Temperature imaging with ultrasonic transmission tomography for treatment control

NASA Astrophysics Data System (ADS)

Chu, Zheqi; Pinter, Stephen. Z.; Yuan, Jie; Scarpelli, Matthew L.; Kripfgans, Oliver D.; Fowlkes, J. Brian; Duric, Neb; Carson, Paul L.

2017-03-01

Hyperthermia is a promising method to enhance chemo- or radiation therapy of breast cancer and the time-temperature profile in the target and surrounding areas is the primary monitoring method. Unlike with thermal ablation of lesions, in hyperthermia there are not good alternative treatment monitoring quantities. However, there is less problem with non-monotonic thermal coefficients of speed of sound used with ultrasonic imaging of temperature. This paper tests a long discussed but little investigated method of imaging temperature using speed of sound and proposes methods of reducing edge enhancement artifacts in the temperature image. Normally, when directly using the speed of sound to reconstruct the temperature image around the tumor, there will be an abnormal bipolar edge enhancement along the boundary between two materials with different speeds of sound at a given temperature. This due to partial volume effects and can be diminished by regularized, weighted deconvolution. An initial, manual deconvolution is shown, as well as an EMD (Empirical Mode Decomposition) method. Here we use the continuity and other constraints to choose the coefficient, reprocess the temperature field image and take the mean variations of the temperature in the adjacent pixels as the judgment criteria. Both methods effectively reduce the edge enhancement and produce a more precise image of temperature.

Sound speed measurements in liquid oxygen-liquid nitrogen mixtures

NASA Technical Reports Server (NTRS)

Zuckerwar, A. J.; Mazel, D. S.

1985-01-01

The sound speed in liquid oxygen (LOX), liquid nitrogen (LN2), and five LOX-LN2 mixtures was measured by an ultrasonic pulse-echo technique at temperatures in the vicinity of -195.8C, the boiling point of N2 at a pressure of I atm. Under these conditions, the measurements yield the following relationship between sound speed in meters per second and LN2 content M in mole percent: c = 1009.05-1.8275M+0.0026507 M squared. The second speeds of 1009.05 m/sec plus or minus 0.25 percent for pure LOX and 852.8 m/sec plus or minus 0.32 percent for pure LN2 are compared with those reported by past investigators. Measurement of sound speed should prove an effective means for monitoring the contamination of LOX by Ln2.

A new ultrasonic temperature measurement system for air conditioners in automobiles

NASA Astrophysics Data System (ADS)

Liao, Teh-Lu; Tsai, Wen-Yuan; Huang, Chih-Feng

2004-02-01

This paper presents a microcomputer-based ultrasonic temperature sensor system to measure the temperature of an air conditioner (AC) in an automobile. It uses the ultrasonic measurement of the changes in the speed of sound in the air to determine the temperature of the environmental air. The changes in the speed of sound are calculated by combining time-of-flight (TOF) and phase shift techniques. This method can work in a wider range than using phase shift alone and is more accurate than the TOF scheme. In the proposed system, we use 40 ± 2 kHz ultrasonic transducers and adopt a single-pass operation. An 89c51 single-chip microcomputer-based binary frequency shift-keyed (BFSK) signal generator and phase detector are designed to record and calculate the TOF, phase shift of the two frequencies and temperature. These data are then sent to either an LCD display or to a PC for calibration and examination. Experimental results show that the proposed measurement system has a high accuracy of ± 0.4 °C from 0 to 80 °C and can reflect the temperature change within 100 ms.

Ultrasonic techniques for measuring physical properties of fluids in harsh environments

NASA Astrophysics Data System (ADS)

Pantea, Cristian

Ultrasonic-based measurement techniques, either in the time domain or in the frequency domain, include a wide range of experimental methods for investigating physical properties of materials. This discussion is specifically focused on ultrasonic methods and instrumentation development for the determination of liquid properties at conditions typically found in subsurface environments (in the U.S., more than 80% of total energy needs are provided by subsurface energy sources). Such sensors require materials that can withstand harsh conditions of high pressure, high temperature and corrosiveness. These include the piezoelectric material, electrically conductive adhesives, sensor housings/enclosures, and the signal carrying cables, to name a few. A complete sensor package was developed for operation at high temperatures and pressures characteristic to geothermal/oil-industry reservoirs. This package is designed to provide real-time, simultaneous measurements of multiple physical parameters, such as temperature, pressure, salinity and sound speed. The basic principle for this sensor's operation is an ultrasonic frequency domain technique, combined with transducer resonance tracking. This multipurpose acoustic sensor can be used at depths of several thousand meters, temperatures up to 250 °C, and in a very corrosive environment. In the context of high precision measurement of sound speed, the determination of acoustic nonlinearity of liquids will also be discussed, using two different approaches: (i) the thermodynamic method, in which precise and accurate frequency domain sound speed measurements are performed at high pressure and high temperature, and (ii) a modified finite amplitude method, requiring time domain measurements of the second harmonic at room temperature. Efforts toward the development of an acoustic source of collimated low-frequency (10-150 kHz) beam, with applications in imaging, will also be presented.

Classical Experiments Revisited: Smartphones and Tablet PCs as Experimental Tools in Acoustics and Optics

ERIC Educational Resources Information Center

Klein, P.; Hirth, M.; Gröber, S.; Kuhn, J.; Müller, A.

2014-01-01

Smartphones and tablets are used as experimental tools and for quantitative measurements in two traditional laboratory experiments for undergraduate physics courses. The Doppler effect is analyzed and the speed of sound is determined with an accuracy of about 5% using ultrasonic frequency and two smartphones, which serve as rotating sound emitter…

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.

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.

In-Line Ultrasonic Monitoring for Sediments Stuck on Inner Wall of a Polyvinyl Chloride Pipe

PubMed Central

2014-01-01

This research verified the applicability and effectiveness of the ultrasonic monitoring of sediments stuck on the inner wall of polyvinyl chloride (PVC) pipes. For identifying the transmittance of acoustic energy and the speed of sound in the PVC material, the pulse-echo ultrasonic testing was conducted for PVC sheets of different thicknesses. To simulate the solidified sediment, the hot melt adhesive (HMA) was covered on the inner wall of the PVC pipe in different heights. From the experiment, the speeds of sound in the PVC and the HMA materials were obtained as about 2258 and 2000 m/s, respectively. The thickness of the materials was calculated through the signal processing such as taking the absolute value and low pass filtering, the echo detection, and the measurement of the time of flight. The errors between actual and measured thicknesses of PVC sheets were below 5%. In the case of the substance stuck on the inner wall, the errors were below 2.5%. Since the pulse-echo ultrasonic inspection is available on the outer surface and its measurement accuracy was over 95%, it can be an efficient and effective in-service structural health monitoring for the sediment on the wall of PVC pipes. PMID:25243223

Highly efficient isolation of waterborne sound by an air-sealed meta-screen

NASA Astrophysics Data System (ADS)

Bai, Xiaoxue; Qiu, Chunyin; Wen, Xinhua; Peng, Shasha; Ke, Manzhu; Liu, Zhengyou

2017-05-01

Underwater sound isolation has been a long-standing fundamental issue in industry and military fields. Starting from a simple theoretical model, here an air-sealed meta-screen is proposed to overcome this problem. Comparing with the sample without filling air, the effective impedance of the air-sealed one is greatly reduced and strikingly mismatch with water, accompanying another merit of low sound speed. Deeply suppressed sound transmission (˜50 dB) through such a meta-screen is observed experimentally over a wide range of ultrasonic frequencies and incident angles.

Attenuation Measurements of Cell Pellets Using Through Transmission

NASA Astrophysics Data System (ADS)

Vadas, Justin; Greene, Claudia; Grygotis, Emma; Kuhn, Stephen; Mahlalela, Sanele; Newland, Tinisha; Ovutmen, Idil; Herd, Maria-Teresa

2011-10-01

A better understanding of differences in ultrasound tissue characteristics (such as speed of sound, attenuation, and backscatter coefficients) of benign compared to malignant cells could lead to improved cancer detection and diagnosis. A narrow band technique for measuring ultrasonic speed of sound and attenuation of small biological materials was developed and tested. Several mechanical improvements were made to the system to drastically improve alignment, allowing for accurate measurements of small cell pellets. Narrow band attenuation measurements were made first with tissue-mimicking phantoms and then with three different types of cell pellets: Chinese hamster ovary cells, healthy human prostate cells, and cancerous human prostate cells. Attenuation and speed of sound results for all three cell types, as well as the culture medium and tissue mimicking phantoms, are presented for a frequency range of 5 to 25 MHz.

An absolute instrument for determination of the speed of sound in water

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

Li, Zhiwei; Zhu, Junchao; Zhang, Baofeng, E-mail: zhangbaofeng@263.net

An apparatus for the absolute determination of the sound speed in water based on the time-of-flight technique is described. The time measurement is realized by hardware circuits and the distance measurement by a double-beam plane-mirror interferometer. A highly accurate time chip, with a resolution of approximately 90 ps, is employed for time measurements. The acoustic path length is adjustable and can be measured directly. Two transducers are used for transmitting and receiving ultrasonic signals without reflection. The transducers are immersed in a thermostatic vessel that maintains bath temperature with high stability. The speed of sound in pure water was measuredmore » at ambient pressure and at the temperatures 308 K, 303 K, 298 K, and 293 K. The achieved measurement uncertainties are 2 mK for temperature and 0.045 m/s for speed of sound. The results are compared to data from the literature, equation of state models, and measurements by two commercial sensors in the same experiment, showing excellent agreement among them.« less

Ultrasonic Estimation of Mechanical Properties of Pulmonary Arterial Wall Under Normoxic and Hypoxic Conditions

NASA Astrophysics Data System (ADS)

Waters, Kendall R.; Mukdadi, Osama M.

2005-04-01

Secondary pediatric pulmonary hypertension is a disease that could benefit from improved ultrasonic diagnostic techniques. We perform high-frequency in vitro ultrasound measurements (25 MHz to 100 MHz) on fresh and fixed pulmonary arterial walls excised from normoxic and hypoxic Long-Evans rat models. Estimates of the elastic stiffness coefficients are determined from measurements of the speed of sound. Preliminary results indicate that hypoxia leads to up to increase of 20 % in stiffening of the pulmonary arterial wall.

Influence of microarchitecture alterations on ultrasonic backscattering in an experimental simulation of bovine cancellous bone aging.

PubMed

Apostolopoulos, K N; Deligianni, D D

2008-02-01

An experimental model which can simulate physical changes that occur during aging was developed in order to evaluate the effects of change of mineral content and microstructure on ultrasonic properties of bovine cancellous bone. Timed immersion in hydrochloric acid was used to selectively alter the mineral content. Scanning electron microscopy and histological staining of the acid-treated trabeculae demonstrated a heterogeneous structure consisting of a mineralized core and a demineralized layer. The presence of organic matrix contributed very little to normalized broadband ultrasound attenuation (nBUA) and speed of sound. All three ultrasonic parameters, speed of sound, nBUA and backscatter coefficient, were sensitive to changes in apparent density of bovine cancellous bone. A two-component model utilizing a combination of two autocorrelation functions (a densely populated model and a spherical distribution) was used to approximate the backscatter coefficient. The predicted attenuation due to scattering constituted a significant part of the measured total attenuation (due to both scattering and absorption mechanisms) for bovine cancellous bone. Linear regression, performed between trabecular thickness values and estimated from the model correlation lengths, showed significant linear correlation, with R(2)=0.81 before and R(2)=0.80 after demineralization. The accuracy of estimation was found to increase with trabecular thickness.

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.

Development of a radial-torsional vibration hybrid type ultrasonic motor with a hollow and short cylindrical structure.

PubMed

Wang, Jian; Guo, Jifeng

2009-05-01

A longitudinal-torsional hybrid-type ultrasonic motor has larger torque and lower revolution speed compared with other kinds of ultrasonic motors. It drives devices directly and precisely, so it is adaptable to many fields, especially aeronautics and astronautics, as a servo actuator. Due to the different sound propagation speeds of longitudinal and torsional vibrations in the stator, it is difficult to match resonant frequencies of longitudinal and torsional vibrations. In this paper, a new radial-torsional vibration hybrid-type ultrasonic motor is put forward, which utilizes longitudinal vibration derived from radial vibration by the Poisson effect. The short, hollow cylindrical structure easily makes resonant frequencies of first-order radial and torsional vibrations into degeneracy. First, the new structure of the motor is presented. Second, the principle of matching the resonant frequencies is developed, and the motor geometry is optimized by ANSYS software. Finally, a 60-mm diameter prototype is fabricated, which performs well. The no-load velocity and maximum torque are 25 r/min and 5 N x m, respectively. This kind of motor is small, light, and noiseless.

Deep sub-wavelength ultrasonic imaging

NASA Astrophysics Data System (ADS)

Amireddy, Kiran Kumar; Balasubramaniam, Krishnan; Rajagopal, Prabhu

2018-04-01

There is much interest in improving the resolution of ultrasonic inspection, which suffers from large wavelengths typically in the range of millimeters, due to low value of speed of sound in solid media. The authors are interested in achieving this through holey structured metamaterial lenses, and have recently demonstrated an experimental subwavelength resolution of λ/25. However the previous work was in through-transmission mode with reception using Laser Doppler Vibrometer (LDV), which may not be suitable for practical applications. This paper discusses the use of optimized holey structured metalens to achieve a deep sub-wavelength imaging up to λ/18 in through-transmission mode, but using commercially available piezoelectric ultrasonic transducers for both generation and reception of ultrasound.

Supporting the potential of quantitative ultrasonic techniques for the evaluation of platelet concentration

NASA Astrophysics Data System (ADS)

Villamarín, J. A.; Jiménez, Y. M.; Molano, L. Tatiana; Gutierrez, W. Edgar; Londoño, L. Fernando; Gutierrez, D. A.

2017-11-01

This article describes the results obtained by making use of a non-destructive, non-invasive ultrasonic system for the acoustic characterization of bovine plasma rich in platelets using digital signal processing techniques. This study includes computational methods based on acoustic spectrometry estimation and experimental measurements of the speed of sound in blood plasma from different samples analyzed, using an ultrasonic field with resonance frequency of 5 MHz. The results showed that the measurements on ultrasonic signals can contribute to the hematological predictions based on the linear regression model applied to the relationship between experimental ultrasonic parameters calculated and platelet concentration, indicating a growth rate of 1 m/s for each 0.90 x103 platelet per mm3. On the other hand, the attenuation coefficient presented changes of 20% in the platelet concentration using a resolution of 0.057 dB/cm MHz.

Robust analysis method for acoustic properties of biological specimens measured by acoustic microscopy

NASA Astrophysics Data System (ADS)

Arakawa, Mototaka; Mori, Shohei; Kanai, Hiroshi; Nagaoka, Ryo; Horie, Miki; Kobayashi, Kazuto; Saijo, Yoshifumi

2018-07-01

We proposed a robust analysis method for the acoustic properties of biological specimens measured by acoustic microscopy. Reflected pulse signals from the substrate and specimen were converted into frequency domains to obtain sound speed and thickness. To obtain the average acoustic properties of the specimen, parabolic approximation was performed to determine the frequency at which the amplitude of the normalized spectrum became maximum or minimum, considering the sound speed and thickness of the specimens and the operating frequency of the ultrasonic device used. The proposed method was demonstrated for a specimen of malignant melanoma of the skin by using acoustic microscopy attaching a concave transducer with a center frequency of 80 MHz. The variations in sound speed and thickness analyzed by the proposed method were markedly smaller than those analyzed by the method based on an autoregressive model. The proposed method is useful for the analysis of the acoustic properties of bilogical tissues or cells.

Nondestructive evaluation of hydrogel mechanical properties using ultrasound

PubMed Central

Walker, Jason M.; Myers, Ashley M.; Schluchter, Mark D.; Goldberg, Victor M.; Caplan, Arnold I.; Berilla, Jim A.; Mansour, Joseph M.; Welter, Jean F.

2012-01-01

The feasibility of using ultrasound technology as a noninvasive, nondestructive method for evaluating the mechanical properties of engineered weight-bearing tissues was evaluated. A fixture was designed to accurately and reproducibly position the ultrasound transducer normal to the test sample surface. Agarose hydrogels were used as phantoms for cartilage to explore the feasibility of establishing correlations between ultrasound measurements and commonly used mechanical tissue assessments. The hydrogels were fabricated in 1–10% concentrations with a 2–10 mm thickness. For each concentration and thickness, six samples were created, for a total of 216 gel samples. Speed of sound was determined from the time difference between peak reflections and the known height of each sample. Modulus was computed from the speed of sound using elastic and poroelastic models. All ultrasonic measurements were made using a 15 MHz ultrasound transducer. The elastic modulus was also determined for each sample from a mechanical unconfined compression test. Analytical comparison and statistical analysis of ultrasound and mechanical testing data was carried out. A correlation between estimates of compressive modulus from ultrasonic and mechanical measurements was found, but the correlation depended on the model used to estimate the modulus from ultrasonic measurements. A stronger correlation with mechanical measurements was found using the poroelastic rather than the elastic model. Results from this preliminary testing will be used to guide further studies of native and engineered cartilage. PMID:21773854

Acoustic Characterization of Fluorinert FC-43 Liquid with Helium Gas Bubbles: Numerical Experiments

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

Vanhille, Christian; Pantea, Cristian; Sinha, Dipen N.

In this work, we define the acoustic characteristics of a biphasic fluid consisting of static helium gas bubbles in liquid Fluorinert FC-43 and study the propagation of ultrasound of finite amplitudes in this medium. Very low sound speed and high sound attenuation are found, in addition to a particularly high acoustic nonlinear parameter. This result suggests the possibility of using this medium as a nonlinear enhancer in various applications. In particular, parametric generation of low ultrasonic frequencies is studied in a resonator cavity as a function of driving pressure showing high conversion efficiency. This work suggests that this medium couldmore » be used for applications such as parametric arrays, nondestructive testing, diagnostic medicine, sonochemistry, underwater acoustics, and ultrasonic imaging and to boost the shock formation in fluids.« less

Acoustic Characterization of Fluorinert FC-43 Liquid with Helium Gas Bubbles: Numerical Experiments

DOE PAGES

Vanhille, Christian; Pantea, Cristian; Sinha, Dipen N.

2017-01-19

In this work, we define the acoustic characteristics of a biphasic fluid consisting of static helium gas bubbles in liquid Fluorinert FC-43 and study the propagation of ultrasound of finite amplitudes in this medium. Very low sound speed and high sound attenuation are found, in addition to a particularly high acoustic nonlinear parameter. This result suggests the possibility of using this medium as a nonlinear enhancer in various applications. In particular, parametric generation of low ultrasonic frequencies is studied in a resonator cavity as a function of driving pressure showing high conversion efficiency. This work suggests that this medium couldmore » be used for applications such as parametric arrays, nondestructive testing, diagnostic medicine, sonochemistry, underwater acoustics, and ultrasonic imaging and to boost the shock formation in fluids.« less

Removing function model and experiments on ultrasonic polishing molding die

NASA Astrophysics Data System (ADS)

Huang, Qitai; Ni, Ying; Yu, Jingchi

2010-10-01

Low temperature glass molding technology is the main method on volume-producing high precision middle and small diameter optical cells in the future. While the accuracy of the molding die will effect the cell precision, so the high precision molding die development is one of the most important part of the low temperature glass molding technology. The molding die is manufactured from high rigid and crisp metal alloy, with the ultrasonic vibration character of high vibration frequency and concentrative energy distribution; abrasive particles will impact the rigid metal alloy surface with very high speed that will remove the material from the work piece. Ultrasonic can make the rigid metal alloy molding die controllable polishing and reduce the roughness and surface error. Different from other ultrasonic fabrication method, untouched ultrasonic polishing is applied on polish the molding die, that means the tool does not touch the work piece in the process of polishing. The abrasive particles vibrate around the balance position with high speed and frequency under the drive of ultrasonic vibration in the liquid medium and impact the workspace surface, the energy of abrasive particles come from ultrasonic vibration, while not from the direct hammer blow of the tool. So a nummular vibrator simple harmonic vibrates on an infinity plane surface is considered as a model of ultrasonic polishing working condition. According to Huygens theory the sound field distribution on a plane surface is analyzed and calculated, the tool removing function is also deduced from this distribution. Then the simple point ultrasonic polishing experiment is proceeded to certificate the theory validity.

A stepped-plate bi-frequency source for generating a difference frequency sound with a parametric array.

PubMed

Je, Yub; Lee, Haksue; Park, Jongkyu; Moon, Wonkyu

2010-06-01

An ultrasonic radiator is developed to generate a difference frequency sound from two frequencies of ultrasound in air with a parametric array. A design method is proposed for an ultrasonic radiator capable of generating highly directive, high-amplitude ultrasonic sound beams at two different frequencies in air based on a modification of the stepped-plate ultrasonic radiator. The stepped-plate ultrasonic radiator was introduced by Gallego-Juarez et al. [Ultrasonics 16, 267-271 (1978)] in their previous study and can effectively generate highly directive, large-amplitude ultrasonic sounds in air, but only at a single frequency. Because parametric array sources must be able to generate sounds at more than one frequency, a design modification is crucial to the application of a stepped-plate ultrasonic radiator as a parametric array source in air. The aforementioned method was employed to design a parametric radiator for use in air. A prototype of this design was constructed and tested to determine whether it could successfully generate a difference frequency sound with a parametric array. The results confirmed that the proposed single small-area transducer was suitable as a parametric radiator in air.

High temperature ultrasonic immersion measurements using a BS-PT based piezoelectric transducer without a delay line

NASA Astrophysics Data System (ADS)

Bilgunde, Prathamesh N.; Bond, Leonard J.

2018-04-01

Ultrasonic imaging is a key enabling technology required for in-service inspection of advanced sodium fast reactors at the hot stand-by operating mode (˜250C). Current work presents development of a single element, 2.4MHz, planar, ultrasonic immersion transducer for a potential application in ranging, inspection and imaging of the reactor components. The prototype immersion transducer is first tested in water for three thermal cycles up to 92C. The transducer is further evaluated for four thermal cycles in silicone oil, with total seven thermal cycles that exceeded operation period of 21 hours. Moreover, the preliminary data acquired for speed of sound in silicone oil indicates 24% reduction from 22C to 142C. Sensitivity of the ultrasonic transducer is also measured as a function of temperature and demonstrates the effect of multiple thermal cycles on the transducer components.

Ultrasonic non invasive techniques for microbiological instrumentation

NASA Astrophysics Data System (ADS)

Elvira, L.; Sierra, C.; Galán, B.; Resa, P.

2010-01-01

Non invasive techniques based on ultrasounds have advantageous features to study, characterize and monitor microbiological and enzymatic reactions. These processes may change the sound speed, viscosity or particle distribution size of the medium where they take place, which makes possible their analysis using ultrasonic techniques. In this work, two different systems for the analysis of microbiological liquid media based on ultrasounds are presented. In first place, an industrial application based on an ultrasonic monitoring technique for microbiological growth detection in milk is shown. Such a system may improve the quality control strategies in food production factories, being able to decrease the time required to detect possible contaminations in packed products. Secondly, a study about the growing of the Escherichia coli DH5 α in different conditions is presented. It is shown that the use of ultrasonic non invasive characterization techniques in combination with other conventional measurements like optical density provides complementary information about the metabolism of these bacteria.

Highly sensitive simple homodyne phase detector for ultrasonic pulse-echo measurements

DOE PAGES

Grossman, John; Suslov, Alexey V.; Yong, Grace; ...

2016-04-07

Progress in microelectronic technology has allowed us to design and develop a simple but, professional quality instrument for ultrasonic pulse-echo probing of the elastic properties of materials. The heart of this interfer- ometer lies in the AD8302 microchip, a gain and phase detector from Analog Devices, Inc. The interferometer was tested by measuring the temperature dependences of the ultrasound speed and attenuation in a ferro- electric KTa 0.92 Nb 0.08O 3 (KTN) crystal at a frequency of about 40 MHz. These tests demonstrated that our instrument is capable of detecting the relative changes in the sound speed v on themore » level of Δv/v ~ 10 –7. In addition, the ultrasound attenuation revealed new features in the development of the low-temperature structure of the ferroelectric KTN crystal.« less

One-Dimensional Model for the Ultrasonic Response of Resin-Filled Gaps in Automated Tape Layup Composites

NASA Technical Reports Server (NTRS)

Johnston, Patrick H.; Juarez, Peter D.

2017-01-01

Automated tow placement has become a widely used fabrication technique, especially for large aerospace structures. Robotic heads lay down strips (tows) of preimpregnated fiber along programmed paths. The intention is to lay adjacent tows abutted to one another, but sometimes a gap is left between a tow and the previously-placed tow. If a tow gap exists, it fills with resin during cure, forming a fiber-free volume. In immersion ultrasonic pulse-echo measurements of a cured laminate, the gap can be observed to produce a noticeable echo, without significantly attenuating the back-wall reflection of the laminate. To understand this behavior, we considered a one dimensional model of the composite laminate, with a thin layer having the ultrasonic sound speed and density of neat resin, sandwiched between two layers of material having the sound speed and density of fiber-reinforced composite and surrounded on both sides by water. Neglecting attenuation, we considered the transmission and reflection coefficients of each interface, as well as that of the thin resin layer. Using the initial water/composite reflection as a reference, we computed the relative magnitude of the back surface/water reflection in the presence and in the absence of a resin-only layer, as well as the relative magnitude of the reflection arising from a thin resin layer in composite. While the one-dimensional model did not fully match the measurements, it did qualitatively explain the observed behavior.

The young's modulus of 1018 steel and 67061-T6 aluminum measured from quasi-static to elastic precursor strain-rates

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

Rae, Philip J; Trujillo, Carl; Lovato, Manuel

2009-01-01

The assumption that Young's modulus is strain-rate invariant is tested for 6061-T6 aluminium alloy and 1018 steel over 10 decades of strain-rate. For the same billets of material, 3 quasi-static strain-rates are investigated with foil strain gauges at room temperature. The ultrasonic sound speeds are measured and used to calculate the moduli at approximately 10{sup 4} s{sup -1}. Finally, ID plate impact is used to generate an elastic pre-cursor in the alloys at a strain-rate of approximately 10{sup 6} s{sup -1} from which the longitudinal sound speed may be obtained. It is found that indeed the Young's modulus is strain-ratemore » independent within the experimental accuracy.« less

Solute-solvent interactions in chloroform solutions of halogenated symmetric double Schiff bases of 1,1'-bis(4-aminophenyl)cyclohexane at 308.15 K according to ultrasonic and viscosity data

NASA Astrophysics Data System (ADS)

Gangani, B. J.; Patel, J. P.; Parsania, P. H.

2015-12-01

The density, viscosity and ultrasonic speed (2 MHz) of chloroform solutions of halogenated symmetric double Schiff bases of 1,1'-bis(4-aminophenyl)cyclohexane were investigated at 308.15 K. Various acoustical parameters such as specific acoustical impedance ( Z), adiabatic compressibility ( Ka), Rao's molar sound function ( R m), van der Waals constant ( b), internal pressure (π), free volume ( V f), intermolecular free path length ( L f), classical absorption coefficient (α/ f 2)Cl) and viscous relaxation time (τ) were determine using ultrasonic speed ( U), viscosity (η) and density (ρ) data of Schiff bases solutions and correlated with concentration. Linear increase of Z, b, R, τ, and (α/ f 2)Cl except π (nonlinear) and linear decrease of Ka and L f except V f (nonlinear) with increasing concentration of Schiff bases suggested presence of strong molecular interactions in the solutions. The positive values of solvation number further supported strong molecular interactions in the solutions. The nature and position of halogen substituent also affected the strength of molecular interactions.

A novel ultrasonic method for measuring breast density and breast cancer risk

NASA Astrophysics Data System (ADS)

Glide-Hurst, Carri K.; Duric, Neb; Littrup, Peter J.

2008-03-01

Women with high mammographic breast density are at 4- to 6-fold increased risk of developing breast cancer compared to women with fatty breasts. However, current breast density estimations rely on mammography, which cannot provide accurate volumetric breast representation. Therefore, we explored two techniques of breast density evaluation via ultrasound tomography. A sample of 93 patients was imaged with our clinical prototype; each dataset contained 45-75 tomograms ranging from near the chest wall through the nipple. Whole breast acoustic velocity was determined by creating image stacks and evaluating the sound speed frequency distribution. Ultrasound percent density (USPD) was determined by segmenting high sound speed areas from each tomogram using k-means clustering, integrating over the entire breast, and dividing by total breast area. Both techniques were independently evaluated using two mammographic density measures: (1) qualitative, determined by a radiologist's visual assessment using BI-RADS Categories, and (2) quantitative, via semi-automatic segmentation to calculate mammographic percent density (MPD) for craniocaudal and medio-lateral oblique mammograms. ~140 m/s difference in acoustic velocity was observed between fatty and dense BI-RADS Categories. Increased sound speed was found with increased BI-RADS Category and quantitative MPD. Furthermore, strong positive associations between USPD, BI-RADS Category, and calculated MPD were observed. These results confirm that utilizing sound speed, both for whole-breast evaluation and segmenting locally, can be implemented to evaluate breast density.

Sound intensity probe for ultrasonic field in water using light-emitting diodes and piezoelectric elements

NASA Astrophysics Data System (ADS)

Zeng, Xi; Mizuno, Yosuke; Nakamura, Kentaro

2017-12-01

The sound intensity vector provides useful information on the state of an ultrasonic field in water, since sound intensity is a vector quantity expressing the direction and magnitude of the sound field. In the previous studies on sound intensity measurement in water, conventional piezoelectric sensors and metal cables were used, and the transmission distance was limited. A new configuration of a sound intensity probe suitable for ultrasonic measurement in water is proposed and constructed for trial in this study. The probe consists of light-emitting diodes and piezoelectric elements, and the output signals are transmitted through fiber optic cables as intensity-modulated light. Sound intensity measurements of a 26 kHz ultrasonic field in water are demonstrated. The difference in the intensity vector state between the water tank with and without sound-absorbing material on its walls was successfully observed.

Effective isolation of primo vessels in lymph using sound- and ultrasonic-wave stimulation.

PubMed

Park, Do-Young; Lee, Hye-Rie; Rho, Min-Suk; Lee, Sang-Suk

2014-12-01

The effects of stimulation with sound and ultrasonic waves of a specific bandwidth on the microdissection of primo vessels in lymphatic vessels of rabbit were investigated. The primo vessels stained with alcian-blue dye injected in the lymph nodes were definitely visualized and more easily isolated by sound-wave vibration and ultrasonic stimulation applied to rabbits at various frequencies and intensities. With sound wave at 7 Hz and ultrasonic waves at 2 MHz, the probability of detecting the primo vessels was improved to 90%; however, without wave stimulation the probability of discovering primo vessels was about 50% only. Sound and ultrasonic waves at specific frequency bands should be effective for microdissection of the primo vessels in the abdominal lymph of rabbit. We suggest that oscillation of the primo vessels by sound and ultrasonic waves may be useful to visualize specific primo structure, and wave vibration can be a very supportive process for observation and isolation of the primo vessels of rabbits. Copyright © 2014. Published by Elsevier B.V.

Method and apparatus for inspecting conduits

DOEpatents

Spisak, Michael J.; Nance, Roy A.

1997-01-01

An apparatus and method for ultrasonic inspection of a conduit are provided. The method involves directing a first ultrasonic pulse at a particular area of the conduit at a first angle, receiving the reflected sound from the first ultrasonic pulse, substantially simultaneously or subsequently in very close time proximity directing a second ultrasonic pulse at said area of the conduit from a substantially different angle than said first angle, receiving the reflected sound from the second ultrasonic pulse, and comparing the received sounds to determine if there is a defect in that area of the conduit. The apparatus of the invention is suitable for carrying out the above-described method. The method and apparatus of the present invention provide the ability to distinguish between sounds reflected by defects in a conduit and sounds reflected by harmless deposits associated with the conduit.

Classical experiments revisited: smartphones and tablet PCs as experimental tools in acoustics and optics

NASA Astrophysics Data System (ADS)

Klein, P.; Hirth, M.; Gröber, S.; Kuhn, J.; Müller, A.

2014-07-01

Smartphones and tablets are used as experimental tools and for quantitative measurements in two traditional laboratory experiments for undergraduate physics courses. The Doppler effect is analyzed and the speed of sound is determined with an accuracy of about 5% using ultrasonic frequency and two smartphones, which serve as rotating sound emitter and stationary sound detector. Emphasis is put on the investigation of measurement errors in order to judge experimentally derived results and to sensitize undergraduate students to the methods of error estimates. The distance dependence of the illuminance of a light bulb is investigated using an ambient light sensor of a mobile device. Satisfactory results indicate that the spectrum of possible smartphone experiments goes well beyond those already published for mechanics.

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.

A forward model and conjugate gradient inversion technique for low-frequency ultrasonic imaging.

PubMed

van Dongen, Koen W A; Wright, William M D

2006-10-01

Emerging methods of hyperthermia cancer treatment require noninvasive temperature monitoring, and ultrasonic techniques show promise in this regard. Various tomographic algorithms are available that reconstruct sound speed or contrast profiles, which can be related to temperature distribution. The requirement of a high enough frequency for adequate spatial resolution and a low enough frequency for adequate tissue penetration is a difficult compromise. In this study, the feasibility of using low frequency ultrasound for imaging and temperature monitoring was investigated. The transient probing wave field had a bandwidth spanning the frequency range 2.5-320.5 kHz. The results from a forward model which computed the propagation and scattering of low-frequency acoustic pressure and velocity wave fields were used to compare three imaging methods formulated within the Born approximation, representing two main types of reconstruction. The first uses Fourier techniques to reconstruct sound-speed profiles from projection or Radon data based on optical ray theory, seen as an asymptotical limit for comparison. The second uses backpropagation and conjugate gradient inversion methods based on acoustical wave theory. The results show that the accuracy in localization was 2.5 mm or better when using low frequencies and the conjugate gradient inversion scheme, which could be used for temperature monitoring.

High frequency signal acquisition using a smartphone in an undergraduate teaching laboratory: Applications in ultrasonic resonance spectra.

PubMed

Sturtevant, Blake T; Pantea, Cristian; Sinha, Dipen N

2016-10-01

A simple and inexpensive approach to acquiring signals in the megahertz frequency range using a smartphone is described. The approach is general, applicable to electromagnetic as well as acoustic measurements, and makes available to undergraduate teaching laboratories experiments that are traditionally inaccessible due to the expensive equipment that are required. This paper focuses on megahertz range ultrasonic resonance spectra in liquids and solids, although there is virtually no upper limit on frequencies measurable using this technique. Acoustic resonance measurements in water and Fluorinert in a one dimensional (1D) resonant cavity were conducted and used to calculate sound speed. The technique is shown to have a precision and accuracy significantly better than one percent in liquid sound speed. Measurements of 3D resonances in an isotropic solid sphere were also made and used to determine the bulk and shear moduli of the sample. The elastic moduli determined from the solid resonance measurements agreed with those determined using a research grade vector network analyzer to better than 0.5%. The apparatus and measurement technique described can thus make research grade measurements using standardly available laboratory equipment for a cost that is two-to-three orders of magnitude less than the traditional measurement equipment used for these measurements.

Microscopic, Macroscopic, and Megascopic Melts: a simple model to synthesize simulation, spectroscopy, shock, and sink/float constraints on silicate melts and magma oceans

NASA Astrophysics Data System (ADS)

Asimow, P. D.; Thomas, C.; Wolf, A. S.

2012-12-01

Silicate melts are the essential agents of planetary differentiation and evolution. Their phase relations, element partitioning preferences, density, and transport properties determine the fates of heat and mass flow in the high-temperature interior of active planets. In the early Earth and in extrasolar super-Earth-mass terrestrial planets it is these properties at very high pressure (> 100 GPa) that control the evolution from possible magma oceans to solid-state convecting mantles. Yet these melts are complex, dynamic materials that present many challenges to experimental, theoretical, and computational understanding or prediction of their properties. There has been encouraging convergence among various approaches to understanding the structure and dynamics of silicate melts at multiple scales: nearest- and next-nearest neighbor structural information is derived from spectroscopic techniques such as high-resolution multinuclear NMR; first-principles molecular dynamics probe structure and dynamics at scales up to hundreds of atoms; Archimedean, ultrasonic, sink/float, and shock wave methods probe macroscopic properties (and occasionally dynamics); and deformation and diffusion experiments probe dynamics at macroscopic scale and various time scales. One challenge that remains to integrating all this information is a predictive model of silicate liquid structure that agrees with experiments and simulation both at microscopic and macroscopic scale. In addition to our efforts to collect macroscopic equation of state data using shock wave methods across ever-wider ranges of temperature, pressure, and composition space, we have introduced a simple model of coordination statistics around cations that can form the basis of a conceptual and predictive link across scales and methods. This idea is explored in this presentation specifically with regard to the temperature dependence of sound speed in ultramafic liquids. This is a highly uncertain quantity and yet it is key, in many models, to extrapolating the equation of state up or down temperature to geophysically relevant conditions. Ultrasonic data on felsic to basaltic melts, across a fairly narrow temperature range from their liquidi to ≤1650 °C, suggest either no temperature dependence or sound speeds that increase with temperature. Simulations, conducted at much higher temperature to obtain relaxation, suggest a strong decrease in sound speed with temperature. Our shock wave data on Mg2SiO4 liquid at 2000 °C yield a sound speed significantly lower than that predicted from data on less mafic liquids collected at lower temperatures where Mg2SiO4 liquid is not stable. The same shock method applied to melt compositions that are stable at 1300-1550 °C, however, yields sound speeds comparable to the ultrasonic results. Although each of these methods has its shortcomings, we show that considerable insight can be obtained in the context of a predictive model of Mg2+ and Si4+ coordination statistics as functions of temperature and pressure. We suggest that this can explain the difference between results obtained at ordinary upper mantle magmatic temperatures and those expected for magma oceans.

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 rodent ultrasound production mechanism.

PubMed

Roberts, L H

1975-03-01

Rodents produce two types of sounds, audible and ultrasonic, that differ markedly in physical structure. Studies of sound production in light gases show that whereas the audible cries appear to be produced, as in the case of most other mammals, by vibrating structures in the larynx, the ultrasonic cries are produced by a different mechanism, probably a whistle. 'Bird-call' whistles are shown to have all the properties of rodent ultrasonic cries and to mimic them in almost every detail. Thus it is concluded that rodents have two distinct sound production mechanisms, one for audible cries and one for ultrasonic cries.

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.

Development of the Noise-Resistant and Sound Focusing Accessory of Ultrasonic Leak Detector for Spacecraft on Orbit

NASA Astrophysics Data System (ADS)

Sun, W.; Yan, R. X.; Sun, L. C.; Shao, R. P.

2017-12-01

Ultrasonic signal produced by the gas leak is so week that it is difficult to detect, and easily interfered. So developing the noise-resistant and sound focusing accessory for the ultrasonic leak detector is very important for improving ultrasonic leak detector sensitivity and noise-resistant capability. Based on the theory analysis of the leak ultrasonic signal reverberation and anacampsis, the 5A06 aluminium alloy and nylon were selected as the material of noise-resistant and sound focusing accessory by calculation and compare. Then the circular cone trumpet structure was design as the accessory main structure, and the nylon expansion port, nylon shrinking port and aluminium alloy expansion port structures were manufactured. The different structure characters were shown by the contrasting experiment. The results indicate that the nylon expansion circular cone trumpet structure has better sound focusing performance and it can improve the testing sound pressure amplitude 10 bigger than the detector without the accessory. And the aluminium alloy expansion circular cone trumpet structure has better noise-resistant ability than others. These conclusions are very important for the spacecraft leak detection and it can provide some references for the design of the noise-resistant and sound focusing structure.

Ultrasonic computed tomography imaging of iron oxide nanoparticles

NASA Astrophysics Data System (ADS)

Perlman, Or; Azhari, Haim

2017-02-01

Iron oxide nanoparticles (IONPs) are becoming increasingly used and intensively investigated in the field of medical imaging. They are currently FDA approved for magnetic resonance imaging (MRI), and it would be highly desirable to visualize them by ultrasound as well. Previous reports using the conventional ultrasound B-scan (pulse-echo) imaging technique have shown very limited detectability of these particles. The aim of this study is to explore the feasibility of imaging IONPs using the through-transmission ultrasound methodology and demonstrate their detectability using ultrasonic computed tomography (UCT). Commercially available IONPs were acoustically analysed to quantify their effect on the speed of sound (SOS) and acoustic attenuation as a function of concentration. Next, through-transmission projection and UCT imaging were performed on a breast mimicking phantom and on an ex vivo tissue model, to which IONPs were injected. Finally, an MRI scan was performed to verify that the same particles examined in the ultrasound experiment can be imaged by magnetic resonance, using the same clinically relevant concentrations. The results have shown a consistent concentration dependent speed of sound increase (1.86 \\text{m}{{\\text{s}}^{-1}} rise per 100 µg · ml-1 IONPs). Imaging based on this property has shown a substantial contrast-to-noise ratio improvement (up to 5 fold, p  <  0.01). The SOS-related effect generated a well discernible image contrast and allowed the detection of the particles existence and location, in both raster-scan projection and UCT imaging. Conversely, no significant change in the acoustic attenuation coefficient was noted. Based on these findings, it is concluded that IONPs can be used as an effective SOS-based contrast agent, potentially useful for ultrasonic breast imaging. Furthermore, the particle offers the capacity of significantly enhancing diagnosis accuracy using multimodal MRI-ultrasound imaging capabilities.

In-situ geophysical measurements in marine sediments: Applications in seafloor acoustics and paleoceanography

NASA Astrophysics Data System (ADS)

Gorgas, Thomas Joerg

Acoustic in-situ sound speeds and attenuation were measured on the Eel River shelf, CA, with the Acoustic Lance between 5 and 15 kHz to 2.0 meters below seafloor (mbsf). A comparison with laboratory ultrasonic geoacoustic data obtained at 400 kHz on cored sediments showed faster in-situ and ultrasonic sound speeds in coarse-grained deposits in water depths to 60 m than in fine-grained deposits below that contour line. Ultrasonic attenuation was often greater than in-situ values and remained almost constant below 0.4 mbsf in these heterogeneous deposits. In-situ attenuation decreased with depth. These observations partly agree with results from other field studies, and with theoretical models that incorporate intergranular friction and dispersion from viscosity as main controls on acoustic wave propagation in marine sediments. Deviations among in-situ and laboratory acoustic data from the Eel Margin with theoretical studies were linked to scattering effects. Acoustic Lance was also deployed in homogeneous, fine-grained sediments on the inner shelf of SE Korea, where free gas was identified in late-September, but not in mid-September 1999. Free gas was evidenced by an abrupt decrease of in-situ sound speed and by characteristic changes in acoustic waveforms. These results suggest the presence of a gassy sediment layer as shallow as 2 mbsf along the 70 m bathymetry line, and was attributed to a variable abundance of free gas on short-term and/or small-regional scales on the SE Korea shelf. Bulk density variations in marine sediments obtained along the Walvis Ridge/Basin, SW Africa, at Ocean Drilling Program (ODP) Sites 1081 to 1084 were spectral-analyzed to compute high-resolution sedimentation rates (SRs) in both the time- and age domains by correctly identifying Milankovitch cycles (MCs). SRs for the ODP sites yielded age-depth models that often correlate positively with biostratigraphic data and with organic mass accumulation rates (MAR Corg), a proxy for productivity, and negatively with Sea Surface Temperatures (SSTs), a proxy for wind strength. These results suggest that strong amplitudes of all main MCs existed for periods of high SRs and high MAR Corg and low SSTs, indicating a positive link between wind stress, upwelling vigor, productivity and insolation patterns in this area.

Effect of ultrasonic cavitation on measurement of sound pressure using hydrophone

NASA Astrophysics Data System (ADS)

Thanh Nguyen, Tam; Asakura, Yoshiyuki; Okada, Nagaya; Koda, Shinobu; Yasuda, Keiji

2017-07-01

Effect of ultrasonic cavitation on sound pressure at the fundamental, second harmonic, and first ultraharmonic frequencies was investigated from low to high ultrasonic intensities. The driving frequencies were 22, 304, and 488 kHz. Sound pressure was measured using a needle-type hydrophone and ultrasonic cavitation was estimated from the broadband integrated pressure (BIP). With increasing square root of electric power applied to a transducer, the sound pressure at the fundamental frequency linearly increased initially, dropped at approximately the electric power of cavitation inception, and afterward increased again. The sound pressure at the second harmonic frequency was detected just below the electric power of cavitation inception. The first ultraharmonic component appeared at around the electric power of cavitation inception at 304 and 488 kHz. However, at 22 kHz, the first ultraharmonic component appeared at a higher electric power than that of cavitation inception.

Old World frog and bird vocalizations contain prominent ultrasonic harmonics

NASA Astrophysics Data System (ADS)

Narins, Peter M.; Feng, Albert S.; Lin, Wenyu; Schnitzler, Hans-Ulrich; Denzinger, Annette; Suthers, Roderick A.; Xu, Chunhe

2004-02-01

Several groups of mammals such as bats, dolphins and whales are known to produce ultrasonic signals which are used for navigation and hunting by means of echolocation, as well as for communication. In contrast, frogs and birds produce sounds during night- and day-time hours that are audible to humans; their sounds are so pervasive that together with those of insects, they are considered the primary sounds of nature. Here we show that an Old World frog (Amolops tormotus) and an oscine songbird (Abroscopus albogularis) living near noisy streams reliably produce acoustic signals that contain prominent ultrasonic harmonics. Our findings provide the first evidence that anurans and passerines are capable of generating tonal ultrasonic call components and should stimulate the quest for additional ultrasonic species.

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.

Non-destructive inspection approach using ultrasound to identify the material state for amorphous and semi-crystalline materials

NASA Astrophysics Data System (ADS)

Jost, Elliott; Jack, David; Moore, David

2018-04-01

At present, there are many methods to identify the temperature and phase of a material using invasive techniques. However, most current methods require physical contact or implicit methods utilizing light reflectance of the specimen. This work presents a nondestructive inspection method using ultrasonic wave technology that circumvents these disadvantages to identify phase change regions and infer the temperature state of a material. In the present study an experiment is performed to monitor the time of flight within a wax as it undergoes melting and the subsequent cooling. Results presented in this work show a clear relationship between a material's speed of sound and its temperature. The phase change transition of the material is clear from the time of flight results, and in the case of the investigated material, this change in the material state occurs over a range of temperatures. The range of temperatures over which the wax material melts is readily identified by speed of sound represented as a function of material temperature. The melt temperature, obtained acoustically, is validated using Differential Scanning Calorimetry (DSC), which uses shifts in heat flow rates to identify phase transition temperature ranges. The investigated ultrasonic NDE method has direct applications in many industries, including oil and gas, food and beverage, and polymer composites, in addition to many implications for future capabilities of nondestructive inspection of multi-phase materials.

Relationships among ultrasonic and mechanical properties of cancellous bone in human calcaneus in vitro.

PubMed

Wear, Keith A; Nagaraja, Srinidhi; Dreher, Maureen L; Sadoughi, Saghi; Zhu, Shan; Keaveny, Tony M

2017-10-01

Clinical bone sonometers applied at the calcaneus measure broadband ultrasound attenuation and speed of sound. However, the relation of ultrasound measurements to bone strength is not well-characterized. Addressing this issue, we assessed the extent to which ultrasonic measurements convey in vitro mechanical properties in 25 human calcaneal cancellous bone specimens (approximately 2×4×2cm). Normalized broadband ultrasound attenuation, speed of sound, and broadband ultrasound backscatter were measured with 500kHz transducers. To assess mechanical properties, non-linear finite element analysis, based on micro-computed tomography images (34-micron cubic voxel), was used to estimate apparent elastic modulus, overall specimen stiffness, and apparent yield stress, with models typically having approximately 25-30 million elements. We found that ultrasound parameters were correlated with mechanical properties with R=0.70-0.82 (p<0.001). Multiple regression analysis indicated that ultrasound measurements provide additional information regarding mechanical properties beyond that provided by bone quantity alone (p≤0.05). Adding ultrasound variables to linear regression models based on bone quantity improved adjusted squared correlation coefficients from 0.65 to 0.77 (stiffness), 0.76 to 0.81 (apparent modulus), and 0.67 to 0.73 (yield stress). These results indicate that ultrasound can provide complementary (to bone quantity) information regarding mechanical behavior of cancellous bone. Published by Elsevier Inc.

Ultrasonic Sound Field Mapping Through Coarse Grained Cast Austenitic Stainless Steel Components

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

Crawford, Susan L.; Prowant, Matthew S.; Cinson, Anthony D.

2014-08-01

The Pacific Northwest National Laboratory (PNNL) has been involved with nondestructive examination (NDE) of coarse-grained cast austenitic stainless steel (CASS) components for over 30 years. More recent work has focused on mapping the ultrasonic sound fields generated by low-frequency phased array probes that are typically used for the evaluation of CASS materials for flaw detection and characterization. The casting process results in the formation of large grained material microstructures that are nonhomogeneous and anisotropic. The propagation of ultrasonic energy for examination of these materials results in scattering, partitioning and redirection of these sound fields. The work reported here provides anmore » assessment of sound field formation in these materials and provides recommendations on ultrasonic inspection parameters for flaw detection in CASS components.« less

Ultrasonic effect on the bubble nucleation and heat transfer of oscillating nanofluid

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

Zhao, Nannan; Fu, Benwei; Key Laboratory of Marine, Mechanical and Manufacturing Engineering of the Ministry of Transport, Dalian 116026

Ultrasonic sound effect on bubble nucleation, oscillating motion activated by bubble formation, and its heat transfer enhancement of nanofluid was experimentally investigated. Nanofluid consists of distilled water and dysprosium (III) oxide (Dy{sub 2}O{sub 3}) nanoparticles with an average size of 98 nm and a mass ratio of 0.5%. Visualization results demonstrate that when the nanoparticles are added in the fluid influenced by the ultrasonic sound, bubble nucleation can be significantly enhanced. The oscillating motion initiated by the bubble formation of nanofluid under the influence of ultrasonic sound can significantly enhance heat transfer of nanofluid in an interconnected capillary loop.

Evidence for gassy sediments on the inner shelf of SE Korea from geoacoustic properties

NASA Astrophysics Data System (ADS)

Gorgas, Thomas J.; Kim, Gil Y.; Park, Soo C.; Wilkens, Roy H.; Kim, Dae C.; Lee, Gwang H.; Seo, Young K.

2003-05-01

The inner shelf of SE Korea is characterized by an up to 40 m thick blanket of soft sediments often characterized by acoustic turbidity (AT). This AT is caused by a layer of sub-surface gas, which prohibits the identification of geological structures below that gas layer. Sound speeds were measured directly in these sediments using the Acoustic Lance (AL) in both mid- and late-September 1999. In situ sound speeds obtained in mid-September varied between 1400 and 1550 m/s, and thus did not confirm the presence of gas within the top 3.5 m of the seafloor. However, signal waveforms suggested that a gassy layer might have been just below the depth penetrated by the Lance. In late-September, on the other hand, two sites showed an abrupt decrease in signal amplitudes and in sound speed (less than 800 m/s) at depths as shallow as 2 m below seafloor, indicating the presence of free gas bubbles. Piston-cored sediments were retrieved at the same sites in February 1999. X-radiographs of some of the cores revealed numerous microcracks caused by the expansion of gas bubbles during core retrieval. In contrast to in situ acoustic data, ultrasonic sound speeds acquired in the laboratory in May 1999 on those cores did not differentiate convincingly between gas-bearing and gas-free sediments. Our measurements on the SE Korean shelf with the AL provide new data on the in situ acoustic behavior of gassy sediments and the sediments that overlie them in zones of AT.

Ultrasonic delineation of aortic microstructure: The relative contribution of elastin and collagen to aortic elasticity

NASA Astrophysics Data System (ADS)

Marsh, Jon N.; Takiuchi, Shin; Lin, Shiow Jiuan; Lanza, Gregory M.; Wickline, Samuel A.

2004-05-01

Aortic elasticity is an important factor in hemodynamic health, and compromised aortic compliance affects not only arterial dynamics but also myocardial function. A variety of pathologic processes (e.g., diabetes, Marfan's syndrome, hypertension) can affect aortic elasticity by altering the microstructure and composition of the elastin and collagen fiber networks within the tunica media. Ultrasound tissue characterization techniques can be used to obtain direct measurements of the stiffness coefficients of aorta by measurement of the speed of sound in specific directions. In this study we sought to define the contributions of elastin and collagen to the mechanical properties of aortic media by measuring the magnitude and directional dependence of the speed of sound before and after selective isolation of either the collagen or elastin fiber matrix. Formalin-fixed porcine aortas were sectioned for insonification in the circumferential, longitudinal, or radial direction and examined using high-frequency (50 MHz) ultrasound microscopy. Isolation of the collagen or elastin fiber matrices was accomplished through treatment with NaOH or formic acid, respectively. The results suggest that elastin is the primary contributor to aortic medial stiffness in the unloaded state, and that there is relatively little anisotropy in the speed of sound or stiffness in the aortic wall.

Support of the eight-foot high-temperature tunnel modifications project

NASA Technical Reports Server (NTRS)

Hodges, Donald Y.; Shebalin, John V.

1987-01-01

An ultrasonic level sensor was developed to measure the liquid level in a storage vessel under high pressures, namely up to 6000 psi. The sensor is described. A prototype sensor was installed in the cooling-water storage vessel of the Eight-Foot High-Temperature Tunnel. Plans are being made to install the readout instrument in the control room, so that tunnel operators can monitor the water level during the course of a tunnel run. It was discovered that the sensor will operate at cryogenic temperatures. Consequently, a sensor will be installed in the modified Eight-Foot High-Temperature Tunnel to measure the sound speed of liquid oxygen (LOX) as it is transferred from a storage vessel to the tunnel combustor at pressure of about 3000 psi. The sound speed is known to be a reliable indicator of contamination of LOX by pressurized gaseous nitrogen, which will be used to effect the transfer. Subjecting the sensor to a temperature cycle from room temperature to liquid nitrogen temperature and back again several times revealed no deterioration in sensor performance. The method using this sensor is superior to the original method, which was to bleed samples of LOX from the storage vessel to an independent chamber for measurement of the sound speed.

Experimental findings on the underwater measurements uncertainty of speed of sound and the alignment system

NASA Astrophysics Data System (ADS)

Santos, T. Q.; Alvarenga, A. V.; Oliveira, D. P.; Mayworm, R. C.; Souza, R. M.; Costa-Félix, R. P. B.

2016-07-01

Speed of sound is an important quantity to characterize reference materials for ultrasonic applications, for instance. The alignment between the transducer and the test body is an key activity in order to perform reliable and consistent measurement. The aim of this work is to evaluate the influence of the alignment system to the expanded uncertainty of such measurement. A stainless steel cylinder was previously calibrated on an out of water system typically used for calibration of non-destructive blocks. Afterwards, the cylinder was calibrated underwater with two distinct alignment system: fixed and mobile. The values were statistically compared to the out-of-water measurement, considered the golden standard for such application. For both alignment systems, the normalized error was less than 0.8, leading to conclude that the both measurement system (under and out-of-water) do not diverge significantly. The gold standard uncertainty was 2.7 m-s-1, whilst the fixed underwater system resulted in 13 m-s-1, and the mobile alignment system achieved 6.6 m-s-1. After the validation of the underwater system for speed of sound measurement, it will be applied to certify Encapsulated Tissue Mimicking Material as a reference material for biotechnology application.

Metal composite as backing for ultrasonic transducers dedicated to non-destructive measurements in hostile

NASA Astrophysics Data System (ADS)

Boubenia, R.; Rosenkrantz, E.; Despetis, F.; P, P.; Ferrandis, J.-Y.

2016-03-01

Our team is specialized in ultrasonic measurements in hostile environment especially under high temperatures. There is a need for acoustic transducers capable of continuous measurement at temperatures up to 700°C. To improve the performances of acoustic sensors we focus our works on the realisation and characterisation of transducer backings able to operate under very high temperature. Commercially, they are produced by the incorporation of tungsten powder in a plastic matrix, which limits the working temperature. The realisation of ultrasonic transducers for non-destructive measures at high temperatures requires adequate materials, manufacturing and assembly processes. To produce the backings, composites were made using very ductile metals such as tin and tungsten. These composites are manufactured by uniaxial hot pressing. First, we studied the influence of temperature and pressure on the densification of tin pellets. Then, several specimens made of tin/W were made and characterised by measuring the specific weight, speed and attenuation of sound. The acoustic measures were realised by ultrasonic spectroscopy. This test-bench was designed and tested on control samples of PMMA and on standard backings (epoxy / tungsten).

Vibration analysis and sound field characteristics of a tubular ultrasonic radiator.

PubMed

Liang, Zhaofeng; Zhou, Guangping; Zhang, Yihui; Li, Zhengzhong; Lin, Shuyu

2006-12-01

A sort of tubular ultrasonic radiator used in ultrasonic liquid processing is studied. The frequency equation of the tubular radiator is derived, and its radiated sound field in cylindrical reactor is calculated using finite element method and recorded by means of aluminum foil erosion. The results indicate that sound field of tubular ultrasonic radiator in cylindrical reactor appears standing waves along both its radial direction and axial direction, and amplitudes of standing waves decrease gradually along its radial direction, and the numbers of standing waves along its axial direction are equal to the axial wave numbers of tubular radiator. The experimental results are in good agreement with calculated results.

Finite-Temperature Behavior of PdH x Elastic Constants Computed by Direct Molecular Dynamics

DOE PAGES

Zhou, X. W.; Heo, T. W.; Wood, B. C.; ...

2017-05-30

In this paper, robust time-averaged molecular dynamics has been developed to calculate finite-temperature elastic constants of a single crystal. We find that when the averaging time exceeds a certain threshold, the statistical errors in the calculated elastic constants become very small. We applied this method to compare the elastic constants of Pd and PdH 0.6 at representative low (10 K) and high (500 K) temperatures. The values predicted for Pd match reasonably well with ultrasonic experimental data at both temperatures. In contrast, the predicted elastic constants for PdH 0.6 only match well with ultrasonic data at 10 K; whereas, atmore » 500 K, the predicted values are significantly lower. We hypothesize that at 500 K, the facile hydrogen diffusion in PdH 0.6 alters the speed of sound, resulting in significantly reduced values of predicted elastic constants as compared to the ultrasonic experimental data. Finally, literature mechanical testing experiments seem to support this hypothesis.« less

Sterilizing effects of high-intensity airborne sonic and ultrasonic waves.

PubMed

Pisano, M A; Boucher, M G; Alcamo, I E

1966-09-01

The lethal effects of high-intensity airborne sonic (9.9 kc/sec) and ultrasonic waves (30.4 kc/sec) on spores of Bacillus subtilis var. niger ATCC 9372 were determined. The spores, which were deposited on filter-paper strips, were exposed to sound waves for periods varying from 1 to 8 hr, at a temperature of 40 C and a relative humidity of 40%. Significant reductions in the viable counts of spores exposed to airborne sonic or ultrasonic irradiations were obtained. The antibacterial activity of airborne sound waves varied with the sound intensity level, the period of irradiation, and the distance of the sample from the sound source. At similar intensity levels, the amplitude of motion of the sound waves appeared to be a factor in acoustic sterilization.

Non-Destructive Inspection Approach Using Ultrasound to Identify the Material State for Amorphous and Semi-Crystalline Materials

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

Jost, Elliott; Jack, David; Moore, David G.

At present, there are many methods to identify the temperature and phase of a material using invasive techniques. However, most current methods require physical contact or implicit methods utilizing light reflectance of the specimen. In this paper, we present a nondestructive inspection method using ultrasonic wave technology that circumvents these disadvantages to identify phase change regions and infer the temperature state of a material. In the present study an experiment is performed to monitor the time of flight within a wax as it undergoes melting and the subsequent cooling. Results presented in this work show a clear relationship between amore » material’s speed of sound and its temperature. The phase change transition of the material is clear from the time of flight results, and in the case of the investigated material, this change in the material state occurs over a range of temperatures. The range of temperatures over which the wax material melts is readily identified by speed of sound represented as a function of material temperature. The melt temperature, obtained acoustically, is validated using Differential Scanning Calorimetry (DSC), which uses shifts in heat flow rates to identify phase transition temperature ranges. Lastly, the investigated ultrasonic NDE method has direct applications in many industries, including oil and gas, food and beverage, and polymer composites, in addition to many implications for future capabilities of nondestructive inspection of multi-phase materials.« less

Non-Destructive Inspection Approach Using Ultrasound to Identify the Material State for Amorphous and Semi-Crystalline Materials

DOE PAGES

Jost, Elliott; Jack, David; Moore, David G.

2018-04-01

At present, there are many methods to identify the temperature and phase of a material using invasive techniques. However, most current methods require physical contact or implicit methods utilizing light reflectance of the specimen. In this paper, we present a nondestructive inspection method using ultrasonic wave technology that circumvents these disadvantages to identify phase change regions and infer the temperature state of a material. In the present study an experiment is performed to monitor the time of flight within a wax as it undergoes melting and the subsequent cooling. Results presented in this work show a clear relationship between amore » material’s speed of sound and its temperature. The phase change transition of the material is clear from the time of flight results, and in the case of the investigated material, this change in the material state occurs over a range of temperatures. The range of temperatures over which the wax material melts is readily identified by speed of sound represented as a function of material temperature. The melt temperature, obtained acoustically, is validated using Differential Scanning Calorimetry (DSC), which uses shifts in heat flow rates to identify phase transition temperature ranges. Lastly, the investigated ultrasonic NDE method has direct applications in many industries, including oil and gas, food and beverage, and polymer composites, in addition to many implications for future capabilities of nondestructive inspection of multi-phase materials.« less

Molecular Interactions in 1,4-Dioxane, Tetrahydrofuran, and Ethyl Acetate Solutions of 1,1'-Bis(4-isopropyloxyacetylphenoxy)cyclohexane on Reological, Density, and Acoustic Behavior

NASA Astrophysics Data System (ADS)

Dhaduk, B. B.; Patel, Ch. B.; Parsania, P. H.

2017-12-01

Various thermo-acoustical parameters of 1,4-dioxane, tetrahydofuran and ethylacetae solutions of 1,1'-bis(4-isopropyloxyacetylphenoxy)cyclohexane were determined at different temperatures using density, viscosity and ultrasonic speed and correlated with concentration. Linear increase of ultrasonic speed, specific acoustical impedance, Rao's molar sound function, Van der Waals constant and free volume with concentration C and decreased with temperature. Linear decrease of adiabatic compressibility, internal pressure, intermolecular free path length, classical absorption coefficient, and viscous relaxation time with concentration and increased with temperature indicated existence of strong molecular interactions in solutions and further supported by positive values of solvation number. Gibbs free energy of activation decreased with C in all three systems. It is decreased with T in 1,4-dioxane, while increased in tetrahydrofuran and ethyl acetate. Both enthalpy of activation and entropy of activation are increased gradually with C in 1,4-dioxane, while they are negative and remained practically independent of concentration in 1,4-dioxane and tetrahydofuran systems.

Enhancement of photoacoustic tomography by ultrasonic computed tomography based on optical excitation of elements of a full-ring transducer array.

PubMed

Xia, Jun; Huang, Chao; Maslov, Konstantin; Anastasio, Mark A; Wang, Lihong V

2013-08-15

Photoacoustic computed tomography (PACT) is a hybrid technique that combines optical excitation and ultrasonic detection to provide high-resolution images in deep tissues. In the image reconstruction, a constant speed of sound (SOS) is normally assumed. This assumption, however, is often not strictly satisfied in deep tissue imaging, due to acoustic heterogeneities within the object and between the object and the coupling medium. If these heterogeneities are not accounted for, they will cause distortions and artifacts in the reconstructed images. In this Letter, we incorporated ultrasonic computed tomography (USCT), which measures the SOS distribution within the object, into our full-ring array PACT system. Without the need for ultrasonic transmitting electronics, USCT was performed using the same laser beam as for PACT measurement. By scanning the laser beam on the array surface, we can sequentially fire different elements. As a first demonstration of the system, we studied the effect of acoustic heterogeneities on photoacoustic vascular imaging. We verified that constant SOS is a reasonable approximation when the SOS variation is small. When the variation is large, distortion will be observed in the periphery of the object, especially in the tangential direction.

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.

Simulation for Carbon Nanotube Dispersion and Microstructure Formation in CNTs/AZ91D Composite Fabricated by Ultrasonic Processing

NASA Astrophysics Data System (ADS)

Yang, Yuansheng; Zhao, Fuze; Feng, Xiaohui

2017-10-01

The dispersion of carbon nanotubes (CNTs) in AZ91D melt by ultrasonic processing and microstructure formation of CNTs/AZ91D composite were studied using numerical and physical simulations. The sound field and acoustic streaming were predicted using finite element method. Meanwhile, optimal immersion depth of the ultrasonic probe and suitable ultrasonic power were obtained. Single-bubble model was used to predict ultrasonic cavitation in AZ91D melt. The relationship between sound pressure amplitude and ultrasonic cavitation was established. Physical simulations of acoustic streaming and ultrasonic cavitation agreed well with the numerical simulations. It was confirmed that the dispersion of carbon nanotubes was remarkably improved by ultrasonic processing. Microstructure formation of CNTs/AZ91D composite was numerically simulated using cellular automation method. In addition, grain refinement was achieved and the growth of dendrites was changed due to the uniform dispersion of CNTs.

Investigation of a dual modal method for bone pathologies using quantitative ultrasound and photoacoustics

NASA Astrophysics Data System (ADS)

Steinberg, Idan; Gannot, Israel; Eyal, Avishay

2015-03-01

Osteoporosis is a widespread disease that has a catastrophic impact on patient's lives and overwhelming related healthcare costs. In recent works, we have developed a multi-spectral, frequency domain photoacoustic method for the evaluation of bone pathologies. This method has great advantages over pure ultrasonic or optical methods as it provides both molecular information from the bone absorption spectrum and bone mechanical status from the characteristics of the ultrasound propagation. These characteristics include both the Speed of Sound (SOS) and Broadband Ultrasonic Attenuation (BUA). To test the method's quantitative predictions, we have constructed a combined ultrasound and photoacoustic setup. Here, we experimentally present a dual modality system, and compares between the methods on bone samples in-vitro. The differences between the two modalities are shown to provide valuable insight into the bone structure and functional status.

Ultrasonic atomization of liquids in drop-chain acoustic fountains

PubMed Central

Simon, Julianna C.; Sapozhnikov, Oleg A.; Khokhlova, Vera A.; Crum, Lawrence A.; Bailey, Michael R.

2015-01-01

When focused ultrasound waves of moderate intensity in liquid encounter an air interface, a chain of drops emerges from the liquid surface to form what is known as a drop-chain fountain. Atomization, or the emission of micro-droplets, occurs when the acoustic intensity exceeds a liquid-dependent threshold. While the cavitation-wave hypothesis, which states that atomization arises from a combination of capillary-wave instabilities and cavitation bubble oscillations, is currently the most accepted theory of atomization, more data on the roles of cavitation, capillary waves, and even heat deposition or boiling would be valuable. In this paper, we experimentally test whether bubbles are a significant mechanism of atomization in drop-chain fountains. High-speed photography was used to observe the formation and atomization of drop-chain fountains composed of water and other liquids. For a range of ultrasonic frequencies and liquid sound speeds, it was found that the drop diameters approximately equalled the ultrasonic wavelengths. When water was exchanged for other liquids, it was observed that the atomization threshold increased with shear viscosity. Upon heating water, it was found that the time to commence atomization decreased with increasing temperature. Finally, water was atomized in an overpressure chamber where it was found that atomization was significantly diminished when the static pressure was increased. These results indicate that bubbles, generated by either acoustic cavitation or boiling, contribute significantly to atomization in the drop-chain fountain. PMID:25977591

A teaching phantom for sonographers.

PubMed

Zagzebski, J A; Madsen, E L; Frank, G R

1991-01-01

An anthropomorphic torso section phantom is described that is intended for use during initial stages of ultrasonographer training. The phantom represents a section of the upper abdomen, with simulated ribs, liver, kidney with fat pad, gallbladder, aorta, and bowel gas. Positioned in the liver are ten simulated soft tissue masses, which produce a variety of typical echographic patterns. All simulated soft tissue components are formed of tissue-mimicking materials that match their corresponding tissue counterparts in terms of speed of sound, ultrasonic attenuation, and density. Construction details are presented and examples of images are shown.

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.

Exploring results of the possibility on detecting cosmic ray particles by acoustic way

NASA Technical Reports Server (NTRS)

Jiang, Y.; Yuan, Y.; Li, Y.; Chen, D.; Zheng, R.; Song, J.

1985-01-01

It has been demonstrated experimentally and theoretically that high energy particles produce detectable sounds in water. However, no one has been able to detect an acoustic signal generated by a high energy cosmic ray particle in water. Results show that transient ultrasonic signals in a large lake or reservoir are fairly complex and that the transient signals under water may arise mainly from sound radiation from microbubbles. This field is not explored in detail. Perhaps, the sounds created by cosmic ray particles hide in these ultrasonic signals. In order to develop the technique of acoustic detection, it is most important to make a thorough investigation of these ultrasonic signals in water.

Determining Position Inside Non-industrial Buildings Using Ultrasound Transducers

PubMed Central

Escudero, Francesc; Margalef, Jordi; Luengo, Sonia; Alsina, Maria; Ribes, Josep M.; Pérez, Juan

2007-01-01

The position determination inside a building where no GPS signal is being received can be ascertained using laser transmitters in industrial situations where there are no people or using triangulation of the signal strength, normally electro-magnetic signals, if the required accuracy is more than a metre. Our solution is aimed at situations where people are present and where the required accuracy is less than 30 cm, such as in shopping precincts or supermarkets. To achieve this, a network of ultrasonic transmitters is fitted into the ceiling which receives a synchronised time signal. Each transmitter has a unique identifier code and emits its code with a delay with respect to the common time signal which is proportional to its code number with an ASK modulation over the ultrasonic band centred on 40 KHz. The receivers circulating beneath the transmitters receive the codes of those within their detection range, translate the time delays into distances and then obtain their position by triangulation since the receivers know the position of every transmitter. Since the receivers are not synchronised with the common time signal or the actual speed of the sound, whose value varies appreciably with temperature, relative humidity and atmospheric pressure, a consecutive approximation algorithm has been introduced. This is based on the fact that the Z coordinator of the receiver is known and constant and thus it is possible, with only three different identifiers received, to deduce the phase of the common time signal and estimate the speed of the sound with a fourth identifier. PMID:28903247

[Evaluation of the cavity cleaning of ultrasonic instruments and slow-speed handpiece in posterior teeth root-end preparation].

PubMed

Zhang, Ping-juan; Chen, Wen-xia; Zeng, Qi-xin; Xie, Fang-fang

2013-04-01

To compare the cleanliness of root end preparations by using ultrasonic instrumentation and slow-speed handpiece. Thirty-two mesial roots of the first mandibular molars with two canals and mature root apices were assigned randomly to 2 groups, each group had 16 teeth. The root-end preparations were made respectively using ultrasonic diamond tip Berutti and NiTi tip RE2 and slow-speed handpiece with No.2 round bur. Root end cavities were examined under scanning electron microscope for further evaluation of the superficial debris and smear layer of the root end preparations. SPSS 13.0 software package was used for Kruskal Wallis test. Ultrasonic preparation had significantly less superficial debris and smear layer than slow-speed handpiece preparation (P<0.05). Ultrasonic instrument creates cleaner surfaces for root end cavities than slow-speed handpiece preparation in posterior teeth root end preparation.

A photoacoustic technique to measure the properties of single cells

NASA Astrophysics Data System (ADS)

Strohm, Eric M.; Berndl, Elizabeth S. L.; Kolios, Michael C.

2013-03-01

We demonstrate a new technique to non-invasively determine the diameter and sound speed of single cells using a combined ultrasonic and photoacoustic technique. Two cell lines, B16-F1 melanoma cells and MCF7 breast cancer cells were examined using this technique. Using a 200 MHz transducer, the ultrasound backscatter from a single cell in suspension was recorded. Immediately following, the cell was irradiated with a 532 nm laser and the resulting photoacoustic wave recorded by the same transducer. The melanoma cells contain optically absorbing melanin particles, which facilitated photoacoustic wave generation. MCF7 cells have negligible optical absorption at 532 nm; the cells were permeabilized and stained with trypan blue prior to measurements. The measured ultrasound and photoacoustic power spectra were compared to theoretical equations with the cell diameter and sound speed as variables (Anderson scattering model for ultrasound, and a thermoelastic expansion model for photoacoustics). The diameter and sound speed were extracted from the models where the spectral shape matched the measured signals. However the photoacoustic spectrum for the melanoma cell did not match theory, which is likely because melanin particles are located around the cytoplasm, and not within the nucleus. Therefore a photoacoustic finite element model of a cell was developed where the central region was not used to generate a photoacoustic wave. The resulting power spectrum was in better agreement with the measured signal than the thermoelastic expansion model. The MCF7 cell diameter obtained using the spectral matching method was 17.5 μm, similar to the optical measurement of 16 μm, while the melanoma cell diameter obtained was 22 μm, similar to the optical measurement of 21 μm. The sound speed measured from the MCF7 and melanoma cell was 1573 and 1560 m/s, respectively, which is within acceptable values that have been published in literature.

Effect of ultrasonic, sonic and rotating-oscillating powered toothbrushing systems on surface roughness and wear of white spot lesions and sound enamel: An in vitro study.

PubMed

Hernandé-Gatón, Patrícia; Palma-Dibb, Regina Guenka; Silva, Léa Assed Bezerra da; Faraoni, Juliana Jendiroba; de Queiroz, Alexandra Mussolino; Lucisano, Marília Pacífico; Silva, Raquel Assed Bezerra da; Nelson Filho, Paulo

2018-04-01

To evaluate the effect of ultrasonic, sonic and rotating-oscillating powered toothbrushing systems on surface roughness and wear of white spot lesions and sound enamel. 40 tooth segments obtained from third molar crowns had the enamel surface divided into thirds, one of which was not subjected to toothbrushing. In the other two thirds, sound enamel and enamel with artificially induced white spot lesions were randomly assigned to four groups (n=10) : UT: ultrasonic toothbrush (Emmi-dental); ST1: sonic toothbrush (Colgate ProClinical Omron); ST2: sonic toothbrush (Sonicare Philips); and ROT: rotating-oscillating toothbrush (control) (Oral-B Professional Care Triumph 5000 with SmartGuide). The specimens were analyzed by confocal laser microscopy for surface roughness and wear. Data were analyzed statistically by paired t-tests, Kruskal-Wallis, two-way ANOVA and Tukey's post-test (α= 0.05). The different powered toothbrushing systems did not cause a significant increase in the surface roughness of sound enamel (P> 0.05). In the ROT group, the roughness of white spot lesion surface increased significantly after toothbrushing and differed from the UT group (P< 0.05). In the ROT group, brushing promoted a significantly greater wear of white spot lesion compared with sound enamel, and this group differed significantly from the ST1 group (P< 0.05). None of the powered toothbrushing systems (ultrasonic, sonic and rotating-oscillating) caused significant alterations on sound dental enamel. However, conventional rotating-oscillating toothbrushing on enamel with white spot lesion increased surface roughness and wear. None of the powered toothbrushing systems (ultrasonic, sonic and rotating-oscillating) tested caused significant alterations on sound dental enamel. However, conventional rotating-oscillating toothbrushing on enamel with white spot lesion increased surface roughness and wear. Copyright©American Journal of Dentistry.

Interaction of Sound with Sound by Novel Mechanisms: Ultrasonic Four-Wave Mixing Mediated by a Suspension and Ultrasonic Three-Wave Mixing at a Free Surface

NASA Astrophysics Data System (ADS)

Simpson, Harry Jay

Two mechanisms of sound interacting with sound are experimentally and theoretically investigated. Ultrasonic four-wave mixing in a dilute particle suspension, analogous to optical four-wave mixing in photorefractive materials, involves the interaction of three ultrasonic wavefields that produces a fourth scattered wavefield. The experimental configuration consists of two ultrasonic (800 kHz) pump waves that are used to produce a grating in a suspension of 25 μm diameter polymer particles in salt water. The pump waves are counter-propagating, which form a standing wavefield in the suspension and the less compressible particles are attracted to the pressure nodes in response to the time averaged radiation pressure. A higher frequency (2-10 MHz) ultrasonic wavefield is used to probe the resulting grating. The ultrasonic Bragg scattering is then measured. The scattering depends strongly on the response to the pump wave and is an unusual class of acoustical nonlinearity. Investigation of very small amplitude gratings are done by studying the temporal response of the Bragg scattering to a sudden turn on of a moderate amplitude pump wavefield in a previously homogeneous particle suspension. The Bragg scattering has been verified experimentally and is modeled for early-time grating formations using a sinusoidal grating. The larger amplitude gratings are studied in equilibrium and are modeled using an Epstein layer approximation. Ultrasonic three-wave mixing at a free surface involves the interaction of a high amplitude 400 kHz plane wavefield incident at 33^circ on a water-air interface with a normally incident high frequency (4.6 MHz) focused wavefield. The 400 kHz "pump" wavefield reflects from the surface and produces an oscillating surface displacement that forms a local traveling phase grating. Simultaneously the 4.6 MHz "probe" wavefield is reflected from the free surface. The grating scatters the focused probe wavefield and produces (or contributes to) spatially and Doppler shifted foci relative to the main focus.

Interaction of sound with sound by novel mechanisms: Ultrasonic four-wave mixing mediated by a suspension and ultrasonic three-wave mixing at a free surface

NASA Astrophysics Data System (ADS)

Simpson, Harry Jay

Two mechanisms of sound interacting with sound are experimentally and theoretically investigated. Ultrasonic four-wave mixing in a dilute particle suspension, analogous to optical four-wave mixing in photorefractive materials, involves the interaction of three ultrasonic wavefields that produces a fourth scattered wavefield. The experimental configuration consists of two ultrasonic (800 kHz) pump waves that are used to produce a grating in a suspension of 25 micron diameter polymer particles in salt water. The pump waves are counter-propagating, which form a standing wavefield in the suspension and the less compressible particles are attracted to the pressure nodes in response to the time averaged radiation pressure. A higher frequency (2 to 10 MHz) ultrasonic wavefield is used to probe the resulting grating. The ultrasonic Bragg scattering is then measured. The scattering depends strongly on the response to the pump wave and is an unusual class of acoustical nonlinearity. Investigation of very small amplitude gratings are done by studying the temporal response of the Bragg scattering to a sudden turn on of a moderate amplitude pump wavefield in a previously homogeneous particle suspension. The Bragg scattering has been verified experimentally and is modeled for early-time grating formations using a sinusoidal grating. The larger amplitude gratings are studied in equilibrium and are modeled using an Epstein layer approximation. Ultrasonic three-wave mixing at a free surface involves the interaction of a high amplitude 400 kHz plane wavefield incident at 33 degrees on a water-air interface with a normally incident high frequency (4.6 MHz) focused wavefield. The 400 kHz 'pump' wavefield reflects from the surface and produces an oscillating surface displacement that forms a local traveling phase grating. Simultaneously the 4.6 MHz 'probe' wavefield is reflected from the free surface. The grating scatters the focused probe wavefield and produces (or contributes to) spatially and Doppler shifted foci relative to the main focus.

Design and analysis of ultrasonic monaural audio guiding device for the visually impaired.

PubMed

Kim, Keonwook; Kim, Hyunjai; Yun, Gihun; Kim, Myungsoo

2009-01-01

The novel Audio Guiding Device (AGD) based on the ultrasonic, which is named as SonicID, has been developed in order to localize point of interest for the visually impaired. The SonicID requires the infrastructure of the transmitters for broadcasting the location information over the ultrasonic carrier. The user with ultrasonic headset receives the information with variable amplitude upon the location and direction of the user due to the ultrasonic characteristic and modulation method. This paper proposes the monaural headset form factor of the SonicID which improves the daily life of the beneficiary compare to the previous version which uses the both ears. Experimental results from SonicID, Bluetooth, and audible sound show that the SonicID demonstrates comparable localization performance to the audible sound with silence to others.

Ultrasonic Emission from Nanocrystalline Porous Silicon

NASA Astrophysics Data System (ADS)

Shinoda, Hiroyuki; Koshida, Nobuyoshi

A simple layer structure composed of a metal thin film and a porous silicon layer on a silicon substrate generates intense and wide-band airborne ultrasounds. The large-bandwidth and the fidelity of the sound reproduction are leveraged in applications varying from sound-based measurement to a scientific study of animal ecology. This chapter describes the basic principle of the ultrasound generation. The macroscopic properties of the low thermal conductivity and the small heat capacity of nanocrystalline porous silicon thermally induce ultrasonic emission. The state-of-the-art of the achievable sound pressure and sound signal properties is introduced, with the technological and scientific applications of the devices.

Ultrasonic search wheel probe

DOEpatents

Mikesell, Charles R.

1978-01-01

A device is provided for reducing internal reflections from the tire of an ultrasonic search wheel probe or from within the material being examined. The device includes a liner with an anechoic chamber within which is an ultrasonic transducer. The liner is positioned within the wheel and includes an aperture through which the ultrasonic sound from the transducer is directed.

Anechoic chamber qualification at ultrasonic frequencies

NASA Astrophysics Data System (ADS)

Jenny, Trevor; Anderson, Brian

2010-10-01

Qualifying an anechoic chamber for frequencies that extend into the ultrasonic range is necessary for research work involving airborne ultrasonic sound. For example, an anechoic chamber allows for measurements of the direct sound radiated by an object without reflections from walls. The ANSI S12.55/ISO 3745 standard which covers anechoic chamber qualification does not extend into the ultrasonic frequency range, nor have others discussed this frequency range in the literature. An increasing number of technologies are employing ultrasound; hence the need to develop facilities to conduct basic research studies on airborne ultrasound. This presentation will discuss the challenges associated with chamber qualification and present the results for qualification of a chamber at Brigham Young University. [This work has been funded by the Los Alamos National Laboratory

Ultrasonic control of ceramic membrane fouling by particles: effect of ultrasonic factors.

PubMed

Chen, Dong; Weavers, Linda K; Walker, Harold W

2006-07-01

Ultrasound at 20 kHz was applied to a cross-flow ultrafiltration system with gamma-alumina membranes in the presence of colloidal silica particles to systematically investigate how ultrasonic factors affect membrane cleaning. Based on imaging of the ultrasonic cavitation region, optimal cleaning occurred when the membrane was outside but close to the cavitation region. Increasing the filtration pressure increased the compressive forces driving cavitation collapse and resulted in fewer cavitation bubbles absorbing and scattering sound waves and increasing sound wave penetration. However, an increased filtration pressure also resulted in greater permeation drag, and subsequently less improvement in permeate flux compared to low filtration pressure. Finally, pulsed ultrasound with short pulse intervals resulted in permeate flux improvement close to that of continuous sonication.

Non-invasive Measurement of Thermal Diffusivity Using High-Intensity Focused Ultrasound and Through-Transmission Ultrasonic Imaging.

PubMed

Yeshurun, Lilach; Azhari, Haim

2016-01-01

Thermal diffusivity at the site ablated by high-intensity focused ultrasound (HIFU) plays an important role in the final therapeutic outcome, as it influences the temperature's spatial and temporal distribution. Moreover, as tissue thermal diffusivity is different in tumors as compared with normal tissue, it could also potentially be used as a new source of imaging contrast. The aim of this study was to examine the feasibility of combining through-transmission ultrasonic imaging and HIFU to estimate thermal diffusivity non-invasively. The concept was initially evaluated using a computer simulation. Then it was experimentally tested on phantoms made of agar and ex vivo porcine fat. A computerized imaging system combined with a HIFU system was used to heat the phantoms to temperatures below 42°C to avoid irreversible damage. Through-transmission scanning provided the time-of-flight values in a region of interest during its cooling process. The time-of-flight values were consequently converted into mean values of speed of sound. Using the speed-of-sound profiles along with the developed model, we estimated the changes in temperature profiles over time. These changes in temperature profiles were then used to calculate the corresponding thermal diffusivity of the studied specimen. Thermal diffusivity for porcine fat was found to be lower by one order of magnitude than that obtained for agar (0.313×10(-7)m(2)/s vs. 4.83×10(-7)m(2)/s, respectively, p < 0.041). The fact that there is a substantial difference between agar and fat implies that non-invasive all-ultrasound thermal diffusivity mapping is feasible. The suggested method may particularly be suitable for breast scanning. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

DEVELOPMENT OF A LOW-COST INFERENTIAL NATURAL GAS ENERGY FLOW RATE PROTOTYPE RETROFIT MODULE

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

E. Kelner; T.E. Owen; D.L. George

2004-03-01

In 1998, Southwest Research Institute{reg_sign} began a multi-year project co-funded by the Gas Research Institute (GRI) and the U.S. Department of Energy. The project goal is to develop a working prototype instrument module for natural gas energy measurement. The module will be used to retrofit a natural gas custody transfer flow meter for energy measurement, at a cost an order of magnitude lower than a gas chromatograph. Development and evaluation of the prototype retrofit natural gas energy flow meter in 2000-2001 included: (1) evaluation of the inferential gas energy analysis algorithm using supplemental gas databases and anticipated worst-case gas mixtures;more » (2) identification and feasibility review of potential sensing technologies for nitrogen diluent content; (3) experimental performance evaluation of infrared absorption sensors for carbon dioxide diluent content; and (4) procurement of a custom ultrasonic transducer and redesign of the ultrasonic pulse reflection correlation sensor for precision speed-of-sound measurements. A prototype energy meter module containing improved carbon dioxide and speed-of-sound sensors was constructed and tested in the GRI Metering Research Facility at SwRI. Performance of this module using transmission-quality natural gas and gas containing supplemental carbon dioxide up to 9 mol% resulted in gas energy determinations well within the inferential algorithm worst-case tolerance of {+-}2.4 Btu/scf (nitrogen diluent gas measured by gas chromatograph). A two-week field test was performed at a gas-fired power plant to evaluate the inferential algorithm and the data acquisition requirements needed to adapt the prototype energy meter module to practical field site conditions.« less

An Ultrasonic Frequency Sweep Interferometer For Sound Speed Measurements On Liquids At High Temperature And Pressure

NASA Astrophysics Data System (ADS)

Ai, Y.; Lange, R. A.

2003-12-01

One of the most direct methods for obtaining melt compressibility is through measurements of sound speed via acoustic interferometry. This technique may be applied to silicate melts by either varying the path length or the frequency of the acoustic wave through the melt. To date, only the variable path length (VPL) technique has been applied, which restricts measurements to atmospheric pressure owing to the requirement of mechanical movement of the upper buffer rod. This, in turn, precludes the study of volatile-bearing liquids at pressure and a systematic study of how melt compressibility varies with pressure. We have developed a frequency sweep (FS) interferometer that can be applied at high pressure, which is based on frequency spectrum analysis on mirror reflection waves from high-temperature liquids. First, a theoretical acoustic model for a rod-liquid-rod (RLR) interferometer is proposed and solutions to the resultant wave equations are obtained. The solutions demonstrate that only two kinds of non-dispersive waves exist within the upper buffer rod. They have computable group velocities and waveform patterns that are entirely dependent on the material and diameter of the buffer rods. Experimental tests verify the theoretical model and indicate that buffer rods made of molybdenum metal and > 1.9 cm diameter are ideal for sound speed measurements in silicate melts with the FS interferometer. On the basis of the theoretical acoustic model, a mechanical assembly and signal-processing algorithm was designed to implement the FS interferometer. A very short pulse (e.g. 1 microsecond) encompassing a range of frequencies that span about 1 MHz is sent down the upper buffer rod and the first two mirror reflections from the liquid are collected and stored. Because they have the same waveform and have 180o phase difference, Fourier spectrum analysis can be performed to find the frequency response function of the two reflections, which is related to the sound speed and thickness of the melt. From the obtained frequency response function, the sound speed is calculated. We have applied this newly designed FS interferometer to two liquids with well-known sound speeds from the literature: NaCl liquid at 930o C and 1026 o C and a sodium aluminosilicate liquid at 1436 o C. Sound speeds were measured for these liquids at three center frequencies (4.5 MHz, 5.0 MHz, and 5.8 MHz). Our results are less than 0.6 % off the literature values and demonstrate the accuracy and precision of the FS interferometer. The principal advantage of the FS interferometer over the VPL method is that it requires no physical intervention or mechanical movement of the micrometer-transducer-rod assembly during a measurement. Thus, the FS method has considerable promise for adaption to high-pressure conditions in an internally-heated pressure vessel.

Hearing and Underwater Noise Exposure

DTIC Science & Technology

1985-08-27

Ordnance Laboratory, White Oak, Silver Springs, Md. Corso, J. F. (1963) Bone-conduction thresholds for sonic and ultrasonic frequencies. J. Acoust...Soc. Am. 35, 1738-1743. Corso, J. F., & Levine, M. (1965a) Sonic and Ultrasonic equal loudness contours. J. Exp. Psychol. 70, 412-416. Corso, J...KEY WORDS (Continue on reverse aide II neceaaary and identity by block number) Hearing, Deafness, Sonar, Noise, Sound, Ultrasound, Infra -sound

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.

Where hearing starts: the development of the mammalian cochlea.

PubMed

Basch, Martin L; Brown, Rogers M; Jen, Hsin-I; Groves, Andrew K

2016-02-01

The mammalian cochlea is a remarkable sensory organ, capable of perceiving sound over a range of 10(12) in pressure, and discriminating both infrasonic and ultrasonic frequencies in different species. The sensory hair cells of the mammalian cochlea are exquisitely sensitive, responding to atomic-level deflections at speeds on the order of tens of microseconds. The number and placement of hair cells are precisely determined during inner ear development, and a large number of developmental processes sculpt the shape, size and morphology of these cells along the length of the cochlear duct to make them optimally responsive to different sound frequencies. In this review, we briefly discuss the evolutionary origins of the mammalian cochlea, and then describe the successive developmental processes that lead to its induction, cell cycle exit, cellular patterning and the establishment of topologically distinct frequency responses along its length. © 2015 Anatomical Society.

An Analysis of Peak Wind Speed Data from Collocated Mechanical and Ultrasonic Anemometers

NASA Technical Reports Server (NTRS)

Short, David A.; Wells, Leonard A.; Merceret, Francis J.; Roeder, William P.

2005-01-01

This study focuses on a comparison of peak wind speeds reported by mechanical and ultrasonic anemometers at Cape Canaveral Air Force Station and Kennedy Space Center (CCAFS/KSC) on the east central coast of Florida and Vandenberg Air Force Base (VAFB) on the central coast of California. The legacy mechanical wind instruments on CCAFS/KSC and VAFB weather towers are being changed from propeller-and-vane (CCAFS/KSC) and cup-and-vane (VAFB) sensors to ultrasonic sensors under the Range Standardization and Automation (RSA) program. The wind tower networks on KSC/CCAFS and VAFB have 41 and 27 towers, respectively. Launch Weather Officers, forecasters, and Range Safety analysts at both locations need to understand the performance of the new wind sensors for a myriad of reasons that include weather warnings, watches, advisories, special ground processing operations, launch pad exposure forecasts, user Launch Commit Criteria (LCC) forecasts and evaluations, and toxic dispersion support. The Legacy sensors measure wind speed and direction mechanically. The ultrasonic RSA sensors have no moving parts. Ultrasonic sensors were originally developed to measure very light winds (Lewis and Dover 2004). The technology has evolved and now ultrasonic sensors provide reliable wind data over a broad range of wind speeds. However, because ultrasonic sensors respond more quickly than mechanical sensors to rapid fluctuations in speed, characteristic of gusty wind conditions, comparisons of data from the two sensor types have shown differences in the statistics of peak wind speeds (Lewis and Dover 2004). The 45th Weather Squadron (45 WS) and the 30 WS requested the Applied Meteorology Unit (AMU) to compare data from RSA and Legacy sensors to determine if there are significant differences in peak wind speed information from the two systems.

Simulation of ultrasonic pulse propagation, distortion, and attenuation in the human chest wall.

PubMed

Mast, T D; Hinkelman, L M; Metlay, L A; Orr, M J; Waag, R C

1999-12-01

A finite-difference time-domain model for ultrasonic pulse propagation through soft tissue has been extended to incorporate absorption effects as well as longitudinal-wave propagation in cartilage and bone. This extended model has been used to simulate ultrasonic propagation through anatomically detailed representations of chest wall structure. The inhomogeneous chest wall tissue is represented by two-dimensional maps determined by staining chest wall cross sections to distinguish between tissue types, digitally scanning the stained cross sections, and mapping each pixel of the scanned images to fat, muscle, connective tissue, cartilage, or bone. Each pixel of the tissue map is then assigned a sound speed, density, and absorption value determined from published measurements and assumed to be representative of the local tissue type. Computational results for energy level fluctuations and arrival time fluctuations show qualitative agreement with measurements performed on the same specimens, but show significantly less waveform distortion than measurements. Visualization of simulated tissue-ultrasound interactions in the chest wall shows possible mechanisms for image aberration in echocardiography, including effects associated with reflection and diffraction caused by rib structures. A comparison of distortion effects for varying pulse center frequencies shows that, for soft tissue paths through the chest wall, energy level and waveform distortion increase markedly with rising ultrasonic frequency and that arrival-time fluctuations increase to a lesser degree.

Continuous Ultrasonic Inspection of Extruded Wood-Plastic Composites

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

Tucker, Brian J.; Bender, Donald A.

Nondestructive evaluation (NDE) techniques are needed for in-line monitoring of wood-plastic composite (WPC) quality during manufacturing for process control. Through-transmission ultrasonic inspection is useful in characterizing stiffness and detecting cracks and voids in a range of materials; however, little is documented about ultrasound propagation in WPC materials. The objectives of this research were to determine applicable ultrasonic transducer frequencies, coupling methods, configurations and placements for wave speed monitoring and web defect detection within an extrusion process; to quantify the effects of temperature on ultrasonic parameters; and to develop a prototype ultrasonic inspection system for a full-size extrusion line. An angledmore » beam, water-coupled ultrasonic inspection system using a pair of 50-kHz narrowband transducers was adequate for monitoring wave speed parallel to the extrusion direction. For locating internal web defects, water-coupled, 500-kHz broadband ultrasonic transducers were used in a through-thickness transmission setup. Temperature compensation factors were developed to adjust ultrasonic wave speed measurements. The prototype inspection system was demonstrated in a 55 mm conical twin-screw extrusion line.« less

Analog Binaural Circuits for Detecting and Locating Leaks

NASA Technical Reports Server (NTRS)

Hartley, Frank T.

2003-01-01

Very-large-scale integrated (VLSI) analog binaural signal-processing circuits have been proposed for use in detecting and locating leaks that emit noise in the ultrasonic frequency range. These circuits would be designed to function even in the presence of intense lower-frequency background noise that could include sounds associated with flow and pumping. Each of the proposed circuits would include the approximate electronic equivalent of a right and a left cochlea plus correlator circuits. A pair of transducers (microphones or accelerometers), corresponding to right and left ears, would provide the inputs to their respective cochleas from different locations (e.g., from different positions along a pipe). The correlation circuits plus some additional external circuits would determine the difference between the times of arrival of a common leak sound at the two transducers. Then the distance along the pipe from either transducer to the leak could be estimated from the time difference and the speed of sound along the pipe. If three or more pairs of transducers and cochlear/correlator circuits were available and could suitably be positioned, it should be possible to locate a leak in three dimensions by use of sound propagating through air.

Characterization of human breast cancer by scanning acoustic microscopy

NASA Astrophysics Data System (ADS)

Chen, Di; Malyarenko, Eugene; Seviaryn, Fedar; Yuan, Ye; Sherman, Mark; Bandyopadhyay, Sudeshna; Gierach, Gretchen; Greenway, Christopher W.; Maeva, Elena; Strumban, Emil; Duric, Neb; Maev, Roman

2013-03-01

Objectives: The purpose of this study was to characterize human breast cancer tissues by the measurement of microacoustic properties. Methods: We investigated eight breast cancer patients using acoustic microscopy. For each patient, seven blocks of tumor tissue were collected from seven different positions around a tumor mass. Frozen sections (10 micrometer, μm) of human breast cancer tissues without staining and fixation were examined in a scanning acoustic microscope with focused transducers at 80 and 200 MHz. Hematoxylin and Eosin (H and E) stained sections from the same frozen breast cancer tissues were imaged by optical microscopy for comparison. Results: The results of acoustic imaging showed that acoustic attenuation and sound speed in cancer cell-rich tissue regions were significantly decreased compared with the surrounding tissue regions, where most components are normal cells/tissues, such as fibroblasts, connective tissue and lymphocytes. Our observation also showed that the ultrasonic properties were influenced by arrangements of cells and tissue patterns. Conclusions: Our data demonstrate that attenuation and sound speed imaging can provide biomechanical information of the tumor and normal tissues. The results also demonstrate the potential of acoustic microscopy as an auxiliary method for operative detection and localization of cancer affected regions.

Lumber defect detection by ultrasonics

Treesearch

K. A. McDonald

1978-01-01

Ultrasonics, the technology of high-frequency sound, has been developed as a viable means for locating most defects In lumber for use in digital form in decision-making computers. Ultrasonics has the potential for locating surface and internal defects in lumber of all species, green or dry, and rough sawn or surfaced.

Ultrasonic Wave Properties in Bone Axis Direction of Bovine Cortical Bone

NASA Astrophysics Data System (ADS)

Yamamoto, Kazufumi; Yaoi, Yuichiro; Yamato, Yu; Yanagitan, Takahiko; Matsukawa, Mami; Yamazaki, Kaoru

2008-05-01

Quantitative ultrasonography (QUS) is a good method for measuring elastic properties of bone in vivo. Bovine cortical bone has two typical microstructures, plexiform and Haversian. In this study, the relationship between the speed of sound (SOS) and the hydroxyapatite (HAp) crystallite orientation in the axial direction was investigated in two different aged bovine cortical bones. The dependence of attenuation on anatomical position was also investigated. Two ring-permanent hyphen shaped cortical bone samples were obtained from 36- and 24-month-old bovine femurs. SOS was measured with a conventional ultrasonic pulse system. The integrated intensity of the (0002) peak obtained by X-ray diffraction was determine to evaluate the amount of preferred orientation. Regardless of the age of the bovine femurs, a significant correlation between SOS and the preferred orientation of HAp crystallites was observed in parts of the plexiform structure, and the gradient of the relationship showed a similar tendency. Attenuation seemed to depend on bone microstructure.

3D simulation of an audible ultrasonic electrolarynx using difference waves.

PubMed

Mills, Patrick; Zara, Jason

2014-01-01

A total laryngectomy removes the vocal folds which are fundamental in forming voiced sounds that make speech possible. Although implanted prosthetics are commonly used in developed countries, simple handheld vibrating electrolarynxes are still common worldwide. These devices are easy to use but suffer from many drawbacks including dedication of a hand, mechanical sounding voice, and sound leakage. To address some of these drawbacks, we introduce a novel electrolarynx that uses vibro-acoustic interference of dual ultrasonic waves to generate an audible fundamental frequency. A 3D simulation of the principles of the device is presented in this paper.

Rapid and Quiet Drill

NASA Technical Reports Server (NTRS)

Sherrit, Stewart; Badescu, Mircea; Bar-Cohen, Yoseph; Chang, Zensheu; Bao, Xiaoqi

2007-01-01

This describes aspects of the rapid and quiet drill (RAQD), which is a prototype apparatus for drilling concrete or bricks. The design and basic principle of operation of the RAQD overlap, in several respects, with those of ultrasonic/ sonic drilling and coring apparatuses described in a number of previous NASA Tech Briefs articles. The main difference is that whereas the actuation scheme of the prior apparatuses is partly ultrasonic and partly sonic, the actuation scheme of the RAQD is purely ultrasonic. Hence, even though the RAQD generates considerable sound, it is characterized as quiet because most or all of the sound is above the frequency range of human hearing.

Ultrasonic superlensing jets and acoustic-fork sheets

NASA Astrophysics Data System (ADS)

Mitri, F. G.

2017-05-01

Focusing acoustical (and optical) beams beyond the diffraction limit has remained a major challenge in imaging instruments and systems, until recent advances on ;hyper; or ;super; lensing and higher-resolution imaging techniques have shown the counterintuitive violation of this rule under certain circumstances. Nonetheless, the proposed technologies of super-resolution acoustical focusing beyond the diffraction barrier require complex tools such as artificially engineered metamaterials, and other hardware equipment that may not be easily synthesized or manufactured. The present contribution therefore suggests a simple and reliable method of using a sound-penetrable circular cylinder lens illuminated by a nonparaxial Gaussian acoustical sheet (i.e. finite beam in 2D) to produce non-evanescent ultrasonic superlensing jets (or bullets) and acoustical 'snail-fork' shaped wavefronts with limited diffraction. The generalized (near-field) scattering theory for acoustical sheets of arbitrary wavefronts and incidence is utilized to synthesize the incident beam based upon the angular spectrum decomposition method and the multipole expansion method in cylindrical wave functions to compute the scattered pressure around the cylinder with particular emphasis on its physical properties. The results show that depending on the beam and lens parameters, a tight focusing (with dimensions much smaller than the beam waist) can be achieved. Subwavelength resolution can be also achieved by selecting a lens material with a speed of sound exceeding that of the host fluid medium. The ultrasonic superlensing jets provide the impetus to develop improved subwavelength microscopy and acoustical image-slicing systems, cell lysis and surgery, and photoacoustic imaging to name a few examples. Moreover, an acoustical fork-sheet generation may open innovative avenues in reconfigurable on-chip micro/nanoparticle tweezers and surface acoustic waves devices.

Optimization of low frequency sound absorption by cell size control and multiscale poroacoustics modeling

NASA Astrophysics Data System (ADS)

Park, Ju Hyuk; Yang, Sei Hyun; Lee, Hyeong Rae; Yu, Cheng Bin; Pak, Seong Yeol; Oh, Chi Sung; Kang, Yeon June; Youn, Jae Ryoun

2017-06-01

Sound absorption of a polyurethane (PU) foam was predicted for various geometries to fabricate the optimum microstructure of a sound absorbing foam. Multiscale numerical analysis for sound absorption was carried out by solving flow problems in representative unit cell (RUC) and the pressure acoustics equation using Johnson-Champoux-Allard (JCA) model. From the numerical analysis, theoretical optimum cell diameter for low frequency sound absorption was evaluated in the vicinity of 400 μm under the condition of 2 cm-80 K (thickness of 2 cm and density of 80 kg/m3) foam. An ultrasonic foaming method was employed to modulate microcellular structure of PU foam. Mechanical activation was only employed to manipulate the internal structure of PU foam without any other treatment. A mean cell diameter of PU foam was gradually decreased with increase in the amplitude of ultrasonic waves. It was empirically found that the reduction of mean cell diameter induced by the ultrasonic wave enhances acoustic damping efficiency in low frequency ranges. Moreover, further analyses were performed with several acoustic evaluation factors; root mean square (RMS) values, noise reduction coefficients (NRC), and 1/3 octave band spectrograms.

Making Sound Connections

ERIC Educational Resources Information Center

Deal, Walter F., III

2007-01-01

Sound provides and offers amazing insights into the world. Sound waves may be defined as mechanical energy that moves through air or other medium as a longitudinal wave and consists of pressure fluctuations. Humans and animals alike use sound as a means of communication and a tool for survival. Mammals, such as bats, use ultrasonic sound waves to…

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.

An underwater ranging system based on photoacoustic effect occurring on target surface

NASA Astrophysics Data System (ADS)

Ni, Kai; Hu, Kai; Li, Xinghui; Wang, Lidai; Zhou, Qian; Wang, Xiaohao

2016-11-01

In this paper, an underwater ranging system based on photoacoustic effect occurring on target surface is proposed. In this proposal, laser pulse generated by blue-green laser is directly incident on target surface, where the photoacoustic effect occurs and a sound source is formed. And then the sound wave which is also called photoacoustic signal is received by the ultrasonic receiver after passing through water. According to the time delay between transmitting laser and receiving photoacoustic signal, and sound velocity in water, the distance between the target and the ultrasonic receiver can be calculated. Differing from underwater range finding by only laser, this approach can avoid backscattering of laser beam, so easier to implement. Experimental system according to this principle has been constructed to verify the feasibility of this technology. The experimental results showed that a ranging accuracy of 1 mm can be effectively achieved when the target is close to the ultrasonic receiver.

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.

Ultrasonic Testing, Aviation Quality Control (Advanced): 9227.03.

ERIC Educational Resources Information Center

Dade County Public Schools, Miami, FL.

This unit of instruction covers the theory of ultrasonic sound, methods of applying soundwaves to test specimens and interpreting results, calibrating the ultrasonic equipment, and the use of standards. Study periods, group discussions, and extensive use of textbooks and training manuals are to be used. These are listed along with references and…

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.

[Verified maximum admissible intensity (MAI) values for the ultrasonic noise in work environment].

PubMed

Pawlaczyk-Łuszcyńska, M; Koton, J; Augustyńska, D; Sliwińska-Kowalska, M; Kameduła, M

2001-01-01

The measurement methods and occupational exposure limits for ultrasonic noise (airborne ultrasound) are described. Typical sources of ultrasonic noise and sound pressure levels measured at workplaces are discussed. The verified Polish regulations on maximum admissible intensity (MAI) values for ultrasonic noise in the work environment and proposals of exposure limits for workers at particular risk (i.e. pregnant women and juveniles) are presented.

High Speed Imaging of Cavitation around Dental Ultrasonic Scaler Tips.

PubMed

Vyas, Nina; Pecheva, Emilia; Dehghani, Hamid; Sammons, Rachel L; Wang, Qianxi X; Leppinen, David M; Walmsley, A Damien

2016-01-01

Cavitation occurs around dental ultrasonic scalers, which are used clinically for removing dental biofilm and calculus. However it is not known if this contributes to the cleaning process. Characterisation of the cavitation around ultrasonic scalers will assist in assessing its contribution and in developing new clinical devices for removing biofilm with cavitation. The aim is to use high speed camera imaging to quantify cavitation patterns around an ultrasonic scaler. A Satelec ultrasonic scaler operating at 29 kHz with three different shaped tips has been studied at medium and high operating power using high speed imaging at 15,000, 90,000 and 250,000 frames per second. The tip displacement has been recorded using scanning laser vibrometry. Cavitation occurs at the free end of the tip and increases with power while the area and width of the cavitation cloud varies for different shaped tips. The cavitation starts at the antinodes, with little or no cavitation at the node. High speed image sequences combined with scanning laser vibrometry show individual microbubbles imploding and bubble clouds lifting and moving away from the ultrasonic scaler tip, with larger tip displacement causing more cavitation.

High Speed Imaging of Cavitation around Dental Ultrasonic Scaler Tips

PubMed Central

Vyas, Nina; Pecheva, Emilia; Dehghani, Hamid; Sammons, Rachel L.; Wang, Qianxi X.; Leppinen, David M.; Walmsley, A. Damien

2016-01-01

Cavitation occurs around dental ultrasonic scalers, which are used clinically for removing dental biofilm and calculus. However it is not known if this contributes to the cleaning process. Characterisation of the cavitation around ultrasonic scalers will assist in assessing its contribution and in developing new clinical devices for removing biofilm with cavitation. The aim is to use high speed camera imaging to quantify cavitation patterns around an ultrasonic scaler. A Satelec ultrasonic scaler operating at 29 kHz with three different shaped tips has been studied at medium and high operating power using high speed imaging at 15,000, 90,000 and 250,000 frames per second. The tip displacement has been recorded using scanning laser vibrometry. Cavitation occurs at the free end of the tip and increases with power while the area and width of the cavitation cloud varies for different shaped tips. The cavitation starts at the antinodes, with little or no cavitation at the node. High speed image sequences combined with scanning laser vibrometry show individual microbubbles imploding and bubble clouds lifting and moving away from the ultrasonic scaler tip, with larger tip displacement causing more cavitation. PMID:26934340

21 CFR 892.1540 - Nonfetal ultrasonic monitor.

Code of Federal Regulations, 2012 CFR

2012-04-01

...) Identification. A nonfetal ultrasonic monitor is a device that projects a continuous high-frequency sound wave... wave and is intended for use in the investigation of nonfetal blood flow and other nonfetal body...

21 CFR 892.1540 - Nonfetal ultrasonic monitor.

Code of Federal Regulations, 2013 CFR

2013-04-01

...) Identification. A nonfetal ultrasonic monitor is a device that projects a continuous high-frequency sound wave... wave and is intended for use in the investigation of nonfetal blood flow and other nonfetal body...

SAFT-assisted sound beam focusing using phased arrays (PA-SAFT) for non-destructive evaluation

NASA Astrophysics Data System (ADS)

Nanekar, Paritosh; Kumar, Anish; Jayakumar, T.

2015-04-01

Focusing of sound has always been a subject of interest in ultrasonic non-destructive evaluation. An integrated approach to sound beam focusing using phased array and synthetic aperture focusing technique (PA-SAFT) has been developed in the authors' laboratory. The approach involves SAFT processing on ultrasonic B-scan image collected by a linear array transducer using a divergent sound beam. The objective is to achieve sound beam focusing using fewer elements than the ones required using conventional phased array. The effectiveness of the approach is demonstrated on aluminium blocks with artificial flaws and steel plate samples with embedded volumetric weld flaws, such as slag and clustered porosities. The results obtained by the PA-SAFT approach are found to be comparable to those obtained by conventional phased array and full matrix capture - total focusing method approaches.

Method for Ultrasonic Imaging and Device for Performing the Method

NASA Technical Reports Server (NTRS)

Madaras, Eric I. (Inventor)

1997-01-01

A method for ultrasonic imaging of interior structures and flaws in a test specimen with a smooth or irregular contact surfaces, in which an ultrasonic transducer is coupled acoustically to the contact surface via a plurality of ultrasonic wave guides with equal delay times. The wave guides are thin and bendable, so they adapt to variations in the distance between the transducer and different parts of the contact surface by bending more or less. All parts of the irregular contact surface accordingly receive sound waves that are in phase, even when the contact surface is irregular, so a coherent sound wave is infused in the test specimen. The wave guides can be arranged in the form of an ultrasonic brush, with a flat head for coupling to a flat transducer, and free bristles that can be pressed against the test specimen. By bevelling the bristle ends at a suitable angle, shear mode waves can be infused into the test specimen from a longitudinal mode transducer.

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.

Ultrasonic detection of knots, cross grain and bark pockets in wooden pallet parts

Treesearch

Mohammed F. Kabir; Daniel L. Schmoldt; Mark E. Schafer

2000-01-01

This study investigates defect detection in wooden pallet parts using ultrasonic scanning. Yellow-poplar (Liriodendron tulipifera, L.) deckboards were scanned using two rolling transducers in a pitch-catch arrangement to detect unsound and sound knots, bark pockets and cross grain. Data were collected, stored, and processed using LabView? software. Six ultrasonic...

A Study on the Model of Detecting the Liquid Level of Sealed Containers Based on Kirchhoff Approximation Theory.

PubMed

Zhang, Bin; Song, Wen-Ai; Wei, Yue-Juan; Zhang, Dong-Song; Liu, Wen-Yi

2017-06-15

By simulating the sound field of a round piston transducer with the Kirchhoff integral theorem and analyzing the shape of ultrasound beams and propagation characteristics in a metal container wall, this study presents a model for calculating the echo sound pressure by using the Kirchhoff paraxial approximation theory, based on which and according to different ultrasonic impedance between gas and liquid media, a method for detecting the liquid level from outside of sealed containers is proposed. Then, the proposed method is evaluated through two groups of experiments. In the first group, three kinds of liquid media with different ultrasonic impedance are used as detected objects; the echo sound pressure is calculated by using the proposed model under conditions of four sets of different wall thicknesses. The changing characteristics of the echo sound pressure in the entire detection process are analyzed, and the effects of different ultrasonic impedance of liquids on the echo sound pressure are compared. In the second group, taking water as an example, two transducers with different radii are selected to measure the liquid level under four sets of wall thickness. Combining with sound field characteristics, the influence of different size transducers on the pressure calculation and detection resolution are discussed and analyzed. Finally, the experimental results indicate that measurement uncertainly is better than ±5 mm, which meets the industrial inspection requirements.

A Study on the Model of Detecting the Liquid Level of Sealed Containers Based on Kirchhoff Approximation Theory

PubMed Central

Zhang, Bin; Song, Wen-Ai; Wei, Yue-Juan; Zhang, Dong-Song; Liu, Wen-Yi

2017-01-01

By simulating the sound field of a round piston transducer with the Kirchhoff integral theorem and analyzing the shape of ultrasound beams and propagation characteristics in a metal container wall, this study presents a model for calculating the echo sound pressure by using the Kirchhoff paraxial approximation theory, based on which and according to different ultrasonic impedance between gas and liquid media, a method for detecting the liquid level from outside of sealed containers is proposed. Then, the proposed method is evaluated through two groups of experiments. In the first group, three kinds of liquid media with different ultrasonic impedance are used as detected objects; the echo sound pressure is calculated by using the proposed model under conditions of four sets of different wall thicknesses. The changing characteristics of the echo sound pressure in the entire detection process are analyzed, and the effects of different ultrasonic impedance of liquids on the echo sound pressure are compared. In the second group, taking water as an example, two transducers with different radii are selected to measure the liquid level under four sets of wall thickness. Combining with sound field characteristics, the influence of different size transducers on the pressure calculation and detection resolution are discussed and analyzed. Finally, the experimental results indicate that measurement uncertainly is better than ±5 mm, which meets the industrial inspection requirements. PMID:28617326

Simulation of ultrasonic focus aberration and correction through human tissue.

PubMed

Tabei, Makoto; Mast, T Douglas; Waag, Robert C

2003-02-01

Ultrasonic focusing in two dimensions has been investigated by calculating the propagation of ultrasonic pulses through cross-sectional models of human abdominal wall and breast. Propagation calculations used a full-wave k-space method that accounts for spatial variations in density, sound speed, and frequency-dependent absorption and includes perfectly matched layer absorbing boundary conditions. To obtain a distorted receive wavefront, propagation from a point source through the tissue path was computed. Receive focusing used an angular spectrum method. Transmit focusing was accomplished by propagating a pressure wavefront from a virtual array through the tissue path. As well as uncompensated focusing, focusing that employed time-shift compensation and time-shift compensation after backpropagation was investigated in both transmit and receive and time reversal was investigated for transmit focusing in addition. The results indicate, consistent with measurements, that breast causes greater focus degradation than abdominal wall. The investigated compensation methods corrected the receive focus better than the transmit focus. Time-shift compensation after backpropagation improved the focus from that obtained using time-shift compensation alone but the improvement was less in transmit focusing than in receive focusing. Transmit focusing by time reversal resulted in lower sidelobes but larger mainlobes than the other investigated transmit focus compensation methods.

Fabrication and characterization of piezoelectric micromachined ultrasonic transducers with thick composite PZT films.

PubMed

Wang, Zhihong; Zhu, Weiguang; Zhu, Hong; Miao, Jianmin; Chao, Chen; Zhao, Changlei; Tan, Ooi Kiang

2005-12-01

Ferroelectric microelectromechanical systems (MEMS) has been a growing area of research in past decades, in which ferroelectric films are combined with silicon technology for a variety of applications, such as piezo-electric micromachined ultrasonic transducers (pMUTs), which represent a new approach to ultrasound detection and generation. For ultrasound-radiating applications, thicker PZT films are preferred because generative force and response speed of the diaphragm-type transducers increase with increasing film thickness. However, integration of 4- to 20-microm thick PZT films on silicon wafer, either the deposition or the patterning, is still a bottleneck in the micromachining process. This paper reports on a diaphragm-type pMUT. A composite coating technique based on chemical solution deposition and high-energy ball milled powder has been used to fabricate thick PZT films. Micromachining of the pMUTs using such thick films has been investigated. The fabricated pMUT with crack-free PZT films up to 7-microm thick was evaluated as an ultrasonic transmitter. The generated sound pressure level of up to 120 dB indicates that the fabricated pMUT has very good ultrasound-radiating performance and, therefore, can be used to compose pMUT arrays for generating ultrasound beam with high directivity in numerous applications. The pMUT arrays also have been demonstrated.

Determination of fish swimming speed by ultrasonic telemetry.

PubMed

Voegeli, F A; Pincock, D G

1980-01-01

Design of a small and simple sensor for direct measurement of swimming speed of fish and its incorporation into ultrasonic telemetry transmitters is described. The sensor used measures the speed of rotation of a free-wheeling propeller which is exposed to water flow. Two transmitters incorporating this sensor are described. The first is a very simple one providing swimming speed while the second incorporates two temperature sensors as well.

Development of aerial ultrasonic source using cylinder typed vibrating plate with axial nodal mode

NASA Astrophysics Data System (ADS)

Asami, Takuya; Miura, Hikaru

2018-07-01

We developed a high-power aerial ultrasonic source with a cylinder typed vibrating plate combined with two rigid walls that can be directly connected to a pipe in order to solve the difficulty in connecting an ultrasonic source to a pipe containing particles while preventing the particles from leaking. The structure of the vibrating plate combined with two rigid walls that do not vibrate and can obtain a high sound pressure in the space inside the vibrating plate was designed using the finite element method (FEM). We found that the aerial ultrasonic source using the designed vibrating plate slightly vibrates at the rigid walls as designed using FEM and can be connected to other devices. In addition, the obtained sound pressure was around 8.0 kPa (172 dB) at an input electrical power of 7 W.

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.

Ultrasonic transducer with laminated coupling wedge

DOEpatents

Karplus, Henry H. B.

1976-08-03

An ultrasonic transducer capable of use in a high-temperature environment incorporates a laminated metal coupling wedge including a reflecting edge shaped as a double sloping roof and a transducer crystal backed by a laminated metal sound absorber disposed so as to direct sound waves through the coupling wedge and into a work piece, reflections from the interface between the coupling wedge and the work piece passing to the reflecting edge. Preferably the angle of inclination of the two halves of the reflecting edge are different.

Ultrasonic and densimetric titration applied for acid-base reactions.

PubMed

Burakowski, Andrzej; Gliński, Jacek

2014-01-01

Classical acoustic acid-base titration was monitored using sound speed and density measurements. Plots of these parameters, as well as of the adiabatic compressibility coefficient calculated from them, exhibit changes with the volume of added titrant. Compressibility changes can be explained and quantitatively predicted theoretically in terms of Pasynski theory of non-compressible hydrates combined with that of the additivity of the hydration numbers with the amount and type of ions and molecules present in solution. It also seems that this development could be applied in chemical engineering for monitoring the course of chemical processes, since the applied experimental methods can be carried out almost independently on the medium under test (harmful, aggressive, etc.).

Calibration of International Space Station (ISS) Node 1 Vibro-Acoustic Model-Report 2

NASA Technical Reports Server (NTRS)

Zhang, Weiguo; Raveendra, Ravi

2014-01-01

Reported here is the capability of the Energy Finite Element Method (E-FEM) to predict the vibro-acoustic sound fields within the International Space Station (ISS) Node 1 and to compare the results with simulated leak sounds. A series of electronically generated structural ultrasonic noise sources were created in the pressure wall to emulate leak signals at different locations of the Node 1 STA module during its period of storage at Stennis Space Center (SSC). The exact sound source profiles created within the pressure wall at the source were unknown, but were estimated from the closest sensor measurement. The E-FEM method represents a reverberant sound field calculation, and of importance to this application is the requirement to correctly handle the direct field effect of the sound generation. It was also important to be able to compute the sound energy fields in the ultrasonic frequency range. This report demonstrates the capability of this technology as applied to this type of application.

Ultrasonic Phased Array Sound Field Mapping Through Large-Bore Coarse Grained Cast Austenitic Stainless Steel (CASS) Piping Materials

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

Cinson, Anthony D.; Crawford, Susan L.; Prowant, Matthew S.

2012-04-16

A sound field beam mapping exercise was conducted to further understand the effects of coarse grained microstructures found in CASS materials on phased array ultrasonic wave propagation. Laboratory measurements were made on three CASS specimens with different microstructures; the specimens were polished and etched to reveal measurable grain sizes, shapes and orientations. Three longitudinal, phased array probes were fixed on a specimen's outside diameter with the sound field directed toward one end (face) of the pipe segment over a fixed range of angles. A point receiver was raster scanned over the surface of the specimen face generating a sound fieldmore » image. A slice of CASS material was then removed from the specimen end and the beam mapping exercise repeated. The sound fields acquired were analyzed for spot size, coherency, and beam redirection. Analyses were conducted between the resulting sound fields and the microstructural characteristics of each specimen.« less

Production of ultrasonic vocalizations by Peromyscus mice in the wild

PubMed Central

Kalcounis-Rueppell, Matina C; Metheny, Jackie D; Vonhof, Maarten J

2006-01-01

Background There has been considerable research on rodent ultrasound in the laboratory and these sounds have been well quantified and characterized. Despite the value of research on ultrasound produced by mice in the lab, it is unclear if, and when, these sounds are produced in the wild, and how they function in natural habitats. Results We have made the first recordings of ultrasonic vocalizations produced by two free-living species of mice in the genus Peromyscus (P. californicus and P. boylii) on long term study grids in California. Over 6 nights, we recorded 65 unique ultrasonic vocalization phrases from Peromyscus. The ultrasonic vocalizations we recorded represent 7 different motifs. Within each motif, there was considerable variation in the acoustic characteristics suggesting individual and contextual variation in the production of ultrasound by these species. Conclusion The discovery of the production of ultrasonic vocalizations by Peromyscus in the wild highlights an underappreciated component in the behavior of these model organisms. The ability to examine the production of ultrasonic vocalizations in the wild offers excellent opportunities to test hypotheses regarding the function of ultrasound produced by rodents in a natural context. PMID:16507093

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.

The ultrasonic characteristics of high frequency modulated arc and its application in material processing.

PubMed

He, Longbiao; Yang, Ping; Li, Luming; Wu, Minsheng

2014-12-01

To solve the difficulty of introducing traditional ultrasonic transducers to welding molten pool, high frequency current is used to modulate plasma arc and ultrasonic wave is excited successfully. The characteristics of the excited ultrasonic field are studied. The results show that the amplitude-frequency response of the ultrasonic emission is flat. The modulating current is the main factor influencing the ultrasonic power and the sound pressure depends on the variation of arc plasma stream force. Experimental study of the welding structure indicates grain refinement by the ultrasonic emission of the modulated arc and the test results showed there should be an energy region for the arc ultrasonic to get best welding joints. Copyright © 2014 Elsevier B.V. All rights reserved.

Modeling the thermo-acoustic effects of thermal-dependent speed of sound and acoustic absorption of biological tissues during focused ultrasound hyperthermia.

PubMed

López-Haro, S A; Gutiérrez, M I; Vera, A; Leija, L

2015-10-01

To evaluate the effects of thermal dependence of speed of sound (SOS) and acoustic absorption of biological tissues during noninvasive focused ultrasound (US) hyperthermia therapy. A finite element (FE) model was used to simulate hyperthermia therapy in the liver by noninvasive focused US. The model consisted of an ultrasonic focused transducer radiating a four-layer biological medium composed of skin, fat, muscle, and liver. The acoustic field and temperature distribution along the layers were obtained after 15 s of hyperthermia therapy using the bio-heat equation. The model solution was found with and without the thermal dependence of SOS and acoustic absorption of biological tissues. The inclusion of the thermal dependence of the SOS generated an increment of 0.4 mm in the longitudinal focus axis of the acoustic field. Moreover, results indicate an increment of the hyperthermia area (zone with temperature above 43 °C), and a maximum temperature difference of almost 3.5 °C when the thermal dependence of absorption was taken into account. The increment of the achieved temperatures at the treatment zone indicated that the effects produced by the thermal dependence of SOS and absorption must be accounted for when planning hyperthermia treatment in order to avoid overheating undesired regions.

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.

Implementation of total focusing method for phased array ultrasonic imaging on FPGA

NASA Astrophysics Data System (ADS)

Guo, JianQiang; Li, Xi; Gao, Xiaorong; Wang, Zeyong; Zhao, Quanke

2015-02-01

This paper describes a multi-FPGA imaging system dedicated for the real-time imaging using the Total Focusing Method (TFM) and Full Matrix Capture (FMC). The system was entirely described using Verilog HDL language and implemented on Altera Stratix IV GX FPGA development board. The whole algorithm process is to: establish a coordinate system of image and divide it into grids; calculate the complete acoustic distance of array element between transmitting array element and receiving array element, and transform it into index value; then index the sound pressure values from ROM and superimpose sound pressure values to get pixel value of one focus point; and calculate the pixel values of all focus points to get the final imaging. The imaging result shows that this algorithm has high SNR of defect imaging. And FPGA with parallel processing capability can provide high speed performance, so this system can provide the imaging interface, with complete function and good performance.

Phased Array Ultrasonic Sound Field Mapping in Cast Austenitic Stainless Steel

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

Crawford, Susan L.; Prowant, Matthew S.; Cinson, Anthony D.

2014-05-31

This study maps the phased array-generated acoustic sound fields through three types of CASS microstructure in four specimens to quantitatively assess the beam formation effectiveness in these materials.

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.

Influence of ultrasonic irradiation on ozone generation in a dielectric barrier discharge

NASA Astrophysics Data System (ADS)

Kusano, Y.; Drews, J.; Leipold, F.; Fateev, A.; Bardenshtein, A.; Krebs, N.

2012-12-01

An atmospheric pressure dielectric barrier discharge (DBD) was generated in an N2/O2 gas mixture at room temperature with and without ultrasonic irradiation to investigate ozone production. Powerful ultrasonic irradiation with the sound pressure level of approximately 150 dB into the DBD can enhance ozone production especially when the DBD was driven at a frequency of 15 kHz.

Relationship Between Speed of Sound in and Density of Normal and Diseased Rat Livers

NASA Astrophysics Data System (ADS)

Hachiya, Hiroyuki; Ohtsuki, Shigeo; Tanaka, Motonao

1994-05-01

Speed of sound is an important acoustic parameter for quantitative characterization of living tissues. In this paper, the relationship between speed of sound in and density of rat liver tissues are investigated. The speed of sound was measured by the nondeformable technique based on frequency-time analysis of a 3.5 MHz pulse response. The speed of sound in normal livers varied minimally between individuals and was not related to body weight or age. In liver tissues which were administered CCl4, the speed of sound was lower than the speed of sound in normal tissues. The relationship between speed of sound and density in normal, fatty and cirrhotic livers can be fitted well on the line which is estimated using the immiscible liquid model assuming a mixture of normal liver and fat tissues. For 3.5 MHz ultrasound, it is considered that the speed of sound in fresh liver with fatty degeneration is responsible for the fat content and is not strongly dependent on the degree of fibrosis.

A Low-Wear Driving Method of Ultrasonic Motors

NASA Astrophysics Data System (ADS)

Ishii, Takaaki; Takahashi, Hisanori; KentaroNakamura, KentaroNakamura; Ueha, Sadayuki

1999-05-01

The life of ultrasonic motors is limited by the wear of friction materials used for the contact surfaces. In order to reduce the wear of the friction material, we have to reduce the sliding speed between the sliding surfaces of the motor. In this report, we propose a new driving method to reduce the sliding speed of the motor by shaping the vibration speed waveform. The sliding loss was calculated and wear reduction effect was confirmed. A wear test was carried out under no-load condition. This method prolongs the life of an ultrasonic motor by about 3.4-fold. The results and wear reduction effects are also described.

Experimental investigation by laser ultrasonics for high speed train axle diagnostics.

PubMed

Cavuto, A; Martarelli, M; Pandarese, G; Revel, G M; Tomasini, E P

2015-01-01

The present paper demonstrates the applicability of a laser-ultrasonic procedure to improve the performances of train axle ultrasonic inspection. The method exploits an air-coupled ultrasonic probe that detects the ultrasonic waves generated by a high-power pulsed laser. As a result, the measurement chain is completely non-contact, from generation to detection, this making it possible to considerably speed up inspection time and make the set-up more flexible. The main advantage of the technique developed is that it works in thermo-elastic regime and it therefore can be considered as a non-destructive method. The laser-ultrasonic procedure investigated has been applied for the inspection of a real high speed train axle provided by the Italian railway company (Trenitalia), on which typical fatigue defects have been expressly created according to standard specifications. A dedicated test bench has been developed so as to rotate the axle with the angle control and to speed up the inspection of the axle surface. The laser-ultrasonic procedure proposed can be automated and is potentially suitable for regular inspection of train axles. The main achievements of the activity described in this paper are: – the study of the effective applicability of laser-ultrasonics for the diagnostic of train hollow axles with variable sections by means of a numerical FE model, – the carrying out of an automated experiment on a real train axle, – the analysis of the sensitivity to experimental parameters, like laser source – receiving probe distance and receiving probe angular position, – the demonstration that the technique is suitable for the detection of surface defects purposely created on the train axle. Copyright © 2014 Elsevier B.V. All rights reserved.

Temperature imaging with speed of ultrasonic transmission tomography for medical treatment control: A physical model-based method

NASA Astrophysics Data System (ADS)

Chu, Zhe-Qi; Yuan, Jie; Stephen, Z. Pinter; Oliver, D. Kripfgans; Wang, Xue-Ding; Paul, L. Carson; Liu, Xiao-Jun

2015-10-01

Hyperthermia is a promising method to enhance chemo and radiation therapy of breast cancer. In the process of hyperthermia, temperature monitoring is of great importance to assure the effectiveness of treatment. The transmission speed of ultrasound in biomedical tissue changes with temperature. However, when mapping the speed of sound directly to temperature in each pixel as desired for using all speeds of ultrasound data, temperature bipolar edge enhancement artifacts occur near the boundary of two tissues with different speeds of ultrasound. After the analysis of the reasons for causing these artifacts, an optimized method is introduced to rebuild the temperature field image by using the continuity constraint as the judgment criterion. The significant smoothness of the rebuilding image in the transitional area shows that our proposed method can build a more precise temperature image for controlling the medical thermal treatment. Project supported in part by DoD/BCRP Idea Award, BC095397P1, the National Natural Science Foundation of China (Grant No. 61201425), the Natural Science Foundation of Jiangsu Province, China (Grant No. BK20131280), the Priority Academic Program Development of Jiangsu Provincial Higher Education Institutions, China, and the National Institutes of Health (NIH) of United States (Grant Nos. R01AR060350, R01CA91713, and R01AR055179).

Ultrasonic waves in classical gases

NASA Astrophysics Data System (ADS)

Magner, A. G.; Gorenstein, M. I.; Grygoriev, U. V.

2017-12-01

The velocity and absorption coefficient for the plane sound waves in a classical gas are obtained by solving the Boltzmann kinetic equation, which describes the reaction of the single-particle distribution function to a periodic external field. Within the linear response theory, the nonperturbative dispersion equation valid for all sound frequencies is derived and solved numerically. The results are in agreement with the approximate analytical solutions found for both the frequent- and rare-collision regimes. These results are also in qualitative agreement with the experimental data for ultrasonic waves in dilute gases.

Human amygdala activation by the sound produced during dental treatment: A fMRI study.

PubMed

Yu, Jen-Fang; Lee, Kun-Che; Hong, Hsiang-Hsi; Kuo, Song-Bor; Wu, Chung-De; Wai, Yau-Yau; Chen, Yi-Fen; Peng, Ying-Chin

2015-01-01

During dental treatments, patients may experience negative emotions associated with the procedure. This study was conducted with the aim of using functional magnetic resonance imaging (fMRI) to visualize cerebral cortical stimulation among dental patients in response to auditory stimuli produced by ultrasonic scaling and power suction equipment. Subjects (n = 7) aged 23-35 years were recruited for this study. All were right-handed and underwent clinical pure-tone audiometry testing to reveal a normal hearing threshold below 20 dB hearing level (HL). As part of the study, subjects initially underwent a dental calculus removal treatment. During the treatment, subjects were exposed to ultrasonic auditory stimuli originating from the scaling handpiece and salivary suction instruments. After dental treatment, subjects were imaged with fMRI while being exposed to recordings of the noise from the same dental instrument so that cerebral cortical stimulation in response to aversive auditory stimulation could be observed. The independent sample confirmatory t-test was used. Subjects also showed stimulation in the amygdala and prefrontal cortex, indicating that the ultrasonic auditory stimuli elicited an unpleasant response in the subjects. Patients experienced unpleasant sensations caused by contact stimuli in the treatment procedure. In addition, this study has demonstrated that aversive auditory stimuli such as sounds from the ultrasonic scaling handpiece also cause aversive emotions. This study was indicated by observed stimulation of the auditory cortex as well as the amygdala, indicating that noise from the ultrasonic scaling handpiece was perceived as an aversive auditory stimulus by the subjects. Subjects can experience unpleasant sensations caused by the sounds from the ultrasonic scaling handpiece based on their auditory stimuli.

Human amygdala activation by the sound produced during dental treatment: A fMRI study

PubMed Central

Yu, Jen-Fang; Lee, Kun-Che; Hong, Hsiang-Hsi; Kuo, Song-Bor; Wu, Chung-De; Wai, Yau-Yau; Chen, Yi-Fen; Peng, Ying-Chin

2015-01-01

During dental treatments, patients may experience negative emotions associated with the procedure. This study was conducted with the aim of using functional magnetic resonance imaging (fMRI) to visualize cerebral cortical stimulation among dental patients in response to auditory stimuli produced by ultrasonic scaling and power suction equipment. Subjects (n = 7) aged 23-35 years were recruited for this study. All were right-handed and underwent clinical pure-tone audiometry testing to reveal a normal hearing threshold below 20 dB hearing level (HL). As part of the study, subjects initially underwent a dental calculus removal treatment. During the treatment, subjects were exposed to ultrasonic auditory stimuli originating from the scaling handpiece and salivary suction instruments. After dental treatment, subjects were imaged with fMRI while being exposed to recordings of the noise from the same dental instrument so that cerebral cortical stimulation in response to aversive auditory stimulation could be observed. The independent sample confirmatory t-test was used. Subjects also showed stimulation in the amygdala and prefrontal cortex, indicating that the ultrasonic auditory stimuli elicited an unpleasant response in the subjects. Patients experienced unpleasant sensations caused by contact stimuli in the treatment procedure. In addition, this study has demonstrated that aversive auditory stimuli such as sounds from the ultrasonic scaling handpiece also cause aversive emotions. This study was indicated by observed stimulation of the auditory cortex as well as the amygdala, indicating that noise from the ultrasonic scaling handpiece was perceived as an aversive auditory stimulus by the subjects. Subjects can experience unpleasant sensations caused by the sounds from the ultrasonic scaling handpiece based on their auditory stimuli. PMID:26356376

Meteorological effects on long-range outdoor sound propagation

NASA Technical Reports Server (NTRS)

Klug, Helmut

1990-01-01

Measurements of sound propagation over distances up to 1000 m were carried out with an impulse sound source offering reproducible, short time signals. Temperature and wind speed at several heights were monitored simultaneously; the meteorological data are used to determine the sound speed gradients according to the Monin-Obukhov similarity theory. The sound speed profile is compared to a corresponding prediction, gained through the measured travel time difference between direct and ground reflected pulse (which depends on the sound speed gradient). Positive sound speed gradients cause bending of the sound rays towards the ground yielding enhanced sound pressure levels. The measured meteorological effects on sound propagation are discussed and illustrated by ray tracing methods.

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)

Analysis of the electromechanical characteristics of a piezoelectric multilayered structure for in-air ultrasound radiation

NASA Astrophysics Data System (ADS)

Shim, Hayeong; Roh, Yongrae

2018-07-01

Ultrasonic sensors in air are used to measure distances from obstacles in household appliances, automobiles, and other areas. Among these ultrasonic sensors in air, sensors using disk-shaped piezoelectric ceramics are composed of a multilayered structure having a vibrational plate, a piezoelectric ceramic disk, and a backing layer. In this study, we derived theoretical equations that can accurately analyze the acoustic characteristics of the piezoelectric multilayered structure, and then analyzed the performance of the ultrasonic sensor according to the geometrical change of the multilayered structure. The characteristics analyzed were the resonant frequency and the radiated sound pressure at a far field of the sensor. The validity of the theoretical analysis was verified by comparing the results with those obtained from the finite element analysis of the same structure. The exact functional forms of the resonant frequency of and the radiated sound pressure from the piezoelectric multilayered structure derived in this study can be directly utilized to maximize the performance of various ultrasonic sensors in air.

Effects of high power ultrasonic vibration on temperature distribution of workpiece in dry creep feed up grinding.

PubMed

Paknejad, Masih; Abdullah, Amir; Azarhoushang, Bahman

2017-11-01

Temperature history and distribution of steel workpiece (X20Cr13) was measured by a high tech infrared camera under ultrasonic assisted dry creep feed up grinding. For this purpose, a special experimental setup was designed and fabricated to vibrate only workpiece along two directions by a high power ultrasonic transducer. In this study, ultrasonic effects with respect to grinding parameters including depth of cut (a e ), feed speed (v w ), and cutting speed (v s ) has been investigated. The results indicate that the ultrasonic vibration has considerable effect on reduction of temperature, depth of thermal damage of workpiece and width of temperature contours. Maximum temperature reduction of 25.91% was reported at condition of v s =15m/s, v w =500mm/min, a e =0.4mm in the presence of ultrasonic vibration. Copyright © 2017 Elsevier B.V. All rights reserved.

On-chip magnetically actuated robot with ultrasonic vibration for single cell manipulations.

PubMed

Hagiwara, Masaya; Kawahara, Tomohiro; Yamanishi, Yoko; Masuda, Taisuke; Feng, Lin; Arai, Fumihito

2011-06-21

This paper presents an innovative driving method for an on-chip robot actuated by permanent magnets in a microfluidic chip. A piezoelectric ceramic is applied to induce ultrasonic vibration to the microfluidic chip and the high-frequency vibration reduces the effective friction on the MMT significantly. As a result, we achieved 1.1 micrometre positioning accuracy of the microrobot, which is 100 times higher accuracy than without vibration. The response speed is also improved and the microrobot can be actuated with a speed of 5.5 mm s(-1) in 3 degrees of freedom. The novelty of the ultrasonic vibration appears in the output force as well. Contrary to the reduction of friction on the microrobot, the output force increased twice as much by the ultrasonic vibration. Using this high accuracy, high speed, and high power microrobot, swine oocyte manipulations are presented in a microfluidic chip.

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

[Effects of ultrasonic pretreatment on drying characteristics of sewage sludge].

PubMed

Li, Run-Dong; Yang, Yu-Ting; Li, Yan-Long; Niu, Hui-Chang; Wei, Li-Hong; Sun, Yang; Ke, Xin

2009-11-01

The high water content of sewage sludge has engendered many inconveniences to its treatment and disposal. While ultrasonic takes on unique advantages on the sludge drying because of its high ultrasonic power, mighty penetrating capability and the ability of causing cavitations. Thus this research studies the characteristics influences of ultrasonic bring to the sludge drying and effects of the exposure time, ultrasonic generator power, temperatures of ultrasonic and drying temperature on the drying characteristics of dewatered sludge. Results indicate that ultrasonic pretreatment could speed up evaporation of the free water in sludge surface and help to end the drying stage with constant speed. In addition, ultrasonic treatment can effectively improve the sludge drying efficiency which could be more evident with the rise of the ultrasonic power (100-250 W), ultrasonic temperature and drying temperature. If dried under low temperature such as 105 degrees C, sludge will have premium drying characteristics when radiated under ultrasound for a shorter time such as 3 min. In the end, the ultrasonic treatment is expected to be an effective way to the low-cost sludge drying and also be an important reference to the optimization of the sludge drying process because of its effects on the increase of sludge drying efficiency.

REDUCED COST SEWER PIPE RELINING USING ULTRASONIC TAPE LAMINATION - PHASE II

EPA Science Inventory

During the Phase I program, Foster-Miller developed techniques based on Ultrasonic Tape Lamination (UTL) for joining of plasticized PVC sewer pipe liner. This effort was undertaken in response to a need for environmentally sound and cost-effective methods for rehabilitation of...

Quantitative ultrasonic testing of acoustically anisotropic materials with verification on austenitic and dissimilar weld joints

NASA Astrophysics Data System (ADS)

Boller, C.; Pudovikov, S.; Bulavinov, A.

2012-05-01

Austenitic stainless steel materials are widely used in a variety of industry sectors. In particular, the material is qualified to meet the design criteria of high quality in safety related applications. For example, the primary loop of the most of the nuclear power plants in the world, due to high durability and corrosion resistance, is made of this material. Certain operating conditions may cause a range of changes in the integrity of the component, and therefore require nondestructive testing at reasonable intervals. These in-service inspections are often performed using ultrasonic techniques, in particular when cracking is of specific concern. However, the coarse, dendritic grain structure of the weld material, formed during the welding process, is extreme and unpredictably anisotropic. Such structure is no longer direction-independent to the ultrasonic wave propagation; therefore, the ultrasonic beam deflects and redirects and the wave front becomes distorted. Thus, the use of conventional ultrasonic testing techniques using fixed beam angles is very limited and the application of ultrasonic Phased Array techniques becomes desirable. The "Sampling Phased Array" technique, invented and developed by Fraunhofer IZFP, allows the acquisition of time signals (A-scans) for each individual transducer element of the array along with fast image reconstruction techniques based on synthetic focusing algorithms. The reconstruction considers the sound propagation from each image pixel to the individual sensor element. For anisotropic media, where the sound beam is deflected and the sound path is not known a-priori, a novel phase adjustment technique called "Reverse Phase Matching" is implemented. By taking into account the anisotropy and inhomogeneity of the weld structure, a ray tracing algorithm for modeling the acoustic wave propagation and calculating the sound propagation time is applied. This technique can be utilized for 2D and 3D real time image reconstruction. The "Gradient Constant Descent Method" (GECDM), an iterative algorithm, is implemented, which is essential for examination of inhomogeneous anisotropic media having unknown properties (elastic constants). The Sampling Phased Array technique with Reverse Phase Matching extended by GECDM-technique determines unknown elastic constants and provides reliable and efficient quantitative flaw detection in the austenitic welds. The validation of ray-tracing algorithm and GECDM-method is performed by number of experiments on test specimens with artificial as well as natural material flaws. A mechanized system for ultrasonic testing of stainless steel and dissimilar welds is developed. The system works on both conventional and Sampling Phased Array techniques. The new frontend ultrasonic unit with optical data link allows the 3D visualization of the inspection results in real time.

Study on the Non-contact Acoustic Inspection Method for Concrete Structures by using Strong Ultrasonic Sound source

NASA Astrophysics Data System (ADS)

Sugimoto, Tsuneyoshi; Uechi, Itsuki; Sugimoto, Kazuko; Utagawa, Noriyuki; Katakura, Kageyoshi

Hammering test is widely used to inspect the defects in concrete structures. However, this method has a major difficulty in inspect at high-places, such as a tunnel ceiling or a bridge girder. Moreover, its detection accuracy is dependent on a tester's experience. Therefore, we study about the non-contact acoustic inspection method of the concrete structure using the air borne sound wave and a laser Doppler vibrometer. In this method, the concrete surface is excited by air-borne sound wave emitted with a long range acoustic device (LRAD), and the vibration velocity on the concrete surface is measured by a laser Doppler vibrometer. A defect part is detected by the same flexural resonance as the hammer method. It is already shown clearly that detection of a defect can be performed from a long distance of 5 m or more using a concrete test object. Moreover, it is shown that a real concrete structure can also be applied. However, when the conventional LRAD was used as a sound source, there were problems, such as restrictions of a measurement angle and the surrounding noise. In order to solve these problems, basic examination which used the strong ultrasonic wave sound source was carried out. In the experiment, the concrete test object which includes an imitation defect from 5-m distance was used. From the experimental result, when the ultrasonic sound source was used, restrictions of a measurement angle become less severe and it was shown that circumference noise also falls dramatically.

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 anechoic chamber qualification: accounting for atmospheric absorption and transducer directivity.

PubMed

Jenny, Trevor; Anderson, Brian E

2011-08-01

Qualifying an anechoic chamber for frequencies that extend into the ultrasonic range is necessary for research work involving airborne ultrasonic sound. The ANSI S12.55/ISO 3745 standard which covers anechoic chamber qualification does not extend into the ultrasonic frequency range, nor have issues pertinent to this frequency range been fully discussed in the literature. An increasing number of technologies employ ultrasound; hence the need for an ultrasonic anechoic chamber. This paper will specifically discuss the need to account for atmospheric absorption and issues pertaining to source transducer directivity by presenting some results for qualification of a chamber at Brigham Young University.

Speed of Sound in Aqueous Solutions at sub-GPa Pressures: a New Experiment to Unveil the Properties of Extra-Terrestrial Oceans

NASA Astrophysics Data System (ADS)

Bollengier, O.; Brown, J. M.; Vance, S.; Shaw, G. H.

2015-12-01

Geophysical data from the Galileo and Cassini-Huygens missions are consistent with the presence of aqueous subsurface oceans in Ganymede, Callisto and Titan, the largest icy satellites of the solar system. To understand the history and present state of these moons, the next generation of evolution models will require an accurate description of the properties of these liquid layers to predict the phase boundaries, heat transports and chemical exchanges within them. Sound speed measurements in pressure and temperature allow for the reconstruction of the Gibbs free energy surface of a phase, which in turn gives access to the desired properties (chemical potential, density, heat capacity...). However, such data are still scarce for aqueous solutions bearing Na+, Mg2+, Cl- and SO42- ions (major ions expected in extra-terrestrial oceans) at the high pressures and low temperatures expected for water inside these moons (up to 1.5 GPa for Ganymede, down to freezing temperatures). For pure water, IAPWS accuracy for sound speeds is given to 0.3% above 0.4 GPa. MgSO4aqueous solutions have been explored to 0.7 GPa with a precision limited to about 0.5%. Most other aqueous solutions bearing any combination of these four ions have not been explored at all above a few hundreds MPa. To acquire new high-precision sound speeds in aqueous solutions of various compositions, we set up a new experimental system working in the 0 - 0.7 GPa pressure range and 240 - 350 K temperature range. The device consists in an oil-pressurized steel vessel enclosing a titanium alloy rod supporting the sample and a sealing bellows. A transducer at the top end of the titanium rod generates ultrasonic waves and collects the series of subsequent reflections. Preliminary tests with pure water illustrate a precision of 0.02% and an accuracy within 0.1% of IAPWS on our whole pressure range. Revision of the properties of pure water and H2O-MgSO4 solutions up to 0.7 GPa along with the first data in the H2O-MgCl2 above 0.1 GPa will be presented, and their implications for the internal structure or large icy moons discussed.

Neuronal encoding of ultrasonic sound by a fish.

PubMed

Plachta, Dennis T T; Song, Jiakun; Halvorsen, Michele B; Popper, Arthur N

2004-06-01

Many species of odontocete cetaceans (toothed whales) use high-frequency clicks (60-170 kHz) to identify objects in their environment, including potential prey. Behavioral studies have shown that American shad, Alosa sapidissima, can detect ultrasonic signals similar to those of odontocetes that are potentially their predators. American shad also show strong escape behavior in response to ultrasonic pulses between 70 and 110 kHz and can determine the location of the sound source at least in the horizontal plane. The present study examines physiological aspects of ultrasound detection by American shad and provides the first insights into the neural encoding of ultrasound signals in any nonmammalian vertebrate. The recordings were obtained by penetration through the cerebellar surface. All but two units responded exclusively to ultrasound. Ultrasound-sensitive units did not phase-couple to any stimulus frequency. Some units resembled the response of constant latency neurons found in the ventral nucleus of the lateral lemniscus of bats. We suggest that ultrasonic and sonic signals are processed along different pathways in Alosa. The ultrasonic pathway in Alosa appears to be a feature detector that is likely to be adapted (e.g., frequency, intensity) to odontocete echolocation signals.

Auditory and Subjective Effects of Airborne Noise from Industrial Ultrasonic Sources

PubMed Central

Acton, W. I.; Carson, M. B.

1967-01-01

This investigation was undertaken primarily to examine the possibility of hearing damage from industrial ultrasonic equipment. In the factory concerned, ultrasonic washers and drills were used at a number of different locations, and girls working 12 ft (3·6 m.) away from one bank of three small washers complained of unpleasant subjective effects which included fatigue, persistent headaches, nausea, and tinnitus. As personnel working in the vicinity of similar washers in other parts of the factory did not complain of these effects, it seemed possible that the noise had been transmitted along a column of air in a bank of dryboxes. Enclosure of these washers by a sliding screen of Perspex had completely abated the trouble. Sound pressure level measurements taken in the positions occupied by the operators indicated that, when the effects occur, they are probably caused by high sound levels at the upper audio-frequencies present with the ultrasonic noise, and this was supported by a limited laboratory investigation. Audiometric investigation showed that hearing damage due to noise from these industrial ultrasonic devices is unlikely. However, extrapolations of currently accepted hearing damage risk criteria may be valid in predicting the occurrence of these subjective effects. Images PMID:6073088

The Design of Artificial Intelligence Robot Based on Fuzzy Logic Controller Algorithm

NASA Astrophysics Data System (ADS)

Zuhrie, M. S.; Munoto; Hariadi, E.; Muslim, S.

2018-04-01

Artificial Intelligence Robot is a wheeled robot driven by a DC motor that moves along the wall using an ultrasonic sensor as a detector of obstacles. This study uses ultrasonic sensors HC-SR04 to measure the distance between the robot with the wall based ultrasonic wave. This robot uses Fuzzy Logic Controller to adjust the speed of DC motor. When the ultrasonic sensor detects a certain distance, sensor data is processed on ATmega8 then the data goes to ATmega16. From ATmega16, sensor data is calculated based on Fuzzy rules to drive DC motor speed. The program used to adjust the speed of a DC motor is CVAVR program (Code Vision AVR). The readable distance of ultrasonic sensor is 3 cm to 250 cm with response time 0.5 s. Testing of robots on walls with a setpoint value of 9 cm to 10 cm produce an average error value of -12% on the wall of L, -8% on T walls, -8% on U wall, and -1% in square wall.

An Analysis of Peak Wind Speed Data from Collocated Mechanical and Ultrasonic Anemometers

NASA Technical Reports Server (NTRS)

Short, David A.; Wells, Leonard; Merceret, Francis J.; Roeder, William P.

2007-01-01

This study compared peak wind speeds reported by mechanical and ultrasonic anemometers at Cape Canaveral Air Force Station and Kennedy Space Center (CCAFS/KSC) on the east central coast of Florida and Vandenberg Air Force Base (VAFB) on the central coast of California. Launch Weather Officers, forecasters, and Range Safety analysts need to understand the performance of wind sensors at CCAFS/KSC and VAFB for weather warnings, watches, advisories, special ground processing operations, launch pad exposure forecasts, user Launch Commit Criteria (LCC) forecasts and evaluations, and toxic dispersion support. The legacy CCAFS/KSC and VAFB weather tower wind instruments are being changed from propeller-and-vane (CCAFS/KSC) and cup-and-vane (VAFB) sensors to ultrasonic sensors under the Range Standardization and Automation (RSA) program. Mechanical and ultrasonic wind measuring techniques are known to cause differences in the statistics of peak wind speed as shown in previous studies. The 45th Weather Squadron (45 WS) and the 30th Weather Squadron (30 WS) requested the Applied Meteorology Unit (AMU) to compare data between the RSA ultrasonic and legacy mechanical sensors to determine if there are significant differences. Note that the instruments were sited outdoors under naturally varying conditions and that this comparison was not designed to verify either technology. Approximately 3 weeks of mechanical and ultrasonic wind data from each range from May and June 2005 were used in this study. The CCAFS/KSC data spanned the full diurnal cycle, while the VAFB data were confined to 1000-1600 local time. The sample of 1-minute data from numerous levels on five different towers on each range totaled more than 500,000 minutes of data (482,979 minutes of data after quality control). The ten towers were instrumented at several levels, ranging from 12 ft to 492 ft above ground level. The ultrasonic sensors were collocated at the same vertical levels as the mechanical sensors and typically within 15 ft horizontally of each another. Data from a total of 53 RSA ultrasonic sensors, collocated with mechanical sensors were compared. The 1- minute average wind speed/direction and the 1-second peak wind speed/direction were compared.

Non-destructive evaluation techniques, high temperature ceramic component parts for gas turbines

NASA Technical Reports Server (NTRS)

Reiter, H.; Hirsekorn, S.; Lottermoser, J.; Goebbels, K.

1984-01-01

This report concerns studies conducted on various tests undertaken on material without destroying the material. Tests included: microradiographic techniques, vibration analysis, high-frequency ultrasonic tests with the addition of evaluation of defects and structure through analysis of ultrasonic scattering data, microwave tests and analysis of sound emission.

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.

Characterization of the acoustic field generated by a horn shaped ultrasonic transducer

NASA Astrophysics Data System (ADS)

Hu, B.; Lerch, J. E.; Chavan, A. H.; Weber, J. K. R.; Tamalonis, A.; Suthar, K. J.; DiChiara, A. D.

2017-09-01

A horn shaped Langevin ultrasonic transducer used in a single axis levitator was characterized to better understand the role of the acoustic profile in establishing stable traps. The method of characterization included acoustic beam profiling performed by raster scanning an ultrasonic microphone as well as finite element analysis of the horn and its interface with the surrounding air volume. The results of the model are in good agreement with measurements and demonstrate the validity of the approach for both near and far field analyses. Our results show that this style of transducer produces a strong acoustic beam with a total divergence angle of 10°, a near-field point close to the transducer surface and a virtual sound source. These are desirable characteristics for a sound source used for acoustic trapping experiments.

Characterization of the acoustic field generated by a horn shaped ultrasonic transducer

DOE PAGES

Hu, B.; Lerch, J. E.; Chavan, A. H.; ...

2017-09-04

A horn shaped Langevin ultrasonic transducer used in a single axis levitator was characterized to better understand the role of the acoustic profile in establishing stable traps. The method of characterization included acoustic beam profiling performed by raster scanning an ultrasonic microphone as well as finite element analysis of the horn and its interface with the surrounding air volume. The results of the model are in good agreement with measurements and demonstrate the validity of the approach for both near and far field analysis. Our results show that this style of transducer produces a strong acoustic beam with a totalmore » divergence angle of 10 degrees, a nearfield point close to the transducer surface and a virtual sound source. These are desirable characteristics for a sound source used for acoustic trapping experiments.« less

Characterization of the acoustic field generated by a horn shaped ultrasonic transducer

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

Hu, B.; Lerch, J. E.; Chavan, A. H.

A horn shaped Langevin ultrasonic transducer used in a single axis levitator was characterized to better understand the role of the acoustic profile in establishing stable traps. The method of characterization included acoustic beam profiling performed by raster scanning an ultrasonic microphone as well as finite element analysis of the horn and its interface with the surrounding air volume. The results of the model are in good agreement with measurements and demonstrate the validity of the approach for both near and far field analyses. Our results show that this style of transducer produces a strong acoustic beam with a totalmore » divergence angle of 10 degree, a near-field point close to the transducer surface and a virtual sound source. These are desirable characteristics for a sound source used for acoustic trapping experiments« less

Characterization of the acoustic field generated by a horn shaped ultrasonic transducer

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

Hu, B.; Lerch, J. E.; Chavan, A. H.

A horn shaped Langevin ultrasonic transducer used in a single axis levitator was characterized to better understand the role of the acoustic profile in establishing stable traps. The method of characterization included acoustic beam profiling performed by raster scanning an ultrasonic microphone as well as finite element analysis of the horn and its interface with the surrounding air volume. The results of the model are in good agreement with measurements and demonstrate the validity of the approach for both near and far field analysis. Our results show that this style of transducer produces a strong acoustic beam with a totalmore » divergence angle of 10 degrees, a nearfield point close to the transducer surface and a virtual sound source. These are desirable characteristics for a sound source used for acoustic trapping experiments.« less

Coupling apparatus for ultrasonic medical diagnostic system

NASA Technical Reports Server (NTRS)

Frazer, R. E. (Inventor)

1978-01-01

An apparatus for the ultrasonic scanning of a breast or other tissue is reported that contains a cavity for receiving the breast, a vacuum for drawing the breast into intimate contact with the walls of the cavity, and transducers coupled through a fluid to the cavity to transmit sound waves through the breast. Each transducer lies at the end of a tapered chamber which has flexible walls and which is filled with fluid, so that the transducer can be moved in a raster pattern while the chamber walls flex accordingly, with sound transmission always occurring through the fluid.

Ultrasonic Bat Deterrent Technology

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

Kinzie, Kevin; Rominger, Kathryn M.

The project objective was to advance the development and testing of an Near commercial bat-deterrent system with a goal to increase the current GE deterrent system effectiveness to over 50% with broad species applicability. Additionally, the research supported by this program has provided insights into bat behavior and ultrasonic deterrent design that had not previously been explored. Prior research and development had demonstrated the effectiveness of a commercial-grade, air-powered, ultrasonic bat deterrent to be between 30-50% depending upon the species of bat. However, the previous research provided limited insight into the behavioral responses of bats in the presence of ultrasonicmore » deterrent sound fields that could be utilized to improve effectiveness. A unique bat flight room was utilized to observe the behavioral characteristics of bats in the presence of ultrasonic sound fields. Behavioral testing in the bat flight facility demonstrated that ultrasonic sounds similar to those produced by the GE deterrent influenced the activities and behaviors, primarily those associated with foraging, of the species exposed. The study also indicated that continuous and pulsing ultrasonic signals had a similar effect on the bats, and confirmed that as ultrasonic sounds attenuate, their influence on the bats’ activities and behavior decreases. Ground testing at Wolf Ridge Wind, LLC and Shawnee National Forest assessed both continuous and pulsing deterrent signals emitted from the GE deterrent system and further enhanced the behavioral understanding of bats in the presence of the deterrent. With these data and observations, the existing 4-nozzle continuous, or steady, emission ultrasonic system was redesigned to a 6-nozzle system that could emit a pulsing signal covering a larger air space around a turbine. Twelve GE 1.6-100 turbines were outfitted with the deterrent system and a formal three-month field study was performed using daily carcass searches beneath the 12 turbines. Additionally, a unique 3D bat flight path visualization system was utilized to monitor for and identify any changes in bat activity caused by the operation of the deterrent system. Both the carcass search and flight path visualization data indicated that the pulsed deterrent system was effective, but not more effective, than the steady system tested in prior years. The pulsed deterrent system was effective at reducing bat fatalities by 38% for all species and 54% effective at reducing fatalities if Eastern Red bats were excluded from the data. However, an unanticipated byproduct of the pulsing system was the emission of intermittent water vapor from the deterrent devices due to the air compression process that powered the devices. This water vapor may have altered the ultrasonic signal and obscured the results in an unknown way. While a qualitative analysis of the effect of the water vapor on the deterrent signal had indicated there was not dramatic change in the expected ultrasonic signal, it was not possible to conclusively determine if the pulse signal would have been more effective in the absence of the water vapor.« less

Criteria for the selection of focusing ultrasonic probes

NASA Technical Reports Server (NTRS)

Schlengermann, U.

1978-01-01

The principles of operation employed in the focusing of a sound field are considered, taking into account the use of solid and liquid coupling media. The focusing limits for a given transducer are investigated. As a diffraction phenomenon, focusing is a function of the system dimensions, the frequency, and the sound velocity. The frequency and the material used for the lenses are in most cases determined in accordance with considerations regarding sound propagation. Changes in the focus are therefore effected mainly by the selection of transducer and lens dimensions. The functions of the focusing factor for a normal immersion probe and a direct contact angle probe are represented in graphs. The deviation of the appropriate parametric values for an ultrasonic probe is illustrated with the aid of examples.

Determining the Time of Flight and Speed of Sound on Different types of Edible Oil

NASA Astrophysics Data System (ADS)

Azman, N. A.; Hamid, S. B. Abd

2017-11-01

Edible oil is most often plant-based oils that have been extracted from various seeds. There are cases where the fully virgin edible oil was found to be a fraud. The adulterated edible oil indicates the intentional, fraudulent addition of extraneous, improper or cheaper ingredients puts into the oil or the dilution or removal of some valuable ingredient of the oil in order to increase profits. Hence, decrease the reliability of the Malaysian food product quality. This research was done by using the method of time of flight obtained using the Texas Instrument board, TDC1000-TDC7200 EVM connected to an ultrasonic transducer with 1 MHz frequency. The authors measured the time of flight and temperatures controlled from 20°C to 40°C of five vegetable oils (olive oil, sunflower oil, corn oil, coconut oil, and mustard oil). The value is observed and compared with other research from the literature review. From the study, time of flight values decreases exponentially while speed of sound value increases. This relationship will be useful in spectrum unfolding method to investigate the adulteration in different type of edible oil.This research outcome is to investigate the quality value of the different type of edible oil while eliminates the issues where the quality of Malaysian food product is not reliable.

Ultrasonically Encoded Photoacoustic Flowgraphy in Biological Tissue

NASA Astrophysics Data System (ADS)

Wang, Lidai; Xia, Jun; Yao, Junjie; Maslov, Konstantin I.; Wang, Lihong V.

2013-11-01

Blood flow speed is an important functional parameter. Doppler ultrasound flowmetry lacks sufficient sensitivity to slow blood flow (several to tens of millimeters per second) in deep tissue. To address this challenge, we developed ultrasonically encoded photoacoustic flowgraphy combining ultrasonic thermal tagging with photoacoustic imaging. Focused ultrasound generates a confined heat source in acoustically absorptive fluid. Thermal waves propagate with the flow and are directly visualized in pseudo color using photoacoustic computed tomography. The Doppler shift is employed to calculate the flow speed. This method requires only acoustic and optical absorption, and thus is applicable to continuous fluid. A blood flow speed as low as 0.24mm·s-1 was successfully measured. Deep blood flow imaging was experimentally demonstrated under 5-mm-thick chicken breast tissue.

Ultrasonic airborne insertion loss measurements at normal incidence (L).

PubMed

Farley, Jayrin; Anderson, Brian E

2010-12-01

Transmission loss and insertion loss measurements of building materials at audible frequencies are commonly made using plane wave tubes or as a panel between reverberant rooms. These measurements provide information for noise isolation control in architectural acoustics and in product development. Airborne ultrasonic sound transmission through common building materials has not been fully explored. Technologies and products that utilize ultrasonic frequencies are becoming increasingly more common, hence the need to conduct such measurements. This letter presents preliminary measurements of the ultrasonic insertion loss levels for common building materials over a frequency range of 28-90 kHz using continuous-wave excitation.

Ultrasonic whistles of killer whales (Orcinus orca) recorded in the North Pacific (L).

PubMed

Filatova, Olga A; Ford, John K B; Matkin, Craig O; Barrett-Lennard, Lance G; Burdin, Alexander M; Hoyt, Erich

2012-12-01

Ultrasonic whistles were previously found in North Atlantic killer whales and were suggested to occur in eastern North Pacific killer whales based on the data from autonomous recorders. In this study ultrasonic whistles were found in the recordings from two encounters with the eastern North Pacific offshore ecotype killer whales and one encounter with the western North Pacific killer whales of unknown ecotype. All ultrasonic whistles were highly stereotyped and all but two had downsweep contours. These results demonstrate that specific sound categories can be shared by killer whales from different ocean basins.

Determinants of the reliability of ultrasound tomography sound speed estimates as a surrogate for volumetric breast density

PubMed Central

Khodr, Zeina G.; Sak, Mark A.; Pfeiffer, Ruth M.; Duric, Nebojsa; Littrup, Peter; Bey-Knight, Lisa; Ali, Haythem; Vallieres, Patricia; Sherman, Mark E.; Gierach, Gretchen L.

2015-01-01

Purpose: High breast density, as measured by mammography, is associated with increased breast cancer risk, but standard methods of assessment have limitations including 2D representation of breast tissue, distortion due to breast compression, and use of ionizing radiation. Ultrasound tomography (UST) is a novel imaging method that averts these limitations and uses sound speed measures rather than x-ray imaging to estimate breast density. The authors evaluated the reproducibility of measures of speed of sound and changes in this parameter using UST. Methods: One experienced and five newly trained raters measured sound speed in serial UST scans for 22 women (two scans per person) to assess inter-rater reliability. Intrarater reliability was assessed for four raters. A random effects model was used to calculate the percent variation in sound speed and change in sound speed attributable to subject, scan, rater, and repeat reads. The authors estimated the intraclass correlation coefficients (ICCs) for these measures based on data from the authors’ experienced rater. Results: Median (range) time between baseline and follow-up UST scans was five (1–13) months. Contributions of factors to sound speed variance were differences between subjects (86.0%), baseline versus follow-up scans (7.5%), inter-rater evaluations (1.1%), and intrarater reproducibility (∼0%). When evaluating change in sound speed between scans, 2.7% and ∼0% of variation were attributed to inter- and intrarater variation, respectively. For the experienced rater’s repeat reads, agreement for sound speed was excellent (ICC = 93.4%) and for change in sound speed substantial (ICC = 70.4%), indicating very good reproducibility of these measures. Conclusions: UST provided highly reproducible sound speed measurements, which reflect breast density, suggesting that UST has utility in sensitively assessing change in density. PMID:26429241

Determinants of the reliability of ultrasound tomography sound speed estimates as a surrogate for volumetric breast density

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

Khodr, Zeina G.; Pfeiffer, Ruth M.; Gierach, Gretchen L., E-mail: GierachG@mail.nih.gov

Purpose: High breast density, as measured by mammography, is associated with increased breast cancer risk, but standard methods of assessment have limitations including 2D representation of breast tissue, distortion due to breast compression, and use of ionizing radiation. Ultrasound tomography (UST) is a novel imaging method that averts these limitations and uses sound speed measures rather than x-ray imaging to estimate breast density. The authors evaluated the reproducibility of measures of speed of sound and changes in this parameter using UST. Methods: One experienced and five newly trained raters measured sound speed in serial UST scans for 22 women (twomore » scans per person) to assess inter-rater reliability. Intrarater reliability was assessed for four raters. A random effects model was used to calculate the percent variation in sound speed and change in sound speed attributable to subject, scan, rater, and repeat reads. The authors estimated the intraclass correlation coefficients (ICCs) for these measures based on data from the authors’ experienced rater. Results: Median (range) time between baseline and follow-up UST scans was five (1–13) months. Contributions of factors to sound speed variance were differences between subjects (86.0%), baseline versus follow-up scans (7.5%), inter-rater evaluations (1.1%), and intrarater reproducibility (∼0%). When evaluating change in sound speed between scans, 2.7% and ∼0% of variation were attributed to inter- and intrarater variation, respectively. For the experienced rater’s repeat reads, agreement for sound speed was excellent (ICC = 93.4%) and for change in sound speed substantial (ICC = 70.4%), indicating very good reproducibility of these measures. Conclusions: UST provided highly reproducible sound speed measurements, which reflect breast density, suggesting that UST has utility in sensitively assessing change in density.« less

Non-Contact Ultrasonic Imaging

DTIC Science & Technology

2016-10-31

difficult to measure because of the amount of sound at the difference frequency still produced in the air. Nonlinear Reflection off of a Curved Surface...separate sound generated in air from sound generated in liquid. Two incoming rays incident upon a curved surface may reflect collinearly. At a different... sound reflecting off of the air-water interface from the air, the energy density of the incident and reflected waves are around 1000x that of the

Laboratory Assessment of Commercially Available Ultrasonic Rangefinders

DTIC Science & Technology

2015-11-01

how the room was designed to prevent sound reflections (a combination of the wedges absorbing the waveforms and not having a flat wall ). When testing... sound booth at 0.5 m. ...................................................................................... 5  iv This page is intentionally...environments for sound measurements using a tape measure. This mapping method can be time- consuming and unreliable as objects frequently move around in

Ultrasonic control of ceramic membrane fouling: Effect of particle characteristics.

PubMed

Chen, Dong; Weavers, Linda K; Walker, Harold W

2006-02-01

In this study, the effect of particle characteristics on the ultrasonic control of membrane fouling was investigated. Ultrasound at 20 kHz was applied to a cross-flow filtration system with gamma-alumina membranes in the presence of colloidal silica particles. Experimental results indicated that particle concentration affected the ability of ultrasound to control membrane fouling, with less effective control of fouling at higher particle concentrations. Measurements of sound wave intensity and images of the cavitation region indicated that particles induced additional cavitation bubbles near the ultrasonic source, which resulted in less turbulence reaching the membrane surface and subsequently less effective control of fouling. When silica particles were modified to be hydrophobic, greater inducement of cavitation bubbles near the ultrasonic source occurred for a fixed concentration, also resulting in less effective control of fouling. Particle size influenced the cleaning ability of ultrasound, with better permeate recovery observed with larger particles. Particle size did not affect sound wave intensity, suggesting that the more effective control of fouling by large particles was due to greater lift and cross-flow drag forces on larger particles compared to smaller particles.

Plate Wave Resonance with Air-Coupled Ultrasonics

NASA Astrophysics Data System (ADS)

Bar, H. N.; Dayal, V.; Barnard, D.; Hsu, D. K.

2010-02-01

Air-coupled ultrasonic transducers can excite plate waves in metals and composites. The coincidence effect, i.e., the wave vector of plate wave coincides with projection of exciting airborne sound vector, leads to a resonance which strongly amplifies the sound transmission through the plate. The resonance depends on the angle of incidence and the frequency. In the present study, the incidence angle for maximum transmission (θmax) is measured in plates of steel, aluminum, carbon fiber reinforced composites and honeycomb sandwich panels. The variations of (θmax) with plate thickness are compared with theoretical values in steel, aluminum and quasi-isotropic carbon fiber composites. The enhanced transmission of air-coupled ultrasound at oblique incidence can substantially improve the probability of flaw detection in plates and especially in honeycomb structures. Experimental air-coupled ultrasonic scan of subtle flaws in CFRP laminates showed definite improvement of signal-to-noise ratio with oblique incidence at θmax.

Ultrasonic wave based pressure measurement in small diameter pipeline.

PubMed

Wang, Dan; Song, Zhengxiang; Wu, Yuan; Jiang, Yuan

2015-12-01

An effective non-intrusive method of ultrasound-based technique that allows monitoring liquid pressure in small diameter pipeline (less than 10mm) is presented in this paper. Ultrasonic wave could penetrate medium, through the acquisition of representative information from the echoes, properties of medium can be reflected. This pressure measurement is difficult due to that echoes' information is not easy to obtain in small diameter pipeline. The proposed method is a study on pipeline with Kneser liquid and is based on the principle that the transmission speed of ultrasonic wave in pipeline liquid correlates with liquid pressure and transmission speed of ultrasonic wave in pipeline liquid is reflected through ultrasonic propagation time providing that acoustic distance is fixed. Therefore, variation of ultrasonic propagation time can reflect variation of pressure in pipeline. Ultrasonic propagation time is obtained by electric processing approach and is accurately measured to nanosecond through high resolution time measurement module. We used ultrasonic propagation time difference to reflect actual pressure in this paper to reduce the environmental influences. The corresponding pressure values are finally obtained by acquiring the relationship between variation of ultrasonic propagation time difference and pressure with the use of neural network analysis method, the results show that this method is accurate and can be used in practice. Copyright © 2015 Elsevier B.V. All rights reserved.

Testing Accuracy of Long-Range Ultrasonic Sensors for Olive Tree Canopy Measurements

PubMed Central

Gamarra-Diezma, Juan Luis; Miranda-Fuentes, Antonio; Llorens, Jordi; Cuenca, Andrés; Blanco-Roldán, Gregorio L.; Rodríguez-Lizana, Antonio

2015-01-01

Ultrasonic sensors are often used to adjust spray volume by allowing the calculation of the crown volume of tree crops. The special conditions of the olive tree require the use of long-range sensors, which are less accurate and faster than the most commonly used sensors. The main objectives of the study were to determine the suitability of the sensor in terms of sound cone determination, angle errors, crosstalk errors and field measurements. Different laboratory tests were performed to check the suitability of a commercial long-range ultrasonic sensor, as were the experimental determination of the sound cone diameter at several distances for several target materials, the determination of the influence of the angle of incidence of the sound wave on the target and distance on the accuracy of measurements for several materials and the determination of the importance of the errors due to interference between sensors for different sensor spacings and distances for two different materials. Furthermore, sensor accuracy was tested under real field conditions. The results show that the studied sensor is appropriate for olive trees because the sound cone is narrower for an olive tree than for the other studied materials, the olive tree canopy does not have a large influence on the sensor accuracy with respect to distance and angle, the interference errors are insignificant for high sensor spacings and the sensor's field distance measurements were deemed sufficiently accurate. PMID:25635414

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

Effects of ultrasonic instrumentation on enamel surfaces with various defects.

PubMed

Kim, S-Y; Kang, M-K; Kang, S-M; Kim, H-E

2018-05-01

The aim of this study was to analyse the enamel damage caused by ultrasonic scaling of teeth with various enamel conditions that are difficult to identify by visual inspection, such as enamel cracks, early caries and resin restorations. In total, 120 tooth surfaces were divided into 4 experimental groups using a quantitative light-induced fluorescence-digital system: sound enamel group, enamel cracks group, early caries group and resin restoration group. A skilled dental hygienist performed ultrasonic scaling under a standardized set of conditions: a ≤ 15° angle between the scaler tip and tooth surface and 40-80 g of lateral pressure at the rate of 12 times/10 s. Following scaling, the depth of enamel damage was measured using a surface profilometer and observed using scanning electron microscopy (SEM). The damage depth was the greatest in the enamel cracks group (37.63 ± 34.42 μm), followed by the early caries group (26.81 ± 8.67 μm), resin restoration group (19.63 ± 6.73 μm) and the sound enamel group (17.00 ± 5.66 μm). The damage depth was significantly deeper in the enamel cracks and early caries groups than in the sound enamel group (P < .05). SEM clearly revealed enamel loss in the enamel cracks, early caries and resin restoration groups. The results of this study suggest that ultrasonic scaling can cause further damage to teeth with enamel cracks, early caries and resin restorations. Therefore, accurate identification of tooth conditions and calculus before the initiation of ultrasonic scaling is necessary to minimize damage. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Comparison of sound speed measurements on two different ultrasound tomography devices

NASA Astrophysics Data System (ADS)

Sak, Mark; Duric, Neb; Littrup, Peter; Bey-Knight, Lisa; Sherman, Mark; Gierach, Gretchen; Malyarenko, Antonina

2014-03-01

Ultrasound tomography (UST) employs sound waves to produce three-dimensional images of breast tissue and precisely measures the attenuation of sound speed secondary to breast tissue composition. High breast density is a strong breast cancer risk factor and sound speed is directly proportional to breast density. UST provides a quantitative measure of breast density based on three-dimensional imaging without compression, thereby overcoming the shortcomings of many other imaging modalities. The quantitative nature of the UST breast density measures are tied to an external standard, so sound speed measurement in breast tissue should be independent of specific hardware. The work presented here compares breast sound speed measurement obtained with two different UST devices. The Computerized Ultrasound Risk Evaluation (CURE) system located at the Karmanos Cancer Institute in Detroit, Michigan was recently replaced with the SoftVue ultrasound tomographic device. Ongoing clinical trials have used images generated from both sets of hardware, so maintaining consistency in sound speed measurements is important. During an overlap period when both systems were in the same exam room, a total of 12 patients had one or both of their breasts imaged on both systems on the same day. There were 22 sound speed scans analyzed from each system and the average breast sound speeds were compared. Images were either reconstructed using saved raw data (for both CURE and SoftVue) or were created during the image acquisition (saved in DICOM format for SoftVue scans only). The sound speed measurements from each system were strongly and positively correlated with each other. The average difference in sound speed between the two sets of data was on the order of 1-2 m/s and this result was not statistically significant. The only sets of images that showed a statistical difference were the DICOM images created during the SoftVue scan compared to the SoftVue images reconstructed from the raw data. However, the discrepancy between the sound speed values could be easily handled by uniformly increasing the DICOM sound speed by approximately 0.5 m/s. These results suggest that there is no fundamental difference in sound speed measurement for the two systems and support combining data generated with these instruments in future studies.

Transcranial Propagation with an Ultrasonic Mono-element Focused Transducer

NASA Astrophysics Data System (ADS)

Iglesias, P. C.; Jiménez, N.; Konofagou, E.; Camarena, F.; Redondo, J.

Focused Ultrasound is the only truly transient, local and non-invasive technique able to induce safe Blood-Brain Barrier Opening (BBBO), technique used in Parkinson or Alzheimer diseases research. However, the presence of the skull in the path usually affects the focus characteristics (gain, beam width, shape and maxima location). In this work, transcranial acoustic wave propagation generated by a mono-element focused transducer has been modeled using 2D and 3D FDTD methods. Skull structure of the non-human primate under test can be compared in terms of density and sound speed with polymethylmethacrylate (PMMA) films. Then, focus aberration and the phenomena that cause it are characterized, providing a better control of the beam focus using the BBBO technique. Results throw that focal axial displacements are constant with the angle of incidence for PMMA flat films. In normal incidence, a shift of 6 mm is given for axial displacement in the 2D transcranial propagation. Moreover, if the skull geometry under the action of the ultrasonic beam can be compared with the curvature radius of the transducer, displacements should be constant with angle independency, like those seeing in the homogenous flat films with the same thickness.

Solute-solvent interactions in 2,4-dihydroxyacetophenone isonicotinoylhydrazone solutions in N, N-dimethylformamide and dimethyl sulfoxide at 298-313 K on ultrasonic and viscometric data

NASA Astrophysics Data System (ADS)

Dikkar, A. B.; Pethe, G. B.; Aswar, A. S.

2016-02-01

The speed of sound ( u), density (ρ), and viscosity (η) of 2,4-dihydroxyacetophenone isonicotinoylhydrazone (DHAIH) have been measured in N, N-dimethyl formamide and dimethyl sulfoxide at equidistance temperatures 298.15, 303.15, 308.15, and 313.15 K. These data were used to calculate some important ultrasonic and thermodynamic parameters such as apparent molar volume ( V ϕ s st ), apparent molar compressibility ( K ϕ), partial molar volume ( V ϕ 0 ) and partial molar compressibility ( K ϕ 0 ), were estimated by using the values of ( V ϕ 0 ) and ( K ϕ), at infinite dilution. Partial molar expansion at infinite dilution, (ϕ E 0 ) has also been calculated from temperature dependence of partial molar volume V ϕ 0 . The viscosity data have been analyzed using the Jones-Dole equation, and the viscosity, B coefficients are calculated. The activation free energy has been calculated from B coefficients and partial molar volume data. The results have been discussed in the term of solute-solvent interaction occurring in solutions and it was found that DHAIH acts as a structure maker in present systems.

Non-destructive ultrasonic measurements of case depth. [in steel

NASA Technical Reports Server (NTRS)

Flambard, C.; Lambert, A.

1978-01-01

Two ultrasonic methods for nondestructive measurements of the depth of a case-hardened layer in steel are described. One method involves analysis of ultrasonic waves diffused back from the bulk of the workpiece. The other method involves finding the speed of propagation of ultrasonic waves launched on the surface of the work. Procedures followed in the two methods for measuring case depth are described.

Speed of sound in muscle for use in sonomicrometry.

PubMed

Marsh, Richard L

2016-12-08

Converting ultrasound transit time into a measure of distance when using sonomicrometry requires that the speed of sound be known. A number of different values for the speed of sound in muscle have been assumed in studies of skeletal and cardiac muscle, and in some cases the effect of temperature has been ignored. The speed of ultrasound with frequencies greater than 1MHz in skeletal and cardiac muscle is briefly reviewed, including the effects of temperature and contractile state. A simplified equation for the speed of sound in pure water is presented for the temperature range from 0-50°C. This equation can be used when calibrating sonomicrometer transducers in water. The data available indicate that the speed of sound in both cardiac and skeletal muscle can be approximated by multiplying the speed of sound in pure water at the measurement temperature by 1.045. Differences in the speed of sound in the longitudinal and transverse directions and changes with contractile state appear to be small and in most cases can probably be safely ignored. The normal variation in muscle composition does not greatly affect the speed of ultrasound in muscle, but investigators placing sonomicrometer transducers near tendons should be conscious of the much greater speed of sound in tendon and variation with loading. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparison of superficial digital flexor tendon loading on asphalt and sand in horses at the walk and trot.

PubMed

Crevier-Denoix, N; Ravary-Plumioën, B; Vergari, C; Camus, M; Holden-Douilly, L; Falala, S; Jerbi, H; Desquilbet, L; Chateau, H; Denoix, J-M; Pourcelot, P

2013-12-01

The incidence of superficial digital flexor tendon (SDFT) injuries is one of the highest of all equine musculoskeletal conditions. Horses with SDFT injuries commonly show no improvement of lameness on soft ground, unlike those suffering from distal bone or joint lesions. The aim of this study was to compare the SDFT loading in five horses at the walk and trot on asphalt and sand using a non-invasive ultrasonic tendon force measurement device. Three horses were equipped with the ultrasonic device, whereas the other two horses were equipped with the ultrasonic device and a dynamometric horseshoe (DHS); the DHS was used to calibrate the measured values of tendon speed of sound (SOS) converted to tendon force, while a previously established ground reaction force pattern was used to calibrate SOS measurements for the other three horses. Although the horses tended to be slower on S, maximal tendon force was higher on sand than on asphalt at the trot (+6%); there was no significant difference between the two surfaces at the walk. The duration of tendon loading was longer on S (+5%) and the area under the tendon force-time curve was larger on S (+10%) at both walk and trot. SDFT loading is significantly affected by the ground surface and the observed increase in SDFT loading on sand compared with asphalt is consistent with clinical observations in horses with SDFT injuries. Copyright © 2013. Published by Elsevier Ltd.

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.

Influence of ultrasonic sound on physico-mechanical characteristics of titanium alloys

NASA Astrophysics Data System (ADS)

Akushskaya, O. M.; Papsheva, N. D.

2018-03-01

The paper presents data on the influence of ultrasonic vibrations on the main physico-mechanical characteristics in the hardening of titanium alloys. Hardening was carried out during rolling and using free balls in a special working chamber with the imposition of ultrasonic vibrations. The studies have shown that ultrasonic hardening of titanium alloys promotes crushing blocks of mosaic and the formation of a fine-grain structure with a high density of dislocations, changes the phase composition of the surface layer and causes the formation of compressive residual stresses. At the same time, technological heredity is practically not manifested. The endurance range of titanium alloys increases.

Imaging and analysis of individual cavitation microbubbles around dental ultrasonic scalers.

PubMed

Vyas, N; Dehghani, H; Sammons, R L; Wang, Q X; Leppinen, D M; Walmsley, A D

2017-11-01

Cavitation is a potentially effective and less damaging method of removing biofilm from biomaterial surfaces. The aim of this study is to characterise individual microbubbles around ultrasonic scaler tips using high speed imaging and image processing. This information will provide improved understanding on the disruption of dental biofilm and give insights into how the instruments can be optimised for ultrasonic cleaning. Individual cavitation microbubbles around ultrasonic scalers were analysed using high speed recordings up to a million frames per second with image processing of the bubble movement. The radius and rate of bubble growth together with the collapse was calculated by tracking multiple points on bubbles over time. The tracking method to determine bubble speed demonstrated good inter-rater reliability (intra class correlation coefficient: 0.993) and can therefore be a useful method to apply in future studies. The bubble speed increased over its oscillation cycle and a maximum of 27ms -1 was recorded during the collapse phase. The maximum bubble radii ranged from 40 to 80μm. Bubble growth was observed when the ultrasonic scaler tip receded from an area and similarly bubble collapse was observed when the tip moved towards an area, corresponding to locations of low pressure around the scaler tip. Previous work shows that this cavitation is involved in biofilm removal. Future experimental work can be based on these findings by using the protocols developed to experimentally analyse cavitation around various clinical instruments and comparing with theoretical calculations. This will help to determine the main cleaning mechanisms of cavitation and how clinical instruments such as ultrasonic scalers can be optimised. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Using speed of sound imaging to characterize breast density

PubMed Central

Sak, Mark; Duric, Neb; Littrup, Peter; Bey-Knight, Lisa; Ali, Haythem; Vallieres, Patricia; Sherman, Mark E.; Gierach, Gretchen L.

2017-01-01

A population of 165 women with negative mammographic screens also received an ultrasound tomography (UST) exam at the Karmanos Cancer Institute (KCI) in Detroit, MI. Standard statistical techniques were employed to measure the associations between the various mammographic and UST related density measures and various participant characteristics such as age, weight and height. The Mammographic percent density (MPD) was found to have similar strength associations with UST mean sound speed (Spearman coefficient, rs = 0.722, p < 0.001) and UST median sound speed (rs = 0.737, p < 0.001). Both were stronger than the associations between MPD with two separate measures of UST percent density, a k-means (rs = 0.568, p < 0.001) or a threshold (rs = 0.715, p < 0.001) measure. Segmentation of the UST sound speed images into dense and non-dense volumes showed weak to moderate associations with the mammographically equivalent measures. Relationships were found to be inversely and weakly associated between age and the UST mean sound speed (rs = −0.239, p = 0.002), UST median sound speed (rs = −0.226, p= 0.004) and MPD (rs = −0.204, p= 0.008). Relationships were found to be inversely and moderately associated between BMI and the UST mean sound speed (rs = −0.429, p < 0.001), UST median sound speed (rs = −0.447, p < 0.001) and MPD (rs = −0.489, p < 0.001). The results confirm and strengthen findings presented in previous work indicating that UST sound speed imaging yields viable markers of breast density in a manner consistent with mammography, the current clinical standard. These results lay the groundwork for further studies to assess the role of sound speed imaging in risk prediction. PMID:27692872

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.

RSA/Legacy Wind Sensor Comparison. Part 2; Eastern Range

NASA Technical Reports Server (NTRS)

Short, David A.; Wheeler, Mark M.

2006-01-01

This report describes a comparison of data from ultrasonic and propeller-and-vane anemometers on 5 wind towers at Kennedy Space Center and Cape Canaveral Air Force Station. The ultrasonic sensors are scheduled to replace the Legacy propeller-and-vane sensors under the Range Standardization and Automation (RSA) program. Because previous studies have noted differences between peak wind speeds reported by mechanical and ultrasonic wind sensors, the latter having no moving parts, the 30th and 45th Weather Squadrons wanted to understand possible differences between the two sensor types. The period-of-record was 13-30 May 2005, A total of 357,626 readings of 1-minute average and peak wind speed/direction from each sensor type were used. Statistics of differences in speed and direction were used to identify 15 out of 19 RSA sensors having the most consistent performance, with respect to the Legacy sensors. RSA average wind speed data from these 15 showed a small positive bias of 0.38 kts. A slightly larger positive bias of 0.94 kts was found in the RSA peak wind speed.

Variation of ultrasound image lateral spectrum with assumed speed of sound and true scatterer density.

PubMed

Gyöngy, Miklós; Kollár, Sára

2015-02-01

One method of estimating sound speed in diagnostic ultrasound imaging consists of choosing the speed of sound that generates the sharpest image, as evaluated by the lateral frequency spectrum of the squared B-mode image. In the current work, simulated and experimental data on a typical (47 mm aperture, 3.3-10.0 MHz response) linear array transducer are used to investigate the accuracy of this method. A range of candidate speeds of sound (1240-1740 m/s) was used, with a true speed of sound of 1490 m/s in simulations and 1488 m/s in experiments. Simulations of single point scatterers and two interfering point scatterers at various locations with respect to each other gave estimate errors of 0.0-2.0%. Simulations and experiments of scatterer distributions with a mean scatterer spacing of at least 0.5 mm gave estimate errors of 0.1-4.0%. In the case of lower scatterer spacing, the speed of sound estimates become unreliable due to a decrease in contrast of the sharpness measure between different candidate speeds of sound. This suggests that in estimating speed of sound in tissue, the region of interest should be dominated by a few, sparsely spaced scatterers. Conversely, the decreasing sensitivity of the sharpness measure to speed of sound errors for higher scatterer concentrations suggests a potential method for estimating mean scatterer spacing. Copyright © 2014 Elsevier B.V. All rights reserved.

A New Look at an Old Activity: Resonance Tubes Used to Teach Resonance

NASA Astrophysics Data System (ADS)

Nelson, Jim; Nelson, Jane

2017-12-01

There are several variations of resonance laboratory activities used to determine the speed of sound. This is not one of them. This activity uses the resonance tube idea to teach resonance, not to verify the speed of sound. Prior to this activity, the speed of sound has already been measured using computer sound-sensors and timing echoes produced in long tubes like carpet tubes. There are other methods to determine the speed of sound. Some methods are referenced at the end of this article. The students already know the speed of sound when they are confronted with data that contradict their prior knowledge. Here, the mystery is something the students solve with the help of a series of demonstrations by the instructor.

Two Capacitive Micro-Machined Ultrasonic Transducers for Wind Speed Measurement

PubMed Central

Bui, Gia Thinh; Jiang, Yu-Tsung; Pang, Da-Chen

2016-01-01

This paper presents a new wind speed measurement method using a single capacitive micro-machined ultrasonic transducer (CMUT). The CMUT was arranged perpendicular to the direction of the wind flow, and a reflector was set up a short distance away, facing the CMUT. To reduce the size, weight, cost, and power consumption of conventional ultrasonic anemometers this study proposes two CMUT designs for the measurement of wind speed using either the amplitude of the signal or the time of flight (TOF). Each CMUT with a double array element design can transmit and receive signals in five different operation modes. Experiments showed that the two CMUT designs utilizing the TOF were better than those utilizing the amplitude of the signal for wind speed measurements ranging from 1 m/s to 10 m/s, providing a measurement error of less than 0.2 m/s. These results indicate that the sensitivity of the TOF is independent of the five operation modes. PMID:27271625

Two Capacitive Micro-Machined Ultrasonic Transducers for Wind Speed Measurement.

PubMed

Bui, Gia Thinh; Jiang, Yu-Tsung; Pang, Da-Chen

2016-06-02

This paper presents a new wind speed measurement method using a single capacitive micro-machined ultrasonic transducer (CMUT). The CMUT was arranged perpendicular to the direction of the wind flow, and a reflector was set up a short distance away, facing the CMUT. To reduce the size, weight, cost, and power consumption of conventional ultrasonic anemometers this study proposes two CMUT designs for the measurement of wind speed using either the amplitude of the signal or the time of flight (TOF). Each CMUT with a double array element design can transmit and receive signals in five different operation modes. Experiments showed that the two CMUT designs utilizing the TOF were better than those utilizing the amplitude of the signal for wind speed measurements ranging from 1 m/s to 10 m/s, providing a measurement error of less than 0.2 m/s. These results indicate that the sensitivity of the TOF is independent of the five operation modes.

40 CFR 205.54-1 - Low speed sound emission test procedures.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 25 2011-07-01 2011-07-01 false Low speed sound emission test....54-1 Low speed sound emission test procedures. (a) Instrumentation. The following instrumentation... checked annually to verify that its output has not changed. (3) An engine-speed tachometer which is...

Characteristics of a multilayer one-touch-point ultrasonic motor for high torque

NASA Astrophysics Data System (ADS)

Jeong, Seong-Su; Park, Tae-Gone; Park, Jong-Kyu

2013-04-01

In this paper, a one-touch-point ultrasonic motor is proposed. Fabricating the stator is easy because of its simple structure and the use of a punching technique. Also, a thin stator is advantageous to use in tight spaces. A thin metal plate was used as a V-shaped stator and two to the upper and two to the lower ceramic plates were attached to the upper and the lower surfaces respectively of the metal plate. When two sinusoidal sources with a phase difference of 90 degrees were applied to the stator, an elliptical displacement was generated at contact tip of the stator. Modeling of the ultrasonic motor was done and the displacement characteristics were defined by using a finite element analysis program (ATILA). To improve the speed and the torque of the ultrasonic motor, we analyzed the effects of the leg angle and the number of ceramic layers. In addition, a model with large x-axis and y-axis displacements was fabricated, and the speed and the torque were measured under various conditions. The elliptical motion of the contact tip of the stator was consistently obtained at the resonance frequency. The maximum speed and torque were obtained by using maximum elliptical displacement model. The speed and the torque increased linearly with increasing voltage.

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.

Capability evaluation of ultrasonic cavitation peening at different standoff distances.

PubMed

Bai, Fushi; Saalbach, Kai-Alexander; Long, Yangyang; Twiefel, Jens; Wallaschek, Jörg

2018-03-01

Ultrasonic cavitation peening is a novel surface treatment technology which utilizes the effect of cavitation bubble collapses to improve the properties of metal surfaces. In order to obtain high impact during ultrasonic cavitation peening, a small standoff distance between a sound radiator and a rigid reflector (the surface of treated specimen) is necessary. However, the effects of different standoff distances on the capability of ultrasonic cavitation peening are not yet clear. In this paper, a simplified model was developed to evaluate the cavitation capability at different standoff distances. Meanwhile, to validate the theoretical model, the plastic deformation or erosion on the peening surface before and after treatment were compared. It was found that at a very small standoff distance the impact pressure generated by cavitation bubbles did not cause much deformation or erosion, as the dynamics of cavitation bubbles was limited. At a large standoff distance, due to much attenuation of sound propagation in the bubbly liquid, little impact pressure was generated by the collapse of cavitation bubbles and reached the treated surface. A fixed vibration amplitude, however, corresponded to a standoff distance which caused the largest deformation or erosion on the treated surface. Copyright © 2017 Elsevier B.V. All rights reserved.

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.

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.

Inspection apparatus for evaluating a partially completed weld

DOEpatents

Smartt, Herschel B.; Larsen, Eric D.; Johnson, Jonn A.

2001-01-01

An inspection apparatus for evaluating a partially completed weld is described and which is utilized in combination with an automated movable welder which moves across a supporting surface, and wherein the inspection apparatus includes a coupling member mounted on the welder; a frame member mounted on the coupling member; an ultrasonic sensor mounted on the frame member and disposed in ultrasonic sound transmitting relation relative to the partially completed weld; and a drive assembly for adjusting the position of the ultrasonic sensor relative to the partially completed weld.

Performances estimation of a rotary traveling wave ultrasonic motor based on two-dimension analytical model.

PubMed

Ming, Y; Peiwen, Q

2001-03-01

The understanding of ultrasonic motor performances as a function of input parameters, such as the voltage amplitude, driving frequency, the preload on the rotor, is a key to many applications and control of ultrasonic motor. This paper presents performances estimation of the piezoelectric rotary traveling wave ultrasonic motor as a function of input voltage amplitude and driving frequency and preload. The Love equation is used to derive the traveling wave amplitude on the stator surface. With the contact model of the distributed spring-rigid body between the stator and rotor, a two-dimension analytical model of the rotary traveling wave ultrasonic motor is constructed. Then the performances of stead rotation speed and stall torque are deduced. With MATLAB computational language and iteration algorithm, we estimate the performances of rotation speed and stall torque versus input parameters respectively. The same experiments are completed with the optoelectronic tachometer and stand weight. Both estimation and experiment results reveal the pattern of performance variation as a function of its input parameters.

Study on sound-speed dispersion in a sandy sediment at frequency ranges of 0.5-3 kHz and 90-170 kHz

NASA Astrophysics Data System (ADS)

Yu, Sheng-qi; Liu, Bao-hua; Yu, Kai-ben; Kan, Guang-ming; Yang, Zhi-guo

2017-03-01

In order to study the properties of sound-speed dispersion in a sandy sediment, the sound speed was measured both at high frequency (90-170 kHz) and low frequency (0.5-3 kHz) in laboratory environments. At high frequency, a sampling measurement was conducted with boiled and uncooked sand samples collected from the bottom of a large water tank. The sound speed was directly obtained through transmission measurement using single source and single hydrophone. At low frequency, an in situ measurement was conducted in the water tank, where the sandy sediment had been homogeneously paved at the bottom for a long time. The sound speed was indirectly inverted according to the traveling time of signals received by three buried hydrophones in the sandy sediment and the geometry in experiment. The results show that the mean sound speed is approximate 1710-1713 m/s with a weak positive gradient in the sand sample after being boiled (as a method to eliminate bubbles as much as possible) at high frequency, which agrees well with the predictions of Biot theory, the effective density fluid model (EDFM) and Buckingham's theory. However, the sound speed in the uncooked sandy sediment obviously decreases (about 80%) both at high frequency and low frequency due to plenty of bubbles in existence. And the sound-speed dispersion performs a weak negative gradient at high frequency. Finally, a water-unsaturated Biot model is presented for trying to explain the decrease of sound speed in the sandy sediment with plenty of bubbles.

Decontamination of blood soaked electronic devices using ultrasonic technology.

PubMed

Dudeck, Kimberly C; Brennan, Tamara C; Embury, Daniel J

2012-01-10

With advancements in technology allowing for the miniaturization of consumer electronics, criminal investigations of all types frequently involve the forensic examination of electronic devices, such as cellular telephones, smartphones, and portable flash memory; in some extreme, violent cases, these devices are found covered in blood. Due to the complexity of such devices, standard operating procedures for the complete removal of blood had not previously been established by the Royal Canadian Mounted Police prior to this study. The electronics industry has adopted the use of the ultrasonic cleaner for sanitizing printed circuit boards (PCBs) by removing residues and contaminants. High frequency sound waves created by the machine penetrate and remove dirt and residues; however, early research during the 1950s recorded these sound waves breaking the internal bonds of integrated circuit chips. Experimentation with modern ultrasonic technology was used to determine if internal components were damaged, as well as if ultrasonic cleaning was the most suitable method for the removal of dried and liquid blood from a PCB. Several disinfectant solutions were compared against the 0.5% Triton(®) X-100 detergent solution in the ultrasonic cleaner, including: 10% sodium hypochlorite bleach, 85% isopropyl alcohol, and Conflikt(®) disinfectant spray. The results not only demonstrated that the ultrasonic cleaner did not damage the vital memory chip on the PCB, but also, with the assistance of Conflikt(®), was able to remove all traces of blood as indicated by Hemastix(®) reagent strips. Of five methods experimented with, two cycles of ultrasonic cleaning followed by sanitization with Conflikt(®) proved to be the only procedure capable of removing all traces of blood, as confirmed with both Hemastix(®) reagent strips and the hemochromogen test. Crown Copyright © 2011. Published by Elsevier Ireland Ltd. All rights reserved.

Kundt's Tube: An Acoustic Gas Analyzer

ERIC Educational Resources Information Center

Aristov, Natasha; Habekost, Gehsa; Habekost, Achim

2011-01-01

A Kundt tube is normally used to measure the speed of sound in gases. Therefore, from known speeds of sound, a Kundt tube can be used to identify gases and their fractions in mixtures. In these experiments, the speed of sound is determined by measuring the frequency of a standing sound wave at a fixed tube length, temperature, and pressure. This…

Synergistic effect of microbubble emulsion and sonic or ultrasonic agitation on endodontic biofilm in vitro.

PubMed

Halford, Andrew; Ohl, Claus-Dieter; Azarpazhooh, Amir; Basrani, Bettina; Friedman, Shimon; Kishen, Anil

2012-11-01

Irrigation dynamics and antibacterial activity determine the efficacy of root canal disinfection. Sonic or ultrasonic agitation of irrigants is expected to improve irrigation dynamics. This study examined the effects of microbubble emulsion (ME) combined with sonic or ultrasonic agitation on irrigation dynamics and reduction of biofilm bacteria within root canal models. Two experiments were conducted. First, high-speed imaging was used to characterize the bubble dynamics generated in ME by sonic or ultrasonic agitation within canals of polymer tooth models. Second, 5.25% NaOCl irrigation or ME was sonically or ultrasonically agitated in canals of extracted teeth with 7-day-grown Enterococcus faecalis biofilms. Dentinal shavings from canal walls were sampled at 1 mm and 3 mm from the apical terminus, and colony-forming units (CFUs) were enumerated. Mean log CFU/mL values were analyzed with analysis of variance and post hoc tests. High-speed imaging demonstrated strongly oscillating and vaporizing bubbles generated within ME during ultrasonic but not sonic agitation. Compared with CFU counts in controls, NaOCl-sonic and NaOCl-ultrasonic yielded significantly lower counts (P < .05) at both measurement levels. ME-sonic yielded significantly lower counts (P = .002) at 3 mm, whereas ME-ultrasonic yielded highly significantly lower counts (P = .000) at both measurement levels. At 3 mm, ME-ultrasonic yielded significantly lower CFU counts (P = .000) than ME-sonic, NaOCl-sonic, and NaOCl-ultrasonic. Enhanced bubble dynamics and reduced E. faecalis biofilm bacteria beyond the level achieved by sonic or ultrasonic agitation of NaOCl suggested a synergistic effect of ME combined with ultrasonic agitation. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Femtosecond ultrasonic spectroscopy using a piezoelectric nanolayer: Hypersound attenuation in vitreous silica films

NASA Astrophysics Data System (ADS)

Wen, Yu-Chieh; Guol, Shi-Hao; Chen, Hung-Pin; Sheu, Jinn-Kong; Sun, Chi-Kuang

2011-08-01

We report ultra-broadband ultrasonic spectroscopy with an impedance-matched piezoelectric nanolayer, which enables optical generation and detection of a 730-fs acoustic pulse (the width of ten lattice constants). The bandwidth improvement facilitates THz laser ultrasonics to bridge the spectral gap between inelastic light and x-ray scatterings (0.1-1 THz) in the studies of lattice dynamics. As a demonstration, this method is applied to measure sound attenuation α in a vitreous SiO2 thin film. Our results extend the existing low-frequency data obtained by ultrasonic-based and light scattering methods and also show a α∝ f2 behavior for frequencies f up to 650 GHz.

Sound control by temperature gradients

NASA Astrophysics Data System (ADS)

Sánchez-Dehesa, José; Angelov, Mitko I.; Cervera, Francisco; Cai, Liang-Wu

2009-11-01

This work reports experiments showing that airborne sound propagation can be controlled by temperature gradients. A system of two heated tubes is here used to demonstrate the collimation and focusing of an ultrasonic beam by the refractive index profile created by the temperature gradients existing around the tubes. Numerical simulations supporting the experimental findings are also reported.

Airborne ultrasonic transducer using polymer-based elastomer with high output-to-weight ratio

NASA Astrophysics Data System (ADS)

Wu, Jiang; Mizuno, Yosuke; Tabaru, Marie; Nakamura, Kentaro

2015-08-01

With the properties of low density, low elastic modulus, and low mechanical loss, poly(phenylene sulfide) (PPS) is a suitable material as the elastomer in an airborne ultrasonic transducer for generating large vibration velocity. In this study, we design and fabricate a transducer composed of a PPS-based longitudinal vibrator and a PPS-based disk of 0.3 mm thickness to obtain high-intensity ultrasound. The rated sound pressure at a distance of 300 mm reached 38.9 Pa (125 dB, 0 dB re. 0.02 mPa) when the frequency and voltage were 58.90 kHz and 20 V. The weight of this transducer is 6.3 g. The ratio of the sound pressure to the weight of the prototype transducer is 1.8 times larger than that of the commercial transducer. The experimental results indicate that PPS is a good substitute for metal as the elastomer for manufacturing airborne ultrasonic transducers with a high output-to-weight ratio.

PLATE WAVE RESONANCE WITH AIR-COUPLED ULTRASONICS

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

Bar, H. N.; Dayal, V.; Barnard, D.

2010-02-22

Air-coupled ultrasonic transducers can excite plate waves in metals and composites. The coincidence effect, i.e., the wave vector of plate wave coincides with projection of exciting airborne sound vector, leads to a resonance which strongly amplifies the sound transmission through the plate. The resonance depends on the angle of incidence and the frequency. In the present study, the incidence angle for maximum transmission (theta{sub max}) is measured in plates of steel, aluminum, carbon fiber reinforced composites and honeycomb sandwich panels. The variations of (theta{sub max}) with plate thickness are compared with theoretical values in steel, aluminum and quasi-isotropic carbon fibermore » composites. The enhanced transmission of air-coupled ultrasound at oblique incidence can substantially improve the probability of flaw detection in plates and especially in honeycomb structures. Experimental air-coupled ultrasonic scan of subtle flaws in CFRP laminates showed definite improvement of signal-to-noise ratio with oblique incidence at theta{sub max}.« less

Design of river height and speed monitoring system by using Arduino

NASA Astrophysics Data System (ADS)

Nasution, T. H.; Siagian, E. C.; Tanjung, K.; Soeharwinto

2018-02-01

River is one part of the hydrologic cycle. Water in rivers is generally collected from precipitation, such as rain, dew, springs, underground runoff, and in certain countries also comes from melt ice/snow. The height and speed of water in a river is always changing. Changes in altitude and speed of water can affect the surrounding environment. In this paper, we will design a system to measure the altitude and speed of the river. In this work we use Arduino Uno, ultrasonic sensors and flow rate sensors. Ultrasonic sensor HC-SR04 is used as a river height meter. Based on the test results, this sensor has an accuracy of 96.6%.

High-speed duetting - latency times of the female acoustic response within the bush-cricket genera Leptophyes and Andreiniimon (Orthoptera, Phaneropteridae).

PubMed

Heller, Klaus-Gerhard; Korsunovskaya, Olga; Massa, Bruno; Iorgu, Ionuț Ștefan

2018-01-01

To find a mate, male and female bush-crickets of the family Phaneropteridae typically engage in duets. The male sings and the female responds. For mutual recognition, the amplitude pattern of the male song and the species-specific timing of the female response have been shown to be very important. In the seven studied species, belonging to the genera Leptophyes and Andreiniimon , these duets are extremely fast and nearly completely in the ultrasonic range. The females produce very short sounds by fast closing movements of the tegmina. They respond with species-specific delays of 20 to 150 ms after the beginning of the male song. The different latency times are probably not important for species recognition, since in sympatric species they are quite similar.

High-speed duetting – latency times of the female acoustic response within the bush-cricket genera Leptophyes and Andreiniimon (Orthoptera, Phaneropteridae)

PubMed Central

Heller, Klaus-Gerhard; Korsunovskaya, Olga; Massa, Bruno; Iorgu, Ionuț Ștefan

2018-01-01

Abstract To find a mate, male and female bush-crickets of the family Phaneropteridae typically engage in duets. The male sings and the female responds. For mutual recognition, the amplitude pattern of the male song and the species-specific timing of the female response have been shown to be very important. In the seven studied species, belonging to the genera Leptophyes and Andreiniimon, these duets are extremely fast and nearly completely in the ultrasonic range. The females produce very short sounds by fast closing movements of the tegmina. They respond with species-specific delays of 20 to 150 ms after the beginning of the male song. The different latency times are probably not important for species recognition, since in sympatric species they are quite similar. PMID:29692644

Speed of Sound and Ultrasound Absorption in Ionic Liquids.

PubMed

Dzida, Marzena; Zorębski, Edward; Zorębski, Michał; Żarska, Monika; Geppert-Rybczyńska, Monika; Chorążewski, Mirosław; Jacquemin, Johan; Cibulka, Ivan

2017-03-08

A complete review of the literature data on the speed of sound and ultrasound absorption in pure ionic liquids (ILs) is presented. Apart of the analysis of data published to date, the significance of the speed of sound in ILs is regarded. An analysis of experimental methods described in the literature to determine the speed of sound in ILs as a function of temperature and pressure is reported, and the relevance of ultrasound absorption in acoustic investigations is discussed. Careful attention was paid to highlight possible artifacts, and side phenomena related to the absorption and relaxation present in such measurements. Then, an overview of existing data is depicted to describe the temperature and pressure dependences on the speed of sound in ILs, as well as the impact of impurities in ILs on this property. A relation between ions structure and speeds of sound is presented by highlighting existing correlation and evaluative methods described in the literature. Importantly, a critical analysis of speeds of sound in ILs vs those in classical molecular solvents is presented to compare these two classes of compounds. The last part presents the importance of acoustic investigations for chemical engineering design and possible industrial applications of ILs.

Non-contact ultrasonic defect imaging in composites

NASA Astrophysics Data System (ADS)

Tenoudji, F. Cohen; Citerne, J. M.; Dutilleul, H.; Busquet, D.

2016-02-01

In the situations where conventional NDT ultrasonic techniques using immersion of the part under inspection or its contact with the transducers cannot be used, in-air investigation presents an alternative. The huge impedance mismatch between the part material and air (transmission loss in the order of 80 dB for a thin metallic plate) induces having to deal very small signals and unfavorable signal to noise ratios. The approach adopted here is the use of the crack of a spark generated by an induction coil as a sound source and an electrostatic polyethylene membrane microphone as a receiver [1]. The advantage of this source is that the spark power is high (several kilowatts) and its power is directly coupled to air during the energy release. In some difficult situations, an elliptical mirror is used to concentrate the sound beam power on the surface of the part [2,3]. Stability and reproducibility of the sound generated by the spark, which are a necessity in order to perform quantitative evaluations, are achieved in our experiment. This permits also an increase of the signal to noise ratio by signal accumulation. The sound pulse duration of few microseconds allows operating in pulse echo in some circumstances. The bandwidth of the source is large, of several hundred of kilohertz, and that of the microphone above 100 kHz allow the flexibility to address different kinds of materials. The technique allows an easy, in-air, non contact, inspection of structural composite parts, with pulse waves, with an excellent signal to noise ratio. An X-Y ultrasonic scanning ultrasonic system for material inspection using this technique has been realized. Results obtained in transmission and reflection are presented. Defects in carbon composite plates and in honeycomb are imaged in transmission Echographic measurements show that defect detection can be performed in thin plates using Lamb waves propagation when only one sided inspection of the part is possible.

A New Look at an Old Activity: Resonance Tubes Used to Teach Resonance

ERIC Educational Resources Information Center

Nelson, Jim; Nelson, Jane

2017-01-01

There are several variations of resonance laboratory activities used to determine the speed of sound. This is "not" one of them. This activity uses the resonance tube idea to teach "resonance," not to verify the speed of sound. Prior to this activity, the speed of sound has already been measured using computer sound-sensors and…

Verification of the helioseismology travel-time measurement technique and the inversion procedure for sound speed using artificial data

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

Parchevsky, K. V.; Zhao, J.; Hartlep, T.

We performed three-dimensional numerical simulations of the solar surface acoustic wave field for the quiet Sun and for three models with different localized sound-speed perturbations in the interior with deep, shallow, and two-layer structures. We used the simulated data generated by two solar acoustics codes that employ the same standard solar model as a background model, but utilize different integration techniques and different models of stochastic wave excitation. Acoustic travel times were measured using a time-distance helioseismology technique, and compared with predictions from ray theory frequently used for helioseismic travel-time inversions. It is found that the measured travel-time shifts agreemore » well with the helioseismic theory for sound-speed perturbations, and for the measurement procedure with and without phase-speed filtering of the oscillation signals. This testing verifies the whole measuring-filtering-inversion procedure for static sound-speed anomalies with small amplitude inside the Sun outside regions of strong magnetic field. It is shown that the phase-speed filtering, frequently used to extract specific wave packets and improve the signal-to-noise ratio, does not introduce significant systematic errors. Results of the sound-speed inversion procedure show good agreement with the perturbation models in all cases. Due to its smoothing nature, the inversion procedure may overestimate sound-speed variations in regions with sharp gradients of the sound-speed profile.« less

Finite Element Simulation of the Shear Effect of Ultrasonic on Heat Exchanger Descaling

NASA Astrophysics Data System (ADS)

Lu, Shaolv; Wang, Zhihua; Wang, Hehui

2018-03-01

The shear effect on the interface of metal plate and its attached scale is an important mechanism of ultrasonic descaling, which is caused by the different propagation speed of ultrasonic wave in two different mediums. The propagating of ultrasonic wave on the shell is simulated based on the ANSYS/LS-DYNA explicit dynamic analysis. The distribution of shear stress in different paths under ultrasonic vibration is obtained through the finite element analysis and it reveals the main descaling mechanism of shear effect. The simulation result is helpful and enlightening to the reasonable design and the application of the ultrasonic scaling technology on heat exchanger.

Adaptive sound speed correction for abdominal ultrasonography: preliminary results

NASA Astrophysics Data System (ADS)

Jin, Sungmin; Kang, Jeeun; Song, Tai-Kyung; Yoo, Yangmo

2013-03-01

Ultrasonography has been conducting a critical role in assessing abdominal disorders due to its noninvasive, real-time, low cost, and deep penetrating capabilities. However, for imaging obese patients with a thick fat layer, it is challenging to achieve appropriate image quality with a conventional beamforming (CON) method due to phase aberration caused by the difference between sound speeds (e.g., 1580 and 1450m/s for liver and fat, respectively). For this, various sound speed correction (SSC) methods that estimate the accumulated sound speed for a region-of interest (ROI) have been previously proposed. However, with the SSC methods, the improvement in image quality was limited only for a specific depth of ROI. In this paper, we present the adaptive sound speed correction (ASSC) method, which can enhance the image quality for whole depths by using estimated sound speeds from two different depths in the lower layer. Since these accumulated sound speeds contain the respective contributions of layers, an optimal sound speed for each depth can be estimated by solving contribution equations. To evaluate the proposed method, the phantom study was conducted with pre-beamformed radio-frequency (RF) data acquired with a SonixTouch research package (Ultrasonix Corp., Canada) with linear and convex probes from the gel pad-stacked tissue mimicking phantom (Parker Lab. Inc., USA and Model539, ATS, USA) whose sound speeds are 1610 and 1450m/s, respectively. From the study, compared to the CON and SSC methods, the ASSC method showed the improved spatial resolution and information entropy contrast (IEC) for convex and linear array transducers, respectively. These results indicate that the ASSC method can be applied for enhancing image quality when imaging obese patients in abdominal ultrasonography.

Imaging of sound speed using reflection ultrasound tomography.

PubMed

Nebeker, Jakob; Nelson, Thomas R

2012-09-01

The goal of this work was to obtain and evaluate measurements of tissue sound speed in the breast, particularly dense breasts, using backscatter ultrasound tomography. An automated volumetric breast ultrasound scanner was constructed for imaging the prone patient. A 5- to 7-MHz linear array transducer acquired 17,920 radiofrequency pulse echo A-lines from the breast, and a back-wall reflector rotated over 360° in 25 seconds. Sound speed images used reflector echoes that after preprocessing were uploaded into a graphics processing unit for filtered back-projection reconstruction. A velocimeter also was constructed to measure the sound speed and attenuation for comparison to scanner performance. Measurements were made using the following: (1) deionized water from 22°C to 90°C; (2) various fluids with sound speeds from 1240 to 1904 m/s; (3) acrylamide gel test objects with features from 1 to 15 mm in diameter; and (4) healthy volunteers. The mean error ± SD between sound speed reference and image data was -0.48% ± 9.1%, and the error between reference and velocimeter measurements was -1.78% ± 6.50%. Sound speed image and velocimeter measurements showed a difference of 0.10% ± 4.04%. Temperature data showed a difference between theory and imaging performance of -0.28% ± 0.22%. Images of polyacrylamide test objects showed detectability of an approximately 1% sound speed difference in a 2.4-mm cylindrical inclusion with a contrast to noise ratio of 7.9 dB. An automated breast scanner offers the potential to make consistent automated tomographic images of breast backscatter, sound speed, and attenuation, potentially improving diagnosis, particularly in dense breasts.

Ultrasonic technique for inspection of GPHS capsule girth weld integrity

NASA Astrophysics Data System (ADS)

Placr, Arnost

1993-05-01

An innovative nondestructive examination (NDE) technique for the inspection of integrity of General Purpose Heat Source (GPHS) capsule girth welds was developed employing a Lamb wave as the mode of the sound propagation. Reliability of the Lamb wave technique was tested on GPHS capsules using plutonium pallet simulators. All ten capsules, which were previously rejected, passed ultrasonic (UT) inspection using the Lamb wave technique.

Two-Element Transducer for Ultrasound

NASA Technical Reports Server (NTRS)

Lecroissette, D. H.; Heyser, R. C.

1986-01-01

Separation of transmitting and receiving units improves probing of deep tissue. Ultrasonic transducer has dual elements to increase depth at which sonic images are made of biological tissue. Transducer uses separate transmitting and receiving elements, and frequency response of receiving element independently designed to accommodate attenuation of higher frequencies by tissue. New transducer intended for pulse-echo ultrasonic systems in which reflected sound pulses reveal features in tissue.

RSA/Legacy Wind Sensor Comparison. Part 1; Western Range

NASA Technical Reports Server (NTRS)

Short, David A.; Wheeler, Mark M.

2006-01-01

This report describes a comparison of data from ultrasonic and cup-and-vane anemometers on 5 wind towers at Vandenberg AFB. The ultrasonic sensors are scheduled to replace the Legacy cup-and-vane sensors under the Range Standardization and Automation (RSA) program. Because previous studies have noted differences between peak wind speeds reported by mechanical and ultrasonic wind sensors, the latter having no moving parts, the 30th and 45th Weather Squadrons wanted to understand possible differences between the two sensor types. The period-of-record was 13-30 May 2005. A total of 153,961 readings of I-minute average and peak wind speed/direction from each sensor type were used. Statistics of differences in speed and direction were used to identify 18 out of 34 RSA sensors having the most consistent performance, with respect to the Legacy sensors. Data from these 18 were used to form a composite comparison. A small positive bias in the composite RSA average wind speed increased from +0.5 kts at 15 kts, to +1 kt at 25 kts. A slightly larger positive bias in the RSA peak wind speed increased from +1 kt at 15 kts, to +2 kts at 30 kts.

Ultrasound tomography imaging with waveform sound speed: parenchymal changes in women undergoing tamoxifen therapy

NASA Astrophysics Data System (ADS)

Sak, Mark; Duric, Neb; Littrup, Peter; Sherman, Mark; Gierach, Gretchen

2017-03-01

Ultrasound tomography (UST) is an emerging modality that can offer quantitative measurements of breast density. Recent breakthroughs in UST image reconstruction involve the use of a waveform reconstruction as opposed to a raybased reconstruction. The sound speed (SS) images that are created using the waveform reconstruction have a much higher image quality. These waveform images offer improved resolution and contrasts between regions of dense and fatty tissues. As part of a study that was designed to assess breast density changes using UST sound speed imaging among women undergoing tamoxifen therapy, UST waveform sound speed images were then reconstructed for a subset of participants. These initial results show that changes to the parenchymal tissue can more clearly be visualized when using the waveform sound speed images. Additional quantitative testing of the waveform images was also started to test the hypothesis that waveform sound speed images are a more robust measure of breast density than ray-based reconstructions. Further analysis is still needed to better understand how tamoxifen affects breast tissue.

Application of Ultrasonic Bone Curette in Endoscopic Endonasal Skull Base Surgery: Technical Note

PubMed Central

Rastelli, Milton M.; Pinheiro-Neto, Carlos D.; Fernandez-Miranda, Juan C.; Wang, Eric W.; Snyderman, Carl H.; Gardner, Paul A.

2014-01-01

Background Endoscopic endonasal surgery (EES) of the skull base often requires extensive bone work in proximity to critical neurovascular structures. Objective To demonstrate the application of an ultrasonic bone curette during EES. Methods Ten patients with skull base lesions underwent EES from September 2011 to April 2012 at the University of Pittsburgh Medical Center. Most of the bone work was done with high-speed drill and rongeurs. The ultrasonic curette was used to remove specific structures. Results All the patients were submitted to fully endoscopic endonasal procedures and had critical bony structures removed with the ultrasonic bone curette. Two patients with degenerative spine diseases underwent odontoid process removal. Five patients with clival and petroclival tumors underwent posterior clinoid removal. Two patients with anterior fossa tumors underwent crista galli removal. One patient underwent unilateral optic nerve decompression. No mechanical or heat injury resulted from the ultrasonic curette. The surrounding neurovascular structures and soft tissue were preserved in all cases. Conclusion In selected EES, the ultrasonic bone curette was successfully used to remove loose pieces of bone in narrow corridors, adjacent to neurovascular structures, and it has advantages to high-speed drills in these specific situations. PMID:24719795

A novel ultrasonic clutch using near-field acoustic levitation.

PubMed

Chang, Kuo-Tsi

2004-10-01

This paper investigates design, fabrication and drive of an ultrasonic clutch with two transducers. For the two transducers, one serving as a driving element of the clutch is connected to a driving shaft via a coupling, and the other serving as a slave element of the clutch is connected to a slave shaft via another coupling. The principle of ultrasonic levitation is first expressed. Then, a series-resonant inverter is used to generate AC voltages at input terminals of each transducer, and a speed measuring system with optic sensors is used to find the relationship between rotational speed of the slave shaft and applied voltage of each transducer. Moreover, contact surfaces of the two transducers are coupled by the frictional force when both the two transducers are not energized, and separated using the ultrasonic levitation when at least one of the two transducers is energized at high voltages at resonance.

High-speed time-reversed ultrasonically encoded (TRUE) optical focusing inside dynamic scattering media at 793 nm

NASA Astrophysics Data System (ADS)

Liu, Yan; Lai, Puxiang; Ma, Cheng; Xu, Xiao; Suzuki, Yuta; Grabar, Alexander A.; Wang, Lihong V.

2014-03-01

Time-reversed ultrasonically encoded (TRUE) optical focusing is an emerging technique that focuses light deep into scattering media by phase-conjugating ultrasonically encoded diffuse light. In previous work, the speed of TRUE focusing was limited to no faster than 1 Hz by the response time of the photorefractive phase conjugate mirror, or the data acquisition and streaming speed of the digital camera; photorefractive-crystal-based TRUE focusing was also limited to the visible spectral range. These time-consuming schemes prevent this technique from being applied in vivo, since living biological tissue has a speckle decorrelation time on the order of a millisecond. In this work, using a Tedoped Sn2P2S6 photorefractive crystal at a near-infrared wavelength of 793 nm, we achieved TRUE focusing inside dynamic scattering media having a speckle decorrelation time as short as 7.7 ms. As the achieved speed approaches the tissue decorrelation rate, this work is an important step forward toward in vivo applications of TRUE focusing in deep tissue imaging, photodynamic therapy, and optical manipulation.

Ultrasound indoor positioning system based on a low-power wireless sensor network providing sub-centimeter accuracy.

PubMed

Medina, Carlos; Segura, José Carlos; De la Torre, Ángel

2013-03-13

This paper describes the TELIAMADE system, a new indoor positioning system based on time-of-flight (TOF) of ultrasonic signal to estimate the distance between a receiver node and a transmitter node. TELIAMADE system consists of a set of wireless nodes equipped with a radio module for communication and a module for the transmission and reception of ultrasound. The access to the ultrasonic channel is managed by applying a synchronization algorithm based on a time-division multiplexing (TDMA) scheme. The ultrasonic signal is transmitted using a carrier frequency of 40 kHz and the TOF measurement is estimated by applying a quadrature detector to the signal obtained at the A/D converter output. Low sampling frequencies of 17.78 kHz or even 12.31 kHz are possible using quadrature sampling in order to optimize memory requirements and to reduce the computational cost in signal processing. The distance is calculated from the TOF taking into account the speed of sound. An excellent accuracy in the estimation of the TOF is achieved using parabolic interpolation to detect of maximum of the signal envelope at the matched filter output. The signal phase information is also used for enhancing the TOF measurement accuracy. Experimental results show a root mean square error (rmse) less than 2 mm and a standard deviation less than 0.3 mm for pseudorange measurements in the range of distances between 2 and 6 m. The system location accuracy is also evaluated by applying multilateration. A sub-centimeter location accuracy is achieved with an average rmse of 9.6 mm.

Characterization of Acoustic Streaming Beyond 100 MHz

NASA Astrophysics Data System (ADS)

Eisener, J.; Lippert, A.; Nowak, T.; Cairós, C.; Reuter, F.; Mettin, R.

The aim of this study is to investigate acoustic streaming in water at very high ultrasonic frequencies, namely beyond 100 MHz. At such high frequencies, the dissipation length of acoustic waves shrinks considerably, and the acoustic streaming transforms from the well-known Eckart type into a Stuart-Lighthill type: While Eckart streaming is driven by a small momentum transfer along the path of a weakly damped travelling sound wave, Stuart-Lighthill streaming is generated by rather local and strong momentum transfer of a highly damped and therefore rapidly decaying wave. Then the inertia of the induced flow cannot be neglected anymore, and a potentially turbulent jet flow emerges. Here we report on streaming velocity measurements for the case where the sound is completely absorbed within a region much smaller than the generated jet. In contrast to previous work in this frequency range, where mainly surface acoustic wave transducers have been employed, we use piston-type transducers that emit vertically to the transducer surface. The acoustic streaming effects are characterized by ink front tracking and particle tracking velocimetry, and by numerical studies. The results show narrow high-speed jet flows that extend much farther into the liquid than the acoustic field. Velocities of several m/s are observed.

Chaotic operation and chaos control of travelling wave ultrasonic motor.

PubMed

Shi, Jingzhuo; Zhao, Fujie; Shen, Xiaoxi; Wang, Xiaojie

2013-08-01

The travelling wave ultrasonic motor, which is a nonlinear dynamic system, has complex chaotic phenomenon with some certain choices of system parameters and external inputs, and its chaotic characteristics have not been studied until now. In this paper, the preliminary study of the chaos phenomenon in ultrasonic motor driving system has been done. The experiment of speed closed-loop control is designed to obtain several groups of time sampling data sequence of the amplitude of driving voltage, and phase-space reconstruction is used to analyze the chaos characteristics of these time sequences. The largest Lyapunov index is calculated and the result is positive, which shows that the travelling wave ultrasonic motor has chaotic characteristics in a certain working condition Then, the nonlinear characteristics of travelling wave ultrasonic motor are analyzed which includes Lyapunov exponent map, the bifurcation diagram and the locus of voltage relative to speed based on the nonlinear chaos model of a travelling wave ultrasonic motor. After that, two kinds of adaptive delay feedback controllers are designed in this paper to control and suppress chaos in USM speed control system. Simulation results show that the method can control unstable periodic orbits, suppress chaos in USM control system. Proportion-delayed feedback controller was designed following and arithmetic of fuzzy logic was used to adaptively adjust the delay time online. Simulation results show that this method could fast and effectively change the chaos movement into periodic or fixed-point movement and make the system enter into stable state from chaos state. Finally the chaos behavior was controlled. Copyright © 2013 Elsevier B.V. All rights reserved.

Structural integrity test and assessment.

NASA Technical Reports Server (NTRS)

Suggs, F.; Poe, R.; Sannicandro, R.

1972-01-01

The feasibility of using an ultrasonic system on board the Space Shuttle Orbiter to facilitate structural evaluation and assessment was studied. Two factors are considered that could limit the capability of an ultrasonic system: (1) the effect of structure configuration and (2) the noise generated during vehicle launch. Results of the study indicate that although the structural configuration has direct bearing on sound propagation, strategic location of transducers will still permit flaw detection. The ultrasonic response data show that a severe acoustic environment does not interfere significantly with either propagation and reflection of surface waves or detection of crack-like flaws in the structure.

Multispectral photoacoustic method for the early detection and diagnosis of osteoporosis

NASA Astrophysics Data System (ADS)

Steinberg, Idan; Eyal, Avishay; Gannot, Israel

2013-03-01

Osteoporosis is a major health problem worldwide, with healthcare costs of billions of dollars annually. The risk of fracture depends on the bone mineral density (measured in clinical practice) as well as on the bone microstructure and functional status. Since pure ultrasonic methods can measure bone strength and spectroscopic optical methods can provide valuable functional information, a hybrid multispectral photoacoustic technique can be of great value. We have developed such a system based on a tunable Ti:Sapph laser at 750 - 950 nm, followed by an acousto-optic modulator to generate photoacoustic signals with frequencies of 0.5 - 2.5 MHz. Another system was based on two directly modulated 830nm laser diodes. The systems were used to photoacoustically excite the proximal end of a rat tibia. Spectrum analyzer with tracking generator was used for measuring both the amplitude and the phase at the distal end. Scanning along both the optical wavelength as well as the acoustic frequency enables full mapping of the bone transfer function. Analyzing this function along the wavelength axis allows deducing the gross biochemical composition related to the bone functional and pathological state. Analyzing the amplitude and phase along the acoustic frequency axis yields the speed of sound dispersion and the broadband ultrasonic attenuation - both have shown clinical relevance.

High-speed scanning of critical structures in aviation using coordinate measurement machine and the laser ultrasonic.

PubMed

Swornowski, Pawel J

2012-01-01

Aviation is one of the know-how spheres containing a great deal of responsible sub-assemblies, in this case landing gear. The necessity for reducing production cycle times while achieving better quality compels metrologists to look for new and improved ways to perform inspection of critical structures. This article describes the ability to determine the shape deviation and location of defects in landing gear using coordinate measuring machines and laser ultrasonic with high-speed scanning. A nondestructive test is the basis for monitoring microcrack and corrosion propagation in the context of a damage-tolerant design approach. This article presents an overview of the basics and of the various metrological aspects of coordinate measurement and a nondestructive testing method in terms of high-speed scanning. The new test method (laser ultrasonic) promises to produce the necessary increase in inspection quality, but this is limited by the wide range of materials, geometries, and structure aeronautic parts used. A technique combining laser ultrasonic and F-SAFT (Fourier-Synthetic Aperture Focusing Technique) processing has been proposed for the detection of small defects buried in landing gear. The experimental results of landing gear inspection are also presented. © Wiley Periodicals, Inc.

Correction factors in determining speed of sound among freshmen in undergraduate physics laboratory

NASA Astrophysics Data System (ADS)

Lutfiyah, A.; Adam, A. S.; Suprapto, N.; Kholiq, A.; Putri, N. P.

2018-03-01

This paper deals to identify the correction factor in determining speed of sound that have been done by freshmen in undergraduate physics laboratory. Then, the result will be compared with speed of sound that determining by senior student. Both of them used the similar instrument, namely resonance tube with apparatus. The speed of sound indicated by senior was 333.38 ms-1 with deviation to the theory about 3.98%. Meanwhile, for freshmen, the speed of sound experiment was categorised into three parts: accurate value (52.63%), middle value (31.58%) and lower value (15.79%). Based on analysis, some correction factors were suggested: human error in determining first and second harmonic, end correction of tube diameter, and another factors from environment, such as temperature, humidity, density, and pressure.

Analysis of dynamic accumulative damage about the lining structure of high speed railway’s tunnel based on ultrasonic testing technology

NASA Astrophysics Data System (ADS)

Wang, Xiang-qiu; Zhang, Huojun; Xie, Wen-xi

2017-08-01

Based on the similar material model test of full tunnel, the theory of elastic wave propagation and the testing technology of intelligent ultrasonic wave had been used to research the dynamic accumulative damage characteristics of tunnel’s lining structure under the dynamic loads of high speed train. For the more, the dynamic damage variable of lining structure of high speed railway’s tunnel was obtained. The results shown that the dynamic cumulative damage of lining structure increases nonlinearly with the times of cumulative vibration, the weakest part of dynamic cumulative damage is the arch foot of tunnel. Much more attention should be paid to the design and operation management of high speed railway’s tunnel.

The power of sound: miniaturized medical implants with ultrasonic links

NASA Astrophysics Data System (ADS)

Wang, Max L.; Chang, Ting Chia; Charthad, Jayant; Weber, Marcus J.; Arbabian, Amin

2017-05-01

Miniaturized wirelessly powered implants capable of operating and communicating deep in the body are necessary for the next-generation of diagnostics and therapeutics. A major challenge in developing these minimally invasive implants is the tradeoff between device size, functionality, and operating depth. Here, we review two different wireless powering methods, inductive and ultrasonic power transfer, examine how to analyze their power transfer efficiency, and evaluate their potential for powering implantable medical devices. In particular, we show how ultrasonic wireless power transfer can address these challenges due to its safety, low attenuation, and millimeter wavelengths in the body. Finally, we demonstrate two ultrasonically powered implants capable of active power harvesting and bidirectional communication for closed-loop operation while functioning through multiple centimeters of tissue.

Ultrasonic Inspection to Quantify Failure Pathologies of Crimped Electrical Connections

NASA Technical Reports Server (NTRS)

Cramer, K. Elliott; Perey, Daniel F.; Yost, William T.

2014-01-01

Previous work has shown that ultrasonic inspection provides a means of assessing electrical crimp quality that ensures the electrical and mechanical integrity of an initial crimp before the installation process is completed. The amplitude change of a compressional ultrasonic wave propagating at right angles to the wire axis and through the junction of a crimp termination was shown to correlate with the results of destructive pull tests, which is a standard for assessing crimp wire junction quality. Of additional concern are crimps made at high speed assembly lines for wiring harnesses, which are used for critical applications, such as in aircraft. During high-speed assembly it is possible that many faulty crimps go undetected until long after assembly, and fail in service. The position and speed of the crimping jaw become factors as the high-speed crimp is formed. The work presented in this paper is designed to cover the more difficult and more subtle area of high-speed crimps by taking into account the rate change of the measurements. Building on the previous work, we present an analysis methodology, based on transmitted ultrasonic energy and timing of the first received pulse that is shown to correlate to the gauge of the crimp/ferrule combination and the position of the crimping jaw. Results demonstrating the detectability of a number of the crimp failure pathologies, such as missing strands, partially inserted wires and incomplete crimp compression, are presented. The ability of this technique to estimate crimp height, a mechanical measure of crimp quality, is discussed.

Ultrasonic inspection to quantify failure pathologies of crimped electrical connections

NASA Astrophysics Data System (ADS)

Cramer, K. Elliott; Perey, Daniel F.; Yost, William T.

2015-03-01

Previous work has shown that ultrasonic inspection provides a means of assessing electrical crimp quality that ensures the electrical and mechanical integrity of an initial crimp before the installation process is completed. The amplitude change of a compressional ultrasonic wave propagating at right angles to the wire axis and through the junction of a crimp termination was shown to correlate with the results of destructive pull tests, which is a standard for assessing crimp wire junction quality. Of additional concern are crimps made at high speed assembly lines for wiring harnesses, which are used for critical applications, such as in aircraft. During high-speed assembly it is possible that many faulty crimps go undetected until long after assembly, and fail in service. The position and speed of the crimping jaw become factors as the high-speed crimp is formed. The work presented in this paper is designed to cover the more difficult and more subtle area of high-speed crimps by taking into account the rate change of the measurements. Building on the previous work, we present an analysis methodology, based on transmitted ultrasonic energy and timing of the first received pulse that is shown to correlate to the gauge of the crimp/ferrule combination and the position of the crimping jaw. Results demonstrating the detectability of a number of the crimp failure pathologies, such as missing strands, partially inserted wires and incomplete crimp compression, are presented. The ability of this technique to estimate crimp height, a mechanical measure of crimp quality, is discussed.

Non-contact transportation using near-field acoustic levitation

PubMed

Ueha; Hashimoto; Koike

2000-03-01

Near-field acoustic levitation, where planar objects 10 kg in weight can levitate stably near the vibrating plate, is successfully applied both to non-contact transportation of objects and to a non-contact ultrasonic motor. Transporting apparatuses and an ultrasonic motor have been fabricated and their characteristics measured. The theory of near-field acoustic levitation both for a piston-like sound source and a flexural vibration source is also briefly described.

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.

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.

The Origin of High-Frequency Hearing in Whales.

PubMed

Churchill, Morgan; Martinez-Caceres, Manuel; de Muizon, Christian; Mnieckowski, Jessica; Geisler, Jonathan H

2016-08-22

Odontocetes (toothed whales) rely upon echoes of their own vocalizations to navigate and find prey underwater [1]. This sensory adaptation, known as echolocation, operates most effectively when using high frequencies, and odontocetes are rivaled only by bats in their ability to perceive ultrasonic sound greater than 100 kHz [2]. Although features indicative of ultrasonic hearing are present in the oldest known odontocetes [3], the significance of this finding is limited by the methods employed and taxa sampled. In this report, we describe a new xenorophid whale (Echovenator sandersi, gen. et sp. nov.) from the Oligocene of South Carolina that, as a member of the most basal clade of odontocetes, sheds considerable light on the evolution of ultrasonic hearing. By placing high-resolution CT data from Echovenator sandersi, 2 hippos, and 23 fossil and extant whales in a phylogenetic context, we conclude that ultrasonic hearing, albeit in a less specialized form, evolved at the base of the odontocete radiation. Contrary to the hypothesis that odontocetes evolved from low-frequency specialists [4], we find evidence that stem cetaceans, the archaeocetes, were more sensitive to high-frequency sound than their terrestrial ancestors. This indicates that selection for high-frequency hearing predates the emergence of Odontoceti and the evolution of echolocation. Copyright © 2016 Elsevier Ltd. All rights reserved.

PSO-based PID Speed Control of Traveling Wave Ultrasonic Motor under Temperature Disturbance

NASA Astrophysics Data System (ADS)

Arifin Mat Piah, Kamal; Yusoff, Wan Azhar Wan; Azmi, Nur Iffah Mohamed; Romlay, Fadhlur Rahman Mohd

2018-03-01

Traveling wave ultrasonic motors (TWUSMs) have a time varying dynamics characteristics. Temperature rise in TWUSMs remains a problem particularly in sustaining optimum speed performance. In this study, a PID controller is used to control the speed of TWUSM under temperature disturbance. Prior to developing the controller, a linear approximation model which relates the speed to the temperature is developed based on the experimental data. Two tuning methods are used to determine PID parameters: conventional Ziegler-Nichols(ZN) and particle swarm optimization (PSO). The comparison of speed control performance between PSO-PID and ZN-PID is presented. Modelling, simulation and experimental work is carried out utilizing Fukoku-Shinsei USR60 as the chosen TWUSM. The results of the analyses and experimental work reveal that PID tuning using PSO-based optimization has the advantage over the conventional Ziegler-Nichols method.

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 the speed of sound in a solid

NASA Astrophysics Data System (ADS)

Key, Tony; Smidrovskis, Robert; From, Milton

2000-02-01

The speed of sound in a solid is measured using an oscilloscope, a square-wave oscillator and a piezo-electric pick-up. A study of the relationship between the distance traveled and the time of arrival of the sound pulse allows a graphical determination of the speed of the pulse in the lucite rod.

Pulse-echo sound speed estimation using second order speckle statistics

NASA Astrophysics Data System (ADS)

Rosado-Mendez, Ivan M.; Nam, Kibo; Madsen, Ernest L.; Hall, Timothy J.; Zagzebski, James A.

2012-10-01

This work presents a phantom-based evaluation of a method for estimating soft-tissue speeds of sound using pulse-echo data. The method is based on the improvement of image sharpness as the sound speed value assumed during beamforming is systematically matched to the tissue sound speed. The novelty of this work is the quantitative assessment of image sharpness by measuring the resolution cell size from the autocovariance matrix for echo signals from a random distribution of scatterers thus eliminating the need of strong reflectors. Envelope data were obtained from a fatty-tissue mimicking (FTM) phantom (sound speed = 1452 m/s) and a nonfatty-tissue mimicking (NFTM) phantom (1544 m/s) scanned with a linear array transducer on a clinical ultrasound system. Dependence on pulse characteristics was tested by varying the pulse frequency and amplitude. On average, sound speed estimation errors were -0.7% for the FTM phantom and -1.1% for the NFTM phantom. In general, no significant difference was found among errors from different pulse frequencies and amplitudes. The method is currently being optimized for the differentiation of diffuse liver diseases.

Photoacoustics and speed-of-sound dual mode imaging with a long depth-of-field by using annular ultrasound array.

PubMed

Ding, Qiuning; Tao, Chao; Liu, Xiaojun

2017-03-20

Speed-of-sound and optical absorption reflect the structure and function of tissues from different aspects. A dual-mode microscopy system based on a concentric annular ultrasound array is proposed to simultaneously acquire the long depth-of-field images of speed-of-sound and optical absorption of inhomogeneous samples. First, speed-of-sound is decoded from the signal delay between each element of the annular array. The measured speed-of-sound could not only be used as an image contrast, but also improve the resolution and accuracy of spatial location of photoacoustic image in inhomogeneous acoustic media. Secondly, benefitting from dynamic focusing of annular array and the measured speed-of-sound, it is achieved an advanced acoustic-resolution photoacoustic microscopy with a precise position and a long depth-of-field. The performance of the dual-mode imaging system has been experimentally examined by using a custom-made annular array. The proposed dual-mode microscopy might have the significances in monitoring the biological physiological and pathological processes.

Shrinking Wings for Ultrasonic Pitch Production: Hyperintense Ultra-Short-Wavelength Calls in a New Genus of Neotropical Katydids (Orthoptera: Tettigoniidae)

PubMed Central

Sarria-S, Fabio A.; Morris, Glenn K.; Windmill, James F. C.; Jackson, Joseph; Montealegre-Z, Fernando

2014-01-01

This article reports the discovery of a new genus and three species of predaceous katydid (Insecta: Orthoptera) from Colombia and Ecuador in which males produce the highest frequency ultrasonic calling songs so far recorded from an arthropod. Male katydids sing by rubbing their wings together to attract distant females. Their song frequencies usually range from audio (5 kHz) to low ultrasonic (30 kHz). However, males of Supersonus spp. call females at 115 kHz, 125 kHz, and 150 kHz. Exceeding the human hearing range (50 Hz–20 kHz) by an order of magnitude, these insects also emit their ultrasound at unusually elevated sound pressure levels (SPL). In all three species these calls exceed 110 dB SPL rms re 20 µPa (at 15 cm). Males of Supersonus spp. have unusually reduced forewings (<0.5 mm2). Only the right wing radiates appreciable sound, the left bears the file and does not show a particular resonance. In contrast to most katydids, males of Supersonus spp. position and move their wings during sound production so that the concave aspect of the right wing, underlain by the insect dorsum, forms a contained cavity with sharp resonance. The observed high SPL at extreme carrier frequencies can be explained by wing anatomy, a resonant cavity with a membrane, and cuticle deformation. PMID:24901234

Attached cavitation at a small diameter ultrasonic horn tip

NASA Astrophysics Data System (ADS)

Žnidarčič, Anton; Mettin, Robert; Cairós, Carlos; Dular, Matevž

2014-02-01

Ultrasonic horn transducers are frequently used in applications of acoustic cavitation in liquids, for instance, for cell disruption or sonochemical reactions. They are operated typically in the frequency range up to about 50 kHz and have tip diameters from some mm to several cm. It has been observed that if the horn tip is sufficiently small and driven at high amplitude, cavitation is very strong, and the tip can be covered entirely by the gas/vapor phase for longer time intervals. A peculiar dynamics of the attached cavity can emerge with expansion and collapse at a self-generated frequency in the subharmonic range, i.e., below the acoustic driving frequency. Here, we present a systematic study of the cavitation dynamics in water at a 20 kHz horn tip of 3 mm diameter. The system was investigated by high-speed imaging with simultaneous recording of the acoustic emissions. Measurements were performed under variation of acoustic power, air saturation, viscosity, surface tension, and temperature of the liquid. Our findings show that the liquid properties play no significant role in the dynamics of the attached cavitation at the small ultrasonic horn. Also the variation of the experimental geometry, within a certain range, did not change the dynamics. We believe that the main two reasons for the peculiar dynamics of cavitation on a small ultrasonic horn are the higher energy density on a small tip and the inability of the big tip to "wash" away the gaseous bubbles. Calculation of the somewhat adapted Strouhal number revealed that, similar to the hydrodynamic cavitation, values which are relatively low characterize slow cavitation structure dynamics. In cases where the cavitation follows the driving frequency this value lies much higher - probably at Str > 20. In the spirit to distinguish the observed phenomenon with other cavitation dynamics at ultrasonic transducer surfaces, we suggest to term the observed phenomenon of attached cavities partly covering the full horn tip as "acoustic supercavitation." This reflects the conjecture that not the sound field in terms of acoustic (negative) pressure in the liquid is responsible for nucleation, but the motion of the transducer surface.

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.

On-line high-speed rail defect detection.

DOT National Transportation Integrated Search

2004-10-01

This report presents the results of phase 2 of the project On-line high-speed rail defect detection aimed at improving the reliability and the speed of current defect detection in rails. Ultrasonic guided waves, traveling in the rail running di...

Solute-solvent interactions in solutions of 2-hydroxy-5-chloro-3-nitroacetophenone isonicotinoylhydrazone in N, N-dimethylformamide at 298-313 K according to ultrasonic and viscometric data

NASA Astrophysics Data System (ADS)

Dikkar, A. B.; Pethe, G. B.; Aswar, A. S.

2015-12-01

Density (ρ), speed of sound ( u), and viscosity (η), measurements have been carried on 2-hydroxy- 5-chloro-3-nitroacetophenone isonicotinoylhydrazone (HCNAIH) in N, N-dimethylformamide at 298.15, 303.15, 308.15, and 313.15 K. Adiabatic compressibility (βs), intermolecular free length ( L f), acoustic impedance ( Z), internal pressure ( P int), the apparent molar volume ( V w), limiting apparent molar volume ( V w 0), partial molar expansibility (wE 0), apparent molar adiabatic compressibility ( K w), limiting apparent molar adiabatic compressibility ( K w 0), viscosity B coefficients of Jones-Dole equation have been calculated. The activation free energy (Δμ 2 0 *) for viscous flow in solution have been calculated from B coefficient and partial molar volume data. The calculated parameters are used to interpret the solute-solvent interactions and structure forming/breaking ability of solute in DMF.

Theoretical analysis and modeling of Thickness-Expansion Mode (TEM) sensors for fluid characterization.

PubMed

Elvira, Luis; Resa, Pablo; Castro, Pedro

2013-03-01

In this paper, the principles of Thickness-Expansion Mode (TEM) resonators for the characterization of fluids are described. From the measurement of the resonance parameters of a TEM piezoelectric transducer, the compressional acoustic impedance of gases and liquids can be determined. Since the propagation of mechanical waves into the fluid is not necessary, information in a wide range of frequencies can be obtained. Alternatively, these sensors can be driven in combination with other ultrasonic techniques to simultaneously determine the density, speed of sound and viscosity of samples. Some potential applications include the probe monitoring of processes and the characterization of fluids under harsh conditions. The main experimental criteria for the design and construction of high-resolution impedance meters (such as piezoelectric material, protective coating or thermal response) have been studied using equivalent electrical circuit modeling and finite element analysis. Copyright © 2012 Elsevier B.V. All rights reserved.

Female mice respond to male ultrasonic ‘songs’ with approach behaviour

PubMed Central

Hammerschmidt, K.; Radyushkin, K.; Ehrenreich, H.; Fischer, J.

2009-01-01

The ultrasonic vocalizations of mice are attracting increasing attention, because they have been recognized as an informative readout in genetically modified strains. In addition, the observation that male mice produce elaborate sequences of ultrasonic vocalizations (‘song’) when exposed to female mice or their scents has sparked a debate as to whether these sounds are—in terms of their structure and function—analogous to bird song. We conducted playback experiments with cycling female mice to explore the function of male mouse songs. Using a place preference design, we show that these vocalizations elicited approach behaviour in females. In contrast, the playback of pup isolation calls or whistle-like artificial control sounds did not evoke approach responses. Surprisingly, the females also did not respond to pup isolation calls. In addition, female responses did not vary in relation to reproductive cycle, i.e. whether they were in oestrus or not. Furthermore, our data revealed a rapid habituation of subjects to the experimental situation, which stands in stark contrast to other species' responses to courtship vocalizations. Nevertheless, our results clearly demonstrate that male mouse songs elicit females' interest. PMID:19515648

Female mice respond to male ultrasonic 'songs' with approach behaviour.

PubMed

Hammerschmidt, K; Radyushkin, K; Ehrenreich, H; Fischer, J

2009-10-23

The ultrasonic vocalizations of mice are attracting increasing attention, because they have been recognized as an informative readout in genetically modified strains. In addition, the observation that male mice produce elaborate sequences of ultrasonic vocalizations ('song') when exposed to female mice or their scents has sparked a debate as to whether these sounds are--in terms of their structure and function--analogous to bird song. We conducted playback experiments with cycling female mice to explore the function of male mouse songs. Using a place preference design, we show that these vocalizations elicited approach behaviour in females. In contrast, the playback of whistle-like artificial control sounds did not evoke approach responses. Surprisingly, the females also did not respond to pup isolation calls. In addition, female responses did not vary in relation to reproductive cycle, i.e. whether they were in oestrus or not. Furthermore, our data revealed a rapid habituation of subjects to the experimental situation, which stands in stark contrast to other species' responses to courtship vocalizations. Nevertheless, our results clearly demonstrate that male mouse songs elicit females' interest.

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

An Inexpensive and Versatile Version of Kundt's Tube for Measuring the Speed of Sound in Air

NASA Astrophysics Data System (ADS)

Papacosta, Pangratios; Linscheid, Nathan

2016-01-01

Experiments that measure the speed of sound in air are common in high schools and colleges. In the Kundt's tube experiment, a horizontal air column is adjusted until a resonance mode is achieved for a specific frequency of sound. When this happens, the cork dust in the tube is disturbed at the displacement antinode regions. The location of the displacement antinodes enables the measurement of the wavelength of the sound that is being used. This paper describes a design that uses a speaker instead of the traditional aluminum rod as the sound source. This allows the use of multiple sound frequencies that yield a much more accurate speed of sound in air.

Plastic Foam Porosity Characterization by Air-Borne Ultrasound

NASA Astrophysics Data System (ADS)

Hoffrén, H.; Karppinen, T.; Hæggström, E.

2006-03-01

We continue to develop an ultrasonic burst-reflection method for estimating porosity and tortuosity of solid materials. As a first step we report on method design considerations and measurements on polyurethane foams (Sylomer® vibration dampener) with well-defined porosity. The ultrasonic method is experimentally tested by measuring 235 kHz and 600 kHz air-borne ultrasound reflection from a foam surface at two incidence angles. The reflected sound wave from different foam samples (32% - 64% porosity) was compared to a wave that had traveled from the transmitter to the detector without reflection. The ultrasonically estimated sample porosities coincided within 8% with the porosity estimates obtained by a gravimetric reference method. This parallels the uncertainty of the gravimetric method, 8%. The repeatability of the ultrasonic porosity measurements was better than 5%.

Reproduction of mouse-pup ultrasonic vocalizations by nanocrystalline silicon thermoacoustic emitter

NASA Astrophysics Data System (ADS)

Kihara, Takashi; Harada, Toshihiro; Kato, Masahiro; Nakano, Kiyoshi; Murakami, Osamu; Kikusui, Takefumi; Koshida, Nobuyoshi

2006-01-01

As one of the functional properties of ultrasound generator based on efficient thermal transfer at the nanocrystalline silicon (nc-Si) layer surface, its potential as an ultrasonic simulator of vocalization signals is demonstrated by using the acoustic data of mouse-pup calls. The device composed of a surface-heating thin-film electrode, an nc-Si layer, and a single-crystalline silicon (c-Si) wafer, exhibits an almost completely flat frequency response over a wide range without any mechanical surface vibration systems. It is shown that the fabricated emitter can reproduce digitally recorded ultrasonic mouse-pups vocalizations very accurately in terms of the call duration, frequency dispersion, and sound pressure level. The thermoacoustic nc-Si device provides a powerful physical means for the understanding of ultrasonic communication mechanisms in various living animals.

The influence of flight speed on the ranging performance of bats using frequency modulated echolocation pulses

NASA Astrophysics Data System (ADS)

Boonman, Arjan M.; Parsons, Stuart; Jones, Gareth

2003-01-01

Many species of bat use ultrasonic frequency modulated (FM) pulses to measure the distance to objects by timing the emission and reception of each pulse. Echolocation is mainly used in flight. Since the flight speed of bats often exceeds 1% of the speed of sound, Doppler effects will lead to compression of the time between emission and reception as well as an elevation of the echo frequencies, resulting in a distortion of the perceived range. This paper describes the consequences of these Doppler effects on the ranging performance of bats using different pulse designs. The consequences of Doppler effects on ranging performance described in this paper assume bats to have a very accurate ranging resolution, which is feasible with a filterbank receiver. By modeling two receiver types, it was first established that the effects of Doppler compression are virtually independent of the receiver type. Then, used a cross-correlation model was used to investigate the effect of flight speed on Doppler tolerance and range-Doppler coupling separately. This paper further shows how pulse duration, bandwidth, function type, and harmonics influence Doppler tolerance and range-Doppler coupling. The influence of each signal parameter is illustrated using calls of several bat species. It is argued that range-Doppler coupling is a significant source of error in bat echolocation, and various strategies bats could employ to deal with this problem, including the use of range rate information are discussed.

Experimental investigations of forces and torque in conventional and ultrasonically-assisted drilling of cortical bone.

PubMed

Alam, K; Mitrofanov, A V; Silberschmidt, V V

2011-03-01

Bone drilling is widely used in orthopaedics and surgery; it is a technically demanding surgical procedure. Recent technological improvements in this area are focused on efforts to reduce forces in bone drilling. This study focuses on forces and a torque required for conventional and ultrasonically-assisted tool penetration into fresh bovine cortical bone. Drilling tests were performed with two drilling techniques, and the influence of drilling speed, feed rate and parameters of ultrasonic vibration on the forces and torque was studied. Ultrasonically-assisted drilling (UAD) was found to reduce a drilling thrust force and torque compared to conventional drilling (CD). The mechanism behind lower levels of forces and torque was explored, using high-speed filming of a drill-bone interaction zone, and was linked to the chip shape and character of its formation. It is expected that UAD will produce holes with minimal effort and avoid unnecessary damage and accompanying pain during the incision. Copyright © 2010 IPEM. Published by Elsevier Ltd. All rights reserved.

In-line mixing states monitoring of suspensions using ultrasonic reflection technique.

PubMed

Zhan, Xiaobin; Yang, Yili; Liang, Jian; Zou, Dajun; Zhang, Jiaqi; Feng, Luyi; Shi, Tielin; Li, Xiwen

2016-02-01

Based on the measurement of echo signal changes caused by different concentration distributions in the mixing process, a simple ultrasonic reflection technique is proposed for in-line monitoring of the mixing states of suspensions in an agitated tank in this study. The relation between the echo signals and the concentration of suspensions is studied, and the mixing process of suspensions is tracked by in-line measurement of ultrasonic echo signals using two ultrasonic sensors. Through the analysis of echo signals over time, the mixing states of suspensions are obtained, and the homogeneity of suspensions is quantified. With the proposed technique, the effects of impeller diameter and agitation speed on the mixing process are studied, and the optimal agitation speed and the minimum mixing time to achieve the maximum homogeneity are acquired under different operating conditions and design parameters. The proposed technique is stable and feasible and shows great potential for in-line monitoring of mixing states of suspensions. Copyright © 2015 Elsevier B.V. All rights reserved.

EFFECTS OF LASER RADIATION ON MATTER. LASER PLASMA: Laser—ultrasonic formation of melts of high-speed tool steels

NASA Astrophysics Data System (ADS)

Gureev, D. M.

1994-09-01

A study was made of the influence of ultrasonic vibrations on the processes of heat and mass transfer, and of structure formation during ultrafast crystallisation of laser melts of T1 high-speed tool steel. Acoustic flows which appeared in laser melts effectively smoothed out the temperature inhomogeneities and flattened the relief of the molten surface even when the laser radiation acted for just ~1 ms. The transformation of the mechanical energy of ultrasonic vibrations into heat increased the depth of the laser melt baths and suppressed crack formation. The observed changes in the structural and phase composition appeared as a change in the microhardness of the solidified laser melts. The geometry of coupling of ultrasound into a laser melt influenced the changes in the microhardness, suggesting a need for a more detailed analysis of the structure formation processes in the course of ultrafast crystallisation of laser melts in an ultrasonic field.

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.

Effectiveness of methods for detaching orthodontic implants likely to fracture upon rotational torque – an animal study

PubMed Central

Nakagaki, Susumu; Yasuda, Yoshitaka; Handa, Keisuke; Koike, Toshiyuki; Saito, Takashi; Mizoguchi, Itaru

2016-01-01

Abstract Orthodontic implants may fracture at the cortical bone level upon rotational torque. The impacted fragment can be detached by a range of methods, which are all more or less time‐consuming and injurious to the cortical bone. The aim of this study was to compare three different methods for detaching an orthodontic implant impacted in cortical bone. Health Sciences University of Hokkaido animal ethics committee approved the study protocol. Orthodontic titanium‐alloy (Ti‐6Al‐4 V) implants were placed bilaterally on the buccal side of the mandible of beagle dogs. Subsequently, the implants were detached using either a low‐speed handpiece with a round bur, alternatively by use of a low‐power or a high‐power ultrasonic instrument. In the first experiment, 56 orthodontic implants were placed into the dissected mandible from 7 animals. The methods for detachment were compared with respect to time interval, as well as associated undesirable bone loss as appraised by use of cone‐beam computed tomography. In experiment two, 2x2 implants were placed bilaterally in the mandible of 8 animals and subsequently detached by manual rotational torque, and the described three methods for detachment. The implant socket was investigated histologically as a function of removal method immediately after removal, and after 1, 3 and 8 weeks and contrasted with the healing of the socket of the implant that was detached by manual rotational torque. Statistical significance was appraised by the use of non‐parametric Kruskal‐Wallis one‐way analysis of variance. The method using the low‐power ultrasonic required significantly longer removal time versus the two other methods, i.e. high‐power ultrasonic and low‐speed handpiece with a round bur (p < 0.02). The amount of undesirable bone loss was substantially larger with low‐speed handpiece with a round bur compared to the two ultrasonic methods (p < 0.05). Bone formation after 3 weeks of healing was more complete following the use of low or high‐power ultrasonic instrument in comparison with a low‐speed handpiece rotary instrument method. Orthodontic implants likely to fracture upon rotational torque or impacted fractured fragments should be detached preferably with an ultrasonic instrument, because of less associated bone loss and more rapid bone healing compared to the use of a low‐speed handpiece rotary instrument. PMID:29744149

Direct Measurement of the Speed of Sound Using a Microphone and a Speaker

ERIC Educational Resources Information Center

Gómez-Tejedor, José A.; Castro-Palacio, Juan C.; Monsoriu, Juan A.

2014-01-01

We present a simple and accurate experiment to obtain the speed of sound in air using a conventional speaker and a microphone connected to a computer. A free open source digital audio editor and recording computer software application allows determination of the time-of-flight of the wave for different distances, from which the speed of sound is…

Using ultrasound tomography to identify the distributions of density throughout the breast

NASA Astrophysics Data System (ADS)

Sak, Mark; Duric, Neb; Littrup, Peter; Sherman, Mark E.; Gierach, Gretchen L.

2016-04-01

Women with high breast density are at increased risk of developing breast cancer. Breast density has usually been defined using mammography as the ratio of fibroglandular tissue to total breast area. Ultrasound tomography (UST) is an emerging modality that can also be used to measure breast density. UST creates tomographic sound speed images of the patient's breast which is useful as sound speed is directly proportional to tissue density. Furthermore, the volumetric and quantitative information contained in the sound speed images can be used to describe the distribution of breast density. The work presented here measures the UST sound speed density distributions of 165 women with negative screening mammography. Frequency distributions of the sound speed voxel information were examined for each patient. In a preliminary analysis, the UST sound speed distributions were averaged across patients and grouped by various patient and density-related factors (e.g., age, body mass index, menopausal status, average mammographic breast density). It was found that differences in the distribution of density could be easily visualized for different patient groupings. Furthermore, findings suggest that the shape of the distributions may be used to identify participants with varying amounts of dense and non-dense tissue.

Modulation frequency as a cue for auditory speed perception.

PubMed

Senna, Irene; Parise, Cesare V; Ernst, Marc O

2017-07-12

Unlike vision, the mechanisms underlying auditory motion perception are poorly understood. Here we describe an auditory motion illusion revealing a novel cue to auditory speed perception: the temporal frequency of amplitude modulation (AM-frequency), typical for rattling sounds. Naturally, corrugated objects sliding across each other generate rattling sounds whose AM-frequency tends to directly correlate with speed. We found that AM-frequency modulates auditory speed perception in a highly systematic fashion: moving sounds with higher AM-frequency are perceived as moving faster than sounds with lower AM-frequency. Even more interestingly, sounds with higher AM-frequency also induce stronger motion aftereffects. This reveals the existence of specialized neural mechanisms for auditory motion perception, which are sensitive to AM-frequency. Thus, in spatial hearing, the brain successfully capitalizes on the AM-frequency of rattling sounds to estimate the speed of moving objects. This tightly parallels previous findings in motion vision, where spatio-temporal frequency of moving displays systematically affects both speed perception and the magnitude of the motion aftereffects. Such an analogy with vision suggests that motion detection may rely on canonical computations, with similar neural mechanisms shared across the different modalities. © 2017 The Author(s).

A traveling wave ultrasonic motor of high torque.

PubMed

Chen, Y; Liu, Q L; Zhou, T Y

2006-12-22

A traveling wave ultrasonic motor of high torque with a new configuration is proposed in this paper. In the new design, a part of the motor serves as the stator. The rotor is the vibrator consisting of a toothed metal ring with piezoelectric ceramic bonded, which generates ultrasonic vibration. The rotor is in contact with the shell of motor and is driven by the friction between the rotor and the stator. This configuration not only removes the rotor in a conventional type of traveling wave ultrasonic motor but also changes the interaction between the rotor and the stator of the motor so that it improves the output performance of the motor. Although an electric brush is added to the ultrasonic motor, it is easy to be fabricated because of the low speed of motor. The finite element method was used to compute the vibration modes of an ultrasonic motor with a diameter of 100mm to optimize the design of the motor. A 9th mode was chosen as the operation mode with a resonance frequency about 25 kHz. According to the design, a prototype was fabricated. Its performance was measured. The rotation speed-torque curves for various frequencies were obtained. The result shows that its stall torque is greater than 4 Nm within a range of 400 Hz. This ultrasonic motor was used to drive the window glass of a mobile car and the result was satisfactory. In the further the research on the friction material between the stator and the rotor is under way to improve the efficiency of the ultrasonic motor.

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

Interfacial Dynamics of Condensing Vapor Bubbles in an Ultrasonic Acoustic Field

NASA Astrophysics Data System (ADS)

Boziuk, Thomas; Smith, Marc; Glezer, Ari

2016-11-01

Enhancement of vapor condensation in quiescent subcooled liquid using ultrasonic actuation is investigated experimentally. The vapor bubbles are formed by direct injection from a pressurized steam reservoir through nozzles of varying characteristic diameters, and are advected within an acoustic field of programmable intensity. While kHz-range acoustic actuation typically couples to capillary instability of the vapor-liquid interface, ultrasonic (MHz-range) actuation leads to the formation of a liquid spout that penetrates into the vapor bubble and significantly increases its surface area and therefore condensation rate. Focusing of the ultrasonic beam along the spout leads to ejection of small-scale droplets from that are propelled towards the vapor liquid interface and result in localized acceleration of the condensation. High-speed video of Schlieren images is used to investigate the effects of the ultrasonic actuation on the thermal boundary layer on the liquid side of the vapor-liquid interface and its effect on the condensation rate, and the liquid motion during condensation is investigated using high-magnification PIV measurements. High-speed image processing is used to assess the effect of the actuation on the dynamics and temporal variation in characteristic scale (and condensation rate) of the vapor bubbles.

Cleaning and activation of beryllium-copper electron multiplier dynodes.

NASA Technical Reports Server (NTRS)

Pongratz, M. B.

1972-01-01

Description of a cleaning and activation procedure followed in preparing beryllium-copper dynodes for electron multipliers used in sounding-rocket experiments to detect auroral electrons. The initial degreasing step involved a 5-min bath in trichloroethylene in an ultrasonic cleaner. This was followed by an ultrasonic rinse in methanol and by a two-step acid pickling treatment to remove the oxides. Additional rinsing in water and methanol was followed by activation in a stainless-steel RF induction oven.

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.

Using a High-Speed Camera to Measure the Speed of Sound

ERIC Educational Resources Information Center

Hack, William Nathan; Baird, William H.

2012-01-01

The speed of sound is a physical property that can be measured easily in the lab. However, finding an inexpensive and intuitive way for students to determine this speed has been more involved. The introduction of affordable consumer-grade high-speed cameras (such as the Exilim EX-FC100) makes conceptually simple experiments feasible. Since the…

How to use a nebulizer

MedlinePlus

... different kind, called an ultrasonic nebulizer, uses sound vibrations. This kind of nebulizer is quieter, but costs ... Chronic obstructive pulmonary disease Wheezing Patient Instructions Asthma - control drugs Asthma - quick-relief drugs Bronchiolitis - discharge COPD - ...

Ultrasonically assisted turning of aviation materials: simulations and experimental study.

PubMed

Babitsky, V I; Mitrofanov, A V; Silberschmidt, V V

2004-04-01

Ultrasonically assisted turning of modern aviation materials is conducted with ultrasonic vibration (frequency f approximately 20 kHz, amplitude a approximately 15 microm) superimposed on the cutting tool movement. An autoresonant control system is used to maintain the stable nonlinear resonant mode of vibration throughout the cutting process. Experimental comparison of roughness and roundness for workpieces machined conventionally and with the superimposed ultrasonic vibration, results of high-speed filming of the turning process and nanoindentation analyses of the microstructure of the machined material are presented. The suggested finite-element model provides numerical comparison between conventional and ultrasonic turning of Inconel 718 in terms of stress/strain state, cutting forces and contact conditions at the workpiece/tool interface.

Can early hepatic fibrosis stages be discriminated by combining ultrasonic parameters?

PubMed

Bouzitoune, Razika; Meziri, Mahmoud; Machado, Christiano Bittencourt; Padilla, Frédéric; Pereira, Wagner Coelho de Albuquerque

2016-05-01

In this study, we put forward a new approach to classify early stages of fibrosis based on a multiparametric characterization using backscatter ultrasonic signals. Ultrasonic parameters, such as backscatter coefficient (Bc), speed of sound (SoS), attenuation coefficient (Ac), mean scatterer spacing (MSS), and spectral slope (SS), have shown their potential to differentiate between healthy and pathologic samples in different organs (eye, breast, prostate, liver). Recently, our group looked into the characterization of stages of hepatic fibrosis using the parameters cited above. The results showed that none of them could individually distinguish between the different stages. Therefore, we explored a multiparametric approach by combining these parameters in two and three, to test their potential to discriminate between the stages of liver fibrosis: F0 (normal), F1, F3, and/without F4 (cirrhosis), according to METAVIR Score. Discriminant analysis showed that the most relevant individual parameter was Bc, followed by SoS, SS, MSS, and Ac. The combination of (Bc, SoS) along with the four stages was the best in differentiating between the stages of fibrosis and correctly classified 85% of the liver samples with a high level of significance (p<0.0001). Nevertheless, when taking into account only stages F0, F1, and F3, the discriminant analysis showed that the parameters (Bc, SoS) and (Bc, Ac) had a better classification (93%) with a high level of significance (p<0.0001). The combination of the three parameters (Bc, SoS, and Ac) led to a 100% correct classification. In conclusion, the current findings show that the multiparametric approach has great potential in differentiating between the stages of fibrosis, and thus could play an important role in the diagnosis and follow-up of hepatic fibrosis. Copyright © 2016 Elsevier B.V. All rights reserved.

Measuring Young's Modulus the Easy Way, and Tracing the Effects of Measurement Uncertainties

ERIC Educational Resources Information Center

Nunn, John

2015-01-01

The speed of sound in a solid is determined by the density and elasticity of the material. Young's modulus can therefore be calculated once the density and the speed of sound in the solid are measured. The density can be measured relatively easily, and the speed of sound through a rod can be measured very inexpensively by setting up a longitudinal…

A Comparative Study of Sound Speed in Air at Room Temperature between a Pressure Sensor and a Sound Sensor

ERIC Educational Resources Information Center

Amrani, D.

2013-01-01

This paper deals with the comparison of sound speed measurements in air using two types of sensor that are widely employed in physics and engineering education, namely a pressure sensor and a sound sensor. A computer-based laboratory with pressure and sound sensors was used to carry out measurements of air through a 60 ml syringe. The fast Fourier…

Research on the processing technology of elongated holes based on rotary ultrasonic drilling

NASA Astrophysics Data System (ADS)

Tong, Yi; Chen, Jianhua; Sun, Lipeng; Yu, Xin; Wang, Xin

2014-08-01

The optical glass is hard, brittle and difficult to process. Based on the method of rotating ultrasonic drilling, the study of single factor on drilling elongated holes was made in optical glass. The processing equipment was DAMA ultrasonic machine, and the machining tools were electroplated with diamond. Through the detection and analysis on the processing quality and surface roughness, the process parameters (the spindle speed, amplitude, feed rate) of rotary ultrasonic drilling were researched, and the influence of processing parameters on surface roughness was obtained, which will provide reference and basis for the actual processing.

Numerical Speed of Sound and its Application to Schemes for all Speeds

NASA Technical Reports Server (NTRS)

Liou, Meng-Sing; Edwards, Jack R.

1999-01-01

The concept of "numerical speed of sound" is proposed in the construction of numerical flux. It is shown that this variable is responsible for the accurate resolution of' discontinuities, such as contacts and shocks. Moreover, this concept can he readily extended to deal with low speed and multiphase flows. As a results, the numerical dissipation for low speed flows is scaled with the local fluid speed, rather than the sound speed. Hence, the accuracy is enhanced the correct solution recovered, and the convergence rate improved. We also emphasize the role of mass flux and analyze the behavior of this flux. Study of mass flux is important because the numerical diffusivity introduced in it can be identified. In addition, it is the term common to all conservation equations. We show calculated results for a wide variety of flows to validate the effectiveness of using the numerical speed of sound concept in constructing the numerical flux. We especially aim at achieving these two goals: (1) improving accuracy and (2) gaining convergence rates for all speed ranges. We find that while the performance at high speed range is maintained, the flux now has the capability of performing well even with the low: speed flows. Thanks to the new numerical speed of sound, the convergence is even enhanced for the flows outside of the low speed range. To realize the usefulness of the proposed method in engineering problems, we have also performed calculations for complex 3D turbulent flows and the results are in excellent agreement with data.

Ultrasonic Characterization of Aging Behavior in M250 Grade Maraging Steel

NASA Astrophysics Data System (ADS)

Yeheskel, Ori

2009-03-01

The increase in sound velocities during the aging of M250 maraging steel reported by Rajkumar et al. was analyzed. The present article provides a new perspective on why and to what extent the sound velocities change during aging. The main parameter that affects the elastic moduli and the sound velocities in the early and intermediate stages of aging in maraging steel is the depletion of Ni from the martensitic matrix due to Ni3Ti and Ni3Mo formation. The issue of sound velocity increase with aging time was addressed here in a few different ways to support the validity of Ni depletion.

Ultrasonic Recovery and Modification of Food Ingredients

NASA Astrophysics Data System (ADS)

Vilkhu, Kamaljit; Manasseh, Richard; Mawson, Raymond; Ashokkumar, Muthupandian

There are two general classes of effects that sound, and ultrasound in particular, can have on a fluid. First, very significant modifications to the nature of food and food ingredients can be due to the phenomena of bubble acoustics and cavitation. The applied sound oscillates bubbles in the fluid, creating intense forces at microscopic scales thus driving chemical changes. Second, the sound itself can cause the fluid to flow vigorously, both on a large scale and on a microscopic scale; furthermore, the sound can cause particles in the fluid to move relative to the fluid. These streaming phenomena can redistribute materials within food and food ingredients at both microscopic and macroscopic scales.

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.

Processing data, for improved, accuracy, from device for measuring speed of sound in a gas

DOEpatents

Owen, Thomas E.

2006-09-19

A method, used in connection with a pulse-echo type sensor for determining the speed of sound in a gas, for improving the accuracy of speed of sound measurements. The sensor operates on the principle that speed of sound can be derived from the difference between the two-way travel time of signals reflected from two different target faces of the sensor. This time difference is derived by computing the cross correlation between the two reflections. The cross correlation function may be fitted to a parabola whose vertex represents the optimum time coordinate of the coherence peak, thereby providing an accurate measure of the two-way time diffference.

Hawkmoths produce anti-bat ultrasound

PubMed Central

Barber, Jesse R.; Kawahara, Akito Y.

2013-01-01

Bats and moths have been engaged in aerial warfare for nearly 65 Myr. This arms race has produced a suite of counter-adaptations in moths, including bat-detecting ears. One set of defensive strategies involves the active production of sound; tiger moths' ultrasonic replies to bat attack have been shown to startle bats, warn the predators of bad taste and jam their biosonar. Here, we report that hawkmoths in the Choerocampina produce entirely ultrasonic sounds in response to tactile stimulation and the playback of biosonar attack sequences. Males do so by grating modified scraper scales on the outer surface of the genital valves against the inner margin of the last abdominal tergum. Preliminary data indicate that females also produce ultrasound to touch and playback of echolocation attack, but they do so with an entirely different mechanism. The anti-bat function of these sounds is unknown but might include startling, cross-family acoustic mimicry, warning of unprofitability or physical defence and/or jamming of echolocation. Hawkmoths present a novel and tractable system to study both the function and evolution of anti-bat defences. PMID:23825084

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

Internal Wave Impact on the Performance of a Hypothetical Mine Hunting Sonar

DTIC Science & Technology

2014-10-01

time steps) to simulate the propagation of the internal wave field through the mine field. Again the transmission loss and acoustic signal strength...dependent internal wave perturbed sound speed profile was evaluated by calculating the temporal variability of the signal excess (SE) of acoustic...internal wave perturbation of the sound speed profile, was calculated for a limited sound speed field time section. Acoustic signals were projected

Ultrasonic technique for detection of liquids in copper tubing process lines

NASA Astrophysics Data System (ADS)

Dudley, W. A.

1980-10-01

An ultrasonic pulse-echo method developed for semiquantitative measurement of liquid levels in copper tubing is described. This ultrasonic approach is of particular value when used as a pre-maintenance diagnostic tool in repairing process lines containing hazardous liquids. Performance tests show that water and similar liquids can be directly detected to fill levels as low as 1/16 in. For water fills below 1/16 in., direct level detection is impractical because of signal resolution limitations. However, this fill condition is indirectly measurable and is detected by the effect of observed degradation of the adjacent wall echo pattern. Fill conditions for liquids associated with high sound attenuation such as oil can be indirectly determined.

Three-dimensional simulation of ultrasound propagation through trabecular bone structures measured by synchrotron microtomography.

PubMed

Bossy, Emmanuel; Padilla, Frédéric; Peyrin, Françoise; Laugier, Pascal

2005-12-07

Three-dimensional numerical simulations of ultrasound transmission were performed through 31 trabecular bone samples measured by synchrotron microtomography. The synchrotron microtomography provided high resolution 3D mappings of bone structures, which were used as the input geometry in the simulation software developed in our laboratory. While absorption (i.e. the absorption of ultrasound through dissipative mechanisms) was not taken into account in the algorithm, the simulations reproduced major phenomena observed in real through-transmission experiments in trabecular bone. The simulated attenuation (i.e. the decrease of the transmitted ultrasonic energy) varies linearly with frequency in the MHz frequency range. Both the speed of sound (SOS) and the slope of the normalized frequency-dependent attenuation (nBUA) increase with the bone volume fraction. Twenty-five out of the thirty-one samples exhibited negative velocity dispersion. One sample was rotated to align the main orientation of the trabecular structure with the direction of ultrasonic propagation, leading to the observation of a fast and a slow wave. Coupling numerical simulation with real bone architecture therefore provides a powerful tool to investigate the physics of ultrasound propagation in trabecular structures. As an illustration, comparison between results obtained on bone modelled either as a fluid or a solid structure suggested the major role of mode conversion of the incident acoustic wave to shear waves in bone to explain the large contribution of scattering to the overall attenuation.

A Comparison of Wind Speed Data from Mechanical and Ultrasonic Anemometers

NASA Technical Reports Server (NTRS)

Short, D.; Wells, L.; Merceret, F.; Roeder, W. P.

2006-01-01

This study compared the performance of mechanical and ultrasonic anemometers at the Eastern Range (ER; Kennedy Space Center and Cape Canaveral Air Force Station on Florida's Atlantic coast) and the Western Range (WR; Vandenberg Air Force Base on California's Pacific coast). Launch Weather Officers, forecasters, and Range Safety analysts need to understand the performance of wind sensors at the ER and WR for weather warnings, watches, advisories, special ground processing operations, launch pad exposure forecasts, user Launch Commit Criteria (LCC) forecasts and evaluations, and toxic dispersion support. The current ER and WR weather tower wind instruments are being changed from the current propeller-and-vane (ER) and cup-and-vane (WR) sensors to ultrasonic sensors through the Range Standardization and Automation (RSA) program. The differences between mechanical and ultrasonic techniques have been found to cause differences in the statistics of peak wind speed in previous studies. The 45th Weather Squadron (45 WS) and the 30th Weather Squadron (30 WS) requested the Applied Meteorology Unit (AMU) to compare data between RSA and current sensors to determine if there are significant differences. Approximately 3 weeks of Legacy and RSA wind data from each range were used in the study, archived during May and June 2005. The ER data spanned the full diurnal cycle, while the WR data was confined to 1000-1600 local time. The sample of 1-minute data from numerous levels on 5 different towers on each range totaled more than 500,000 minutes of data (482,979 minutes of data after quality control). The 10 towers were instrumented at several levels, ranging from 12 ft to 492 ft above ground level. The RSA sensors were collocated at the same vertical levels as the present sensors and typically within 15 ft horizontally of each another. Data from a total of 53 RSA ultrasonic sensors, collocated with present sensors were compared. The 1-minute average wind speed/direction and the 1-second peak wind speed/direction were compared.

Real-time sound speed correction using golden section search to enhance ultrasound imaging quality

NASA Astrophysics Data System (ADS)

Yoon, Chong Ook; Yoon, Changhan; Yoo, Yangmo; Song, Tai-Kyong; Chang, Jin Ho

2013-03-01

In medical ultrasound imaging, high-performance beamforming is important to enhance spatial and contrast resolutions. A modern receive dynamic beamfomer uses a constant sound speed that is typically assumed to 1540 m/s in generating receive focusing delays [1], [2]. However, this assumption leads to degradation of spatial and contrast resolutions particularly when imaging obese patients or breast since the sound speed is significantly lower than the assumed sound speed [3]; the true sound speed in the fatty tissue is around 1450 m/s. In our previous study, it was demonstrated that the modified nonlinear anisotropic diffusion is capable of determining an optimal sound speed and the proposed method is a useful tool to improve ultrasound image quality [4], [5]. In the previous study, however, we utilized at least 21 iterations to find an optimal sound speed, which may not be viable for real-time applications. In this paper, we demonstrates that the number of iterations can be dramatically reduced using the GSS(golden section search) method with a minimal error. To evaluate performances of the proposed method, in vitro experiments were conducted with a tissue mimicking phantom. To emulate a heterogeneous medium, the phantom was immersed in the water. From the experiments, the number of iterations was reduced from 21 to 7 with GSS method and the maximum error of the lateral resolution between direct and GSS was less than 1%. These results indicate that the proposed method can be implemented in real time to improve the image quality in the medical ultrasound imaging.

Ultrasonic speed, densities and viscosities of xylitol in water and in aqueous tyrosine and phenylalanine solutions at different temperatures

NASA Astrophysics Data System (ADS)

Ali, A.; Bidhuri, P.; Uzair, S.

2014-07-01

Ultrasonic speed u, densities ρ and viscosities η of xylitol in water and in 0.001 m aqueous l-tyrosine (Tyr) and l-phenylalanine (Phe) have been measured at different temperatures. From the density and ultrasonic speed measurements apparent molar isentropic compression κ_{φ}, apparent molar isentropic compressions at infinite dilution κ_{{S,φ}}0 , experimental slope S K , hydration number n H , transfer partial molar isentropic compressibility Δ_{tr} κ_{{S,φ}}0 of xylitol from water to aqueous Tyr and Phe have been obtained. From the viscosity data, B-coefficient and B-coefficient of transfer Δ tr B of xylitol from water to aqueous Phe and Tyr at different temperatures have also been estimated. Gibbs free energies of activation of viscous flow per mole of solvent Δ μ 1 0# and per mole of solute Δ μ 2 0# have been calculated by using Feakins transition state theory for the studied systems. The calculated parameters have been interpreted in terms of solute-solute and solute-solvent interactions and hydration behavior of xylitol.

Sound propagation in light-modulated carbon nanosponge suspensions

NASA Astrophysics Data System (ADS)

Zhou, W.; Tiwari, R. P.; Annamalai, R.; Sooryakumar, R.; Subramaniam, V.; Stroud, D.

2009-03-01

Single-walled carbon nanotube bundles dispersed in a highly polar fluid are found to agglomerate into a porous structure when exposed to low levels of laser radiation. The phototunable nanoscale porous structures provide an unusual way to control the acoustic properties of the suspension. Despite the high sound speed of the nanotubes, the measured speed of longitudinal-acoustic waves in the suspension decreases sharply with increasing bundle concentration. Two possible explanations for this reduction in sound speed are considered. One is simply that the sound speed decreases because of fluid heat induced by laser light absorption by the carbon nanotubes. The second is that this decrease results from the smaller sound velocity of fluid confined in a porous medium. Using a simplified description of convective heat transport, we estimate that the increase in temperature is too small to account for the observed decrease in sound velocity. To test the second possible explanation, we calculate the sound velocity in a porous medium, using a self-consistent effective-medium approximation. The results of this calculation agree qualitatively with experiment. In this case, the observed sound wave would be the analog of the slow compressional mode of porous solids at a structural length scale of order of 100 nm.

Active Acoustic Array for Ultrasonic Biomedical Applications

DTIC Science & Technology

2001-07-30

of the human anatomy and means to 3 acoustically couple the acoustic array to the portion of the 4 human anatomy . The acoustic array is doubly...ultrasonic sound wave to be generated into the portion 14 of the 22 human anatomy . As previously mentioned, each of the acoustic 23 elements 28 acts as...human breast, it should be 3 recognized that the device can be adapted to detect cancer in 4 other portions of the human anatomy . 5 It is apparent

Relaxation of the residual defect structure in deformed polycrystals under ultrasonic action

NASA Astrophysics Data System (ADS)

Murzaev, R. T.; Bachurin, D. V.; Nazarov, A. A.

2017-07-01

Using numerical computer simulation, the behavior of disordered dislocation systems under the action of monochromatic standing sound wave has been investigated in the grain of the model two-dimensional polycrystal containing nonequilibrium grain boundaries. It has been found that the presence of grain boundaries markedly affects the behavior of dislocations. The relaxation process and changes in the level of internal stresses caused by the rearrangement of the dislocation structure due to the ultrasonic action have been studied.

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.

Ultrasonic vocalisation emitted by infant rodents: a tool for assessment of neurobehavioural development.

PubMed

Branchi, I; Santucci, D; Alleva, E

2001-11-01

Ultrasonic vocalisations (USVs) emitted by altricial rodent pups are whistle-like sounds with frequencies between 30 and 90 kHz. These signals play an important communicative role in mother-offspring interaction since they elicit in the dam a prompt response concerning caregiving behaviours. Both physical and social parameters modulate the USV emission in the infant rodent. Recently, a more detailed analysis of the ultrasonic vocalisation pattern, considering the spectrographic structure of sounds has allowed a deeper investigation of this behaviour. In order to investigate neurobehavioural development, the analysis of USVs presents several advantages, mainly: (i) USVs are one of the few responses produced by very young mice that can be quantitatively analysed and elicited by quantifiable stimuli; (ii) USV production follows a clear ontogenetic profile from birth to PND 14-15, thus allowing longitudinal neurobehavioural analysis during very early postnatal ontogeny. The study of this ethologically-ecologically relevant behaviour represent a valid model to evaluate possible alterations in the neurobehavioural development of perinatally treated or genetically modified infant rodents. Furthermore, the role played by several receptor agonists and antagonists in modulating USV rate makes this measure particularly important when investigating the effects of anxiogenic and anxiolytic compounds, and emotional behaviour in general.

Laryngeal airway reconstruction indicates that rodent ultrasonic vocalizations are produced by an edge-tone mechanism

PubMed Central

Borgard, Heather L.

2017-01-01

Some rodents produce ultrasonic vocalizations (USVs) for social communication using an aerodynamic whistle, a unique vocal production mechanism not found in other animals. The functional anatomy and evolution of this sound production mechanism remains unclear. Using laryngeal airway reconstruction, we identified anatomical specializations critical for USV production. A robust laryngeal cartilaginous framework supports a narrow supraglottal airway. An intralaryngeal airsac-like cavity termed the ventral pouch was present in three muroid rodents (suborder Myomorpha), but was absent in a heteromyid rodent (suborder Castorimorpha) that produces a limited vocal repertoire and no documented USVs. Small lesions to the ventral pouch in laboratory rats caused dramatic changes in USV production, supporting the hypothesis that an interaction between a glottal exit jet and the alar edge generates ultrasonic signals in rodents. The resulting undulating airflow around the alar edge interacts with the resonance of the ventral pouch, which may function as a Helmholtz resonator. The proposed edge-tone mechanism requires control of intrinsic laryngeal muscles and sets the foundation for acoustic variation and diversification among rodents. Our work highlights the importance of anatomical innovations in the evolution of animal sound production mechanisms. PMID:29291091

Experimental study of sound propagation in a flexible duct

PubMed

Huang; Choy; So; Chong

2000-08-01

Propagation of sound in a flexible duct is investigated both theoretically and experimentally. Strong coupling of sound and flexural waves on the duct wall is found when the wall-to-air mass ratio is of the order of unity. The axial phase speed of sound approaches the in vacuo speed of flexural waves (subsonic in this case) at low frequencies. However, a speed higher than the isentropic sound speed in free space (340 m/s) is found beyond a critical frequency which is a function of the mass ratio. Experiments using a duct with a finite section of tensioned membrane are compared with the propagating modes pertaining to the infinite membrane model. Satisfactory quantitative agreement is obtained and the measured phase speed ranges from 8.3 to 1348 m/s. In the moderate frequency range, the theory predicts high spatial damping rate for the subsonic waves, which is consistent with the experimental observation that subsonic waves become increasingly undetectable as the frequency increases. Substantial sound reflection is observed at the interface between the rigid and the flexible segments of the duct without cross-section discontinuity, which, together with the high spatial damping, could form a basis for passive control of low-frequency duct noise.

A System And Method To Determine Thermophysical Properties Of A Multi-Component Gas At Arbitrary Temperature And Pressure

DOEpatents

Morrow, Thomas E.; Behring, II, Kendricks A.

2004-03-09

A method to determine thermodynamic properties of a natural gas hydrocarbon, when the speed of sound in the gas is known at an arbitrary temperature and pressure. Thus, the known parameters are the sound speed, temperature, pressure, and concentrations of any dilute components of the gas. The method uses a set of reference gases and their calculated density and speed of sound values to estimate the density of the subject gas. Additional calculations can be made to estimate the molecular weight of the subject gas, which can then be used as the basis for mass flow calculations, to determine the speed of sound at standard pressure and temperature, and to determine various thermophysical characteristics of the gas.

Device For Determining Therophysical Properties Of A Multi-Component Gas At Arbitrary Temperature And Pressure

DOEpatents

Morrow, Thomas B.; Behring, II, Kendricks A.

2005-02-01

A computer product for determining thermodynamic properties of a natural gas hydrocarbon, when the speed of sound in the gas is known at an arbitrary temperature and pressure. Thus, the known parameters are the sound speed, temperature, pressure, and concentrations of any dilute components of the gas. The method uses a set of reference gases and their calculated density and speed of sound values to estimate the density of the subject gas. Additional calculations can be made to estimate the molecular weight of the subject gas, which can then be used as the basis for mass flow calculations, to determine the speed of sound at standard pressure and temperature, and to determine various thermophysical characteristics of the gas.

System and method to determine thermophysical properties of a multi-component gas

DOEpatents

Morrow, Thomas B.; Behring, II, Kendricks A.

2003-08-05

A system and method to characterize natural gas hydrocarbons using a single inferential property, such as standard sound speed, when the concentrations of the diluent gases (e.g., carbon dioxide and nitrogen) are known. The system to determine a thermophysical property of a gas having a first plurality of components comprises a sound velocity measurement device, a concentration measurement device, and a processor to determine a thermophysical property as a function of a correlation between the thermophysical property, the speed of sound, and the concentration measurements, wherein the number of concentration measurements is less than the number of components in the gas. The method includes the steps of determining the speed of sound in the gas, determining a plurality of gas component concentrations in the gas, and determining the thermophysical property as a function of a correlation between the thermophysical property, the speed of sound, and the plurality of concentrations.

Assessment of Virginia's hybrid South Dakota road profiling system.

DOT National Transportation Integrated Search

1996-01-01

South Dakota Road Profiling (SDRP) systems have been widely sanctioned for use in assessing road roughness and rutting at highway speeds. Traditionally, these high-speed profiling systems have been built around ultrasonic height sensors. More recentl...

Research and development of ultrasonic tomography technology for three-dimensional imaging of internal rail flaws : modeling and simulation.

DOT National Transportation Integrated Search

2013-04-01

This report covers the work performed under the FRA High-Speed BAA 20102011 program to demonstrate the technology of ultrasonic tomography for 3-D imaging of internal rail flaws. There is a need to develop new technologies that are able to quantif...

Research on Ultrasonic Flaw Detection of Steel Weld in Spatial Grid Structure

NASA Astrophysics Data System (ADS)

Du, Tao; Sun, Jiandong; Fu, Shengguang; Zhang, Changquan; Gao, Qing

2017-06-01

The welding quality of spatial grid member is an important link in quality control of steel structure. The paper analyzed the reasons that the welding seam of small-bore pipe with thin wall grid structure is difficult to be detected by ultrasonic wave from the theoretical and practical aspects. A series of feasible detection methods was also proposed by improving probe and operation approaches in this paper, and the detection methods were verified by project cases. Over the years, the spatial grid structure is widely used the engineering by virtue of its several outstanding characteristics such as reasonable structure type, standard member, excellent space integrity and quick installation. The wide application of spatial grid structure brings higher requirements on nondestructive test of grid structure. The implementation of new Code for Construction Quality Acceptance of Steel Structure Work GB50205-2001 strengthens the site inspection of steel structure, especially the site inspection of ultrasonic flaw detection in steel weld. The detection for spatial grid member structured by small-bore and thin-walled pipes is difficult due to the irregular influence of sound pressure in near-field region of sound field, sound beam diffusion generated by small bore pipe and reduction of sensitivity. Therefore, it is quite significant to select correct detecting conditions. The spatial grid structure of welding ball and bolt ball is statically determinate structure with high-order axial force which is connected by member bars and joints. It is welded by shrouding or conehead of member bars and of member bar and bolt-node sphere. It is obvious that to ensure the quality of these welding positions is critical to the quality of overall grid structure. However, the complexity of weld structure and limitation of ultrasonic detection method cause many difficulties in detection. No satisfactory results will be obtained by the conventional detection technology, so some special approaches must be used.

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.

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.

A multi points ultrasonic detection method for material flow of belt conveyor

NASA Astrophysics Data System (ADS)

Zhang, Li; He, Rongjun

2018-03-01

For big detection error of single point ultrasonic ranging technology used in material flow detection of belt conveyor when coal distributes unevenly or is large, a material flow detection method of belt conveyor is designed based on multi points ultrasonic counter ranging technology. The method can calculate approximate sectional area of material by locating multi points on surfaces of material and belt, in order to get material flow according to running speed of belt conveyor. The test results show that the method has smaller detection error than single point ultrasonic ranging technology under the condition of big coal with uneven distribution.

Ex vivo optimisation of a heterogeneous speed of sound model of the human skull for non-invasive transcranial focused ultrasound at 1 MHz.

PubMed

Marsac, L; Chauvet, D; La Greca, R; Boch, A-L; Chaumoitre, K; Tanter, M; Aubry, J-F

2017-09-01

Transcranial brain therapy has recently emerged as a non-invasive strategy for the treatment of various neurological diseases, such as essential tremor or neurogenic pain. However, treatments require millimetre-scale accuracy. The use of high frequencies (typically ≥1 MHz) decreases the ultrasonic wavelength to the millimetre scale, thereby increasing the clinical accuracy and lowering the probability of cavitation, which improves the safety of the technique compared with the use of low-frequency devices that operate at 220 kHz. Nevertheless, the skull produces greater distortions of high-frequency waves relative to low-frequency waves. High-frequency waves require high-performance adaptive focusing techniques, based on modelling the wave propagation through the skull. This study sought to optimise the acoustical modelling of the skull based on computed tomography (CT) for a 1 MHz clinical brain therapy system. The best model tested in this article corresponded to a maximum speed of sound of 4000 m.s -1 in the skull bone, and it restored 86% of the optimal pressure amplitude on average in a collection of six human skulls. Compared with uncorrected focusing, the optimised non-invasive correction led to an average increase of 99% in the maximum pressure amplitude around the target and an average decrease of 48% in the distance between the peak pressure and the selected target. The attenuation through the skulls was also assessed within the bandwidth of the transducers, and it was found to vary in the range of 10 ± 3 dB at 800 kHz and 16 ± 3 dB at 1.3 MHz.

Ultrasonic sensing of GMAW: Laser/EMAT defect detection system

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

Carlson, N.M.; Johnson, J.A.; Larsen, E.D.

1992-08-01

In-process ultrasonic sensing of welding allows detection of weld defects in real time. A noncontacting ultrasonic system is being developed to operate in a production environment. The principal components are a pulsed laser for ultrasound generation and an electromagnetic acoustic transducer (EMAT) for ultrasound reception. A PC-based data acquisition system determines the quality of the weld on a pass-by-pass basis. The laser/EMAT system interrogates the area in the weld volume where defects are most likely to occur. This area of interest is identified by computer calculations on a pass-by-pass basis using weld planning information provided by the off-line programmer. Themore » absence of a signal above the threshold level in the computer-calculated time interval indicates a disruption of the sound path by a defect. The ultrasonic sensor system then provides an input signal to the weld controller about the defect condition. 8 refs.« less

A high-power ultrasonic microreactor and its application in gas-liquid mass transfer intensification.

PubMed

Dong, Zhengya; Yao, Chaoqun; Zhang, Xiaoli; Xu, Jie; Chen, Guangwen; Zhao, Yuchao; Yuan, Quan

2015-02-21

The combination of ultrasound and microreactor is an emerging and promising area, but the report of designing high-power ultrasonic microreactor (USMR) is still limited. This work presents a robust, high-power and highly efficient USMR by directly coupling a microreactor plate with a Langevin-type transducer. The USMR is designed as a longitudinal half wavelength resonator, for which the antinode plane of the highest sound intensity is located at the microreactor. According to one dimension design theory, numerical simulation and impedance analysis, a USMR with a maximum power of 100 W and a resonance frequency of 20 kHz was built. The strong and uniform sound field in the USMR was then applied to intensify gas-liquid mass transfer of slug flow in a microfluidic channel. Non-inertial cavitation with multiple surface wave oscillation was excited on the slug bubbles, enhancing the overall mass transfer coefficient by 3.3-5.7 times.

Listening in Pheromone Plumes: Disruption of Olfactory-Guided Mate Attraction in a Moth by a Bat-Like Ultrasound

PubMed Central

Svenssona, Glenn P.; Löfstedt, Christer; Skals, Niels

2007-01-01

Nocturnal moths often use sex pheromones to find mates and ultrasonic hearing to evade echolocating bat predators. Male moths, when confronted with both pheromones and sound, thus have to trade off reproduction and predator avoidance depending on the relative strengths of the perceived conflicting stimuli. The ultrasonic hearing of Plodia interpunctella was investigated. A threshold curve for evasive reaction to ultrasound of tethered moths was established, and the frequency of best hearing was found to be between 40 and 70 kHz. Flight tunnel experiments were performed where males orienting in a sex pheromone plume were stimulated with 50 kHz pulses of different intensities. Pheromone-stimulated males showed increased defensive response with increased intensity of the sound stimulus, and the acoustic cue had long-lasting effects on their pheromone-mediated flight, revealing a cost associated with vital evasive behaviours. PMID:20331396

Passive Environmental ASW Prediction System (PEAPS)

DTIC Science & Technology

1975-03-01

Because the Frye and Pugh equation [1] for sound speed is dominated by temperature terms and requires relatively few program steps compared with...other speed of sound equations , it was used in the sound speed profile sub- program . The equation was modified to use the approximation ASS ASS AP • ASS AZ...in ppt (parts per thousand). 21 The SSP sub- program converts the input data to MKS units for use in the above equation and then converts the resultant

Direct measurement of the speed of sound using a microphone and a speaker

NASA Astrophysics Data System (ADS)

Gómez-Tejedor, José A.; Castro-Palacio, Juan C.; Monsoriu, Juan A.

2014-05-01

We present a simple and accurate experiment to obtain the speed of sound in air using a conventional speaker and a microphone connected to a computer. A free open source digital audio editor and recording computer software application allows determination of the time-of-flight of the wave for different distances, from which the speed of sound is calculated. The result is in very good agreement with the reported value in the literature.

On-line high-speed rail defect detection : part II.

DOT National Transportation Integrated Search

2012-03-01

The objectives of this project were (1) to improve the defect detection reliability and (2) to improve the inspection speed of conventional rail defect detection methods. The prototype developed in this work uses noncontact transducers, ultrasonic gu...

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

Research of Adhesion Bonds Between Gas-Thermal Coating and Pre-Modified Base

NASA Astrophysics Data System (ADS)

Kovalevskaya, Z.; Zaitsev, K.; Klimenov, V.

2016-08-01

Nature of adhesive bonds between gas-thermal nickel alloy coating and carbon steel base was examined using laser profilometry, optical metallography, transmission and scanning electron microscopy. The steel surface was plastically pre-deformed by an ultrasonic tool. Proved that ultrasound pre-treatment modifies the steel surface. Increase of dislocation density and formation of sub micro-structure are base elements of surface modification. While using high-speed gas-flame, plasma and detonation modes of coatings, surface activation occurs and durable adhesion is formed. Ultrasonic pre-treatment of base material is effective when sprayed particles and base material interact through physical-chemical bond formation. Before applying high-speed gas flame and plasma sprayed coatings, authors recommend ultrasonic pretreatment, which creates periodic wavy topography with a stroke of 250 microns on the steel surface. Before applying detonation sprayed coatings, authors recommend ultrasound pretreatment that create modified surface with a uniform micro-topography.

A novel serrated columnar phased array ultrasonic transducer

NASA Astrophysics Data System (ADS)

Zou, Cheng; Sun, Zhenguo; Cai, Dong; Song, Hongwei; Chen, Qiang

2016-02-01

Traditionally, wedges are required to generate transverse waves in a solid specimen and mechanical rotation device is needed for interrogation of a specimen with a hollow bore, such as high speed railway locomotive axles, turbine rotors, etc. In order to eliminate the mechanical rotation process, a novel array pattern of phased array ultrasonic transducers named as serrated columnar phased array ultrasonic transducer (SCPAUT) is designed. The elementary transducers are planar rectangular, located on the outside surface of a cylinder. This layout is aimed to generate electrically rotating transverse waveforms so as to inspect the longitudinal cracks on the outside surface of a specimen which has a hollow bore at the center, such as the high speed railway locomotive axles. The general geometry of the SCPAUT and the inspection system are illustrated. A FEM model and mockup experiment has been carried out. The experiment results are in good agreement with the FEM simulation results.

Error-eliminating rapid ultrasonic firing

DOEpatents

Borenstein, Johann; Koren, Yoram

1993-08-24

A system for producing reliable navigation data for a mobile vehicle, such as a robot, combines multiple range samples to increase the "confidence" of the algorithm in the existence of an obstacle. At higher vehicle speed, it is crucial to sample each sensor quickly and repeatedly to gather multiple samples in time to avoid a collision. Erroneous data is rejected by delaying the issuance of an ultrasonic energy pulse by a predetermined wait-period, which may be different during alternate ultrasonic firing cycles. Consecutive readings are compared, and the corresponding data is rejected if the readings differ by more than a predetermined amount. The rejection rate for the data is monitored and the operating speed of the navigation system is reduced if the data rejection rate is increased. This is useful to distinguish and eliminate noise from the data which truly represents the existence of an article in the field of operation of the vehicle.

Error-eliminating rapid ultrasonic firing

DOEpatents

Borenstein, J.; Koren, Y.

1993-08-24

A system for producing reliable navigation data for a mobile vehicle, such as a robot, combines multiple range samples to increase the confidence'' of the algorithm in the existence of an obstacle. At higher vehicle speed, it is crucial to sample each sensor quickly and repeatedly to gather multiple samples in time to avoid a collision. Erroneous data is rejected by delaying the issuance of an ultrasonic energy pulse by a predetermined wait-period, which may be different during alternate ultrasonic firing cycles. Consecutive readings are compared, and the corresponding data is rejected if the readings differ by more than a predetermined amount. The rejection rate for the data is monitored and the operating speed of the navigation system is reduced if the data rejection rate is increased. This is useful to distinguish and eliminate noise from the data which truly represents the existence of an article in the field of operation of the vehicle.

Study on the ultrasonic inspection method using the full matrix capture for the in service railway wheel

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

Peng, Jianping; Wang, Li; Zhang, Yu

The quality of wheel is especially important for the safety of high speed railway. In this paper, a new ultrasonic array inspection method, the Full Matrix Capture (FMC) has been studied and applied to the high speed railway wheel inspection, especially in the wheel web from the tread. Firstly, the principle of FMC and TFM algorithm is discussed, and then the new optimization is applied to the standard FMC; Secondly the fundamentals of optimization is described in detail and the performance is analyzed. Finally, the experiment has been built with a standard phased array block and railway wheel, and thenmore » the testing results are discussed and analyzed. It is demonstrated that this change for the ultrasonic data acquisition and image reconstruction has higher efficiency and lower cost comparing to the FMC's procedure.« less

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.

Ultrasound transmission measurements for tensile strength evaluation of tablets.

PubMed

Simonaho, Simo-Pekka; Takala, T Aleksi; Kuosmanen, Marko; Ketolainen, Jarkko

2011-05-16

Ultrasound transmission measurements were performed to evaluate the tensile strength of tablets. Tablets consisting of one ingredient were compressed from dibasic calcium phosphate dehydrate, two grades of microcrystalline cellulose and two grades of lactose monohydrate powders. From each powder, tablets with five different tensile strengths were directly compressed. Ultrasound transmission measurements were conducted on every tablet at frequencies of 2.25 MHz, 5 MHz and 10 MHz and the speed of sound was calculated from the acquired waveforms. The tensile strength of the tablets was determined using a diametrical mechanical testing machine and compared to the calculated speed of sound values. It was found that the speed of sound increased with the tensile strength for the tested excipients. There was a good correlation between the speed of sound and tensile strength. Moreover, based on the statistical tests, the groups with different tensile strengths can be differentiated from each other by measuring the speed of sound. Thus, the ultrasound transmission measurement technique is a potentially useful method for non-destructive and fast evaluation of the tensile strength of tablets. Copyright © 2011 Elsevier B.V. All rights reserved.

Metastable sound speed in gas-liquid mixtures

NASA Technical Reports Server (NTRS)

Bursik, J. W.; Hall, R. M.

1979-01-01

A new method of calculating speed of sound for two-phase flow is presented. The new equation assumes no phase change during the propagation of an acoustic disturbance and assumes that only the total entropy of the mixture remains constant during the process. The new equation predicts single-phase values for the speed of sound in the limit of all gas or all liquid and agrees with available two-phase, air-water sound speed data. Other expressions used in the two-phase flow literature for calculating two-phase, metastable sound speed are reviewed and discussed. Comparisons are made between the new expression and several of the previous expressions -- most notably a triply isentropic equation as used, a triply isentropic equation as used, among others, by Karplus and by Wallis. Appropriate differences are pointed out and a thermodynamic criterion is derived which must be satisfied in order for the triply isentropic expression to be thermodynamically consistent. This criterion is not satisfied for the cases examined, which included two-phase nitrogen, air-water, two-phase parahydrogen, and steam-water. Consequently, the new equation derived is found to be superior to the other equations reviewed.

Relation between hardness and ultrasonic velocity on pipeline steel welded joints

NASA Astrophysics Data System (ADS)

Carreón, H.; Barrera, G.; Natividad, C.; Salazar, M.; Contreras, A.

2016-04-01

In general, the ultrasonic techniques have been used to determine the mechanical properties of materials based on their relationship with metallurgical characteristics. In this research work, the relationship between ultrasonic wave velocity, hardness and the microstructure of steel pipeline welded joints is investigated. Measurements of ultrasonic wave velocity were made as a function of the location across the weld. Hardness measurements were performed in an attempt to correlate with ultrasonic response. In addition, the coarse and dendritic grain structure of the weld material is extreme and unpredictably anisotropic. Thus, due to the acoustic anisotropy of the crystal, weld material of studied joints is anisotropic too. Such structure is no longer direction-independent to the ultrasonic wave propagation; therefore, the ultrasonic beam deflects and redirects and the wave front becomes distorted. Thus, the use of conventional ultrasonic testing techniques using fixed beam angles is very limited and the application of conventional ultrasonic phased array techniques becomes desirable. This technique is proposed to assist pipeline operators in estimating the hardness through ultrasonic measures to evaluate the susceptibility to stress sulphide cracking and hydrogen-induced cracking due to hard spots in steel pipeline welded joints in service. Sound wave velocity and hardness measurements have been carried out on a steel welded joint. For each section of the welding, weld bead, fusion zone, heat affected zone and base metal were found to correspond particular values of the ultrasound velocity. These results were correlated with electron microscopy observations of the microstructure and sectorial scan view of welded joints by ultrasonic phased array.

Model-free adaptive speed control on travelling wave ultrasonic motor

NASA Astrophysics Data System (ADS)

Di, Sisi; Li, Huafeng

2018-01-01

This paper introduced a new data-driven control (DDC) method for the speed control of ultrasonic motor (USM). The model-free adaptive control (MFAC) strategy was presented in terms of its principles, algorithms, and parameter selection. To verify the efficiency of the proposed method, a speed-frequency-time model, which contained all the measurable nonlinearity and uncertainties based on experimental data was established for simulation to mimic the USM operation system. Furthermore, the model was identified using particle swarm optimization (PSO) method. Then, the control of the simulated system using MFAC was evaluated under different expectations in terms of overshoot, rise time and steady-state error. Finally, the MFAC results were compared with that of proportion iteration differentiation (PID) to demonstrate its advantages in controlling general random system.

Bulk-wave ultrasonic propagation imagers

NASA Astrophysics Data System (ADS)

Abbas, Syed Haider; Lee, Jung-Ryul

2018-03-01

Laser-based ultrasound systems are described that utilize the ultrasonic bulk-wave sensing to detect the damages and flaws in the aerospace structures. These systems apply pulse-echo or through transmission methods to detect longitudinal through-the-thickness bulk-waves. These thermoelastic waves are generated using Q-switched laser and non-contact sensing is performed using a laser Doppler vibrometer (LDV). Laser-based raster scanning is performed by either twoaxis translation stage for linear-scanning or galvanometer-based laser mirror scanner for angular-scanning. In all ultrasonic propagation imagers, the ultrasonic data is captured and processed in real-time and the ultrasonic propagation can be visualized during scanning. The scanning speed can go up to 1.8 kHz for two-axis linear translation stage based B-UPIs and 10 kHz for galvanometer-based laser mirror scanners. In contrast with the other available ultrasound systems, these systems have the advantage of high-speed, non-contact, real-time, and non-destructive inspection. In this paper, the description of all bulk-wave ultrasonic imagers (B-UPIs) are presented and their advantages are discussed. Experiments are performed with these system on various structures to proof the integrity of their results. The C-scan results produced from non-dispersive, through-the-thickness, bulk-wave detection show good agreement in detection of structural variances and damage location in all inspected structures. These results show that bulk-wave UPIs can be used for in-situ NDE of engineering structures.

Concerns of the Institute of Transport Study and Research for reducing the sound level inside completely repaired buses. [noise and vibration control

NASA Technical Reports Server (NTRS)

Groza, A.; Calciu, J.; Nicola, I.; Ionasek, A.

1974-01-01

Sound level measurements on noise sources on buses are used to observe the effects of attenuating acoustic pressure levels inside the bus by sound-proofing during complete repair. A spectral analysis of the sound level as a function of motor speed, bus speed along the road, and the category of the road is reported.

A Flexible 360-Degree Thermal Sound Source Based on Laser Induced Graphene

PubMed Central

Tao, Lu-Qi; Liu, Ying; Ju, Zhen-Yi; Tian, He; Xie, Qian-Yi; Yang, Yi; Ren, Tian-Ling

2016-01-01

A flexible sound source is essential in a whole flexible system. It’s hard to integrate a conventional sound source based on a piezoelectric part into a whole flexible system. Moreover, the sound pressure from the back side of a sound source is usually weaker than that from the front side. With the help of direct laser writing (DLW) technology, the fabrication of a flexible 360-degree thermal sound source becomes possible. A 650-nm low-power laser was used to reduce the graphene oxide (GO). The stripped laser induced graphene thermal sound source was then attached to the surface of a cylindrical bottle so that it could emit sound in a 360-degree direction. The sound pressure level and directivity of the sound source were tested, and the results were in good agreement with the theoretical results. Because of its 360-degree sound field, high flexibility, high efficiency, low cost, and good reliability, the 360-degree thermal acoustic sound source will be widely applied in consumer electronics, multi-media systems, and ultrasonic detection and imaging. PMID:28335239

Experiment on Finite Amplitude Sound Propagation in a Fluid with a Strong Sound Speed Gradient

NASA Astrophysics Data System (ADS)

Hobæk, H.; Voll, A.˚.; Fardal, R.; Calise, L.

2006-05-01

A closed tank of dimensions 0.5 × 0.5 × 2.7 m3, filled with a mixture of ethanol and water to produce an almost linear sound speed profile with a gradient near 450 (m/s)/m, served the purpose for investigating shocked sound wave propagation in a stratified environment. As the sound speed profile evolved by diffusion a number of different measurements were taken, both in areas with caustics, shadow zones, along the main beam and along the bottom. After about one year, part of the fluid was re-mixed to obtain a pronounced sound speed maximum some 20 cm above the bottom. The high intensity sound was produced by a plane circular piston type sound source with near-field length 45 cm and half power angle 0.8° at 1.1 MHz, placed near one end of the tank. Its tilt angle and depth could be varied. A 0.5 mm diameter PVDF needle hydrophone (Precision Acoustics) mapped the sound field in a vertical slice in the range 0.9 - 2.4 m, remotely controlled by a PC. We present results from measurements in a shadow zone and along the bottom. The latter, in particular, displays unexpected amplitude variations. The project was funded by the European Commission, contract number G4RD-CT-2000-00398.

Experimental Study on Ultrasonic Computed Tomography Using Transducers Arrayed on the Internal Surface of a Cylinder

NASA Astrophysics Data System (ADS)

Kim, Jung-Soon; Kim, Moo-Joon; Kim, Jung-Ho; Ha, Kang-Lyeol

2005-06-01

In this study, ultrasonic array transducers with 32 vibrators arranged on the internal surface of a part of a cylinder were fabricated. The vibrators were operated by the piezoelectric transverse effect. By controlling the phase of the input signal for every vibrator, a quasi plane wave was synthesized. Using the fabricated array, inverse scattering ultrasonic computed tomography (UCT) was carried out with a phantom specimen after checking the plane wave generation. It was confirmed that the plane wave was synthesized successfully and a sound velocity image of the phantom was obtained by the plane wave. Consequently, it was noted that the array could be employed as a transmitter and receiver for data acquisition in UCT.

Advanced ultrasonic techniques for nondestructive testing of austenitic and dissimilar welds in nuclear facilities

NASA Astrophysics Data System (ADS)

Juengert, Anne; Dugan, Sandra; Homann, Tobias; Mitzscherling, Steffen; Prager, Jens; Pudovikov, Sergey; Schwender, Thomas

2018-04-01

Austenitic stainless steel welds as well as dissimilar metal welds with nickel alloy filler material, used in safety relevant parts of nuclear power plants, still challenge the ultrasonic inspection. The weld material forms large oriented grains that lead, on the one hand, to high sound scattering and, on the other hand, to inhomogeneity and to the acoustic anisotropy of the weld structure. The ultrasonic wave fronts do not propagate linearly, as in ferritic weld joints, but along the curves, which depend on the specific grain structure of the weld. Due to the influence of these phenomena, it is difficult to analyze the inspection results and to classify the ultrasonic indications, which could be both from the weld geometry and from the material defects. A correct flaw sizing is not possible. In an ongoing research project, different techniques to improve the reliability of ultrasonic testing at these kinds of welds are investigated. In a first step (in the previous research project) two ultrasonic inspection techniques were developed and validated on plane test specimens with artificial and realistic flaws. In the ongoing project, these techniques are applied to circumferential pipe welds with longitudinal and transverse flaws. The technique developed at the Federal Institute for Materials Research and Testing (BAM) in Germany uses a combination of ray tracing and synthetic aperture focusing technique (SAFT). To investigate the unknown grain structure, the velocity distribution of weld-transmitting ultrasound waves is measured and used to model the weld by ray tracing. The second technique, developed at the Fraunhofer Institute for Nondestructive Testing (IZFP) in Germany, uses Sampling Phased Array (Full Matrix Capture) combined with the reverse phase matching (RPM) and the gradient elastic constant descent algorithm (GECDM). This inspection method is able to estimate the elastic constants of the columnar grains in the weld and offers an improvement of the reliability of ultrasonic testing through the correction of the sound field distortion. The unknown inhomogeneity and anisotropy are investigated using a reference indication and the special optimization algorithm. Both reconstruction techniques give quantitative inspection results and allow the defect sizing. They have been compared to conventional ultrasonic testing with techniques that are state of the art for components in nuclear power plants. The improvement will be quantified by the comparison of the probability of detection (POD) of each technique.

The Acoustic Model Evaluation Committee (AMEC) Reports. Volume 3. Evaluation of the RAYMODE X Propagation Loss Model. Book 1

DTIC Science & Technology

1982-09-01

and run on single sound speed profile. This model the UNIVAC 1108 computer. Other RAYMODE is in exteasive fleet usage, supporting versions were not...sought for significant disparities. (U) In addition to a sound speed versus depth or temperature versus depth plus a (U) Taken together, the two accuracy...as- constant salinity value, the program can sessment techniques, the Difference and access historical sound speed data FOM techniques, lead to

Absolute calibration technique for broadband ultrasonic transducers

NASA Technical Reports Server (NTRS)

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

1994-01-01

Calibrating an ultrasonic transducer can be performed with a reduced number of calculations and testing. A wide-band pulser is connected to an ultrasonic transducer under test to generate ultrasonic waves in a liquid. A single frequency is transmitted to the electrostatic acoustic transducer (ESAT) and the voltage change produced is monitored. Then a broadband ultrasonic pulse is generated by the ultrasonic transducer and received by the ESAT. The output of the ESAT is amplified and input to a digitized oscilloscope for fast Fourier transform. The resulting plot is normalized with the monitored signal from the single frequency pulse. The plot is then corrected for characteristics of the membrane and diffraction effects. The transfer function of the final plot is determined. The transfer function gives the final sensitivity of the ultrasonic transducer as a function of frequency. The advantage of the system is the speed of calibrating the transducer by a reduced number of measurements and removal of the membrane and diffraction effects.

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.

Measuring the speed of sound in air using smartphone applications

NASA Astrophysics Data System (ADS)

Yavuz, A.

2015-05-01

This study presents a revised version of an old experiment available in many textbooks for measuring the speed of sound in air. A signal-generator application in a smartphone is used to produce the desired sound frequency. Nodes of sound waves in a glass pipe, of which one end is immersed in water, are more easily detected, so results can be obtained more quickly than from traditional acoustic experiments using tuning forks.

Short-Range Acoustic Propagation Using Mobile Transmitters Under Arctic Ice Cover

DTIC Science & Technology

2017-09-01

predict the surface water/ice scattering and absorptive effects on transmitted sound . In addition, sound speed variability by range (usually...receivers at ranges out to 10 kilometers. Sound speed profile data was also measured on site. Transmission loss models were created as a baseline at the...received sound level (on the level of 30 to 40 decibels) at the same range and depth but different directions. 14. SUBJECT TERMS Arctic, Beaufort Sea

Sound Propagation in Shallow Water with an Inhomogeneous GAS-Saturated Bottom

NASA Astrophysics Data System (ADS)

Grigor'ev, V. A.; Petnikov, V. G.; Roslyakov, A. G.; Terekhina, Ya. E.

2018-05-01

We present the methods and results of numerical experiments studying the low-frequency sound propagation in one of the areas of the Arctic shelf with a randomly inhomogeneous gas-saturated bottom. The characteristics of the upper layer of bottom sedimentary rocks (sediments) used in calculations were obtained during a 3D seismic survey and trial drilling of the seafloor. We demonstrate the possibilities of substituting in numerical simulation a real bottom with a fluid homogeneous half-space where the effective value of the sound speed is equal to the average sound speed in the bottom, with averaging along the sound propagation path to a sediment depth of 0.6 wavelength in the bottom. An original technique is proposed for estimating the sound speed propagation in an upper inhomogeneous sediment layer. The technique is based on measurements of acoustic wave attenuation in water during waveguide propagation.

Application of ultrasound in periodontics: Part I

PubMed Central

Bains, Vive K.; Mohan, Ranjana; Bains, Rhythm

2008-01-01

Ultrasonic is a branch of acoustics concerned with sound vibrations in frequency ranges above audible level. Ultrasound uses the transmission and reflection of acoustic energy. A pulse is propagated and its reflection is received, both by the transducer. For clinical purposes ultrasound is generated by transducers, which converts electrical energy into ultrasonic waves. This is usually achieved by magnetostriction or piezoelectricity. Primary effects of ultrasound are thermal, mechanical (cavitation and microstreaming), and chemical (sonochemicals). Knowledge of the basic and other secondary effects of ultrasound is essential for the development of techniques of application. PMID:20142941

Determining the speed of sound in the air by sound wave interference

NASA Astrophysics Data System (ADS)

Silva, Abel A.

2017-07-01

Mechanical waves propagate through material media. Sound is an example of a mechanical wave. In fluids like air, sound waves propagate through successive longitudinal perturbations of compression and decompression. Audible sound frequencies for human ears range from 20 to 20 000 Hz. In this study, the speed of sound v in the air is determined using the identification of maxima of interference from two synchronous waves at frequency f. The values of v were correct to 0 °C. The experimental average value of {\\bar{ν }}\\exp =336 +/- 4 {{m}} {{{s}}}-1 was found. It is 1.5% larger than the reference value. The standard deviation of 4 m s-1 (1.2% of {\\bar{ν }}\\exp ) is an improved value by the use of the concept of the central limit theorem. The proposed procedure to determine the speed of sound in the air aims to be an academic activity for physics classes of scientific and technological courses in college.

Elastic-Plastic Behaviour of Ultrasonic Assisted Compression of Polyvinyl Chloride (PVC) Foam

NASA Astrophysics Data System (ADS)

Muhalim, N. A. D.; Hassan, M. Z.; Daud, Y.

2018-04-01

The present study aims to investigate the elastic-plastic behaviour of ultrasonic assisted compression of PVC closed-cell foam. A series of static and ultrasonic compression test of PVC closed-cell foam were conducted at a constant cross head speed of 30 mm/min on dry surface condition. For quasi-static test, specimen was compressed between two rigid platens using universal testing machine. In order to evaluate the specimen behavior under ultrasonic condition, specimen was placed between a specifically design double-slotted block horn and rigid platen. The horn was designed and fabricated prior to the test as a medium to transmit the ultrasonic vibration from the ultrasonic transducer to the working specimen. It was tuned to a frequency of 19.89 kHz in longitudinal mode and provided an average oscillation amplitude at 6 µm on the uppermost surface. Following, the characteristics of stress-strain curves for quasi-static and ultrasonic compression tests were analyzed. It was found that the compressive stress was significantly reduced at the onset of superimposed ultrasonic vibration during plastic deformation.

Determining Ultrasonic Vocalization Preferences in Mice using a Two-choice Playback Test

PubMed Central

Asaba, Akari; Kato, Masahiro; Koshida, Nobuyoshi; Kikusui, Takefumi

2015-01-01

Mice emit ultrasonic vocalizations (USVs) during a variety of conditions, such as pup isolation and adult social interactions. These USVs differ with age, sex, condition, and genetic background of the emitting animal. Although many studies have characterized these differences, whether receiver mice can discriminate among objectively different USVs and show preferences for particular sound traits remains to be elucidated. To determine whether mice can discriminate between different characteristics of USVs, a playback experiment was developed recently, in which preference responses of mice to two different USVs could be evaluated in the form of a place preference. First, USVs from mice were recorded. Then, the recorded USVs were edited, trimmed accordingly, and exported as stereophonic sound files. Next, the USV amplitudes generated by the two ultrasound emitters used in the experiment were adjusted to the same sound pressure level. Nanocrystalline silicon thermo-acoustic emitters were used to play the USVs back. Finally, to investigate the preference of subject mice to selected USVs, pairs of two differing USV signals were played back simultaneously in a two-choice test box. By repeatedly entering a defined zone near an ultrasound emitter and searching the wire mesh in front of the emitter, the mouse reveals its preference for one sound over another. This model allows comparing the attractiveness of the various features of mouse USVs, in various contexts. PMID:26381885

The Frank Stinchfield Award. Pulmonary fat embolism in revision hip arthroplasty.

PubMed

Woo, R; Minster, G J; Fitzgerald, R H; Mason, L D; Lucas, D R; Smith, F E

1995-10-01

Unilateral cemented hip hemiarthroplasty was done on 16 dogs who subsequently had revision arthroplasty and who were divided into 1 control and 3 experimental groups: The first group had cement extraction using osteotomes; the second, using a high speed burr; the third, an ultrasonic tool. Hemodynamic and transesophageal echocardiographic monitoring were done. Postmortem pulmonary specimens were examined for differences in the quantity of fat emboli. There was a significant increase in emboli with the ultrasonic tool as compared with osteotomes and high speed burr. There was no significant difference in emboli between the osteotomes and high speed burr. Fat emboli syndrome is related to mechanical compression of the femoral canal. The ultrasonic instrument was unique in its tendency to cause large embolic showers, especially during extraction of the distal cement plug. In these young dogs, minimal hemodynamic changes and no cardiac dysrhythmias occurred, which in part may be attributed to their good health. These changes may remain subclinical for patients with good cardiorespiratory reserve, or may become life threatening for those with poor reserve. By outlining the mechanisms of fat embolism in revision total hip arthroplasty, it may be possible to decrease future morbidity, especially in patients who frequently have cardiopulmonary disease.

Measuring the Speed of Sound in Water

ERIC Educational Resources Information Center

Ward, Richard J.

2015-01-01

This paper begins with an early measurement of the speed of sound in water. A historical overview of the consequent development of SONAR and medical imaging is given. A method of measuring the speed suitable for demonstration to year 10 students is described in detail, and an explanation of its systematic error examined.

Some applications of equilibrium thermodynamic properties to continuum gasdynamics

NASA Technical Reports Server (NTRS)

1976-01-01

The speed of sound for the propagation of isentropic disturbances in a gas is developed, including corrections for chemical reaction. The term zero frequency is used to describe this isentropic limit sound speed; the term signifies that change in the gasdynamic variables are all very slow compared with the chemical rate changes in the gas. A faster, nonisentropic speed of propagation occurs for disturbances where the changes in gasdynamic variables are fast compared with the chemical rate changes. In the limit, this is known as the infinite frequency or frozen sound speed - the former term calling attention to the very high frequency of the disturbance, the latter term calling attention to the frozen character of the chemical reactions under such rapid changes of state. The true sound speed for a disturbance of finite frequency is shown to be between these two limits and is expressed in terms of the chemical relaxation time. The Riemann invariants that are useful in determining the changes in flow speed along characteristic directions in supersonic flow are derived in terms of integrations of acoustic impedance, and example results are given for air.

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.

A continuous-wave ultrasound system for displacement amplitude and phase measurement.

PubMed

Finneran, James J; Hastings, Mardi C

2004-06-01

A noninvasive, continuous-wave ultrasonic technique was developed to measure the displacement amplitude and phase of mechanical structures. The measurement system was based on a method developed by Rogers and Hastings ["Noninvasive vibration measurement system and method for measuring amplitude of vibration of tissue in an object being investigated," U.S. Patent No. 4,819,643 (1989)] and expanded to include phase measurement. A low-frequency sound source was used to generate harmonic vibrations in a target of interest. The target was simultaneously insonified by a low-power, continuous-wave ultrasonic source. Reflected ultrasound was phase modulated by the target motion and detected with a separate ultrasonic transducer. The target displacement amplitude was obtained directly from the received ultrasound frequency spectrum by comparing the carrier and sideband amplitudes. Phase information was obtained by demodulating the received signal using a double-balanced mixer and low-pass filter. A theoretical model for the ultrasonic receiver field is also presented. This model coupled existing models for focused piston radiators and for pulse-echo ultrasonic fields. Experimental measurements of the resulting receiver fields compared favorably with theoretical predictions.

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.

A spherical harmonic approach for the determination of HCP texture from ultrasound: A solution to the inverse problem

NASA Astrophysics Data System (ADS)

Lan, Bo; Lowe, Michael J. S.; Dunne, Fionn P. E.

2015-10-01

A new spherical convolution approach has been presented which couples HCP single crystal wave speed (the kernel function) with polycrystal c-axis pole distribution function to give the resultant polycrystal wave speed response. The three functions have been expressed as spherical harmonic expansions thus enabling application of the de-convolution technique to enable any one of the three to be determined from knowledge of the other two. Hence, the forward problem of determination of polycrystal wave speed from knowledge of single crystal wave speed response and the polycrystal pole distribution has been solved for a broad range of experimentally representative HCP polycrystal textures. The technique provides near-perfect representation of the sensitivity of wave speed to polycrystal texture as well as quantitative prediction of polycrystal wave speed. More importantly, a solution to the inverse problem is presented in which texture, as a c-axis distribution function, is determined from knowledge of the kernel function and the polycrystal wave speed response. It has also been explained why it has been widely reported in the literature that only texture coefficients up to 4th degree may be obtained from ultrasonic measurements. Finally, the de-convolution approach presented provides the potential for the measurement of polycrystal texture from ultrasonic wave speed measurements.

Influence of track surface on the equine superficial digital flexor tendon loading in two horses at high speed trot.

PubMed

Crevier-Denoix, N; Pourcelot, P; Ravary, B; Robin, D; Falala, S; Uzel, S; Grison, A C; Valette, J P; Denoix, J M; Chateau, H

2009-03-01

Although track surfaces are a risk factor of tendon injuries, their effects on tendon loading at high speed are unknown. Using a noninvasive ultrasonic technique, it is now possible to evaluate the forces in the superficial digital flexor tendon (SDFT) in exercise conditions. To compare the effects of an all-weather waxed track (W) vs. a crushed sand track (S), on the SDFT loading in the trotter horse at high speed. Two trotter horses were equipped with the ultrasonic device (1 MHz ultrasonic probe, fixed on the palmar metacarpal area of the right forelimb). For each trial, data acquisition was made at 400 Hz and 10 consecutive strides were analysed. In each session, the 2 track surfaces were tested in a straight line. The speed was imposed at 10 m/s and recorded. The right forelimb was also equipped with a dynamometric horseshoe and skin markers. The horse was filmed with a high-speed camera (600 Hz); all recordings were synchronised. Statistical differences were tested using the GLM procedure (SAS; P < 0.05). Maximal tendon force was significantly lower on W compared with S. In addition to maximal force peaks around mid-stance, earlier peaks were observed, more pronounced on S than on W, at about 13% (horse 2) and 30% (both horses) of the stance phase. Comparison with kinematic data revealed that these early peaks were accompanied by plateaux in the fetlock angle-time chart. For high tendon forces, the tendon maximal loading rate was significantly lower on W than on S. CONCLUSIONS AND POTENTIAL CLINICAL RELEVANCE: The all-weather waxed track appears to induce a lesser and more gradual SDFT loading than crushed sand. The SDFT loading pattern at high speed trot suggests proximal interphalangeal joint movements during limb loading.

Application of the ultrasonic technique and high-speed filming for the study of the structure of air-water bubbly flows

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

Carvalho, R.D.M.; Venturini, O.J.; Tanahashi, E.I.

2009-10-15

Multiphase flows are very common in industry, oftentimes involving very harsh environments and fluids. Accordingly, there is a need to determine the dispersed phase holdup using noninvasive fast responding techniques; besides, knowledge of the flow structure is essential for the assessment of the transport processes involved. The ultrasonic technique fulfills these requirements and could have the capability to provide the information required. In this paper, the potential of the ultrasonic technique for application to two-phase flows was investigated by checking acoustic attenuation data against experimental data on the void fraction and flow topology of vertical, upward, air-water bubbly flows inmore » the zero to 15% void fraction range. The ultrasonic apparatus consisted of one emitter/receiver transducer and three other receivers at different positions along the pipe circumference; simultaneous high-speed motion pictures of the flow patterns were made at 250 and 1000 fps. The attenuation data for all sensors exhibited a systematic interrelated behavior with void fraction, thereby testifying to the capability of the ultrasonic technique to measure the dispersed phase holdup. From the motion pictures, basic gas phase structures and different flows patterns were identified that corroborated several features of the acoustic attenuation data. Finally, the acoustic wave transit time was also investigated as a function of void fraction. (author)« less

In-vitro analysis of forces in conventional and ultrasonically assisted drilling of bone.

PubMed

Alam, K; Hassan, Edris; Imran, Syed Husain; Khan, Mushtaq

2016-05-12

Drilling of bone is widely performed in orthopaedics for repair and reconstruction of bone. Current paper is focused on the efforts to minimize force generation during the drilling process. Ultrasonically Assisted Drilling (UAD) is a possible option to replace Conventional Drilling (CD) in bone surgical procedures. The purpose of this study was to investigate and analyze the effect of drilling parameters and ultrasonic parameters on the level of drilling thrust force in the presence of water irrigation. Drilling tests were performed on young bovine femoral bone using different parameters such as spindle speeds, feed rates, coolant flow rates, frequency and amplitudes of vibrations. The drilling force was significantly dropped with increase in drill rotation speed in both types of drilling. Increase in feed rate was more influential in raising the drilling force in CD compared to UAD. The force was significantly dropped when ultrasonic vibrations up to 10 kHz were imposed on the drill. The drill force was found to be unaffected by the range of amplitudes and the amount of water supplied to the drilling region in UAD. Low frequency vibrations with irrigation can be successfully used for safe and efficient drilling in bone.

Universal formula for the holographic speed of sound

NASA Astrophysics Data System (ADS)

Anabalón, Andrés; Andrade, Tomás; Astefanesei, Dumitru; Mann, Robert

2018-06-01

We consider planar hairy black holes in five dimensions with a real scalar field in the Breitenlohner-Freedman window and derive a universal formula for the holographic speed of sound for any mixed boundary conditions of the scalar field. As an example, we numerically construct the most general class of planar black holes coupled to a single scalar field in the consistent truncation of type IIB supergravity that preserves the SO (3) × SO (3) R-symmetry group of the gauge theory. For this particular family of solutions, we find that the speed of sound exceeds the conformal value. From a phenomenological point of view, the fact that the conformal bound can be violated by choosing the right mixed boundary conditions is relevant for the existence of neutron stars with a certain mass-size relationship for which a large value of the speed of sound codifies a stiff equation of state. In the way, we also shed light on a puzzle regarding the appearance of the scalar charges in the first law. Finally, we generalize the formula of the speed of sound to arbitrary dimensional scalar-metric theories whose parameters lie within the Breitenlohner-Freedman window.

Acoustic impedance properties of seafloor sediments off the coast of Southeastern Hainan, South China Sea

NASA Astrophysics Data System (ADS)

Hou, Zhengyu; Chen, Zhong; Wang, Jingqiang; Zheng, Xufeng; Yan, Wen; Tian, Yuhang; Luo, Yun

2018-04-01

Geoacoustic parameters are essential inputs to sediment wave propagation theories and are vital to underwater acoustic environment and explorations of the sea bottom. In this study, 21 seafloor sediment samples were collected off the coast of southeastern Hainan in the South China Sea. The sound speed was measured using a portable WSD-3 digital sonic instrument and the coaxial differential distance measurement method. Based on the measured sound speed and physical properties, the acoustic impedance and the pore-water-independent index of impedance (IOI) were calculated in this study. Similar to the sound speed, the IOI values are closely related to the sediment physical properties and change gradually from the northwest to the southeast. The relations between IOI and physical properties were studied and compared to the relations between the sound speed and physical properties. IOI is better correlated to physical properties than sound speed. This study also uses an error norm method to analyze the sensitivity of IOI to the physical parameters in the double-parameter equations and finds that the most influential physical parameters are as follows: wet bulk density > porosity > clay content > mean particle size.

Direct speed of sound measurement within the atmosphere during a national holiday in New Zealand

NASA Astrophysics Data System (ADS)

Vollmer, M.

2018-05-01

Measuring the speed of sound belongs to almost any physics curriculum. Two methods dominate, measuring resonance phenomena of standing waves or time-of-flight measurements. The second type is conceptually simpler, however, performing such experiments with dimensions of meters usually requires precise electronic time measurement equipment if accurate results are to be obtained. Here a time-of-flight measurement from a video recording is reported with a dimension of several km and an accuracy for the speed of sound of the order of 1%.

Calibration of International Space Station (ISS) Node 1 Vibro-Acoustic Model

NASA Technical Reports Server (NTRS)

Zhang, Weiguo; Raveendra, Ravi

2014-01-01

Reported here is the ability of utilizing the Energy Finite Element Method (E-FEM) to predict the vibro-acoustic sound fields within the International Space Station (ISS) Node 1 and to compare the results with actual measurements of leak sounds made by a one atmosphere to vacuum leak through a small hole in the pressure wall of the Node 1 STA module during its period of storage at Stennis Space Center (SSC). While the E-FEM method represents a reverberant sound field calculation, of importance to this application is the requirement to also handle the direct field effect of the sound generation. It was also important to be able to compute the sound fields in the ultrasonic frequency range. This report demonstrates the capability of this technology as applied to this type of application.

Speed and Accuracy of Rapid Speech Output by Adolescents with Residual Speech Sound Errors Including Rhotics

ERIC Educational Resources Information Center

Preston, Jonathan L.; Edwards, Mary Louise

2009-01-01

Children with residual speech sound errors are often underserved clinically, yet there has been a lack of recent research elucidating the specific deficits in this population. Adolescents aged 10-14 with residual speech sound errors (RE) that included rhotics were compared to normally speaking peers on tasks assessing speed and accuracy of speech…

Efficient subtle motion detection from high-speed video for sound recovery and vibration analysis using singular value decomposition-based approach

NASA Astrophysics Data System (ADS)

Zhang, Dashan; Guo, Jie; Jin, Yi; Zhu, Chang'an

2017-09-01

High-speed cameras provide full field measurement of structure motions and have been applied in nondestructive testing and noncontact structure monitoring. Recently, a phase-based method has been proposed to extract sound-induced vibrations from phase variations in videos, and this method provides insights into the study of remote sound surveillance and material analysis. An efficient singular value decomposition (SVD)-based approach is introduced to detect sound-induced subtle motions from pixel intensities in silent high-speed videos. A high-speed camera is initially applied to capture a video of the vibrating objects stimulated by sound fluctuations. Then, subimages collected from a small region on the captured video are reshaped into vectors and reconstructed to form a matrix. Orthonormal image bases (OIBs) are obtained from the SVD of the matrix; available vibration signal can then be obtained by projecting subsequent subimages onto specific OIBs. A simulation test is initiated to validate the effectiveness and efficiency of the proposed method. Two experiments are conducted to demonstrate the potential applications in sound recovery and material analysis. Results show that the proposed method efficiently detects subtle motions from the video.

Ultrasonic cleaning of interior surfaces

DOEpatents

MacKenzie, D.; Odell, C.

1994-03-01

An ultrasonic cleaning apparatus is described for cleaning the interior surfaces of tubes. The apparatus includes an ultrasonic generator and reflector each coupled to opposing ends of the open-ended, fluid-filled tube. Fluid-tight couplings seal the reflector and generator to the tube, preventing leakage of fluid from the interior of the tube. The reflector and generator are operatively connected to actuators, whereby the distance between them can be varied. When the distance is changed, the frequency of the sound waves is simultaneously adjusted to maintain the resonant frequency of the tube so that a standing wave is formed in the tube, the nodes of which are moved axially to cause cavitation along the length of the tube. Cavitation maximizes mechanical disruption and agitation of the fluid, dislodging foreign material from the interior surface. 3 figures.

Ultrasonic cleaning of interior surfaces

DOEpatents

Odell, D. MacKenzie C.

1996-01-01

An ultrasonic cleaning method for cleaning the interior surfaces of tubes. The method uses an ultrasonic generator and reflector each coupled to opposing ends of the open-ended, fluid-filled tube. Fluid-tight couplings seal the reflector and generator to the tube, preventing leakage of fluid from the interior of the tube. The reflector and generator are operatively connected to actuators, whereby the distance between them can be varied. When the distance is changed, the frequency of the sound waves is simultaneously adjusted to maintain the resonant frequency of the tube so that a standing wave is formed in the tube, the nodes of which are moved axially to cause cavitation along the length of the tube. Cavitation maximizes mechanical disruption and agitation of the fluid, dislodging foreign material from the interior surface.

Ultrasonic cleaning of interior surfaces

DOEpatents

Odell, D. MacKenzie C.

1994-01-01

An ultrasonic cleaning apparatus for cleaning the interior surfaces of tubes. The apparatus includes an ultrasonic generator and reflector each coupled to opposing ends of the open-ended, fluid-filled tube. Fluid-tight couplings seal the reflector and generator to the tube, preventing leakage of fluid from the interior of the tube. The reflector and generator are operatively connected to actuators, whereby the distance between them can be varied. When the distance is changed, the frequency of the sound waves is simultaneously adjusted to maintain the resonant frequency of the tube so that a standing wave is formed in the tube, the nodes of which are moved axially to cause cavitation along the length of the tube. Cavitation maximizes mechanical disruption and agitation of the fluid, dislodging foreign material from the interior surface.

Development and evaluation of a SUAS perching system

NASA Astrophysics Data System (ADS)

Reynolds, Ryan

Perching has been proposed as a possible landing technique for Small Unmanned Aircraft Systems (SUAS). The current research study develops an onboard open loop perching system for a fixed-wing SUAS and examines the impact of initial flight speed and sensor placement on the perching dynamics. A catapult launcher and modified COTS aircraft were used for the experiments, while an ultrasonic sensor on the aircraft was used to detect the perching target. Thirty tests were conducted varying the initial launch speed and ultrasonic sensor placement to see if they affected the time the aircraft reaches its maximum pitch angle, since the maximum pitch angle is the optimum perching point for the aircraft. High-speed video was analyzed to obtain flight data, along with data from an onboard inertial measuring unit. The data were analyzed using a model 1, two-way ANOVA to determine if launch speed and sensor placement affect the optimum perching point where the aircraft reaches its maximum pitch angle during the maneuver. The results show the launch speed does affect the time at which the maximum pitch angle occurs, but sensor placement does not. This means a closed loop system will need to adjust its perching distance based on its initial velocity. The sensor placement not having any noticeable effect means the ultrasonic sensor can be placed on the nose or the wing of the aircraft as needed for the design. There was also no noticeable interaction between the two variables. Aerodynamic parameters such as lift, drag, and moment coefficients were derived from the dynamic equations of motion for use in numerical simulations and dynamic perching models.

Quantitative ultrasound method for assessing stress-strain properties and the cross-sectional area of Achilles tendon

NASA Astrophysics Data System (ADS)

Du, Yi-Chun; Chen, Yung-Fu; Li, Chien-Ming; Lin, Chia-Hung; Yang, Chia-En; Wu, Jian-Xing; Chen, Tainsong

2013-12-01

The Achilles tendon is one of the most commonly observed tendons injured with a variety of causes, such as trauma, overuse and degeneration, in the human body. Rupture and tendinosis are relatively common for this strong tendon. Stress-strain properties and shape change are important biomechanical properties of the tendon to assess surgical repair or healing progress. Currently, there are rather limited non-invasive methods available for precisely quantifying the in vivo biomechanical properties of the tendons. The aim of this study was to apply quantitative ultrasound (QUS) methods, including ultrasonic attenuation and speed of sound (SOS), to investigate porcine tendons in different stress-strain conditions. In order to find a reliable method to evaluate the change of tendon shape, ultrasound measurement was also utilized for measuring tendon thickness and compared with the change in tendon cross-sectional area under different stress. A total of 15 porcine tendons of hind trotters were examined. The test results show that the attenuation and broadband ultrasound attenuation decreased and the SOS increased by a smaller magnitude as the uniaxial loading of the stress-strain upon tendons increased. Furthermore, the tendon thickness measured with the ultrasound method was significantly correlated with tendon cross-sectional area (Pearson coefficient = 0.86). These results also indicate that attenuation of QUS and ultrasonic thickness measurement are reliable and potential parameters for assessing biomechanical properties of tendons. Further investigations are needed to warrant the application of the proposed method in a clinical setting.

Oral and Hand Movement Speeds Are Associated with Expressive Language Ability in Children with Speech Sound Disorder

ERIC Educational Resources Information Center

Peter, Beate

2012-01-01

This study tested the hypothesis that children with speech sound disorder have generalized slowed motor speeds. It evaluated associations among oral and hand motor speeds and measures of speech (articulation and phonology) and language (receptive vocabulary, sentence comprehension, sentence imitation), in 11 children with moderate to severe SSD…

Dynamic Substrate for the Physical Encoding of Sensory Information in Bat Biosonar

NASA Astrophysics Data System (ADS)

Müller, Rolf; Gupta, Anupam K.; Zhu, Hongxiao; Pannala, Mittu; Gillani, Uzair S.; Fu, Yanqing; Caspers, Philip; Buck, John R.

2017-04-01

Horseshoe bats have dynamic biosonar systems with interfaces for ultrasonic emission (reception) that change shape while diffracting the outgoing (incoming) sound waves. An information-theoretic analysis based on numerical and physical prototypes shows that these shape changes add sensory information (mutual information between distant shape conformations <20 %), increase the number of resolvable directions of sound incidence, and improve the accuracy of direction finding. These results demonstrate that horseshoe bats have a highly effective substrate for dynamic encoding of sensory information.

Dynamic Substrate for the Physical Encoding of Sensory Information in Bat Biosonar.

PubMed

Müller, Rolf; Gupta, Anupam K; Zhu, Hongxiao; Pannala, Mittu; Gillani, Uzair S; Fu, Yanqing; Caspers, Philip; Buck, John R

2017-04-14

Horseshoe bats have dynamic biosonar systems with interfaces for ultrasonic emission (reception) that change shape while diffracting the outgoing (incoming) sound waves. An information-theoretic analysis based on numerical and physical prototypes shows that these shape changes add sensory information (mutual information between distant shape conformations <20%), increase the number of resolvable directions of sound incidence, and improve the accuracy of direction finding. These results demonstrate that horseshoe bats have a highly effective substrate for dynamic encoding of sensory information.

Theory for a gas composition sensor based on acoustic properties

NASA Technical Reports Server (NTRS)

Phillips, Scott; Dain, Yefim; Lueptow, Richard M.

2003-01-01

Sound travelling through a gas propagates at different speeds and its intensity attenuates to different degrees depending upon the composition of the gas. Theoretically, a real-time gaseous composition sensor could be based on measuring the sound speed and the acoustic attenuation. To this end, the speed of sound was modelled using standard relations, and the acoustic attenuation was modelled using the theory for vibrational relaxation of gas molecules. The concept for a gas composition sensor is demonstrated theoretically for nitrogen-methane-water and hydrogen-oxygen-water mixtures. For a three-component gas mixture, the measured sound speed and acoustic attenuation each define separate lines in the composition plane of two of the gases. The intersection of the two lines defines the gas composition. It should also be possible to use the concept for mixtures of more than three components, if the nature of the gas composition is known to some extent.

Optical Measurement of the Speed of Sound in Air Over the Temperature Range 300-650 K

NASA Technical Reports Server (NTRS)

Hart, Roger C.; Balla, R. Jeffrey; Herring, G. C.

2000-01-01

Using laser-induced thermal acoustics (LITA), the speed of sound in room air (1 atm) is measured over the temperature range 300-650 K. Since the LITA apparatus maintains a fixed sound wavelength as temperature is varied, this temperature range simultaneously corresponds to a sound frequency range of 10-15 MHz. The data are compared to a published model and typically agree within 0.1%-0.4% at each of 21 temperatures.

Temporal ventriloquism along the path of apparent motion: speed perception under different spatial grouping principles.

PubMed

Ogulmus, Cansu; Karacaoglu, Merve; Kafaligonul, Hulusi

2018-03-01

The coordination of intramodal perceptual grouping and crossmodal interactions plays a critical role in constructing coherent multisensory percepts. However, the basic principles underlying such coordinating mechanisms still remain unclear. By taking advantage of an illusion called temporal ventriloquism and its influences on perceived speed, we investigated how audiovisual interactions in time are modulated by the spatial grouping principles of vision. In our experiments, we manipulated the spatial grouping principles of proximity, uniform connectedness, and similarity/common fate in apparent motion displays. Observers compared the speed of apparent motions across different sound timing conditions. Our results revealed that the effects of sound timing (i.e., temporal ventriloquism effects) on perceived speed also existed in visual displays containing more than one object and were modulated by different spatial grouping principles. In particular, uniform connectedness was found to modulate these audiovisual interactions in time. The effect of sound timing on perceived speed was smaller when horizontal connecting bars were introduced along the path of apparent motion. When the objects in each apparent motion frame were not connected or connected with vertical bars, the sound timing was more influential compared to the horizontal bar conditions. Overall, our findings here suggest that the effects of sound timing on perceived speed exist in different spatial configurations and can be modulated by certain intramodal spatial grouping principles such as uniform connectedness.

Speed of sound estimation for thermal monitoring using an active ultrasound element during liver ablation therapy (Conference Presentation)

NASA Astrophysics Data System (ADS)

Kim, Younsu; Audigier, Chloé; Dillow, Austin; Cheng, Alexis; Boctor, Emad M.

2017-03-01

Thermal monitoring for ablation therapy has high demands for preserving healthy tissues while removing malignant ones completely. Various methods have been investigated. However, exposure to radiation, cost-effectiveness, and inconvenience hinder the use of X-ray or MRI methods. Due to the non-invasiveness and real-time capabilities of ultrasound, it is widely used in intraoperative procedures. Ultrasound thermal monitoring methods have been developed for affordable monitoring in real-time. We propose a new method for thermal monitoring using an ultrasound element. By inserting a Lead-zirconate-titanate (PZT) element to generate the ultrasound signal in the liver tissues, the single travel time of flight is recorded from the PZT element to the ultrasound transducer. We detect the speed of sound change caused by the increase in temperature during ablation therapy. We performed an ex vivo experiment with liver tissues to verify the feasibility of our speed of sound estimation technique. The time of flight information is used in an optimization method to recover the speed of sound maps during the ablation, which are then converted into temperature maps. The result shows that the trend of temperature changes matches with the temperature measured at a single point. The estimation error can be decreased by using a proper curve linking the speed of sound to the temperature. The average error over time was less than 3 degrees Celsius for a bovine liver. The speed of sound estimation using a single PZT element can be used for thermal monitoring.

Effects of small variations of speed of sound in optoacoustic tomographic imaging

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

Deán-Ben, X. Luís; Ntziachristos, Vasilis; Razansky, Daniel, E-mail: dr@tum.de

2014-07-15

Purpose: Speed of sound difference in the imaged object and surrounding coupling medium may reduce the resolution and overall quality of optoacoustic tomographic reconstructions obtained by assuming a uniform acoustic medium. In this work, the authors investigate the effects of acoustic heterogeneities and discuss potential benefits of accounting for those during the reconstruction procedure. Methods: The time shift of optoacoustic signals in an acoustically heterogeneous medium is studied theoretically by comparing different continuous and discrete wave propagation models. A modification of filtered back-projection reconstruction is subsequently implemented by considering a straight acoustic rays model for ultrasound propagation. The results obtainedmore » with this reconstruction procedure are compared numerically and experimentally to those obtained assuming a heuristically fitted uniform speed of sound in both full-view and limited-view optoacoustic tomography scenarios. Results: The theoretical analysis showcases that the errors in the time-of-flight of the signals predicted by considering the straight acoustic rays model tend to be generally small. When using this model for reconstructing simulated data, the resulting images accurately represent the theoretical ones. On the other hand, significant deviations in the location of the absorbing structures are found when using a uniform speed of sound assumption. The experimental results obtained with tissue-mimicking phantoms and a mouse postmortem are found to be consistent with the numerical simulations. Conclusions: Accurate analysis of effects of small speed of sound variations demonstrates that accounting for differences in the speed of sound allows improving optoacoustic reconstruction results in realistic imaging scenarios involving acoustic heterogeneities in tissues and surrounding media.« less

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.

Measuring Speed Using a Computer--Several Techniques.

ERIC Educational Resources Information Center

Pearce, Jon M.

1988-01-01

Introduces three different techniques to facilitate the measurement of speed and the associated kinematics and dynamics using a computer. Discusses sensing techniques using optical or ultrasonic sensors, interfacing with a computer, software routines for the interfaces, and other applications. Provides circuit diagrams, pictures, and a program to…

Natural and synthetic vocalizations of brown rat pups, Rattus norvegicus, enhance attractiveness of bait boxes in laboratory and field experiments.

PubMed

Takács, Stephen; Kowalski, Pawel; Gries, Gerhard

2016-10-01

Rats are often neophobic and thus do not readily enter trap boxes which are mandated in rodent management to help reduce the risk of accidental poisoning or capture of non-target animals. Working with brown rats, Rattus norvegicus, as a model species, our overall objective was to test whether sound cues from pups could be developed as a means to enhance captures of rats in trap boxes. Recording vocalizations from three-day-old pups after removal from their natal nest with both sonic and ultrasonic microphones revealed frequency components in the sonic range (1.8-7.5 kHz) and ultrasonic range (18-24 kHz, 33-55 kHz, 60-96 kHz). In two-choice laboratory bioassays, playback recordings of these vocalizations induced significant phonotactic and arrestment responses by juvenile, subadult and adult female and male rats. The effectiveness of engineered 'synthetic' rat pup sounds was dependent upon their frequency components, sound durations and the sound delivery system. Unlike other speakers, a piezoelectric transducer emitting sound bursts of 21 kHz with a 63-KHz harmonic, and persisting for 20-300 ms, proved highly effective in attracting and arresting adult female rats. In a field experiment, a battery-powered electronic device fitted with a piezoelectric transducer and driven by an algorithm that randomly generated sound cues resembling those recorded from rat pups and varying in fundamental frequency (19-23 kHz), duration (20-300 ms) and intermittent silence (300-5000 ms) significantly enhanced captures of rats in trap boxes baited with a food lure and soiled bedding material of adult female rats. Our study provides proof of concept that rat-specific sound cues or signals can be effectively reproduced and deployed as a means to enhance capture of wild rats. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Ultrasonic sensing of GMAW: Laser/EMAT defect detection system. [Gas Metal Arc Welding (GMAW), Electromagnetic acoustic transducer (EMAT)

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

Carlson, N.M.; Johnson, J.A.; Larsen, E.D.

1992-01-01

In-process ultrasonic sensing of welding allows detection of weld defects in real time. A noncontacting ultrasonic system is being developed to operate in a production environment. The principal components are a pulsed laser for ultrasound generation and an electromagnetic acoustic transducer (EMAT) for ultrasound reception. A PC-based data acquisition system determines the quality of the weld on a pass-by-pass basis. The laser/EMAT system interrogates the area in the weld volume where defects are most likely to occur. This area of interest is identified by computer calculations on a pass-by-pass basis using weld planning information provided by the off-line programmer. Themore » absence of a signal above the threshold level in the computer-calculated time interval indicates a disruption of the sound path by a defect. The ultrasonic sensor system then provides an input signal to the weld controller about the defect condition. 8 refs.« less

Simulation and experiment for the inspection of stainless steel bolts in servicing using an ultrasonic phased array

NASA Astrophysics Data System (ADS)

Chen, Jinzhong; He, Renyang; Kang, Xiaowei; Yang, Xuyun

2015-10-01

The non-destructive testing of small-sized (M12-M20) stainless steel bolts in servicing is always a technical problem. This article focuses on the simulation and experimental research of stainless steel bolts with an artificial defect reflector using ultrasonic phased array inspection. Based on the observation of the sound field distribution of stainless steel bolts in ultrasonic phased array as well as simulation modelling and analysis of the phased array probes' detection effects with various defect sizes, different artificial defect reflectors of M16 stainless steel bolts are machined in reference to the simulation results. Next, those bolts are tested using a 10-wafer phased array probe with 5 MHz. The test results finally prove that ultrasonic phased array can detect 1-mm cracks in diameter with different depths of M16 stainless steel bolts and a metal loss of Φ1 mm of through-hole bolts, which provides technical support for future non-destructive testing of stainless steel bolts in servicing.

Interferometric imaging of acoustical phenomena using high-speed polarization camera and 4-step parallel phase-shifting technique

NASA Astrophysics Data System (ADS)

Ishikawa, K.; Yatabe, K.; Ikeda, Y.; Oikawa, Y.; Onuma, T.; Niwa, H.; Yoshii, M.

2017-02-01

Imaging of sound aids the understanding of the acoustical phenomena such as propagation, reflection, and diffraction, which is strongly required for various acoustical applications. The imaging of sound is commonly done by using a microphone array, whereas optical methods have recently been interested due to its contactless nature. The optical measurement of sound utilizes the phase modulation of light caused by sound. Since light propagated through a sound field changes its phase as proportional to the sound pressure, optical phase measurement technique can be used for the sound measurement. Several methods including laser Doppler vibrometry and Schlieren method have been proposed for that purpose. However, the sensitivities of the methods become lower as a frequency of sound decreases. In contrast, since the sensitivities of the phase-shifting technique do not depend on the frequencies of sounds, that technique is suitable for the imaging of sounds in the low-frequency range. The principle of imaging of sound using parallel phase-shifting interferometry was reported by the authors (K. Ishikawa et al., Optics Express, 2016). The measurement system consists of a high-speed polarization camera made by Photron Ltd., and a polarization interferometer. This paper reviews the principle briefly and demonstrates the high-speed imaging of acoustical phenomena. The results suggest that the proposed system can be applied to various industrial problems in acoustical engineering.

Sample-based engine noise synthesis using an enhanced pitch-synchronous overlap-and-add method.

PubMed

Jagla, Jan; Maillard, Julien; Martin, Nadine

2012-11-01

An algorithm for the real time synthesis of internal combustion engine noise is presented. Through the analysis of a recorded engine noise signal of continuously varying engine speed, a dataset of sound samples is extracted allowing the real time synthesis of the noise induced by arbitrary evolutions of engine speed. The sound samples are extracted from a recording spanning the entire engine speed range. Each sample is delimitated such as to contain the sound emitted during one cycle of the engine plus the necessary overlap to ensure smooth transitions during the synthesis. The proposed approach, an extension of the PSOLA method introduced for speech processing, takes advantage of the specific periodicity of engine noise signals to locate the extraction instants of the sound samples. During the synthesis stage, the sound samples corresponding to the target engine speed evolution are concatenated with an overlap and add algorithm. It is shown that this method produces high quality audio restitution with a low computational load. It is therefore well suited for real time applications.

An Inexpensive and Versatile Version of Kundt's Tube for Measuring the Speed of Sound in Air

ERIC Educational Resources Information Center

Papacosta, Pangratios; Linscheid, Nathan

2016-01-01

Experiments that measure the speed of sound in air are common in high schools and colleges. In the Kundt's tube experiment, a horizontal air column is adjusted until a resonance mode is achieved for a specific frequency of sound. When this happens, the cork dust in the tube is disturbed at the displacement antinode regions. The location of the…

Development of ultrasonic atomizer and its application to S. I. engines

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

Namiyama, K.; Nakamura, H.; Kokubo, K.

1989-01-01

This paper describes a fuel atomizer developed for S.I. engines based on ultrasonic vibrations. As the spray is characterized by fine droplet size and low penetration, it facilitates fuel movement and the formation of a homogeneous mixture. The spray behavior of this atomizer is easily influenced by ambient air motion. Therefore, the spray is most effectively delivered to the cylinders by precise injection timing. The ultrasonic atomizer disperses a fine spray over a wide flow rate range. A single cylinder engine fitted with the atomizer showed advantages in combustion speed and transient response performance.

JPL-20140817-LDSDf-0001-Flying Saucer Test Flight

NASA Image and Video Library

2014-08-17

Ian Clark, Low Density Supersonic Decelerator (LDSD) Principal Investigator, narrates balloon launch, rocket firing and parachute testing on June 28, 2014. The LDSD is a concept for slowing a spacecraft entering Mars' atmosphere at supersonic speeds. For this test, the goal was to slow the test vehicle from four times the speed of sound to 2.5 times the speed of sound.

Effect of stress on ultrasonic pulses in fiber reinforced composites

NASA Technical Reports Server (NTRS)

Hemann, J. H.; Baaklini, G. Y.

1986-01-01

An acoustical-ultrasonic technique was used to demonstrate relationships existing between changes in attenuation of stress waves and tensile stress on an eight ply 0 degree graphite-epoxy fiber reinforced composite. All tests were conducted in the linear range of the material for which no mechanical or macroscopic damage was evident. Changes in attenuation were measured as a function of tensile stress in the frequency domain and in the time domain. Stress wave propagation in these specimens was dispersive, i.e., the wave speed depends on frequency. Wave speeds varied from 267,400 cm/sec to 680,000 cm/sec as the frequency of the signal was varied from 150 kHz to 1.9 MHz which strongly suggests that flexural/lamb wave modes of propagation exist. The magnitude of the attenuation changes depended strongly on tensile stress. It was further observed that the wave speeds increased slightly for all tested frequencies as the stress was increased.

DEVELOPMENT OF AN ULTRASONIC INDIRECT BLOOD PRESSURE SENSING TECHNIQUE FOR AEROSPACE APPLICATION,

DTIC Science & Technology

with arterial opening motion, comparing systolic and diastolic pressures thus obtained to those acquired by auscultation and recording Korotkoff sounds...level airborne noise environments where auscultation techniques were not usable. Tests made with patients in shock showed performance of the

The Influence of Inspection Angle, Wave Type and Beam Shape on Signal-to-Noise Ratios in Ultrasonic Pitch-Catch Inspections

NASA Astrophysics Data System (ADS)

Margetan, F. J.; Li, Anxiang; Thompson, R. B.

2007-03-01

Grain noise, which arises from the scattering of sound waves by microstructure, can limit the detection of small internal defects in metal components. Signal-to-noise (S/N) ratios for ultrasonic pitch/catch inspections are primarily determined by three factors: the scattering ability of the defect; the inherent noisiness of the microstructure (per unit volume); and finite-beam effects. An approximate single-scattering model has been formulated which contains terms representing each of these factors. In this paper the model is applied to a representative pitch/catch inspection problem, namely, the detection of a circular crack in a nickel cylinder. The object is to estimate S/N ratios for various choices of the inspection angle and sonic wave types, and to demonstrate how S/N is determined by the interplay of the defect, microstructure, and finite-beam factors. We also explore how S/N is influenced by the sizes, shapes, and orientations of the transmitter and receiver sound beams.

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.

Grating lobe elimination in steerable parametric loudspeaker.

PubMed

Shi, Chuang; Gan, Woon-Seng

2011-02-01

In the past two decades, the majority of research on the parametric loudspeaker has concentrated on the nonlinear modeling of acoustic propagation and pre-processing techniques to reduce nonlinear distortion in sound reproduction. There are, however, very few studies on directivity control of the parametric loudspeaker. In this paper, we propose an equivalent circular Gaussian source array that approximates the directivity characteristics of the linear ultrasonic transducer array. By using this approximation, the directivity of the sound beam from the parametric loudspeaker can be predicted by the product directivity principle. New theoretical results, which are verified through measurements, are presented to show the effectiveness of the delay-and-sum beamsteering structure for the parametric loudspeaker. Unlike the conventional loudspeaker array, where the spacing between array elements must be less than half the wavelength to avoid spatial aliasing, the parametric loudspeaker can take advantage of grating lobe elimination to extend the spacing of ultrasonic transducer array to more than 1.5 wavelengths in a typical application.

Killer whales (Orcinus orca) produce ultrasonic whistles.

PubMed

Samarra, Filipa I P; Deecke, Volker B; Vinding, Katja; Rasmussen, Marianne H; Swift, René J; Miller, Patrick J O

2010-11-01

This study reports that killer whales, the largest dolphin, produce whistles with the highest fundamental frequencies ever reported in a delphinid. Using wide-band acoustic sampling from both animal-attached (Dtag) and remotely deployed hydrophone arrays, ultrasonic whistles were detected in three Northeast Atlantic populations but not in two Northeast Pacific populations. These results are inconsistent with analyses suggesting a correlation of maximum frequency of whistles with body size in delphinids, indicate substantial intraspecific variation in whistle production in killer whales, and highlight the importance of appropriate acoustic sampling techniques when conducting comparative analyses of sound repertoires.

Quantitative diagnostics of multilayered composite structures with ultrasonic guided waves

NASA Astrophysics Data System (ADS)

Bunget, Gheorghe; Friedersdorf, Fritz; Na, Jeong K.

2015-03-01

The main objective of the current work is to develop a practical nondestructive inspection methodology for a highly sound absorbing composite structural system consisting of polymeric and metallic materials. Due to constraints in geometrical shapes and thicknesses of the composite system used in this work, ultrasonic guided wave approach has been chosen. Since the polymer coatings have high damping properties, less energy is dissipated into the adjacent media in the presence of interface delaminations. Experimental measurements performed on a targeted composite system, whether it has an aluminum, carbon-fiber-composite, or steel outer casing, show promising results.

Sub-Microsecond Temperature Measurement in Liquid Water Using Laser Induced Thermal Acoustics

NASA Technical Reports Server (NTRS)

Alderfer, David W.; Herring, G. C.; Danehy, Paul M.; Mizukaki, Toshiharu; Takayama, Kazuyoshi

2005-01-01

Using laser-induced thermal acoustics, we demonstrate non-intrusive and remote sound speed and temperature measurements over the range 10 - 45 C in liquid water. Averaged accuracy of sound speed and temperature measurements (10 s) are 0.64 m/s and 0.45 C respectively. Single-shot precisions based on one standard deviation of 100 or greater samples range from 1 m/s to 16.5 m/s and 0.3 C to 9.5 C for sound speed and temperature measurements respectively. The time resolution of each single-shot measurement was 300 nsec.

Sound from a Two-Blade Propeller at Supersonic Tip Speeds

NASA Technical Reports Server (NTRS)

Hubbard, Harvey H; Lassiter, Leslie W

1952-01-01

Report presents the results of sound measurements at static conditions made for a two-blade 47-inch-diameter propeller in the tip Mach number range 0.75 to 1.30. For comparison, spectrums have been obtained at both subsonic and supersonic tip speeds. In addition, the measured data are compared with calculations by the theory of Gutin which has previously been found adequate for predicting the sound at subsonic tip speeds. Curves are presented from which the maximum over-all noise levels in free space may be estimated if the power, tip Mach number, and distance are known.

Observations of sound-speed fluctuations in the western Philippine Sea in the spring of 2009.

PubMed

Colosi, John A; Van Uffelen, Lora J; Cornuelle, Bruce D; Dzieciuch, Matthew A; Worcester, Peter F; Dushaw, Brian D; Ramp, Steven R

2013-10-01

As an aid to understanding long-range acoustic propagation in the Philippine Sea, statistical and phenomenological descriptions of sound-speed variations were developed. Two moorings of oceanographic sensors located in the western Philippine Sea in the spring of 2009 were used to track constant potential-density surfaces (isopycnals) and constant potential-temperature surfaces (isotherms) in the depth range 120-2000 m. The vertical displacements of these surfaces are used to estimate sound-speed fluctuations from internal waves, while temperature/salinity variability along isopycnals are used to estimate sound-speed fluctuations from intrusive structure often termed spice. Frequency spectra and vertical covariance functions are used to describe the space-time scales of the displacements and spiciness. Internal-wave contributions from diurnal and semi-diurnal internal tides and the diffuse internal-wave field [related to the Garrett-Munk (GM) spectrum] are found to dominate the sound-speed variability. Spice fluctuations are weak in comparison. The internal wave and spice frequency spectra have similar form in the upper ocean but are markedly different below 170-m depth. Diffuse internal-wave mode spectra show a form similar to the GM model, while internal-tide mode spectra scale as mode number to the minus two power. Spice decorrelates rapidly with depth, with a typical correlation scale of tens of meters.

Relationship between breast sound speed and mammographic percent density

NASA Astrophysics Data System (ADS)

Sak, Mark; Duric, Nebojsa; Boyd, Norman; Littrup, Peter; Myc, Lukasz; Faiz, Muhammad; Li, Cuiping; Bey-Knight, Lisa

2011-03-01

Despite some shortcomings, mammography is currently the standard of care for breast cancer screening and diagnosis. However, breast ultrasound tomography is a rapidly developing imaging modality that has the potential to overcome the drawbacks of mammography. It is known that women with high breast densities have a greater risk of developing breast cancer. Measuring breast density is accomplished through the use of mammographic percent density, defined as the ratio of fibroglandular to total breast area. Using an ultrasound tomography (UST) prototype, we created sound speed images of the patient's breast, motivated by the fact that sound speed in a tissue is proportional to the density of the tissue. The purpose of this work is to compare the acoustic performance of the UST system with the measurement of mammographic percent density. A cohort of 251 patients was studied using both imaging modalities and the results suggest that the volume averaged breast sound speed is significantly related to mammographic percent density. The Spearman correlation coefficient was found to be 0.73 for the 175 film mammograms and 0.69 for the 76 digital mammograms obtained. Since sound speed measurements do not require ionizing radiation or physical compression, they have the potential to form the basis of a safe, more accurate surrogate marker of breast density.

Analysis of temperature in conventional and ultrasonically-assisted drilling of cortical bone with infrared thermography.

PubMed

Alam, K; Silberschmidt, Vadim V

2014-01-01

Bone drilling is widely used in orthopaedics, dental and neurosurgeries for repair and fixation purposes. One of the major concerns in drilling of bone is thermal necrosis that may seriously affect healing at interfaces with fixtures and implants. Ultrasonically-assisted drilling (UAD) is recently introduced as alternative to conventional drilling (CD) to minimize invasiveness of the procedure. This paper studies temperature rise in bovine cortical bone drilled with CD and UAD techniques and their comparison using infrared thermography. A parametric investigation was carried out to evaluate effects of drilling conditions (drilling speed and feed rate) and parameters of ultrasonic vibration (frequency and amplitude) on the temperature elevation in bone. Higher levels of the drilling speed and feed rate were found responsible for generating temperatures above a thermal threshold level in both types of drilling. UAD with frequency below 20 kHz resulted in lower temperature compared to CD with the same drilling parameters. The temperatures generated in cases with vibration frequency exceeding 20 kHz were significantly higher than those in CD for the range of drilling speeds and feed rates. The amplitude of vibration was found to have no significant effect on bone temperature. UAD may be investigated further to explore its benefits over the existing CD techniques.

Piezoelectric parametric effects on wave vibration and contact mechanics of traveling wave ultrasonic motor.

PubMed

Zhang, Dongsheng; Wang, Shiyu; Xiu, Jie

2017-11-01

Elastic wave quality determines the operating performance of traveling wave ultrasonic motor (TWUM). The time-variant circumferential force from the shrink of piezoelectric ceramic is one of the factors that distort the elastic wave. The distorted waveshape deviates from the ideal standard sinusoidal fashion and affects the contact mechanics and driving performance. An analytical dynamic model of ring ultrasonic motor is developed. Based on this model, the piezoelectric parametric effects on the wave distortion and contact mechanics are examined. Multi-scale method is employed to obtain unstable regions and distorted wave response. The unstable region is verified by Floquét theory. Since the waveshape affects the contact mechanism, a contact model involving the distorted waveshape and normal stiffness of the contact layer is established. The contact model is solved by numerical calculation. The results verify that the deformation of the contact layer deviates from sinusoidal waveshape and the pressure distribution is changed, which influences the output characteristics directly. The surface speed within the contact region is averaged such that the rotor speed decreases for lower torque and increases for larger torque. The effects from different parametric strengths, excitation frequencies and pre-pressures on pressure distribution and torque-speed relation are compared. Copyright © 2017 Elsevier B.V. All rights reserved.

Development of an ICT-Based Air Column Resonance Learning Media

NASA Astrophysics Data System (ADS)

Purjiyanta, Eka; Handayani, Langlang; Marwoto, Putut

2016-08-01

Commonly, the sound source used in the air column resonance experiment is the tuning fork having disadvantage of unoptimal resonance results due to the sound produced which is getting weaker. In this study we made tones with varying frequency using the Audacity software which were, then, stored in a mobile phone as a source of sound. One advantage of this sound source is the stability of the resulting sound enabling it to produce the same powerful sound. The movement of water in a glass tube mounted on the tool resonance and the tone sound that comes out from the mobile phone were recorded by using a video camera. Sound resonances recorded were first, second, and third resonance, for each tone frequency mentioned. The resulting sound stays longer, so it can be used for the first, second, third and next resonance experiments. This study aimed to (1) explain how to create tones that can substitute tuning forks sound used in air column resonance experiments, (2) illustrate the sound wave that occurred in the first, second, and third resonance in the experiment, and (3) determine the speed of sound in the air. This study used an experimental method. It was concluded that; (1) substitute tones of a tuning fork sound can be made by using the Audacity software; (2) the form of sound waves that occured in the first, second, and third resonance in the air column resonance can be drawn based on the results of video recording of the air column resonance; and (3) based on the experiment result, the speed of sound in the air is 346.5 m/s, while based on the chart analysis with logger pro software, the speed of sound in the air is 343.9 ± 0.3171 m/s.

Design and Development of a Mobile Sensor Based the Blind Assistance Wayfinding System

NASA Astrophysics Data System (ADS)

Barati, F.; Delavar, M. R.

2015-12-01

The blind and visually impaired people are facing a number of challenges in their daily life. One of the major challenges is finding their way both indoor and outdoor. For this reason, routing and navigation independently, especially in urban areas are important for the blind. Most of the blind undertake route finding and navigation with the help of a guide. In addition, other tools such as a cane, guide dog or electronic aids are used by the blind. However, in some cases these aids are not efficient enough in a wayfinding around obstacles and dangerous areas for the blind. As a result, the need to develop effective methods as decision support using a non-visual media is leading to improve quality of life for the blind through their increased mobility and independence. In this study, we designed and implemented an outdoor mobile sensor-based wayfinding system for the blind. The objectives of this study are to guide the blind for the obstacle recognition and the design and implementation of a wayfinding and navigation mobile sensor system for them. In this study an ultrasonic sensor is used to detect obstacles and GPS is employed for positioning and navigation in the wayfinding. This type of ultrasonic sensor measures the interval between sending waves and receiving the echo signals with respect to the speed of sound in the environment to estimate the distance to the obstacles. In this study the coordinates and characteristics of all the obstacles in the study area are already stored in a GIS database. All of these obstacles were labeled on the map. The ultrasonic sensor designed and constructed in this study has the ability to detect the obstacles in a distance of 2cm to 400cm. The implementation and the results obtained from the interview of a number of blind persons who employed the sensor verified that the designed mobile sensor system for wayfinding was very satisfactory.

Speed-of-Sound Measurements in (Argon + Carbon Dioxide) over the Temperature Range from (275 to 500) K at Pressures up to 8 MPa.

PubMed

Wegge, Robin; McLinden, Mark O; Perkins, Richard A; Richter, Markus; Span, Roland

2016-08-01

The speed of sound of two (argon + carbon dioxide) mixtures was measured over the temperature range from (275 to 500) K with pressures up to 8 MPa utilizing a spherical acoustic resonator. The compositions of the gravimetrically prepared mixtures were (0.50104 and 0.74981) mole fraction carbon dioxide. The vibrational relaxation of pure carbon dioxide led to high sound absorption, which significantly impeded the sound-speed measurements on carbon dioxide and its mixtures; pre-condensation may have also affected the results for some measurements near the dew line. Thus, in contrast to the standard operating procedure for speed-of-sound measurements with a spherical resonator, non-radial resonances at lower frequencies were taken into account. Still, the data show a comparatively large scatter, and the usual repeatability of this general type of instrument could not be realized with the present measurements. Nonetheless, the average relative combined expanded uncertainty ( k = 2) in speed of sound ranged from (0.042 to 0.056)% for both mixtures, with individual state-point uncertainties increasing to 0.1%. These uncertainties are adequate for our intended purpose of evaluating thermodynamic models. The results are compared to a Helmholtz energy equation of state for carbon capture and storage applications; relative deviations of (-0.64 to 0.08)% for the (0.49896 argon + 0.50104 carbon dioxide) mixture, and of (-1.52 to 0.77)% for the (0.25019 argon + 0.74981 carbon dioxide) mixture were observed.

Study on characteristics of single cavitation bubble considering condensation and evaporation of kerosene steam under ultrasonic vibration honing.

PubMed

Ye, Linzheng; Zhu, Xijing; Wang, Lujie; Guo, Ce

2018-01-01

Ultrasonic vibration honing technology is an effective means for materials difficult to machine, where cavitation occurs in grinding fluid under the action of ultrasound. To investigate the changes of single cavitation bubble characteristics in the grinding area and how honing parameters influence bubble characteristics, a dynamic model of single cavitation bubble in the ultrasonic vibration honing grinding area was established. The model was based on the bubble dynamics and considered the condensation and evaporation of kerosene steam and honing processing environment. The change rules of bubble radius, temperature, pressure and number of kerosene steam molecules inside the bubble were numerically simulated in the process of bubble moving. The results show that the condensation and evaporation of kerosene steam can help to explain the changes of temperature and pressure inside the bubble. Compared with ultrasonic vibration, the amplitude of bubble radius is greatly suppressed in the ultrasonic honing environment. However, the rate of movement of the bubble is faster. Meanwhile, the minimum values of pressure and temperature are larger, and the number of kerosene steam molecules is less. By studying the effect of honing factors on the movement of the cavitation bubble, it is found that honing pressure has a greater influence on bubble evolution characteristics, while rotation speed of honing head has a minor effect and the reciprocating speed of honing head has little impacts. Copyright © 2017 Elsevier B.V. All rights reserved.

Constant frequency pulsed phase-locked-loop instrument for measurement of ultrasonic velocity

NASA Technical Reports Server (NTRS)

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

1991-01-01

A new instrument based on a constant-frequency pulsed phase-locked-loop (CFPPLL) concept has been developed to accurately measure the ultrasonic wave velocity in liquids and changes in ultrasonic wave velocity in solids and liquids. An analysis of the system shows that it is immune to many of the frequency-dependent effects that plague other techniques. Measurements of the sound velocity in ultrapure water are used to confirm the analysis. The results are in excellent agreement with values from the literature, and establish that the CFPPLL provides a reliable, accurate way to measure velocities, as well as for monitoring small changes in velocity without the sensitivity to frequency-dependent phase shifts common to other measurement systems. The estimated sensitivity to phase changes is better than a few parts in 10 to the 7th.

Energy shadowing correction of ultrasonic pulse-echo records by digital signal processing

NASA Technical Reports Server (NTRS)

Kishonio, D.; Heyman, J. S.

1985-01-01

A numerical algorithm is described that enables the correction of energy shadowing during the ultrasonic testing of bulk materials. In the conventional method, an ultrasonic transducer transmits sound waves into a material that is immersed in water so that discontinuities such as defects can be revealed when the waves are reflected and then detected and displayed graphically. Since a defect that lies behind another defect is shadowed in that it receives less energy, the conventional method has a major drawback. The algorithm normalizes the energy of the incoming wave by measuring the energy of the waves reflected off the water/air interface. The algorithm is fast and simple enough to be adopted for real time applications in industry. Images of material defects with the shadowing corrections permit more quantitative interpretation of the material state.

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.

Non-contact transportation system of small objects using Ultrasonic Waveguides

NASA Astrophysics Data System (ADS)

Nakamura, K.; Koyama, D.

2012-12-01

A transportation system for small object or fluid without contact is investigated being based on ultrasonic levitation. Small objects are suspended against gravity at the nodal points in ultrasonic pressure field due to the sound radiation force generated as the gradient of the energy density of the field. In this study, the trapped object is transported in the horizontal plane by introducing the spatial shift of the standing waves by the switching the lateral modes or travelling waves. The goal of the study is to establish a technology which can provide a total system with the flexibility in composing various transportation paths. Methods for linear/rotary stepping motions and continuous linear transportation are explained in this report. All the transportation tracks are composed of a bending vibrator and a reflector. The design for these acoustic cavity/waveguide is discussed.

An on-line acoustic fluorocarbon coolant mixture analyzer for the ATLAS silicon tracker

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

Bates, R.; Battistin, M.; Berry, S.

2011-07-01

The ATLAS silicon tracker community foresees an upgrade from the present octafluoro-propane (C{sub 3}F{sub 8}) evaporative cooling fluid - to a composite fluid with a probable 10-20% admixture of hexafluoro-ethane (C{sub 2}F{sub 6}). Such a fluid will allow a lower evaporation temperature and will afford the tracker silicon substrates a better safety margin against leakage current-induced thermal runaway caused by cumulative radiation damage as the luminosity profile at the CERN Large Hadron Collider increases. Central to the use of this new fluid is a new custom-developed speed-of-sound instrument for continuous real-time measurement of the C{sub 3}F{sub 8}/C{sub 2}F{sub 6} mixturemore » ratio and flow. An acoustic vapour mixture analyzer/flow meter with new custom electronics allowing ultrasonic frequency transmission through gas mixtures has been developed for this application. Synchronous with the emission of an ultrasound 'chirp' from an acoustic transmitter, a fast readout clock (40 MHz) is started. The clock is stopped on receipt of an above threshold sound pulse at the receiver. Sound is alternately transmitted parallel and anti-parallel with the vapour flow for volume flow measurement from transducers that can serve as acoustic transmitters or receivers. In the development version, continuous real-time measurement of C{sub 3}F{sub 8}/C{sub 2}F{sub 6} flow and calculation of the mixture ratio is performed within a graphical user interface developed in PVSS-II, the Supervisory, Control and Data Acquisition standard chosen for LHC and its experiments at CERN. The described instrument has numerous potential applications - including refrigerant leak detection, the analysis of hydrocarbons, vapour mixtures for semiconductor manufacture and anesthetic gas mixtures. (authors)« less

An On-Line Acoustic Fluorocarbon Coolant Mixture Analyzer for the ATLAS Silicon Tracker

NASA Astrophysics Data System (ADS)

Bates, R.; Battistin, M.; Berry, S.; Bitadze, A.; Bonneau, P.; Bousson, N.; Boyd, G.; Botelho-Direito, J.; DiGirolamo, B.; Doubek, M.; Egorov, K.; Godlewski, J.; Hallewell, G.; Katunin, S.; Mathieu, M.; McMahon, S.; Nagai, K.; Perez-Rodriguez, E.; Rozanov, A.; Vacek, V.; Vitek, M.

2012-10-01

The ATLAS silicon tracker community foresees an upgrade from the present octafluoropropane (C3F8) evaporative cooling fluid to a composite fluid with a probable 10-20% admixture of hexafluoroethane (C2F6). Such a fluid will allow a lower evaporation temperature and will afford the tracker silicon substrates a better safety margin against leakage current-induced thermal runaway caused by cumulative radiation damage as the luminosity profile at the CERN Large Hadron Collider increases. Central to the use of this new fluid is a new custom-developed speed-of-sound instrument for continuous real-time measurement of the C3F8/C2F6 mixture ratio and flow. An acoustic vapour mixture analyzer/flow meter with new custom electronics allowing ultrasonic frequency transmission through gas mixtures has been developed for this application. Synchronous with the emission of an ultrasound `chirp' from an acoustic transmitter, a fast readout clock (40 MHz) is started. The clock is stopped on receipt of an above threshold sound pulse at the receiver. Sound is alternately transmitted parallel and anti-parallel with the vapour flow for volume flow measurement from transducers that can serve as acoustic transmitters or receivers. In the development version, continuous real-time measurement of C3F8/C2F6 flow and calculation of the mixture ratio is performed within a graphical user interface developed in PVSS-II, the Supervisory, Control and Data Acquisition standard chosen for LHC and its experiments at CERN. The described instrument has numerous potential applications - including refrigerant leak detection, the analysis of hydrocarbons, vapour mixtures for semi-conductor manufacture and anesthetic gas mixtures.

Micromachined ultrasonic transducers for air-coupled nondestructive evaluation

NASA Astrophysics Data System (ADS)

Hansen, Sean T.; Degertekin, F. Levent; Khuri-Yakub, Butrus T.

1999-01-01

Conventional methods of ultrasonic non-destructive evaluation (NDE) use liquids to couple sound waves into the test samples. This either requires immersion of the parts to be examined or the use of complex and bulky water squirting systems that must be scanned over the structure. Air-coupled ultrasonic systems eliminate these requirements if the losses at air-solid interfaces are tolerable. Micromachined capacitive ultrasonic transducers (cMUTs) have been shown to have more than 100 dB dynamic range when used in the bistatic transmission mode. In this paper, we present results of a pitch-catch transmission system using cMUTs that achieves a 103 dB dynamic range. Each transducer consists of 10,000 silicon nitride membranes of 100 micrometers diameter connected in parallel. This geometry result in transducers with a resonant frequency around 2.3 MHz. These transducers can be used in transmission experiments at normal incident to the sample or to excite and detect guided waves in aluminum and composite plates. In this paper we present ultrasonic defect detection results from both through transmission and guided Lamb wave experiments in aluminum and composite plates, such as those used in aircraft.

Ultrasonics as a Method of Bird Control

DTIC Science & Technology

1992-04-01

determine changes in frequencies. As occurs in humans, European Starling, House Sparrow (Passer domesticus), and Rock Dove/Pigeon ( Columba livia ) sound...Wassiljew Columba livia (1933) 50 1800- 11500 Wever & Bray 2400 (1936) 200 7500 Brand & Kell- ogg (1939) 300 1000- 5800 Trainer 2000 (1946) 300 1000- 5500

Modification of Kirchhoff migration with variable sound speed and attenuation for acoustic imaging of media and application to tomographic imaging of the breast

PubMed Central

Schmidt, Steven; Duric, Nebojsa; Li, Cuiping; Roy, Olivier; Huang, Zhi-Feng

2011-01-01

Purpose: To explore the feasibility of improving cross-sectional reflection imaging of the breast using refractive and attenuation corrections derived from ultrasound tomography data. Methods: The authors have adapted the planar Kirchhoff migration method, commonly used in geophysics to reconstruct reflection images, for use in ultrasound tomography imaging of the breast. Furthermore, the authors extended this method to allow for refractive and attenuative corrections. Using clinical data obtained with a breast imaging prototype, the authors applied this method to generate cross-sectional reflection images of the breast that were corrected using known distributions of sound speed and attenuation obtained from the same data. Results: A comparison of images reconstructed with and without the corrections showed varying degrees of improvement. The sound speed correction resulted in sharpening of detail, while the attenuation correction reduced the central darkening caused by path length dependent losses. The improvements appeared to be greatest when dense tissue was involved and the least for fatty tissue. These results are consistent with the expectation that denser tissues lead to both greater refractive effects and greater attenuation. Conclusions: Although conventional ultrasound techniques use time-gain control to correct for attenuation gradients, these corrections lead to artifacts because the true attenuation distribution is not known. The use of constant sound speed leads to additional artifacts that arise from not knowing the sound speed distribution. The authors show that in the context of ultrasound tomography, it is possible to construct reflection images of the breast that correct for inhomogeneous distributions of both sound speed and attenuation. PMID:21452737

Unparalleled sample treatment throughput for proteomics workflows relying on ultrasonic energy.

PubMed

Jorge, Susana; Araújo, J E; Pimentel-Santos, F M; Branco, Jaime C; Santos, Hugo M; Lodeiro, Carlos; Capelo, J L

2018-02-01

We report on the new microplate horn ultrasonic device as a powerful tool to speed proteomics workflows with unparalleled throughput. 96 complex proteomes were digested at the same time in 4min. Variables such as ultrasonication time, ultrasonication amplitude, and protein to enzyme ratio were optimized. The "classic" method relying on overnight protein digestion (12h) and the sonoreactor-based method were also employed for comparative purposes. We found the protein digestion efficiency homogeneously distributed in the entire microplate horn surface using the following conditions: 4min sonication time and 25% amplitude. Using this approach, patients with lymphoma and myeloma were classified using principal component analysis and a 2D gel-mass spectrometry based approach. Furthermore, we demonstrate the excellent performance by using MALDI-mass spectrometry based profiling as a fast way to classify patients with rheumatoid arthritis, systemic lupus erythematosus, and ankylosing spondylitis. Finally, the speed and simplicity of this method were demonstrated by clustering 90 patients with knee osteoarthritis disease (30), with a prosthesis (30, control group) and healthy individuals (30) with no history of joint disease. Overall, the new approach allows profiling a disease in just one week while allows to match the minimalism rules as outlined by Halls. Copyright © 2017 Elsevier B.V. All rights reserved.

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.

Noise from high speed maglev systems: Noise sources, noise criteria, preliminary design guidelines for noise control, recommendations for acoustical test facility for maglev research. Final report, July 1991-October 1992

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

Hanson, C.E.; Abbot, P.; Dyer, I.

1993-01-01

Noise levels from magnetically-levitated trains (maglev) at very high speed may be high enough to cause environmental noise impact in residential areas. Aeroacoustic sources dominate the sound at high speeds and guideway vibrations generate noticeable sound at low speed. In addition to high noise levels, the startle effect as a result of sudden onset of sound from a rapidly moving nearby maglev vehicle may lead to increased annoyance to neighbors of a maglev system. The report provides a base for determining the noise consequences and potential mitigation for a high speed maglev system in populated areas of the United States.more » Four areas are included in the study: (1) definition of noise sources; (2) development of noise criteria; (3) development of design guidelines; and (4) recommendations for a noise testing facility.« less

Transcranial Assessment and Visualization of Acoustic Cavitation: Modeling and Experimental Validation

PubMed Central

Clement, Gregory T.; McDannold, Nathan

2015-01-01

The interaction of ultrasonically-controlled microbubble oscillations (acoustic cavitation) with tissues and biological media has been shown to induce a wide range of bioeffects that may have significant impact to therapy and diagnosis of central nervous system diseases and disorders. However, the inherently non-linear microbubble oscillations combined with the micrometer and microsecond scales involved in these interactions and the limited methods to assess and visualize them transcranially hinder both their optimal use and translation to the clinics. To overcome these challenges, we present a noninvasive and clinically relevant framework that combines numerical simulations with multimodality imaging to assess and visualize the microbubble oscillations transcranially. In the present work, acoustic cavitation was studied with an integrated US and MR imaging guided clinical FUS system in non-human primates. This multimodality imaging system allowed us to concurrently induce and visualize acoustic cavitation transcranially. A high-resolution brain CT-scan that allowed us to determine the head acoustic properties (density, speed of sound, and absorption) was also co-registered to the US and MR images. The derived acoustic properties and the location of the targets that were determined by the 3D-CT scans and the post sonication MRI respectively were then used as inputs to two-and three-dimensional Finite Difference Time Domain (2D, 3D-FDTD) simulations that matched the experimental conditions and geometry. At the experimentally-determined target locations, synthetic point sources with pressure amplitude traces derived by either a Gaussian function or the output of a microbubble dynamics model were numerically excited and propagated through the skull towards a virtual US imaging array. Then, using passive acoustic mapping that was refined to incorporate variable speed of sound, we assessed the losses and aberrations induced by the skull as a function of the acoustic emissions recorded by the virtual US imaging array. Next, the simulated passive acoustic maps (PAMs) were compared to experimental PAMs. Finally, using clinical CT and MR imaging as input to the numerical simulations, we evaluated the clinical utility of the proposed framework. The simulations indicated that the diverging pressure waves propagating through the skull lose 95% of their intensity as compared to propagation in water-only. Further, the incorporation of a variable speed of sound to the PAM back-projection algorithm indeed corrected the aberrations introduced by the skull and substantially improved the resolution. More than 94% agreement in the FWHM of the axial and transverse line profiles between the simulations incorporating microbubble emissions and experimentally-determined PAMs was observed. Finally, the results of the 2D simulations that used clinical datasets are promising for the prospective use of transcranial PAM in a human with an 82 mm aperture broadband linear array. Incorporation of variable speed of sound to the PAM back-projection algorithm appeared capable of correcting the aberrations introduced by the human skull. These results suggest that this integrated approach can provide a physically accurate and clinically-relevant framework for developing a comprehensive treatment guidance for therapeutic applications of acoustic cavitation in the brain. Ultimately it may enable the quantification of the emissions and provide more control over this nonlinear process. PMID:25546857

Flying Faster Than The Speed of Sound

NASA Image and Video Library

2017-10-10

It's been 70 years since Chuck Yeager broke the sound barrier in his experimental airplane, the X-1. Today, NASA is working to make supersonic air travel across the U.S. a reality with its Low Boom Flight Demonstration aircraft. Decades of NASA research in supersonics have gone into the unique design of this aircraft, which aims to reduce the loudness of the sonic boom associated with planes traveling faster than the speed of sound.

Stationary waves in tubes and the speed of sound

NASA Astrophysics Data System (ADS)

Kasper, Lutz; Vogt, Patrik; Strohmeyer, Christine

2015-01-01

The opportunity to plot oscillograms and frequency spectra with smartphones creates many options for experiments in acoustics, including several that have been described in this column.1-3 The activities presented in this paper are intended to complement these applications, and include an approach to determine sound velocity in air by using standard drain pipes4 and an outline of an investigation of the temperature dependency of the speed of sound.

Sound Shell Model for Acoustic Gravitational Wave Production at a First-Order Phase Transition in the Early Universe.

PubMed

Hindmarsh, Mark

2018-02-16

A model for the acoustic production of gravitational waves at a first-order phase transition is presented. The source of gravitational radiation is the sound waves generated by the explosive growth of bubbles of the stable phase. The model assumes that the sound waves are linear and that their power spectrum is determined by the characteristic form of the sound shell around the expanding bubble. The predicted power spectrum has two length scales, the average bubble separation and the sound shell width when the bubbles collide. The peak of the power spectrum is at wave numbers set by the sound shell width. For a higher wave number k, the power spectrum decreases to k^{-3}. At wave numbers below the inverse bubble separation, the power spectrum goes to k^{5}. For bubble wall speeds near the speed of sound where these two length scales are distinguished, there is an intermediate k^{1} power law. The detailed dependence of the power spectrum on the wall speed and the other parameters of the phase transition raises the possibility of their constraint or measurement at a future space-based gravitational wave observatory such as LISA.

Sound Shell Model for Acoustic Gravitational Wave Production at a First-Order Phase Transition in the Early Universe

NASA Astrophysics Data System (ADS)

Hindmarsh, Mark

2018-02-01

A model for the acoustic production of gravitational waves at a first-order phase transition is presented. The source of gravitational radiation is the sound waves generated by the explosive growth of bubbles of the stable phase. The model assumes that the sound waves are linear and that their power spectrum is determined by the characteristic form of the sound shell around the expanding bubble. The predicted power spectrum has two length scales, the average bubble separation and the sound shell width when the bubbles collide. The peak of the power spectrum is at wave numbers set by the sound shell width. For a higher wave number k , the power spectrum decreases to k-3. At wave numbers below the inverse bubble separation, the power spectrum goes to k5. For bubble wall speeds near the speed of sound where these two length scales are distinguished, there is an intermediate k1 power law. The detailed dependence of the power spectrum on the wall speed and the other parameters of the phase transition raises the possibility of their constraint or measurement at a future space-based gravitational wave observatory such as LISA.

Measurement and characterisation of radiated underwater sound from a 3.6 MW monopile wind turbine.

PubMed

Pangerc, Tanja; Theobald, Peter D; Wang, Lian S; Robinson, Stephen P; Lepper, Paul A

2016-10-01

This paper describes underwater sound pressure measurements obtained in close proximity (∼50 m) to two individual wind turbines, over a 21-day period, capturing the full range of turbine operating conditions. The sound radiated into the water was characterised by a number of tonal components, which are thought to primarily originate from the gearbox for the bandwidth measured. The main signal associated with the turbine operation had a mean-square sound pressure spectral density level which peaked at 126 dB re 1 μPa 2  Hz -1 at 162 Hz. Other tonal components were also present, notably at frequencies between about 20 and 330 Hz, albeit at lower amplitudes. The measured sound characteristics, both in terms of frequency and amplitude, were shown to vary with wind speed. The sound pressure level increased with wind speed up to an average value of 128 dB re 1 μPa at a wind speed of about 10 ms -1 , and then showed a general decrease. Overall, differences in the mean-square sound pressure spectral density level of over 20 dB were observed across the operational envelope of the turbine.

A sound budget for the southeastern Bering Sea: measuring wind, rainfall, shipping, and other sources of underwater sound.

PubMed

Nystuen, Jeffrey A; Moore, Sue E; Stabeno, Phyllis J

2010-07-01

Ambient sound in the ocean contains quantifiable information about the marine environment. A passive aquatic listener (PAL) was deployed at a long-term mooring site in the southeastern Bering Sea from 27 April through 28 September 2004. This was a chain mooring with lots of clanking. However, the sampling strategy of the PAL filtered through this noise and allowed the background sound field to be quantified for natural signals. Distinctive signals include the sound from wind, drizzle and rain. These sources dominate the sound budget and their intensity can be used to quantify wind speed and rainfall rate. The wind speed measurement has an accuracy of +/-0.4 m s(-1) when compared to a buoy-mounted anemometer. The rainfall rate measurement is consistent with a land-based measurement in the Aleutian chain at Cold Bay, AK (170 km south of the mooring location). Other identifiable sounds include ships and short transient tones. The PAL was designed to reject transients in the range important for quantification of wind speed and rainfall, but serendipitously recorded peaks in the sound spectrum between 200 Hz and 3 kHz. Some of these tones are consistent with whale calls, but most are apparently associated with mooring self-noise.

Variable sound speed in interacting dark energy models

NASA Astrophysics Data System (ADS)

Linton, Mark S.; Pourtsidou, Alkistis; Crittenden, Robert; Maartens, Roy

2018-04-01

We consider a self-consistent and physical approach to interacting dark energy models described by a Lagrangian, and identify a new class of models with variable dark energy sound speed. We show that if the interaction between dark energy in the form of quintessence and cold dark matter is purely momentum exchange this generally leads to a dark energy sound speed that deviates from unity. Choosing a specific sub-case, we study its phenomenology by investigating the effects of the interaction on the cosmic microwave background and linear matter power spectrum. We also perform a global fitting of cosmological parameters using CMB data, and compare our findings to ΛCDM.

Statistical inference of seabed sound-speed structure in the Gulf of Oman Basin.

PubMed

Sagers, Jason D; Knobles, David P

2014-06-01

Addressed is the statistical inference of the sound-speed depth profile of a thick soft seabed from broadband sound propagation data recorded in the Gulf of Oman Basin in 1977. The acoustic data are in the form of time series signals recorded on a sparse vertical line array and generated by explosive sources deployed along a 280 km track. The acoustic data offer a unique opportunity to study a deep-water bottom-limited thickly sedimented environment because of the large number of time series measurements, very low seabed attenuation, and auxiliary measurements. A maximum entropy method is employed to obtain a conditional posterior probability distribution (PPD) for the sound-speed ratio and the near-surface sound-speed gradient. The multiple data samples allow for a determination of the average error constraint value required to uniquely specify the PPD for each data sample. Two complicating features of the statistical inference study are addressed: (1) the need to develop an error function that can both utilize the measured multipath arrival structure and mitigate the effects of data errors and (2) the effect of small bathymetric slopes on the structure of the bottom interacting arrivals.

Ear Deformations Give Bats a Physical Mechanism for Fast Adaptation of Ultrasonic Beam Patterns

NASA Astrophysics Data System (ADS)

Gao, Li; Balakrishnan, Sreenath; He, Weikai; Yan, Zhen; Müller, Rolf

2011-11-01

A large number of mammals, including humans, have intricate outer ear shapes that diffract incoming sound in a direction- and frequency-specific manner. Through this physical process, the outer ear shapes encode sound-source information into the sensory signals from each ear. Our results show that horseshoe bats could dynamically control these diffraction processes through fast nonrigid ear deformations. The bats’ ear shapes can alter between extreme configurations in about 100 ms and thereby change their acoustic properties in ways that would suit different acoustic sensing tasks.

A thermophone on porous polymeric substrate

NASA Astrophysics Data System (ADS)

Chitnis, G.; Kim, A.; Song, S. H.; Jessop, A. M.; Bolton, J. S.; Ziaie, B.

2012-07-01

In this Letter, we present a simple, low-temperature method for fabricating a wide-band (>80 kHz) thermo-acoustic sound generator on a porous polymeric substrate. We were able to achieve up to 80 dB of sound pressure level with an input power of 0.511 W. No significant surface temperature increase was observed in the device even at an input power level of 2.5 W. Wide-band ultrasonic performance, simplicity of structure, and scalability of the fabrication process make this device suitable for many ranging and imaging applications.

A novel contact model of piezoelectric traveling wave rotary ultrasonic motors with the finite volume method.

PubMed

Renteria-Marquez, I A; Renteria-Marquez, A; Tseng, B T L

2018-06-06

The operating principle of the piezoelectric traveling wave rotary ultrasonic motor is based on two energy conversion processes: the generation of the stator traveling wave and the rectification of the stator movement through the stator-rotor contact mechanism. This paper presents a methodology to model in detail the stator-rotor contact interface of these motors. A contact algorithm that couples a model of the stator which is discretized with the finite volume method and an analytical model of the rotor is presented. The outputs of the proposed model are the normal and tangential force distribution produced at the stator-rotor contact interface, contact length, height and shape of the stator traveling wave and rotor speed. The torque-speed characteristic of the USR60 is calculated with the proposed model, and the results of the model are compared versus the real torque-speed of the motor. A good agreement between the proposed model results and the torque-speed characteristic of the USR60 was observed. Copyright © 2018 Elsevier B.V. All rights reserved.

Nondestructive Evaluation of Friction Stir-Welded Aluminum Alloy to Coated Steel Sheet Lap Joint

NASA Astrophysics Data System (ADS)

Das, H.; Kumar, A.; Rajkumar, K. V.; Saravanan, T.; Jayakumar, T.; Pal, Tapan Kumar

2015-11-01

Dissimilar lap joints of aluminum sheet (AA 6061) of 2 mm thickness and zinc-coated steel sheet of 1 mm thickness were produced by friction stir welding with different combinations of rotational speed and travel speed. Ultrasonic C- and B-scanning, and radiography have been used in a complementary manner for detection of volumetric (cavity and flash) and planar (de bond) defects as the defects are in micron level. Advanced ultrasonic C-scanning did not provide any idea about the defects, whereas B-scanning cross-sectional image showed an exclusive overview of the micron-level defects. A digital x-ray radiography methodology is proposed for quality assessment of the dissimilar welds which provide three-fold increase in signal-to-noise ratio with improved defect detection sensitivity. The present study clearly shows that the weld tool rotational speed and travel speed have a decisive role on the quality of the joints obtained by the friction stir welding process. The suitability of the proposed NDE techniques to evaluate the joint integrity of dissimilar FSW joints is thus established.

Laser based structural health monitoring for civil, mechanical, and aerospace systems

NASA Astrophysics Data System (ADS)

Sohn, Hoon

2012-04-01

This paper provides an overview of ongoing laser ultrasonics based structural health monitoring (SHM) activities being performed by the author. Particular focus is given to (1) the development of a fully noncontact laser ultrasonic system that can easily visualize defects with high spatial resolution, (2) laser based wireless power and data transmission schemes for remote guided waves and impedance measurements, (3) minimization of false alarms due to varying operational and environmental conditions, and (4) extension to embedded laser ultrasonic excitation and sensing. SHM examples ranging from bridges to airplanes, as well as nuclear power plants, high-speed rails and wind turbines are also presented.

An Accelerated Method for Testing Soldering Tendency of Core Pins

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

Han, Qingyou; Xu, Hanbing; Ried, Paul

2010-01-01

An accelerated method for testing die soldering has been developed. High intensity ultrasonic vibrations has been used to simulate the die casting conditions such as high pressure and high impingement speed of molten metal on the pin. Soldering tendency of steels and coated pins has been examined. The results indicate that in the low carbon steel/Al system, the onset of soldering is 60 times faster with ultrasonic vibration than that without ultrasonic vibration. In the H13/A380 system, the onset of soldering reaction is accelerated to 30-60 times. Coating significantly reduces the soldering tendency of the core pins.

Chemical coloring on stainless steel by ultrasonic irradiation.

PubMed

Cheng, Zuohui; Xue, Yongqiang; Ju, Hongbin

2018-01-01

To solve the problems of high temperature and non-uniformity of coloring on stainless steel, a new chemical coloring process, applying ultrasonic irradiation to the traditional chemical coloring process, was developed in this paper. The effects of ultrasonic frequency and power density (sound intensity) on chemical coloring on stainless steel were studied. The uniformity of morphology and colors was observed with the help of polarizing microscope and scanning electron microscopy (SEM), and the surface compositions were characterized by X-ray photoelectric spectroscopy (XPS), meanwhile, the wear resistance and the corrosion resistance were investigated, and the effect mechanism of ultrasonic irradiation on chemical coloring was discussed. These results show that in the process of chemical coloring on stainless steel by ultrasonic irradiation, the film composition is the same as the traditional chemical coloring, and this method can significantly enhance the uniformity, the wear and corrosion resistances of the color film and accelerate the coloring rate which makes the coloring temperature reduced to 40°C. The effects of ultrasonic irradiation on the chemical coloring can be attributed to the coloring rate accelerated and the coloring temperature reduced by thermal-effect, the uniformity of coloring film improved by dispersion-effect, and the wear and corrosion resistances of coloring film enhanced by cavitation-effect. Ultrasonic irradiation not only has an extensive application prospect for chemical coloring on stainless steel but also provides an valuable reference for other chemical coloring. Copyright © 2017 Elsevier B.V. All rights reserved.

Time-of-Flight Measurement of the Speed of Sound in Water

ERIC Educational Resources Information Center

Ganci, Salvatore

2016-01-01

A simple setup is designed to investigate a "time-of-flight" measurement of the speed of sound in water. This experiment only requires low cost components and is also very simple to understand by students. It could be easily used as a demonstration experiment.

Ubiquitous Fast Propagating Intensity Disturbances in Solar Chromosphere

NASA Technical Reports Server (NTRS)

Kubo, M.; Katsukawa, Y.; Suematsu, Y.; Kano, R.; Bando, T.; Narukage, N.; Ishikawa, R.; Hara, H.; Giono, G.; Winebarger, A.;

A DIY Ultrasonic Signal Generator for Sound Experiments

ERIC Educational Resources Information Center

Riad, Ihab F.

2018-01-01

Many physics departments around the world have electronic and mechanical workshops attached to them that can help build experimental setups and instruments for research and the training of undergraduate students. The workshops are usually run by experienced technicians and equipped with expensive lathing, computer numerical control (CNC) machines,…

Viscothermal Coupling Effects on Sound Attenuation in Concentrated Colloidal Dispersions.

NASA Astrophysics Data System (ADS)

Han, Wei

1995-11-01

This thesis describes a Unified Coupled Phase Continuum (UCPC) model to analyze sound propagation through aerosols, emulsions and suspensions in terms of frequency dependent attenuation coefficient and sound speed. Expressions for the viscous and thermal coupling coefficients explicitly account for the effects of particle size, shape factor, orientation as well as concentration and the sound frequency. The UCPC model also takes into account the intrinsic acoustic absorption within the fluid medium due to its viscosity and heat conductivity. The effective complex wave number as a function of frequency is derived. A frequency- and concentration-dependent complex Nusselt number for the interfacial thermal coupling coefficient is derived using an approximate similarity between the 'viscous skin drag' and 'heat conduction flux' associated with the discontinuous suspended phase, on the basis of a cell model. The theoretical predictions of attenuation spectra provide satisfactory agreement with reported experimental data on two concentrated suspensions (polystyrene latex and kaolin pigment), two concentrated emulsions (toluene -in-water, n-hexadecane-in-water), and two aerosols (oleic acid droplets-in-nitrogen, alumina-in-air), covering a wide range of relative magnitudes (from 10^ {-3} to 10^{3}) of thermal versus viscous contributions, for dispersed phase volume fractions as high as 50%. The relative differences between the additive result of separate viscous and thermal loss estimates and combined viscothermal absorption results are also presented. Effects of particle shape on viscous attenuation of sound in concentrated suspensions of non-spherical clay particles are studied. Attenuation spectra for 18 frequencies from 3 to 100 MHz are measured and analyzed for eleven kaolin clay slurries with solid concentrations ranging from 0.6% to 35% (w/w). A modified viscous drag coefficient that considers frequency, concentration, particle size, shape and orientation of spheroids, is developed and applied to estimate the viscous attenuation coefficients. With incorporation of particle size and shape distributions (PSSD), predictions agree quantitatively with observed attenuation coefficients. The effects of particle aspect ratio and orientation become more evident as particle concentrations and frequencies are increased. The UCPC model combined with the ultrasonic spectroscopy techniques can provide for theoretical and experimental frameworks in characterization of concentrated colloidal dispersions.

Measurement of Sound Speed in Thread

NASA Astrophysics Data System (ADS)

Saito, Shigemi; Shibata, Yasuhiro; Ichiki, Akira; Miyazaki, Akiho

2006-05-01

By employing thin wires, human hairs and threads, the measurement of sound speed in a thread whose diameter is smaller than 0.2 mm has been attempted. Preparing two cylindrical ceramic transducers with a 300 kHz resonance frequency, a perforated glass bead to be knotted by a sample thread is bonded to the center of the end surface of each transducer. After connecting these transducers with a sample thread, a receiving transducer is attached at a ceiling so as to hang another transmitting transducer with the thread. A glass bead is bonded to another end surface of the transmitting transducer so that tension, varied with a hanged plumb, can be applied to the sample thread. The time delay of the received signal relative to the transmitting pulse is measured while gradually shortening the thread. Sound speed is determined by the proportionality of time delay with thread length. Although the measured values for metallic wires are somewhat different from the values derived from the density and Young’s modulus cited in references, they are reproducible. The sound speed for human hairs of over twenty samples, which varies between 2000 and 2500 m/s, seems to depend on hair quality. Sound speed in a cotton thread is found to approach a constant value under large tension. An advanced measurement system available for uncut threads is also presented, where semi cylindrical transducers pinch the thread.

Speed-of-Sound Measurements in (Argon + Carbon Dioxide) over the Temperature Range from (275 to 500) K at Pressures up to 8 MPa

PubMed Central

Wegge, Robin; McLinden, Mark O.; Perkins, Richard A.; Richter, Markus; Span, Roland

2016-01-01

The speed of sound of two (argon + carbon dioxide) mixtures was measured over the temperature range from (275 to 500) K with pressures up to 8 MPa utilizing a spherical acoustic resonator. The compositions of the gravimetrically prepared mixtures were (0.50104 and 0.74981) mole fraction carbon dioxide. The vibrational relaxation of pure carbon dioxide led to high sound absorption, which significantly impeded the sound-speed measurements on carbon dioxide and its mixtures; pre-condensation may have also affected the results for some measurements near the dew line. Thus, in contrast to the standard operating procedure for speed-of-sound measurements with a spherical resonator, non-radial resonances at lower frequencies were taken into account. Still, the data show a comparatively large scatter, and the usual repeatability of this general type of instrument could not be realized with the present measurements. Nonetheless, the average relative combined expanded uncertainty (k = 2) in speed of sound ranged from (0.042 to 0.056)% for both mixtures, with individual state-point uncertainties increasing to 0.1%. These uncertainties are adequate for our intended purpose of evaluating thermodynamic models. The results are compared to a Helmholtz energy equation of state for carbon capture and storage applications; relative deviations of (−0.64 to 0.08)% for the (0.49896 argon + 0.50104 carbon dioxide) mixture, and of (−1.52 to 0.77)% for the (0.25019 argon + 0.74981 carbon dioxide) mixture were observed. PMID:27458321

Detecting interferences with iOS applications to measure speed of sound

NASA Astrophysics Data System (ADS)

Yavuz, Ahmet; Kağan Temiz, Burak

2016-01-01

Traditional experiments measuring the speed of sound consist of studying harmonics by changing the length of a glass tube closed at one end. In these experiments, the sound source and observer are outside of the tube. In this paper, we propose the modification of this old experiment by studying destructive interference in a pipe using a headset, iPhone and iPad. The iPhone is used as an emitter with signal generator application and the iPad is used as the receiver with a spectrogram application. Two experiments are carried out for measures: the emitter inside of the tube with the receiver outside, and vice versa. We conclude that it is even possible to adequately and easily measure the speed of sound using a cup or a can of coke with the method described in this paper.

Development of Bone-Conducted Ultrasonic Hearing Aid for the Profoundly Deaf: Assessments of the Modulation Type with Regard to Intelligibility and Sound Quality

NASA Astrophysics Data System (ADS)

Nakagawa, Seiji; Fujiyuki, Chika; Kagomiya, Takayuki

2012-07-01

Bone-conducted ultrasound (BCU) is perceived even by the profoundly sensorineural deaf. A novel hearing aid using the perception of amplitude-modulated BCU (BCU hearing aid: BCUHA) has been developed; however, further improvements are needed, especially in terms of articulation and sound quality. In this study, the intelligibility and sound quality of BCU speech with several types of amplitude modulation [double-sideband with transmitted carrier (DSB-TC), double-sideband with suppressed carrier (DSB-SC), and transposed modulation] were evaluated. The results showed that DSB-TC and transposed speech were more intelligible than DSB-SC speech, and transposed speech was closer than the other types of BCU speech to air-conducted speech in terms of sound quality. These results provide useful information for further development of the BCUHA.

In Vivo Determination of the Complex Elastic Moduli of Cetacean Head Tissue

DTIC Science & Technology

2013-09-30

of an ultrasonic Doppler vibration measurement system called NVMS developed at Georgia Tech iii. Algorithms have been developed to enable the...magnitude and phase of vibration to be determined as a function of range (tissue depth) along the ultrasonic beam. By measuring the differential phase of...The frequency dependence of the propagation speed is then used to determine the shear loss factor. The elastic properties of tissue phantoms

Ultrasonic power measurement system based on acousto-optic interaction.

PubMed

He, Liping; Zhu, Fulong; Chen, Yanming; Duan, Ke; Lin, Xinxin; Pan, Yongjun; Tao, Jiaquan

2016-05-01

Ultrasonic waves are widely used, with applications including the medical, military, and chemical fields. However, there are currently no effective methods for ultrasonic power measurement. Previously, ultrasonic power measurement has been reliant on mechanical methods such as hydrophones and radiation force balances. This paper deals with ultrasonic power measurement based on an unconventional method: acousto-optic interaction. Compared with mechanical methods, the optical method has a greater ability to resist interference and also has reduced environmental requirements. Therefore, this paper begins with an experimental determination of the acoustic power in water contained in a glass tank using a set of optical devices. Because the light intensity of the diffraction image generated by acousto-optic interaction contains the required ultrasonic power information, specific software was written to extract the light intensity information from the image through a combination of filtering, binarization, contour extraction, and other image processing operations. The power value can then be obtained rapidly by processing the diffraction image using a computer. The results of this work show that the optical method offers advantages that include accuracy, speed, and a noncontact measurement method.

Ultrasonic power measurement system based on acousto-optic interaction

NASA Astrophysics Data System (ADS)

He, Liping; Zhu, Fulong; Chen, Yanming; Duan, Ke; Lin, Xinxin; Pan, Yongjun; Tao, Jiaquan

2016-05-01

Ultrasonic waves are widely used, with applications including the medical, military, and chemical fields. However, there are currently no effective methods for ultrasonic power measurement. Previously, ultrasonic power measurement has been reliant on mechanical methods such as hydrophones and radiation force balances. This paper deals with ultrasonic power measurement based on an unconventional method: acousto-optic interaction. Compared with mechanical methods, the optical method has a greater ability to resist interference and also has reduced environmental requirements. Therefore, this paper begins with an experimental determination of the acoustic power in water contained in a glass tank using a set of optical devices. Because the light intensity of the diffraction image generated by acousto-optic interaction contains the required ultrasonic power information, specific software was written to extract the light intensity information from the image through a combination of filtering, binarization, contour extraction, and other image processing operations. The power value can then be obtained rapidly by processing the diffraction image using a computer. The results of this work show that the optical method offers advantages that include accuracy, speed, and a noncontact measurement method.

System and method of reducing motion-induced noise in the optical detection of an ultrasound signal in a moving body of material

DOEpatents

Habeger, Jr., Charles C.; LaFond, Emmanuel F.; Brodeur, Pierre; Gerhardstein, Joseph P.

2002-01-01

The present invention provides a system and method to reduce motion-induced noise in the detection of ultrasonic signals in a moving sheet or body of material. An ultrasonic signal is generated in a sheet of material and a detection laser beam is moved along the surface of the material. By moving the detection laser in the same direction as the direction of movement of the sheet of material the amount of noise induced in the detection of the ultrasonic signal is reduced. The scanner is moved at approximately the same speed as the moving material. The system and method may be used for many applications, such in a paper making process or steel making process. The detection laser may be directed by a scanner. The movement of the scanner is synchronized with the anticipated arrival of the ultrasonic signal under the scanner. A photodetector may be used to determine when a ultrasonic pulse has been directed to the moving sheet of material so that the scanner may be synchronized the anticipated arrival of the ultrasonic signal.

Infrared Thermal Imaging During Ultrasonic Aspiration of Bone

NASA Astrophysics Data System (ADS)

Cotter, D. J.; Woodworth, G.; Gupta, S. V.; Manandhar, P.; Schwartz, T. H.

Ultrasonic surgical aspirator tips target removal of bone in approaches to tumors or aneurysms. Low profile angled tips provide increased visualization and safety in many high risk surgical situations that commonly were approached using a high speed rotary drill. Utilization of the ultrasonic aspirator for bone removal raised questions about relative amount of local and transmitted heat energy. In the sphenoid wing of a cadaver section, ultrasonic bone aspiration yielded lower thermal rise in precision bone removal than rotary mechanical drills, with maximum temperature of 31 °C versus 69 °C for fluted and 79 °C for diamond drill bits. Mean ultrasonic fragmentation power was about 8 Watts. Statistical studies using tenacious porcine cranium yielded mean power levels of about 4.5 Watts to 11 Watts and mean temperature of less than 41.1 °C. Excessively loading the tip yielded momentary higher power; however, mean thermal rise was less than 8 °C with bone removal starting at near body temperature of about 37 °C. Precision bone removal and thermal management were possible with conditions tested for ultrasonic bone aspiration.

Time-of-Flight Measurement of the Speed of Sound in a Metal Bar

ERIC Educational Resources Information Center

Ganci, Salvatore

2016-01-01

A simple setup was designed for a "time-of-flight" measurement of the sound speed in a metal bar. The experiment requires low cost components and is very simple to understand by students. A good use of it is as a demonstration experiment.

40 CFR 205.54-1 - Low speed sound emission test procedures.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 26 2012-07-01 2011-07-01 true Low speed sound emission test procedures. 205.54-1 Section 205.54-1 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED.... Operating manuals or other literature furnished by the instrument manufacturer shall be referred to for both...

40 CFR 205.54-1 - Low speed sound emission test procedures.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Low speed sound emission test procedures. 205.54-1 Section 205.54-1 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE ABATEMENT PROGRAMS TRANSPORTATION EQUIPMENT NOISE EMISSION CONTROLS Medium and Heavy Trucks § 205...

Detonation models of fast combustion waves in nanoscale Al-MoO3 bulk powder media

NASA Astrophysics Data System (ADS)

Shaw, Benjamin D.; Pantoya, Michelle L.; Dikici, Birce

2013-02-01

The combustion of nanometric aluminum (Al) powder with an oxidiser such as molybdenum trioxide (MoO3) is studied analytically. This study focuses on detonation wave models and a Chapman-Jouget detonation model provides reasonable agreement with experimentally-observed wave speeds provided that multiphase equilibrium sound speeds are applied at the downstream edge of the detonation wave. The results indicate that equilibrium sound speeds of multiphase mixtures can play a critical role in determining speeds of fast combustion waves in nanoscale Al-MoO3 powder mixtures.

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.

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

Preparation of CuO Quantum Dots by Cost-Effective Ultrasonication Technique

NASA Astrophysics Data System (ADS)

Rathod, K. N.; Savaliya, Chirag; Babiya, K. R.; Vasvani, S. H.; Ramani, Rupeshkumar V.; Ramani, Bharat M.; Joshi, Ashvini D.; Pandya, Dhiren; Shah, N. A.; Markna, J. H.

Due to exciting size-dependent chemical and physical properties, nanoscale materials have extensive range of applications compared with microstructural particles. CuO nanoparticles are very important among transition metal oxides because of their large number of applications. Quantum dots (QDs) of CuO (copper oxide) were prepared by the innovative ultrasonication method. Ultrasonic sound is used in this synthesis method to synthesize QDs of copper oxide. Structural and optical properties were studied in this research work. X-ray diffraction was used to study the formation of structural phase CuO QDs and found to be single phasic without any impurity. Transmission electron microscopic measurements were performed to study the morphology of QDs of CuO, which confirms spherical QDs with an average diameter of ˜4nm. In optical studies, absorption spectra of the CuO were analyzed by using UV-visible spectroscopy.

Optimization of an angle-beam ultrasonic approach for characterization of impact damage in composites

NASA Astrophysics Data System (ADS)

Henry, Christine; Kramb, Victoria; Welter, John T.; Wertz, John N.; Lindgren, Eric A.; Aldrin, John C.; Zainey, David

2018-04-01

Advances in NDE method development are greatly improved through model-guided experimentation. In the case of ultrasonic inspections, models which provide insight into complex mode conversion processes and sound propagation paths are essential for understanding the experimental data and inverting the experimental data into relevant information. However, models must also be verified using experimental data obtained under well-documented and understood conditions. Ideally, researchers would utilize the model simulations and experimental approach to efficiently converge on the optimal solution. However, variability in experimental parameters introduce extraneous signals that are difficult to differentiate from the anticipated response. This paper discusses the results of an ultrasonic experiment designed to evaluate the effect of controllable variables on the anticipated signal, and the effect of unaccounted for experimental variables on the uncertainty in those results. Controlled experimental parameters include the transducer frequency, incidence beam angle and focal depth.

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.

Three-dimensional mid-air acoustic manipulation by ultrasonic phased arrays.

PubMed

Ochiai, Yoichi; Hoshi, Takayuki; Rekimoto, Jun

2014-01-01

The essence of levitation technology is the countervailing of gravity. It is known that an ultrasound standing wave is capable of suspending small particles at its sound pressure nodes. The acoustic axis of the ultrasound beam in conventional studies was parallel to the gravitational force, and the levitated objects were manipulated along the fixed axis (i.e. one-dimensionally) by controlling the phases or frequencies of bolted Langevin-type transducers. In the present study, we considered extended acoustic manipulation whereby millimetre-sized particles were levitated and moved three-dimensionally by localised ultrasonic standing waves, which were generated by ultrasonic phased arrays. Our manipulation system has two original features. One is the direction of the ultrasound beam, which is arbitrary because the force acting toward its centre is also utilised. The other is the manipulation principle by which a localised standing wave is generated at an arbitrary position and moved three-dimensionally by opposed and ultrasonic phased arrays. We experimentally confirmed that expanded-polystyrene particles of 0.6 mm, 1 mm, and 2 mm in diameter could be manipulated by our proposed method.

Underwater detection by using ultrasonic sensor

NASA Astrophysics Data System (ADS)

Bakar, S. A. A.; Ong, N. R.; Aziz, M. H. A.; Alcain, J. B.; Haimi, W. M. W. N.; Sauli, Z.

2017-09-01

This paper described the low cost implementation of hardware and software in developing the system of ultrasonic which can visualize the feedback of sound in the form of measured distance through mobile phone and monitoring the frequency of detection by using real time graph of Java application. A single waterproof transducer of JSN-SR04T had been used to determine the distance of an object based on operation of the classic pulse echo detection method underwater. In this experiment, the system was tested by placing the housing which consisted of Arduino UNO, Bluetooth module of HC-06, ultrasonic sensor and LEDs at the top of the box and the transducer was immersed in the water. The system which had been tested for detection in vertical form was found to be capable of reporting through the use of colored LEDs as indicator to the relative proximity of object distance underwater form the sensor. As a conclusion, the system can detect the presence of an object underwater within the range of ultrasonic sensor and display the measured distance onto the mobile phone and the real time graph had been successfully generated.

Three-Dimensional Mid-Air Acoustic Manipulation by Ultrasonic Phased Arrays

PubMed Central

Ochiai, Yoichi; Hoshi, Takayuki; Rekimoto, Jun

2014-01-01

The essence of levitation technology is the countervailing of gravity. It is known that an ultrasound standing wave is capable of suspending small particles at its sound pressure nodes. The acoustic axis of the ultrasound beam in conventional studies was parallel to the gravitational force, and the levitated objects were manipulated along the fixed axis (i.e. one-dimensionally) by controlling the phases or frequencies of bolted Langevin-type transducers. In the present study, we considered extended acoustic manipulation whereby millimetre-sized particles were levitated and moved three-dimensionally by localised ultrasonic standing waves, which were generated by ultrasonic phased arrays. Our manipulation system has two original features. One is the direction of the ultrasound beam, which is arbitrary because the force acting toward its centre is also utilised. The other is the manipulation principle by which a localised standing wave is generated at an arbitrary position and moved three-dimensionally by opposed and ultrasonic phased arrays. We experimentally confirmed that expanded-polystyrene particles of 0.6 mm, 1 mm, and 2 mm in diameter could be manipulated by our proposed method. PMID:24849371

A Liquid Level Measurement Technique Outside a Sealed Metal Container Based on Ultrasonic Impedance and Echo Energy

PubMed Central

Zhang, Bin; Wei, Yue-Juan; Liu, Wen-Yi; Zhang, Yan-Jun; Yao, Zong; Zhao, Li-Hui; Xiong, Ji-Jun

2017-01-01

The proposed method for measuring the liquid level focuses on the ultrasonic impedance and echo energy inside a metal wall, to which the sensor is attached directly, not on ultrasonic waves that penetrate the gas–liquid medium of a container. Firstly, by analyzing the sound field distribution characteristics of the sensor in a metal wall, this paper proposes the concept of an "energy circle" and discusses how to calculate echo energy under three different states in detail. Meanwhile, an ultrasonic transmitting and receiving circuit is designed to convert the echo energy inside the energy circle into its equivalent electric power. Secondly, in order to find the two critical states of the energy circle in the process of liquid level detection, a program is designed to help with calculating two critical positions automatically. Finally, the proposed method is evaluated through a series of experiments, and the experimental results indicate that the proposed method is effective and accurate in calibration of the liquid level outside a sealed metal container. PMID:28106857

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.

Spatio-Temporal Evolution of Sound Speed Channels on the Chukchi Shelf

NASA Astrophysics Data System (ADS)

Eickmeier, J.; Badiey, M.; Wan, L.

2017-12-01

The physics of an acoustic waveguide are influenced by various boundary conditions as well as spatial and temporal fluctuations in temperature and salinity profiles the water column. The shallow water Canadian Basin Acoustic Propagation Experiment (CANAPE) experiment was designed to study the effect of oceanographic variability on the acoustic field. A pilot study was conducted in the summer of 2015, full deployment of acoustic and environmental moorings took place in 2016, and recovery will occur in late 2017. An example of strong oceanographic variability in the SW region is depicted in Figure 1. Over the course of 7 days, warm Bering Sea water arrived on the Chukchi Shelf and sank in the water column to between 25 m and 125 m depth. This warm water spread to a range of 10 km and a potential eddy of warm water formed causing an increase in sound speed between 15 km and 20 km range in Fig. 1(b). Due to the increased sound speed, a strong sound channel evolved between 100 m and 200 m for acoustic waves arriving from off the shelf, deep water sources. In Fig. 1(a), the initial formation of the acoustic channel is only evident in 50 m to 100 m of water out to a range of 5 km. Recorded environmental data will be used to study fluctuations in sound speed channel formation on the Chukchi Shelf. Data collected in 2015 and 2016 have shown sound duct evolution over 7 days and over a one-month period. Analysis is projected to show sound channel formation over a new range of spatio-temporal scales. This analysis will show a cycle of sound channels opening and closing on the shelf, where this cycle strongly influences the propagation path, range and attenuation of acoustic waves.

Angular coherence in ultrasound imaging: Theory and applications

PubMed Central

Li, You Leo; Dahl, Jeremy J.

2017-01-01

The popularity of plane-wave transmits at multiple transmit angles for synthetic transmit aperture (or coherent compounding) has spawned a number of adaptations and new developments of ultrasonic imaging. However, the coherence properties of backscattered signals with plane-wave transmits at different angles are unknown and may impact a subset of these techniques. To provide a framework for the analysis of the coherence properties of such signals, this article introduces the angular coherence theory in medical ultrasound imaging. The theory indicates that the correlation function of such signals forms a Fourier transform pair with autocorrelation function of the receive aperture function. This conclusion can be considered as an extended form of the van Cittert Zernike theorem. The theory is validated with simulation and experimental results obtained on speckle targets. On the basis of the angular coherence of the backscattered wave, a new short-lag angular coherence beamformer is proposed and compared with an existing spatial-coherence-based beamformer. An application of the theory in phase shift estimation and speed of sound estimation is also presented. PMID:28372139

Transcranial photoacoustic tomography of the monkey brain

NASA Astrophysics Data System (ADS)

Nie, Liming; Huang, Chao; Guo, Zijian; Anastasio, Mark; Wang, Lihong V.

2012-02-01

A photoacoustic tomography (PAT) system using a virtual point ultrasonic transducer was developed for transcranial imaging of monkey brains. The virtual point transducer provided a 10 times greater field-of-view (FOV) than finiteaperture unfocused transducers, which enables large primate imaging. The cerebral cortex of a monkey brain was accurately mapped transcranially, through up to two skulls ranging from 4 to 8 mm in thickness. The mass density and speed of sound distributions of the skull were estimated from adjunct X-ray CT image data and utilized with a timereversal algorithm to mitigate artifacts in the reconstructed image due to acoustic aberration. The oxygenation saturation (sO2) in blood phantoms through a monkey skull was also imaged and quantified, with results consistent with measurements by a gas analyzer. The oxygenation saturation (sO2) in blood phantoms through a monkey skull was also imaged and quantified, with results consistent with measurements by a gas analyzer. Our experimental results demonstrate that PAT can overcome the optical and ultrasound attenuation of a relatively thick skull, and the imaging aberration caused by skull can be corrected to a great extent.

Indirect Measurement Of Nitrogen In A Multi-Component Gas By Measuring The Speed Of Sound At Two States Of The Gas.

DOEpatents

Morrow, Thomas B.; Behring, II, Kendricks A.

2004-10-12

A methods of indirectly measuring the nitrogen concentration in a gas mixture. The molecular weight of the gas is modeled as a function of the speed of sound in the gas, the diluent concentrations in the gas, and constant values, resulting in a model equation. Regression analysis is used to calculate the constant values, which can then be substituted into the model equation. If the speed of sound in the gas is measured at two states and diluent concentrations other than nitrogen (typically carbon dioxide) are known, two equations for molecular weight can be equated and solved for the nitrogen concentration in the gas mixture.

Measuring Sound Speed in Gas Mixtures Using a Photoacoustic Generator

NASA Astrophysics Data System (ADS)

Suchenek, Mariusz; Borowski, Tomasz

2018-01-01

We present a new method which allows us to percentage distinction of gas composition with a fast response time. This system uses the speed of sound in a resonant cell along with temperature to determine the gas mixture composition. The gas mixtures contain two gases with an unknown combination. In our experiment, the acoustic waves were excited inside the acoustic longitudinal resonator with the use of a positive feedback. This feedback provides fast tracking of a resonance frequency of the cell and causes fast tracking changes in the speed of sound. The presented method corresponds to the theoretical description of this topic. Two gas mixtures—carbon dioxide and argon mixed with nitrogen—were tested.

THE SYMBOLS OF CREATIVE ENERGY IN THE LITERATURE ON MYSTICSM AND ON ALCHEMY

PubMed Central

Mahdihassan, S.

1989-01-01

Alchemy as art tries to imitate creation such as spontaneous generation. The magic wands of creation, of Chinese origin, would be a compass and a triangular carpenter's square. Creation is represented by the dual-natured soul, comprising of the spirit (Ruh) and “the” soul (Nafs). The ultimate source is creative energy which emanates form the Divine word of command. Creative energy, in its non-manifest form, would be ultrasonic energy, which can be represented by a humming sourd. This would be sympolized by the humming sound. This would be symbolized by the humming sound of bees represent creative energy and in fig 3 the fiddle, as direct producers of a humming sound. PMID:22557649

Dispersion of sound in a combustion duct by fuel droplets and soot particles

NASA Technical Reports Server (NTRS)

Miles, J. H.; Raftopoulos, D. D.

1979-01-01

Dispersion and attenuation of acoustic plane wave disturbances propagating in a ducted combustion system are studied. The dispersion and attenuation are caused by fuel droplet and soot emissions from a jet engine combustor. The attenuation and dispersion are due to heat transfer and mass transfer and viscous drag forces between the emissions and the ambient gas. Theoretical calculations show sound propagation at speeds below the isentropic speed of sound at low frequencies. Experimental results are in good agreement with the theory.

Rotating bouncing disks, tossing pizza dough, and the behavior of ultrasonic motors

NASA Astrophysics Data System (ADS)

Liu, Kuang-Chen; Friend, James; Yeo, Leslie

2009-10-01

Pizza tossing and certain forms of standing-wave ultrasonic motors (SWUMs) share a similar process for converting reciprocating input into continuous rotary motion. We show that the key features of this motion conversion process such as collision, separation and friction coupling are captured by the dynamics of a disk bouncing on a vibrating platform. The model shows that the linear or helical hand motions commonly used by pizza chefs and dough-toss performers for single tosses maximize energy efficiency and the dough’s airborne rotational speed; on the other hand, the semielliptical hand motions used for multiple tosses make it easier to maintain dough rotation at the maximum speed. The system’s bifurcation diagram and basins of attraction also provide a physical basis for understanding the peculiar behavior of SWUMs and provide a means to design them. The model is able to explain the apparently chaotic oscillations that occur in SWUMs and predict the observed trends in steady-state speed and stall torque as preload is increased.

Rotating bouncing disks, tossing pizza dough, and the behavior of ultrasonic motors.

PubMed

Liu, Kuang-Chen; Friend, James; Yeo, Leslie

2009-10-01

Pizza tossing and certain forms of standing-wave ultrasonic motors (SWUMs) share a similar process for converting reciprocating input into continuous rotary motion. We show that the key features of this motion conversion process such as collision, separation and friction coupling are captured by the dynamics of a disk bouncing on a vibrating platform. The model shows that the linear or helical hand motions commonly used by pizza chefs and dough-toss performers for single tosses maximize energy efficiency and the dough's airborne rotational speed; on the other hand, the semielliptical hand motions used for multiple tosses make it easier to maintain dough rotation at the maximum speed. The system's bifurcation diagram and basins of attraction also provide a physical basis for understanding the peculiar behavior of SWUMs and provide a means to design them. The model is able to explain the apparently chaotic oscillations that occur in SWUMs and predict the observed trends in steady-state speed and stall torque as preload is increased.

Online hyphenation of extraction, Sephadex LH-20 column chromatography, and high-speed countercurrent chromatography: A highly efficient strategy for the preparative separation of andrographolide from Andrographis paniculata in a single step.

PubMed

Zhang, Ying-Qi; Wang, Shan-Shan; Han, Chao; Xu, Jin-Fang; Luo, Jian-Guang; Kong, Ling-Yi

2017-12-01

A novel isolation strategy, online hyphenation of ultrasonic extraction, Sephadex LH-20 column chromatography combined with high-speed countercurrent chromatography, was developed for pure compounds extraction and purification. Andrographolide from Andrographis paniculata was achieved only in a single step purification protocol via the present strategy. The crude powder was ultrasonic extracted and extraction was pumped into Sephadex LH-20 column directly to cut the nontarget fractions followed by the second-dimensional high-speed countercurrent chromatography, hyphenated by a six-port valve equipped at the post-end of Sephadex LH-20 column, for the final purification. The results yielded andrographolide with the amount of 1.02 mg and a purity of 98.5% in a single step, indicating that the present method is effective to harvest target compound from medicinal plant. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The effect of stress on ultrasonic pulses in fiber reinforced composites

NASA Technical Reports Server (NTRS)

Hemann, J. H.; Baaklini, G. Y.

1983-01-01

An acoustical-ultrasonic technique was used to demonstrate relationships existing between changes in attenuation of stress waves and tensile stress for an eight ply 0 degree graphite-epoxy fiber reinforced composite. All tests were conducted in the linear range of the material for which no mechanical or macroscopic damage was evident. Changes in attenuation were measured as a function of tensile stress in the frequency domain and in the time domain. Stress wave propagation in these specimens was dispersive, i.e., the wave speed depends on frequency. Wave speeds varied from 267 400 cm/sec to 680 000 cm/sec as the frequency of the signal was varied from 150 kHz to 1.9 MHz which strongly suggests that flexural/lamb wave modes of propagation exist. The magnitude of the attenuation changes depended strongly on tensile stress. It was further observed that the wave speeds increased slightly for all tested frequencies as the stress was increased.

Flextensional ultrasonic piezoelectric micro-motor.

PubMed

Leinvuo, Joni T; Wilson, Stephen A; Whatmore, Roger W; Cain, Markys G

2006-12-01

This paper presents the experimental design, construction, and operational characteristics of a new type of standing wave piezoelectric ultrasonic micro-motor. The motor uses a composite stator, consisting of a metallic flex-tensional mode converter, or "cymbal", bonded to a 2-mm-square piezoelectric plate. The cymbal converts contour-mode vibrations of the plate into oscillations in the cymbal, perpendicular to the stator plane. These are further converted into rotational movement in a rotor pressed against the cymbal by means of an elastic-fin friction drive to produce the required rotary actuation. The motor operates on a single-phase electrical supply, and direct control of the output speed and torque can be achieved by adjusting the amplitude and frequency of the supply voltage. Noncontact optical techniques were used to assess the performance of the developed micro-motor. The operational characteristics were developed from the acceleration and deceleration characteristics. No-load output speed (11 rev s(-1)) and stall torque (27 nNm) were derived using high-speed imaging and image analysis. Maximum efficiency was 0.6%.

Ultrasonic Relaxation Study of 1-Alkyl-3-methylimidazolium-Based Room-Temperature Ionic Liquids: Probing the Role of Alkyl Chain Length in the Cation.

PubMed

Zorębski, Michał; Zorębski, Edward; Dzida, Marzena; Skowronek, Justyna; Jężak, Sylwia; Goodrich, Peter; Jacquemin, Johan

2016-04-14

Ultrasound absorption spectra of four 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imides were determined as a function of the alkyl chain length on the cation from 1-propyl to 1-hexyl from 293.15 to 323.15 K at ambient pressure. Herein, the ultrasound absorption measurements were carried out using a standard pulse technique within a frequency range from 10 to 300 MHz. Additionally, the speed of sound, density, and viscosity have been measured. The presence of strong dissipative processes during the ultrasound wave propagation was found experimentally, i.e., relaxation processes in the megahertz range were observed for all compounds over the whole temperature range. The relaxation spectra (both relaxation amplitude and relaxation frequency) were shown to be dependent on the alkyl side chain length of the 1-alkyl-3-methylimidazolium ring. In most cases, a single-Debye model described the absorption spectra very well. However, a comparison of the determined spectra with the spectra of a few other imidazolium-based ionic liquids reported in the literature (in part recalculated in this work) shows that the complexity of the spectra increases rapidly with the elongation of the alkyl chain length on the cation. This complexity indicates that both the volume viscosity and the shear viscosity are involved in relaxation processes even in relatively low frequency ranges. As a consequence, the sound velocity dispersion is present at relatively low megahertz frequencies.

Estimating the sound speed of a shallow-water marine sediment from the head wave excited by a low-flying helicopter.

PubMed

Bevans, Dieter A; Buckingham, Michael J

2017-10-01

The frequency bandwidth of the sound from a light helicopter, such as a Robinson R44, extends from about 13 Hz to 2.5 kHz. As such, the R44 has potential as a low-frequency sound source in underwater acoustics applications. To explore this idea, an experiment was conducted in shallow water off the coast of southern California in which a horizontal line of hydrophones detected the sound of an R44 hovering in an end-fire position relative to the array. Some of the helicopter sound interacted with seabed to excite the head wave in the water column. A theoretical analysis of the sound field in the water column generated by a stationary airborne source leads to an expression for the two-point horizontal coherence function of the head wave, which, apart from frequency, depends only on the sensor separation and the sediment sound speed. By matching the zero crossings of the measured and theoretical horizontal coherence functions, the sound speed in the sediment was recovered and found to take a value of 1682.42 ± 16.20 m/s. This is consistent with the sediment type at the experiment site, which is known from a previous survey to be a fine to very-fine sand.

Ultrasonic/Sonic Driller/Corer (USDC) as a Subsurface Sampler and Sensors Platform for Planetary Exploration Applications

NASA Technical Reports Server (NTRS)

Bar-Cohen, Yoseph; Sherrit, Stewart; Bao, Xiaoqi; Badescu, Mircea; Aldrich, Jack; Chang, Zensheu

2006-01-01

The search for existing or past life in the Universe is one of the most important objectives of NASA's mission. For this purpose, effective instruments that can sample and conduct in-situ astrobiology analysis are being developed. In support of this objective, a series of novel mechanisms that are driven by an Ultrasonic/Sonic actuator have been developed to probe and sample rocks, ice and soil. This mechanism is driven by an ultrasonic piezoelectric actuator that impacts a bit at sonic frequencies through the use of an intermediate free-mass. Ultrasonic/Sonic Driller/Corer (USDC) devices were made that can produce both core and powdered cuttings, operate as a sounder to emit elastic waves and serve as a platform for sensors. For planetary exploration, this mechanism has the important advantage of requiring low axial force, virtually no torque, and can be duty cycled for operation at low average power. The advantage of requiring low axial load allows overcoming a major limitation of planetary sampling in low gravity environments or when operating from lightweight robots and rovers. The ability to operate at duty cycling with low average power produces a minimum temperature rise allowing for control of the sample integrity and preventing damage to potential biological markers in the acquired sample. The development of the USDC is being pursued on various fronts ranging from analytical modeling to mechanisms improvements while considering a wide range of potential applications. While developing the analytical capability to predict and optimize its performance, efforts are made to enhance its capability to drill at higher power and high speed. Taking advantage of the fact that the bit does not require rotation, sensors (e.g., thermocouple and fiberoptics) were integrated into the bit to examine the borehole during drilling. The sounding effect of the drill was used to emit elastic waves in order to evaluate the surface characteristics of rocks. Since the USDC is driven by piezoelectric actuation mechanism it can designed to operate at extreme temperature environments from very cold as on Titan and Europa to very hot as on Venus. In this paper, a review of the latest development and applications of the USDC will be given.

Smartphone-aided measurements of the speed of sound in different gaseous mixtures

NASA Astrophysics Data System (ADS)

Parolin, Sara Orsola; Pezzi, Giovanni

2013-11-01

Here we describe classroom-based procedures aiming at the estimation of the speed of sound in different gas mixtures with the help of a plastic drain pipe and two iPhones or iPod touches. The procedures were conceived to be performed with simple and readily available tools.

Smartphone-Aided Measurements of the Speed of Sound in Different Gaseous Mixtures

ERIC Educational Resources Information Center

Parolin, Sara Orsola; Pezzi, Giovanni

2013-01-01

Here we describe classroom-based procedures aiming at the estimation of the speed of sound in different gas mixtures with the help of a plastic drain pipe and two iPhones or iPod touches. The procedures were conceived to be performed with simple and readily available tools.

Planck limits on non-canonical generalizations of large-field inflation models

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

Stein, Nina K.; Kinney, William H., E-mail: ninastei@buffalo.edu, E-mail: whkinney@buffalo.edu

2017-04-01

In this paper, we consider two case examples of Dirac-Born-Infeld (DBI) generalizations of canonical large-field inflation models, characterized by a reduced sound speed, c {sub S} < 1. The reduced speed of sound lowers the tensor-scalar ratio, improving the fit of the models to the data, but increases the equilateral-mode non-Gaussianity, f {sup equil.}{sub NL}, which the latest results from the Planck satellite constrain by a new upper bound. We examine constraints on these models in light of the most recent Planck and BICEP/Keck results, and find that they have a greatly decreased window of viability. The upper bound onmore » f {sup equil.}{sub NL} corresponds to a lower bound on the sound speed and a corresponding lower bound on the tensor-scalar ratio of r ∼ 0.01, so that near-future Cosmic Microwave Background observations may be capable of ruling out entire classes of DBI inflation models. The result is, however, not universal: infrared-type DBI inflation models, where the speed of sound increases with time, are not subject to the bound.« less

Electric reaction arising in bone subjected to mechanical loadings

NASA Astrophysics Data System (ADS)

Murasawa, Go; Cho, Hideo; Ogawa, Kazuma

2006-03-01

The aim of present study is the investigation of the electric reaction arising in bone subjected to mechanical loadings. Firstly, specimen was fabricated from femur of cow, and ultrasonic propagation in bone was measured by ultrasonic technique. Secondary, 4-point bending test was conducted up to fracture, and electric reaction arising in bone was measured during loading. Thirdly, cyclic 4-point bending test was conducted to investigate the effect of applied displacement speed on electric reaction.

Role of Friction on the Thermal Development in Ultrasonically Consolidated Aluminum Foils and Composites

DTIC Science & Technology

2011-01-01

amplitude, . The third input parameter, weld speed, s, is inversely proportional to N, the num- ber of cycles as shown in Eq. (3). In summary, F is...though, an extensive body of work on mechanical testing of ultrasonically consolidated thin foils has been performed at Loughborough University. In...comprehensive textbook on tribology presents a preliminary derivation for plastic contact of ductile metals which suggests ≤ 1/5; this is much lower