Further calibration research is recommended to ascertain the constraints and limitations of the technology to specific wood species and dimension.

Changes in Ultrasonic Velocity from Fluid Substitution, Calculated with Laboratory Methods, Digital Rock Physics, and Biot Theory

NASA Astrophysics Data System (ADS)

Goldfarb, E. J.; Ikeda, K.; Tisato, N.

2017-12-01

Seismic and ultrasonic velocities of rocks are function of several variables including fluid saturation and type. Understanding the effect of each variable on elastic waves can be valuable when using seismic methods for subsurface modeling. Fluid type and saturation are of specific interest to volcanology, water, and hydrocarbon exploration. Laboratory testing is often employed to understand the effects of fluids on elastic waves. However, laboratory testing is expensive and time consuming. It normally requires cutting rare samples into regular shapes. Fluid injection can also destroy specimens as removing the fluid after testing can prove difficult. Another option is theoretical modeling, which can be used to predict the effect of fluids on elastic properties, but it is often inaccurate. Alternatively, digital rock physics (DRP) can be used to investigate the effect of fluid substitution. DRP has the benefit of being non invasive, as it does not require regular sample shapes or fluid injection. Here, we compare the three methods for dry and saturated Berea sandstone to test the reliability of DRP. First, ultrasonic velocities were obtained from laboratory testing. Second, for comparison, we used a purely theoretical approach - i.e., Hashin-Shtrikman and Biot theory - to estimate the wave speeds at dry and wet conditions. Third, we used DRP. The dry sample was scanned with micro Computed Tomography (µCT), and a three dimensional (3D) array was recorded. We employed a segmentation-less method to convert each 3D array value to density, porosity, elastic moduli, and wave speeds. Wave propagation was simulated numerically at similar frequency as the laboratory. To simulate fluid substitution, we numerically substituted air values for water and repeated the simulation. The results from DRP yielded similar velocities to the laboratory, and accurately predicted the velocity change from fluid substitution. Theoretical modeling could not accurately predict velocity, and under-predicted the velocity change from fluid substitution. The mathematical approach proved to be a poor comparison for the laboratory measurement. DRP proved to be effective, and could be used in future with drill cuttings, perhaps to limit the use of expensive cores. DRP could also limit the requirement for physically testing fluid substitution.

Aging Wire Insulation Assessment by Phase Spectrum Examination of Ultrasonic Guided Waves

NASA Technical Reports Server (NTRS)

Anastasi, Robert F.; Madaras, Eric I.

2003-01-01

Wire integrity has become an area of concern to the aerospace community including DoD, NASA, FAA, and Industry. Over time and changing environmental conditions, wire insulation can become brittle and crack. The cracks expose the wire conductor and can be a source of equipment failure, short circuits, smoke, and fire. The technique of using the ultrasonic phase spectrum to extract material properties of the insulation is being examined. Ultrasonic guided waves will propagate in both the wire conductor and insulation. Assuming the condition of the conductor remains constant then the stiffness of the insulator can be determined by measuring the ultrasonic guided wave velocity. In the phase spectrum method the guided wave velocity is obtained by transforming the time base waveform to the frequency domain and taking the phase difference between two waveforms. The result can then be correlated with a database, derived by numerical model calculations, to extract material properties of the wire insulator. Initial laboratory tests were performed on a simple model consisting of a solid cylinder and then a solid cylinder with a polymer coating. For each sample the flexural mode waveform was identified. That waveform was then transformed to the frequency domain and a phase spectrum was calculated from a pair of waveforms. Experimental results on the simple model compared well to numerical calculations. Further tests were conducted on aircraft or mil-spec wire samples, to see if changes in wire insulation stiffness can be extracted using the phase spectrum technique.

Secondary flow structures in large rivers

NASA Astrophysics Data System (ADS)

Chauvet, H.; Devauchelle, O.; Metivier, F.; Limare, A.; Lajeunesse, E.

2012-04-01

Measuring the velocity field in large rivers remains a challenge, even with recent measurement techniques such as Acoustic Doppler Current Profiler (ADCP). Indeed, due to the diverging angle between its ultrasonic beams, an ADCP cannot detect small-scale flow structures. However, when the measurements are limited to a single location for a sufficient period of time, averaging can reveal large, stationary flow structures. Here we present velocity measurements in a straight reach of the Seine river in Paris, France, where the cross-section is close to rectangular. The transverse modulation of the streamwise velocity indicates secondary flow cells, which seem to occupy the entire width of the river. This observation is reminiscent of the longitudinal vortices observed in laboratory experiments (e.g. Blanckaert et al., Advances in Water Resources, 2010, 33, 1062-1074). Although the physical origin of these secondary structures remains unclear, their measured velocity is sufficient to significantly impact the distribution of streamwise momentum. We propose a model for the transverse profile of the depth-averaged velocity based on a crude representation of the longitudinal vortices, with a single free parameter. Preliminary results are in good agreement with field measurements. This model also provides an estimate for the bank shear stress, which controls bank erosion.

Characteristics of the First Longitudinal-Fourth Bending Mode Linear Ultrasonic Motors

NASA Astrophysics Data System (ADS)

Park, Taegone; Kim, Beomjin; Kim, Myong-Ho; Uchino, Kenji

2002-11-01

Linear ultrasonic motors using a combination of the first longitudinal mode and the fourth bending mode were designed and fabricated. The driving characteristics of the motors, which were composed of a straight metal bar bonded with piezoelectric ceramic vibrators as a driving element, were measured. Unimorph and bimorph ceramic vibrators were attached on three kinds of metal bars for constructing the stators of the linear motors. As results, motors made with the bimorph ceramic vibrators had higher velocity than motors of the unimorph vibrators. As a metal bar for stator, magnesium alloy, which has lower elastic coefficient than aluminum alloy, was better for the motors.

Compensating effect of ultrasonic waves on retarding action of nanoparticles in drops liquid-liquid extraction.

PubMed

Saien, Javad; Daneshamoz, Sana

2018-03-01

The influence of ultrasonic waves on liquid-liquid extraction of circulating drops and in the presence of magnetite nanoparticles was investigated. Experiments were conducted in a column equipped with an ultrasound transducer. The frequency and intensity of received waves, measured by the hydrophone standard method, were 35.40 kHz and 0.37 mW/cm 2 , respectively. The recommended chemical system of cumene-isobutyric acid-water was used in which mass transfer resistance lies in the aqueous phase. Nanoparticles, within concentration range of (0.0003-0.0030) wt%, were added to the aqueous continuous phase. The presence of nanoparticles and ultrasonic waves provided no sensible change in drop size (within 2.49-4.17 mm) and measured terminal velocities were close to Grace model. However, presence of nanoparticles, caused mass transfer to decrease. This undesired effect was significantly diminished by using ultrasonic waves so that mass transfer coefficient increased from (73.0-178.2) to (130.2-240.2) µm/s, providing a 55.6% average enhancement. It is presumably due to disturbing the accumulated nanoparticles around the drops. The current innovative study highlights the fact that using ultrasonic waves is an interesting way to improve liquid-liquid extraction in the presence and absence of nanoparticles. Copyright © 2017 Elsevier B.V. All rights reserved.

Geometric Limitations Of Ultrasonic Measurements

NASA Astrophysics Data System (ADS)

von Nicolai, C.; Schilling, F.

2006-12-01

Laboratory experiments are a key for interpreting seismic field observations. Due to their potential in many experimental set-ups, the determination of elastic properties of minerals and rocks by ultrasonic measurements is common in Geosciences. The quality and thus use of ultrasonic data, however, strongly depends on the sample geometry and wavelength of the sound wave. Two factors, the diameter-to-wavelength- ratio and the diameter-to-length-ratio, are believed to be the essential parameters to affect ultrasonic signal quality. In this study, we determined under well defined conditions the restricting dimensional parameters to test the validity of published assumptions. By the use of commercial ultrasonic transducers a number of experiments were conducted on aluminium, alumina, and acrylic glass rods of varying diameter (30-10 mm) and constant length. At each diameter compressional wave travel times were measured by pulse- transmission method. From the observed travel times ultrasonic wave velocities were calculated. One additional experiment was performed with a series of square-shaped aluminium blocks in order to investigate the effect of the geometry of the samples cross-sectional area. The experimental results show that the simple diameter-to-wavelength ratios are not valid even under idealized experimental conditions and more complex relation has to be talen into account. As diameter decreases the P-waves direct phase is increasingly interfered and weakened by sidewall reflections. At very small diameters compressional waves are replaced by bar waves and P-wave signals become non resolvable. Considering the suppression of both effects, a critical D/ë-ratio was determined and compared to experimental set-ups from various publications. These tests indicate that some published and cited data derived from small diameter set-ups are out off the range of physical possibility.

A study of the river velocity measurement techniques and analysis methods

NASA Astrophysics Data System (ADS)

Chung Yang, Han; Lun Chiang, Jie

2013-04-01

Velocity measurement technology can be traced back to the pitot tube velocity measurement method in the 18th century and today's velocity measurement technology use the acoustic and radar technology, with the Doppler principle developed technology advances, in order to develop the measurement method is more suitable for the measurement of velocity, the purpose is to get a more accurate measurement data and with the surface velocity theory, the maximum velocity theory and the indicator theory to obtain the mean velocity. As the main research direction of this article is to review the literature of the velocity measurement techniques and analysis methods, and to explore the applicability of the measurement method of the velocity measurement instruments, and then to describe the advantages and disadvantages of the different mean velocity profiles analysis method. Adequate review of the references of this study will be able to provide a reference for follow-up study of the velocity measurement. Review velocity measurement literature that different velocity measurement is required to follow the different flow conditions measured be upgraded its accuracy, because each flow rate measurement method has its advantages and disadvantages. Traditional velocity instrument can be used at low flow and RiverRAD microwave radar or imaging technology measurement method may be applied in high flow. In the tidal river can use the ADCP to quickly measure river vertical velocity distribution. In addition, urban rivers may be used the CW radar to set up on the bridge, and wide rivers can be used RiverRAD microwave radar to measure the velocities. Review the relevant literature also found that using Ultrasonic Doppler Current Profiler with the Chiu's theory to the velocity of observing automation work can save manpower and resources to improve measurement accuracy, reduce the risk of measurement, but the great variability of river characteristics in Taiwan and a lot of drifting floating objects in water in high flow, resulting in measurement automation work still needs further study. If the priority for the safety of personnel and instruments, we can use the non-contact velocity measurement method with the theoretical analysis method to achieve real-time monitoring.

Dispersion curve estimation via a spatial covariance method with ultrasonic wavefield imaging.

PubMed

Chong, See Yenn; Todd, Michael D

2018-05-01

Numerous Lamb wave dispersion curve estimation methods have been developed to support damage detection and localization strategies in non-destructive evaluation/structural health monitoring (NDE/SHM) applications. In this paper, the covariance matrix is used to extract features from an ultrasonic wavefield imaging (UWI) scan in order to estimate the phase and group velocities of S0 and A0 modes. A laser ultrasonic interrogation method based on a Q-switched laser scanning system was used to interrogate full-field ultrasonic signals in a 2-mm aluminum plate at five different frequencies. These full-field ultrasonic signals were processed in three-dimensional space-time domain. Then, the time-dependent covariance matrices of the UWI were obtained based on the vector variables in Cartesian and polar coordinate spaces for all time samples. A spatial covariance map was constructed to show spatial correlations within the full wavefield. It was observed that the variances may be used as a feature for S0 and A0 mode properties. The phase velocity and the group velocity were found using a variance map and an enveloped variance map, respectively, at five different frequencies. This facilitated the estimation of Lamb wave dispersion curves. The estimated dispersion curves of the S0 and A0 modes showed good agreement with the theoretical dispersion curves. Copyright © 2018 Elsevier B.V. All rights reserved.

Structural health monitoring ultrasonic thickness measurement accuracy and reliability of various time-of-flight calculation methods

NASA Astrophysics Data System (ADS)

Eason, Thomas J.; Bond, Leonard J.; Lozev, Mark G.

2016-02-01

The accuracy, precision, and reliability of ultrasonic thickness structural health monitoring systems are discussed in-cluding the influence of systematic and environmental factors. To quantify some of these factors, a compression wave ultrasonic thickness structural health monitoring experiment is conducted on a flat calibration block at ambient temperature with forty four thin-film sol-gel transducers and various time-of-flight thickness calculation methods. As an initial calibration, the voltage response signals from each sensor are used to determine the common material velocity as well as the signal offset unique to each calculation method. Next, the measurement precision of the thickness error of each method is determined with a proposed weighted censored relative maximum likelihood analysis technique incorporating the propagation of asymmetric measurement uncertainty. The results are presented as upper and lower confidence limits analogous to the a90/95 terminology used in industry recognized Probability-of-Detection assessments. Future work is proposed to apply the statistical analysis technique to quantify measurement precision of various thickness calculation methods under different environmental conditions such as high temperature, rough back-wall surface, and system degradation with an intended application to monitor naphthenic acid corrosion in oil refineries.

Monitoring stress related velocity variation in concrete with a 2 x 10(-5) relative resolution using diffuse ultrasound.

PubMed

Larose, Eric; Hall, Stephen

2009-04-01

Ultrasonic waves propagating in solids have stress-dependent velocities. The relation between stress (or strain) and velocity forms the basis of non-linear acoustics. In homogeneous solids, conventional time-of-flight techniques have measured this dependence with spectacular precision. In heterogeneous media such as concrete, the direct (ballistic) wave around 500 kHz is strongly attenuated and conventional techniques are less efficient. In this manuscript, the effect of weak stress changes on the late arrivals constituting the acoustic diffuse coda is tracked. A resolution of 2 x 10(-5) in relative velocity change is attained which corresponds to a sensitivity to stress change of better than 50 kPa. Therefore, the technique described here provides an original way to measure the non-linear parameter with stress variations on the order of tens of kPa.

Setting behaviour of luting cements monitored by an ultrasonic method.

PubMed

Tsubota, Keishi; Mori, Kentarou; Yasuda, Genta; Kawamoto, Ryo; Yoshida, Takeshi; Yamaguchi, Kanako; Kurokawa, Hiroyasu; Miyazaki, Masashi

2008-06-01

The purpose of this study was to monitor the setting behaviour and elastic modulus of luting cements using an ultrasonic device. The ultrasonic equipment comprised a pulser-receiver, transducers and an oscilloscope. The transit time through the cement disk was multiplied by the thickness of the specimen, and the sonic velocity within the material was then calculated. The sonic velocities of the longitudinal and shear waves were used to determine the elastic modulus. Analysis of variance and the Tukey HSD test were used to compare the elastic moduli of the set cements. In the earliest stages of the setting process, most of the ultrasound energy was absorbed by the cements and the sound waves were relatively weak. As the cements hardened, the sound velocities increased and this tendency differed among the luting cements used. The mean elastic moduli of the specimens ranged from 2.9 to 9.9 GPa after 15 min, from 14.4 to 20.3 GPa after 24 h and from 12.1 to 15.9 GPa after 1 month. The setting processes of the luting cements were thus clearly defined by using the present ultrasonic method.

A pressure core ultrasonic test system for on-board analysis of gas hydrate-bearing sediments under in situ pressures.

PubMed

Yang, Lei; Zhou, Weihua; Xue, Kaihua; Wei, Rupeng; Ling, Zheng

2018-05-01

The enormous potential as an alternative energy resource has made natural gas hydrates a material of intense research interest. Their exploration and sample characterization require a quick and effective analysis of the hydrate-bearing cores recovered under in situ pressures. Here a novel Pressure Core Ultrasonic Test System (PCUTS) for on-board analysis of sediment cores containing gas hydrates at in situ pressures is presented. The PCUTS is designed to be compatible with an on-board pressure core transfer device and a long gravity-piston pressure-retained corer. It provides several advantages over laboratory core analysis including quick and non-destructive detection, in situ and successive acoustic property acquisition, and remission of sample storage and transportation. The design of the unique assembly units to ensure the in situ detection is demonstrated, involving the U-type protecting jackets, transducer precession device, and pressure stabilization system. The in situ P-wave velocity measurements make the detection of gas hydrate existence in the sediments possible on-board. Performance tests have verified the feasibility and sensitivity of the ultrasonic test unit, showing the dependence of P-wave velocity on gas hydrate saturation. The PCUTS has been successfully applied for analysis of natural samples containing gas hydrates recovered from the South China Sea. It is indicated that on-board P-wave measurements could provide a quick and effective understanding of the hydrate occurrence in natural samples, which can assist further resource exploration, assessment, and subsequent detailed core analysis.

A pressure core ultrasonic test system for on-board analysis of gas hydrate-bearing sediments under in situ pressures

NASA Astrophysics Data System (ADS)

Yang, Lei; Zhou, Weihua; Xue, Kaihua; Wei, Rupeng; Ling, Zheng

2018-05-01

The enormous potential as an alternative energy resource has made natural gas hydrates a material of intense research interest. Their exploration and sample characterization require a quick and effective analysis of the hydrate-bearing cores recovered under in situ pressures. Here a novel Pressure Core Ultrasonic Test System (PCUTS) for on-board analysis of sediment cores containing gas hydrates at in situ pressures is presented. The PCUTS is designed to be compatible with an on-board pressure core transfer device and a long gravity-piston pressure-retained corer. It provides several advantages over laboratory core analysis including quick and non-destructive detection, in situ and successive acoustic property acquisition, and remission of sample storage and transportation. The design of the unique assembly units to ensure the in situ detection is demonstrated, involving the U-type protecting jackets, transducer precession device, and pressure stabilization system. The in situ P-wave velocity measurements make the detection of gas hydrate existence in the sediments possible on-board. Performance tests have verified the feasibility and sensitivity of the ultrasonic test unit, showing the dependence of P-wave velocity on gas hydrate saturation. The PCUTS has been successfully applied for analysis of natural samples containing gas hydrates recovered from the South China Sea. It is indicated that on-board P-wave measurements could provide a quick and effective understanding of the hydrate occurrence in natural samples, which can assist further resource exploration, assessment, and subsequent detailed core analysis.

Ultrasonic Determination of the Elastic Constants of Epoxy-natural Fiber Composites

NASA Astrophysics Data System (ADS)

Valencia, C. A. Meza; Pazos-Ospina, J. F.; Franco, E. E.; Ealo, Joao L.; Collazos-Burbano, D. A.; Garcia, G. F. Casanova

This paper shows the applications ultrasonic through-transmission technique to determine the elastic constants of two polymer-natural fiber composite materials with potential industrial application and economic and environmental advantages. The transversely isotropic coconut-epoxy and fique-epoxy samples were analyzed using an experimental setup which allows the sample to be rotated with respect to transducers faces and measures the time-of-flight at different angles of incidence. Then, the elastic properties of the material were obtained by fitting the experimental data to the Christoffel equation. Results show a good agreement between the measured elastic constants and the values predicted by an analytical model. The velocities as a function of the incidence angle are reported and the effect of the natural fiber on the stiffness of the composite is discussed.

In situ acoustic and laboratory ultrasonic sound speed and attenuation measured in heterogeneous soft seabed sediments: Eel River shelf, California

USGS Publications Warehouse

Gorgas, T.J.; Wilkens, R.H.; Fu, S.S.; Neil, Frazer L.; Richardson, M.D.; Briggs, K.B.; Lee, H.

2002-01-01

We compared in situ and laboratory velocity and attenuation values measured in seafloor sediments from the shallow water delta of the Eel River, California. This region receives a substantial volume of fluvial sediment that is discharged annually onto the shelf. Additionally, a high input of fluvial sediments during storms generates flood deposits that are characterized by thin beds of variable grain-sizes between the 40- and 90-m isobaths. The main objectives of this study were (1) to investigate signatures of seafloor processes on geoacoustic and physical properties, and (2) to evaluate differences between geoacoustic parameters measured in situ at acoustic (7.5 kHz) and in the laboratory at ultrasonic (400 kHz) frequencies. The in situ acoustic measurements were conducted between 60 and 100 m of water depth. Wet-bulk density and porosity profiles were obtained to 1.15 m below seafloor (m bsf) using gravity cores of the mostly cohesive fine-grained sediments across- and along-shelf. Physical and geoacoustic properties from six selected sites obtained on the Eel margin revealed the following. (1) Sound speed and wet-bulk density strongly correlated in most cases. (2) Sediment compaction with depth generally led to increased sound speed and density, while porosity and in situ attenuation values decreased. (3) Sound speed was higher in coarser- than in finer-grained sediments, on a maximum average by 80 m s-1. (4) In coarse-grained sediments sound speed was higher in the laboratory (1560 m s-1) than in situ (1520 m s-1). In contrast, average ultrasonic and in situ sound speed in fine-grained sediments showed only little differences (both approximately 1480 m s-1). (5) Greater attenuation was commonly measured in the laboratory (0.4 and 0.8 dB m-1 kHz-1) than in situ (0.02 and 0.65 dB m-1 kHz-1), and remained almost constant below 0.4 m bsf. We attributed discrepancies between laboratory ultrasonic and in situ acoustic measurements to a frequency dependence of velocity and attenuation. In addition, laboratory attenuation was most likely enhanced due to scattering of sound waves at heterogeneities that were on the scale of ultrasonic wavelengths. In contrast, high in situ attenuation values were linked to stratigraphic scattering at thin-bed layers that form along with flood deposits. ?? 2002 Published by Elsevier Science B.V.

Analytical ultrasonics for characterization of metallurgical microstructures and transformations

NASA Technical Reports Server (NTRS)

Rosen, M.

1986-01-01

The application of contact (piezoelectric) and noncontact (laser generation and detection) ultrasonic techniques for dynamic investigation of precipitation hardening processes in aluminum alloys, as well as crystallization and phase transformation in rapidly solidified amorphous and microcrystalline alloys is discussed. From the variations of the sound velocity and attenuation the precipitation mechanism and kinetics were determined. In addition, a correlation was established between the observed changes in the velocity and attenuation and the mechanical properties of age-hardenable aluminum alloys. The behavior of the elastic moduli, determined ultrasonically, were found to be sensitive to relaxation, crystallization and phase decomposition phenomena in rapidly solidified metallic glasses. Analytical ultrasonics enables determination of the activation energies and growth parameters of the reactions. Therefrom theoretical models can be constructed to explain the changes in mechanical and physical properties upon heat treatment of glassy alloys. The composition dependence of the elastic moduli in amorphous Cu-Zr alloys was found to be related to the glass transition temperature, and consequently to the glass forming ability of these alloys. Dynamic ultrasonic analysis was found to be feasible for on-line, real-time, monitoring of metallurgical processes.

Evaluation of taste solutions by sensor fusion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kojima, Yohichiro; Sato, Eriko; Atobe, Masahiko

In our previous studies, properties of taste solutions were discriminated based on sound velocity and amplitude of ultrasonic waves propagating through the solutions. However, to make this method applicable to beverages which contain many taste substances, further studies are required. In this study, the waveform of an ultrasonic wave with frequency of approximately 5 MHz propagating through a solution was measured and subjected to frequency analysis. Further, taste sensors require various techniques of sensor fusion to effectively obtain chemical and physical parameter of taste solutions. A sensor fusion method of ultrasonic wave sensor and various sensors, such as the surfacemore » plasmon resonance (SPR) sensor, to estimate tastes were proposed and examined in this report. As a result, differences among pure water and two basic taste solutions were clearly observed as differences in their properties. Furthermore, a self-organizing neural network was applied to obtained data which were used to clarify the differences among solutions.« less

Wave speed propagation measurements on highly attenuative heated materials

DOE PAGES

Moore, David G.; Ober, Curtis C.; Rodacy, Phil J.; ...

2015-09-19

Ultrasonic wave propagation decreases as a material is heated. Two factors that can characterize material properties are changes in wave speed and energy loss from interactions within the media. Relatively small variations in velocity and attenuation can detect significant differences in microstructures. This paper discusses an overview of experimental techniques that document the changes within a highly attenuative material as it is either being heated or cooled from 25°C to 90°C. The experimental set-up utilizes ultrasonic probes in a through-transmission configuration. The waveforms are recorded and analyzed during thermal experiments. To complement the ultrasonic data, a Discontinuous-Galerkin Model (DGM) wasmore » also created which uses unstructured meshes and documents how waves travel in these anisotropic media. This numerical method solves particle motion travel using partial differential equations and outputs a wave trace per unit time. As a result, both experimental and analytical data are compared and presented.« less

Effect of temperature on thermoacoustic properties of olive oil in alcohol mixtures

NASA Astrophysics Data System (ADS)

Shriwas, R. S.; Chimankar, O. P.; Tabhane, P. V.; Dange, S. P.; Tembhurkar, Y. D.

2012-12-01

The ultrasonic studies in liquids are great use in understanding the nature and strength of molecular interactions. Recently ultrasonic is the rapidly growing field research, which has been used in the food industry for both analysis and modification of food products. This paper presents ultrasonic velocity, density, adiabatic compressibility in olive oil with alcohol at different concentration that has been measured in the temperature range from 283.15K to 298.15K. The Moelwyn-Hughes parameter has been utilised to establish some simple relations between the available volumes, Bayer's non- linearity parameter, internal pressure, van der Waal's constant, Debye temperature etc. a relationship among the isobaric, isothermal and isochoric thermo-acoustical parameter have been studied and analyzed in the case olive oil with alcohol mixture. The present treatments had the distinct advantages of the thermo-acoustic parameters in the particular mixture.

Evaluation of ultrasound techniques for brain injury detection

NASA Astrophysics Data System (ADS)

Mobley, Joel; Kasili, Paul M.; Norton, Stephen J.; Vo-Dinh, Tuan

1998-05-01

In this work, we examine the physics underlying wave propagation in the head to evaluate various ultrasonic transducers for use in a brian injury detection device. The results of measurements of the attenuation coefficient and phase velocity for ultrasonic propagation in samples of brain tissue and skull bone from sheep are presented. The material properties are then used to investigate the propagation of ultrasonic pressure fields in the head. The ultrasound fields for three different transducers are calculated for propagation in a simulated brain/skull model. The model is constructed using speed-of-sound and mass density values of the two tissue types. The impact of the attenuation on the ultrasound fields is then examined. Finally, the relevant points drawn from these discussions are summarized. We hope to minimize the confounding effects of the skull by using sub-MHz ultrasound while maintaining the necessary temporal and spatial resolution to successfully detect injury in the brain.

The design and experiment of a novel ultrasonic motor based on the combination of bending modes.

PubMed

Yan, Jipeng; Liu, Yingxiang; Liu, Junkao; Xu, Dongmei; Chen, Weishan

2016-09-01

This paper presents a new-type linear ultrasonic motor which takes advantage of the combination of two orthogonal bending vibration modes. The proposed ultrasonic motor consists of eight pieces of PZT ceramic plates and a metal beam that includes two cone-shaped horns and a cylindrical driving foot. The finite element analyses were finished to verify the working principle of the proposed motor. The mode shapes of the motor were obtained by modal analysis; the elliptical trajectories of nodes on the driving foot were obtained by time-domain analysis. Based on the analyses, a prototype of the proposed motor was fabricated and measured. The mechanical output characteristics were obtained by experiments. The maximal velocity of the proposed motor is 735mm/s and the maximal thrust is 1.1N. Copyright © 2016 Elsevier B.V. All rights reserved.

In situ assessment of structural timber elements of a historic building by infrared thermography and ultrasonic velocity

NASA Astrophysics Data System (ADS)

Kandemir-Yucel, A.; Tavukcuoglu, A.; Caner-Saltik, E. N.

2007-01-01

The infrared thermography (IRT) and the ultrasonic velocity measurements (UVM) promise to be particularly important to assess the state of deterioration and the adequacy of the boundary and microclimatic conditions for timber elements. These non-destructive methods supported by laboratory analyses of timber samples were conducted on a 13th century monument, Aslanhane Mosque in Ankara, Turkey. The combined interpretation of the results was done to assess the condition of structural timber elements in terms of their state of preservation, the dampness problems and the recent incompatible repairs affecting them. Results indicated that moist areas in the structure were associated with roof drainage problems and the repairs undertaken with cement-based mortars and plasters and oil-based paints. Juxtaposition of the IRT and UVM together with laboratory analyses was found to be useful to assess the soundness of timber, enhanced the accuracy and effectiveness of the survey and facilitated to build up the urgent and long-term conservation programs.

Online monitoring of cartilage tissue in a novel bioreactor

NASA Astrophysics Data System (ADS)

von der Burg, E.; von Buttlar, M.; Grill, W.

2011-04-01

Standard techniques for the analysis of biological tissues like immunohistochemical staining are typically invasive and lead to mortification of cells. Non-invasive monitoring is an important element of regenerative medicine because implants and components of implants should be 100% quality-checked with non-invasive and therefore also marker-free methods. We report on a new bioreactor for the production of collagen scaffolds seeded with Mesenchymal Stem Cells (MSCs). It contains a computer controlled mechanical activation and ultrasonic online monitoring and has been constructed for the in situ determination of ultrasonic and rheological parameters. During the cultivation period of about two weeks the scaffold is periodically compressed by two movable pistons for improved differentiation of the MSCs. This periodic compression beneficially ensures the supply with nutrition even inside the sample. During the physiological stimuli, rheological properties are measured by means of highly sensitive load cells. In addition measurements of the speed of sound in the sample and in the culture medium, with frequencies up to 16 MHz, are performed continuously. Therefore piezoceramic transducers are attached to the pistons and emit and detect ultrasonic waves, travelling through the pistons, the sample and the culture medium. The time-of-flight (TOF) of the ultrasonic signals is determined in real time with the aid of chirped excitation and correlation procedures with a resolution of at least 10 ps. The implemented ultrasonic measurement scheme allows beside the speed of sound measurements the detection of the distance between the pistons with a resolution better than 100 nm. The developed monitoring delivers information on rigidity, fluid dynamics and velocity of sound in the sample and in the culture medium. The hermetically sealed bioreactor with its life support system provides a biocompatible environment for MSCs for long time cultivation.

Comparison of Ultrasound with Tensile Testing of Thermally Damaged Polyimide Insulated Wiring (MIL-W-81381)

NASA Technical Reports Server (NTRS)

Madaras, Eric I.; Anastasi, Robert F.

2002-01-01

Ultrasonic measurements were performed on MIL-W-81381/7, /12, and /21 wire, a polyimide (Kapton) insulated wire. The phase velocity for the 20-gauge MIL-W-81381/7 wire had a baseline value of 3023 plus or minus 78 m/s. After exposure to high temperatures, the wire's phase velocity rapidly increased, and reached an asymptotic value of 3598 plus or minus 20 m/s after 100 hours exposure. Similar responses were measured in other gauges. The baseline measurements of Young's moduli resulted in values of 5636 plus or minus 486, 7714 plus or minus 505, and 8767 plus or minus 292 KSI for the 20 ga, 16 ga, and 12 ga. wires respectively.

Turbulence Measurements in a Tropical Zoo Hall

NASA Astrophysics Data System (ADS)

Eugster, Werner; Denzler, Basil; Bogdal, Christian

2017-04-01

The Masoala rainforest hall of the Zurich Zoo, Switzerland, covers a ground surface area of 10,856 m2 and reaches 30 m in height. With its transparent ETFE foiled roof it provides a tropical climate for a large diversity of plants and animals. In combination with an effort to estimate dry deposition of elemental mercury, we made an attempt to measure turbulent transfer velocity with an ultrasonic anemometer inside the hall. Not surprising, the largest turbulence elements were on the order of the hall dimension. Although the dimensions of the hall seem to be small (200,000 m3) for eddy covariance flux measurements and the air circulation inside the hall was extremely weak, the spectra of wind velocity components and virtual (sonic) temperature obeyed the general statistical description expected under unconstrained outdoor measurement conditions. We will present results from a two-week measurement campaign in the Masoala rainforest hall and make a suggestion for the deposition velocity to be used to estimate dry deposition of atmospheric components to the tropical vegetation surface.

Temperature dependent of viscoelasticity measurement on fat emulsion phantom using acoustic radiation force elasticity imaging method

PubMed Central

Xie, Peng; Wang, Mengke; Guo, Yanrong; Wen, Huiying; Chen, Xin; Chen, Siping; Lin, Haoming

2018-01-01

During the past two decades, tissue elasticity has been extensively studied and has been used in clinical disease diagnosis. But biological soft tissues are viscoelastic in nature. Therefore, they should be simultaneously characterized in terms of elasticity and viscosity. In addition, the mechanical properties of soft tissues are temperature dependent. However, how the temperature influences the shear wave dispersion and the viscoelasticity of soft tissue are still unclear. The aim of this study is to compare viscoelasticity of fat emulsion phantom with different temperature using acoustic radiation force elasticity imaging method. In our experiment, we produced four proportions of ultrasonic phantom by adding fat emulsion gelatin. Through adjusting the component of the fat emulsion, we change the viscoelasticity of the ultrasonic phantom. We used verasonics system to gather data and voigt model to fit the elasticity and viscosity value of the ultrasonic phantom we made. The influence of temperature to the ultrasonic phantom also measured in our study. The results show that the addition of fat emulsion to the phantom can increase the viscosity of the phantom, and the shear wave phase velocity decreases gradually at each frequency with the temperature increases, which provides a new material for the production of viscoelastic phantom. PMID:29758968

Real-time Monitoring Of Damage Evolution In Aerospace Materials Using Nonlinear Acoustics

NASA Astrophysics Data System (ADS)

Matikas, T. E.; Paipetis, A.; Kostopoulos, V.

2008-06-01

This work deals with the development of a novel non-destructive technique based on nonlinear acoustics, enabling real-time monitoring of material degradation in aerospace structures. When a sinusoidal ultrasonic wave of a given frequency and of sufficient amplitude is introduced into a nonlinear or an-harmonic solid, the fundamental wave distorts as it propagates, so that the second and higher harmonics of the fundamental frequency are generated. The measurement of the amplitude of these harmonics provides information on the coefficient of the second and higher order terms of the stress-strain relation for a nonlinear solid. It is demonstrated here that the material bulk nonlinear parameter for titanium alloy samples at different fatigue levels exhibits large changes compared to linear ultrasonic parameters such as velocity and attenuation. However, the use of bulk ultrasonic waves has serious disadvantages for the health monitoring of aerospace structures since it requires the placement of ultrasonic transducers on two, perfectly parallel, opposite sides of the samples. Such a setup is hardly feasible in real field conditions. For this reason, surface acoustic waves (SAW) were used in this study enabling the in-situ characterization of fatigue damage. The experimental setup for measuring the material nonlinear parameter using SAW was realised and the feasibility of the technique for health monitoring of aerospace structures was evaluated.

Temperature dependent of viscoelasticity measurement on fat emulsion phantom using acoustic radiation force elasticity imaging method.

PubMed

Xie, Peng; Wang, Mengke; Guo, Yanrong; Wen, Huiying; Chen, Xin; Chen, Siping; Lin, Haoming

2018-04-27

During the past two decades, tissue elasticity has been extensively studied and has been used in clinical disease diagnosis. But biological soft tissues are viscoelastic in nature. Therefore, they should be simultaneously characterized in terms of elasticity and viscosity. In addition, the mechanical properties of soft tissues are temperature dependent. However, how the temperature influences the shear wave dispersion and the viscoelasticity of soft tissue are still unclear. The aim of this study is to compare viscoelasticity of fat emulsion phantom with different temperature using acoustic radiation force elasticity imaging method. In our experiment, we produced four proportions of ultrasonic phantom by adding fat emulsion gelatin. Through adjusting the component of the fat emulsion, we change the viscoelasticity of the ultrasonic phantom. We used verasonics system to gather data and voigt model to fit the elasticity and viscosity value of the ultrasonic phantom we made. The influence of temperature to the ultrasonic phantom also measured in our study. The results show that the addition of fat emulsion to the phantom can increase the viscosity of the phantom, and the shear wave phase velocity decreases gradually at each frequency with the temperature increases, which provides a new material for the production of viscoelastic phantom.

Experimental measurements of seismic attenuation in microfracture sedimentary rock

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peacock, S.; McCann, C.; Sothcott, J.

1994-09-01

In a previous paper (Peacock et al., 1994), the authors related ultrasonic velocities in water-saturated Carrara Marble to crack densities in polished sections to verify Hudson's (1980, 1981, 1986) theory for velocities in cracked rock. They describe the empirical relationships between attenuation and crack density that they established during these experiments in the hope of clarifying the mechanism of attenuation in rocks with fluid-filled cracks. Relating seismic velocity and attenuation to crack density is important in predicting the productivity of fractured petroleum reservoirs such as the North Sea Brent Field. It also allows cracks to be used as stress indicatorsmore » throughout the shallow crust (Crampin and Lovell, 1991).« less

Time-resolved tomography using acoustic emissions in the laboratory, and application to sandstone compaction

NASA Astrophysics Data System (ADS)

Brantut, Nicolas

2018-02-01

Acoustic emission and active ultrasonic wave velocity monitoring are often performed during laboratory rock deformation experiments, but are typically processed separately to yield homogenised wave velocity measurements and approximate source locations. Here I present a numerical method and its implementation in a free software to perform a joint inversion of acoustic emission locations together with the three-dimensional, anisotropic P-wave structure of laboratory samples. The data used are the P-wave first arrivals obtained from acoustic emissions and active ultrasonic measurements. The model parameters are the source locations and the P-wave velocity and anisotropy parameter (assuming transverse isotropy) at discrete points in the material. The forward problem is solved using the fast marching method, and the inverse problem is solved by the quasi-Newton method. The algorithms are implemented within an integrated free software package called FaATSO (Fast Marching Acoustic Emission Tomography using Standard Optimisation). The code is employed to study the formation of compaction bands in a porous sandstone. During deformation, a front of acoustic emissions progresses from one end of the sample, associated with the formation of a sequence of horizontal compaction bands. Behind the active front, only sparse acoustic emissions are observed, but the tomography reveals that the P-wave velocity has dropped by up to 15%, with an increase in anisotropy of up to 20%. Compaction bands in sandstones are therefore shown to produce sharp changes in seismic properties. This result highlights the potential of the methodology to image temporal variations of elastic properties in complex geomaterials, including the dramatic, localised changes associated with microcracking and damage generation.

Ultrasonic and dielectric studies of polymer PDMS composites with ZnO and onion-like carbons nanoinclusions

NASA Astrophysics Data System (ADS)

Samulionis, V.; Macutkevic, J.; Banys, J.; Belovickis, J.; Shenderova, O.

2015-07-01

The ultrasonic and dielectric temperature investigations were performed in polydi- methylsiloxane (PDMS) with zinc oxide (ZnO) and onion-like carbon (OLC) nanocomposites. In the glass transition region, the ultrasonic velocity dispersion and large ultrasonic attenuation maxima were observed. The positions of ultrasonic attenuation peaks were slightly shifted to higher temperatures after doping PDMS with OLC and ZnO nanoparticles. The ultrasonic relaxation was compared to that of dielectric and such behaviour was described by Vogel- Fulcher law. The upshift of the glass transition temperature with addition of nanoparticles was confirmed by both methods. The additional increase of ultrasonic attenuation in composites doped with OLC and ZnO was observed at room temperature and such behaviour we attributed to ultrasound-nanofiller interaction in polymer matrix.

Velocimetry using scintillation of a laser beam for a laser-based gas-flux monitor

NASA Astrophysics Data System (ADS)

Kagawa, Naoki; Wada, Osami; Koga, Ryuji

1999-05-01

This paper describes a velocimetry system using scintillation of a laser-beam with spatial filters based on sensor arrays for a laser- based gas flux monitor. In the eddy correlation method, gas flux is obtained by mutual relation between the gas density and the flow velocity. The velocimetry system is developed to support the flow velocity monitor portion of the laser-based gas flux monitor with a long span for measurement. In order to sense not only the flow velocity but also the flow direction, two photo diode arrays are arranged with difference of a quarter period of the weighting function between them; the two output signals from the sensor arrays have phase difference of either (pi) /2 or -(pi) /2 depending on the sense of flow direction. In order to obtain the flow velocity and the flow direction instantly, an electronic apparatus built by the authors extracts frequency and phase from crude outputs of the pair of sensors. A feasibility of the velocimetry was confirmed indoors by measurement of the flow- velocity vector of the convection. Measured flow-velocity vector of the upward flow agreed comparatively with results of an ultrasonic anemometer.

An investigation on characterizing dense coal-water slurry with ultrasound: theoretical and experimental method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xue, M.H.; Su, M.X.; Dong, L.L.

2010-07-01

Particle size distribution and concentration in particulate two-phase flow are important parameters in a wide variety of industrial areas. For the purpose of online characterization in dense coal-water slurries, ultrasonic methods have many advantages such as avoiding dilution, the capability for being used in real time, and noninvasive testing, while light-based techniques are not capable of providing information because optical methods often require the slurry to be diluted. In this article, the modified Urick equation including temperature modification, which can be used to determine the concentration by means of the measurement of ultrasonic velocity in a coal-water slurry, is evaluatedmore » on the basis of theoretical analysis and experimental study. A combination of the coupled-phase model and the Bouguer-Lambert-Beer law is employed in this work, and the attenuation spectrum is measured within the frequency region from 3 to 12 MHz. Particle size distributions of the coal-water slurry at different volume fractions are obtained with the optimum regularization technique. Therefore, the ultrasonic technique presented in this work brings the possibility of using ultrasound for online measurements of dense slurries.« less

Further testing and development of simulation models for UT inspections of armor

NASA Astrophysics Data System (ADS)

Margetan, Frank J.; Richter, Nathaniel; Thompson, R. Bruce

2012-05-01

In previous work we introduced an approach for simulating ultrasonic pulse/echo immersion inspections of multi-layer armor panels. Model inputs include the thickness, density, velocity and attenuation of each armor layer, the focal properties of the transducer, and a measured calibration signal. The basic model output is a response-versus-time waveform (ultrasonic A-scan) which includes echoes from all interfaces including those arising from reverberations within layers. Such A-scans can be predicted both for unflawed panels and panels containing a large disbond at any given interface. In this paper we continue our testing of the simulation software, applying it now to an armor panel consisting of SiC ceramic tiles fully embedded in a titanium-alloy matrix. An interesting specimen of such armor became available in which some tile/metal interfaces appear to be well bonded, while others have disbonded areas of various sizes. We compare measured and predicted A-scans for UT inspections, and also demonstrate an extension of the model to predict ultrasonic C-scans over regions containing a small, isolated disbond.

Application of Ultrasonic Guided Waves for Evaluating Aging Wire Insulation

NASA Technical Reports Server (NTRS)

Anastasi, Robert F.; Madaras, Eric I.

2005-01-01

Aging wiring has become a critical issue to the aerospace and aircraft industries due to Shuttle and aircraft incidents. The problem is that over time the insulation on wire becomes brittle and cracks. This exposes the underlying conductive wire to the potential for short circuits and fire. Popular methods of monitoring aging wire problems focuses on applying electrical sensing techniques that are sensitive to the conductor's condition, but not very sensitive to the wire insulation's condition. Measurement of wire insulation stiffness and ultrasonic properties by ultrasonic guided waves is being examined. Experimental measurements showed that the lowest order extensional mode could be sensitive to stiffness changes in the wire insulation. To test this theory conventional wire samples were heat damaged in an oven, in a range of heating conditions. The samples were 12, 16, and 20 gauge and the heat damage introduced material changes in the wire insulation that made the originally flexible insulation brittle and darker in color. Results showed that extensional mode phase velocity increased for the samples that were exposed to heat for longer duration.

Topography of Acoustical Properties of Long Bones: From Biomechanical Studies to Bone Health Assessment

PubMed Central

Tatarinov, Alexey; Sarvazyan, Armen

2010-01-01

The article presents a retrospective view on the assessment of long bones condition using topographical patterns of the acoustic properties. The application of ultrasonic point-contact transducers with exponential waveguides on a short acoustic base for detailed measurements in human long bones by the surface transmission was initiated during the 1980s in Latvia. The guided wave velocity was mapped on the surface of the long bones and the topographical patterns reflected the biomechanical peculiarities. Axial velocity profiles obtained in vivo by measurements along the medial surface of tibia varied due to aging, hypokinesia, and physical training. The method has been advanced at Artann Laboratories (West Trenton, NJ) by the introduction of multifrequency data acquisition and axial scanning. The model studies carried out on synthetic phantoms and in bone specimens confirmed the potential to evaluate separately changes of the bone material properties and of the cortical thickness by multifrequency acoustic measurements at the 0.1 to 1 MHz band. The bone ultrasonic scanner (BUSS) is an axial mode ultrasonometer developed to depict the acoustic profile of bone that will detect the onset of bone atrophy as a spatial process. Clinical trials demonstrated a high sensitivity of BUSS to osteoporosis and the capability to assess early stage of osteopenia. PMID:18599416

Noninvasive characterization of a flowing multiphase fluid using ultrasonic interferometry

DOEpatents

Sinha, Dipen N.

2003-11-11

An apparatus for noninvasively monitoring the flow and/or the composition of a flowing liquid using ultrasound is described. The position of the resonance peaks for a fluid excited by a swept-frequency ultrasonic signal have been found to change frequency both in response to a change in composition and in response to a change in the flow velocity thereof. Additionally, the distance between successive resonance peaks does not change as a function of flow, but rather in response to a change in composition. Thus, a measurement of both parameters (resonance position and resonance spacing), once calibrated, permits the simultaneous determination of flow rate and composition using the apparatus and method of the present invention.

Non-Invasive Characterization Of A Flowing Multi-Phase Fluid Using Ultrasonic Interferometry

DOEpatents

Sinha, Dipen N.

2005-11-01

An apparatus for noninvasively monitoring the flow and/or the composition of a flowing liquid using ultrasound is described. The position of the resonance peaks for a fluid excited by a swept-frequency ultrasonic signal have been found to change frequency both in response to a change in composition and in response to a change in the flow velocity thereof. Additionally, the distance between successive resonance peaks does not change as a function of flow, but rather in response to a change in composition. Thus, a measurement of both parameters (resonance position and resonance spacing), once calibrated, permits the simultaneous determination of flow rate and composition using the apparatus and method of the present invention.

Noninvasive Characterization Of A Flowing Multiphase Fluid Using Ultrasonic Interferometry

DOEpatents

Sinha, Dipen N.

2005-05-10

An apparatus for noninvasively monitoring the flow and/or the composition of a flowing liquid using ultrasound is described. The position of the resonance peaks for a fluid excited by a swept-frequency ultrasonic signal have been found to change frequency both in response to a change in composition and in response to a change in the flow velocity thereof. Additionally, the distance between successive resonance peaks does not change as a function of flow, but rather in response to a change in composition. Thus, a measurement of both parameters (resonance position and resonance spacing), once calibrated, permits the simultaneous determination of flow rate and composition using the apparatus and method of the present invention.

Noninvasive characterization of a flowing multiphase fluid using ultrasonic interferometry

DOEpatents

Sinha, Dipen N [Los Alamos, NM

2007-06-12

An apparatus for noninvasively monitoring the flow and/or the composition of a flowing liquid using ultrasound is described. The position of the resonance peaks for a fluid excited by a swept-frequency ultrasonic signal have been found to change frequency both in response to a change in composition and in response to a change in the flow velocity thereof. Additionally, the distance between successive resonance peaks does not change as a function of flow, but rather in response to a change in composition. Thus, a measurement of both parameters (resonance position and resonance spacing), once calibrated, permits the simultaneous determination of flow rate and composition using the apparatus and method of the present invention.

Floquet wave ultrasonic method for determination of single ply moduli in multidirectional composites.

PubMed

Wang, L; Rokhlin, S I

2002-09-01

An inversion method based on Floquet wave velocity in a periodic medium has been introduced to determine the single ply elastic moduli of a multi-ply composite. The stability of this algorithm is demonstrated by numerical simulation. The applicability of the plane wave approximation to the velocity measurement in the double-through-transmission self-reference method has been analyzed using a time-domain beam model. It shows that the finite width of the transmitter affects only the amplitudes of the signals and has almost no effect on the time delay. Using this method, the ply moduli for a multiply composite have been experimentally determined. While the paper focuses on elastic constant reconstruction from phase velocity measurements by the self-reference double-through-transmission method, the reconstruction methodology is also applicable to assessment of data collected by other methods.

Photo-acoustic excitation and detection of guided ultrasonic waves in bone samples covered by a soft coating layer

NASA Astrophysics Data System (ADS)

Zhao, Zuomin; Moilanen, Petro; Karppinen, Pasi; Määttä, Mikko; Karppinen, Timo; Hæggström, Edward; Timonen, Jussi; Myllylä, Risto

2012-12-01

Photo-acoustic (PA) excitation was combined with skeletal quantitative ultrasound (QUS) for multi-mode ultrasonic assessment of human long bones. This approach permits tailoring of the ultrasonic excitation and detection so as to efficiently detect the fundamental flexural guided wave (FFGW) through a coating of soft tissue. FFGW is a clinically relevant indicator of cortical thickness. An OPO laser with tunable optical wavelength, was used to excite a photo-acoustic source in the shaft of a porcine femur. Ultrasonic signals were detected by a piezoelectric transducer, scanning along the long axis of the bone, 20-50 mm away from the source. Five femurs were measured without and with a soft coating. The coating was made of an aqueous gelatin-intralipid suspension that optically and acoustically mimicked real soft tissue. An even coating thickness was ensured by using a specific mold. The optical wave length of the source (1250 nm) was tuned to maximize the amplitude of FFGW excitation at 50 kHz frequency. The experimentally determined FFGW phase velocity in the uncoated samples was consistent with that of the fundamental antisymmetric Lamb mode (A0). Using appropriate signal processing, FFGW was also identified in the coated bone samples, this time with a phase velocity consistent with that theoretically predicted for the first mode of a fluid-solid bilayer waveguide (BL1). Our results suggest that photo-acoustic quantitative ultrasound enables assessment of the thickness-sensitive FFGW in bone through a layer of soft tissue. Photo-acoustic characterization of the cortical bone thickness may thus become possible.

Lamb wave dispersion and anisotropy profiling of composite plates via non-contact air-coupled and laser ultrasound

NASA Astrophysics Data System (ADS)

Harb, M. S.; Yuan, F. G.

2015-03-01

Conventional ultrasound inspection has been a standard non-destructive testing method for providing an in-service evaluation and noninvasive means of probing the interior of a structure. In particular, measurement of the propagation characteristics of Lamb waves allows inspection of plates that are typical components in aerospace industry. A rapid, complete non-contact hybrid approach for excitation and detection of Lamb waves is presented and applied for non-destructive evaluation of composites. An air-coupled transducer (ACT) excites ultrasonic waves on the surface of a composite plate, generating different propagating Lamb wave modes and a laser Doppler vibrometer (LDV) is used to measure the out-of-plane velocity of the plate. This technology, based on direct waveform imaging, focuses on measuring dispersive curves for A0 mode in a composite laminate and its anisotropy. A two-dimensional fast Fourier transform (2D-FFT) is applied to out-of-plane velocity data captured experimentally using LDV to go from the time-spatial domain to frequency-wavenumber domain. The result is a 2D array of amplitudes at discrete frequencies and wavenumbers for A0 mode in a given propagation direction along the composite. The peak values of the curve are then used to construct frequency wavenumber and phase velocity dispersion curves, which are also obtained directly using Snell's law and the incident angle of the excited ultrasonic waves. A high resolution and strong correlation between numerical and experimental results are observed for dispersive curves with Snell's law method in comparison to 2D-FFT method. Dispersion curves as well as velocity curves for the composite plate along different directions of wave propagation are measured. The visual read-out of the dispersion curves at different propagation directions as well as the phase velocity curves provide profiling and measurements of the composite anisotropy. The results proved a high sensitivity of the air-coupled and laser ultrasound technique in non-contact characterization of Lamb wave dispersion and material anisotropy of composite plates using simple Snell's law method.

Evaluation of interlayer interfacial stiffness and layer wave velocity of multilayered structures by ultrasonic spectroscopy.

PubMed

Ishii, Yosuke; Biwa, Shiro

2014-07-01

An ultrasonic evaluation procedure for the interlayer interfacial normal stiffness and the intralayer longitudinal wave velocity of multilayered plate-like structures is proposed. Based on the characteristics of the amplitude reflection spectrum of ultrasonic wave at normal incidence to a layered structure with spring-type interlayer interfaces, it is shown that the interfacial normal stiffness and the longitudinal wave velocity in the layers can be simultaneously evaluated from the frequencies of local maxima and minima of the spectrum provided that all interfaces and layers have the same properties. The effectiveness of the proposed procedure is investigated from the perspective of the sensitivity of local extremal frequencies of the reflection spectrum. The feasibility of the proposed procedure is also investigated when the stiffness of each interface is subjected to small random fluctuations about a certain average value. The proposed procedure is applied to a 16-layered cross-ply carbon-fiber-reinforced composite laminate. The normal stiffness of resin-rich interfaces and the longitudinal wave velocity of plies in the thickness direction evaluated from the experimental reflection spectrum are shown to be consistent with simple theoretical estimations.

Effect of flow velocity on the photoacoustic detection for glucose aqueous solutions

NASA Astrophysics Data System (ADS)

Ren, Zhong; Liu, Guodong; Ding, Yu; Yao, Qingkai

2018-01-01

The blood glucose non-invasive detection has become the research hot-spot. The photoacoustic spectroscopy is a well-promising, high-efficient and noninvasive detection method because it combines the advantages of the pure optic and pure ultrasonic. In practice, the photoacoustic detection of blood glucose is impacted by many factors because the human body is a complicated bio-system. To study the effect of flow velocity in the blood vessel on the photoacoustic detection of blood glucose, a photoacoustic detection system based on optical parameter oscillator (OPO) pulsed laser induced ultrasonic was established. In this system, a 532nm pumped Nd: YAG OPO pulsed laser was used as the excitation source, and the photoacoustic signals of glucose were captured by ultrasonic transducer. Moreover, a set of blood circulation system was built to simulate the real blood flow situation in the human body. The experiments of the photoacoustic detection of glucose aqueous solutions with different concentrations at different flow velocities were experimentally investigated. Experimental results show that the photoacoustic peak-to-peak value linearly increases with the glucose concentration, but it decreases with the increase of the flow velocity although the profiles of photoacoustic signals don't change.

Influence of power density on polymerization behavior and bond strengths of dual-cured resin direct core foundation systems.

PubMed

Oto, Tatsuki; Yasuda, Genta; Tsubota, Keishi; Kurokawa, Hiroyasu; Miyazaki, Masashi; Platt, Jeffrey A

2009-01-01

This study examined the influence of power density on dentin bond strength and polymerization behavior of dual-cured direct core foundation resin systems. Two commercially available dual-cured direct core foundation resin systems, Clearfil DC Core Automix with Clearfil DC Bond and UniFil Core with Self-Etching Bond, were studied. Bovine mandibular incisors were mounted in autopolymerizing resin and the facial dentin surfaces were ground wet on 600-grit SiC paper. Dentin surfaces were treated according to manufacturer's recommendations. The resin pastes were condensed into the mold and cured with the power densities of 0 (no irradiation), 100, 200, 400 and 600 mW/cm2. Ten specimens per group were stored in 37 degrees C water for 24 hours, then shear tested at a crosshead speed of 1.0 mm/minute in a universal testing machine. An ultrasonic measurement device was used to measure the ultrasonic velocities through the core foundation resins. The power densities selected were 0 (no irradiation), 200, and 600 mW/cm2, and ultrasonic velocity was calculated. ANOVA and Tukey HSD tests were performed at a level of 0.05. The highest bond strengths were obtained when the resin pastes were cured with the highest power density for both core foundation systems (16.8 +/- 1.9 MPa for Clearfil DC Core Automix, 15.6 +/- 2.9 MPa for UniFil Core). When polymerized with the power densities under 200 mW/cm2, significantly lower bond strengths were observed compared to those obtained with the power density of 600 mW/cm2. As the core foundation resins hardened, the sonic velocities increased and this tendency differed among the power density of the curing unit. When the sonic velocities at three minutes after the start of measurements were compared, there were no significant differences among different irradiation modes for UniFil Core, while a significant decrease in sonic velocity was obtained when the resin paste was chemically polymerized compared with dual-polymerization for Clearfil DC Core Automix. The data suggests that the dentin bond strengths and polymerization behavior of the dual-cured, direct core foundation systems are still affected by the power density of the curing unit. With a careful choice of the core foundation systems and power density of the curing unit, the benefit of using resin composites to endodontically-treated teeth might be acceptable.

Simple model for piezoelectric ceramic/polymer 1-3 composites used in ultrasonic transducer applications.

PubMed

Chan, H W; Unsworth, J

1989-01-01

A theoretical model is presented for combining parameters of 1-3 ultrasonic composite materials in order to predict ultrasonic characteristics such as velocity, acoustic impedance, electromechanical coupling factor, and piezoelectric coefficients. Hence, the model allows the estimation of resonance frequencies of 1-3 composite transducers. This model has been extended to cover more material parameters, and they are compared to experimental results up to PZT volume fraction nu of 0.8. The model covers calculation of piezoelectric charge constants d(33) and d(31). Values are found to be in good agreement with experimental results obtained for PZT 7A/Araldite D 1-3 composites. The acoustic velocity, acoustic impedance, and electromechanical coupling factor are predicted and found to be close to the values determined experimentally.

Non-destructive investigations at the Dionisiac Frieze in the Villa of Mysteries, Pompeii

NASA Astrophysics Data System (ADS)

Cristiano, Luigia; Erkul, Ercan; Jepsen, Kalle; Meier, Thomas; Vanacore, Stefano; Stefani, Grete

2014-05-01

The Villa of Mysteries with its Dionisiac Frieze is one of the well-known buildings of ancient Pompeii. It has been excavated in the early 20th century. Since then many initiatives have been taken for its preservation. Currently, the Frieze is investigated in detail and tests have been made to clean the wall paintings. Non-destructive investigations as infrared thermography (IR), Ground penetrating radar (GPR), and ultrasonic measurements have been performed in order to test if these methods are well suited to reveal the walls' and paintings' structure and to identify the detachments or cracks. IR, GPR and ultrasonic measurements have different penetration capabilities and resolution in depths. So, using these three methods simultaneously can improve the knowledge of the investigated structures at several depths from millimetres and centimetres to metres. It has been tested if detachments of the paintings, cracks, or alterations of the paintings can be detected by passive and active IR measurements. 6 passive and 3 active measurements have been conducted on the Dionisiac Frieze. Lateral temperature differences present at the Frieze are mapped by passive measurements. Here, we show that temperature differences up to about 0.3°C are present and detectable. These small changes in temperature may be related to detachments, cracks, or wet areas. By active IR measurements the paintings are artificially heated by about 1°C and the cooling to normal temperature is observed and analyzed. Lateral differences in the heating and cooling behavior are related to variability in the heat absorption properties and in thermal conductivity. It is shown that detachments as well as restorative treatments are associated with changes in the thermal behavior. In order to image the construction and the condition of the investigated walls, Ground Penetrating Radar (GPR) was measured with a 2 GHz antenna. Each profile was 1.2 m long, the spacing cross-line was 3 cm and in-line 1 mm. The vertical sections contain reflection horizons of the plaster layer, the second wall layer and the back wall. Additional diffractions of objects with high differences in electrical properties i.e. bricks, cavities, cracks enables to estimate the travelling velocity of electromagnetic waves and the deep penetration. In addition, calculated time slices show areas with concentrated high and low reflection energy of different depth layers of the wall inside structure, which can related to changes in the composition and the water saturation. Ultrasonic experiments with frequencies between about 5 kHz and 500 kHz may be applied to non-destructive testing of structures made of natural stone for example facades, engineering structures, Usually, traveltimes of first-arriving P-waves are measured in ultrasonic transmission experiments. The resolution for changes of uppermost structures in transmission configuration is however limited. Therefore, we firstly perform surface measurements and secondly the full waveform is investigated. That means source and receiver are coupled to nearly plane parts of the object's surface and the receiver is moved along profiles with lengths between about 10 cm to 30 cm. These measurements are simple to perform because the object under consideration has to be accessible only from one side and the source and receiver configuration is easier to control. In this configuration, P-waves show generally very low signal-to-noise ratios but surface waves propagating along the free surface - here Rayleigh waves - show large amplitudes and are well suited for the investigation of superficial layering. Furthermore, surface wave dispersion is sensitive also to gradual changes of the structure with depth as usually present in real structures. This is another advantage of ultrasonic surface wave studies as body waves are not reflected by gradual internal changes in the structure and methods based on reflected body waves may not be applied in these cases. Here, we show examples for ultrasonic surface measurements that are generally of high quality. Forward modelling and inversion of ultrasonic waveforms reveal strong changes of the material properties with depth: in the upper millimetres, high shear-wave velocities are observed while the plaster below is characterized by much lower shear-wave velocities. The paintings form a layer of about 3 mm to 6 mm thickness with larger strength than the underlying plaster. Furthermore, a pronounced lateral changes in the properties of the paintings are detected by the strong variability of the ultrasonic surface measurements. They are caused by changes in the structure of the paintings as well as by alterations as detachments or cracks.

Novel characterization method for fibrous materials using non-contact acoustics: material properties revealed by ultrasonic perturbations.

PubMed

Periyaswamy, Thamizhisai; Balasubramanian, Karthikeyan; Pastore, Christopher

2015-02-01

Fibrous materials are unique hierarchical complex structures exhibiting a range of mechanical, thermal, optical and electrical properties. The inherent discontinuity at micro and macro levels, heterogeneity and multi-scale porosity differentiates fibrous materials from other engineering materials that are typically continuum in nature. These structural complexities greatly influence the techniques and modalities that can be applied to characterize fibrous materials. Typically, the material response to an applied external force is measured and used as a characteristic number of the specimen. In general, a range of equipment is in use to obtain these numbers to signify the material properties. Nevertheless, obtaining these numbers for materials like fiber ensembles is often time consuming, destructive, and requires multiple modalities. It is hypothesized that the material response to an applied acoustic frequency would provide a robust alternative characterization mode for rapid and non-destructive material analysis. This research proposes applying air-coupled ultrasonic acoustics to characterize fibrous materials. Ultrasonic frequency waves transmitted through fibrous assemblies were feature extracted to understand the correlation between the applied frequency and the material properties. Mechanical and thermal characteristics were analyzed using ultrasonic features such as time of flight, signal velocity, power and the rate of attenuation of signal amplitude. Subsequently, these temporal and spectral characteristics were mapped with the standard low-stress mechanical and thermal properties via an empirical artificial intelligence engine. A high correlation of >0.92 (S.D. 0.06) was observed between the ultrasonic features and the standard measurements. The proposed ultrasonic technique can be used toward rapid characterization of dynamic behavior of flexible fibrous assemblies. Copyright © 2014 Elsevier B.V. All rights reserved.

Evaluation of stress and saturation effects on seismic velocity and electrical resistivity - laboratory testing of rock samples

NASA Astrophysics Data System (ADS)

Vilhelm, Jan; Jirků, Jaroslav; Slavík, Lubomír; Bárta, Jaroslav

2016-04-01

Repository, located in a deep geological formation, is today considered the most suitable solution for disposal of spent nuclear fuel and high-level waste. The geological formations, in combination with an engineered barrier system, should ensure isolation of the waste from the environment for thousands of years. For long-term monitoring of such underground excavations special monitoring systems are developed. In our research we developed and tested monitoring system based on repeated ultrasonic time of flight measurement and electrical resistivity tomography (ERT). As a test site Bedřichov gallery in the northern Bohemia was selected. This underground gallery in granitic rock was excavated using Tunnel Boring Machine (TBM). The seismic high-frequency measurements are performed by pulse-transmission technique directly on the rock wall using one seismic source and three receivers in the distances of 1, 2 and 3 m. The ERT measurement is performed also on the rock wall using 48 electrodes. The spacing between electrodes is 20 centimeters. An analysis of relation of seismic velocity and electrical resistivity on water saturation and stress state of the granitic rock is necessary for the interpretation of both seismic monitoring and ERT. Laboratory seismic and resistivity measurements were performed. One series of experiments was based on uniaxial loading of dry and saturated granitic samples. The relation between stress state and ultrasonic wave velocities was tested separately for dry and saturated rock samples. Other experiments were focused on the relation between electrical resistivity of the rock sample and its saturation level. Rock samples with different porosities were tested. Acknowledgments: This work was partially supported by the Technology Agency of the Czech Republic, project No. TA 0302408

Ultrasound Velocity Measurements in High-Chromium Steel Under Plastic Deformation

NASA Astrophysics Data System (ADS)

Lunev, Aleksey; Bochkareva, Anna; Barannikova, Svetlana; Zuev, Lev

2016-04-01

In the present study, the variation of the propagation velocity of ultrasound in the plastic deformation of corrosion-resistant high-chromium steel 40X13 with ferrite-carbide (delivery status), martensitic (quenched) and sorbitol (after high-temperature tempering) structures have beem studied/ It is found that each state shows its view of the loading curve. In the delivery state diagram loading is substantially parabolic throughout, while in the martensitic state contains only linear strain hardening step and in the sorbitol state the plastic flow curve is three-step. The velocity of ultrasonic surface waves (Rayleigh waves) was measured simultaneously with the registration of the loading curve in the investigated steel in tension. It is shown that the dependence of the velocity of ultrasound in active loading is determined by the law of plastic flow, that is, the staging of the corresponding diagram of loading. Structural state of the investigated steel is not only changing the type of the deformation curve under uniaxial tension, but also changes the nature of ultrasound speed of deformation.

Analysis of Critically Refracted Longitudinal and Lamb Waves for Stress Characterization

NASA Astrophysics Data System (ADS)

Pei, Ning

The global production of metal, in particular, steel and aluminum keeps increasing. This material is used with various fabrication processes, such as, welding, forging, and rolling that can induce stresses in the material that can subsequently impact product performance and cause phenomena such as cracking and corrosion. When investigating plate materials it is necessary to map both texture and stress under a range of loading conditions. To address these needs a wide range of both destructive and nondestructive tools have been used. One family of methods are those based on ultrasonic measurements that relate ultrasonic velocity to properties, in particular stress. Two particular challenges are faced which are the relative insensitivity of compression and shear waves to stress and that there are also other factors which can also change velocity and these are temperature, texture and grain size. This project focused on an analysis of ultrasonic velocity measurements and specifically ways to improve performance and capabilities for stress characterization. Two approaches were considered and are reported: the critically refracted ultrasonic longitudinal (LCR) wave and higher order Lamb waves. The LCR wave method was modelled and optimized based on the fact that the sensitivity between waves and stress can reach maximum when they propagate in the same direction. However, in reality this wave typically propagates at an angle to stress, which will decrease its sensitivity. This thesis reports a numerical model used to investigate the transducers parameters that can influence the directivity of the LCR wave and hence enable performance optimization when used for industrial applications. An orthogonal test method is used to study the transducer parameters which influence the LCR wave beams and this method provides a design tool that can be used to study and optimize multiple parameter experiments and identify which parameter or parameters are of most significance. The example considered simulation of the acoustic field in a 2-D water-steel model is obtained using a Spatial Fourier Analysis method. The significance of the effects of incident angle, the aperture and the center frequency of the transducer were studied. Results show that the aperture, the center frequency and the incident angle are the most important factors in controlling the directivity of the resulting LCR wave fields.

Ultrasonic monitoring of spontaneous imbibition experiments: Precursory moisture diffusion effects ahead of water front

NASA Astrophysics Data System (ADS)

David, Christian; Sarout, Joël.; Dautriat, Jérémie; Pimienta, Lucas; Michée, Marie; Desrues, Mathilde; Barnes, Christophe

2017-07-01

Fluid substitution processes have been investigated in the laboratory on 14 carbonate and siliciclastic reservoir rock analogues through spontaneous imbibition experiments on vertical cylindrical specimens with simultaneous ultrasonic monitoring and imaging. The motivation of our study was to identify the seismic attributes of fluid substitution in reservoir rocks and to link them to physical processes. It is shown that (i) the P wave velocity either decreases or increases when the capillary front reaches the Fresnel clearance zone, (ii) the P wave amplitude is systematically impacted earlier than the velocity is, (iii) this precursory amplitude decrease occurs when the imbibition front is located outside of the Fresnel zone, and (iv) the relative variation of the P wave amplitude is always much larger than that of the P wave velocity. These results suggest that moisture diffuses into the pore space ahead of the water front. This postulate is further supported by a quantitative analysis of the time evolution of the observed P wave amplitudes. In a sense, P wave amplitude acts as a precursor of the arrival of the capillary front. This phenomenon is used to estimate the effective diffusivity of moisture in the tested rocks. The effective moisture diffusivity estimated from the ultrasonic data is strongly correlated with permeability: a power law with exponent 0.96 predicts permeability from ultrasonic monitoring within a factor 3 without noticeable bias. When the effective diffusivity is high, moisture diffusion affects ultrasonic P wave attributes even before the imbibition starts and impacts the P wave reflectivity as evidenced by the variations recorded in the waveform coda.

Instantaneous stroke volume in man during lower body negative pressure /LBNP/

NASA Technical Reports Server (NTRS)

Loeppky, J. A.; Richards, K. L.; Greene, E. R.; Eldridge, M. W.; Hoekenga, D. E.; Venters, M. D.; Luft, U. C.

1982-01-01

Results of an examination of the instantaneous time course of the stroke volume (SV) and cardiac output (Q) in response to the onset and release of -50 torr lower body negative pressure (LBNP) are reported. Six male subjects were sealed into a LBNP box up to the iliac crest while being monitored by echocardiograph for centerlamina blood velocity, fluid displacement, stroke volume, heart rate, and leg volume. Particular use was made of pulsed ultrasonic Doppler velocity meters for measuring the blood velocities and flow dynamics. Measurements were made of the subjects continuously beginning from 20 sec prior to and one min after LBNP onset and release. A linear fall in the SV was observed with LBNP at 49% of the baseline value after 33 sec. A 62% drop, the lowest, was detected after 8 min of LBNP. The leg volume was inversely related to Q for the duration of the experiment.

In vivo noninvasive method for measuring local wave velocity in femoral arteries of pig

NASA Astrophysics Data System (ADS)

Zhang, Xiaoming; Kinnick, Randall; Pislaru, Cristina; Fatemi, Mostafa; Greenleaf, James

2005-09-01

We have proposed generating a bending wave in the arterial wall using ultrasound radiation force and measuring the wave velocity along the arterial wall [Zhang et al., IEEE Trans. Ultrason. Ferroelectr. Freq. Control 52, 642-652 (2005)]. Here, we report the results of in vivo studies on pigs. The pig was anesthetized, and a micromanometer tip catheter was inserted into the femoral artery to measure luminal pressure. A water bath was created on the animal's groin to allow unimpeded access of the ultrasound beams to the femoral artery. The femoral artery was first located using a 13-MHz linear-array transducer. Then, a vibro-acoustography image was obtained to ensure precise positioning of the excitation force relative to the artery. The artery was excited by the force transducer and the resulting vibration of the arterial wall was measured by a sensing Doppler transceiver. Measured wave velocity was 3.1 m/s at 300 Hz. With this new method wave velocity over a distance of 5 mm, and therefore stiffness of arteries, can be measured locally and non-invasively. Measurement time is short in a few tens of milliseconds, which allows pressure dependence and pharmacological effect on the wall properties to be measured at different cardiac times.

Ultrasonic Seismic Wave Elastic Moduli and Attenuation, Petro physical Models and Work Flows for Better Subsurface Imaging Related to Monitoring of Sequestrated Supercritical CO2 and Geothermal Energy Exploration

NASA Astrophysics Data System (ADS)

Harbert, W.; Delaney, D.; Mur, A. J.; Purcell, C.; Zorn, E.; Soong, Y.; Crandall, D.; Haljasmaa, I.

2016-12-01

To better understand the petrophysical response at ultrasonic frequencies in rhyolite and carbonate (relevant to CO2 storage and CO2 enhanced oil recovery) lithologies we conducted core analysis incorporating variation in temperature, effective pressure and pore filling fluid. Ultrasonic compressive and shear wave (VP, VS1 and VS2) velocities were measured allowing calculation of the Bulk modulus (K), Young's modulus (E), Lamè's first parameter (λ), Shear modulus (G), Poisson's ratio (ν), and P-wave modulus (M). In addition, from the ultrasonic waveform data collected, we employed the spectral ratio method to estimate the quality factor. Carbonate samples were tested dry, using atmospheric gas as the pore phase, and with deionized water, oil, and supercritical CO2. We observed that Qp was directly proportional to effective pressure in our rhyolite samples. In addition, we observed effects of core anisotropy on Qp, however this was not apparent in higher porosity samples. Increasing effective pressure seems to decrease the effects of ultrasonic P-wave anisotropy. Qp was inversely proportional to temperature, however this was not observed for higher porosity samples. Qp was highly dependent on the rock porosity. Higher porosity samples displayed significantly lower values of Qp. In our experiments we observed that ultrasonic wave scattering due to heterogeneities in the carbonate samples was dominant. Although we observed lower μρ values, trends in our data strongly agreed with the model proposed workers interpreting AVO trends in a LMR cross plot space. We found that μρ was proportional to temperature while λρ was temperature independent and that λρ-μρ trends were extremely dependent on porosity. Higher porosity results in lower values for both λρ and μρ. The presence of fluids causes a distinct shift in λρ values, an observation which could provide insight into subsurface exploration using amplitude variation with offset (AVO) classification. We present approaches to incorporate these laboratory results into well log calibrated MATLAB based Gassmann-Biot fluid substitution models incorporating compliant porosity, Thomsen parameters models that utilize orthorhombic velocity anisotropy to predict seismic responses.

Time-resolved tomography using acoustic emissions in the laboratory, and application to sandstone compaction

NASA Astrophysics Data System (ADS)

Brantut, Nicolas

2018-06-01

Acoustic emission (AE) and active ultrasonic wave velocity monitoring are often performed during laboratory rock deformation experiments, but are typically processed separately to yield homogenized wave velocity measurements and approximate source locations. Here, I present a numerical method and its implementation in a free software to perform a joint inversion of AE locations together with the 3-D, anisotropic P-wave structure of laboratory samples. The data used are the P-wave first arrivals obtained from AEs and active ultrasonic measurements. The model parameters are the source locations and the P-wave velocity and anisotropy parameter (assuming transverse isotropy) at discrete points in the material. The forward problem is solved using the fast marching method, and the inverse problem is solved by the quasi-Newton method. The algorithms are implemented within an integrated free software package called FaATSO (Fast Marching Acoustic Emission Tomography using Standard Optimisation). The code is employed to study the formation of compaction bands in a porous sandstone. During deformation, a front of AEs progresses from one end of the sample, associated with the formation of a sequence of horizontal compaction bands. Behind the active front, only sparse AEs are observed, but the tomography reveals that the P-wave velocity has dropped by up to 15 per cent, with an increase in anisotropy of up to 20 per cent. Compaction bands in sandstones are therefore shown to produce sharp changes in seismic properties. This result highlights the potential of the methodology to image temporal variations of elastic properties in complex geomaterials, including the dramatic, localized changes associated with microcracking and damage generation.

Ultrasonic sensing of powder densification

NASA Technical Reports Server (NTRS)

Lu, Yichi; Wadley, Haydn N. G.; Parthasarathi, Sanjai

1992-01-01

An independent scattering theory has been applied to the interpretation of ultrasonic velocity measurements made on porous metal samples produced either by a cold or a high-temperature compaction process. The results suggest that the pores in both processes are not spherical, an aspect ration of 1:3 fitting best with the data for low (less than 4 percent) pore volume fractions. For the hot compacted powders, the pores are smooth due to active diffusional processes during processing. For these types of voids, the results can be extended to a pore fraction of 10 percent, at which point voids form an interconnected network that violates the model assumptions. The cold pressed samples are not as well predicted by the theory because of poor particle bonding.

Ultrasonic flowmeters offer oil line leak-detection potential

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hettrich, U.

1995-04-01

Ultrasonic flowmeters (USFM) installed on Transalpine Pipeline Co.`s (TAL) crude-oil system have proven to be a cost-effective flow measurement technique and beneficial in batch identification and leak detection. Through close examination, TAL has determined that clamp-on USFMs offer cost-saving advantages in installation, maintenance and operation. USFMs do not disturb pig passage. The technique also provides sound velocity capabilities, which can be used for liquid identification and batch tracking. The instruments have a repeatability of better than 0.25% and achieve an accuracy of better than 1%, depending on the flow profiles predictability. Using USFMs with multiple beams probably will improve accuracymore » further and it should be possible to find leaks even smaller than 1% of flow.« less

Stress wave attenuation in thin structures by ultrasonic through-transmission

NASA Technical Reports Server (NTRS)

Lee, S. S.; Williams, J. H., Jr.

1980-01-01

The steady state amplitude of the output of an ultrasonic through transmission measurement is analyzed and the result is given in closed form. Provided that the product of the input and output transduction ratios; the specimen-transducer reflection coefficient; the specimen-transducer phase shift parameter; and the material phase velocity are known, this analysis gives a means for determining the through-thickness attenuation of an individual thin sample. Multiple stress wave reflections are taken into account and so signal echoes do not represent a difficulty. An example is presented for a graphite fiber epoxy composite (Hercules AS/3501-6). A direct method for continuous or intermittent monitoring of through thickness attenuation of plate structures which may be subject to service structural degradation is provided.

Contactless ultrasonic device to measure surface acoustic wave velocities versus temperature.

PubMed

Hubert, C; Nadal, M H; Ravel-Chapuis, G; Oltra, R

2007-02-01

A complete optical experimental setup for generating and detecting surface acoustic waves [Rayleigh waves (RWs)] in metals versus temperature up to the melting point is described. The RWs were excited by a pulsed Nd:YAG laser and detected by a high sensitivity subangstrom heterodyne interferometer. A special furnace was used to heat the sample using infrared radiation with a regulation of the sample temperature less than 0.1 K. First measurements on an aluminum alloy sample are presented to validate the setup.

Echocardiographic strain and strain-rate imaging: a new tool to study regional myocardial function.

PubMed

D'hooge, Jan; Bijnens, Bart; Thoen, Jan; Van de Werf, Frans; Sutherland, George R; Suetens, Paul

2002-09-01

Ultrasonic imaging is the noninvasive clinical imaging modality of choice for diagnosing heart disease. At present, two-dimensional ultrasonic grayscale images provide a relatively cheap, fast, bedside method to study the morphology of the heart. Several methods have been proposed to assess myocardial function. These have been based on either grayscale or motion (velocity) information measured in real-time. However, the quantitative assessment of regional myocardial function remains an important goal in clinical cardiology. To do this, ultrasonic strain and strain-rate imaging have been introduced. In the clinical setting, these techniques currently only allow one component of the true three-dimensional deformation to be measured. Clinical, multidimensional strain (rate) information can currently thus only be obtained by combining data acquired using different transducer positions. Nevertheless, given the appropriate postprocessing, the clinical value of these techniques has already been shown. Moreover, multidimensional strain and strain-rate estimation of the heart in vivo by means of a single ultrasound acquisition has been shown to be feasible. In this paper, the new techniques of ultrasonic strain rate and strain imaging of the heart are reviewed in terms of definitions, data acquisition, strain-rate estimation, postprocessing, and parameter extraction. Their clinical validation and relevance will be discussed using clinical examples on relevant cardiac pathology. Based on these examples, suggestions are made for future developments of these techniques.

Ultrasonic bulk wave measurements on composite using fiber from recycled CFRP

NASA Astrophysics Data System (ADS)

Paterson, David; Ijomah, Winifred L.; Windmill, James F. C.; Kao, Chih-Chuan; Smillie, Grant

2018-04-01

This study investigates the velocity profile for both a virgin carbon fiber reinforced plastic (v-CFRP) and a reused fiber CFRP (rf-CFRP) which exhibit quasi-isotropy; all samples have 3 iterations of symmetry type [0, -45, +45, 90]s. An isotropic virgin CFRP (v-CFRP), produced by using a hand layup process, is presented along with a pyrolysis recycling process (at 600°C) designed to extract the carbon fibers. A virgin carbon fiber mat with a similar architecture was also thermally conditioned under the same pyrolysis conditions. Both resultant carbon fiber mats were used to produce the rf-CFRPs. Ultrasonic wave velocities at different angles of incidence for both v-CFRP and rf-CFRP were recorded. In the case of v-CFRP, two samples were studied, and it was recorded that the velocity for both a longitudinal wave and transverse wave remained relatively constant up until these waves completely attenuated at observed angles, indicating what would be expected from an isotropic sample. A close relationship in terms of waves speed was also recorded for the two v-CFRP samples. In the case of rf-CFRP, the longitudinal wave velocities were generally less closely related when compared to the v-CFRP, with a maximum of approximately 32% difference being recorded. The transverse wave velocity was also found to decrease incident angle indicating sample anisotropy. The authors suggest that the more severe decreasing velocity with increasing incident angle, when compared to v-CFRP, may be caused by resin impregnation issues and not by changes that occur during the recycling process. Therefore, a hypothesis that both the rf-CFRP and the V-CFRP will return a similar wave profile given an identical resin fiber content is put forward.

Noncontact Determination of Antisymmetric Plate Wave Velocity in Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Kautz, Harold E.

1998-01-01

High-temperature materials are of increasing importance in the development of more efficient engines and components for the aeronautics industry. In particular, ceramic matrix composite (CMC) and metal matrix composite (MMC) structures are under active development for these applications. The acousto-ultrasonic (AU) method has been shown to be useful for assessing mechanical properties in composite structures. In particular, plate wave analysis can characterize composites in terms of their stiffness moduli. It is desirable to monitor changes in mechanical properties that occur during thermomechanical testing and to monitor the health of components whose geometry or position make them hard to reach with conventional ultrasonic probes. In such applications, it would be useful to apply AU without coupling directly to the test surface. For a number of years, lasers have been under investigation as remote ultrasonic input sources and ultrasound detectors. The use of an ultrasonic transducer coupled through an air gap has also been under study. So far at the NASA Lewis Research Center, we have been more successful in using lasers as ultrasonic sources than as output devices. On the other hand, we have been more successful in using an air-coupled piezoelectric transducer as an output device than as an input device. For this reason, we studied the laser in/air-coupled-transducer out combination-using a pulsed NdYAG laser as the ultrasonic source and an air-coupled-transducer as the detector. The present work is focused on one of the AU parameters of interest, the ultrasonic velocity of the antisymmetric plate-wave mode. This easily identified antisymmetric pulse can be used to determine shear and flexure modulus. It was chosen for this initial work because the pulse arrival times are likely to be the most precise. The following schematic illustrates our experimental arrangement for using laser in/air-transducer out on SiC/SiC composite tensile specimens. The NdYAG pulse was directed downward by a 90 infrared prism to the top of the specimen, but at the edge of one end. An energy sensor measured a single pulse at 13 millijoules (mJ) before it passed through the prism, which attenuated 15 percent of its energy. It also provided an output trigger for the waveform time-delay synthesizer.

Non-Contact Evaluation for Articular Cartilage Using Ultrasound

NASA Astrophysics Data System (ADS)

Mori, Koji; Nakagawa, Yasuaki; Kuroki, Hiroshi; Nakashima, Keisuke; Ikeuchi, Ken; Mine, Takatomo; Nakamura, Takashi; Kawai, Shinya; Saito, Takashi

In orthopedic field, various new treatments of articular cartilage defect, for example autogenous osteochondral grafts, have been developed. With the spread of these treatments, orthopedists began to focus on the mechanical properties of recovered articular cartilage. The quantitative evaluation of articular cartilage before and after these treatments gives orthopedists the important information to improve these treatments and develop new treatments. We have been investigating the non-contact ultrasonic evaluation for articular cartilage under arthroscopy. In this paper, it was hypothesized that the ultrasonic evaluation depended on the collagen fiber in cartilage. The enzymatically degradation of collagen fiber in cartilage surface was performed. The effect of the degradation on sound velocity, attenuation coefficient and signal intensity, which is the index of cartilage stiffness calculated from the proposed method, was measured. The numerical analysis was performed to clear the relation between the cartilage character and ultrasonic parameters. Experimental and numerical results suggest that the present method can be expanded the sensitive evaluation for cartilage disease in clinical field.

Mapping of power consumption and friction reduction in piezoelectrically-assisted ultrasonic lubrication

NASA Astrophysics Data System (ADS)

Dong, Sheng; Dapino, Marcelo J.

2015-04-01

Ultrasonic lubrication has been proven effective in reducing dynamic friction. This paper investigates the relationship between friction reduction, power consumption, linear velocity, and normal stress. A modified pin-on-disc tribometer was adopted as the experimental set-up, and a Labview system was utilized for signal generation and data acquisition. Friction reduction was quantified for 0.21 to 5.31 W of electric power, 50 to 200 mm/s of linear velocity, and 23 to 70 MPa of normal stress. Friction reduction near 100% can be achieved under certain conditions. Lower linear velocity and higher electric power result in greater friction reduction, while normal stress has little effect on friction reduction. Contour plots of friction reduction, power consumption, linear velocity, and normal stress were created. An efficiency coefficient was proposed to calculate power requirements for a certain friction reduction or reduced friction for a given electric power.

Erosive Burning Study Utilizing Ultrasonic Measurement Techniques

NASA Technical Reports Server (NTRS)

Furfaro, James A.

2003-01-01

A 6-segment subscale motor was developed to generate a range of internal environments from which multiple propellants could be characterized for erosive burning. The motor test bed was designed to provide a high Mach number, high mass flux environment. Propellant regression rates were monitored for each segment utilizing ultrasonic measurement techniques. These data were obtained for three propellants RSRM, ETM- 03, and Castor@ IVA, which span two propellant types, PBAN (polybutadiene acrylonitrile) and HTPB (hydroxyl terminated polybutadiene). The characterization of these propellants indicates a remarkably similar erosive burning response to the induced flow environment. Propellant burnrates for each type had a conventional response with respect to pressure up to a bulk flow velocity threshold. Each propellant, however, had a unique threshold at which it would experience an increase in observed propellant burn rate. Above the observed threshold each propellant again demonstrated a similar enhanced burn rate response corresponding to the local flow environment.

Assessment of precipitation in alloy steel using nonlinear Rayleigh surface waves

NASA Astrophysics Data System (ADS)

Thiele, Sebastian; Matlack, Kathryn H.; Kim, Jin-Yeon; Qu, Jianmin; Wall, James J.; Jacobs, Laurence J.

2014-02-01

Nonlinear ultrasonic waves have shown to be sensitive to various microstructural changes in metals including coherent precipitates; these precipitates introduce a strain field in the lattice structure. The thermal aging of certain alloy steels leads to the formation of coherent precipitates, which pin dislocations and contribute to the generation of a second harmonic component. A precipitate hardenable material namely 17-4 PH stainless steel is thermally treated in this research to obtain different precipitation stages, and then the influence of precipitates on the acoustic nonlinearity parameter is assessed. Conclusions about the microstrucutural changes in the material are drawn based on the results from a nonlinear Rayleigh surface wave measurement and complementary thermo-electric power, hardness and ultrasonic velocity measurements. The results show that the nonlinear parameter is sensitive to coherent precipitates in the material and moreover that precipitation characteristics can be characterized based on the obtained experimental data.

Non-Contact Determination of Antisymmetric Plate Wave Velocity in Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Kautz, Harold E.

1996-01-01

A 13 mJ NdYAG 1064 nm, 4 ns, laser pulse was employed to produce ultrasonic plate waves in 20 percent porous SiC/SiC composite tensile specimens of three different architectures. An air coupled 0.5 MHz transducer was used to detect and collect the waveforms which contained first antisymmetric plate wave pulses for determining the shear wave velocity (VS). These results were compared to VS values determined on the same specimens with 0.5 MHz ultrasonic transducers with contact coupling. Averages of four noncontact determinations on each of 18 specimens were compared to averages of four contact values. The noncontact VS's fall in the same range as the contact. The standard deviations for the noncontact VS's averaged 2.8 percent. The standard deviations for the contact measurements averaged 2.3 percent, indicating similar reproducibility. Repeated laser pulsing at the same location always lead to deterioration of the ulu-"nic signal. The signal would recover in about 24 hr in air however, indicating that no permanent damage was produced.

Effects of maximum aggregate size on UPV of brick aggregate concrete.

PubMed

Mohammed, Tarek Uddin; Mahmood, Aziz Hasan

2016-07-01

Investigation was carried out to study the effects of maximum aggregate size (MAS) (12.5mm, 19.0mm, 25.0mm, 37.5mm, and 50.0mm) on ultrasonic pulse velocity (UPV) of concrete. For investigation, first class bricks were collected and broken to make coarse aggregate. The aggregates were tested for specific gravity, absorption capacity, unit weight, and abrasion resistance. Cylindrical concrete specimens were made with different sand to aggregate volume ratio (s/a) (0.40 and 0.45), W/C ratio (0.45, 0.50, and 0.55), and cement content (375kg/m(3) and 400kg/m(3)). The specimens were tested for compressive strength and Young's modulus. UPV through wet specimen was measured using Portable Ultrasonic Non-destructive Digital Indicating Tester (PUNDIT). Results indicate that the pulse velocity through concrete increases with an increase in MAS. Relationships between UPV and compressive strength; and UPV and Young's modulus of concrete are proposed for different maximum sizes of brick aggregate. Copyright © 2016 Elsevier B.V. All rights reserved.

Acoustic and mechanical response of reservoir rocks under variable saturation and effective pressure.

PubMed

Ravazzoli, C L; Santos, J E; Carcione, J M

2003-04-01

We investigate the acoustic and mechanical properties of a reservoir sandstone saturated by two immiscible hydrocarbon fluids, under different saturations and pressure conditions. The modeling of static and dynamic deformation processes in porous rocks saturated by immiscible fluids depends on many parameters such as, for instance, porosity, permeability, pore fluid, fluid saturation, fluid pressures, capillary pressure, and effective stress. We use a formulation based on an extension of Biot's theory, which allows us to compute the coefficients of the stress-strain relations and the equations of motion in terms of the properties of the single phases at the in situ conditions. The dry-rock moduli are obtained from laboratory measurements for variable confining pressures. We obtain the bulk compressibilities, the effective pressure, and the ultrasonic phase velocities and quality factors for different saturations and pore-fluid pressures ranging from normal to abnormally high values. The objective is to relate the seismic and ultrasonic velocity and attenuation to the microstructural properties and pressure conditions of the reservoir. The problem has an application in the field of seismic exploration for predicting pore-fluid pressures and saturation regimes.

Ultrasonic attenuation and phase velocity of high-density polyethylene pipe material.

PubMed

Egerton, J S; Lowe, M J S; Huthwaite, P; Halai, H V

2017-03-01

Knowledge of acoustic properties is crucial for ultrasonic or sonic imaging and signal detection in nondestructive evaluation (NDE), medical imaging, and seismology. Accurately and reliably obtaining these is particularly challenging for the NDE of high-density polyethylene (HDPE), such as is used in many water or gas pipes, because the properties vary greatly with frequency, temperature, direction and spatial location. Therefore the work reported here was undertaken in order to establish a basis for such a multiparameter description. The approach is general but the study specifically addresses HDPE and includes measured data values. Applicable to any such multiparameter acoustic properties dataset is a devised regression method that uses a neural network algorithm. This algorithm includes constraints to respect the Kramers-Kronig causality relationship between speed and attenuation of waves in a viscoelastic medium. These constrained acoustic properties are fully described in a multidimensional parameter space to vary with frequency, depth, temperature, and direction. The resulting uncertainties in acoustic properties dependence on the above variables are better than 4% and 2%, respectively, for attenuation and phase velocity and therefore can prevent major defect imaging errors.

Detecting Lamb waves with broadband acousto-ultrasonic signals in composite structures

NASA Technical Reports Server (NTRS)

Kautz, Harold E.

1992-01-01

Lamb waves can be produced and detected in ceramic matrix composites (CMC) and metal matrix composites (MMC) plates using the acousto-ultrasonic configuration employing broadband transducers. Experimental dispersion curves of lowest symmetric and lowest antisymmetric modes behave in a manner analogous to the graphite/polymer theoretical curves. In this study a basis has been established for analyzing Lamb wave velocities for characterizing composite plates. Lamb wave disperison curves and group velocities were correlated with variations in axial stiffness and shear stiffness in MMC and CMC. For CMCs, interfacial shear strength was also correlated with the first antisymmetric Lamb mode.

Detecting Lamb waves with broad-band acousto-ultrasonic signals in composite structures

NASA Technical Reports Server (NTRS)

Kautz, Harold E.

1992-01-01

Lamb waves can be produced and detected in ceramic matrix composites (CMC) and metal matrix composites (MMC) plates using the acousto-ultrasonic configuration employing broadband transducers. Experimental dispersion curves of lowest symmetric and antisymmetric modes behave in a manner analogous to the graphite/polymer theoretical curves. In this study a basis has been established for analyzing Lamb wave velocities for characterizing composite plates. Lamb wave dispersion curves and group velocities were correlated with variations in axial stiffness and shear stiffness in MMC and CMC. For CMC, interfacial shear strength was also correlated with the first antisymmetric Lamb mode.

Precision Thickness Variation Mapping Via One-Transducer Ultrasonic High Resolution Profilometry for Sample With Irregular or Rough Surface

NASA Technical Reports Server (NTRS)

Roth, Don J. (Inventor)

1996-01-01

An apparatus and method for determination of sample thickness and surface depression utilizing ultrasonic pulses is discussed. The sample is held in a predetermined position by a support member having a reference surface. Ultrasonic pulses travel through a medium of known velocity propagation and reflect off the reference surface and a sample surface. Time of flight data of surface echoes are converted to distances between sample surfaces to obtain computer-generated thickness profiles and surface mappings.

Ultrasonic imaging of textured alumina

NASA Technical Reports Server (NTRS)

Stang, David B.; Salem, Jonathan A.; Generazio, Edward R.

1989-01-01

Ultrasonic images representing the bulk attenuation and velocity of a set of alumina samples were obtained by a pulse-echo contact scanning technique. The samples were taken from larger bodies that were chemically similar but were processed by extrusion or isostatic processing. The crack growth resistance and fracture toughness of the larger bodies were found to vary with processing method and test orientation. The results presented here demonstrate that differences in texture that contribute to variations in structural performance can be revealed by analytic ultrasonic techniques.

Noninvasive ultrasonic examination technology in support of counter-terrorism and drug interdiction activities: the acoustic inspection device (AID)

NASA Astrophysics Data System (ADS)

Diaz, Aaron A.; Burghard, Brion J.; Skorpik, James R.; Shepard, Chester L.; Samuel, Todd J.; Pappas, Richard A.

2003-07-01

The Pacific Northwest National Laboratory (PNNL) has developed a portable, battery-operated, handheld ultrasonic device that provides non-invasive container interrogation and material identification capabilities. The technique governing how the acoustic inspection device (AID) functions, involves measurements of ultrasonic pulses (0.1 to 5 MHz) that are launched into a container or material. The return echoes from these pulses are analyzed in terms of time-of-flight and frequency content to extract physical property measurements (the acoustic velocity and attenuation coefficient) of the material under test. The AID performs an automated analysis of the return echoes to identify the material, and detect contraband in the form of submerged packages and concealed compartments in liquid filled containers and solid-form commodities. An inspector can quickly interrogate outwardly innocuous commodity items such as shipping barrels, tanker trucks, and metal ingots. The AID can interrogate container sizes ranging from approximately 6 inches in diameter to over 96 inches in diameter and allows the inspector to sort liquid and material types into groups of like and unlike; a powerful method for discovering corrupted materials or miss-marked containers co-mingled in large shipments. This manuscript describes the functionality, capabilities and measurement methodology of the technology as it relates to homeland security applications.

Vector Doppler: spatial sampling analysis and presentation techniques for real-time systems

NASA Astrophysics Data System (ADS)

Capineri, Lorenzo; Scabia, Marco; Masotti, Leonardo F.

2001-05-01

The aim of the vector Doppler (VD) technique is the quantitative reconstruction of a velocity field independently of the ultrasonic probe axis to flow angle. In particular vector Doppler is interesting for studying vascular pathologies related to complex blood flow conditions. Clinical applications require a real-time operating mode and the capability to perform Doppler measurements over a defined volume. The combination of these two characteristics produces a real-time vector velocity map. In previous works the authors investigated the theory of pulsed wave (PW) vector Doppler and developed an experimental system capable of producing off-line 3D vector velocity maps. Afterwards, for producing dynamic velocity vector maps, we realized a new 2D vector Doppler system based on a modified commercial echograph. The measurement and presentation of a vector velocity field requires a correct spatial sampling that must satisfy the Shannon criterion. In this work we tackled this problem, establishing a relationship between sampling steps and scanning system characteristics. Another problem posed by the vector Doppler technique is the data representation in real-time that should be easy to interpret for the physician. With this in mine we attempted a multimedia solution that uses both interpolated images and sound to represent the information of the measured vector velocity map. These presentation techniques were experimented for real-time scanning on flow phantoms and preliminary measurements in vivo on a human carotid artery.

Guided waves and ultrasonic characterization of three-dimensional composites

NASA Astrophysics Data System (ADS)

Leymarie, Nicolas; Baste, Stéphane

2000-05-01

Ultrasonic NDE of anisotropic media appears nowadays as one of the best experimental approaches in studying mechanical properties. A complete identification of stiffness tensor can be performed with phase velocity measurements of obliquely incidence ultrasonic bulk waves from water onto a plate. The medium considered, however, has to be homogeneous with respect to wavelength used. In the case of 3D-composites, textures scales may reach one millimeter and their cut-off frequency is less than MHz. The dispersion curves observed in the considered range of frequencies are often very close and sometimes may be overlapped. Experimental studies show complex signals, which are due to a combination of both bulk and guided waves. Wave-speed measurements of the bulk wave and its detection become unreliable with classical techniques of signal processing (simple time or spectral analysis). Moreover, even if the coupled time-frequency analysis with wavelet transforms allows a better interpretation of the signal, the time delay estimation for the bulk wave and so the characterization of the material remains uncertain. To understand blended signals more accurately, different analytical and numerical models are proposed to show the advantages and disadvantages of methods used in NDE.

Mechanical and Thermal Properties of Praseodymium Monopnictides: AN Ultrasonic Study

NASA Astrophysics Data System (ADS)

Bhalla, Vyoma; Kumar, Raj; Tripathy, Chinmayee; Singh, Devraj

2013-09-01

We have computed ultrasonic attenuation, acoustic coupling constants and ultrasonic velocities of praseodymium monopnictides PrX(X: N, P, As, Sb and Bi) along the <100>, <110>, <111> in the temperature range 100-500 K using higher order elastic constants. The higher order elastic constants are evaluated using Coulomb and Born-Mayer potential with two basic parameters viz. nearest-neighbor distance and hardness parameter in the temperature range of 0-500 K. Several other mechanical and thermal parameters like bulk modulus, shear modulus, Young's modulus, Poisson ratio, anisotropic ratio, tetragonal moduli, Breazeale's nonlinearity parameter and Debye temperature are also calculated. In the present study, the fracture/toughness (B/G) ratio is less than 1.75 which implies that PrX compounds are brittle in nature at room temperature. The chosen material fulfilled Born criterion of mechanical stability. We also found the deviation of Cauchy's relation at higher temperatures. PrN is most stable material as it has highest valued higher order elastic constants as well as the ultrasonic velocity. Further, the lattice thermal conductivity using modified approach of Slack and Berman is determined at room temperature. The ultrasonic attenuation due to phonon-phonon interaction and thermoelastic relaxation mechanisms have been computed using modified Mason's approach. The results with other well-known physical properties are useful for industrial applications.

Three-dimensional imaging of biological cells with picosecond ultrasonics

NASA Astrophysics Data System (ADS)

Danworaphong, Sorasak; Tomoda, Motonobu; Matsumoto, Yuki; Matsuda, Osamu; Ohashi, Toshiro; Watanabe, Hiromu; Nagayama, Masafumi; Gohara, Kazutoshi; Otsuka, Paul H.; Wright, Oliver B.

2015-04-01

We use picosecond ultrasonics to image animal cells in vitro—a bovine aortic endothelial cell and a mouse adipose cell—fixed to Ti-coated sapphire. Tightly focused ultrashort laser pulses generate and detect GHz acoustic pulses, allowing three-dimensional imaging (x, y, and t) of the ultrasonic propagation in the cells with ˜1 μm lateral and ˜150 nm depth resolutions. Time-frequency representations of the continuous-wavelet-transform amplitude of the optical reflectivity variations inside and outside the cells show GHz Brillouin oscillations, allowing the average sound velocities of the cells and their ultrasonic attenuation to be obtained as well as the average bulk moduli.

Numerical simulation and experiment on effect of ultrasonic in polymer extrusion processing

NASA Astrophysics Data System (ADS)

Wan, Yue; Fu, ZhiHong; Wei, LingJiao; Zang, Gongzheng; Zhang, Lei

2018-01-01

The influence of ultrasonic wave on the flow field parameters and the precision of extruded products are studied. Firstly, the effect of vibration power on the average velocity of the outlet, the average viscosity of the die section, the average shear rate and the inlet pressure of the die section were studied by using the Polyflow software. Secondly, the effects of ultrasonic strength on the die temperature and the drop of die pressure were studied experimentally by different head temperature and different screw speed. Finally, the relationship between die pressure and extrusion flow rate under different ultrasonic power were studied through experiments.

In-situ monitoring of acoustic linear and nonlinear behavior of titanium alloys during cycling loading

NASA Astrophysics Data System (ADS)

Frouin, Jerome; Matikas, Theodore E.; Na, Jeong K.; Sathish, Shamachary

1999-02-01

An in-situ technique to measure sound velocity, ultrasonic attenuation and acoustic nonlinear property has been developed for characterization and early detection of fatigue damage in aerospace materials. A previous experiment using the f-2f technique on Ti-6Al-4V dog bone specimen fatigued at different stage of fatigue has shown that the material nonlinearity exhibit large change compared to the other ultrasonic parameter. Real-time monitoring of the nonlinearity may be a future tool to characterize early fatigue damage in the material. For this purpose we have developed a computer software and measurement technique including hardware for the automation of the measurement. New transducer holder and special grips are designed. The automation has allowed us to test the long-term stability of the electronics over a period of time and so proof of the linearity of the system. For the first time, a real-time experiment has been performed on a dog-bone specimen from zero fatigue al the way to the final fracture.

Ultrasonic measurements of the bulk flow field in foams

NASA Astrophysics Data System (ADS)

Nauber, Richard; Büttner, Lars; Eckert, Kerstin; Fröhlich, Jochen; Czarske, Jürgen; Heitkam, Sascha

2018-01-01

The flow field of moving foams is relevant for basic research and for the optimization of industrial processes such as froth flotation. However, no adequate measurement technique exists for the local velocity distribution inside the foam bulk. We have investigated the ultrasound Doppler velocimetry (UDV), providing the first two-dimensional, non-invasive velocity measurement technique with an adequate spatial (10 mm ) and temporal resolution (2.5 Hz ) that is applicable to medium scale foam flows. The measurement object is dry aqueous foam flowing upward in a rectangular channel. An array of ultrasound transducers is mounted within the channel, sending pulses along the main flow axis, and receiving echoes from the foam bulk. This results in a temporally and spatially resolved, planar velocity field up to a measurement depth of 200 mm , which is approximately one order of magnitude larger than those of optical techniques. A comparison with optical reference measurements of the surface velocity of the foam allows to validate the UDV results. At 2.5 Hz frame rate an uncertainty below 15 percent and an axial spatial resolution better than 10 mm is found. Therefore, UDV is a suitable tool for monitoring of industrial processes as well as the scientific investigation of three-dimensional foam flows on medium scales.

ULTRASONIC FLAW DETECTION METHOD AND MEANS

DOEpatents

Worlton, D.C.

1961-08-15

A method of detecting subsurface flaws in an object using ultrasonic waves is described. An ultnasonic wave of predetermined velocity and frequency is transmitted to engage the surface of the object at a predetermined angle of inci dence thereto. The incident angle of the wave to the surface is determined with respect to phase velocity, incident wave velocity, incident wave frequency, and the estimated depth of the flaw so that Lamb waves of a particular type and mode are induced only in the portion of the object between the flaw and the surface. These Lamb waves are then detected as they leave the object at an angle of exit equal to the angle of incidence. No waves wlll be generated in the object and hence received if no flaw exists beneath the surface. (AEC)

Characterization of sintered SiC by using NDE

NASA Technical Reports Server (NTRS)

Baaklini, George Y.

1988-01-01

Capabilities of projection microfocus X-radiography and of ultrasonic velocity and attenuation for characterizing silicon carbide specimens were assessed. Silicon carbide batches covered a range of densities and different microstructural characteristics. Room-temperature, four-point flexural strength tests were conducted. Fractography was used to identify types, sizes, and locations of fracture origins. Fracture toughness values were calculated from fracture strength and flaw characterization data. Detection capabilities of radiography for fracture-causing flaws were evaluated. Applicability of ultrasonics for verifying material strength and toughness was examined. Radiography proved useful in detecting high-density inclusions and isolated voids, but failed in detecting surface and subsurface agglomerates and large grains as fracture origins. Ultrasonic velocity dependency on density was evident. Attenuation dependency on density and mean pore size was clearly demonstrated. Understanding attenuation as a function of toughness was limited by shortcomings in K sub IC determination.

Investigating the Use of Ultrasonic Guided Waves for Aging Wire Insulation Assessment

NASA Technical Reports Server (NTRS)

Anastasi, Robert F.; Madaras, Eric I.

2002-01-01

Aging wiring has become a critical issue to DoD, NASA, FAA, and Industry. The problem is that insulation on environmentally aged wire becomes brittle and cracks. This exposes the underlying conductive wire to the potential for short circuits and fire. The difficulty is that techniques to monitor aging wire problems focus on applying electrical sensing techniques that are not very sensitive to the wire insulation. Thus, the development of methods to quantify and monitor aging wire insulation is highly warranted. Measurement of wire insulation stiffness by ultrasonic guided waves is being examined. Initial laboratory tests were performed on a simple model consisting of a solid cylinder and then a solid cylinder with a polymer coating. Experimental measurements showed that the lowest order axisymmetric mode may be sensitive to stiffness changes in the wire insulation. To test this theory, mil-spec wire samples MIL-W-81381, MIL-W-22759/34, and MIL-W-22759/87 (typically found in aircraft) were heat-damaged in an oven, in a range of heating conditions. The samples were 12, 16, and 20 gauge and the heat-damage introduced material changes in the wire-insulation that made the originally flexible insulation brittle and darker in color. Axisymmetric mode phase velocity increased for the samples that were exposed to heat for longer duration. For example, the phase velocity in the 20-gauge MIL-W-22759/34 wire changed from a baseline value of 2790m/s to 3280m/s and 3530m/s for one-hour exposures to 3490C and 3990C, respectively. Although the heat-damage conditions are not the same as environmental aging, we believe that with further development and refinements, the ultrasonic guided waves can be used to inspect wire-insulation for detrimental environmental aging conditions.

Study of Lamb Waves for Non-Destructive Testing Behind Screens

NASA Astrophysics Data System (ADS)

Kauffmann, P.; Ploix, M.-A.; Chaix, J.-F.; Gueudré, C.; Corneloup, G.; Baqué, F. AF(; )

2018-01-01

The inspection and control of sodium-cooled fast reactors (SFR) is a major issue for the nuclear industry. Ultrasonic solutions are under study because of the opacity of liquid sodium. In this paper, the use of leaky Lamb waves is considered for non-destructive testing (NDT) on parallel and immersed structures assimilated as plates. The first phase of our approach involved studying the propagation properties of leaky Lamb waves. Equations that model the propagation of Lamb waves in an immersed plate were solved numerically. The phase velocity can be experimentally measured using a two dimensional Fourier transform. The group velocity can be experimentally measured using a short-time Fourier transform technique. Attenuation of leaky Lamb waves is mostly due to the re-emission of energy into the surrounding fluid, and it can be measured by these two techniques.

Elastic wave velocities of iron-bearing Ringwoodite (Mg0.8Fe0.2)2SiO2 to 12GPa at room temperature

NASA Astrophysics Data System (ADS)

Higo, Y.; Li, B.; Inoue, T.; Irifune, T.; Libermann, R. C.

2002-12-01

At present, it is widely accepted that olivine is the most important mineral in the Earth's upper mantle. The elastic property changes associated with the phase transformations to its high-pressure polymorphs are very important parameters to constrain the composition of the mantle transition zone. In this study, we measured the elastic wave velocity of iron-bearing Ringwoodite (Mg0.8Fe0.2)2SiO4. The specimen was hot-pressed at 18GPa and 1273K in a 2000-ton Uniaxial Split Sphere Apparatus (ORANGE-2000: GRC at ehime university). The recovered polycrystalline specimen was characterized by x-ray diffraction, EPMA, ultrasonic techniques, and the density was determined by Archimedes' method, and found to be single-phase and fine-grained. Bench top measurements of the compressional and shear wave velocities yielded Vp=9.10 km/s and Vs=5.52 km/s. High-pressure ultrasonic measurement was carried out in a 1000-ton Uniaxial Split-Cylinder Apparatus (USCA-1000: SUNY) at pressures up to 12GPa at room temperature using ZnTe as internal pressure marker. The sample was surrounded by lead to minimize the deviatoric stress. Also in this experiment, the travel times of the Al2O3 buffer rod were used for pressure calculation. The travel times of the buffer rod under the same cell geometry have been calibrated as a function of sample pressure by the thermal equation of state of NaCl using in-situ X-ray diffraction techniques. The results of our high-pressure experiment, including the elastic moduli and their pressure dependence, effect of iron on the elastic moduli, as well as their implication for the mantle transition zone, will be presented.

Ultrasonic pulse velocity for the evaluation of physical and mechanical properties of a highly porous building limestone.

PubMed

Vasanelli, Emilia; Colangiuli, Donato; Calia, Angela; Sileo, Maria; Aiello, Maria Antonietta

2015-07-01

UPV as non-destructive technique can effectively contribute to the low invasive in situ analysis and diagnosis of masonry elements related to the conservation, rehabilitation and strengthening of the built heritage. The use of non-destructive and non-invasive techniques brings all the times many advantages in diagnostic activities on pre-existing buildings in terms of sustainability; moreover, it is a strong necessity with respect to the conservation constraints when dealing with the historical-architectural heritage. In this work laboratory experiments were carried out to investigate the effectiveness of ultrasonic pulse velocity (UPV) in evaluating physical and mechanical properties of Lecce stone, a soft and porous building limestone. UPV and selected physical-mechanical parameters such as density and uniaxial compressive strength (UCS) were determined. Factors such as anisotropy and water presence that induce variations on the ultrasonic velocity were also assessed. Correlations between the analysed parameters are presented and discussed. The presence of water greatly affected the values of the analysed parameters, leading to a decrease of UPV and to a strong reduction of the compressive strength. A discussion of the role of the water on these results is provided. Regression analysis showed a reliable linear correlation between UPV and compressive strength, which allows a reasonable estimation of the strength of Lecce stone by means of non-destructive testing methods such as the ultrasonic wave velocity. Low correlation between UPV and density was found, suggesting that other factors than density, related to the fabric and composition, also influence the response of the selected stone to the UPV. They have no influence on the UCS, that instead showed to be highly correlated with the packing density. Copyright © 2015 Elsevier B.V. All rights reserved.

An acoustic sensor for monitoring airflow in pediatric tracheostomy patients.

PubMed

Ruscher, Thomas; Wicks Phd, Alexandrina; Muelenaer Md, Andre

2012-01-01

Without proper monitoring, patients with artificial airways in the trachea are at high risk for complications or death. Despite routine maintenance of the tube, dislodged or copious mucus can obstruct the airway. Young children ( 3yrs) have difficulty tending to their own tubes and are particularly vulnerable to blockages. They require external respiratory sensors. In a hospital environment, ventilators, end-tidal CO2 monitors, thermistors, and other auxiliary equipment provide sufficient monitoring of respiration. However, outpatient monitoring methods, such as thoracic impedance and pulse oximetry, are indirect and prone to false positives. Desensitization of caregivers to frequent false alarms has been cited in medical literature as a contributing factor in cases of child death. Ultrasonic time-of-flight (TOF) is a technique used in specialized industrial applications to non-invasively measure liquid and gas flow. Two transducers are oriented at a diagonal across a flow channel. Velocity measurement is accomplished by detecting slight variations in transit time of contra-propagating acoustic signals with a directional component parallel to air flow. Due to the symmetry of acoustic pathway between sensors, velocity measurements are immune to partial fouling in the tube from mucus, saliva, and condensation. A first generation proof of concept prototype was constructed to evaluate the ultrasonic TOF technique for medical tracheostomy monitoring. After successful performance, a second generation prototype was designed with a smaller form factor and more advanced electronics. This prototype was tested and found to measure inspired volume with a root-mean-square error < 2% during initial trials.

Study of ultrasonic thermometry based on ultrasonic time-of-flight measurement

NASA Astrophysics Data System (ADS)

Jia, Ruixi; Xiong, Qingyu; Wang, Lijie; Wang, Kai; Shen, Xuehua; Liang, Shan; Shi, Xin

2016-03-01

Ultrasonic thermometry is a kind of acoustic pyrometry and it has been evolving as a new temperature measurement technology for various environment. However, the accurate measurement of the ultrasonic time-of-flight is the key for ultrasonic thermometry. In this paper, we study the ultrasonic thermometry technique based on ultrasonic time-of-flight measurement with a pair of ultrasonic transducers for transmitting and receiving signal. The ultrasonic transducers are installed in a single path which ultrasonic travels. In order to validate the performance of ultrasonic thermometry, we make a contrast about the absolute error between the measured temperature value and the practical one. With and without heater source, the experimental results indicate ultrasonic thermometry has high precision of temperature measurement.

Geophysical Measurements at Merseburg Cathedral

NASA Astrophysics Data System (ADS)

Meier, Thomas; Erkul, Ercan; Schulte-Kortnack, Detlef; Sobott, Robert; Hilbert, Helene; Esel, Yunus; Tesch, Marcel; Wiemann, Timo

2017-04-01

Merseburg Cathedral has been founded in 1015 by Bishop Thietmar von Merseburg and has been converted into a gothic cathedral from 1510 to 1517 by Bishop Thilo von Trotha. The cathedral together with the cloister, the castle and several appurtenant buildings are well preserved. The entire complex represents one of the most complete examples of medieval royal palaces and bishop's sees in Germany northeast of the Roman Limes. Here we present examples of geophysical measurements at the cathedral namely ultrasonic surface measurements, ground penetrating radar (GPR) as well as thermographic measurements. Ultrasonic surface measurements have been carried out at epitaphs made of sandstone to quantify changes in stone properties due to weathering. The 95 measurements reveal a strong variability in Rayleigh wave velocities ranging from about 800 m/s to 2000 m/s. Unweathered parts of the sandstone epitaphs show Rayleigh wave velocities of about 1500 m/s. A reduction in Rayleigh wave velocities hints at loosening of the rock surface whereas an increase is due to surficial black crusts with pores filled mainly by gypsum. Waveform inversion of the dispersed Rayleigh waveform yields depth profiles of the shear-wave velocity indicating the thickness of altered surficial layers. Also a loosening below the black crust may be detected non-destructively. A number of measurements have been repeated after one year and after a rainy day. Statistical analysis shows that random errors in Rayleigh wave velocities are less than about 3 %. Increase of moisture in porous sandstones leads to stronger damping of the Rayleigh wave and consequently to a reduction in Rayleigh wave velocities by up to about 10 %. At strongly altered epitaphs a reduction in Rayleigh wave velocity by up to 20 % has been observed within one year. Within one day an increase of up to about 7 % may indicate stiffening of black crusts due to moisture absorption. GPR measurements have been performed at several locations within the cathedral and in the cloister to clarify the location of medial graves. The measurements partly confirm archaeological reports from the 19th century. In addition, a number of hitherto unknown graves have been detected. An east-west oriented high-reflective anomaly at a depth of about 1 m with a width of about 0.6 m and a length of about 2 m in the central crossing of the cathedral may be related to the unknown location of the grave of the anti-king Rudolf von Rheinfelden who was buried at Merseburg Cathedral in 1080. Graves have also been detected in the cloister of the cathedral. Moreover, we show that archeological excavations may lead to significant changes in the reflectivity of electromagnetic waves by the ground so that the location of previous excavations may be detected by GPR measurements. Furthermore, a number of passive and active thermographic measurements reveal increased moisture, detachments of plaster and the structure of the stonework below the plaster.

High Accuracy Acoustic Relative Humidity Measurement in Duct Flow with Air

PubMed Central

van Schaik, Wilhelm; Grooten, Mart; Wernaart, Twan; van der Geld, Cees

2010-01-01

An acoustic relative humidity sensor for air-steam mixtures in duct flow is designed and tested. Theory, construction, calibration, considerations on dynamic response and results are presented. The measurement device is capable of measuring line averaged values of gas velocity, temperature and relative humidity (RH) instantaneously, by applying two ultrasonic transducers and an array of four temperature sensors. Measurement ranges are: gas velocity of 0–12 m/s with an error of ±0.13 m/s, temperature 0–100 °C with an error of ±0.07 °C and relative humidity 0–100% with accuracy better than 2 % RH above 50 °C. Main advantage over conventional humidity sensors is the high sensitivity at high RH at temperatures exceeding 50 °C, with accuracy increasing with increasing temperature. The sensors are non-intrusive and resist highly humid environments. PMID:22163610

High accuracy acoustic relative humidity measurement in duct flow with air.

PubMed

van Schaik, Wilhelm; Grooten, Mart; Wernaart, Twan; van der Geld, Cees

2010-01-01

An acoustic relative humidity sensor for air-steam mixtures in duct flow is designed and tested. Theory, construction, calibration, considerations on dynamic response and results are presented. The measurement device is capable of measuring line averaged values of gas velocity, temperature and relative humidity (RH) instantaneously, by applying two ultrasonic transducers and an array of four temperature sensors. Measurement ranges are: gas velocity of 0-12 m/s with an error of ± 0.13 m/s, temperature 0-100 °C with an error of ± 0.07 °C and relative humidity 0-100% with accuracy better than 2 % RH above 50 °C. Main advantage over conventional humidity sensors is the high sensitivity at high RH at temperatures exceeding 50 °C, with accuracy increasing with increasing temperature. The sensors are non-intrusive and resist highly humid environments.

The assessment of ultrasonic tests as a tool for qualification and diagnostic study of traditional highly porous and soft stone materials used in the built heritage of the past.

NASA Astrophysics Data System (ADS)

Calia, A.; Sileo, M.; Leucci, G.

2012-04-01

Ultrasonic tests are performing tools for the quality assessment and selection of stone as building materials, as well as for the detection of faults within architectural and structural elements. The use of the non destructive and non invasive diagnostic techniques has always advantages in the activities on pre-existing buildings, in terms of sustainability; moreover, it is a need with respect to the conservation constraints when we act on the historical-architectural heritage. Ultrasonic technique is widely and successfully performed in the diagnosis and control of the restoration works on concrete and compact stone artefacts. Specific problems arise from its use with reference to highly porous and soft stones, in particular bi-component materials with grains-cement binder structure, such as calcarenites. Low ultrasonic propagation velocity, typically associated to the soft and porous materials can be easily affected by disturbing factors, in primis water (in vapour or liquid state), that can easily and frequently penetrates inside them and in significant amounts, due to their high open porosity. The analysis and interpretation of the data acquired by in situ investigations have to take into account this additional contribution. In the same way, on site structures and materials can be easily interested by salt presence and deposition within the pores, that can furtherly interfere on the data significance, as well as it is important to know the variability of data due to the different state of conservation of the stones. The influence of all these factors on the response to the ultrasonic tests needs to be investigated by laboratory controlled conditions, preliminarily to the in situ application. The present work refers to the experimental activity devoted to investigate the critical aspects that have been mentioned above and the results obtained. It is a part of a larger activity with the final aim to set up non invasive diagnostic procedures for the analysis and qualification of ancient masonries, realised with traditional soft stones, used as building materials in the Southern Italy. This activity is carried out within the AITECH network (Applied Innovation Technologies for Diagnosis and Conservation of Built Heritage), a regional research laboratory infrastructure (Apulian region, Southern Italy) funded within the FSE and FESR programs and realised by the contribution of the Italian CNR and Salento University. In particular, ultrasonic velocity propagation have been measured on different petrographic kinds of calcarenitic materials. The influence of the sample size -the scale effect- has also been investigated. Velocity data have been recorded on the samples in the following conditions: a) dry, wet and different rates of the humidity content b) salt saturation c) after ageing by salt crystallisation cycles. Finally, ultrasonic tests have been performed on some samples treated by inorganic silica consolidant. This experimental laboratory investigation is the preliminary activity to assess the performance potential of the ultrasonic tests as effective tool for the qualification and diagnosis before and after treatments, with reference to the specific critical aspects related to highly porous and soft stone materials, traditionally used in the built heritage of the past.

Non-contact ultrasonic gas flow metering using air-coupled leaky Lamb waves.

PubMed

Fan, Zichuan; Jiang, Wentao; Wright, William M D

2018-04-23

This paper describes a completely non-contact ultrasonic method of gas flow metering using air-coupled leaky Lamb waves. To show proof of principle, a simplified representation of gas flow in a duct, comprising two separated thin isotropic plates with a gas flowing between them, has been modelled and investigated experimentally. An airborne compression wave emitted from an air-coupled capacitive ultrasonic transducer excited a leaky Lamb wave in the first plate in a non-contact manner. The leakage of this Lamb wave crossed the gas flow at an angle between the two plates as a compression wave, and excited a leaky Lamb wave in the second plate. An air-coupled capacitive ultrasonic transducer on the opposite side of this second plate then detected the airborne compression wave leakage from the second Lamb wave. As the gas flow shifted the wave field between the two plates, the point of Lamb wave excitation in the second plate was displaced in proportion to the gas flow rate. Two such measurements, in opposite directions, formed a completely non-contact contra-propagating Lamb wave flow meter, allowing measurement of the flow velocity between the plates. A COMSOL Multiphysics® model was used to visualize the wave fields, and accurately predicted the time differences that were then measured experimentally. Experiments using different Lamb wave frequencies and plate materials were also similarly verified. This entirely non-contact airborne approach to Lamb wave flow metering could be applied in place of clamp-on techniques in thin-walled ducts or pipes. Copyright © 2018 Elsevier B.V. All rights reserved.

Micro-fractures produced in the Cadalso de los Vidrios granite (Madrid) subjected to Freeze-Thaw Durability Testing

NASA Astrophysics Data System (ADS)

Freire-Lista, D. M.; Varas-Muriel, M. J.; Fort, R.

2012-04-01

A specific leucogranite (fine to medium grain sized) from Cadalso de los Vidrios, Madrid, Spain, from where it takes the name of the stone variety, which is a traditional heritage building material used in Central Spain, was subjected to freezing-thaw durability tests or accelerated artificial ageing tests (according to Spanish standard EN 12371:2001) to assess its durability by means of ultrasonic velocity measurements (a non-destructive technique), and optical and fluorescence petrography using a polarized optical microscope (destructive technique), both techniques used before, during and after laboratory ageing tests, or in other words, what is determined is the improvement or deterioration in some properties. The measurement of the ultrasonic velocity in the leucogranite cubic test specimens along the freezing-thaw cycles shown that the velocity diminishes with the number of cycles, in relation to the decay that the stones were experiencing. This deterioration can be observed by the loss of crystalline minerals in the surface of the analyzed samples and by the micro-fractures appearance up to one centimeter deep, which have been detected by the petrographic techniques previously mentioned. The images taken by means of the fluorescence microscope clearly show the micro-fractures generated during the durability test. These images have been processed and analyzed by the UTHSCSA Image Tool program with the purpose of being able to quantify the degree of decay that this type of crystalline materials undergone, when subjected to a number of freezing-thaw test cycles. It is therefore an effective, reliable and complementary technique to that of the petrography analysis, both optical and fluorescence ones. In the first cycles of the ageing test, the micro-fractures propagate along crystals edges and during the last cycles of the test, intracrystalline micro-fractures are generated, which are developed in different ways depending on the mineralogy of the crystals. Thus, the quartz crystals are those that undergo more intracrystalline micro-fractures, whereas the biotites, behave in a more ductile form and they are not micro-fractured. Both analytical techniques give information of this granite deterioration, showing a relation between the number of freezing-thaw cycles, the superficial micro-fractures proliferation and the decrease of ultrasonic waves propagation velocity produced by the ageing cycles.

Ultrasonic survey and monitoring of the excavation damaged zone in callovo-oxfordian argillaceous rock

NASA Astrophysics Data System (ADS)

Balland, C.; Morel, J.

2010-12-01

The mining of galleries in geological claystones formation induces a stress redistribution that can cause a microfissuration of the rock around the works which, by coalescence, may generate macro field fractures. In this area called EDZ (Excavation Damaged Zone), permeability is expected to increase drastically. Those induced cracking along with increased permeability, shall be taken into account in safety assessment of deep geological disposal. Ultrasonic survey and monitoring experiments have been performed in the Underground Research Laboratory of Meuse/Haute-Marne to contribute to the understanding of the extension and evolution of this damage. Ultrasonic devices have been deployed around shaft, gallery, slot and borehole to characterize the initiation, the extension and the level of the EDZ, P-wave velocity being very sensitive to the mechanical rock perturbations. The analysis of spatial and temporal velocity field changes gave reliable information on the cracks characteristics of the especially about their opening or their preferential orientation. The results provided by an ultrasonic device around shaft mine by test highlighted the initialization and extension of the damage as the shaft front proceeded. They also showed a polarisation of the velocity field and an oscillation of the transversal isotropy with a preferential orientation of the stress release and the microcracking. Otherwise, with a new automatic and ultrasonic probe, we have found around a borehole that the damage zone extends up to 0.175 diameter of depth with an anisotropic damage pattern oriented according to the regional stress field (Figure 1). Nevertheless, the evolution of this damaged zone is still not well known at longer term, particularly under the influence of parameters such as the reconfining rock in contact with a rigid concrete surface. Is it possible that cracks close up significantly toward their seal? Induced mechanical perturbations are in this case much weaker than those generated by the excavation itself. A new ultrasonic experiment has been designed to be more sensitive to the frequency modulation of the P and S-wave sources. The purpose is to determine on site the dynamic elastic stiffness and the corresponding crack density tensors change before and during the resaturation and reconfining of the damaged and undamaged excavation vicinity. P-wave velocity field around a vertical borehole

Experimental Investigation on Acoustic Control Droplet Transfer in Ultrasonic-Wave-Assisted Gas Metal Arc Welding

NASA Astrophysics Data System (ADS)

Weifeng, Xie; Chenglei, Fan; Chunli, Yang; Sanbao, Lin

2018-02-01

Ultrasonic-wave-assisted gas metal arc welding (U-GMAW) is a new, advanced arc welding method that uses an ultrasonic wave emitted from an ultrasonic radiator above the arc. However, it remains unclear how the ultrasonic wave affects the metal droplet, hindering further application of U-GMAW. In this paper, an improved U-GMAW system was used and its superiority was experimentally demonstrated. Then a series of experiments were designed and performed to study how the ultrasonic wave affects droplet transfer, including droplet size, velocity, and motion trajectory. The behavior of droplet transfer was observed in high-speed images. The droplet transfer is closely related to the distribution of the acoustic field, determined by the ultrasonic current. Moreover, by analyzing the variably accelerated motion of the droplet, the acoustic control of the droplet transfer was intuitively demonstrated. Finally, U-GMAW was successfully used in vertical-up and overhead welding experiments, showing that U-GMAW is promising for use in welding in all positions.

Tracking silica in Earth's upper mantle using new sound velocity data for coesite to 5.8 GPa and 1073 K

NASA Astrophysics Data System (ADS)

Chen, Ting; Liebermann, Robert C.; Zou, Yongtao; Li, Ying; Qi, Xintong; Li, Baosheng

2017-08-01

The compressional and shear wave velocities for coesite have been measured simultaneously up to 5.8 GPa and 1073 K by ultrasonic interferometry for the first time. The shear wave velocity decreases with pressure along all isotherms. The resulting contrasts between coesite and stishovite reach 34% and 45% for P and S wave velocities, respectively, and 64% and 75% for their impedance at mantle conditions. The large velocity and impedance contrasts across coesite-stishovite transition imply that to generate the velocity and impedance contrasts observed at the X-discontinuity, only a small amount of silica would be required. The velocity jump dependences on silica, d(lnVP)/d(SiO2) = 0.38 (wt %)-1 and d(lnVS)/d(SiO2) = 0.52 (wt %)-1, are utilized to place constraints on the amount of silica in the upper mantle and provide a geophysical approach to track mantle eclogite materials and ancient subducted oceanic slabs.

Tracking silica in Earth's upper mantle using new sound velocity data for coesite to 5.8 GPa and 1073 K: Tracking Silica in Earth's Upper Mantle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Ting; Liebermann, Robert C.; Zou, Yongtao

The compressional and shear wave velocities for coesite have been measured simultaneously up to 5.8 GPa and 1073 K by ultrasonic interferometry for the first time. The shear wave velocity decreases with pressure along all isotherms. The resulting contrasts between coesite and stishovite reach ~34% and ~45% for P and S wave velocities, respectively, and ~64% and ~75% for their impedance at mantle conditions. The large velocity and impedance contrasts across coesite-stishovite transition imply that to generate the velocity and impedance contrasts observed at the X-discontinuity, only a small amount of silica would be required. The velocity jump dependences onmore » silica, d(lnVP)/d(SiO2) = 0.38 (wt %)-1 and d(lnVS)/d(SiO2) = 0.52 (wt %)-1, are utilized to place constraints on the amount of silica in the upper mantle and provide a geophysical approach to track mantle eclogite materials and ancient subducted oceanic slabs.« less

Micro-scale finite element modeling of ultrasound propagation in aluminum trabecular bone-mimicking phantoms: A comparison between numerical simulation and experimental results.

PubMed

Vafaeian, B; Le, L H; Tran, T N H T; El-Rich, M; El-Bialy, T; Adeeb, S

2016-05-01

The present study investigated the accuracy of micro-scale finite element modeling for simulating broadband ultrasound propagation in water-saturated trabecular bone-mimicking phantoms. To this end, five commercially manufactured aluminum foam samples as trabecular bone-mimicking phantoms were utilized for ultrasonic immersion through-transmission experiments. Based on micro-computed tomography images of the same physical samples, three-dimensional high-resolution computational samples were generated to be implemented in the micro-scale finite element models. The finite element models employed the standard Galerkin finite element method (FEM) in time domain to simulate the ultrasonic experiments. The numerical simulations did not include energy dissipative mechanisms of ultrasonic attenuation; however, they expectedly simulated reflection, refraction, scattering, and wave mode conversion. The accuracy of the finite element simulations were evaluated by comparing the simulated ultrasonic attenuation and velocity with the experimental data. The maximum and the average relative errors between the experimental and simulated attenuation coefficients in the frequency range of 0.6-1.4 MHz were 17% and 6% respectively. Moreover, the simulations closely predicted the time-of-flight based velocities and the phase velocities of ultrasound with maximum relative errors of 20 m/s and 11 m/s respectively. The results of this study strongly suggest that micro-scale finite element modeling can effectively simulate broadband ultrasound propagation in water-saturated trabecular bone-mimicking structures. Copyright © 2016 Elsevier B.V. All rights reserved.

Ultrasonic nondestructive evaluation of impact-damaged graphite fiber composite

NASA Technical Reports Server (NTRS)

Williams, J. H., Jr.; Lampert, N. R.

1980-01-01

Unidirectional Hercules AS/3501-6 graphite fiber epoxy composites were subjected to repeated controlled low-velocity drop weight impacts in the laminate direction. The degradation was ultrasonically monitored using through-thickness attenuation and a modified stress wave factor (SWF). There appears to be strong correlations between the number of drop-weight impacts, the residual tensile strength, the through-thickness attenuation, and the SWF. The results are very encouraging with respect to the NDE potential of both of these ultrasonic parameters to provide strength characterizations in virgin as well as impact-damaged fiber composite structures.

Ultrasonic assessment of bonding integrity in foam-based hybrid composite materials

NASA Astrophysics Data System (ADS)

Chen, M. Y.; Ko, R. T.; Hoppe, W. C.; Blackshire, J. L.

2013-01-01

Ultrasonic assessment of the bonding integrity between a composite layer and a foam substrate in foam-based hybrid composite materials was explored. The challenges of this task are: (1) the foam has air-like acoustic impedance and (2) contact surface wave generation on polymer matrix composites (PMC) is not conventional. To meet these challenges, a novel wedge made of a low velocity material was developed. The results showed that the bonding condition in these composites can be identified by monitoring the amplitude of the ultrasonic signals received.

Radiographic and ultrasonic characterization of sintered silicon carbide

NASA Technical Reports Server (NTRS)

Baaklini, G. Y.; Abel, P. B.

1988-01-01

The capabilities were investigated of projection microfocus X-radiography, ultrasonic velocity and attenuation, and reflection scanning acoustic microscopy for characterizing silicon carbide specimens. Silicon carbide batches covered a range of densities and different microstructural characteristics. Room temperature, four point flexural strength tests were conducted. Fractography was used to identify types, sizes, and locations of fracture origins. Fracture toughness values were calculated from fracture strength and flaw characterization data. Detection capabilities of radiography and acoustic microscopy for fracture-causing flaws were evaluated. Applicability of ultrasonics for verifying material strength and toughness was examined.

Flaw imaging and ultrasonic techniques for characterizing sintered silicon carbide

NASA Technical Reports Server (NTRS)

Baaklini, George Y.; Abel, Phillip B.

1987-01-01

The capabilities were investigated of projection microfocus x-radiography, ultrasonic velocity and attenuation, and reflection scanning acoustic microscopy for characterizing silicon carbide specimens. Silicon carbide batches covered a range of densities and different microstructural characteristics. Room temperature, four point flexural strength tests were conducted. Fractography was used to identify types, sizes, and locations of fracture origins. Fracture toughness values were calculated from fracture strength and flaw characterization data. Detection capabilities of radiography and acoustic microscopy for fracture-causing flaws were evaluated. Applicability of ultrasonics for verifying material strength and toughness was examined.

Ceramic Gas Turbine Engine Demonstration Program

DTIC Science & Technology

1982-05-01

of Radiographs 124 5.2.3 Ultrasonic NDE 127 5.2.4 Scanning Laser Acoustic Microscopy 132 5.2.5 Microwave NDE 134 5.2.6 Neutron Radiography 134 5.2.7...microwaves, and scanning loser acoustic microscopy (SLAM) were evaluated using the standards containing known defects. Component shape standards...mounted in a carousel and rotated in the high velocity combustor gases. The temperature is measured by an infrared pyrometer 95 TABLE 4-3. SUMMARY OF

Sound velocity of 23 Å phase (a new Al-bearing hydrous Mg-silicate) to 14 GPa

NASA Astrophysics Data System (ADS)

Cai, N.; Chen, T.; Qi, X.; Inoue, T.; Li, B.

2016-12-01

Dense hydrous phases are believed to play an important role in transporting water back into the deep interior of the Earth. Recently, a new Al-bearing hydrous Mg-silicate named 23 Å phase (ideal composition Mg11Al2Si4O16(OH)12) was reported (Cai et al., 2015), which could be a very important hydrous phase in subducting slab. Here for the first time we measured the compressional and shear wave velocities of this new hydrous phase under mantle pressures. The sample was synthesized at 10 GPa and 1000 ºC using the chemical mixture of stoichiometric as starting materials. The recovered sample was then crushed into fine powder and hot pressed at 10 GPa and 900 ºC for 3 hours. X-ray diffraction, density measurement, and SEM characterization indicated that the specimen is nearly a pure phase, 20 µm in grain size, with a bulk density of 3.004 g/cm3. The acoustic measurements were conducted in a 1000-ton uniaxial split-cylinder multi-anvil apparatus using ultrasonic interferometry techniques (Li et al., 1996) up to 14 GPa at room temperature. The pressures were determined in situ by using alumina buffer rod as a pressure marker (Wang et al., 2015). A dual-mode piezoelectric transducer enables us to measure P and S wave travel times simultaneously, which in turn allows for a precise determination of the sound velocities and elastic bulk and shear moduli at high pressures. Preliminary results suggest that the velocities, (especially for S wave) of this 23 Å phase are slower than that of phase A and most of the mantle minerals. These results may have important implications for understanding some localized low velocity zones in subduction zones. Cai, N., T. Inoue, K. Fujino, H. Ohfuji and H. Yurimoto (2015) A Possible New Al-bearing Hydrous Mg-silicate (23 Å phase) in the Deep Upper Mantle. Am Mineral. 100: 2330-2335. Li, B., I. Jackson, T. Gasparik, and R. C. Liebermann (1996), Elastic wave velocity measurement in multianvil apparatus to 10 GPa using ultrasonic interferometry, Phys. Earth Planet. Inter., 98,79-91. Wang, X., T. Chen, X. Qi, Y. Zou, J. Kung, T. Yu, Y. Wang, R. C. Liebermann and B. Li (2015), Acoustic travel time gauges for in-situ determination of pressure and temperature in multi-anvil apparatus, J. Appl. Phys., 118, 065901.

Anisotropic physical properties of myocardium characterized by ultrasonic measurements of backscatter, attenuation, and velocity

NASA Astrophysics Data System (ADS)

Baldwin, Steven L.

The goal of elucidating the physical mechanisms underlying the propagation of ultrasonic waves in anisotropic soft tissue such as myocardium has posed an interesting and largely unsolved problem in the field of physics for the past 30 years. In part because of the vast complexity of the system being studied, progress towards understanding and modeling the mechanisms that underlie observed acoustic parameters may first require the guidance of careful experiment. Knowledge of the causes of observed ultrasonic properties in soft tissue including attenuation, speed of sound, and backscatter, and how those properties are altered with specific pathophysiologies, may lead to new noninvasive approaches to the diagnosis of disease. The primary aim of this Dissertation is to contribute to an understanding of the physics that underlies the mechanisms responsible for the observed interaction of ultrasound with myocardium. To this end, through-transmission and backscatter measurements were performed by varying acoustic properties as a function of angle of insonification relative to the predominant myofiber direction and by altering the material properties of myocardium by increased protein cross-linking induced by chemical fixation as an extreme form of changes that may occur in certain pathologies such as diabetes. Techniques to estimate acoustic parameters from backscatter were broadened and challenges to implementing these techniques in vivo were addressed. Provided that specific challenges identified in this Dissertation can be overcome, techniques to estimate attenuation from ultrasonic backscatter show promise as a means to investigate the physical interaction of ultrasound with anisotropic biological media in vivo. This Dissertation represents a step towards understanding the physics of the interaction of ultrasonic waves with anisotropic biological media.

Fast simulated annealing inversion of surface waves on pavement using phase-velocity spectra

USGS Publications Warehouse

Ryden, N.; Park, C.B.

2006-01-01

The conventional inversion of surface waves depends on modal identification of measured dispersion curves, which can be ambiguous. It is possible to avoid mode-number identification and extraction by inverting the complete phase-velocity spectrum obtained from a multichannel record. We use the fast simulated annealing (FSA) global search algorithm to minimize the difference between the measured phase-velocity spectrum and that calculated from a theoretical layer model, including the field setup geometry. Results show that this algorithm can help one avoid getting trapped in local minima while searching for the best-matching layer model. The entire procedure is demonstrated on synthetic and field data for asphalt pavement. The viscoelastic properties of the top asphalt layer are taken into account, and the inverted asphalt stiffness as a function of frequency compares well with laboratory tests on core samples. The thickness and shear-wave velocity of the deeper embedded layers are resolved within 10% deviation from those values measured separately during pavement construction. The proposed method may be equally applicable to normal soil site investigation and in the field of ultrasonic testing of materials. ?? 2006 Society of Exploration Geophysicists.

The ultrasonic-enhanced factor of mass-transfer coefficient in the supercritical carbon dioxide extraction

NASA Astrophysics Data System (ADS)

Luo, Benyi; Lu, Yigang

2008-10-01

Based on several hypotheses about the process of supercritical carbon dioxide extraction, the onflow around the solute granule is figured out by the Navier-Stocks equation. In combination with the Higbie’s solute infiltration model, the link between the mass-transfer coefficient and the velocity of flow is found. The mass-transfer coefficient with the ultrasonical effect is compared with that without the ultrasonical effect, and then a new parameter named the ultrasonic-enhanced factor of mass-transfer coefficient is brought forward, which describes the mathematical model of the supercritical carbon dioxide extraction process enhanced by ultrasonic. The model gives out the relationships among the ultrasonical power, the ultrasonical frequency, the radius of solute granule and the ultrasonic-enhanced factor of mass-transfer coefficient. The results calculated by this model fit well with the experimental data, including the extraction of Coix Lacryma-jobi Seed Oil (CLSO) and Coix Lacryma-jobi Seed Ester (CLSE) from coix seeds and the extraction of Eicosapentaenoic Acid (EPA) and Docosahexaenoic Acid (DHA) from the alga by means of the ultrasonic-enhanced supercritical carbon dioxide extraction (USFE) and the supercritical carbon dioxide extraction (SFE) respectively. This proves the rationality of the ultrasonic-enhanced factor model. The model provides a theoretical basis for the application of ultrasonic-enhanced supercritical fluid extraction technique.

Dynamics of cavitation clouds within a high-intensity focused ultrasonic beam

NASA Astrophysics Data System (ADS)

Lu, Yuan; Katz, Joseph; Prosperetti, Andrea

2013-07-01

In this experimental study, we generate a 500 kHz high-intensity focused ultrasonic beam, with pressure amplitude in the focal zone of up to 1.9 MPa, in initially quiescent water. The resulting pressure field and behavior of the cavitation bubbles are measured using high-speed digital in-line holography. Variations in the water density and refractive index are used for determining the spatial distribution of the acoustic pressure nonintrusively. Several cavitation phenomena occur within the acoustic partially standing wave caused by the reflection of sound from the walls of the test chamber. At all sound levels, bubbly layers form in the periphery of the focal zone in the pressure nodes of the partial standing wave. At high sound levels, clouds of vapor microbubbles are generated and migrate in the direction of the acoustic beam. Both the cloud size and velocity vary periodically, with the diameter peaking at the pressure nodes and velocity at the antinodes. A simple model involving linearized bubble dynamics, Bjerknes forces, sound attenuation by the cloud, added mass, and drag is used to predict the periodic velocity of the bubble cloud, as well as qualitatively explain the causes for the variations in the cloud size. The analysis shows that the primary Bjerknes force and drag dominate the cloud motion, and suggests that the secondary Bjerknes force causes the oscillations in the cloud size.

Pressure measurement in supersonic air flow by differential absorptive laser-induced thermal acoustics.

PubMed

Hart, Roger C; Herring, G C; Balla, R Jeffrey

2007-06-15

Nonintrusive, off-body flow barometry in Mach 2 airflow has been demonstrated in a large-scale supersonic wind tunnel using seedless laser-induced thermal acoustics (LITA). The static pressure of the gas flow is determined with a novel differential absorption measurement of the ultrasonic sound produced by the LITA pump process. Simultaneously, the streamwise velocity and static gas temperature of the same spatially resolved sample volume were measured with this nonresonant time-averaged LITA technique. Mach number, temperature, and pressure have 0.2%, 0.4%, and 4% rms agreement, respectively, in comparison with known free-stream conditions.

Pressure Measurement in Supersonic Air Flow by Differential Absorptive Laser-Induced Thermal Acoustics

NASA Technical Reports Server (NTRS)

Hart, Roger C.; Herring, Gregory C.; Balla, Robert J.

2007-01-01

Nonintrusive, off-body flow barometry in Mach-2 airflow has been demonstrated in a large-scale supersonic wind tunnel using seedless laser-induced thermal acoustics (LITA). The static pressure of the gas flow is determined with a novel differential absorption measurement of the ultrasonic sound produced by the LITA pump process. Simultaneously, stream-wise velocity and static gas temperature of the same spatially-resolved sample volume were measured with this nonresonant time-averaged LITA technique. Mach number, temperature and pressure have 0.2%, 0.4%, and 4% rms agreement, respectively, in comparison with known free-stream conditions.

Evaluation of multilayered pavement structures from measurements of surface waves

USGS Publications Warehouse

Ryden, N.; Lowe, M.J.S.; Cawley, P.; Park, C.B.

2006-01-01

A method is presented for evaluating the thickness and stiffness of multilayered pavement structures from guided waves measured at the surface. Data is collected with a light hammer as the source and an accelerometer as receiver, generating a synthetic receiver array. The top layer properties are evaluated with a Lamb wave analysis. Multiple layers are evaluated by matching a theoretical phase velocity spectrum to the measured spectrum. So far the method has been applied to the testing of pavements, but it may also be applicable in other fields such as ultrasonic testing of coated materials. ?? 2006 American Institute of Physics.

Indoor seismology by probing the Earth's interior by using sound velocity measurements at high pressures and temperatures.

PubMed

Li, Baosheng; Liebermann, Robert C

2007-05-29

The adiabatic bulk (K(S)) and shear (G) moduli of mantle materials at high pressure and temperature can be obtained directly by measuring compressional and shear wave velocities in the laboratory with experimental techniques based on physical acoustics. We present the application of the current state-of-the-art experimental techniques by using ultrasonic interferometry in conjunction with synchrotron x radiation to study the elasticity of olivine and pyroxenes and their high-pressure phases. By using these updated thermoelasticity data for these phases, velocity and density profiles for a pyrolite model are constructed and compared with radial seismic models. We conclude that pyrolite provides an adequate explanation of the major seismic discontinuities at 410- and 660-km depths, the gradient in the transition zone, as well as the velocities in the lower mantle, if the uncertainties in the modeling and the variations in different seismic models are considered. The characteristics of the seismic scaling factors in response to thermal anomalies suggest that anticorrelations between bulk sound and shear wave velocities, as well as the large positive density anomalies observed in the lower mantle, cannot be explained fully without invoking chemical variations.

Scaling up the Single Transducer Thickness-Independent Ultrasonic Imaging Method for Accurate Characterization of Microstructural Gradients in Monolithic and Composite Tubular Structures

NASA Technical Reports Server (NTRS)

Roth, Don J.; Carney, Dorothy V.; Baaklini, George Y.; Bodis, James R.; Rauser, Richard W.

1998-01-01

Ultrasonic velocity/time-of-flight imaging that uses back surface reflections to gauge volumetric material quality is highly suited for quantitative characterization of microstructural gradients including those due to pore fraction, density, fiber fraction, and chemical composition variations. However, a weakness of conventional pulse-echo ultrasonic velocity/time-of-flight imaging is that the image shows the effects of thickness as well as microstructural variations unless the part is uniformly thick. This limits this imaging method's usefulness in practical applications. Prior studies have described a pulse-echo time-of-flight-based ultrasonic imaging method that requires using a single transducer in combination with a reflector plate placed behind samples that eliminates the effect of thickness variation in the image. In those studies, this method was successful at isolating ultrasonic variations due to material microstructure in plate-like samples of silicon nitride, metal matrix composite, and polymer matrix composite. In this study, the method is engineered for inspection of more complex-shaped structures-those having (hollow) tubular/curved geometry. The experimental inspection technique and results are described as applied to (1) monolithic mullite ceramic and polymer matrix composite 'proof-of-concept' tubular structures that contain machined patches of various depths and (2) as-manufactured monolithic silicon nitride ceramic and silicon carbide/silicon carbide composite tubular structures that might be used in 'real world' applications.

Rainbow trapping of ultrasonic guided waves in chirped phononic crystal plates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tian, Zhenhua; Yu, Lingyu

The rainbow trapping effect has been demonstrated in electromagnetic and acoustic waves. In this study, rainbow trapping of ultrasonic guided waves is achieved in chirped phononic crystal plates that spatially modulate the dispersion, group velocity, and stopband. The rainbow trapping is related to the progressively slowing group velocity, and the extremely low group velocity near the lower boundary of a stopband that gradually varies in chirped phononic crystal plates. As guided waves propagate along the phononic crystal plate, waves gradually slow down and finally stop forward propagating. The energy of guided waves is concentrated at the low velocity region nearmore » the stopband. Moreover, the guided wave energy of different frequencies is concentrated at different locations, which manifests as rainbow guided waves. We believe implementing the rainbow trapping will open new paradigms for guiding and focusing of guided waves. Furthermore, the rainbow guided waves with energy concentration and spatial separation of frequencies may have potential applications in nondestructive evaluation, spatial wave filtering, energy harvesting, and acoustofluidics.« less

Rainbow trapping of ultrasonic guided waves in chirped phononic crystal plates

DOE PAGES

Tian, Zhenhua; Yu, Lingyu

2017-01-05

The rainbow trapping effect has been demonstrated in electromagnetic and acoustic waves. In this study, rainbow trapping of ultrasonic guided waves is achieved in chirped phononic crystal plates that spatially modulate the dispersion, group velocity, and stopband. The rainbow trapping is related to the progressively slowing group velocity, and the extremely low group velocity near the lower boundary of a stopband that gradually varies in chirped phononic crystal plates. As guided waves propagate along the phononic crystal plate, waves gradually slow down and finally stop forward propagating. The energy of guided waves is concentrated at the low velocity region nearmore » the stopband. Moreover, the guided wave energy of different frequencies is concentrated at different locations, which manifests as rainbow guided waves. We believe implementing the rainbow trapping will open new paradigms for guiding and focusing of guided waves. Furthermore, the rainbow guided waves with energy concentration and spatial separation of frequencies may have potential applications in nondestructive evaluation, spatial wave filtering, energy harvesting, and acoustofluidics.« less

Rainbow trapping of ultrasonic guided waves in chirped phononic crystal plates.

PubMed

Tian, Zhenhua; Yu, Lingyu

2017-01-05

The rainbow trapping effect has been demonstrated in electromagnetic and acoustic waves. In this study, rainbow trapping of ultrasonic guided waves is achieved in chirped phononic crystal plates that spatially modulate the dispersion, group velocity, and stopband. The rainbow trapping is related to the progressively slowing group velocity, and the extremely low group velocity near the lower boundary of a stopband that gradually varies in chirped phononic crystal plates. As guided waves propagate along the phononic crystal plate, waves gradually slow down and finally stop forward propagating. The energy of guided waves is concentrated at the low velocity region near the stopband. Moreover, the guided wave energy of different frequencies is concentrated at different locations, which manifests as rainbow guided waves. We believe implementing the rainbow trapping will open new paradigms for guiding and focusing of guided waves. Moreover, the rainbow guided waves with energy concentration and spatial separation of frequencies may have potential applications in nondestructive evaluation, spatial wave filtering, energy harvesting, and acoustofluidics.

Ultrasonic device for real-time sewage velocity and suspended particles concentration measurements.

PubMed

Abda, F; Azbaid, A; Ensminger, D; Fischer, S; François, P; Schmitt, P; Pallarès, A

2009-01-01

In the frame of a technological research and innovation network in water and environment technologies (RITEAU, Réseau de Recherche et d'Innovation Technologique Eau et Environnement), our research group, in collaboration with industrial partners and other research institutions, has been in charge of the development of a suitable flowmeter: an ultrasonic device measuring simultaneously the water flow and the concentration of size classes of suspended particles. Working on the pulsed ultrasound principle, our multi-frequency device (1 to 14 MHz) allows flow velocity and water height measurement and estimation of suspended solids concentration. Velocity measurements rely on the coherent Doppler principle. A self developed frequency estimator, so called Spectral Identification method, was used and compared to the classical Pulse-Pair method. Several measurements campaigns on one wastewater collector of the French city of Strasbourg gave very satisfactory results and showed smaller standard deviation values for the Doppler frequency extracted by the Spectral Identification method. A specific algorithm was also developed for the water height measurements. It relies on the water surface acoustic impedance rupture and its peak localisation and behaviour in the collected backscattering data. This algorithm was positively tested on long time measurements on the same wastewater collector. A large part of the article is devoted to the measurements of the suspended solids concentrations. Our data analysis consists in the adaptation of the well described acoustic behaviour of sand to the behaviour of wastewater particles. Both acoustic attenuation and acoustic backscattering data over multiple frequencies are analyzed for the extrapolation of size classes and respective concentrations. Under dry weather conditions, the massic backscattering coefficient and the overall size distribution showed similar evolution whatever the measurement site was and were suggesting a global wastewater particles behaviour. By comparison to sampling data, our data analysis lead to the characterization of two particle groups: the ones occurring during rain events and the ones typical of wastewater under dry weather conditions. Even with already encouraging results on the several weeks of data recorded on several wastewater collectors, the validation of our data inversion method is still under progress.

Biomechanical implications of cortical elastic properties of the macaque mandible.

PubMed

Dechow, Paul C; Panagiotopoulou, Olga; Gharpure, Poorva

2017-10-01

Knowledge of the variation in the elastic properties of mandibular cortical bone is essential for modeling bone function. Our aim was to characterize the elastic properties of rhesus macaque mandibular cortical bone and compare these to the elastic properties from mandibles of dentate humans and baboons. Thirty cylindrical samples were harvested from each of six adult female rhesus monkey mandibles. Assuming orthotropy, axes of maximum stiffness in the plane of the cortical plate were derived from ultrasound velocity measurements. Further velocity measurements with longitudinal and transverse ultrasonic transducers along with measurements of bone density were used to compute three-dimensional cortical elastic properties using equations based on Hooke's law. Results showed regional variations in the elastic properties of macaque mandibular cortical bone that have both similarities and differences with that of humans and baboons. So far, the biological and structural basis of these differences is poorly understood. Copyright © 2017 Elsevier GmbH. All rights reserved.

Surface Brillouin scattering of opaque solids and thin supported films

PubMed

Comins; Every; Stoddart; Zhang; Crowhurst; Hearne

2000-03-01

Surface Brillouin scattering (SBS) has been used successfully for the study of acoustic excitations in opaque solids and thin supported films, at both ambient and high temperatures. A number of different systems have been investigated recently by SBS including crystalline silicon, amorphous silicon layers produced by ion bombardment and their high temperature recrystallisation, vanadium carbides, and a nickel-based superalloy. The most recent development includes the measurement of a supported gold film at high pressure. The extraction of the elastic constants is successfully accomplished by a combination of the angular dependence of surface wave velocities and the longitudinal wave threshold within the Lamb shoulder. The application of surface Green's function methods successfully reproduces the experimental SBS spectra. The discrepancies often observed between surface wave velocities and by ultrasonics measurements have been investigated and a detailed correction procedure for the SBS measurements has been developed.

Mechanism of ultrasonic energy-assisted formation of V-, Y-shaped nano-structures in conjugated polymers.

PubMed

Majumdar, D; Maiti, R P; Basu, S; Saha, S K

2009-12-01

Recently, hydrocarbon-nanostructures from organic solvent using ultrasonic energy were reported. However, their formation-dynamics remained unexplored. Here, we describe a new technique to synthesize controlled nanostructures (V-, Y-shape) from nanorods of conducting polyaniline applying ultrasonic energy. To characterize the conducting state (emaraldine) of these polyaniline nanorods, electrical measurements have been carried out from which it is seen that there is a crossover from metallic to semiconductor as temperature increases. The observed crossover has been explained by the core-shell structure of the nanorods with core resistivity much higher than the shell resistivity. The nonlinear current-voltage behavior is attributed to the formation of alternate ordered/disordered chain segments along the length of the nanorods. We also propose a model to explore the mechanism of formation of these V-, Y-shaped nanostructures. It is believed that bubble-formation occurs in liquid due to ultrasonic vibration; and asymmetry in the bubble is created when formed near the solid surface leading to jet formation. Liquid jets of collapsing bubble move with incredible velocity (400 km/h); collide with the nanorod to cause fragmentations followed by V-, Y-shaped structure formation when the imparted kinetic energy of jets is comparable with elastic energy of fragments.

Influence of the Ultrasonic Power Applied on Freeze Drying Kinetics

NASA Astrophysics Data System (ADS)

Brines, C.; Mulet, A.; García-Pérez, J. V.; Riera, E.; Cárcel, J. A.

The atmospheric freeze drying (AFD) constitutes an interesting alternative to vacuum freeze drying providing products with similar quality at lowest cost. However, the long process time needed represent an important drawback. In this sense, the application of high intensity ultrasound can enhance heat and mass transfer and intensify the operation. In hot air drying operation, the ultrasonic effects are dependent on the process variables such as air velocity, internal sample structure or ultrasonic power applied. However, in AFD processes, the internal structure of material or the air velocity has not significant influence on the magnitude of ultrasonic effects. The aim of this work was to determine the influence on drying kinetics of the ultrasonic power applied during the AFD of apple. For that purpose, AFD experiments (-10 °C, 2 m/s and 15% relative humidity) of apple slabs (cv. Granny Smith, 30 x 30 x 10 mm) were carried out with ultrasound application (21 kHz) at different power levels (0, 10.3, 20.5 and 30.8 kW/m3). The drying kinetics was obtained from the initial moisture content and the weight evolution of samples during drying. Experimental results showed a significant (p<0.05) influence of the ultrasound application on drying. Thus, drying time was shorter as higher the ultrasonic power applied. From modeling, it was observed that the effective diffusion coefficient identified was 4.8 times higher when ultrasound was applied at the lowest power tested (10.3 kW/m3) that illustrated the high intensification potential of ultrasound application in the AFD.

Structure of large-scale flows and their oscillation in the thermal convection of liquid gallium.

PubMed

Yanagisawa, Takatoshi; Yamagishi, Yasuko; Hamano, Yozo; Tasaka, Yuji; Yoshida, Masataka; Yano, Kanako; Takeda, Yasushi

2010-07-01

This investigation observed large-scale flows in liquid gallium and the oscillation with Rayleigh-Bénard convection. An ultrasonic velocity profiling method was used to visualize the spatiotemporal flow pattern of the liquid gallium in a horizontally long rectangular vessel. Measuring the horizontal component of the flow velocity at several lines, an organized roll-like structure with four cells was observed in the 1×10(4)-2×10(5) range of Rayleigh numbers, and the rolls show clear oscillatory behavior. The long-term fluctuations in temperature observed in point measurements correspond to the oscillations of the organized roll structure. This flow structure can be interpreted as the continuous development of the oscillatory instability of two-dimensional roll convection that is theoretically investigated around the critical Rayleigh number. Both the velocity of the large-scale flows and the frequency of the oscillation increase proportional to the square root of the Rayleigh number. This indicates that the oscillation is closely related to the circulation of large-scale flow.

Deduction of two-dimensional blood flow vector by dual angle diverging waves from a cardiac sector probe

NASA Astrophysics Data System (ADS)

Maeda, Moe; Nagaoka, Ryo; Ikeda, Hayato; Yaegashi, So; Saijo, Yoshifumi

2018-07-01

Color Doppler method is widely used for noninvasive diagnosis of heart diseases. However, the method can measure one-dimensional (1D) blood flow velocity only along an ultrasonic beam. In this study, diverging waves with two different angles were irradiated from a cardiac sector probe to estimate a two-dimensional (2D) blood flow vector from each velocity measured with the angles. The feasibility of the proposed method was evaluated in experiments using flow poly(vinyl alcohol) (PVA) gel phantoms. The 2D velocity vectors obtained with the proposed method were compared with the flow vectors obtained with the particle image velocimetry (PIV) method. Root mean square errors of the axial and lateral components were 11.3 and 29.5 mm/s, respectively. The proposed method was also applied to echo data from the left ventricle of the heart. The inflow from the mitral valve in diastole and the ejection flow concentrating in the aorta in systole were visualized.

Cyclic variation of ultrasonic backscattering from porcine whole blood under pulsatile flow

NASA Astrophysics Data System (ADS)

Lin, Yu-Hong

1997-10-01

The cyclic variation of ultrasonic backscattering from blood under pulsatile flow is believed to be related to the change of aggregation state of red cells and is only observed in whole blood. This study was to investigate the phenomenon by an invasive approach which was performed by inserting a 10 MHz catheter mounted transducer into a vessel. For ultrasonic measurement from blood, the most fundamental scheme is the hematocrit dependence. The backscatter maximum location was changed as the blood was stirred or stationary, as well as under steady laminar or turbulent flows. The same trend was also observed under pulsatile flow with 10% to 50% hematocrits in this study, as the backscattering to hematocrit curves were plotted at different times during a flow cycle. When the cyclic variation at 20 beats per minute (BPM) was interpreted in time domain, the enhanced aggregation at the beginning of shearing was observed. At 20 BPM with 40% hematocrit, the amplitude of cyclic variation was reduced when the shear rate was increased and the threshold of 150 s-1 was estimated. The results showed that there was no cyclic variation at 60 BPM. The backscattering was also plotted against the mean flow velocity, which demonstrated the hysteresis loops. The ultrasonic measurements showed that the relationship between the forward and backward paths of the loops were altered as beat rate, hematocrit, and shear rate were varied. Since the pulsatile flow was very complicated, a computational fluid dynamics package, FIDAPTM, was used to compute the shear rate based on the Power Law Model for non-Newtonian fluid viscosity. The non- Newtonian index and consistency in the model were computed from the viscosity to shear rate curves at 10% to 50% hematocrits measured by a cone-plate viscometer. For in vivo measurements, small pigs were used as models. Ultrasonic backscattering measurements were performed in the arteries and veins. The effect of stenosis was also investigated at the site below the renal branch in the artery. The results show that the cyclic variation from whole blood was mediated by the shear rate, hematocrit, beat rate, and fibrinogen concentration.

Basic Study for Ultrasound-Based Navigation for Pedicle Screw Insertion Using Transmission and Backscattered Methods

PubMed Central

Chen, Ziqiang; Wu, Bing; Zhai, Xiao; Bai, Yushu; Zhu, Xiaodong; Luo, Beier; Chen, Xiao; Li, Chao; Yang, Mingyuan; Xu, Kailiang; Liu, Chengcheng; Wang, Chuanfeng; Zhao, Yingchuan; Wei, Xianzhao; Chen, Kai; Yang, Wu; Ta, Dean; Li, Ming

2015-01-01

The purpose of this study was to understand the acoustic properties of human vertebral cancellous bone and to study the feasibility of ultrasound-based navigation for posterior pedicle screw fixation in spinal fusion surgery. Fourteen human vertebral specimens were disarticulated from seven un-embalmed cadavers (four males, three females, 73.14 ± 9.87 years, two specimens from each cadaver). Seven specimens were used to measure the transmission, including tests of attenuation and phase velocity, while the other seven specimens were used for backscattered measurements to inspect the depth of penetration and A-Mode signals. Five pairs of unfocused broadband ultrasonic transducers were used for the detection, with center frequencies of 0.5 MHz, 1 MHz, 1.5 MHz, 2.25 MHz, and 3.5 MHz. As a result, good and stable results were documented. With increased frequency, the attenuation increased (P<0.05), stability of the speed of sound improved (P<0.05), and penetration distance decreased (P>0.05). At about 0.6 cm away from the cortical bone, warning signals were easily observed from the backscattered measurements. In conclusion, the ultrasonic system proved to be an effective, moveable, and real-time imaging navigation system. However, how ultrasonic navigation will benefit pedicle screw insertion in spinal surgery needs to be determined. Therefore, ultrasound-guided pedicle screw implantation is theoretically effective and promising. PMID:25861053

A new method for ultrasound detection of interfacial position in gas-liquid two-phase flow.

PubMed

Coutinho, Fábio Rizental; Ofuchi, César Yutaka; de Arruda, Lúcia Valéria Ramos; Neves, Flávio; Morales, Rigoberto E M

2014-05-22

Ultrasonic measurement techniques for velocity estimation are currently widely used in fluid flow studies and applications. An accurate determination of interfacial position in gas-liquid two-phase flows is still an open problem. The quality of this information directly reflects on the accuracy of void fraction measurement, and it provides a means of discriminating velocity information of both phases. The algorithm known as Velocity Matched Spectrum (VM Spectrum) is a velocity estimator that stands out from other methods by returning a spectrum of velocities for each interrogated volume sample. Interface detection of free-rising bubbles in quiescent liquid presents some difficulties for interface detection due to abrupt changes in interface inclination. In this work a method based on velocity spectrum curve shape is used to generate a spatial-temporal mapping, which, after spatial filtering, yields an accurate contour of the air-water interface. It is shown that the proposed technique yields a RMS error between 1.71 and 3.39 and a probability of detection failure and false detection between 0.89% and 11.9% in determining the spatial-temporal gas-liquid interface position in the flow of free rising bubbles in stagnant liquid. This result is valid for both free path and with transducer emitting through a metallic plate or a Plexiglas pipe.

A New Method for Ultrasound Detection of Interfacial Position in Gas-Liquid Two-Phase Flow

PubMed Central

Coutinho, Fábio Rizental; Ofuchi, César Yutaka; de Arruda, Lúcia Valéria Ramos; Jr., Flávio Neves; Morales, Rigoberto E. M.

2014-01-01

Ultrasonic measurement techniques for velocity estimation are currently widely used in fluid flow studies and applications. An accurate determination of interfacial position in gas-liquid two-phase flows is still an open problem. The quality of this information directly reflects on the accuracy of void fraction measurement, and it provides a means of discriminating velocity information of both phases. The algorithm known as Velocity Matched Spectrum (VM Spectrum) is a velocity estimator that stands out from other methods by returning a spectrum of velocities for each interrogated volume sample. Interface detection of free-rising bubbles in quiescent liquid presents some difficulties for interface detection due to abrupt changes in interface inclination. In this work a method based on velocity spectrum curve shape is used to generate a spatial-temporal mapping, which, after spatial filtering, yields an accurate contour of the air-water interface. It is shown that the proposed technique yields a RMS error between 1.71 and 3.39 and a probability of detection failure and false detection between 0.89% and 11.9% in determining the spatial-temporal gas-liquid interface position in the flow of free rising bubbles in stagnant liquid. This result is valid for both free path and with transducer emitting through a metallic plate or a Plexiglas pipe. PMID:24858961

Observation of laser-induced elastic waves in agar skin phantoms using a high-speed camera and a laser-beam-deflection probe

PubMed Central

Laloš, Jernej; Gregorčič, Peter; Jezeršek, Matija

2018-01-01

We present an optical study of elastic wave propagation inside skin phantoms consisting of agar gel as induced by an Er:YAG (wavelength of 2.94 μm) laser pulse. A laser-beam-deflection probe is used to measure ultrasonic propagation and a high-speed camera is used to record displacements in ablation-induced elastic transients. These measurements are further analyzed with a custom developed image recognition algorithm utilizing the methods of particle image velocimetry and spline interpolation to determine point trajectories, material displacement and strain during the passing of the transients. The results indicate that the ablation-induced elastic waves propagate with a velocity of 1 m/s and amplitudes of 0.1 mm. Compared to them, the measured velocities of ultrasonic waves are much higher, within the range of 1.42–1.51 km/s, while their amplitudes are three orders of magnitude smaller. This proves that the agar gel may be used as a rudimental skin and soft tissue substitute in biomedical research, since its polymeric structure reproduces adequate soft-solid properties and its transparency for visible light makes it convenient to study with optical instruments. The results presented provide an insight into the distribution of laser-induced elastic transients in soft tissue phantoms, while the experimental approach serves as a foundation for further research of laser-induced mechanical effects deeper in the tissue. PMID:29675327

Observation of laser-induced elastic waves in agar skin phantoms using a high-speed camera and a laser-beam-deflection probe.

PubMed

Laloš, Jernej; Gregorčič, Peter; Jezeršek, Matija

2018-04-01

We present an optical study of elastic wave propagation inside skin phantoms consisting of agar gel as induced by an Er:YAG (wavelength of 2.94 μm) laser pulse. A laser-beam-deflection probe is used to measure ultrasonic propagation and a high-speed camera is used to record displacements in ablation-induced elastic transients. These measurements are further analyzed with a custom developed image recognition algorithm utilizing the methods of particle image velocimetry and spline interpolation to determine point trajectories, material displacement and strain during the passing of the transients. The results indicate that the ablation-induced elastic waves propagate with a velocity of 1 m/s and amplitudes of 0.1 mm. Compared to them, the measured velocities of ultrasonic waves are much higher, within the range of 1.42-1.51 km/s, while their amplitudes are three orders of magnitude smaller. This proves that the agar gel may be used as a rudimental skin and soft tissue substitute in biomedical research, since its polymeric structure reproduces adequate soft-solid properties and its transparency for visible light makes it convenient to study with optical instruments. The results presented provide an insight into the distribution of laser-induced elastic transients in soft tissue phantoms, while the experimental approach serves as a foundation for further research of laser-induced mechanical effects deeper in the tissue.

Grain fragmentation in ultrasonic-assisted TIG weld of pure aluminum.

PubMed

Chen, Qihao; Lin, Sanbao; Yang, Chunli; Fan, Chenglei; Ge, Hongliang

2017-11-01

Under the action of acoustic waves during an ultrasonic-assisted tungsten inert gas (TIG) welding process, a grain of a TIG weld of aluminum alloy is refined by nucleation and grain fragmentation. Herein, effects of ultrasound on grain fragmentation in the TIG weld of aluminum alloy are investigated via systematic welding experiments of pure aluminum. First, experiments involving continuous and fixed-position welding are performed, which demonstrate that ultrasound can break the grain of the TIG weld of pure aluminum. The microstructural characteristics of an ultrasonic-assisted TIG weld fabricated by fixed-position welding are analyzed. The microstructure is found to transform from plane crystal, columnar crystal, and uniform equiaxed crystal into plane crystal, deformed columnar crystal, and nonuniform equiaxed crystal after application of ultrasound. Second, factors influencing ultrasonic grain fragmentation are investigated. The ultrasonic amplitude and welding current are found to have a considerable effect on grain fragmentation. The degree of fragmentation first increases and then decreases with an increase in ultrasonic amplitude, and it increases with an increase in welding current. Measurement results of the vibration of the weld pool show that the degree of grain fragmentation is related to the intensity of acoustic nonlinearity in the weld pool. The greater the intensity of acoustic nonlinearity, the greater is the degree of grain fragmentation. Finally, the mechanism of ultrasonic grain fragmentation in the TIG weld of pure aluminum is discussed. A finite element simulation is used to simulate the acoustic pressure and flow in the weld pool. The acoustic pressure in the weld pool exceeds the cavitation threshold, and cavitation bubbles are generated. The flow velocity in the weld pool does not change noticeably after application of ultrasound. It is concluded that the high-pressure conditions induced during the occurrence of cavitation, lead to grain fragmentation in a pure aluminum TIG weld during an ultrasonic-assisted TIG welding process. Copyright © 2017 Elsevier B.V. All rights reserved.

Experimental investigation of conical bubble structure and acoustic flow structure in ultrasonic field.

PubMed

Ma, Xiaojian; Huang, Biao; Wang, Guoyu; Zhang, Mindi

2017-01-01

The objective of this paper is to investigate the transient conical bubble structure (CBS) and acoustic flow structure in ultrasonic field. In the experiment, the high-speed video and particle image velocimetry (PIV) techniques are used to measure the acoustic cavitation patterns, as well as the flow velocity and vorticity fields. Results are presented for a high power ultrasound with a frequency of 18kHz, and the range of the input power is from 50W to 250W. The results of the experiment show the input power significantly affects the structures of CBS, with the increase of input power, the cavity region of CBS and the velocity of bubbles increase evidently. For the transient motion of bubbles on radiating surface, two different types could be classified, namely the formation, aggregation and coalescence of cavitation bubbles, and the aggregation, shrink, expansion and collapse of bubble cluster. Furthermore, the thickness of turbulent boundary layer near the sonotrode region is found to be much thicker, and the turbulent intensities are much higher for relatively higher input power. The vorticity distribution is prominently affected by the spatial position and input power. Copyright © 2016 Elsevier B.V. All rights reserved.

Quantitative sensing of corroded steel rebar embedded in cement mortar specimens using ultrasonic testing

NASA Astrophysics Data System (ADS)

Owusu Twumasi, Jones; Le, Viet; Tang, Qixiang; Yu, Tzuyang

2016-04-01

Corrosion of steel reinforcing bars (rebars) is the primary cause for the deterioration of reinforced concrete structures. Traditional corrosion monitoring methods such as half-cell potential and linear polarization resistance can only detect the presence of corrosion but cannot quantify it. This study presents an experimental investigation of quantifying degree of corrosion of steel rebar inside cement mortar specimens using ultrasonic testing (UT). A UT device with two 54 kHz transducers was used to measure ultrasonic pulse velocity (UPV) of cement mortar, uncorroded and corroded reinforced cement mortar specimens, utilizing the direct transmission method. The results obtained from the study show that UPV decreases linearly with increase in degree of corrosion and corrosion-induced cracks (surface cracks). With respect to quantifying the degree of corrosion, a model was developed by simultaneously fitting UPV and surface crack width measurements to a two-parameter linear model. The proposed model can be used for predicting the degree of corrosion of steel rebar embedded in cement mortar under similar conditions used in this study up to 3.03%. Furthermore, the modeling approach can be applied to corroded reinforced concrete specimens with additional modification. The findings from this study show that UT has the potential of quantifying the degree of corrosion inside reinforced cement mortar specimens.

Ultrasonics and space instrumentation

NASA Technical Reports Server (NTRS)

1987-01-01

The design topic selected was an outgrowth of the experimental design work done in the Fluid Behavior in Space experiment, which relies on the measurement of minute changes of the pressure and temperature to obtain reasonably accurate volume determinations. An alternative method of volume determination is the use of ultrasonic imaging. An ultrasonic wave system is generated by wall mounted transducer arrays. The interior liquid configuration causes reflection and refraction of the pattern so that analysis of the received wave system provides a description of the configuration and hence volume. Both continuous and chirp probe beams were used in a laboratory experiment simulating a surface wetting propellant. The hardware included a simulated tank with gaseous voids, transmitting and receiving transducers, transmitters, receivers, computer interface, and computer. Analysis software was developed for image generation and interpretation of results. Space instrumentation was pursued in support of a number of experiments under development for GAS flights. The program included thirty undergraduate students pursuing major qualifying project work under the guidance of eight faculty supported by a teaching assistant. Both mechanical and electrical engineering students designed and built several microprocessor systems to measure parameters such as temperature, acceleration, pressure, velocity, and circulation in order to determine combustion products, vortex formation, gas entrainment, EMR emissions from thunderstorms, and milli-g-accelerations due to crew motions.

Guided ultrasonic wave beam skew in silicon wafers

NASA Astrophysics Data System (ADS)

Pizzolato, Marco; Masserey, Bernard; Robyr, Jean-Luc; Fromme, Paul

2018-04-01

In the photovoltaic industry, monocrystalline silicon wafers are employed for solar cells with high conversion efficiency. Micro-cracks induced by the cutting process in the thin wafers can lead to brittle wafer fracture. Guided ultrasonic waves would offer an efficient methodology for the in-process non-destructive testing of wafers to assess micro-crack density. The material anisotropy of the monocrystalline silicon leads to variations of the guided wave characteristics, depending on the propagation direction relative to the crystal orientation. Selective guided ultrasonic wave excitation was achieved using a contact piezoelectric transducer with custom-made wedges for the A0 and S0 Lamb wave modes and a transducer holder to achieve controlled contact pressure and orientation. The out-of-plane component of the guided wave propagation was measured using a non-contact laser interferometer. The phase slowness (velocity) of the two fundamental Lamb wave modes was measured experimentally for varying propagation directions relative to the crystal orientation and found to match theoretical predictions. Significant wave beam skew was observed experimentally, especially for the S0 mode, and investigated from 3D finite element simulations. Good agreement was found with the theoretical predictions based on nominal material properties of the silicon wafer. The important contribution of guided wave beam skewing effects for the non-destructive testing of silicon wafers was demonstrated.

Transthoracic ultrasonic tissue indices identify patients with severe left anterior descending artery stenosis. Correlation with fractional flow reserve. Pilot study.

PubMed

Dobrowolski, Piotr; Kowalski, Mirosław; Rybicka, Justyna; Lech, Agnieszka; Tyczyński, Paweł; Witkowski, Adam; Hoffman, Piotr

2016-01-01

The aim of this study was to evaluate the potential clinical application of ultrasonic tissue indices, with a focus on systolic strain (SS) and systolic strain rate (SSR) parameters derived from transthoracic echocardiography, in the assessment of left anterior descending artery (LAD) stenosis. The data of 30 patients with significant LAD stenosis were analysed. All patients underwent transthoracic echocardiography to obtain systolic myocardial velocity (Sm), longitudinal SS, and SSR from basal, mid, and apical segments of anterior and inferior walls in two-chamber apical view. Severity of LAD obstruction was measured by means of fractional flow reserve (FFR) during coronary catheterisation. Systolic velocities, strain, and strain rate measured in basal, middle, and apical segments of the anterior left ventricular (LV) wall were lower when compared to those obtained from the corresponding, i.e. unaffected, inferior LV wall. There was a significant correlation between FFR and the value of SS, SSR characterising the apical LV segment of the anterior wall (r = -0.583, p = 0.01; r = -0.598, p = 0.01, respectively). Moreover, we found significant correlation between FFR and Sm in the mid-segment of the LV anterior wall (r = 0.611, p = 0.009). We conclude that SS and SSR obtained from the apical segment of the anterior LV wall may be related to the severity of LAD stenosis.

In-Service Monitoring of Steam Pipe Systems at High Temperatures

NASA Technical Reports Server (NTRS)

Bar-Cohen, Yoseph; Lih, Shyh-Shiuh; Badescu, Mircea; Bao, Xiaoqi; Sherrit, Stewart; Scott, James S.; Blosiu, Julian O.; Widholm, Scott E.

2011-01-01

An effective, in-service health monitoring system is needed to track water condensation in real time through the walls of steam pipes. The system is required to measure the height of the condensed water from outside the pipe, while operating at temperatures that are as high as 250 C. The system needs to account for the effects of water flow and cavitation. In addition, it is desired that the system does not require perforating the pipes and thereby reducing the structural integrity. Generally, steam pipes are used as part of the district heating system carrying steam from central power stations under the streets to heat, cool, or supply power to high-rise buildings and businesses. This system uses ultrasonic waves in pulse-echo and acquires reflected signal data. Via autocorrelation, it determines the water height while eliminating the effect of noise and multiple reflections from the wall of the pipe. The system performs nondestructive monitoring through the walls of steam pipes, and automatically measures the height of condensed water while operating at the high-temperature conditions of 250 C. For this purpose, the ultrasonic pulse-echo method is used where the time-of-flight of the wave reflections inside the water are measured, and it is multiplied by the wave velocity to determine the height. The pulse-echo test consists of emitting ultrasonic wave pulses from a piezoelectric transducer and receiving the reflections from the top and bottom of the condensed water. A single transducer is used as a transmitter as well as the receiver of the ultrasonic waves. To obtain high resolution, a broadband transducer is used and the frequency can be in the range of 2.25 to 10 MHz, providing sharp pulses in the time domain allowing for higher resolution in identifying the individual reflections.

Inspection of Piezoceramic Transducers Used for Structural Health Monitoring

PubMed Central

Mueller, Inka; Fritzen, Claus-Peter

2017-01-01

The use of piezoelectric wafer active sensors (PWAS) for structural health monitoring (SHM) purposes is state of the art for acousto-ultrasonic-based methods. For system reliability, detailed information about the PWAS itself is necessary. This paper gives an overview on frequent PWAS faults and presents the effects of these faults on the wave propagation, used for active acousto-ultrasonics-based SHM. The analysis of the wave field is based on velocity measurements using a laser Doppler vibrometer (LDV). New and established methods of PWAS inspection are explained in detail, listing advantages and disadvantages. The electro-mechanical impedance spectrum as basis for these methods is discussed for different sensor faults. This way this contribution focuses on a detailed analysis of PWAS and the need of their inspection for an increased reliability of SHM systems. PMID:28772431

Estimation of spatial-temporal gait parameters using a low-cost ultrasonic motion analysis system.

PubMed

Qi, Yongbin; Soh, Cheong Boon; Gunawan, Erry; Low, Kay-Soon; Thomas, Rijil

2014-08-20

In this paper, a low-cost motion analysis system using a wireless ultrasonic sensor network is proposed and investigated. A methodology has been developed to extract spatial-temporal gait parameters including stride length, stride duration, stride velocity, stride cadence, and stride symmetry from 3D foot displacements estimated by the combination of spherical positioning technique and unscented Kalman filter. The performance of this system is validated against a camera-based system in the laboratory with 10 healthy volunteers. Numerical results show the feasibility of the proposed system with average error of 2.7% for all the estimated gait parameters. The influence of walking speed on the measurement accuracy of proposed system is also evaluated. Statistical analysis demonstrates its capability of being used as a gait assessment tool for some medical applications.

Method for digital measurement of phase-frequency characteristics for a fixed-length ultrasonic spectrometer

NASA Astrophysics Data System (ADS)

Astashev, M. E.; Belosludtsev, K. N.; Kharakoz, D. P.

2014-05-01

One of the most accurate methods for measuring the compressibility of liquids is resonance measurement of sound velocity in a fixed-length interferometer. This method combines high sensitivity, accuracy, and small sample volume of the test liquid. The measuring principle is to study the resonance properties of a composite resonator that contains a test liquid sample. Ealier, the phase-locked loop (PLL) scheme was used for this. In this paper, we propose an alternative measurement scheme based on digital analysis of harmonic signals, describe the implementation of this scheme using commercially available data acquisition modules, and give examples of test measurements with accuracy evaluations of the results.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wardaya, P. D., E-mail: pongga.wardaya@utp.edu.my; Noh, K. A. B. M., E-mail: pongga.wardaya@utp.edu.my; Yusoff, W. I. B. W., E-mail: pongga.wardaya@utp.edu.my

This paper discusses a new approach for investigating the seismic wave velocity of rock, specifically carbonates, as affected by their pore structures. While the conventional routine of seismic velocity measurement highly depends on the extensive laboratory experiment, the proposed approach utilizes the digital rock physics view which lies on the numerical experiment. Thus, instead of using core sample, we use the thin section image of carbonate rock to measure the effective seismic wave velocity when travelling on it. In the numerical experiment, thin section images act as the medium on which wave propagation will be simulated. For the modeling, anmore » advanced technique based on artificial neural network was employed for building the velocity and density profile, replacing image's RGB pixel value with the seismic velocity and density of each rock constituent. Then, ultrasonic wave was simulated to propagate in the thin section image by using finite difference time domain method, based on assumption of an acoustic-isotropic medium. Effective velocities were drawn from the recorded signal and being compared to the velocity modeling from Wyllie time average model and Kuster-Toksoz rock physics model. To perform the modeling, image analysis routines were undertaken for quantifying the pore aspect ratio that is assumed to represent the rocks pore structure. In addition, porosity and mineral fraction required for velocity modeling were also quantified by using integrated neural network and image analysis technique. It was found that the Kuster-Toksoz gives the closer prediction to the measured velocity as compared to the Wyllie time average model. We also conclude that Wyllie time average that does not incorporate the pore structure parameter deviates significantly for samples having more than 40% porosity. Utilizing this approach we found a good agreement between numerical experiment and theoretically derived rock physics model for estimating the effective seismic wave velocity of rock.« less

A non-invasive photoacoustic and ultrasonic method for the measurement of glucose solution concentration

NASA Astrophysics Data System (ADS)

Zhao, Siwei; Tao, Wei; He, Qiaozhi; Zhao, Hui; Cao, Wenwu

2017-03-01

Diabetes mellitus (DM) is a chronic disease affecting nearly 400 million people worldwide. In order to manage the disease, patients need to monitor the blood glucose level by puncturing the finger several times a day, which is uncomfortable and inconvenient. We present here a potential non-invasive monitoring method based on the velocity of ultrasonic waves generated in glucose solution by the photoacoustic principal, which can recognize the glucose concentration down to 20mg/dL. In order to apply this method to warm bodies, we carefully designed the experiment and performed measurements from 30 °C to 50 °C to generate a set of calibration curves, which may be used by engineers to build devices. Most importantly, we have theoretically explained the relationship between the compressibility and the glucose concentration. Our results show that the compressibility of solution decreases with the glucose concentration, which clarified the controversy between theory and experiment results in the literature. The derived formula is generally validity, which can be used to nondestructively measure solution concentration for other types of solutions using photoacoustic principle.

Advanced Bode Plot Techniques for Ultrasonic Transducers

NASA Astrophysics Data System (ADS)

DeAngelis, D. A.; Schulze, G. W.

The Bode plot, displayed as either impedance or admittance versus frequency, is the most basic test used by ultrasonic transducer designers. With simplicity and ease-of-use, Bode plots are ideal for baseline comparisons such as spacing of parasitic modes or impedance, but quite often the subtleties that manifest as poor process control are hard to interpret or are nonexistence. In-process testing of transducers is time consuming for quantifying statistical aberrations, and assessments made indirectly via the workpiece are difficult. This research investigates the use of advanced Bode plot techniques to compare ultrasonic transducers with known "good" and known "bad" process performance, with the goal of a-priori process assessment. These advanced techniques expand from the basic constant voltage versus frequency sweep to include constant current and constant velocity interrogated locally on transducer or tool; they also include up and down directional frequency sweeps to quantify hysteresis effects like jumping and dropping phenomena. The investigation focuses solely on the common PZT8 piezoelectric material used with welding transducers for semiconductor wire bonding. Several metrics are investigated such as impedance, displacement/current gain, velocity/current gain, displacement/voltage gain and velocity/voltage gain. The experimental and theoretical research methods include Bode plots, admittance loops, laser vibrometry and coupled-field finite element analysis.

Frictional, Hydraulic, and Acoustic Properties of Alpine Fault DFDP-1 Core

NASA Astrophysics Data System (ADS)

Carpenter, B. M.; Ikari, M.; Kitajima, H.; Kopf, A.; Marone, C.; Saffer, D. M.

2012-12-01

The Alpine Fault, a transpressional plate-boundary fault transecting the South Island of New Zealand, is the current focus of the Deep Fault Drilling Project (DFDP), a major fault zone drilling initiative. Phase 1 of this project included 2 boreholes that penetrated the active fault at depths of ˜100 m and ˜150 m, and provided a suite of core samples crossing the fault. Here, we report on laboratory measurements of frictional strength and constitutive behavior, permeability, and ultrasonic velocities for a suite of the recovered core samples We conducted friction experiments on powdered samples in a double-direct shear configuration at room temperature and humidity. Our results show that over a range of effective normal stresses from 10-100 MPa, friction coefficients are ~0.60-0.70, and are similar for all of the materials we tested. Rate-stepping tests document velocity-weakening behavior in the majority of wall rock samples, whereas the principal slip surface (PSS) and an adjacent clay-rich cataclasite exhibit velocity-strengthening behavior. We observe significant rates of frictional healing in all of our samples, indicating that that the fault easily regains its strength during interseismic periods. Our results indicate that seismic slip is not likely to nucleate in the clay-rich PSS at shallow depths, but might nucleate and propagate on the gouge/wall rock interface. We measured permeability using a constant head technique, on vertically oriented cylindrical mini-cores (i.e. ˜45 degrees to the plane of the Alpine Fault). We conducted these tests in a triaxial configuration, under isotropic stress conditions and effective confining pressures from ~2.5 - 63.5 MPa. We conducted ultrasonic wavespeed measurements concurrently with the permeability measurements to determine P- and S-wave velocities from time-of-flight. The permeability of all samples decreases systematically with increasing effective stress. The clay-rich cataclasite (1.37 x 10-19 m2) and PSS (1.62 x 10-20 m2) samples exhibit the lowest permeabilities. The cataclasite, and wall rock mylonite and gravel samples, all exhibit permeabilities > 10-18 m2. We also observe that permeability of the cataclasites appears to decrease with proximity to the active fault zone. Our laboratory measurements are consistent with borehole slug tests that show the fault is a hydraulic barrier, and suggest that fault rock permeability is sufficiently low to facilitate transient pore pressure effects during rapid slip, including thermal pressurization and dilatancy hardening. Elastic wave velocity increases systematically with increasing effective stress. We find the lowest P-wave velocities in clay-rich, poorly lithified samples from within and near the active fault, including hanging wall cataclasite, fault gouge, and footwall gravel. Our results are consistent with borehole logging data that show an increase in P-wave velocity from the mylonite into the competent cataclasites, and a decrease in P-wave velocity through the clay-rich cataclasite and into the fault zone.

On-line noninvasive one-point measurements of pulse wave velocity.

PubMed

Harada, Akimitsu; Okada, Takashi; Niki, Kiyomi; Chang, Dehua; Sugawara, Motoaki

2002-12-01

Pulse wave velocity (PWV) is a basic parameter in the dynamics of pressure and flow waves traveling in arteries. Conventional on-line methods of measuring PWV have mainly been based on "two-point" measurements, i.e., measurements of the time of travel of the wave over a known distance. This paper describes two methods by which on-line "one-point" measurements can be made, and compares the results obtained by the two methods. The principle of one method is to measure blood pressure and velocity at a point, and use the water-hammer equation for forward traveling waves. The principle of the other method is to derive PWV from the stiffness parameter of the artery. Both methods were realized by using an ultrasonic system which we specially developed for noninvasive measurements of wave intensity. We applied the methods to the common carotid artery in 13 normal humans. The regression line of the PWV (m/s) obtained by the former method on the PWV (m/s) obtained by the latter method was y = 1.03x - 0.899 (R(2) = 0.83). Although regional PWV in the human carotid artery has not been reported so far, the correlation between the PWVs obtained by the present two methods was so high that we are convinced of the validity of these methods.

The thin section rock physics: Modeling and measurement of seismic wave velocity on the slice of carbonates

NASA Astrophysics Data System (ADS)

Wardaya, P. D.; Noh, K. A. B. M.; Yusoff, W. I. B. W.; Ridha, S.; Nurhandoko, B. E. B.

2014-09-01

This paper discusses a new approach for investigating the seismic wave velocity of rock, specifically carbonates, as affected by their pore structures. While the conventional routine of seismic velocity measurement highly depends on the extensive laboratory experiment, the proposed approach utilizes the digital rock physics view which lies on the numerical experiment. Thus, instead of using core sample, we use the thin section image of carbonate rock to measure the effective seismic wave velocity when travelling on it. In the numerical experiment, thin section images act as the medium on which wave propagation will be simulated. For the modeling, an advanced technique based on artificial neural network was employed for building the velocity and density profile, replacing image's RGB pixel value with the seismic velocity and density of each rock constituent. Then, ultrasonic wave was simulated to propagate in the thin section image by using finite difference time domain method, based on assumption of an acoustic-isotropic medium. Effective velocities were drawn from the recorded signal and being compared to the velocity modeling from Wyllie time average model and Kuster-Toksoz rock physics model. To perform the modeling, image analysis routines were undertaken for quantifying the pore aspect ratio that is assumed to represent the rocks pore structure. In addition, porosity and mineral fraction required for velocity modeling were also quantified by using integrated neural network and image analysis technique. It was found that the Kuster-Toksoz gives the closer prediction to the measured velocity as compared to the Wyllie time average model. We also conclude that Wyllie time average that does not incorporate the pore structure parameter deviates significantly for samples having more than 40% porosity. Utilizing this approach we found a good agreement between numerical experiment and theoretically derived rock physics model for estimating the effective seismic wave velocity of rock.

Estimation of in-situ stresses in concrete members using polarized ultrasonic shear waves

NASA Astrophysics Data System (ADS)

Chen, Andrew; Schumacher, Thomas

2014-02-01

Ultrasonic testing is commonly used to detect flaws, estimate geometries, and characterize properties of materials and structures. Acoustoelasticity refers to the dependency of stress wave velocity with applied stresses and is a phenomenon that has been known by geophysicists since the 1960s. A way to capitalize on this effect for concrete applications is by using ultrasonic shear waves which are particularly sensitive to applied stresses when polarized in the direction of the applied stress. The authors conducted an experiment on a 150 mm (6 in.) diameter concrete cylinder specimen with a length of 305 mm (12 in.) that was loaded in discrete load steps to failure. At each load step two ultrasonic shear waves were transmitted through the specimen, one with the polarization perpendicular and the other transverse to the applied stress. The velocity difference between the two sets of polarized shear waves was found to correlate with the applied stress in the specimen. Two potential applications for this methodology include estimation of stresses in pre-stressed concrete bridge girders and investigation of load redistribution in structural support elements after extreme events. This paper introduces the background of the methodology, presents an analysis of the collected data, and discusses the relationship between the recorded signals and the applied stress.

Proceedings of the Workshop on Nondestructive Evaluation (NDE) of Titanium Alloys (2nd) Held on 2-4 February 1982 at the Naval Research Laboratory, Underwater Sound Reference Detachment, Orlando, Florida.

DTIC Science & Technology

1984-07-01

phase. The second step, swabbing with a 1 ml HF, 2 ml HN0 3 , 97 ml water solution, removed the stain, leaving a light field of alpha phase material in...microscope (SEM), the beta phase appeared as finely dispersed light lines in a dark - field of alpha phase material. 4.2 Ultrasonic Measurements The...appropriate couplants were used in this research. Aerotech couplant • (a light oil) was used for the wave velocity measurements. A 2 mm thick elastomer

Spectroscopic and ultrasonic investigations on structural characterization of borate glass specimen doped with transition metal ions.

PubMed

Sathish, K; Thirumaran, S

2015-08-05

The present work describes the glass samples of composition (x% V₂O₅-(80-x)% B₂O₃-20% Na₂CO₃) VBS glass system and (x%MnO₂-(80-x)% B₂O₃-20% Na₂CO₃) in MBS glass system with mol% ranging from x=3, 6, 9, 12, 15 and 18 in steps of 3 mol% are prepared by melt quenching technique. For these prepared glass systems, sound velocity (longitudinal and shear velocities) and density have been measured. The sound velocity (longitudinal and shear) was measured by using pulse-echo technique at 5 MHz. The XRD study was carried to out to ascertain the amorphous nature of the glass specimen. Using these measured values, the elastic moduli, Poisson's ratio, Debye temperature, acoustic impedance and thermal expansion coefficient of the two glass systems were evaluated. The elastic and mechanical properties of the prepared glass systems are analyzed from ultrasonic study and the structural characterization from spectroscopic study. The effects due to the doping of transition metal ions with borate have been discussed. In the V₂O₅ doped glass system,(VBS glass system) the sound velocity, density and elastic moduli, steeply increases after 12 mol% comparatively with MnO₂ doped glass system (VBS glass system). The present study critically observes the doping of V₂O₅ with borate enhances the strengthening of network linkage and hardening of the glassy network structure than MnO₂. The IR spectral analysis reveals depolymerization of the borate network and conversion of BO₃ or BO4 units with the formation of non-bridging oxygen. The FTIR spectral studies confirm the presence of various functional groups of the sample. FTIR spectrum of sample exhibits broad absorption bands indicating the wide distribution of borate structural units. The effect of Na₂CO₃, V₂O₅ and MnO₂ contents on the structures of borate glass is evaluated from the FTIR spectra. The topological aspects of the prepared glass samples are exhaustively reported from SEM micrographs. Copyright © 2015 Elsevier B.V. All rights reserved.

Spectroscopic and ultrasonic investigations on structural characterization of borate glass specimen doped with transition metal ions

NASA Astrophysics Data System (ADS)

Sathish, K.; Thirumaran, S.

2015-08-01

The present work describes the glass samples of composition (x% V2O5-(80-x)% B2O3-20% Na2CO3) VBS glass system and (x% MnO2-(80-x)% B2O3-20% Na2CO3) in MBS glass system with mol% ranging from x = 3, 6, 9, 12, 15 and 18 in steps of 3 mol% are prepared by melt quenching technique. For these prepared glass systems, sound velocity (longitudinal and shear velocities) and density have been measured. The sound velocity (longitudinal and shear) was measured by using pulse-echo technique at 5 MHz. The XRD study was carried to out to ascertain the amorphous nature of the glass specimen. Using these measured values, the elastic moduli, Poisson's ratio, Debye temperature, acoustic impedance and thermal expansion coefficient of the two glass systems were evaluated. The elastic and mechanical properties of the prepared glass systems are analyzed from ultrasonic study and the structural characterization from spectroscopic study. The effects due to the doping of transition metal ions with borate have been discussed. In the V2O5 doped glass system, (VBS glass system) the sound velocity, density and elastic moduli, steeply increases after 12 mol% comparatively with MnO2 doped glass system (VBS glass system). The present study critically observes the doping of V2O5 with borate enhances the strengthening of network linkage and hardening of the glassy network structure than MnO2. The IR spectral analysis reveals depolymerization of the borate network and conversion of BO3 or BO4 units with the formation of non-bridging oxygen. The FTIR spectral studies confirm the presence of various functional groups of the sample. FTIR spectrum of sample exhibits broad absorption bands indicating the wide distribution of borate structural units. The effect of Na2CO3, V2O5 and MnO2 contents on the structures of borate glass is evaluated from the FTIR spectra. The topological aspects of the prepared glass samples are exhaustively reported from SEM micrographs.

Particle velocity measurements with macroscopic fluorescence imaging in lymph tissue mimicking microfluidic phantoms

NASA Astrophysics Data System (ADS)

Hennessy, Ricky; Koo, Chiwan; Ton, Phuc; Han, Arum; Righetti, Raffaella; Maitland, Kristen C.

2011-03-01

Ultrasound poroelastography can quantify structural and mechanical properties of tissues such as stiffness, compressibility, and fluid flow rate. This novel ultrasound technique is being explored to detect tissue changes associated with lymphatic disease. We have constructed a macroscopic fluorescence imaging system to validate ultrasonic fluid flow measurements and to provide high resolution imaging of microfluidic phantoms. The optical imaging system is composed of a white light source, excitation and emission filters, and a camera with a zoom lens. The field of view can be adjusted from 100 mm x 75 mm to 10 mm x 7.5 mm. The microfluidic device is made of polydimethylsiloxane (PDMS) and has 9 channels, each 40 μm deep with widths ranging from 30 μm to 200 μm. A syringe pump was used to propel water containing 15 μm diameter fluorescent microspheres through the microchannels, with flow rates ranging from 0.5 μl/min to 10 μl/min. Video was captured at a rate of 25 frames/sec. The velocity of the microspheres in the microchannels was calculated using an algorithm that tracked the movement of the fluorescent microspheres. The imaging system was able to measure particle velocities ranging from 0.2 mm/sec to 10 mm/sec. The range of flow velocities of interest in lymph vessels is between 1 mm/sec to 10 mm/sec; therefore our imaging system is sufficient to measure particle velocity in phantoms modeling lymphatic flow.

Simulation study of axial ultrasound transmission in heterogeneous cortical bone model

NASA Astrophysics Data System (ADS)

Takano, Koki; Nagatani, Yoshiki; Matsukawa, Mami

2017-07-01

Ultrasound propagation in a heterogeneous cortical bone was studied. Using a bovine radius, the longitudinal wave velocity distribution in the axial direction was experimentally measured in the MHz range. The bilinear interpolation and piecewise cubic Hermite interpolation methods were applied to create a three-dimensional (3D) precise velocity model of the bone using experimental data. By assuming the uniaxial anisotropy of the bone, the distributions of all elastic moduli of a 3D heterogeneous model were estimated. The elastic finite-difference time-domain method was used to simulate axial ultrasonic wave propagation. The wave propagation in the initial model was compared with that in the thinner model, where the inner part of the cortical bone model was removed. The wave front of the first arriving signal (FAS) slightly depended on the heterogeneity in each model. Owing to the decrease in bone thickness, the propagation behavior also changed and the FAS velocity clearly decreased.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Praher, B., E-mail: bernhard.praher@jku.at, E-mail: klaus.straka@jku.at, E-mail: jesenka.usanovic@jku.at, E-mail: georg.steinbichler@jku.at; Straka, K., E-mail: bernhard.praher@jku.at, E-mail: klaus.straka@jku.at, E-mail: jesenka.usanovic@jku.at, E-mail: georg.steinbichler@jku.at; Usanovic, J., E-mail: bernhard.praher@jku.at, E-mail: klaus.straka@jku.at, E-mail: jesenka.usanovic@jku.at, E-mail: georg.steinbichler@jku.at

We developed novel non-invasive ultrasound based systems for the measurement of temperature distributions in the screw-ante chamber, the detection of unmelted granules and for the monitoring of the plasticizing process along the screw channel. The temperature of the polymer melt stored in the screw ante-chamber after the plasticization should be homogeneous. However, in reality the polymer melt in the screw ante-chamber is not homogeneous. Due to the fact the sound velocity in a polymer melt is temperature depending, we developed a tomography system using the measured transit times of ultrasonic pulses along different sound paths for calculating the temperature distributionmore » in radial direction of a polymer melt in the screw ante-chamber of an injection moulding machine. For the detection of unmelted granules in the polymer melt we implemented an ultrasound transmission measurement. By analyzing the attenuation of the received pulses it is possible to detect unwanted inclusions. For the monitoring of the plasticizing process in the channels of the screw an ultrasonic pulse is transmitted into the barrel. By analyzing the reflected pulses it is possible to estimate solid bed and melt regions in the screw channel. The proposed systems were tested for accuracy and validity by simulations and test measurements.« less

Comparison among GPR measurements and ultrasonic tomographies with different inversion strategies applied to the basement of an ancient egyptian sculpture.

NASA Astrophysics Data System (ADS)

Sambuelli, Luigi; Bohm, Gualtiero; Capizzi, Patrizia; Cardarelli, Ettore; Cosentino, Pietro; D'Onofrio, Laurent; Marchisio, Mario

2010-05-01

By the late 2008 one of the most important pieces of the "Museo delle Antichità Egizie" in Turin, the sculpture of the Pharaoh with god Amun, was planned to be one of the masterpieces of a travelling exhibition in Japan. The "Fondazione Museo delle Antichità Egizie di Torino", managing the museum, was concerned with the integrity of the basement of the statue which actually presents visible signs of restorations dating back to the early IXX century. The questions put by the museum managers were to estimate the internal extension of some visible fractures, to search for unknown internal ones and to provide information about the overall mechanical strength of the basement. In order to tackle the first and second questions a GPR reflection survey of the basement along three sides was performed and the results were assembled in a 3D rendering. As far as the third question is concerned, two parallel, horizontal ultrasonic 2D tomographies across the basement were made with a source-receiver layout able to acquire, for each section, 723 ultrasonic signals correspondent to different transmitter and receiver positions. The ultrasonic tomographic data were inverted using different software based upon different algorithms. The obtained velocity images were then compared with the GPR results and with the visible joints on the basement. A critical analysis of the comparisons is finally presented.

Some investigations on the use of ultrasonics in travelling bubble cavitation control

NASA Astrophysics Data System (ADS)

Chatterjee, Dhiman; Arakeri, Vijay H.

2004-04-01

In this paper we report results from some investigations on the use of ultrasonics in controlling travelling bubble cavitation. Control of this type of cavitation, generated using a venturi device, has been achieved by manipulation of potential nuclei using a piezoelectric device, termed the Ultrasonic Nuclei Manipulator (UNM). The performance of the UNM, activated in continuous-wave (CW) and pulsed modes, has been studied over a range of dissolved gas concentration (C). The performance under CW-excitation is found to depend sensitively on C, with lack of control in near-saturated water samples. Failure to control cavitation at C ≈ 1 under CW-excitation is suggested to be a result of bubble growth by rectified diffusion under these conditions. The pulsed mode of excitation of the UNM, in such cases, seems to be a very promising alternative. Further improvement is observed by using two piezoelectric crystals, one driven in the CW-mode and the second in pulsed mode, as the UNM. Through carefully designed experimentation, this has been traced to the movement of nuclei under the influence of Bjerknes forces. Besides reduction of noise, other measures of control have been identified and investigated. For example, it has been found that the maximum velocity achievable at the venturi throat can be increased from about 15 m s(-1) to about 22 m s(-1) with nuclei manipulation using ultrasonics.

CFD study of the flow pattern in an ultrasonic horn reactor: Introducing a realistic vibrating boundary condition.

PubMed

Rahimi, Masoud; Movahedirad, Salman; Shahhosseini, Shahrokh

2017-03-01

Recently, great attention has been paid to predict the acoustic streaming field distribution inside the sonoreactors, induced by high-power ultrasonic wave generator. The focus of this paper is to model an ultrasonic vibrating horn and study the induced flow pattern with a newly developed moving boundary condition. The numerical simulation utilizes the modified cavitation model along with the "mixture" model for turbulent flow (RNG, k-ε), and a moving boundary condition with an oscillating parabolic-logarithmic profile, applied to the horn tip. This moving-boundary provides the situation in which the center of the horn tip vibrates stronger than that of the peripheral regions. The velocity field obtained by computational fluid dynamic was in a reasonably good agreement with the PIV results. The moving boundary model is more accurate since it better approximates the movement of the horn tip in the ultrasonic assisted process. From an optimizing point of view, the model with the new moving boundary is more suitable than the conventional models for design purposes because the displacement magnitude of the horn tip is the only fitting parameter. After developing and validating the numerical model, the model was utilized to predict various quantities such as cavitation zone, pressure field and stream function that are not experimentally feasible to measure. Copyright © 2016 Elsevier B.V. All rights reserved.

CMC determination of nonionic surfactants in protein formulations using ultrasonic resonance technology.

PubMed

Horiuchi, Shohei; Winter, Gerhard

2015-05-01

Biological products often contain surfactants as stabilizers in their formulations to avoid surface adsorption, interfacial denaturation and aggregation of the protein drug and thereby improve the overall pharmaceutical quality of the product. On the other hand, when the surfactant concentration exceeds the critical micelle concentration (CMC) in a protein formulation, protein-loaded micelles could be formed which could potentially be the cause of immunogenicity. Therefore, the actual CMC and the presence of micelles generally need to be confirmed for each protein formulation because the CMC is affected by the presence of protein and other formulation factors. In this study, the ultrasonic resonance technology (URT) was applied to determine CMC of surfactants in pharmaceutical protein solutions in comparison with surface tensiometry (TE) and dynamic light scattering (DLS). According to our results, the ultrasonic resonance technology can easily and precisely provide CMCs of surfactants in protein formulations while it is not working for protein-free formulations. This indicates that the signal we measure with ultrasonic velocity comes from complex micelles composed of surfactant and protein molecules. DLS did not provide reliable data for protein/surfactant systems. Interestingly, a protein formulation with arginine and polysorbate 20 behaved differently when studied with TE and URT allowing us to see that arginine is bound to protein and that the complex interacts with the surfactant. Copyright © 2015 Elsevier B.V. All rights reserved.

Ultrasonic diagnostic in porous media and suspensions

NASA Astrophysics Data System (ADS)

Bacri, J.-C.; Hoyos, M.; Rakotomalala, N.; Salin, D.; Bourlion, M.; Daccord, G.; Lenormand, R.; Soucemarianadin, S.

1991-08-01

An apparatus has been constructed to characterize transient fluid displacements in porous media, and probe sedimenting suspensions. The technique used is to propagate an ultrasonic wave in the sample. Both ultrasonic attenuation and velocity are related to the static and hydrodynamic properties of the medium. The system was built so as to perform array imaging (mapping) and tested with different fluids and suspensions. It is suggested that the ultrasonic technique can be suitable whenever transient, low cost and safe saturation and concentration measurements are to be performed. Nous avons réalisé un appareil pour étudier l'évolution temporelle des écoulements en milieux poreux et au cours de la sédimentation des suspensions. La technique employée utilise la propagation d'une onde ultrasonore dans l'échantillon. L'atténuation et la vitesse ultrasonores sont toutes deux reliées aux propriétés statique et dynamique du mileu. Le système d'imagerie acoustique permet une cartographie à deux dimensions de l'échantillon , ce système a été testé avec différents fluides et suspensions. Notre étude montre que la technique ultrasonore est bien adaptée à la détermination de la dépendance temporelle de la concentration et de la saturation dans des conditions de sécurité et de coût optimales.

Comparison of high-resolution ultrasonic resonator technology and Raman spectroscopy as novel process analytical tools for drug quantification in self-emulsifying drug delivery systems.

PubMed

Stillhart, Cordula; Kuentz, Martin

2012-02-05

Self-emulsifying drug delivery systems (SEDDS) are complex mixtures in which drug quantification can become a challenging task. Thus, a general need exists for novel analytical methods and a particular interest lies in techniques with the potential for process monitoring. This article compares Raman spectroscopy with high-resolution ultrasonic resonator technology (URT) for drug quantification in SEDDS. The model drugs fenofibrate, indomethacin, and probucol were quantitatively assayed in different self-emulsifying formulations. We measured ultrasound velocity and attenuation in the bulk formulation containing drug at different concentrations. The formulations were also studied by Raman spectroscopy. We used both, an in-line immersion probe for the bulk formulation and a multi-fiber sensor for measuring through hard-gelatin capsules that were filled with SEDDS. Each method was assessed by calculating the relative standard error of prediction (RSEP) as well as the limit of quantification (LOQ) and the mean recovery. Raman spectroscopy led to excellent calibration models for the bulk formulation as well as the capsules. The RSEP depended on the SEDDS type with values of 1.5-3.8%, while LOQ was between 0.04 and 0.35% (w/w) for drug quantification in the bulk. Similarly, the analysis of the capsules led to RSEP of 1.9-6.5% and LOQ of 0.01-0.41% (w/w). On the other hand, ultrasound attenuation resulted in RSEP of 2.3-4.4% and LOQ of 0.1-0.6% (w/w). Moreover, ultrasound velocity provided an interesting analytical response in cases where the drug strongly affected the density or compressibility of the SEDDS. We conclude that ultrasonic resonator technology and Raman spectroscopy constitute suitable methods for drug quantification in SEDDS, which is promising for their use as process analytical technologies. Copyright © 2011 Elsevier B.V. All rights reserved.

Photo-Ultrasonic Study of Extrinsic Photoconductivity in N-Gallium Arsenide

NASA Astrophysics Data System (ADS)

Bradshaw, Randall Grant

We have measured the velocity of piezoelectrically -active, ultrasonic shear waves between 1.5 K and 68 K for undoped and for oxygen-doped n-type GaAs, during and after illumination at 4.2 K. The results reveal photoconductivity, persistent photoconductivity, and thermally stimulated conductivity. In both samples the Fermi level in the dark is controlled by excess non-shallow donors near 0.2 eV below the conduction band. Analysis of these effects in oxygen-doped material indicates that there are mid-gap and much shallower photoionizable levels and that there is an electron trap near 20 meV below the conduction band. The undoped n-GaAs sample exhibits photoconductivity quenching with photons in the range 0.95-1.26 eV which, by analysis of the quenching rate, is attributed to the EL2 defect. In addition, levels with large hole capture coefficients have been detected.

Probing the Effect of Hydrogen on Elastic Properties and Plastic Deformation in Nickel Using Nanoindentation and Ultrasonic Methods

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lawrence, Samantha K.; Somerday, Brian P.; Ingraham, Mathew Duffy

Hydrogen effects on small-volume plasticity and elastic stiffness constants are investigated with nanoindentation of Ni-201 and sonic velocity measurements of bulk Ni single crystals. Elastic modulus of Ni-201, calculated from indentation data, decreases ~22% after hydrogen charging. This substantial decrease is independently confirmed by sonic velocity measurements of Ni single crystals; c 44 decreases ~20% after hydrogen exposure. Furthermore, clear hydrogen-deformation interactions are observed. The maximum shear stress required to nucleate dislocations in hydrogen-charged Ni-201 is markedly lower than in as-annealed material, driven by hydrogen-reduced shear modulus. Additionally, a larger number of depth excursions are detected prior to general yieldingmore » in hydrogen-charged material, suggesting cross-slip restriction. Together, these data reveal direct correlation between hydrogen-affected elastic properties and plastic deformation in Ni alloys.« less

Probing the Effect of Hydrogen on Elastic Properties and Plastic Deformation in Nickel Using Nanoindentation and Ultrasonic Methods

DOE PAGES

Lawrence, Samantha K.; Somerday, Brian P.; Ingraham, Mathew Duffy; ...

2018-04-11

Hydrogen effects on small-volume plasticity and elastic stiffness constants are investigated with nanoindentation of Ni-201 and sonic velocity measurements of bulk Ni single crystals. Elastic modulus of Ni-201, calculated from indentation data, decreases ~22% after hydrogen charging. This substantial decrease is independently confirmed by sonic velocity measurements of Ni single crystals; c 44 decreases ~20% after hydrogen exposure. Furthermore, clear hydrogen-deformation interactions are observed. The maximum shear stress required to nucleate dislocations in hydrogen-charged Ni-201 is markedly lower than in as-annealed material, driven by hydrogen-reduced shear modulus. Additionally, a larger number of depth excursions are detected prior to general yieldingmore » in hydrogen-charged material, suggesting cross-slip restriction. Together, these data reveal direct correlation between hydrogen-affected elastic properties and plastic deformation in Ni alloys.« less

Probing the Effect of Hydrogen on Elastic Properties and Plastic Deformation in Nickel Using Nanoindentation and Ultrasonic Methods

NASA Astrophysics Data System (ADS)

Lawrence, S. K.; Somerday, B. P.; Ingraham, M. D.; Bahr, D. F.

2018-04-01

Hydrogen effects on small-volume plasticity and elastic stiffness constants are investigated with nanoindentation of Ni-201 and sonic velocity measurements of bulk Ni single crystals. Elastic modulus of Ni-201, calculated from indentation data, decreases 22% after hydrogen charging. This substantial decrease is independently confirmed by sonic velocity measurements of Ni single crystals; c 44 decreases 20% after hydrogen exposure. Furthermore, clear hydrogen-deformation interactions are observed. The maximum shear stress required to nucleate dislocations in hydrogen-charged Ni-201 is markedly lower than in as-annealed material, driven by hydrogen-reduced shear modulus. Additionally, a larger number of depth excursions are detected prior to general yielding in hydrogen-charged material, suggesting cross-slip restriction. Together, these data reveal a direct correlation between hydrogen-affected elastic properties and plastic deformation in Ni alloys.