Science.gov

Sample records for ultrasonic pulse transmission

  1. Tunable time-reversal cavity for high-pressure ultrasonic pulses generation: A tradeoff between transmission and time compression

    NASA Astrophysics Data System (ADS)

    Arnal, Bastien; Pernot, Mathieu; Fink, Mathias; Tanter, Mickael

    2012-08-01

    This Letter presents a time reversal cavity that has both a high reverberation time and a good transmission factor. A multiple scattering medium has been embedded inside a fluid-filled reverberating cavity. This allows creating smart ultrasonic sources able to generate very high pressure pulses at the focus outside the cavity with large steering capabilities. Experiments demonstrate a 25 dB gain in pressure at the focus. This concept will enable us to convert conventional ultrasonic imaging probes driven by low power electronics into high power probes for therapeutic applications requiring high pressure focused pulses, such as histotripsy or lithotripsy.

  2. Experiments in Pulsed Ultrasonics

    ERIC Educational Resources Information Center

    Palmer, S. B.; Forster, G. A.

    1970-01-01

    Describes and apparatus designed to generate and detect pulsed ultrasonics in solids and liquids over the frequency range 1-20 MHz. Experiments are suggested for velocity of sound, elastic constant and ultrasonic attenuation measurements on various materials over a wide temperature range. The equipment should be useful for demonstration purposes.…

  3. Pulsed ultrasonic stir welding system

    NASA Technical Reports Server (NTRS)

    Ding, R. Jeffrey (Inventor)

    2013-01-01

    An ultrasonic stir welding system includes a welding head assembly having a plate and a rod passing through the plate. The rod is rotatable about a longitudinal axis thereof. During a welding operation, ultrasonic pulses are applied to the rod as it rotates about its longitudinal axis. The ultrasonic pulses are applied in such a way that they propagate parallel to the longitudinal axis of the rod.

  4. Pulsed ultrasonic stir welding method

    NASA Technical Reports Server (NTRS)

    Ding, R. Jeffrey (Inventor)

    2013-01-01

    A method of performing ultrasonic stir welding uses a welding head assembly to include a plate and a rod passing through the plate. The rod is rotatable about a longitudinal axis thereof. In the method, the rod is rotated about its longitudinal axis during a welding operation. During the welding operation, a series of on-off ultrasonic pulses are applied to the rod such that they propagate parallel to the rod's longitudinal axis. At least a pulse rate associated with the on-off ultrasonic pulses is controlled.

  5. Ultrasonic flowmetering with reflected pulses

    E-print Network

    Hoyle, David C.

    1984-01-01

    A transit time type ultrasonic flowmeter was tested with two different reflected pulse trajectories in flowing air at ambient conditions against an orifice meter. The flowmeter was designed to be highly accurate, to require ...

  6. A transmission oscillator ultrasonic spectrometer

    NASA Technical Reports Server (NTRS)

    Conradi, M. S.; Miller, J. G.; Heyman, J. S.

    1974-01-01

    A continuous wave ultrasonic instrument capable of measuring very small changes in acoustic attenuation and phase velocity is described. This transmission oscillator ultrasonic spectrometer (TOUS) exhibits high sensitivity because it oscillates marginally. In spite of this high sensitivity, the TOUS system is relatively simple, compact, and inexpensive. These features suggest that the TOUS is suitable not only for precise laboratory measurements of the physical properties of materials, but also for field applications in nondestructive testing.

  7. Ultrasonic-Transmission Testing Device

    NASA Technical Reports Server (NTRS)

    Atkins, Victor Ray; Bouvier, Carl

    1996-01-01

    Ultrasonic-testing apparatus measures transmission through component under inspection. Includes hand-held ultrasonic transmitter placed on one side of component and ultrasonic receiver placed on other side. However, no need to hold or manually align receiving transducer after initial setup. Transmitter loosely inserted in magnetic assembly on one side, while receiver placed in another magnetic assembly on other side. Magnetic coupling keeps transmitter and receiver assemblies pressed against component and keeps receiver alligned with transmitter as transmitter scans across surface of component. Receiver moved to locations otherwise inaccessible.

  8. 21 CFR 892.1560 - Ultrasonic pulsed echo imaging system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... false Ultrasonic pulsed echo imaging system. 892.1560...892.1560 Ultrasonic pulsed echo imaging system. (a) Identification. An ultrasonic pulsed echo imaging system is a device intended to project a pulsed sound beam into body...

  9. 21 CFR 892.1560 - Ultrasonic pulsed echo imaging system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... false Ultrasonic pulsed echo imaging system. 892.1560...892.1560 Ultrasonic pulsed echo imaging system. (a) Identification. An ultrasonic pulsed echo imaging system is a device intended to project a pulsed sound beam into body...

  10. 21 CFR 892.1560 - Ultrasonic pulsed echo imaging system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... false Ultrasonic pulsed echo imaging system. 892.1560...892.1560 Ultrasonic pulsed echo imaging system. (a) Identification. An ultrasonic pulsed echo imaging system is a device intended to project a pulsed sound beam into body...

  11. 21 CFR 892.1560 - Ultrasonic pulsed echo imaging system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... false Ultrasonic pulsed echo imaging system. 892.1560...892.1560 Ultrasonic pulsed echo imaging system. (a) Identification. An ultrasonic pulsed echo imaging system is a device intended to project a pulsed sound beam into body...

  12. 21 CFR 892.1550 - Ultrasonic pulsed doppler imaging system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...Ultrasonic pulsed doppler imaging system. 892.1550 Section 892...Ultrasonic pulsed doppler imaging system. (a) Identification...ultrasonic pulsed doppler imaging system is a device that combines...location of tissue interfaces or dynamic tissue characteristics...

  13. 21 CFR 892.1550 - Ultrasonic pulsed doppler imaging system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...Ultrasonic pulsed doppler imaging system. 892.1550 Section 892...Ultrasonic pulsed doppler imaging system. (a) Identification...ultrasonic pulsed doppler imaging system is a device that combines...location of tissue interfaces or dynamic tissue characteristics...

  14. 21 CFR 892.1550 - Ultrasonic pulsed doppler imaging system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...Ultrasonic pulsed doppler imaging system. 892.1550 Section 892...Ultrasonic pulsed doppler imaging system. (a) Identification...ultrasonic pulsed doppler imaging system is a device that combines...location of tissue interfaces or dynamic tissue characteristics...

  15. 21 CFR 892.1550 - Ultrasonic pulsed doppler imaging system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...Ultrasonic pulsed doppler imaging system. 892.1550 Section 892...Ultrasonic pulsed doppler imaging system. (a) Identification...ultrasonic pulsed doppler imaging system is a device that combines...location of tissue interfaces or dynamic tissue characteristics...

  16. 21 CFR 892.1550 - Ultrasonic pulsed doppler imaging system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...Ultrasonic pulsed doppler imaging system. 892.1550 Section 892...Ultrasonic pulsed doppler imaging system. (a) Identification...ultrasonic pulsed doppler imaging system is a device that combines...location of tissue interfaces or dynamic tissue characteristics...

  17. Lab Exercise Ultrasonic pulse-echo technique

    E-print Network

    Daraio, Chiara

    Lab Exercise Ultrasonic pulse-echo technique Sebastian Kr¨odel October 21, 2013 1 Ultrasonic Principle The propagation of ultrasonic waves (100kHz - 100MHz) in solid media is widely used for nondestructive testing. The wave velocity is the most common param- eter in these methods and describes

  18. A Pulse Generator Based on an Arduino Platform for Ultrasonic Applications

    NASA Astrophysics Data System (ADS)

    Acevedo, Pedro; Vázquez, Mónica; Durán, Joel; Petrearce, Rodolfo

    The objective of this work is to use the Arduino platform as an ultrasonic pulse generator to excite PVDF ultrasonic arrays in transmission. An experimental setup was implemented using a through-transmission configuration to evaluate the performance of the generator.

  19. 21 CFR 892.1560 - Ultrasonic pulsed echo imaging system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ultrasonic pulsed echo imaging system. 892.1560... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1560 Ultrasonic pulsed echo imaging system. (a) Identification. An ultrasonic pulsed echo imaging system is a device intended to project...

  20. 21 CFR 892.1560 - Ultrasonic pulsed echo imaging system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Ultrasonic pulsed echo imaging system. 892.1560... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1560 Ultrasonic pulsed echo imaging system. (a) Identification. An ultrasonic pulsed echo imaging system is a device intended to project...

  1. 21 CFR 892.1550 - Ultrasonic pulsed doppler imaging system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Ultrasonic pulsed doppler imaging system. 892.1550... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1550 Ultrasonic pulsed doppler imaging system. (a) Identification. An ultrasonic pulsed doppler imaging system is a device that combines...

  2. 21 CFR 892.1560 - Ultrasonic pulsed echo imaging system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ultrasonic pulsed echo imaging system. 892.1560... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1560 Ultrasonic pulsed echo imaging system. (a) Identification. An ultrasonic pulsed echo imaging system is a device intended to project...

  3. 21 CFR 892.1550 - Ultrasonic pulsed doppler imaging system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Ultrasonic pulsed doppler imaging system. 892.1550... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1550 Ultrasonic pulsed doppler imaging system. (a) Identification. An ultrasonic pulsed doppler imaging system is a device that combines...

  4. 21 CFR 892.1560 - Ultrasonic pulsed echo imaging system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Ultrasonic pulsed echo imaging system. 892.1560... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1560 Ultrasonic pulsed echo imaging system. (a) Identification. An ultrasonic pulsed echo imaging system is a device intended to project...

  5. 21 CFR 892.1550 - Ultrasonic pulsed doppler imaging system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ultrasonic pulsed doppler imaging system. 892.1550... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1550 Ultrasonic pulsed doppler imaging system. (a) Identification. An ultrasonic pulsed doppler imaging system is a device that combines...

  6. Method and means of transmitting and receiving broad-band unipolar, ultrasonic pulses for ultrasonic inspection

    DOEpatents

    Thompson, Donald O. (Ames, IA); Hsu, David K. (Ames, IA)

    1993-12-14

    The invention includes a means and method for transmitting and receiving broadband, unipolar, ultrasonic pulses for ultrasonic inspection. The method comprises generating a generally unipolar ultrasonic stress pulse from a low impedance voltage pulse transmitter along a low impedance electrical pathway to an ultrasonic transducer, and receiving the reflected echo of the pulse by the transducer, converting it to a voltage signal, and passing it through a high impedance electrical pathway to an output. The means utilizes electrical components according to the method. The means and method allow a single transducer to be used in a pulse/echo mode, and facilitates alternatingly transmitting and receiving the broadband, unipolar, ultrasonic pulses.

  7. Method and means of transmitting and receiving broad-band unipolar, ultrasonic pulses for ultrasonic inspection

    DOEpatents

    Thompson, D.O.; Hsu, D.K.

    1993-12-14

    The invention includes a means and method for transmitting and receiving broadband, unipolar, ultrasonic pulses for ultrasonic inspection. The method comprises generating a generally unipolar ultrasonic stress pulse from a low impedance voltage pulse transmitter along a low impedance electrical pathway to an ultrasonic transducer, and receiving the reflected echo of the pulse by the transducer, converting it to a voltage signal, and passing it through a high impedance electrical pathway to an output. The means utilizes electrical components according to the method. The means and method allow a single transducer to be used in a pulse/echo mode, and facilitates alternatingly transmitting and receiving the broadband, unipolar, ultrasonic pulses. 25 figures.

  8. Ultrasonic unipolar pulse/echo instrument

    DOEpatents

    Hughes, M.J.; Hsu, D.K.; Thompson, D.O.; Wormley, S.J.

    1993-04-06

    An ultrasonic unipolar pulse/echo instrument uses active switches and a timing and drive circuitry to control electrical energy to a transducer, the discharging of the transducer, and the opening of an electrical pathway to the receiving circuitry for the returning echoes. The active switches utilize MOSFET devices along with decoupling circuitry to insure the preservation of the unipolar nature of the pulses, insure fast transition times, and maintain broad band width and time resolution. A housing contains the various circuitry and switches and allows connection to a power supply and a movable ultrasonic transducer. The circuitry maintains low impedance input to the transducer during transmitting cycles, and high impedance between the transducer and the receiving circuit during receive cycles to maintain the unipolar pulse shape. A unipolar pulse is valuable for nondestructive evaluation, a prime use for the present instrument.

  9. Ultrasonic unipolar pulse/echo instrument

    DOEpatents

    Hughes, Michael S. (Ames, IA); Hsu, David K. (Ames, IA); Thompson, Donald O. (Ames, IA); Wormley, Samuel J. (Ames, IA)

    1993-01-01

    An ultrasonic unipolar pulse/echo instrument uses active switches and a timing and drive circuitry to control electrical energy to a transducer, the discharging of the transducer, and the opening of an electrical pathway to the receiving circuitry for the returning echoes. The active switches utilize MOSFET devices along with decoupling circuitry to insure the preservation of the unipolar nature of the pulses, insure fast transition times, and maintain broad band width and time resolution. A housing contains the various circuitry and switches and allows connection to a power supply and a movable ultrasonic transducer. The circuitry maintains low impedance input to the transducer during transmitting cycles, and high impedance between the transducer and the receiving circuit during receive cycles to maintain the unipolar pulse shape. A unipolar pulse is valuable for nondestructive evaluation, a prime use for the present instrument.

  10. Pulse shaping with transmission lines

    DOEpatents

    Wilcox, R.B.

    1985-08-15

    A method and apparatus for forming shaped voltage pulses uses passive reflection from a transmission line with nonuniform impedance. The impedance of the reflecting line varies with length in accordance with the desired pulse shape. A high voltage input pulse is transmitted to the reflecting line. A reflected pulse is produced having the desired shape and is transmitted by pulse removal means to a load. Light activated photoconductive switches made of silicon can be utilized. The pulse shaper can be used to drive a Pockels cell to produce shaped optical pulses.

  11. Pulse shaping with transmission lines

    DOEpatents

    Wilcox, Russell B. (Oakland, CA)

    1987-01-01

    A method and apparatus for forming shaped voltage pulses uses passive reflection from a transmission line with nonuniform impedance. The impedance of the reflecting line varies with length in accordance with the desired pulse shape. A high voltage input pulse is transmitted to the reflecting line. A reflected pulse is produced having the desired shape and is transmitted by pulse removal means to a load. Light activated photoconductive switches made of silicon can be utilized. The pulse shaper can be used to drive a Pockels cell to produce shaped optical pulses.

  12. Simulation of ultrasonic pulse propagation through the abdominal wall

    E-print Network

    Mast, T. Douglas

    Simulation of ultrasonic pulse propagation through the abdominal wall T. Douglas Mast,a) Laura M 1997 Ultrasonic pulse propagation through the human abdominal wall has been simulated using a model characteristics of ultrasonic wavefront distortion in vivo. However, quantitative agreement was limited by the two

  13. Variable pulse width piezoelectric ultrasonic transducer driver

    NASA Astrophysics Data System (ADS)

    Martin, R.

    1983-11-01

    Requirements of ceramic piezoelectric ultrasonic transducer drive circuits are discussed in the light of today's advanced nondestructive testing techniques. A new drive circuit based upon power MOSFET devices, which overcomes many of the shortcomings of capacitor discharge circuits, is described. This new driving technique enables transducers of a wide range of resonant frequencies to be driven from a simple drive unit. It also enables transducer characteristics to be optimized for particular applications by control of the drive pulse shape.

  14. Wireless power transmission using ultrasonic guided waves

    NASA Astrophysics Data System (ADS)

    Kural, A.; Pullin, R.; Featherston, C.; Paget, C.; Holford, K.

    2011-07-01

    The unavailability of suitable power supply at desired locations is currently an important obstacle in the development of distributed, wireless sensor networks for applications such as structural health monitoring of aircraft. Proposed solutions range from improved batteries to energy harvesting from vibration, temperature gradients and other sources. A novel approach is being investigated at Cardiff University School of Engineering in cooperation with Airbus. It aims to utilise ultrasonic guided Lamb waves to transmit energy through the aircraft skin. A vibration generator is to be placed in a location where electricity supply is readily available. Ultrasonic waves generated by this device will travel through the aircraft structure to a receiver in a remote wireless sensor node. The receiver will convert the mechanical vibration of the ultrasonic waves back to electricity, which will be used to power the sensor node. This paper describes the measurement and modelling of the interference pattern which emerges when Lamb waves are transmitted continuously as in this power transmission application. The discovered features of the pattern, such as a large signal amplitude variation and a relatively high frequency, are presented and their importance for the development of a power transmission system is discussed.

  15. Coiled transmission line pulse generators

    DOEpatents

    McDonald, Kenneth Fox (Columbia, MO)

    2010-11-09

    Methods and apparatus are provided for fabricating and constructing solid dielectric "Coiled Transmission Line" pulse generators in radial or axial coiled geometries. The pour and cure fabrication process enables a wide variety of geometries and form factors. The volume between the conductors is filled with liquid blends of monomers, polymers, oligomers, and/or cross-linkers and dielectric powders; and then cured to form high field strength and high dielectric constant solid dielectric transmission lines that intrinsically produce ideal rectangular high voltage pulses when charged and switched into matched impedance loads. Voltage levels may be increased by Marx and/or Blumlein principles incorporating spark gap or, preferentially, solid state switches (such as optically triggered thyristors) which produce reliable, high repetition rate operation. Moreover, these Marxed pulse generators can be DC charged and do not require additional pulse forming circuitry, pulse forming lines, transformers, or an a high voltage spark gap output switch. The apparatus accommodates a wide range of voltages, impedances, pulse durations, pulse repetition rates, and duty cycles. The resulting mobile or flight platform friendly cylindrical geometric configuration is much more compact, light-weight, and robust than conventional linear geometries, or pulse generators constructed from conventional components. Installing additional circuitry may accommodate optional pulse shape improvements. The Coiled Transmission Lines can also be connected in parallel to decrease the impedance, or in series to increase the pulse length.

  16. Medical tomograph system using ultrasonic transmission

    NASA Technical Reports Server (NTRS)

    Heyser, Richard C. (Inventor); Nathan, Robert (Inventor)

    1978-01-01

    Ultrasonic energy transmission in rectilinear array scanning patterns of soft tissue provides projection density values of the tissue which are recorded as a function of scanning position and angular relationship, .theta., of the subject with a fixed coordinate system. A plurality of rectilinear scan arrays in the same plane for different angular relationships .theta..sub.1 . . . .theta..sub.n thus recorded are superimposed. The superimposition of intensity values thus yields a tomographic image of an internal section of the tissue in the scanning plane.

  17. Portable apparatus with CRT display for nondestructive testing of concrete by the ultrasonic pulse method

    NASA Technical Reports Server (NTRS)

    Manta, G.; Gurau, Y.; Nica, P.; Facacaru, I.

    1974-01-01

    The development of methods for the nondestructive study of concrete structures is discussed. The nondestructive test procedure is based on the method of ultrasonic pulse transmission through the material. The measurements indicate that the elastic properties of concrete or other heterogeneous materials are a function of the rate of ultrasonic propagation. Diagrams of the test equipment are provided. Mathematical models are included to support the theoretical aspects.

  18. Inline Ultrasonic Rheometry by Pulsed Doppler

    SciTech Connect

    Pfund, David M.; Greenwood, Margaret S.; Bamberger, Judith A.; Pappas, Richard A.

    2006-12-22

    This will be a discussion of the non-invasive determination of the viscosity of a non-Newtonian fluid in laminar pipe flow over the range of shear rates present in the pipe. The procedure used requires knowledge of the flow profile in and the pressure drop along a long straight run of pipe. The profile is determined by using a pulsed ultrasonic Doppler velocimeter. This approach is ideal for making non-invasive, real-time measurements for monitoring and control. Rheograms of a shear thinning, thixotropic gel will be presented. The operating parameters and limitations of the Doppler-based instrument will be discussed. The most significant limitation is velocity gradient broadening of the Doppler spectra near the walls of the pipe. This limitation can be significant for strongly shear thinning fluids (depending also on the ratio of beam to pipe diameter and the transducer's insertion angle).

  19. 21 CFR 892.1560 - Ultrasonic pulsed echo imaging system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1560 Ultrasonic pulsed echo imaging system. (a) Identification....

  20. Capacitive micromachined ultrasonic transducer design for high power transmission.

    PubMed

    Bayram, Baris; Oralkan, Omer; Ergun, A Sanli; Haeggström, Edward; Yaralioglu, Goksen G; Khuri-Yakub, Butrus T

    2005-02-01

    Capacitive micromachined ultrasonic transducers (cMUTs) were developed to meet the demands of the ultrasonic industry. To achieve maximum efficiency, the conventional operation of the cMUT requires a bias voltage close to the collapse voltage. Total acoustic output pressure is limited by the efficiency of the cMUT and the maximum-allowed pulse voltage on the membrane. In this paper, we propose the collapse-snapback operation of the cMUT: the membrane is collapsed onto the substrate in the collapsing cycle, and released in the snapback cycle. The collapse-snapback operation overcomes the above-mentioned limitations of the conventional operation. The collapse-snapback operation utilizes a larger range of membrane deflection profiles (both collapsed and released profiles) and generates higher acoustic output pressures. The static finite element calculations were performed to design cMUTs with specific collapse and snapback voltages by changing the electrode parameters (radius (re), position (de), and thickness (te)). These designs were refined for optimum average displacement per cycle. An electrode radius greater than 60% of the membrane radius significantly improved the displacement per volt. Moderately thick membranes (te approximately 0.2 microm) were preferred, as thicker membranes reduced the displacement per volt. Under proper bias conditions, the collapse-snapback operation, designed for high-power transmission, allowed the application of pulse voltages larger than the difference of collapse and snapback voltages. Dynamic finite element calculations of an infinite cMUT array on the substrate loaded with acoustic fluid medium were performed to determine the dynamic response of the cMUT. Commercially available FEM packages ANSYS and LS-DYNA were used for static and dynamic calculations, respectively. The cMUTs were fabricated for optimal performance in the collapse-snapback operation. The transmit experiments were performed on a 2-D cMUT array using a calibrated hydrophone. Taking into account the attenuation and diffraction losses, the pressure on the cMUT surface was extracted. The cMUT generated 0.47 MPa (6 kPa/V) and 1.04 MPa (11 kPa/V) in the conventional and collapse-snapback operations, respectively. Therefore, collapse-snapback operation of the cMUTs was superior for high-power transmission. PMID:15801320

  1. Probing of ultrasonic pulses by multidirectional K. Van Den Abeele" and 0. Leroy

    E-print Network

    Probing of ultrasonic pulses by multidirectional light K. Van Den Abeele" and 0. Leroy K.U. Leuven multidirectional light diffraction by finite amplitude ultrasonic pulses is presented. When crossing the ultrasonic modulated in time. It is found that for special conditions, concerning direction of observation, ultrasonic

  2. Using piezoelectric sensors for ultrasonic pulse velocity measurements in concrete

    NASA Astrophysics Data System (ADS)

    Kee, Seong-Hoon; Zhu, Jinying

    2013-11-01

    The ultrasonic pulse velocity (UPV) test has been a widely used non-destructive testing method for concrete structures. However, the conventional UPV test has limitations in consistency of results and applicability in hard-to-access regions of structures. The authors explore the feasibility of embedded piezoelectric (PZT) sensors for ultrasonic measurements in concrete structures. Two PZT sensors were embedded in a reinforced concrete specimen. One sensor worked as an actuator driven by an ultrasonic pulse-receiver, and another sensor worked as a receiver. A series of ultrasonic tests were conducted to investigate the performance of the embedded sensors in crack-free concrete and concrete specimens having a surface-breaking crack under various external loadings. Signals measured by the embedded sensors show a broad bandwidth with a centre frequency around 80 kHz, and very good coherence in the frequency range from 30 to 180 kHz. Furthermore, experimental variability in ultrasonic pulse velocity and attenuation is substantially reduced compared to previously reported values from conventional UPV equipment. Findings from this study demonstrate that the embedded sensors have great potential as a low-cost solution for ultrasonic transducers for health monitoring of concrete in structures.

  3. Resonant ultrasonic wireless power transmission for bio-implants

    NASA Astrophysics Data System (ADS)

    Lee, Sung Q.; Youm, Woosub; Hwang, Gunn; Moon, Kee S.; Ozturk, Yusuf

    2014-03-01

    In this paper, we present the ultrasonic wireless power transmission system as part of a brain-machine interface (BMI) system in development to supply the required electric power. Making a small-size implantable BMI, it is essential to design a low power unit with a rechargeable battery. The ultrasonic power transmission system has two piezoelectric transducers, facing each other between skin tissues converting electrical energy to mechanical vibrational energy or vice versa. Ultrasound is free from the electromagnetic coupling effect and medical frequency band limitations which making it a promising candidate for implantable purposes. In this paper, we present the design of piezoelectric composite transducer, the rectifier circuit, and rechargeable battery that all packaged in biocompatible titanium can. An initial prototype device was built for demonstration purpose. The early experimental results demonstrate the prototype device can reach 50% of energy transmission efficiency in a water medium at 20mm distance and 18% in animal skin tissue at 18mm distance, respectively.

  4. The effect of abdominal wall morphology on ultrasonic pulse distortion. Part I. Measurements

    E-print Network

    Mast, T. Douglas

    , a hemispheric transducer transmitted a 3.75-MHz ultrasonic pulse through a tissue section. The receivedThe effect of abdominal wall morphology on ultrasonic pulse distortion. Part I. Measurements Laura abdominal wall in producing ultrasonic wavefront distortion was assessed by means of direct measurements

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

    E-print Network

    Mast, T. Douglas

    Simulation of ultrasonic pulse propagation, distortion, and attenuation in the human chest wall T 1999; accepted for publication 23 August 1999 A finite-difference time-domain model for ultrasonic as longitudinal-wave propagation in cartilage and bone. This extended model has been used to simulate ultrasonic

  6. Layered material characterization using ultrasonic transmission. An inverse estimation methodology.

    PubMed

    Messineo, María G; Rus, Guillermo; Eliçabe, Guillermo E; Frontini, Gloria L

    2016-02-01

    This paper presents an inverse methodology with the aim to characterize a layered material through the identification of acoustical and mechanical properties of its layers. The framework to accomplish this objective is provided by the Inverse Problems (IPs) theory. Material characterization refers to the detection and localization of discontinuities, as well as to the identification of physical properties, in order to predict the material behaviour. In this particular case, the IP is solved in the form of a parameter estimation problem, in which the goal is the estimation of the characteristic acoustic impedance, transit time, and attenuation of each layer. These parameters are directly related to relevant material properties, such as the speed of sound, density, elastic modulus and elastic energy dissipation constants. The IP solution is obtained by minimizing a cost functional formulated as the least squares error between the waveform calculated using an equivalent model, and the measured waveform obtained from ultrasonic transmission tests. The applied methodology allowed the accurate estimation of the desired parameters in materials composed of up to three layers. As a second contribution, a power law frequency dependence of the wave attenuation was identified for several homogeneous materials, based on the same ultrasonic transmission experiments. PMID:26456278

  7. Numerical Evaluation of Ultrasonic Pulse-echo Subwavelength Defect Detection Xiangtao Yin

    E-print Network

    Illinois at Urbana-Champaign, University of

    Numerical Evaluation of Ultrasonic Pulse-echo Subwavelength Defect Detection Xiangtao Yin£½ , Scott. Pennsylvania Avenue, Urbana, IL 61801 Abstract -- The ultrasonic pulse-echo Backscattered Am- plitude Integral-diameter channels occasionally using a 17.3-MHz focused transducer in water (20o C, 86 Ñ, total sample thickness 220

  8. Simulation of ultrasonic pulse propagation through the abdominal wall.

    PubMed

    Mast, T D; Hinkelman, L M; Orr, M J; Sparrow, V W; Waag, R C

    1997-08-01

    Ultrasonic pulse propagation through the abdominal wall has been simulated using a model for two-dimensional propagation through anatomically realistic tissue cross sections. The time-domain equations for wave propagation in a medium of variable sound speed and density were discretized to obtain a set of coupled finite-difference equations. These difference equations were solved numerically using a two-step MacCormack scheme that is fourth-order accurate in space and second-order accurate in time. The inhomogeneous tissue of the abdominal wall was represented by two-dimensional matrices of sound speed and density values. These values were determined by processing scanned images of abdominal wall cross sections stained to identify connective tissue, muscle, and fat, each of which was assumed to have a constant sound speed and density. The computational configuration was chosen to simulate that of wavefront distortion measurements performed on the same specimens. Qualitative agreement was found between those measurements and the results of the present computations, indicating that the computational model correctly depicts the salient characteristics of ultrasonic wavefront distortion in vivo. However, quantitative agreement was limited by the two-dimensionality of the computation and the absence of detailed tissue microstructure. Calculations performed using an asymptotic straight-ray approximation showed good agreement with time-shift aberrations predicted by the full-wave method, but did not explain the amplitude fluctuations and waveform distortion found in the experiments and the full-wave calculations. Visualization of computed wave propagation within tissue cross sections suggests that amplitude fluctuations and waveform distortion observed in ultrasonic propagation through the abdominal wall are associated with scattering from internal inhomogeneities such as septa within the subcutaneous fat. These observations, as well as statistical analysis of computed and observed amplitude fluctuations, suggest that weak fluctuation models do not fully describe ultrasonic wavefront distortion caused by the abdominal wall. PMID:9265762

  9. Pulse transmission transceiver architecture for low power communications

    DOEpatents

    Dress, Jr., William B.; Smith, Stephen F.

    2003-08-05

    Systems and methods for pulse-transmission low-power communication modes are disclosed. A method of pulse transmission communications includes: generating a modulated pulse signal waveform; transforming said modulated pulse signal waveform into at least one higher-order derivative waveform; and transmitting said at least one higher-order derivative waveform as an emitted pulse. The systems and methods significantly reduce lower-frequency emissions from pulse transmission spread-spectrum communication modes, which reduces potentially harmful interference to existing radio frequency services and users and also simultaneously permit transmission of multiple data bits by utilizing specific pulse shapes.

  10. Monitoring of concrete structures using the ultrasonic pulse velocity method

    NASA Astrophysics Data System (ADS)

    Karaiskos, G.; Deraemaeker, A.; Aggelis, D. G.; Van Hemelrijck, D.

    2015-11-01

    Concrete is the material most produced by humanity. Its popularity is mainly based on its low production cost and great structural design flexibility. Its operational and ambient loadings including environmental effects have a great impact in the performance and overall cost of concrete structures. Thus, the quality control, the structural assessment, the maintenance and the reliable prolongation of the operational service life of the existing concrete structures have become a major issue. In the recent years, non-destructive testing (NDT) is becoming increasingly essential for reliable and affordable quality control and integrity assessment not only during the construction of new concrete structures, but also for the existing ones. Choosing the right inspection technique is always followed by a compromise between its performance and cost. In the present paper, the ultrasonic pulse velocity (UPV) method, which is the most well known and widely accepted ultrasonic concrete NDT method, is thoroughly reviewed and compared with other well-established NDT approaches. Their principles, inherent limitations and reliability are reviewed. In addition, while the majority of the current UPV techniques are based on the use of piezoelectric transducers held on the surface of the concrete, special attention is paid to a very promising technique using low-cost and aggregate-size piezoelectric transducers embedded in the material. That technique has been evaluated based on a series of parameters, such as the ease of use, cost, reliability and performance.

  11. The contribution of tympanic transmission to fine temporal signal evaluation in an ultrasonic moth

    E-print Network

    Rodriguez, R. L.; Schul, J.; Cocroft, R. B.; Greenfield, Michael D.

    2005-11-01

    In lesser waxmoths Achroia grisella, pair formation and female mate choice involve very fine discrimination of male ultrasonic signals. Female A. grisella prefer male signals with longer pulses and longer 'asynchrony ...

  12. Pulse transmission receiver with higher-order time derivative pulse correlator

    DOEpatents

    Dress, Jr., William B.; Smith, Stephen F.

    2003-09-16

    Systems and methods for pulse-transmission low-power communication modes are disclosed. A pulse transmission receiver includes: a higher-order time derivative pulse correlator; a demodulation decoder coupled to the higher-order time derivative pulse correlator; a clock coupled to the demodulation decoder; and a pseudorandom polynomial generator coupled to both the higher-order time derivative pulse correlator and the clock. The systems and methods significantly reduce lower-frequency emissions from pulse transmission spread-spectrum communication modes, which reduces potentially harmful interference to existing radio frequency services and users and also simultaneously permit transmission of multiple data bits by utilizing specific pulse shapes.

  13. Application of digital pulse shaping by least squares method to ultrasonic signals in composites

    NASA Technical Reports Server (NTRS)

    Kishoni, D.

    1985-01-01

    For ultrasonic testing in composites, a signal processing tool is identified that can significantly enhance the sharpness of ultrasonic waveforms and provide clearer pictures of the nature of the material flaw. The technique artificially improves the resolution of the system to discrete events by pulse shaping the measured waveform based on the signal from a reference. The optimum pulse shape operator is determined from a least-squares method in the z-domain.

  14. Pulse transmission transmitter including a higher order time derivate filter

    DOEpatents

    Dress, Jr., William B.; Smith, Stephen F.

    2003-09-23

    Systems and methods for pulse-transmission low-power communication modes are disclosed. A pulse transmission transmitter includes: a clock; a pseudorandom polynomial generator coupled to the clock, the pseudorandom polynomial generator having a polynomial load input; an exclusive-OR gate coupled to the pseudorandom polynomial generator, the exclusive-OR gate having a serial data input; a programmable delay circuit coupled to both the clock and the exclusive-OR gate; a pulse generator coupled to the programmable delay circuit; and a higher order time derivative filter coupled to the pulse generator. The systems and methods significantly reduce lower-frequency emissions from pulse transmission spread-spectrum communication modes, which reduces potentially harmful interference to existing radio frequency services and users and also simultaneously permit transmission of multiple data bits by utilizing specific pulse shapes.

  15. Detection of cystic structures using pulsed ultrasonically induced resonant cavitation

    NASA Technical Reports Server (NTRS)

    Bar-Cohen, Yoseph (Inventor); Kovach, John S. (Inventor)

    2002-01-01

    Apparatus and method for early detection of cystic structures indicative of ovarian and breast cancers uses ultrasonic wave energy at a unique resonance frequency for inducing cavitation in cystic fluid characteristic of cystic structures in the ovaries associated with ovarian cancer, and in cystic structures in the breast associated with breast cancer. Induced cavitation bubbles in the cystic fluid implode, creating implosion waves which are detected by ultrasonic receiving transducers attached to the abdomen of the patient. Triangulation of the ultrasonic receiving transducers enables the received signals to be processed and analyzed to identify the location and structure of the cyst.

  16. Method of estimating tissue attenuation using wideband ultrasonic pulse and apparatus for use therein

    SciTech Connect

    Flax, S.W.

    1986-11-11

    This patent describes a method of estimating tissue attenuation of ultrasound energy comprising the steps of: transmitting a wide band ultrasonic pulse into the tissue, the pulse having a frequency spectrum with a center frequency, detecting the pulse as reflected by the tissue, estimating decay of a measure of amplitude of the reflected pulse between two levels in the tissue to approximate the slope of the decay, estimating center frequency of the reflected pulse between the two levels, and obtaining tissue attenuation from the approximated slope of a measure of amplitude and the center frequency.

  17. Fundamental Development of Ultrasonic Information Transmission System for Wearable Devices

    NASA Astrophysics Data System (ADS)

    Suzuki, Shin-nosuke; Ishihara, Manabu; Kobayashi, Yukio; Katane, Tamotsu; Saito, Osami; Kobayashi, Kazuto

    2009-07-01

    A wearable device is an electronic device miniaturized to a wearable size with computing and wireless communication functions. In this study, we have applied a communication system using ultrasonic waves to a wearable device. Ultrasonic waves are safe for the human body and do not cause the malfunction of electronic equipment. In addition, communication using ultrasonic waves is effective for preventing “skimming” because ultrasonic waves can transmit through the human body and have a large attenuation in air. Wearable devices can also be used in areas where electromagnetic waves are limited. We have developed an experimental prototype device. The prototype contains a one-chip microcomputer used to verify the size and battery consumption of the wearable device. As a result, the developed prototype realized bidirectional communication with a suitable device size and power consumption. The communication speed corresponds to 250 kbps. This value is equivalent to that of a conventional IC card system using electromagnetic waves. With this proposed system, we can achive various practical applications that can maintain absolute privacy while transmitting information through the human body.

  18. Transmission Oscillator Ultrasonic Spectrometer (TOUS): A new research instrument

    NASA Technical Reports Server (NTRS)

    Heyman, J. S.; Stone, F. D.; Conradi, M. S.; Miller, J. G.

    1975-01-01

    TOUS is capable for measuring very small changes in acoustic attenuation and phase velocity. Its high sensitivity to small changes in ultrasonic absorption results in part from operation under marginal conditions. In spite of high sensitivity, TOUS system is relatively simple, inexpensive, and compact.

  19. Gas ultrasonic flow rate measurement through genetic-ant colony optimization based on the ultrasonic pulse received signal model

    NASA Astrophysics Data System (ADS)

    Hou, Huirang; Zheng, Dandan; Nie, Laixiao

    2015-04-01

    For gas ultrasonic flowmeters, the signals received by ultrasonic sensors are susceptible to noise interference. If signals are mingled with noise, a large error in flow measurement can be caused by triggering mistakenly using the traditional double-threshold method. To solve this problem, genetic-ant colony optimization (GACO) based on the ultrasonic pulse received signal model is proposed. Furthermore, in consideration of the real-time performance of the flow measurement system, the improvement of processing only the first three cycles of the received signals rather than the whole signal is proposed. Simulation results show that the GACO algorithm has the best estimation accuracy and ant-noise ability compared with the genetic algorithm, ant colony optimization, double-threshold and enveloped zero-crossing. Local convergence doesn’t appear with the GACO algorithm until -10?dB. For the GACO algorithm, the converging accuracy and converging speed and the amount of computation are further improved when using the first three cycles (called GACO-3cycles). Experimental results involving actual received signals show that the accuracy of single-gas ultrasonic flow rate measurement can reach 0.5% with GACO-3?cycles, which is better than with the double-threshold method.

  20. PROOF COPY 509501JMM Inductive pulse transmission by amplitude

    E-print Network

    Wu, Jayne

    be expanded to the transmission of pulse trains for deep brain stimulation (DBS). Using a passive envelope detector and an integrated coil, pulse trains can be obtained with high fidelity across a load representing-up and recovery. The advantages are less surgery, less risk of infection, flexibility with parameter adjustment

  1. 21 CFR 892.1560 - Ultrasonic pulsed echo imaging system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... pulsed sound beam into body tissue to determine the depth or location of the tissue interfaces and to measure the duration of an acoustic pulse from the transmitter to the tissue interface and back to...

  2. Superluminal pulse transmission through a phase-conjugating mirror

    NASA Astrophysics Data System (ADS)

    Blaauboer, M.; Kozhekin, A. E.; Kofman, A. G.; Kurizki, G.; Lenstra, D.; Lodder, A.

    1998-03-01

    We theoretically analyze wave packet transmission through a phase-conjugating mirror and show that the transmission of a suitably chosen input pulse is superluminal, i.e. the peak of the pulse emerges from the mirror before the time it takes to travel the same distance in vacuum. This pulse reshaping effect can be attributed directly to the dispersion relation in the nonlinear medium constituting the mirror. Thus, for the first time a connection is laid between optical phase conjugation and superluminal behavior. In view of its additional amplifying ability, a phase-conjugating mirror is a most promising candidate for an experimental observation of tachyonic signatures.

  3. Ultrasonic Pulse-Echo Subwavelength Defect Detection Mechanism: Experiment and Simulation

    E-print Network

    Illinois at Urbana-Champaign, University of

    -filled channel defects as small as 6 m in diameter could intermittently be detected.(2) The BAI-mode image pixelUltrasonic Pulse-Echo Subwavelength Defect Detection Mechanism: Experiment and Simulation Xiangtao Trans. UFFC, 45:30 (1998)] has demonstrated sensitive detection of subwavelength channel defects (38- m

  4. Compressive strength evaluation of structural lightweight concrete by non-destructive ultrasonic pulse velocity method.

    PubMed

    Bogas, J Alexandre; Gomes, M Glória; Gomes, Augusto

    2013-07-01

    In this paper the compressive strength of a wide range of structural lightweight aggregate concrete mixes is evaluated by the non-destructive ultrasonic pulse velocity method. This study involves about 84 different compositions tested between 3 and 180 days for compressive strengths ranging from about 30 to 80 MPa. The influence of several factors on the relation between the ultrasonic pulse velocity and compressive strength is examined. These factors include the cement type and content, amount of water, type of admixture, initial wetting conditions, type and volume of aggregate and the partial replacement of normal weight coarse and fine aggregates by lightweight aggregates. It is found that lightweight and normal weight concretes are affected differently by mix design parameters. In addition, the prediction of the concrete's compressive strength by means of the non-destructive ultrasonic pulse velocity test is studied. Based on the dependence of the ultrasonic pulse velocity on the density and elasticity of concrete, a simplified expression is proposed to estimate the compressive strength, regardless the type of concrete and its composition. More than 200 results for different types of aggregates and concrete compositions were analyzed and high correlation coefficients were obtained. PMID:23351273

  5. Haykin Chapter 4 Baseband Pulse Transmission

    E-print Network

    Al-Ghadhban, Samir

    Sources in Baseband Transmission Intersymbol Interference (ISI) · The result of data transmission over to a common form of interference called intersymbol interference (ISI). · Intersymbol interference system is the channel noise. · Naturally, noise and ISI arise in the system simultaneously. 5 4

  6. Pulse transmission receiver with higher-order time derivative pulse generator

    DOEpatents

    Dress, Jr., William B.; Smith, Stephen F.

    2003-08-12

    Systems and methods for pulse-transmission low-power communication modes are disclosed. A pulse transmission receiver includes: a front-end amplification/processing circuit; a synchronization circuit coupled to the front-end amplification/processing circuit; a clock coupled to the synchronization circuit; a trigger signal generator coupled to the clock; and at least one higher-order time derivative pulse generator coupled to the trigger signal generator. The systems and methods significantly reduce lower-frequency emissions from pulse transmission spread-spectrum communication modes, which reduces potentially harmful interference to existing radio frequency services and users and also simultaneously permit transmission of multiple data bits by utilizing specific pulse shapes.

  7. Micromachined ultrasonic transducers: 11.4 MHz transmission in air and Igal Ladabaum, B. T. KhuriYakub, and Dimitri Spoliansky

    E-print Network

    Khuri-Yakub, Butrus T. "Pierre"

    Micromachined ultrasonic transducers: 11.4 MHz transmission in air and more Igal Ladabaum, B. T ultrasonic levitation device Rev. Sci. Instrum. 82, 105111 (2011) Modeling of ultrasound transmission through ultrasonic elastic wave velocity and microtomography measurements at high pressures Rev. Sci. Instrum. 82

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

    NASA Astrophysics Data System (ADS)

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

    2015-07-01

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

  9. Elastic moduli of precompressed pyrophyllite used in ultrahigh pressure research. [propagation of ultrasonic pulses

    NASA Technical Reports Server (NTRS)

    Sachse, W.; Ruoff, A. L.

    1974-01-01

    The propagation of ultrasonic pulses in pyrophyllite specimens was studied to determine the effect of specimen precompression on the measured elastic moduli. Measurements were made at room pressure and, for the precompressed specimens, to pressures of 3 kbar. Pyrophyllite was found to be elastically anisotropic, apparently the result of the fabric present in our material. The room pressure adiabatic bulk modulus as measured on specimens made of isostatically compacted powered pyrophyllite was determined to be 96.1 kbar. The wave speeds of ultrasonic pulses in pyrophyllite were found to decrease with increasing specimen precompression. A limiting value of precompression was found, above which no further decrease in wave speed was observed. For the shear wave speeds this occurs at 10 kbar while for the longitudinal wave at 25 kbar. In the limit, the shear waves propagate 20% slower than in the unprecompressed samples; for the longitudinal wave the difference is 30%.

  10. A Digital Ultrasonic Pulse-Echo Overlap System and Algorithm for Unambiguous Determination of Pulse Transit Time

    SciTech Connect

    Cristian,P.; Rickel, D.; Migliori, A.; Zhang, J.; Zhao, Y.; Leisure, R.; Li, B.

    2005-01-01

    We report an evolution of an all-digital ultrasonic pulse technique for measurements of elastic constants of solids. An unambiguous analytical procedure is described for determining the correct time delay of echoes without any need for actual echo overlap. We also provide a simple procedure for making corrections for transducer-bond-induced phase shifts. The precision of a measurement made with this system at ambient temperature exceeds one part in 107 without the use of mixers, gates, time delays, and other complications normally associated with such measurements.

  11. Nano features of Al/Au ultrasonic bond interface observed by high resolution transmission electron microscopy

    SciTech Connect

    Ji Hongjun; Li Mingyu Kim, Jong-Myung; Kim, Dae-Won; Wang Chunqing

    2008-10-15

    Nano-scale interfacial details of ultrasonic AlSi1 wire wedge bonding to a Au/Ni/Cu pad were investigated using high resolution transmission electron microscopy (HRTEM). The intermetallic phase Au{sub 8}Al{sub 3} formed locally due to diffusion and reaction activated by ultrasound at the Al/Au bond interface. Multilayer sub-interfaces roughly parallel to the wire/pad interface were observed among this phase, and interdiffusional features near the Au pad resembled interference patterns, alternately dark and bright bars. Solid-state diffusion theory cannot be used to explain why such a thick compound formed within milliseconds at room temperature. The major formation of metallurgical bonds was attributed to ultrasonic cyclic vibration.

  12. Pulsed Power for a Dynamic Transmission Electron Microscope

    SciTech Connect

    dehope, w j; browning, n; campbell, g; cook, e; king, w; lagrange, t; reed, b; stuart, b; Shuttlesworth, R; Pyke, B

    2009-06-25

    Lawrence Livermore National Laboratory (LLNL) has converted a commercial 200kV transmission electron microscope (TEM) into an ultrafast, nanoscale diagnostic tool for material science studies. The resulting Dynamic Transmission Electron Microscope (DTEM) has provided a unique tool for the study of material phase transitions, reaction front analyses, and other studies in the fields of chemistry, materials science, and biology. The TEM's thermionic electron emission source was replaced with a fast photocathode and a laser beam path was provided for ultraviolet surface illumination. The resulting photoelectron beam gives downstream images of 2 and 20 ns exposure times at 100 and 10 nm spatial resolution. A separate laser, used as a pump pulse, is used to heat, ignite, or shock samples while the photocathode electron pulses, carefully time-synchronized with the pump, function as probe in fast transient studies. The device functions in both imaging and diffraction modes. A laser upgrade is underway to make arbitrary cathode pulse trains of variable pulse width of 10-1000 ns. Along with a fast e-beam deflection scheme, a 'movie mode' capability will be added to this unique diagnostic tool. This talk will review conventional electron microscopy and its limitations, discuss the development and capabilities of DTEM, in particularly addressing the prime and pulsed power considerations in the design and fabrication of the DTEM, and conclude with the presentation of a deflector and solid-state pulser design for Movie-Mode DTEM.

  13. Pulse compression in a time variant system with application to ultrasonic vibrometry.

    PubMed

    Martin, J S; Rogers, P H; Gray, M D

    2013-03-01

    Pulse compression is normally applied only to time-invariant systems, as the variation of a system's properties during its interrogation violates assumptions of the compression process. However, there is an exact solution to the pulse-compression problem when the time variance satisfies two criteria, which are the same as those required for the operation of an ultrasonic vibrometer in the context of a tissue elastography system. One is that the variations be very small in comparison with the wavelength of the interrogating ultrasound. The other is that the bandwidth of the variations be within one Nyquist band as sampled by the periodic interrogation signal. The solution to this problem involves a step-wise interpolation of the static pulse-compression transfer function in the frequency domain. This technique, in conjunction with the selection of an appropriate interrogation signal, offers significant advantages in measurement time or measurement resolution for an ultrasonic vibrometer limited by additive noise at the receiver. The characteristics of optimal interrogation signals for this technique are the signal's crest factor, spectral energy distribution, and phasing. These relate to the intended compression pulse, the noise, and the static response of the system. The technique has been demonstrated analytically, experimentally, and with numerical models. PMID:23464021

  14. Envelope pulsed ultrasonic distance measurement system based upon amplitude modulation and phase modulation

    SciTech Connect

    Huang, Y. P.; Wang, J. S.; Huang, K. N.; Ho, C. T.; Huang, J. D.; Young, M. S.

    2007-06-15

    A novel microcomputer-based ultrasonic distance measurement system is presented. This study proposes an efficient algorithm which combines both the amplitude modulation (AM) and the phase modulation (PM) of the pulse-echo technique. The proposed system can reduce error caused by inertia delay and amplitude attenuation effect when using the AM and PM envelope square wave form (APESW). The APESW ultrasonic driving wave form causes a phase inversion phenomenon in the relative wave form of the receiver. The phase inversion phenomenon sufficiently identifies the ''measurement pulse'' in the received wave forms, which can be used for accurate time-of-flight (TOF) measurement. In addition, combining a countertechnique to compute the phase shifts of the last cycle for TOF, the presented system can obtain distance resolution of 0.1% of the wavelength corresponding to the 40 kHz frequency of the ultrasonic wave. The standard uncertainty of the proposed distance measurement system is found to be 0.2 mm at a range of 50-500 mm. The APESW signal generator and phase detector of this measuring system are designed on a complex programmable logic device, which is used to govern the TOF measurement and send the data to a personal computer for distance calibration and examination. The main advantages of this APESW system are high resolution, low cost, narrow bandwidth requirement, and ease of implementation.

  15. Envelope pulsed ultrasonic distance measurement system based upon amplitude modulation and phase modulation

    NASA Astrophysics Data System (ADS)

    Huang, Y. P.; Wang, J. S.; Huang, K. N.; Ho, C. T.; Huang, J. D.; Young, M. S.

    2007-06-01

    A novel microcomputer-based ultrasonic distance measurement system is presented. This study proposes an efficient algorithm which combines both the amplitude modulation (AM) and the phase modulation (PM) of the pulse-echo technique. The proposed system can reduce error caused by inertia delay and amplitude attenuation effect when using the AM and PM envelope square wave form (APESW). The APESW ultrasonic driving wave form causes a phase inversion phenomenon in the relative wave form of the receiver. The phase inversion phenomenon sufficiently identifies the "measurement pulse" in the received wave forms, which can be used for accurate time-of-flight (TOF) measurement. In addition, combining a countertechnique to compute the phase shifts of the last cycle for TOF, the presented system can obtain distance resolution of 0.1% of the wavelength corresponding to the 40kHz frequency of the ultrasonic wave. The standard uncertainty of the proposed distance measurement system is found to be 0.2mm at a range of 50-500mm. The APESW signal generator and phase detector of this measuring system are designed on a complex programmable logic device, which is used to govern the TOF measurement and send the data to a personal computer for distance calibration and examination. The main advantages of this APESW system are high resolution, low cost, narrow bandwidth requirement, and ease of implementation.

  16. Envelope pulsed ultrasonic distance measurement system based upon amplitude modulation and phase modulation.

    PubMed

    Huang, Y P; Wang, J S; Huang, K N; Ho, C T; Huang, J D; Young, M S

    2007-06-01

    A novel microcomputer-based ultrasonic distance measurement system is presented. This study proposes an efficient algorithm which combines both the amplitude modulation (AM) and the phase modulation (PM) of the pulse-echo technique. The proposed system can reduce error caused by inertia delay and amplitude attenuation effect when using the AM and PM envelope square wave form (APESW). The APESW ultrasonic driving wave form causes a phase inversion phenomenon in the relative wave form of the receiver. The phase inversion phenomenon sufficiently identifies the "measurement pulse" in the received wave forms, which can be used for accurate time-of-flight (TOF) measurement. In addition, combining a countertechnique to compute the phase shifts of the last cycle for TOF, the presented system can obtain distance resolution of 0.1% of the wavelength corresponding to the 40 kHz frequency of the ultrasonic wave. The standard uncertainty of the proposed distance measurement system is found to be 0.2 mm at a range of 50-500 mm. The APESW signal generator and phase detector of this measuring system are designed on a complex programmable logic device, which is used to govern the TOF measurement and send the data to a personal computer for distance calibration and examination. The main advantages of this APESW system are high resolution, low cost, narrow bandwidth requirement, and ease of implementation. PMID:17614634

  17. Analysis of Ultrasound Propagation in A Steel Pipe Using Ultrasonic Pulse Doppler Method

    NASA Astrophysics Data System (ADS)

    Tezuka, Kenichi; Wada, Sanehiro; Mori, Michitsugu; Kikura, Hiroshige; Aritomi, Masanori

    Thermal powers of nuclear reactors are calculated by the enthalpy difference between reactor feed water and main steam. Improvement of the measurement accuracy in the flow rate measurements of reactor feed water enables us to uprate reactor thermal power, called MUR (Measurement Uncertainly Recapture) uprate. The ultrasonic pulse Doppler system is expected to be a suitable method featuring the capability o measuring the flow profile directly in a pipe. For the optimum measurements, ultrasound path from ultrasonic transducer into the fluid through steel pipe wall should be carefully predicted in high temperature water. This paper presents analytical results of ultrasound propagation using FEM simulation code and experimental results of pipe flow rate at high temperature thermal conditions.

  18. 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.

  19. Transmission of ultrasonic waves at oblique incidence to composite laminates with spring-type interlayer interfaces.

    PubMed

    Ishii, Yosuke; Biwa, Shiro

    2015-11-01

    The transmission characteristics of ultrasonic waves at oblique incidence to composite laminates are analyzed theoretically by the stiffness matrix method. The analysis takes into account the presence of thin resin-rich regions between adjacent plies as spring-type interfaces with normal and shear stiffnesses. The amplitude transmission coefficient of longitudinal wave through a unidirectional laminate immersed in water is shown to be significantly influenced by the frequency, the interlayer interfacial stiffnesses, and the incident angle. Using Floquet's theorem, the dispersion relation of the infinitely extended laminate structure is calculated and compared to the transmission coefficient of laminates of finite thickness. This reveals that the ranges of frequency and interfacial stiffnesses where the Floquet waves lie in the band-gaps agree well with those where the transmission coefficient of the finite layered structure is relatively small, indicating that the band-gaps appear even in the laminate with a finite number of plies. The amplitude transmission coefficient for an 11-ply carbon-epoxy unidirectional composite laminate is experimentally obtained for various frequencies and incident angles. The low-transmission zones observed in the experimental results, which are due to the critical angle of the quasi-longitudinal wave and the Bragg reflection, are shown to be favorably compared with the theory. PMID:26627756

  20. Ultrasonics

    NASA Technical Reports Server (NTRS)

    Leonard, B. E.; Gardner, C. G.

    1973-01-01

    Ultrasonic testing is discussed as a primary means of nondestructive evaluation of subsurface flaws. The advantages and disadvantages are listed. The elementary principles, basic components of test units, scan modes, resonance testing, detection of fatigue cracks, monitoring fatigue crack growth, and determination of residual stress are discussed.

  1. Spark ultrasonic transducer

    NASA Technical Reports Server (NTRS)

    Hoop, J. M.

    1972-01-01

    Nondestructive testing by spark transducer induces ultrasonic pulses in materials without physical contact. High power pulse generator connected to step up transformer produces sparking between two tungsten rods and ultrasonic energy pulses in test samples placed between rods.

  2. Application of laser generated ultrasonic pulses in diagnostics of residual stresses in welds

    NASA Astrophysics Data System (ADS)

    Ivochkin, A. Yu.; Karabutov, A. A.; Pelivanov, I. M.; Lyamshev, M. L.; Rohadgi, U. M.; Subudhi, M.

    2006-01-01

    The laser optoacoustic method is applied for nondestructive evaluation of residual stresses in metals. Theoretical background establishes the acoustoelasticity relationships between applied biaxial stresses and deviations of the longitudinal wave velocity in solids. The experimental technique bases on laser thermoptical excitation of nanosecond ultrasonic pulses on the surface of samples under study and their backward mode piezodetection with a high temporal resolution. The samples, produced from stainless steel, had thickness from 1.67 mm to 8.87 mm. Welds are made up by means of electronic beam overheating of the samples with different intensities of the beam. Plane distributions of relative longitudinal wave velocity deviations, produced by stresses, were obtained.

  3. Ultrasonic ranging and data telemetry system

    DOEpatents

    Brashear, Hugh R. (Farragut, TN); Blair, Michael S. (Knoxville, TN); Phelps, James E. (Knoxville, TN); Bauer, Martin L. (Oak Ridge, TN); Nowlin, Charles H. (Oak Ridge, TN)

    1990-01-01

    An ultrasonic ranging and data telemetry system determines a surveyor's position and automatically links it with other simultaneously taken survey data. An ultrasonic and radio frequency (rf) transmitter are carried by the surveyor in a backpack. The surveyor's position is determined by calculations that use the measured transmission times of an airborne ultrasonic pulse transmitted from the backpack to two or more prepositioned ultrasonic transceivers. Once a second, rf communications are used both to synchronize the ultrasonic pulse transmission-time measurements and to transmit other simultaneously taken survey data. The rf communications are interpreted by a portable receiver and microcomputer which are brought to the property site. A video display attached to the computer provides real-time visual monitoring of the survey progress and site coverage.

  4. Waveguide piezoelectric micromachined ultrasonic transducer array for short-range pulse-echo imaging

    NASA Astrophysics Data System (ADS)

    Lu, Y.; Tang, H.; Wang, Q.; Fung, S.; Tsai, J. M.; Daneman, M.; Boser, B. E.; Horsley, D. A.

    2015-05-01

    This paper presents an 8 × 24 element, 100 ?m-pitch, 20 MHz ultrasound imager based on a piezoelectric micromachined ultrasonic transducer (PMUT) array having integrated acoustic waveguides. The 70 ?m diameter, 220 ?m long waveguides function both to direct acoustic waves and to confine acoustic energy, and also to provide mechanical protection for the PMUT array used for surface-imaging applications such as an ultrasonic fingerprint sensor. The imager consists of a PMUT array bonded with a CMOS ASIC using wafer-level conductive eutectic bonding. This construction allows each PMUT in the array to have a dedicated front-end receive amplifier, which together with on-chip analog multiplexing enables individual pixel read-out with high signal-to-noise ratio through minimized parasitic capacitance between the PMUT and the front-end amplifier. Finite element method simulations demonstrate that the waveguides preserve the pressure amplitude of acoustic pulses over distances of 600 ?m. Moreover, the waveguide design demonstrated here enables pixel-by-pixel readout of the ultrasound image due to improved directivity of the PMUT by directing acoustic waves and creating a pressure field with greater spatial uniformity at the end of the waveguide. Pulse-echo imaging experiments conducted using a one-dimensional steel grating demonstrate the array's ability to form a two-dimensional image of a target.

  5. Assessment of strength properties of cemented paste backfill by ultrasonic pulse velocity test.

    PubMed

    Y?lmaz, Tekin; Ercikdi, Bayram; Karaman, Kadir; Külekçi, Gökhan

    2014-07-01

    Ultrasonic pulse velocity (UPV) test is one of the most popular non-destructive techniques used in the assessment of the mechanical properties of concrete or rock materials. In this study, the effects of binder type/dosage, water to cement ratio (w/c) and fines content (<20 ?m) of the tailings on ultrasonic pulse velocity (UPV) of cemented paste backfill (CPB) samples were investigated and correlated with the corresponding unconfined compressive strength (UCS) data. A total of 96 CPB samples prepared at different mixture properties were subjected to the UPV and UCS tests at 7, 14, 28 and 56-days of curing periods. UPV and UCS of CPB samples of ordinary Portland cement (CEM I 42.5 R) and sulphate resistant cement (SRC 32.5) initially increased rapidly, but, slowed down after 14 days. However, UPV and UCS of CPB samples of the blast furnace slag cement (CEM III/A 42.5 N) steadily increased between 7 and 56 days. Increasing binder dosage or reducing w/c ratio and fines content (<20 ?m) increased the UCS and UPV of CPB samples. UPV was found to be particularly sensitive to fines content. UCS data were correlated with the corresponding UPV data. A linear relation appeared to exist between the UCS and UPV of CPB samples. These findings have demonstrated that the UPV test can be reliably used for the estimation of the strength of CPB samples. PMID:24602334

  6. Exploring diffusion of ultrasonically consolidated aluminum and copper films through scanning and transmission electron microscopy

    NASA Astrophysics Data System (ADS)

    Sietins, Jennifer Mueller

    Ultrasonic consolidation (UC) is a promising manufacturing method for metal matrix composite pre-preg tapes or foils that utilizes a layer build-up technique. The process involves three main variables: applied load, oscillation amplitude, and rolling speed. A main advantage of this process is the ability to manufacture multi-material parts at lower processing temperatures compared to other metal matrix composites processes. A major disadvantage, however, is a lack of understanding of diffusion during the ultrasonic consolidation process, which is expected to affect the microstructure, bond quality, and strength within the interface region. The role of diffusion during the low temperature, short duration ultrasonic consolidation process was explored. First, scanning electron microscopy (SEM) x-ray energy dispersive spectroscopy (XEDS) was used to measure concentration profiles of ultrasonically consolidated high purity aluminum and copper through which the interdiffusion coefficients were calculated. It was found that the experimental accelerating voltage had a significant impact on the measurement of the concentration profiles, and associated interdiffusion coefficients, due to the interaction volume interference. The effect of the interaction volume on the concentration profiles was confirmed through Monte Carlo simulations of electron trajectories, and the error due the interaction volume was quantified. The results showed the diffusion distance was too small for accurate measurements with SEM XEDS even at low accelerating voltages. To significantly reduce the error due to the interaction volume, transmission electron microscopy (TEM) samples were prepared using a focused ion beam (FIB) to ensure a uniform thickness. The TEM XEDS concentration profile and images revealed intermetallic phase transformations that occurred during the welding process. TEM images also showed dislocation pile-up located at the subgrain/bulk aluminum interface. This microstructural feature supports continuous dynamic recrystallization of grains through the rearrangement of dislocations. The apparent interdiffusion coefficient closely matched the bulk diffusion concentration profile for the times and temperatures of the ultrasonically consolidated sample. Support for bulk diffusion was independently found through calculating the minimum critical temperature for bulk diffusion dominance over grain boundary diffusion for the grain sizes measured.

  7. Stress wave attenuation in thin structures by ultrasonic through-transmission

    NASA Technical Reports Server (NTRS)

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

    1980-01-01

    The steady state amplitude of the output of an ultrasonic through transmission measurement is analyzed and the result is given in closed form. Provided that the product of the input and output transduction ratios; the specimen-transducer reflection coefficient; the specimen-transducer phase shift parameter; and the material phase velocity are known, this analysis gives a means for determining the through-thickness attenuation of an individual thin sample. Multiple stress wave reflections are taken into account and so signal echoes do not represent a difficulty. An example is presented for a graphite fiber epoxy composite (Hercules AS/3501-6). A direct method for continuous or intermittent monitoring of through thickness attenuation of plate structures which may be subject to service structural degradation is provided.

  8. Development of an ultrasonic pulse-echo (UPE) technique for aircraft icing studies

    SciTech Connect

    Liu, Yang; Hu, Hui; Chen, Wen-Li; Bond, Leonard J.

    2014-02-18

    Aircraft operating in some cold weather conditions face the risk of icing. Icing poses a threat to flight safety and its management is expensive. Removing light frost on a clear day from a medium-size business jet can cost $300, heavy wet snow removal can cost $3,000 and removal of accumulated frozen/freezing rain can cost close to $10,000. Understanding conditions that lead to severe icing events is important and challenging. When an aircraft or rotorcraft flies in a cold climate, some of the super cooled droplets impinging on exposed aircraft surfaces may flow along the surface prior to freezing and give various forms and shapes of ice. The runback behavior of a water film on an aircraft affects the morphology of ice accretion and the rate of formation. In this study, we report the recent progress to develop an Ultrasonic Pulse-Echo (UPE) technique to provide real-time thickness distribution measurements of surface water flows driven by boundary layer airflows for aircraft icing studies. A series of initial experimental investigations are conducted in an ice wind tunnel employing an array of ultrasonic transducers placed underneath the surface of a flat plate. The water runback behavior on the plate is evaluated by measuring the thickness profile variation of the water film along the surface by using the UPE technique under various wind speed and flow rate conditions.

  9. Development of an ultrasonic pulse-echo (UPE) technique for aircraft icing studies

    NASA Astrophysics Data System (ADS)

    Liu, Yang; Chen, Wen-Li; Bond, Leonard J.; Hu, Hui

    2014-02-01

    Aircraft operating in some cold weather conditions face the risk of icing. Icing poses a threat to flight safety and its management is expensive. Removing light frost on a clear day from a medium-size business jet can cost 300, heavy wet snow removal can cost 3,000 and removal of accumulated frozen/freezing rain can cost close to 10,000. Understanding conditions that lead to severe icing events is important and challenging. When an aircraft or rotorcraft flies in a cold climate, some of the super cooled droplets impinging on exposed aircraft surfaces may flow along the surface prior to freezing and give various forms and shapes of ice. The runback behavior of a water film on an aircraft affects the morphology of ice accretion and the rate of formation. In this study, we report the recent progress to develop an Ultrasonic Pulse-Echo (UPE) technique to provide real-time thickness distribution measurements of surface water flows driven by boundary layer airflows for aircraft icing studies. A series of initial experimental investigations are conducted in an ice wind tunnel employing an array of ultrasonic transducers placed underneath the surface of a flat plate. The water runback behavior on the plate is evaluated by measuring the thickness profile variation of the water film along the surface by using the UPE technique under various wind speed and flow rate conditions.

  10. Detection of Arterial Wall Boundaries Using an Echo Model Composed of Multiple Ultrasonic Pulses

    NASA Astrophysics Data System (ADS)

    Ibrahim, Nabilah; Hasegawa, Hideyuki; Kanai, Hiroshi

    2013-07-01

    The assessment of the intima-media thickness (IMT) of the carotid arterial wall, which is the most frequently used indicator to diagnose atherosclerosis by ultrasound, involves the measurement of the lumen-intima boundary (LIB) and media-adventitia boundary (MAB). In this study, using the mean squared error (MSE) method and by applying the template matching technique, an adaptive model of an ultrasonic echo, which is obtained from an ultrasonic pulse measured with a hydrophone, was fitted with the measured in vivo RF echo to estimate the boundaries of the carotid arterial wall. In the present study, the frequency and phase of the adaptive model were considered to improve the accuracy in the determination of the LIB and MAB. For a 7.5-mm-long short segment of the carotid artery in the longitudinal direction, the average IMTs estimated by the improved technique and the previous method were 502+/-61 and 558+/-120 µm, respectively, showing a decrease in the standard deviation by the proposed method. Moreover, the result obtained by the improved technique presented only 0.4% difference between the automatically detected boundary and the manually detected boundary, which is smaller than that obtained by the previous method (10.7% difference). These results verified that the boundary detected by the improved technique was more accurate than that detected by the previous method.

  11. Ultrasonic pulse echography for bubbles traveling in the proximity of a wall

    NASA Astrophysics Data System (ADS)

    Park, Hyun Jin; Tasaka, Yuji; Murai, Yuichi

    2015-12-01

    The behavior of a bubbly two-phase flow in the vicinity of a wall affects heat, mass, and momentum transfer; therefore, there is great interest in developing a quantitative technique to monitor this behavior. Herein we propose a new method based on ultrasound echo signal processing that it feasible for industrial applications where the boundary layer is modified by traveling bubbles. By introducing time-resolved direct waveform analysis at 100 MHz, we have succeeded in the spatio-temporal detection of bubble surfaces at echographic profiling frequencies in the range of 15–20?kHz. Unlike conventional approaches, which use short pulses, a relatively long pulse length is applied to allow ultrasound Doppler velocimetry in the liquid phase. Examination of the horizontal bubbly two-phase turbulent channel flows demonstrated the feasibility of this method; spatio-temporal echography of moving bubble surfaces is successfully achieved as the bubbles travel on length scales smaller than the spatial ultrasonic pulse length near the wall. The applicable range of parameters (e.g. bubble size and shape, and flow speed) was determined by 3D numerical analysis of the wave equation and its application to bubbles flowing beneath a flat-bottom model ship.

  12. Evaluation of Piezoelectric Ceramic Substrates for Ultrasonic Bulk Wave Filters and Resonators Using Pulse Interference Method

    NASA Astrophysics Data System (ADS)

    Kitamura, Takeshi; Kadota, Michio; Kasanami, Toru; Kushibiki, Jun-ichi; Chubachi, Noriyoshi

    1994-05-01

    In recent years, market demand has creared a need for high reproducibility in the frequency characteristics of piezoelectric ceramic filters and resonators that use the thickness extension mode. In order to increase this reproducibility, it is necessary mainly to improve accuracy in controlling the substrate thickness, and to reduce variations in elastic properties of substrate materials prior to the completion of products. The pulse interference method using longitudinal waves has been applied to the evaluation of piezoelectric ceramic substrates. A good correlation has been obtained between the interference frequencies, measured with this method, of substrates immediately after polishing and the frequency characteristics of completed products. It has been shown that this method is extremely useful for improving productivity of ultrasonic bulk-wave filters and resonators whose frequency characteristics directly depend upon the longitudinal wave velocities of substrate materials and their thicknesses.

  13. Pulse-Echo Ultrasonic Imaging Method for Eliminating Sample Thickness Variation Effects

    NASA Technical Reports Server (NTRS)

    Roth, Don J. (Inventor)

    1997-01-01

    A pulse-echo, immersion method for ultrasonic evaluation of a material which accounts for and eliminates nonlevelness in the equipment set-up and sample thickness variation effects employs a single transducer and automatic scanning and digital imaging to obtain an image of a property of the material, such as pore fraction. The nonlevelness and thickness variation effects are accounted for by pre-scan adjustments of the time window to insure that the echoes received at each scan point are gated in the center of the window. This information is input into the scan file so that, during the automatic scanning for the material evaluation, each received echo is centered in its time window. A cross-correlation function calculates the velocity at each scan point, which is then proportionalized to a color or grey scale and displayed on a video screen.

  14. Pulse-echo ultrasonic imaging method for eliminating sample thickness variation effects

    NASA Technical Reports Server (NTRS)

    Roth, Don J. (Inventor)

    1995-01-01

    A pulse-echo, immersion method for ultrasonic evaluation of a material is discussed. It accounts for and eliminates nonlevelness in the equipment set-up and sample thickness variation effects employs a single transducer, automatic scanning and digital imaging to obtain an image of a property of the material, such as pore fraction. The nonlevelness and thickness variation effects are accounted for by pre-scan adjusments of the time window to insure that the echoes received at each scan point are gated in the center of the window. This information is input into the scan file so that, during the automatic scanning for the material evaluation, each received echo is centered in its time window. A cross-correlation function calculates the velocity at each scan point, which is then proportionalized to a color or grey scale and displayed on a video screen.

  15. 3-D Surface Depression Profiling Using High Frequency Focused Air-Coupled Ultrasonic Pulses

    NASA Technical Reports Server (NTRS)

    Roth, Don J.; Kautz, Harold E.; Abel, Phillip B.; Whalen, Mike F.; Hendricks, J. Lynne; Bodis, James R.

    1999-01-01

    Surface topography is an important variable in the performance of many industrial components and is normally measured with diamond-tip profilometry over a small area or using optical scattering methods for larger area measurement. This article shows quantitative surface topography profiles as obtained using only high-frequency focused air-coupled ultrasonic pulses. The profiles were obtained using a profiling system developed by NASA Glenn Research Center and Sonix, Inc (via a formal cooperative agreement). (The air transducers are available as off-the-shelf items from several companies.) The method is simple and reproducible because it relies mainly on knowledge and constancy of the sound velocity through the air. The air transducer is scanned across the surface and sends pulses to the sample surface where they are reflected back from the surface along the same path as the incident wave. Time-of-flight images of the sample surface are acquired and converted to depth/surface profile images using the simple relation (d = V*t/2) between distance (d), time-of-flight (t), and the velocity of sound in air (V). The system has the ability to resolve surface depression variations as small as 25 microns, is useable over a 1.4 mm vertical depth range, and can profile large areas only limited by the scan limits of the particular ultrasonic system. (Best-case depth resolution is 0.25 microns which may be achievable with improved isolation from vibration and air currents.) The method using an optimized configuration is reasonably rapid and has all quantitative analysis facilities on-line including 2-D and 3-D visualization capability, extreme value filtering (for faulty data), and leveling capability. Air-coupled surface profilometry is applicable to plate-like and curved samples. In this article, results are shown for several proof-of-concept samples, plastic samples burned in microgravity on the STS-54 space shuttle mission, and a partially-coated cylindrical ceramic composite sample. Impressive results were obtained for all samples when compared with diamond-tip profiles and measurements from micrometers. The method is completely nondestructive, noninvasive, non-contact and does not require light-reflective surfaces.

  16. Continued Evaluation of the Pulse-Echo Ultrasonic Instrument for Critical Velocity Determination during Hanford Tank Waste Transfer Operations

    SciTech Connect

    Denslow, Kayte M.; Bontha, Jagannadha R.; Adkins, Harold E.; Jenks, Jeromy WJ; Burns, Carolyn A.; Schonewill, Philip P.; Hopkins, Derek F.; Thien, Michael G.; Wooley, Theodore A.

    2012-04-01

    Laboratory (PNNL) conducted an extensive evaluation of the ability of three ultrasonic instruments to detect critical velocity for a broad range of simulated Hanford nuclear waste streams containing particles with mean particle sizes of >50 microns. Evaluations were perform using the pipe loop at the Process Development Laboratory – East (PDL-E) at PNNL that was designed and built to evaluate the pipeline plugging issue during slurry transfer operations at the Hanford Waste Treatment Plant. In 2011 the ability of the ultrasonic PulseEcho system to detect critical velocity continued to be evaluated using the PDL-E flow loop and new simulants containing high-density particles with a mean particle size of < 15 microns. The PDL-E flow loop was modified for the 2011 testing to include a new test section that contained 5-MHz and 10-MHz ultrasonic transducers non-invasively mounted to schedule 40 pipe. The test section also contained reference instrumentation to facilitate direct comparison of the real-time PulseEcho transducer responses with experimentally observed critical velocities. This paper presents the results from the 2011 PulseEcho evaluation using a variety of simulated Hanford nuclear waste streams that were selected to encompass the expected high-level waste feed properties.

  17. Increased range of ultrasonic guided wave testing of overhead transmission line cables using dispersion compensation.

    PubMed

    Legg, Mathew; Yücel, Mehmet K; Kappatos, Vassilios; Selcuk, Cem; Gan, Tat-Hean

    2015-09-01

    Overhead Transmission Line (OVTL) cables can experience structural defects and are, therefore, inspected using Non-Destructive Testing (NDT) techniques. Ultrasonic Guided Waves (UGW) is one NDT technique that has been investigated for inspection of these cables. For practical use, it is desirable to be able to inspect as long a section of cable as possible from a single location. This paper investigates increasing the UGW inspection range on Aluminium Conductor Steel Reinforced (ACSR) cables by compensating for dispersion using dispersion curve data. For ACSR cables, it was considered to be difficult to obtain accurate dispersion curves using modelling due to the complex geometry and unknown coupling between wire strands. Group velocity dispersion curves were, therefore, measured experimentally on an untensioned, 26.5m long cable and a method of calculating theoretical dispersion curves was obtained. Attenuation and dispersion compensation were then performed for a broadband Maximum Length Sequence (MLS) excitation signal. An increase in the Signal to Noise Ratio (SNR) of about 4-8dB compared to that of the dispersed signal was obtained. However, the main benefit was the increased ability to resolve the individual echoes from the end of the cable and an introduced defect in the form of a cut, which was 7 to at least 13dB greater than that of the dispersed signal. Five echoes were able to be clearly detected using MLS excitation signal, indicating the potential for an inspection range of up to 130m in each direction. To the best of the authors knowledge, this is the longest inspection range for ACSR cables reported in the literature, where typically cables, which were only one or two meter long, have been investigated previously. Narrow band tone burst and Hann windowed tone burst excitation signal also showed increased SNR and ability to resolve closely spaced echoes. PMID:25991388

  18. Fiber Optic Picosecond Laser Pulse Transmission Line for Hydrogen Ion Beam Profile Measurement

    SciTech Connect

    Liu, Yun; Huang, Chunning; Aleksandrov, Alexander V

    2013-01-01

    We present a fiber optic laser pulse transmission line for non-intrusive longitudinal profile measurement of the hydrogen ion (H-) beam at the front-end of the Spallation Neutron Source (SNS) accelerator. The 80.5 MHz, 2.5 ps, multi-killowatt optical pulses are delivered to the accelerator beam line through a large mode area polarization maintaining optical fiber to ensure a high measurement stability. The transmission efficiency, output laser beam quality, pulse jitter and pulse width broadening over a 100-ft fiber line are experimentally investigated. A successful measurement of the H- beam microbunch (~130 ps) profile is obtained. Our experiment is the first demonstration of particle beam profile diagnostics using fiber optic laser pulse transmission line.

  19. Real-time measurement of ice growth during simulated and natural icing conditions using ultrasonic pulse-echo techniques

    NASA Technical Reports Server (NTRS)

    Hansman, R. J., Jr.; Kirby, M. S.

    1986-01-01

    Results of tests to measure ice accretion in real-time using ultrasonic pulse-echo techniques are presented. Tests conducted on a 10.2 cm diameter cylinder exposed to simulated icing conditions in the NASA Lewis Icing Research Tunnel and on an 11.4 cm diameter cylinder exposed to natural icing conditions in flight are described. An accuracy of + or - 0.5 mm is achieved for real-time ice thickness measurements. Ice accretion rate is determined by differentiating ice thickness with respect to time. Icing rates measured during simulated and natural icing conditions are compared and related to icing cloud parameters. The ultrasonic signal characteristics are used to detect the presence of surface water on the accreting ice shape and thus to distinguish between dry ice growth and wet growth. The surface roughness of the accreted ice is shown to be related to the width of the echo signal received from the ice surface.

  20. Ultrasonic detection of photothermal interaction of lasers with tissue using a pulsed Doppler system

    NASA Astrophysics Data System (ADS)

    Ying, Hao; Azeemi, Aamer; Hartley, Craig J.; Motamedi, Massoud; Bell, Brent A.; Rastegar, Sohi; Sheppard, L. C.

    1995-05-01

    Thermal therapy using various heating sources such as lasers or microwaves to destroy benign and malignant lesions has recently gained widespread acceptance. However, the accurate prediction of thermal damage in tissue according to theoretical or computer modeling is difficult and unreliable due to target variability with respect to physical properties, geometry, and blood perfusion. Thus, one of the major obstacles to application of thermal therapies has been the lack of a noninvasive, real-time method that could determine the extent and geometry of treated tissue. To evaluate the effects of laser heating on tissue, we have developed an analog-digital hybrid Doppler ultrasound system to measure the phase and amplitude of ultrasonic echoes returned from the heated tissue. The system consists of an eight-gate pulsed Doppler detector, a 16-channel 12-bit A/D converter, and a signal analysis and visualization software package. In vitro studies using canine liver showed two distinct types of modulation of the echoes along the ultrasound beam path during laser irradiation using an 810 nm diode laser. Type 1 signals showed a small and slow variation in amplitude and phase, and were attributed to tissue coagulation. Type 1 signals showed a small and slow variation in amplitude and phase, and were attributed to tissue coagulation. Type 2 signals showed large and rapid variations in amplitude and phase which usually appeared after tissue surface explosion and were indicative of tissue ablation. We hypothesize that the observed phase changes in type 1 signals are due to thermal effects within the tissue consistent with tissue expansion and contraction while the phase changes in type 2 signals are likely due to formation and motion of gas bubbles in the tissue. A further development of the Doppler ultrasound technique could lead to the generation of feedback information needed for monitoring and automatic control of thermal treatment using various heating modalities such as laser, high intensity focused ultrasound, microwaves, or radio frequency waves.

  1. Method and apparatus for ultrasonic doppler velocimetry using speed of sound and reflection mode pulsed wideband doppler

    DOEpatents

    Shekarriz, Alireza (Kennewick, WA); Sheen, David M. (Richland, WA)

    2000-01-01

    According to the present invention, a method and apparatus rely upon tomographic measurement of the speed of sound and fluid velocity in a pipe. The invention provides a more accurate profile of velocity within flow fields where the speed of sound varies within the cross-section of the pipe. This profile is obtained by reconstruction of the velocity profile from the local speed of sound measurement simultaneously with the flow velocity. The method of the present invention is real-time tomographic ultrasonic Doppler velocimetry utilizing a to plurality of ultrasonic transmission and reflection measurements along two orthogonal sets of parallel acoustic lines-of-sight. The fluid velocity profile and the acoustic velocity profile are determined by iteration between determining a fluid velocity profile and measuring local acoustic velocity until convergence is reached.

  2. Continued Evaluation of the Pulse-Echo Ultrasonic Instrument for Critical Velocity Determination during Hanford Tank Waste Transfer Operations - 12518

    SciTech Connect

    Denslow, Kayte M.; Bontha, Jagannadha R.; Adkins, Harold E.; Jenks, Jeromy W.J.; Burns, Carolyn A.; Schonewill, Philip P.; Hopkins, Derek F.; Thien, Michael G.; Wooley, Theodore A.

    2012-07-01

    The delivery of Hanford double-shell tank waste to the Hanford Tank Waste Treatment and Immobilization Plant (WTP) will be governed by specific Waste Acceptance Criteria that are identified in ICD 19 - Interface Control Document for Waste Feed. Waste must be certified as acceptable before it can be delivered to the WTP. The fluid transfer velocity at which solid particulate deposition occurs in waste slurry transport piping (critical velocity) is a key waste parameter that must be accurately characterized to determine if the waste is acceptable for transfer to the WTP. In 2010 Washington River Protection Solutions and the Pacific Northwest National Laboratory began evaluating the ultrasonic PulseEcho instrument to accurately identify critical velocities in a horizontal slurry transport pipeline for slurries containing particles with a mean particle diameter of >50 micrometers. In 2011 the PulseEcho instrument was further evaluated to identify critical velocities for slurries containing fast-settling, high-density particles with a mean particle diameter of <15 micrometers. This two-year evaluation has demonstrated the ability of the ultrasonic PulseEcho instrument to detect the onset of critical velocity for a broad range of physical and rheological slurry properties that are likely encountered during the waste feed transfer operations between the Hanford tank farms and the WTP. (authors)

  3. Pulse-Echo Phased Array Ultrasonic Inspection of Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS)

    NASA Technical Reports Server (NTRS)

    Johnston, Pat H.

    2010-01-01

    A PRSEUS test article was subjected to controlled impact on the skin face followed by static and cyclic axial compressions. Phased array ultrasonic inspection was conducted before impact, and after each of the test conditions. A linear phased array probe with a manual X-Y scanner was used for interrogation. Ultrasound showed a delamination between the skin and stringer flange adjacent to the impact. As designed, the stitching in the flange arrested the lateral flaw formation. Subsequent ultrasonic data showed no delamination growth due to continued loading. Keywords: Phased Array, Ultrasonics, Composites, Out-of-Autoclave

  4. Ultrasonics 36 ( 1998) 25~29 Miniature drumheads: microfabricated ultrasonic transducers

    E-print Network

    Khuri-Yakub, Butrus T. "Pierre"

    Ultrasonics 36 ( 1998) 25~29 Miniature drumheads: microfabricated ultrasonic transducers I'A 94305. USA Abstract Significant improvement in the performance of capacitive microfabricated ultrasonic-coupled through-transmission; Capacitive ultrasonic transducer: Immersion transducer: Microfabrication process

  5. Applications of tunable high energy/pressure pulsed lasers to atmospheric transmission and remote sensing

    NASA Technical Reports Server (NTRS)

    Hess, R. V.; Seals, R. K.

    1974-01-01

    Atmospheric transmission of high energy C12 O2(16) lasers were improved by pulsed high pressure operation which, due to pressure broadening of laser lines, permits tuning the laser 'off' atmospheric C12 O2(16) absorption lines. Pronounced improvement is shown for horizontal transmission at altitudes above several kilometers, and for vertical transmission through the entire atmosphere. The atmospheric transmission of tuned C12 O2(16) lasers compares favorably with C12 O2(18) isotope lasers and CO lasers. The advantages of tunable, high energy, high pressure pulsed lasers over tunable diode lasers and waveguide lasers, in combining high energies with a large tuning range, are evaluated for certain applications to remote sensing of atmospheric constituents and pollutants. Pulsed operation considerably increases the signal to noise ratio without seriously affecting the high spectral resolution of signal detection obtained with laser heterodyning.

  6. Finger blood content, light transmission, and pulse oximetry errors.

    PubMed

    Craft, T M; Lawson, R A; Young, J D

    1992-01-01

    The changes in light emitting diode current necessary to maintain a constant level of light incident upon a photodetector were measured in 20 volunteers at the two wavelengths employed by pulse oximeters. Three states of finger blood content were assessed; exsanguinated, hyperaemic, and normal. The changes in light emitting diode current with changes in finger blood content were small and are not thought to represent a significant source of error in saturation as measured by pulse oximetry. PMID:1536406

  7. Ultrasonic probe deployment device for increased wave transmission and rapid area scan inspections

    SciTech Connect

    DiMambro, Joseph; Roach, Dennis P.; Rackow, Kirk A.; Nelson, Ciji L.; Dasch, Cameron J.; Moore, David G.

    2012-01-03

    An ultrasonic probe deployment device in which an ultrasound-transmitting liquid forms the portion of the ultrasonic wave path in contact with the surface being inspected (i.e., the inspection surface). A seal constrains flow of the liquid, for example preventing the liquid from surging out and flooding the inspection surface. The seal is not rigid and conforms to variations in the shape and unevenness of the inspection surface, thus forming a seal (although possibly a leaky seal) around the liquid. The probe preferably is held in place to produce optimum ultrasonic focus on the area of interest. Use of encoders can facilitate the production of C-scan area maps of the material being inspected.

  8. Ultrasonic probe deployment device for increased wave transmission and rapid area scan inspections

    SciTech Connect

    DiMambro, Joseph; Roach, Dennis P; Rackow, Kirk A; Nelson, Ciji L; Dasch, Cameron J; Moore, David G

    2013-02-12

    An ultrasonic probe deployment device in which an ultrasound-transmitting liquid forms the portion of the ultrasonic wave path in contact with the surface being inspected (i.e., the inspection surface). A seal constrains flow of the liquid, for example preventing the liquid from surging out and flooding the inspection surface. The seal is not rigid and conforms to variations in the shape and unevenness of the inspection surface, thus forming a seal (although possibly a leaky seal) around the liquid. The probe preferably is held in place to produce optimum ultrasonic focus on the area of interest. Use of encoders can facilitate the production of C-scan area maps of the material being inspected.

  9. High pulse repetition frequency, multiple wavelength, pulsed CO(2) lidar system for atmospheric transmission and target reflectance measurements.

    PubMed

    Ben-David, A; Emery, S L; Gotoff, S W; D'Amico, F M

    1992-07-20

    A multiple wavelength, pulsed CO(2) lidar system operating at a pulse repetition frequency of 200 Hz and permitting the random selection of CO(2) laser wavelengths for each laser pulse is presented. This system was employed to measure target reflectance and atmospheric transmission by using laser pulse bursts consisting of groups with as many as 16 different wavelengths at a repetition rate of 12 Hz. The wavelength tuning mechanism of the transversely excited atmospheric laser consists of a stationary grating and a flat mirror controlled by a galvanometer. Multiple wavelength, differential absorption lidar (DIAL) measurements reduce the effects of differential target reflectance and molecular absorption interference. Examples of multiwavelength DIAL detection for ammonia and water vapor show the dynamic interaction between these two trace gases. Target reflectance measurements for maple trees in winter and autumn are presented. PMID:20725406

  10. Ultrasonic pulser-receiver

    DOEpatents

    Taylor, Steven C.

    2006-09-12

    Ultrasonic pulser-receiver circuitry, for use with an ultrasonic transducer, the circuitry comprising a circuit board; ultrasonic pulser circuitry supported by the circuit board and configured to be coupled to an ultrasonic transducer and to cause the ultrasonic transducer to emit an ultrasonic output pulse; receiver circuitry supported by the circuit board, coupled to the pulser circuitry, including protection circuitry configured to protect against the ultrasonic pulse and including amplifier circuitry configured to amplify an echo, received back by the transducer, of the output pulse; and a connector configured to couple the ultrasonic transducer directly to the circuit board, to the pulser circuitry and receiver circuitry, wherein impedance mismatches that would result if the transducer was coupled to the circuit board via a cable can be avoided.

  11. Pulse-excited, auto-zeroing multiple channel data transmission system

    DOEpatents

    Fasching, George E. (Morgantown, WV)

    1987-01-01

    A multiple channel data transmission system is provided in which signals from a plurality of pulse operated transducers and a corresponding plurality of pulse operated signal processor channels are multiplexed for single channel FM transmission to a receiving station. The transducers and corresponding channel amplifiers are powered by pulsing the dc battery power to these devices to conserve energy and battery size for long-term data transmission from remote or inaccessible locations. Auto zeroing of the signal channel amplifiers to compensate for drift associated with temperature changes, battery decay, component aging, etc., in each channel is accomplished by means of a unique auto zero feature which between signal pulses holds a zero correction voltage on an integrating capacitor coupled to the corresponding channel amplifier output. Pseudo-continuous outputs for each channel are achieved by pulsed sample-and-hold circuits which are updated at the pulsed operation rate. The sample-and-hold outputs are multiplexed into an FM/FM transmitter for transmission to an FM receiver station for demultiplexing and storage in separate channel recorders.

  12. Pulse-excited, auto-zeroing multiple channel data transmission system

    DOEpatents

    Fasching, G.E.

    1985-02-22

    A multiple channel data transmission system is provided in which signals from a plurality of pulse operated transducers and a corresponding plurality of pulse operated signal processor channels are multiplexed for single channel FM transmission to a receiving station. The transducers and corresponding channel amplifiers are powered by pulsing the dc battery power to these devices to conserve energy and battery size for long-term data transmission from remote or inaccessible locations. Auto zeroing of the signal channel amplifiers to compensate for drift associated with temperature changes, battery decay, component aging, etc., in each channel is accomplished by means of a unique auto zero feature which between signal pulses holds a zero correction voltage on an integrating capacitor coupled to the corresponding channel amplifier output. Pseudo-continuous outputs for each channel are achieved by pulsed sample-and-hold circuits which are updated at the pulsed operation rate. The sample-and-hold outputs are multiplexed into an FM/FM transmitter for transmission to an FM receiver station for demultiplexing and storage in separate channel recorders.

  13. Full circuit calculation for electromagnetic pulse transmission in a high current facility

    NASA Astrophysics Data System (ADS)

    Zou, Wenkang; Guo, Fan; Chen, Lin; Song, Shengyi; Wang, Meng; Xie, Weiping; Deng, Jianjun

    2014-11-01

    We describe herein for the first time a full circuit model for electromagnetic pulse transmission in the Primary Test Stand (PTS)—the first TW class pulsed power driver in China. The PTS is designed to generate 8-10 MA current into a z -pinch load in nearly 90 ns rise time for inertial confinement fusion and other high energy density physics research. The PTS facility has four conical magnetic insulation transmission lines, in which electron current loss exists during the establishment of magnetic insulation. At the same time, equivalent resistance of switches and equivalent inductance of pinch changes with time. However, none of these models are included in a commercially developed circuit code so far. Therefore, in order to characterize the electromagnetic transmission process in the PTS, a full circuit model, in which switch resistance, magnetic insulation transmission line current loss and a time-dependent load can be taken into account, was developed. Circuit topology and an equivalent circuit model of the facility were introduced. Pulse transmission calculation of shot 0057 was demonstrated with the corresponding code FAST (full-circuit analysis and simulation tool) by setting controllable parameters the same as in the experiment. Preliminary full circuit simulation results for electromagnetic pulse transmission to the load are presented. Although divergences exist between calculated and experimentally obtained waveforms before the vacuum section, consistency with load current is satisfactory, especially at the rising edge.

  14. Pulse-shaping versus digital backpropagation in 224Gbit/s PDM-16QAM transmission.

    PubMed

    Behrens, Carsten; Makovejs, Sergejs; Killey, Robert I; Savory, Seb J; Chen, Ming; Bayvel, Polina

    2011-07-01

    We investigate the transmission performance of 224Gbit/s polarization-division-multiplexed 16-state quadrature amplitude modulation (PDM-16QAM) for systems employing standard single mode fiber (SSMF) and erbium doped fiber amplifiers (EDFAs). We consider the effectiveness of return-to-zero (RZ) data pulses with varying duty cycles and digital backpropagation (DBP) in reducing nonlinear distortion in wavelength-division- multiplexed (WDM) links with 3, 5, 7 and 9 channels. Similar improvement in transmission reach of 18-25% was achieved either by pulse-carving at the transmitter or by DBP, yielding maximum transmission distances of up to 1760km for RZ-pulse-shapes and 1280km for NRZ. PMID:21747439

  15. Reflection and Transmission of Pulsed Electromagnetic Fields through Multilayered

    E-print Network

    Oughstun, Kurt

    skin, fat and muscle is analyzed. The fre- quency dependent reflection and transmission coeffi- cients of the multilayer stack are computed using the transfer matrix method. Each of the three tissues is modeled based on empirical data suggest penetration depths much greater than that previously described by simple

  16. Pulse-echo phased array ultrasonic inspection of pultruded rod stitched efficient unitized structure (PRSEUS)

    SciTech Connect

    Johnston, P. H.

    2011-06-23

    A PRSEUS test article was subjected to controlled impact on the skin face followed by static and cyclic axial compressions. Phased array ultrasonic inspection was conducted before impact, and after each of the test conditions. A linear phased array probe with a manual X-Y scanner was used for interrogation. Ultrasound showed a delamination between the skin and stringer flange adjacent to the impact. As designed, the stitching in the flange arrested the lateral flaw formation. Subsequent ultrasonic data showed no delamination growth due to continued loading.

  17. Optimized transmission-line impedance transformers for petawatt-class pulsed-power accelerators

    NASA Astrophysics Data System (ADS)

    Welch, D. R.; Genoni, T. C.; Rose, D. V.; Bruner, N. L.; Stygar, W. A.

    2008-03-01

    We have developed 1D analytic and 2D fully electromagnetic models of radial transmission-line impedance transformers. The models have been used to quantify the power-transport efficiency and pulse sharpening of such transformers as a function of voltage pulse width and impedance profile. For the cases considered, we find that in the limit as ??0 (where ? is the ratio of the pulse width to the one-way transit time of the transformer), the transport efficiency is maximized when the impedance profile is exponential. As ? increases from zero, the optimum profile gradually deviates from an exponential. A numerical procedure is presented that determines the optimum profile for a given pulse shape and width. The procedure can be applied to optimize the design of impedance transformers used in petawatt-class pulsed-power accelerators.

  18. Ultrasonic pulse velocity for the evaluation of physical and mechanical properties of a highly porous building limestone.

    PubMed

    Vasanelli, Emilia; Colangiuli, Donato; Calia, Angela; Sileo, Maria; Aiello, Maria Antonietta

    2015-07-01

    UPV as non-destructive technique can effectively contribute to the low invasive in situ analysis and diagnosis of masonry elements related to the conservation, rehabilitation and strengthening of the built heritage. The use of non-destructive and non-invasive techniques brings all the times many advantages in diagnostic activities on pre-existing buildings in terms of sustainability; moreover, it is a strong necessity with respect to the conservation constraints when dealing with the historical-architectural heritage. In this work laboratory experiments were carried out to investigate the effectiveness of ultrasonic pulse velocity (UPV) in evaluating physical and mechanical properties of Lecce stone, a soft and porous building limestone. UPV and selected physical-mechanical parameters such as density and uniaxial compressive strength (UCS) were determined. Factors such as anisotropy and water presence that induce variations on the ultrasonic velocity were also assessed. Correlations between the analysed parameters are presented and discussed. The presence of water greatly affected the values of the analysed parameters, leading to a decrease of UPV and to a strong reduction of the compressive strength. A discussion of the role of the water on these results is provided. Regression analysis showed a reliable linear correlation between UPV and compressive strength, which allows a reasonable estimation of the strength of Lecce stone by means of non-destructive testing methods such as the ultrasonic wave velocity. Low correlation between UPV and density was found, suggesting that other factors than density, related to the fabric and composition, also influence the response of the selected stone to the UPV. They have no influence on the UCS, that instead showed to be highly correlated with the packing density. PMID:25769219

  19. The use of ultrasonic pulse velocity tests for the diagnosis of ancient masonries: the influence of the applied load

    NASA Astrophysics Data System (ADS)

    Leucci, Giovanni; Vasanelli, Emilia; Calia, Angela; Micelli, Francesco; Aiello, Maria Antonietta

    2014-05-01

    Sophisticated non destructive techniques for the diagnosis of existing masonry structures have been developed and improved throughout the years, such as ground penetrating radar, thermography, sonic and ultrasonic tomography, laser scanner survey, etc.: by using an integrated approach it is possible to reconstruct the morphology of the masonry walls, to detect the presence of cracks and voids, achieving an accurate and reliable diagnosis of the construction, which is the basis for the restoration design. The ultrasonic pulse velocity (UPV) method can be conveniently used to check the quality of stones, but it can be used also for material characterization. Both the intrinsic characteristic of the stone (porosity, grain size, anisotropy, etc.) and the external factors (humidity, stress, temperature, presence of cracks) may affect the elastic wave propagation, thus in order to correctly estimate the ultrasonic behaviour of the material investigated it is important to know in what manner and how much the variation of the experimental conditions may modify the characteristics of the waves being measured. This aspect is of crucial importance when in situ measurements are made. In this work the influence of the applied load on UPV results has been investigated. In particular, the research has been carried out on ashlars and on sample masonry panels made of lime mortar joints and Lecce stone, a soft calcarenitic stone traditionally used in the Lecce district, South of Italy. The presence of load strongly influenced the UPV measures, due to the particular microstructural characteristic of the stone. The work aim at quantify this influence in order to correctly interpret in situ measurements.

  20. Wind turbines and bat mortality: Doppler shift profiles and ultrasonic bat-like pulse reflection from moving turbine blades.

    PubMed

    Long, Chloe V; Flint, James A; Lepper, Paul A

    2010-10-01

    Bat mortality resulting from actual or near-collision with operational wind turbine rotors is a phenomenon that is widespread but not well understood. Because bats rely on information contained in high-frequency echoes to determine the nature and movement of a target, it is important to consider how ultrasonic pulses similar to those used by bats for echolocation may be interacting with operational turbine rotor blades. By assessing the characteristics of reflected ultrasonic echoes, moving turbine blades operating under low wind speed conditions (<6 m s(-1)) were found to produce distinct Doppler shift profiles at different angles to the rotor. Frequency shifts of up to ±700-800 Hz were produced, which may not be perceptible by some bat species. Monte Carlo simulation of bat-like sampling by echolocation revealed that over 50 rotor echoes could be required by species such as Pipistrellus pipistrellus for accurate interpretation of blade movement, which may not be achieved in the bat's approach time-window. In summary, it was found that echoes returned from moving blades had features which could render them attractive to bats or which might make it difficult for the bat to accurately detect and locate blades in sufficient time to avoid a collision. PMID:20968394

  1. The next linear collider test accelerator's RF pulse compression and transmission systems

    NASA Astrophysics Data System (ADS)

    Tantawi, S. G.; Vlieks, A. E.; Fant, K.; Lavine, T.; Loewen, R. J.; Pearson, C.; Pope, R.; Rifkin, J.; Ruth, R. D.

    1997-03-01

    The overmoded rf transmission and pulsed power compression system for SLAC's Next Linear Collider (NLC) program requires a high degree of transmission efficiency and mode purity to be economically feasible. To this end, a number of new, high power components and systems have been developed at X-band, which transmit rf power in the low loss, circular TE01 mode with negligible mode conversion. In addition, a highly efficient SLED-II [1] pulse compressor has been developed and successfully tested at high power at two accelerator test facilities at SLAC. The systems produced a 200 MW pulse with a near-perfect flat-top with pulse widths ranging from 150-245 ns. In this paper we describe the design and test results of a rectangular-to-circular mode converter and the components/transmission systems based on them, as well as the design and measurements of the high power pulse compression systems using SLED-II. We will also describe how these components are being used to efficiently provide high power rf in the NLC Test Accelerator (NLCTA) program at SLAC.

  2. 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.

  3. Pulse shaping and extraction of information from ultrasonic reflections in composite materials

    NASA Technical Reports Server (NTRS)

    Kishoni, Doron

    1988-01-01

    The application of ultrasonic inspection to the nondestructive testing of composite materials is examined with reference to specific examples including monitoring of epoxy curing, evaluation of impact damage in a graphite/epoxy laminate, and monitoring of a repaired area in a composite wing plate. Signal processing methods are described which improve time resolution, facilitating identification of discrete echoes corresponding to events in the material.

  4. Development of a New High-Frame-Rate Camera for Pulsed Neutron Transmission Spectroscopic Radiography

    NASA Astrophysics Data System (ADS)

    Mochiki, K.; Ishizuka, K.; Morikawa, K.; Kamiyama, T.; Kiyanagi, Y.

    Pulsed neutron transmission spectroscopic radiography is an attractive new technique in energy-resolved neutron radiography.The imaging technique is based on the spectralanalysis of neutrons throughthe time-of-flight (TOF) method.The neutron transmission spectrum that can be obtained usinga time-resolved neutron imaging system includes the Bragg-scattering edges with crystallographic information and thetransmission dips duetotheresonanceabsorptionofthenuclei.To obtain the neutron transmission spectrum with high-power neutron sources, we developed anew high-performance imaging system consisting of a neutroncolor image intensifier, photon image intensifier, high-resolution CMOS camera, and high-frame-rate camera. The system was used for experiments at the electron linac pulsed neutron source in Hokkaido University, and the targeted function was proved to be successful.

  5. Critical evaluation of pulse-echo ultrasonic test method for the determination of setting and mechanical properties of acrylic bone cement: influence of mixing technique.

    PubMed

    Hagan, Christopher P; Orr, John F; Mitchell, Christina A; Dunne, Nicholas J

    2015-02-01

    Currently there is no reliable objective method to quantify the setting properties of acrylic bone cements within an operating theatre environment. Ultrasonic technology can be used to determine the acoustic properties of the polymerising bone cement, which are linked to material properties and provide indications of the physical and chemical changes occurring within the cement. The focus of this study was the critical evaluation of pulse-echo ultrasonic test method in determining the setting and mechanical properties of three different acrylic bone cement when prepared under atmospheric and vacuum mixing conditions. Results indicated that the ultrasonic pulse-echo technique provided a highly reproducible and accurate method of monitoring the polymerisation reaction and indicating the principal setting parameters when compared to ISO 5833 standard, irrespective of the acrylic bone cement or mixing method used. However, applying the same test method to predict the final mechanical properties of acrylic bone cement did not prove a wholly accurate approach. Inhomogeneities within the cement microstructure and specimen geometry were found to have a significant influence on mechanical property predictions. Consideration of all the results suggests that the non-invasive and non-destructive pulse-echo ultrasonic test method is an effective and reliable method for following the full polymerisation reaction of acrylic bone cement in real-time and then determining the setting properties within a surgical theatre environment. However the application of similar technology for predicting the final mechanical properties of acrylic bone cement on a consistent basis may prove difficult. PMID:25260486

  6. Performance comparison of RZ pulse formats in PDM-16QAM high rates transmissions with optical pre-filtering

    NASA Astrophysics Data System (ADS)

    Silva, E. P.; Carvalho, L. H. H.; Lopes, M. L.; Ribeiro, V. B.; Bordonalli, A. C.; Oliveira, J. C. R. F.

    2013-01-01

    The digitally modulated signals spectral density depends directly on pulse format used for information symbols transmission. The modulated signal spectral occupancy can be modified according to the channel frequency response to facilitate information retrieval at the receiver. New generation of coherent optical transmission systems operating at high rates are subject to various bandwidth restrictions aspects, such as electronic components limitations and optical filtering via ROADMs deployed on networks. As noted in technical literature, the RZ pulse formats have some advantages compared to traditional NRZ pulses in optical fiber transmissions. In particular, RZ pulses have a better performance in situations where nonlinear effects of the fiber severely impact the quality of transmission. Among other situations, this occurs in systems that employ modulation formats for high order QAM (16QAM, 64QAM, etc.). Moreover, since RZ pulses have shorter duty cycle, temporal spread of the transmitted symbols causes less performance degradation due to ISI compared with NRZ pulses. This report presents results of experiments carried out in a 226 km recirculation loop, to evaluate the performance of NRZ, RZ 67%, 50% RZ and RZ 33% pulse shapes in a transmission of DP-16QAM (or PDM-16QAM). As application it is proposed and experimentally demonstrated a transmission system that employ 28 GBaud dual carrier PDM-16QAM channels operating with a total line rate of 448 Gb/s each, utilizing RZ pulse format and carrier narrow pre-filtering to increase spectral efficiency of transmission, aggregating a 400G channel in a 75 GHz WDM grid.

  7. DONAR - A computer processing system to extend ultrasonic pulse-echo testing.

    NASA Technical Reports Server (NTRS)

    Lees, S.; Gerhard, F. B.; Barber, F. E.; Cheney, S. P.

    1973-01-01

    A dedicated general purpose digital computer has been built on the principle of a sampled-data system to run an ultrasonic subsystem under programmed control. A most significant application is the ability to extract a signal from an interfering background. As illustrated in the paper, a 1 mm diameter transducer was used to measure the diameter of a 2.5 mm OD plastics tube with 0.4 mm wall thickness. Echoes from all four surfaces were displayed and the measurements indicated an uncertainty of less than 0.1 mm.

  8. Measurement of ultrasonic velocity with improved accuracy in pulse echo setup

    SciTech Connect

    Rajagopalan, S.; Sharma, S. J.; Dubey, P. K.

    2007-08-15

    In the present work a personal computer based circuit adopted in pulseecho setup has been developed for the measurement of time-of-flight between the two successive echoes using a differential time measurement with a 16 bit counter and an external clock frequency of 32 MHz. A control program is developed in C to display the time of flight and wave propagation velocity on a user screen. The technique, so developed, minimizes the errors in time delay measurements due to the variation in threshold trigger points of echoes and improves the ultrasonic velocity measurement.

  9. Shape of Short Ultrasonic Echo-pulses Focused in the Solid Plate

    NASA Astrophysics Data System (ADS)

    Petronyuk, Y. S.; Levin, V. M.; Titov, S. A.

    Application of broadband probing impulses in acoustic microscopy allows to increase depth resolution of visualization system and to improve measuring possibilities at fixed frequencies. The echo-pulse method with measuring the delay times is a basis of quantitative techniques of the pulse acoustic microscopy. To improve the accuracy of the method the attention should be paid to the changes in the echo-pulse shape that is caused by the focusing of elastic waves at the boundaries of a sample. Features of the separated echo-pulses formation, which is caused by reflecting the acoustic waves of various polarizations in the plate, are studied. The method of a stationary phase is applied to analyze the expression for the output echo-signal; dynamics in the shape transformation for individual echo-pulses depending on the focus position z are studied. Occurrence of the echo-pulse shifting dt outside the focal position is found theoretically. It is shown experimentally the echo-pulses shaping depends on focus position under the specimen. The technique with time delay correction has been applied to measure sonic velocity for standard steel gauge block. Systematic error avoided by the shape correction was 1% for the measured value of sonic velocity.

  10. Experimental spatial sampling study of the real-time ultrasonic pulse-echo BAI-mode imaging technique.

    PubMed

    Yin, Xiangtao; Morris, Scott A; O'Brien, William D

    2003-04-01

    The ultrasonic pulse-echo backscattered amplitude integral (BAI)-mode imaging technique has been developed to inspect the seal integrity of hermetically sealed, flexible food packages. With a focused 17.3-MHz transducer acquiring radio frequency (RF) echo data in a static rectilinear stop-and-go pattern, this technique was able to reliably detect channel defects as small as 38 microm in diameter and occasionally detect 6-microm-diameter channels. This contribution presents our experimental spatial sampling study of the BAI-mode imaging technique with a continuous zigzag scanning protocol that simulates a real-time production line inspection method in continuous motion. Two transducers (f/2 17.3 MHz and f/3 20.3 MHz) were used to acquire RF echo data in a zigzag raster pattern from plastic film samples bearing rectilinear point reflector arrays of varying grid spacings. The average BAI-value difference (deltaBAI) between defective and intact regions and the contrast-to-noise ratio (CNR) were used to assess image quality as a function of three spatial sampling variables: transducer spatial scanning step size, array sample grid spacing, and transducer -6-dB pulse-echo focal beam spot size. For a given grid size, the deltaBAI and CNR degraded as scanning step size in each spatial dimension increased. There is an engineering trade-off between the BAI-mode image quality and the transducer spatial sampling. The optimal spatial sampling step size has been identified to be between one and two times the -6-dB pulse-echo focal beam lateral diameter. PMID:12744399

  11. Ultrasonic Inspection Of Thick Sections

    NASA Technical Reports Server (NTRS)

    Friant, C. L.; Djordjevic, B. B.; O'Keefe, C. V.; Ferrell, W.; Klutz, T.

    1993-01-01

    Ultrasonics used to inspect large, relatively thick vessels for hidden defects. Report based on experiments in through-the-thickness transmission of ultrasonic waves in both steel and filament-wound composite cases of solid-fuel rocket motors.

  12. Flashover vulnerability of transmission and distribution lines to high-altitude electromagnetic pulse (HEMP)

    SciTech Connect

    Kruse, V.J.; Liu, T.K.; Tesche, F.M.; Barnes, P.R.

    1989-01-01

    This paper estimates the vulnerability of transmission and distribution lines to flashover from the electromagnetic pulse generated by a nuclear detonation 400 kilometers above the earth. The analysis consists of first determining the cumulative probability of induced-voltage on three-phase lines, including shield and neutral conductors, for four operating voltages and then comparing these stresses to estimates of line insulation strength. 11 refs., 9 figs., 5 tabs.

  13. Mid IR pulsed light source for laser ultrasonic testing of carbon-fiber-reinforced plastic

    NASA Astrophysics Data System (ADS)

    Hatano, H.; Watanabe, M.; Kitamura, K.; Naito, M.; Yamawaki, H.; Slater, R.

    2015-09-01

    A quasi-phase-matched (QPM) optical parametric oscillator (OPO) was developed using a periodically poled Mg-doped stoichiometric LiTaO3 crystal to generate mid-IR light for excitation of laser ultrasound in carbon fiber reinforced plastic (CFRP). The ultrasound generation efficiency was measured at the three different wavelengths that emanate from the OPO: 1.064 ?m, 1.59/1.57 ?m, and 3.23/3.30 ?m. The measurements indicate that mid-IR 3.2-3.3 ?m light generates the most efficient ultrasonic waves in CFRP with the least laser damage. We used mid-IR light in conjunction with a laser interferometer to demonstrate the detection of flaws/defects in CFRP such as the existence of air gaps that mimic delamination and voids in CFRP, and the inhomogeneous adhesion of CFRP material to a metal plate was also clearly detected.

  14. Viscoelasticity influence on frequency dependence of the ultrasonic transmission through plates of composite materials

    NASA Astrophysics Data System (ADS)

    Deschamps, Marc; Hosten, Bernard

    The present elucidation of the influence of attenuation on reflection and transmission by an anisotropic plate indicates that the generation and propagation of leaky Lamb waves (LLWs) can be affected by this phenomenon, as noted in the case of specific angular areas and/or high frequencies. Anisotropic materials' damping is dealt with within the framework of plane wave theory. At frequencies higher than 1 MHz, the attenuation of the wave remains the major effect precluding the use of LLWs in certain cases.

  15. A long-pulse repetitive operation magnetically insulated transmission line oscillator.

    PubMed

    Fan, Yu-Wei; Zhong, Hui-Huang; Zhang, Jian-De; Shu, Ting; Liu, Jin Liang

    2014-05-01

    The improved magnetically insulated transmission line oscillator (MILO) is a gigawatt-class L-band high power microwave tube. It has allowed us to generate 3.1 GW pulse of 40 ns duration in the single-pulse operation and 500 MW pulse of 25 ns duration in the repetition rate operation. However, because of the severe impedance mismatch, the power conversion efficiency is only about 4% in the repetition rate operation. In order to eliminate the impedance mismatch and obtain repetitive long-pulse high-power microwave (HPM), a series of experiments are carried out and the recent progress is presented in this paper. In the single-pulse operation, when the diode voltage is 466 kV and current is 41.6 kA, the radiated microwave power is above 2.2 GW, the pulse duration is above 102 ns, the microwave frequency is about 1.74 GHz, and the power conversion efficiency is about 11.5%. In the repetition rate operation, under the condition of the diode voltage about 400 kV, beam current about 38 kA, the radiated microwave power is about 1.0 GW, the pulse duration is about 85 ns. Moreover, the radiated microwave power and the pulse duration decline little by little when the shot numbers increase gradually. The experimental results show that the impedance matching is a vital factor for HPM systems and one of the major technical challenges is to improve the cathode for the repetition rate operation MILO. PMID:24880374

  16. A long-pulse repetitive operation magnetically insulated transmission line oscillator

    NASA Astrophysics Data System (ADS)

    Fan, Yu-Wei; Zhong, Hui-Huang; Zhang, Jian-De; Shu, Ting; Liu, Jin Liang

    2014-05-01

    The improved magnetically insulated transmission line oscillator (MILO) is a gigawatt-class L-band high power microwave tube. It has allowed us to generate 3.1 GW pulse of 40 ns duration in the single-pulse operation and 500 MW pulse of 25 ns duration in the repetition rate operation. However, because of the severe impedance mismatch, the power conversion efficiency is only about 4% in the repetition rate operation. In order to eliminate the impedance mismatch and obtain repetitive long-pulse high-power microwave (HPM), a series of experiments are carried out and the recent progress is presented in this paper. In the single-pulse operation, when the diode voltage is 466 kV and current is 41.6 kA, the radiated microwave power is above 2.2 GW, the pulse duration is above 102 ns, the microwave frequency is about 1.74 GHz, and the power conversion efficiency is about 11.5%. In the repetition rate operation, under the condition of the diode voltage about 400 kV, beam current about 38 kA, the radiated microwave power is about 1.0 GW, the pulse duration is about 85 ns. Moreover, the radiated microwave power and the pulse duration decline little by little when the shot numbers increase gradually. The experimental results show that the impedance matching is a vital factor for HPM systems and one of the major technical challenges is to improve the cathode for the repetition rate operation MILO.

  17. A long-pulse repetitive operation magnetically insulated transmission line oscillator

    SciTech Connect

    Fan, Yu-Wei; Zhong, Hui-Huang; Zhang, Jian-De; Shu, Ting; Liu, Jin Liang

    2014-05-15

    The improved magnetically insulated transmission line oscillator (MILO) is a gigawatt-class L-band high power microwave tube. It has allowed us to generate 3.1 GW pulse of 40 ns duration in the single-pulse operation and 500 MW pulse of 25 ns duration in the repetition rate operation. However, because of the severe impedance mismatch, the power conversion efficiency is only about 4% in the repetition rate operation. In order to eliminate the impedance mismatch and obtain repetitive long-pulse high-power microwave (HPM), a series of experiments are carried out and the recent progress is presented in this paper. In the single-pulse operation, when the diode voltage is 466 kV and current is 41.6 kA, the radiated microwave power is above 2.2 GW, the pulse duration is above 102 ns, the microwave frequency is about 1.74 GHz, and the power conversion efficiency is about 11.5%. In the repetition rate operation, under the condition of the diode voltage about 400 kV, beam current about 38 kA, the radiated microwave power is about 1.0 GW, the pulse duration is about 85 ns. Moreover, the radiated microwave power and the pulse duration decline little by little when the shot numbers increase gradually. The experimental results show that the impedance matching is a vital factor for HPM systems and one of the major technical challenges is to improve the cathode for the repetition rate operation MILO.

  18. 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. PMID:26489364

  19. Investigations on optimizing the energy transmission of ultrafast optical pulses in pure water

    NASA Astrophysics Data System (ADS)

    Lukofsky, David

    Many of today's communication and imaging technologies share the common challenge of signal deterioration due to water's large absorption coefficient. As an example, it is water molecules that contaminate the fused silica of optical fibers and account for most of the absorption they exhibit at communication wavelengths. It is also water (in the form of vapor) that makes it challenging to devise practical THz spectroscopic systems. As such, this thesis examines how the transmission of electromagnetic radiation through water could be improved as a stepping stone towards bettering a wide array of communication and imaging applications. Recent time-domain approaches have noted the connection between pulse rise-time and precursor waveform absorption. This thesis represents the first in-depth analysis of precursors using an intuitive frequency-domain approach. It was shown with well-known physical metrics that precursors are a linear effect resulting from the temporal representation of a Beer's law of absorption for broadband pulses. Experimental validation was achieved with a spatial light modulator used in conjunction with Frequency-Resolved-Optical-Gating (FROG) to obtain the first measurement of the amplitude and phase of an optical precursor. The semi-classical two-level atom model was used to infer the transitional dipole moments of the 1447 nm and 2:94 mum vibrational resonances of the medium. These values supported finite-difference-time-domain simulations suggesting how 52 fs sech2 pulses of 220 GW/cm2 peak intensity could propagate with negligible attenuation over 15 absorption lengths when tuned to the 2:94 mum transition of water. Extensive use of 1550 nm lasers in communication systems and the presence of the second vibrational overtone resonance of water at 1447 nm were the motivation for transmission experiments completed at the Naval Research Laboratory (Washington, DC) at this transition. As much as a 500% increase in absolute transmission was observed in a 5 mm sample of distilled water when compared to steady-state transmission. Different causes for this increase in transmission were examined, including coherent and incoherent bleaching effects. Overall, this study reveals that efficient propagation of optical pulses in water requires pulses of near single-cycle duration and large intensities and/or fluence. While these large intensities would make it difficult to apply this work to medical imaging applications, there remains a window of opportunity for efficient underwater communication. Indeed, assuming a channel of water with few physical obstructions, the advent of sufficiently intense, robust, and high repetition-rate laser technology might one day lead to the implementation of a practical underwater communication link at optical wavelengths.

  20. Does transmission of a weak optical pulse in a dense absorption medium require quantization of the optical field?

    NASA Astrophysics Data System (ADS)

    Reintjes, J.; Bashkansky, Mark

    2013-08-01

    We present an analysis of the transmission of a weak optical pulse, with energy 1??0, through a dense absorbing medium with absorption frequency ?0. We analyze the system by treating the optical pulse classically and the absorbing medium quantum mechanically. We find that the probabilistic back reaction of the quantum absorber on the classical pulse impresses statistical behavior on the pulse that does not arise from quantization of the optical field. All properties of the optical transmission and atomic absorption are self-consistent without contradiction. Issues relating to conservation of energy are resolved by considering the impact of superposition states on conservation laws in individual interactions. As a result, we conclude that transmission of a weak optical pulse with energy 1??0 through a dense atomic absorber does not require quantization of the field.

  1. 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.

  2. Modeling the Effects of Beam Size and Flaw Morphology on Ultrasonic Pulse/Echo Sizing of Delaminations in Carbon Composites

    NASA Technical Reports Server (NTRS)

    Margetan, Frank J.; Leckey, Cara A.; Barnard, Dan

    2012-01-01

    The size and shape of a delamination in a multi-layered structure can be estimated in various ways from an ultrasonic pulse/echo image. For example the -6dB contours of measured response provide one simple estimate of the boundary. More sophisticated approaches can be imagined where one adjusts the proposed boundary to bring measured and predicted UT images into optimal agreement. Such approaches require suitable models of the inspection process. In this paper we explore issues pertaining to model-based size estimation for delaminations in carbon fiber reinforced laminates. In particular we consider the influence on sizing when the delamination is non-planar or partially transmitting in certain regions. Two models for predicting broadband sonic time-domain responses are considered: (1) a fast "simple" model using paraxial beam expansions and Kirchhoff and phase-screen approximations; and (2) the more exact (but computationally intensive) 3D elastodynamic finite integration technique (EFIT). Model-to-model and model-to experiment comparisons are made for delaminations in uniaxial composite plates, and the simple model is then used to critique the -6dB rule for delamination sizing.

  3. Transmission line pulse system for avalanche characterization of high power semiconductor devices

    NASA Astrophysics Data System (ADS)

    Riccio, Michele; Ascione, Giovanni; De Falco, Giuseppe; Maresca, Luca; De Laurentis, Martina; Irace, Andrea; Breglio, Giovanni

    2013-05-01

    Because of the increasing in power density of electronic devices for medium and high power application, reliabilty of these devices is of great interest. Understanding the avalanche behaviour of a power device has become very important in these last years because it gives an indication of the maximum energy ratings which can be seen as an index of the device ruggedness. A good description of this behaviour is given by the static IV blocking characteristc. In order to avoid self heating, very relevant in high power devices, very short pulses of current have to be used, whose value can change from few milliamps up to tens of amps. The most used method to generate short pulses is the TLP (Transmission Line Pulse) test, which is based on charging the equivalent capacitance of a transmission line to high value of voltage and subsequently discharging it onto a load. This circuit let to obtain very short square pulses but it is mostly used for evaluate the ESD capability of semiconductor and, in this environment, it generates pulses of low amplitude which are not high enough to characterize the avalanche behaviour of high power devices . Advanced TLP circuit able to generate high current are usually very expensive and often suffer of distorption of the output pulse. In this article is proposed a simple, low cost circuit, based on a boosted-TLP configuration, which is capable to produce very square pulses of about one hundreds of nanosecond with amplitude up to some tens of amps. A prototype is implemented which can produce pulses up to 20A of amplitude with 200 ns of duration which can characterize power devices up to 1600V of breakdown voltage. Usage of microcontroller based logic make the circuit very flexible. Results of SPICE simulation are provided, together with experimental results. To prove the effectiveness of the circuit, the I-V blocking characteristics of two commercial devices, namely a 600V PowerMOS and a 1200V Trench-IGBT, are measured at different operating temperature.

  4. Ultrasonic meters measure gas pipeline flow

    SciTech Connect

    1995-04-01

    New ultrasonic meters from Stork Ultrasonic Technologies, Houston are improving pipeline gas flow measurements, custody transfers, process gas flow measurements, and flare gas applications. The meters are easy to install, extremely accurate, and all feature realtime measurements. This meter (Gassonic 400) is designed for use in 8-in. to 64-in. gas pipelines and features a dual transducer device which uses the absolute digital travel time method of pulse transmission. Wide band piezoceramic transducers are used in this bi-directional, single bounce system which includes pulse verification and high-speed electronic processing by a central processing unit. Measuring values of this meter are obtained by direct digital measurement of travel time of each individual ultrasonic pulse which covers a pre-determined distance between two transducers inserted in the pipe wall. These transducers cause negligible flow restriction and absolute digital reference and excellent repeatability is possible without adjustment or re-calibration. Dozens of measurements can be processed so that average output values are updated every second during use. It is a field-programmable meter for variations in site parameters, presentation of service diagnostics, user selected velocity or quantity outputs, and has standard analog and digital interfaces. Also, it is suitable for swirl measurement or compensation. Since it relies on a reflection method, the ultrasonic meter allows easy, one-sided insertion and it is suitable for hot-tapping. This instrument is especially useful in gas blending stations, compressor control, leak detection, salt dome storage applications, pipeline balancing, and additive injection systems.

  5. Ultrasonic measurement of elastic moduli in slender specimens using extensional and torsional wave pulses.

    NASA Technical Reports Server (NTRS)

    Lynnworth, L. C.

    1973-01-01

    The pulse-echo method using extensional and torsional waves is described relative to determining elastic properties and other characteristics of specimens which are slender acoustically. Several applications are reviewed, including: glass fibers of diameter 16 to 42 microns; glass rods of diameter about 1 mm, tested to 700 C; iron-base alloys of diameter 3.2 mm, tested from nearly -200 up to +200 C; titanium specimens of rectangular cross section, 1.5 by 3 mm; and tantalum-base alloys of diameter 6.4 mm, tested up to 1400 C. Limitations are pointed out regarding dispersive materials and geometry.

  6. Impedance matching network for high frequency ultrasonic transducer for cellular applications.

    PubMed

    Kim, Min Gon; Yoon, Sangpil; Kim, Hyung Ham; Shung, K Kirk

    2016-02-01

    An approach for the design of an impedance matching network (IMN) for high frequency ultrasonic transducers with large apertures based on impedance analysis for cellular applications is presented in this paper. The main objectives were to maximize energy transmission from the excitation source to the ultrasonic transducers for cell manipulation and to achieve low input parameters for the safe operation of an ultrasonic transducer because the piezoelectric material in high frequency ultrasonic transducers is prone to breakage due to its being extremely thin. Two ultrasonic transducers, which were made of lithium niobate single crystal with the thickness of 15?m, having apertures of 4.3mm (fnumber=1.23) and 2.6mm (fnumber=0.75) were tested. L-type IMN was selected for high sensitivity and compact design of the ultrasonic transducers. The target center frequency was chosen as the frequency where the electrical admittance (|Y|) and phase angle (?z) from impedance analysis was maximal and zero, respectively. The reference center frequency and reference echo magnitude were selected as the center frequency and echo magnitude, measured by pulse-echo testing, of the ultrasonic transducer without IMN. Initial component values and topology of IMN were determined using the Smith chart, and pulse-echo testing was analyzed to verify the performance of the ultrasonic transducers with and without IMN. After several iterations between changing component values and topology of IMN, and pulse-echo measurement of the ultrasonic transducer with IMN, optimized component values and topology of IMN were chosen when the measured center frequency from pulse-echo testing was comparable to the target frequency, and the measured echo magnitude was at least 30% larger than the reference echo magnitude. Performance of an ultrasonic transducer with and without IMN was tested by observing a tangible dent on the surface of a plastic petridish and single cell response after an acoustic pulse was applied on a target cell. PMID:26442434

  7. Frequency division multiple transmission method to utilize the wide bandwidth property of capacitive micromachined ultrasonic transducer arrays

    NASA Astrophysics Data System (ADS)

    Lee, Seunghun; Kim, Bae-Hyung; Jeon, Taeho; Kim, Youngil; Cho, Kyungil; Song, Jongkeun

    2013-03-01

    CMUT-on-ASIC integration techniques are promising for the development of lower cost smaller volume scanners with higher performance in terms of features and image qualities because it minimizes parasitic capacitances and ultimately improves signal-to-noise ratio (SNR). Moreover, a frequency bandwidth of CMUT array is known as relatively broader than that of other ultrasonic transducer arrays. To utilize the wide bandwidth characteristic of the CMUT arrays, in this paper, we introduce a FDMA (frequency division multiple access) based ultrasound imaging technique using orthogonally band-divided coded signals to provide dynamic transmit focused imaging without sacrificing the frame rate. In the presented method, the orthogonal sub-band coded signals are simultaneously fired on multiple ranges, in which each signal is focused at a different range, in one transmission event. This paper also presents an ultrasound imageformation method and a modulation and demodulation process of orthogonal sub-band coded signals designed within the frequency bandwidth of the CMUT arrays. The presented method is verified by computer simulations using Field II and experiments. The simulation results using a computer generated tissue mimicking phantom show that the presented method can be achieved with both increased image quality and frame rate. The experimental results to verify the feasibility of the presented method using orthogonal sub-band coded signals show that the reflected signals from targets are successfully separated into two compressed signals. Currently, we are extending the presented approach to ultrasound imaging technique for volumetric ultrasound scanners using 2-D CMUT-on-ASIC arrays.

  8. Novel high-frequency, high-power, pulsed oscillator based on a transmission line transformer

    NASA Astrophysics Data System (ADS)

    Burdt, R.; Curry, R. D.

    2007-07-01

    Recent analysis and experiments have demonstrated the potential for transmission line transformers to be employed as compact, high-frequency, high-power, pulsed oscillators with variable rise time, high output impedance, and high operating efficiency. A prototype system was fabricated and tested that generates a damped sinusoidal wave form at a center frequency of 4MHz into a 200? load, with operating efficiency above 90% and peak power on the order of 10MW. The initial rise time of the pulse is variable and two experiments were conducted to demonstrate initial rise times of 12 and 3ns, corresponding to a spectral content from 4-30 and from 4-100MHz, respectively. A SPICE model has been developed to accurately predict the circuit behavior and scaling laws have been identified to allow for circuit design at higher frequencies and higher peak power. The applications, circuit analysis, test stand, experimental results, circuit modeling, and design of future systems are all discussed.

  9. STEM (scanning transmission electron microscopy) analysis of femtosecond laser pulse induced damage to bulk silicon

    NASA Astrophysics Data System (ADS)

    Coyne, E.; Magee, J. P.; Mannion, P.; O'Connor, G. M.; Glynn, T. J.

    2005-07-01

    This work reports on the structural changes that take place in wafer grade silicon when it is micro-machined with ultra-short laser pulses of 150 fs duration. A Chirped Pulse Amplification (CPA) Ti:Sapphire laser was used, with an operating wavelength centered on 775 nm and a maximum repetition rate of 1 KHz. The laser induced damage was characterized over the fluence range 0.43 14 J cm-2, and for each fluence a progressively increasing number of pulses was used. The analytical tools used to characterize the samples were all based upon electron microscopy. A 30 KeV scanning transmission electron microscope (STEM) imaging technique was developed to observe defects in the crystal lattice and the thermal-mechanical damage in the area surrounding the laser machined region. Mechanical cross sectioning (in conjunction with Scanning Electron Microscope (SEM) surface imaging) was also used to reveal the internal structure, composition, and dimensions of the laser machined structures. Based on this analysis, it will be shown that laser machining of silicon with femtosecond pulses can produce features with minimal thermal damage, although lattice damage created by mechanical stresses and the deposition of ablated material both limit the extent to which this can be achieved, particularly with high aspect ratios. A key feature of the work presented here is the high-resolution STEM images of the laser-machined structures.

  10. Pulse reflection and transmission due to impurities in a granular chain.

    PubMed

    Liu, Shi Wei; Yang, Yang Yang; Duan, Wen Shan; Yang, Lei

    2015-07-01

    Reflection and transmission due to the incident wave in one-dimensional bead chains when there are impurities have been studied. The impurities can be any kind of material, any size, and their numbers are arbitrary. The dependence of the transmission and the reflection on the numbers and the material parameters of the impurities are given. The analytical results are given by using the inverse scattering method. Substantial reflection is observed if there is only one steel bead. However, the reflection is negligible if there are two steel beads. The reflection monotonously increases as the numbers of the steel beads increase. The reflection remains a constant when the numbers of the steel beads are so many that the length composed by the steel beads is larger than the width of the solitary wave. It can be used to detect the impurities in the beads' chain by measuring the reflection of a pulse. PMID:26274296

  11. Influence of transmural pressure on retrograde pressure pulse transmission velocity in the canine superior vena cava.

    PubMed

    Minten, J; Van de Werf, F; Aubert, A E; Kesteloot, H; De Geest, H

    1984-11-01

    The influence of intrathoracic and intraluminal pressure on venous pressure pulse propagation velocity in the superior vena cava was investigated in acute canine experiments. The propagation velocity of distinct points of the venous pressure curve was measured under different conditions of preload, during expiratory and inspiratory apnea and during positive-negative pressure respiration. Under control conditions transmission velocities varied from 1.07 m/s to 3.29 m/s. After volume expansion propagation velocities rose significantly and varied from 1.09 m/s to 6.48 m/s. During expiratory apnea and at peak negative expiratory pressure, the propagation speed of distinct pressure points was higher than during inspiratory apnea and at peak positive inspiratory pressure. Significant linear correlation coefficients were found between the transmission velocities of different distinct pressure points and the transmural pressure, but not between the propagation speed and the intraluminal pressure. PMID:6085251

  12. Broadband THz pulse emission and transmission properties of nanostructured Pt thin films

    NASA Astrophysics Data System (ADS)

    Hu, Mingzhe; Mu, Kaijun; Zhang, Cunlin; Gu, Haoshuang; Ding, Zhao

    2015-10-01

    The THz transmission and emitting properties of a composite metallic nanostructure, composed of Ag nanowires electrodeposited in an anodic aluminum oxide (AAO) template and a Pt thin film, were investigated by using a femtosecond pulse laser irradiation. The microstructure of the above sub-wavelength nanostructure was investigated by XRD, SEM, AFM and TEM. The results indicated that the thickness of the Pt thin film was about 200 nm and the Ag nanowire array had a sparse and random distribution inside the AAO template, with a length distribution in the range of 10-25 ?m. The THz radiation properties of above sub-wavelength nanostructure indicated that the generated THz fluence from the Pt film was a magnitude of ?W scale with a broadband frequency range and its subsequent transmission could be significantly improved by the better impedance matching property of the Ag nanowire embedded AAO film compared with that of the empty AAO film.

  13. Constant frequency pulsed phase-locked-loop instrument for measurement of ultrasonic velocity

    SciTech Connect

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

    1991-10-01

    A new instrument based on a constant frequency pulsed phase-locked-loop (CFPPLL) concept has been developed to accurately measure the ultrasonicwavevelocity in liquids and changes in ultrasonicwavevelocity 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 including the constant phase shifts of reflectors placed in the path of the ultrasonicwave.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 measurevelocities, 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{sup 7}.

  14. Ultrasonic bone densitometer

    NASA Technical Reports Server (NTRS)

    Hoop, J. M. (inventor)

    1974-01-01

    A device, for measuring the density of a bone structure so as to monitor the calcium content, is described. A pair of opposed spaced ultrasonic transducers are held within a clamping apparatus closely adjacent the bone being analyzed. These ultrasonic transducers incude piezoelectric crystals shaped to direct signals through the bone encompassed in the heel and finger of the subject being tested. A pulse generator is coupled to one of the transducers and generates an electric pulse for causing the transducers to generate an ultrasonic sound wave which is directed through the bone structure to the other transducer. An electric circuit, including an amplifier and a bandpass filter couples the signals from the receiver transducer back to the pulse generator for retriggering the pulse generator at a frequency proportional to the duration that the ultrasonic wave takes to travel through the bone structure being examined.

  15. The Next Linear Collider Test Accelerator's RF Pulse Compression And Transmission

    SciTech Connect

    Tantawi, S.G.; Adelphson, C.; Holmes, S.; Lavine, Theodore L.; Loewen, R.J.; Nantista, C.; Pearson, C.; Pope, R.; Rifkin, J.; Ruth, R.D.; Vlieks, A.E.; /SLAC

    2011-09-14

    The overmoded rf transmission and pulsed power compression system for SLAC's Next Linear Collider (NLC) program requires a high degree of transmission efficiency and mode purity to be economically feasible. To this end, a number of new, high power components and systems have been developed at X-band, which transmit rf power in the low loss, circular TE01 mode with negligible mode conversion. In addition, a highly efficient SLED-II* pulse compressor has been developed and successfully tested at high power. The system produced a 200 MW, 250 ns wide pulse with a near-perfect flat-top. In this paper we describe the design and test results of the high power pulse compression system using SLED-II. The NLC rf systems use low loss highly over-moded circular waveguides operating in the TE01 mode. The efficiency of the systems is sensitive to the mode purity of the mode excited inside these guides. We used the so called flower petal mode transducer [2] to excite the TE01 mode. This type of mode transducer is efficient, compact and capable of handling high levels of power. To make more efficient systems, we modified this device by adding several mode selective chokes to act as mode purifiers. To manipulate the rf signals we used these modified mode converters to convert back and forth between over-moded circular waveguides and single-moded WR90 rectangular waveguides. Then, we used the relatively simple rectangular waveguide components to do the actual manipulation of rf signals. For example, two mode transducers and a mitered rectangular waveguide bend comprise a 90 degree bend. Also, a magic tee and four mode transducers would comprise a four-port-hybrid, etc. We will discuss the efficiency of an rf transport system based on the above methodology. We also used this methodology in building the SLEDII pulse compression system. At SLAC we built 4 of these pulse systems. In this paper we describe the SLEDII system and compare the performance of these 4 systems at SLAC. We report the experimental procedures used to measure their performance as well as the results of high power tests.

  16. Ultrasonic pulse detection with split spectrum processing and consecutive polarity coincidence

    SciTech Connect

    Ericsson, L.; Stepinski, T.; Dahlgren, S.

    1995-08-01

    The subject of signal processing for material noise reduction has been addressed in a large number of papers during the last decade. Several processing algorithms have been proposed, of which the Split Spectrum Processing (SSP) probably is the most renowned. The SSP technique is based on a synthetic frequency diversity approach, i.e. a filter bank is applied in order to obtain a set of signals with decorrelated noise components. Provided that the target echoes meet certain requirements, they will remain correlated in the generated set of signals. Target echo extraction may then be implemented using a suitable correlation measure. Simple target extractors such as Polarity Thresholding and Amplitude Minimization have been suggested and proven successful if the processing parameters had been correctly tuned. However, parameter tuning is not a trivial matter and relevant echoes may be lost due to the parameter sensitivity. In the paper a new target extraction algorithm, which avoids the requirement for a priori knowledge of frequency range, is introduced. The algorithm, referred to as Consecutive Polarity Coincidence, makes explicit use of the pulse characteristics of the target echo in order to implement local bandwidth estimation. If desired, a gating signal could be constructed by comparing the calculated bandwidth with a user defined threshold. Setting the threshold equal to the frequency range utilized for processing will generate a gating signal identical to the one obtained when using conventional Polarity Thresholding.

  17. System Performance Testing of the Pulse-Echo Ultrasonic Instrument for Critical Velocity Determination during Hanford Tank Waste Transfer Operations - 13584

    SciTech Connect

    Denslow, Kayte M.; Bontha, Jagannadha R.; Adkins, Harold E.; Jenks, Jeromy WJ; Hopkins, Derek F.; Thien, Michael G.; Kelly, Steven E.; Wooley, Theodore A.

    2013-06-01

    The delivery of Hanford double-shell tank waste to the Hanford Tank Waste Treatment and Immobilization Plant (WTP) is governed by specific Waste Acceptance Criteria that are identified in ICD 19 - Interface Control Document for Waste Feed. Waste must be certified as acceptable before it can be delivered to the WTP. The fluid transfer velocity at which solid particulate deposition occurs in waste slurry transport piping (critical velocity) is a key waste acceptance parameter that must be accurately characterized to determine if the waste is acceptable for transfer to the WTP. Washington River Protection Solutions and the Pacific Northwest National Laboratory have been evaluating the ultrasonic PulseEcho instrument since 2010 for its ability to detect particle settling and determine critical velocity in a horizontal slurry transport pipeline for slurries containing particles with a mean particle diameter of ?14 micrometers (?m). In 2012 the PulseEcho instrument was further evaluated under WRPS’ System Performance test campaign to identify critical velocities for slurries that are expected to be encountered during Hanford tank waste retrieval operations or bounding for tank waste feed. This three-year evaluation has demonstrated the ability of the ultrasonic PulseEcho instrument to detect the onset of critical velocity for a broad range of physical and rheological slurry properties that are likely encountered during the waste feed transfer operations between the Hanford tank farms and the WTP.

  18. System Performance Testing of the Pulse-Echo Ultrasonic Instrument for Critical Velocity Determination during Hanford Tank Waste Transfer Operations - 13584

    SciTech Connect

    Denslow, Kayte M.; Bontha, Jagannadha R.; Adkins, Harold E.; Jenks, Jeromy W.J.; Hopkins, Derek F.; Thien, Michael G.; Kelly, Steven E.; Wooley, Theodore A.

    2013-07-01

    The delivery of Hanford double-shell tank waste to the Hanford Tank Waste Treatment and Immobilization Plant (WTP) is governed by specific Waste Acceptance Criteria that are identified in ICD 19 - Interface Control Document for Waste Feed. Waste must be certified as acceptable before it can be delivered to the WTP. The fluid transfer velocity at which solid particulate deposition occurs in waste slurry transport piping (critical velocity) is a key waste acceptance parameter that must be accurately characterized to determine if the waste is acceptable for transfer to the WTP. Washington River Protection Solutions and the Pacific Northwest National Laboratory have been evaluating the ultrasonic PulseEcho instrument since 2010 for its ability to detect particle settling and determine critical velocity in a horizontal slurry transport pipeline for slurries containing particles with a mean particle diameter of =14 micrometers (?m). In 2012 the PulseEcho instrument was further evaluated under WRPS' System Performance test campaign to identify critical velocities for slurries that are expected to be encountered during Hanford tank waste retrieval operations or bounding for tank waste feed. This three-year evaluation has demonstrated the ability of the ultrasonic PulseEcho instrument to detect the onset of critical velocity for a broad range of physical and rheological slurry properties that are likely encountered during the waste feed transfer operations between the Hanford tank farms and the WTP. (authors)

  19. Magnetohydrodynamic electromagnetic pulse (MHD-EMP) interaction with power transmission and distribution systems

    SciTech Connect

    Tesche, F.M.; Barnes, P.R.; Meliopoulos, A.P.S.

    1992-02-01

    This report discusses the effects of the late-time high-altitude electromagnetic pulse (HEMP) on electrical transmission and distribution (T&D) systems. This environment, known as the magnetohydrodynamic electromagnetic pulse (MHD-EMP), is a very slowly varying electric field induced in the earth`s surface, similar to the field induced by a geomagnetic storm. It can result in the flow of a quasi-dc current in grounded power lines and in the subsequent magnetic saturation of transformers. This saturation, in turn, causes 6-Hz harmonic distortion and an increase in the reactive power required by generation facilities. This report analyzes and discusses these phenomena. The MHD-EMP environment is briefly discussed, and a simplified form of the earth-induced electric field is developed for use in a parametric study of transmission line responses. Various field coupling models are described, and calculated results for the responses of both transmission- and distribution-class power lines are presented. These calculated responses are compared with measurements of transformer operation under dc excitation to infer the MHD-EMP response of these power system components. It is found that the MHD-EMP environment would have a marked effect on a power system by inducing up to several hundreds of amperes of quasi-dc current on power lines. These currents will cause transformers to saturate which could result in excessive harmonic generation, voltage swings, and voltage suppression. The design of critical facilities which are required to operate during and after MHD-EMP events will have to be modified in order to mitigate the effects of these abnormal power system conditions.

  20. Magnetohydrodynamic electromagnetic pulse (MHD-EMP) interaction with power transmission and distribution systems

    SciTech Connect

    Tesche, F.M. , Dallas, TX ); Barnes, P.R. ); Meliopoulos, A.P.S. . Dept. of Electrical Engineering)

    1992-02-01

    This report discusses the effects of the late-time high-altitude electromagnetic pulse (HEMP) on electrical transmission and distribution (T D) systems. This environment, known as the magnetohydrodynamic electromagnetic pulse (MHD-EMP), is a very slowly varying electric field induced in the earth's surface, similar to the field induced by a geomagnetic storm. It can result in the flow of a quasi-dc current in grounded power lines and in the subsequent magnetic saturation of transformers. This saturation, in turn, causes 6-Hz harmonic distortion and an increase in the reactive power required by generation facilities. This report analyzes and discusses these phenomena. The MHD-EMP environment is briefly discussed, and a simplified form of the earth-induced electric field is developed for use in a parametric study of transmission line responses. Various field coupling models are described, and calculated results for the responses of both transmission- and distribution-class power lines are presented. These calculated responses are compared with measurements of transformer operation under dc excitation to infer the MHD-EMP response of these power system components. It is found that the MHD-EMP environment would have a marked effect on a power system by inducing up to several hundreds of amperes of quasi-dc current on power lines. These currents will cause transformers to saturate which could result in excessive harmonic generation, voltage swings, and voltage suppression. The design of critical facilities which are required to operate during and after MHD-EMP events will have to be modified in order to mitigate the effects of these abnormal power system conditions.

  1. ELSEVIER Ultrasonics 35 (1997) 525-531 High-order spectra-based deconvolution of ultrasonic NDT

    E-print Network

    Ghouti, Lahouari

    1997-01-01

    ELSEVIER Ultrasonics 35 (1997) 525-531 High-order spectra-based deconvolution of ultrasonic NDTPetroleumund Mineruls, KFUPM Box 181 I, Dhahran 31261, Saudi Arabiu Received 14 April 1997 Abstract In ultrasonic of the measuring instruments, the propagation paths taken by the ultrasonic pulses, and noise. This measured pulse

  2. High spatial resolution fast-neutron imaging detectors for Pulsed Fast-Neutron Transmission Spectroscopy

    NASA Astrophysics Data System (ADS)

    Mor, I.; Vartsky, D.; Bar, D.; Feldman, G.; Goldberg, M. B.; Katz, D.; Sayag, E.; Shmueli, I.; Cohen, Y.; Tal, A.; Vagish, Z.; Bromberger, B.; Dangendorf, V.; Mugai, D.; Tittelmeier, K.; Weierganz, M.

    2009-05-01

    Two generations of a novel detector for high-resolution transmission imaging and spectrometry of fast-neutrons are presented. These devices are based on a hydrogenous fiber scintillator screen and single- or multiple-gated intensified camera systems (ICCD). This detector is designed for energy-selective neutron radiography with nanosecond-pulsed broad-energy (1-10 MeV) neutron beams. Utilizing the Time-of-Flight (TOF) method, such a detector is capable of simultaneously capturing several images, each at a different neutron energy (TOF). In addition, a gamma-ray image can also be simultaneously registered, allowing combined neutron/gamma inspection of objects. This permits combining the sensitivity of the fast-neutron resonance method to low-Z elements with that of gamma radiography to high-Z materials.

  3. Ultrasonic Monitor

    NASA Technical Reports Server (NTRS)

    1983-01-01

    MicroUltrasonics PLR-1000 is a refined microprocessor-controlled version (usable on bolts, plates, liquids and gases) of the P2L2 developed by Langley Research Center. New technique is for nondestructive measurement of residual stress in various types of structures, for example, nuclear pressure vessels, pipes in nuclear reactors, offshore platforms, bridges, railroad tracks and wheels, aircraft wings, and engines. The instrument produces sound tone pulses that travel through a test specimen. PLR-1000 precisely measures speeds as stress increases speed of sound, tone changes, making precise measurements possible.

  4. Modeling NDT piezoelectric ultrasonic transmitters.

    PubMed

    San Emeterio, J L; Ramos, A; Sanz, P T; Ruíz, A; Azbaid, A

    2004-04-01

    Ultrasonic NDT applications are frequently based on the spike excitation of piezoelectric transducers by means of efficient pulsers which usually include a power switching device (e.g. SCR or MOS-FET) and some rectifier components. In this paper we present an approximate frequency domain electro-acoustic model for pulsed piezoelectric ultrasonic transmitters which, by integrating partial models of the different stages (driving electronics, tuning/matching networks and broadband piezoelectric transducer), allows the computation of the emission transfer function and output force temporal waveform. An approximate frequency domain model is used for the evaluation of the electrical driving pulse from the spike generator. Tuning circuits, interconnecting cable and mechanical impedance matching layers are modeled by means of transmission lines and the classical quadripole approach. The KLM model is used for the piezoelectric transducer. In addition, a PSPICE scheme is used for an alternative simulation of the broadband driving spike, including the accurate evaluation of non-linear driving effects. Several examples illustrate the capabilities of the specifically developed software. PMID:15047298

  5. Defect detection and size estimation in billet from profile of time-of-flight using ultrasonic transmission method with linear scanning

    NASA Astrophysics Data System (ADS)

    Miyamoto, Ryusuke; Mizutani, Koichi; Ebihara, Tadashi; Wakatsuki, Naoto

    2015-07-01

    In this study, defect detection and size estimation in billet by transmission method with linear scanning were carried out and the validity of the method was evaluated by numerical simulation. In addition, the suitable signal frequency and aperture of transducers were clarified. As a result, the following were found: a defect can be detected, signals with frequencies lower than those generally used in conventional ultrasonic testing (i.e., 0.5-1.5 MHz) are desirable, and the time-of-flight (TOF) deviation ?? becomes largest when the wavelength at center frequency and the aperture of transducers are comparable. Defect size can be estimated when a single defect exists alone and the defect is not near the surface of a billet. Although defect size estimation becomes difficult when the defect is near the surface of a billet, the defect can be detected by our proposed method.

  6. Ultrasonic meters prove reliability on Nova Gas pipeline

    SciTech Connect

    Rogi, M.

    1995-08-01

    Getting the job done efficiently, safely, and economically are the main reasons Nova Gas Transmission Ltd. (NGTL) of Alberta, Canada looked to an ultrasonic gas flow meter for its flow measurement applications. In the past, NGTL relied mainly on orifice plates to measure mainline flow. In 1990, as a result of an increased requirement for reliable mainline measurement, NGTL initiated a Mainline Measurement Task group to review available metering devices and recommend the best solution. This task group compiled a list of acceptance criteria against which to assess various options. They were looking for mainline measurement devices with high accuracy and performance. After developing the acceptance criteria and researching other pipeline companies in North America and Europe, the Task Group narrowed the list of options to four measurement devices, including two single-path ultrasonic meters. Further evaluation conducted at NGTL`s research facility concluded that the single-path ultrasonic gas flow meter was best suited for NGTL`s system requirements. The single-path ultrasonic gas flow meter, selected by the Task Group, uses direct digital time measurement of the difference between travel times of individual upstream and downstream ultrasonic pulses. This paper reviews the complexity of flow measurements and the types of information that is necessary to accurately calculate flow. The performance and accuracy of the ultrasonic meter are provided based on this company`s experience.

  7. Phase calibration of sonar systems using standard targets and dual-frequency transmission pulses.

    PubMed

    Islas-Cital, Alan; Atkins, Philip R; Foo, Kae Y; Picó, Ruben

    2011-10-01

    The phase angle component of the complex frequency response of a sonar system operating near transducer resonance is usually distorted. Interpretation and classification of the received sonar signal benefits from the preservation of waveform fidelity over the full bandwidth. A calibration process that measures the phase response in addition to the amplitude response is thus required. This paper describes an extension to the standard-target calibration method to include phase angle, without affecting the experimental apparatus, by using dual-frequency transmission pulses and frequency-domain data processing. This approach reduces the impact of unknown range and sound speed parameters upon phase calibration accuracy, as target phase is determined from the relationship of the two frequency components instead of relying on a local phase reference. Tungsten carbide spheres of various sizes were used to simultaneously calibrate the amplitude and phase response of an active sonar system in a laboratory tank. Experimental measurements of target phase spectra are in good agreement with values predicted from a theoretical model based upon full-wave analysis, over an operating frequency of 50-125 kHz. PMID:21973342

  8. Ringing in the pulse response of long and wideband coaxial transmission lines due to group delay dispersion

    SciTech Connect

    Kotzian,G.; de Maria,R.; Caspers, F.; Federmann, S.; Hofle, W.

    2009-05-04

    In particle accelerators coaxial cables are commonly used to transmit wideband beam signals covering many decades of frequencies over long distances. Those transmission lines often have a corrugated outer and/or inner conductor. This particular construction exhibits a significant amount of frequency dependent group delay variation. A comparison of simulations based on theoretical models, numerical simulations and S{sub 21} network analyzer measurements up to 2.5 GHz is presented. It is shown how the non-linear phase response and varying group delay leads to ringing in the pulse response and subsequent distortion of signal s transmitted through such coaxial transmission lines.

  9. Ultrasonic extensometer measures bolt preload

    NASA Technical Reports Server (NTRS)

    Daniels, C. M., Jr.

    1978-01-01

    Extensometer using ultrasonic pulse reflections to measure elongations in tightened belts and studs is much more accurate than conventional torque wrenches in application of specified preload to bolts and other threaded fasteners.

  10. Design of high-efficiency broad-bandwidth pulse compression device based on composite transmission grating with high damage threshold

    NASA Astrophysics Data System (ADS)

    Chen, Xinrong; Li, Chaoming; Liu, Linyue; Li, Lin; Wu, Jianhong; Chang, Zenghu

    2014-11-01

    A novel pulse compression device has been developed for femto-second Ti: sapphire laser at 800nm center wavelength with 700nm~900nm bandwidth. This new kind of composite pulse compression device consists of two fused silica transmission gratings with 1250lp/mm and 3300lp/mm respectively and these two fused silica transmission gratings are located in two optical surfaces of the same fused silica plate. Owing to use anti-reflection transmission gratings with high space frequency (3300lp/mm), it can avoid the wave-front distort derived from coating antireflection film on one surface of the fused silica plate. Being made of fused silica, this new composite pulse compression device will be expected to have high laser damage threshold. The calculation results show that: the -1st order diffraction efficiency of 1250lp/mm grating is over 87% within the 700nm and 900nm broad-bandwidth for rectangular groove and TE polarization state. And the average diffraction efficiency within the 700nm and 900nm broad-bandwidth is more than 92%. At 800nm, the -1st transmitted order diffraction efficiency is great to 96% while the transmittance of 3300lp/mm grating is up to 99.9%.

  11. Pulse-echo ultrasonic inspection system for in-situ nondestructive inspection of Space Shuttle RCC heat shields.

    SciTech Connect

    Roach, Dennis Patrick; Walkington, Phillip D.; Rackow, Kirk A.

    2005-06-01

    The reinforced carbon-carbon (RCC) heat shield components on the Space Shuttle's wings must withstand harsh atmospheric reentry environments where the wing leading edge can reach temperatures of 3,000 F. Potential damage includes impact damage, micro cracks, oxidation in the silicon carbide-to-carbon-carbon layers, and interlaminar disbonds. Since accumulated damage in the thick, carbon-carbon and silicon-carbide layers of the heat shields can lead to catastrophic failure of the Shuttle's heat protection system, it was essential for NASA to institute an accurate health monitoring program. NASA's goal was to obtain turnkey inspection systems that could certify the integrity of the Shuttle heat shields prior to each mission. Because of the possibility of damaging the heat shields during removal, the NDI devices must be deployed without removing the leading edge panels from the wing. Recently, NASA selected a multi-method approach for inspecting the wing leading edge which includes eddy current, thermography, and ultrasonics. The complementary superposition of these three inspection techniques produces a rigorous Orbiter certification process that can reliably detect the array of flaws expected in the Shuttle's heat shields. Sandia Labs produced an in-situ ultrasonic inspection method while NASA Langley developed the eddy current and thermographic techniques. An extensive validation process, including blind inspections monitored by NASA officials, demonstrated the ability of these inspection systems to meet the accuracy, sensitivity, and reliability requirements. This report presents the ultrasonic NDI development process and the final hardware configuration. The work included the use of flight hardware and scrap heat shield panels to discover and overcome the obstacles associated with damage detection in the RCC material. Optimum combinations of custom ultrasonic probes and data analyses were merged with the inspection procedures needed to properly survey the heat shield panels. System features were introduced to minimize the potential for human factors errors in identifying and locating the flaws. The in-situ NDI team completed the transfer of this technology to NASA and USA employees so that they can complete 'Return-to-Flight' certification inspections on all Shuttle Orbiters prior to each launch.

  12. Pulsed current wave shaping with a transmission line by utilizing superposition of a forward and a backward voltage wave for fast capillary Z-pinch discharge

    SciTech Connect

    Sakai, Y.; Takahashi, S.; Watanabe, M.; Hotta, E.; Kim, G.-H.

    2010-04-15

    By using a water transmission line, current wave shaping was demonstrated for a fast capillary Z-pinch discharge recombination soft x-ray laser study. The pulsed power system consists of a water capacitor, a gap switch, a transmission line, and a capillary plasma load. A voltage wave initiated at the water capacitor propagates toward the capillary load through the transmission line. Control of the pulse delay that occurred in the transmission line provides the superposition of the forward and the backward voltage waves effectively in order to perform current wave shaping with higher current amplitude and rapid current decay.

  13. The influence of local heating by nonlinear pulsed laser excitation on the transmission characteristics of a ZnO nanowire waveguide

    NASA Astrophysics Data System (ADS)

    Voss, Tobias; Svacha, Geoffry T.; Mazur, Eric; Müller, Sven; Ronning, Carsten

    2009-03-01

    We perform a transmission experiment on a ZnO nanowire waveguide to study its transmission characteristics under nonlinear femtosecond-pulse excitation. We find that both the second harmonic and the photoluminescence couple into low-order waveguide modes of the nanowires but with distinctly different efficiencies. We measure the transmission spectrum of a single ZnO nanowire waveguide for near-UV light generated by interband recombination processes. The transmission spectrum allows us to determine the absorption edge of the excited nanowire and to study the temperature profile of the nanowire under femtosecond-pulse excitation.

  14. Pulsed current wave shaping with a transmission line by utilizing superposition of a forward and a backward voltage wave for fast capillary Z-pinch discharge.

    PubMed

    Sakai, Y; Takahashi, S; Watanabe, M; Kim, G-H; Hotta, E

    2010-04-01

    By using a water transmission line, current wave shaping was demonstrated for a fast capillary Z-pinch discharge recombination soft x-ray laser study. The pulsed power system consists of a water capacitor, a gap switch, a transmission line, and a capillary plasma load. A voltage wave initiated at the water capacitor propagates toward the capillary load through the transmission line. Control of the pulse delay that occurred in the transmission line provides the superposition of the forward and the backward voltage waves effectively in order to perform current wave shaping with higher current amplitude and rapid current decay. PMID:20441338

  15. Ultrasonic evaluation of high voltage circuit boards

    NASA Technical Reports Server (NTRS)

    Klima, S. J.; Riley, T. J.

    1976-01-01

    Preliminary observations indicate that an ultrasonic scanning technique may be useful as a quick, low cost, nondestructive method for judging the quality of circuit board materials for high voltage applications. Corona inception voltage tests were conducted on fiberglass-epoxy and fiberglass-polyimide high pressure laminates from 20 to 140 C. The same materials were scanned ultrasonically by utilizing the single transducer, through-transmission technique with reflector plate, and recording variations in ultrasonic energy transmitted through the board thickness. A direct relationship was observed between ultrasonic transmission level and corona inception voltage. The ultrasonic technique was subsequently used to aid selection of high quality circuit boards for the Communications Technology Satellite.

  16. Ultrasonic Imaging Transceiver Design for CMUT: A Three-Level 30-Vpp Pulse-Shaping Pulser With Improved Efficiency and a Noise-Optimized Receiver

    E-print Network

    Chen, Kailiang

    This paper demonstrates a four-channel transceiver chip for medical ultrasonic imaging, interfacing to the capacitive micromachined ultrasonic transducers (CMUTs). The high-voltage transmitter (Tx) uses a three-level ...

  17. Transmission of 1064 nm laser radiation during ablation with an ultra-short pulse laser (USPL) system

    NASA Astrophysics Data System (ADS)

    Schelle, Florian; Meister, Jörg; Oehme, Bernd; Frentzen, Matthias

    2012-01-01

    During ablation of oral hard tissue with an USPL system a small amount of the incident laser power does not contribute to the ablation process and is being transmitted. Partial transmission of ultra-short laser pulses could potentially affect the dental pulp. The aim of this study was to assess the transmission during ablation and to deduce possible risks for the patient. The study was performed with an Nd:YVO4 laser, emitting pulses with a duration of 8 ps at a wavelength of 1064 nm. A repetition rate of 500 kHz and an average power of 9 W were chosen to achieve high ablation efficiency. A scanner system created square cavities with an edge length of 1 mm. Transmission during ablation of mammoth ivory and dentin slices with a thickness of 2 mm and 5 mm was measured with a power meter, placed directly beyond the samples. Effects on subjacent blood were observed by ablating specimens placed in contact to pork blood. In a separate measurement the temperature increase during ablation was monitored using an infrared camera. The influence of transmission was assessed by tuning down the laser to the corresponding power and then directly irradiating the blood. Transmission during ablation of 2 mm specimens was about 7.7% (ivory) and 9.6% (dentin) of the incident laser power. Ablation of specimens directly in contact to blood caused coagulation at longer irradiation times (t~18s). Direct irradiation of blood with the transmitted power provoked bubbling and smoke formation. Temperature measurements identified heat generation as the main reason for the observed coagulation.

  18. Effect of bone cortical thickness on velocity measurements using ultrasonic axial transmission: a 2D simulation study.

    PubMed

    Bossy, Emmanuel; Talmant, Maryline; Laugier, Pascal

    2002-07-01

    In recent years, quantitative ultrasound (QUS) has played an increasing role in the assessment of bone status. The axial transmission technique allows to investigate skeletal sites such as the cortical layer of long bones (radius, tibia), inadequate to through-transmission techniques. Nevertheless, the type of propagation involved along bone specimens has not been clearly elucidated. Axial transmission is investigated here by means of two-dimensional simulations at 1 MHz. We focus our interest on the apparent speed of sound (SOS) of the first arriving signal (FAS). Its dependence on the thickness of the plate is discussed and compared to previous work. Different time criteria are used to derive the apparent SOS of the FAS as a function of source-receiver distance. Frequency-wave number analysis is performed in order to understand the type of propagation involved. For thick plates (thickness>lambdabone, longitudinal wavelength in bone), and for a limited range of source-receiver distances, the FAS corresponds to the lateral wave. Its velocity equals the longitudinal bulk velocity of the bone. For plate thickness less than lambdabone, some plate modes contribute to the FAS, and the apparent SOS decreases with the thickness in a way that depends on both the time criterion and on the source-receiver distance. The FAS corresponds neither to the lateral wave nor to a single plate mode. For very thin plates (thickness< lambdabone/4), the apparent SOS tends towards the velocity of the lowest order symmetrical vibration mode (S0 Lamb mode). PMID:12141355

  19. A high-performance ultrasonic system for the simultaneous transmission of data and power through solid metal barriers.

    PubMed

    Lawry, Tristan J; Wilt, Kyle R; Ashdown, Jon D; Scarton, Henry A; Saulnier, Gary J

    2013-01-01

    This paper presents a system capable of simultaneous high-power and high-data-rate transmission through solid metal barriers using ultrasound. By coaxially aligning a pair of piezoelectric transducers on opposite sides of a metal wall and acoustically coupling them to the barrier, an acoustic- electric transmission channel is formed which prevents the need for physical penetration. Independent data and power channels are utilized, but they are only separated by 25.4 mm to reduce the system's form factor. Commercial off-the-shelf components and evaluation boards are used to create realtime prototype hardware and the full system is capable of transmitting data at 17.37 Mbps and delivering 50 W of power through a 63.5-mm thick steel wall. A synchronous multi-carrier communication scheme (OFDM) is used to achieve a very high spectral efficiency and to ensure that there is only minor interference between the power and data channels. Also presented is a discussion of potential enhancements that could be made to greatly improve the power and data-rate capabilities of the system. This system could have a tremendous impact on improving safety and preserving structural integrity in many military applications (submarines, surface ships, unmanned undersea vehicles, armored vehicles, planes, etc.) as well as in a wide range of commercial, industrial, and nuclear systems. PMID:23287924

  20. Improvement of ultrasonic characteristics in butt-welded joint of austenitic stainless steel using magnetic stirring method

    SciTech Connect

    Tanosaki, M.; Yoshikawa, K.; Arakawa, T.

    1995-08-01

    Magnetic Stirring Method of Tungsten Inert Gas(TIG) Welding are applied to butt-welded joint of austenitic stainless steel. The purpose of this method is to refine the welded structure and to improve the ultrasonic characteristics. In the conventional method of ultrasonic test in austenitic stainless steel weldments, dendritic solidification structure of weldment prevents smooth ultrasonic beam transmission. The tests are performed in three welding conditions; One is conventional TIG welding (without magnetic stirring), the other two are TIG welding using magnetic stirring method. Each test piece is evaluated by observing macro structure of cross section and by several ultrasonic tests examining pulse amplitudes, beam path length and proceeding beam direction. The detectability of artificial notches in weldment is also investigated and compared.

  1. Improved ultrasonic biomedical measuring apparatus

    NASA Technical Reports Server (NTRS)

    Lee, R. D.

    1972-01-01

    Device for making measurements of organs in living specimens and recording movements of organs is described. System uses series of ultrasonic pulses beamed into body of animal and reflected echo pulses are picked up by transducers and recorded. Diagram of equipment required and method of application is included.

  2. Detection of laser-induced nanosecond ultrasonic pulses in metals using a pancake coil and a piezoelectric sensor.

    PubMed

    Kozhushko, Victor V; Krenn, Heinz

    2012-06-01

    A piezoelectric sensor and a pancake coil sensor were used for broadband detection of laser-induced ultrasound in single-crystal aluminum and polycrystalline nickel. Pressure pulses with pronounced compression phases were induced by laser pulses of 5 ns duration from one side of the specimens and detected from the opposite side. A coupling layer of water was required for the piezoelectric method, whereas the pancake coil placed in the biasing permanent field of a cylindrical magnet ~0.25 T allowed noncontact detection. The signals detected by a piezoelectric transducer showed bipolar form and their spectra covered the range from 5 to 90 MHz. The signal measured in aluminum by a pancake coil was assigned to the eddy current sources and had single polarity. The peak-to-peak value of the signal in nickel was higher and had bipolar form because of the inverse magnetostrictive effect. The high-frequency limit detected by the pancake coil approached 200 MHz. PMID:22718873

  3. 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).

  4. Pulse

    MedlinePLUS

    ... resting for at least 10 minutes. Take the exercise heart rate while you are exercising. ... pulse rate can help determine if the patient's heart is pumping. ... rate gives information about your fitness level and health.

  5. SOLITONS AND OPTICAL FIBERS: Multiwavelength pulse transmission in an optical fibre — amplifier system

    NASA Astrophysics Data System (ADS)

    Panoiu, N.-C.; Mel'nikov, I. V.; Mihalache, D.; Etrich, C.; Lederer, F.

    2002-11-01

    The structure and dynamics of solitary waves created in the interaction of multiwavelength pulses in a single-mode optical fibre with amplification, filtering, and amplitude modulation is analysed. It is shown that there is a critical wavelength separation between channels above which wavelength-division multiplexing with solitons is feasible and that this separation increases with the number of channels.

  6. Fiber optic cables for transmission of high-power laser pulses

    NASA Astrophysics Data System (ADS)

    Thomes, W. Joe, Jr.; Ott, Melanie N.; Chuska, Richard F.; Switzer, Robert C.; Blair, Diana E.

    2011-09-01

    High power pulsed lasers are commonly deployed in harsh environments, like space flight and military missions, for a variety of systems such as LIDAR, optical communications over long distances, or optical firing of explosives. Fiber coupling of the laser pulse from the laser to where it is needed can often save size, reduce weight, and lead to a more robust and reliable system. Typical fiber optic termination procedures are not sufficient for injection of these high power laser pulses without catastrophic damage to the fiber endface. In the current study, we will review the causes of fiber damage during high power injection and discuss methods used to avoid these issues to permit fiber use with high reliability in these applications. A brief review of the design considerations for high peak power laser pulse injection will be presented to familiarize the audience with all the areas that need to be considered during the design phase. The majority of this paper focuses on the proper fiber polishing methods for high power use with an emphasis on laser polishing of the fibers. Results from recently build fibers will be shown to demonstrate the techniques.

  7. Evaluation of the phase correlation between the optical pulses for transmission in quantum key distribution

    NASA Astrophysics Data System (ADS)

    Kobayashi, Toshiya; Tomita, Akihisa; Okamoto, Atsushi

    2014-02-01

    One of the key assumptions in the security proof of BB84 quantum key distribution (QKD) protocol with a weak coherent light source is that the phase of each pulse emitted from the source is random. If the phases correlated, an efficient eavesdropping method exists, and more sacrifice bits are necessary to guarantee the security of the protocol. The phase correlation between the adjacent pulses was examined experimentally, for the first time, by measuring the visibility of interference. An asymmetric Mach-Zehnder interferometer was used to observe the interference between adjacent pulses from a distributed feedback (DFB) laser diode driven by 10 GHz clock signal. Clear interference was observed when the DC bias current exceeds the laser threshold. This high visibility implies phase correlation between pulses. In contrast, only a low visibility, i.e. very weak phase correlation, was observed when the DC bias current was set far below the threshold. The phase correlation became stronger as the DC bias current increased. The experimental results imply that a QKD equipment implementing BB84 protocol with a coherent light source is secure as long as the laser is operated in gain-switch even for 10 GHz clock frequency.

  8. Ultrasonic Imaging Of Deep Arteries

    NASA Technical Reports Server (NTRS)

    Rooney, James A.; Heyser, Richard C.; Lecroissette, Dennis H.

    1990-01-01

    Swept-frequency sound replaces pulsed sound. Ultrasonic medical instrument produces images of peripheral and coronary arteries with resolutions higher and at depths greater than attainable by previous ultrasonic systems. Time-delay-spectrometry imager includes scanning, image-processing, and displaying equipment. It sweeps in frequency from 0 to 10 MHz in 20 ms, pauses for 5 ms, and repeats sweep. Intended for use in noninvasive detection and measurement of atherosclerotic lesions.

  9. Multi-slice parallel transmission three-dimensional tailored RF (PTX 3DTRF) pulse design for signal recovery in ultra high field functional MRI

    NASA Astrophysics Data System (ADS)

    Zheng, Hai; Zhao, Tiejun; Qian, Yongxian; Schirda, Claudiu; Ibrahim, Tamer S.; Boada, Fernando E.

    2013-03-01

    T2? weighted fMRI at high and ultra high field (UHF) is often hampered by susceptibility-induced, through-plane, signal loss. Three-dimensional tailored RF (3DTRF) pulses have been shown to be an effective approach for mitigating through-plane signal loss at UHF. However, the required RF pulse lengths are too long for practical applications. Recently, parallel transmission (PTX) has emerged as a very effective means for shortening the RF pulse duration for 3DTRF without sacrificing the excitation performance. In this article, we demonstrate a RF pulse design strategy for 3DTRF based on the use of multi-slice PTX 3DTRF to simultaneously and precisely recover signal with whole-brain coverage. Phantom and human experiments are used to demonstrate the effectiveness and robustness of the proposed method on three subjects using an eight-channel whole body parallel transmission system.

  10. Design of broadband transmission quarter-wave plates for polarization control of isolated attosecond pulses

    NASA Astrophysics Data System (ADS)

    Chen, Shujing; Lin, Chengyou; Gao, Hua

    2015-07-01

    Using a standard Levenberg-Marquardt algorithm, broadband quarter-wave plates (QWPs) with bandwidth from 3 to 18 eV in the extreme ultraviolet (EUV) region were designed using aperiodic Mo/Si multilayers. By analyzing the design results of the Mo/Si multiayers with different bilayer numbers, we found that a Mo/Si multilayer with more bilayers can achieve broader phase control, but suffers from lower total throughput and a degree of circular polarization. In addition, the pulse broadenings caused by the group delay dispersions of the designed broadband QWPs were studied, and their layer distributions were investigated. The oscillating distribution of bilayer thickness in optimized multilayers was observed, which is considered to be the reason for forming the broadband phase control. Such broadband QWPs can be applied to generate a circularly polarized broadband EUV source, such as isolated attosecond pulse, directly from a linearly polarized source.

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

    PubMed

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

    2014-01-01

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

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

    PubMed Central

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

    2014-01-01

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

  13. Temperature dependence of ultrasonic propagation speed and attenuation in excised canine liver tissue measured using transmitted and reflected pulses

    NASA Astrophysics Data System (ADS)

    Techavipoo, U.; Varghese, T.; Chen, Q.; Stiles, T. A.; Zagzebski, J. A.; Frank, G. R.

    2004-06-01

    Previous reported data from our laboratory demonstrated the temperature dependence of propagation speed and attenuation of canine tissue in vitro at discrete temperatures ranging from 25 to 95 °C. However, concerns were raised regarding heating the same tissue specimen over the entire temperature range, a process that may introduce irreversible and, presumably, cumulative tissue degradation. In this paper propagation speed and attenuation vs temperature are measured using multiple groups of samples, each group heated to a different temperature. Sample thicknesses are measured directly using a technique that uses both transmitted and reflected ultrasound pulses. Results obtained using 3 and 5 MHz center frequencies demonstrate a propagation speed elevation of around 20 m/s in the 22-60 °C range, and a decrease of 15 m/s in the 60-90 °C range, in agreement with previous results where the same specimens were subjected to the entire temperature range. However, sound speed results reported here are slightly higher than those reported previously, probably due to more accurate measurements of sample thickness in the present experiments. Results also demonstrate that while the propagation speed varies with temperature, it is not a function of tissue coagulation. In contrast, the attenuation coefficient depends on both tissue coagulation effects and temperature elevation.

  14. Transmission

    SciTech Connect

    Sugano, K.

    1988-12-27

    A transmission is described which consists of: an input shaft; an output shaft; a first planetary gear set including a first sun gear selectively connectable by a first clutch to the input shaft, a first carrier selectively connectable by a second clutch to the input shaft and a first ring gear connected to the output shaft. The first sun gear selectively held stationary by a first brake, the first carrier is allowed to rotate in the same forward direction as the input shaft when the second clutch is engaged, but prevented from rotating in a reverse direction opposite to the forward direction by a first one-way clutch, the first carrier being selectively held stationary by a second brake; a second planetary gear set including a second sun gear connected to the input shaft, a second carrier connected to the first ring gear and also the the output shaft, and a second ring gear.

  15. Ultrasonic absortion in fatigued materials

    NASA Astrophysics Data System (ADS)

    Dugan, S.; Arnold, W.

    2013-01-01

    Non-destructive detection of fatigue damage, allowing an estimate of the residual life-time of components, could contribute to a safe and reliable operation of components and installations. Ultrasonic absorption, i.e. the internal friction, of a material increases with increasing fatigue or creep damage and there are many theories trying to explain the physics behind this phenomenon. Measurement of ultrasonic absorption directly on components could provide information on the degree of damage. A laser ultrasonic method, using laser-generated pulses and optical detection, was applied to study ultrasonic absorption in fatigue specimens of different metals. A characteristic behavior of the ultrasonic absorption coefficient with increasing levels of fatigue damage was found for the titanium alloy Ti-6Al-4V. Another aim of this study was to relate the absorption mechanisms to the behavior of ultrasonic absorption observed in metals with complex microstructure. To achieve this, different ultrasonic absorption mechanisms were analyzed with respect to experimental data. A thermoelastic effect related to the size and elasticity of the microstructure is discussed as the origin of the increased ultrasonic absorption.

  16. Modeling Methods for the Main Switch of High Pulsed-Power Facilities Based on Transmission Line Code

    NASA Astrophysics Data System (ADS)

    Hu, Yixiang; Zeng, Jiangtao; Sun, Fengju; Wei, Hao; Yin, Jiahui; Cong, Peitian; Qiu, Aici

    2014-09-01

    Based on the transmission line code (TLCODE), a circuit model is developed here for analyses of main switches in the high pulsed-power facilities. With the structure of the ZR main switch as an example, a circuit model topology of the switch is proposed, and in particular, calculation methods of the dynamic inductance and resistance of the switching arc are described. Moreover, a set of closed equations used for calculations of various node voltages are theoretically derived and numerically discretized. Based on these discrete equations and the Matlab program, a simulation procedure is established for analyses of the ZR main switch. Voltages and currents at different key points are obtained, and comparisons are made with those of a PSpice L-C model. The comparison results show that these two models are perfectly in accord with each other with discrepancy less than 0.1%, which verifies the effectiveness of the TLCODE model to a certain extent.

  17. 512QAM Nyquist sinc-pulse transmission at 54 Gbit/s in an optical bandwidth of 3 GHz.

    PubMed

    Schmogrow, R; Hillerkuss, D; Wolf, S; Bäuerle, B; Winter, M; Kleinow, P; Nebendahl, B; Dippon, T; Schindler, P C; Koos, C; Freude, W; Leuthold, J

    2012-03-12

    We demonstrate for the first time transmission of 54 Gbit/s and 48 Gbit/s over 44 km and 150 km, respectively, utilizing an optical bandwidth of only 3 GHz. We used polarization division multiplexed 512QAM and 256QAM modulation formats in combination with Nyquist pulse shaping having virtually zero roll-off. The resulting spectral efficiencies range up to 18 bit/s/Hz and 16 bit/s/Hz, respectively. Taking into account the overhead required for forward error correction, the occupied signal bandwidth corresponds to net spectral efficiencies of 14.4 bit/s/Hz and 15 bit/s/Hz, which could be achieved in a wavelength division multiplexed network without spectral guard bands. PMID:22418526

  18. Ultrasonic Technology

    NASA Astrophysics Data System (ADS)

    Cho, Byoung-Kwan

    Ultrasonic has proven its merit as one of the most promising sensing methods for food quality evaluation due to its non-destructive, noninvasive, precise, rapid, and on-line potential. Ultrasonic is mechanical wave at frequencies above 20 kHz propagating by vibration of the particles in the medium and penetrating through optically opaque materials to provide internal or surface information of physical attributes, such as texture and structure. Ultrasonic non-destructive testing is a way of characterizing materials by transmitting ultrasonic waves into a material, and investigating the characteristics of the transmitted and/or reflected ultrasonic waves. For the purpose of quality measurement of materials, low-intensity ultrasonic with the power level of up to 1 W/cm2 has been used. The low-intensity ultrasonic doesn't cause physical or chemical changes in the properties of the specimen when it transmits through the material. However, high-intensity ultrasonic of the power range above 1 W/cm2 may produce physical/chemical disruption and alteration in the material through which the wave propagates. High-intensity ultrasonic is usually used in cleaning, promotion of chemical reactions, homogenization, etc

  19. Wire Crimp Connectors Verification using Ultrasonic Inspection

    NASA Technical Reports Server (NTRS)

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

    2007-01-01

    The development of a new ultrasonic measurement technique to quantitatively assess wire crimp connections is discussed. The amplitude change of a compressional ultrasonic wave propagating through the junction of a crimp connector and wire is shown to correlate with the results of a destructive pull test, which previously has been used to assess crimp wire junction quality. Various crimp junction pathologies (missing wire strands, incorrect wire gauge, incomplete wire insertion in connector) are ultrasonically tested, and their results are correlated with pull tests. Results show that the ultrasonic measurement technique consistently (as evidenced with pull-testing data) predicts good crimps when ultrasonic transmission is above a certain threshold amplitude level. A physics-based model, solved by finite element analysis, describes the compressional ultrasonic wave propagation through the junction during the crimping process. This model is in agreement within 6% of the ultrasonic measurements. A prototype instrument for applying the technique while wire crimps are installed is also presented.

  20. Ultrasonic Imaging of Immersed Objects using Migration Tomas Olofsson

    E-print Network

    The synthetic aperture focusing technique (SAFT) is often used for imaging in non-destructive ultrasonic testing ultrasonic immersion tests. 1 Introduction Non-destructive testing (NDT) using pulse-echo data have much be successfully applied to data from ultrasonic immersion tests. The paper starts by noting some differences

  1. Transmission line pulse properties for a bidirectional transient voltage suppression diode fabricated using low-temperature epitaxy

    NASA Astrophysics Data System (ADS)

    Bouangeune, Daoheung; Cho, Deok-Ho; Yun, Hyung-Joong; Shim, Kyu-Hwan; Choi, Chel-Jong

    2015-01-01

    Based on low temperature epitaxy technology, a bidirectional transient voltage suppression (TVS) diode with abrupt multi-junctions was developed. The bidirectional triggering voltage of ±16 V was controlled by the thickness and dopant concentration in the multi-junctions using a reduced-pressure chemical vapor deposition (RPCVD) process. The manufactured TVS diode showed a small leakage current density and dynamic resistance of less than 5.1 × 10-14 A/ µm2 and 1 O, respectively, which could be associated with the epitaxially grown abrupt multijunctions. The transmission line pulse (TLP) analysis results demonstrated that the bidirectional TVS diodes were capable of withstanding a peak pulse current of up to ±20 A or ±1.02 × 10-3 A/ µm2, which is equivalent to ±40 kV of the human body model (HBM) and ±12 kV of IEC61000-4-2 (IEC). Nevertheless, the electrostatic discharge (ESD) design window showed that bidirectional TVS diodes meet IEC level 4 standard ESD protection requirements (8 kV in contact discharge). In addition, because of the bidirectional structure, the TVS devices exhibited a small capacitance of 4.9 pF, which confirms that the TVS diode can be used for protecting high data rate communication lines (over 500 Mbps) from ESD shock.

  2. Active Monitoring of a Fault with Seismogenic Potential Using an Ultrasonic Transmission at 1 km Deep in the Ezulwini Mine, South Africa

    NASA Astrophysics Data System (ADS)

    Kawakata, H.; Yoshimitsu, N.; Nakatani, M.; Philipp, J.; Naoi, M.; Ward, A.; Doi, I.; Masakale, T.; Durrheim, R. J.; Ribeiro, L.; Morema, S.; Ogasawara, H.

    2014-12-01

    Not only the stress state but also the elastic and inelastic properties of rocks around a target fault may be key information on seismogenic processes. Monitoring them may help us improve earthquake hazard assessment. In laboratory, elastic wave speed has been found to decrease prior to the main fracture (e.g., Lockner et al., 1977; Yoshimitsu et al., 2009). At the Ezulwini mine in South Africa, a fault with a high potential for mining-induced earthquakes with a relatively large magnitude (M ~2) was specified based on boring-core observation, tunnel wall observation, and mining plans. We started monitoring transmitted waves across the fault at about 1 km deep (Kawakata et al., 2011). We installed a piezoelectric transmitter as a wave source about 20 m away from the fault in the hanging wall. Three accelerometers of 3-component were installed along the acoustic beam from the transmitter; one in the hanging wall, and the other two in the footwall. Ultrasonic pulses were repeatedly transmitted, and the received waves were recorded at 400 ksps. Transmitted signals can be clearly recognized in stacked waveforms of all channels. In May 2012, increases in travel times (5-10 ms) from 2011 were observed for all the three stations. The common delay suggested that the decrease in wave speed was not localized at the fault. After that, there was a long strike in the mine, and the data were missed for about 100 days and 300 days due to the lack of maintenance of the monitoring system. By September 2013, when the data recording was resumed, travel times to the two receivers located after crossing the fault had increased greatly to ~60 ms, while that to the receiver before the fault increased only to 20 ms. Assuming that the thickness of the fault is 5 m, the difference in delay of 40 ms corresponds to a wave speed decrease of 8 %. We have not identified a relatively large event that might be associated with this change in travel times, but the event search is not completed.

  3. Improved Ultrasonic Transducer For Measuring Cryogenic Flow

    NASA Technical Reports Server (NTRS)

    Barkhoudarian, Sarkis

    1991-01-01

    Improved ultrasonic transducer used to measure flow of cryogenic fluid. Includes wedge made nonintrusive by machining it out of bulk material of duct carrying fluid. Skewed surfaces of wedge suppress standing waves, thus reducing ringing and increasing signal-to-noise ratio. Increases accuracy of measurements of times of arrival of ultrasonic pulses, from which times flow inferred.

  4. Flight tests of a digital data acquisition system for analysis of ultrasonic pulse-echo signals used to measure ice accretion

    E-print Network

    Ryan, Justin Mark

    1986-01-01

    A number of signal processing algorithms were developed for analyzing ultrasonic signals used to measure aircraft ice accretion in flight. A high speed digital signal acquisition system was designed and constructed to ...

  5. Experimental study of transmission of a pulsed focused beam through a skull phantom in nonlinear regime

    NASA Astrophysics Data System (ADS)

    Tsysar, S. A.; Nikolaeva, A. V.; Svet, V. D.; Khokhlova, V. A.; Yuldashev, P. V.; Sapozhnikov, O. A.

    2015-10-01

    In the paper the use of receiving and radiating system, which allows to determine the parameters of bone by nonlinear pulse-echo technique and to image of brain structures through the skull bones, was proposed. Accuracy of the skull bone characterization is due to higher measured harmonic and is significantly better than in linear case. In the experimental part focused piezoelectric transducer with diameter 100 mm, focal distance 100 mm, the frequency of 1.092 MHz was used. It was shown that skull bone profiling can be performed with the use of 3rd harmonic since 1st harmonic can be used for visualization of the underlying objects. The use of wideband systems for both skull profiling and brain visualization is restricted by skull attenuation and resulting low effective sensitivity.

  6. Long range transmission loss of broadband seismic pulses in the Arctic under ice-free conditions.

    PubMed

    Thode, Aaron; Kim, Katherine H; Greene, Charles R; Roth, Ethan

    2010-10-01

    In 2008 the Louis S. St-Laurent (LSSL) surveyed deep Arctic waters using a three-airgun seismic source. Signals from the seismic survey were detected between 400 km and 1300 km range on a directional autonomous acoustic recorder deployed in water 53 m deep off the Alaskan North Slope. Observations of received signal levels between 10-450 Hz versus LSSL range roughly fit a cylindrical transmission loss model plus 0.01 dB/km attenuation in deep ice-free waters, and fit previous empirical models in ice-covered waters. The transition between ice-free and ice-covered propagation conditions shifted 200 km closer to the recorder during the survey. PMID:20968323

  7. Segmented Motion Compensation for Complementary Coded Ultrasonic Imaging 

    E-print Network

    Cannon, Cormac; Hannah, John; McLaughlin, Steve

    Ultrasonic imaging using complementary coded pulses offers the SNR improvements of signal coding without the filter side-lobes introduced by single-transmit codes. Tissue motion between coded pulse emissions, however, can introduce high side...

  8. Imaging Inhomogeneities From Dry-Coupled Ultrasonic Scans

    NASA Technical Reports Server (NTRS)

    Roth, Don J.

    1995-01-01

    Method of imaging spatial distribution of selected physical properties and microstructure of specimen of material based on dry-coupled contact ultrasonic pulse/echo scanning. Ultrasonic transducer scanned across top surface of specimen. At each of many positions on two-dimensional grid on top surface, ultrasonic pulse/echo measurements taken and processed. Offers rapid, nondestructive alternative to destructive metallographic sectioning to obtain picture of inhomogeneity of specimen.

  9. Transmission electron microscopy investigation of crystalline silicon surface irradiated by femtosecond laser pulses in different background atmospheres

    NASA Astrophysics Data System (ADS)

    Wen, C.; Yang, H. D.; Li, X. H.; Cui, Y. X.; He, X. Q.; Duan, X. F.; Li, Z. H.

    2012-11-01

    This article aims to obtain structural and compositional characteristics of a crystalline silicon surface irradiated by femtosecond laser pulses in SF6, N2, air, and vacuum background atmospheres by performing transmission electron microscopy observation of <110> cross-sectional specimens. Conical microstructures covered with defective outer layers were formed in SF6 gas. The elemental sulfur dopants in the surface microstructure, which located in close proximity to defects, were mainly concentrated at the tip region of the microcones, and about several hundred nanometers thick. In N2 atmosphere, the defects produced regularly on the silicon surface were of the same types with those formed in SF6 gas and confirmed to be stacking faults and overlapped twins. Furthermore, silicon crystalline grains with different orientations were observed on the silicon surface irradiated in N2, air, and vacuum atmospheres. Especially, ?-Si3N4 crystalline grains were found to be formed in N2 and air as chemical products when elemental nitrogen exists, and the SiO2 amorphous phase was formed in air by the oxidation effect. Based on these experimental results, the relevant interaction mechanisms between pulsed laser and crystalline silicon were suggested to be mainly attributed to laser-assisted chemical etching and laser ablation, i.e., if volatile silicon compounds can be produced in a reactive gas atmosphere (e.g., SF6), the strong laser-assisted chemical etching dominates over the laser irradiation process. Otherwise, laser ablation is the dominant mechanism such as in N2, air, and vacuum.

  10. Ultrasonic Maintenance

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The Ultraprobe 2000, manufactured by UE Systems, Inc., Elmsford, NY, is a hand-held ultrasonic system that detects indications of bearing failure by analyzing changes in amplitude. It employs the technology of a prototype ultrasonic bearing-failure monitoring system developed by Mechanical Technology, Inc., Latham, New York and Marshall Space Flight Center (which was based on research into Skylab's gyroscope bearings). Bearings on the verge of failure send ultrasonic signals indicating their deterioration; the Ultraprobe changes these to audible signals. The operator hears the signals and gages their intensity with a meter in the unit.

  11. Effective transformation of the energy of high-voltage pulses into high-frequency oscillations using a saturated-ferrite-loaded transmission line

    NASA Astrophysics Data System (ADS)

    Gubanov, V. P.; Gunin, A. V.; Koval'Chuk, O. B.; Kutenkov, V. O.; Romanchenko, I. V.; Rostov, V. V.

    2009-07-01

    A new method of converting a high-voltage video pulse into high-frequency oscillations using a nonlinear transmission line with temporal dispersion has been studied. The dispersion was provided by pulsed magnetization reversal in a ferrite, which was initially magnetized to saturation in an external magnetic field. For a 9-ns pulse, an average energy conversion efficiency of about 10% was achieved. It is demonstrated that oscillations at frequencies within 600 MHz-1.1 GHz with a spectral width of about 15% (at a -3 dB level) can be excited using voltage pulses with an amplitude of 110-290 kV. The optimum bias magnetization fields are within 20-40 kA/m.

  12. System and technique for ultrasonic determination of degree of cooking

    DOEpatents

    Bond, Leonard J. (Richland, WA); Diaz, Aaron A. (W. Richland, WA); Judd, Kayte M. (Richland, WA); Pappas, Richard A. (Richland, WA); Cliff, William C. (Richland, WA); Pfund, David M. (Richland, WA); Morgen, Gerald P. (Kennewick, WA)

    2007-03-20

    A method and apparatus are described for determining the doneness of food during a cooking process. Ultrasonic signal are passed through the food during cooking. The change in transmission characteristics of the ultrasonic signal during the cooking process is measured to determine the point at which the food has been cooked to the proper level. In one aspect, a heated fluid cooks the food, and the transmission characteristics along a fluid-only ultrasonic path provides a reference for comparison with the transmission characteristics for a food-fluid ultrasonic path.

  13. THRESHOLD ESTIMATES OF ULTRASOUND-INDUCED LUNG HEMORRHAGE IN ADULT RATS: ROLE OF PULSE DURATION

    E-print Network

    Illinois at Urbana-Champaign, University of

    -diameter, lithium niobate ultrasonic transducer. Water-based (highly degassed water, 22°C) pulse-echo ultrasonic ultrasonically exposed groups (10 rats/group) and one sham group (20 rats). The 20 ultrasonically exposed groups duration is warranted. Methods Exposimetry Ultrasonic exposures were conducted using one focused, 19-mm

  14. Pulse based sensor networking using mechanical waves through metal substrates

    NASA Astrophysics Data System (ADS)

    Lorenz, S.; Dong, B.; Huo, Q.; Tomlinson, W. J.; Biswas, S.

    2013-05-01

    This paper presents a novel wireless sensor networking technique using ultrasonic signal as the carrier wave for binary data exchange. Using the properties of lamb wave propagation through metal substrates, the proposed network structure can be used for runtime transport of structural fault information to ultrasound access points. Primary applications of the proposed sensor networking technique will include conveying fault information on an aircraft wing or on a bridge to an ultrasonic access point using ultrasonic wave through the structure itself (i.e. wing or bridge). Once a fault event has been detected, a mechanical pulse is forwarded to the access node using shortest path multi-hop ultrasonic pulse routing. The advantages of mechanical waves over traditional radio transmission using pulses are the following: First, unlike radio frequency, surface acoustic waves are not detectable outside the medium, which increases the inherent security for sensitive environments in respect to tapping. Second, event detection can be represented by the injection of a single mechanical pulse at a specific temporal position, whereas radio messages usually take several bits. The contributions of this paper are: 1) Development of a transceiver for transmitting/receiving ultrasound pulses with a pulse loss rate below 2·10-5 and false positive rate with an upper bound of 2·10-4. 2) A novel one-hop distance estimation based on the properties of lamb wave propagation with an accuracy of above 80%. 3) Implementation of a wireless sensor network using mechanical wave propagation for event detection on a 2024 aluminum alloy commonly used for aircraft skin construction.

  15. Ultrasonic Inspection Near Small Bores

    NASA Technical Reports Server (NTRS)

    Parent, R. G.

    1986-01-01

    Portable ultrasonic probe makes it possible to inspect for hidden cracks near insides of narrow tubes. Using pulse-echo technique, instrument detects cracks as small as 0.015-in. (0.38-mm) deep. Used for nondestructive inspection of other hard-to-reach places where conventional large transducers will not fit or where difficult to apply coupling liquid for contact ultrasonic testing. Inspects bore of tubelike fitting. Instrument makes it unnecessary to disassemble fitting to check for cracks. Precise orientation of transducer with respect to part not necessary for detecting cracks.

  16. Ultrasonic Polishing

    NASA Technical Reports Server (NTRS)

    Gilmore, Randy

    1993-01-01

    The ultrasonic polishing process makes use of the high-frequency (ultrasonic) vibrations of an abradable tool which automatically conforms to the work piece and an abrasive slurry to finish surfaces and edges on complex, highly detailed, close tolerance cavities in materials from beryllium copper to carbide. Applications range from critical deburring of guidance system components to removing EDM recast layers from aircraft engine components to polishing molds for forming carbide cutting tool inserts or injection molding plastics. A variety of materials including tool steels, carbides, and even ceramics can be successfully processed. Since the abradable tool automatically conforms to the work piece geometry, the ultrasonic finishing method described offers a number of important benefits in finishing components with complex geometries.

  17. Ultrasonic polishing

    NASA Astrophysics Data System (ADS)

    Gilmore, Randy

    1993-02-01

    The ultrasonic polishing process makes use of the high-frequency (ultrasonic) vibrations of an abradable tool which automatically conforms to the work piece and an abrasive slurry to finish surfaces and edges on complex, highly detailed, close tolerance cavities in materials from beryllium copper to carbide. Applications range from critical deburring of guidance system components to removing EDM recast layers from aircraft engine components to polishing molds for forming carbide cutting tool inserts or injection molding plastics. A variety of materials including tool steels, carbides, and even ceramics can be successfully processed. Since the abradable tool automatically conforms to the work piece geometry, the ultrasonic finishing method described offers a number of important benefits in finishing components with complex geometries.

  18. Studies on Laser Generated Ultrasonic Waves in Inconel Super Alloy

    SciTech Connect

    Pramila, T.; Shukla, Anita; Raghuram, V.

    2010-05-28

    This paper deals with the generation, characterization and analysis of ultrasonic waves generated in a thick stepped sample of inconel super alloy using Laser Based Ultrasonic Technique. Nd-YAG pulsed laser is used for ultrasonic generation while He-Ne laser is used for heterodyne detection. Ultrasonic signals are analyzed using Fourier and wavelet transforms. Here the identification and estimation of velocity of pressure waves is presented. The mechanism of pressure wave generation is discussed in brief. Laser ultrasonics studies of inconel are being reported for the first time.

  19. Out-of-plane ultrasonic velocity measurement

    DOEpatents

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

    1998-07-14

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

  20. Out-of-plane ultrasonic velocity measurement

    DOEpatents

    Hall, Maclin S. (Marietta, GA); Brodeur, Pierre H. (Smyrna, GA); Jackson, Theodore G. (Atlanta, GA)

    1998-01-01

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

  1. Ultrasonic angioplasty

    NASA Astrophysics Data System (ADS)

    Siegel, Robert J.

    1990-08-01

    Over the past 3 years we have developed a percutaneous ultrasonic angioplasty device and recently applied it in human peripheral arteries. This paper describes some of the background preceding the development of intravascular ultrasound for arterial recanalization. The chronology of our development of ultrasonic angioplasty is discussed from in vitro studies on atherosclerotic plaque to in vivo studies in canine models with differing types of arterial occlusions (thrombotic fibrotic calcific-atherosclerotic) and to initial human application. SPIE Vol. 1321 Modern Technologies Applied to Medical Practice (1989) / 69

  2. Ultrasonic generator and detector using an optical mask having a grating for launching a plurality of spatially distributed, time varying strain pulses in a sample

    DOEpatents

    Maris, Humphrey J. (Barrington, RI)

    2003-01-01

    A method and a system are disclosed for determining at least one characteristic of a sample that contains a substrate and at least one film disposed on or over a surface of the substrate. The method includes a first step of placing a mask over a free surface of the at least one film, where the mask has a top surface and a bottom surface that is placed adjacent to the free surface of the film. The bottom surface of the mask has formed therein or thereon a plurality of features for forming at least one grating. A next step directs optical pump pulses through the mask to the free surface of the film, where individual ones of the pump pulses are followed by at least one optical probe pulse. The pump pulses are spatially distributed by the grating for launching a plurality of spatially distributed, time varying strain pulses within the film, which cause a detectable change in optical constants of the film. A next step detects a reflected or a transmitted portion of the probe pulses, which are also spatially distributed by the grating. A next step measures a change in at least one characteristic of at least one of reflected or transmitted probe pulses due to the change in optical constants, and a further step determines the at least one characteristic of the sample from the measured change in the at least one characteristic of the probe pulses. An optical mask is also disclosed herein, and forms a part of these teachings.

  3. Ultrasonic generator and detector using an optical mask having a grating for launching a plurality of spatially distributed, time varying strain pulses in a sample

    DOEpatents

    Maris, Humphrey J. (Barrington, RI)

    2002-01-01

    A method and a system are disclosed for determining at least one characteristic of a sample that contains a substrate and at least one film disposed on or over a surface of the substrate. The method includes a first step of placing a mask over a free surface of the at least one film, where the mask has a top surface and a bottom surface that is placed adjacent to the free surface of the film. The bottom surface of the mask has formed therein or thereon a plurality of features for forming at least one grating. A next step directs optical pump pulses through the mask to the free surface of the film, where individual ones of the pump pulses are followed by at least one optical probe pulse. The pump pulses are spatially distributed by the grating for launching a plurality of spatially distributed, time varying strain pulses within the film, which cause a detectable change in optical constants of the film. A next step detects a reflected or a transmitted portion of the probe pulses, which are also spatially distributed by the grating. A next step measures a change in at least one characteristic of at least one of reflected or transmitted probe pulses due to the change in optical constants, and a further step determines the at least one characteristic of the sample from the measured change in the at least one characteristic of the probe pulses. An optical mask is also disclosed herein, and forms a part of these teachings.

  4. Graphene electrostatic microphone and ultrasonic radio.

    PubMed

    Zhou, Qin; Zheng, Jinglin; Onishi, Seita; Crommie, M F; Zettl, Alex K

    2015-07-21

    We present a graphene-based wideband microphone and a related ultrasonic radio that can be used for wireless communication. It is shown that graphene-based acoustic transmitters and receivers have a wide bandwidth, from the audible region (20?20 kHz) to the ultrasonic region (20 kHz to at least 0.5 MHz). Using the graphene-based components, we demonstrate efficient high-fidelity information transmission using an ultrasonic band centered at 0.3 MHz. The graphene-based microphone is also shown to be capable of directly receiving ultrasound signals generated by bats in the field, and the ultrasonic radio, coupled to electromagnetic (EM) radio, is shown to function as a high-accuracy rangefinder. The ultrasonic radio could serve as a useful addition to wireless communication technology where the propagation of EM waves is difficult. PMID:26150483

  5. Ultrasonic Frequency Difference Generation to Characterize Fluids in Saturated Berea Sandstone.

    SciTech Connect

    Keatkowski, C. S.; Sinha, D. N.

    2001-01-01

    The use of nonlinear acoustics to characterize fluids in porous media is presented. The acoustic nonlinearity in sandstone is affected by the presence of water or oil. This difference in properties that affect the sound propagation through such media can be used to determine whether a piece of sandstone contains water or oil. Traditional methods of characterizing porous media usually rely on the transmission or reflection of a single ultrasonic probe pulse. The technique presented in this paper uses a method of generating a probe pulse inside the porous medium from the interaction of two pulses. Information about the medium is then contained in the propagation of this probe signal back to a receiver. The main advantage of this approach is that it allows implementation of this technique inside a borehole for characterizing the porous media outside.

  6. Ultrasonic techniques for aircraft ice accretion measurement

    NASA Technical Reports Server (NTRS)

    Hansman, R. John, Jr.; Kirby, Mark S.; Lichtenfelts, Fred

    1988-01-01

    Ultrasonic pulse-echo measurements of ice growth on cylinders and airfoils exposed to both artificial (icing wind tunnel) and natural (flight) icing conditions are presented. An accuracy of + or - 0.5 mm is achieved with the present method. The ultrasonic signal characteristics associated with each of the two types of icing regimes identified, wet and dry ice growth, are discussed. Heat transfer coefficients are found to be higher in the wind tunnel environment than in flight. Results for ice growth on airfoils have also been obtained using an array of ultrasonic transducers. Icing profiles obtained during flight are compared with mechanical and stereo image measurements.

  7. Piezoelectric Ultrasonic Micromotors

    E-print Network

    Flynn, Anita M.

    1995-06-01

    This report describes development of micro-fabricated piezoelectric ultrasonic motors and bulk-ceramic piezoelectric ultrasonic motors. Ultrasonic motors offer the advantage of low speed, high torque operation without ...

  8. Ultrasonic inspection apparatus and method using a focused wave device

    DOEpatents

    Gieske, John H. (Albuquerque, NM); Roach, Dennis P. (Albuquerque, NM); Walkington, Phillip D. (Albuquerque, NM)

    2001-01-01

    An ultrasonic pulse echo inspection apparatus and method for detecting structural failures. A focus lens is coupled to the transducer to focus the ultrasonic signal on an area to be inspected and a stop is placed in the focus lens to block selected ultrasonic waves. Other waves are not blocked and are transmitted through the structure to arrive at interfaces therein concurrently to produce an echo response with significantly less distortion.

  9. Ultrasonic imaging front-end design for CMUT: A 3-level 30Vpp pulse-shaping pulser with improved efficiency and a noise-optimized receiver

    E-print Network

    Chen, Kailiang

    A four-channel analog front-end (AFE) transceiver chip for medical ultrasound imaging is demonstrated. The high voltage transmitter uses a 3-level pulse-shaping technique to deliver over 50% more acoustic power for the ...

  10. Transmission and full-band coherent detection of polarization-multiplexed all-optical Nyquist signals generated by Sinc-shaped Nyquist pulses.

    PubMed

    Zhang, Junwen; Yu, Jianjun; Chi, Nan

    2015-01-01

    All optical method is considered as a promising technique for high symbol rate Nyquist signal generation, which has attracted a lot of research interests for high spectral-efficiency and high-capacity optical communication system. In this paper, we extend our previous work and report the fully experimental demonstration of polarization-division multiplexed (PDM) all-optical Nyquist signal generation based on Sinc-shaped Nyquist pulse with advanced modulation formats, fiber-transmission and single-receiver full-band coherent detection. Using this scheme, we have successfully demonstrated the generation, fiber transmission and single-receiver full-band coherent detection of all-optical Nyquist PDM-QPSK and PDM-16QAM signals up to 125-GBaud. 1-Tb/s single-carrier PDM-16QAM signal generation and full-band coherent detection is realized, which shows the advantage and feasibility of the single-carrier all-optical Nyquist signals. PMID:26323238

  11. Transmission and full-band coherent detection of polarization-multiplexed all-optical Nyquist signals generated by Sinc-shaped Nyquist pulses

    NASA Astrophysics Data System (ADS)

    Zhang, Junwen; Yu, Jianjun; Chi, Nan

    2015-09-01

    All optical method is considered as a promising technique for high symbol rate Nyquist signal generation, which has attracted a lot of research interests for high spectral-efficiency and high-capacity optical communication system. In this paper, we extend our previous work and report the fully experimental demonstration of polarization-division multiplexed (PDM) all-optical Nyquist signal generation based on Sinc-shaped Nyquist pulse with advanced modulation formats, fiber-transmission and single-receiver full-band coherent detection. Using this scheme, we have successfully demonstrated the generation, fiber transmission and single-receiver full-band coherent detection of all-optical Nyquist PDM-QPSK and PDM-16QAM signals up to 125-GBaud. 1-Tb/s single-carrier PDM-16QAM signal generation and full-band coherent detection is realized, which shows the advantage and feasibility of the single-carrier all-optical Nyquist signals.

  12. Transmission and full-band coherent detection of polarization-multiplexed all-optical Nyquist signals generated by Sinc-shaped Nyquist pulses

    PubMed Central

    Zhang, Junwen; Yu, Jianjun; Chi, Nan

    2015-01-01

    All optical method is considered as a promising technique for high symbol rate Nyquist signal generation, which has attracted a lot of research interests for high spectral-efficiency and high-capacity optical communication system. In this paper, we extend our previous work and report the fully experimental demonstration of polarization-division multiplexed (PDM) all-optical Nyquist signal generation based on Sinc-shaped Nyquist pulse with advanced modulation formats, fiber-transmission and single-receiver full-band coherent detection. Using this scheme, we have successfully demonstrated the generation, fiber transmission and single-receiver full-band coherent detection of all-optical Nyquist PDM-QPSK and PDM-16QAM signals up to 125-GBaud. 1-Tb/s single-carrier PDM-16QAM signal generation and full-band coherent detection is realized, which shows the advantage and feasibility of the single-carrier all-optical Nyquist signals. PMID:26323238

  13. Ultrasonic Investigation of the Gelation Process of Poly(Acrylamide) Gels

    E-print Network

    Page, John

    Ultrasonic Investigation of the Gelation Process of Poly(Acrylamide) Gels Tomohisa Norisuye,*1 Anatoliy Strybulevych,2 Martin Scanlon,3 John Page2 Summary: The time evolution of ultrasonic velocity. Longitudinal ultrasonic pulses were transmitted through the gel samples and continuously recorded to obtain

  14. DECONVOLUTION OF ULTRASONIC NONDESTRUCTIVE EVALUATION SIGNALS USING HIGHER-ORDER STATISTICS

    E-print Network

    Ghouti, Lahouari

    DECONVOLUTION OF ULTRASONIC NONDESTRUCTIVE EVALUATION SIGNALS USING HIGHER-ORDER STATISTICS Darmouth North Darmouth, MA 02747-2300. USA. E-mail: ghoutiBccse.kfupm.edu.sa ABSTRACT In ultrasonic of the measuring instruments, the prop- agation paths taken by the ultrasonic pulses, and are corrupted by additive

  15. High-resolution photoacoustic imaging with focused laser and ultrasonic beams

    E-print Network

    High-resolution photoacoustic imaging with focused laser and ultrasonic beams Fanting Kong,1 Y. C is based on a ring transducer that combines ultrasonic and laser beams collinearly and confocally improvement in lateral and axial resolutions compared to the pulse-echo ultrasonic imaging technique

  16. Accurate estimation of airborne ultrasonic time-of-flight for overlapping echoes.

    PubMed

    Sarabia, Esther G; Llata, Jose R; Robla, Sandra; Torre-Ferrero, Carlos; Oria, Juan P

    2013-01-01

    In this work, an analysis of the transmission of ultrasonic signals generated by piezoelectric sensors for air applications is presented. Based on this analysis, an ultrasonic response model is obtained for its application to the recognition of objects and structured environments for navigation by autonomous mobile robots. This model enables the analysis of the ultrasonic response that is generated using a pair of sensors in transmitter-receiver configuration using the pulse-echo technique. This is very interesting for recognizing surfaces that simultaneously generate a multiple echo response. This model takes into account the effect of the radiation pattern, the resonant frequency of the sensor, the number of cycles of the excitation pulse, the dynamics of the sensor and the attenuation with distance in the medium. This model has been developed, programmed and verified through a battery of experimental tests. Using this model a new procedure for obtaining accurate time of flight is proposed. This new method is compared with traditional ones, such as threshold or correlation, to highlight its advantages and drawbacks. Finally the advantages of this method are demonstrated for calculating multiple times of flight when the echo is formed by several overlapping echoes. PMID:24284774

  17. Accurate Estimation of Airborne Ultrasonic Time-of-Flight for Overlapping Echoes

    PubMed Central

    Sarabia, Esther G.; Llata, Jose R.; Robla, Sandra; Torre-Ferrero, Carlos; Oria, Juan P.

    2013-01-01

    In this work, an analysis of the transmission of ultrasonic signals generated by piezoelectric sensors for air applications is presented. Based on this analysis, an ultrasonic response model is obtained for its application to the recognition of objects and structured environments for navigation by autonomous mobile robots. This model enables the analysis of the ultrasonic response that is generated using a pair of sensors in transmitter-receiver configuration using the pulse-echo technique. This is very interesting for recognizing surfaces that simultaneously generate a multiple echo response. This model takes into account the effect of the radiation pattern, the resonant frequency of the sensor, the number of cycles of the excitation pulse, the dynamics of the sensor and the attenuation with distance in the medium. This model has been developed, programmed and verified through a battery of experimental tests. Using this model a new procedure for obtaining accurate time of flight is proposed. This new method is compared with traditional ones, such as threshold or correlation, to highlight its advantages and drawbacks. Finally the advantages of this method are demonstrated for calculating multiple times of flight when the echo is formed by several overlapping echoes. PMID:24284774

  18. Hand-Held Ultrasonic Instrument for Reading Matrix Symbols

    NASA Technical Reports Server (NTRS)

    Schramm, Harry F.; Kula, John P.; Gurney, John W.; Lior, Ephraim D.

    2008-01-01

    A hand-held instrument that would include an ultrasonic camera has been proposed as an efficient means of reading matrix symbols. The proposed instrument could be operated without mechanical raster scanning. All electronic functions from excitation of ultrasonic pulses through final digital processing for decoding matrix symbols would be performed by dedicated circuitry within the single, compact instrument housing.

  19. Femtosecond measurements of near-infrared pulse induced mid-infrared transmission modulation of quantum cascade lasers

    SciTech Connect

    Cai, Hong; Liu, Sheng; Lalanne, Elaine; Guo, Dingkai; Chen, Xing; Choa, Fow-Sen; Wang, Xiaojun; Johnson, Anthony M.

    2014-05-26

    We temporally resolved the ultrafast mid-infrared transmission modulation of quantum cascade lasers (QCLs) using a near-infrared pump/mid-infrared probe technique at room temperature. Two different femtosecond wavelength pumps were used with photon energy above and below the quantum well (QW) bandgap. The shorter wavelength pump modulates the mid-infrared probe transmission through interband transition assisted mechanisms, resulting in a high transmission modulation depth and several nanoseconds recovery lifetime. In contrast, pumping with a photon energy below the QW bandgap induces a smaller transmission modulation depth but much faster (several picoseconds) recovery lifetime, attributed to intersubband transition assisted mechanisms. The latter ultrafast modulation (>60?GHz) could provide a potential way to realize fast QCL based free space optical communication.

  20. Ultrasonic attenuation - Q measurements on 70215,29. [lunar rock

    NASA Technical Reports Server (NTRS)

    Warren, N.; Trice, R.; Stephens, J.

    1974-01-01

    Ultrasonic attenuation measurements have been made on an aluminum alloy, obsidian, and rock samples including lunar sample 70215,29. The measurement technique is based on a combination of the pulse transmission method and the forced resonance method. The technique is designed to explore the problem of defining experimentally, the Q of a medium or sample in which mode conversion may occur. If modes are coupled, the measured attenuation is strongly dependent on individual modes of vibration, and a range of Q-factors may be measured over various resonances or from various portions of a transient signal. On 70215,29, measurements were made over a period of a month while the sample outgassed in hard varuum. During this period, the highest measured Q of this sample increased from a few hundred into the range of 1000-1300.

  1. Evaluation of Defects in the Seal Region of Food Packages Using the Ultrasonic Contrast

    E-print Network

    Illinois at Urbana-Champaign, University of

    , speed and safety. A US patent6 describes an ultrasonic transmission technique for testing the sealEvaluation of Defects in the Seal Region of Food Packages Using the Ultrasonic Contrast Descriptor and trays, by reducing inspection costs. To evaluate high-frequency ultrasonic imaging as a sensing method

  2. Ultrasonic Interferometers Revisited

    ERIC Educational Resources Information Center

    Greenslade, Thomas B., Jr.

    2007-01-01

    I have been tinkering with ultrasonic transducers once more. In earlier notes I reported on optics-like experiments performed with ultrasonics, described a number of ultrasonic interferometers, and showed how ultrasonic transducers can be used for Fourier analysis. This time I became interested in trying the technique of using two detectors in…

  3. Ultrasonic pipe assessment

    DOEpatents

    Thomas, Graham H.; Morrow, Valerie L.; Levie, Harold; Kane, Ronald J.; Brown, Albert E.

    2003-12-23

    An ultrasonic pipe or other structure assessment system includes an ultrasonic transducer positioned proximate the pipe or other structure. A fluid connection between the ultrasonic transducer and the pipe or other structure is produced. The ultrasonic transducer is moved relative to the pipe or other structure.

  4. Ultrasonic transducer

    DOEpatents

    Taylor, Steven C.; Kraft, Nancy C.

    2007-03-13

    An ultrasonic transducer having an effective center frequency of about 42 MHz; a bandwidth of greater than 85% at 6 dB; a spherical focus of at least 0.5 inches in water; an F4 lens; a resolution sufficient to be able to detect and separate a 0.005 inch flat-bottomed hole at 0.005 inches below surface; and a beam size of approximately 0.006–0.008 inches measured off a 11/2 mm ball in water at the transducer's focal point.

  5. Digital ultrasonic signal processing: Primary ultrasonics task and transducer characterization use and detailed description

    NASA Technical Reports Server (NTRS)

    Hammond, P. L.

    1979-01-01

    This manual describes the use of the primary ultrasonics task (PUT) and the transducer characterization system (XC) for the collection, processing, and recording of data received from a pulse-echo ultrasonic system. Both PUT and XC include five primary functions common to many real-time data acquisition systems. Some of these functions are implemented using the same code in both systems. The solicitation and acceptance of operator control input is emphasized. Those operations not under user control are explained.

  6. 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.

  7. Ultrasonic techniques for aircraft ice accretion measurement

    NASA Technical Reports Server (NTRS)

    Hansman, R. John, Jr.; Kirby, Mark S.; Lichtenfelts, Fred

    1990-01-01

    Results of tests to measure ice growth in natural (flight) and artificial (icing wind tunnel) icing conditions are presented. Ice thickness is measured using an ultrasonic pulse-echo technique. Two icing regimes, wet and dry ice growth, are identified and the unique ultrasonic signal characteristics associated with these different types of ice growth are described. Ultrasonic measurements of ice growth on cylinders and airfoils exposed to artificial and natural icing conditions are presented. An accuracy of plus or minus 0.5 mm is achieved for ice thickness measurement using the pulse-echo technique. The performance of two-probe type ice detectors is compared to the surface mounted ultrasonic system. The ultrasonically measured ice accretion rates and ice surface condition (wet or dry) are used to compare the heat transfer characteristics for flight and icing wind tunnel environments. In general the heat transfer coefficient is inferred to be higher in the wind tunnel environment, not likely due to higher freestream turbulence levels. Finally, preliminary results of tests to measure ice growth on airfoil using an array of ultrasonic transducers are described. Ice profiles obtained during flight in natural icing conditions are shown and compared with mechanical and stereo image measurements.

  8. Transmission electron microscopy studying of structural features of NiTi B2 phase formed under pulsed electron-beam impact

    NASA Astrophysics Data System (ADS)

    Meisner, Ludmila L.; Neiman, Alexey A.; Lotkov, Alexander I.; Koval, Nikolai N.; Semin, Viktor O.; Ostapenko, Marina G.; Gudimova, Ekaterina Y.; Teresov, Anton D.

    2015-10-01

    By transmission electron microscopy method the evolution of structural-phase states on a depth of close to equiatomic NiTi modified layer has been studied. Modification performed by pulse impact on its surface low-energy high-current electron beam (beam energy density 10 J/sm2, 10 pulses, pulse duration 50mks). It is established that during the treatment in the layer thickness of 8-10 ?m, the melting of primary B2 phase and contained therein as Ti2Ni phase particles occurs. The result is change in the concentration ratio of titanium and nickel in the direction of increasing titanium content, which was confirmed by X-ray analysis in the form of increased unit cell parameter B2 phase. Analysis of the electron diffraction pattern showed that the modified layer is characterized as a highly distorted structure on the basis of bcc lattice. Lattice distortions are maximal near the surface and extends to a depth of melt. In subjacent layer there is gradual decline lattice distortions is observed.

  9. 326 ieee transactions on ultrasonics, ferroelectrics, and frequency control, vol. 52, no. 2, february 2005 Capacitive Micromachined Ultrasonic

    E-print Network

    Khuri-Yakub, Butrus T. "Pierre"

    , february 2005 Capacitive Micromachined Ultrasonic Transducer Design for High Power Transmission Baris. Introduction Capacitive micromachined ultrasonic transducers (cMUTs) emerged as an alternative to piezoelectric¨om, Goksen G. Yaralioglu, Member, IEEE, and Butrus T. Khuri-Yakub, Fellow, IEEE Abstract--Capacitive

  10. Assessment and Calibration of a Crimp Tool Equipped with Ultrasonic Analysis Features

    NASA Technical Reports Server (NTRS)

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

    2013-01-01

    A method is provided for calibrating ultrasonic signals passed through a crimp formed with respect to a deformable body via an ultrasonically-equipped crimp tool (UECT). The UECT verifies a crimp quality using the ultrasonic signals. The method includes forming the crimp, transmitting a first signal, e.g., a pulse, to a first transducer of the UECT, and converting the first signal, using the first transducer, into a second signal which defines an ultrasonic pulse. This pulse is transmitted through the UECT into the crimp. A second transducer converts the second signal into a third signal, which may be further conditioned, and the ultrasonic signals are calibrated using the third signal or its conditioned variant. An apparatus for calibrating the ultrasonic signals includes a pulse module (PM) electrically connected to the first and second transducers, and an oscilloscope or display electrically connected to the PM for analyzing an electrical output signal therefrom.

  11. Noncontact Acousto-Ultrasonics for Material Characterization

    NASA Technical Reports Server (NTRS)

    Kautz, Harold E.

    1998-01-01

    A NdYAG 1064 nm, laser pulse was employed to produce ultrasonic waves in specimens of SiC/SiC and SiC/Ti 6-4 composites which are high temperature materials of interest for aerospace applications. Air coupled transducers were used to detect and collect the signals used for acousto-ultrasonic analysis. Conditions for detecting ultrasonic decay signals were examined. The results were compared to those determined on the same specimens with contact coupling. Some non-contact measurements were made employing conventional air focused detectors. Others were performed with a more novel micromachined capacitance transducer. Concerns of the laser-in technology include potential destructiveness of the laser pulse. Repeated laser pulsing at the same location does lead to deterioration of the ultrasonic signal in some materials, but seems to recover with time. Also, unlike contact AU, the frequency regime employed is a function of laser-material interaction rather than the choice of transducers. Concerns of the air coupled-out technology include the effect of air attenuation. This imposes a practical upper limit to frequency of detection. In the case of the experimental specimens studied ultrasonic decay signals could be imaged satisfactorily.

  12. Ultrasonic hydrometer

    SciTech Connect

    Swoboda, C.A.

    1984-04-17

    The disclosed ultrasonic hydrometer determines the specific gravity (density) of the electrolyte of a wet battery, such as a lead-acid battery. The hydrometer utilizes a transducer that when excited emits an ultrasonic impulse that traverses through the electrolyte back and forth between spaced sonic surfaces. The transducer detects the returning impulse, and means measures the time ''t'' between the initial and returning impulses. Considering the distance ''d'' between the spaced sonic surfaces and the measured time ''t'', the sonic velocity ''V'' is calculated with the equation ''V=2d/t''. The hydrometer also utilizes a thermocouple to measure the electrolyte temperature. A hydrometer database correlates three variable parameters including sonic velocity in and temperature and specific gravity of the electrolyte, for temperature values between 0/sup 0/ and 40/sup 0/ C. and for specific gravity values between 1.05 and 1.30. Upon knowing two parameters (the calculated sonic velocity and the measured temperature), the third parameter (specific gravity) can be uniquely found in the database. The hydrometer utilizes a microprocessor for data storage and manipulation. The disclosed modified battery has a hollow spacer nub on the battery side wall, the sonic surfaces being on the inside of the nub and the electrolyte filling between the surfaces to the exclusion of intervening structure. An accessible pad exposed on the nub wall opposite one sonic surface allows the reliable placement thereagainst of the transducer.

  13. Ultrasonic hydrometer

    DOEpatents

    Swoboda, Carl A. (Naperville, IL)

    1984-01-01

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

  14. Design of polarizers for a mega-watt long-pulse millimeter-wave transmission line on the large helical device

    SciTech Connect

    Ii, T. Kubo, S.; Shimozuma, T.; Kobayashi, S.; Okada, K.; Yoshimura, Y.; Igami, H.; Takahashi, H.; Ito, S.; Mizuno, Y.; Okada, K.; Mutoh, T.; Makino, R.; Kobayashi, K.; Goto, Y.

    2015-02-15

    The polarizer is one of the critical components in a high-power millimeter-wave transmission line. It requires full and highly efficient coverage of any polarization states, high-power tolerance, and low-loss feature. Polarizers with rounded shape at the edge of the periodic groove surface are designed and fabricated by the machining process for a mega-watt long-pulse millimeter-wave transmission line of the electron cyclotron resonance heating system in the large helical device. The groove shape of ?/8- and ?/4-type polarizers for an 82.7 GHz transmission line is optimally designed in an integral method developed in the vector theories of diffraction gratings so that the efficiency to realize any polarization state can be maximized. The dependence of the polarization states on the combination of the two polarizer rotation angles (?{sub ?/8}, ?{sub ?/4}) is examined experimentally in a low-power test with the newly developed polarization monitor. The results show that the measured polarization characteristics are in good agreement with the calculated ones.

  15. Calibration method for an ultrasonic gray-scale recorder

    NASA Technical Reports Server (NTRS)

    Moorhead, P. E.

    1978-01-01

    Calibrated method for ultrasonic C-scanning is based on direct correlation of gray-scale response to electronic signal used. In procedure, optical density of reference recording is measured to generate curve of reflective intensity versus transmission.

  16. An ultrasonic plethysmograph for space flight applications

    NASA Technical Reports Server (NTRS)

    Bhagat, P. K.; Lafferty, J. F.; Bowman, D.; Kadaba, M. P.

    1980-01-01

    The development of an ultrasonic plethysmograph based on the transit time measurement principle is reported, which meets the space-imposed requirements for evaluating cardiovascular deconditioning. It consists of a pulse generator, pulse receiver amplifier, voltage comparator, synchronous pulse generator, elapsed time counter, and transmit and receive piezoelectric crystals resonant at 2 MHz and of 3 mm diameter. The transit time for an ultrasonic pulse to propagate across a limb cross section is computed in a digital fashion using a 32 MHz clock, and resolution is 0.049 mm with the range being approximately 200 mm. Experimental results regarding dynamic system response were found comparable in both accuracy and sensitivity to those of a Whitney strain gage using a 50 torr venous occlusion.

  17. Wire Crimp Termination Verification Using Ultrasonic Inspection

    NASA Technical Reports Server (NTRS)

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

    2007-01-01

    The development of a new ultrasonic measurement technique to quantitatively assess wire crimp terminations is discussed. The amplitude change of a compressional ultrasonic wave propagating through the junction of a crimp termination and wire is shown to correlate with the results of a destructive pull test, which is a standard for assessing crimp wire junction quality. Various crimp junction pathologies such as undercrimping, missing wire strands, incomplete wire insertion, partial insulation removal, and incorrect wire gauge are ultrasonically tested, and their results are correlated with pull tests. Results show that the nondestructive ultrasonic measurement technique consistently (as evidenced with destructive testing) predicts good crimps when ultrasonic transmission is above a certain threshold amplitude level. A physics-based model, solved by finite element analysis, describes the compressional ultrasonic wave propagation through the junction during the crimping process. This model is in agreement within 6% of the ultrasonic measurements. A prototype instrument for applying this technique while wire crimps are installed is also presented. The instrument is based on a two-jaw type crimp tool suitable for butt-splice type connections. Finally, an approach for application to multipin indenter type crimps will be discussed.

  18. 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 ?m 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.

  19. Numerical simulation of ultrasonic tomography inspections of highly heterogeneous materials

    NASA Astrophysics Data System (ADS)

    Molero, M.; Medina, L.; Lluveras, D.; Izquierdo, M. A. G.; Anaya, J. J.

    2012-12-01

    This paper deals with the simulation of ultrasonic transmission tomography systems in water-immersed to nondestructively inspect highly heterogeneous materials with fractures. The time-domain Elastodynamic Finite Integration Technique (EFIT) was employed for all numerical simulations because is able to reliably simulate this type of ultrasonic problems. The EFIT code was implemented using OpenCL and PyOpenCL. Several ultrasonic tomography inspection setups were numerically simulated under different conditions varying the number of ultrasonic sources and their size and number and different operation schemes. Sinograms of concrete scenarios were computed and compared for each configuration, using homogeneous materials with similar fracture types and experimentally validated.

  20. Federal technology alert: Ultrasonic humidifiers

    SciTech Connect

    1998-11-01

    Humidifiers are used in buildings to maintain humidity levels to ensure quality and handling capabilities in manufacturing processes, to lower the transmission rate of disease-causing bacteria in hospitals, to reduce static electricity in manufacturing clean rooms and in computer rooms, and to provide higher levels of employee comfort in offices. Ultrasonic humidifiers generate a water mist without raising its temperature. An electronic oscillation is converted to a mechanical oscillation using a piezo disk immersed in a reservoir of mineral-free water. The mechanical oscillation is directed at the surface of the water, where at very high frequencies it creates a very fine mist of water droplets. This adiabatic process, which does not heat the supply water, reduces humidifier energy use by 90 to 93% compared with systems that do boil the water. Ultrasonic humidifiers have been demonstrated to be more efficient and to require less maintenance than competing humidifier technologies such as electrode canisters, quartz lamps, and indirect steam-to-steam. They do not require anticorrosive additives that affect the indoor air quality of buildings using direct steam humidifiers. There are two potential disadvantages of ultrasonic humidifiers. They must use mineral-free, deionized water or water treated with reverse osmosis. Treated water reduces maintenance costs because it eliminates calcium deposits, but increases other operating costs. Also, the cool mist from ultrasonic humidifiers absorbs energy from the supply air as it evaporates and provides a secondary cooling effect.

  1. Electrochemical 'bubble swarm' enhancement of ultrasonic surface cleaning.

    PubMed

    Birkin, P R; Offin, D G; Vian, C J B; Leighton, T G

    2015-09-01

    An investigation of surface cleaning using a swarm of gas bubbles within an acoustically activated stream is presented. Electrolysis of water at Pt microwires (100 ?m diameter) to produce both hydrogen and oxygen bubbles is shown to enhance the extent of ultrasonic surface cleaning in a free flowing water stream containing an electrolyte (0.1 M Na2SO4) and low surfactant concentration (2 mM SDS). The surfactant was employed to allow control of the average size of the bubble population within the swarm. The electrochemical bubble swarm (EBS) is shown to perturb acoustic transmission through the stream. To optimise the cleaning process both the ultrasonic field and the electrochemical current are pulsed and synchronized but with different duty cycles. Cleaning action is demonstrated on structured surfaces (porcine skin and finger mimics) loaded with fluorescent particles. This action is shown to be significantly enhanced compared to that found with an inherent bubble population produced by the flow and acoustic regime alone under the same conditions. PMID:26234563

  2. Measuring Thicknesses With In Situ Ultrasonic Transducers

    NASA Technical Reports Server (NTRS)

    Dunn, Daniel E.; Cerino, Joseph R.

    1995-01-01

    Several pulsed ultrasonic transducers attached to workpiece for measurement of changes in thicknesses of workpiece at transducer locations during grinding and polishing, according to proposal. Once attached, each transducer remains attached at original position until all grinding and polishing operations complete. In typical application, workpiece glass or ceramic blank destined to become component of optical system.

  3. Prototype ultrasonic instrument for quantitative testing

    NASA Technical Reports Server (NTRS)

    Lynworth, L. C.; Dubois, J. L.; Kranz, P. R.

    1973-01-01

    Ultrasonic instrument has been developed for use in quantitative nondestructive evaluation of material defects such as cracks, voids, inclusions, and unbonds. Instrument is provided with standard pulse source and transducer for each frequency range selected and includes integral aids that allow calibration to prescribed standards.

  4. Pulse stretcher

    DOEpatents

    Horton, J.A.

    1994-05-03

    Apparatus for increasing the length of a laser pulse to reduce its peak power without substantial loss in the average power of the pulse is disclosed. The apparatus uses a White cell having a plurality of optical delay paths of successively increasing number of passes between the field mirror and the objective mirrors. A pulse from a laser travels through a multi-leg reflective path between a beam splitter and a totally reflective mirror to the laser output. The laser pulse is also simultaneously injected through the beam splitter to the input mirrors of the optical delay paths. The pulses from the output mirrors of the optical delay paths go simultaneously to the laser output and to the input mirrors of the longer optical delay paths. The beam splitter is 50% reflective and 50% transmissive to provide equal attenuation of all of the pulses at the laser output. 6 figures.

  5. Ultrasonic analysis of bolt preloads

    NASA Technical Reports Server (NTRS)

    Rollins, F. R., Jr.

    1977-01-01

    This paper covers an investigation into the feasibility of analyzing bolt preloads by ultrasonic techniques. Various techniques were evaluated and a pulse echo inteferometric method was selected for experimental testing. In agreement with theoretical predictions, the interferometer response was found to be linearly related to tensile stresses oriented parallel to the bolt axis. Under rather idealized conditions, bolt loads can be determined with errors of less than 1%. The ultimate operational accuracy depends on a number of variables, such as bolt dimensions and geometry, bolt temperature, uniformity of stresses, and bolt materials, but load analyses to within + or - 3% are readily achievable. Best results are obtained with the ultrasonic transducer contact coupled to a small flat area near the center of the bolt head. The transducer can be applied and measurements made without interfering with normal wrenching operations. Prototype instrumentation is described and calibration results are tabulated for numerous bolt sizes and materials.

  6. Effective ultrasonication process for better colloidal dispersion of nanofluid.

    PubMed

    Mahbubul, I M; Saidur, R; Amalina, M A; Elcioglu, E B; Okutucu-Ozyurt, T

    2015-09-01

    Improving dispersion stability of nanofluids through ultrasonication has been shown to be effective. Determining specific conditions of ultrasonication for a certain nanofluid is necessary. For this purpose, nanofluids of varying nanoparticle concentrations were prepared and studied to find out a suitable and rather mono-dispersed concentration (i.e., 0.5 vol.%, determined through transmission electron microscopy (TEM) analyses). This study aims to report applicable ultrasonication conditions for the dispersion of Al2O3 nanoparticles within H2O through the two-step production method. The prepared samples were ultrasonicated via an ultrasonic horn for 1-5h at two different amplitudes (25% and 50%). The microstructure, particle size distribution (PSD), and zeta potentials were analyzed to investigate the dispersion characteristics. Better particle dispersion, smaller aggregate sizes, and higher zeta potentials were observed at 3 and 5h of ultrasonication duration for the 50% and 25% of sonicator power amplitudes, respectively. PMID:25616639

  7. Ultrasonic position and velocity measurement for a moving object by M-sequence pulse compression using Doppler velocity estimation by spectrum-pattern analysis

    NASA Astrophysics Data System (ADS)

    Ikari, Yohei; Hirata, Shinnosuke; Hachiya, Hiroyuki

    2015-07-01

    Pulse compression using a maximum-length sequence (M-sequence) can improve the signal-to-noise ratio (SNR) of the reflected echo in the pulse-echo method. In the case of a moving object, however, the echo is modulated owing to the Doppler effect. The Doppler-shifted M-sequence-modulated signal cannot be correlated with the reference signal that corresponds to the transmitted M-sequence-modulated signal. Therefore, Doppler velocity estimation by spectrum-pattern analysis of a cyclic M-sequence-modulated signal and cross correlations with Doppler-shifted reference signals that correspond to the estimated Doppler velocities has been proposed. In this paper, measurements of the position and velocity of a moving object by the proposed method are described. First, Doppler velocities of the object are estimated using a microphone array. Secondly, the received signal from each microphone is correlated with each Doppler-shifted reference signal. Then, the position of the object is determined from the B-mode image formed from all cross-correlation functions. After that, the velocity of the object is calculated from velocity components estimated from the Doppler velocities and the position. Finally, the estimated Doppler velocities, determined positions, and calculated velocities are evaluated.

  8. System and method for ultrasonic tomography

    DOEpatents

    Haddad, Waleed Sami (Dublin, CA)

    2002-01-01

    A system and method for doing both transmission mode and reflection mode three-dimensional ultrasonic imagining. The multimode imaging capability may be used to provide enhanced detectability of cancer tumors within human breast, however, similar imaging systems are applicable to a number of other medical problems as well as a variety of non-medical problems in non-destructive evaluation (NDE).

  9. The quasi-harmonic ultrasonic polar scan for material characterization: experiment and numerical modeling.

    PubMed

    Kersemans, Mathias; Martens, Arvid; Van Den Abeele, Koen; Degrieck, Joris; Pyl, Lincy; Zastavnik, Filip; Sol, Hugo; Van Paepegem, Wim

    2015-04-01

    Conventionally, the ultrasonic polar scan (UPS) records the amplitude or time-of-flight in transmission using short ultrasonic pulses for a wide range of incidence angles, resulting in a fingerprint of the critical bulk wave angles of the material at the insonified spot. Here, we investigate the use of quasi-harmonic ultrasound (bursts) in a polar scan experiment, both experimentally and numerically. It is shown that the nature of the fingerprint drastically changes, and reveals the positions of the leaky Lamb angles. To compare with experiments, both plane wave and bounded beam simulations have been performed based on the recursive stiffness matrix method. Whereas the plane wave computations yield a pure Lamb wave angle fingerprint, this is no longer valid for the more realistic case of a bounded beam. The experimental recordings are fully supported by the bounded beam simulations. To complement the traditional amplitude measurement, experimental and numerical investigations have been performed to record, predict and analyze the phase of the transmitted ultrasonic beam. This results in the conceptual introduction of the 'phase polar scan', exposing even more intriguing and detailed patterns. In fact, the combination of the amplitude and the phase polar scan provides the complete knowledge about the complex transmission coefficient for every possible angle of incidence. This comprehensive information will be very valuable for inverse modeling of the local elasticity tensor based on a single UPS experiment. Finally, the UPS method has been applied for the detection of an artificial delamination. Compared to the pulsed UPS, the quasi-harmonic UPS (both the amplitude and phase recording) shows a superior sensitivity to the presence of a delamination. PMID:25620710

  10. An adaptive neuro fuzzy inference system controlled space cector pulse width modulation based HVDC light transmission system under AC fault conditions

    NASA Astrophysics Data System (ADS)

    Ajay Kumar, M.; Srikanth, N.

    2014-03-01

    In HVDC Light transmission systems, converter control is one of the major fields of present day research works. In this paper, fuzzy logic controller is utilized for controlling both the converters of the space vector pulse width modulation (SVPWM) based HVDC Light transmission systems. Due to its complexity in the rule base formation, an intelligent controller known as adaptive neuro fuzzy inference system (ANFIS) controller is also introduced in this paper. The proposed ANFIS controller changes the PI gains automatically for different operating conditions. A hybrid learning method which combines and exploits the best features of both the back propagation algorithm and least square estimation method is used to train the 5-layer ANFIS controller. The performance of the proposed ANFIS controller is compared and validated with the fuzzy logic controller and also with the fixed gain conventional PI controller. The simulations are carried out in the MATLAB/SIMULINK environment. The results reveal that the proposed ANFIS controller is reducing power fluctuations at both the converters. It also improves the dynamic performance of the test power system effectively when tested for various ac fault conditions.

  11. Modeling of ultrasonic processing

    E-print Network

    Zhao, Wenguang, S.M. Massachusetts Institute of Technology

    2005-01-01

    This paper presents a finite element analysis (FEA) of ultrasonic processing of an aerospace-grade carbon-epoxy composite laminate. An ultrasonic (approximately 30 kHz) loading horn is applied to a small region at the ...

  12. Ultrasonic imaging techniques for breast cancer detection.

    SciTech Connect

    Goulding, N. R.; Marquez, J. D.; Prewett, E. M.; Claytor, T. N.; Nadler, B. R.; Huang, L.

    2006-01-01

    Improving the resolution and specificity of current ultrasonic imaging technology can enhance its relevance to detection of early-stage breast cancers. Ultrasonic evaluation of breast lesions is desirable because it is quick, inexpensive, and does not expose the patient to potentially harmful ionizing radiation. Improved image quality and resolution enables earlier detection and more accurate diagnoses of tumors, thus reducing the number of biopsies performed, increasing treatment options, and lowering mortality, morbidity, and remission percentages. In this work, a novel ultrasonic imaging reconstruction method that exploits straight-ray migration is described. This technique, commonly used in seismic imaging, accounts for scattering more accurately than standard ultrasonic approaches, thus providing superior image resolution. A breast phantom with various inclusions is imaged using a pulse-echo approach. The data are processed using the ultrasonic migration method and results are compared to standard linear ultrasound and to x-ray computed tomography (CT) scans. For an ultrasonic frequency of 2.25 MHz, imaged inclusions and features of approximately 1mm are resolved, although better resolution is expected with minor modifications. Refinement of this application using other imaging techniques such as time-reversal mirrors (TRM), synthetic aperture focusing technique (SAFT), decomposition of the time reversal operator (DORT), and factorization methods is also briefly discussed.

  13. Ultrasonic and mechanical characterizations of fatigue states of graphite epoxy composite laminates

    NASA Technical Reports Server (NTRS)

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

    1982-01-01

    Results of an exploration of the relationship between ultrasonic attenuation and fatigue survivability of graphite fiber epoxy composites fabricated under different cure conditions are reported. A total of 9 27 x 40 cm eight-ply graphite epoxy laminated specimens were formed, and fatigue tests were run on five partial samples at 73.5 N varying at 30 Hz, with tests ending at a 1.27 cm deflection. A pulsed oscillator generated sinusoidal waves and transducers recorded the passage of the ultrasonic waves for display on oscilloscopes. Cure pressures ranged from 0.52-0.85 MPa and cure temperatures were in the 150-200 C interval. Ultrasonic through-transmission at 4 MHz was performed prior to and during fatigue testing. The minimum void volume fraction occurred at 175 C and 0.86 MPa. The flexural stiffness decreased with the number of fatigue cycles past 10,000, when the attenuation also increased. Correlations were found between the 4.0 MHz signal attenuation and the void volume fraction, and between the number of fatigue cycles to failure and the 4.0 MHz signal attenuation.

  14. Analysis of microcracks in dry polycrystalline NaCl by ultrasonic signal processing

    SciTech Connect

    Sears, F.M.

    1980-07-01

    The attenuation of energy and the change in shape of transient waveforms is a basic feature associated with the propagation of waves in crustal rocks. The dimensionless quality factor Q is observed as a useful quantity to characterize the attenuation of energy. Existing an elastic (attenuation) theories on the Q-determination problem are compared with experimental measurements to better understand rock properties. Experimental attenuation measurements were made on Avery Island (Louisiana) rock salt, Westerly (Rhode Island) granite, and Creighton (Ontario) quartz biotite gabbro. The attenuation mechanisms and how they affect the agreement between the an elastic theories were examined. Ultrasonic pulse methods were utilized of examine crack geometries as a function of frequency and thermal cycling temperature in dry polycrystalline rock salt. The attenuation of compressional (P) and shear (S) waves was studied in a thermally-induced, isotropic distribution of microcracks using ultrasonic-transmission techniques. These attenuation measurements led to the following series of generalities: ultrasonic or seismic attenuation depends on frequency in the rocks tested; thermal cycling of rock salt increases the porosity and attenuation; grain scattering seems to be the dominant loss mechanism at the higher frequencies in rocks; friction explains why the introduction of cracks into rock salt increases the attenuation; and attenuation appears to be independent of strain amplitude for low strains (10/sup -6/) such as those associated with these measurements. Much work remains to be done to adequately describe the attenuation loss mechanisms and the an elasticity of rocks both experimentally and theoretically.

  15. PHASEBASED ULTRASONIC DEFORMATION ESTIMATION

    E-print Network

    Drummond, Tom

    PHASE­BASED ULTRASONIC DEFORMATION ESTIMATION J. E. Lindop, G. M. Treece, A. H. Gee and R. W Cambridge CB2 1PZ United Kingdom Email: jel35/gmt11/ahg/rwp @eng.cam.ac.uk #12; PHASE­BASED ULTRASONIC theoretical analysis and experimental results for an inves­ tigation of phase­based ultrasonic deformation

  16. Autonomous data transmission apparatus

    DOEpatents

    Kotlyar, Oleg M. (4675 W. 3825 S, Salt Lake City, UT 84120)

    1997-01-01

    A autonomous borehole data transmission apparatus for transmitting measurement data from measuring instruments at the downhole end of a drill string by generating pressure pulses utilizing a transducer longitudinally responsive to magnetic field pulses caused by electrical pulses corresponding to the measured downhole parameters.

  17. Autonomous data transmission apparatus

    DOEpatents

    Kotlyar, O.M.

    1997-03-25

    A autonomous borehole data transmission apparatus is described for transmitting measurement data from measuring instruments at the downhole end of a drill string by generating pressure pulses utilizing a transducer longitudinally responsive to magnetic field pulses caused by electrical pulses corresponding to the measured downhole parameters. 4 figs.

  18. 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. PMID:26206527

  19. Design of embedded endoscopic ultrasonic imaging system

    NASA Astrophysics Data System (ADS)

    Li, Ming; Zhou, Hao; Wen, Shijie; Chen, Xiodong; Yu, Daoyin

    2008-12-01

    Endoscopic ultrasonic imaging system is an important component in the endoscopic ultrasonography system (EUS). Through the ultrasonic probe, the characteristics of the fault histology features of digestive organs is detected by EUS, and then received by the reception circuit which making up of amplifying, gain compensation, filtering and A/D converter circuit, in the form of ultrasonic echo. Endoscopic ultrasonic imaging system is the back-end processing system of the EUS, with the function of receiving digital ultrasonic echo modulated by the digestive tract wall from the reception circuit, acquiring and showing the fault histology features in the form of image and characteristic data after digital signal processing, such as demodulation, etc. Traditional endoscopic ultrasonic imaging systems are mainly based on image acquisition and processing chips, which connecting to personal computer with USB2.0 circuit, with the faults of expensive, complicated structure, poor portability, and difficult to popularize. To against the shortcomings above, this paper presents the methods of digital signal acquisition and processing specially based on embedded technology with the core hardware structure of ARM and FPGA for substituting the traditional design with USB2.0 and personal computer. With built-in FIFO and dual-buffer, FPGA implement the ping-pong operation of data storage, simultaneously transferring the image data into ARM through the EBI bus by DMA function, which is controlled by ARM to carry out the purpose of high-speed transmission. The ARM system is being chosen to implement the responsibility of image display every time DMA transmission over and actualizing system control with the drivers and applications running on the embedded operating system Windows CE, which could provide a stable, safe and reliable running platform for the embedded device software. Profiting from the excellent graphical user interface (GUI) and good performance of Windows CE, we can not only clearly show 511×511 pixels ultrasonic echo images through application program, but also provide a simple and friendly operating interface with mouse and touch screen which is more convenient than the traditional endoscopic ultrasonic imaging system. Including core and peripheral circuits of FPGA and ARM, power network circuit and LCD display circuit, we designed the whole embedded system, achieving the desired purpose by implementing ultrasonic image display properly after the experimental verification, solving the problem of hugeness and complexity of the traditional endoscopic ultrasonic imaging system.

  20. Ultrasonic angle beam standard reflector. [ultrasonic nondestructive inspection

    NASA Technical Reports Server (NTRS)

    Berry, R. F., Jr. (inventor)

    1985-01-01

    A method that provides an impression profile in a reference standard material utilized in inspecting critically stressed components with pulsed ultrasound is described. A die stamp having an I letter is used to impress the surface of a reference material. The die stamp is placed against the surface and struck with an inertia imparting member to impress the I in the reference standard material. Upset may appear on the surface as a result of the impression and is removed to form a smooth surface. The stamping and upset removal is repeated until the entire surface area of a depth control platform on the die stamp uniformly contacts the material surface. The I impression profile in the reference standard material is utilized for reflecting pulsed ultrasonic beams for inspection purposes.

  1. MEASUREMENT AND DYNAMIC DISPLAY OF ACOUSTIC WAVE PULSES* J-y. Lu, T. Kinter, and J. F. Greenleaf

    E-print Network

    Lu, Jian-yu

    of an ultrasonic transducer in pulse-echo imaging, it is useful to visualize how the ultrasonic pulse travels 1989 ULTRASONICS SYMPOSIUM -673 #12;/ 1Transducer 0- mm. respectively. Each of the imageswas composed by three types of transducers: commercialPZT, air-hacked PZT, and PZT ~eramic/~ol~mercomposite. The signds

  2. Acousto-ultrasonic characterization of fiber reinforced composites

    NASA Technical Reports Server (NTRS)

    Vary, A.

    1981-01-01

    The acousto-ultrasonic technique combines advantageous aspects of acoustic emission and ultrasonic methodologies. Acousto-ultrasonics operates by introducing a repeating series of ultrasonic pulses into a material. The waves introduced simulate the spontaneous stress waves that would arise if the material were put under stress as in the case of acoustic emission measurements. These benign stress waves are detected by an acoustic emission sensor. The physical arrangement of the ultrasonic (input) transducer and acoustic emission (output) sensor is such that the resultant waveform carries an imprint of morphological factors that govern or contribute to material performance. The output waveform is complex, but it can be quantitized in terms of a 'stress wave factor.' The stress wave factor, which can be defined in a number of ways, is a relative measure of the efficiency of energy dissipation in a material. If flaws or other material anomalies exist in the volume being examined, their combined effect appears in the stress wave factor.

  3. Ultrasonic Method for Measuring Internal Temperature Profile in Heated Materials

    NASA Astrophysics Data System (ADS)

    Ihara, I.; Takahashi, M.

    2008-02-01

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

  4. High voltage pulse conditioning

    DOEpatents

    Springfield, Ray M. (Sante Fe, NM); Wheat, Jr., Robert M. (Los Alamos, NM)

    1990-01-01

    Apparatus for conditioning high voltage pulses from particle accelerators in order to shorten the rise times of the pulses. Flashover switches in the cathode stalk of the transmission line hold off conduction for a determinable period of time, reflecting the early portion of the pulses. Diodes upstream of the switches divert energy into the magnetic and electrostatic storage of the capacitance and inductance inherent to the transmission line until the switches close.

  5. Measurement of intergranular attack in stainless steel using ultrasonic energy

    DOEpatents

    Mott, Gerry (Pittsburgh, PA); Attaar, Mustan (Monroeville, PA); Rishel, Rick D. (Monroeville, PA)

    1989-08-08

    Ultrasonic test methods are used to measure the depth of intergranular attack (IGA) in a stainless steel specimen. The ultrasonic test methods include a pitch-catch surface wave technique and a through-wall pulse-echo technique. When used in combination, these techniques can establish the extent of IGA on both the front and back surfaces of a stainless steel specimen from measurements made on only one surface.

  6. Ultrasonic Nondestructive Characterization of Adhesive Bonds

    NASA Technical Reports Server (NTRS)

    Qu, Jianmin

    1999-01-01

    Adhesives and adhesive joints are widely used in various industrial applications to reduce weight and costs, and to increase reliability. For example, advances in aerospace technology have been made possible, in part, through the use of lightweight materials and weight-saving structural designs. Joints, in particular, have been and continue to be areas in which weight can be trimmed from an airframe through the use of novel attachment techniques. In order to save weight over traditional riveted designs, to avoid the introduction of stress concentrations associated with rivet holes, and to take full advantage of advanced composite materials, engineers and designers have been specifying an ever-increasing number of adhesively bonded joints for use on airframes. Nondestructive characterization for quality control and remaining life prediction has been a key enabling technology for the effective use of adhesive joints. Conventional linear ultrasonic techniques generally can only detect flaws (delamination, cracks, voids, etc) in the joint assembly. However, more important to structural reliability is the bond strength. Although strength, in principle, cannot be measured nondestructively, a slight change in material nonlinearity may indicate the onset of failure. Furthermore, microstructural variations due to aging or under-curing may also cause changes in the third order elastic constants, which are related to the ultrasonic nonlinear parameter of the polymer adhesive. It is therefore reasonable to anticipate a correlation between changes in the ultrasonic nonlinear acoustic parameter and the remaining bond strength. It has been observed that higher harmonics of the fundamental frequency are generated when an ultrasonic wave passes through a nonlinear material. It seems that such nonlinearity can be effectively used to characterize bond strength. Several theories have been developed to model this nonlinear effect. Based on a microscopic description of the nonlinear interface binding force, a quantitative method was presented. Recently, a comparison between the experimental and simulated results based on a similar theoretical model was presented. A through-transmission setup for water immersion mode-converted shear waves was used to analyze the ultrasonic nonlinear parameter of an adhesive bond. In addition, ultrasonic guided waves have been used to analyze adhesive or diffusion bonded joints. In this paper, the ultrasonic nonlinear parameter is used to characterize the curing state of a polymer/aluminum adhesive joint. Ultrasonic through-transmission tests were conducted on samples cured under various conditions. The magnitude of the second order harmonic was measured and the corresponding ultrasonic nonlinear parameter was evaluated. A fairly good correlation between the curing condition and the nonlinear parameter is observed. The results show that the nonlinear parameter might be used as a good indicator of the cure state for adhesive joints.

  7. Thermogenesis During Ultrasonic Vocalization by

    E-print Network

    Thermogenesis During Ultrasonic Vocalization by Rat Pups Isolated in a Warm Environment University Bloomington, Indiana Ultrasonic vocalizations, emitted by rat pups when separated from nervous and systemic structures during cold exposure (Smith, 1964). The 40 kHz ultrasonic vocalization

  8. Sparsely Sampled Phase-Insensitive Ultrasonic Transducer Arrays

    NASA Technical Reports Server (NTRS)

    Johnston, Patrick H.

    1992-01-01

    Three methods of interpretation of outputs from sparsely sampled two-dimensional array of receiving ultrasonic transducers used in transmission experiments investigated. Methods are: description of sampled beam in terms of first few spatial moments of sampled distribution of energy; use of signal-dependent cutoff to limit extent of effective receiver aperture; and use of spatial interpolation to increase apparent density of sampling during computation. Methods reduce errors in computations of shapes of ultrasonic beams.

  9. Continuous Ultrasonic Inspection of Extruded Wood-Plastic Composites

    SciTech Connect

    Tucker, Brian J. ); Bender, Donald A.

    2003-06-19

    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 angled 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.

  10. Wedges for ultrasonic inspection

    DOEpatents

    Gavin, Donald A. (Rexford, NY)

    1982-01-01

    An ultrasonic transducer device is provided which is used in ultrasonic inspection of the material surrounding a threaded hole and which comprises a wedge of plastic or the like including a curved threaded surface adapted to be screwed into the threaded hole and a generally planar surface on which a conventional ultrasonic transducer is mounted. The plastic wedge can be rotated within the threaded hole to inspect for flaws in the material surrounding the threaded hole.

  11. Sonochemical Effect Using Ultrasonic Atomizer at 2.4 MHz

    NASA Astrophysics Data System (ADS)

    Shinashi, Kiyoaki; Houkin, Toshinori; Harada, Hisashi

    2012-07-01

    Sonochemical reactions were demonstrated using a commercial ultrasonic atomizer at 2.4 MHz. The influences of experimental conditions, bottom shape and glass thickness of reactors, irradiation method, and liquid height on the sonochemical yield were discussed. The sonochemical effect was evaluated by potassium iodide dosimetry and degradation of methylene blue. Direct and indirect irradiations were examined. The former had the highest yield. In the latter case, sonochemical yield decreased in the solution because glass prevented the transmission of ultrasonic waves. Poly film, on the other hand, could transmit ultrasonic waves very well without damage.

  12. High resolution in situ ultrasonic corrosion monitor

    DOEpatents

    Grossman, Robert J. (Schenectady, NY)

    1985-01-01

    An ultrasonic corrosion monitor is provided which produces an in situ measurement of the amount of corrosion of a monitoring zone or zones of an elongate probe placed in the corrosive environment. A monitoring zone is preferably formed between the end of the probe and the junction of the zone with a lead-in portion of the probe. Ultrasonic pulses are applied to the probe and a determination made of the time interval between pulses reflected from the end of the probe and the junction referred to, both when the probe is uncorroded and while it is corroding. Corresponding electrical signals are produced and a value for the normalized transit time delay derived from these time interval measurements is used to calculate the amount of corrosion.

  13. High resolution in situ ultrasonic corrosion monitor

    DOEpatents

    Grossman, R.J.

    1984-01-10

    An ultrasonic corrosion monitor is provided which produces an in situ measurement of the amount of corrosion of a monitoring zone or zones of an elongate probe placed in the corrosive environment. A monitoring zone is preferably formed between the end of the probe and the junction of the zone with a lead-in portion of the probe. Ultrasonic pulses are applied to the probe and a determination made of the time interval between pulses reflected from the end of the probe and the junction referred to, both when the probe is uncorroded and while it is corroding. Corresponding electrical signals are produced and a value for the normalized transit time delay derived from these time interval measurements is used to calculate the amount of corrosion.

  14. High temperature immersion type ultrasonic imaging probes

    NASA Astrophysics Data System (ADS)

    Rehman, A.-U.; Jen, C.-K.; Ihara, I.

    2001-04-01

    Ultrasonic probes for high temperature measurements in immersion are presented. These probes consist of piezoelectric transducers and buffer rods, are operated in the pulse-echo mode. The operating temperature is up to 215 °C and there is no need for a cooling system. For imaging purposes, one end of the clad buffer rod is attached with a piezoelectric transducer and the other end is machined into a semi-spherical concave shape that provides the focus. The operating frequency is 5 MHz. Ultrasonic images produced using mechanical raster scan and the measurements, when the probes are fully immersed in silicone oil at elevated temperatures, are presented. The importance of the signal-to-noise ratio in the pulse-echo measurement is discussed.

  15. Ultrasonic probes for high temperature immersion measurements

    NASA Astrophysics Data System (ADS)

    Rehman, A.-U.; Jen, C.-K.; Ihara, I.

    2001-03-01

    Ultrasonic probes for high temperature measurements in immersion are presented. These probes consist of piezoelectric transducers and buffer rods, and may be operated in the pulse echo mode. The probes can operate to temperatures as high as 215 °C without requiring a cooling system. For imaging purposes, one end of the clad buffer rod is machined into a semi-spherical concave shape, of which the purpose is to focus the ultrasound. The operating frequency is between 5 and 9 MHz. Ultrasonic images, produced using a mechanical raster scan with the probes fully immersed in silicone oil at elevated temperatures, are presented. The importance of the signal-to-noise ratio in the pulse-echo measurement is discussed.

  16. Ultrasonic Bolt Gage

    NASA Technical Reports Server (NTRS)

    Gleman, Stuart M. (Inventor); Rowe, Geoffrey K. (Inventor)

    1999-01-01

    An ultrasonic bolt gage is described which uses a crosscorrelation algorithm to determine a tension applied to a fastener, such as a bolt. The cross-correlation analysis is preferably performed using a processor operating on a series of captured ultrasonic echo waveforms. The ultrasonic bolt gage is further described as using the captured ultrasonic echo waveforms to perform additional modes of analysis, such as feature recognition. Multiple tension data outputs, therefore, can be obtained from a single data acquisition for increased measurement reliability. In addition, one embodiment of the gage has been described as multi-channel, having a multiplexer for performing a tension analysis on one of a plurality of bolts.

  17. The 2004 Ultrasonic Benchmark Problem - SDH Response Under Oblique Incidence: Measurements and Patch Element Model Calculations

    SciTech Connect

    Krishnamurthy, C. V.; Shankar, M.; Vardhan, J. Vishnu; Balasubramaniam, Krishnan

    2006-03-06

    The 2004 ultrasonic benchmark problem requires models to predict, given a reference pulse waveform, the pulse echo response of cylindrical voids of various radii located in an elastic solid for various incidence angles of a transducer immersed in water. We present the results of calculations based on the patch element model, recently developed at CNDE, to determine the response of an SDH in aluminum for specific oblique incidence angles. Patch element model calculations for a scan across the SDH, involving a range of oblique incidence angles, are also presented. Measured pulse-echo scans involving the SDH response under oblique incidence conditions are reported. In addition, through transmission measurements involving a pinducer as a receiver and an immersion planar probe as a transmitter under oblique incidence conditions are also reported in a defect-free Aluminum block. These pinducer-based measurements on a defect-free block are utilised to characterize the fields at the chosen depth. Comparisons are made between predictions and measurements for the pulse-echo response of a SDH.

  18. Pulsed ultrasound assisted dehydration of waste oil.

    PubMed

    Xie, Wei; Li, Rui; Lu, Xiaoping

    2015-09-01

    A method to aid the separation of the oil phase from waste oil emulsion of refineries had been developed by using a pulsed ultrasonic irradiation technology. Compared with conventional continuous ultrasonic irradiation, it is found that pulsed ultrasonic irradiation is much better to make water drop coalescence and hence dehydration of waste oil. The effects of ultrasonic irradiation parameters on waste oil dehydration are further discussed. The orthogonal experiment is also designed to investigate the degrees of influence of ultrasonic parameters and the optimal technological conditions. Under the optimal experimental conditions, the water content of waste oil is decreased from 65% to 8%, which thereby satisfies the requirements of refineries on the water content of waste oil after treatment (<10%). PMID:25795000

  19. An ultrasonic method for studying elastic moduli as a function of temperature

    NASA Technical Reports Server (NTRS)

    Peterson, R. G.

    1969-01-01

    Ultrasonic method is used to determine the elastic moduli of materials used in components of high-temperature nuclear reactors. An ultrasonic, pulse-echo technique determines the velocity of sound waves propogating in a heated region of rod-shaped specimens. From these velocities, the elastic moduli are calculated.

  20. Ultrasonic Wave Propagation in Heterogeneous Media

    NASA Astrophysics Data System (ADS)

    Mulholland, Anthony J.

    2010-09-01

    Piezoelectric ultrasonic transducers typically employ composite structures to improve their transmission and reception sensitivities. The geometry of the composite is regular with one dominant length scale and, since these are resonant devices, this dictates the central operating frequency of the device. In order to construct a wide bandwidth device it would seem natural therefore to utilise resonators that span a range of length scales. In this paper we consider such a device and build a theoretical model to predict its performance. A fractal medium is used as this contains a wide range of length scales and yields to a renormalisation approach. The propagation of an ultrasonic wave in this heterogeneous medium is then analysed and used to construct expressions for the electrical impedance, and the transmission and reception sensitivities of this device as a function of the driving frequency.

  1. Ultrasonic Communication Project, Phase 1, FY1999

    SciTech Connect

    Haynes, H.D.; Akerman, M.A.; Baylor, V.M.

    2000-06-01

    This Phase 1 project has been successful in identifying, exploring, and demonstrating methods for ultrasonic-based communication with an emphasis on the application of digital signal processing techniques. During the project, at the direction of the agency project monitor, particular attention was directed at sending and receiving ultrasonic data through air and through pipes that would be commonly found in buildings. Efforts were also focused on development of a method for transmitting computer files ultrasonically. New methods were identified and evaluated for ultrasonic communication. These methods are based on a technique called DFS. With DFS, individual alphanumeric characters are broken down into a sequence of bits, and each bit is used to generate a discrete ultrasonic frequency. Characters are then transmitted one-bit-at-a-time, and reconstructed by the receiver. This technique was put into practice through the development of LabVIEW{trademark}VIs. These VIs were integrated with specially developed electronic circuits to provide a system for demonstrating the transmission and reception/reconstruction of typed messages and computer files. Tests were performed to determine the envelope for ultrasound transmission through pipes (with and without water) versus through air. The practical aspects of connections, efficient electronics, impedance matching, and the effect of damping mechanisms were all investigated. These tests resulted in a considerable number of reference charts that illustrate the absorption of ultrasound through different pipe materials, both with and without water, as a function of distance. Ultrasound was found to be least attenuated by copper pipe and most attenuated by PVC pipe. Water in the pipe provides additional damping and attenuation of ultrasonic signals. Dramatic improvements are observed, however, in ultrasound signal strength if the transducers are directly coupled to the water, rather than simply attaching them to the outside of the pipe. A major accomplishment of this project was the development and integration of hardware and software into a fully functional ultrasonic communication system for demonstration purposes. The development of this system was a major deliverable of this project and has been successfully demonstrated to the program monitor. Major system considerations are discussed in this report, including signal conditioning electronics, speed and distance of transmission, triggering and noise filtering, and error checking. The methods employed by this system are believed to be capable of transmitting information over long distances (greater than 200 ft) under ideal conditions, and under extreme conditions if several improvements are made. Several improvements are suggested as follow-on work. Brief descriptions of these activities are given.

  2. 646 ULTRASONIC PHYSICAL MECHANISMS AND CHEMICAL EFFECTS ULTRASONIC PHYSICAL MECHANISMS

    E-print Network

    Suslick, Kenneth S.

    646 ULTRASONIC PHYSICAL MECHANISMS AND CHEMICAL EFFECTS ULTRASONIC PHYSICAL MECHANISMS AND CHEMICAL. Copyright # 1999 John Wiley & Sons, Inc. #12;ULTRASONIC PHYSICAL MECHANISMS AND CHEMICAL EFFECTS 647 sion. In addition, high- velocity interparticle collisions will occur during ultrasonic ir- can be extremely violent

  3. Ultrasonic/Sonic Anchor

    NASA Technical Reports Server (NTRS)

    Bar-Cohen, Yoseph; Sherrit, Stewart

    2009-01-01

    The ultrasonic/sonic anchor (U/S anchor) is an anchoring device that drills a hole for itself in rock, concrete, or other similar material. The U/S anchor is a recent addition to a series of related devices, the first of which were reported in "Ultrasonic/Sonic Drill/Corers With Integrated Sensors"

  4. Ultrasonic corona sensor study

    NASA Technical Reports Server (NTRS)

    Harrold, R. T.

    1976-01-01

    The overall objective of this program is to determine the feasibility of using ultrasonic (above 20 kHz) corona detection techniques to detect low order (non-arcing) coronas in varying degrees of vacuum within large high vacuum test chambers, and to design, fabricate, and deliver a prototype ultrasonic corona sensor.

  5. Pulse stretcher

    DOEpatents

    Horton, James A. (Livermore, CA)

    1994-01-01

    Apparatus (20) for increasing the length of a laser pulse to reduce its peak power without substantial loss in the average power of the pulse. The apparatus (20) uses a White cell (10) having a plurality of optical delay paths (18a-18d) of successively increasing number of passes between the field mirror (13) and the objective mirrors (11 and 12). A pulse (26) from a laser (27) travels through a multi-leg reflective path (28) between a beam splitter (21) and a totally reflective mirror (24) to the laser output (37). The laser pulse (26) is also simultaneously injected through the beam splitter (21) to the input mirrors (14a-14d) of the optical delay paths (18a-18d). The pulses from the output mirrors (16a-16d) of the optical delay paths (18a-18d) go simultaneously to the laser output (37) and to the input mirrors ( 14b-14d) of the longer optical delay paths. The beam splitter (21) is 50% reflective and 50% transmissive to provide equal attenuation of all of the pulses at the laser output (37).

  6. Structure and properties of fixed joints formed by ultrasonic-assisted friction-stir welding

    NASA Astrophysics Data System (ADS)

    Fortuna, S. V.; Ivanov, K. V.; Tarasov, S. Yu.; Eliseev, A. A.; Ivanov, A. N.; Rubtsov, V. E.; Kolubaev, E. A.

    2015-10-01

    This paper deals with structure and properties of aluminum alloy 7475 and its joints obtained by friction stir welding including under ultrasonic action. Microhardness measurements show that ultrasonic action increases strength properties of the joints. Optical and transmission electron microscopy reveals that this effect is related to the precipitation of tertiary coherent S-and T-phase particles.

  7. 906 IEEE SENSORS JOURNAL, VOL. 6, NO. 4, AUGUST 2006 Adaptive Pulse Repetition Frequency Technique for

    E-print Network

    Khuri-Yakub, Butrus T. "Pierre"

    transducer (CUT), exhaust gas, high temper- ature, mass flow sensor, pulsating gas flow, ultrasonic flowmeter for an Ultrasonic Transit-Time Gas Flowmeter for Hot Pulsating Gases Mario Kupnik, Andreas Schröder, Paul O pulse repetition frequency (PRF) to operate an ultrasonic contrapropagation transit-time gas flowmeter

  8. Measurement of the spectral directivity of optoacoustic and ultrasonic transducers with a laser ultrasonic source

    PubMed Central

    Conjusteau, André; Ermilov, Sergey A.; Su, Richard; Brecht, Hans-Peter; Fronheiser, Matthew P.; Oraevsky, Alexander A.

    2009-01-01

    Comprehensive characterization of wideband ultrasonic transducers and specifically optoacoustic detectors is achieved through the analysis of their frequency response as a function of the incident angle. The tests are performed under well-defined, repeatable operating conditions. Backillumination of a blackened, acoustically matched planar surface with a short laser pulse creates an acoustic impulse which is used as a wideband ultrasonic source. Upon illumination with a short laser pulse, the bandwidth of our source shows a ?6 dB point of 12 MHz and a low-frequency roll-off around 300 kHz. Using proprietary software, we examine thoroughly the planarity of the emitted wave front within a specified amplitude cutoff and phase incoherence. Analysis of the angular dependence of the frequency response yields invaluable directivity information about the detector under study: a necessary component toward accurate optoacoustic image reconstruction and quantitative tomography. The laser ultrasonic source we developed is the main feature of our directivity measurement setup. Due to its simplicity, it can easily be adapted to various calibration devices. This paper focuses on the development and characterization of the flatness and the bandwidth of our wideband ultrasonic source. PMID:19791945

  9. Ultrasonic Digital Communication System for a Steel Wall Multipath Channel: Methods and Results

    SciTech Connect

    TL Murphy

    2006-02-16

    As of the development of this thesis, no commercially available products have been identified for the digital communication of instrumented data across a thick ({approx} 6 n.) steel wall using ultrasound. The specific goal of the current research is to investigate the application of methods for digital communication of instrumented data (i.e., temperature, voltage, etc.) across the wall of a steel pressure vessel. The acoustic transmission of data using ultrasonic transducers prevents the need to breach the wall of such a pressure vessel which could ultimately affect its safety or lifespan, or void the homogeneity of an experiment under test. Actual digital communication paradigms are introduced and implemented for the successful dissemination of data across such a wall utilizing solely an acoustic ultrasonic link. The first, dubbed the ''single-hop'' configuration, can communicate bursts of digital data one-way across the wall using the Differential Binary Phase-Shift Keying (DBPSK) modulation technique as fast as 500 bps. The second, dubbed the ''double-hop'' configuration, transmits a carrier into the vessel, modulates it, and retransmits it externally. Using a pulsed carrier with Pulse Amplitude Modulation (PAM), this technique can communicate digital data as fast as 500 bps. Using a CW carrier, Least Mean-Squared (LMS) adaptive interference suppression, and DBPSK, this method can communicate data as fast as 5 kbps. A third technique, dubbed the ''reflected-power'' configuration, communicates digital data by modulating a pulsed carrier by varying the acoustic impedance at the internal transducer-wall interface. The paradigms of the latter two configurations are believed to be unique. All modulation methods are based on the premise that the wall cannot be breached in any way and can therefore be viably implemented with power delivered wirelessly through the acoustic channel using ultrasound. Methods, results, and considerations for future research are discussed herein.

  10. Method for the concurrent ultrasonic inspection of partially completed welds

    SciTech Connect

    Johnson, John A.; Larsen, Eric D.; Miller, Karen S.; Smartt, Herschel B.; McJunkin, Timothy R.

    2002-01-01

    A method for the concurrent ultrasonic inspection of partially completed welds is disclosed and which includes providing a pair of transducers which are individually positioned on the opposite sides of a partially completed weld to be inspected; moving the transducers along the length of and laterally inwardly and outwardly relative to the partially completed weld; pulsing the respective transducers to produce an ultrasonic signal which passes through or is reflected from the partially completed weld; receiving from the respective transducers ultrasonic signals which pass through or are reflected from the partially completed welds; and analyzing the ultrasonic signal which has passed through or is reflected from the partially completed weld to determine the presence of any weld defects.

  11. Ultrasonic wave propagation through a layer of spherical inclusions with random of periodic arrangements 

    E-print Network

    Day, Nathan Allan

    1994-01-01

    This thesis presents experimental results obtained by examining ultrasonic wave propagation through a layer of spherical lead inclusions embedded in a polyester matrix. Through transmission tests were conducted on several area fractions...

  12. Ultrasonic Imaging Techniques for Breast Cancer Detection

    NASA Astrophysics Data System (ADS)

    Goulding, N. R.; Marquez, J. D.; Prewett, E. M.; Claytor, T. N.; Nadler, B. R.

    2008-02-01

    Improving the resolution and specificity of current ultrasonic imaging technology is needed to enhance its relevance to breast cancer detection. A novel ultrasonic imaging reconstruction method is described that exploits classical straight-ray migration. This novel method improves signal processing for better image resolution and uses novel staging hardware options using a pulse-echo approach. A breast phantom with various inclusions is imaged using the classical migration method and is compared to standard computed tomography (CT) scans. These innovative ultrasonic methods incorporate ultrasound data acquisition, beam profile characterization, and image reconstruction. For an ultrasonic frequency of 2.25 MHz, imaged inclusions of approximately 1 cm are resolved and identified. Better resolution is expected with minor modifications. Improved image quality and resolution enables earlier detection and more accurate diagnoses of tumors thus reducing the number of biopsies performed, increasing treatment options, and lowering remission percentages. Using these new techniques the inclusions in the phantom are resolved and compared to the results of standard methods. Refinement of this application using other imaging techniques such as time-reversal mirrors (TRM), synthetic aperture focusing technique (SAFT), decomposition of the time reversal operator (DORT), and factorization methods is also discussed.

  13. Ultrasonic washing of textiles.

    PubMed

    Choi, Junhee; Kim, Tae-Hong; Kim, Ho-Young; Kim, Wonjung

    2016-03-01

    We present the results of experimental investigation of ultrasonic washing of textiles. The results demonstrate that cavitation bubbles oscillating in acoustic fields are capable of removing soils from textiles. Since the washing performance is mitigated in a large washing bath when using an ultrasonic transducer, we propose a novel washing scheme by combining the ultrasonic vibration with a conventional washing method utilizing kinetic energy of textiles. It is shown that the hybrid washing scheme achieves a markedly enhanced performance up to 15% in comparison with the conventional washing machine. This work can contribute to developing a novel laundry machine with reduced washing time and waste water. PMID:26215790

  14. Ultrasonic liquid level detector

    DOEpatents

    Kotz, Dennis M. (North Augusta, SC); Hinz, William R. (Augusta, GA)

    2010-09-28

    An ultrasonic liquid level detector for use within a shielded container, the detector being tubular in shape with a chamber at its lower end into which liquid from in the container may enter and exit, the chamber having an ultrasonic transmitter and receiver in its top wall and a reflector plate or target as its bottom wall whereby when liquid fills the chamber a complete medium is then present through which an ultrasonic wave may be transmitted and reflected from the target thus signaling that the liquid is at chamber level.

  15. Ultrasonic drilling apparatus

    DOEpatents

    Duran, Edward L. (Santa Fe, NM); Lundin, Ralph L. (Los Alamos, NM)

    1989-01-01

    Apparatus attachable to an ultrasonic drilling machine for drilling deep holes in very hard materials, such as boron carbide, is provided. The apparatus utilizes a hollow spindle attached to the output horn of the ultrasonic drilling machine. The spindle has a hollow drill bit attached at the opposite end. A housing surrounds the spindle, forming a cavity for holding slurry. In operation, slurry is provided into the housing, and into the spindle through inlets while the spindle is rotating and ultrasonically reciprocating. Slurry flows through the spindle and through the hollow drill bit to cleanse the cutting edge of the bit during a drilling operation.

  16. Ultrasonic drilling apparatus

    DOEpatents

    Duran, E.L.; Lundin, R.L.

    1988-06-20

    Apparatus attachable to an ultrasonic drilling machine for drilling deep holes in very hard materials, such as boron carbide, is provided. The apparatus utilizes a hollow spindle attached to the output horn of the ultrasonic drilling machine. The spindle has a hollow drill bit attached at the opposite end. A housing surrounds the spindle, forming a cavity for holding slurry. In operation, slurry is provided into the housing, and into the spindle through inlets while the spindle is rotating and ultrasonically reciprocating. Slurry flows through the spindle and through the hollow drill bit to cleanse the cutting edge of the bit during a drilling operation. 3 figs.

  17. Ultrasonic Imaging System

    NASA Technical Reports Server (NTRS)

    Youngquist, Robert C. (Inventor); Moerk, Steven (Inventor)

    1999-01-01

    An imaging system is described which can be used to either passively search for sources of ultrasonics or as an active phase imaging system. which can image fires. gas leaks, or air temperature gradients. This system uses an array of ultrasonic receivers coupled to an ultrasound collector or lens to provide an electronic image of the ultrasound intensity in a selected angular region of space. A system is described which includes a video camera to provide a visual reference to a region being examined for ultrasonic signals.

  18. Photoconductive circuit element pulse generator

    DOEpatents

    Rauscher, Christen (Alexandria, VA)

    1989-01-01

    A pulse generator for characterizing semiconductor devices at millimeter wavelength frequencies where a photoconductive circuit element (PCE) is biased by a direct current voltage source and produces short electrical pulses when excited into conductance by short laser light pulses. The electrical pulses are electronically conditioned to improve the frequency related amplitude characteristics of the pulses which thereafter propagate along a transmission line to a device under test.

  19. Detonator comprising a nonlinear transmission line

    DOEpatents

    Elizondo-Decanini, Juan M

    2014-12-30

    Detonators are described herein. In a general embodiment, the detonator includes a nonlinear transmission line that has a variable capacitance. Capacitance of the nonlinear transmission line is a function of voltage on the nonlinear transmission line. The nonlinear transmission line receives a voltage pulse from a voltage source and compresses the voltage pulse to generate a trigger signal. Compressing the voltage pulse includes increasing amplitude of the voltage pulse and decreasing length of the voltage pulse in time. An igniter receives the trigger signal and detonates an explosive responsive to receipt of the trigger signal.

  20. Reverberation Reduction in Capacitive Micromachined Ultrasonic Transducers (CMUTs) by Front-face Reflectivity Minimization

    NASA Astrophysics Data System (ADS)

    Savoia, Alessandro Stuart; La Mura, Monica; Mauti, Barbara; Lamberti, Nicola; Caliano, Giosuè

    Front-face acoustic reflectivity of ultrasonic imaging transducers, due to acoustic impedance mismatch with the propagation medium, may cause reverberation phenomena during wideband pulse-echo operation. Front-face reflectivity may be reduced by promoting the transmission of the echoes, received from the medium, to the transducer backing, and by maximizing the mechanical-to-electrical energy conversion and dissipation by tuning the electrical load impedance connected to the transducer. In Capacitive Micromachined Ultrasonic Transducers (CMUTs), the energy transfer from the medium to the backing is very low due to the large impedance mismatch between the medium and the transducer substrate, typically made of silicon. Reverse Fabrication Process (RFP) makes it possible providing CMUTs with custom substrate materials, thus eliminating the original silicon microfabrication support. In this paper, we propose two methods for the front-face reflectivity reduction in RFP-CMUTs: the first one is based on the use of low-impedance, highly attenuating backing materials, and the second one is based on the maximization of the mechanoelectrical energy conversion and dissipation. We analyze the methods by finite element simulations and experimentally validate the obtained results by fabricating and characterizing single-element RFP-CMUTs provided with different backing materials and electrical loads.

  1. Detection and characterization of impact damage in composite panels using multiple ultrasonic methods

    NASA Astrophysics Data System (ADS)

    Williams, Westin B.; Michaels, Thomas E.; Michaels, Jennifer E.

    2015-03-01

    Abrupt impacts to solid laminate composite panels often produce internal damage that is not visible on the impacted surface. It is important that such damage be promptly detected since it can compromise the strength of composite structures. Ultrasonic C-scan imaging has been extensively used to detect and characterize impact damage using both pulse-echo and through-transmission methods. More recently developed guided wave imaging methods, such as sparse array imaging with baseline subtraction and wavefield imaging, have also been used to successfully detect damage in composite panels; however, their performance is generally not comparable to that achieved with bulk wave C-scans. For this study, various force impacts were used to create defect conditions ranging from barely detectable damage to extensive damage that was visible on the impact surface. Guided wave signals were recorded from an attached sparse transducer array before and after the impacts, and panels were scanned using both conventional ultrasonic C-scan methods and acoustic wavefield imaging. For each method, imaging results are presented and compared in terms of their ability to locate and characterize impact damage.

  2. Testing Results of Magnetostrictive Ultrasonic Sensor Cables for Signal Loss

    SciTech Connect

    JT Evans

    2005-05-01

    The purpose of this test was to determine the signal strength and resolution losses of a magnetostrictive ultrasonic system with an extended signal cable. The cable of interest carries electrical signals between the pulse generator/receiver and the magnetostrictive transducer. It was desired to determine the loss introduced by different lengths of the signal cable (6', 100', and 200').

  3. Development of ultrasonic methods of hemodynamic measurements. [rheoencephalography/flowmeters

    NASA Technical Reports Server (NTRS)

    Histand, M. B.; Mcleod, F. D.; Miller, C. W.

    1975-01-01

    A pulsed ultrasonic Doppler velocity meter which can be used (by modifying transducers) as a flowmeter for blood circulation was experimentally studied. Calculations and profiles of turbulent and laminar flow within blood vessels are shown. Graphs and charts of transducers are included.

  4. Ultrasonic Benchmarking with UTDefect

    NASA Astrophysics Data System (ADS)

    Jansson, Per-A.?Ke; Boström, Anders

    2010-02-01

    UTDefect is a program for simulation of ultrasonic testing with emphasis on applications within the nuclear power industry. The entire testing process, including the ultrasonic transmitter, the receiver, and scattering from various types of defects of simple shape, is modelled. The basic idea behind UTDefect is to use solutions to the elastodynamic wave equation that are esentially exact. For the 2009 benchmark problems the results obtained from UTDefect are in most cases in fairly good agreement with the experimental data from CEA.

  5. A Novel Application of Ultrasonic Imaging to Study Smoldering Combustion

    NASA Technical Reports Server (NTRS)

    Tse, S. D.; Anthenien, R. A.; Fernandez-Pello, A. Carlos; Miyasaka, K.

    1997-01-01

    An ultrasonic imaging technique has been developed to examine the propagation of a smolder reaction within a porous combustible material. The technique provides information about the location of a propagating smolder front, as well as line-of-sight average permeability variations of the smoldering material. The method utilizes the observation that transmission of an ultrasonic signal through a porous material increases with permeability. Since a propagating smolder reaction leaves behind char with a higher permeability than the original material, ultrasound transmission can be employed to monitor smolder progress. The technique can also be used to track the char evolution as it continues to react. Experiments are presented where the technique is applied to smoldering combustion in a two-dimensional geometry. The results have furthered the understanding of two-dimensional smolder, especially in identifying the controlling mechanisms leading to the transition from smoldering to flaming. The applicability of ultrasonic tomography to smoldering combustion has also been investigated.

  6. Error-eliminating rapid ultrasonic firing

    DOEpatents

    Borenstein, Johann (Ann Arbor, MI); Koren, Yoram (Ann Arbor, MI)

    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.

  7. 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.

  8. Generation of low repetition rate sub-nanosecond pulses in doubly QML Nd:Lu0.5Y0.5VO4 and Nd:YVO4 lasers with EO and transmission SSA

    NASA Astrophysics Data System (ADS)

    Zhang, Haijuan; Zhao, Shengzhi; Zhao, Jia; Yang, Kejian; Li, Guiqiu; Li, Dechun; Li, Tao; Qiao, Wenchao; Wang, Yonggang

    2015-06-01

    By employing the mixed crystal Nd:Lu0.5Y0.5VO4 and the single crystal Nd:YVO4 as the laser media, the characteristics of the QML laser doubly modulated by electro-optic (EO) modulator and transmission semiconductor saturable absorber (T-SSA) are studied. Under the same cavity parameters, the properties of the low repetition rate sub-nanosecond pulses generated from Nd:Lu0.5Y0.5VO4 and Nd:YVO4 laser are compared. The experimental results show that Nd:Lu0.5Y0.5VO4 laser can generate shorter pulse width than Nd:YVO4 laser, and meanwhile, needs lower pump power to generate low repetition rate sub-nanosecond pulses. The shortest pulse durations obtained from the doubly QML Nd:Lu0.5Y0.5VO4 and Nd:YVO4 lasers are estimated to be 204 and 294 ps, with the corresponding peak power of 3.4 and 3.04 MW, respectively.

  9. Integrated ultrasonic and petrographical characterization of carbonate building materials

    NASA Astrophysics Data System (ADS)

    Ligas, Paola; Fais, Silvana; Cuccuru, Francesco

    2014-05-01

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

  10. Ultrasonic standing wave manipulation technology integrated into a dielectrophoretic chip

    E-print Network

    , Accepted 22nd August 2006 First published as an Advance Article on the web 11th September 2006 DOI: 10 manipulation technologies based on ultrasonic standing waves (USWs) and dielectrophoresis (DEP allowing transmission light microscopy to continuously monitor the biological process. The DEP manipulation

  11. ieee transactions on ultrasonics, ferroelectrics, and frequency control, vol. 53, no. 8, august 2006 1513 Experimental Characterization of

    E-print Network

    Khuri-Yakub, Butrus T. "Pierre"

    . Introduction Capacitive micromachined ultrasonic transducers (CMUTs) are in the process of moving from research of collapse-mode operation of capacitive mi- cromachined ultrasonic transducers (CMUTs). CMUTs is used. By reducing the parasitic capacitance, the use of a custom IC enables pulse- echo measurements

  12. Ultrasonics in Dentistry

    NASA Astrophysics Data System (ADS)

    Walmsley, A. D.

    Ultrasonic instruments have been used in dentistry since the 1950's. Initially they were used to cut teeth but very quickly they became established as an ultrasonic scaler which was used to remove deposits from the hard tissues of the tooth. This enabled the soft tissues around the tooth to return to health. The ultrasonic vibrations are generated in a thin metal probe and it is the working tip that is the active component of the instrument. Scanning laser vibrometry has shown that there is much variability in their movement which is related to the shape and cross sectional shape of the probe. The working instrument will also generate cavitation and microstreaming in the associated cooling water. This can be mapped out along the length of the instrument indicating which are the active areas. Ultrasonics has also found use for cleaning often inaccessible or different surfaces including root canal treatment and dental titanium implants. The use of ultrasonics to cut bone during different surgical techniques shows considerable promise. More research is indicated to determine how to maximize the efficiency of such instruments so that they are more clinically effective.

  13. Exploring the use of Low-intensity Ultrasonics as a Tool for Assessing the Salt Content in Pork Meat Products

    NASA Astrophysics Data System (ADS)

    García-Pérez, J. V.; de Prados, M.; Martínez-Escrivá, G.; González, R.; Mulet, A.; Benedito, J.

    Meat industry demands non-destructive techniques for the control of the salting process to achieve a homogeneous final salt content in salted meat products. The feasibility of using low-intensity ultrasound for characterizing the salting process of pork meat products was evaluated. The ultrasonic velocity (V) and time of flight (TF) were measured by through-transmission and pulse-echo methods, respectively, in salted meat products. Salting involved an increase of the V in meat muscles and a decrease of the time of flight in whole hams. Measuring the V before and after salting, the salt content could be estimated. Moreover, online monitoring of the salting process by computing the TF could be considered a reliable tool for quality control purposes.

  14. Artificial Intelligence Assists Ultrasonic Inspection

    NASA Technical Reports Server (NTRS)

    Schaefer, Lloyd A.; Willenberg, James D.

    1992-01-01

    Subtle indications of flaws extracted from ultrasonic waveforms. Ultrasonic-inspection system uses artificial intelligence to help in identification of hidden flaws in electron-beam-welded castings. System involves application of flaw-classification logic to analysis of ultrasonic waveforms.

  15. Determination of avocado and mango fruit properties by ultrasonic technique.

    PubMed

    Mizrach, A

    2000-03-01

    A nondestructive ultrasonic measurement system was developed for the assessment of some transmission parameters which might have quantitative relations with the maturity, firmness and other quality-related properties of avocado and mango fruits. The system utilizes a set of low-frequency probes arranged to measure the ultrasonic signal transmitted and received over a short distance across the peel. The attenuation of the ultrasonic waves, transmitted through the peel and the attached fruit tissue, changes as a result of the progressive ripening and softening of the fruit during the fruiting season and in the course of storage. The present study quantitatively addressed the linkage between the ultrasonic attenuation and the physiological parameters of the flesh of the fruits. Results were obtained in the time and frequency domain, and the data set was analyzed statistically to identify the relations between the major physiological indices and the ultrasonic parameters. Quantitative relations were developed to describe the linkage between ultrasonic parameters and the maturity, firmness and other quality-related properties in mango and avocado fruits. PMID:10829759

  16. Ultrasonic breast imaging using a wave-equation migration method

    NASA Astrophysics Data System (ADS)

    Huang, Lianjie; Duric, Nebojsa; Littrup, Peter J.

    2003-05-01

    Reflection imaging has the potential to produce higher-resolution breast images than transmission tomography; however, the current clinical reflection imaging technique yields poor-quality breast images due to speckle. We present a new ultrasonic breast imaging method for obtaining high-resolution and clear breast images using ultrasonic reflection data acquired by a new ultrasonic scanning device that provides a better illumination of targets of interest than the clinical B-scan. The new imaging method is based on the solution of the wave equation in Cartesian coordinates and is implemented using Fast Fourier Transform algorithms. We apply the new ultrasonic breast imaging method to two ultrasonic data sets obtained using an experimental ultrasound scanner recently developed by the Karmanos Cancer Institute. One data set was acquired for a "cyst" phantom using 360 transmitter positions and 321 receiver positions along a 20-cm diameter ring. Another data set was collected with 180 transmitter positions and 1601 receiver positions along a 30-cm diameter ring with the breast specimen located at the center of the ring. We report on the breast imaging results for these two data sets using the new breast imaging method. The results demonstrate that the wave-equation-based ultrasonic breast imaging has the potential to produce high-resolution breast images.

  17. Ultrasonic verification of microstructural changes due to heat treatment

    NASA Technical Reports Server (NTRS)

    Generazio, E. R.

    1986-01-01

    Ultrasonic attenuation was measured for polycrystalline samples of nickel and copper with various grain-size distributions produced by heat treatment. Attenuation as a function of frequency was determined for a sample having a known mean grain diameter. Once this function was determined, it could be scaled to determine the mean grain size of other samples of the same material with different mean grain diameters. These results were obtained by using broadband pulse-echo ultrasound in the 25 to 100 MHz frequency range. The results suggest an ultrasonic, nondestructive approach for verifying heat treatment of metals.

  18. ULTRASOUND PULSE-ECHO IMAGING USING THE SPLIT-STEP FOURIER PROPAGATOR

    SciTech Connect

    HUANG, LIANJIE; QUAN, YOULI

    2007-01-31

    Ultrasonic reflection imaging has the potential to produce higher image resolution than transmission tomography, but imaging resolution and quality still need to be further improved for early cancer detection and diagnosis. We present an ultrasound reflection image reconstruction method using the split-step Fourier propagator. It is based on recursive inward continuation of ultrasonic wavefields in the frequency-space and frequency-wavenumber domains. The inward continuation within each extrapolation interval consists of two steps. In the first step, a phase-shift term is applied to the data in the frequency-wavenumber domain for propagation in a reference medium. The second step consists of applying another phase-shift term to data in the frequency-space domain to approximately compensate for ultrasonic scattering effects of heterogeneities within the breast. We use synthetic ultrasound pulse-echo data recorded around a ring for heterogeneous, computer-generated numerical breast phantoms to study the imaging capability of the method. The phantoms are derived from an experimental breast phantom and a sound-speed tomography image of an in-vivo ultrasound breast data collected usi ng a ring array. The heterogeneous sound-speed models used for pulse-echo imaging are obtained using a computationally efficient, first-arrival-time (time-of-flight) transmission tomography method. Our studies demonstrate that reflection image reconstruction using the split-step Fourier propagator with heterogeneous sound-speed models significantly improves image quality and resolution. We also numerically verify the spatial sampling criterion of wavefields for a ring transducer array.

  19. Ultrasonic Leak Detection System

    NASA Technical Reports Server (NTRS)

    Youngquist, Robert C. (Inventor); Moerk, J. Steven (Inventor)

    1998-01-01

    A system for detecting ultrasonic vibrations. such as those generated by a small leak in a pressurized container. vessel. pipe. or the like. comprises an ultrasonic transducer assembly and a processing circuit for converting transducer signals into an audio frequency range signal. The audio frequency range signal can be used to drive a pair of headphones worn by an operator. A diode rectifier based mixing circuit provides a simple, inexpensive way to mix the transducer signal with a square wave signal generated by an oscillator, and thereby generate the audio frequency signal. The sensitivity of the system is greatly increased through proper selection and matching of the system components. and the use of noise rejection filters and elements. In addition, a parabolic collecting horn is preferably employed which is mounted on the transducer assembly housing. The collecting horn increases sensitivity of the system by amplifying the received signals. and provides directionality which facilitates easier location of an ultrasonic vibration source.

  20. Ultrasonic Stir Welding

    NASA Technical Reports Server (NTRS)

    Nabors, Sammy

    2015-01-01

    NASA Marshall Space Flight Center (MSFC) developed Ultrasonic Stir Welding (USW) to join large pieces of very high-strength metals such as titanium and Inconel. USW, a solid-state weld process, improves current thermal stir welding processes by adding high-power ultrasonic (HPU) energy at 20 kHz frequency. The addition of ultrasonic energy significantly reduces axial, frictional, and shear forces; increases travel rates; and reduces wear on the stir rod, which results in extended stir rod life. The USW process decouples the heating, stirring, and forging elements found in the friction stir welding process allowing for independent control of each process element and, ultimately, greater process control and repeatability. Because of the independent control of USW process elements, closed-loop temperature control can be integrated into the system so that a constant weld nugget temperature can be maintained during welding.

  1. High Frequency Ultrasonic Imaging

    PubMed Central

    Shung, K Kirk

    2010-01-01

    High frequency ultrasonic imaging is considered by many to be the next frontier in ultrasound. It has many clinical applications ranging from imaging the eye and skin to small animal imaging. Small animal imaging has recently generated intense interest for the purpose of evaluating the efficacy of drugs and gene therapy. Commercial high frequency scanners often termed “ultrasonic biomicroscope”, or UBM, all use mechanically scanned single element transducers at frequencies between 30 to 60 MHz with a frame rate of 30 frames/second or lower. To alleviate problems with UBMs which include mechanical motion and fixed focusing, high frequency linear arrays and imaging systems in the 20–50 MHz range have been developed. In this paper, current efforts in the development of high frequency ultrasonic imaging will be reviewed and potential biomedical applications discussed. PMID:20445825

  2. Acousto-ultrasonics

    NASA Technical Reports Server (NTRS)

    Vary, Alex

    1990-01-01

    The theoretical development, methodology, and potential applications of acousto-ultrasonic nondestructive testing are set forth in an overview to assess the effectiveness of the technique. Stochastic wave propagation is utilized to isolate and describe defects in fiber-reinforced composites, particularly emphasizing the integrated effects of diffuse populations of subcritical flaws. The generation and nature of acousto-ultrasonic signals are described in detail, and stress-wave factor analysis of the signals is discussed. Applications of acousto-ultrasonics are listed including the prediction of failure sites, assessing fatique and impact damage, calculating ultimate tensile strength, and determining interlaminar bond strength. The method can identify subtle but important variations in fiber-reinforced composites, and development of the related instrumentation technology is emphasized.

  3. Ultrasonic Processing of Materials

    NASA Astrophysics Data System (ADS)

    Han, Qingyou

    2015-08-01

    Irradiation of high-energy ultrasonic vibration in metals and alloys generates oscillating strain and stress fields in solids, and introduces nonlinear effects such as cavitation, acoustic streaming, and radiation pressure in molten materials. These nonlinear effects can be utilized to assist conventional material processing processes. This article describes recent research at Oak Ridge National Labs and Purdue University on using high-intensity ultrasonic vibrations for degassing molten aluminum, processing particulate-reinforced metal matrix composites, refining metals and alloys during solidification process and welding, and producing bulk nanostructures in solid metals and alloys. Research results suggest that high-intensity ultrasonic vibration is capable of degassing and dispersing small particles in molten alloys, reducing grain size during alloy solidification, and inducing nanostructures in solid metals.

  4. Ultrasonic/Sonic Jackhammer

    NASA Technical Reports Server (NTRS)

    Bar-Cohen, Yoseph (Inventor); Sherrit, Stewart (Inventor); Herz, Jack L. (Inventor)

    2014-01-01

    The invention provides a novel jackhammer that utilizes ultrasonic and/or sonic vibrations as source of power. It is easy to operate and does not require extensive training, requiring substantially less physical capabilities from the user and thereby increasing the pool of potential operators. An important safety benefit is that it does not fracture resilient or compliant materials such as cable channels and conduits, tubing, plumbing, cabling and other embedded fixtures that may be encountered along the impact path. While the ultrasonic/sonic jackhammer of the invention is able to cut concrete and asphalt, it generates little back-propagated shocks or vibrations onto the mounting fixture, and can be operated from an automatic platform or robotic system. PNEUMATICS; ULTRASONICS; IMPACTORS; DRILLING; HAMMERS BRITTLE MATERIALS; DRILL BITS; PROTOTYPES; VIBRATION

  5. Laser ultrasonic generation at the surface of a liquid metal

    SciTech Connect

    Walter, J.B.; Telschow, K.L.; Conant, R.J.

    1995-01-01

    The noncontacting nature of laser-based ultrasonic measurement has made it attractive in many applications. While most applications thus far involve solid samples, molten metals encountered in some stages of metal processing appear well suited to this technique. Possible applications for liquid metals include locating and characterizing the liquid/solid interface; characterizing a surface layer, contaminant, or alloying constituent; and measuring the temperature of the sample surface or bulk. This work aimed to characterize laser generation of ultrasound in liquid metals to facilitate the development of techniques for these applications. This paper describes measurements of the angular distribution and energy dependence of laser-generated ultrasound in mercury at ambient temperature. Mercury was chosen as the model liquid metal because it is liquid at room temperature, and so should have negligible temperature gradients beyond those produced in the laser generation process, and because it exhibits a very shallow optical penetration depth. Brief descriptions about the theory of laser generation by thermoelastic and ablation sources at the surface of a liquid metal are included. Both thermoelastic expansion and ablation cause similar ultrasound generation in liquid metals when laser generated ultrasonic pulses are directed perpendicular to the surface of liquid metals. The ultrasonic pulse amplitude is proportional to the absorbed laser pulse energy for both mechanisms. The simple threshold model presented for ablation describes the transition from thermoelastic generation with the model`s two parameters being material dependent. For mercury, ablation produces about 100 times larger ultrasonic pulse amplitudes than thermoelastic expansion and has a threshold of about 6 MW/square cm. Molten metals offer a good medium for studying ablation, since the surface is always refreshed and ablation, at least for mercury, dominates ultrasonic generation above the threshold.

  6. Ultrasonic shear wave couplant

    DOEpatents

    Kupperman, David S. (Oak Park, IL); Lanham, Ronald N. (Lockport, IL)

    1985-01-01

    Ultrasonically testing of an article at high temperatures is accomplished by the use of a compact layer of a dry ceramic powder as a couplant in a method which involves providing an ultrasonic transducer as a probe capable of transmitting shear waves, coupling the probe to the article through a thin compact layer of a dry ceramic powder, propagating a shear wave from the probe through the ceramic powder and into the article to develop echo signals, and analyzing the echo signals to determine at least one physical characteristic of the article.

  7. Ultrasonic shear wave couplant

    DOEpatents

    Kupperman, D.S.; Lanham, R.N.

    1984-04-11

    Ultrasonically testing of an article at high temperatures is accomplished by the use of a compact layer of a dry ceramic powder as a couplant in a method which involves providing an ultrasonic transducer as a probe capable of transmitting shear waves, coupling the probe to the article through a thin compact layer of a dry ceramic powder, propagating a shear wave from the probe through the ceramic powder and into the article to develop echo signals, and analyzing the echo signals to determine at least one physical characteristic of the article.

  8. Automated ultrasonic measuring system

    NASA Astrophysics Data System (ADS)

    Umeagukwu, C. I.; Peters, W. H.; Dickerson, J. R.; Ranson, W. F.

    1987-01-01

    An experiment in which a microcomputer in the single-chip mode is utilized to control an acoustic-imaging process is described. The experiment was conducted using an aluminum specimen with a spherical deformation on the upper surface, a noncontact-piezoelectric transducers to transmit waves, and an eight-bit microprocessor. The effects of deformation on the transmitted acoustic waves and on the reflected ultrasonic waves are investigated. Intensity distributions for the specimen are studied. Block diagrams of the automated ultrasonic-measuring system are provided.

  9. Ultrasonic/Sonic Jackhammer

    NASA Technical Reports Server (NTRS)

    Bar-Cohen, Yoseph; Sherrit, Stewart; Herz, Jack

    2005-01-01

    An ultrasonic/sonic jackhammer (USJ) is the latest in a series of related devices. Each of these devices cuts into a brittle material by means of hammering and chiseling actions of a tool bit excited with a combination of ultrasonic and sonic vibrations. A small-scale prototype of the USJ has been demonstrated. A fully developed, full-scale version of the USJ would be used for cutting through concrete, rocks, hard asphalt, and other materials to which conventional pneumatic jackhammers are applied, but the USJ would offer several advantages over conventional pneumatic jackhammers.

  10. Ultrasonic thermoacoustic energy converter.

    PubMed

    Flitcroft, Myra; Symko, Orest G

    2013-03-01

    Thermoacoustic prime movers have been developed for operation in the low ultrasonic frequency range by scaling down the device size. The developed engines operate at frequencies up to 23 kHz. They are self-sustained oscillators whose dimensions scale inversely with operating frequency. The smallest one being 3.4 mm long with a 1mm diameter bore, i.e. the engine inner volume of 2.67 mm(3). The generated sound levels reached intensities in the range of 143-150 dB in the low ultrasonic range. The miniaturization of thermoacoustic engines will lead to the development of device arrays. PMID:23218928

  11. Precision Thickness Variation Mapping Via One-Transducer Ultrasonic High Resolution Profilometry for Sample With Irregular or Rough Surface

    NASA Technical Reports Server (NTRS)

    Roth, Don J. (Inventor)

    1996-01-01

    An apparatus and method for determination of sample thickness and surface depression utilizing ultrasonic pulses is discussed. The sample is held in a predetermined position by a support member having a reference surface. Ultrasonic pulses travel through a medium of known velocity propagation and reflect off the reference surface and a sample surface. Time of flight data of surface echoes are converted to distances between sample surfaces to obtain computer-generated thickness profiles and surface mappings.

  12. Precision Thickness Variation Mapping via One-Transducer Ultrasonic High Resolution Profilometry for Sample with Irregular or Rough Surface

    NASA Technical Reports Server (NTRS)

    Roth, Don J. (Inventor)

    1997-01-01

    An apparatus and method for determination of sample thickness and surface depression utilizing ultrasonic pulses. The sample is held in a predetermined position by a support member having a reference surface. Ultrasonic pulses travel through a medium of known velocity propagation and reflect off the reference surface and a sample surface. Time of flight data of surface echoes are converted to distances between sample surfaces to obtain computer-generated thickness profiles and surface mappings.

  13. Ultrasonic shear wave velocity in CLF/CMT graphite from room temperature to 2000/sup 0/F

    SciTech Connect

    Gieske, J.H.

    1980-11-01

    The temperature dependence of the ultrasonic shear velocity in CLF/CMT graphite was determined from room temperature to 2000/sup 0/F using a pulse-echo technique. Data are presented for five 0.75-inch-diameter specimens all machined from the same CLF/CMT billet. Plots of ultrasonic pulse-echo radial and axial scans of the billet which characterize the material property uniformity of the billet are also given.

  14. High energy, low frequency, ultrasonic transducer

    DOEpatents

    Brown, Albert E. (Hayward, CA)

    2000-01-01

    A wide bandwidth, ultrasonic transducer to generate nondispersive, extensional, pulsed acoustic pressure waves into concrete reinforced rods and tendons. The wave propagation distance is limited to double the length of the rod. The transducer acoustic impedance is matched to the rod impedance for maximum transfer of acoustic energy. The efficiency of the transducer is approximately 60 percent, depending upon the type of active elements used in the transducer. The transducer input energy is, for example, approximately 1 mJ. Ultrasonic reflections will occur at points along the rod where there are changes of one percent of a wavelength in the rod diameter. A reduction in the rod diameter will reflect a phase reversed echo, as compared with the reflection from an incremental increase in diameter. Echo signal processing of the stored waveform permits a reconstruction of those echoes into an image of the rod. The ultrasonic transducer has use in the acoustic inspection of long (40+foot) architectural reinforcements and structural supporting members, such as in bridges and dams.

  15. Nondestructive Ultrasonic Inspection of Friction Stir Welds

    NASA Astrophysics Data System (ADS)

    Tabatabaeipour, M.; Hettler, J.; Delrue, S.; Van Den Abeele, K.

    Friction Stir Welding (FSW) is a relatively new solid-state welding procedure developed at The Welding Institute (TWI-UK) and the technique is widely employed for welding aluminum alloys in various applications. In order to examine the quality of the welds and to detect a variety of welding flaws such as wormholes and root-flaws, it is required to develop a methodical inspection technique that can be used for the identification and localization of such defects. The most prevalent and risky defect in this type of welding is the barely visible root flaw with a length varying from 100-700 ?m. Due to the extreme characteristics of the flaw, off-the-shelf ultrasonic weld inspection methods are not always able to readily detect this type of minute defect feature. Here, we propose a novel approach to characterize root flaws using an oblique incident ultrasonic C-scan backscattering analysis. The implementation consists of an immersion ultrasonic testing method in pulse echo (i.e. backscatter) mode with a 3.5 MHz transducer, and makes use of an empirical procedure to engender of a shear wave dominated excitation at the root surface, and to properly gate the received signal for root flaw examination. By scanning the surface above the welded component, a C-scan image displaying the backscatter response from the root surface of the nugget zone can be obtained which allows a simple interpretation of the root flaw status of the weld.

  16. A device for human ultrasonic echolocation

    PubMed Central

    Gaub, Benjamin M.; Rodgers, Chris C.; Li, Crystal; DeWeese, Michael R.; Harper, Nicol S.

    2015-01-01

    Objective We present a device that combines principles of ultrasonic echolocation and spatial hearing to provide human users with environmental cues that are 1) not otherwise available to the human auditory system and 2) richer in object, and spatial information than the more heavily processed sonar cues of other assistive devices. The device consists of a wearable headset with an ultrasonic emitter and stereo microphones with affixed artificial pinnae. The goal of this study is to describe the device and evaluate the utility of the echoic information it provides. Methods The echoes of ultrasonic pulses were recorded and time-stretched to lower their frequencies into the human auditory range, then played back to the user. We tested performance among naive and experienced sighted volunteers using a set of localization experiments in which the locations of echo-reflective surfaces were judged using these time stretched echoes. Results Naive subjects were able to make laterality and distance judgments, suggesting that the echoes provide innately useful information without prior training. Naive subjects were generally unable to make elevation judgments from recorded echoes. However trained subjects demonstrated an ability to judge elevation as well. Conclusion This suggests that the device can be used effectively to examine the environment and that the human auditory system can rapidly adapt to these artificial echolocation cues. Significance Interpreting and interacting with the external world constitutes a major challenge for persons who are blind or visually impaired. This device has the potential to aid blind people in interacting with their environment. PMID:25608301

  17. Ultrasonic characterization of solid liquid suspensions

    DOEpatents

    Panetta, Paul D.

    2010-06-22

    Using an ultrasonic field, properties of a solid liquid suspension such as through-transmission attenuation, backscattering, and diffuse field are measured. These properties are converted to quantities indicating the strength of different loss mechanisms (such as absorption, single scattering and multiple scattering) among particles in the suspension. Such separation of the loss mechanisms can allow for direct comparison of the attenuating effects of the mechanisms. These comparisons can also indicate a model most likely to accurately characterize the suspension and can aid in determination of properties such as particle size, concentration, and density of the suspension.

  18. 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.

  19. One-step 3D full-colour and achromatic transmission holograms digitally printed using a 440nm pulsed laser for embossed applications

    NASA Astrophysics Data System (ADS)

    Zacharovas, Stanislovas; Nikolskij, Andrej; Bakanas, Ramunas; Brotherton-Ratcliffe, David

    2013-03-01

    The Direct Write Digital Holography (DWDH) technique has been used to print master-original holograms for embossed applications using a 440nm pulsed laser. Holograms were recorded on both Silver Halide photo-plates and Shipley photoresist photo-plates. Shipley photoresist consistently exhibited a sensitivity to pulsed radiation several times better than that observed on exposure to CW radiation. In addition, image quality of the recorded holograms using pulsed radiation appeared very similar to that obtainable with CW exposure. The clear implication is that pulsed lasers emitting at 440nm can replace the CW HeCd lasers currently used for the origination of embossed holograms. Master-original holograms recorded with the DWDH technique are able to record deep 3D imagery. The origination technique described allows the production of master-original holograms with achromatic or full colour images. In addition the DWDH technique allows one to combine achromatic and full colour images on one hologram. As a proof of concept, embossing matrix shims were produced from our master-original holograms and embossed holograms were stamped.

  20. Ultrasonic Transducer Analyzer

    NASA Technical Reports Server (NTRS)

    Grounds, M. K.

    1982-01-01

    Ultrasonic transducer-beam-intensity distributions are determined by analyzing echoes from a spherical ball. Computers control equipment and process data. Important beam characteristics, such as location of best beam focus and beam diameter at focus, can be determined quickly from extensive set of plots generated by apparatus.

  1. Scanning ultrasonic probe

    DOEpatents

    Kupperman, D.S.; Reimann, K.J.

    1980-12-09

    The invention is an ultrasonic testing device for rapid and complete examination of the test specimen, and is particularly well suited for evaluation of tubular test geometries. A variety of defect categories may be detected and anlayzed at one time and their positions accurately located in a single pass down the test specimen.

  2. Scanning ultrasonic probe

    DOEpatents

    Kupperman, David S. (Oak Park, IL); Reimann, Karl J. (Lisle, IL)

    1982-01-01

    The invention is an ultrasonic testing device for rapid and complete examination of the test specimen, and is particularly well suited for evaluation of tubular test geometries. A variety of defect categories may be detected and analyzed at one time and their positions accurately located in a single pass down the test specimen.

  3. Broadband Ultrasonic Transducers

    NASA Technical Reports Server (NTRS)

    Heyser, R. C.

    1986-01-01

    New geometry spreads out resonance region of piezoelectric crystal. In new transducer, crystal surfaces made nonparallel. One surface planar; other, concave. Geometry designed to produce nearly uniform response over a predetermined band of frequencies and to attenuate strongly frequencies outside band. Greater bandwidth improves accuracy of sonar and ultrasonic imaging equipment.

  4. Experiments with Ultrasonic Transducers.

    ERIC Educational Resources Information Center

    Greenslade, Thomas R., Jr.

    1994-01-01

    Discusses the use of 40 kHz ultrasonic transducers to study wave phenomena. Determines that the resulting wavelength of 9 mm allows acoustic experiments to be performed on a tabletop. Includes transducer characteristics and activities on speed of sound, reflection, double- and single-slit diffraction, standing waves, acoustical zone plate, and…

  5. Ultrasonic Drilling and Coring

    NASA Technical Reports Server (NTRS)

    Bar-Cohen, Yoseph

    1998-01-01

    A novel drilling and coring device, driven by a combination, of sonic and ultrasonic vibration, was developed. The device is applicable to soft and hard objects using low axial load and potentially operational under extreme conditions. The device has numerous potential planetary applications. Significant potential for commercialization in construction, demining, drilling and medical technologies.

  6. A model for correlating damage and ultrasonic attenuation in composites

    NASA Technical Reports Server (NTRS)

    Hayford, D. T.; Henneke, E. G., II

    1979-01-01

    Ultrasonic attenuation data measured by the pulse-echo technique have been obtained versus load for two graphite-epoxy laminates and are presented. The attenuation-load data display distinct changes at load values associated with the initiation of transverse cracks in the weakest plies and with the knee in the bilinear stress-strain curve. It was intended to determine if a simplified diffraction model could be used to account for the attenuation changes. The basis of the diffraction model is that transverse cracks or delaminations, or both, initiating and progressing in the specimen under the area covered by the ultrasonic transducer would cause diffraction of the ultrasonic beam and changes in the measured attenuation.

  7. Simulation of transducer-couplant effects on broadband ultrasonic signals

    NASA Technical Reports Server (NTRS)

    Vary, A.

    1980-01-01

    The increasing use of broadband, pulse-echo ultrasonics in nondestructive evaluation of flaws and material properties has generated a need for improved understanding of the way signals are modified by coupled and bonded thin-layer interfaces associated with transducers. This understanding is most important when using frequency spectrum analyses for characterizing material properties. In this type of application, signals emanating from material specimens can be strongly influenced by couplant and bond-layers in the acoustic path. Computer synthesized waveforms were used to simulate a range of interface conditions encountered in ultrasonic transducer systems operating in the 20 to 80 MHz regime. The adverse effects of thin-layer multiple reflections associated with various acoustic impedance conditions are demonstrated. The information presented is relevant to ultrasonic transducer design, specimen preparation, and couplant selection.

  8. A Sparse Reconstruction Algorithm for Ultrasonic Images in Nondestructive Testing

    PubMed Central

    Guarneri, Giovanni Alfredo; Pipa, Daniel Rodrigues; Junior, Flávio Neves; de Arruda, Lúcia Valéria Ramos; Zibetti, Marcelo Victor Wüst

    2015-01-01

    Ultrasound imaging systems (UIS) are essential tools in nondestructive testing (NDT). In general, the quality of images depends on two factors: system hardware features and image reconstruction algorithms. This paper presents a new image reconstruction algorithm for ultrasonic NDT. The algorithm reconstructs images from A-scan signals acquired by an ultrasonic imaging system with a monostatic transducer in pulse-echo configuration. It is based on regularized least squares using a l1 regularization norm. The method is tested to reconstruct an image of a point-like reflector, using both simulated and real data. The resolution of reconstructed image is compared with four traditional ultrasonic imaging reconstruction algorithms: B-scan, SAFT, ?-k SAFT and regularized least squares (RLS). The method demonstrates significant resolution improvement when compared with B-scan—about 91% using real data. The proposed scheme also outperforms traditional algorithms in terms of signal-to-noise ratio (SNR). PMID:25905700

  9. Multimode-Guided-Wave Ultrasonic Scanning of Materials

    NASA Technical Reports Server (NTRS)

    Roth, Don

    2006-01-01

    Two documents discuss a method of characterizing advanced composite materials by use of multimode-guided ultrasonic waves. A transmitting transducer excites modulated (e.g., pulsed) ultrasonic waves at one location on a surface of a plate specimen. The waves interact with microstructure and flaws as they propagate through the specimen to a receiving transducer at a different location. The received signal is analyzed to determine the total (multimode) ultrasonic response of the specimen and utilize this response to evaluate microstructure and flaws. The analysis is performed by software that extracts parameters of signals in the time and frequency domains. Scanning is effected by using computer-controlled motorized translation stages to position the transducers at specified pairs of locations and repeating the measurement, data-acquisition, and data-analysis processes at the successive locations. One document presents results of a scan of a specimen containing a delamination.

  10. A sparse reconstruction algorithm for ultrasonic images in nondestructive testing.

    PubMed

    Guarneri, Giovanni Alfredo; Pipa, Daniel Rodrigues; Neves Junior, Flávio; de Arruda, Lúcia Valéria Ramos; Zibetti, Marcelo Victor Wüst

    2015-01-01

    Ultrasound imaging systems (UIS) are essential tools in nondestructive testing (NDT). In general, the quality of images depends on two factors: system hardware features and image reconstruction algorithms. This paper presents a new image reconstruction algorithm for ultrasonic NDT. The algorithm reconstructs images from A-scan signals acquired by an ultrasonic imaging system with a monostatic transducer in pulse-echo configuration. It is based on regularized least squares using a l1 regularization norm. The method is tested to reconstruct an image of a point-like reflector, using both simulated and real data. The resolution of reconstructed image is compared with four traditional ultrasonic imaging reconstruction algorithms: B-scan, SAFT, ?-k SAFT and regularized least squares (RLS). The method demonstrates significant resolution improvement when compared with B-scan-about 91% using real data. The proposed scheme also outperforms traditional algorithms in terms of signal-to-noise ratio (SNR). PMID:25905700

  11. Silicon micromachined ultrasonic immersion transducers H. T. Soh, I. Ladabaum,a)

    E-print Network

    Khuri-Yakub, Butrus T. "Pierre"

    in water using capacitive, micromachined transducers is reported. Transmission experiments using the sameSilicon micromachined ultrasonic immersion transducers H. T. Soh, I. Ladabaum,a) A. Atalar,b) C. F ultrasound transmission in air at 6 MHz. The versatile transducers are made using silicon surface

  12. Ultrasonic cleaning: Fundamental theory and application

    NASA Technical Reports Server (NTRS)

    Fuchs, F. John

    1995-01-01

    This presentation describes: the theory of ultrasonics, cavitation and implosion; the importance and application of ultrasonics in precision cleaning; explanations of ultrasonic cleaning equipment options and their application; process parameters for ultrasonic cleaning; and proper operation of ultrasonic cleaning equipment to achieve maximum results.

  13. Ultrasonic wave velocity measurement in small polymeric and cortical bone specimens

    NASA Technical Reports Server (NTRS)

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

    1997-01-01

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

  14. Non-contact feature detection using ultrasonic Lamb waves

    DOEpatents

    Sinha, Dipen N. (Los Alamos, NM)

    2011-06-28

    Apparatus and method for non-contact ultrasonic detection of features on or within the walls of hollow pipes are described. An air-coupled, high-power ultrasonic transducer for generating guided waves in the pipe wall, and a high-sensitivity, air-coupled transducer for detecting these waves, are disposed at a distance apart and at chosen angle with respect to the surface of the pipe, either inside of or outside of the pipe. Measurements may be made in reflection or transmission modes depending on the relative position of the transducers and the pipe. Data are taken by sweeping the frequency of the incident ultrasonic waves, using a tracking narrow-band filter to reduce detected noise, and transforming the frequency domain data into the time domain using fast Fourier transformation, if required.

  15. Pulse shaping system

    DOEpatents

    Skeldon, Mark D. (Penfield, NY); Letzring, Samuel A. (Jemez Springs, NM)

    1999-03-23

    Temporally shaped electrical waveform generation provides electrical waveforms suitable for driving an electro-optic modulator (EOM) which produces temporally shaped optical laser pulses for inertial confinement fusion (ICF) research. The temporally shaped electrical waveform generation is carried out with aperture coupled transmission lines having an input transmission line and an aperture coupled output transmission line, along which input and output pulses propagate in opposite directions. The output electrical waveforms are shaped principally due to the selection of coupling aperture width, in a direction transverse to the lines, which varies along the length of the line. Specific electrical waveforms, which may be high voltage (up to kilovolt range), are produced and applied to the EOM to produce specifically shaped optical laser pulses.

  16. Pulse shaping system

    DOEpatents

    Skeldon, M.D.; Letzring, S.A.

    1999-03-23

    Temporally shaped electrical waveform generation provides electrical waveforms suitable for driving an electro-optic modulator (EOM) which produces temporally shaped optical laser pulses for inertial confinement fusion (ICF) research. The temporally shaped electrical waveform generation is carried out with aperture coupled transmission lines having an input transmission line and an aperture coupled output transmission line, along which input and output pulses propagate in opposite directions. The output electrical waveforms are shaped principally due to the selection of coupling aperture width, in a direction transverse to the lines, which varies along the length of the line. Specific electrical waveforms, which may be high voltage (up to kilovolt range), are produced and applied to the EOM to produce specifically shaped optical laser pulses. 8 figs.

  17. In-flight measurement of ice growth on an airfoil using an array of ultrasonic transducers

    NASA Technical Reports Server (NTRS)

    Hansman, R. John, Jr.; Kirby, Mark S.; Mcknight, Robert C.; Humes, Robert L.

    1988-01-01

    Results of preliminary tests to measure ice growth on an airfoil during flight icing conditions are presented. Ultrasonic pulse echo measurements of ice thickness are obtained from an array of eight ultrasonic transducers mounted flush with the leading edge of the airfoil. These thickness measurements are used to document the evolution of the ice shape during the encounter in the form of successive ice profiles. Results from 3 research flights are presented and discussed. The accuracy of the ultrasonic measurements is found to be within 0.5 mm of mechanical and stereo photograph measurements of the ice accretion.

  18. High-temperature ultrasonic sensor for in-situ monitoring of hot isostatic processing

    NASA Astrophysics Data System (ADS)

    Stubbs, David A.; Dutton, Rollie E.

    1996-11-01

    A sensor has been developed and tested that is capable of emitting and receiving ultrasonic energy at temperatures exceeding 900 degrees C and pressures above 150 MPa. The sensor is based on a unique form of aluminum nitride that retains tits piezoelectric properties at high temperatures. The sensor works with standard ultrasonic pulse-receivers and has demonstrated the capability of measuring workpiece deformation during hot isostatic pressing (HIP). Details of the sensor design, performance, and coupling of the ultrasound to the workpiece are described. Ultrasonic data acquired by the sensor, in situ, during HIP runs and at elevated temperatures in air are presented.

  19. A New Approach to Ultrasonic Tissue Characterization on Second Harmonic Component of 100 MHz

    NASA Astrophysics Data System (ADS)

    Nishimura, Toshihiro; Kubota, Akira; Yoshihara, Sozaboru; Kanda, Hiroshi; Senda, Syoichi; Saito, Masao

    In order to evaluate the properties of ultrasonic nonlinear scattering, the ultrasonic attenuation characteristics using the second harmonic component of the transmitted ultrasonic signal through normal and fatty hen liver as well as the fundamental component were measured. In The experiment, a 50MHz transducer was by reflection method and its frequency dependency was analyzed. The second harmonic component was detected by using pulse inversion detection technique. The experimental results showed that the attenuation coefficient was almost constant around second harmonic frequency dependence can identify the property of normal and fatty hen liver.

  20. Effect of Thermal Degradation on High Temperature Ultrasonic Transducer Performance in Small Modular Reactors

    NASA Astrophysics Data System (ADS)

    Bilgunde, Prathamesh N.; Bond, Leonard J.

    Prototype ultrasonic NDT transducers for use in immersion in coolants for small modular reactors have shown low signal to noise ratio. The reasons for the limitations in performance at high temperature are under investigation, and include changes in component properties. This current work seeks to quantify the issue of thermal expansion and degradation of the piezoelectric material in a transducer using a finite element method. The computational model represents an experimental set up for an ultrasonic transducer in a pulse-echo mode immersed in a liquid sodium coolant. Effect on transmitted and received ultrasonic signal due to elevated temperature (?200oC) has been analysed.

  1. Measurements of coating density using ultrasonic reflection coefficient phase spectrum.

    PubMed

    Zhao, Y; Li, X M; Lin, L; Lei, M K

    2011-07-01

    A nondestructive method to determine the density of coating has been proposed in this paper based on the ultrasonic reflection coefficient phase spectrum (URCPS). A model was set up first to represent the ultrasonic waves reflected from a coating system at normal incident, and the relation between the extremum of URCPS and the coating density was established to provide the principle of determining the density. The ultrasonic method was validated on a series of ZrO2-7wt.%Y2O3 (YSZ) coatings with various density. The specimens were prepared by electric beam physical vapor deposit (EB-PVD). After deposition, the specimens were irradiated using high-intensity pulsed ion beam (HIPIB) at different ion current density of 100 and 200A/cm2 to change coating density. The coating densities of as-deposited and post irradiation by HIPIB were derived to be 4940-5030, 5200-5320 and 5390-5470kg/m3, respectively. The relative error between the coating density measured by the ultrasonic method and Archimedean principle ranging from 2.53% to 6.11%, indicates that the proposed ultrasonic quantification method provides a reliable nondestructive way to determine coating density. PMID:21255813

  2. Photodistruptive laser nucleation of ultrasonic cavitation for biomedical applications

    NASA Astrophysics Data System (ADS)

    Miller, Doug L.; Spooner, Greg J.; Williams, Alun R.

    2001-07-01

    Pulses of high intensity laser light, when focused into transparent materials, may produce localized electron-ion plasmas through optical breakdown. By simultaneously incorporating the resulting volume of vaporized material within the focal volume of a high intensity ultrasound source, the photodisruption (1.05 micrometers wavelength) void served as a nucleation site for ultrasonic cavitation. Dilute suspensions of canine erythrocytes in phosphate buffered saline were exposed in a flow-through exposure chamber and the percentage of lysed cells was used as a measure of the biologically effective cavitation activity produced in the chamber. Brief (about 30 microsecond(s) ) acoustic emissions were detected from the photodisruption alone (indicating laser nucleation of bubbles), but the cell lysis produced was undetectable against the background. However, combined exposure greatly increased both the duration of the acoustic emissions (up to 1.5 ms) and the amount of cell lysis above an ultrasonic pressure amplitude threshold of about 4.3 MPa at 2.5 MHz. The amount of cell lysis (sometimes approaching 100%) increased with increasing ultrasonic intensity, laser pulse energy and laser PRF. Addition of 5% serum albumin enhanced the effect, apparently by stabilizing bubbles and nuclei. Photodisruptive laser nucleation of ultrasonic cavitation can provide controlled and synergistic enhancement of bioeffects.

  3. Aircraft components structural health monitoring using flexible ultrasonic transducer arrays

    NASA Astrophysics Data System (ADS)

    Liu, W.-L.; Jen, C.-K.; Kobayashi, M.; Mrad, N.

    2011-04-01

    A damage detection capability based on a flexible ultrasonic transducer (FUT) array bonded onto a planar and a curved surface is presented. The FUT array was fabricated on a 75 ?m titanium substrate using sol-gel spray technique. Room temperature curable adhesive is used as the bonding agent and ultrasonic couplant between the transducer and the test article. The bonding agent was successfully tested for aircraft environmental temperatures between -80 °C and 100 °C. For a planar test article, selected FUT arrays were able to detect fasteners damage within a planar distance of 176 mm, when used in the pulse-echo mode. Such results illustrate the effectiveness of the developed FUT transducer as compared to commercial 10MHz ultrasonic transducer (UT). These FUT arrays were further demonstrated on a curved test article. Pulse-echo measurements confirmed the reflected echoes from the specimen. Such measurement was not possible with commercial UTs due to the curved nature of the test article and its accessibility, thus demonstrating the suitability and superiority of the developed flexible ultrasonic transducer capability.

  4. 21 CFR 870.2880 - Ultrasonic transducer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Ultrasonic transducer. 870.2880 Section 870...Cardiovascular Monitoring Devices § 870.2880 Ultrasonic transducer. (a) Identification. An ultrasonic transducer is a device applied to...

  5. 21 CFR 870.2880 - Ultrasonic transducer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Ultrasonic transducer. 870.2880 Section 870...Cardiovascular Monitoring Devices § 870.2880 Ultrasonic transducer. (a) Identification. An ultrasonic transducer is a device applied to...

  6. 21 CFR 870.2880 - Ultrasonic transducer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Ultrasonic transducer. 870.2880 Section 870...Cardiovascular Monitoring Devices § 870.2880 Ultrasonic transducer. (a) Identification. An ultrasonic transducer is a device applied to...

  7. 21 CFR 870.2880 - Ultrasonic transducer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Ultrasonic transducer. 870.2880 Section 870...Cardiovascular Monitoring Devices § 870.2880 Ultrasonic transducer. (a) Identification. An ultrasonic transducer is a device applied to...

  8. NOVEL TECHNIQUES IN ULTRASONIC CORRELATION SPECTROSCOPY

    E-print Network

    Page, John

    1 NOVEL TECHNIQUES IN ULTRASONIC CORRELATION SPECTROSCOPY: Characterizing the Dynamics of Strongly or inclusions), traditional ultrasonic imaging techniques break down, motivating the search for other approaches together collectively throughout the scattering volume probed by the ultrasonic beam. However

  9. 21 CFR 870.2880 - Ultrasonic transducer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Ultrasonic transducer. 870.2880 Section 870...Cardiovascular Monitoring Devices § 870.2880 Ultrasonic transducer. (a) Identification. An ultrasonic transducer is a device applied to...

  10. Rat Pups Reduce Ultrasonic Vocalization After Exposure

    E-print Network

    Barr, Gordon A.

    Rat Pups Reduce Ultrasonic Vocalization After Exposure to an Adult Male Rat Christoph P to the male emitted significantly fewer ultrasonic vocalizations than controls, but did not differ. Keywords: rat; ultrasonic vocalization; immobility; infanticide; anxiety-like behavior Animals have

  11. COMPRESSION, ESTIMATION, AND ANALYSIS OF ULTRASONIC SIGNALS

    E-print Network

    Saniie, Jafar

    COMPRESSION, ESTIMATION, AND ANALYSIS OF ULTRASONIC SIGNALS BY GUILHERME CARDOSO DE CARDOSO .................................................................. 5 2.2 Ultrasonic Imaging ................................................................ 7 2. THRESHOLDING TECHNIQUES FOR DENOISING AND COMPRESSING ULTRASONIC SIGNALS ........................... 19 3

  12. Borehole data transmission apparatus

    DOEpatents

    Kotlyar, Oleg M. (1739 Grandview #2, Idaho Falls, ID 83402)

    1993-01-01

    A borehole data transmission apparatus whereby a centrifugal pump impeller(s) is used to provide a turbine stage having substantial pressure characteristics in response to changing rotational speed of a shaft for the pressure pulsing of data from the borehole through the drilling mud to the surface of the earth.

  13. Borehole data transmission apparatus

    DOEpatents

    Kotlyar, O.M.

    1993-03-23

    A borehole data transmission apparatus is described whereby a centrifugal pump impeller(s) is used to provide a turbine stage having substantial pressure characteristics in response to changing rotational speed of a shaft for the pressure pulsing of data from the borehole through the drilling mud to the surface of the earth.

  14. Study of microstructure of surface layers of low-carbon steel after turning and ultrasonic finishing

    NASA Astrophysics Data System (ADS)

    Kovalevskaya, Zh. G.; Ivanov, Yu. F.; Perevalova, O. B.; Klimenov, V. A.; Uvarkin, P. V.

    2013-01-01

    Profilometry and optical and transmission electron microscopy are used to examine the microstructure of surface layers of a low-carbon ferrite-pearlite steel subjected to turning and ultrasonic finishing. It is shown that turning peaks and valleys have different microstructures, which stipulates manifestation of technological hereditary when processing surfaces of machined parts. Ultrasonic finishing causes the severe plastic deformation of the surface layer, which favors the elimination of a technological heredity that is acquired during turning.

  15. Ultrasonic techniques for process monitoring and control.

    SciTech Connect

    Chien, H.-T.

    1999-03-24

    Ultrasonic techniques have been applied successfully to process monitoring and control for many industries, such as energy, medical, textile, oil, and material. It helps those industries in quality control, energy efficiency improving, waste reducing, and cost saving. This paper presents four ultrasonic systems, ultrasonic viscometer, on-loom, real-time ultrasonic imaging system, ultrasonic leak detection system, and ultrasonic solid concentration monitoring system, developed at Argonne National Laboratory in the past five years for various applications.

  16. Fresnel lenses for ultrasonic inspection

    NASA Technical Reports Server (NTRS)

    Kammerer, C. C.

    1980-01-01

    Ultrasonic Fresnel lenses are effective focusing elements with potential applications in ultrasonic "contact" testing for defects in materials. Ultrasonic beams focused on concave lenses are used successfully with immersion transducers, for which test object is immersed in water bath. However, for large objects, objects that are already installed, objects on production lines, and objects that can be damaged by water, contact testing is more practical than immersion.

  17. Ultrasonic Doppler measurement of renal artery blood flow

    NASA Technical Reports Server (NTRS)

    1974-01-01

    Implantable pulsed Doppler ultrasonic flowmeter development has resulted in designs for application to the aortas of dogs and humans, and to human renal and coronary arteries. A figure of merit was derived for each design, indicating the degree of its precision. An H-array design for transcutaneous observation of blood flow was developed and tested in vitro. Two other simplified designs for the same purpose obviate the need to determine vessel orientation. One of these will be developed in the next time period. Techniques for intraoperative use and for implantation have had mixed success. While satisfactory on large vessels, higher ultrasonic frequencies and alteration of transducer design are required for satisfactory operation of pulsed Doppler flowmeters with small vessels.

  18. Magnetic sensing via ultrasonic excitation

    NASA Astrophysics Data System (ADS)

    Yamada, Hisato; Takashima, Kazuya; Ikushima, Kenji; Toida, Hiraku; Sato, Michitaka; Ishizawa, Yoshiichi

    2013-04-01

    We present ultrasonic techniques for magnetic measurements. Acoustically modulated magnetization is investigated with sensitive rf detection by narrowband loop antennas. Magnetization on the surface of ferromagnetic metals is temporally modulated with the rf frequency of the irradiated ultrasonic waves, and the near-field components emitted from the focal point of the ultrasonic beam are detected. Based on the principle of the acoustically stimulated electromagnetic (ASEM) response, magnetic sensing and tomography are demonstrated by ultrasonic scanning. We show that ASEM imaging combines good acoustic resolution with magnetic contrast. The sensitivity of this method is estimated to be about 6 G/Hz1/2 in our current setup.

  19. Ultrasonic Transducers for Fourier Analysis.

    ERIC Educational Resources Information Center

    Greenslade, Thomas B., Jr.

    1995-01-01

    Describes an experiment that uses the ultrasonic transducer for demonstrating the Fourier components of waveshapes such as the square and triangular waves produced by laboratory function generators. (JRH)

  20. Process tomography using ultrasonic sensors

    NASA Astrophysics Data System (ADS)

    Hoyle, B. S.

    1996-03-01

    The use of ultrasonic transducers for process tomography is in its infancy relative to many other techniques, in particular considering the widespread use of ultrasonic transducers in a variety of non-tomographic sensing applications. This review deals with the background sensing principles of ultrasound transducers employed in tomography, their associated advantages and their difficulties, including the critical time required for data collection, and implications for multiple projection tomography. The theoretical and basic practical implementation of tomography systems using ultrasonic transducers is then considered. Finally a review is included of research investigations into the use of ultrasonic-based process tomography systems.

  1. Ultrasonic differential measurement

    DOEpatents

    Rhodes, George W. (Albuquerque, NM); Migliori, Albert (Santa Fe, NM)

    1995-01-01

    A method and apparatus for ultrasonic resonance testing of an object is shown and described. Acoustic vibrations are applied to an object at a plurality of frequencies. Measurements of the object's vibrational response are made simultaneously at different locations on said object. The input frequency is stepped by using small frequency changes over a predetermined range. There is a pause interval or ring delay which permits the object to reach a steady state resonance before a measurement is taken.

  2. Miniature implantable ultrasonic echosonometer

    NASA Technical Reports Server (NTRS)

    Kojima, G. K. (inventor)

    1978-01-01

    A miniature echosonometer adapted for implantation in the interior of an animal for imaging the internal structure of a organ, tissue or vessel is presented. The echosonometer includes a receiver/transmitter circuit which is coupled to an ultrasonic transducer. Power is coupled to the echosonometer by electromagnetic induction through the animal's skin. Imaging signals from the echosonometer are electromagnetically transmitted through the animal's skin to an external readout apparatus.

  3. Ultrasonic Cutting of Foods

    NASA Astrophysics Data System (ADS)

    Schneider, Yvonne; Zahn, Susann; Rohm, Harald

    In the field of food engineering, cutting is usually classified as a mechanical unit operation dealing with size reduction by applying external forces on a bulk product. Ultrasonic cutting is realized by superpositioning the macroscopic feed motion of the cutting device or of the product with a microscopic vibration of the cutting tool. The excited tool interacts with the product and generates a number of effects. Primary energy concentration in the separation zone and the modification of contact friction along the tool flanks arise from the cyclic loading and are responsible for benefits such as reduced cutting force, smooth cut surface, and reduced product deformation. Secondary effects such as absorption and cavitation originate from the propagation of the sound field in the product and are closely related to chemical and physical properties of the material to be cut. This chapter analyzes interactions between food products and ultrasonic cutting tools and relates these interactions with physical and chemical product properties as well as with processing parameters like cutting velocity, ultrasonic amplitude and frequency, and tool design.

  4. Application of multi-channel photoelastic imaging technology in array type ultrasonic nondestructive testing

    NASA Astrophysics Data System (ADS)

    Fan, Zhen-zhong; Bi, Chao

    2015-08-01

    With the rapid development of modern nondestructive testing technologies, ultrasonic phased array and Ultrasonic array testing technology has been used widely, at the same time the propagation process of ultrasonic in the material becomes more and more complex. In order to make the ultrasonic propagation path become visible and researchers can observe the acoustic field directly, considering the properties of the ultrasonic as a stress wave, according to the theory of polarized light interference, a multi-channel dynamic photoelastic imaging system is developed successfully. The system can generate many kinds of focusing ultrasonic fields in optical specimen by controlling the ultrasonic transmission delay time of each equipment channel, and the system has the ability to simulate the acoustic field's focusing process of the ultrasonic phased array. The image shot by CCD camera reflects the propagation process of the acoustic field in the specimen, and the dynamic video is formed under control of the timing circuit, and the system has the ability to save the captured image in the computer.

  5. A Method For The Verification Of Wire Crimp Compression Using Ultrasonic Inspection

    NASA Technical Reports Server (NTRS)

    Cramer, K. E.; Perey, Daniel F.; Yost, William t.

    2010-01-01

    The development of a new ultrasonic measurement technique to assess quantitatively wire crimp terminations is discussed. The amplitude change of a compressional ultrasonic wave propagating at right angles to the wire axis and through the junction of a crimp termination is shown to correlate with the results of a destructive pull test, which is a standard for assessing crimp wire junction quality. To demonstrate the technique, the case of incomplete compression of crimped connections is ultrasonically tested, and the results are correlated with pull tests. Results show that the nondestructive ultrasonic measurement technique consistently predicts good crimps when the ultrasonic transmission is above a certain threshold amplitude level. A quantitative measure of the quality of the crimped connection based on the ultrasonic energy transmitted is shown to respond accurately to crimp quality. A wave propagation model, solved by finite element analysis, describes the compressional ultrasonic wave propagation through the junction during the crimping process. This model is in agreement within 6% of the ultrasonic measurements. A prototype instrument for applying this technique while wire crimps are installed is also presented. The instrument is based on a two-jaw type crimp tool suitable for butt-splice type connections. A comparison of the results of two different instruments is presented and shows reproducibility between instruments within a 95% confidence bound.

  6. Acoustooptic pulse-echo transducer system

    NASA Technical Reports Server (NTRS)

    Claus, R. O.; Wade, J. C.

    1983-01-01

    A pulse-echo transducer system which uses an ultrasonic generating element and an optical detection technique is described. The transmitting transducer consists of a concentric ring electrode pattern deposited on a circular, X-cut quartz substrate with a circular hole in the center. The rings are independently pulsed with a sequence high voltage signals phased in such a way that the ultrasonic waves generated by the separate rings superimpose to produce a composite field which is focused at a controllable distance below the surface of the specimen. The amplitude of the field reflected from this focus position is determined by the local reflection coefficient of the medium at the effective focal point. By processing the signals received for a range of ultrasonic transducer array focal lengths, the system can be used to locate and size anomalies within solids and liquids. Applications in both nondestructive evaluation and biomedical scanning are suggested.

  7. Elastic moduli of boron carbide/copper composites from -40/sup 0/C to 800/sup 0/C by ultrasonic methods

    SciTech Connect

    Gieske, J.H.

    1980-10-01

    An ultrasonic through-transmission technique for high attenuating materials was developed to determine the ultrasonic longitudinal and shear velocities in B/sub 4/C/Cu composites to 800/sup 0/C. Ultrasonic velocity data was used to calculate Young's modulus, shear modulus, and Poisson's ratio for the composites from -40/sup 0/C to 800/sup 0/C. 5 figures, 1 table.

  8. Transmission electron microscopy study of amorphous Ge2Sb2Te5 films induced by an ultraviolet single-pulse laser

    NASA Astrophysics Data System (ADS)

    Zhao, J. J.; Liu, F. R.; Han, X. X.; Zhu, Z.; Lin, X.; Liu, F.; Sun, N. X.

    2014-08-01

    Crystallization behaviors of ?-GST films with the thickness of 80 and 30 nm induced by an ultraviolet pulse laser were investigated by using TEM integrated with SAED. Firstly, crystalline phase morphologies were shown and analyzed. Both plate grains and spherical grains were found for 80 nm thick film, while only plate grains were found for 30 nm thick film. Then the relationship between the grain size and laser fluence for the 80 nm thick film was studied and the effects of film thickness on crystallization morphology were analyzed. Finally a crystallization process model based on the relationship of the crystallization starting temperature and heating temperature was constructed to elucidate how the solid-phase crystallization and melt-cooling crystallization occurred and developed. It also unified the crystallization starting temperature under static conditions and the crystallization starting temperature under laser inducing conditions.

  9. Ultrasonic nondestructive characterization of composites with 3-dimensional architectures

    NASA Technical Reports Server (NTRS)

    Miller, James G.

    1992-01-01

    The development and implementation of advanced composite material systems and their associated technologies are critical for success in the highly competitive world aerospace market. Acceptance of advance production methods and field support of structures made with these new materials require the development of quantitative, cost-effective, inspection methods. The results of quantitative ultrasonic through-transmission imaging of composites with complex three-dimensional architecture using phase-insensitive and phase-sensitive techniques are presented.

  10. Acousto-ultrasonics - An update

    NASA Technical Reports Server (NTRS)

    Vary, Alex

    1989-01-01

    The application possibilities and limitations of acoustoultrasonics are reviewed. One of the most useful aspects of acousto-ultrasonics is its ability to assess degradation and damage states in composites. The sensitivity of the acousto-ultrasonic approach for detecting and measuring subtle but significant material property variations in composites has been demonstrated.

  11. Ultrasonic cleaning: An historical perspective.

    PubMed

    Mason, Timothy J

    2016-03-01

    The development of ultrasonic cleaning dates from the middle of the 20th century and has become a method of choice for a range of surface cleaning operations. The reasons why this has happened and the methods of assessing the efficiency of ultrasonic cleaning baths are reviewed. PMID:26054698

  12. Ultrasonic imaging of static objects through an aberrating layer using harmonic phase conjugation approach.

    PubMed

    Mirzania, Raheleh; Shapoori, Kiyanoosh; Malyarenko, Eugene; Maev, Roman Gr

    2015-04-01

    The main goal of this study is to develop a new image reconstruction approach for the ultrasonic detection of small objects (comparable to or smaller than the ultrasonic wavelength) behind an aberrating layer. Instead of conventional pulse-echo experimental setup we used through transmission, as the backscattered field after going twice through the layer becomes much weaker than the through-transmitted field. The proposed solution is based on the Harmonic Phase Conjugation (HPC) technique. The developed numerical model allows to calculate the amplitude and phase distributions of the through-transmitted acoustic field interacting with the objects and received by a linear transducer array either directly or after passing through an additional aberrating layer. Then, the digitized acoustic field received by the array is processed, phase-conjugated, and finally, numerically propagated back through the medium in order to reconstruct the image of the target objects. The reconstruction quality of the algorithm was systematically tested on a numerical model, which included a barrier, a medium behind it, and a group of three scatterers, by varying scatterer distances from the source transducer, their mutual arrangement, and the angle of the incident field. Subsequently, a set of laboratory experiments was conducted (at transmit frequency of 2 MHz) to verify the accuracy of the developed simulation. The results demonstrate feasibility of imaging multiple scattering objects through a barrier using the HPC method with better than 1mm accuracy. The results of these tests are presented, and the feasibility of implementing this approach for various biomedical and NDT imaging applications is discussed. PMID:25553713

  13. Ultrasonic flow nozzle cleaning apparatus

    SciTech Connect

    Fridsma, D.E.; Silvestri, G.J. Jr.; Twerdochlib, M.

    1992-06-23

    This patent describes an ultrasonic cleaning apparatus for a venturi flow measuring nozzle mounted in a pipe of a steam power plant and having an inlet, venturi throat, and an outlet, the pipe and nozzle having fluid flowing therethrough, the cleaning occurring while the fluid is flowing. It comprises first ultrasonic transducer means mounted to connect to the inside of the pipe, disposed adjacent the inlet of the venturi flow nozzle and the means being in direct contact with the fluid flowing through the pipe for transmitting ultrasonic waves directly into and thereby exciting the fluid flowing through the venturi flow nozzle; and control means coupled to the first ultrasonic transducer means for activating the first ultrasonic transducer means.

  14. Enzyme-catalyzed synthesis and kinetics of ultrasonic-assisted biodiesel production from waste tallow.

    PubMed

    Adewale, Peter; Dumont, Marie-Josée; Ngadi, Michael

    2015-11-01

    The use of ultrasonic processing was evaluated for its ability to achieve adequate mixing while providing sufficient activation energy for the enzymatic transesterification of waste tallow. The effects of ultrasonic parameters (amplitude, cycle and pulse) and major reaction factors (molar ratio and enzyme concentration) on the reaction kinetics of biodiesel generation from waste tallow bio-catalyzed by immobilized lipase [Candida antarctica lipase B (CALB)] were investigated. Three sets of experiments namely A, B, and C were conducted. In experiment set A, two factors (ultrasonic amplitude and cycle) were investigated at three levels; in experiment set B, two factors (molar ratio and enzyme concentration) were examined at three levels; and in experiment set C, two factors (ultrasonic amplitude and reaction time) were investigated at five levels. A Ping Pong Bi Bi kinetic model approach was employed to study the effect of ultrasonic amplitude on the enzymatic transesterification. Kinetic constants of transesterification reaction were determined at different ultrasonic amplitudes (30%, 35%, 40%, 45%, and 50%) and enzyme concentrations (4, 6, and 8 wt.% of fat) at constant molar ratio (fat:methanol); 1:6, and ultrasonic cycle; 5 Hz. Optimal conditions for ultrasound-assisted biodiesel production from waste tallow were fat:methanol molar ratio, 1:4; catalyst level 6% (w/w of fat); reaction time, 20 min (30 times less than conventional batch processes); ultrasonic amplitude 40% at 5 Hz. The kinetic model results revealed interesting features of ultrasound assisted enzyme-catalyzed transesterification (as compared to conventional system): at ultrasonic amplitude 40%, the reaction activities within the system seemed to be steady after 20 min which means the reaction could proceed with or without ultrasonic mixing. Reversed phase high performance liquid chromatography indicated the biodiesel yield to be 85.6±0.08%. PMID:26186814

  15. Petawatt pulsed-power accelerator

    DOEpatents

    Stygar, William A. (Albuquerque, NM); Cuneo, Michael E. (Albuquerque, NM); Headley, Daniel I. (Albuquerque, NM); Ives, Harry C. (Albuquerque, NM); Ives, legal representative; Berry Cottrell (Albuquerque, NM); Leeper, Ramon J. (Albuquerque, NM); Mazarakis, Michael G. (Albuquerque, NM); Olson, Craig L. (Albuquerque, NM); Porter, John L. (Sandia Park, NM); Wagoner; Tim C. (Albuquerque, NM)

    2010-03-16

    A petawatt pulsed-power accelerator can be driven by various types of electrical-pulse generators, including conventional Marx generators and linear-transformer drivers. The pulsed-power accelerator can be configured to drive an electrical load from one- or two-sides. Various types of loads can be driven; for example, the accelerator can be used to drive a high-current z-pinch load. When driven by slow-pulse generators (e.g., conventional Marx generators), the accelerator comprises an oil section comprising at least one pulse-generator level having a plurality of pulse generators; a water section comprising a pulse-forming circuit for each pulse generator and a level of monolithic triplate radial-transmission-line impedance transformers, that have variable impedance profiles, for each pulse-generator level; and a vacuum section comprising triplate magnetically insulated transmission lines that feed an electrical load. When driven by LTD generators or other fast-pulse generators, the need for the pulse-forming circuits in the water section can be eliminated.

  16. Ultrasonic scanning of multilayer ceramic chip capacitors

    NASA Technical Reports Server (NTRS)

    Bradley, F. N.

    1981-01-01

    Ultrasonic scanning is compared to neutron radiography and scanning laser acoustic microscopy (SLAM). Data show that SLAM and ultrasonic scanning evaluations are in good agreement. There is poor agreement between N-ray and both ultrasonic techniques because N-ray is insensitive to all but the grossest delaminations. Statistical analysis show a good correlation between ultrasonic scanning and destructive physical analysis.

  17. Hydrodynamic ultrasonic probe

    DOEpatents

    Day, Robert A. (Livermore, CA); Conti, Armond E. (San Jose, CA)

    1980-01-01

    An improved probe for in-service ultrasonic inspection of long lengths of a workpiece, such as small diameter tubing from the interior. The improved probe utilizes a conventional transducer or transducers configured to inspect the tubing for flaws and/or wall thickness variations. The probe utilizes a hydraulic technique, in place of the conventional mechanical guides or bushings, which allows the probe to move rectilinearly or rotationally while preventing cocking thereof in the tube and provides damping vibration of the probe. The probe thus has lower friction and higher inspection speed than presently known probes.

  18. Ultrasonic Vitrectomy Instrument

    NASA Astrophysics Data System (ADS)

    Wuchinich, D.

    Contemporary vitrectomy devices utilize an air driven stylus reciprocating within a sheath at a sonic frequency, guillotining and then aspirating the vitreous gel admitted through a distal port in the side of the sheath. A small handheld ultrasonic instrument (Banko 1971) operating at 50 kHz, utilizing a solid titanium stylus, within a 20 needle gauge sheath, vibrating at an excursion between 150 and 200 microns, has been developed to precisely and rapidly liquefy and aspirate, at 360 mmHg vacuum, vitreous humor from bovine eyes.

  19. Ultrasonic linear measurement system

    NASA Technical Reports Server (NTRS)

    Marshall, Scot H. (Inventor)

    1991-01-01

    An ultrasonic linear measurement system uses the travel time of surface waves along the perimeter of a three-dimensional curvilinear body to determine the perimeter of the curvilinear body. The system can also be used piece-wise to measure distances along plane surfaces. The system can be used to measure perimeters where use of laser light, optical means or steel tape would be extremely difficult, time consuming or impossible. It can also be used to determine discontinuities in surfaces of known perimeter or dimension.

  20. Ultrasonic cleaner evaluation

    SciTech Connect

    Gillespie, T.J.

    1980-10-08

    A method has been developed to evaluate the capabilities of ultrasonic cleaners. This method utilizes a ceramic plate on which a metallized coating has been deposited. The plate is immersed in a beaker filled with DI water and a few drops of liquid detergent. The plate is then subjected to a two-minute cleaning cycle. Measurement of the amount of metallized coating that has been removed is determined with an image enhancement system. Use of this test has also revealed several factors that influence cleaning capabilities. These include system frequency, use of a wetting agent in the bath, bath temperature, fixture materials and fixture mounting.

  1. Ultrasonic characterization of delamination in aeronautical composites using noncontact laser generation and detection.

    PubMed

    Sun, Guangkai; Zhou, Zhenggan; Chen, Xiucheng; Wang, Jie

    2013-09-10

    The characterization of delamination in composite plates with ultrasonic waves generated and detected by lasers is presented. Composite materials have become one of the most important structural materials in the aviation industry because of their excellent mechanical properties, such as high specific stiffness and antifatigue. This paper reports a new application of the laser ultrasonic technique to perform nondestructive detection of carbon-fiber-reinforced plastic (CFRP) and continuous-fiber-reinforced ceramic matrix composites (CFCCs) containing artificial internal defects, based on propagation characteristic of ultrasonic waves generated by pulse laser with a wavelength of 1064 nm and pulse duration of 10 ns. A laser interferometer based on two-wave mixing is used to measure ultrasonic wave signals. The main advantage of this technique over conventional ultrasonic testing techniques is the ability to carry out detection without using coupling agents. The research results prove that the laser ultrasonic technique is effective for the detection of internal defects in both CFRP and CFCC composite components, which should promote and expand the application of the technique in the aviation industry. PMID:24085123

  2. Analysis of laser ultrasonic measurements of surface waves on elastic spheres

    SciTech Connect

    Koo, L.S.; Telschow, K.L.

    1991-01-01

    In conventional ultrasonic nondestructive evaluation studies, piezoelectric transducers are used to generate sound waves in solids via a couplant that transmits the mechanical motions. In recent years, a different method of generating sound in solids, pulsed laser heating, was introduced by White. This method is noncontacting, requires no coupling medium, and operates directly on the surface of the specimen. Noncontacting ultrasonic detection using laser interferometers of several types has also been developed. Laser techniques can achieve essentially point source and point detection of ultrasonic motion through focusing. Laser ultrasonics can, therefore, be used on objects with complex shapes, e.g. curved surfaces, and are applicable to material shapes more commonly found in industry. Often the goal of ultrasonic measurements is to determine material properties such as Lame's elastic constants. The conventional approach measures longitudinal and shear wave speeds between two parallel flat surfaces. The work reported here demonstrates the versatility of laser ultrasonics by directly measuring the surface motion of a solid sphere generated by ablation from a pulsed laser beam in the ablation regime. The results compare well with elastodynamic theoretical calculations, where the ablation source is approximated well with elastodynamic theoretical calculations, where the ablation source is approximated as a normal impulse on the surface. This work suggests that an algorithm could be formulated to measure elastic properties of targets with curved surfaces. 15 refs., 5 figs.

  3. Robust Ultrasonic Waveguide Based Distributed Temperature Sensing

    NASA Astrophysics Data System (ADS)

    Periyannan, S.; Rajagopal, P.; Balasubramaniam, K.

    This is a novel technique for distributed temperature measurements, using single robust ultrasonic wire or strip-like waveguides, special embodiments in the form of Helical or Spiral configurations that can cover large area/volume in enclosed regions. Such distributed temperature sensing has low cost applications in the long term monitoring critical enclosures such as containment vessels, flue gas stacks, furnaces, underground storage tanks, buildings for fire, etc. The range of temperatures that can be measured are from very low to elevated temperatures. The transduction is performed using Piezo-electric crystals that are bonded to one end of the waveguide which acts as both transmitter and receivers. The wires will have periodic reflector embodiments (bends, gratings, etc.) that allow reflections of an input ultrasonic wave, in a pulse echo mode, back to the crystal. Using the time of fight (TOF) variations at the multiple predefined reflector locations, the measured temperatures are mapped with multiple thermocouples. Using either the L(0,1) or the T(0,1)modes, or simultaneously, measurements other than temperature may also be included. This paper will describe the demonstration of this technology using a 0.5 MHz longitudinal piezo-crystal for transmitting and receiving the L (0, 1) mode through the special form of waveguide at various temperatures zones.

  4. Laser-ultrasonic technologies for medicine

    NASA Astrophysics Data System (ADS)

    Zharov, Vladimir P.; Latyshev, Alexei S.

    1999-06-01

    This review tackles the problem of further developing laser- ultrasonic medical technologies and gives the comparison of different laser and ultrasound combinations. The features of combined influence on biotissue are explicated with due regard for mechanic, ultrasonic (US), and thermal effects. The review present the effect of self-cleaning an optical fiber tip from the laser destruction products of biotissue, the result of research on the possibility of laser-US technology applications in endoscopy, and the ways of suppressing unwanted bending oscillations. Various spheres and peculiarities of applying laser-US technologies are discussed, including microsurgery, cosmetology, transcutaneous drug delivery, and the treatment of chronic prostatitis and infected wounds. Furthermore, the analysis of transcutaneous drug delivery methods employing a portable pulsed Er:YAG laser is presented. Drug diffusion has been shown to be enhanced under acoustic and US effects. The photo-vacuum drug injection mechanism recently suggested is discussed. It turned out that laser-US technology can be suitable for both impregnating the photosensitizer in local photodynamic therapy procedures and conducting microsurgery operations involving drug injection. Treatment of infectious processes based on the bactericidal action of photosensitizers and ultrasound due to the cavitation effect in solutions is described. An additional therapeutic effect can be achieved via the US intermingling of solutions with their simulations illumination by a matrix of red lasers or light diodes. An outlook on further developing laser-US technology and the ways of its apparatus realization are considered.

  5. Photorefractive Interferometers for Ultrasonic Measurements on Paper

    SciTech Connect

    Lafond, E. F.; Brodeur, P. H.; Gerhardstein, J. P.; Habeger, C. C.; Telschow, Kenneth Louis

    2002-12-01

    Photorefractive interferometers have been employed for the detection of ultrasound in metals and composites since 1991 [1–4]. Instances of laser-generated ultrasound and laser-based detection in paper were reported in 1996 [5]. More recently, bismuth silicon oxide (BSO) photorefractive interferometers were adapted to detect ultrasound in paper [6]. In this article we discuss BSO and GaAs photorefractive detection of ultrasound on different paper grades and present the resulting waveforms. Compared to contact piezoelectric transducer methods, laser interferometry offers signifcant advantages. One of these is that it is a noncontact technique. This is especially important for on-line application to lightweight papers which could be marked or damaged by contact transducers. Broadband ultrasonic laser generation matched with the broadband sensitivity of laser interferometers is another beneft. This is important for obtaining narrow pulses in nondispersive time-of-fight determinations and for measuring the phase velocity of dispersive modes over a wide frequency band. Also, laser ultrasonic techniques provide a measure of bending stiffness through the analysis of low frequency A0 waves.

  6. Ultrasonic thermoacoustic cooler

    NASA Astrophysics Data System (ADS)

    Kwon, Young S.; El-Gendy, H.; Symko, O. G.

    2005-09-01

    The development of a thermoacoustic cooler in the ultrasonic range is presented. This cooler was designed to operate at a drive frequency of 24 kHz using air as the working fluid; the resonator is 7.1 mm long and it contains a cotton wool stack with copper heat exchangers at each end. Since the ultrasonic driver is a key element in this device, a major effort was made to optimize its performance and coupling to the resonator. It is a resonant piezoelectric monomorph loaded with a metallic cone for impedance matching to the resonator. By its design it is capable of intense sound levels, of order 140 dB and higher. The attained cooling power scales with the sound power levels and a COP larger than one is achieved. Studies of heat losses consist of PIV imaging of acoustic streaming (such as Eckart) in this device and back heat flow along the stack. The developed device shows much promise for rapid cooling of small samples. [Work supported by the Office of Naval Research.

  7. Ultrasonics and space instrumentation

    NASA Technical Reports Server (NTRS)

    1987-01-01

    The design topic selected was an outgrowth of the experimental design work done in the Fluid Behavior in Space experiment, which relies on the measurement of minute changes of the pressure and temperature to obtain reasonably accurate volume determinations. An alternative method of volume determination is the use of ultrasonic imaging. An ultrasonic wave system is generated by wall mounted transducer arrays. The interior liquid configuration causes reflection and refraction of the pattern so that analysis of the received wave system provides a description of the configuration and hence volume. Both continuous and chirp probe beams were used in a laboratory experiment simulating a surface wetting propellant. The hardware included a simulated tank with gaseous voids, transmitting and receiving transducers, transmitters, receivers, computer interface, and computer. Analysis software was developed for image generation and interpretation of results. Space instrumentation was pursued in support of a number of experiments under development for GAS flights. The program included thirty undergraduate students pursuing major qualifying project work under the guidance of eight faculty supported by a teaching assistant. Both mechanical and electrical engineering students designed and built several microprocessor systems to measure parameters such as temperature, acceleration, pressure, velocity, and circulation in order to determine combustion products, vortex formation, gas entrainment, EMR emissions from thunderstorms, and milli-g-accelerations due to crew motions.

  8. Superlattice ultrasonic generation

    NASA Astrophysics Data System (ADS)

    Wilson, T. E.; Oehme, M.; Kasper, E.; Gossmann, H.-J. L.

    2011-01-01

    We report the first experimental evidence for the resonant excitation of coherent high-frequency acoustic phonons in semiconducting doping superstructures by far-infrared laser radiation. After a grating-coupled delta-doped silicon doping superlattice is illuminated with ~1 kW/mm2 nanosecond-pulsed 246 GHz laser radiation, a delayed nanosecond pulse is detected by a superconducting bolometer at a time corresponding to the appropriate time-of-flight for ballistic longitudinal acoustic phonons across the (100) silicon substrate. The absorbed phonon power density in the microbolometer is observed to be ~10 ?W/mm2, in agreement with theory. The phonon pulse duration also matches the laser pulse duration. The absence of any delayed transverse acoustic phonon signal by the superconducting bolometer is particularly striking and implies there is little or no incoherent phonon generation occurring in the process.

  9. 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. PMID:14749304

  10. Irradiation Testing of Ultrasonic Transducers

    SciTech Connect

    Daw, Joshua; Tittmann, Bernhard; Reinhardt, Brian; Kohse, Gordon E.; Ramuhalli, Pradeep; Montgomery, Robert O.; Chien, Hual-Te; Villard, Jean-Francois; Palmer, Joe; Rempe, Joy

    2014-07-30

    Ultrasonic technologies offer the potential for high accuracy and resolution in-pile measurement of a range of parameters, including geometry changes, temperature, crack initiation and growth, gas pressure and composition, and microstructural changes. Many Department of Energy-Office of Nuclear Energy (DOE-NE) programs are exploring the use of ultrasonic technologies to provide enhanced sensors for in-pile instrumentation during irradiation testing. For example, the ability of single, small diameter ultrasonic thermometers (UTs) to provide a temperature profile in candidate metallic and oxide fuel would provide much needed data for validating new fuel performance models. Other efforts include an ultrasonic technique to detect morphology changes (such as crack initiation and growth) and acoustic techniques to evaluate fission gas composition and pressure. These efforts are limited by the lack of existing knowledge of ultrasonic transducer material survivability under irradiation conditions. For this reason, the Pennsylvania State University (PSU) was awarded an Advanced Test Reactor National Scientific User Facility (ATR NSUF) project to evaluate promising magnetostrictive and piezoelectric transducer performance in the Massachusetts Institute of Technology Research Reactor (MITR) up to a fast fluence of at least 1021 n/cm2 (E> 0.1 MeV). The goal of this research is to characterize magnetostrictive and piezoelectric transducer survivability during irradiation, enabling the development of novel radiation tolerant ultrasonic sensors for use in Material and Test Reactors (MTRs). As such, this test will be an instrumented lead test and real-time transducer performance data will be collected along with temperature and neutron and gamma flux data. The current work bridges the gap between proven out-of-pile ultrasonic techniques and in-pile deployment of ultrasonic sensors by acquiring the data necessary to demonstrate the performance of ultrasonic transducers.

  11. Irradiation Testing of Ultrasonic Transducers

    SciTech Connect

    Daw, Joshua; Tittmann, Bernhard; Reinhardt, Brian; Kohse, Gordon E.; Ramuhalli, Pradeep; Montgomery, Robert O.; Chien, Hual-Te; Villard, Jean-Francois; Palmer, Joe; Rempe, Joy

    2013-12-01

    Ultrasonic technologies offer the potential for high accuracy and resolution in-pile measurement of a range of parameters, including geometry changes, temperature, crack initiation and growth, gas pressure and composition, and microstructural changes. Many Department of Energy-Office of Nuclear Energy (DOE-NE) programs are exploring the use of ultrasonic technologies to provide enhanced sensors for in-pile instrumentation during irradiation testing. For example, the ability of single, small diameter ultrasonic thermometers (UTs) to provide a temperature profile in candidate metallic and oxide fuel would provide much needed data for validating new fuel performance models. Other efforts include an ultrasonic technique to detect morphology changes (such as crack initiation and growth) and acoustic techniques to evaluate fission gas composition and pressure. These efforts are limited by the lack of existing knowledge of ultrasonic transducer material survivability under irradiation conditions. For this reason, the Pennsylvania State University (PSU) was awarded an Advanced Test Reactor National Scientific User Facility (ATR NSUF) project to evaluate promising magnetostrictive and piezoelectric transducer performance in the Massachusetts Institute of Technology Research Reactor (MITR) up to a fast fluence of at least 1021 n/cm2 (E> 0.1 MeV). The goal of this research is to characterize magnetostrictive and piezoelectric transducer survivability during irradiation, enabling the development of novel radiation tolerant ultrasonic sensors for use in Material and Test Reactors (MTRs). As such, this test will be an instrumented lead test and real-time transducer performance data will be collected along with temperature and neutron and gamma flux data. The current work bridges the gap between proven out-of-pile ultrasonic techniques and in-pile deployment of ultrasonic sensors by acquiring the data necessary to demonstrate the performance of ultrasonic transducers.

  12. Ultrasonic Transducer Irradiation Test Results

    SciTech Connect

    Daw, Joshua; Palmer, Joe; Ramuhalli, Pradeep; Keller, Paul; Montgomery, Robert; Chien, Hual-Te; Kohse, Gordon; Tittmann, Bernhard; Reinhardt, Brian; Rempe, Joy

    2015-02-01

    Ultrasonic technologies offer the potential for high-accuracy and -resolution in-pile measurement of a range of parameters, including geometry changes, temperature, crack initiation and growth, gas pressure and composition, and microstructural changes. Many Department of Energy-Office of Nuclear Energy (DOE-NE) programs are exploring the use of ultrasonic technologies to provide enhanced sensors for in-pile instrumentation during irradiation testing. For example, the ability of small diameter ultrasonic thermometers (UTs) to provide a temperature profile in candidate metallic and oxide fuel would provide much needed data for validating new fuel performance models. Other ongoing efforts include an ultrasonic technique to detect morphology changes (such as crack initiation and growth) and acoustic techniques to evaluate fission gas composition and pressure. These efforts are limited by the lack of identified ultrasonic transducer materials capable of long term performance under irradiation test conditions. For this reason, the Pennsylvania State University (PSU) was awarded an ATR NSUF project to evaluate the performance of promising magnetostrictive and piezoelectric transducers in the Massachusetts Institute of Technology Research Reactor (MITR) up to a fast fluence of at least 1021 n/cm2. The goal of this research is to characterize and demonstrate magnetostrictive and piezoelectric transducer operation during irradiation, enabling the development of novel radiation-tolerant ultrasonic sensors for use in Material Testing Reactors (MTRs). As such, this test is an instrumented lead test and real-time transducer performance data is collected along with temperature and neutron and gamma flux data. The current work bridges the gap between proven out-of-pile ultrasonic techniques and in-pile deployment of ultrasonic sensors by acquiring the data necessary to demonstrate the performance of ultrasonic transducers. To date, one piezoelectric transducer and two magnetostrictive transducers have demonstrated reliable operation under irradiation. The irradiation is ongoing.

  13. Acousto-optical tunable transmissive grating beam splitter

    NASA Astrophysics Data System (ADS)

    Dieulangard, Anthony; Kastelik, Jean-Claude; Dupont, Samuel; Gazalet, Joseph

    2014-03-01

    We present a tunable transmissive grating beam splitter for multiple laser line separation based on acousto-optic interaction in tellurium dioxide. Acousto-optic devices are well known for light modulation, frequency shifting, filtration or deflection. For a deflector, the incident light beam is monochromatic and the angular deviation is proportional to the ultrasonic frequency excursion. For a tunable filter, the selected wavelength is determined by the ultrasonic frequency. Several wavelengths may be simultaneously diffracted using several associated ultrasonic frequencies and all the diffracted beams have the same angular deviation. Unlike the classical operating modes of acousto-optic devices, we consider the simultaneous diffraction of several optical wavelengths by a single ultrasonic frequency. The device is based on Bragg anisotropic interaction in the specific "Tangent Phase Matching" configuration. The acousto-optic interaction takes place with a single ultrasonic frequency and the diffraction efficiency remains high over a wide optical spectral range. The different diffracted beams are then angularly well separated, due to the slow velocity of the ultrasonic wave propagating in tellurium dioxide. The optical bandwidth is directly related to the operating ultrasonic frequency. Numerical calculations were carried out to determine the main parameters of the device: operating ultrasonic frequency, optical bandwidth, tunability range, crystalline cut and transducer length. A practical device has been designed for visible spectrum. Experimental results will be presented as for example a spectral bandwidth from 450 nm to 550 nm with a RF carrier frequency f = 125 MHz.

  14. Ultrasonic fuel quantity gauging system

    SciTech Connect

    Ellinger, S.M.; Jones, H.P.

    1989-03-28

    A method is described for measuring aircraft fuel quantity and density comprising: an ultrasonic transducer, a temperature sensor means, liquid fuel, computer control, and an indicator. The computer control consists a central processing unit and memory means, the memory having container volume and fuel temperature data stored therein. The central processing unit is connected to each ultrasonic sensor means, the central processing unit being connected to the temperature sensor means. The indicator is connected to the central processing means. The ultrasonic transducer is supported within a stillwell by the container means; and the liquid fuel being supported within the container means.

  15. Ultrasonic tomography for in-process measurements of temperature in a multi-phase medium

    DOEpatents

    Beller, L.S.

    1993-01-26

    A method and apparatus are described for the in-process measurement of internal particulate temperature utilizing ultrasonic tomography techniques to determine the speed of sound through a specimen material. Ultrasonic pulses are transmitted through a material, which can be a multi-phase material, over known flight paths and the ultrasonic pulse transit times through all sectors of the specimen are measured to determine the speed of sound. The speed of sound being a function of temperature, it is possible to establish the correlation between speed of sound and temperature, throughout a cross-section of the material, which correlation is programmed into a computer to provide for a continuous in-process measurement of temperature throughout the specimen.

  16. Ultrasonic tomography for in-process measurements of temperature in a multi-phase medium

    DOEpatents

    Beller, Laurence S. (Idaho Falls, ID)

    1993-01-01

    A method and apparatus for the in-process measurement of internal particulate temperature utilizing ultrasonic tomography techniques to determine the speed of sound through a specimen material. Ultrasonic pulses are transmitted through a material, which can be a multi-phase material, over known flight paths and the ultrasonic pulse transit times through all sectors of the specimen are measured to determine the speed of sound. The speed of sound being a function of temperature, it is possible to establish the correlation between speed of sound and temperature, throughout a cross-section of the material, which correlation is programmed into a computer to provide for a continuous in-process measurement of temperature throughout the specimen.

  17. Method and apparatus for dual amplitude dual time-of-flight ultrasonic imaging

    NASA Technical Reports Server (NTRS)

    Chern, Engmin James (Inventor); Butler, David W. (Inventor)

    1998-01-01

    A method and apparatus for ultrasonic imaging which includes scanning a test specimen located in a test fixture in a predetermined scan pattern. Propagating and receiving reflected pulses of ultrasonic energy from an ultrasonic transducer directed to a surface of the test specimen. Detecting and generating data of both the amplitude and the depth of a defect in the test specimen from the pulses received from the test specimen. Merging the data of the amplitude and the data of the depth of the defect into composite data and then displaying the composite data in a three dimensional image whereby a mesh of both amplitude and depth data of the defect is displayed in a single image of the defect.

  18. Development of Multiple-Frequency Ultrasonic Imaging System Using Multiple Resonance Piezoelectric Transducer

    NASA Astrophysics Data System (ADS)

    Akiyama, Iwaki; Yoshizumi, Natsuki; Saito, Shigemi; Wada, Yuji; Koyama, Daisuke; Nakamura, Kentaro

    2012-07-01

    The authors have developed a multiple frequency imaging system using a multiple resonance transducer (MRT) consisting of 1-3 composite materials with a low mechanical quality factor Q bonded together. The MRT has a structure consisting of thin and thick piezoelectric plates, two matching layers, and a backing layer. This makes it possible to obtain B-mode images of satisfactory resolution using ultrasonic pulses owing to their short duration. In this paper, the vibration property of the MRT derived through equivalent-circuit analysis is first shown. By utilizing the result, an MRT capable of transmitting ultrasonic pulses for generation of the images of biological tissues with satisfactory resolution is designed and prototyped. Setting the prototype transducer in the mechanical sector probe of commercial ultrasonic diagnosis equipment, the speckle reduction effect is demonstrated using images of various phantoms to mimic biological tissues and a human thyroid.

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

    NASA Astrophysics Data System (ADS)

    He, Q.; Zhang, H. J.; Zhou, H. L.

    2006-10-01

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

  20. Ultrasonic Wave Propagation in Particle Compounded Gels

    NASA Astrophysics Data System (ADS)

    Ueba, Shizuko; Matsukawa, Mami; TakahikoOtani, TakahikoOtani

    1999-05-01

    Attenuation and sound velocity in particle compounded agar weremeasured by an ultrasonic wave transmission technique at frequenciesranging from 1 MHz to 8 MHz. The observed values were discussed usingUrick's theory for viscous suspensions. The measured values ofattenuation and sound velocity were in good agreement with thecalculated values using Urick's theory up to a particle concentrationof 10%. This means that Urick's theory can be applied not only tosuspensions, but also to particle compounded gels. Furthermore, fromthe investigation of the experimental results obtained using thistheory, it was clarified that the attenuation depends on the particledensity. In particular, it should be noted that n depends on theparticle diameter (the attenuation ? can be expressed with theequation ?= ?0fn, where ?0 and n are constants and f isfrequency). All measured and calculated results suggested that theacoustic properties in these kinds of particle compounded gels could beestimated theoretically.

  1. Computer automation of ultrasonic testing. [inspection of ultrasonic welding

    NASA Technical Reports Server (NTRS)

    Yee, B. G. W.; Kerlin, E. E.; Gardner, A. H.; Dunmyer, D.; Wells, T. G.; Robinson, A. R.; Kunselman, J. S.; Walker, T. C.

    1974-01-01

    Report describes a prototype computer-automated ultrasonic system developed for the inspection of weldments. This system can be operated in three modes: manual, automatic, and computer-controlled. In the computer-controlled mode, the system will automatically acquire, process, analyze, store, and display ultrasonic inspection data in real-time. Flaw size (in cross-section), location (depth), and type (porosity-like or crack-like) can be automatically discerned and displayed. The results and pertinent parameters are recorded.

  2. Parallel strip waveguide for ultrasonic flow measurement in harsh environments.

    PubMed

    Laws, Michael; Ramadas, Sivaram N; Lynnworth, Lawrence C; Dixon, Steve

    2015-04-01

    Wetted ultrasonic transit time flow meters typically consist of one or more pairs of transducers, containing piezoelectric elements, which alternate between transmitting and detecting an ultrasonic pulse. Typical piezoelectric materials and the adhesives used to attach the piezoelectric element in such devices can be damaged by hostile environments, such as extreme temperature, potentially limiting possible applications of ultrasonic flow measurement techniques. We have investigated a design for a flow meter with an integrated thermal buffer waveguide consisting of five parallel stainless steel strips. These, in addition to thermal protection, may function as a transducer array, with the possibility of steering the emitted field. Because the buffer strips used in the transducer assembly are thin, one might expect Lamb-like guided waves to propagate along it. However, the finite width of the strips has a significant effect on the propagation characteristics of the guided waves. In this work, the effect of the waveguide's small rectangular cross-section has been studied. Additionally, we have examined the effect of thermal gradients on the average sound speed and dispersion characteristics of such strip waveguides. We also suggest modifications to the plate geometry, which can alter both the frequency content and the shape of the transmitted pulse, potentially giving a better signal to use in flow measurement. PMID:25881347

  3. Inspection of composite materials by laser-ultrasonics

    SciTech Connect

    Monchalin, J.P.; Neron, C.; Vaudreuil, G.

    1995-10-01

    Laser-ultrasonics, a technique that uses lasers for the generation and detection of ultrasound circumvents a number of limitations associated with conventional ultrasonics and offers a unique method for inspecting polymer-matrix composite materials. The technique operates at a distance of several feet or meters from the inspected part. The normalcy requirement of classical ultrasonics is eliminated, since generation occurs at the surface of the material and detection is performed directly off its surface, so parts with complex geometries can be more easily inspected. In this paper, the authors describe the system that has been developed, which comprises a high power short pulse laser for ultrasound generation, a long pulse receiving laser for ultrasound detection, a demodulating interferometer, an optical scanner and a data analysis system for data acquisition and processing. Following many tests performed on composite parts in the laboratory, the authors present demonstration tests performed with this system on a CF-18 aircraft in a maintenance hangar. These tests show that the technology is now sufficiently advanced to be readily applicable to the inspection of detached components following manufacturing and for the in-service inspection of aircrafts. Recent developments of quantitative models which describe the generation of ultrasound in composite materials are outlined, as well as on-going improvements to the detection sensor.

  4. Ultrasonic Evaluation of Deeply Located Trabecular Bones - Preliminary Results

    NASA Astrophysics Data System (ADS)

    Cie?lik, Lucyna; Litniewski, Jerzy

    The analysis of ultrasonic signals scattered by soft tissues have been successfully applied for their characterization. Similarly, the trabecular bone backscattered signal contains information about the properties of the bone structure. Therefore scattering-based ultrasonic technique potentially enables the assessment of microstructure characteristics of a bone. The femoral neck fracture often occurs in the course of osteoporosis and can lead to severe complications. Therefore assessment of femoral bone microstructure and condition is important and essential for the diagnosis and treatment monitoring. As far most of the trabecular bone investigations have been performed in vitro. The only in vivo measurements were carried out in transmission and mostly concerned estimation of the attenuation in heel bone. We have built the ultrasonic scanner that could be useful in acquiring the RF (Radio Frequency) echoes backscattered by the trabecular bone in vivo. Moreover, the bone scanner provides data not only from heel bone but from deeply located bones as well (e.g. femoral bone). It can be also used for easily accessible bones like heel bone or breastbone. In this case a gel-pad is applied to assure focusing of ultrasound in trabecular bone (approximately 10 mm beneath the cortical bone). This study presents preliminary results of the attenuating properties evaluation of trabecular bone from the ultrasonic echoes backscattered by heel bone and femoral neck.

  5. Damage detection and characterization of fiber-reinforced composites using ultrasonics

    NASA Astrophysics Data System (ADS)

    Subramanian, Ajith

    Due to the prevalence of fiber-reinforced composites in industrial applications, the need for damage-detection and characterization has increased. Ultrasonic nondestructive testing (NDT) is a powerful and non-invasive method of detecting flaws and defects in composite materials. Air-coupled and immersion UT techniques are used to quantify the effect of matrix microcracking and delamination within the composite laminate. Detection of matrix microcracks in the laminate is of primary concern since microcracking is one of the initial damage modes resulting in local stiffness reduction. The techniques considered include pulse-echo in immersion, angle-beam through-transmission Lamb wave time-of-flight shift and velocity measurements, and angle-beam backscatter measurements from single microcracks within the composite laminate. The time-of-flight measurements are shown to be a reasonable method for quantifying stiffness reduction in the laminate, however special attention must be provided to the Lamb modes considered and their sensitivity to the independent stiffness components. The angle-beam backscatter technique may be used to detect individual microcracks but poses a limitation on the frequency and depth of inspection. Ultimately, the quantification of microcracking will provide an early descriptor of failure in the laminate.

  6. Ultrasonic transient bounded-beam propagation in a solid cylinder waveguide embedded in a solid medium.

    PubMed

    Laguerre, Laurent; Grimault, Anne; Deschamps, Marc

    2007-04-01

    A semianalytical solution alternative and complementary to modal technique is presented to predict and interpret the ultrasonic pulsed-bounded-beam propagation in a solid cylinder embedded in a solid matrix. The spectral response to an inside axisymmetric velocity source of longitudinal and transversal cylindrical waves is derived from Debye series expansion of the embedded cylinder generalized cylindrical reflection/transmission coefficients. So, the transient guided wave response, synthesized by inverse double Fourier-Bessel transform, is expressed as a combination of the infinite medium contribution, longitudinal, transversal, and coupled longitudinal and transversal waveguide sidewall interactions. Simulated (f, 1/lambdaz) diagrams show the influence of the number of waveguide sidewall interactions to progressively recover dispersion curves. Besides, they show the embedding material filters specific signal portions by concentrating the propagating signal in regions where phase velocity is closer to phase velocity in steel. Then, simulated time waveforms using broadband high-frequency excitation show that signal leading portions exhibit a similar periodical pattern, for both free and embedded waveguides. Debye series-based interpretation shows that double longitudinal/transversal and transversal/longitudinal conversions govern the time waveform leading portion as well as the radiation attenuation in the surrounding cement grout. Finally, a methodology is deduced to minimize the radiation attenuation for the long-range inspection of embedded cylinders. PMID:17471708

  7. 21 CFR 1050.10 - Ultrasonic therapy products.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...FOR SONIC, INFRASONIC, AND ULTRASONIC RADIATION-EMITTING PRODUCTS § 1050.10 ...product that is designed to emit ultrasonic radiation and which includes one or more ultrasonic...therapy product that affects the ultrasonic radiation emitted by the applicator....

  8. 21 CFR 1050.10 - Ultrasonic therapy products.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...FOR SONIC, INFRASONIC, AND ULTRASONIC RADIATION-EMITTING PRODUCTS § 1050.10 ...product that is designed to emit ultrasonic radiation and which includes one or more ultrasonic...therapy product that affects the ultrasonic radiation emitted by the applicator....

  9. Ultrasonic Technology in Duress Alarms.

    ERIC Educational Resources Information Center

    Lee, Martha A.

    2000-01-01

    Provides the pros and cons of the most commonly used technologies in personal duress alarm systems in the school environment. Discussed are radio frequency devices, infrared systems, and ultrasonic technology. (GR)

  10. Metrology for ultrasonic applications.

    PubMed

    Zeqiri, Bajram

    2007-01-01

    This paper provides a review of current metrological capability applied to the characterisation of the acoustic output of equipment used within medical ultrasonic applications. Key measurement devices, developed to underpin metrology in this area, are the radiation force balance, used to determine total output power, and the piezo-electric hydrophone, used to resolve the spatial and temporal distribution of acoustic pressure. The measurement infrastructure in place within the United Kingdom ensuring users are able to carry out traceable measurements of these quantities in a meaningful way, is described. This includes the relevant primary standards, the way international equivalence of national standards is demonstrated and the routes by which the standards are disseminated to the user community. Emerging measurement techniques that may in future lead to improved measurement capability, are also briefly discussed. PMID:17081597

  11. Ultra-short pulse generator

    DOEpatents

    McEwan, T.E.

    1993-12-28

    An inexpensive pulse generating circuit is disclosed that generates ultra-short, 200 picosecond, and high voltage 100 kW, pulses suitable for wideband radar and other wideband applications. The circuit implements a nonlinear transmission line with series inductors and variable capacitors coupled to ground made from reverse biased diodes to sharpen and increase the amplitude of a high-voltage power MOSFET driver input pulse until it causes non-destructive transit time breakdown in a final avalanche shock wave diode, which increases and sharpens the pulse even more. 5 figures.

  12. Ultra-short pulse generator

    DOEpatents

    McEwan, Thomas E. (Livermore, CA)

    1993-01-01

    An inexpensive pulse generating circuit is disclosed that generates ultra-short, 200 picosecond, and high voltage 100 kW, pulses suitable for wideband radar and other wideband applications. The circuit implements a nonlinear transmission line with series inductors and variable capacitors coupled to ground made from reverse biased diodes to sharpen and increase the amplitude of a high-voltage power MOSFET driver input pulse until it causes non-destructive transit time breakdown in a final avalanche shockwave diode, which increases and sharpens the pulse even more.

  13. Ultrasonic effect on multicomponent nanoheterostructures

    SciTech Connect

    Naimi, E. K. Rabinovich, O. I.

    2011-05-15

    The ultrasonic effect on the characteristics of GaP and AlGaInN multicomponent nanohetero-structures has been studied. It is found that the ultrasonic irradiation at frequencies of {approx}10{sup 5} Hz for several hours leads to a significant degradation of the characteristics of multicomponent nanoheterostructures and shifts the luminescence spectral peak of LEDs based on these structures. The results obtained are qualitatively explained.

  14. Ultrasonic monitoring of asymmetric carbon fibre reinforced aluminum laminates

    NASA Astrophysics Data System (ADS)

    Zhao, Junqing; Yang, Fan; Wang, Rongguo

    2013-08-01

    Asymmetric carbon fibre reinforced aluminum alloy laminates was manufactured for the purpose with repeat tensile test, which will be applied in composite pressure vessel. Ultrasonic C scan and A scan approach are used to evaluate the damage of the asymmetric CFRP-Al (carbon fibre reinforced aluminum alloy) laminates. Nondestructive detection is carried out for the CFRP-Al laminates before and after tensile test. Comparison results and pulse echo analysis show that when subjected to repeat tensile test with 70% elastic limit strain load of the CFRP laminates, the interface debonding between CFRP and Al will not occur but the delamination within CFRP laminates becomes the main damage of the asymmetric CFRP-Al laminates. This investigation indicated that combined ultrasonic C scan and A scan is available for damage evaluation of fibre metal laminates.

  15. Assessment of ultrasonic NDT methods for high speed rail inspection

    NASA Astrophysics Data System (ADS)

    Cheng, Jianzheng; Bond, Leonard J.

    2015-03-01

    This article reviews some new ultrasonic rail inspection methods emerging in recent years. It focuses on the state of the art for guided wave technologies and their potential use for used for rail inspection. It considers ultrasound transduction options including EMATs, air coupled, pulsed laser and wheel probe guided wave methods. It compares performances in terms of frequency ranges, energy delivered, ultrasonic wave modes excited, sensitivity, potential speeds of inspection, inspection regions, transducer angle and positioning. The advantages and disadvantages of each transduction modality for possible use in high speed railway are discussed. It is concluded that an EMAT and laser method, or their combination has the potential to provide a new tool for higher speed rail in-service inspection.

  16. Bayesian separation of Lamb wave signatures in laser ultrasonics

    NASA Astrophysics Data System (ADS)

    Kercel, Stephen W.; Klein, Marvin B.; Pouet, Bruno F.

    2000-03-01

    Laser-based ultrasonic (LBU) measurement shows great promise for on-line monitoring of weld quality in tailor-welded blanks. Tailor-welded blanks are steel blanks made from plates of differing thickness and/or properties butt-welded together; they are used in automobile manufacturing to produce body, frame, and closure panels. LBU uses a pulsed laser to generate the ultrasound and a continuous wave laser interferometer to detect the ultrasound at the point of interrogation to perform ultrasonic inspection. LBU enables in-process measurements since there is no sensor contact or near-contact with the workpiece. The authors are using laser-generated plate waves to propagate from one plate into the weld nugget as a means of detecting defects.

  17. Ultrasonic probe of the AuZn Fermi surface.

    SciTech Connect

    Svitelskiy, O.; Suslov, A. V.; Singleton, J. M.; Lashley, J. C.

    2005-01-01

    We, for the first time, apply the ultrasonic pulse-echo technique to explore the Fermi surface of the martensite phase of the single crystalline AuZn shape memory alloy. The ultrasonic measurements were performed in the magnetic fields of up to 45 T in the temperature range of 0.07 < T < 300 K. In the martensite phase (T < 64 K), the oscillations of the speed of the longitudinal sound wave propagating in the (110) direction indicated a strong acoustic de Haas - van Alphen effect. In addition to the earlier described oscillations with frequencies of 1140 and 4720 Tesla, we observed a new frequency of 120 Tesla, which was predicted theoretically. Corresponding effective masses were in favorable agreement with those expected from band structure calculations.

  18. 2008 IEEE International Ultrasonics Symposium (IUS) IEEE Ultrasonics, Ferroelectrics, and Frequency Control Society Organization of the 2008 IEEE International

    E-print Network

    Lu, Jian-yu

    2008 IEEE International Ultrasonics Symposium (IUS) IEEE Ultrasonics, Ferroelectrics, and Frequency Control Society Organization of the 2008 IEEE International Ultrasonics Symposium (IUS) --- Including Ultrasonics Symposium (IUS) Beijing International Convention Center (BICC) Beijing, China, November 2-5, 2008

  19. Structure fragmentation of a surface layer of commercial purity titanium during ultrasonic impact treatment

    NASA Astrophysics Data System (ADS)

    Kozelskaya, Anna; Panin, Alexey; Kazachenok, Marina; Hairullin, Rustam; Sinyakova, Elena; Pochivalov, Yurii; Perevalova, Olga

    2015-10-01

    The mechanisms of surface layer fragmentation of titanium specimens subjected to ultrasonic impact treatment is investigated by atomic force microscopy, transmission electron microscopy and electron backscatter diffraction. It is shown that the twin boundaries ?7b and ?11b are unable to be strong obstacles for propagation of dislocations and other twins.

  20. Ultrasonic speech translator and communications system

    DOEpatents

    Akerman, M. Alfred (Knoxville, TN); Ayers, Curtis W. (Clinton, TN); Haynes, Howard D. (Knoxville, TN)

    1996-01-01

    A wireless communication system undetectable by radio frequency methods for converting audio signals, including human voice, to electronic signals in the ultrasonic frequency range, transmitting the ultrasonic signal by way of acoustical pressure waves across a carrier medium, including gases, liquids, or solids, and reconverting the ultrasonic acoustical pressure waves back to the original audio signal. The ultrasonic speech translator and communication system (20) includes an ultrasonic transmitting device (100) and an ultrasonic receiving device (200). The ultrasonic transmitting device (100) accepts as input (115) an audio signal such as human voice input from a microphone (114) or tape deck. The ultrasonic transmitting device (100) frequency modulates an ultrasonic carrier signal with the audio signal producing a frequency modulated ultrasonic carrier signal, which is transmitted via acoustical pressure waves across a carrier medium such as gases, liquids or solids. The ultrasonic receiving device (200) converts the frequency modulated ultrasonic acoustical pressure waves to a frequency modulated electronic signal, demodulates the audio signal from the ultrasonic carrier signal, and conditions the demodulated audio signal to reproduce the original audio signal at its output (250).

  1. Ultrasonic speech translator and communications system

    DOEpatents

    Akerman, M.A.; Ayers, C.W.; Haynes, H.D.

    1996-07-23

    A wireless communication system undetectable by radio frequency methods for converting audio signals, including human voice, to electronic signals in the ultrasonic frequency range, transmitting the ultrasonic signal by way of acoustical pressure waves across a carrier medium, including gases, liquids, or solids, and reconverting the ultrasonic acoustical pressure waves back to the original audio signal. The ultrasonic speech translator and communication system includes an ultrasonic transmitting device and an ultrasonic receiving device. The ultrasonic transmitting device accepts as input an audio signal such as human voice input from a microphone or tape deck. The ultrasonic transmitting device frequency modulates an ultrasonic carrier signal with the audio signal producing a frequency modulated ultrasonic carrier signal, which is transmitted via acoustical pressure waves across a carrier medium such as gases, liquids or solids. The ultrasonic receiving device converts the frequency modulated ultrasonic acoustical pressure waves to a frequency modulated electronic signal, demodulates the audio signal from the ultrasonic carrier signal, and conditions the demodulated audio signal to reproduce the original audio signal at its output. 7 figs.

  2. Ultrasonic enhancement of chemical cleaning of steam generators

    NASA Astrophysics Data System (ADS)

    Scharton, T.

    1983-04-01

    The results of an investigation into the use of ultrasound to enhance the chemical cleaning of steam generator tube and support crevices are presented. Primary attention was focused on a configuration with ultrasonic transducers in the downcomer region of the steam generator in conjunction with the EPRI Steam Generator Owners Group (SGOG) crevice solvent at 200 F. The investigation consisted primarily of experiments conducted in facilities designed to simulate the geometry and acoustics of a steam generator. The largest facility holds approximately 1000 gallons of solvent and simulates a 40 deg sector of a steam generator with two support plates. The testing demonstrated that ultrasonics is indeed an effective means of enhancing the crevice cleaning if sound levels sufficient to cause cavitation can be transmitted to the crevices. The effort focused on the coupling of the transducers to the wrapper plate, on the transmission of sound through the tube bundle, and on the determination of cavitation threshold levels.

  3. Magnetic and ultrasonic studies on stable cobalt ferrite magnetic nanofluid.

    PubMed

    Nabeel Rashin, M; Hemalatha, J

    2014-03-01

    Stable cobalt ferrite nanofluids of various concentrations have been prepared through co-precipitation method. Structural and morphological studies of nanoparticles are made with the help of X-ray diffraction technique and Transmission Electron Microscope respectively and it is found that the particles exhibit face centered cubic structure with an average size of 14 nm. The magnetic properties of the nanofluids have been analyzed at room temperature which revealed ferromagnetic behavior and also the very low value of coupling constant which ensures the negligible interparticle interaction in the absence of magnetic field. Ultrasonic investigations have been made for the nanofluids at different temperatures and magnetic fields. The temperature effects are explained with the help of open and close-packed water structure. The inter particle interactions of surface modified CoFe2O4 particles and the cluster formation at higher concentrations are realized through the variations in ultrasonic parameters. PMID:24188514

  4. Ultrasonic transducers for cure monitoring: design, modelling and validation

    NASA Astrophysics Data System (ADS)

    Lionetto, Francesca; Montagna, Francesco; Maffezzoli, Alfonso

    2011-12-01

    The finite element method (FEM) has been applied to simulate the ultrasonic wave propagation in a multilayered transducer, expressly designed for high-frequency dynamic mechanical analysis of polymers. The FEM model includes an electro-acoustic (active element) and some acoustic (passive elements) transmission lines. The simulation of the acoustic propagation accounts for the interaction between the piezoceramic and the materials in the buffer rod and backing, and the coupling between the electric and mechanical properties of the piezoelectric material. As a result of the simulations, the geometry and size of the modelled ultrasonic transducer has been optimized and used for the realization of a prototype transducer for cure monitoring. The transducer performance has been validated by measuring the velocity changes during the polymerization of a thermosetting matrix of composite materials.

  5. RIIM two-pulse injector experiments

    NASA Astrophysics Data System (ADS)

    Mazarakis, M. G.; Smith, D. L.; Jones, E. E.; Hasti, D. E.; Jojola, J. M.; Lehmann, M.

    The RADLAC-II foilless diode injector was operated under double pulse conditions utilizing the RIIM accelerator as the test bed. The original RIIM accelerator pulse-power network was modified to provide for the generation, transmission, and delivery to the foilless diode of two distinct voltage pulses with variable interpulse separation from 0 to 2 ms. Two pulse-power assemblies were investigated and will be presented in connection with the diode performance. In both cases, the generated plasma and an excessive neutral gas release, following the first pulse, prevented the diode from producing a second beam pulse for interpulse separations larger than approx 1 microsec.

  6. Ultrasonic estimate of the modulus of rupture and quantification of the frequency dependent dynamic modulus in Norway Spruce

    NASA Astrophysics Data System (ADS)

    Salmi, Ari; Karppinen, Timo; Montonen, Risto; Saranpää, Pekka; Hæggström, Edward

    2013-01-01

    Ultrasonic measurements allow non-destructive evaluation of mechanical properties of wood. However, it is unclear how these ultrasonically determined properties relate to comparable values obtained by traditional mechanical experiments, e.g., three point bending performed at different probing frequencies. In addition, although a link between the modulus of rupture (MOR) and the modulus of elasticity (MOE) obtained with static methods is established, little research exists on the correlation between the ultrasonically determined dynamic elastic modulus and MOR. Therefore, we set out to link the modulus values obtained by three-point bending to those obtained by ultrasonic measurements at different frequencies. We compared the modalities using a fractional derivative model that theoretically predicts a frequency dependency of the dynamic elastic modulus. We determined MOE and MOR in 102 Norway Spruce samples (340 to 510 kg/m3 density) by three-point bending followed by ultrasonic through-transmission measurements that quantified the dynamic modulus at 500 kHz, 4 MHz, and 8 MHz. This is the first report on such a frequency series for Norway Spruce. Our results provide a conversion factor that permits comparing ultrasonically and statically measured MOE values. Depending on the ultrasonic frequency, correlations ranging from 0.3 to 0.53 between the ultrasonic dynamic modulus and MOR were found.

  7. Running Head: ULTRASONIC CLAY SEPARATOR Title: AN ULTRASONIC METHOD FOR ISOLATING NON-CLAY COMPONENTS

    E-print Network

    Meyers, Stephen R.

    1 Running Head: ULTRASONIC CLAY SEPARATOR Title: AN ULTRASONIC METHOD FOR ISOLATING NON method for high-volume heavy mineral separation from clay-rich rocks using an ultrasonic probe. The ultrasonic clay separator (UCS) is an easily constructed device that allows for the recovery of high density

  8. Ultrasonic characterization of silicate glasses, polymer composites and hydrogels

    NASA Astrophysics Data System (ADS)

    Lee, Wan Jae

    In many applications of material designing and engineering, high-frequency linear viscoelastic properties of materials are essential. Traditionally, the high-frequency properties are estimated through the time-temperature superposition (WLF equation) of low-frequency data, which are questionable because the existence of multi-phase in elastomer compounds. Moreover, no reliable data at high frequencies over MHz have been available thus far. Ultrasound testing is cost-effective for measuring high-frequency properties. Although both ultrasonic longitudinal and shear properties are necessary in order to fully characterize high-frequency mechanical properties of materials, longitudinal properties will be extensively explored in this thesis. Ultrasonic pulse echo method measures longitudinal properties. A precision ultrasonic measurement system has been developed in our laboratory, which allows us to monitor the in-situ bulk and/or surface properties of silicate glasses, polymer composites and even hydrogels. The system consists of a pulse-echo unit and an impedance measurement unit. A pulse echo unit is explored mainly. First, a systematic procedure was developed to obtain precise water wavespeed value. A calibration curve of water wavespeed as a function of temperature has been established, and water wavespeed at 23°C serves as a yardstick to tell whether or not a setup is properly aligned. Second, a sound protocol in calculating attenuation coefficient and beam divergence effects was explored using three kinds of silicate glass of different thicknesses. Then the system was applied to four composite slabs, two slabs for each type of fiberglass reinforced plastics, phenolic and polyester manufactured under different processing conditions: one was made by the normal procedures and the other with deliberate flaws such as voids, tapes and/or prepared at improper operation temperature and pressure. The experiment was conducted under the double blind test protocol. After carefully and methodically analyzing the data, we are able to detect defected specimens from all the specimens supplied to us, differentiate polyester-based composite from the phenolic-based composite and even recognized types of defects. Lastly, ultrasonic monitoring of advancement of the swollen-unswollen fronts, and hence monitor phase transition from glassy state to rubbery state, of poly(acrylic-acid) hydrogel of one of the three different crosslinking densities is performed. With ultrasonic measurement, swelling monitoring is possible since the structural and mechanical changes during swelling of a dry hydrogel are related to changes in density and elastic constants. Using our carefully developed methodology from previous chapters, we may obtain and monitor average acoustic properties of each layer of hydrogel as it swells.

  9. Measurement of alkali-silica reaction progression by ultrasonic waves attenuation

    SciTech Connect

    Saint-Pierre, Francois; Rivard, Patrice . E-mail: Patrice.Rivard@Usherbrooke.ca; Ballivy, Gerard

    2007-06-15

    Development of non-destructive methods, developed specifically for assessing the damage induced by alkali-silica reaction (ASR) in concrete structures, is needed in order to carry out a systematic evaluation of the concrete condition. The aim of this study is to monitor the evolution of the ASR-damage in laboratory with concrete samples with ultrasonic pulse velocity and attenuation of ultrasonic waves methods. For this study, results of both methods were compared with expansion and mass variation. One reactive concrete mixture was made with reactive aggregate, and one other mixture, incorporating non-reactive aggregate, was made as a control. Specimens were kept at 38 deg. C in a 1 mol l{sup -1} NaOH solution to accelerate the reaction. Attenuation of transmitted ultrasonic waves appeared to be more appropriate for the evaluation of ASR-damage compared with pulse velocity. The attenuation of accelerated reactive concrete cylinders increased by 90% after 1 year while it increased by 40% for the non-reactive concrete used as a control. Major part of the attenuation increase in the non-reactive concrete is due to liquid absorption. This work suggests that in-situ non-destructive techniques based on ultrasonic wave attenuation, like ultrasonic attenuation tomography, should be developed in order to evaluate the development of ASR in concrete structures. Petrographic examination confirmed that damage to concrete is associated with ASR.

  10. High repetition ration solid state switched CO2 TEA laser employed in industrial ultrasonic testing of aircraft parts

    NASA Astrophysics Data System (ADS)

    von Bergmann, Hubertus; Morkel, Francois; Stehmann, Timo

    2015-02-01

    Laser Ultrasonic Testing (UT) is an important technique for the non-destructive inspection of composite parts in the aerospace industry. In laser UT a high power, short pulse probe laser is scanned across the material surface, generating ultrasound waves which can be detected by a second low power laser system and are used to draw a defect map of the part. We report on the design and testing of a transversely excited atmospheric pressure (TEA) CO2 laser system specifically optimised for laser UT. The laser is excited by a novel solid-state switched pulsing system and utilises either spark or corona preionisation. It provides short output pulses of less than 100 ns at repetition rates of up to 1 kHz, optimised for efficient ultrasonic wave generation. The system has been designed for highly reliable operation under industrial conditions and a long term test with total pulse counts in excess of 5 billion laser pulses is reported.

  11. FABRICATION AND TESTING OF MICROWAVE SINTERED SOL-GEL SPRAY-ON BISMUTH TITANATE-LITHIUM NIOBATE BASED PIEZOELECTRIC COMPOSITE FOR USE AS A HIGH TEMPERATURE (>500 deg. C) ULTRASONIC TRANSDUCER

    SciTech Connect

    Searfass, C. T.; Baba, A.; Tittmann, B. R.; Agrawal, D. K.

    2010-02-22

    Bismuth titanate-lithium niobate based ultrasonic transducers have been fabricated using a sol-gel spray-on deposition technique. These transducers were then tested to determine their potential as high temperature ultrasonic transducers. Fabricated transducers were capable of operating to 1000 deg. C in pulse-echo mode; however, the exposure to such extreme temperatures appears to be destructive to the transducers.

  12. Ultrasonic Tissue Characterization Using Neural Networks

    E-print Network

    Schouten, Theo

    Ultrasonic Tissue Characterization Using Neural Networks Maurice S. klein Gebbinck November 4, 1992 #12; #12; Abstract Ultrasonic tissue characterization is a technique where on the basis of pa : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 3 2 Ultrasound imaging 5 2.1 The transducer

  13. LASER-ULTRASONIC TESTING AND ITS APPLICATIONS TO NUCLEAR REACTOR INTERNALS

    SciTech Connect

    Ochiai, M.; Miura, T.; Yamamoto, S.

    2008-02-28

    A new nondestructive testing technique for surface-breaking microcracks in nuclear reactor components based on laser-ultrasonics is developed. Surface acoustic wave generated by Q-switched Nd:YAG laser and detected by frequency-stabilized long pulse laser coupled with confocal Fabry-Perot interferometer is used to detect and size the cracks. A frequency-domain signal processing is developed to realize accurate sizing capability. The laser-ultrasonic testing allows the detection of surface-breaking microcrack having a depth of less than 0.1 mm, and the measurement of their depth with an accuracy of 0.2 mm when the depth exceeds 0.5 mm including stress corrosion cracking. The laser-ultrasonic testing system combined with laser peening system, which is another laser-based maintenance technology to improve surface stress, for inner surface of small diameter tube is developed. The generation laser in the laser-ultrasonic testing system can be identical to the laser source of the laser peening. As an example operation of the system, the system firstly works as the laser-ultrasonic testing mode and tests the inner surface of the tube. If no cracks are detected, the system then changes its work mode to the laser peening and improves surface stress to prevent crack initiation. The first nuclear industrial application of the laser-ultrasonic testing system combined with the laser peening was completed in Japanese nuclear power plant in December 2004.

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

    PubMed

    Choi, Hajin; Popovics, John S

    2015-06-01

    Newly developed ultrasonic imaging technology for large concrete elements, based on tomographic reconstruction, is presented. The developed 3-D internal images (velocity tomograms) are used to detect internal defects (polystyrene foam and pre-cracked concrete prisms) that represent structural damage within a large steel reinforced concrete element. A hybrid air-coupled/contact transducer system is deployed. Electrostatic air-coupled transducers are used to generate ultrasonic energy and contact accelerometers are attached on the opposing side of the concrete element to detect the ultrasonic pulses. The developed hybrid testing setup enables collection of a large amount of high-quality, through-thickness ultrasonic data without surface preparation to the concrete. The algebraic reconstruction technique is used to reconstruct p-wave velocity tomograms from the obtained time signal data. A comparison with a one-sided ultrasonic imaging method is presented for the same specimen. Through-thickness tomography shows some benefit over one-sided imaging for highly reinforced concrete elements. The results demonstrate that the proposed through-thickness ultrasonic technique shows great potential for evaluation of full-scale concrete structures in the field. PMID:26067042

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

    PubMed Central

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

    2014-01-01

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

  16. Health monitoring of complex curved structures using an ultrasonic wavefield propagation imaging system

    NASA Astrophysics Data System (ADS)

    Lee, Jung-Ryul; Takatsubo, Junji; Toyama, Nobuyuki; Kang, Dong-Hoon

    2007-12-01

    An ultrasonic wavefield propagation imaging system is introduced and then applied for ultrasonic wavefield imaging of complex curved surfaces. A Q-switched pulsed laser is utilized as a moving ultrasonic generator, and a PZT ultrasonic sensor is fixed during the laser beam scanning and detects the ultrasonic waves propagated from the points excited by the laser beam. The waveforms are allocated in the spatial domain of the scanned points and then manipulated in the form of a time versus wavefield movie. The visualized wavefields enable easy detection and interpretation of structural defects because anomalies during wavefield propagation can be visualized. Furthermore, this ultrasonic wavefield propagation imaging system enables reference-free inspection, complex curved surface scanning because it does not require control of focal length and incidence angle of the laser beam, and excellent adaptability with built-in structural health monitoring sensors, such as piezoelectric and fiber optic sensors. The system is demonstrated in the applications of wavefield visualization on a drill surface, detection of mass loss parts inside an elbow pipe joint, and detection and characterization of impact damage and stringer disbond in a composite skin-stringer structure.

  17. New acousto-ultrasonic techniques applied to aerospace materials

    NASA Technical Reports Server (NTRS)

    Kautz, Harold E.

    1988-01-01

    The use of an NdYAG pulsed laser for generating ultrasonic waves for NDE in resin matrix composites was investigated. A study was conducted of the use of the 1.064 micron wavelength NdYAG pulsed laser with the neat, unreinforced resin as well as graphite fiber/polymer composite specimens. In the case of the neat resins it was found that, at normal incidence, about 25 percent of the laser pulse energy was reflected at the incident surface. An attenuation coefficient for the polyimide resin, PMR-15 was determined to be approximately 5.8 np/cm. It was found in energy balance studies that graphite fiber/polymer specimens attenuate the laser beam more than do neat resins. The increase absorption is in the graphite fibers. The occurrence of laser induced surface damage was also studied. For the polymer neat resin, damage appears as pit formation over a small fraction of the pulse impact area and discoloration over a larger part of the area. A damage threshold was inferred from observed damage as a function of pulse energy. The 600 F cured PMR-15 and PMR-11 exhibit about the same amount of damage for a given laser pulse energy. The damage threshold is between 0.06 and 0.07 J/sq cm.

  18. Ultrasonic Measurement Of Elastic Constants Of Composites

    NASA Technical Reports Server (NTRS)

    Bar-Cohen, Yoseph; Mal, Ajit K.

    1994-01-01

    Ultrasonic testing system yields data on elastic constants of matrix/fiber laminated composite material. Related to one described in "Ultrasonic System Measures Elastic Properties of Composites" (NPO-18729). Tests performed nondestructive, and involve access by ultrasonic probes to only one side of material specimen. In comparison with other available ultrasonic testing systems, this system relatively inexpensive, and based on testing technique that is simpler and rapidly yields more-accurate results.

  19. Ultrasonic stir welding process and apparatus

    NASA Technical Reports Server (NTRS)

    Ding, R. Jeffrey (Inventor)

    2009-01-01

    An ultrasonic stir welding device provides a method and apparatus for elevating the temperature of a work piece utilizing at least one ultrasonic heater. Instead of relying on a rotating shoulder to provide heat to a workpiece an ultrasonic heater is utilized to provide ultrasonic energy to the workpiece. A rotating pin driven by a motor assembly performs the weld on the workpiece. A handheld version can be constructed as well as a fixedly mounted embodiment.

  20. Magnetostrictive materials and ultrasonics

    SciTech Connect

    Hansen, T.T.

    1996-08-01

    In the early 1970s a group of Navy scientists led by A.E. Clark began experimenting with highly magnetostrictive rare earth metals, substances that would lengthen in response to a magnetic field. By 1976 the group had discovered an alloy of iron and terbium that exhibited tremendous levels of magnetostriction. They also discovered that, by adding dysprosium, they could lessen the degree of anisotropy in the magnetization of the alloy. Clark named the new material Terfenol-D after terbium, iron, the Naval Ordinance Lab, and dysprosium. Because Terfenol-D was originally developed for sonar applications, it was regarded as usable at low frequencies only from direct current (dc) to 2 kHz. Furthermore, eddy current activity was believed to be so great that high-frequency operation was deemed impractical. However, Terfenol-D can be used into the ultrasonic frequency range. It exhibits the greatest magnetostrictive effects of any commercially available material and is now positioned for a wide range of high-frequency uses--in which piezoceramic materials were formerly used exclusively. The authors have harnessed the energy efficiency of this alloy and discuss the use of this material in actuators.

  1. Downhole pulse radar

    DOEpatents

    Chang, Hsi-Tien (Albuquerque, NM)

    1989-01-01

    A borehole logging tool generates a fast rise-time, short duration, high peak-power radar pulse having broad energy distribution between 30 MHz and 300 MHz through a directional transmitting and receiving antennas having barium titanate in the electromagnetically active region to reduce the wavelength to within an order of magnitude of the diameter of the antenna. Radar returns from geological discontinuities are sampled for transmission uphole.

  2. Downhole pulse radar

    DOEpatents

    Chang, Hsi-Tien

    1987-09-28

    A borehole logging tool generates a fast rise-time, short duration, high peak-power radar pulse having broad energy distribution between 30 MHz and 300 MHz through a directional transmitting and receiving antennas having barium titanate in the electromagnetically active region to reduce the wavelength to within an order of magnitude of the diameter of the antenna. Radar returns from geological discontinuities are sampled for transmission uphole. 7 figs.

  3. High temperature pressure coupled ultrasonic waveguide

    DOEpatents

    Caines, Michael J. (Forest Park, IL)

    1983-01-01

    A pressure coupled ultrasonic waveguide is provided to which one end may be attached a transducer and at the other end a high temperature material for continuous ultrasonic testing of the material. The ultrasonic signal is coupled from the waveguide into the material through a thin, dry copper foil.

  4. Pitch-catch only ultrasonic fluid densitometer

    DOEpatents

    Greenwood, M.S.; Harris, R.V.

    1999-03-23

    The present invention is an ultrasonic fluid densitometer that uses a material wedge and pitch-catch only ultrasonic transducers for transmitting and receiving ultrasonic signals internally reflected within the material wedge. Density of a fluid is determined by immersing the wedge into the fluid and measuring reflection of ultrasound at the wedge-fluid interface. 6 figs.

  5. DYNAMIC RESOLUTION SELECTION IN ULTRASONIC STRAIN IMAGING

    E-print Network

    Drummond, Tom

    DYNAMIC RESOLUTION SELECTION IN ULTRASONIC STRAIN IMAGING J. E. Lindop, G. M. Treece, A. H. Gee RESOLUTION SELECTION IN ULTRASONIC STRAIN IMAGING Joel E. Lindop, Graham M. Treece, Andrew H. Gee and Richard Abstract Ultrasonic strain imaging promises to be a valuable tool in medical diagnostics. Reliability

  6. Pitch-catch only ultrasonic fluid densitometer

    DOEpatents

    Greenwood, Margaret S. (Richland, WA); Harris, Robert V. (Pasco, WA)

    1999-01-01

    The present invention is an ultrasonic fluid densitometer that uses a material wedge and pitch-catch only ultrasonic transducers for transmitting and receiving ultrasonic signals internally reflected within the material wedge. Density of a fluid is determined by immersing the wedge into the fluid and measuring reflection of ultrasound at the wedge-fluid interface.

  7. MEASUREMENT AND CORRECTION OF ULTRASONIC ANEMOMETER ERRORS

    E-print Network

    Heinemann, Detlev

    on statistical quantities. 2 THE SOLENT SONIC ANEMOMETER Ultrasonic anemometers measure the flight timeMEASUREMENT AND CORRECTION OF ULTRASONIC ANEMOMETER ERRORS AND IMPACT ON TURBULENCE MEASUREMENTS-3206, email: office@ehf.uni-oldenburg.de http://www.physik.uni-oldenburg.de/ehf Ultrasonic anemometers

  8. Direct ultrasonic velocity measurements of mammalian collagenthreadsa)

    E-print Network

    Illinois at Urbana-Champaign, University of

    Direct ultrasonic velocity measurements of mammalian collagenthreadsa) S.A.Gossb)andW. Dsuggeststhattissueswithhigher- collagen content appear to exhibit ultrasonic velocities greater than those of lesser amounts of collagen, the quantitative determination of ultrasonic velocity in tis- sues which predominately comprise

  9. PHASE-BASED ULTRASONIC DEFORMATION ESTIMATION

    E-print Network

    Drummond, Tom

    PHASE-BASED ULTRASONIC DEFORMATION ESTIMATION J. E. Lindop, G. M. Treece, A. H. Gee and R. W Cambridge CB2 1PZ United Kingdom Email: jel35/gmt11/ahg/rwp @eng.cam.ac.uk #12;PHASE-BASED ULTRASONIC theoretical analysis and experimental results for an inves- tigation of phase-based ultrasonic deformation

  10. Ultrasonically driven nanomechanical single-electron shuttle

    E-print Network

    Ludwig-Maximilians-Universität, München

    Ultrasonically driven nanomechanical single-electron shuttle DANIEL R. KOENIG*, EVA M. WEIG show that it is possible to overcome this problem by using ultrasonic waves rather than electrical systems to be achieved13 . Actuation of the MSETs is realized by applying ultrasonic waves, which

  11. Inhibition of Ultrasonic Vocalizations by Beta-

    E-print Network

    Inhibition of Ultrasonic Vocalizations by Beta- Adrenoceptor Agonists Mark S. Blumberg Eric D-mail: mark-blumberg@uiowa.edu ABSTRACT: Infant rat ultrasonic vocalizations (USVs) are widely believed The ultrasonic vocalization (USV) of infant rats has been variously interpreted as a signal of the emotional

  12. Analysis of Ultrasonic Velocities in Hydrocarbon Mixtures

    E-print Network

    Analysis of Ultrasonic Velocities in Hydrocarbon Mixtures James G. Berryman Lawrence Livermore National Laboratory P. O. Box 808 L­202 Livermore, CA 94551­9900 #12; Abstract Ultrasonic velocity data of measurements on ultrasonic velocities of liquid hydrocarbons and mixtures. They found that their data

  13. Ultrasonic Imaging 34(4) 237260

    E-print Network

    van Vliet, Lucas J.

    Ultrasonic Imaging 34(4) 237­260 ©Author(s) 2012 Reprints and permission: sagepub field method,time-space decomposition,impulse response 463847UIXXXX10.1177/01617346 12463847Ultrasonic;238 Ultrasonic Imaging 34(4) Introduction As applications of diagnostic ultrasound that repeatedly process

  14. Rolling dry-coupled transducers for ultrasonic inspections of aging aircraft structures

    NASA Astrophysics Data System (ADS)

    Komsky, Igor N.

    2004-07-01

    Some advanced aircraft materials or coatings are porous or otherwise sensitive to the application of water, gel, or some other ultrasonic couplants. To overcome the problems associated with the liquid coupling medium, dry-coupled rolling modules were developed at Northwestern University for the transmission of both longitudinal and transverse ultrasonic waves at frequencies up to 10 MHz. Dry-coupled ultrasonic modules contain solid core internal stators and solid or flexible external rotors with the flexible polymer substrates. Two types of the dry-coupled modules are under development. Cylindrical base transducer modules include solid core cylindrical rotors with flexible polymer substrates that rotate around the stators with ultrasonic elements. Dry-coupled modules with elongated bases contain solid core stators and flexible track-like polymer substrates that rotate around the stators as rotors of the modules. The elongated base modules have larger contact interfaces with the inspection surface in comparison with the cylindrical base modules. Some designs of the dry-coupled rolling modules contain several ultrasonic elements with different incident angles or a variable angle unit for rapid adjustments of incident angles. The prototype dry-coupled rolling modules were integrated with the portable ultrasonic inspection systems and tested on a number of Boeing aircraft structures.

  15. System and technique for characterizing fluids using ultrasonic diffraction grating spectroscopy

    DOEpatents

    Greenwood, Margaret S.

    2005-04-12

    A system for determining a property of a fluid based on ultrasonic diffraction grating spectroscopy includes a diffraction grating on a solid in contact with the fluid. An interrogation device delivers ultrasound through the solid and a captures a reflection spectrum from the diffraction grating. The reflection spectrum including a diffraction order equal to zero exhibits a peak whose location is used to determine speed of sound in the fluid. A separate measurement of the acoustic impedance is combined with the determined speed of sound to yield a measure of fluid density. A system for determining acoustic impedance includes an ultrasonic transducer on a first surface of a solid member, and an opposed second surface of the member is in contact with a fluid to be monitored. A longitudinal ultrasonic pulse is delivered through the solid member, and a multiplicity of pulse echoes caused by reflections of the ultrasonic pulse between the solid-fluid interface and the transducer-solid interface are detected. The decay rate of the detected echo amplitude as a function of echo number is used to determine acoustic impedance.

  16. Ultrasonic imaging of materials under unconventional circumstances

    SciTech Connect

    Declercq, Nico Felicien McKeon, Peter Liu, Jingfei; Shaw, Anurupa; Slah, Yaacoubi

    2015-03-31

    This paper reflects the contents of the plenary talk given by Nico Felicien Declercq. “Ultrasonic Imaging of materials” covers a wide technological area with main purpose to look at and to peek inside materials. In an ideal world one would manage to examine materials like a clairvoyant. Fortunately this is impossible hence nature has offered sufficient challenges to mankind to provoke curiosity and to develop science and technology. Here we focus on the appearance of certain undesired physical effects that prohibit direct imaging of materials in ultrasonic C-scans. Furthermore we try to make use of these effects to obtain indirect images of materials and therefore make a virtue of necessity. First we return to one of the oldest quests in the progress of mankind: how thick is ice? Our ancestors must have faced this question early on during migration to Northern Europe and to the America’s and Asia. If a physicist or engineer is not provided with helpful tools such as a drill or a device based on ultrasound, it is difficult to determine the ice thickness. Guided waves, similar to those used for nondestructive testing of thin plates in structural health monitoring can be used in combination with the human ear to determine the thickness of ice. To continue with plates, if an image of its interior is desired high frequency ultrasonic pulses can be applied. It is known by the physicist that the resolution depends on the wavelength and that high frequencies usually result in undesirably high damping effects inhibiting deep penetration into the material. To the more practical oriented engineer it is known that it is advantageous to polish surfaces before examination because scattering and diffraction of sound lowers the image resolution. Random scatterers cause some blurriness but cooperating scatters, causing coherent diffraction effects similar to the effects that cause DVD’s to show rainbow patterns under sunlight, can cause spooky images and erroneous measurements of material properties. However when properly understood, diffraction effects, for instance if one has no other options but to work with frequencies that are fortuitously very effectively diffracted by the surface structure of a material under investigation, can be used to obtain high contract images or to obtain information that would normally be hidden from standard C-scan techniques. Similar contrast enhancement is also obtained for oblique C-scans of composites.

  17. Ultrasonic imaging of materials under unconventional circumstances

    NASA Astrophysics Data System (ADS)

    Declercq, Nico Felicien; McKeon, Peter; Slah, Yaacoubi; Liu, Jingfei; Shaw, Anurupa

    2015-03-01

    This paper reflects the contents of the plenary talk given by Nico Felicien Declercq. "Ultrasonic Imaging of materials" covers a wide technological area with main purpose to look at and to peek inside materials. In an ideal world one would manage to examine materials like a clairvoyant. Fortunately this is impossible hence nature has offered sufficient challenges to mankind to provoke curiosity and to develop science and technology. Here we focus on the appearance of certain undesired physical effects that prohibit direct imaging of materials in ultrasonic C-scans. Furthermore we try to make use of these effects to obtain indirect images of materials and therefore make a virtue of necessity. First we return to one of the oldest quests in the progress of mankind: how thick is ice? Our ancestors must have faced this question early on during migration to Northern Europe and to the America's and Asia. If a physicist or engineer is not provided with helpful tools such as a drill or a device based on ultrasound, it is difficult to determine the ice thickness. Guided waves, similar to those used for nondestructive testing of thin plates in structural health monitoring can be used in combination with the human ear to determine the thickness of ice. To continue with plates, if an image of its interior is desired high frequency ultrasonic pulses can be applied. It is known by the physicist that the resolution depends on the wavelength and that high frequencies usually result in undesirably high damping effects inhibiting deep penetration into the material. To the more practical oriented engineer it is known that it is advantageous to polish surfaces before examination because scattering and diffraction of sound lowers the image resolution. Random scatterers cause some blurriness but cooperating scatters, causing coherent diffraction effects similar to the effects that cause DVD's to show rainbow patterns under sunlight, can cause spooky images and erroneous measurements of material properties. However when properly understood, diffraction effects, for instance if one has no other options but to work with frequencies that are fortuitously very effectively diffracted by the surface structure of a material under investigation, can be used to obtain high contract images or to obtain information that would normally be hidden from standard C-scan techniques. Similar contrast enhancement is also obtained for oblique C-scans of composites.

  18. Use Of Video In Microscopic And Ultrasonic Inspection

    NASA Technical Reports Server (NTRS)

    Generazio, Edward R.; Roth, Don J.

    1994-01-01

    Two combinations of video and image-data-processing techniques, tone-pulse encoding and precision acoustic imaging, yield grain- and pore-size distributions. Knowledge of such and of fiber orientation important because these characteristics directly related to tensile strength, hardness, fracture toughness, fracture stress, and resistance to impact. One of these combinations of techniques used in nondestructive evaluation of composite parts; both play important roles in development of lightweight composites for use at high temperatures in advanced engines and aircraft. Video system provides easy access to information on diffraction and refraction like that described in article, "Ultrasonic Inspection With Angular-Power-Spectrum Scanning" (LEW-15386).

  19. Ultrasonic Band Gaps in Periodic Stack of Plates - Simulation and Experiments

    SciTech Connect

    Ram, B. C.; Padma, Kumar P.; Krishnamurthy, C. V.; Balasubramaniam, Krishnan

    2006-03-06

    Ultrasonic band gaps were simulated using various numerical techniques for 1-D periodic structures. The pulse propagation characteristics were simulated using transient finite element analysis. The frequency domain characteristics were simulated using forced periodic response analysis, Thompson Haskell transfer matrix and acoustic impedance based calculations. Dispersion curves were also obtained using eigen value lattice simulations. Simulation of the band gaps obtained using these numerical methods agreed well with each other. Experiments were carried out on layered material (aluminum-plexiglas) at ultrasonic frequencies. The measured band gaps matched with the simulation results. Numerical and experimental results are also presented for mirror symmetric periodic stacks.

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

    NASA Technical Reports Server (NTRS)

    Prosser, William H.

    1987-01-01

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