WorldWideScience

Sample records for angle-dependent ultrasonic detection

  1. Ultrasonic guided wave tomography for ice detection.

    Science.gov (United States)

    Zhao, Xiang; Rose, Joseph L

    2016-04-01

    Of great concern for many structures, particularly critical sections of rotary and fixed wing aircrafts, is the ability to detect ice either on grounded or in-flight vehicles. As a consequence, some work is reported here that could be useful for a variety of different industries where ice formation is an important problem. This paper presents experimental validations of a probability-based reconstruction algorithm (PRA) on ice detection of plate-like structures. The ice detection tests are performed for three different specimens: a single layer aluminum plate with a circular ice sensing array, a titanium plate with a sparse rectangular ice sensing array, and a carbon-fiber-reinforced titanium plate with an embedded ice sensing array mounted on a carbon fiber back plate. Cases from the simple to the more challenging exemplify that special modes can be used to differentiate ice from water, a sparse rectangular array could also be used for ice detection, and an ice sensing array could be further used to detect the ice on the sensor free side, a very useful application of ice sensing for aircraft wings, for example. Ice detection images for the respective cases are reconstructed to investigate the feasibility of ice sensing with ultrasonic guided wave tomography technology. The results show that the PRA based ultrasonic guided wave tomography method successfully detected and showed ice spots correctly for all three cases. This corroborates the fact that ultrasonic guided wave imaging technology could be a potential useful ice sensing tool in plate-like structures.

  2. Spatial correlation coefficient images for ultrasonic detection.

    Science.gov (United States)

    Cepel, Raina; Ho, K C; Rinker, Brett A; Palmer, Donald D; Lerch, Terrence P; Neal, Steven P

    2007-09-01

    In ultrasonics, image formation and detection are generally based on signal amplitude. In this paper, we introduce correlation coefficient images as a signal-amplitude independent approach for image formation. The correlation coefficients are calculated between A-scans digitized at adjacent measurement positions. In these images, defects are revealed as regions of high or low correlation relative to the background correlations associated with noise. Correlation coefficient and C-scan images are shown to demonstrate flat-bottom-hole detection in a stainless steel annular ring and crack detection in an aluminum aircraft structure.

  3. Research on ultrasonic detection of complex surfaces

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Parts of complex surface are widely used now in many fields, and their detection has caused much concern. In China many manufactories still carry on the traditional way of manual detection, which requires highly skilled personnel and efficiency is low. Some large manufactories have imported auto-detecting equipments, which require CAD data on the parts, or just divide the surface into several approximate planes for automatic detection. Phased-array system is seldom used, and the cost is high. Besides,most of the systems have not considered the automatic sensitivity compensation of parts with varying thickness. To improve the detection quality and efficiency of nondestructive test (NDT) of parts of complex surface, this paper puts forward an integrated ultrasonic NDT system characterized by: (1) Use of ultrasonic measurement and reverse of curved surface to solve the CAD data problem; (2) Use of an automatic sensitivity compensation algorithm (based on the part's modelling information obtained in surface reverse) to fit the variety of the thickness; (3) Use of template matching and pseudo-color imaging to improve the quality of detection results. The system features integration of low cost mature technologies, and is suitable for detection of various parts of different complex surfaces in medium-and-small enterprises. The test results showed that the system can automatically detect parts of complex surface successfully, and that the inspection result is good and reliable.

  4. Empirical angle-dependent Biot and MBA models for acoustic anisotropy in cancellous bone.

    Science.gov (United States)

    Lee, Kang Il; Hughes, E R; Humphrey, V F; Leighton, T G; Choi, Min Joo

    2007-01-01

    The Biot and the modified Biot-Attenborough (MBA) models have been found useful to understand ultrasonic wave propagation in cancellous bone. However, neither of the models, as previously applied to cancellous bone, allows for the angular dependence of acoustic properties with direction. The present study aims to account for the acoustic anisotropy in cancellous bone, by introducing empirical angle-dependent input parameters, as defined for a highly oriented structure, into the Biot and the MBA models. The anisotropy of the angle-dependent Biot model is attributed to the variation in the elastic moduli of the skeletal frame with respect to the trabecular alignment. The angle-dependent MBA model employs a simple empirical way of using the parametric fit for the fast and the slow wave speeds. The angle-dependent models were used to predict both the fast and slow wave velocities as a function of propagation angle with respect to the trabecular alignment of cancellous bone. The predictions were compared with those of the Schoenberg model for anisotropy in cancellous bone and in vitro experimental measurements from the literature. The angle-dependent models successfully predicted the angular dependence of phase velocity of the fast wave with direction. The root-mean-square errors of the measured versus predicted fast wave velocities were 79.2 m s(-1) (angle-dependent Biot model) and 36.1 m s(-1) (angle-dependent MBA model). They also predicted the fact that the slow wave is nearly independent of propagation angle for angles about 50 degrees , but consistently underestimated the slow wave velocity with the root-mean-square errors of 187.2 m s(-1) (angle-dependent Biot model) and 240.8 m s(-1) (angle-dependent MBA model). The study indicates that the angle-dependent models reasonably replicate the acoustic anisotropy in cancellous bone.

  5. Air coupled ultrasonic detection of surface defects in food cans

    Science.gov (United States)

    Seco, Fernando; Ramón Jiménez, Antonio; del Castillo, María Dolores

    2006-06-01

    In this paper, we describe an ultrasonic inspection system used for detection of surface defects in food cans. The system operates in the pulse-echo mode and analyses the 220 kHz ultrasonic signal backscattered by the object. The classification of samples into valid or defective is achieved with χ2 statistics and the k nearest neighbour method, applied to features computed from the envelope of the ultrasonic echo. The performance of the system is demonstrated empirically in detection of the presence of the pull tab on the removable lid of easy-open food cans, in a production line. It is found that three factors limit the performance of the classification: the misalignment of the samples, their separation of the ultrasonic transducer, and the vibration of the conveyor belt. When these factors are controlled, classification success rates between 94% and 99% are achieved.

  6. Detection of Laser Generated Ultrasonic Wave Using Michelson Interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyung Cho; Yamawaki, Hisashi [Japan National Research Institute, Ibaraki (Japan); Jhang, Kyung Young [Hanyang University, Seoul (Korea, Republic of)

    2000-02-15

    In this paper, ultrasonic wave in the thermoelastic regime was generated in a steel disk by illuminating a pulse laser (Q-switched Nd:YAG) on the surface of the sample and was detected on the other side by Michelson interferometer which was stabilized by feed back control. The experimentally detected displacement waveform of the ultrasonic wave showed good agreement with the theoretically expected one. Also it was shown that sound speeds of longitudinal and shear wave were similar to ones measured by pulse-echo method using a contact transducer. As an application of the noncontact ultrasonic measurement by using laser based ultrasonics, the sound speed in the sample was monitored while the sample was heated in a furnace, and the result showed that it decreased according to the increase of sample temperature

  7. Potential pitfalls of strain rate imaging: angle dependency

    Science.gov (United States)

    Castro, P. L.; Greenberg, N. L.; Drinko, J.; Garcia, M. J.; Thomas, J. D.

    2000-01-01

    Strain Rate Imaging (SRI) is a new echocardiographic technique that allows for the real-time determination of myocardial SR, which may be used for the early and accurate detection of coronary artery disease. We sought to study whether SR is affected by scan line alignment in a computer simulation and an in vivo experiment. Through the computer simulation and the in vivo experiment we generated and validated safe scanning sectors within the ultrasound scan sector and showed that while SRI will be an extremely valuable tool in detecting coronary artery disease there are potential pitfalls for the unwary clinician. Only after accounting for these affects due to angle dependency, can clinicians utilize SRI's potential as a valuable tool in detecting coronary artery disease.

  8. Analysis of Vehicle Detection with WSN-Based Ultrasonic Sensors

    Directory of Open Access Journals (Sweden)

    Youngtae Jo

    2014-08-01

    Full Text Available Existing traffic information acquisition systems suffer from high cost and low scalability. To address these problems, the application of wireless sensor networks (WSNs has been studied, as WSN-based systems are highly scalable and have a low cost of installing and replacing the systems. Magnetic, acoustic and accelerometer sensors have been considered for WSN-based traffic surveillance, but the use of ultrasonic sensors has not been studied. The limitations of WSN-based systems make it necessary to employ power saving methods and vehicle detection algorithms with low computational complexity. In this paper, we model and analyze optimal power saving methodologies for an ultrasonic sensor and present a computationally-efficient vehicle detection algorithm using ultrasonic data. The proposed methodologies are implemented and evaluated with a tiny microprocessor on real roads. The evaluation results show that the low computational complexity of our algorithm does not compromise the accuracy of vehicle detection.

  9. Non-contact feature detection using ultrasonic Lamb waves

    Science.gov (United States)

    Sinha, Dipen N.

    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.

  10. Analysis of vehicle detection with WSN-based ultrasonic sensors.

    Science.gov (United States)

    Jo, Youngtae; Jung, Inbum

    2014-08-04

    Existing traffic information acquisition systems suffer from high cost and low scalability. To address these problems, the application of wireless sensor networks (WSNs) has been studied, as WSN-based systems are highly scalable and have a low cost of installing and replacing the systems. Magnetic, acoustic and accelerometer sensors have been considered for WSN-based traffic surveillance, but the use of ultrasonic sensors has not been studied. The limitations of WSN-based systems make it necessary to employ power saving methods and vehicle detection algorithms with low computational complexity. In this paper, we model and analyze optimal power saving methodologies for an ultrasonic sensor and present a computationally-efficient vehicle detection algorithm using ultrasonic data. The proposed methodologies are implemented and evaluated with a tiny microprocessor on real roads. The evaluation results show that the low computational complexity of our algorithm does not compromise the accuracy of vehicle detection.

  11. Ultrasonic Adaptive Detection for Aerospace Components with Varying Thickness

    Directory of Open Access Journals (Sweden)

    Zhen Xiao

    2017-01-01

    Full Text Available Automatic inspection of microdefects located in the aerospace components is difficult due to the imprecise scanning trajectory, especially for those specimens with varying thickness. In this paper, a new ultrasonic nondestructive testing (NDT system using the robotic scanning trajectory is constructed for inspecting turbine blades. Additionally, an approach based on the analysis of ultrasonic signals is proposed to calibrate the trajectory; the ultrasonic image based on the threshold function represents the distribution of inner defects when the following gate is used to track the flaw echo. Therefore, the characteristic parameters of the flaw echo signals are easy to be discriminated if the reflection waves are stable in the time domain. Experimental result verified the effective and feasibility of the proposed approach; the distribution of inner defects can be shown with a higher resolution than other NDT methods when robotic orientation is correct at each point of scanning trajectory. Furthermore, the feature signals can be tracked more accurately during the ultrasonic signal processing if the ultrasonic distance was considered as a calibration coefficient of positional matrix. The proposed ultrasonic adaptive detection is adapted to complex geometric structure with a minimum resolution of equivalent diameter of the inner flaw being 0.15 millimeters.

  12. Ultrasonic flaw detection using EMD-based signal processing

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The precise detection of flaw echoes buried in backscattering noise caused by material microstructure is a problem of great importance in ultrasonic non-destructive testing (NDT). In this work, empirical mode decomposition (EMD) is proposed to deal with ultrasonic signal. A time-frequency filtering method based on EMD is designed to suppress noise and enhance flaw signals. Simulated results are presented,showing that the proposed method has an excellent performance even for a very low signal-to-noise ratio(SNR). The improvement in flaw detection was experimentally verified using stainless steel pipe sample with artificial flaws.

  13. Presence detection under optimum fusion in an ultrasonic sensor system.

    Science.gov (United States)

    Srinivasan, Sriram; Pandharipande, Ashish

    2012-04-01

    Reliable presence detection is a requirement in energy-efficient occupancy-adaptive indoor lighting systems. A system of multiple ultrasonic sensors is considered for presence detection, and the performance gain from optimum fusion is studied. Two cases are considered wherein an individual sensor determines presence based on (i) local detection by processing echoes at its receiver, and (ii) the optimum Chair-Varshney fusion rule using multiple sensor detection results. The performance gains of using optimum fusion over local detection are characterized under different sensor system configurations and it is shown that improved detection sensitivity is obtained over a larger detection coverage region.

  14. Detection of laser generated ultrasonic wave using Michelson interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyung Cho; Nakano, Hidetoshi [Japan National Research Laboratory of Metrology, Tokyo (Korea, Republic of); Jhang, Kyung Young [School of Mechanical Engineering, Seoul (Korea, Republic of)

    1999-05-15

    A stabilized Michelson Interferometer is proposed in order to detect the laser-generated ultrasonic waves in fee from the external noise such as low frequency mechanical vibration. In order to confirm the performance, theoretically expected waveforms were compared with experimentally detected ones in thermo-elastic region, where we generated ultrasonic wave in steel disk by using a Q-switched Nd:YAG laser. Also sound velocities of longitudinal and shear components were measured and they showed good agreement with the typical values in steel. Finally, the change of sound velocity according to the temperature change was measured to show that the proposed technique could be applied to the characterization of high temperature materials.

  15. Detection and sizing of underbead cracks using ultrasonic nondestructive examination

    Energy Technology Data Exchange (ETDEWEB)

    Scarbrough, J.D.; Wierzbicki, W.M.

    1982-02-11

    Ultrasonic nondestructive examination (NDE) will detect three mil deep underbead cracks in welds joining thin walled iridium hemishells. A correlation was developed to relate the amplitude of the signal reflected from the crack with crack wall area. The observed cracks occur in the weld underbead in the arc taper area during encapsulation of /sup 238/PuO/sub 2/ pellets for thermoelectric generators used in deep space exploration.

  16. Ultrasonic Detection of Microscopic Breast Cancer in Cell Cultures

    Science.gov (United States)

    Goodrich, Jeffrey B.; Patel, Hemang; Doyle, Timothy E.; Kwon, Soonjo

    2010-10-01

    A current problem in breast cancer treatment is the detection of microscopic cancer in surgical margins to ensure all of the cancer has been removed. Current methods rely on extensive pathology work that may take several days to complete. Positive findings for cancer in margins require follow-up surgery for up to 50% of lumpectomy patients to remove more tissue. A microscopic detection method for use during surgery would be preferable to reduce the risks, costs, and patient suffering of follow-up operations. Ultrasound is a promising in vivo detection method due to its low cost, portability, and ability to detect malignant tissue changes. Recent experiments have demonstrated the ultrasonic detection of microscopic cancer in cell cultures. Ultrasonic waveforms from pulse echo measurements showed significant differences between normal and malignant cell monolayers. The ultrasound also detected normal and malignant monolayer growth that displayed good correlations with cell counts. These results support the use of ultrasound as a viable method for in vivo detection. Testing of surgical samples at the Huntsman Cancer Institute is now in progress.

  17. Ultrasonic gas accumulation detection and evaluation in nuclear cooling pipes

    Science.gov (United States)

    Yu, Lingyu; Lin, Bin; Shin, Yong-June; Wang, Jingjiang; Tian, Zhenhua

    2012-04-01

    This paper presents a novel ultrasonic guided wave based inspection methodology for detecting and evaluating gas accumulation in nuclear cooling pipe system. The sensing is in-situ by means of low-profile permanently installed piezoelectric wafer sensors to excite interrogating guided waves and to receive the propagating waves in the pipe structure. Detection and evaluation is established through advanced cross time-frequency analysis to extract the phase change in the sensed signal when the gas is accumulating. A correlation between the phase change and the gas amount has been established to provide regulatory prediction capability based on measured sensory data.

  18. Ultrasonic detection of cardiovascular flow disturbances.

    Science.gov (United States)

    Winter, D C; Wells, M K; Morgan, R J

    1976-01-01

    Blood flow that is disturbed or turbulent may have a significant effect on the development of cardiovascular disease. A method is presented here for detecting periods of disturbed flow using autocorrelograms of the audio signal from a pulsed ultrasound Doppler velocity meter (PUDVM). Autocorrelograms describe quantitatively how the form of a signal changes over time. We produced steady laminar and turbulent pipe flow in a hydraulic test tank, and computed autocorrelograms of the audio signal of the centerline velocity as detected by the PUDVM using fast Fourier transform techniques. We have shown that the autocorrelation coefficient averaged over a short length of time (64 ms) is significantly higher for laminar than for turbulent flow. We have also produced pulsatile flow in our hydraulic tank and computed the mean autocorrelation coefficient at different phases of the flow cycle. The regions of disturbed and undisturbed flow were predicted from the steady flow results. The disturbed flow first appears during the period of the highest forward velocities. These results indicate that the mean autocorrelation coefficient can serve as an indicator of the presence of flow disturbances.

  19. Ultrasonic flaw detection using radial basis function networks (RBFNs).

    Science.gov (United States)

    Gil Pita, R; Vicen, R; Rosa, M; Jarabo, M P; Vera, P; Curpian, J

    2004-04-01

    Ultrasonic flaw detection has been studied many times in the literature. Schemes based on thresholding after a previous matched filter use to be the best solution, but results obtained with this method are only satisfactory when scattering and attenuation are not considered. In this paper, we propose an alternative solution to thresholding detection method. We deal with the usage of different flaw detection methods comparing them with the proposed one. The experiment tries to determinate whether a given ultrasonic signal contains a flaw echo or not. Starting with a set of 24,000 patterns with 750 samples each one, two subsets are defined for the experiments. The first one, the training set, is used to obtain the detection parameters of the different methods, and the second one is used to test the performance of them. The proposed method is based on radial basis functions networks, one of the most powerful neural network techniques. This signal processing technique tries to find the optimal decision criterion. Comparing this method with thresholding based ones, an improvement over 25-30% is obtained, depending on the probability of false alarm. So our new method is a good alternative to flaw detection problem.

  20. An Ultrasonic System for Weed Detection in Cereal Crops

    Directory of Open Access Journals (Sweden)

    Dionisio Andújar

    2012-12-01

    Full Text Available Site-specific weed management requires sensing of the actual weed infestation levels in agricultural fields to adapt the management accordingly. However, sophisticated sensor systems are not yet in wider practical use, since they are not easily available for the farmers and their handling as well as the management practice requires additional efforts. A new sensor-based weed detection method is presented in this paper and its applicability to cereal crops is evaluated. An ultrasonic distance sensor for the determination of plant heights was used for weed detection. It was hypothesised that the weed infested zones have a higher amount of biomass than non-infested areas and that this can be determined by plant height measurements. Ultrasonic distance measurements were taken in a winter wheat field infested by grass weeds and broad-leaved weeds. A total of 80 and 40 circular-shaped samples of different weed densities and compositions were assessed at two different dates. The sensor was pointed directly to the ground for height determination. In the following, weeds were counted and then removed from the sample locations. Grass weeds and broad-leaved weeds were separately removed. Differences between weed infested and weed-free measurements were determined. Dry-matter of weeds and crop was assessed and evaluated together with the sensor measurements. RGB images were taken prior and after weed removal to determine the coverage percentages of weeds and crop per sampling point. Image processing steps included EGI (excess green index computation and thresholding to separate plants and background. The relationship between ultrasonic readings and the corresponding coverage of the crop and weeds were assessed using multiple regression analysis. Results revealed a height difference between infested and non-infested sample locations. Density and biomass of weeds present in the sample influenced the ultrasonic readings. The possibilities of weed group

  1. An ultrasonic system for weed detection in cereal crops.

    Science.gov (United States)

    Andújar, Dionisio; Weis, Martin; Gerhards, Roland

    2012-12-13

    Site-specific weed management requires sensing of the actual weed infestation levels in agricultural fields to adapt the management accordingly. However, sophisticated sensor systems are not yet in wider practical use, since they are not easily available for the farmers and their handling as well as the management practice requires additional efforts. A new sensor-based weed detection method is presented in this paper and its applicability to cereal crops is evaluated. An ultrasonic distance sensor for the determination of plant heights was used for weed detection. It was hypothesised that the weed infested zones have a higher amount of biomass than non-infested areas and that this can be determined by plant height measurements. Ultrasonic distance measurements were taken in a winter wheat field infested by grass weeds and broad-leaved weeds. A total of 80 and 40 circular-shaped samples of different weed densities and compositions were assessed at two different dates. The sensor was pointed directly to the ground for height determination. In the following, weeds were counted and then removed from the sample locations. Grass weeds and broad-leaved weeds were separately removed. Differences between weed infested and weed-free measurements were determined. Dry-matter of weeds and crop was assessed and evaluated together with the sensor measurements. RGB images were taken prior and after weed removal to determine the coverage percentages of weeds and crop per sampling point. Image processing steps included EGI (excess green index) computation and thresholding to separate plants and background. The relationship between ultrasonic readings and the corresponding coverage of the crop and weeds were assessed using multiple regression analysis. Results revealed a height difference between infested and non-infested sample locations. Density and biomass of weeds present in the sample influenced the ultrasonic readings. The possibilities of weed group discrimination were

  2. Ultrasonic techniques for the detection of discontinuities in aluminum foams

    Science.gov (United States)

    Katchadjian, Pablo; García, Alejandro; Brizuela, Jose; Camacho, Jorge; Álvarez-Arenas, Tomás Gómez; Chiné, Bruno; Mussi, Valerio

    2017-02-01

    Metal foams are interesting materials with many potential applications. They are characterized by a cellular structure, that is the metals or metal alloys foamed include gas voids in the material. Their particular lightweight structure and physical, chemical and mechanical properties make them suitable for a wide range of industrial applications in different sectors. For industrial applications, metal foams offer attractive combinations of low density, high stiffness to weight ratio, good energy absorption and vibration damping capacity that cannot be obtained with other materials. The control of the foaming process and the characterization of the metal foam are important issues in order to obtain a product with good properties and guarantee the quality of a mechanical component. The characterization and control of mechanical components and sandwich panels manufactured with metal foams require the assessment of the defects present in this material, like large pores or imperfections which are responsible of deteriorating the mechanical performance. Therefore, specific methods of non-destructive testing are required, both in the manufacturing process and during the life of the component. In this work, some ultrasonic transmission techniques developed for detection of defects associated with the manufacturing process of aluminum foams are proposed. These techniques were used on plates and structures of different thicknesses and geometries formed with this material. Ultrasonic transmission techniques were carried out both, with low frequency air coupled transducers, and higher frequency transducers, focused and unfocused, by contact and immersion. To validate the results, the ultrasonic images obtained were compared with radiographic images of the foam.

  3. Evaluation of angle dependence in spectral emissivity of ceramic tiles measured by FT-IR

    Science.gov (United States)

    Kobayashi, C.; Ogasawara, N.; Yamada, H.; Yamada, S.; Kikuchi, T.

    2015-05-01

    Ceramic tiles are widely used for building walls. False detections are caused in inspections by infrared thermography because of the infrared reflection and angle dependence of emissivity. As the first problem, ceramic tile walls are influenced from backgrounds reflection. As the second problem, in inspection for tall buildings, the camera angles are changed against the height. Thus, to reveal the relation between the emissivity and angles is needed. However, there is very little data about it. It is impossible to decrease the false detection on ceramic tile walls without resolving these problems; background reflection and angle dependence of emissivity. In this study, the angle problem was investigated. The purpose is to establish a revision method in the angle dependence of the emissivity for infrared thermography. To reveal the relation between the emissivity and angles, the spectral emissivity of a ceramic tile at various angles was measured by FT-IR and infrared thermographic instrument. These two experimental results were compared with the emissivity-angle curves from the theoretical formula. In short wavelength range, the two experimental results showed similar behavior, but they did not agree with the theoretical curve. This will be the subject of further study. In long wavelength range, the both experimental results almost obeyed the theoretical curve. This means that it is possible to revise the angle dependence of spectral emissivity, for long wavelength range.

  4. Theoretical and experimental investigation of fiber Bragg gratings with different lengths for ultrasonic detection

    Science.gov (United States)

    Yu, Zhouzhou; Jiang, Qi; Zhang, Hao; Wang, Junjie

    2016-06-01

    In this paper, the response of fiber Bragg gratings (FBGs) subjected to the ultrasonic wave has been theoretically and experimentally investigated. Although FBG sensors have been widely used in the ultrasonic detection for practical structural health monitoring, the relationship between the grating length and ultrasonic frequency is not yet to be obtained. To address this problem, an ultrasound detection system based on FBGs is designed and the response sensitivity of different lengths gratings are detected. Experimental results indicate that the grating with 3 mm length has a higher sensitivity when detecting high frequency ultrasonic wave, and the amplitude can be up to 0.6 mV. The 10 mm length grating has better detection sensitivity for low frequency ultrasonic wave and the amplitude is 0.8 mV. The results of this analysis provide useful tools for high sensitivity ultrasound detection in damage detection systems.

  5. Angle dependence of Andreev scattering at semiconductor-superconductor interfaces

    DEFF Research Database (Denmark)

    Mortensen, Asger; Flensberg, Karsten; Jauho, Antti-Pekka

    1999-01-01

    We study the angle dependence of the Andreev scattering at a semiconductor-superconductor interface, generalizing the one-dimensional theory of Blonder, Tinkham, and Klapwijk (BTK),An increase of the momentum parallel to the interface leads to suppression of the probability of Andreev reflection...

  6. Symmetry constraints for the emission angle dependence of HBT radii

    CERN Document Server

    Heinz, Ulrich W; Lisa, M A; Wiedemann, Urs Achim

    2002-01-01

    We discuss symmetry constraints on the azimuthal oscillations of two-particle correlation (Hanbury Brown--Twiss interferometry) radii for non-central collisions between equal spherical nuclei. We also propose a new method for correcting in a model-independent way the emission angle dependent correlation function for finite event plane resolution and angular binning effects.

  7. Ultrasonic defect detection and size approximation using thin annulus probes

    Energy Technology Data Exchange (ETDEWEB)

    Light, G.M.; Fisher, J.L.; Tennis, R.F.; Stolte, J.S.; Hendrix, G.J. [Southwest Research Inst., San Antonio, TX (United States)

    1994-12-31

    Concern has been generated recently about the capabilities of performing nondestructive evaluation (NDE) of the closure head penetrations in nuclear-reactor pressure vessels (PV). These penetrations, primarily for instrumentation and control rod drive mechanisms (CRDMs), are usually thick-walled Inconel tubes, shrink-fitted into the steel closure head. The penetrations are then welded between the outside surface of the penetration and inside surface of the closure head. Stress corrosion cracks initiating at the inner surface of the penetration have been reported at several plants. Through wall cracks in the CRDM penetration or CRDM weld could lead to loss of PV coolant. The penetration presents a complex geometry for conventional NDE techniques. A thermal sleeve, through which pass the mechanical linkages for control-rod operation, is inserted into the penetration so that only a small annulus (nominally 3 mm) exists between the thermal sleeve and inside surface of the penetration. SwRI has developed and evaluated ultrasonic techniques for sizing defects in this area. Long, thin probes were designed to fit into the annulus to carry irrigated ultrasonic transducers into the region of interest. The probes were used to detect cracks in the penetration and to estimate remaining wall thickness.

  8. XFEL OSCILLATOR SIMULATION INCLUDING ANGLE-DEPENDENT CRYSTAL REFLECTIVITY

    Energy Technology Data Exchange (ETDEWEB)

    Fawley, William; Lindberg, Ryan; Kim, K-J; Shvyd' ko, Yuri

    2010-08-23

    The oscillator package within the GINGER FEL simulation code has now been extended to include angle-dependent reflectivity properties of Bragg crystals. Previously, the package was modified to include frequencydependent reflectivity in order to model x-ray FEL oscillators from start-up from shot noise through to saturation. We present a summary of the algorithms used for modeling the crystal reflectivity and radiation propagation outside the undulator, discussing various numerical issues relevant to the domain of high Fresnel number and efficient Hankel transforms. We give some sample XFEL-O simulation results obtained with the angle-dependent reflectivity model, with particular attention directed to the longitudinal and transverse coherence of the radiation output.

  9. Ultrasonic sensor based defect detection and characterisation of ceramics.

    Science.gov (United States)

    Kesharaju, Manasa; Nagarajah, Romesh; Zhang, Tonzhua; Crouch, Ian

    2014-01-01

    Ceramic tiles, used in body armour systems, are currently inspected visually offline using an X-ray technique that is both time consuming and very expensive. The aim of this research is to develop a methodology to detect, locate and classify various manufacturing defects in Reaction Sintered Silicon Carbide (RSSC) ceramic tiles, using an ultrasonic sensing technique. Defects such as free silicon, un-sintered silicon carbide material and conventional porosity are often difficult to detect using conventional X-radiography. An alternative inspection system was developed to detect defects in ceramic components using an Artificial Neural Network (ANN) based signal processing technique. The inspection methodology proposed focuses on pre-processing of signals, de-noising, wavelet decomposition, feature extraction and post-processing of the signals for classification purposes. This research contributes to developing an on-line inspection system that would be far more cost effective than present methods and, moreover, assist manufacturers in checking the location of high density areas, defects and enable real time quality control, including the implementation of accept/reject criteria.

  10. Ultrasonic C-scan Detection for Stainless Steel Spot Welding Based on Wavelet Package Analysis

    Institute of Scientific and Technical Information of China (English)

    LIU Jing; XU Guocheng; XU Desheng; ZHOU Guanghao; FAN Qiuyue

    2015-01-01

    An ultrasonic test of spot welding for stainless steel is conducted. Based on wavelet packet decomposition, the ultrasonic echo signal has been analyzed deeply in time - frequency domain, which can easily distinguish the nugget from the corona bond. The 2D C-scan images produced by ultrasonic C scan which contribute to quantitatively calculate the nugget diameter for the computer are further analyzed. The spot welding nugget diameter can be automatically obtained by image enhancement, edge detection and equivalent diameter algorithm procedure. The ultrasonic detection values in this paper show good agreement with the metallographic measured values. The mean value of normal distribution curve is 0.006 67, and the standard deviation is 0.087 11. Ultrasonic C-scan test based on wavelet packet signal analysis is of high accuracy and stability.

  11. Fracture detection in crystalline rock using ultrasonic shear waves

    Energy Technology Data Exchange (ETDEWEB)

    Waters, K.H.; Palmer, S.P.; Farrell, W.E.

    1978-12-01

    An ultrasonic shear wave reflection profiling system for use in the detection of water-filled cracks occurring within a crystalline rock mass is being tested in a laboratory environment. Experiments were performed on an irregular tensile crack induced approximately 0.5 m below one circular face of a 1.0-m-dia, 1.8-m-long granite cylinder. Good reflection data were obtained from this irregular crack with the crack either air filled or water filled. Data were collected that suggest a frequency-dependent S/sub H/ wave reflection coefficient for a granite-water interface. Waves that propagate along the free surface of a rock mass (surface waves) can severely hinder the detection of reflected events. Two methods of reducing this surface wave noise were investigated. The first technique uses physical obstructions (such as a slit trench) to scatter the surface waves. The second technique uses a linear array of receivers located on the free surface to cancel waves that are propagating parallel to the array (e.g., surface waves), thus enhancing waves with propagation vectors orthogonal to the linear array (e.g., reflected events). Deconvolution processing was found to be another method useful in surface wave cancellation.

  12. Center crack detection during continuous casting of aluminum by laser ultrasonic measurements

    Science.gov (United States)

    Grün, Hubert; Mitter, Thomas; Roither, Jürgen; Betz, Andreas; Bozorgi, Salar; Burgholzer, Peter

    2014-05-01

    Crack detection during continuous direct chill casting of aluminum is a matter of economics. Determining cracks during production process saves money, energy and raw material. Of course, a non-destructive method is required for this evaluation. Because of temperature concerns conventional ultrasound is not applicable. One non-contact alternative is laser ultrasonics. In laser ultrasonics short laser pulses illuminate the sample. The electromagnetic energy gets absorbed at the surface of the sample and results in local heating followed by expansion. Thereby broadband ultrasonic waves are launched which propagate through the sample and get back reflected or scattered at interfaces (cracks, blowholes,…) like conventional ultrasonic waves. Therefore laser ultrasonics is an alternative thermal infrared technology. By using an interferometer also the detection of the ultrasonic waves at the sample surface is done in a remote manner. During preliminary examinations in the lab by scanning different aluminum studs it was able to distinguish between studs with and without cracks. The prediction of the dimension of the crack by evaluation of the damping of the broadband ultrasonic waves was possible. With simple image reconstruction methods one can localize the crack and give an estimation of its extent and even its shape. Subsequent first measurements using this laser ultrasonic setup during the continuous casting of aluminum were carried out and showed the proof of principle in an industrial environment with elevated temperatures, dust, cooling water and vibrations.

  13. Ultrasonication of pyrogenic microorganisms improves the detection of pyrogens in the Mono Mac 6 assay

    DEFF Research Database (Denmark)

    Moesby, Lise; Hansen, E W; Christensen, J D

    2000-01-01

    of the assay. The interleukin-6 inducing capacity of a broad spectrum of UV-killed and ultrasonicated microorganisms is examined in Mono Mac 6 cells. The interleukin-6 secretion is determined in a sandwich immunoassay (DELFIA). The Mono Mac 6 assay is able to detect UV-killed Bacillus subtilis, Staphylococcus...... aureus and Salmonella typhimurium, but neither Candida albicans nor Aspergillus niger. After ultrasonication of the microorganisms it is possible to detect C. albicans and A. niger. The interleukin-6 inducing ability of the examined microorganisms is in no case reduced after ultrasonic treatment. However...

  14. View angle dependence of cloud optical thicknesses retrieved by MODIS

    Science.gov (United States)

    Marshak, Alexander; Varnai, Tamas

    2005-01-01

    This study examines whether cloud inhomogeneity influences the view angle dependence of MODIS cloud optical thickness (tau) retrieval results. The degree of cloud inhomogeneity is characterized through the local gradient in 11 microns brightness temperature. The analysis of liquid phase clouds in a one year long global dataset of Collection 4 MODIS data reveals that while optical thickness retrievals give remarkably consistent results for all view directions if clouds are homogeneous, they give much higher tau-values for oblique views than for overhead views if clouds are inhomogeneous and the sun is fairly oblique. For solar zenith angles larger than 55deg, the mean optical thickness retrieved for the most inhomogeneous third of cloudy pixels is more than 30% higher for oblique views than for overhead views. After considering a variety of possible scenarios, the paper concludes that the most likely reason for the increase lies in three-dimensional radiative interactions that are not considered in current, one-dimensional retrieval algorithms. Namely, the radiative effect of cloud sides viewed at oblique angles seems to contribute most to the enhanced tau-values. The results presented here will help understand cloud retrieval uncertainties related to cloud inhomogeneity. They complement the uncertainty estimates that will start accompanying MODIS cloud products in Collection 5 and may eventually help correct for the observed view angle dependent biases.

  15. Chemical vapor detection using a capacitive micromachined ultrasonic transducer.

    Science.gov (United States)

    Lee, Hyunjoo J; Park, Kwan Kyu; Kupnik, Mario; Oralkan, O; Khuri-Yakub, Butrus T

    2011-12-15

    Distributed sensing of gas-phase chemicals using highly sensitive and inexpensive sensors is of great interest for many defense and consumer applications. In this paper we present ppb-level detection of dimethyl methylphosphonate (DMMP), a common simulant for sarin gas, with a ppt-level resolution using an improved capacitive micromachined ultrasonic transducer (CMUT) as a resonant chemical sensor. The improved CMUT operates at a higher resonant frequency of 47.7 MHz and offers an improved mass sensitivity of 48.8 zg/Hz/μm(2) by a factor of 2.7 compared to the previous CMUT sensors developed. A low-noise oscillator using the CMUT resonant sensor as the frequency-selective device was developed for real-time sensing, which exhibits an Allan deviation of 1.65 Hz (3σ) in the presence of a gas flow; this translates into a mass resolution of 80.5 zg/μm(2). The CMUT resonant sensor is functionalized with a 50-nm thick DKAP polymer developed at Sandia National Laboratory for dimethyl methylphosphonate (DMMP) detection. To demonstrate ppb-level detection of the improved chemical sensor system, the sensor performance was tested at a certified lab (MIT Lincoln Laboratory), which is equipped with an experimental chemical setup that reliably and accurately delivers a wide range of low concentrations down to 10 ppb. We report a high volume sensitivity of 34.5 ± 0.79 pptv/Hz to DMMP and a good selectivity of the polymer to DMMP with respect to dodecane and 1-octanol.

  16. Model-Assisted POD for Ultrasonic Detection of Cracks at Fastener Holes

    Science.gov (United States)

    Harding, C. A.; Hugo, G. R.; Bowles, S. J.

    2006-03-01

    To reduce the cost of conducting experimental probability of detection (POD) trials, methods which utilize models to account for factors that influence the inspection reliability are being developed. This paper reports the application of POD modeling to ultrasonic detection of cracks emanating from fastener holes. The differences between ultrasonic responses from EDM notches compared to fatigue cracks are examined, including the effects of natural variation in fatigue cracks and crack closure due to residual stresses.

  17. Multi-level damage detection with nonlinear ultrasonic methods

    Science.gov (United States)

    Matlack, Kathryn H.; Kim, Jin-Yeon; Jacobs, Laurence J.; Qu, Jianmin

    2013-01-01

    The nonlinear ultrasonic method of second harmonic generation is used to detect multiple levels of damage on a single specimen. There is a breadth of research in the literature that measures the second harmonic and the resulting nonlinear parameter to monitor increasing amounts of uniform damage, but for this method to be applicable as an in situ technique, it must be able to scan an area of a structure with varying amounts of damage over a region. To investigate this, an aluminum alloy sample is shot-peened to two intensity levels along its length, to produce different sections of cold work and residual stress as a function of spatial location. Previous research has shown that the residual stress and cold work introduced in a material from shot peening causes an increase in the nonlinear parameter. Rayleigh waves are generated in the sample and the first and second harmonic amplitudes are measured at increasing propagation distances that encompass an undamaged section and two sections, each with different levels of shot peening. Results show that the nonlinear parameter increases as the Rayleigh wedge sensor is scanned over the shot peening sections.

  18. Fiber-optic Michelson interferometer fixed in a tilted tube for direction-dependent ultrasonic detection

    Science.gov (United States)

    Gang, Tingting; Hu, Manli; Qiao, Xueguang; Li, JiaCheng; Shao, Zhihua; Tong, Rongxin; Rong, Qiangzhou

    2017-01-01

    A fiber-optic interferometer is proposed and demonstrated experimentally for ultrasonic detection. The sensor consists of a compact Michelson interferometer (MI), which is fixed in a tilted-tube end-face (45°). Thin gold films are used for the reflective coatings of two arms and one of the interference arms is etched serving as the sensing arm. The spectral sideband filter technique is used to interrogate the continuous and pulse ultrasonic signals (with frequency of 300 KHz). Furthermore, because of the asymmetrical structure of the sensor, it presents strong direction-dependent ultrasonic sensitivity, such that the sensor can be considered a vector detector. The experimental results show that the sensor is highly sensitive to ultrasonic signals, and thus it can be a candidate for ultrasonic imaging of seismic physical models.

  19. Advanced defect detection algorithm using clustering in ultrasonic NDE

    Science.gov (United States)

    Gongzhang, Rui; Gachagan, Anthony

    2016-02-01

    A range of materials used in industry exhibit scattering properties which limits ultrasonic NDE. Many algorithms have been proposed to enhance defect detection ability, such as the well-known Split Spectrum Processing (SSP) technique. Scattering noise usually cannot be fully removed and the remaining noise can be easily confused with real feature signals, hence becoming artefacts during the image interpretation stage. This paper presents an advanced algorithm to further reduce the influence of artefacts remaining in A-scan data after processing using a conventional defect detection algorithm. The raw A-scan data can be acquired from either traditional single transducer or phased array configurations. The proposed algorithm uses the concept of unsupervised machine learning to cluster segmental defect signals from pre-processed A-scans into different classes. The distinction and similarity between each class and the ensemble of randomly selected noise segments can be observed by applying a classification algorithm. Each class will then be labelled as `legitimate reflector' or `artefacts' based on this observation and the expected probability of defection (PoD) and probability of false alarm (PFA) determined. To facilitate data collection and validate the proposed algorithm, a 5MHz linear array transducer is used to collect A-scans from both austenitic steel and Inconel samples. Each pulse-echo A-scan is pre-processed using SSP and the subsequent application of the proposed clustering algorithm has provided an additional reduction to PFA while maintaining PoD for both samples compared with SSP results alone.

  20. Epoxy Thermosets: The Detection of Adverse Stoichiometry Using Ultrasonic, Dielectric and NMR Techniques

    Science.gov (United States)

    Unwin, M. E.; Challis, R. E.

    2004-02-01

    The relative proportions of hardener and resin (the stoichiometric ratio, SR) in a curing epoxy thermoset strongly influence the engineering properties of the material. We investigate how NMR, dielectric and ultrasonic techniques can be used to track cure and estimate SR in the material. We show that all three methods are sensitive to SR and can give clear and quantitative indications of excess resin. Detection of excess hardener in the finally cured material is more difficult but can be achieved by combined measures of elastic modulus, from the ultrasonic velocity, and loss angle, from ultrasonic attenuation.

  1. Ultrasonic characterization of delamination in aeronautical composites using noncontact laser generation and detection.

    Science.gov (United States)

    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.

  2. In vivo ultrasonic detection of polyurea crosslinked silica aerogel implants.

    Directory of Open Access Journals (Sweden)

    Firouzeh Sabri

    Full Text Available BACKGROUND: Polyurea crosslinked silica aerogels are highly porous, lightweight, and mechanically strong materials with great potential for in vivo applications. Recent in vivo and in vitro studies have demonstrated the biocompatibility of this type of aerogel. The highly porous nature of aerogels allows for exceptional thermal, electric, and acoustic insulating capabilities that can be taken advantage of for non-invasive external imaging techniques. Sound-based detection of implants is a low cost, non-invasive, portable, and rapid technique that is routinely used and readily available in major clinics and hospitals. METHODOLOGY: In this study the first in vivo ultrasound response of polyurea crosslinked silica aerogel implants was investigated by means of a GE Medical Systems LogiQe diagnostic ultrasound machine with a linear array probe. Aerogel samples were inserted subcutaneously and sub-muscularly in a fresh animal model and b cadaveric human model for analysis. For comparison, samples of polydimethylsiloxane (PDMS were also imaged under similar conditions as the aerogel samples. CONCLUSION/SIGNIFICANCE: Polyurea crosslinked silica aerogel (X-Si aerogel implants were easily identified when inserted in either of the regions in both fresh animal model and cadaveric model. The implant dimensions inferred from the images matched the actual size of the implants and no apparent damage was sustained by the X-Si aerogel implants as a result of the ultrasonic imaging process. The aerogel implants demonstrated hyperechoic behavior and significant posterior shadowing. Results obtained were compared with images acquired from the PDMS implants inserted at the same location.

  3. Damage detection in submerged plates using ultrasonic guided waves

    Indian Academy of Sciences (India)

    Sandeep Sharma; Abhijit Mukherjee

    2014-10-01

    This paper describes a non-contact and non-invasive health monitoring strategy for submerged plate structures using guided waves. The structure under consideration is immersed in water and subjected to longitudinal ultrasonic waves at specific angles of incidence using a cylindrical piezoelectric transducer using the surrounding water as coupling medium. Suitable ultrasonic guided wave modes with optimum scanning capabilities have been generated and identified in submerged plate system. Finally, the propagation of selected modes through submerged notched plates is investigated. Sensitivity of leaky waves to the notches has been studied. The methodology would help in identifying damages in the submerged plate structures.

  4. Detection of drilling-induced delamination in aeronautical composites by noncontact laser ultrasonic method.

    Science.gov (United States)

    Zhou, Zhenggan; Sun, Guangkai; Chen, Xiucheng; Wang, Jie

    2014-04-20

    A novel application of the laser ultrasonic technique for the detection of drilling-induced delamination in composite components of aircrafts is proposed. Numerous key components of aircrafts are made of composite materials, and drilling is often a final operation during assembly. Drilling-induced delamination significantly reduces the structural reliability, and it is rather difficult to be detected effectively and automatically. The laser ultrasonic technique is a promising method to solve the problem. This paper investigates the characterization of drilling-induced delamination in composites by a noncontact laser ultrasonic method. A carbon fiber reinforced plastic laminate with drilling holes is prepared as a specimen. The characterization of drilling-induced delamination with laser-generated ultrasonic waves is investigated theoretically and experimentally, and the morphology features of the delamination are obtained by laser ultrasonic C-scan testing. The results prove that the laser ultrasonic technique is effective for the detection of drilling-induced delamination in composite components, and it is a feasible solution for evaluating the drilling quality during assembly.

  5. Detection of vascular morphology by high frequency intravascular ultrasonic imaging

    NARCIS (Netherlands)

    W.J. Gussenhoven (Wilhelmina Johanna); G.S. Madretsma (Guno); H. Pieterman; S.H.K. The (Salem); L. Wenguang; F.C. van Egmond (F.); N. Bom (Klaas)

    1991-01-01

    textabstractThis study was designed to validate the potential clinical utility of intravascular ultrasonic imaging in vitro and in vivo. In vitro studies were performed to assess the accuracy of dimensional and morphological information. In vitro images of human vessels (n = 75) demonstrated that le

  6. Model based defect detection for free stator of ultrasonic motor

    DEFF Research Database (Denmark)

    Amini, Rouzbeh; Mojallali, Hamed; Izadi-Zamanabadi, Roozbeh;

    2007-01-01

    In this paper, measurements of admittance magnitude and phase are used to identify the complex values of equivalent circuit model for free stator of an ultrasonic motor. The model is used to evaluate the changes in the admittance and relative changes in the values of equivalent circuit elements....... This method identifies the damages and categorizes them. The validity of the method is verified by using free stator measurements of defect free stators of a recently developed multilayer piezoelectric motor....

  7. Detection of wheel rim by immersion scan of phased array ultrasonic flaw testing

    Science.gov (United States)

    Cai, Yi-He; Guo, Jian-qiang; Wang, Ze-yong; Gao, Xiao-rong; Jiang, Xiang-dong; Li, Xi

    2015-02-01

    In order to achieve the in-service detection to high speed train wheel rims, this article analyzed the effects of the number of array elements to image focusing and image quality using water immersion ultrasonic phased array technology. Also, the effects of the depth of water to detecting technique had been researched. According to the results of the experiments, the number of optimal array elements, the corresponding thickness of immersion layer, and the optimal range of water's depth had been obtained. Thus, appropriate references had been provided to water immersion ultrasonic phased array testing.

  8. Ultrasonic Detection in Welds%超声检测在焊缝中的应用

    Institute of Scientific and Technical Information of China (English)

    朱学耕

    2015-01-01

    As long as the existence of internal defects in the weld porosity, slag, cracks and other defects for these internal paper introduces the common method in which ultrasonic testing applications, and analysis of the conventional ultrasonic testing, phased array ultrasonic testing, TOFD detects three detection method in practical applications require attention.%焊缝中只要存在气孔、夹渣、裂纹等内部缺陷,针对这些内部缺陷文中主要介绍了常见的超声检测方法在其中的应用,并分析了常规超声检测、相控阵超声检测、TOFD检测三种检测方法在实际应用中需要注意的问题。

  9. Aerial ultrasonic micro Doppler sonar detection range in outdoor environments.

    Science.gov (United States)

    Bradley, Marshall; Sabatier, James M

    2012-03-01

    Current research demonstrates that micro Doppler sonar has the capability to uniquely identify the presence of a moving human, making it an attractive component in surveillance systems for border security applications. Primary environmental factors that limit sonar performance are two-way spreading losses, ultrasonic absorption, and backscattered energy from the ground that appears at zero Doppler shift in the sonar signal processor. Spectral leakage from the backscatter component has a significant effect on sonar performance for slow moving targets. Sonar performance is shown to rapidly decay as the sensor is moved closer to the ground due to increasing surface backscatter levels.

  10. Detection of Microcracks in Trunnion Rods Using Ultrasonic Guided Waves

    Science.gov (United States)

    2015-07-01

    image (Figure 1), a blue arrow has been drawn to indicate the fracture origin with white arrows drawn to indicate the crack propagating direction...The green ellipse encircles an area that appears to have been a pre-existing crack, which is more heavily oxidized than the rest of the fracture ... Tungsten 5200 19.4 101.0 Gallium 2740 5.9 16.3 Field’s metal 2617 7.8 20.6 4.3.2 Low melting point metals for ultrasonic coupling In searching for

  11. Data Mining Rules for Ultrasonic B-Type Detection and Diagnosis for Cholecystolithiasis

    Institute of Scientific and Technical Information of China (English)

    LOU Wei; YAN Li-min; HE Guo-sen

    2004-01-01

    This paper presents realistic data mining based on the data of B-type ultrasonic detection and diagnosis for cholrcystolithiasis (gallbladder stone in biliary tract) recorded by a district central hospital in Shanghai during the past several years. Computer simulation and modeling is described.

  12. Laser detection of ultrasonic waves with concave portions of the wave fronts.

    Science.gov (United States)

    Korkh, Yulia; Perov, Dmitry; Rinkevich, Anatoly

    2012-10-01

    Special features of ultrasonic pulse wave field detection with concave regions of the wave fronts are investigated with the use of ultrasonic laser interferometry technique. Experimental proofs of the wave front with concave regions are obtained and it is found that the nonmonotonic wave front profiles are well described by the fourth-order even polynomial. The model proposed is applied to the investigation of the spatiotemporal structure of elastic wave fields on solid surfaces. The results obtained can be used for estimating the local wave front curvature.

  13. Hidden disbond detection in spent nuclear fuel storage systems using air-coupled ultrasonics

    Science.gov (United States)

    Song, Homin; Popovics, John S.

    2016-04-01

    This paper studies an air-coupled ultrasonic scanning approach for damage assessment in steel-clad concrete structures. An air-coupled ultrasonic sender generates guided plate waves in the steel cladding and a small contact-type receiver measures the corresponding wave responses. A frequency-wavenumber (f-k) domain signal filtering technique is used to isolate the behavior of the fundamental symmetric (S0) mode of the guided plate waves. The behavior of the S0 mode is sensitive to interface bonding conditions. The proposed inspection approach is verified by a series of experiments performed on laboratory-scale specimens. The experimental results demonstrate that hidden disbond between steel cladding and underlying concrete substrate can be successfully detected with the ultrasonic test setup and the f-k domain signal filtering technique.

  14. Evaluation of Internal Defect of Composite Laminates Using A Novel Hybrid Laser Generation/Air-Coupled Detection Ultrasonic System

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Joon Hyun; Lee, Seung Joon [Pusan National University, Busan (Korea, Republic of); Byun, Joon Hyung [KIMM, Daejeon (Korea, Republic of)

    2008-02-15

    Ultrasonic C-scan technique is one of very popular techniques being used for detection of flaws in polymer matrix composite(PMC). However, the application of this technique is very limited for evaluation of defects in PMC fabricated by the automated fiber placement process. The purpose of this study is to develop a novel ultrasonic hybrid system based on nondestructive and non-contact ultrasonic techniques for evaluation of delamination in carbon/epoxy and carbon/PPS composite laminates. It was shown that the newly developed ultrasonic hybrid system based on dual air-coupled pitch-catch technique with ultrasonic scattering reflection concept could provide excellent image with higher resolution of delamination in PMC compared with the conventional pitch-catch method. It is expected that this ultrasonic hybrid technique can be applied for on-line inspection of flaws in PMC during the fabrication process

  15. Design of a structure with low incident and viewing angle dependence inspired by Morpho butterflies

    Science.gov (United States)

    Wang, Wanlin; Zhang, Wang; Gu, Jiajun; Liu, Qinglei; Deng, Tao; Zhang, Di; Lin, Hai-Qing

    2013-01-01

    Morpho butterflies are well known for their brilliant iridescent colors, which arise from periodic arrays of scales. These brilliant colors have a low angle dependence, in contrast to similar phenomena that are commonly caused by the periodic structures. We designed a structure with a low incident and viewing angle dependence inspired by Morpho butterflies. This structure was studied using the finite-difference time-domain method. The lamellae distribution of tree-like structure was found to be the determining factor for producing a low incident angle dependence. Two advanced models were designed to produce a low viewing angle dependence. Model I was constructed using two layers of scales. The particle swarm optimization algorithm was used to construct Model II. The angle dependence of Model II exhibited a large viewing angle range under various incident angles. PMID:24305852

  16. Application of Compactness Detection to Complicated Concrete-Filled Steel Tube by Ultrasonic Method

    Institute of Scientific and Technical Information of China (English)

    杨建江; 王飞; 陆苏亮; 王川

    2014-01-01

    An example of using ultrasonic method to detect the compactness of complicated concrete-filled steel tube in certain high-rise building was discussed in this study. Because of the particularity of the complicated concrete-filled steel tubular column, the plane detection method and embedded sounding pipe method were adopted in the process of effectively detecting the column. According to the results of the plane detection method and embedded sounding pipe method, the cementing status of steel tube and concrete can be concluded, which cannot be judged by the hammering method in the rectangular steel tube-reinforced concrete.

  17. Ultrasonic physics

    CERN Document Server

    Richardson, E G

    1962-01-01

    Ultrasonic Physics, Second Edition, provides an introduction to the fundamental principles of ultrasonic physics. The book opens with a discussion of the sources of ultrasound. This is followed by separate chapters on the properties and detection of ultrasonic radiation; measurement of propagation constants, i.e., the velocity and absorption, of ultrasound; ultrasound propagation in gases, liquids, and solids; and ultrasound propagation in aerosols, suspensions, and emulsions. The final chapter covers miscellaneous physical and physico-chemical actions, including dispersion and coagulation of

  18. Ultrasonic Guided Wave Method For Crack Detection In Buried Plastic Pipe

    Directory of Open Access Journals (Sweden)

    Wan Hamat Wan Sofian

    2016-01-01

    Full Text Available Plastic pipe are widely used in many fields for the fluid or gaseous product conveyance but basic components of a plastic material made it very sensitive to damage, which requires techniques for detecting damage reliable and efficient. Ultrasonic guided wave is a sensitive method based on propagation of low-frequency excitation in solid structures for damage detection. Ultrasonic guided wave method are performed to investigate the effect of crack to the frequency signal using Fast Fourier Transform (FFT analysis. This paper researched to determine performance of ultrasonic guided wave method in order to detect crack in buried pipeline. It was found that for an uncrack pipe, FFT analysis shows one peak which is the operating frequency by the piezoelectric actuator itself while the FFT analysis for single cracked pipe shows two peak which is the operating frequency by the piezoelectric actuator itself and the resultant frequency from the crack. For multi cracked pipe, the frequency signal shows more than two peak depend the number of crack. The results presented here may facilitate improvements in the accuracy and precision of pipeline crack detection.

  19. Feature extraction for ultrasonic sensor based defect detection in ceramic components

    Science.gov (United States)

    Kesharaju, Manasa; Nagarajah, Romesh

    2014-02-01

    High density silicon carbide materials are commonly used as the ceramic element of hard armour inserts used in traditional body armour systems to reduce their weight, while providing improved hardness, strength and elastic response to stress. Currently, armour ceramic tiles are inspected visually offline using an X-ray technique that is time consuming and very expensive. In addition, from X-rays multiple defects are also misinterpreted as single defects. Therefore, to address these problems the ultrasonic non-destructive approach is being investigated. Ultrasound based inspection would be far more cost effective and reliable as the methodology is applicable for on-line quality control including implementation of accept/reject criteria. This paper describes a recently developed methodology to detect, locate and classify various manufacturing defects in ceramic tiles using sub band coding of ultrasonic test signals. The wavelet transform is applied to the ultrasonic signal and wavelet coefficients in the different frequency bands are extracted and used as input features to an artificial neural network (ANN) for purposes of signal classification. Two different classifiers, using artificial neural networks (supervised) and clustering (un-supervised) are supplied with features selected using Principal Component Analysis(PCA) and their classification performance compared. This investigation establishes experimentally that Principal Component Analysis(PCA) can be effectively used as a feature selection method that provides superior results for classifying various defects in the context of ultrasonic inspection in comparison with the X-ray technique.

  20. New electronic white cane for stair case detection and recognition using ultrasonic sensor

    Directory of Open Access Journals (Sweden)

    Sonda Ammar Bouhamed

    2013-07-01

    Full Text Available Blinds people need some aid to interact with their environment with more security. A new device is then proposed to enable them to see the world with their ears. Considering not only system requirements but also technology cost, we used, for the conception of our tool, ultrasonic sensors and one monocular camera to enable user being aware of the presence and nature of potential encountered obstacles. In this paper, we are involved in using only one ultrasonic sensor to detect stair-cases in electronic cane. In this context, no previous work has considered such a challenge. Aware that the performance of an object recognition system depends on both object representation and classification algorithms, we have used in our system, one representation of ultrasonic signal in frequency domain: spectrogram representation explaining how the spectral density of signal varies with time, spectrum representation showing the amplitudes as a function of the frequency, periodogram representation estimating the spectral density of signal. Several features, thus extracted from each representation, contribute in the classification process. Our system was evaluated on a set of ultrasonic signal where stair-cases occur with different shapes. Using a multiclass SVM approach, recognition rates of 82.4% has been achieved.

  1. Application of Ultrasonic Phased Array Technology to the Detection of Defect in Composite Stiffened-structures

    Science.gov (United States)

    Zhou, Yuan-Qi; Zhan, Li-Hua

    2016-05-01

    Composite stiffened-structure consists of the skin and stringer has been widely used in aircraft fuselage and wings. The main purpose of the article is to detect the composite material reinforced structure accurately and explore the relationship between defect formation and structural elements or curing process. Based on ultrasonic phased array inspection technology, the regularity of defects in the manufacture of composite materials are obtained, the correlation model between actual defects and nondestructive testing are established. The article find that the forming quality of deltoid area in T-stiffened structure is obviously improved by pre-curing, the defects of hat-stiffened structure are affected by the mandrel. The results show that the ultrasonic phased array inspection technology can be an effectively way for the detection of composite stiffened-structures, which become an important means to control the defects of composite and improve the quality of the product.

  2. Hardware-efficient realization of a real-time ultrasonic target detection system using IIR filters.

    Science.gov (United States)

    Oruklu, Erdal; Saniie, Jafar

    2009-06-01

    In this study, we address the increased computational demands of a frequency-diverse ultrasonic target detection system by developing a zero-phase IIR (ZP-IIR) filter. Several ZP-IIR filter types including Chebyshev-I, Chebyshev- II, and Butterworth were analyzed for their detection performance. The 4th-order filters with 8-bit quantized coefficients are shown to improve the flaw-to-clutter ratio by approximately 10 dB. Furthermore, the reduced adder graph algorithm is used for a hardware realization of ZP-IIR filters that does not require any dedicated multipliers. A small number of coefficients inherent to IIR filters and their multiplierless implementation provide efficient architecture suitable for compact, real-time ultrasonic imaging devices.

  3. Defects detection in thin components using two-dimensional ultrasonic arrays

    Science.gov (United States)

    Velichko, A.; Wilcox, P. D.; Drinkwater, B. W.

    2013-01-01

    The use of 2D ultrasonic arrays provides great flexibility, as one array probe allows a given defect to be illuminated from a wide range of angles. However there are a number of challenges in the application of 2D arrays to detection and characterization of 3D defects. In the current paper the problem of finding the optimal array configuration for defects detection in thin sections is investigated. The efficient FE scattering model is used to simulate an ultrasonic array response for different 3D defects. The data provided by this model is then used to analyze the influence of different parameters on the array performance (signal to noise ratio, sensitivity, resolution). Finally, experimental results are shown that illustrate the imaging performance of optimal 2D array configuration.

  4. A new ultrasonic method to detect chemical additives in branded milk

    Indian Academy of Sciences (India)

    S Mohanan; P G Thomas Panicker; Lilly Iype; M Laila; I Domini; R G Bindu

    2002-09-01

    A new ultrasonic method – thermoacoustic analysis – is reported for the detection of the added chemical preservatives in branded milk. The nature of variation and shift in the thermal response of the acoustic parameters specific acoustic impedance, adiabatic compressibility and Rao’s specific sound velocity for different samples of branded milk as compared to the chemical added pure milk are explained as due to the presence of chemicals in these branded samples.

  5. A SENSITIVE AND STABLE CONFOCAL FABRY-PEROT INTERFEROMETER FOR SURFACE ULTRASONIC VIBRATION DETECTION

    Institute of Scientific and Technical Information of China (English)

    DING HONG-SHENG; TONG LI-GE; CHEN GENG-HUA

    2001-01-01

    A new confocal Fabry-Pérot interferometer (CFPI) has been constructed. By using both of the conjugate rays,the sensitivity of the system was doubled. Moreover, the negative feedback control loop of a single-chip microcomputer (MCS-51) was applied to stabilize the working point at an optimum position. The system has been used in detecting the piezoelectric ultrasonic vibration on the surface of an aluminium sample.

  6. Spatial Correlation Coefficient Images for Ultrasonic Detection (Preprint)

    Science.gov (United States)

    2006-07-01

    for image formation and detection based on the similarity of adjacent signals. Signal similarity is quantified in terms of the correlation coefficient calculated...between A-scans digitized at adjacent measurement positions. Correlation coefficient images are introduced for visualizing the similarity...beam field with the defect. Correlation coefficient and C-scan images are shown to demonstrate flat-bottom-hole detection in a stainless steel annular

  7. A control system of mobile navigation robot for precise spraying based ultrasonic detecting and ARM embedded technologies

    Science.gov (United States)

    Tang, Xiuying; Li, Cuiling; Wang, Xiu; Yue, Xinpeng; Peng, Yankun

    2011-06-01

    This paper described a control system of mobile navigation robot for precision spraying in greenhouse environment, which were composed of main control module, motor driving module, ultrasonic detecting module and wirless remote control module. The hard circuits of control system were built. The main control module used ARM7TDMI-S-based LPC2210 micro-processing controller. The motor driving module consisted of voltage amplifier circuit based SN74LS245N and DM74LS244N chips, RC filter circuit, and HM-YZ-30 DC brush motor driver. The ultrasonic detecting module consisted of four standard ultrasonic ranging modules which were arranged on the four sides around the mobile navigation robot, and used GM8125 chip to expand serial communication interfaces. An obstacle-avoiding strategy and its algorithm were proposed and the control programs of mobile navigation robot were programmed. The mobile navigation robot for spraying can realize the actions such as starting and stopping, forward and backward moving, accelerate and decelerate motion, and right and left turn. Finally, the functional experiments of the mobile navigation robot were conducted in the laboratory environment. The results showed that the ultrasonic detecting distance of the robot was 50.5mm-1832.0mm and detecting blind zone was less than 50mm, the ultrasonic detecting angle of individual ultrasonic detecting module of robot was similar to U-shaped and its vaule was about 45.66°, and the moving path of navigation robot was approximately linear.

  8. Contact angle dependence of the resonant properties of sessile drops

    Science.gov (United States)

    Sharp, James

    2012-02-01

    A simple optical deflection technique was used to monitor the vibrations of microlitre sessile drops of glycerol/water mixtures with glycerol compositions ranging from 0% to 75%. A photodiode was used to detect time dependent variations in the intensity of laser light reflected from the droplets. The intensity variations were Fourier transformed to obtain information about the resonant properties of the drops (frequency and width of the resonance). These experiments were performed on a range of different substrates where the contact angle formed by the droplets varied between 38±2^o and 160±4^o. The measured resonant frequency values were found to be in agreement with a recently developed theory of vibrations which considers standing wave states along the profile length of the droplet. The widths of the resonances were also compared with theories which predict the influence of substrate effects, surface contamination effects and bulk viscous effects on the damping of capillary waves at the free surface of the droplets. These experiments indicate that the dominant source of damping in sessile liquid droplet is due to bulk viscous effects but that for small contact angles damping due to the droplet/substrate interaction becomes more important.

  9. Refined Monte Carlo method for simulating angle-dependent partial frequency redistributions

    Science.gov (United States)

    Lee, J.-S.

    1982-01-01

    A refined algorithm for generating emission frequencies from angle-dependent partial frequency redistribution functions R sub II and R sub III is described. The improved algorithm has as its basis a 'rejection' technique that, for absorption frequencies x less than 5, involves no approximations. The resulting procedure is found to be essential for effective studies of radiative transfer in optically thick or temperature varying media involving angle-dependent partial frequency redistributions.

  10. Applications of Flexible Ultrasonic Transducer Array for Defect Detection at 150 °C

    Directory of Open Access Journals (Sweden)

    Jiunn-Woei Liaw

    2013-01-01

    Full Text Available In this study, the feasibility of using a one dimensional 16-element flexible ultrasonic transducer (FUT array for nondestructive testing at 150 °C is demonstrated. The FUT arrays were made by a sol-gel sprayed piezoelectric film technology; a PZT composite film was sprayed on a titanium foil of 75 µm thickness. Since the FUT array is flexible, it was attached to a steel pipe with an outer diameter of 89 mm and a wall thickness of 6.5 mm at 150 °C. Using the ultrasonic pulse-echo mode, pipe thickness measurements could be performed. Moreover, using the ultrasonic pulse-echo and pitch-catch modes of each element of FUT array, the defect detection was performed on an Al alloy block of 30 mm thickness with a side-drilled hole (SDH of f3 mm at 150 °C. In addition, a post-processing algorithm based on the total focusing method was used to process the full matrix of these A-scan signals of each single transmitter and multi-receivers, and then the phase-array image was obtained to indicate this defect- SDH. Both results show the capability of FUT array being operated at 150 °C for the corrosion and defect detections.

  11. Reference-free fatigue crack detection using nonlinear ultrasonic modulation under various temperature and loading conditions

    Science.gov (United States)

    Lim, Hyung Jin; Sohn, Hoon; DeSimio, Martin P.; Brown, Kevin

    2014-04-01

    This study presents a reference-free fatigue crack detection technique using nonlinear ultrasonic modulation. When low frequency (LF) and high frequency (HF) inputs generated by two surface-mounted lead zirconate titanate (PZT) transducers are applied to a structure, the presence of a fatigue crack can provide a mechanism for nonlinear ultrasonic modulation and create spectral sidebands around the frequency of the HF signal. The crack-induced spectral sidebands are isolated using a combination of linear response subtraction (LRS), synchronous demodulation (SD) and continuous wavelet transform (CWT) filtering. Then, a sequential outlier analysis is performed on the extracted sidebands to identify the crack presence without referring any baseline data obtained from the intact condition of the structure. Finally, the robustness of the proposed technique is demonstrated using actual test data obtained from simple aluminum plate and complex aircraft fitting-lug specimens under varying temperature and loading variations.

  12. An integrated ultrasonic-inductive pulse sensor for wear debris detection

    Science.gov (United States)

    Du, Li; Zhe, Jiang

    2013-02-01

    One approach to detect signs of potential machine failure is to detect wear debris in the lubrication oil of a rotating or reciprocating machine because the size and the concentration of wear debris particles in the oil show a direct relationship with the level of wear. In this article, a proof-of-principle integrated wear debris sensor consisting of an ultrasonic pulse sensor and an inductive pulse sensor for detecting wear debris in lubrication oil is presented. The ultrasonic pulse sensor detects all solid debris (metallic and non-metallic debris). A flow recess structure is utilized to ensure that all wear debris passes the acoustic focal region so that all debris can be accurately counted and sized. The inductive pulse sensor detects and counts all metallic debris (ferrous and non-ferrous) based on the inductive Coulter counting principle. By comparing the results from the two sensing components, the sensor is capable of differentiating and detecting non-metallic debris, ferrous metallic debris and non-ferrous metallic debris.

  13. Ultrasonic imaging in liquid sodium: topological energy for damages detection

    Energy Technology Data Exchange (ETDEWEB)

    Lubeigt, E.; Gobillot, G. [CEA, Cadarache (France); Mensah, S.; Chaix, J.F.; Rakotonarivo, S. [LMA, CNRS - UPR 70 51, Aix-en-Provence (France)

    2015-07-01

    Under-sodium imaging at high temperature is an important requirement in sodium cooled fast reactors during structural inspection. It aims at checking the integrity of immersed structures and assessing component degradation. The work presented in this paper focuses on designing an advanced ultrasound methodology for detecting damages such as deep crack defects. For that purpose, a topological imaging approach was implemented. This method takes advantage of all available prior knowledge about the environment through the integration of differential imaging and time reversal techniques. The quality of the topological energy distribution (the image) is further enhanced by applying a time gating related to each reconstructed pixel. Numerical and experimental results are presented using this method in order to confirm its reliability. These images are compared to a B-scan to emphasize the localization performances of this method. (authors)

  14. Flow angle dependent photoacoustic Doppler power spectra under intensity-modulated continuous wave laser excitation

    Directory of Open Access Journals (Sweden)

    Yu Tong

    2016-02-01

    Full Text Available Photoacoustic Doppler (PAD power spectra showing an evident Doppler shift represent the major characteristics of the continuous wave-excited or burst wave-excited versions of PAD flow measurements. In this paper, the flow angle dependences of the PAD power spectra are investigated using an experiment setup that was established based on intensity-modulated continuous wave laser excitation. The setup has an overall configuration that is similar to a previously reported configuration, but is more sophisticated in that it accurately aligns the laser illumination with the ultrasound detection process, and in that it picks up the correct sample position. In the analysis of the power spectra data, we find that the background power spectra can be extracted by combining the output signals from the two channels of the lock-in amplifier, which is very useful for identification of the PAD power spectra. The power spectra are presented and analyzed in opposite flow directions, at different flow speeds, and at different flow angles. The power spectra at a 90° flow angle show the unique properties of symmetrical shapes due to PAD broadening. For the other flow angles, the smoothed power spectra clearly show a flow angle cosine relationship.

  15. Crack detection and sizing technique by ultrasonic and electromagnetic methods

    Energy Technology Data Exchange (ETDEWEB)

    Komura, Ichiro E-mail: ichiro.komura@toshiba.co.jp; Hirasawa, Taiji; Nagai, Satoshi; Takabayashi, Jun-ichi; Naruse, Katsuhiko

    2001-06-01

    Improvements in defect detection and sizing capabilities for non-destructive inspection techniques have been required in order to ensure the reliable operation and life extension of nuclear power plants. For the volumetric inspection, the phased array UT technique has superior capabilities for beam steering and focusing to objective regions, and real-time B-scan imaging without mechanical scanning. In contrast to the conventional UT method, high-speed inspection is realized by the unique feature of the phased array technique. A 256-channel array system has developed for the inspection of weldment of BWR internal components such as core shrouds. The TOFD crack sizing technique also can be applied using this system. For the surface inspection, potential drop techniques and eddy current techniques have been improved, which combined the theoretical analysis. These techniques have the crack sizing capability for surface breaking cracks to which UT method is difficult to apply. This paper provides the recent progress of these phased array and electromagnetic inspection techniques.

  16. Design of an ultrasonic sensor for measuring distance and detecting obstacles.

    Science.gov (United States)

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

    2010-03-01

    This paper introduces a novel method for designing the transducer of a highly directional ultrasonic range sensor for detecting obstacles in mobile robot applications. The transducer consists of wave generation, amplification, and radiation sections, and a countermass. The operating principle of this design is based on the parametric array method where the frequency difference between two ultrasonic waves is used to generate a highly directional low-frequency wave with a small aperture. The aim of this study was to design an optimal transducer to generate the two simultaneous longitudinal modes efficiently. We first derived an appropriate mathematical model by combining the continuum model of a bar and countermass with the compatibility condition between a piezoelectric actuator and a linear horn. Then we determined the optimal length of the aluminum horn and the piezoelectric actuator using a finite element method. The proposed sensor exhibited a half-power bandwidth of less than+/-1.3 degrees at 44.8 kHz, a much higher directivity than existing conventional ultrasonic range sensors.

  17. Improvement to defect detection by ultrasonic data processing: the DTVG method; Amelioration de detection de defaut par ultrasons: la methode DTVG

    Energy Technology Data Exchange (ETDEWEB)

    Francois, D.

    1995-10-01

    The cast elbows of the pipes of the principal primary circuit of French PWR, made of austenitic-ferritic stainless steel, pose problems to control. In order to improve the ultrasonic detection of defects in coarse-grained materials, we propose a method (called DTVG) based on the statistic study of the spatial stability of events contained in temporal signals. At the Beginning, the method was developed during a thesis (G. Corneloup, 1998) to improve the detection of cracks in thin thickness austenitic welds. Here, we propose to adapt the DTVG method and estimate its performances in detection of defects in thick materials representative of cast austenitic-ferritic elbows steels. The first objective of the study is adapting the original treatment applied to the thin thickness austenitic welds for the detection of defects in thick thickness austenitic-ferritic cast steels. The second objective consist of improving the algorithm to take in account the difference between thin and thick material and estimating the performances of the DTVG method in detection in specimen block with artificial defects. This work has led to adapt the original DTVG method to control thick cast austenitic-ferritic specimen (80 mm) under normal and oblique incidence. More, the study has allowed to make the the treatment automatic (automatic research of parameters). The results have shown that the DTVG method is fitted to detect artificial defects in thick cast austenitic-ferritic sample steel. All the defects in the specimen block have been detected without revealing false indication. (author). 4 refs., 4 figs.

  18. Detecting Lamb waves with broad-band acousto-ultrasonic signals in composite structures

    Science.gov (United States)

    Kautz, Harold E.

    1992-01-01

    Lamb waves can be produced and detected in ceramic matrix composites (CMC) and metal matrix composites (MMC) plates using the acousto-ultrasonic configuration employing broadband transducers. Experimental dispersion curves of lowest symmetric and antisymmetric modes behave in a manner analogous to the graphite/polymer theoretical curves. In this study a basis has been established for analyzing Lamb wave velocities for characterizing composite plates. Lamb wave dispersion curves and group velocities were correlated with variations in axial stiffness and shear stiffness in MMC and CMC. For CMC, interfacial shear strength was also correlated with the first antisymmetric Lamb mode.

  19. Detecting Lamb waves with broadband acousto-ultrasonic signals in composite structures

    Science.gov (United States)

    Kautz, Harold E.

    1992-01-01

    Lamb waves can be produced and detected in ceramic matrix composites (CMC) and metal matrix composites (MMC) plates using the acousto-ultrasonic configuration employing broadband transducers. Experimental dispersion curves of lowest symmetric and lowest antisymmetric modes behave in a manner analogous to the graphite/polymer theoretical curves. In this study a basis has been established for analyzing Lamb wave velocities for characterizing composite plates. Lamb wave disperison curves and group velocities were correlated with variations in axial stiffness and shear stiffness in MMC and CMC. For CMCs, interfacial shear strength was also correlated with the first antisymmetric Lamb mode.

  20. Ultrasonic array for obstacle detection based on CDMA with Kasami codes.

    Science.gov (United States)

    Diego, Cristina; Hernández, Alvaro; Jiménez, Ana; Alvarez, Fernando J; Sanz, Rebeca; Aparicio, Joaquín

    2011-01-01

    This paper raises the design of an ultrasonic array for obstacle detection based on Phased Array (PA) techniques, which steers the acoustic beam through the environment by electronics rather than mechanical means. The transmission of every element in the array has been encoded, according to Code Division for Multiple Access (CDMA), which allows multiple beams to be transmitted simultaneously. All these features together enable a parallel scanning system which does not only improve the image rate but also achieves longer inspection distances in comparison with conventional PA techniques.

  1. A Digital Method for the Detection of Blood Flow Direction in Ultrasonic Doppler Systems

    Directory of Open Access Journals (Sweden)

    P. Acevedo–Contla.

    2010-01-01

    Full Text Available Doppler ultrasound systems are widely used to study blood flow and diagnosis of vascular diseases. An important characteristic of these systems is the ability to detect the direction of the blood flow. Most Doppler ultrasound systems apply a quadrature demodulation technique on the ultrasonic transducer output signal. Therefore additional treatment is necessary to separate forward and reverse flow signals. This work presents a digital method to convert signals in quadrature into directional signals using a Fast Fourier Transform (FFT approach. Validation of the method has been achieved using simulated Doppler ultrasound signals.

  2. Ultrasonic Array for Obstacle Detection Based on CDMA with Kasami Codes

    Directory of Open Access Journals (Sweden)

    Joaqúın Aparicio

    2011-12-01

    Full Text Available This paper raises the design of an ultrasonic array for obstacle detection based on Phased Array (PA techniques, which steers the acoustic beam through the environment by electronics rather than mechanical means. The transmission of every element in the array has been encoded, according to Code Division for Multiple Access (CDMA, which allows multiple beams to be transmitted simultaneously. All these features together enable a parallel scanning system which does not only improve the image rate but also achieves longer inspection distances in comparison with conventional PA techniques.

  3. Assessment of Foot Trajectory for Human Gait Phase Detection Using Wireless Ultrasonic Sensor Network.

    Science.gov (United States)

    Qi, Yongbin; Soh, Cheong Boon; Gunawan, Erry; Low, Kay-Soon; Thomas, Rijil

    2016-01-01

    This paper presents a new highly accurate gait phase detection system using wearable wireless ultrasonic sensors, which can be used in gait analysis or rehabilitation applications. The gait phase detection system uses the foot displacement information during walking to extract the following gait phases: heel-strike, heel-off, toe-off, and mid-swing. The displacement of foot-mounted ultrasonic sensor is obtained from several passive anchors placed at known locations by employing local spherical positioning technique, which is further enhanced by the combination of recursive Newton-Gauss method and Kalman Filter. The algorithm performance is examined by comparing with a commercial optical motion tracking system with ten healthy subjects and two foot injured subjects. Accurate estimates of gait cycle (with an error of -0.02 ±0.01 s), stance phase(with an error of 0.04±0.03 s), and swing phase (with an error of -0.05±0.03 s) compared to the reference system are obtained. We have also investigated the influence of walking velocities on the performance of the proposed gait phase detection algorithm. Statistical analysis shows that there is no significant difference between both systems during different walking speeds. Moreover, we have tested and discussed the possibility of the proposed system for clinical applications by analyzing the experimental results for both healthy and injured subjects. The experiments show that the estimated gait phases have the potential to become indicators for sports and rehabilitation engineering.

  4. Damage detection using the signal entropy of an ultrasonic sensor network

    Science.gov (United States)

    Rojas, E.; Baltazar, A.; Loh, K. J.

    2015-07-01

    Piezoelectric ultrasonic sensors used to propagate guided waves can potentially be implemented to inspect large areas in engineering structures. However, the inherent dispersion and noise of guided acoustic signals, multiple echoes in the structure, as well as a lack of an approximate or exact model, limit their use as a continuous structural health monitoring system. In this work, the implementation of a network of piezoelectric sensors randomly placed on a plate-like structure to detect and locate artificial damage is studied. A network of macro fiber composite (MFC) sensors working in a pitch-catch configuration was set on an aluminum thin plate 1.9 mm in thickness. Signals were analyzed in the time-scale domain using the discrete wavelet transform. The objectives of this work were threefold, namely to first develop a damage index based on the entropy distribution using short time wavelet entropy of the ultrasonic waves generated by a sensor network, second to determine the performance of an array of spare MFC sensors to detect artificial damage, and third to implement a time-of-arrival (TOA) algorithm on the gathered signals for damage location of an artificial circular discontinuity. Our preliminary test results show that the proposed methodology provides sufficient information for damage detection, which, once combined with the TOA algorithm, allows localization of the damage.

  5. Parametric Study of Defect Detection in Pipes with Bend Using Guided Ultrasonic Waves

    Directory of Open Access Journals (Sweden)

    Jack Tan Jin

    2016-01-01

    Full Text Available The propagation behaviour of guided ultrasonic waves in a steel pipe with welded bend is studied by finite element simulation. The effectiveness of the longitudinal L(0,2 and torsional T(0,1 guided waves in detecting circumferential cut near the weld is investigated. In order to identify the presence of the defect, the reflection strength due to the cut is studied. The geometry of the weld is constructed based on common V-bevel butt joints and the anisotropy of the 316L stainless steel weld is included to correctly predict the scattering of ultrasonic waves. The finite element model is built to allow high accuracy. Detection of small circumferential cut (up to 60° circumferential extent can be achieved with longitudinal L(0,2 mode. Detection of moderate to large circumferential cut can be achieved by torsional T(0,1 or longitudinal L(0,2 modes, with T(0,1 mode preferred due to its less mode conversion to higher order modes.

  6. Low noise techniques applied to a piezoceramic receiver for gas coupled ultrasonic flaw detection

    CERN Document Server

    Farlow, R

    1998-01-01

    Piezoelectric plate transducers are commonly used for the generation and detection of ultrasonic signals and have applications in, for example, non-destructive testing and medical imaging. A rigorous theoretical investigation of thermal noise in plate transducers has been undertaken with the aim of establishing the absolute limits of receiver sensitivity in terms of both Minimum Detectable Power (MDP) and Minimum Detectable Force (MDF). The central feature of the work has been the development of two independent theories which provide identical results. One theory is based on an electrical approach which makes use of an extensively modified version of Hayward's linear systems model of the piezoelectric plate transducer, along with the well known work of Johnson and Nyquist. The other theory is based on a mechanical approach which makes use of the less well known work of Callen and Welton. Both theories indicate that only two parameters are required in order to determine the MDP and MDF of an open circuit trans...

  7. Ultrasonic guided wave detection of scatterers on large clad steel plates

    Science.gov (United States)

    Gong, Peng; Harley, Joel B.; Berges, Mario; Junker, Warren R.; Greve, David W.; Oppenheim, Irving J.

    2016-04-01

    "Clad steel" refers to a thick carbon steel structural plate bonded to a corrosion resistant alloy (CRA) plate, such as stainless steel or titanium, and is widely used in industry to construct pressure vessels. The CRA resists the chemically aggressive environment on the interior, but cannot prevent the development of corrosion losses and cracks that limit the continued safe operation of such vessels. At present there are no practical methods to detect such defects from the exposed outer surface of the thick carbon steel plate, often necessitating removing such vessels from service and inspecting them visually from the interior. In previous research, sponsored by industry to detect and localize damage in pressurized piping systems under operational and environmental changes, we investigated a number of data-driven signal processing methods to extract damage information from ultrasonic guided wave pitch-catch records. We now apply those methods to relatively large clad steel plate specimens. We study a sparse array of wafer-type ultrasonic transducers adhered to the carbon steel surface, attempting to localize mass scatterers grease-coupled to the stainless steel surface. We discuss conditions under which localization is achieved by relatively simple first-arrival methods, and other conditions for which data-driven methods are needed; we also discuss observations of plate-like mode properties implied by these results.

  8. Detection of fatigue crack on a rotating steel shaft using air-coupled nonlinear ultrasonic modulation

    Science.gov (United States)

    Song, Byeongju; Park, Byeongjin; Sohn, Hoon; Lim, Cheol-Woo; Park, Jae-Roung

    2015-04-01

    Rotating shafts in drop lifts of manufacturing facilities are susceptible to fatigue cracks as they are under repetitive heavy loading and high speed spins. However, it is challenging to use conventional contact transducers to monitor these shafts as they are continuously spinning with a high speed. In this study, a noncontact crack detection technique for a rotating shaft is proposed using air-coupled transducers (ACTs). (1) Low frequency (LF) and high frequency (HF) sinusoidal inputs are simultaneously applied to a shaft using two ACTs, respectively. A fatigue crack can provide a mechanism for nonlinear ultrasonic modulation and create spectral sidebands at the modulation frequencies, which are the sum and difference of the two input frequencies Then LF and HF inputs are independently applied to the shaft using each ACT. These three ultrasonic responses are measured using another ACT. (2) The damage index (DI) is defined as the energy of the first sideband components, which corresponding to the frequency sum and difference between HF and LF inputs. (3) Steps 1 and 2 are repeated with various combinations of HF and LF inputs. Crack existence is detected through an outlier analysis of the DIs. The effectiveness of the proposed technique is investigated using a steel shaft with a real fatigue crack.

  9. Defects detection in typical positions of bend pipes using low-frequency ultrasonic guided wave

    Institute of Scientific and Technical Information of China (English)

    罗更生; 谭建平; 汪亮; 许焰

    2015-01-01

    In order to analyze the possibility of detecting defects in bend pipe using low-frequency ultrasonic guided wave, the propagation of T(0,1) mode and L(0,2) mode through straight-curved-straight pipe sections was studied. FE (finite element) models of bend pipe without defects and those with defects were introduced to analyze energy distribution, mode transition and defect detection of ultrasonic guided wave. FE simulation results were validated by experiments of four different bend pipes with circumferential defects in different positions. It is shown that most energy of T(0,1) mode or L(0,2) mode focuses on extrados of bend but little passes through intrados of bend, and T(0,1) mode or L(0,2) mode is converted to other possible non-axisymmetric modes when propagating through the bend and the defect after bend respectively. Furthermore, L(0,2) mode is more sensitive to circumferential notch than T(0,1) mode. The results of this work are beneficial for practical testing of pipes.

  10. Detection of moving capillary front in porous rocks using X-ray and ultrasonic methods

    Directory of Open Access Journals (Sweden)

    Christian eDavid

    2015-07-01

    Full Text Available Several methods are compared for the detection of moving capillary fronts in spontaneous imbibition experiments where water invades dry porous rocks. These methods are: (i the continuous monitoring of the mass increase during imbibition, (ii the imaging of the water front motion using X-ray CT scanning, (iii the use of ultrasonic measurements allowing the detection of velocity, amplitude and spectral content of the propagating elastic waves, and (iv the combined use of X-ray CT scanning and ultrasonic monitoring. It is shown that the properties of capillary fronts depend on the heterogeneity of the rocks, and that the information derived from each method on the dynamics of capillary motion can be significantly different. One important result from the direct comparison of the moving capillary front position and the P wave attributes is that the wave amplitude is strongly impacted before the capillary front reaches the sensors, in contrast with the velocity change which is concomitant with the fluid front arrival in the sensors plane.

  11. Novel wavelet threshold denoising method in axle press-fit zone ultrasonic detection

    Science.gov (United States)

    Peng, Chaoyong; Gao, Xiaorong; Peng, Jianping; Wang, Ai

    2017-02-01

    Axles are important part of railway locomotives and vehicles. Periodic ultrasonic inspection of axles can effectively detect and monitor axle fatigue cracks. However, in the axle press-fit zone, the complex interface contact condition reduces the signal-noise ratio (SNR). Therefore, the probability of false positives and false negatives increases. In this work, a novel wavelet threshold function is created to remove noise and suppress press-fit interface echoes in axle ultrasonic defect detection. The novel wavelet threshold function with two variables is designed to ensure the precision of optimum searching process. Based on the positive correlation between the correlation coefficient and SNR and with the experiment phenomenon that the defect and the press-fit interface echo have different axle-circumferential correlation characteristics, a discrete optimum searching process for two undetermined variables in novel wavelet threshold function is conducted. The performance of the proposed method is assessed by comparing it with traditional threshold methods using real data. The statistic results of the amplitude and the peak SNR of defect echoes show that the proposed wavelet threshold denoising method not only maintains the amplitude of defect echoes but also has a higher peak SNR.

  12. A Canopy Density Model for Planar Orchard Target Detection Based on Ultrasonic Sensors.

    Science.gov (United States)

    Li, Hanzhe; Zhai, Changyuan; Weckler, Paul; Wang, Ning; Yang, Shuo; Zhang, Bo

    2016-12-24

    Orchard target-oriented variable rate spraying is an effective method to reduce pesticide drift and excessive residues. To accomplish this task, the orchard targets' characteristic information is needed to control liquid flow rate and airflow rate. One of the most important characteristics is the canopy density. In order to establish the canopy density model for a planar orchard target which is indispensable for canopy density calculation, a target density detection testing system was developed based on an ultrasonic sensor. A time-domain energy analysis method was employed to analyze the ultrasonic signal. Orthogonal regression central composite experiments were designed and conducted using man-made canopies of known density with three or four layers of leaves. Two model equations were obtained, of which the model for the canopies with four layers was found to be the most reliable. A verification test was conducted with different layers at the same density values and detecting distances. The test results showed that the relative errors of model density values and actual values of five, four, three and two layers of leaves were acceptable, while the maximum relative errors were 17.68%, 25.64%, 21.33% and 29.92%, respectively. It also suggested the model equation with four layers had a good applicability with different layers which increased with adjacent layers.

  13. A Study on Advanced Ultrasonic Technique for Thermal Fatigue Crack Detection of Thermal Stratification Pipeline in NPPs

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Won Geun; Lee, Min Rae; Choi, Snag Woo; Lee, Joon Hyun [Pusan National University, Busan (Korea, Republic of); Lee, Bo Young [Hankook Aviation Univ., Goyang (Korea, Republic of)

    2005-07-01

    Ultrasonic inspection techniques are widely used to ensure the reliable operation and lifetime extension of nuclear power plants. Thermal stratification typically occurs in the surge line or the main feed water lines in nuclear power plants. Thermal stratification is a flow condition in which hotter fluid flows over a colder region of fluid in pipeline. Since a change in temperature causes a change in the density of the pipe wall, these thermal conditions might lead to increased overall bending stresses in pipelines. In addition, cyclic changes in stratification height cause thermal stress. This cycling can lead to thermal fatigue crack initiation and crack growth. If thermal fatigue crack grows continuously, the leakage of water or steam will occur and this may cause serious problems on reactor cooling system. Therefore, these cracks must be detected before the crack growth reaches for leakage. In this study, an ultrasonic technique was employed for evaluation of thermal fatigue cracks due to thermal stratification in pipelines of nuclear power plants. The angle beam ultrasonic techniques(time-of-flight diffraction(TOFD) and shadow effect method) were used to detect thermal fatigue cracks which grow from the inner surface of the pipeline. The angle beam ultrasonic technique is usually used for the detection of cracks on the inside of the structures. When ultrasonic waves generated from the angle probe encounters a crack, ultrasonic waves of the shear modes are reflect or transmit from the crack wall. Also ultrasonic waves generated from the angle probe shear modes are diffracted from the tip of the crack, and the shear wave is reflected from the corner of the crack.

  14. Detection and classification of defects in ultrasonic NDE signals using time-frequency representations

    Science.gov (United States)

    Qidwai, Uvais; Costa, Antonio H.; Chen, C. H.

    2000-05-01

    The ultrasonic wave, generated by a piezoelectric transducer coupled to the test specimen, propagates through the material and part of its energy is reflected when it encounters an non-homogeneity or discontinuity in its path, while the remainder is reflected by the back surface of the test specimen. Defect echo signals are masked by the characteristics of the measuring instruments, the propagation paths taken by the ultrasonic wave, and are corrupted by additive noise. This leads to difficulties in comparing and analyzing signals, particularly in automated defect identification systems employing different transducers. Further, the multi-component nature of material defects can add to the complexity of the defect identification criteria. With many one-dimensional (1-D) approaches, the multi-component defects can not be detected. Another drawback is that these techniques are not very robust for sharp ultrasonic peaks especially in a very hazardous environment. This paper proposes a technique based on the time-frequency representations (TFRs) of the real defect signals corresponding to artificially produced defects of various geometries in metals. Cohen's class (quadratic) TFRs with Gaussian kernels are then used to represent the signals in the time-frequency (TF) plane. Once the TFR is obtained, various image processing morphological techniques are applied to the TFR (e.g. region of interest masking, edge detection, and profile separation). Based on the results of these operations, a binary image is produced which, in turn, leads to a novel set of features. Using these new features, defects have not only been detected but also classified as flat-cut, angular-cut, and circular-drills. Moreover, with some modifications of the threshold levels of the TFR kernel design, our technique can be used in relatively hostile environments with SNRs as low as 0 dB. Another important characteristic of our approach is the detection of multiple defects. This consists of detection of

  15. High-frequency guided ultrasonic waves for hidden defect detection in multi-layer aircraft structures

    Science.gov (United States)

    Masserey, B.; Raemy, C.; Fromme, P.

    2012-05-01

    Aerospace structures contain multi-layer components subjected to cyclic loading conditions; fatigue cracks and disbonds can develop, often at fastener holes. High-frequency guided waves have the potential for non-destructive damage detection at critical and difficult to access locations from a stand-off distance. Using commercially available ultrasonic transducers, high frequency guided waves were generated that penetrate through the complete thickness of a model structure, consisting of two adhesively bonded aluminum plates. The wave propagation along the specimen was measured and quantified using a laser interferometer. The wave propagation and scattering at internal defects was simulated using Finite Element (FE) models and good agreement with the measurement results found. The detection sensitivity using standard pulse-echo measurements was verified and the influence of the stand-off distance predicted from the FE simulation results.

  16. APPROACH OF IMPROVING PRECISION IN ULTRASONIC DOPPLER BLOODSTREAM SPEED MEASUREMENT BY CHAOS-BASED FREQUENCY DETECTING

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    It is critical for cerebral vascular disease diagnosis through Doppler to detect the maximum and the minimum of the carotid blood flow speed accurately. A kind of Duffing system under an external periodic power with dump is introduced in the letter, numerical analysis is carried out by four-order Runge-Kutta method. An oscillator array is designed according to the frequency of the ultrasonic wave. When the external signals are inputted, computational algorithm is used to scan the array in turn and analyze the result, and the frequency can be determined. Based on the methods above, detecting the carotid blood flow speed accurately is realized. The Signal-to-Noise Ratio (SNR) of-20.23dB is obtained by the result of experiments. In conclusion, the SNR has been improved and the precision of the measured bloodstream speed has been increased,which can be 0.069% to 0.13%.

  17. On-loom, real-time, noncontact detection of fabric defects by ultrasonic imaging.

    Energy Technology Data Exchange (ETDEWEB)

    Chien, H. T.

    1998-09-08

    A noncontact, on-loom ultrasonic inspection technique was developed for real-time 100% defect inspection of fabrics. A prototype was built and tested successfully on loom. The system is compact, rugged, low cost, requires minimal maintenance, is not sensitive to fabric color and vibration, and can easily be adapted to current loom configurations. Moreover, it can detect defects in both the pick and warp directions. The system is capable of determining the size, location, and orientation of each defect. To further improve the system, air-coupled transducers with higher efficiency and sensitivity need to be developed. Advanced detection algorithms also need to be developed for better classification and categorization of defects in real-time.

  18. Ultrasonic Imaging in Liquid Sodium: A Differential Method for Damages Detection

    Science.gov (United States)

    Lubeigt, Emma; Mensah, Serge; Chaix, Jean-François; Rakotonarivo, Sandrine; Gobillot, Gilles; Baqué, François

    The fourth generation of nuclear reactor can use liquid sodium as the core coolant. Under-sodium imaging aims at checking the health of immersed structures and especially at detecting and characterizing potential hazardous damage. The differential approach allows detecting a perturbation by comparison with a reference measurement and by focusing back to any change in the inspected region. The imaging method relies on the adequate combination of two computed ultrasonic fields, one forward and one adjoint. The adjoint field design offers new opportunities to reconstruct either the "scattered" or "shadow" fields respectively in order to form an image of the illuminated contours of an inclusion and an image of the shadow field induced by the presence of that inclusion. Numerical simulations have been carried out to illustrate the complementarycontent of the information conveyed by each of the reconstructions.

  19. High-speed defect detection in rails by non-contact guided ultrasonic testing

    Science.gov (United States)

    Rizzo, Piervincenzo; Bartoli, Ivan; Lanza di Scalea, Francesco; Coccia, Stefano; Fateh, Mahmood

    2005-05-01

    Recent train accidents and associated direct and indirect repair costs have reaffirmed the need for developing rail defect detection systems more effective than those used today. The group at the UCSD NDE & Structural Health Monitoring Laboratory, in collaboration with the US Federal Railroad Administration, is conducting a study that aims at developing an inspection strategy for rails based on guided ultrasonic waves. This paper illustrates a guided-wave inspection system that is targeted to the detection of transverse-type cracks in the rail head, that are among the most dangerous flaws in rails. The methodology is based on a hybrid non-contact system that uses a pulsed laser for generating waves and multiple air-coupled sensors for detecting waves. The remote sensors are positioned as far away as 76 mm (3") from the top of rail head. Signal processing based on the Continuous Wavelet Transform is used to characterize the time-frequency content of the propagating waves. Features extracted after Discrete Wavelet processing of the wave signals result in a damage index that is robust with respect to noise and is related to the crack depth; the method allows for fast inspection with the potential for quantifying the extent of the flaw. It is demonstrated that the adopted setup allows for the detection of small cracks, as shallow as 1 mm in depth. It is also shown that the ultrasonic wave features considered in this study are directly related to the reduction of the rail head cross-sectional area caused by a transverse crack.

  20. Application and assessment of ultrasonic inspection methods for flaw detection and characterization of manganese steel frogs

    Science.gov (United States)

    Cinson, A.; Diaz, A.; Prowant, M.

    2011-04-01

    Ultrasonic nondestructive examination (NDE) has a long and successful history of application across a wide array of industries, including nuclear, aerospace, and transportation sectors. In coarse-grained, cast Manganese (Mn) steel frog components, NDE/inspection challenges are encountered both in-field (after the frogs have been installed on a rail line) and at the manufacturing facilities during post-fabrication QA/QC activities. Periodically inherently flawed frogs are received from a manufacturer, and put into service, as most railroad operators do not have a means to conduct pre-service examinations on received components. Accordingly, there is a need for a pre-service inspection system that can provide a rapid, cost-effective and non-intrusive inspection capability for detection of defects, flaws, and other anomalies in frog components, in order to avoid premature initiation of cracks or failures of these components during service. This study focused on evaluating use of a volumetric phased-array ultrasonic testing (PA-UT) method to monitor fabrication quality assurance. In this preliminary assessment of using PA-UT, data were acquired at a frequency of 2.0 MHz on a known, flawed Mn steel frog component directly from a manufacturing facility. The component contained flaws commonly found as a result of the manufacturing process of these cast rail components. The data were analyzed and the anomalies were detected, localized and characterized. Results were compared against baseline radiographic data. A detection metric was reported in the form of signal-to-noise values.

  1. Auditory detection of ultrasonic coded transmitters by seals and sea lions.

    Science.gov (United States)

    Cunningham, Kane A; Hayes, Sean A; Michelle Wargo Rub, A; Reichmuth, Colleen

    2014-04-01

    Ultrasonic coded transmitters (UCTs) are high-frequency acoustic tags that are often used to conduct survivorship studies of vulnerable fish species. Recent observations of differential mortality in tag control studies suggest that fish instrumented with UCTs may be selectively targeted by marine mammal predators, thereby skewing valuable survivorship data. In order to better understand the ability of pinnipeds to detect UCT outputs, behavioral high-frequency hearing thresholds were obtained from a trained harbor seal (Phoca vitulina) and a trained California sea lion (Zalophus californianus). Thresholds were measured for extended (500 ms) and brief (10 ms) 69 kHz narrowband stimuli, as well as for a stimulus recorded directly from a Vemco V16-3H UCT, which consisted of eight 10 ms, 69 kHz pure-tone pulses. Detection thresholds for the harbor seal were as expected based on existing audiometric data for this species, while the California sea lion was much more sensitive than predicted. Given measured detection thresholds of 113 dB re 1 μPa and 124 dB re 1 μPa, respectively, both species are likely able to detect acoustic outputs of the Vemco V16-3H under water from distances exceeding 200 m in typical natural conditions, suggesting that these species are capable of using UCTs to detect free-ranging fish.

  2. Detection of cold cracks in the cast-steels by the methods of ultrasonic and eddy-current infrared thermography

    Science.gov (United States)

    Cheprasov, A. I.; Knyazev, S. V.; Usoltsev, A. A.; Dolgopolov, A. E.; Mamedov, R. O.

    2016-09-01

    The aim of this study was to investigate the possibility of detection of cold cracks in the massive steel products using ultrasonic and eddy-current excitation, as well as the thermal imaging method of temperature recording, that in the perspective should be completed by the development of requirements for the monitoring equipment.

  3. FBG-based ultrasonic wave detection and acoustic emission linear location system

    Science.gov (United States)

    Jiang, Ming-shun; Sui, Qing-mei; Jia, Lei; Peng, Peng; Cao, Yuqiang

    2012-05-01

    The ultrasonic (US) wave detection and an acoustic emission (AE) linear location system are proposed, which employ fiber Bragg gratings (FBGs) as US wave sensors. In the theoretical analysis, the FBG sensor response to longitudinal US wave is investigated. The result indicates that the FBG wavelength can be modulated as static case when the grating length is much shorter than US wavelength. The experimental results of standard sinusoidal and spindle wave test agree well with the generated signal. Further research using two FBGs for realizing linear location is also achieved. The maximum linear location error is obtained as less than 5 mm. FBG-based US wave sensor and AE linear location provide useful tools for specific requirements.

  4. FBG-based ultrasonic wave detection and acoustic emission linear location system

    Institute of Scientific and Technical Information of China (English)

    JIANG Ming-shun; SUI Qing-mei; JIA Lei; PENG Peng; CAO Yu-qiang

    2012-01-01

    The ultrasonic (US) wave detection and an acoustic emission (AE) linear location system are proposed,which employ fiber Bragg gratings (FBGs) as US wave sensors.In the theoretical analysis,the FBG sensor response to longitudinal US wave is investigated.The result indicates that the FBG wavelength can be modulated as static case when the grating length is much shorter than US wavelength.The experimental results of standard sinusoidal and spindle wave test agree well with the generated signal.Further research using two FBGs for realizing linear location is also achieved.The maximumlinear location error is obtained as less than 5 mm.FBG-based US wave sensor and AE linear location provide useful tools for specific requirements.

  5. Fast recognition algorithm of underwater micro-terrain based on ultrasonic detection

    Institute of Scientific and Technical Information of China (English)

    LUO Bo-wen; ZHOU Zhi-jin; BU Ying-yong; ZHAO Hai-ming

    2008-01-01

    An algorithm was proposed to fast recognize three types of underwater micro-terrain, i.e. the level, the gradient and the uneven. With pendulum single beam bathymeter, the hard level concrete floor, the random uneven floor and the gradient wood panel (8°) were ultrasonically detected 20 times, respectively. The results show that the algorithm is right from fact that the first clustering values of the uneven are all less than the threshold value of 60.0% that is obtained by the level and gradient samples. The algorithm based on the dynamic clustering theory can effectively eliminate the influences of the exceptional elevation values produced by the disturbances resulted from the grazing angle, the characteristic of bottom material and environmental noises, and its real-time capability is good. Thus, the algorithm provides a foundation for the next restructuring of the micro-terrain.

  6. Artificial intelligence and ultrasonic tests in detection of defects; Inteligencias artificiales y ensayos ultrasonicos para la deteccion de defectos

    Energy Technology Data Exchange (ETDEWEB)

    Barrera Cardiel, G.; Fabian Alvarez, M. a.; Velez Martinez, M.; Villasenor, L.

    2001-07-01

    One of the most serious problems in the quality control of welded unions is the location, identification and classification of defects. As a solution to this problem, a technique for classification, applicable to welded unions done by electric arc welding as well as by friction, is proposed; it is based on ultrasonic signals. The neuronal networks proposed are Kohonen and Multilayer Percept ron, all in a virtual instrument environment. Currently the techniques most used in this field are: radiological analysis (X-rays) and ultrasonic analysis (ultrasonic waves). The X-ray technique in addition to being dangerous requires highly specialized personnel and equipment, therefore its use is restricted. The ultrasonic technique, in spite of being one of the most used for detection of discontinuities, requires personnel with wide experience in the interpretation of ultrasonic signals, this is a time-consuming process which necessarily increases its operation cost. The classification techniques that we propose turn out to be safe, reliable, inexpensive and easy to implement for the solution of this important problem. (Author) 8 refs.

  7. Ultrasonic Determination Of Recrystallization

    Science.gov (United States)

    Generazio, Edward R.

    1988-01-01

    State of recrystallization identified. Measurement of ultrasonic attenuation shows promise as means of detecting recrystallization in metal. Technique applicable to real-time acoustic monitoring of thermomechanical treatments. Starting with work-hardened material, one ultrasonically determines effect of annealing, using correlation between ultrasonic attenuation and temperature.

  8. Object Detection for Agricultural and Construction Environments Using an Ultrasonic Sensor.

    Science.gov (United States)

    Dvorak, J S; Stone, M L; Self, K P

    2016-04-01

    This study tested an ultrasonic sensor's ability to detect several objects commonly encountered in outdoor agricultural or construction environments: a water jug, a sheet of oriented strand board (OSB), a metalfence post, a human model, a wooden fence post, a Dracaena plant, a juniper plant, and a dog model. Tests were performed with each target object at distances from 0.01 to 3 m. Five tests were performed with each object at each location, and the sensor's ability to detect the object during each test was categorized as "undetected," "intermittent," "incorrect distance," or "good." Rigid objects that presented a larger surface area to the sensor, such as the water jug and OSB, were better detected than objects with a softer surface texture, which were occasionally not detected as the distance approached 3 m. Objects with extremely soft surface texture, such as the dog model, could be undetected at almost any distance from the sensor. The results of this testing should help designers offuture systems for outdoor environments, as the target objects tested can be found in nearly any agricultural or construction environment.

  9. Parametric Study of the Device Angle Dependency of a Single Vortex Generator on a Flat Plate

    DEFF Research Database (Denmark)

    Fernandez, U.; Réthoré, Pierre-Elouan; Sørensen, Niels N.

    . The computational fluid dynamic (CFD) simulations have been com-pared with a wind tunnel experiment, where the corresponding parametric study was per-formed over a single vane mounted on the test section wall in low-speed wind tunnel. In this experiment the flow was recorded using Stereoscopic Particle Image...... Velocimetry (S-PIV) in cross-planes at various positions downstream of the vane. The main goal of this article is to study the angle dependency of a single VG mounted on a test section wall; for this purpose CFD simulations have been carried out and compared with a wind tunnel experiment and an analytical......A detailed study of the device angle dependency of a single vortex generator (VG) is presented in this paper. A single Vortex Generator on a test section wall case, with four different positions of the device angle to the incoming flow, has been designed and solved by computational methods...

  10. Angle-dependent discoloration structures in wing scales of Morpho menelaus butterfly

    Institute of Scientific and Technical Information of China (English)

    NIU ShiChao; LI Bo; YE JunFeng; MU ZhengZhi; ZHANG JunQiu; LIU Yan; HAN ZhiWu

    2016-01-01

    The Morpho butterfly is famous for its typical structural color and has increasingly attracted the interest of scholars in a wide variety of research fields.Herein,it was found that the color of Morpho menelaus butterfly wings is not only structure-based but also viewing-angle-dependent.Firstly,the discoloration effect of this typical butterfly was confirmed by a series of experiments.Then,the general form,arrangements,and geometrical dimensions of the scales were observed using a stereomicroscope.Scanning electron microscopy was also used to examine the two-dimensional morphologies and structures of a single scale.Afterwards,one model with the optimized three-dimensional profile of the structure was described using Pro-engineer software.The associate model was then analyzed to reconstruct the process between the incident light and the model surface.Finally,the mechanism of the angle-dependent discoloration effect was analyzed by theoretical calculation and optical simulation.Different light propagation paths and the length of the incident light at different angles caused destructive or constructive interference between the light reflected from the different layers.The different spectra of the reflected light make the wings appear with different structural colors,thereby endowing the angle-dependent discoloration effect.The consistency of the calculation and simulation results confirms that these structures possess an excellent angle-dependent discoloration effect.This functional "biomimetic structure" would not only be of great scientific interest but could also have a great impact in a wide range of applications such as reflective displays,credit card security,and military stealth technology.

  11. Automated Flaw Detection Scheme For Cast Austenitic Stainless Steel Weld Specimens Using Hilbert Huang Transform Of Ultrasonic Phased Array Data

    Energy Technology Data Exchange (ETDEWEB)

    Khan, T.; Majumdar, Shantanu; Udpa, L.; Ramuhalli, Pradeep; Crawford, Susan L.; Diaz, Aaron A.; Anderson, Michael T.

    2012-01-01

    The objective of this work is to develop processing algorithms to detect and localize the flaws using NDE ultrasonic data. Data was collected using cast austenitic stainless steel (CASS) weld specimens on-loan from the U.S. nuclear power industry’s Pressurized Water Reactor Owners Group (PWROG) specimen set. Each specimen consists of a centrifugally cast stainless steel (CCSS) pipe section welded to a statically cast (SCSS) or wrought (WRSS) section. The paper presents a novel automated flaw detection and localization scheme using low frequency ultrasonic phased array inspection signals in the weld and heat affected zone of the base materials. The major steps of the overall scheme are preprocessing and region of interest (ROI) detection followed by the Hilbert Huang transform (HHT) of A-scans in the detected ROIs. HHT offers time-frequency-energy distribution for each ROI. The accumulation of energy in a particular frequency band is used as a classification feature for the particular ROI.

  12. Effect of Crack Closure on Ultrasonic Detection of Fatigue Cracks at Fastener Holes

    Science.gov (United States)

    Bowles, S. J.; Harding, C. A.; Hugo, G. R.

    2009-03-01

    The ultrasonic response from closed fatigue cracks grown in aluminium alloy specimens using a representative aircraft spectrum loading has been characterised as a function of tensile applied load using pulse-echo 45° shear-wave ultrasonic C-scans with focused immersion transducers. Observed trends with crack size and applied load are described and compared to results for artificial machined defects. The results demonstrate that crack closure significantly reduces the ultrasonic response compared to open cracks or machined defects.

  13. Ex vivo detection of macrophages in atherosclerotic plaques using intravascular ultrasonic-photoacoustic imaging

    Science.gov (United States)

    Quang Bui, Nhat; Hlaing, Kyu Kyu; Lee, Yong Wook; Kang, Hyun Wook; Oh, Junghwan

    2017-01-01

    Macrophages are excellent imaging targets for detecting atherosclerotic plaques as they are involved in all the developmental stages of atherosclerosis. However, no imaging technique is currently capable of visualizing macrophages inside blood vessel walls. The current study develops an intravascular ultrasonic-photoacoustic (IVUP) imaging system combined with indocyanine green (ICG) as a contrast agent to provide morphological and compositional information about the targeted samples. Both tissue-mimicking vessel phantoms and atherosclerotic plaque-mimicking porcine arterial tissues are used to demonstrate the feasibility of mapping macrophages labeled with ICG by endoscopically applying the proposed hybrid technique. A delay pulse triggering technique is able to sequentially acquire photoacoustic (PA) and ultrasound (US) signals from a single scan without using any external devices. The acquired PA and US signals are used to reconstruct 2D cross-sectional and 3D volumetric images of the entire tissue with the ICG-loaded macrophages injected. Due to high imaging contrast and sensitivity, the IVUP imaging vividly reveals structural information and detects the spatial distribution of the ICG-labeled macrophages inside the samples. ICG-assisted IVUP imaging can be a feasible imaging modality for the endoscopic detection of atherosclerotic plaques.

  14. An ultrasonic sensor system based on a two-dimensional state method for highway vehicle violation detection applications.

    Science.gov (United States)

    Liu, Jun; Han, Jiuqiang; Lv, Hongqiang; Li, Bing

    2015-04-16

    With the continuing growth of highway construction and vehicle use expansion all over the world, highway vehicle traffic rule violation (TRV) detection has become more and more important so as to avoid traffic accidents and injuries in intelligent transportation systems (ITS) and vehicular ad hoc networks (VANETs). Since very few works have contributed to solve the TRV detection problem by moving vehicle measurements and surveillance devices, this paper develops a novel parallel ultrasonic sensor system that can be used to identify the TRV behavior of a host vehicle in real-time. Then a two-dimensional state method is proposed, utilizing the spacial state and time sequential states from the data of two parallel ultrasonic sensors to detect and count the highway vehicle violations. Finally, the theoretical TRV identification probability is analyzed, and actual experiments are conducted on different highway segments with various driving speeds, which indicates that the identification accuracy of the proposed method can reach about 90.97%.

  15. The detection of cavitation in hydraulic machines by use of ultrasonic signal analysis

    Science.gov (United States)

    Gruber, P.; Odermatt, P.; Etterlin, M.; Lerch, T.; Frei, M.; Farhat, M.

    2014-03-01

    This presentation describes an experimental approach for the detection of cavitation in hydraulic machines by use of ultrasonic signal analysis. Instead of using the high frequency pulses (typically 1MHz) only for transit time measurement different other signal characteristics are extracted from the individual signals and its correlation function with reference signals in order to gain knowledge of the water conditions. As the pulse repetition rate is high (typically 100Hz), statistical parameters can be extracted of the signals. The idea is to find patterns in the parameters by a classifier that can distinguish between the different water states. This classification scheme has been applied to different cavitation sections: a sphere in a water flow in circular tube at the HSLU in Lucerne, a NACA profile in a cavitation tunnel and a Francis model test turbine both at LMH in Lausanne. From the signal raw data several statistical parameters in the time and frequency domain as well as from the correlation function with reference signals have been determined. As classifiers two methods were used: neural feed forward networks and decision trees. For both classification methods realizations with lowest complexity as possible are of special interest. It is shown that three signal characteristics, two from the signal itself and one from the correlation function are in many cases sufficient for the detection capability. The final goal is to combine these results with operating point, vibration, acoustic emission and dynamic pressure information such that a distinction between dangerous and not dangerous cavitation is possible.

  16. Defect detection of pipes using Lyapunov dimension of Duffing oscillator based on ultrasonic guided waves

    Science.gov (United States)

    Wu, Jing; Wang, Yu; Zhang, Weiwei; Nie, Zhenhua; Lin, Rong; Ma, Hongwei

    2017-01-01

    This study proposes a novel small defect detection approach for steel pipes using the Lyapunov dimension (D) of the Duffing chaotic system based on ultrasonic guided waves. In this paper, inspection model is constructed by inputting the measured guided wave signal into the Duffing equation as the external turbulent driving force term and then Dis calculated. The properties of the Duffing system's noise immunity are first demonstrated theoretically based on the Lyapunov exponents. By comparing Dof the Duffing inspection system between the conditions of the inputted pure noise and the guided wave signal, the amplitude of the periodic force (F), the important parameter of the Duffing inspection system, could be determined. The values of other parameters of the Duffing inspection system are subsequently determined according to the numerical investigation. Furthermore, a time-moving window function is constructed to scan along the measured signal to locate the defect. And the small defect echo signal polluted by the noise is illustrated to prove the availability of the proposed method. Both numerical and experimental results show that the proposed approach can be used to improve the sensitivity of small defect detection and locate the small defect in pipes.

  17. Future constraints on angle-dependent non-Gaussianity from large radio surveys

    Science.gov (United States)

    Raccanelli, Alvise; Shiraishi, Maresuke; Bartolo, Nicola; Bertacca, Daniele; Liguori, Michele; Matarrese, Sabino; Norris, Ray P.; Parkinson, David

    2017-03-01

    We investigate how well future large-scale radio surveys could measure different shapes of primordial non-Gaussianity; in particular we focus on angle-dependent non-Gaussianity arising from primordial anisotropic sources, whose bispectrum has an angle dependence between the three wavevectors that is characterized by Legendre polynomials PL and expansion coefficients cL. We provide forecasts for measurements of galaxy power spectrum, finding that Large-Scale Structure (LSS) data could allow measurements of primordial non-Gaussianity that would be competitive with, or improve upon, current constraints set by CMB experiments, for all the shapes considered. We argue that the best constraints will come from the possibility to assign redshift information to radio galaxy surveys, and investigate a few possible scenarios for the EMU and SKA surveys. A realistic (futuristic) modeling could provide constraints of fNLloc ≈ 1(0 . 5) for the local shape, fNL of O(10) (O(1)) for the orthogonal, equilateral and folded shapes, and cL=1 ≈ 80(2) , cL=2 ≈ 400(10) for angle-dependent non-Gaussianity showing that only futuristic galaxy surveys will be able to set strong constraints on these models. Nevertheless, the more futuristic forecasts show the potential of LSS analyses to considerably improve current constraints on non-Gaussianity, and so on models of the primordial Universe. Finally, we find the minimum requirements that would be needed to reach σ(cL=1) = 10, which can be considered as a typical (lower) value predicted by some (inflationary) models.

  18. Ultrasonic Inspection

    Science.gov (United States)

    1976-01-01

    Automation Industries Inc. has had more than $2 million in contracts to produce innovative equipment for the Apollo program. When Marshall Space Flight Center sought a fast nondestructive way to inspect butt welds in aluminum alloys for spacecraft, the company developed a reliable ultrasonic device using multiple transducers called "delta manipulators" which detect lack of weld penetration not readily seen in radiograph automation. Industry soon adapted the ultrasonic equipment to a unique rail inspection device that saves countless man hours. Device is contained in self propelled railroad cars produced and operated by the company to check old track welds for deterioration.

  19. Determination of selected polychlorinated biphenyls in soil by miniaturised ultrasonic solvent extraction and gas chromatography-mass-selective detection.

    Science.gov (United States)

    Aydin, Mehmet Emin; Tor, Ali; Ozcan, Senar

    2006-09-08

    Miniaturised ultrasonic solvent extraction procedure was developed for the determination of selected polychlorinated biphenyls (PCBs) in soil samples by gas chromatography-mass-selective detection by using 2(3) factorial experimental design. Recoveries of PCBs from fortified soil samples are over 90% for three different fortification levels between 40 and 120 microg kg(-1), and relative standard deviations of the recoveries are below 7%. The limits of detection (LODs) ranged from 0.003 to 0.006 microg kg(-1). The performance of the proposed method was compared to traditional shake flask extraction method on the spiked real soil sample and extraction methods showed comparable efficiencies. Proposed miniaturised ultrasonic solvent extraction offers several advantages, i.e., reducing sample requirement for measurement of target compound, less solvent consumption and reducing the costs associated with solvent purchase and waste disposal.

  20. An Ultrasonic and Air Pressure Sensing System for Detection of Behavior before Getting out of Bed Aided by Fuzzy Theory

    Science.gov (United States)

    Yamaguchi, Hayato; Nakajima, Hiroshi; Taniguchi, Kazuhiko; Kobashi, Syoji; Hata, Yutaka

    This paper proposes a sensing system for a behavior detection system using an ultrasonic oscillosensor and an air pressure sensor. The ultrasonic oscillosensor sensor has a cylindrical tank filled with water. It detects the vibration of the target object from the signal reflected from the water surface. This sensor can detect a biological vibration by setting to the bottom bed frame. The air pressure sensor consists of a polypropylene sheet and an air pressure sensor, and detects the pressure information by setting under the bed's mattress. An increase (decrease) in the load placed on the bed is detected by the increase (decrease) in the pressure of the air held in the tube attached to the sheet. We propose a behavior detection system using both sensors, complementally. The system recognizes three states (nobody in bed, keeping quiet in bed, moving in bed) using both sensors, and we detect the behavior before getting out of bed by recognized these states. Fuzzy logic plays a primary role in the system. As the fundamental experiment, we applied the system to five healthy volunteers, the system successfully recognized three states, and detected the behavior before getting out of bed. As the clinical experiment, we applied the system to four elderly patients with dementia, the system exactly detected the behavior before getting out of the bed with enough time for medical care support.

  1. Detection and sizing of defects in control rod drive mechanism penetrations using eddy current and ultrasonics

    Energy Technology Data Exchange (ETDEWEB)

    Light, G.M.; Fisher, J.L.; Tennis, R.F.; Stolte, J.S.; Hendrix, G.J. [Southwest Research Inst., San Antonio, TX (United States)

    1996-08-01

    Over the last two years, concern has been generated about the capabilities of performing nondestructive evaluation (NDE) of the closure-head penetrations in nuclear-reactor pressure vessels. These penetrations are primarily for instrumentation and control rod drive mechanisms (CRDMs) and are usually thick-walled Inconel tubes, which are shrink-fitted into the steel closure head. The penetrations are then welded between the outside surface of the penetration and the inside surface of the closure head. Stress corrosion cracks initiating at the inner surface of the penetration have been reported at several plants. Through-wall cracks in the CRDM penetration or CRDM weld could lead to loss of coolant in the reactor vessel. The CRDM penetration presents a complex inspection geometry for conventional NDE techniques. A thermal sleeve, through which pass the mechanical linkages for operating the control rods, is inserted into the penetration in such a way that only a small annulus (nominally 3 mm) exists between the thermal sleeve and inside surface of the penetration. Ultrasonic (UT) and eddy current testing (ET) techniques that could be used to provide defect detection and sizing capability were investigated. This paper describes the ET and UT techniques, the probes developed, and the results obtained using these probes and techniques on CRDM penetration mock-ups.

  2. Future Constraints on Angle-Dependent Non-Gaussianity from Large Radio Surveys

    CERN Document Server

    Raccanelli, Alvise; Bartolo, Nicola; Bertacca, Daniele; Liguori, Michele; Matarrese, Sabino; Norris, Ray P; Parkinson, David

    2015-01-01

    We investigate how well future large-scale radio surveys could measure different shapes of primordial non-Gaussianity; in particular we focus on angle-dependent non-Gaussianity arising from primordial anisotropic sources, whose bispectrum has an angle dependence between the three wavevectors that is characterized by Legendre polynomials $\\mathcal{P}_L$ and expansion coefficients $c_L$. We provide forecasts for measurements of galaxy power spectrum, finding that Large-Scale Structure (LSS) data could allow measurements of primordial non-Gaussianity competitive or improving upon current constraints set by CMB experiments, for all the shapes considered. We argue that the best constraints will come from the possibility to assign redshift information to radio galaxy surveys, and investigate a few possible scenarios for the EMU and SKA surveys. A realistic (futuristic) modeling could provide constraints of $f_{\\rm NL}^{\\rm loc} \\approx 1 (0.5)$ for the local shape, $f_{\\rm NL}$ of $\\mathcal{O}(10) (\\mathcal{O}(1))$...

  3. Depth resolution, angle dependence, and the sputtering yield of Irganox 1010 by coronene primary ions.

    Science.gov (United States)

    Seah, Martin P; Spencer, Steve J; Shard, Alex G

    2013-10-01

    A study is reported of the depth resolution and angle dependence of sputtering yields using the reference organic material, Irganox 1010, for a new coronene(+) depth profiling ion source at 8 and 16 keV beam energies. This source provides excellent depth profiles as shown by 8.5 nm marker layers of Irganox 3114. Damage occurs but may be ignored for angles of incidence above 70° from the surface normal, as shown by X-ray photoelectron spectroscopy (XPS) of the C 1s peak structure. Above 70°, XPS profiles of excellent depth resolution are obtained. The depth resolution, after removal of the thickness of the delta layers, shows a basic contribution of 5.7 nm together with a contribution of 0.043 times the depth sputtered. This is lower than generally reported for cluster sources. The coronene(+) source is thus found to be a useful and practical source for depth profiling organic materials. The angle dependencies of both the undamaged and damaged materials are described by a simple equation. The sputtering yields for the undamaged material are described by a universal equation and are consistent with those obtained for C60(+) sputtering. Comparison with the sputtering yields using an argon gas cluster ion source shows great similarities, but the yields for both the coronene(+) and C60(+) primary ion sources are slightly lower.

  4. Theoretical assessment of different ultrasonic configurations for defects detection in composite components

    DEFF Research Database (Denmark)

    Kappatos, Vassilios; Asfis, Georgios; Salonitis, Konstantinos

    2017-01-01

    physical models representative of laminated Carbon Fiber Reinforced Polymer (CFRP) composites, consisting of a variety of artificial delamination defect modes (different sizes and depth), were numerically tested. Different ultrasonic configurations on both the positioning and the firing of the probe...

  5. Total Internal Reflection Ultrasonic Sensor for Detection of Subsurface Flaws: Research into Underlying Physics

    Science.gov (United States)

    2014-11-24

    from 1 September 2012 to 31 August 2014 Air Force Research Laboratory Air Force Office of Scientific Research European Office of Aerospace...wave and ray vectors. 11.5 Displacement of an Ultrasonic Beam Optical visualisation of reflection of the SH-wave type pulse from the inclined face...Photoelastic Technique,” Journal of Nondestructive Evaluation, vol. 4, no. 2, pp. 65-73, 1984. [12] E. Ginzel, “Photoelastic Visualisation of Ultrasonic

  6. Impacts of gantry angle dependent scanning beam properties on proton PBS treatment

    Science.gov (United States)

    Lin, Yuting; Clasie, Benjamin; Lu, Hsiao-Ming; Flanz, Jacob; Shen, Tim; Jee, Kyung-Wook

    2017-01-01

    While proton beam models in treatment planning systems are generally assumed invariant with respect to the beam deliveries at different gantry angles. Physical properties of scanning pencil beams can change. The gantry angle dependent properties include the delivered charge to the monitor unit chamber, the spot position and the spot shape. The aim of this study is to investigate the extent of the changes and their dosimetric impacts using historical pencil beam scanning (PBS) treatment data. Online beam delivery records at the time of the patient-specific qualify assurance were retrospectively collected for a total of 34 PBS fields from 28 patients treated at our institution. For each field, proton beam properties at two different gantry angles (the planned and zero gantry angles) were extracted by a newly-developed machine log analysis method and used to reconstruct the delivered dose distributions in the cubic water phantom geometry. The reconstructed doses at the two different angles and a planar dose measurement by a 2D ion-chamber array were compared and the dosimetric impacts of the gantry angle dependency were accessed by a 3D γ-index analysis. In addition, the pencil beam spot size was independently characterized as a function of the gantry angle and the beam energy. The dosimetric effects of the perturbed beam shape were also investigated. Comparisons of spot-by-spot beam positions between both gantry angles show a mean deviation of 0.4 and 0.7 mm and a standard deviation of 0.3 and 0.6 mm for x and y directions, respectively. The delivered giga-protons per spot show a percent mean difference and a standard deviation of 0.01% and 0.3%, respectively, from each planned spot weight. These small deviations lead to an excellent agreement in dose comparisons with an average γ passing rate of 99.1%. When each calculation for both planned and zero gantry angles was compared to the measurement, a high correlation in γ values was also observed, also

  7. Impacts of gantry angle dependent scanning beam properties on proton PBS treatment.

    Science.gov (United States)

    Lin, Yuting; Clasie, Benjamin; Lu, Hsiao-Ming; Flanz, Jacob; Shen, Tim; Jee, Kyung-Wook

    2017-01-21

    While proton beam models in treatment planning systems are generally assumed invariant with respect to the beam deliveries at different gantry angles. Physical properties of scanning pencil beams can change. The gantry angle dependent properties include the delivered charge to the monitor unit chamber, the spot position and the spot shape. The aim of this study is to investigate the extent of the changes and their dosimetric impacts using historical pencil beam scanning (PBS) treatment data. Online beam delivery records at the time of the patient-specific qualify assurance were retrospectively collected for a total of 34 PBS fields from 28 patients treated at our institution. For each field, proton beam properties at two different gantry angles (the planned and zero gantry angles) were extracted by a newly-developed machine log analysis method and used to reconstruct the delivered dose distributions in the cubic water phantom geometry. The reconstructed doses at the two different angles and a planar dose measurement by a 2D ion-chamber array were compared and the dosimetric impacts of the gantry angle dependency were accessed by a 3D γ-index analysis. In addition, the pencil beam spot size was independently characterized as a function of the gantry angle and the beam energy. The dosimetric effects of the perturbed beam shape were also investigated. Comparisons of spot-by-spot beam positions between both gantry angles show a mean deviation of 0.4 and 0.7 mm and a standard deviation of 0.3 and 0.6 mm for x and y directions, respectively. The delivered giga-protons per spot show a percent mean difference and a standard deviation of 0.01% and 0.3%, respectively, from each planned spot weight. These small deviations lead to an excellent agreement in dose comparisons with an average γ passing rate of 99.1%. When each calculation for both planned and zero gantry angles was compared to the measurement, a high correlation in γ values was also observed, also

  8. 油箱泄漏的超声检测方法%Ultrasonic Leak Detection Methods of Fuel Tank

    Institute of Scientific and Technical Information of China (English)

    薛花; 吴迪; 王亚平; 赵振宁; 陈天夫; 滕永平

    2016-01-01

    The paper analyzed the factors influencing the bubble detection rate in ultrasonic leak detection for fuel tank,studied the characteristics of ultrasonic reflection field of transducer,and proposed a new 8-channel parallel cyclic scanning detection mode, maximizing the repetition frequency of each transducer.Then comparative experiment tests were conducted between our 8-channel parallel ultrasonic leak detector and the traditional one.The results showed that,compared to single-channel scanning mode,the multi-channel parallel testing method had much higher detection rates when the single air bubble or long time interval bubbles needed to be detected.So this method was more effective to detect smaller tank leakage (μm diameter).%分析了影响油箱泄漏超声检测中气泡检出率的相关因素,研究了超声检测探头声场特点,提出了8路并行循环检测的工作模式,最大限度地提高了每个探头的重复工作频率.将自行搭建的8路并行超声波检测装置和传统超声测漏仪器进行了对比试验.结果表明,相对于单路扫描工作方式,多路并行检测对产生时间间隔较大气泡和单个气泡具有较高的检出率,可以检出更微小的缺陷(微米量级).

  9. Ultrasonic corona sensor study

    Science.gov (United States)

    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.

  10. Angle dependent magnetothermopower of α-(ET)2KHg(SCN)4

    Science.gov (United States)

    Krstovska, D.; Steven, E.; Choi, E. S.; Brooks, J. S.

    2011-10-01

    The magnetic field and angle dependences of the thermopower and Nernst effect for the quasi-two dimensional (q2D) organic conductor α-(ET)2KHg(SCN)4 are measured at temperatures below (4 K) and above (9 K) the transition temperature in fields of up to 31 T. In addition, a theoretical model involving a magnetic breakdown effect between the q1D and q2D bands is proposed in order to simulate the data. Analysis of the background components of the thermopower and Nernst effect imply that at low temperatures, in the CDW state, the properties of α-(ET)2KHg(SCN)4 are determined mostly by the orbits on new, open Fermi sheets. The quantum oscillations observed in both thermoelectric effects at fields above 8 T are caused only by the α orbit.

  11. Plasmonic nanowires arranged in Fibonacci number chain: Excitation angle-dependent optical properties

    Directory of Open Access Journals (Sweden)

    Mohit Raghuwanshi

    2013-02-01

    Full Text Available Herein we numerically study the excitation angle-dependant far-field and near-field optical properties of vertical plasmonic nanowires arranged in an unconventional linear geometry: Fibonacci number chain. The first five numbers in the Fibonacci series (1, 1, 2, 3, 5 were mapped to the size of gold nanowires, and arranged in a linear chain to study their optical interactions, and compared them to conventional chain of vertical gold nanowires. By harnessing the radiative and evanescent coupling regimes in the geometry, we found a systematic variation in the far-field extinction and near-field confinement in the geometries. Our simulation studies revealed enhanced backscattered intensity in the far-field radiation pattern at excitation angles along the chain-length of Fibonacci geometry, which was otherwise absent for conventional chain of plasmonic nanowires. Such angular reconfiguration of optical fields in unconventional linear geometries can be harnessed for tunable on-chip plasmonics.

  12. Angular phase shift in polarization-angle dependence of microwave-induced magnetoresistance oscillations

    Science.gov (United States)

    Liu, Han-Chun; Samaraweera, Rasanga L.; Mani, R. G.; Reichl, C.; Wegscheider, W.

    2016-12-01

    We examine the microwave frequency (f ) variation of the angular phase shift, θ0, observed in the polarization-angle dependence of microwave-induced magnetoresistance oscillations in a high-mobility GaAs/AlGaAs two-dimensional electron system. By fitting the diagonal resistance Rx x versus θ plots to an empirical cosine square law, we extract θ0 and trace its quasicontinuous variation with f . The results suggest that the overall average of θ0 extracted from Hall bar device sections with length-to-width ratios of L /W =1 and 2 is the same. We compare the observations with expectations arising from the "ponderomotive force" theory for microwave radiation-induced transport phenomena.

  13. Determination of light output function and angle dependent correction for a stilbene crystal scintillation neutron spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, W. E-mail: hansen@metrs1.mw.tu-dresden.de; Richter, D

    2002-01-01

    In addition to liquid NE213 scintillators also stilbene solid crystals are applied traditionally for fast neutron spectrometry. A proper evaluation of experimental data provides a precise determination of the nonlinear light output function for the given scintillator/photomultiplier combination, and for stilbene additionally an adequate correction of the anisotropy effect. Calibration experiments with monoenergetic neutrons (1.2, 2.5, 5.0, 13.95, 14.8, 19.0 MeV) and various neutron incidence angles were carried out at the accelerator facility of the PTB Braunschweig for two cylindrical scintillators (diameter 30 mm x 25 mm, diameter 10 mm x 10 mm). An improved analytic light output function as well as an adequate angle dependent correction function were derived.

  14. Electromagnetic ultrasonic guided waves

    CERN Document Server

    Huang, Songling; Li, Weibin; Wang, Qing

    2016-01-01

    This book introduces the fundamental theory of electromagnetic ultrasonic guided waves, together with its applications. It includes the dispersion characteristics and matching theory of guided waves; the mechanism of production and theoretical model of electromagnetic ultrasonic guided waves; the effect mechanism between guided waves and defects; the simulation method for the entire process of electromagnetic ultrasonic guided wave propagation; electromagnetic ultrasonic thickness measurement; pipeline axial guided wave defect detection; and electromagnetic ultrasonic guided wave detection of gas pipeline cracks. This theory and findings on applications draw on the author’s intensive research over the past eight years. The book can be used for nondestructive testing technology and as an engineering reference work. The specific implementation of the electromagnetic ultrasonic guided wave system presented here will also be of value for other nondestructive test developers.

  15. Porosity Detection in Ceramic Armor Tiles via Ultrasonic Time-Of

    Science.gov (United States)

    Margetan, Frank J.; Richter, Nathaniel; Jensen, Terrence

    2011-06-01

    Some multilayer armor panels contain ceramic tiles as one constituent, and porosity in the tiles can affect armor performance. It is well known that porosity in ceramic materials leads to a decrease in ultrasonic velocity. We report on a feasibility study exploring the use of ultrasonic time-of-flight (TOF) to locate and characterize porous regions in armor tiles. The tiles in question typically have well-controlled thickness, thus simplifying the translation of TOF data into velocity data. By combining UT velocity measurements and X-ray absorption measurements on selected specimens, one can construct a calibration curve relating velocity to porosity. That relationship can then be used to translate typical ultrasonic C-scans of TOF-versus-position into C-scans of porosity-versus-position. This procedure is demonstrated for pulse/echo, focused-transducer inspections of silicon carbide (SiC) ceramic tiles.

  16. Characterization of Angle Dependent Color Travel of Printed Multi-Color Effect Pigment on Different Color Substrates

    Directory of Open Access Journals (Sweden)

    Mirica Karlovits

    2015-03-01

    Full Text Available Color-travel pigments, which exhibit much more extensive color change as well provide angle-dependent optical effect can be used in many industrial products. In present paper the multi-color effect pigment printed on three different foils with different background color (black, silver and transparent was investigated. The pigment was based on synthetically produced transparent silicon dioxide platelets coated with titanium dioxide. CIEL*a*b* values and reflection of prints were measured by multi-angle spectrophotometer at constant illumination at an angle of 45º and different viewing angles (-15º, 15°, 25º, 45º, 75º and 110º were used. The measurements of printed multi-color pigment showed that CIEL*a*b* color coordinates varied to great extents, depending on detection angles as well on color of the printing substrate. The study revealed that pigmnet printed on black background obtained significant change in color. The study has also shown that when viewing angle increases, the reflection curves decreases.

  17. Detection of plating defects using ultrasonic and eddy current test methods; Nachweis von Plattierungsfehlern mit Ultraschall- und Wirbelstromverfahren

    Energy Technology Data Exchange (ETDEWEB)

    Waidele, H.; Knoch, P. [MPA, Univ. Stuttgart (Germany); Gersinska, R. [BfS Salzgitter (Germany); Brenner, W.; Seidenkranz, T. [TUeV Sued (Germany); Csapo, G.; Just, T. [TUeV Nord (Germany); Weiss, R. [IzfP Saarbruecken (Germany); Rathgeb, W. [IntelligeNDT, Erlangen (Germany)

    2004-07-01

    The validity of ultrasonic and eddy current testing of austenitic platings of reactor pressure vessels was investigated in the context of a project funded by the Federal Radiation Protection Office (Bundesamt fuer Strahlenschutz). In the first phase, test specimens with natural defects were fabricated at MPA Stuttgart; in the second phase, plating defects were introduced in a MPA large-size vessel. Measurements showed that most plating defects will be detected by standard ultrasonic testing. The highest accuracy was achieved by a combination of ultrasonic and eddy current testing. (orig.) [German] Im Rahmen eines vom Bundesamt fuer Strahlenschutz gefoerderten Vorhabens wurde die Aussagefaehigkeit von Ultraschall- und Wirbelstrompruefungen an austenitischen Plattierungen von Reaktordruckbehaeltern untersucht. In der ersten Phase des Vorhabens wurden an der MPA Stuttgart Testkoerper mit natuerlichen Fehlern im Plattierungsbereich gefertigt, in einer zweiten Phase wurden Plattierungsfehler in den MPA-Grossbehaelter eingebracht. Die Messungen haben gezeigt, dass die meisten Plattierungsfehler mit Ultraschall-Standardprueftechniken nachweisbar sind, wobei die groesste Aussagekraft bei einer Kombination von Ultraschall- und Wirbelstrompruefung gegeben ist. (orig.)

  18. Ultrasonic techniques for process monitoring and control.

    Energy Technology Data Exchange (ETDEWEB)

    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.

  19. Development and field application of a nonlinear ultrasonic modulation technique for fatigue crack detection without reference data from an intact condition

    Science.gov (United States)

    Lim, Hyung Jin; Kim, Yongtak; Koo, Gunhee; Yang, Suyoung; Sohn, Hoon; Bae, In-hwan; Jang, Jeong-Hwan

    2016-09-01

    In this study, a fatigue crack detection technique, which detects a fatigue crack without relying on any reference data obtained from the intact condition of a target structure, is developed using nonlinear ultrasonic modulation and applied to a real bridge structure. Using two wafer-type lead zirconate titanate (PZT) transducers, ultrasonic excitations at two distinctive frequencies are applied to a target inspection spot and the corresponding ultrasonic response is measured by another PZT transducer. Then, the nonlinear modulation components produced by a breathing-crack are extracted from the measured ultrasonic response, and a statistical classifier, which can determine if the nonlinear modulation components are statistically significant in comparison with the background noise level, is proposed. The effectiveness of the proposed fatigue crack detection technique is experimentally validated using the data obtained from aluminum plates and aircraft fitting-lug specimens under varying temperature and loading conditions, and through a field testing of Yeongjong Grand Bridge in South Korea. The uniqueness of this study lies in that (1) detection of a micro fatigue crack with less than 1 μm width and fatigue cracks in the range of 10-20 μm in width using nonlinear ultrasonic modulation, (2) automated detection of fatigue crack formation without using reference data obtained from an intact condition, (3) reliable and robust diagnosis under varying temperature and loading conditions, (4) application of a local fatigue crack detection technique to online monitoring of a real bridge.

  20. Multi-damage detection with embedded ultrasonic structural radar algorithm using piezoelectric wafer active sensors through advanced signal processing

    Science.gov (United States)

    Yu, Lingyu; Giurgiutiu, Victor

    2005-05-01

    The embedded ultrasonic structural radar (EUSR) algorithm was developed by using piezoelectric wafer active sensor (PWAS) array to detect defects within a large area of a thin-plate specimen. EUSR has been verified to be effective for detecting a single crack either at a broadside or at an offside position. In this research, advanced signal processing techniques were included to enhance inspection image quality and detect multiple damage. The signal processing methods include discrete wavelet transform for signal denoising, short-time Fourier transform and continuous wavelet transform for time-frequency analysis, continuous wavelet transform for frequency filtering, and Hilbert transform for envelope extraction. All these signal processing modules were implemented by developing a graphical user-friendly interface program in LabVIEW. The paper starts with an introduction of embedded ultrasonic structural radar algorithm, followed with the theoretical aspect of the phased array signal processing method. Then, the mathematical algorithms for advanced signal processing are introduced. In the end, laboratory experimental results are presented to show how efficiently the improved EUSR works. The results are analyzed and EUSR is concluded to have been improved by using the advanced signal processing techniques. The improvements include: 1) EUSR is able to provide better image of the specimen under monitoring; 2) it is able to detect multi-damage such as several cracks; 3) it is able to identify different damage types.

  1. Optimum Detection of Ultrasonic Echoes Applied to the Analysis of the First Layer of a Restored Dome

    Directory of Open Access Journals (Sweden)

    Addisson Salazar

    2007-01-01

    Full Text Available Optimum detection is applied to ultrasonic signals corrupted with significant levels of grain noise. The aim is to enhance the echoes produced by the interface between the first and second layers of a dome to obtain interface traces in echo pulse B-scan mode. This is useful information for the restorer before restoration of the dome paintings. Three optimum detectors are considered: matched filter, signal gating, and prewhitened signal gating. Assumed models and practical limitations of the three optimum detectors are considered. The results obtained in the dome analysis show that prewhitened signal gating outperforms the other two optimum detectors.

  2. An Ultrasonic Sensor System Based on a Two-Dimensional State Method for Highway Vehicle Violation Detection Applications

    Directory of Open Access Journals (Sweden)

    Jun Liu

    2015-04-01

    Full Text Available With the continuing growth of highway construction and vehicle use expansion all over the world, highway vehicle traffic rule violation (TRV detection has become more and more important so as to avoid traffic accidents and injuries in intelligent transportation systems (ITS and vehicular ad hoc networks (VANETs. Since very few works have contributed to solve the TRV detection problem by moving vehicle measurements and surveillance devices, this paper develops a novel parallel ultrasonic sensor system that can be used to identify the TRV behavior of a host vehicle in real-time. Then a two-dimensional state method is proposed, utilizing the spacial state and time sequential states from the data of two parallel ultrasonic sensors to detect and count the highway vehicle violations. Finally, the theoretical TRV identification probability is analyzed, and actual experiments are conducted on different highway segments with various driving speeds, which indicates that the identification accuracy of the proposed method can reach about 90.97%.

  3. Angle-dependent magnetoresistance and quantum oscillations in high-mobility semimetal LuPtBi

    KAUST Repository

    Xu, Guizhou

    2017-03-14

    The recent discovery of ultrahigh mobility and large positive magnetoresistance in topologically non-trivial Half-Heusler semimetal LuPtBi provides a unique playground for studying exotic physics and significant perspective for device applications. As an fcc-structured electron-hole-compensated semimetal, LuPtBi theoretically exhibits six symmetrically arranged anisotropic electron Fermi pockets and two nearly-spherical hole pockets, offering the opportunity to explore the physics of Fermi surface with a simple angle-related magnetotransport properties. In this work, through the angle-dependent transverse magnetoresistance measurements, in combination with high-field SdH quantum oscillations, we achieved to map out a Fermi surface with six anisotropic pockets in the high-temperature and low-field regime, and furthermore, identify a possible magnetic field driven Fermi surface change at lower temperatures. Reasons account for the Fermi surface change in LuPtBi are discussed in terms of the field-induced electron evacuation due to Landau quantization.

  4. Angle-dependent quantum Otto heat engine based on coherent dipole-dipole coupling

    Science.gov (United States)

    Su, Shan-He; Luo, Xiao-Qing; Chen, Jin-Can; Sun, Chang-Pu

    2016-08-01

    Electromagnetic interactions between molecules or within a molecule have been widely observed in biological systems and exhibit broad application for molecular structural studies. Quantum delocalization of molecular dipole moments has inspired researchers to explore new avenues to utilize this physical effect for energy harvesting devices. Herein, we propose a simple model of the angle-dependent quantum Otto heat engine which seeks to facilitate the conversion of heat to work. Unlike previous studies, the adiabatic processes are accomplished by varying only the directions of the magnetic field. We show that the heat engine continues to generate power when the angle relative to the vector r joining the centres of coupled dipoles departs from the magic angle θm where the static coupling vanishes. A significant improvement in the device performance has to be attributed to the presence of the quantum delocalized levels associated with the coherent dipole-dipole coupling. These results obtained may provide a promising model for the biomimetic design and fabrication of quantum energy generators.

  5. Peeling-angle dependence of the stick-slip instability during adhesive tape peeling.

    Science.gov (United States)

    Dalbe, Marie-Julie; Santucci, Stéphane; Vanel, Loïc; Cortet, Pierre-Philippe

    2014-12-28

    The influence of peeling angle on the dynamics observed during the stick-slip peeling of an adhesive tape has been investigated. This study relies on a new experimental setup for peeling at a constant driving velocity while keeping constant the peeling angle and peeled tape length. The thresholds of the instability are shown to be associated with a subcritical bifurcation and bistability of the system. The velocity onset of the instability is moreover revealed to strongly depend on the peeling angle. This could be the consequence of peeling angle dependance of either the fracture energy of the adhesive-substrate joint or the effective stiffness at play between the peeling front and the point at which the peeling is enforced. The shape of the peeling front velocity fluctuations is finally shown to progressively change from typical stick-slip relaxation oscillations to nearly sinusoidal oscillations as the peeling angle is increased. We suggest that this transition might be controlled by inertial effects possibly associated with the propagation of the peeling force fluctuations through elongation waves in the peeled tape.

  6. T1rho mapping of entire femoral cartilage using depth- and angle-dependent analysis

    Energy Technology Data Exchange (ETDEWEB)

    Nozaki, Taiki; Kaneko, Yasuhito; Yu, Hon J.; Yoshioka, Hiroshi [University of California Irvine, Department of Radiological Sciences, Orange, CA (United States); Kaneshiro, Kayleigh [University of California Irvine, School of Medicine, Irvine, CA (United States); Schwarzkopf, Ran [University of California Irvine, Department of Orthopedic Surgery, Irvine, CA (United States); Hara, Takeshi [Gifu University Graduate School of Medicine, Department of Intelligent Image Information, Division of Regeneration and Advanced Medical Sciences, Gifu (Japan)

    2016-06-15

    To create and evaluate normalized T1rho profiles of the entire femoral cartilage in healthy subjects with three-dimensional (3D) angle- and depth-dependent analysis. T1rho images of the knee from 20 healthy volunteers were acquired on a 3.0-T unit. Cartilage segmentation of the entire femur was performed slice-by-slice by a board-certified radiologist. The T1rho depth/angle-dependent profile was investigated by partitioning cartilage into superficial and deep layers, and angular segmentation in increments of 4 over the length of segmented cartilage. Average T1rho values were calculated with normalized T1rho profiles. Surface maps and 3D graphs were created. T1rho profiles have regional and depth variations, with no significant magic angle effect. Average T1rho values in the superficial layer of the femoral cartilage were higher than those in the deep layer in most locations (p < 0.05). T1rho values in the deep layer of the weight-bearing portions of the medial and lateral condyles were lower than those of the corresponding non-weight-bearing portions (p < 0.05). Surface maps and 3D graphs demonstrated that cartilage T1rho values were not homogeneous over the entire femur. Normalized T1rho profiles from the entire femoral cartilage will be useful for diagnosing local or early T1rho abnormalities and osteoarthritis in clinical applications. (orig.)

  7. Applying a nonlinear, pitch-catch, ultrasonic technique for the detection of kissing bonds in friction stir welds.

    Science.gov (United States)

    Delrue, Steven; Tabatabaeipour, Morteza; Hettler, Jan; Van Den Abeele, Koen

    2016-05-01

    Friction stir welding (FSW) is a promising technology for the joining of aluminum alloys and other metallic admixtures that are hard to weld by conventional fusion welding. Although FSW generally provides better fatigue properties than traditional fusion welding methods, fatigue properties are still significantly lower than for the base material. Apart from voids, kissing bonds for instance, in the form of closed cracks propagating along the interface of the stirred and heat affected zone, are inherent features of the weld and can be considered as one of the main causes of a reduced fatigue life of FSW in comparison to the base material. The main problem with kissing bond defects in FSW, is that they currently are very difficult to detect using existing NDT methods. Besides, in most cases, the defects are not directly accessible from the exposed surface. Therefore, new techniques capable of detecting small kissing bond flaws need to be introduced. In the present paper, a novel and practical approach is introduced based on a nonlinear, single-sided, ultrasonic technique. The proposed inspection technique uses two single element transducers, with the first transducer transmitting an ultrasonic signal that focuses the ultrasonic waves at the bottom side of the sample where cracks are most likely to occur. The large amount of energy at the focus activates the kissing bond, resulting in the generation of nonlinear features in the wave propagation. These nonlinear features are then captured by the second transducer operating in pitch-catch mode, and are analyzed, using pulse inversion, to reveal the presence of a defect. The performance of the proposed nonlinear, pitch-catch technique, is first illustrated using a numerical study of an aluminum sample containing simple, vertically oriented, incipient cracks. Later, the proposed technique is also applied experimentally on a real-life friction stir welded butt joint containing a kissing bond flaw.

  8. Angle-Dependent Ionization of Small Molecules by Time-Dependent Configuration Interaction and an Absorbing Potential.

    Science.gov (United States)

    Krause, Pascal; Schlegel, H Bernhard

    2015-06-04

    The angle-dependence of strong field ionization of O2, N2, CO2, and CH2O has been studied theoretically using a time-dependent configuration interaction approach with a complex absorbing potential (TDCIS-CAP). Calculation of the ionization yields as a function of the direction of polarization of the laser pulse produces three-dimensional surfaces of the angle-dependent ionization probability. These three-dimensional shapes and their variation with laser intensity can be interpreted in terms of ionization from the highest occupied molecular orbital (HOMO) and lower lying orbitals, and the Dyson orbitals for the ground and excited states of the cations.

  9. Detection of anomalies in NLO sulphamic acid single crystals by ultrasonic and thermal studies

    Indian Academy of Sciences (India)

    GEORGE VARUGHESE

    2016-09-01

    The ultrasonic pulse echo overlap technique (PEO) has been used to measure the velocities of 10 MHz acoustic waves in sulphamic acid single crystals in the range of 300–400 K. This study evaluated all the elastic stiffnessconstants, compliance constants and Poisson’s ratios of the crystal. The temperature variations of the elastic constants have been determined. The phase transition studies above room temperature were investigated using ultrasonic PEO technique. This study has suggested new weak elastic anomalies for the crystal around 330 K. The transverse elastic constants C44 and C66 have shown clear thermal hysteresis of 2 K. The present differential scanningcalorimetric (DSC) studies carried out at a slow heating rate have also suggested weak phase transition around 331 K. The present elastic and thermal studies have been substantiated by already reported DC electrical conductivitystudies around 330 K.

  10. Laser ultrasonics detection of an embedded crack in a composite spherical particle.

    Science.gov (United States)

    Amziane, Ahmed; Amari, Mohamed; Mounier, Denis; Breteau, Jean-Marc; Joly, Nicolas; Banchet, Julien; Tisseur, David; Gusev, Vitalyi

    2012-01-01

    Laser ultrasonics was applied to the manufacturing control of the integrity (no failure) of coated spherical particles designed for High Temperature Reactors (HTR). This control is of major importance, since the coating of the nuclear fuel kernel is designed to prevent from the diffusion of fission products outside the particle during reactor operation. The SiC layer composing the coating is particularly important, since this layer must be an impenetrable barrier for fission products. The integrity of the SiC shell (no crack within the shell) can be assessed by the ultrasonic vibration spectrum of the HTR particle, which is significantly changed, compared to the reference spectrum of a defect-free particle. Spheroidal vibration modes of defect-free dummy particles with a zirconium dioxide (ZrO(2)) core were observed in the 2-5MHz range. A theoretical analysis is presented to account for the observed vibration spectra of defect-free or cracked HTR particles.

  11. A phase deviation based split-spectrum processing algorithm for ultrasonic flaw detection

    Institute of Scientific and Technical Information of China (English)

    LIU Zhenqing

    2002-01-01

    The Split Spectrum Processing (SSP) technique has proved its ability in reduction of interference noise in ultrasonic nondestructive testing for coarse grained materials. However,the results of SSP algorithms are not sufficiently stable since they are sensitive to the filter bank and filter parameters. And the mechanism of the technique to fully explore the signals is not clear. The statistical phase response characteristic of filter outputs for ultrasonic testing is discussed. Thus, a new SSP algorithm based on phase standard deviation is proposed. The performance is examined for both computer simulated and experimental data, and compared to commonly used minimum algorithm. The phase standard deviation algorithm is proved its superior effect and is less sensitive on the number of filters.

  12. Simulation research on ultrasonic guided waves detection of metal rod buffer system bonding quality

    Directory of Open Access Journals (Sweden)

    Yang Hu

    2013-01-01

    Full Text Available The judgment of metal rod buffer system bonding quality depends on the bond of the metal rods with the surrounding medium. System bonding area will lead to different reflection amplitude. Compared the simulation with the experiment, it can be concluded that different bonding area can measure bond quality, i.e, the greater the bonding area is the more excellent bonding quality will be. This conclusion provides the basis for the system ultrasonic testing.

  13. An optimal baseline selection methodology for data-driven damage detection and temperature compensation in acousto-ultrasonics

    Science.gov (United States)

    Torres-Arredondo, M.-A.; Sierra-Pérez, Julián; Cabanes, Guénaël

    2016-05-01

    The process of measuring and analysing the data from a distributed sensor network all over a structural system in order to quantify its condition is known as structural health monitoring (SHM). For the design of a trustworthy health monitoring system, a vast amount of information regarding the inherent physical characteristics of the sources and their propagation and interaction across the structure is crucial. Moreover, any SHM system which is expected to transition to field operation must take into account the influence of environmental and operational changes which cause modifications in the stiffness and damping of the structure and consequently modify its dynamic behaviour. On that account, special attention is paid in this paper to the development of an efficient SHM methodology where robust signal processing and pattern recognition techniques are integrated for the correct interpretation of complex ultrasonic waves within the context of damage detection and identification. The methodology is based on an acousto-ultrasonics technique where the discrete wavelet transform is evaluated for feature extraction and selection, linear principal component analysis for data-driven modelling and self-organising maps for a two-level clustering under the principle of local density. At the end, the methodology is experimentally demonstrated and results show that all the damages were detectable and identifiable.

  14. 产前超声检测胎儿胸腺%Prenatal ultrasonic detecting and evaluating for fetal thymus

    Institute of Scientific and Technical Information of China (English)

    凌乐文

    2012-01-01

    Detecting and evaluating for fetal thymus with prenatal ultrasound is very important for diagnosis of dysplastic thymus and relative malformations or diseases. The development and application of new technology helps to the assessment of development of the fetal thymus. Ultrasonic technologies of detecting and evaluating for fetal thymus were reviewed in the article.%产前超声检测胎儿胸腺对诊断胎儿胸腺发育异常及相关畸形或疾病有重要作用,新技术的发展和应用可更全面地评估胎儿胸腺的发育.本文对胎儿胸腺超声检测技术及临床应用进行综述.

  15. Assessment of Crack Detection in Heavy-Walled Cast Stainless Steel Piping Welds Using Advanced Low-Frequency Ultrasonic Methods

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Michael T.; Crawford, Susan L.; Cumblidge, Stephen E.; Denslow, Kayte M.; Diaz, Aaron A.; Doctor, Steven R.

    2007-03-01

    Studies conducted at the Pacific Northwest National Laboratory in Richland, Washington, have focused on assessing the effectiveness and reliability of novel approaches to nondestructive examination (NDE) for inspecting coarse-grained, cast stainless steel reactor components. The primary objective of this work is to provide information to the U.S. Nuclear Regulatory Commission on the effectiveness and reliability of advanced NDE methods as related to the inservice inspection of safety-related components in pressurized water reactors (PWRs). This report provides progress, recent developments, and results from an assessment of low frequency ultrasonic testing (UT) for detection of inside surface-breaking cracks in cast stainless steel reactor piping weldments as applied from the outside surface of the components. Vintage centrifugally cast stainless steel piping segments were examined to assess the capability of low-frequency UT to adequately penetrate challenging microstructures and determine acoustic propagation limitations or conditions that may interfere with reliable flaw detection. In addition, welded specimens containing mechanical and thermal fatigue cracks were examined. The specimens were fabricated using vintage centrifugally cast and statically cast stainless steel materials, which are typical of configurations installed in PWR primary coolant circuits. Ultrasonic studies on the vintage centrifugally cast stainless steel piping segments were conducted with a 400-kHz synthetic aperture focusing technique and phased array technology applied at 500 kHz, 750 kHz, and 1.0 MHz. Flaw detection and characterization on the welded specimens was performed with the phased array method operating at the frequencies stated above. This report documents the methodologies used and provides results from laboratory studies to assess baseline material noise, crack detection, and length-sizing capability for low-frequency UT in cast stainless steel piping.

  16. A novel real-time ultrasonic method for prion protein detection using plasminogen as a capture molecule

    Directory of Open Access Journals (Sweden)

    Sweeney Torres

    2007-07-01

    Full Text Available Abstract Background High resolution ultrasonography (HR-US can monitor the molecular changes and biochemical interactions between proteins in real-time. The aim of this study was to use HR-US to characterize the real-time interactions between plasminogen coated beads and PrPSc and to determine if this approach could be applied to the identification of animals affected by prion diseases. Plasminogen, immobilized to beads, was used as a capturing tool for PrPSc in brain homogenates from scrapie affected sheep and the binding reaction was monitored in real-time in an ultrasonic cell. Results Changes in the ultrasonic parameters suggested that three processes occurred during the incubation: binding, protein-protein network formation and precipitation and that these processes occurred in a concentration dependent manner. Conversely, when homogenates from normal sheep were similarly examined, no evidence for the occurrence of these processes was found indicating the specificity of the interaction between the plasminogen coated beads and PrPSc. Conclusion These results indicate firstly, that the plasminogen coated beads binded selectively to PrPSc and secondly, that a HR-US system can discriminate between scrapie affected and non-affected samples and thus has potential as a tool for the rapid diagnosis for prion diseases. This approach has the significant advantage of not requiring a proteinase K pre-digestion step, which is routinely used in current PrPSc detection assays.

  17. Ultrasonic detection of embedded and surface defects in thin plates using Lamb waves

    Science.gov (United States)

    Conry, M. J.; Crane, L. J.; Gilchrist, Michael

    2003-03-01

    Non-destructive Testing and Evaluation (NDT&E) is critical in the safety assurance of modern engineering structures, particularly when using high performance materials. Frequently, such materials are subject to mechanisms of damage uncommon in conventional structures. Additionally, many high performance alloys such as advanced aerospace aluminiums are more susceptible to fatigue failure than more traditional metals. In all such cases, it is essential to have good knowledge of the defects present in a component in order to assess its soundness. One of the most common and verstaile techniques used in NDT&E is ultrasonic testing, where the integrity of a component is characterized using acoustic waves.

  18. Detection of near-surface and surface-breaking defects using ultrasonic arrays

    Science.gov (United States)

    Velichko, A.; Wilcox, P. D.; Drinkwater, B. W.

    2012-05-01

    An efficient Finite Element procedure for predicting the complete scattering behavior for an arbitrarily-shaped defect which is located near a free surface in an otherwise homogeneous isotropic half-space is presented. The data provided by this model is then used for simulating an ultrasonic array response for different near-surface and surface-breaking defects. Example results for 2D array (3D defects) are presented and compared with the experiment. Its practical application to the volumetric inspections of thin section is discussed.

  19. NEAs: Phase Angle Dependence of Asteroid Class and Diameter from Observational Studies

    Science.gov (United States)

    Wooden, Diane H.; Lederer, Susan M.; Bus, Schelte; Tokunaga, Alan; Jehin, Emmanuel; Howell, Ellen S.; Nolan, Michael C.; Ryan, Erin; Fernandez, Yan; Harker, David; Reddy, Vishnu; Benner, Lance AM; Lovell, Amy; Moskovitz, Nicholas; Kerr, Tom; Woodward, Charles

    2015-08-01

    We will discuss the results of a planned observation campaign of Near Earth Asteroids (NEAs), 1999 CU3, 2002 GM2, 2002 FG7, and 3691 Bede with instruments on the United Kingdom Infrared Telescope (UKIRT) from 15-Mar-2015 to 28-April 2015 UT. We will study the phase-angle dependence of the reflectance and thermal emission spectra. Recent publications reveal that the assignment of the asteroid class from visible and near-IR spectroscopy can change with phase angle for NEAs with silicate-bearing minerals on their surfaces (S-class asteroids) (Thomas et al. 2014, Icarus 228, 217; Sanchez et al. 2012 Icarus 220, 36). Only three of the larger NEAs have been measured at a dozen phase angles and the trends are not all the same, so there is not yet enough information to create a phase-angle correction. Also, the phase angle effect is not characterized well for the thermal emission including determination of the albedo and the thermal emission. The few NEAs were selected for our study amongst many possible targets based on being able to observe them through a wide range of phase angles, ranging from less than about 10 degrees to greater than 45 degrees over the constrained date range. The orbits of NEAs often generate short observing windows at phase angles higher than 45 deg (i.e., whizzing by Earth and/or close to dawn or dusk). Ultimately, lowering the uncertainty of the translation of asteroid class to meteorite analog and of albedo and size determinations are amongst our science goals. On a few specific nights, we plan to observe the 0.75-2.5 micron spectra with IRTF+SpeX for comparison with UKIRT data including 5-20 micron with UKIRT+UIST/Michelle to determine as best as possible the albedos. To ensure correct phasing of spectroscopic data, we augment with TRAPPIST-telescope light curves and R-band guider image data. Our observations will contribute to understanding single epoch mid-IR and near-IR measurements to obtain albedo, size and IR beaming parameters (the

  20. NEAs: Phase Angle Dependence of Asteroid Class and Diameter from Observational Studies

    Science.gov (United States)

    Wooden, Diane H.; Lederer, Susan M.; Bus, Schlete; Tokunaga, Alan; Jehin, Emmanuel; Howell, Ellen S.; Nolan, Michael C.; Ryan, Erin; Fernandez, Yan; Harker, David; Benner, Lance A.; Lovell, Amy; Moskovitz, Nicholas; Kerr, Tom; Woodward, Charles

    2015-01-01

    We will discuss the results of a planned observation campaign of Near Earth Asteroids (NEAs), 1999 CU3, 2002 GM2, 2002 FG7, and 3691 Bede with instruments on the United Kingdom Infrared Telescope (UKIRT) from 15-Mar-2015 to 28-April 2015 UT. We will study the phase-angle dependence of the reflectance and thermal emission spectra. Recent publications reveal that the assignment of the asteroid class from visible and near-IR spectroscopy can change with phase angle for NEAs with silicate-bearing minerals on their surfaces (S-class asteroids) (Thomas et al. 2014, Icarus 228, 217; Sanchez et al. 2012 Icarus 220, 36). Only three of the larger NEAs have been measured at a dozen phase angles and the trends are not all the same, so there is not yet enough information to create a phase-angle correction. Also, the phase angle effect is not characterized well for the thermal emission including determination of the albedo and the thermal emission. The few NEAs were selected for our study amongst many possible targets based on being able to observe them through a wide range of phase angles, ranging from less than about 10 degrees to greater than 45 degrees over the constrained date range. The orbits of NEAs often generate short observing windows at phase angles higher than 45 deg (i.e., whizzing by Earth and/or close to dawn or dusk). Ultimately, lowering the uncertainty of the translation of asteroid class to meteorite analog and of albedo and size determinations are amongst our science goals. On a few specific nights, we plan to observe the 0.75-2.5 micron spectra with IRTF+SpeX for comparison with UKIRT data including 5-20 micron with UKIRT+UIST/Michelle to determine as best as possible the albedos. To ensure correct phasing of spectroscopic data, we augment with TRAPPIST-telescope light curves and R-band guider image data. Our observations will contribute to understanding single epoch mid-IR and near-IR measurements to obtain albedo, size and IR beaming parameters (the

  1. Effect of adaptive threshold filtering on ultrasonic nakagami parameter to detect variation in scatterer concentration.

    Science.gov (United States)

    Tsui, Po-Hsiang; Wan, Yung-Liang; Huang, Chih-Chung; Wang, Ming-Chen

    2010-10-01

    The Nakagami parameter is associated with the Nakagami distribution estimated from ultrasonic backscattered signals and closely reflects the scatterer concentrations in tissues. There is an interest in exploring the possibility of enhancing the ability of the Nakagami parameter to characterize tissues. In this paper, we explore the effect of adaptive thresholdfiltering based on the noise-assisted empirical mode decomposition of the ultrasonic backscattered signals on the Nakagami parameter as a function of scatterer concentration for improving the Nakagami parameter performance. We carried out phantom experiments using 5 MHz focused and nonfocused transducers. Before filtering, the dynamic ranges of the Nakagami parameter, estimated using focused and nonfocused transducers between the scatterer concentrations of 2 and 32 scatterers/mm3, were 0.44 and 0.1, respectively. After filtering, the dynamic ranges of the Nakagami parameter, using the focused and nonfocused transducers, were 0.71 and 0.79, respectively. The experimental results showed that the adaptive threshold filter makes the Nakagami parameter measured by a focused transducer more sensitive to the variation in the scatterer concentration. The proposed method also endows the Nakagami parameter measured by a nonfocused transducer with the ability to differentiate various scatterer concentrations. However, the Nakagami parameters estimated by focused and nonfocused transducers after adaptive threshold filtering have different physical meanings: the former represents the statistics of signals backscattered from unresolvable scatterers while the latter is associated with stronger resolvable scatterers or local inhomogeneity due to scatterer aggregation.

  2. Simulation of ultrasonic lamb wave generation, propagation and detection for a reconfigurable air coupled scanner.

    Science.gov (United States)

    Dobie, Gordon; Spencer, Andrew; Burnham, Kenneth; Pierce, S Gareth; Worden, Keith; Galbraith, Walter; Hayward, Gordon

    2011-04-01

    A computer simulator, to facilitate the design and assessment of a reconfigurable, air-coupled ultrasonic scanner is described and evaluated. The specific scanning system comprises a team of remote sensing agents, in the form of miniature robotic platforms that can reposition non-contact Lamb wave transducers over a plate type of structure, for the purpose of non-destructive evaluation (NDE). The overall objective is to implement reconfigurable array scanning, where transmission and reception are facilitated by different sensing agents which can be organised in a variety of pulse-echo and pitch-catch configurations, with guided waves used to generate data in the form of 2-D and 3-D images. The ability to reconfigure the scanner adaptively requires an understanding of the ultrasonic wave generation, its propagation and interaction with potential defects and boundaries. Transducer behaviour has been simulated using a linear systems approximation, with wave propagation in the structure modelled using the local interaction simulation approach (LISA). Integration of the linear systems and LISA approaches are validated for use in Lamb wave scanning by comparison with both analytic techniques and more computationally intensive commercial finite element/difference codes. Starting with fundamental dispersion data, the paper goes on to describe the simulation of wave propagation and the subsequent interaction with artificial defects and plate boundaries, before presenting a theoretical image obtained from a team of sensing agents based on the current generation of sensors and instrumentation.

  3. Application of subband adaptive filtering techniques to ultrasonic detection in multilayers

    Institute of Scientific and Technical Information of China (English)

    MAO Jie; LI Mingxuan

    2003-01-01

    The ultrasonic testing for the defects of complete disbond in multi-layered structure with lower acoustic impedance beneath a high acoustic impedance overburden is one of the difficult problems in ultrasonic nondestructive testing field. A model of a multi-layered steel-rubber composite plate is depicted. Because the acoustic impedance of the steel differs far from that of the couplant water and the rubber, the energy of the signal reflected from the debonded rubber layers is very weak. More over, the flaw echoes are masked by the strong echoes reverberated in the steel plate. It's nearly impossible to identify the debonding echoes directly. The subband adaptive filtering method is discussed in the paper, where the subband decomposition is performed by mutual wavelet packets decomposition on the criterion of maximizing the cross-correlation between the signals. The simulations on both synthetic and real signals are presented. The echoes from the delaminated flaw at the depth of 5 mm in the rubber from the calculated signal, and echoes from the flaw at the depth of 3 mm from the real signal are extracted successfully.

  4. Developing Wide Angle Detection Equipment for Ultrasonic Sensors%一种超声波传感器广角检测设备的研制

    Institute of Scientific and Technical Information of China (English)

    王钦若; 张霄扬; 彭义

    2011-01-01

    The limited angle of sensing can restrain ultrasonic sensor's wide application in locating the moving objects and in guided system. Basing on analyzing the ultrasonic transmission process and the influence of off-axis ultrasonic wave, the design method for relevant circuits and the sensor array based on -3dB angle of the sensor was put forward and many experiments for it were implemented simultaneously. The experimental results show that, in the premise of no ultrasonic waveform is affected, this design can expand the detection angle of ultrasonic sensors.%为了实现扩展超声波传感器检测角度的目的,通过对超声波传输过程以及超声波斜入射影响的分析,提出了基于传感器半功率角的传感器阵列及相关电路的设计方法,并对此设计进行了大量试验,证明此设计在不影响超声波波形的前提下,能够扩展超声波传感器的检测角度,并且易于实施.

  5. Ultrasonic-assisted self-assembly of monolayer graphene oxide for rapid detection of Escherichia coli bacteria

    Science.gov (United States)

    Chang, Jingbo; Mao, Shun; Zhang, Yang; Cui, Shumao; Zhou, Guihua; Wu, Xiaogang; Yang, Ching-Hong; Chen, Junhong

    2013-04-01

    Due to potential risks to the environment and human health arising from pathogens/chemical contaminants, novel devices are being developed for rapid and precise detection of those contaminants. Here, we demonstrate highly sensitive and selective field-effect transistor (FET) sensor devices for detection of Escherichia coli (E. coli) bacteria using thermally reduced monolayer graphene oxide (TRMGO) sheets as semiconducting channels. The graphene oxide (GO) sheets are assembled on the aminoethanethiol (AET)-functionalized gold (Au) electrodes through electrostatic interactions with ultrasonic assistance. Anti-Escherichia coli (anti-E. coli) antibodies are used as receptors for selective detection of E. coli cells and integrated on the FET device through covalent bonding with Au nanoparticles on the GO surface. The TRMGO FET device shows great electronic stability and high sensitivity to E. coli cells with a concentration as low as 10 colony-forming units (cfu) per mL. The biosensing platform reported here is promising for large-scale, sensitive, selective, low-cost, and real-time detection of E. coli bacteria.

  6. Development and Evaluation of Real-time Acoustic Detection System of Harmful Red-tide Using Ultrasonic Sound

    Directory of Open Access Journals (Sweden)

    Donhyug Kang

    2013-03-01

    Full Text Available The toxic, Harmful Algal Blooms (HABs caused by the Cochlodinium polykrikoides have a serious impact on the coastal waters of Korea. In this study, the acoustic detection system was developed for rapid HABs detection, based on the acoustic backscattering properties of the C. polykrikoides. The developed system was mainly composed of a pulser-receiver board, a signal processor board, a control board, a network board, a power board, ultrasonic sensors (3.5 and 5.0 MHz, an environmental sensor, GPS, and a land-based control unit. To evaluate the performance of the system, a trail was done at a laboratory, and two in situ trials were conducted: (1 when there was no red tide, and (2 when there was red tide. In the laboratory evaluation, the system performed well in accordance with the number of C. polykrikoides in the received level. Second, under the condition when there was no red tide in the field, there was a good correlation between the acoustic data and sampling data. Finally, under the condition when there was red tide in the field, the system successfully worked at various densities in accordance with the number of C. polykrikoides, and the results corresponded with the sampling data and monitoring result of NFRDI (National Fisheries Research & Development Institute. From the laboratory and field evaluations, the developed acoustic detection system for early detecting HABs has demonstrated that it could be a significant system to monitor the occurrence of HABs in coastal regions.

  7. Polarization-angle dependence of photoluminescence intensity of ordered GaInP{sub 2} layers: observation of polarization memory

    Energy Technology Data Exchange (ETDEWEB)

    Prutskij, T.; Brito-Orta, R. [Instituto de Ciencias, BUAP, Puebla (Mexico); Pelosi, C. [IMEM/CNR, Parma (Italy)

    2008-09-15

    We compare measured and calculated polarization-angle dependencies of the intensity of the photoluminescence emission from MOVPE-grown GaInP{sub 2} layers with different ordering parameters. We measured the polarization-angle dependencies of the emission propagating along the [001],[110] and [1 anti 10] directions at room temperature. Symmetry considerations were used to calculate the dependence of the relative intensity of the PL emission which was linearly polarized along different directions and to estimate the value of the valence-band splitting by fitting the measured dependencies with calculated curves. An intriguing influence of the polarization of the exciting beam on the relative amount of the polarized PL emission was observed in the emission from the (110) plane. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  8. Flash Flood Detection in Urban Cities Using Ultrasonic and Infrared Sensors

    KAUST Repository

    Mousa, Mustafa

    2016-07-19

    Floods are the most common type of natural disaster. Often leading to loss of lives and properties in the thousands yearly. Among these events, urban flash floods are particularly deadly because of the short timescales on which they occur, and because of the population density of cities. Since most flood casualties are caused by a lack of information on the impending flood (type, location, severity), sensing these events is critical to generate accurate and detailed warnings and short term forecasts. However, no dedicated flash flood sensing systems, that could monitor the propagation of flash floods, in real time, currently exist in cities. In the present paper, firstly a new sensing device that can simultaneously monitor urban flash floods and traffic congestion has been presented. This sensing device is based on the combination of ultrasonic range-finding with remote temperature sensing, and can sense both phenomena with a high degree of accuracy, using a combination of L1-regularized reconstruction and artificial neural networks to process measurement data. Secondly, corresponding algorithms have been implemented on a low-power wireless sensor platform, and their performance in water level estimation in a 6 months test involving four different sensors is illustrated. The results demonstrate that urban water levels can be reliably estimated with error less than 2 cm, and that the preprocessing and machine learning schemes can run in real-time on currently available wireless sensor platforms.

  9. A rare diagnosis: testicular dysgenesis with carcinoma in situ detected in a patient with ultrasonic microlithiasis

    Institute of Scientific and Technical Information of China (English)

    Christina E. Hoei-Hansen; Peter Sommer; Ewa Rajpert-De Meyts; Niels E. Skakkebaek

    2005-01-01

    A rare case is presented where a dysgenetic testis with microinvasive carcinoma in situ (CIS, also known as intratubular germ cell neoplasm of unclassified type [IGCNU] and testicular intraepithelial neoplasia [TIN]) with microinvasion to fete testis and the interstitial tissue was found in a 32-year-old man presenting with mild scrotal pain and ultrasonic testicular microlithiasis. Knowledge of the association of ultrasound and CIS is important to diagnose patients at the stage prior to development of an overt germ cell tumor. The patient had three of four disorders considered symptoms of the testicular dysgenesis syndrome (TDS): a dysgenetic left testicle with CIS, a mild left-sided cryptorchidism (high positioned scrotal hypotrophic testis) and a slightly reduced semen quality. Therefore, it should be kept in mind that a patient with one TDS symptom may harbour the other, even CIS or testicular cancer. Accordingly, patients with one TDS symptom ought to be examined for the presence of the others, and if more that one is present, extra concern is warranted.

  10. First observation of angle-dependent Stark cyclotron resonance in bulk crystals: High-electric-field interlayer magnetotransport in a layered organic conductor

    Energy Technology Data Exchange (ETDEWEB)

    Kumagai, A.; Konoike, T.; Uchida, K. [Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581 (Japan); Osada, T., E-mail: osada@issp.u-tokyo.ac.j [Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581 (Japan)

    2010-06-01

    We report a novel angle-dependent magnetotransport phenomenon in layered conductors under strong interlayer electric fields. Interlayer conduction shows the Stark cyclotron resonance (SCR) when electron orbital motion becomes periodic in k-space. The SCR amplitude oscillates depending on magnetic field orientations. The conventional angle-dependent magnetoresistance oscillation (AMRO) switches to the angle-dependent SCR in high electric fields. We predict angle-dependent SCR due to electron orbital motion in layered conductors with coherent interlayer coupling. In addition, we demonstrate the expected switching from conventional AMRO to angle-dependent SCR in high electric fields using an organic conductor {alpha}-(BEDT-TTF){sub 2}NH{sub 4}Hg(SCN){sub 4}. This is the first observation of the SCR with orbital origin in bulk crystals.

  11. Angle-dependent hard X-ray photoemission study of Nb hydride formation in high-pressure supercritical water

    Energy Technology Data Exchange (ETDEWEB)

    Soda, Kazuo, E-mail: j45880a@cc.nagoya-u.ac.jp [Department of Quantum Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Kondo, Hiroki; Yamaguchi, Kanta; Kato, Masahiko [Department of Quantum Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Shiraki, Tatsuhito; Niwa, Ken; Kusaba, Keiji; Hasegawa, Masashi [Department of Crystalline Materials Science, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Xeniya, Kozina; Ikenaga, Eiji [Japan Synchrotron Radiation Research Institute, 1-1-1, Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan)

    2015-09-15

    Highlights: • Nb hydrides in 10-GPa supercritical water are studied by photoelectron spectroscopy. • The hydride components of the Nb 3d core-level spectra are increased with the depth. • The bulk valence-band spectrum shows a split band due to the Nb–H bond formation. • The hydrides are formed in the bulk and their surfaces are covered with Nb oxides. - Abstract: Nb hydrides formation in 10-GPa supercritical water has been investigated by angle-dependent micro-beam hard X-ray photoemission spectroscopy. In the Nb 3d core-level spectra, Nb hydride components are found in the slightly high binding energy side of the metallic components, and the oxide ones are observed even though little oxides are recognized in X-ray diffraction patterns. Obtained emission-angle dependence of the Nb 3d core-level spectra of Nb hydride specimens shows that the Nb hydride components increase with the emission angle decreased i.e. the sampling depth increased, while the oxide ones decrease. The bulk valence-band spectrum is obtained by decomposing the measured valence-band spectra into a bulk and surface components with use of the emission-angle dependence of the core-level and valence-band spectra; it consists of two bands. This implies the Nb–H chemical bond formation and Nb in an oxidation state, consistent with reported band structure calculations and the observed core-level chemical shifts. Thus it is confirmed by valence-band and core-level photoelectron spectroscopy that the Nb hydrides are formed inside the specimen, irrespective to the well-known high oxidation ability of supercritical water.

  12. Model for the dynamics of liquid penetration into porous structures and its detection with the help of changes in ultrasonic attenuation

    OpenAIRE

    Daun, Matias

    2007-01-01

    The dynamics of liquid penetration into porous networks is important for many processes during the production and printing of paper. One commercially available device to measure liquid penetration indirectly uses the change of ultrasonic attenuation when a specimen is brought into contact with liquid. In order to interpret results obtained by this device the generation and detection of ultra-sound are modelled as functions of the Sender and the Receiver, their material properties, their diame...

  13. Ultrasonic guided wave characterization and damage detection in foam-core sandwich panel using PWAS and LDV

    Science.gov (United States)

    Chakraborty, Nibir; Roy Mahapatra, D.; Srinivasan, Gopalakrishnan

    2012-04-01

    Lamb wave type guided wave propagation in foam core sandwich structures and detectability of damages using spectral analysis method are reported in this paper. An experimental study supported by theoretical evaluation of the guided wave characteristics is presented here that shows the applicability of Lamb wave type guided ultrasonic wave for detection of damage in foam core sandwich structures. Sandwich beam specimens were fabricated with 10 mm thick foam core and 0.3 mm thick aluminum face sheets. Thin piezoelectric patch actuators and sensors are used to excite and sense guided wave. Group velocity dispersion curves and frequency response of sensed signal are obtained experimentally. The nature of damping present in the sandwich panel is monitored by measuring the sensor signal amplitude at various different distances measured from the center of the linear phased array. Delaminations of increasing width are created and detected experimentally by pitch-catch interrogation with guided waves and wavelet transform of the sensed signal. Signal amplitudes are analyzed for various different sizes of damages to differentiate the damage size/severity. A sandwich panel is also fabricated with a planer dimension of 600 mm x 400 mm. Release film delamination is introduced during fabrication. Non-contact Laser Doppler Vibrometer (LDV) is used to scan the panel while exciting with a surface bonded piezoelectric actuator. Presence of damage is confirmed by the reflected wave fringe pattern obtained from the LDV scan. With this approach it is possible to locate and monitor the damages by tracking the wave packets scattered from the damages.

  14. Research on model testing of a new ultrasonic multi-wave detecting method

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ The traditional crack exploring method with echo (reflected wave) in metals is called the "single-wave detecting method" that uses a probe of single weight. This method is not able to detect directly the size and shape of the crack and the result can only be obtained by relative comparison, that is to compare the echo amplitudes of the unknown quantity (crack) with the known quantity (regular artificial crack) to determine the equivalent size and shape of a certain crack. In this way, the site of a crack can be basically determined, but it is not the size, scale and site of the actual crack. So the traditional method is incapable to satisfy the demands in real applications, and there was not any big improvement in the past several decades. Therefore, we introduce a new method called the "multi-wave detecting method" in the paper, which is capable to detect directly the size, scale and site of a crack.

  15. Modelling and Numerical Simulations of In-Air Reverberation Images for Fault Detection in Medical Ultrasonic Transducers: A Feasibility Study

    Directory of Open Access Journals (Sweden)

    W. Kochański

    2015-01-01

    Full Text Available A simplified two-dimensional finite element model which simulates the in-air reverberation image produced by medical ultrasonic transducers has been developed. The model simulates a linear array consisting of 128 PZT-5A crystals, a tungsten-epoxy backing layer, an Araldite matching layer, and a Perspex lens layer. The thickness of the crystal layer is chosen to simulate pulses centered at 4 MHz. The model is used to investigate whether changes in the electromechanical properties of the individual transducer layers (backing layer, crystal layer, matching layer, and lens layer have an effect on the simulated in-air reverberation image generated. Changes in the electromechanical properties are designed to simulate typical medical transducer faults such as crystal drop-out, lens delamination, and deterioration in piezoelectric efficiency. The simulations demonstrate that fault-related changes in transducer behaviour can be observed in the simulated in-air reverberation image pattern. This exploratory approach may help to provide insight into deterioration in transducer performance and help with early detection of faults.

  16. Research and Improvement of Transmitting/Receiving Circuits for Ultrasonic Detection%超声探伤仪收发电路的改进研究

    Institute of Scientific and Technical Information of China (English)

    李勇峰; 杨录; 张艳花

    2013-01-01

    针对现有超声探伤系统电路复杂、设计成本高的缺点,提出了一种以12 V电源供电的超声谐振发射电路,设计实现了以谐振接收、差分可变增益放大以及峰值保持的回波处理硬件电路设计.系统采用2.5M超声探伤传感器.实验表明,系统性能稳定,精度高,成本低,有广阔的应用前景.%Considering the disadvantages of present ultrasonic detection system,such as complexity circuit system,high design costs,and put forward a transmitting circuit by using 12 V single power source circuit.The design achieved echo signal processing of ultrasonic detection with resonant receiver,differential variable gain amplifier and peak hold.The system adopted ultrasonic sendreceive sensor of 2.5 M.The experiment results show that this system has more stable performance,higher precision and lower cost than the present system has.Thus,the system has broad application prospects.

  17. Ultrasonic evaluation of residual stresses in flat glass tempering by an original double interferometric detection.

    Science.gov (United States)

    Devos, D; Duquennoy, M; Roméro, E; Jenot, F; Lochegnies, D; Ouaftouh, M; Ourak, M

    2006-12-22

    In industrial thermal tempering of glass, the knowledge of the homogeneity of compressive residual stress field on the glass product is fundamental to guarantee the quality of the tempered glass product. In this paper, we use the acoustoelasticity phenomenon in order to estimate the residual stress distribution by using acoustic surface wave. We present an experimental setup based on a double interferometric detection in which an aspheric lens is associated with a beam splitter and a YAG laser whose power is 100 mW. This relative high power enables us to carry out measurements on surface flat glass although optical reflection coefficient is typically weak (glass tempering.

  18. Angle-dependent magnetoresistance oscillations and magnetic breakdown in {alpha}-(BEDT-TTF){sub 2}KHg(SCN){sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Uchida, K., E-mail: uchida@issp.u-tokyo.ac.j [Institute for Solid State Physics, University of Tokyo, Kashiwanoha 5-1-5, Kashiwa, Chiba 277-8581 (Japan); Konoike, T.; Osada, T. [Institute for Solid State Physics, University of Tokyo, Kashiwanoha 5-1-5, Kashiwa, Chiba 277-8581 (Japan)

    2010-06-01

    We present results of stereographic measurements of interlayer magnetoresistance in the quasi-two-dimensional (Q2D) organic conductor, {alpha}-(BEDT-TTF){sub 2}KHg(SCN){sub 4}, at around charge density wave (CDW) transition temperature T{sub c{approx}}8K. At 2 K in the CDW phase, there exists the anomalous Lebed resonance pattern, the amplitude of which is modulated by Danner-Chaikin oscillations in case of applied magnetic field close to the Q2D conducting plane. On the contrary, at 7 K just below T{sub c}, we have found that the Kajita oscillation of the cylindrical Fermi surfaces appears superposed on the anomalous Lebed resonance. A quantum model of interlayer tunneling demonstrates these behaviors qualitatively. These results suggest that magnetic breakdown plays a key role in anomalous angle-dependent magnetoresistance oscillations.

  19. Angle-dependent magnetoresistance oscillations and magnetic breakdown in α-(BEDT-TTF)2KHg(SCN)4

    Science.gov (United States)

    Uchida, K.; Konoike, T.; Osada, T.

    2010-06-01

    We present results of stereographic measurements of interlayer magnetoresistance in the quasi-two-dimensional (Q2D) organic conductor, α-(BEDT-TTF)2KHg(SCN)4, at around charge density wave (CDW) transition temperature Tc˜8K. At 2 K in the CDW phase, there exists the anomalous Lebed resonance pattern, the amplitude of which is modulated by Danner-Chaikin oscillations in case of applied magnetic field close to the Q2D conducting plane. On the contrary, at 7 K just below Tc, we have found that the Kajita oscillation of the cylindrical Fermi surfaces appears superposed on the anomalous Lebed resonance. A quantum model of interlayer tunneling demonstrates these behaviors qualitatively. These results suggest that magnetic breakdown plays a key role in anomalous angle-dependent magnetoresistance oscillations.

  20. Evolution of the linear-polarization-angle-dependence of the radiation-induced magnetoresistance-oscillations with microwave power

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Tianyu; Mani, R. G. [Department of Physics and Astronomy, Georgia State University, Atlanta, Georgia 30303 (United States); Wegscheider, W. [Laboratorium für Festkörperphysik, ETH Zürich, 8093 Zürich (Switzerland)

    2014-11-10

    We examine the role of the microwave power in the linear polarization angle dependence of the microwave radiation induced magnetoresistance oscillations observed in the high mobility GaAs/AlGaAs two dimensional electron system. The diagonal resistance R{sub xx} was measured at the fixed magnetic fields of the photo-excited oscillatory extrema of R{sub xx} as a function of both the microwave power, P, and the linear polarization angle, θ. Color contour plots of such measurements demonstrate the evolution of the lineshape of R{sub xx} versus θ with increasing microwave power. We report that the non-linear power dependence of the amplitude of the radiation-induced magnetoresistance oscillations distorts the cosine-square relation between R{sub xx} and θ at high power.

  1. A Feasibility Study on the Application of Ultrasonic Method for Surface Crack Detection of SiC/SiC Composite Ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Ki Woo [Pukyong National University, Busan (Korea, Republic of); Lee, Kun Chan; Kohyma, Akira [National Research Council of Canada, Ontario (Canada)

    2009-10-15

    Nondestructive evaluation(NDE) of ceramic matrix composites is essential for developing reliable ceramics for industrial applications. In the work, C-Scan image analysis has been used to characterize surface crack of SiC ceramics nondestructively. The possibility of detection of surface crack were carried out experimentally by two types of ultrasonic equipment of SDS-win and {mu}-SDS, and three types of transducer of 25, 50 and 125 MHz. A surface micro-crack of ceramics was not detected by transducer of 25 MHz and 50 MHz. Though the focus method was detected dimly the crack by transducer of 125 MHz, the defocus method could detect the shape of diamond indenter. As a whole, the focus method and the defocus method came to the conclusion that micro crack have a good possibility for detection

  2. [Ultrasonic and biochemical detection and prenatal treatments of intra-uterine fetal growth retardation (author's transl)].

    Science.gov (United States)

    Kaneoka, T; Aso, M; Nobori, M; Aonuma, M; Shimizu, H; Shirakawa, K

    1980-01-01

    Efficacy of three ultrasonographic and six biochemical methods for the detection of intrauterine growth retardation were assessed in prospective studies of 40 cases associated with short uterine fundal height less than -1.5 SD and/or small ultrasonographically determined total intrauterine volume (TIUV) less than -1 SD of normal populations. Prenatal treatments, consisting of bed rest, high protein diet, intravenous drip infusion of 10% maltose, 500 ml per day, for more than 12 days, etc., were administered on them. Fifteen cases (37.5%) delivered small-for-date infants, 9 of which complicated by toxemia of pregnancy. At the final determinations, small TIUV were found in all small-for-date cases (100%), short biparietal diameter 80.0%, and short longitudinal intracavital uterine length 53.3% of 15 small-for-date cases. In biochemical parameters, low maternal plasma estriol levels were found in 73.3%, low plasma human placental lactogen levels 66.7%, low urinary estriol excretion 53.3%, abnormal plasma alpha-fetoprotein levels 33.3%, and low plasma progesterone levels 20.0% of 15 small-for-date cases. Nineteen cases (47.5%) demonstrated remarkable increases in TIUV following prenatal treatments, and delivered appropriate-for-date infants. Despite of marked growth in biophysical parameters, abnormal biochemical values were mostly not improved by these treatments.

  3. Ultrasonic detection of spall damage nucleation under low-velocity repeated impact

    Directory of Open Access Journals (Sweden)

    Watanabe T.

    2012-08-01

    Full Text Available Repeated plate impact testing with impact stress well below the threshold spall-stress (2.6 GPa on medium carbon steel was carried out to the identical target plate by impacting the flyer plate. Occurrence of spall damage under low-velocity repeated impact was evaluated nondestructively with a low frequency scanning acoustic microscope. We observed the spall damage distribution by the B- and C-scan images. In order to initiate the spall damage (voids in a ductile material or cracks in a brittle one the particular value of threshold spall-stress should be exceeded what already belongs to a commonly accepted knowledge. Generally, the spall damage development is dependent on the amplitude and the duration of the stress pulse. If the stress is high and duration is long enough to create tensile failure of material, the voids or cracks nucleate along the spall plane, and consequently, they form macrocracks. Therefore, the spall damage does not create when the first impact stress is less than the threshold spall-stress. However, after the fifth low-velocity repeated impact test, the generation of the spall damage was detected, even if the impact stress (1.1–1.7 GPa was lower than the threshold spall-stress (2.6 GPa.

  4. An optodynamic determination of the depth of laser-drilled holes by the simultaneous detection of ultrasonic waves in the air and in the workpiece.

    Science.gov (United States)

    Strgar, Simon; Mozina, Janez

    2002-05-01

    A sufficiently powerful pulsed-laser beam can be used to 'drill' a hole in a stainless-steel workpiece. Here we present a real-time method for determining the depth of such a hole produced by multi-pulse laser drilling with a Q-switched Nd:YAG laser. The developed experimental setup allowed us to detect the laser-induced ultrasonic waves in the surrounding air and in the workpiece simultaneously by means of a probe-beam-deflection method and a piezoelectric transducer. Our optodynamic approach involved an analysis of these ultrasonic waves in order to determine the depth of the hole at any stage of the process. The increasing depth of the hole and its maximum extent were estimated from changes in the propagation time of the ultrasonic waves traveling from the bottom of the hole to both detectors. Measurements of the maximum hole depth were compared with the predictions of a theoretical model and they were found to be in a good agreement.

  5. Ultrasonic quantitative detection of elasticity of jugular vessel wall of female pilots and its application value

    Directory of Open Access Journals (Sweden)

    Long-fang ZHANG

    2011-11-01

    Full Text Available Objective To observe the elasticity of the jugular vessel wall of female aerotransport pilots on active duty,provide a reference for the selection of female pilots,and the prevention and therapy of cardiovascular diseases in female pilots.Methods Using the Echo-Tracking technique,the elastic parameters of the carotid artery were quantitatively detected in nineteen female pilots who were first selected as female astronauts.Twenty male pilots who were selected as astronauts were randomly chosen as the control group.No statistical difference in age and blood pressure between the two groups was found.No history of cardiovascular diseases was recorded,and no abnormal signs were revealed in the results of the physical examination.Electrocardiogram,chest radiography,hepatic and kidney function,and biochemical examination showed normal results.The factors affecting the elasticity of the artery could possibly be avoided for the male pilots except for the fighter pilots or the smokers.Results No statistical difference was found in the clinical and biochemical data between the pilot groups(P > 0.05.As for carotid artery elastic parameters,no statistical difference between the left and right sides of the artery was indicated.The elastic modulus,arterial stiffness index,and pulse wave velocity of the carotid artery wall of the female pilots were significantly lower than those of the male pilots(P < 0.05,and the arterial compliance was significantly higher than that of the male pilots(P < 0.05.Conclusion All of the elastic parameters of the vessel wall of female pilots were better than those of the male pilots.

  6. Detection of single nucleotide polymorphisms associated with ultrasonic backfat depth in a segregating Meishan x White Composite population.

    Science.gov (United States)

    Kuehn, L A; Rohrer, G A; Nonneman, D J; Thallman, R M; Leymaster, K A

    2007-05-01

    Multiple genomic scans have identified QTL for backfat deposition across the porcine genome. The objective of this study was to detect SNP and genomic regions associated with ultrasonic backfat. A total of 74 SNP across 5 chromosomes (SSC 1, 3, 7, 8, and 10) were selected based on their proximity to backfat QTL or to QTL for other traits of interest in the experimental population. Gilts were also genotyped for a SNP thought to influence backfat in the thyroxine-binding globulin gene (TBG) on SSC X. Genotypic data were collected on 298 gilts, divided between the F8 and F10 generations of the US Meat Animal Research Center Meishan resource population (composition, one-quarter Meishan). Backfat depths were recorded by ultrasound from 3 locations along the back at approximately 210 and 235 d of age in the F8 and F10 generations, respectively. Ultrasound measures were averaged for association analyses. Regressors for additive, dominant, and parent-of-origin effects of each SNP were calculated using genotypic probabilities computed by allelic peeling algorithms in GenoProb. The association model included the fixed effects of scan date and TBG genotype, the covariates of weight and SNP regressors, and random additive polygenic effects to account for genetic similarities between animals not explained by known genotypes. Variance components for polygenic effects and error were estimated using MTDFREML. Initially, each SNP was fitted (once with and once without parent-of-origin effects) separately due to potential multi-collinearity between regressions of closely linked markers. To form a final model, all significant SNP across chromosomes were included in a common model and were individually removed in successive iterations based on their significance. Across all analyses, TBG was significant, with an additive effect of approximately 1.2 to 1.6 mm of backfat. Three SNP on SSC3 remained in the final model even though few studies have identified QTL for backfat on this

  7. Time-frequency analysis of neonatal cranial ultrasonic movies for selective detection of pulsatile tissues by avoiding probe-motion artifact

    Science.gov (United States)

    Fukuzawa, Masayuki; Tabata, Yuki; Izuwaki, Yusuke; Nakamori, Nobuyuki; Kitsunezuka, Yoshiki

    2015-03-01

    In order to detect the pulsatile tissues in neonatal cranial ultrasonic movies by avoiding probe-motion artifact, a time-frequency analysis has been performed in several movie fragments at typical three scenes: (a) a brain-lost, (b) a brain-captured and probe-stabilized, and (c) a brain-captured and probe-swayed ones. The pulsatile tissue, which is a key point of pediatric diagnosis, had successfully detected with an algorithm based on Fourier transform but it had required us to extract the probe-stabilized scene manually by visual observation of the movie. A spatial mean square of echo intensity Etot and a total AC power Ptot over a fan-shape of field of view were evaluated according to a power spectrum of a time-variation of 64 samples of echo intensity at each pixel in each movie fragment split from actual B-mode ultrasonic movies taken at coronal sections of a neonate. The results revealed that (1) significant low Etot was found at the brain-lost scene rather than that at the other scenes, and (2) lower Ptot was found at the probe-stabilized scene rather than the probe-swayed ones. This fact strongly suggests that the Etot and Ptot are promising features for automatic extraction of probe-stabilized scenes. It must lead to detect the pulsatile tissues selectively by avoiding probe-motion artifact and to realize systematic analysis of the whole of our extensive movie archives, which is useful not only for retrospective study of ischemic diseases but also for bedside diagnosis to stabilize the freehand ultrasonic probe.

  8. Geothermal Ultrasonic Fracture Imager

    Energy Technology Data Exchange (ETDEWEB)

    Patterson, Doug [Baker-Hughes Oilfield Operation Inc., Houston, TX (United States); Leggett, Jim [Baker-Hughes Oilfield Operation Inc., Houston, TX (United States)

    2013-07-29

    The Geothermal Ultrasonic Fracture Imager project has a goal to develop a wireline ultrasonic imager that is capable of operating in temperatures up to 300°C (572°F) and depths up to 10 km (32,808 ft). This will address one of the critical needs in any EGS development of understanding the hydraulic flow paths in the reservoir. The ultrasonic imaging is well known in the oil and gas industry as one of the best methods for fracture evaluation; providing both high resolution and complete azimuthal coverage of the borehole. This enables fracture detection and characterization, both natural and induced, providing information as to their location, dip direction and dip magnitude. All of these factors are critical to fully understand the fracture system to enable the optimization of the thermal drainage through injectors and producers in a geothermal resource.

  9. Ultrasonic Motors

    Science.gov (United States)

    2003-06-01

    and T. Higuchi, "Cylindrical Micro Ultrasonic Motor Utilizing Bulk Lead Zirconate Titanate (PZT)," Japanese Journal of Applied Physics Part 1-Regular Papers Short Notes & Review Papers, vol. 38, pp. 3347-3350, 1999.

  10. A Comparison of the Detectability of Dry Contact Kissing Bonds in Adhesive Joints Using Longitudinal, Shear and High Power Ultrasonic Techniques

    Science.gov (United States)

    Brotherhood, C. J.; Drinkwater, B. W.; Guild, F. J.

    2003-03-01

    This paper details a study on the detectability of dry contact kissing bonds in adhesive joints using three ultrasonic inspection techniques. Conventional normal incidence longitudinal and shear wave inspection were conducted on dry contact kissing bonds using a standard immersion transducer and an EMAT respectively. The detectability of the dry contact kissing bonds was assessed by calculating the reflection coefficient of the interface at varying loads for a number of surface roughnesses. A high power ultrasonic method was also employed to determine the non-linear behavior of the adhesive interface. The non-linearity of the interface was determined by the ratio of the amplitudes of the first harmonic and fundamental frequencies of the transmitted waveform. It was found that the high power technique showed the greatest sensitivity to kissing bonds at low contact pressures, however at high loads conventional longitudinal wave testing was more sensitive. It was also noted that a combination of two or more techniques could provide enhanced information about the kissing bond compared to a single technique alone.

  11. Ultrasonic neuromodulation

    Science.gov (United States)

    Naor, Omer; Krupa, Steve; Shoham, Shy

    2016-06-01

    Ultrasonic waves can be non-invasively steered and focused into mm-scale regions across the human body and brain, and their application in generating controlled artificial modulation of neuronal activity could therefore potentially have profound implications for neural science and engineering. Ultrasonic neuro-modulation phenomena were experimentally observed and studied for nearly a century, with recent discoveries on direct neural excitation and suppression sparking a new wave of investigations in models ranging from rodents to humans. In this paper we review the physics, engineering and scientific aspects of ultrasonic fields, their control in both space and time, and their effect on neuronal activity, including a survey of both the field’s foundational history and of recent findings. We describe key constraints encountered in this field, as well as key engineering systems developed to surmount them. In closing, the state of the art is discussed, with an emphasis on emerging research and clinical directions.

  12. Ultrasonic Polishing

    Science.gov (United States)

    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.

  13. Angle-dependent strong-field molecular ionization rates with tuned range-separated time-dependent density functional theory.

    Science.gov (United States)

    Sissay, Adonay; Abanador, Paul; Mauger, François; Gaarde, Mette; Schafer, Kenneth J; Lopata, Kenneth

    2016-09-07

    Strong-field ionization and the resulting electronic dynamics are important for a range of processes such as high harmonic generation, photodamage, charge resonance enhanced ionization, and ionization-triggered charge migration. Modeling ionization dynamics in molecular systems from first-principles can be challenging due to the large spatial extent of the wavefunction which stresses the accuracy of basis sets, and the intense fields which require non-perturbative time-dependent electronic structure methods. In this paper, we develop a time-dependent density functional theory approach which uses a Gaussian-type orbital (GTO) basis set to capture strong-field ionization rates and dynamics in atoms and small molecules. This involves propagating the electronic density matrix in time with a time-dependent laser potential and a spatial non-Hermitian complex absorbing potential which is projected onto an atom-centered basis set to remove ionized charge from the simulation. For the density functional theory (DFT) functional we use a tuned range-separated functional LC-PBE*, which has the correct asymptotic 1/r form of the potential and a reduced delocalization error compared to traditional DFT functionals. Ionization rates are computed for hydrogen, molecular nitrogen, and iodoacetylene under various field frequencies, intensities, and polarizations (angle-dependent ionization), and the results are shown to quantitatively agree with time-dependent Schrödinger equation and strong-field approximation calculations. This tuned DFT with GTO method opens the door to predictive all-electron time-dependent density functional theory simulations of ionization and ionization-triggered dynamics in molecular systems using tuned range-separated hybrid functionals.

  14. Angle-dependent strong-field molecular ionization rates with tuned range-separated time-dependent density functional theory

    Science.gov (United States)

    Sissay, Adonay; Abanador, Paul; Mauger, François; Gaarde, Mette; Schafer, Kenneth J.; Lopata, Kenneth

    2016-09-01

    Strong-field ionization and the resulting electronic dynamics are important for a range of processes such as high harmonic generation, photodamage, charge resonance enhanced ionization, and ionization-triggered charge migration. Modeling ionization dynamics in molecular systems from first-principles can be challenging due to the large spatial extent of the wavefunction which stresses the accuracy of basis sets, and the intense fields which require non-perturbative time-dependent electronic structure methods. In this paper, we develop a time-dependent density functional theory approach which uses a Gaussian-type orbital (GTO) basis set to capture strong-field ionization rates and dynamics in atoms and small molecules. This involves propagating the electronic density matrix in time with a time-dependent laser potential and a spatial non-Hermitian complex absorbing potential which is projected onto an atom-centered basis set to remove ionized charge from the simulation. For the density functional theory (DFT) functional we use a tuned range-separated functional LC-PBE*, which has the correct asymptotic 1/r form of the potential and a reduced delocalization error compared to traditional DFT functionals. Ionization rates are computed for hydrogen, molecular nitrogen, and iodoacetylene under various field frequencies, intensities, and polarizations (angle-dependent ionization), and the results are shown to quantitatively agree with time-dependent Schrödinger equation and strong-field approximation calculations. This tuned DFT with GTO method opens the door to predictive all-electron time-dependent density functional theory simulations of ionization and ionization-triggered dynamics in molecular systems using tuned range-separated hybrid functionals.

  15. Final Assessment of Manual Ultrasonic Examinations Applied to Detect Flaws in Primary System Dissimilar Metal Welds at North Anna Power Station

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Michael T.; Diaz, Aaron A.; Cinson, Anthony D.; Crawford, Susan L.; Prowant, Matthew S.; Doctor, Steven R.

    2014-03-24

    PNNL conducted a technical assessment of the NDE issues and protocols that led to missed detections of several axially oriented flaws in a steam generator primary inlet dissimilar metal weld at North Anna Power Station, Unit 1 (NAPS-1). This particular component design exhibits a significant outside-diameter (OD) taper that is not included as a blind performance demonstration mock-up within the industry’s Performance Demonstration Initiative, administered by EPRI. For this reason, the licensee engaged EPRI to assist in the development of a technical justification to support the basis for a site-specific qualification. The service-induced flaws at NAPS-1 were eventually detected as a result of OD surface machining in preparation for a full structural weld overlay. The machining operation uncovered the existence of two through-wall flaws, based on the observance of primary water leaking from the dissimilar metal weld. A total of five axially oriented flaws were detected in varied locations around the weld circumference. The field volumetric examination that was conducted at NAPS-1 was a non-encoded, real-time manual ultrasonic examination. PNNL conducted both an initial assessment, and subsequently, a more rigorous technical evaluation (reported here), which has identified an array of NDE issues that may have led to the subject missed detections. These evaluations were performed through technical reviews and discussions with NRC staff, EPRI NDE Center personnel, industry and ISI vendor personnel, and ultrasonic transducer manufacturers, and laboratory tests, to better understand the underlying issues at North Anna.

  16. Detection and comparison of reactive oxygen species (ROS) generated by chlorophyllin metal (Fe, Mg and Cu) complexes under ultrasonic and visible-light irradiation.

    Science.gov (United States)

    Wang, Jun; Guo, Yuwei; Gao, Jingqun; Jin, Xudong; Wang, Zhiqiu; Wang, Baoxin; Li, Kai; Li, Ying

    2011-09-01

    In this paper, in order to examine the mechanisms of sonodynamic and photodynamic reactions, the chlorophyllin metal (Chl-M (M=Fe, Mg and Cu)) complexes were irradiated by ultrasound (US) and visible-light (VL), respectively, and the generation of reactive oxygen species (ROS) were detected by the method of Oxidation-Extraction Spectrometry (OES). That is, the 1,5-diphenyl carbazide (DPCI) is oxidized by the generated ROS into 1,5-diphenyl carbazone (DPCO), which can display a various visible absorption around 563 nm wavelength. Besides, some influence parameters on the generation of ROS were also reviewed. The results demonstrated an apparent synergistic effect of Chl-M and ultrasonic or visible-light irradiation for the generation of ROS. Moreover, the quantities of generated ROS increase with the increase of (ultrasonic or visible-light) irradiation time and Chl-M (M=Fe, Mg and Cu) concentration. Finally, several quenchers were used to determine the kind of the generated ROS. It is wished that this paper might offer some valuable references for the study on the sonodynamic therapy (SDT) and photodynamic therapy (PDT) mechanisms and the application of Chl-M in tumor treatment.

  17. Detection of Early Atherosclerosis in M. Fascicularis with Transcutaneous Ultrasonic Measurement of the Elastic Properties of the Common Carotid Artery

    OpenAIRE

    Farrar, David J; Riley, Ward A.; Bond, M Gene; Barnes, Ralph N.; Love, L. Alan

    1982-01-01

    The elastic properties of 22 common carotid arteries from 13 male cynomolgus monkeys (M. fascicularis) that were fed either a high cholesterol (test) diet or a standard monkey chow (control) diet for 18 months were measured noninvasively with 5MHz ultrasound. A B-mode image of the artery was obtained with a 32-element linear array transducer, and a single line of video ultrasonic information was selected for tracking the echoes from the adventitial side of the near wall to the lumen-intima in...

  18. Irradiation Testing of Ultrasonic Transducers

    Energy Technology Data Exchange (ETDEWEB)

    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.

  19. Ultrasonic Transducer Irradiation Test Results

    Energy Technology Data Exchange (ETDEWEB)

    Daw, Joshua [Idaho National Lab. (INL), Idaho Falls, ID (United States); Palmer, Joe [Idaho National Lab. (INL), Idaho Falls, ID (United States); Ramuhalli, Pradeep [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Keller, Paul [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Montgomery, Robert [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Chien, Hual-Te [Argonne National Lab. (ANL), Argonne, IL (United States); Kohse, Gordon [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States); Tittmann, Bernhard [Pennsylvania State Univ., University Park, PA (United States); Reinhardt, Brian [Pennsylvania State Univ., University Park, PA (United States); Rempe, Joy [Rempe and Associates, Idaho Falls, ID (United States)

    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

  20. Digital image correlation, acoustic emission and ultrasonic pulse velocity for the detection of cracks in the concrete buffer of the Belgian nuclear supercontainer

    Energy Technology Data Exchange (ETDEWEB)

    Iliopoulos, Sokratis; Tsangouri, Eleni; Aggelis, Dimitrios G.; Pyl, Lincy [Vrije Univ., Brussels (Belgium). Dept. of Mechanics of Materials and Constructions; Vantomme, John [Vrije Univ., Brussels (Belgium). Dept. of Mechanics of Materials and Constructions; Royal Military Academy, Brussels (Belgium). Civil and Material Engineering Dept.; Marcke, Philippe van [ONDRAF/NIRAS (Belgium); Areias, Lou [EURIDICE GIE/SCK.CEN, Mol (Belgium); Vrije Univ., Brussels (Belgium). Dept. of Mechanics of Materials and Constructions

    2014-11-01

    The long term management of high-level and heat emitting radioactive waste is a worldwide concern, as it directly influences the environment and future generations. To address this issue, the Belgian Agency for Radioactive Waste and Enriched Fissile Materials has come up with the conceptual design of a massive concrete structure called Supercontainer. The feasibility to construct these structures is being evaluated through a number of scaled models that are tested using classical as well as state of the art measurement techniques. In the current paper, the results obtained from the simultaneous application of the Digital Image Correlation (DIC), the Acoustic Emission (AE) and the Ultrasonic Pulse Velocity (UPV) nondestructive testing techniques on the second scaled model for the detection and monitoring of cracks will be presented.

  1. Computations of Ultrasonic Parameters in Zr−Sn Alloys

    Directory of Open Access Journals (Sweden)

    Pramod Kumar Yadawa

    2011-01-01

    Full Text Available The ultrasonic properties like ultrasonic attenuation, sound velocity in the hexagonal Zr100−Sn alloys have been studied along unique axis at room temperature. The second- and third-order elastic constants (SOEC & TOEC have been calculated for these alloys using Lennard-Jones potential. The velocities and 1 have minima and maxima, respectively, at 45° with unique axis of the crystal, while 2 increases with the angle from unique axis. The inconsistent behaviour of angle-dependent velocities is associated to the action of second-order elastic constants. Debye average sound velocities of these alloys are increasing with the angle and has maximum at 55° with unique axis at room temperature. Hence, when a sound wave travels at 55° with unique axis of these alloys, then the average sound velocity is found to be maximum. The mechanical and ultrasonic properties of these alloys will be better than pure Zr and Sn due to their high SOEC and ultrasonic velocity and low ultrasonic attenuation. The comparison of calculated ultrasonic parameters with available theoretical/experimental physical parameters gives information about classification of these alloys.

  2. Analysis of field-angle dependent specific heat in unconventional superconductors: A comparison between Doppler-shift method and Kramer-Pesch approximation

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, Nobuhiko, E-mail: n-hayashi@21c.osakafu-u.ac.j [Nanoscience and Nanotechnology Research Center (N2RC), Osaka Prefecture University, 1-2 Gakuen-cho, Sakai 599-8570 (Japan) and CREST (JST), 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan); Nagai, Yuki [Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan); JST, TRIP, Chiyoda, Tokyo 102-0075 (Japan); Higashi, Yoichi [Department of Mathematical Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai 599-8531 (Japan)

    2010-12-15

    We theoretically discuss the magnetic-field-angle dependence of the zero-energy density of states (ZEDOS) in superconductors. Point-node and line-node superconducting gaps on spherical and cylindrical Fermi surfaces are considered. The Doppler-shift (DS) method and the Kramer-Pesch approximation (KPA) are used to calculate the ZEDOS. Numerical results show that consequences of the DS method are corrected by the KPA.

  3. Analysis of field-angle dependent specific heat in unconventional superconductors: A comparison between Doppler-shift method and Kramer-Pesch approximation

    Science.gov (United States)

    Hayashi, Nobuhiko; Nagai, Yuki; Higashi, Yoichi

    2010-12-01

    We theoretically discuss the magnetic-field-angle dependence of the zero-energy density of states (ZEDOS) in superconductors. Point-node and line-node superconducting gaps on spherical and cylindrical Fermi surfaces are considered. The Doppler-shift (DS) method and the Kramer-Pesch approximation (KPA) are used to calculate the ZEDOS. Numerical results show that consequences of the DS method are corrected by the KPA.

  4. Wavelet Transform Signal Processing Applied to Ultrasonics.

    Science.gov (United States)

    1995-05-01

    THE WAVELET TRANSFORM IS APPLIED TO THE ANALYSIS OF ULTRASONIC WAVES FOR IMPROVED SIGNAL DETECTION AND ANALYSIS OF THE SIGNALS. In instances where...the mother wavelet is well defined, the wavelet transform has relative insensitivity to noise and does not need windowing. Peak detection of...ultrasonic pulses using the wavelet transform is described and results show good detection even when large white noise was added. The use of the wavelet

  5. An Airborne Ultrasonic Imaging System Based on 16 Elements: 150 kHz Piezopolymer Transducer Arrays—Preliminary Simulated and Experimental Results for Cylindrical Targets Detection

    Science.gov (United States)

    Capineri, L.; Bulletti, A.; Calzolai, M.; Giannelli, P.

    2016-12-01

    This paper describes the design and fabrication of a 16-element transducer array for airborne ultrasonic imaging operating at 150 kHz, that can operate both at close range (50 mm) in the near field of a synthetic aperture, and up to 250 mm. The proposed imaging technique is based on a modified version of the delay and sum algorithm implemented with a synthetic aperture where each pixel amplitude is determined by the integration of the signal obtained by the coherent summation of the acquired signals over a delayed window with fixed length. The image reconstruction methods using raw data provides the possibility to detect targets with smaller feature size on the order of one wavelength because the coherent signals summation over the selected window length while the image reconstruction methods using the summation of enveloped signals increases the amplitude response at the expenses of a lower spatial resolution. For the implementation of this system it is important to design compact airborne transducers with large field of view and this can be obtained with a new design of hemi-cylindrical polyvinylidene fluoride film transducers directly mounted on a printed circuit board. This new method is low cost and has repeatable transducer characteristics. The complete system is compact, with a modular architecture, in which eight boards with dual ultrasonic channels are mounted on a mother board. Each daughter board hosts a microcontroller unit and can operate with transducers in the bandwidth 40-200 kHz with on-board data acquisition, pre-processing and transfer on a dedicated bus.

  6. Nitrogen monoxide vector of ultrasonic atomizing inhalation improves vertebro-basilar artery insufficiency Hemodynamic changes are detected by transcranial Doppler test

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    BACKGROUND: Latest researches at home and abroad indicate that glycerol trinitrate plays its function because it can metabolize into nitrogen monoxide (NO) in vivo.OBJECTIVE: To study the therapeutic effects of NO vector of ultrasonic atomizing inhalation on vertebro-basilar artery insufficiency (VBI) through transcranial Doppler (TCD) detection and serum NO content and indirect effect of TCD on cerebral blood flow changes.DESIGN: Randomized grouping and controlled clinical study.SETTING: Department of Neurology, the Fourth People's Hospital of Jinan.PARTICIPANTS: A total of 130 patients who were diagnosed as VBI were selected from Department of Neurology, the Fourth People's Hospital of Jinan from December 2001 to December 2005. The involved inpatients were checked by CT and MRI, and met the VBI diagnostic standard enacted by the Fourth National Academic Meeting of Cerebrovascular Disease in 1995. All patients and their relatives provided the confirmed consent. They were randomly divided into low-dose treatment group (n =60), high-lose treatment group (n =30) and control group (n =40).METHODS: Patients in the low-dose and high-dose treatment groups were given ultrasonic atomizing inhalation of 3 mg and 5 mg glycerol trinitrate, respectively, for 20 minutes, once a day. In addition,ligustrazine and energy mixture were used once a day for three days in a course. Cases in the control group were only given ligustrazine and energy mixture. All selected cases accepted TCD, blood NO content was checked at the time of beginning, after the first time and after a period of treatment. According to the TCD test, VBI patients were divided into two groups (high-low flow velocity). The vertebral artery (VA) and basal artery (BA) of left or right sides were detected by 2 Hz detector via occipital window.MAIN OUTCOME MEASURES: ① Blood flow velocity of systolic phase, blood flow velocity of diastole phase and vascular resistance in left and right VA and BA detected by using TCD

  7. 非介入式超声波液位检测系统设计%The Designing of Non Invading Ultrasonic Liquid Level Detecting System

    Institute of Scientific and Technical Information of China (English)

    高丙坤; 潘翔

    2012-01-01

    设计了超声波液位检测系统.只需将探头侧贴在容器外壁上就能够检测探头所在位置液位的有无,并用红绿指示灯指示,可以在不破坏压力容器的情况下实现液位检测.重点设计了超声波高压脉冲发射电路、限幅保护电路、信号放大电路、检波电路及结果指示电路.最后通过用一组比较器输出的高低电平控制红绿指示灯的亮灭以显示测量结果.%A liquid level detection system is designed here, which uses the ultrasonic wave. The liquid level where the sensor is can be detected just by sticking the sensor to the outside wall of the container, with the result indicated by red or green led lights. Therefore, the liquid level detection can be carried on without a damage to the pressure container. Designing circuits are fucused on as follows:high voltage pulse trigger circuit;amplitude limiting protection circuit;signal amplifying circuit;wave detecting circuit and result indicating circuit. In the end, the result is shown by the indicating lights which is controlled by the output of a voltage comparator.

  8. Ultrasonic Force Microscopies

    Science.gov (United States)

    Kolosov, Oleg; Briggs, Andrew

    Ultrasonic Force Microscopy, or UFM, allows combination of two apparently mutually exclusive requirements for the nanomechanical probe—high stiffness for the efficient indentation and high mechanical compliance that brings force sensitivity. Somewhat inventively, UFM allows to combine these two virtues in the same cantilever by using indention of the sample at high frequency, when cantilever is very rigid, but detecting the result of this indention at much lower frequency. That is made possible due to the extreme nonlinearity of the nanoscale tip-surface junction force-distance dependence, that acts as "mechanical diode" detecting ultrasound in AFM. After introducing UFM principles, we discuss features of experimental UFM implementation, and the theory of contrast in this mode, progressing to quantitative measurements of contact stiffness. A variety of UFM applications ranging from semiconductor quantum nanostructures, graphene, very large scale integrated circuits, and reinforced ceramics to polymer composites and biological materials is presented via comprehensive imaging gallery accompanied by the guidance for the optimal UFM measurements of these materials. We also address effects of adhesion and topography on the elasticity imaging and the approaches for reducing artifacts connected with these effects. This is complemented by another extremely useful feature of UFM—ultrasound induced superlubricity that allows damage free imaging of materials ranging from stiff solid state devices and graphene to biological materials. Finally, we proceed to the exploration of time-resolved nanoscale phenomena using nonlinear mixing of multiple vibration frequencies in ultrasonic AFM—Heterodyne Force Microscopy, or HFM, that also include mixing of ultrasonic vibration with other periodic physical excitations, eg. electrical, photothermal, etc. Significant section of the chapter analyzes the ability of UFM and HFM to detect subsurface mechanical inhomogeneities, as well as

  9. 基于超声TOFD法的近表面缺陷检测实验研究%Experimental study on near surface defect detection based on ultrasonic TOFD

    Institute of Scientific and Technical Information of China (English)

    徐海卫; 曹江萍; 李刚; 杜文波

    2015-01-01

    在传统的超声TOFD法当中,存在着一定的表面检测盲区。针对这一情况,可采用TOFD与A型脉冲反射超声检测结合以及采用TOFD纵波三次反射的TOFDW检测模式检测近表面缺陷。本文阐述了这两种检测近表面缺陷方法的检测原理,然后结合人工缺陷试块,对这两种检测方法进行了实验验证。结果表明,TOFD与A型脉冲反射超声检测结合以及采用TOFDW检测模式均能够对近表面缺陷进行有效的检测。%In the traditional ultrasonic TOFD method, there is a certain surface detection blind area. In this case, the TOFD and A type pulse reflection ultrasonic detection is used, and the near surface defect is detected by the TOFDW detection mode of wave and TOFD wave. In this paper, the detection principle of these two methods of detecting near surface defects is described, and the experimental verification is carried out with the method of two kinds of detection methods. The results show that the combination of TOFD and A pulse echo ultrasonic detection and TOFDW detection mode can be used to detect near surface defects.

  10. Application of Leak Detection and Location Technology Based on Ultrasonic for Manned Spacecraft%基于超声的气体泄漏检测与定位技术在载人航天器中的应用

    Institute of Scientific and Technical Information of China (English)

    马永成; 陈青松

    2009-01-01

    The fundamental principle of leak detection and location technology based on ultrasonic is introduced in this paper.Both portable leak detection equipment and autonomous ultrasonic leak detection and location equipment are introduced,including their system composition,principle and working mode.The application of these equipments for the ISS and Shuttle is introduced.A scheme of ultrasonic leak detection and location that can be used for the space station of China is developed.%介绍了基于超声的气体泄漏检测与定位技术的基本原理;介绍了便携式超声检漏、无线超声自动检漏这两类已有设备的组成、工作原理及其在国际空间站、美国航天飞机上的应用情况.以此为参照,初步提出了一种可用于我国未来空间站建设的气体泄漏检测与定位方案.

  11. Leak detection method for in-orbit spacecraft using circular ultrasonic sensor array%基于圆形超声阵列传感器的在轨泄漏定位方法

    Institute of Scientific and Technical Information of China (English)

    孟冬辉; 闫荣鑫; 郭欣

    2011-01-01

    In view of more and more debris in space, it is an important issue to locate the leak point in manned spacecraft cabin. In this paper, a leak detection method is developed for spacecraft on orbit using circular ultrasonic array sensors. The time difference of the ultrasonic signal reaching different ultrasonic units is calculated by cross correlation, and then the direction of the leak is determined. The leak location can then be identified by triangulation with three ultrasonic array sensors.%随着空间碎片数量的不断增加,载人航天器在轨泄漏定位问题成为一个亟待解决的问题.文章研究了一种基于圆形超声阵列传感器的在轨泄漏定位方法,利用互相关原理计算泄漏超声信号传播到不同测试单元的时间差,从而确定泄漏所在的方向,并根据三角定位方法确定漏孔的具体位置.

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

    Science.gov (United States)

    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.

  13. Determination of the Fermi velocity by angle-dependent periodic orbit resonance measurements in the organic conductor α-(BEDT-TTF)2KHg(SCN)4

    Science.gov (United States)

    Kovalev, A. E.; Hill, S.; Qualls, J. S.

    2002-10-01

    We report on detailed angle-dependent studies of the microwave (ν=50-90 GHz) interlayer magnetoelectrodynamics of a single crystal sample of the organic charge-density-wave (CDW) conductor α-(BEDT-TTF)2KHg(SCN)4. Recently developed instrumentation enables both magnetic-field (B) sweeps for a fixed sample orientation and angle sweeps at fixed ν/B. We observe series' of resonant absorptions, which we attribute to periodic orbit resonances (POR)-a phenomenon closely related to cyclotron resonance. The angle dependence of the POR indicates that they are associated with the low-temperature quasi-one-dimensional (Q1D) Fermi surface (FS) of the title compound; indeed, all of the resonance peaks collapse onto a single set of ν/B versus angle curves, generated using a semiclassical magnetotransport theory for a single Q1D FS. We show that Q1D POR measurements provide one of the most direct methods for determining the Fermi velocity, without any detailed assumptions concerning the band structure; our analysis yields an average value of vF=6.5×104 m/s. Quantitative analysis of the POR harmonic content indicates that the Q1D FS is strongly corrugated. This is consistent with the assumption that the low-temperature FS derives from a reconstruction of the high-temperature quasi-two-dimensional FS, caused by the CDW instability. Detailed analysis of the angle dependence of the POR yields parameters associated with the CDW superstructure, which are consistent with published results. Finally, we address the issue as to whether or not the interlayer electrodynamics are coherent in the title compound. We obtain a relaxation time from the POR linewidths, which is considerably longer than the interlayer hopping time, indicating that the transport in this direction is coherent.

  14. Field angle dependence of the zero-energy density of states in unconventional superconductors: analysis of the borocarbide superconductor YNi{sub 2}B{sub 2}C

    Energy Technology Data Exchange (ETDEWEB)

    Nagai, Yuki; Kato, Yusuke [Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan); Hayashi, Nobuhiko [CCSE, Japan Atomic Energy Agency, 6-9-3 Higashi-Ueno, Tokyo 110-0015 (Japan); Yamauchi, Kunihiko [CNR-INFM, CASTI Regional Lab, I-67010 Coppito (L' Aqulia) (Italy); Harima, Hisatomo, E-mail: ynagai@Vortex.c.u-tokyo.ac.j [Department of Physics, Kobe University, Nada, Kobe 657-8501 (Japan)

    2009-03-01

    We investigate the field-angle-dependent zero-energy density of states for YNi{sub 2}B{sub 2}C with using realistic Fermi surfaces obtained by band calculations. Both the 17th and 18th bands are taken into account. For calculating the oscillating density of states, we adopt the Kramer-Pesch approximation, which is found to improve accuracy in the oscillation amplitude. We show that superconducting gap structure determined by analyzing STM experiments is consistent with thermal transport and heat capacity measurements.

  15. Field angle dependence of the zero-energy density of states in unconventional superconductors: analysis of the borocarbide superconductor YNi2B2C

    Science.gov (United States)

    Nagai, Yuki; Hayashi, Nobuhiko; Kato, Yusuke; Yamauchi, Kunihiko; Harima, Hisatomo

    2009-03-01

    We investigate the field-angle-dependent zero-energy density of states for YNi2B2C with using realistic Fermi surfaces obtained by band calculations. Both the 17th and 18th bands are taken into account. For calculating the oscillating density of states, we adopt the Kramer-Pesch approximation, which is found to improve accuracy in the oscillation amplitude. We show that superconducting gap structure determined by analyzing STM experiments is consistent with thermal transport and heat capacity measurements.

  16. Detection Method of High Voltage Circuit Breaker and Its Application Based on Ultrasonic Sensor%基于超声波传感器的高压断路器检测方法及应用

    Institute of Scientific and Technical Information of China (English)

    程旭东; 王兰芳

    2011-01-01

    In order to improve the efficiency and precision of velocity detection of High voltage circuit breaker (HVCB), a detection method based on ultrasonic sensor is proposed. The TR40 series of ultrasonic transducer is adopted to generate ultrasonic signals. The emission sensor is fixed on the breaker's closing/opening connection rod while receiving sensor installed in the universal triangular bracket. By measuring the frequency difference between emission signals and receiving signals, instantaneous velocity of the current circuit breaker operation can be calculated. Furthermore, a mechanical characteristic detection instrument for HVCB is developed. Field test results show that the ultrasonic sensor is convenient to be installed and the results has high accuracy and small uncertainty, which satisfies the field test requirements for velocity detection of HVCB.%为提高高压断路器速度检测效率与精度,提出了一种基于超声波传感器的高压断路器速度检测方法,利用TR40系列超声波换能器产生超声波信号,将发射传感器固定于断路器合/分连接杆上,接收传感器安装在万能三角支架上,通过统计接收和发送信号的频率差,计算当前断路器运行的瞬时速度,并在此基础上开发了断路器机械特性测试仪.现场试验结果表明,超声波传感器安装方便、测试数据精度较高、不确定度小,能满足高压断路器现场速度检测的需求.

  17. Multivariate data-driven modelling and pattern recognition for damage detection and identification for acoustic emission and acousto-ultrasonics

    DEFF Research Database (Denmark)

    Torres-Arredondo, M.A.; Tibaduiza, D.-A.; McGugan, Malcolm

    2013-01-01

    and pattern recognition are evaluated and integrated into the different proposed methodologies. As a contribution to solve the problem, this paper presents results in damage detection and classification using a methodology based on hierarchical nonlinear principal component analysis, square prediction...

  18. 电磁超声兰姆波的无损探伤技术%Electromagnetic Ultrasonic Lamb Wave Defect Detection of Metal

    Institute of Scientific and Technical Information of China (English)

    杨理践; 梁震; 高松巍

    2012-01-01

    针对金属薄板的缺陷检测问题,进行了电磁超声兰姆波无损探伤技术的研究.基于兰姆波的频散特性,推导出了兰姆波各模式相(群)速度关于线圈间距、频厚积及激励频率的表达式,确定了电磁超声换能器的结构参数.设计了一种DDS与FPGA相结合,产生串码、频率可调的脉冲激励信号串发生电路,利用H桥放大电路对激励信号进行了升压处理,并对激励线圈进行了阻抗匹配.试验结论表明:永磁铁与激励线圈的不同组合形式可以分别在铁磁性和非铁磁性金属薄板中激发出兰姆波.研制的功率放大电路及信号处理电路能够在金属薄板中激发出高性能的兰姆波并实现稳定接收,具有较高的信噪比,能够实现对金属薄板的无损探伤.%For the sheet metal defect detection problem, advanced the electromagnetic ultrasonic Lamb wave nondestructive testing technology research. Based on the dispersion characteristics of Lamb waves, derived out the model of the Lamb wave phase ( group) velocity of the coil spacing, frequency and excitation frequency thickness product expression and determine the electromagnetic ultrasonic transducer structure parameters. Design a DDS and FPGA combined generating circuit, which can generate string of code, adjustable pulse frequency excitation signal string, Used the H-bridge amplifier circuit excitation signal for the boost treatment and then impedance matched the excitation coil. Experiment concluded shown, different form of permanent magnet and excitation coils combination can respectively stimulate Lamb in the ferromagnetic and non-ferromagnetic metal sheet. Developed power amplifier circuit and signal processing circuit can stimulate high-performance in sheet metal and realize stable reception, has a high signal to noise ratio and can execute Non-destructive testing of metal sheet.

  19. Inspection of copper canisters for spent nuclear fuel by means of ultrasonic array system. Modelling, defect detection and grain noise estimation

    Energy Technology Data Exchange (ETDEWEB)

    Wu Ping; Stepinski, T. [Uppsala Univ., (Sweden). Dept. of Material Science

    1998-07-01

    The work presented in the report has been split into three overlapping tasks which have the following objectives: (1) development of beam-forming tools, and verification of modeling tools; (2) investigation of detection and resolution limits; (3) evaluation of attenuation, estimation and suppression of grain noise. For beam-forming tools, a method of designing steered and/or focused beams in immersed solids is presented based on geometrical acoustics. Presently, the beam designs are only related to delays but not to apodization. These focused, steered beams are intended to be used for sizing defects and inspecting the regions close to canisters outer walls. The modeling tool developed previously for simulating elastic fields radiated by planar arrays into immersed solids has been verified by comparing with the results obtained from PASS, a software developed by Dr. Didier Cassereau, France. The results from our modeling tool are in excellent agreement with those from PASS. Since the array coming with the ALLIN ultrasonic array system is not planar, but cylindrically curved in elevation, and it works not in transmission mode, but in pulse echo mode, the above modeling tool for the planar arrays cannot be applied directly. Therefore, the modeling tool has been upgraded for the ALLIN array. The theory underlying this modeling tool is the extended angular spectrum approach (ASA) which was developed based on the conventional ASA that only applies to planar sources. Experimental verification of the modeling tool has shown that the results from the tool agree very well with the measurements. To quantify the fields from the ALLIN array and to facilitate the comparison of simulated results with the measured ones, the ALLIN array system has been calibrated based on the existing functionality, and an analytical model has been proposed for simulating measured acoustic echo pulses. To investigate the detection and resolution limits, we have carried out a series of experiments

  20. Study on Ultrasonic Detection Under Complex Electromagnetic Environment%复杂电磁环境下的超声探伤研究

    Institute of Scientific and Technical Information of China (English)

    穆洪彬; 齐世海; 孟晓梅; 唐茜; 牛余朋

    2014-01-01

    Focusing on the defect of traditional ultrasonic technical, which is easily being influenced under electromagnetic environment, two types of fiber Bragg grating (FBG) ultrasonic sensing system were constructed using different light source. Introducing the principle of FBG, using the two types of FBG ultrasonic sensing system for ultrasonic testing, and some experiments has been made for research. Results shows, the FBG ultrasonic sensing system including a tunable laser possessed high sensitivity to ultrasonic wave and proved to be an alternative to conventional piezoelectric sensors in ultrasonic inspection of structural composite materials.%针对复杂电磁环境下传统超声波探头易受电磁波干扰的缺陷,构建基于布拉格光栅传感器的2种超声传感系统。介绍布拉格光栅的原理,利用宽带光源和可调激光系统进行超声探测,构建2种布拉格光栅传感系统,采用布拉格光栅超声传感系统进行伤情探伤,并进行实验验证对比。结果表明:具备可调激光光源布拉格光栅传感器的超声探测系统对超声波具有相当高的灵敏度,在复杂电磁环境下对结构复合材料的超声探伤中可以作为传统的压电传感器的替代品。

  1. Ultrasonic vibration for structural health monitoring

    Science.gov (United States)

    Liang, Y.; Yan, F.; Borigo, C.; Rose, J. L.

    2013-01-01

    Guided waves and vibration analysis are two useful techniques in Nondestructive Evaluation and Structural Health Monitoring. Bridging the gap between guided waves and vibration, a novel testing method ultrasonic vibration is demonstrated here. Ultrasonic vibration is capable to achieve defect detection sensitivity as ultrasonic guided waves, while maintaining the efficiency of traditional vibration in the way of adopting several sensors to cover the whole structure. In this new method, continuous guided wave energy will impinge into the structure to make the structure vibrate steadily. The steady state vibration is achieved after multiple boundary reflections of the continuous guided wave. In ultrasonic vibration experiments, annual array transducer is used as the actuator. The loading functions are tuned by the frequencies and phase delays among each transducer element. Experiments demonstrate good defect detection ability of by optimally selecting guided wave loadings.

  2. Ultrasonic colour Doppler imaging

    DEFF Research Database (Denmark)

    Evans, David H.; Jensen, Jørgen Arendt; Nielsen, Michael Bachmann

    2011-01-01

    Ultrasonic colour Doppler is an imaging technique that combines anatomical information derived using ultrasonic pulse-echo techniques with velocity information derived using ultrasonic Doppler techniques to generate colour-coded maps of tissue velocity superimposed on grey-scale images of tissue ...

  3. Ultrasonic Evaluation and Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, Susan L.; Anderson, Michael T.; Diaz, Aaron A.; Larche, Michael R.; Prowant, Matthew S.; Cinson, Anthony D.

    2015-10-01

    Ultrasonic evaluation of materials for material characterization and flaw detection is as simple as manually moving a single-element probe across a speci-men and looking at an oscilloscope display in real time or as complex as automatically (under computer control) scanning a phased-array probe across a specimen and collecting encoded data for immediate or off-line data analyses. The reliability of the results in the second technique is greatly increased because of a higher density of measurements per scanned area and measurements that can be more precisely related to the specimen geometry. This chapter will briefly discuss applications of the collection of spatially encoded data and focus primarily on the off-line analyses in the form of data imaging. Pacific Northwest National Laboratory (PNNL) has been involved with as-sessing and advancing the reliability of inservice inspections of nuclear power plant components for over 35 years. Modern ultrasonic imaging techniques such as the synthetic aperture focusing technique (SAFT), phased-array (PA) technolo-gy and sound field mapping have undergone considerable improvements to effec-tively assess and better understand material constraints.

  4. Ultrasonic study of adhesive bond quality at a steel-to-rubber interface by using quadrature phase detection techniques

    Science.gov (United States)

    Smith, A. C.; Yang, H.

    1989-01-01

    The quadrature phase detection technique was used to simultaneously monitor the phase and amplitude of a toneburst signal normally reflected from an adhesively bonded steel-to-rubber interface. The measured phase was found to show a positive shift for all bonded samples with respect to the disbonded state - the phase shift being larger for samples with weaker bonds, as manifested by smaller values of applied tensile loads at failure. A model calculation, which incorporates the concept of interfacial strength into the usual problem of wave propagation in multilayered media, was used to deduce a bond-quality parameter from an experimentally measured phase shift. This bond-quality parameter was found to be correlated with the tensile strength of the adhesive bonds at failure loads.

  5. Controlled variation of the information depth by angle dependent soft X-ray emission spectroscopy: A study on polycrystalline Cu(In,Ga)Se 2

    Science.gov (United States)

    Mönig, H.; Lauermann, I.; Grimm, A.; Camus, C.; Kaufmann, C. A.; Pistor, P.; Jung, Ch.; Kropp, T.; Lux-Steiner, M. C.; Fischer, Ch.-H.

    2008-12-01

    Angle dependent X-ray emission spectroscopy (AXES) is introduced as a tool for depth dependent composition analysis. A controlled variation of the information depth is demonstrated by changing the geometry from grazing exit to grazing incidence geometry. First results are presented from Cu(In,Ga)Se 2 (CIGSe)-based polycrystalline thin film solar cell bi-layer components. A mathematical model explains changes in relative intensity due to the absorption and emission behavior of thin CdS and Zn(S,O) cover layers. The fact that the presented data can be modelled by ideal bi-layer structures, provides both, proof of concept in general and the proof of applicability to the relatively rough layered structures based on CIGSe. In bare CIGSe a homogeneous distribution of Cu and Ga is found in a depth range between 22 and 470 nm.

  6. Optimization of Ultrasonic Extraction and Clean-up Protocol for the Determination of Polycyclic Aromatic Hydrocarbons in Marine Sediments by High-performance Liquid Chromatography Coupled with Fluorescence Detection

    Institute of Scientific and Technical Information of China (English)

    PENG Xuewei; YAN Guofang; LI Xianguo; GUO Xinyun; ZHOU Xiao; WANG Yan

    2012-01-01

    The procedures of ultrasonic extraction and clean-up were optimized for the determination of polycyclic aromatic hydrocarbons(PAHs)in marine sediments.Samples were ultrasonically extracted,and the extracts were purified with a miniaturized silica gel chromatographic column and analyzed with high performance liquid chromatography(HPLC)with a fluorescence detector.Ultrasonication with methanol-dichloromethane(2:1,v/v)mixture gave higher extraction efficiency than that with dichloromethane.Among the three elution solvents used in clean-up step,dichloromethane-hexane(2:3,v/v)mixture was the most satisfactory.Under the optimized conditions,the recoveries in the range of 54.82% to 94.70% with RSDs of 3.02% to 23.22% for a spiked blank,and in the range of 61.20% to 127.08% with RSDs of 7.61% to 26.93% for a spiked matrix,were obtained for the 15 PAHs studied,while the recoveries for a NIST standard reference SRM 1941b were in the range of 50.79% to 83.78% with RSDs of 5.24% to 21.38%.The detection limits were between 0.75ngL-1 and 10.99ngL-1for different PAHs.A sample from the Jiaozhou Bay area was examined to test the established methods.

  7. Optimization of ultrasonic extraction and clean-up protocol for the determination of polycyclic aromatic hydrocarbons in marine sediments by high-performance liquid chromatography coupled with fluorescence detection

    Science.gov (United States)

    Peng, Xuewei; Yan, Guofang; Li, Xianguo; Guo, Xinyun; Zhou, Xiao; Wang, Yan

    2012-09-01

    The procedures of ultrasonic extraction and clean-up were optimized for the determination of polycyclic aromatic hydrocarbons (PAHs) in marine sediments. Samples were ultrasonically extracted, and the extracts were purified with a miniaturized silica gel chromatographic column and analyzed with high performance liquid chromatography (HPLC) with a fluorescence detector. Ultrasonication with methanol-dichloromethane (2:1, v/v) mixture gave higher extraction efficiency than that with dichloromethane. Among the three elution solvents used in clean-up step, dichloromethane-hexane (2:3, v/v) mixture was the most satisfactory. Under the optimized conditions, the recoveries in the range of 54.82% to 94.70% with RSDs of 3.02% to 23.22% for a spiked blank, and in the range of 61.20% to 127.08% with RSDs of 7.61% to 26.93% for a spiked matrix, were obtained for the 15 PAHs studied, while the recoveries for a NIST standard reference SRM 1941b were in the range of 50.79% to 83.78% with RSDs of 5.24% to 21.38%. The detection limits were between 0.75 ng L-1 and 10.99 ng L-1for different PAHs. A sample from the Jiaozhou Bay area was examined to test the established methods.

  8. Lamb Wave Multitouch Ultrasonic Touchscreen.

    Science.gov (United States)

    Firouzi, Kamyar; Nikoozadeh, Amin; Carver, Thomas E; Khuri-Yakub, Butrus Pierre T

    2016-12-01

    Touchscreen sensors are widely used in many devices such as smart phones, tablets, and laptops with diverse applications. We present the design, analysis, and implementation of an ultrasonic touchscreen system that utilizes the interaction of transient Lamb waves with objects in contact with the screen. It attempts to improve on the existing ultrasound technologies, with the potential of addressing some of the weaknesses of the dominant technologies, such as the capacitive or resistive ones. Compared with the existing ultrasonic and acoustic modalities, among other advantages, it provides the capability of detecting several simultaneous touch points and also a more robust performance. The localization algorithm, given the hardware design, can detect several touch points with a very limited number of measurements (one or two). This in turn can significantly reduce the manufacturing cost.

  9. Fast detection of leakages. Ultrasonic sensors: Fast and reliable detection of leakages in compressed-air networks; Schnelle Fehlerortung. Leckagen in Druckluftnetzen mit Ultraschallsensoren zuverlaessig detektieren

    Energy Technology Data Exchange (ETDEWEB)

    Muench, H.J.; Streuber, W. [Sonotec Ultraschallsensorik GmbH, Halle/Saale (Germany)

    2002-03-18

    Leakage points can be detected easily even at high production noise levels. Probes focusing on structure-borne noise instead of airborne noise have a wider range of applications. [German] Druckluftverluste koennen schon am Entstehungsort einfach nachgewiesen werden. Die Lecksuche ist auch bei starkem Produktionslaerm noch moeglich. Eine Koerperschallsonde anstelle der Luftschallsonde bietet weitere Einsatzmoeglichkeiten. (orig.)

  10. Software Design and Application of Ultrasonic Automatic Flaw Detection System of Welded Steel Pipes%焊接钢管超声波自动探伤系统中的软件设计与应用

    Institute of Scientific and Technical Information of China (English)

    常少文

    2011-01-01

    The software design of pipe ultrasonic automatic flaw detection system, and its application on welded steel pipes production were introduced. It combined traditional ultrasonic inspection technology with some advanced technologies, such as industrial control computer, virtual instrument, intelligent flaw detection, etc. With the careful programming flaw detection operation, it could evaluate correctly and select strictly for complex flaw echo, its error in alarm could be effectively avoided. The review of flaw echo waveform overcame insufficiency of flaw category identification in ultrasonic automatic inspection, and achieved misinformation rate being smaller than 2%, and fail to report rate being zero.%分析了焊接钢管超声波自动探伤系统的软件设计以及在焊接钢管检测中的应用状况.把传统的超声波检测技术和先进的工业控制计算机、虚拟仪器和智能化探伤等技术相结合,配合精心编制的探伤操作程序,可做到对复杂缺陷回波的准确评价和严格筛选,有效地避免了系统的误报警.缺陷波形回放功能克服了超声波自动探伤中的缺陷种类难以识别的不足,并做到误报率<2%,漏报率为0.

  11. Hand Gesture Recognition Using Ultrasonic Waves

    KAUST Repository

    AlSharif, Mohammed Hussain

    2016-04-01

    Gesturing is a natural way of communication between people and is used in our everyday conversations. Hand gesture recognition systems are used in many applications in a wide variety of fields, such as mobile phone applications, smart TVs, video gaming, etc. With the advances in human-computer interaction technology, gesture recognition is becoming an active research area. There are two types of devices to detect gestures; contact based devices and contactless devices. Using ultrasonic waves for determining gestures is one of the ways that is employed in contactless devices. Hand gesture recognition utilizing ultrasonic waves will be the focus of this thesis work. This thesis presents a new method for detecting and classifying a predefined set of hand gestures using a single ultrasonic transmitter and a single ultrasonic receiver. This method uses a linear frequency modulated ultrasonic signal. The ultrasonic signal is designed to meet the project requirements such as the update rate, the range of detection, etc. Also, it needs to overcome hardware limitations such as the limited output power, transmitter, and receiver bandwidth, etc. The method can be adapted to other hardware setups. Gestures are identified based on two main features; range estimation of the moving hand and received signal strength (RSS). These two factors are estimated using two simple methods; channel impulse response (CIR) and cross correlation (CC) of the reflected ultrasonic signal from the gesturing hand. A customized simple hardware setup was used to classify a set of hand gestures with high accuracy. The detection and classification were done using methods of low computational cost. This makes the proposed method to have a great potential for the implementation in many devices including laptops and mobile phones. The predefined set of gestures can be used for many control applications.

  12. 导波检测技术在“抚-鲅”线上的应用%Application of Ultrasonic Guided Wave Detection Technology in Fushun-Bayuquan Pipe

    Institute of Scientific and Technical Information of China (English)

    牛迎战; 张利民; 林猛

    2014-01-01

    The uitrasonic guided wave technology for pipeline defect detection has been applied in industrial field. In this paper, the development history and basic theory of the ultrasonic guided wave technology were introduced. Concrete application of the guided wave inspection technology in defect detection of Fushun-Bayuquan pipe was discussed. Testing conclusion was verified by in-situ observation, which showed that application of the guided wave inspection technology in pipeline defect detection was successful. At last, development trend of the ultrasonic guided wave inspection technology was prospected.%用导波技术对管道缺陷检测进入工业现场应用阶段。介绍了超声导波技术的发展历史及基本理论。表述了导波检测技术“抚-鲅”线缺陷检测中的具体应用过程,检测缺陷结论经现场观测验证准确。表明管道缺陷导波检测技术在“抚-鲅”线上的应用成功。幵指出随着超声导波技术的发展,其在管道缺陷检测工程中将得到广泛的应用。

  13. Design of a Cortex-M4 based ultrasonic phased array detection system%基于Cortex-M4的超声相控阵探测系统的设计

    Institute of Scientific and Technical Information of China (English)

    赵连睿; 杨济民; 李振江; 李玉坤

    2013-01-01

    We design an obstacle detection system with ultrasonic phased array detection and the microcontroller Cortex-M4 as a processor. Experiments show that the actual sound field strength of the focal area is greater than that of conventional ultrasonic technology and sound energy is more convergent. Its detection distance is from 0.3 to 5.5 m, and measurement accuracy is ±1 cm. The system is therefore effective and satisfactory.%设计了一种以Cortex-M4微控制器STM32F407为核心,采用超声相控阵技术对障碍物进行探测的系统.实验结果表明,该系统聚焦探测区域的实际声场强度大于常规的超声波技术,声波能量更为集中.系统的探测范围在0.3~5.5m,探测精度±1 cm,稳定性好,准确方便.

  14. 多阵元超声换能器阵列涡轮机全覆盖故障检测研究%Research on Comprehensive Fault Detection of Turbine Engine Based on Ultrasonic Transducer with Multi Array Elements

    Institute of Scientific and Technical Information of China (English)

    高之圣; 王海燕; 张日刚

    2013-01-01

    提出了一种基于多阵元超声换能器阵列的航空涡轮发动机的超声波相控阵故障检测方法,采用面阵列分布设计了36个多阵元的超声换能器阵列,通过多次多方向的检测方法降低虚警概率,一次检测就可全覆盖整个叶片,不用多次检测,提高了检测速度。检测过程中由于有多个超声阵元可以接收到声波,所以检测的增益、信噪比也得到了提高。仿真实验表明,采用新方法检测的对象既可以是整块的平面,又可以覆盖到涡轮叶片中的整个散热管道,检测概率比传统超声故障检测提高了20%以上。%An ultrasonic phased array fault detection method of aviation turbine engine array ultrasound transducer array based, more than 36 ultrasonic transducer array design using area array distribution, detection method by multi direction to reduce the false alarm probability, a test can fully cover the entire leaf, without repeated testing to improve the detec-tion speed. The detection process as a plurality of ultrasound array can receive sound wave, so the gain, signal to noise ratio is improved detection. Simulation results show that, by using object detection method can be the whole plane, and can cover of the turbine blade is the heat pipe, the probability of detection than traditional ultrasonic fault detection in-creased more than 20%.

  15. Research on axial flow pump cavitation monitoring method based on the active ultrasonic detection%基于主动超声的轴流水泵空化监测方法研究

    Institute of Scientific and Technical Information of China (English)

    陈笑然; 章林柯; 阎兆立; 陈杰; 程晓斌

    2011-01-01

    Cavitation phenomena is one of the principal factors which compromise the life-span and performance of the fluid machinery. A novel method named active ultrasonic detection was proposed, which emitted a high frequency carrier wave to the area round cavitation district with transmission method. The fluid motion would exert an influence on the high frequency carrier wave, which induced that the fluid field information was modulated on the ultrasonic carrier wave, so the fluid field information could be gained through the demodulation of the ultrasonic carrier signal. Based on the experimental dataset from shaft flow pump in different flow rates,combining high speed photography verifying method, a pattern classifier based on support vector machine was set up to achive the active ultrasonic detection of the pump cavitation. This method can detect the new born cavitation accurately, and supply the relevant alarm, to avoid the further development of cavitation.%空化是影响液流机械使用寿命与性能的主要因素之一.提出一种主动超声探测方法,该方法通过透射方式对空化区域或其附近发射高频超声波,流体的运动会对其中传播的超声波产生影响,流体运动信息调制到超声载波上,通过对已调超声信号的解调,得到流场相关信息.以不同状态下的轴流泵空化流场实验数据为依据,结合高速摄像验证手段,建立基于支持向量机的SVM模式识别分类,实现对螺旋桨空化的主动超声监测.该方法可以较精确地探测到空化初生阶段,及时提供早期的空化状态报警,避免空化进一步发展.

  16. 钢管超声波自动探伤横向扫查系统的改造%Reform to Steel Pipe Automatic Ultrasonic Flaw Detection Transverse Scanning

    Institute of Scientific and Technical Information of China (English)

    汪超; 张兴权; 刘胜斌

    2014-01-01

    Through analysis on the configuration of steel pipe automatic ultrasonic flaw detection and defects type after pipe expansion in some steel pipe company,it got the reason of weld transverse defects occasionally found out during automatic ultrasonic inspection after pipe expansion,and put forward the reform measures of the existing automatic ultrasonic inspection transverse scanning. That is varying the arrangement of transverse probes and probe frame,adding monitor channel quantity. After reform,the testing system is with high reliability,simple operation,good stability,and the inspection personnel easy to master. The reforms decrease the risk of steel pipe missing detection,and enhance the productivity.%通过分析某钢管公司目前钢管超声波自动探伤设备的配置和钢管在扩径后发现的缺陷类型,找出了钢管扩径后超声波自动检测时偶尔发现焊缝横向缺陷的原因,提出了对现有钢管超声波自动探伤横向扫查系统的改造措施,即改变了横向探头及探头架的布置,增加了检测监视的通道数量。改造后的检测系统可靠性高,操作简便,稳定性好,探伤人员容易掌握。通过对该自动探伤横向扫查的改造,降低了钢管缺陷漏检的风险,提高了生产效率。

  17. An application of ultrasonic phased array imaging in electron beam welding inspection

    Institute of Scientific and Technical Information of China (English)

    周琦; 刘方军; 李志军; 李旭东; 齐铂金

    2002-01-01

    The basic principle and features of ultrasonic phased array imaging are discussed in this paper. Through the ultrasonic phased array technology, the electron beam welding defects and frozen keyholes characterization and imaging were realized. The ultrasonic phased array technology can detect kinds of defects in electron beam welding (EBW) quickly and easily.

  18. Analysis on the Causes of Nonconformity in Ultrasonic Flaw Detection of X60 Steel Plate%X60管线钢超声波探伤不合原因分析

    Institute of Scientific and Technical Information of China (English)

    李雪东

    2015-01-01

    利用超声波探伤、磁粉探伤、金相显微镜等检测手段对X60管线钢板探伤不合部位取样进行分析。结果表明:试样内部的夹杂、微裂纹是产生缺陷回波的主要原因。采取强化精炼以及连铸坯下线后堆垛缓冷等措施,提高了探伤合格率。%The samples from Nonconformity in Ultrasonic Flaw Detection of X60 steel plate was studied by means of Magnetic particle inspection and Metallurgical Microscopy etc. It has been proved that Micro-cracks and internal inclusions were the main causes of the echoes from defects. Through the technology improvement on refining measure controlling, stacking slow cooling to off line continuous casting slabs, the Conformity Ratio of Ultrasonic Flaw Detection has been improved.

  19. 薄板钢结构超声检测Lamb波激励与模态分析%Ultrasonic Detection of Lamb Wave Stimulation and Modal Analysis of Thin Steel Plate Structure

    Institute of Scientific and Technical Information of China (English)

    艾春安; 王学勇; 刘瑜

    2012-01-01

    运用超声Lamb波对薄板钢结构进行检测,采用斜入射方式实施Lamb波的激励,并对检测信号进行模态分析.经实验发现选择合适的频率/入射角组合可实现对Lamb波模态的选择和控制,实现对检测对象的检测策略,并具有一定的工程应用价值.%This paper studies a common method and its procedure of ultrasonic detection of Lamb wave stimulation in thin steel plate structure. The signal was stimulated by ultrasonic oblique incident Lamb wave and the modes of the signal were analyzed. According to the experiment, it is found that with a proper combination of frequency and incident angle, selection and control of the modes of the Lamb wave can be realized. Thus, the best stimulating strategy of the detection can be obtained. This study is of important significance for the Lamb wave testing in engineering application.

  20. Electromagnetic ultrasonic detection method for steel plate based on phase control technique%基于相控技术的钢板电磁超声检测方法

    Institute of Scientific and Technical Information of China (English)

    杨理践; 刘珂丞; 高松巍; 邢燕好

    2016-01-01

    In order to improve the electromagnetic ultrasonic echo signal in the steel plate,an electromagnetic ultrasonic detection method for steel plate based on phase control technique was proposed.The phase control focusing technique and the transduction mechanism of electromagnetic ultrasonic transducer in steel plate were studied,and the excitation transducer array was composed of multi array elements.With the time delay rule,the equiphase superposition of ultrasonic was achieved in the target area,and the ultrasonic focusing was realized.In addition,the experimental verification was carried out on Q235 steel plate with the discrete structure.The results show that the proposed method can effectively compensate the phase deviation caused by the sound path difference between exciting and receiving transducers.When the excitation voltage is consistent,the amplitude of the echo signal received at 658 mm from the transducer array increases as 2 times as that of echo signal with the single excitation of central transducer.With the three-element excitation transducer array detection method,the ultrasonic focusing of defects can be realized.Furthermore,the amplitude of defect echo signal at 520 mm increases as 1.83 times as that of echo signal with the single excitation of central transducer.%为了提高钢板中电磁超声回波信号,提出了一种基于相控技术的钢板电磁超声检测方法.研究了相控聚焦技术和钢板中电磁超声换能器的换能机理,通过多阵元组成激发换能器阵列,运用延时法使超声波在目标区等相位叠加,实现超声波聚焦,并在 Q235钢板上采用分立式结构进行实验验证.结果表明:该方法有效弥补了收发换能器间声程差引起的相位偏移,激励电压一致时,658 mm处接收的回波信号幅值提高为中心换能器单独激发时的2倍;采用三阵元激励换能器阵列检测方法可实现缺陷处的超声波聚焦,520 mm 处缺陷回波幅

  1. Ultrasonic Hot Embossing

    Directory of Open Access Journals (Sweden)

    Werner Karl Schomburg

    2011-05-01

    Full Text Available Ultrasonic hot embossing is a new process for fast and low-cost production of micro systems from polymer. Investment costs are on the order of 20.000 € and cycle times are a few seconds. Microstructures are fabricated on polymer foils and can be combined to three-dimensional systems by ultrasonic welding.

  2. Ultrasonic non invasive techniques for microbiological instrumentation

    Science.gov (United States)

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

    2010-01-01

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

  3. Towards monomaterial p-n junctions: Single-step fabrication of tin oxide films and their non-destructive characterisation by angle-dependent X-ray photoelectron spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Krzywiecki, Maciej, E-mail: Maciej.Krzywiecki@polsl.pl [Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Str. 1, 40237 Düsseldorf (Germany); Institute of Physics–CSE, Silesian University of Technology, Konarskiego 22B, 44-100 Gliwice (Poland); Sarfraz, Adnan; Erbe, Andreas [Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Str. 1, 40237 Düsseldorf (Germany)

    2015-12-07

    The application of a non-destructive method for characterization of electronic structure of an ultra-thin SnO{sub 1angle dependent XPS, we quantified stoichiometry changes inside the SnO{sub 1detected upward energy levels shift in the substrate's electronic structure, these results suggest a negative charge displacement across the SiO{sub 2} layer. As a consequence, there is a significant carrier concentration gradient in the layer, from a nearly insulating oxide at the SnO{sub x} surface to a semiconducting one at the bottom of the SnO{sub x} film. The results showed that the application of a simple and cost-effective method allows tuning the materials' properties towards the one-step fabrication of materials with ambipolar doping.

  4. Application of ultrasonic wave in compactness detection of giant steel tube concrete%超声波在巨型钢管混凝土密实性检测中的应用

    Institute of Scientific and Technical Information of China (English)

    许明耀

    2016-01-01

    The theory of ultrasonic wave in comPactness detection of giant steel tube concrete was introduced. It summarizes three common detec-tion methods including Plane detection,Pre-embedded sonic-testing tube detection and comPosite detection. Combined with the engineering Pro-ject,the integrated detection methods can be realized for giant steel tube concrete comPactness detection and can Provide a reference for similar Projects.%介绍了超声波检测巨型钢管混凝土密实性的原理,归纳了平面检测、预埋声测管检测、混合检测三种常规检测方法,结合工程实例,综合运用三种检测方法,实现了对巨型钢管混凝土密实性的检测,可供类似工程参考使用。

  5. Effect of Tube Curvature Concerning Second Wave Detection Based on Calculation of Ultrasonic Filed%基于声场计算的管道曲率对焊缝二次波检测的影响

    Institute of Scientific and Technical Information of China (English)

    张益成; 李晓红; 丁辉

    2011-01-01

    The connection hetween the curvature of tube and the sizing of the defect in small diameter tube,detected by ultrasonic, was little concerned about. Based on the sound field calculation model, scattering ultrasonic field of the beam coming from the probe and reflected by the different tube curvature wall was studied, and tben different regular reflector echo signals were calculated, and the comparison of the echo computed and DAC from DL1 sample was analyzed, the regulation of connection was found, which could support the defect sizing with sccondwave reflection methods.%超声检测小径管焊缝时的缺陷定量与内壁曲率的关系鲜有研究.基于声场计算模型,研究了斜探头发射声束经不同曲率的小径管内壁反射后的散射声场,并以此计算出焊缝中点状、条状和球状三种不同反射体的回波信号.与DL-1试块DAC曲线作对比,得出了小径管内壁曲率对焊缝二次波检测的影响规律,为小径管二次波或多次波反射法检测评定缺陷的大小提供了理论依据.

  6. A remote and autonomous continuous monitoring ultrasonic system for flood detection in sub-sea members of offshore steel oil rigs

    Energy Technology Data Exchange (ETDEWEB)

    Mijarez-Castro, Rito

    2006-07-01

    This thesis presents a novel and autonomous continuous monitoring system for flood detection in the hollow sub-sea members of offshore steel oil rigs. The technique offers an alternative to underwater nondestructive testing methods based on ultrasound and x-rays, which have been used to detect the presence of seawater in these applications, often with divers or remote operating vehicles. The research consists of theoretical and experimental work necessary for the development of an integral system that can be used in new fixed offshore oil rig designs. The system employs a single piezoelectric transducer which can be permanently attached to the inner wall of every sub-sea structure and which is powered by a normally inert seawater battery. Upon activation, the sensor transmits ultrasonic chirp or tone encoded pulses in the range of 21 k Hz to 42 k Hz, to a monitoring system at deck level for decoding and identifying flooded members. Two approaches to the system were considered during the investigation, depending on the communication channel exploited. These were based on either using the seawater as a propagation medium or using the steel structure as a wave-guide. A system based on theoretical models was built and field experiments were conducted using a purpose built jointed steel pipe structure, 7 m in length, 0.5 m in diameter and 16 mm in thickness. This structure was flooded by complete immersion in seawater. Results obtained using water as communication medium and a frequency in the order of 38 k Hz yielded an attenuation figure of 0.4 d B m{sub -}1 over 100 m, since losses were predominantly geometric. In contrast, using the tubular structure as a wave-guide and axis symmetric guided waves as the excitation, a gross attenuation figure of 1.3 d B m{sub -}1 was attained. In the straight parts of the structure, the attenuation ranged from 0.3 d B m{sub -} 1 to 0.6 d B m{sub -}1. The modes most likely to have been excited within the structure were L(0,5) - L(0

  7. Design of embedded endoscopic ultrasonic imaging system

    Science.gov (United States)

    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

  8. On-line detection of power ultrasonic transducer clamping capacitance%功率超声换能器夹持电容的在线检测的研究

    Institute of Scientific and Technical Information of China (English)

    朱武; 赵空勤; 金长善; 蔡鹤皋

    2001-01-01

    Presents the simple but highly reliable on-line detection of ultrasonic transducer clamping capacitance based on the impedance circuit model constructed through the impedance characteristics of the ultrasonic transducer under triple harmonics, and concludes from experimental results that this method can be used to effectively detect the variation of clamping capacitance while the transducer is operating, and the matching inductance can be dynamically regulated according to the results of detection, and dynamic matching can therefore be achieved in the real sense at the end of the transducer to improve the overall performance of the whole system.%为了解决大功率超声应用的换能器电端匹配问题,分析了超声波换能器在谐振频率三次谐波下的阻抗特性,给出了超声换能器三次谐波下的阻抗电路模型.并根据阻抗电路模型建立了对超声换能器的夹持电容实现在线检测简单、可靠性高的方法,实验证明该方法有效的.该方法可以在换能器工作过程中随时检测夹持电容的变化,根据检测结果对匹配电感进行动态调整,实现真正意义上的换能器电端的动态匹配,从而大大改善匹配质量,提高系统的工作性能.

  9. Ultrasonic materials characterization

    Science.gov (United States)

    Smith, R. L.

    1987-02-01

    The National NDT Center at Harwell has been developing methods for the characterization of materials using ultrasonics. This paper reviews the progress made in applying ultrasonic attenuation measurements to the determination of such quantities as grain size and dislocation content. A method, ultrasonic attenuation spectral analysis, has been developed, which enables the contributions of scattering and absorption to the total attenuation to be separated. The theoretical advances that have been made are also described. Some of the practical applications of the technique are illustrated and future development discussed.

  10. Ultrasonic washing of textiles.

    Science.gov (United States)

    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.

  11. Ultrasonic Phased-Array Characterization for NDE Applications

    Science.gov (United States)

    Hanley, John J.; Tennis, Richard F.; Pickens, Keith S.

    1995-01-01

    Southwest Research Institute (SwRI) recently fabricated and delivered the 100-channel Ultrasonic Phased-Array Testbed System (UPATS) for NASA's Langley Research Center. NASA prepared the specifications and provided the funding to develop UPATS in order to provide a tool for the improvement of ultrasonic nondestructive evaluation (NDE) and characterization of materials. UPATS incorporates state-of-the-art phased-array concepts such as beam steering, focusing, apodization, and phase-sensitive detection which make it possible to develop more sophisticated testing methodologies. It also can be used to investigate fundamental ultrasonic propagation and detection phenomena such as refraction, diffraction, scattering, and beam broadening.

  12. Laser ultrasonic diagnostics of residual stress.

    Science.gov (United States)

    Karabutov, Alexander; Devichensky, Anton; Ivochkin, Alexander; Lyamshev, Michael; Pelivanov, Ivan; Rohadgi, Upendra; Solomatin, Vladimir; Subudhi, Manomohan

    2008-11-01

    Ultrasonic NDE is one of the most promising methods for non-destructive diagnostics of residual stresses. However the relative change of sound velocity, which is directly proportional to applied stress, is extremely small. An initial stress of 100 MPa produces the result of deltaV/V approximately 10(-4). Therefore measurements must be performed with high precision. The required accuracy can be achieved with laser-exited ultrasonic transients. Radiation from a Nd-YAG laser (pulse duration 7 ns, pulse energy 100 microJ) was absorbed by the surface of the sample. The exited ultrasonic transients resembled the form of laser pulses. A specially designed optoacoustic transducer was used both for the excitation and detecting of the ultrasonic pulses. The wide frequency band of the piezodetector made it possible to achieve the time-of-flight measurements with an accuracy of about 0.5 ns. This technique was used for measuring of plane residual stress in welds and for in-depth testing of subsurface residual stresses in metals. Plane stress distribution for welded metallic plates of different thicknesses (2-8 mm) and the subsurface stress distribution for titanium and nickel alloys were obtained. The results of conventional testing are in good agreement with the laser ultrasonic method.

  13. Monitoring Thermal Coagulation with Ultrasonic Textures

    Institute of Scientific and Technical Information of China (English)

    YANG Wei; ZHANG Su; CHEN Ya-zhu; CHEN Lei; HU Bing; MA Wei-yin

    2007-01-01

    The feasibility of using B-mode ultrasound image textures and pattern recognition technique to characterize the thermal coagulation in vitro during radiofrequency ablation was investigated.The changes of ultrasonic textures in the different regions of samples varied with the heating time in the in-vitro experiments, which would result in that the coagulated and noncoagulated regions of tissue had different ultrasonic textures.Using support vector machine to extract the ultrasonic texture features and characterize the state of tissue, the size and boundaries of thermal lesions could be detected and measured more exactly than only using the gray scale information of B-mode ultrasound image.The proposed method would be applied to the image-guided radiofrequency ablation (IGRA) procedure for monitoring the thermal coagulation.

  14. 基于超声波的室内移动机器人贴地障碍物检测%Ultrasonic Detection to the Obstacles Clung to Ground for Indoor Mobile Robots

    Institute of Scientific and Technical Information of China (English)

    张海鹰; 王昉

    2012-01-01

    The indoor mobile robots systems always ignore the low obstacles which clung to ground while don't really hinder the robot. In order to enhance the stability of driving for the robots, a special ultrasonic ranging system is put forward to detect the obstacles cling to ground. Design requirements of such systems are analyzed, and realization methods are summarized.%通常的室内移动机器人系统,往往忽视环境中存在的贴近地面、但并不阻碍机器人行驶的低矮障碍物。为增强机器人行驶的稳定性,提出了专门用于检测贴地障碍物的超声波测距系统,并分析总结了此类系统的设计要求与实现方法。

  15. Metalworking with ultrasonic energy

    Science.gov (United States)

    Sonea, I.; Minca, M.

    1974-01-01

    The application of ultrasonic radiation for metal working of steel is discussed. It is stated that the productivity of the ultrasonic working is affected by the hardness of the material to be worked, the oscillation amplitude, the abrasive temperature, and the grain size. The factors that contribute to an increase in the dislocation speed are analyzed. Experimental data are provided to substantiate the theoretical parameters.

  16. Fundamentals of Medical Ultrasonics

    CERN Document Server

    Postema, Michiel

    2011-01-01

    This book sets out the physical and engineering principles of acoustics and ultrasound as used for medical applications. It covers the basics of linear acoustics, wave propagation, non-linear acoustics, acoustic properties of tissue, transducer components, and ultrasonic imaging modes, as well as the most common diagnostic and therapeutic applications. It offers students and professionals in medical physics and engineering a detailed overview of the technical aspects of medical ultrasonic imaging, whilst serving as a reference for clinical and research staff.

  17. ULTRASONIC ASSEMBLY [REVIEW

    Directory of Open Access Journals (Sweden)

    PORAV Viorica

    2015-05-01

    Full Text Available The paper exposes the possibility of machine producesers to optimize the costs of clothes assembling. Ultrasonic systems being frequently utilized have many advantages on semi products of synthetic textile and technical textile. First of all, sewing – cutting process can be accomplished under high speeds and rate of losses can be minimized. Cutting seal applications are frequently used for underwear and sportswear. Slicing and unit cutting machines, as well as portable sealing machines are available for labeling sector. Products such as bag, pocket and cover can be sewed in a seamless manner for promotion purposes. All objects in terms of accessories are obtained in same standard. Our quilting machines are preferred in worldwide due to its threadless, high quality sealing. An alternative to the classic sewing assembly, with thread and needles is ultrasonic seaming. In ultrasonic welding, there are no connective bolts, nails, soldering materials, or adhesives necessary to bind the materials together. Ultrasonic is defined as acoustic frequencies above the range audible to the human ear. Ultrasonic frequencies are administered to the fabric from the sonotrode of bonding machine. The high frequency and powerful energy produced, when is release in one special environment, the ultrasound heating this environment. The ability to ultrasonic weld textiles and films depend on their thermoplastic contents and the desired end results. The paper defines the weld ability of more common textiles and films. The welding refers to all types of bonding and sealing, as in point bonding of fabric, or continuous sealing of film.

  18. Flaw detection in multi-layer, multi-material composites by resonance imaging: Utilizing Air-coupled Ultrasonics and Finite Element Modeling

    Science.gov (United States)

    Livings, Richard Andrew

    2011-12-01

    Ceramic tiles are the main ingredient of a multi-material, multi-layered composite being considered for the modernization of tank armors. The high stiffness, low attenuation, and precise dimensions of these uniform tiles make them remarkable resonators when driven to vibrate. Defects in the tile, during manufacture or after usage, are expected to change the resonance frequencies and resonance images of the tile. The comparison of the resonance frequencies and resonance images of a pristine tile/lay-up to a defective tile/lay-up will thus be a quantitative damage metric. By examining the vibrational behavior of these tiles and the composite lay-up with Finite Element Modeling and analytical plate vibration equations, the development of a new Nondestructive Evaluation technique is possible. This study examines the development of the Air-Coupled Ultrasonic Resonance Imaging technique as applied to a hexagonal ceramic tile and a multi-material, multi-layered composite.

  19. Sensor Conditioning for Ultrasonic Remote Sensing Immersion

    OpenAIRE

    Breton, Sylvie; Benbouzid, Mohamed

    2013-01-01

    International audience; Ultrasonic detection has many applications in military, medical, marine biology, and physics domains. This paper presents then an emitting signal design for several immersion applications such as liquid level measurement, wall detection for submarine robots, and fish species behavior study. The designed and realized circuits are very simple, of flexible use, and cost-effective. Sensor sealing problems are also discussed in this paper.

  20. Ultrasonics in Dentistry

    Science.gov (United States)

    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.

  1. Cracks assessment using ultrasonic technology

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Maria Pia; Tomasella, Marcelo [OLDELVAL S.A. Oleoductos del Valle, Rio Negro (Argentina). Pipeline Integrity Dept.

    2005-07-01

    The goal of Oldelval Integrity Program is to prevent ruptures and leaks, developing strategies for a better handling of the integrity of our pipelines. In order to achieve it we have studied and modeled each process that involved in the integrity pipeline. Those processes are mainly based on defects reported by an internal inspection tool and supplied with field inspection and monitoring data. Years of evaluation, study and the continuous effort overturned towards a phenomenon that worries to the industry, as it is the SCC. Since 1998 up to 2004 SCC was included in the integrity program with some preventive maintenance programs. The accomplishment of the inspection based on ultrasound tools, is the culmination of years of evaluation and investigations supported by field digs and materials susceptibility. This paper describes Oldelval's results with ultrasonic crack detection tool, and how it can be reliably to detect SCC. (author)

  2. Study on real-time ultra-sonic kick detection technique along riser during deep water drilling operations%深水钻井沿隔水管超声波气侵实时监测技术研究

    Institute of Scientific and Technical Information of China (English)

    耿亚楠; 李轶明; 朱磊; 马昭华; 朱连望; 周云健

    2016-01-01

    早期溢流监测对预防石油开发钻井过程中井喷失控恶性事故具有至关重要的作用.深水钻井作业过程中在不破坏钻井隔水管力学结构的前提下,基于非接触式超声波测量手段沿程监测隔水管内部钻井液流动特征参数,设计了适合深水钻井隔水管气侵监测系统.实验模拟分析了深水钻井隔水管气侵监测系统超声波时差法和超声波多普勒法的气侵监测效果,结果表明:超声波时差法虽然在清水中可以实现含气率测量,但是对于水基钻井液并不适合;极小含气情况下,多普勒频移量出现极大衰减,并随着含气率的增加而下降,因此超声波多普勒方法对气侵早期识别具有可行性.上述成果对于深水钻井早期溢流监测有指导意义.%Early kick detection is of great significance to prevent blowout in well drilling operations.During deep water drilling operations,early kick detection can be realized by using non-intrusive ultrasonic meas-urements to monitor the flow characteristics of the drilling fluid inside the riser without changing the riser's mechanical structure.And then the kick detection system for deep water drilling operations was designed. The phenomena of kicking inside the riser were experimentally investigated in the laboratory by ultrasonic time difference method and ultrasonic Doppler method.It is found that the time difference method is suit-able to measure the void fraction of water,but not for the water-based drilling fluid.It is also found that the frequency shift of Doppler severely attenuates when the void fraction is tiny,and it keeps decreasing as the void fraction increases.Hence the feasibility of using Doppler method to detect the early kick inside the riser is proved from this study.The above findings can be used for guiding the early kick detection during deep water drilling operations.

  3. Artificial Intelligence Assists Ultrasonic Inspection

    Science.gov (United States)

    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.

  4. Ultrasonic Processing of Materials

    Science.gov (United States)

    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.

  5. Ultrasonic colour Doppler imaging

    DEFF Research Database (Denmark)

    Evans, David H; Jensen, Jørgen Arendt; Nielsen, Michael Bachmann

    2011-01-01

    anatomy. The most common use of the technique is to image the movement of blood through the heart, arteries and veins, but it may also be used to image the motion of solid tissues such as the heart walls. Colour Doppler imaging is now provided on almost all commercial ultrasound machines, and has been......Ultrasonic colour Doppler is an imaging technique that combines anatomical information derived using ultrasonic pulse-echo techniques with velocity information derived using ultrasonic Doppler techniques to generate colour-coded maps of tissue velocity superimposed on grey-scale images of tissue...... vectors. This review briefly introduces the principles behind colour Doppler imaging and describes some clinical applications. It then describes the basic components of conventional colour Doppler systems and the methods used to derive velocity information from the ultrasound signal. Next, a number of new...

  6. Ultrasonic Stir Welding

    Science.gov (United States)

    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.

  7. Ultrasonic Detection of Cesarean Section Incision Healing Value%超声检测剖宫产切口愈合情况的价值

    Institute of Scientific and Technical Information of China (English)

    赵建婷

    2014-01-01

    目的:探讨应用超声观察剖宫产切口愈合情况的价值。方法经腹超声检测389例剖宫产术后切口愈合情况,观察其声像图特点。结果子宫切口愈合良好365例,子宫切口愈合不良24例,子宫切口憩室2例。结论超声能够无创、实时的观察子宫切口愈合情况。%Objective To investigate the application of ultrasonic on cesarean incision healing value. Methods Transabdominal ultrasound in 389 cases after cesarean section incision healing, observe the ultrasonographic features. Results 365 cases got good healing of uterus incision poor healing of uterus incision, 24 cases, 2 cases of uterine incision diverticulum. Conclusion Ultrasound can noninvasive, real-time observation of the healing of uterine incision.

  8. 基于时延的高精度泄漏点超声定向检测方法%High accuracy method of ultrasonic gas leak direction detection based on time delay estimation

    Institute of Scientific and Technical Information of China (English)

    廖平平; 蔡茂林

    2013-01-01

    In order to solve the low accuracy problem in current gas leak detection, a new ultrasonic leak detection method based on time delay estimation (TDE) was proposed. Three ultrasonic sensors arranged in an equilateral triangle and received the ultrasound generated by a gas leak and the leak direction can be determined according to time delays between the outputs of every two sensors. A TDE algorithm based on cubic spline interpolation was adopted to overcome the accuracy limit caused by sampling interval. For each kernel window length, delay estimates of 100 sets of experimental data were obtained and their mean squared errors (MSE) were calculated. Comparison between MSE of experimental data and Cramer-Rao lower bound showed that their changing tendency was accordant. Influences of MSE, the space between sensors and the distance between leak and sensor on direction accuracy were analyzed. Results show that the direction error increases with MSE, decreases with the space between sensors, and increases with distance between leak and sensor. The direction detection accuracy is improved by 7 ~10 times compared with detection method with single ultrasonic sensor.%针对当前气体泄漏点检测定向精度低的情况,提出一种基于时延的高精度超声检测方法.该方法利用3个呈等边三角形分布的超声传感器接收由泄漏点产生的超声波,根据3路信号的相对时延值确定泄漏点的方向.为克服采样间隔对时延估计精度的限制,采用基于三次样条插值的时延估计算法估计信号时延值,并对不同核窗长度下的各100组实验数据的时延值进行误差统计,得到其均方差并与其Cramér-Rao下界比较,发现二者的变化趋势具有良好的一致性.在此基础上研究了时延值均方差,超声传感器间距和泄漏点距离对定向精度的影响.结果表明:定向误差随时延值均方差增大而增大,随超声传感器间距增大而减小,随泄漏点距离增大而增大

  9. Stress Evaluation and Model Validation Using Laser Ultrasonics

    Energy Technology Data Exchange (ETDEWEB)

    Dike, Jay J.; Lu, Wei-yang; Peng, Lawrence W.; Wang, James C. F.

    1999-02-01

    Rayleigh surface waves can be used to evaluate surface stresses and through-thickness stress gradients based on acoustoelasticity. Laser based ultrasonic techniques, which generate and detect surface waves, have the advantages of good spatial resolution and remote operation. The techniques have many potential applications. This is the final report of a LDRD project that is the first to exploit the benefits of laser ultrasonics for stress and stress gradient evaluation.

  10. Waveform reconstruction for an ultrasonic fiber Bragg grating sensor demodulated by an erbium fiber laser.

    Science.gov (United States)

    Wu, Qi; Okabe, Yoji

    2015-02-01

    Fiber Bragg grating (FBG) demodulated by an erbium fiber laser (EFL) has been used for ultrasonic detection recently. However, due to the inherent relaxation oscillation (RO) of the EFL, the detected ultrasonic signals have large deformations, especially in the low-frequency range. We proposed a novel data processing method to reconstruct an actual ultrasonic waveform. The noise spectrum was smoothed first; the actual ultrasonic spectrum was then obtained by deconvolution in order to mitigate the influence of the RO of the EFL. We proved by experiment that this waveform reconstruction method has high precision, and demonstrated that the FBG sensor demodulated by the EFL will have large practical applications in nondestructive testing.

  11. 超声萃取-紫外分光法快速测定茶叶中咖啡因%The Rapid Detection of Caffeine in Tea by Ultrasonic Extraction and UV Spectrophotometry

    Institute of Scientific and Technical Information of China (English)

    高海荣; 陈秀丽; 杨玉珍; 金岳恒

    2015-01-01

    By ultrasonic extraction and UV spectrophotometry detection the caffeine contents in five different types of tea were detected. The results showed the optimum ultrasonic extraction conditions: power 150 W, temperature 60℃, time of 30 min;the contentions of caffeine in five different tea are coarse old green tea﹥Pu 'er tea﹥Jinjunmei﹥Xingyang maojian﹥Tie Guanyin. The max absorbance of caffeine was detected by ultraviolet spectrophotometry at wavelength 273 nm.The relationship of the absorbance (A) and the concentration (C) was linear from 0.00 to 25.00μg/mL (r=0.999 2), The linear equation was A=0.048 55C-0.028 54.The average recovery was 95.46%,the relative standard deviations were less than 2.0%.This method can he used for the determination of caffeine in tea because of its its simple ,rapid and accurate characteristics.%采用超声萃取-紫外分光光度法测定五种不同的茶叶中咖啡因的含量,结果表明:最佳超声提取条件:超声功率150 W,温度60℃,时间30 min;5种不同茶叶咖啡因含量顺序为:粗老绿茶﹥普洱﹥金骏眉﹥信阳毛尖﹥铁观音。紫外分光光度计法显示:水溶剂咖啡因的最大吸收波长为273 nm,线性回归方程为:A=0.04855C-0.02854,r为0.9992,浓度在0.00~25.00μg/mL,线性关系良好,平均回收率为96.42%,RSD﹤2.0%。该方法简便快速,准确,可用于茶叶中咖啡因含量测定。

  12. Ultrasonic Characterization of Aerospace Composites

    Science.gov (United States)

    Leckey, Cara; Johnston, Patrick; Haldren, Harold; Perey, Daniel

    2015-01-01

    Composite materials have seen an increased use in aerospace in recent years and it is expected that this trend will continue due to the benefits of reduced weight, increased strength, and other factors. Ongoing work at NASA involves the investigation of the large-scale use of composites for spacecraft structures (SLS components, Orion Composite Crew Module, etc). NASA is also involved in work to enable the use of composites in advanced aircraft structures through the Advanced Composites Project (ACP). In both areas (space and aeronautics) there is a need for new nondestructive evaluation and materials characterization techniques that are appropriate for characterizing composite materials. This paper will present an overview of NASA's needs for characterizing aerospace composites, including a description of planned and ongoing work under ACP for the detection of composite defects such as fiber waviness, reduced bond strength, delamination damage, and microcracking. The research approaches include investigation of angle array, guided wave, and phase sensitive ultrasonic methods. The use of ultrasonic simulation tools for optimizing and developing methods will also be discussed.

  13. Ultrasonic magnetic abrasive finishing

    Institute of Scientific and Technical Information of China (English)

    LU Ya-ping; MA Ji; ZHANG Jun-qiang; WANG Long-shan

    2006-01-01

    Put forward a new kind of polishing method, ultrasonic magnetic abrasive finishing (UMAF), and studied its mechanism of improving polishing efficiency. By analyzing all kind of forces acting on single abrasive particle in the polishing process and calculating the size of the composition of forces, get the conclusion that UMAF will enhance the efficiency of the normal magnetic abrasive finishing(MAF) due to the ultrasonic vibration increases the cutting force and depth. At last the idea of designing the UMAF system based on numerical control milling machine is put forward which is convenient to setup and will accelerate the practical application of MAF.

  14. Ultrasonic/Sonic Jackhammer

    Science.gov (United States)

    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.

  15. 基于超声相控阵的轮辋探伤实证分析%Empirical analysis of the rim flaw detection based on ultrasonic phased array

    Institute of Scientific and Technical Information of China (English)

    杨洋; 王泽勇; 李金龙; 高晓蓉

    2012-01-01

    基于相控阵超声探伤技术,采用直射声束法对轮辋轴向缺陷试块中横孔的径向深度和轴向深度进行了检测,精确定位了横孔的位置,并通过AVG曲线法对缺陷的尺寸进行了定量评定和分析.实验结果表明,缺陷较浅则检测的误差波动较小、干扰波较少;缺陷较深则可能出现轮廓回波等非缺陷波,对缺陷回波的分析有较大影响;远场区的缺陷可以通过AVG曲线进行精确评定.%In this paper, direct sound beam method was used to detect the radial and axial depth of the transverse hole in the rim based on the ultrasonic flaw detection technology. The transverse hole was precisely orientated and the defect size was quantitatively evaluated by AVG curve. As the experiment showed, if the defect was shallow, the error fluctuation and interference wave were less. If the defect was deeper, non-defect wave like profile echo would appear, which would affect the analysis of the defect echo. Defects in far-field region could be accurately assessed through the AVG curve.

  16. Comparison of piezoresistive and capacitive ultrasonic transducers

    Science.gov (United States)

    Neumann, John J.; Greve, David W.; Oppenheim, Irving J.

    2004-07-01

    MEMS ultrasonic transducers for flaw detection have heretofore been built as capacitive diaphragm-type devices. A diaphragm forms a moveable electrode, placed at a short gap from a stationary electrode, and diaphragm movement has been detected by capacitance change. Although several research teams have successfully demonstrated that technology, the detection of capacitance change is adversely affected by stray and parasitic capacitances, limiting the sensitivity of such transducers and typically requiring relatively large diaphragm areas. We describe the design and fabrication of what to our knowledge is the first CMOS-MEMS ultrasonic phased array transducer using piezoresistive strain sensing. Piezoresistors have been patterned within the diaphragms, and diaphragm movement creates bending strain which is detected by a bridge circuit, for which conductor losses will be less significant. The prospective advantage of such piezoresistive transducers is that sufficient sensitivity may be achieved with very small diaphragms. We compare transducer response under fluid-coupled ultrasonic excitation and report the experimental gauge factor for the piezoresistors. We also discuss the phased array performance of the transducer in sensing the direction of an incoming wave.

  17. Ultrasonic testing of reactive powder concrete.

    Science.gov (United States)

    Washer, Glenn; Fuchs, Paul; Graybeal, Benjamin A; Hartmann, Joseph Lawrence

    2004-02-01

    Concrete is a critical material for the construction of infrastructure facilities throughout the world. Traditional concretes consist of cement paste and aggregates ranging in size from 6 to 25 mm that form a heterogeneous material with substantial compressive strength and a very low tensile strength. Steel reinforcement is used to provide tensile strength for reinforced concrete structures and as a composite the material is useful for structural applications. A new material known as reactive powder concrete (RPC) is becoming available. It differs significantly from traditional concrete; RPC has no large aggregates, and contains small steel fibers that provide additional strength and, in some cases, can replace traditional steel reinforcement. Due to its high density and lack of aggregates, ultrasonic inspections at frequencies 10 to 20 times that of traditional concrete inspections are possible. This paper reports on the initial findings of research conducted to determine the applicability of ultrasonic testing techniques for the condition assessment of RPC. Pulse velocities for shear and longitudinal waves and ultrasonic measurement of the modulus of elasticity for RPC are reported. Ultrasonic crack detection for RPC also is investigated.

  18. Lamb Wave Multi-touch Ultrasonic Touchscreen.

    Science.gov (United States)

    Firouzi, Kamyar; Nikoozadeh, Amin; Carver, Thomas; Khuri-Yakub, Butrus

    2016-09-13

    Touchscreen sensors are widely used in many devices such as smart phones, tablets, laptops, etc., with diverse applications. We present the design, analysis, and implementation of an ultrasonic touchscreen system that utilizes interaction of transient Lamb waves with objects in contact with the screen. It attempts to improve on the existing ultrasound technologies, with the potential of addressing some of the weaknesses of the dominant technologies, such as the capacitive or resistive ones. Compared to the existing ultrasonic and acoustic modalities, among other advantages, it provides the capability of detecting several simultaneous touch points, and also a more robust performance. The localization algorithm, given the hardware design, can detect several touch points with a very limited number of measurements (one or two). This in turn can significantly reduce the manufacturing cost.

  19. Ultrasonic inspection for circumferential butt joint of austenitic stainless steel with carbon steel

    Institute of Scientific and Technical Information of China (English)

    Wan Shengyun; Xiong Lasen

    2006-01-01

    Tthe practical application of ultrasonic wave inspection in welded joint by austenitic stainless steel with carbon steel is presented. It is shown from the experimental results that the high frequency narrow-pulsed longitudinal ultrasonic wave inspection technique can detect the defects in deferent sound path and location within the tested welded joint clearly and exactly. The study in the paper may provide a new approach for further application of ultrasonic inspection in coarse-grained materials.

  20. Field-Angle-Dependent Low-Energy Excitations around a Vortex in the Superconducting Topological Insulator CuxBi2Se3

    Science.gov (United States)

    Nagai, Yuki

    2014-06-01

    We study the quasiparticle excitations around a single vortex in the superconducting topological insulator CuxBi2Se3, focusing on a superconducting state with point nodes. Inspired by the recent Knight shift measurements, we propose two ways to detect the positions of point nodes, using an explicit formula of the density of states with Kramer-Pesch approximation in the quasiclassical treatment. The zero-energy local density of states around a vortex parallel to the c-axis has a twofold shape and splits along the nodal direction with increasing energy; these behaviors can be detected by the scanning tunneling microscopy. An angular dependence of the density of states with a rotating magnetic field on the a-b plane has deep minima when the magnetic field is parallel to the directions of point nodes, which can be detected by angular-resolved heat capacity and thermal conductivity measurements. All the theoretical predictions are detectable via standard experimental techniques in magnetic fields.

  1. Measurement of ultrasonic nonlinear parameter by using electromagnetic acoustic transducer

    Science.gov (United States)

    Cai, Zhichao; Liu, Suzhen; Zhang, Chuang

    2017-02-01

    The nonlinear ultrasonic technology is generally known as an effective method for the microcrack detection. However, most of the previous experimental studies were limited by a contact nonlinearity method. Since measurement by the contact method is affected by the coupling conditions, additional nonlinear coefficient are lead into the measurement. This research presents a novel technique for nonlinear ultrasonic wave measurements that uses a non-contact electromagnetic ultrasonic transducer (EMAT). And for a better understanding and a more in-depth analysis of the macroscopic nonlinear behavior of microcrack, the developed FEM modeling approach was built to simulate microcrack induced nonlinearities manifested in electromagnetic ultrasonic waves and validated experimentally. This study has yielded a quantitative characterization strategy for microcrack using EMAT, facilitating deployment of structural health monitoring by noncontact electromagnetic nondestructive testing.

  2. The technique of detecting the laser-ultrasonic vector displacement with a confocal Fabry-Perot interferometer waves in a plate

    Institute of Scientific and Technical Information of China (English)

    PAN Yongdong; QIAN Menglu

    2003-01-01

    Generally, a confocal Fabry-Perot interferometer is only able to detect the out-of-plane component of a displacement field; while the in-plane component often has the information about the material which cannot be found in this out-of-plane component. In this paper, based on a confocal Fabry-Perot interferometer set-up for detecting the out-of-plane component of a laser generated acoustic field, a technique is developed to detect both the out-of-plane and inplane displacement components simultaneously with a novel two-channel confocal Fabry-Perot interferometer.

  3. Corresponding parameter analysis on ultra-sonic transmission defect detection%超声波透射法检测基桩完整性常见缺陷对应声参量特性分析

    Institute of Scientific and Technical Information of China (English)

    刘雨岚; 周茗如

    2016-01-01

    超声波透射法在全国桩基检测中应用比较普遍。文章主要以钻孔灌注桩为检测对象,在国家相关桩基检测技术规范的基础上,结合我省在建项目,通过大量的检测工作,在得到充分详实的数据资料后,对桩基缺陷部位进行多角度、多层次的分析研究,进行超声波法检测桩身完整性常见缺陷对应声参量特性分析。对从事桩基工程设计、施工、监理,特别是从事检测工作的人员提供准确的前鉴性资料和技术参考。%This paper mainly aim at the cast-in piles as testing object. On the basis of related national foundation pile detection specifications, along with a large amount of accurate data through the work in progress of Gansu Province,this paper analyze defects of foundation pile from a multi-perspective,multi-leveled angle.To detect the completeness of foundation pile,ultrasonic transmission method is used to analyze corresponding acoustic parameter.This paper provides those who work on Engineering design, construction,supervision,and detection in particular,of the foundation pile with accurate prospective materials and technical references.

  4. 超声相控阵PE检测图像缺陷定位算法研究%Study on flaw orientation algorithm of ultrasonic phased array PE detection image

    Institute of Scientific and Technical Information of China (English)

    高扬清; 王黎; 李金龙; 杨宇

    2012-01-01

    针对车轮无损检测图像中对缺陷评判的不足,提出一种能够自动定位检测图像中缺陷的算法.该算法是在相控阵技术的车轮超声探伤基础上,运用数字图像处理技术,对检测图像进行时域的处理.对算法的流程进行了详细介绍,并对每一步给出说明和处理结果.通过对比得知,这一算法对图像中缺陷的检测精度高于90%,大为提高识别效率,并减少人为因素引起的误判.%In order to overcome the shortcomings of flaw evaluations to nondestructive detecting images of wheels, an algorithm was developed to orientate the positions of flaws in images automatically. This algorithm is based on ultrasonic test of wheels with phased array technology, using digital image processing technology in the time - domain. This paper introduces the processes of the algorithm, and makes an instruction to each step and shows the result, comparison with the standard images shows that the accuracy of the positioning algorithm is higher than 90%. The algorithm greatly improves the recognition efficiency and reduces incorrect judgments caused by human factors.

  5. 广州新客站大型铸钢件超声波探伤方法浅析%Guangzhou New Railway Station Ultrasonic Flaw Detecting Method for Analysis of Large Steel Castings

    Institute of Scientific and Technical Information of China (English)

    陈会龙

    2012-01-01

    铸钢件铸造表面粗糙,导致声耦合不良,造成散乱反射,形成干扰杂波,使超声波探伤变得困难,本文探讨用工件底波法调整探伤灵敏度,比较在不同加工面测得的回波声压(实测耦合补偿值),在实际检测工件时进行耦合补偿,便利在现场探伤条件下,针对工件厚度及表面状况的变化作出及时的修整,保证探伤结果的准确、可靠。%When the surface of steel castings is roughness, it will lead to poor acoustic coupling, causing scattered reflection, interference noise and a worse ultrasonic testing. This article compares the different echo pressure between different processing surfaces which are adjusted by the sensitivity of flaw detection under the bottom wave method. In an actual measurement, using a coupling compensation can make the testing become more convenience. According to the thickness of the piece and the changed surface condition, the operator can fix timely to ensure the testing results are accurate and reliable.

  6. Introduction to ultrasonic motors

    Energy Technology Data Exchange (ETDEWEB)

    Sashida, Toshiiku; Kenjo, Takashi.

    1993-01-01

    The ultrasonic motor, invented in 1980, utilizes the piezoelectric effect in the ultrasonic frequency range to provide the motive force. (In conventional electric motors the motive force is electromagnetic.) The result is a motor with unusually good low-speed high-torque and power-to-weight characteristics. It has already found applications in camera autofocus mechanisms, medical equipment subject to high magnetic fields, and motorized car accessories. Its applications will increase as designers become more familiar with its unique characteristics. This book is the result of a collaboration between the inventor and an expert in conventional electric motors: the result is an introduction to the general theory presented in a way that links it to conventional motor theory. It will be invaluable both to motor designers and to those who design with and use electric motors as an introduction to this important new invention.

  7. Inspection system for welded tubular joint based on ultrasonic phased array

    Institute of Scientific and Technical Information of China (English)

    Hao Guangping; Deng Zongquan; Shan Baohua; Yu Weizhen; Li Lifang

    2010-01-01

    A manual inspection of large-diameter tubular joints is difficult. As a result a scanner with three degrees of freedom (DOFs) was developed based on the scanning principle of ultrasonic phased array. The weld tracing is realized by a 2D0F motion of scanner. The pose of ultrasonic probe is controlled by the third one. The control strategy is put forward based on a programmable multi-axis controller. Four kinds of scanning modes can be implemented simultaneously employing this ultrasonic inspection system. Experiments on reference blocks of tubular joints reveal that the automatic ultrasonic phased array inspection system has the same inspection accuracy as a manual ultrasonic inspection. This system is superior to the manual ultrasonic system in terms of reliability and repeatability. The artificial defects of weld at tubular joint can be detected accurately with the presented inspection system.

  8. Pulsed ultrasonic stir welding system

    Science.gov (United States)

    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.

  9. An energy-based sparse representation of ultrasonic guided-waves for online damage detection of pipelines under varying environmental and operational conditions

    Science.gov (United States)

    Eybpoosh, Matineh; Berges, Mario; Noh, Hae Young

    2017-01-01

    This work addresses the main challenges in real-world application of guided-waves for damage detection of pipelines, namely their complex nature and sensitivity to environmental and operational conditions (EOCs). Different propagation characteristics of the wave modes, their distinctive sensitivities to different types and ranges of EOCs, and to different damage scenarios, make the interpretation of diffuse-field guided-wave signals a challenging task. This paper proposes an unsupervised feature-extraction method for online damage detection of pipelines under varying EOCs. The objective is to simplify diffuse-field guided-wave signals to a sparse subset of the arrivals that contains the majority of the energy carried by the signal. We show that such a subset is less affected by EOCs compared to the complete time-traces of the signals. Moreover, it is shown that the effects of damage on the energy of this subset suppress those of EOCs. A set of signals from the undamaged state of a pipe are used as reference records. The reference dataset is used to extract the aforementioned sparse representation. During the monitoring stage, the sparse subset, representing the undamaged pipe, will not accurately reconstruct the energy of a signal from a damaged pipe. In other words, such a sparse representation of guided-waves is sensitive to occurrence of damage. Therefore, the energy estimation errors are used as damage-sensitive features for damage detection purposes. A diverse set of experimental analyses are conducted to verify the hypotheses of the proposed feature-extraction approach, and to validate the detection performance of the damage-sensitive features. The empirical validation of the proposed method includes (1) detecting a structural abnormality in an aluminum pipe, under varying temperature at different ranges, (2) detecting multiple small damages of different types, at different locations, in a steel pipe, under varying temperature, (3) detecting a structural

  10. 基于复频域B样条小波与高斯函数的超声信号波至检测%Arrival Time of Ultrasonic Signal Detection Based on Complex Frequency B-spline Wavelet and Gaussian Function

    Institute of Scientific and Technical Information of China (English)

    刘运峰; 宋寿鹏; 马晓鲲; 王成

    2012-01-01

    在超声检测中,液位、压力、应力等参数的测量实际上转化为超声信号度越时间的测量,如何有效地提取超声回波信号的波至时刻成为能否准确测量的关键.在分析了连续复小波变换的模极大值包络提取和小波的奇异点检测理论的基础上,提出了一种新的超声信号波至检测函数,并选用复频域B样条和高斯函数为小波基,在MATLAB上对仿真信号及原始超声信号分析处理.实验结果表明,此检测函数在较低的信噪比条件下也可有效地提取到超声回波信号的波至时刻.%In ultrasonic testing,the measurement of the liquid level,the pressure, the stress and so on is in fact the measurement of the time-of-flight of the ultrasonic signal. Then how to implement the extraction of ultrasonic signal arrival time precisely becomes so important. Based on envelop extraction of continuous complex wavelet transform and the singularity point detection theory , a new arrival time detection function is shown. Emulation and the real acquired ultrasonic data were processed with MATLAB u-sing complex frequency B-spline and Gaussian function as wavelet. It is proved that the function has good detection effect even under low SNR condition.

  11. HIGHER FREQUENCY ULTRASONIC LIGHT MODULATORS.

    Science.gov (United States)

    LIGHT), (* MODULATORS , (*ULTRASONIC RADIATION, MODULATORS ), OPTICAL COMMUNICATIONS, BANDWIDTH, TRANSDUCERS, HIGH FREQUENCY, VERY HIGH FREQUENCY, ATTENUATION, DATA PROCESSING, OPTICAL EQUIPMENT, ANALOG COMPUTERS, THEORY.

  12. Ultrasonic investigations in intermetallics

    Indian Academy of Sciences (India)

    Devraj Singh; D K Pandey

    2009-02-01

    Ultrasonic attenuation for the longitudinal and shear waves due to phonon–phonon interaction and thermoelastic mechanism have been evaluated in B2 structured in-termetallic compounds AgMg, CuZr, AuMg, AuTi, AuMn, AuZn and AuCd along $\\langle 1 0 0 \\rangle, \\langle 1 1 1 \\rangle and \\langle 1 1 0 \\rangle crystallographic directions at room temperature. For the same evaluations, second- and third-order elastic constants, ultrasonic velocities, Grüneisen parameters, non-linearity parameter, Debye temperature and thermal relaxation time are also computed. Although the molecular weight of these materials increases from AgMg to AuCd, the obtained results are affected with the deviation number. Attenuation of ultrasonic waves due to phonon–phonon interaction is predominant over thermoelastic loss. Results are compared with available theoretical and experimental results. The results with other well-known physical properties are useful for industrial purposes.

  13. Ultrasonic Cutting of Foods

    Science.gov (United States)

    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.

  14. Ultrasonic Flaw Imaging via Multipath Exploitation

    Directory of Open Access Journals (Sweden)

    Yimin D. Zhang

    2012-01-01

    Full Text Available We consider ultrasonic imaging for the visualization of flaws in a material. Ultrasonic imaging is a powerful nondestructive testing (NDT tool which assesses material conditions via the detection, localization, and classification of flaws inside a structure. We utilize reflections of ultrasonic signals which occur when encountering different media and interior boundaries. These reflections can be cast as direct paths to the target corresponding to the virtual sensors appearing on the top and bottom side of the target. Some of these virtual sensors constitute a virtual aperture, whereas in others, the aperture changes with the transmitter position. Exploitations of multipath extended virtual array apertures provide enhanced imaging capability beyond the limitation of traditional multisensor approaches. The waveforms observed at the physical as well as the virtual sensors yield additional measurements corresponding to different aspect angles, thus allowing proper multiview imaging of flaws. We derive the wideband point spread functions for dominant multipaths and show that fusion of physical and virtual sensor data improves the flaw perimeter detection and localization performance. The effectiveness of the proposed multipath exploitation approach is demonstrated using real data.

  15. Nondestructive Ultrasonic Inspection of Friction Stir Welds

    Science.gov (United States)

    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 μm. 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. Dempster-Shafer Fusion for Personnel Detection: Application of Dempster-Shafer Theory with Ultrasonic Micro-Doppler and PIR Sensors

    Science.gov (United States)

    2012-07-01

    Gonzalez , Rafael , Richard Woods, Digital Image Processing . Upper Saddle River, NJ: Prentice Hall, 2002 \\ 2214 ...dimensional image with the axes image is then post processed to ach class nodes ction ltrasonic and profiling data sor r sensor used here...detection. The focus is on using low cost non- imaging sensors for applications such as border crossings where issues of rapid deployment and

  17. Ultrasonic characterization of single drops of liquids

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, Dipen N. (Los Alamos, NM)

    1998-01-01

    Ultrasonic characterization of single drops of liquids. The present invention includes the use of two closely spaced transducers, or one transducer and a closely spaced reflector plate, to form an interferometer suitable for ultrasonic characterization of droplet-size and smaller samples without the need for a container. The droplet is held between the interferometer elements, whose distance apart may be adjusted, by surface tension. The surfaces of the interferometer elements may be readily cleansed by a stream of solvent followed by purified air when it is desired to change samples. A single drop of liquid is sufficient for high-quality measurement. Examples of samples which may be investigated using the apparatus and method of the present invention include biological specimens (tear drops; blood and other body fluid samples; samples from tumors, tissues, and organs; secretions from tissues and organs; snake and bee venom, etc.) for diagnostic evaluation, samples in forensic investigations, and detection of drugs in small quantities.

  18. The ultrasonic detection system for the drilling process of deep holes%深孔钻削过程中的超声监测系统

    Institute of Scientific and Technical Information of China (English)

    马清艳; 王彪

    2012-01-01

    由于深孔在封闭或半封闭的状况下进行,钻头的走偏情况无法直接观察,以致于无法保证产品的加工质量,采用工控机、PLC和超声检测技术相结合,设计深孔在线超声监测系统,根据壁厚可以实时检测刀具的走偏情况,为深孔加工提供重要理论依据.%Due to the deep hole is processing in the closed or semi-closed state,the slant state of drill will not be directly monitored and the product quality will not be assured,based on IPC and PLC,ul-trasonic technique is adopted,the real-time detection system for the drilling process of deep holes is estab-lished,wall thickness of work piece will be detected, which can real-time detect the slant state of drill and lay a good foundation for the processing quality of deep hole.

  19. A Study on TOFD Inspection Using Phased Array Ultrasonic Technique

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Byung Sik; Kim, Yong Sik; Lee, Hee Jong [Korea Electric Power Research Institute, Daejeon (Korea, Republic of); Lee, Young Ho [Chungnam National University, Daejeon (Korea, Republic of)

    2005-08-15

    The techniques in order to measure the depth of defect in weldment and structure accurately have been developed. Many researches have made efforts to develop the methods for the accurate depth sizing of defect. TOFD is known as the most accurate method of various methods for measuring depth sizing. However, there is a possibility to miss defects because of the limitation of beam coverage for the ultrasound incident angle. In this study, the results for detectability and depth sizing using phased array ultrasonic technique for thick body were compared with those of conventional TOFD technique. It was experimentally confirmed that the phased array ultrasonic TOFD technique gives good detectability and accurate depth measurement for the various types of defects. The phased array ultrasonic TOFD technique developed in this study will contribute to increase the inspection reliability in thick component such as the pressure vessel of power generation industry

  20. Ultrasonic actuators for nanometre positioning

    Science.gov (United States)

    Snitka

    2000-03-01

    This paper deals with ultrasonic motors based on bimodal plate vibrations and their application to nanometre resolution stepper positioning systems. The concept of a linear ultrasonic motor drive capable of nanometric steps, long-range travel and reversible controlled motion is presented. The motor concept developed is based on the superposition of a longitudinal and bending vibrations of a rectangular resonator. The ultrasonic motor model based on system identification via discrete observations and prediction has been developed for control applications. The control algorithm for ultrasonic motors has been developed and theoretical investigations have been made. The open loop positioning system with designed stepper ultrasonic drive produced 10 nm resolution and 5% displacement repeatability. The system with computer controlled position feedback has shown 0.3 micron positioning accuracy over the 100 mm positioning range.

  1. Ultrasonic dyeing of cellulose nanofibers.

    Science.gov (United States)

    Khatri, Muzamil; Ahmed, Farooq; Jatoi, Abdul Wahab; Mahar, Rasool Bux; Khatri, Zeeshan; Kim, Ick Soo

    2016-07-01

    Textile dyeing assisted by ultrasonic energy has attained a greater interest in recent years. We report ultrasonic dyeing of nanofibers for the very first time. We chose cellulose nanofibers and dyed with two reactive dyes, CI reactive black 5 and CI reactive red 195. The cellulose nanofibers were prepared by electrospinning of cellulose acetate (CA) followed by deacetylation. The FTIR results confirmed complete conversion of CA into cellulose nanofibers. Dyeing parameters optimized were dyeing temperature, dyeing time and dye concentrations for each class of the dye used. Results revealed that the ultrasonic dyeing produced higher color yield (K/S values) than the conventional dyeing. The color fastness test results depicted good dye fixation. SEM analysis evidenced that ultrasonic energy during dyeing do not affect surface morphology of nanofibers. The results conclude successful dyeing of cellulose nanofibers using ultrasonic energy with better color yield and color fastness results than conventional dyeing.

  2. Fiber-optic ultrasonic hydrophone using short Fabry-Perot cavity with multilayer reflectors deposited on small stub.

    Science.gov (United States)

    Kim, Kyung-Su; Mizuno, Yosuke; Nakamura, Kentaro

    2014-04-01

    A fiber-optic probe with dielectric multilayer films deposited on a small stub is studied for mega-hertz ultrasonic-wave detection in water. The small stub with a short Fabry-Perot cavity and distributed reflectors is attached on the fiber end. The structure is mechanically strong and withstands intense ultrasonic pressure. Ultrasonic waves at 1.56MHz are successfully detected in water with a good signal-to-noise ratio. The working principle and the characteristics are studied by comparing the ultrasonic sensitivity with that of a conventional piezoelectric hydrophone. The distance response and directional response are also investigated.

  3. Piezoelectric paint sensor for ultrasonic NDE

    Science.gov (United States)

    Li, X.; Zhang, Y.

    2007-04-01

    This paper deals with a distributed acoustic emission sensing method, which is especially suitable for piezoelectric paint. Piezoelectric paint is a composite piezoelectric material that is comprised of tiny piezoelectric particles randomly dispersed within a polymer matrix phase. An overview of the distributed acoustic emission sensing method for defect monitoring is given in this paper. The use of piezoelectric materials for ultrasonic signal measurements is next discussed along with a series of ultrasonic tests performed to verify the ultrasonic sensing capability of piezoelectric paint. To examine the mechanism of the distributed acoustic emission sensing method for crack initiation detection, the results of a finite element simulation based study is presented in this paper. The finite element model used in the parametric study is calibrated with experimental data. The effect of sensor numbers included in the array has been studied using both simulation and experimental data. Based on the preliminary results of this study, piezoelectric paint sensor appears to hold a potential for use in on-line monitoring of cracks such as those caused by fatigue in metal structures although more work is still needed before successful practical application can be made.

  4. Ultrasonic imaging of material flaws exploiting multipath information

    Science.gov (United States)

    Shen, Xizhong; Zhang, Yimin D.; Demirli, Ramazan; Amin, Moeness G.

    2011-05-01

    In this paper, we consider ultrasonic imaging for the visualization of flaws in a material. Ultrasonic imaging is a powerful nondestructive testing (NDT) tool which assesses material conditions via the detection, localization, and classification of flaws inside a structure. Multipath exploitations provide extended virtual array apertures and, in turn, enhance imaging capability beyond the limitation of traditional multisensor approaches. We utilize reflections of ultrasonic signals which occur when encountering different media and interior discontinuities. The waveforms observed at the physical as well as virtual sensors yield additional measurements corresponding to different aspect angles. Exploitation of multipath information addresses unique issues observed in ultrasonic imaging. (1) Utilization of physical and virtual sensors significantly extends the array aperture for image enhancement. (2) Multipath signals extend the angle of view of the narrow beamwidth of the ultrasound transducers, allowing improved visibility and array design flexibility. (3) Ultrasonic signals experience difficulty in penetrating a flaw, thus the aspect angle of the observation is limited unless access to other sides is available. The significant extension of the aperture makes it possible to yield flaw observation from multiple aspect angles. We show that data fusion of physical and virtual sensor data significantly improves the detection and localization performance. The effectiveness of the proposed multipath exploitation approach is demonstrated through experimental studies.

  5. Ultrasonic Evaluation of Two Dissimilar Metal Weld Overlay Specimens

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, Susan L.; Cinson, Anthony D.; Prowant, Matthew S.; Moran, Traci L.; Anderson, Michael T.

    2012-06-30

    Two dissimilar metal weld (DMW) pipe-to-nozzle specimens were implanted with thermal fatigue cracks in the 13% to 90% through-wall depth range. The specimens were ultrasonically evaluated with phased-array probes having center frequencies of 0.8, 1.0, 1.5, and 2.0 megahertz (MHz). An Alloy 82/182 weld overlay (WOL) was applied and the specimens were ultrasonically re-evaluated for flaw detection and characterization. The Post-WOL flaw depths were approximately 10% to 56% through-wall. This study has shown the effectiveness of ultrasonic examinations of Alloy 82/182 overlaid DMW specimens. Phased-array probes with center frequency in the 0.8- to 1.0-MHz range provide a strong coherent signal but the greater ultrasonic wavelength and larger beam spot size prevent the reliable detection of small flaws. These small flaws had nominal through-wall depths of less than 15% and length in the 50-60 mm (2-2.4 in.) range. Flaws in the 19% and greater through-wall depth range were readily detected with all four probes. At the higher frequencies, the reflected signals are less coherent but still provide adequate signal for flaw detection and characterization. A single inspection at 2.0 MHz could provide adequate detection and sizing information but a supplemental inspection at 1.0 or 1.5 MHz is recommended.

  6. Azimuthal-angle dependence of charged-pion-interferometry measurements with respect to 2$^{\\rm nd}$- and $3^{\\rm rd}$-order event planes in Au$+$Au collisions at $\\sqrt{s_{_{NN}}}=200$ GeV

    CERN Document Server

    Adare, A; Aidala, C; Ajitanand, N N; Akiba, Y; Al-Bataineh, H; Alexander, J; Aoki, K; Aramaki, Y; Atomssa, E T; Averbeck, R; Awes, T C; Azmoun, B; Babintsev, V; Bai, M; Baksay, G; Baksay, L; Barish, K N; Bassalleck, B; Basye, A T; Bathe, S; Baublis, V; Baumann, C; Bazilevsky, A; Belikov, S; Belmont, R; Bennett, R; Berdnikov, A; Berdnikov, Y; Bickley, A A; Bok, J S; Boyle, K; Brooks, M L; Buesching, H; Bumazhnov, V; Bunce, G; Butsyk, S; Camacho, C M; Campbell, S; Chen, C -H; Chi, C Y; Chiu, M; Choi, I J; Choudhury, R K; Christiansen, P; Chujo, T; Chung, P; Chvala, O; Cianciolo, V; Citron, Z; Cole, B A; Connors, M; Constantin, P; Csanád, M; Csörgő, T; Dahms, T; Dairaku, S; Danchev, I; Das, K; Datta, A; David, G; Denisov, A; Deshpande, A; Desmond, E J; Dietzsch, O; Dion, A; Donadelli, M; Drapier, O; Drees, A; Drees, K A; Durham, J M; Durum, A; Dutta, D; Edwards, S; Efremenko, Y V; Ellinghaus, F; Engelmore, T; Enokizono, A; En'yo, H; Esumi, S; Fadem, B; Fields, D E; Finger, M; Jr., \\,; Fleuret, F; Fokin, S L; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fujiwara, K; Fukao, Y; Fusayasu, T; Garishvili, I; Glenn, A; Gong, H; Gonin, M; Goto, Y; de Cassagnac, R Granier; Grau, N; Greene, S V; Perdekamp, M Grosse; Gunji, T; Gustafsson, H -Å; Haggerty, J S; Hahn, K I; Hamagaki, H; Hamblen, J; Han, R; Hanks, J; Hartouni, E P; Haslum, E; Hayano, R; He, X; Heffner, M; Hemmick, T K; Hester, T; Hill, J C; Hohlmann, M; Holzmann, W; Homma, K; Hong, B; Horaguchi, T; Hornback, D; Huang, S; Ichihara, T; Ichimiya, R; Ide, J; Ikeda, Y; Imai, K; Inaba, M; Isenhower, D; Ishihara, M; Isobe, T; Issah, M; Isupov, A; Ivanischev, D; Jacak, B V; Jia, J; Jin, J; Johnson, B M; Joo, K S; Jouan, D; Jumper, D S; Kajihara, F; Kametani, S; Kamihara, N; Kamin, J; Kang, J H; Kapustinsky, J; Karatsu, K; Kawall, D; Kawashima, M; Kazantsev, A V; Kempel, T; Khanzadeev, A; Kijima, K M; Kim, B I; Kim, D H; Kim, D J; Kim, E; Kim, E -J; Kim, S H; Kim, Y -J; Kinney, E; Kiriluk, K; Kiss, Á; Kistenev, E; Kochenda, L; Komkov, B; Konno, M; Koster, J; Kotchetkov, D; Kozlov, A; Král, A; Kravitz, A; Kunde, G J; Kurita, K; Kurosawa, M; Kwon, Y; Kyle, G S; Lacey, R; Lai, Y S; Lajoie, J G; Lebedev, A; Lee, D M; Lee, J; Lee, K; Lee, K B; Lee, K S; Leitch, M J; Leite, M A L; Leitner, E; Lenzi, B; Li, X; Liebing, P; Levy, L A Linden; Liška, T; Litvinenko, A; Liu, H; Liu, M X; Love, B; Luechtenborg, R; Lynch, D; Maguire, C F; Makdisi, Y I; Malakhov, A; Malik, M D; Manko, V I; Mannel, E; Mao, Y; Masui, H; Matathias, F; McCumber, M; McGaughey, P L; Means, N; Meredith, B; Miake, Y; Mignerey, A C; Mikeš, P; Miki, K; Milov, A; Mishra, M; Mitchell, J T; Mohanty, A K; Morino, Y; Morreale, A; Morrison, D P; Moukhanova, T V; Murata, J; Nagamiya, S; Nagle, J L; Naglis, M; Nagy, M I; Nakagawa, I; Nakamiya, Y; Nakamura, T; Nakano, K; Newby, J; Nguyen, M; Niida, T; Nouicer, R; Nyanin, A S; O'Brien, E; Oda, S X; Ogilvie, C A; Oka, M; Okada, K; Onuki, Y; Oskarsson, A; Ouchida, M; Ozawa, K; Pak, R; Pantuev, V; Papavassiliou, V; Park, I H; Park, J; Park, S K; Park, W J; Pate, S F; Pei, H; Peng, J -C; Pereira, H; Peresedov, V; Peressounko, D Yu; Pinkenburg, C; Pisani, R P; Proissl, M; Purschke, M L; Purwar, A K; Qu, H; Rak, J; Rakotozafindrabe, A; Ravinovich, I; Read, K F; Reygers, K; Riabov, V; Riabov, Y; Richardson, E; Roach, D; Roche, G; Rolnick, S D; Rosati, M; Rosen, C A; Rosendahl, S S E; Rosnet, P; Rukoyatkin, P; Ružička, P; Sahlmueller, B; Saito, N; Sakaguchi, T; Sakashita, K; Samsonov, V; Sano, S; Sato, T; Sawada, S; Sedgwick, K; Seele, J; Seidl, R; Semenov, A Yu; Seto, R; Sharma, D; Shein, I; Shibata, T -A; Shigaki, K; Shimomura, M; Shoji, K; Shukla, P; Sickles, A; Silva, C L; Silvermyr, D; Silvestre, C; Sim, K S; Singh, B K; Singh, C P; Singh, V; Slunečka, M; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Sparks, N A; Stankus, P W; Stenlund, E; Stoll, S P; Sugitate, T; Sukhanov, A; Sziklai, J; Takagui, E M; Taketani, A; Tanabe, R; Tanaka, Y; Tanida, K; Tannenbaum, M J; Tarafdar, S; Taranenko, A; Tarján, P; Themann, H; Thomas, T L; Todoroki, T; Togawa, M; Toia, A; Tomášek, L; Torii, H; Towell, R S; Tserruya, I; Tsuchimoto, Y; Vale, C; Valle, H; van Hecke, H W; Vazquez-Zambrano, E; Veicht, A; Velkovska, J; Vértesi, R; Vinogradov, A A; Virius, M; Vrba, V; Vznuzdaev, E; Wang, X R; Watanabe, D; Watanabe, K; Watanabe, Y; Wei, F; Wei, R; Wessels, J; White, S N; Winter, D; Wood, J P; Woody, C L; Wright, R M; Wysocki, M; Xie, W; Yamaguchi, Y L; Yamaura, K; Yang, R; Yanovich, A; Ying, J; Yokkaichi, S; You, Z; Young, G R; Younus, I; Yushmanov, I E; Zajc, W A; Zhang, C; Zhou, S; Zolin, L

    2014-01-01

    Charged-pion-interferometry measurements were made with respect to the 2$^{\\rm nd}$- and 3$^{\\rm rd}$-order event plane for Au$+$Au collisions at $\\sqrt{s_{_{NN}}}=200$ GeV. A strong azimuthal-angle dependence of the extracted Gaussian-source radii was observed with respect to both the 2$^{\\rm nd}$- and 3$^{\\rm rd}$-order event planes. The results for the 2$^{\\rm nd}$-order dependence indicate that the initial eccentricity is reduced during the medium evolution, but not reversed in the final state, which is consistent with previous results. In contrast, the results for the 3$^{\\rm rd}$-order dependence indicate that the initial triangular shape is significantly reduced and potentially reversed by the end of the medium evolution, and that the 3$^{\\rm rd}$-order oscillations are largely dominated by the dynamical effects from triangular flow.

  7. Stereoscopic study of the angle-dependent magnetoresistance oscillations across the charge-density-wave transition of the organic conductor α-(BEDT-TTF)2KHg(SCN)4

    Science.gov (United States)

    Kang, W.; Osada, T.; Konoike, T.; Uchida, K.

    2013-11-01

    The stereoscopic angle-dependent magnetoresistance oscillations (AMRO) in an organic conductor α-(BEDT-TTF)2KHg(SCN)4 were measured across the temperature-pressure boundary that separates the charge-density-wave state from the metallic state. The gnomonic projections of the data clearly resolved the contributions from different parts of the Fermi surfaces. The temperature and pressure dependencies of the AMRO results revealed the progressive formation of a quasi-one-dimensional orbit in the charge-density-wave state. The AMRO measurements at ambient pressures and at low temperatures revealed the presence of two sets of quasi-one-dimensional Fermi surfaces. Additional evidence for multiple quasi-one-dimensional orbits was obtained from the data collected in conjunction with the in-plane field rotations.

  8. Azimuthal-angle dependence of charged-pion-interferometry measurements with respect to second- and third-order event planes in Au+Au collisions at √[S(NN)]=200  GeV.

    Science.gov (United States)

    Adare, A; Afanasiev, S; Aidala, C; Ajitanand, N N; Akiba, Y; Al-Bataineh, H; Alexander, J; Aoki, K; Aramaki, Y; Atomssa, E T; Averbeck, R; Awes, T C; Azmoun, B; Babintsev, V; Bai, M; Baksay, G; Baksay, L; Barish, K N; Bassalleck, B; Basye, A T; Bathe, S; Baublis, V; Baumann, C; Bazilevsky, A; Belikov, S; Belmont, R; Bennett, R; Berdnikov, A; Berdnikov, Y; Bickley, A A; Bok, J S; Boyle, K; Brooks, M L; Buesching, H; Bumazhnov, V; Bunce, G; Butsyk, S; Camacho, C M; Campbell, S; Chen, C-H; Chi, C Y; Chiu, M; Choi, I J; Choudhury, R K; Christiansen, P; Chujo, T; Chung, P; Chvala, O; Cianciolo, V; Citron, Z; Cole, B A; Connors, M; Constantin, P; Csanád, M; Csörgő, T; Dahms, T; Dairaku, S; Danchev, I; Das, K; Datta, A; David, G; Denisov, A; Deshpande, A; Desmond, E J; Dietzsch, O; Dion, A; Donadelli, M; Drapier, O; Drees, A; Drees, K A; Durham, J M; Durum, A; Dutta, D; Edwards, S; Efremenko, Y V; Ellinghaus, F; Engelmore, T; Enokizono, A; En'yo, H; Esumi, S; Fadem, B; Fields, D E; Finger, M; Finger, M; Fleuret, F; Fokin, S L; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fujiwara, K; Fukao, Y; Fusayasu, T; Garishvili, I; Glenn, A; Gong, H; Gonin, M; Goto, Y; Granier de Cassagnac, R; Grau, N; Greene, S V; Grosse Perdekamp, M; Gunji, T; Gustafsson, H-Å; Haggerty, J S; Hahn, K I; Hamagaki, H; Hamblen, J; Han, R; Hanks, J; Hartouni, E P; Haslum, E; Hayano, R; He, X; Heffner, M; Hemmick, T K; Hester, T; Hill, J C; Hohlmann, M; Holzmann, W; Homma, K; Hong, B; Horaguchi, T; Hornback, D; Huang, S; Ichihara, T; Ichimiya, R; Ide, J; Ikeda, Y; Imai, K; Inaba, M; Isenhower, D; Ishihara, M; Isobe, T; Issah, M; Isupov, A; Ivanischev, D; Jacak, B V; Jia, J; Jin, J; Johnson, B M; Joo, K S; Jouan, D; Jumper, D S; Kajihara, F; Kametani, S; Kamihara, N; Kamin, J; Kang, J H; Kapustinsky, J; Karatsu, K; Kawall, D; Kawashima, M; Kazantsev, A V; Kempel, T; Khanzadeev, A; Kijima, K M; Kim, B I; Kim, D H; Kim, D J; Kim, E; Kim, E-J; Kim, S H; Kim, Y-J; Kinney, E; Kiriluk, K; Kiss, A; Kistenev, E; Kochenda, L; Komkov, B; Konno, M; Koster, J; Kotchetkov, D; Kozlov, A; Král, A; Kravitz, A; Kunde, G J; Kurita, K; Kurosawa, M; Kwon, Y; Kyle, G S; Lacey, R; Lai, Y S; Lajoie, J G; Lebedev, A; Lee, D M; Lee, J; Lee, K; Lee, K B; Lee, K S; Leitch, M J; Leite, M A L; Leitner, E; Lenzi, B; Li, X; Liebing, P; Linden Levy, L A; Liška, T; Litvinenko, A; Liu, H; Liu, M X; Love, B; Luechtenborg, R; Lynch, D; Maguire, C F; Makdisi, Y I; Malakhov, A; Malik, M D; Manko, V I; Mannel, E; Mao, Y; Masui, H; Matathias, F; McCumber, M; McGaughey, P L; Means, N; Meredith, B; Miake, Y; Mignerey, A C; Mikeš, P; Miki, K; Milov, A; Mishra, M; Mitchell, J T; Mohanty, A K; Morino, Y; Morreale, A; Morrison, D P; Moukhanova, T V; Murata, J; Nagamiya, S; Nagle, J L; Naglis, M; Nagy, M I; Nakagawa, I; Nakamiya, Y; Nakamura, T; Nakano, K; Newby, J; Nguyen, M; Niida, T; Nouicer, R; Nyanin, A S; O'Brien, E; Oda, S X; Ogilvie, C A; Oka, M; Okada, K; Onuki, Y; Oskarsson, A; Ouchida, M; Ozawa, K; Pak, R; Pantuev, V; Papavassiliou, V; Park, I H; Park, J; Park, S K; Park, W J; Pate, S F; Pei, H; Peng, J-C; Pereira, H; Peresedov, V; Peressounko, D Yu; Pinkenburg, C; Pisani, R P; Proissl, M; Purschke, M L; Purwar, A K; Qu, H; Rak, J; Rakotozafindrabe, A; Ravinovich, I; Read, K F; Reygers, K; Riabov, V; Riabov, Y; Richardson, E; Roach, D; Roche, G; Rolnick, S D; Rosati, M; Rosen, C A; Rosendahl, S S E; Rosnet, P; Rukoyatkin, P; Ružička, P; Sahlmueller, B; Saito, N; Sakaguchi, T; Sakashita, K; Samsonov, V; Sano, S; Sato, T; Sawada, S; Sedgwick, K; Seele, J; Seidl, R; Semenov, A Yu; Seto, R; Sharma, D; Shein, I; Shibata, T-A; Shigaki, K; Shimomura, M; Shoji, K; Shukla, P; Sickles, A; Silva, C L; Silvermyr, D; Silvestre, C; Sim, K S; Singh, B K; Singh, C P; Singh, V; Slunečka, M; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Sparks, N A; Stankus, P W; Stenlund, E; Stoll, S P; Sugitate, T; Sukhanov, A; Sziklai, J; Takagui, E M; Taketani, A; Tanabe, R; Tanaka, Y; Tanida, K; Tannenbaum, M J; Tarafdar, S; Taranenko, A; Tarján, P; Themann, H; Thomas, T L; Todoroki, T; Togawa, M; Toia, A; Tomášek, L; Torii, H; Towell, R S; Tserruya, I; Tsuchimoto, Y; Vale, C; Valle, H; van Hecke, H W; Vazquez-Zambrano, E; Veicht, A; Velkovska, J; Vértesi, R; Vinogradov, A A; Virius, M; Vrba, V; Vznuzdaev, E; Wang, X R; Watanabe, D; Watanabe, K; Watanabe, Y; Wei, F; Wei, R; Wessels, J; White, S N; Winter, D; Wood, J P; Woody, C L; Wright, R M; Wysocki, M; Xie, W; Yamaguchi, Y L; Yamaura, K; Yang, R; Yanovich, A; Ying, J; Yokkaichi, S; You, Z; Young, G R; Younus, I; Yushmanov, I E; Zajc, W A; Zhang, C; Zhou, S; Zolin, L

    2014-06-01

    Charged-pion-interferometry measurements were made with respect to the second- and third-order event plane for Au+Au collisions at sqrt[s_{NN}]=200  GeV. A strong azimuthal-angle dependence of the extracted Gaussian-source radii was observed with respect to both the second- and third-order event planes. The results for the second-order dependence indicate that the initial eccentricity is reduced during the medium evolution, which is consistent with previous results. In contrast, the results for the third-order dependence indicate that the initial triangular shape is significantly reduced and potentially reversed by the end of the medium evolution, and that the third-order oscillations are largely dominated by the dynamical effects from triangular flow.

  9. Azimuthal-Angle Dependence of Charged-Pion-Interferometry Measurements with Respect to Second- and Third-Order Event Planes in Au +Au Collisions at √sNN =200 GeV

    Science.gov (United States)

    Adare, A.; Afanasiev, S.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Al-Bataineh, H.; Alexander, J.; Aoki, K.; Aramaki, Y.; Atomssa, E. T.; Averbeck, R.; Awes, T. C.; Azmoun, B.; Babintsev, V.; Bai, M.; Baksay, G.; Baksay, L.; Barish, K. N.; Bassalleck, B.; Basye, A. T.; Bathe, S.; Baublis, V.; Baumann, C.; Bazilevsky, A.; Belikov, S.; Belmont, R.; Bennett, R.; Berdnikov, A.; Berdnikov, Y.; Bickley, A. A.; Bok, J. S.; Boyle, K.; Brooks, M. L.; Buesching, H.; Bumazhnov, V.; Bunce, G.; Butsyk, S.; Camacho, C. M.; Campbell, S.; Chen, C.-H.; Chi, C. Y.; Chiu, M.; Choi, I. J.; Choudhury, R. K.; Christiansen, P.; Chujo, T.; Chung, P.; Chvala, O.; Cianciolo, V.; Citron, Z.; Cole, B. A.; Connors, M.; Constantin, P.; Csanád, M.; Csörgő, T.; Dahms, T.; Dairaku, S.; Danchev, I.; Das, K.; Datta, A.; David, G.; Denisov, A.; Deshpande, A.; Desmond, E. J.; Dietzsch, O.; Dion, A.; Donadelli, M.; Drapier, O.; Drees, A.; Drees, K. A.; Durham, J. M.; Durum, A.; Dutta, D.; Edwards, S.; Efremenko, Y. V.; Ellinghaus, F.; Engelmore, T.; Enokizono, A.; En'yo, H.; Esumi, S.; Fadem, B.; Fields, D. E.; Finger, M.; Finger, M.; Fleuret, F.; Fokin, S. L.; Fraenkel, Z.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fujiwara, K.; Fukao, Y.; Fusayasu, T.; Garishvili, I.; Glenn, A.; Gong, H.; Gonin, M.; Goto, Y.; Granier de Cassagnac, R.; Grau, N.; Greene, S. V.; Grosse Perdekamp, M.; Gunji, T.; Gustafsson, H.-Å.; Haggerty, J. S.; Hahn, K. I.; Hamagaki, H.; Hamblen, J.; Han, R.; Hanks, J.; Hartouni, E. P.; Haslum, E.; Hayano, R.; He, X.; Heffner, M.; Hemmick, T. K.; Hester, T.; Hill, J. C.; Hohlmann, M.; Holzmann, W.; Homma, K.; Hong, B.; Horaguchi, T.; Hornback, D.; Huang, S.; Ichihara, T.; Ichimiya, R.; Ide, J.; Ikeda, Y.; Imai, K.; Inaba, M.; Isenhower, D.; Ishihara, M.; Isobe, T.; Issah, M.; Isupov, A.; Ivanischev, D.; Jacak, B. V.; Jia, J.; Jin, J.; Johnson, B. M.; Joo, K. S.; Jouan, D.; Jumper, D. S.; Kajihara, F.; Kametani, S.; Kamihara, N.; Kamin, J.; Kang, J. H.; Kapustinsky, J.; Karatsu, K.; Kawall, D.; Kawashima, M.; Kazantsev, A. V.; Kempel, T.; Khanzadeev, A.; Kijima, K. M.; Kim, B. I.; Kim, D. H.; Kim, D. J.; Kim, E.; Kim, E.-J.; Kim, S. H.; Kim, Y.-J.; Kinney, E.; Kiriluk, K.; Kiss, Á.; Kistenev, E.; Kochenda, L.; Komkov, B.; Konno, M.; Koster, J.; Kotchetkov, D.; Kozlov, A.; Král, A.; Kravitz, A.; Kunde, G. J.; Kurita, K.; Kurosawa, M.; Kwon, Y.; Kyle, G. S.; Lacey, R.; Lai, Y. S.; Lajoie, J. G.; Lebedev, A.; Lee, D. M.; Lee, J.; Lee, K.; Lee, K. B.; Lee, K. S.; Leitch, M. J.; Leite, M. A. L.; Leitner, E.; Lenzi, B.; Li, X.; Liebing, P.; Linden Levy, L. A.; Liška, T.; Litvinenko, A.; Liu, H.; Liu, M. X.; Love, B.; Luechtenborg, R.; Lynch, D.; Maguire, C. F.; Makdisi, Y. I.; Malakhov, A.; Malik, M. D.; Manko, V. I.; Mannel, E.; Mao, Y.; Masui, H.; Matathias, F.; McCumber, M.; McGaughey, P. L.; Means, N.; Meredith, B.; Miake, Y.; Mignerey, A. C.; Mikeš, P.; Miki, K.; Milov, A.; Mishra, M.; Mitchell, J. T.; Mohanty, A. K.; Morino, Y.; Morreale, A.; Morrison, D. P.; Moukhanova, T. V.; Murata, J.; Nagamiya, S.; Nagle, J. L.; Naglis, M.; Nagy, M. I.; Nakagawa, I.; Nakamiya, Y.; Nakamura, T.; Nakano, K.; Newby, J.; Nguyen, M.; Niida, T.; Nouicer, R.; Nyanin, A. S.; O'Brien, E.; Oda, S. X.; Ogilvie, C. A.; Oka, M.; Okada, K.; Onuki, Y.; Oskarsson, A.; Ouchida, M.; Ozawa, K.; Pak, R.; Pantuev, V.; Papavassiliou, V.; Park, I. H.; Park, J.; Park, S. K.; Park, W. J.; Pate, S. F.; Pei, H.; Peng, J.-C.; Pereira, H.; Peresedov, V.; Peressounko, D. Yu.; Pinkenburg, C.; Pisani, R. P.; Proissl, M.; Purschke, M. L.; Purwar, A. K.; Qu, H.; Rak, J.; Rakotozafindrabe, A.; Ravinovich, I.; Read, K. F.; Reygers, K.; Riabov, V.; Riabov, Y.; Richardson, E.; Roach, D.; Roche, G.; Rolnick, S. D.; Rosati, M.; Rosen, C. A.; Rosendahl, S. S. E.; Rosnet, P.; Rukoyatkin, P.; Ružička, P.; Sahlmueller, B.; Saito, N.; Sakaguchi, T.; Sakashita, K.; Samsonov, V.; Sano, S.; Sato, T.; Sawada, S.; Sedgwick, K.; Seele, J.; Seidl, R.; Semenov, A. Yu.; Seto, R.; Sharma, D.; Shein, I.; Shibata, T.-A.; Shigaki, K.; Shimomura, M.; Shoji, K.; Shukla, P.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Silvestre, C.; Sim, K. S.; Singh, B. K.; Singh, C. P.; Singh, V.; Slunečka, M.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Sourikova, I. V.; Sparks, N. A.; Stankus, P. W.; Stenlund, E.; Stoll, S. P.; Sugitate, T.; Sukhanov, A.; Sziklai, J.; Takagui, E. M.; Taketani, A.; Tanabe, R.; Tanaka, Y.; Tanida, K.; Tannenbaum, M. J.; Tarafdar, S.; Taranenko, A.; Tarján, P.; Themann, H.; Thomas, T. L.; Todoroki, T.; Togawa, M.; Toia, A.; Tomášek, L.; Torii, H.; Towell, R. S.; Tserruya, I.; Tsuchimoto, Y.; Vale, C.; Valle, H.; van Hecke, H. W.; Vazquez-Zambrano, E.; Veicht, A.; Velkovska, J.; Vértesi, R.; Vinogradov, A. A.; Virius, M.; Vrba, V.; Vznuzdaev, E.; Wang, X. R.; Watanabe, D.; Watanabe, K.; Watanabe, Y.; Wei, F.; Wei, R.; Wessels, J.; White, S. N.; Winter, D.; Wood, J. P.; Woody, C. L.; Wright, R. M.; Wysocki, M.; Xie, W.; Yamaguchi, Y. L.; Yamaura, K.; Yang, R.; Yanovich, A.; Ying, J.; Yokkaichi, S.; You, Z.; Young, G. R.; Younus, I.; Yushmanov, I. E.; Zajc, W. A.; Zhang, C.; Zhou, S.; Zolin, L.; Phenix Collaboration

    2014-06-01

    Charged-pion-interferometry measurements were made with respect to the second- and third-order event plane for Au +Au collisions at √sNN =200 GeV. A strong azimuthal-angle dependence of the extracted Gaussian-source radii was observed with respect to both the second- and third-order event planes. The results for the second-order dependence indicate that the initial eccentricity is reduced during the medium evolution, which is consistent with previous results. In contrast, the results for the third-order dependence indicate that the initial triangular shape is significantly reduced and potentially reversed by the end of the medium evolution, and that the third-order oscillations are largely dominated by the dynamical effects from triangular flow.

  10. Phased array ultrasonic technology (PAUT) contribution to detection and sizing of microbially influenced corrosion (MIC) of service water systems and shutdown coolers heat exchangers in OPG CANDU stations

    Energy Technology Data Exchange (ETDEWEB)

    Ciorau, P.; Pullia, L.; Hazelton, T., E-mail: peter.ciorau@opg.com, E-mail: lou.pullia@opg.com, E-mail: trek.hazelton@opg.com [Ontario Power Generation, Toronto, Ontario (Canada); Daks, W. [CAD WIRE, Markham, Ontario (Canada)

    2008-07-01

    Three PAUT techniques [linear scan - longitudinal waves, sector scan -longitudinal waves and sector scan-transverse waves] were developed and validated to assess the MIC attack in service water systems (SWS) and shutdown coolers heat-exchangers (SDC-HX) of Darlington and Pickering CANDU stations. PAUT employs linear array probes with a frequency between 4-12 MHz, depending on surface conditions, component geometry and MIC size/category to be detected. Examples from lab validation and field trials are presented. Based on field trials results, the techniques were optimized and new cal blocks were manufactured. It was demonstrated for mid-length pipes and for SDC-HX, the PAUT is the best technique compared with D-meter conventional UT and with guided waves. The expected field accuracy is about 0.5 mm (0.020{sup )} for large MIC attack. The ligament evaluation is technically achievable for colonies / pin holes located 2 mm under the outer surface. Improvements were identified and implemented for the next outages. (author)

  11. 基于超声波声呐的水面快速探测技术%Water surface detection technology based on ultrasonic sonar

    Institute of Scientific and Technical Information of China (English)

    李建华

    2012-01-01

    以声呐探鱼器为参考,对超声波发生、接收、显示进行改进设计.束级高频声呐技术探测回波经处理后能最终在人机界面上形成探测目标平面轮廓和坐标等数据,利用其实现水下目标的准确判断.选用50、200 kHz的高频超声波声呐进行了水面物体的探测实验,结合实验结果和人体特性给出设计改装方案.%Research and design were conducted on ultrasound generation, reception and display, with the reference to similar functions from sonar fish finder. Beam class sonar technology was used to develop the search and rescue equipment, which will produce datum including targets' one-dimensional contour as well as coordinates on human-machine interface, achieving accurate underwater targets location. Experiments of objects detecting were carried out using 50 kHZ and 200 kHZ ultrasound sonar,the relatively developed design ideas for modification were put forward combining the experiments results and human body characteristics.

  12. Research on Partial Discharge Detection and Localization of Dry-Type Transformer Based on UHF and Ultrasonic Wave%基于超高频和超声波的干式变压器局部放电检测与定位的研究

    Institute of Scientific and Technical Information of China (English)

    王永强; 张涛; 王慧君

    2013-01-01

    The demand for the safety and effective of the dry-type transformer is high in the process of operation, therefore the partial discharge detection of dry-type transformer is particularly important. This paper mainly analyzes the principle and test methods of UHF and ultrasonic wave based partial discharge detection methods for dry-type transformer. A partial discharge detection system is built based on the combination of UHF and ultrasonic wave methods, which can locate the partial discharge source. This system provides reference for partial discharge detection.%对于干式变压器在运行过程中的安全有效性要求越来越高,因此对其进行局部放电检测尤为重要。本文主要分析了检测干式变压器局部放电的超高频方法与超声波方法的原理及检测方法,并设计了一套超高频与超声波相联合的局部放电检测系统,通过该系统,对局部放电源进行定位,对干式变压器的局部放电检测提供了参考。

  13. Ultrasonic Guided Wave Simulation Toolbox for Virtual Inspection of Composites Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Ultrasonic guided wave nondestructive evaluation (NDE) techniques are being used to detect flaws and damage in fracture critical structures such as composites. In...

  14. Bicycle helmet ventilation and comfort angle dependence.

    Science.gov (United States)

    Brühwiler, Paul A; Ducas, Charline; Huber, Roman; Bishop, Phillip A

    2004-09-01

    Five modern bicycle helmets were studied to elucidate some of the variations in ventilation performance, using both a heated manikin headform and human subjects (n = 7). Wind speed and head angle were varied to test their influence on the measured steady-state heat exchange (cooling power) in the skull section of the headform. The cooling power transmitted by the helmets varied from about 60% to over 90% of that of the nude headform, illustrating the range of present manufacturer designs. Angling the head forward by 30 degrees was found to provide better cooling power to the skull (up to 25%) for three of the helmets and almost equal cooling power in the remaining two cases. Comparisons of skull ventilation at these angles with human subjects strongly supported the headform results.

  15. Laboratory and Field Tests of Ultrasonic Sensors for Precision Sprayers

    Science.gov (United States)

    Reliable function of sensors under rough field conditions is required for the development of variable-rate sprayers to deliver pest control agents to tree liners in ornamental nurseries. Two ultrasonic sensors were examined to identify how their durability and detection stability would be influenced...

  16. Fundamentals of ultrasonic phased arrays

    CERN Document Server

    Schmerr, Lester W

    2014-01-01

    This book describes in detail the physical and mathematical foundations of ultrasonic phased array measurements.?The book uses linear systems theory to develop a comprehensive model of the signals and images that can be formed with phased arrays. Engineers working in the field of ultrasonic nondestructive evaluation (NDE) will find in this approach a wealth of information on how to design, optimize and interpret ultrasonic inspections with phased arrays. The fundamentals and models described in the book will also be of significant interest to other fields, including the medical ultrasound and

  17. Pulsed ultrasonic stir welding method

    Science.gov (United States)

    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.

  18. Ultrasonic Assembly of Thermoplastic Parts

    Energy Technology Data Exchange (ETDEWEB)

    Schurman, W. R.

    1970-03-31

    Four ultrasonic methods were evaluated for assembly of experimental plastic parts for detonators: (1) welding, (2) crimping and staking, (3) insertion, and (4) reactivation of adhesives. For welding, staking and insertion, plastics with low elastic moduli, such as acrylics and polycarbonate, produced the best results. Thermosetting, hot-melt, and solution adhesives could all be activated ultrasonically to form good bonds on plastics and other materials. This evaluation indicated that thermoplastic detonator parts could be assembled ultrasonically in shorter times than by present production techniques with high bond strengths and high product acceptance rates.

  19. Ultrasonic Time of Flight Diffraction Technique for Weld Defects: A Review

    Directory of Open Access Journals (Sweden)

    K. Manjula

    2012-12-01

    Full Text Available To achieve the quality and safety in industrial applications, the damaged products must be detected. To do that NDT is used. In NDT, Ultrasonic Time-of-Flight Diffraction is a well-known technique for detecting the size and location of the defects. Nowadays the Time of Flight Diffraction (ToFD is used for inspecting the materials during production than that of radiography and other ultrasonic NDT procedures. ToFD technique can be used into many different ways. This study gives a review of various ultrasonic ToFD techniques for welding defects and aims at the usage of it.

  20. Laser-scanning photoacoustic microscopy with ultrasonic phased array transducer

    OpenAIRE

    Zheng, Fan; Zhang, Xiangyang; Chiu, Chi Tat; Zhou, Bill L.; Shung, K. Kirk; Zhang, Hao F.; Jiao, Shuliang

    2012-01-01

    In this paper, we report our latest progress on proving the concept that ultrasonic phased array can improve the detection sensitivity and field of view (FOV) in laser-scanning photoacoustic microscopy (LS-PAM). A LS-PAM system with a one-dimensional (1D) ultrasonic phased array was built for the experiments. The 1D phased array transducer consists of 64 active elements with an overall active dimension of 3.2 mm × 2 mm. The system was tested on imaging phantom and mouse ear in vivo. Experimen...

  1. Inspection of pipeline girth welds with ultrasonic phased array technique

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A novel automatic ultrasonic system used for the inspection of pipeline girth welds is developed, in which a linear phased array transducer using electronic scan is adopted. Optimal array parameters are determined based on a mathematical model of acoustic field for linear phased array derived from Huygens' principle. The testing method and the system structure are introduced. The experimental results show that the phased array transducer system has the same detectability as that of conventional ultrasonic transducer system, but the system architecture can be simplified greatly, and the testing flexibility and the testing speed can be improved greatly.

  2. Comparison of the Inspections of Smooth and Rough Crack-Like Defects Using Ultrasonic Arrays

    Science.gov (United States)

    Zhang, J.; Drinkwater, B. W.; Wilcox, P. D.

    2011-06-01

    The use of ultrasonic arrays to detect crack-like defects is an important area in nondestructive evaluation. The array data, which contains scattered ultrasonic waves from a scatterer, can be used to reconstruct a high resolution image, e.g., using the total focusing method (TFM). In this paper, the TFM images from smooth and rough crack-like defects are compared. It is shown that roughness can be either beneficial or detrimental to the detectability of crack-like defects.

  3. A practical ultrasonic plethysmograph

    Science.gov (United States)

    Wu, V. C.; Nickell, W. T.; Bhagat, P. K.

    1982-01-01

    An ultrasonic plethysmograph, which gives improved performance over the standard Whitney Strain Gauge, is described. This instrument monitors dimension changes in human limbs by measuring the transit times of acoustic pulses across two chords of the limb. In the case of a small uniform expansion, the percentage change in limb volume is shown to be proportional to twice the percentage change in either of the measured chords. Measurement of two chords allows correction for possible non-uniform expansion. In addition, measurement of two chords allows an estimate of the absolute cross-sectional area of the limb. The developed instrument incorporates a microprocessor, which performs necessary calculation and control functions. Use of the microprocessor allows the instrument to be self-calibrating. In addition, the device can be easily reprogrammed to incorporate improvements in operating features or computational schemes.

  4. Computer-aided ultrasonic inspection of steam turbine rotors

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, K.H.; Weber, M.; Weiss, M. [GEC ALSTHOM Energie GmbH, Nuremberg (Germany)

    1998-12-31

    As the output and economic value of power plants increase, the detection and sizing of the type of flaws liable to occur in the rotors of turbines using ultrasonic methods assumes increasing importance. An ultrasonic inspection carried out at considerable expense is expected to bring to light all safety-relevant flaws and to enable their size to be determined so as to permit a fracture-mechanics analysis to assess the reliability of the rotor under all possible stresses arising in operation with a high degree of accuracy. The advanced computer-aided ultrasonic inspection of steam turbine rotors have improved reliability, accuracy and reproducibility of ultrasonic inspection. Further, there has been an improvement in the resolution of resolvable group indications by applying reconstruction and imagine methods. In general, it is also true for the advanced computer-aided ultrasonic inspection methods that, in the case of flaw-affected forgings, automated data acquisition provides a substantial rationalization and a significant documentation of the results for the fracture mechanics assessment compared to manual inspection. (orig.) 8 refs.

  5. A Simple Model for Nonlinear Confocal Ultrasonic Beams

    Institute of Scientific and Technical Information of China (English)

    ZHANG Dong; ZHOU Lin; SI Li-Sheng; GONG Xiu-Fen

    2007-01-01

    @@ A confocally and coaxially arranged pair of focused transmitter and receiver represents one of the best geometries for medical ultrasonic imaging and non-invasive detection. We develop a simple theoretical model for describing the nonlinear propagation of a confocal ultrasonic beam in biological tissues. On the basis of the parabolic approximation and quasi-linear approximation, the nonlinear Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation is solved by using the angular spectrum approach. Gaussian superposition technique is applied to simplify the solution, and an analytical solution for the second harmonics in the confocal ultrasonic beam is presented.Measurements are performed to examine the validity of the theoretical model. This model provides a preliminary model for acoustic nonlinear microscopy.

  6. [Ultrasonic diagnosis of neuroinfections in the newborn and infants].

    Science.gov (United States)

    Filippkin, M A; Kal'naia, T V; Kal'noĭ, A M

    1993-01-01

    The authors discuss the potentialities of the ultrasonic method in the diagnosis of brain involvement in the newborns and infants with neuroinfections. Ultrasonic examination was carried out in 75 infants aged 4 days to 15 months. Fifteen infants suffered from specific neuroinfections that developed in utero (toxoplasmosis, cytomegalia, listerosis), the rest 60 developed inflammatory diseases of the central nervous system (meningitis, meningoencephalitis, ventriculitis). The examinations were performed in the real time regimen with a frequency of 3.5-7.5 MHz. In all the cases the diagnosis was confirmed by clinical and laboratory findings. Specific changes in the brain morphology were detected at the early stages of inflammatory processes of various origins. Ultrasonic examinations help identify the type of the pathologic process, its dissemination and complications (dislocation, cerebral ventricles dilatation, abscesses, hygromas).

  7. Laser-scanning photoacoustic microscopy with ultrasonic phased array transducer.

    Science.gov (United States)

    Zheng, Fan; Zhang, Xiangyang; Chiu, Chi Tat; Zhou, Bill L; Shung, K Kirk; Zhang, Hao F; Jiao, Shuliang

    2012-11-01

    In this paper, we report our latest progress on proving the concept that ultrasonic phased array can improve the detection sensitivity and field of view (FOV) in laser-scanning photoacoustic microscopy (LS-PAM). A LS-PAM system with a one-dimensional (1D) ultrasonic phased array was built for the experiments. The 1D phased array transducer consists of 64 active elements with an overall active dimension of 3.2 mm × 2 mm. The system was tested on imaging phantom and mouse ear in vivo. Experiments showed a 15 dB increase of the signal-to-noise ratio (SNR) when beamforming was employed compared to the images acquired with each single element. The experimental results demonstrated that ultrasonic phased array can be a better candidate for LS-PAM in high sensitivity applications like ophthalmic imaging.

  8. Fractional Fourier Transform for Ultrasonic Chirplet Signal Decomposition

    Directory of Open Access Journals (Sweden)

    Yufeng Lu

    2012-01-01

    Full Text Available A fractional fourier transform (FrFT based chirplet signal decomposition (FrFT-CSD algorithm is proposed to analyze ultrasonic signals for NDE applications. Particularly, this method is utilized to isolate dominant chirplet echoes for successive steps in signal decomposition and parameter estimation. FrFT rotates the signal with an optimal transform order. The search of optimal transform order is conducted by determining the highest kurtosis value of the signal in the transformed domain. A simulation study reveals the relationship among the kurtosis, the transform order of FrFT, and the chirp rate parameter in the simulated ultrasonic echoes. Benchmark and ultrasonic experimental data are used to evaluate the FrFT-CSD algorithm. Signal processing results show that FrFT-CSD not only reconstructs signal successfully, but also characterizes echoes and estimates echo parameters accurately. This study has a broad range of applications of importance in signal detection, estimation, and pattern recognition.

  9. Material Property Measurement of Metallic Parts using the INEEL Laser Ultrasonic Camera

    Energy Technology Data Exchange (ETDEWEB)

    K. L. Telschow; R. S. Schley; S. M. Watson; V. A. Deason

    1999-08-22

    Ultrasonic waves form a useful nondestructive evaluation (NDE) probe for determining physical, microstructural, and mechanical properties of materials and parts. Noncontacting laser ultrasonic methods are desired for remote measurements and on-line manufacture process monitoring. Researchers at the Idaho National Engineering & Environmental Laboratory (INEEL) have developed a versatile new method for detection of ultrasonic motion at surfaces. This method directly images, without the need for scanning, the surface distribution of subnanometer ultrasonic motion. By eliminating the need for scanning over large areas or complex parts, the inspection process can be greatly speeded up. Examples include measurements on parts with complex geometries through resonant ultrasound spectroscopy and of the properties of sheet materials determined through anisotropic elastic Lamb wave propagation. The operation and capabilities of the INEEL Laser Ultrasonic Camera are described along with measurement results.

  10. Material Property Measurement of Metallic Parts using the INEEL Laser Ultrasonic Camera

    Energy Technology Data Exchange (ETDEWEB)

    Telschow, Kenneth Louis; Deason, Vance Albert; Schley, Robert Scott; Watson, Scott Marshall

    1999-08-01

    Ultrasonic waves form a useful nondestructive evaluation (NDE) probe for determining physical, microstructural, and mechanical properties of materials and parts. Noncontacting laser ultrasonic methods are desired for remote measurements and on-line manufacture process monitoring. Researchers at the Idaho National Engineering & Environmental Laboratory (INEEL) have developed a versatile new method for detection of ultrasonic motion at surfaces. This method directly images, without the need for scanning, the surface distribution of subnanometer ultrasonic motion. By eliminating the need for scanning over large areas or complex parts, the inspection process can be greatly speeded up. Examples include measurements on parts with complex geometries through resonant ultrasound spectroscopy and of the properties of sheet materials determined through anisotropic elastic Lamb wave propagation. The operation and capabilities of the INEEL Laser Ultrasonic Camera are described along with measurement results.

  11. Ultrasonic Atomization Amount for Different Frequencies

    Science.gov (United States)

    Yasuda, Keiji; Honma, Hiroyuki; Xu, Zheng; Asakura, Yoshiyuki; Koda, Shinobu

    2011-07-01

    The mass flow rate of ultrasonic atomization was estimated by measuring the vaporization amount from a bulk liquid with a fountain. The effects of ultrasonic frequency and intensity on the atomization characteristics were investigated when the directivities of the acoustic field from a transducer were almost the same. The sample was distillated water and the ultrasonic frequencies were 0.5, 1.0, and 2.4 MHz. The mass flow rate of ultrasonic atomization increased with increasing ultrasonic intensity and decreasing ultrasonic frequency. The fountain was formed at the liquid surface where the effective value of acoustic pressure was above atmospheric pressure. The fountain height was strongly governed by the acoustic pressure at the liquid surface of the transducer center. At the same ultrasonic intensity, the dependence of ultrasonic frequency on the number of atomized droplets was small. At the same apparent surface area of the fountain, the number of atomized droplets became larger as the ultrasonic frequency increased.

  12. Monitoring of fatigue crack growth using guided ultrasonic waves

    Science.gov (United States)

    Masserey, B.; Kostson, E.; Fromme, P.

    2010-04-01

    Varying loading conditions of aircraft structures result in stress concentration at fastener holes, where multi layer components are connected, possibly leading to the development of fatigue cracks. Guided ultrasonic waves propagating along a structure allow in principle for the efficient non-destructive testing of large plate-like structures, such as aircraft wings. This contribution presents a study of the detection and monitoring of fatigue crack growth using both low frequency and higher frequency guided ultrasonic wave modes. Two types of structures were used, single layer aluminum tensile specimens, and multi layer structures consisting of two adhesively bonded aluminum plate-strips. Fatigue experiments were carried out and it was shown that fatigue crack detection and growth monitoring at a fastener hole during cyclic loading using both guided wave types is possible. The sensitivity and repeatability of the measurements were ascertained, having the potential for fatigue crack detection at critical and difficult to access fastener locations. Good agreement was observed between the experimental results and predictions from full three-dimensional numerical simulations of the scattering of the low frequency guided ultrasonic wave at the fastener hole and crack. The robustness of the methodology for practical in-situ ultrasonic monitoring of fatigue crack growth is discussed.

  13. Measurement of low-frequency ultrasonic wave in water using an acoustic fiber sensor.

    Science.gov (United States)

    Sakoda, Tatsuya; Sonoda, Yoshito

    2006-04-01

    An acoustic fiber sensor for measurement of ultrasonic waves, which used the approximate Raman-Nath diffraction effect where light diffraction waves were generated in an optical fiber by strain due to the ultrasonic waves, was proposed and examined. In order to characterize the acoustic fiber sensor as a basic study, measurements of low-frequency ultrasonic waves in water were examined using a step index fiber operating as a detection sensor. The results showed that characteristics of detected signals agreed with the theoretical prediction based on Fraunhofer diffraction. This indicates that our proposed fiber sensor can be used for the detection of low-frequency ultrasonic waves as well as the transmission of light diffraction signals.

  14. Ultrasonically detectable cerebellar haemorrhage in preterm infants.

    LENUS (Irish Health Repository)

    McCarthy, Lisa Kenyon

    2011-07-01

    To determine the frequency and pattern of cerebellar haemorrhage (CBH) on routine cranial ultrasound (cUS) imaging in infants of ≤32 weeks gestation, and to investigate how extremely preterm infants with CBH differ from those with severe intraventricular haemorrhage (IVH).

  15. Study on Effect of Ultrasonic Vibration on Grinding Force and Surface Quality in Ultrasonic Assisted Micro End Grinding of Silica Glass

    Directory of Open Access Journals (Sweden)

    Zhang Jianhua

    2014-01-01

    Full Text Available Ultrasonic vibration assisted micro end grinding (UAMEG is a promising processing method for micro parts made of hard and brittle materials. First, the influence of ultrasonic assistance on the mechanism of this processing technology is theoretically analyzed. Then, in order to reveal the effects of ultrasonic vibration and grinding parameters on grinding forces and surface quality, contrast grinding tests of silica glass with and without ultrasonic assistance using micro radial electroplated diamond wheel are conducted. The grinding forces are measured using a three-component dynamometer. The surface characteristics are detected using the scanning electron microscope. The experiment results demonstrate that grinding forces are significantly reduced by introducing ultrasonic vibration into conventional micro end grinding (CMEG of silica glass; ultrasonic assistance causes inhibiting effect on variation percentages of tangential grinding force with grinding parameters; ductile machining is easier to be achieved and surface quality is obviously improved due to ultrasonic assistance in UAMEG. Therefore, larger grinding depth and feed rate adopted in UAMEG can lead to the improvement of removal rate and machining efficiency compared with CMEG.

  16. Real time monitoring of accelerated chemical reactions by ultrasonication-assisted spray ionization mass spectrometry.

    Science.gov (United States)

    Lin, Shu-Hsuan; Lo, Ta-Ju; Kuo, Fang-Yin; Chen, Yu-Chie

    2014-01-01

    Ultrasonication has been used to accelerate chemical reactions. It would be ideal if ultrasonication-assisted chemical reactions could be monitored by suitable detection tools such as mass spectrometry in real time. It would be helpful to clarify reaction intermediates/products and to have a better understanding of reaction mechanism. In this work, we developed a system for ultrasonication-assisted spray ionization mass spectrometry (UASI-MS) with an ~1.7 MHz ultrasonic transducer to monitor chemical reactions in real time. We demonstrated that simply depositing a sample solution on the MHz-based ultrasonic transducer, which was placed in front of the orifice of a mass spectrometer, the analyte signals can be readily detected by the mass spectrometer. Singly and multiply charged ions from small and large molecules, respectively, can be observed in the UASI mass spectra. Furthermore, the ultrasonic transducer used in the UASI setup accelerates the chemical reactions while being monitored via UASI-MS. The feasibility of using this approach for real-time acceleration/monitoring of chemical reactions was demonstrated. The reactions of Girard T reagent and hydroxylamine with steroids were used as the model reactions. Upon the deposition of reactant solutions on the ultrasonic transducer, the intermediate/product ions are readily generated and instantaneously monitored using MS within 1 s. Additionally, we also showed the possibility of using this reactive UASI-MS approach to assist the confirmation of trace steroids from complex urine samples by monitoring the generation of the product ions.

  17. Model-based inversion for the characterization of crack-like defects detected by ultrasound in a cladded component; Etude d'une methode d'inversion basee sur la simulation pour la caracterisation de fissures detectees par ultrasons dans un composant revetu

    Energy Technology Data Exchange (ETDEWEB)

    Haiat, G

    2004-03-01

    This work deals with the inversion of ultrasonic data. The industrial context of the study in the non destructive evaluation of the internal walls of French reactor pressure vessels. Those inspections aim at detecting and characterizing cracks. Ultrasonic data correspond to echographic responses obtained with a transducer acting in pulse echo mode. Cracks are detected by crack tip diffraction effect. The analysis of measured data can become difficult because of the presence of a cladding, which surface is irregular. Moreover, its constituting material differs from the one of the reactor vessel. A model-based inverse method uses simulation of propagation and of diffraction of ultrasound taking into account the irregular properties of the cladding surface, as well as the heterogeneous nature of the component. The method developed was implemented and tested on a set of representative cases. Its performances were evaluated by the analysis of experimental results. The precision obtained in the laboratory on experimental cases treated is conform with industrial expectations motivating this study. (author)

  18. Influence of axle-wheel interface on ultrasonic testing of fatigue cracks in wheelset.

    Science.gov (United States)

    Makino, Kazunari; Biwa, Shiro

    2013-01-01

    For the ultrasonic testing at the wheel seat of railway axles, quantitative investigation of the reflection and transmission phenomena at the axle-wheel interface is important. This paper describes the influence of the axle-wheel interface on the ultrasonic testing of a fatigue crack in a wheelset by applying the spring interface model. The normal and tangential stiffnesses were identified experimentally for an as-manufactured wheelset at the normal incidence, and the reflection coefficient for the shear-wave oblique incidence was calculated. A parametric study was performed to clarify the influence of these interfacial stiffnesses on the incident-angle dependence of the reflection coefficient. The calculated reflection coefficient at the incident angle of 45° qualitatively explained the relative echo-height decrease due to the presence of a wheel observed experimentally for a wheelset in fatigue loading by rotating bending. The quantitative difference between the experimental and calculated results was considered to be due to the reduction of the effective interference of shrink fit by the wear at the axle-wheel interface during the fatigue loading as well as by the applied bending moment. For the estimated relative echo-height decrease to agree with the experimental results, the interfacial stiffnesses were found to be smaller than the values identified for the as-manufactured wheelset by a factor of 0.5-0.7.

  19. 21 CFR 872.4850 - Ultrasonic scaler.

    Science.gov (United States)

    2010-04-01

    ... DEVICES DENTAL DEVICES Surgical Devices § 872.4850 Ultrasonic scaler. (a) Identification. An ultrasonic scaler is a device intended for use during dental cleaning and periodontal (gum) therapy to...

  20. Inspection of Single Crystal Aerospace Components with Ultrasonic Arrays

    Science.gov (United States)

    Lane, C. J. L.; Dunhill, A.; Drinkwater, B. W.; Wilcox, P. D.

    2010-02-01

    Single crystal metal alloys are used extensively in the manufacture of jet engine components for their excellent mechanical properties at elevated temperatures. The increasing use of these materials and demand for longer operational life and improved reliability motivates the requirement to have capable NDE methods available. Ultrasonic arrays are well established at detecting sub-surface defects however these methods are not currently suitable to the inspection of single crystal components due to their high elastic anisotropy causing directional variation in ultrasonic waves. In this paper a model of wave propagation in anisotropic material is used to correct an ultrasonic imaging algorithm and is applied to single crystal test specimens. The orientation of the crystal in a specimen must be known for this corrected-algorithm; therefore a crystal orientation method is also presented that utilizes surface skimming longitudinal waves under a 2D array. The work detailed in this paper allows an ultrasonic 2D array to measure the orientation of a single crystal material and then perform accurate volumetric imaging to detect and size defects.

  1. Ultrasonic measurements and technologies

    CERN Document Server

    Kočiš, Štefan

    1996-01-01

    An impulse for writing this book has originated from the effort to sum­ marize and publicise the acquired results of a research team at the De­ partment of Automation of the Faculty of Electrical Engineering and In­ formatics, Slovak Technical University in Bratislava. The research team has been involved for a long time with control problems for machine production mechanisms and, in recent (approximately 15) years, its effort was aimed mostly at the control of electrical servosystems of robots. Within this scope, the members of the authors' staff solved the State Re­ search Task Ultrasonic sensing of the position of a robot hand, which was coordinated by the Institute of Technical Cybernetics of the Slovak Academy of Sciences in Bratislava. The problem was solved in a complex way, i.e. from a conceptual de­ sign of the measurement, through the measurement and evaluation sys­ tem, up to connection to the control system of a robot. Compensation of the atmospheric influence on the precision of measurement,...

  2. Simulation of the ultrasonic array response from real branched cracks using an efficient finite element method

    Energy Technology Data Exchange (ETDEWEB)

    Felice, Maria V. [Department of Mechanical Engineering, University of Bristol, Bristol BS8 1TR, United Kingdom and Rolls-Royce plc., Bristol BS34 7QE (United Kingdom); Velichko, Alexander; Wilcox, Paul D. [Department of Mechanical Engineering, University of Bristol, Bristol BS8 1TR (United Kingdom); Barden, Tim J.; Dunhill, Tony K. [Rolls-Royce plc., Bristol BS34 7QE (United Kingdom)

    2014-02-18

    A hybrid model to simulate the ultrasonic array response from stress corrosion cracks is presented. These cracks are branched and difficult to detect so the model is required to enable optimization of an array design. An efficient frequency-domain finite element method is described and selected to simulate the ultrasonic scattering. Experimental validation results are presented, followed by an example of the simulated ultrasonic array response from a real stress corrosion crack whose geometry is obtained from an X-ray Computed Tomography image. A simulation-assisted array design methodology, which includes the model and use of real crack geometries, is proposed.

  3. Analysis of partial discharge Ultrasonic wave characteristic on typical Defects in GIS

    Directory of Open Access Journals (Sweden)

    Yang Jing Gang

    2016-01-01

    Full Text Available For analyzing partial discharge ultrasonic wave characteristic on typical defects in SF6 gas insulation switchgear (GIS, a 110 kV GIS was taken as an object to design and simulate the typical partial discharge models in GIS. There are point electrode model on bus and cavity of GIS, floating electrode model, air interstice model in insulator, metal particle and iron core electromagnetic shock models. PD signals on different defects were thus detected with the ultrasonic method. The experimental results indicated that the ultrasonic signals of different defects showed different characteristics in waveform, amplitude and phase resolved partial discharge chart, which is helpful in PD pattern recognition for GIS.

  4. Application Research on On-line Detection of GIS Partial Discharge Based on Ultrahigh Frequency Method and Ultrasonic Method%超高频与超声波法在GIS局部放电现场检测中的应用研究

    Institute of Scientific and Technical Information of China (English)

    刘君华; 吴晓春; 徐敏骅

    2011-01-01

    As an effective insulation diagnostic technique, Partial discharge (PD) detection has received broad attention in GIS online monitoring and maintenance. After the feature analysis of ultrahigh frequency (UHF) method and ultrasonic method, and the application research in PD on-line detection, a PD detection method is proposed. In the case of PD on-line detection, UHF method is taken as the main way and ultrasonic method as the supplementary way, combined with the analysis of GIS component construction. The field application experience also shows that this PD detection method can be used effectively for the PD occurances in different GIS components, providing an important and useful support for the GIS insulation diagnosis and the arrangement of device maintenance.%局部放电检测作为二种有效的绝缘诊断技术在GIS现场安全维护中得到广泛的关注。通过分析局部放电检测超高频法与超声波法的技术特点,并在现场检测中进行应用研究,提出以超高频法为主,超声波法为辅,结合GIS设备部件结构特点进行局部放电现场检测分析的方法。现场应用情况表明,该方法能够有效处理GIS不同结构部件发生局部放电情况时的检测分析,为GIS设备绝缘诊断与检修策略的制定提供了有力支持。

  5. Application and development of ultrasonics in dentistry.

    Science.gov (United States)

    Chen, Yen-Liang; Chang, Hao-Hueng; Chiang, Yu-Chih; Lin, Chun-Pin

    2013-11-01

    Since the 1950s, dentistry's ultrasonic instruments have developed rapidly. Because of better visualization, operative convenience, and precise cutting ability, ultrasonic instruments are widely and efficiently applied in the dental field. This article describes the development and improvement of ultrasonic instruments in several dental fields. Although some issues still need clarification, the results of previous studies indicate that ultrasonic instruments have a high potential to become convenient and efficient dental tools and deserve further development.

  6. Ultrasonic stir welding process and apparatus

    Science.gov (United States)

    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.

  7. Pressure vessel inspections using ultrasonic phased arrays

    Energy Technology Data Exchange (ETDEWEB)

    Moles, M.D.C. [R/D Tech Toronto, Toronto, ON (Canada); Jacques, F.; Dube, N. [R/D Tech Quebec PQ (Canada)

    2003-07-01

    Pressure vessels are used in several industries, including the petrochemical and petroleum industries. Welds in the pressure vessels often produce defects which propagate and fail with time. Many types of pressure vessel weld inspections can now be conducted using automated ultrasonics which offers several advantages over radiography. In terms of phased arrays, custom tailored time-of-flight diffraction (TOFD) and ASME code Section V raster scans, can successfully perform high speed inspections with minimal operator subjectivity. The phased array beams can be steered, scanned, swept and focused electronically. Beam steering can be used to map welds at appropriate angles to optimize probability of defect detection. The main challenge lies with the initial equipment cost, technology awareness, and availability of trained operators. Phased arrays offer great flexibility for different components, defect detection and tailored imaging. 8 refs., 10 figs.

  8. Including frequency-dependent attenuation for the deconvolution of ultrasonic signals

    OpenAIRE

    Carcreff, Ewen; Bourguignon, Sébastien; Idier, Jérôme; Simon, Laurent; Duclos, Aroune

    2013-01-01

    International audience; Ultrasonic non-destructive testing (NDT) is a standard process for detecting flaws or discontinuities in industrial parts. A pulse is emitted by an ultrasonic transducer through a material, and a reflected wave is produced at each impedance change. In many cases, echoes can overlap in the received signal and deconvolution can be applied to perform echo separation and to enhance the resolution. Common deconvolution techniques assume that the shape of the echoes is invar...

  9. Reconstruction of laser ultrasonic wavefield images from reduced sparse measurements using compressed sensing aided super-resolution

    Science.gov (United States)

    Park, Byeongjin; Sohn, Hoon

    2017-02-01

    Laser ultrasonic scanning is attractive for damage detection due to its noncontact nature, sensitivity to local damage, and high spatial resolution. However, its practicality is limited because scanning at a high spatial resolution demands a prohibitively long scanning time. Recently, compressed sensing (CS) and super-resolution (SR) are gaining popularity in the image recovery field. CS estimates unmeasured ultrasonic responses from measured responses, and SR recovers high spatial frequency information from low resolution images. Inspired by these techniques, a laser ultrasonic wavefield reconstruction technique is developed to localize and visualize damage with a reduced number of ultrasonic measurements. First, a low spatial resolution ultrasonic wavefield image for a given inspection region is reconstructed from reduced number of ultrasonic measurements using CS. Here, the ultrasonic waves are generated using a pulsed laser, and measured at a fixed sensing point using a laser Doppler vibrometer (LDV). Then, a high spatial resolution ultrasonic wave image is recovered from the reconstructed low spatial resolution image using SR. The number of measurement points required for ultrasonic wavefield imaging is significantly reduced over 90%. The performance of the proposed technique is validated by an experiment performed on a cracked aluminum plate.

  10. Ultrasonics: Fundamentals, Technologies, and Applications

    Energy Technology Data Exchange (ETDEWEB)

    Ensminger, Dale; Bond, Leonard J.

    2011-09-17

    This is a new edition of a bestselling industry reference. Discusses the science, technology, and applications of low and high power ultrasonics, including industrial implementations and medical uses. Reviews the basic equations of acoustics, starting from basic wave equations and their applications. New material on property determination, inspection of metals (NDT) and non-metals, imaging, process monitoring and control. Expanded discussion of transducers, transducer wave-fields, scattering, attenuation and measurement systems and models. New material that discusses high power ultrasonics - in particular using mechanical effects and sonochemistry, including applications to nano-materials. Examines diagnosis, therapy, and surgery from a technology and medical physics perspective.

  11. Adaptive ultrasonic sensor using a fiber ring laser with tandem fiber Bragg gratings.

    Science.gov (United States)

    Liu, Tongqing; Hu, Lingling; Han, Ming

    2014-08-01

    We propose and demonstrate an intensity-demodulated fiber-optic ultrasonic sensor system that can be self-adaptive to large quasi-static background strain perturbations. The sensor system is based on a fiber ring laser (FRL) whose laser cavity includes a pair of fiber Bragg gratings (FBGs). Self-adaptive ultrasonic detection is achieved by a tandem design where the two FBGs are engineered to have differential spectral responses to ultrasonic waves and are installed side-by-side at the same location on a structure. As a result, ultrasonic waves lead to relative spectral shifts of the FBGs and modulations to the cold-cavity loss of the FRL. Ultrasonic waves can then be detected directly from the laser intensity variations in response to the cold-cavity loss modulation. The sensor system is insensitive to quasi-static background strains because they lead to identical responses of the tandem FBGs. Based on the principle, a FRL sensor system was demonstrated and tested for adaptive ultrasonic detection when large static strains as well as dynamic sinusoidal vibrations were applied to the sensor.

  12. Dental hard tissue characterization using laser-based ultrasonics

    Science.gov (United States)

    Blodgett, David W.; Massey, Ward L.

    2003-07-01

    Dental health care and research workers require a means of imaging the structures within teeth in vivo. One critical need is the detection of tooth decay in its early stages. If decay can be detected early enough, the process can be monitored and interventional procedures, such as fluoride washes and controlled diet, can be initiated to help re-mineralize the tooth. Currently employed x-ray imaging is limited in its ability to visualize interfaces and incapable of detecting decay at a stage early enough to avoid invasive cavity preparation followed by a restoration. To this end, non-destructive and non-contact in vitro measurements on extracted human molars using laser-based ultrasonics are presented. Broadband ultrasonic waves are excited in the extracted sections by using a pulsed carbon-dioxide (CO2) laser operating in a region of high optical absorption in the dental hard tissues. Optical interferometric detection of the ultrasonic wave surface displacements in accomplished with a path-stabilized Michelson-type interferometer. Results for bulk and surface in-vitro characterization of caries are presented on extracted molars with pre-existing caries.

  13. Research on Phased Array Ultrasonic Methods for Defect Detection of Compressor Impeller Blade Root%压缩机叶轮叶根缺陷相控阵超声检测方法研究

    Institute of Scientific and Technical Information of China (English)

    朱学耕; 董世运; 徐滨士

    2015-01-01

    Compressor impeller blade root was easy to occur fatigue cracks,holes and other inter-nal defects.Based on the principles of ultrasonic pulse reflection and phased array ultrasonic method, the testing positions of blade root defects were analysed by voice model,and the experimental plan was optimized with sound field simulation and defect testing simulation.An experiment of artificial flat bottom hole defect testing was made by focus scanning.The results show an evident defect signal of blade root is found by phased array ultrasonic testing when scanning through impeller internal.The defect location error is only 0.1 9% which shows a high accuracy.%压缩机叶轮叶根易出现疲劳裂纹、气孔等内部缺陷。基于超声脉冲反射法原理,利用相控阵超声检测技术,采用声线模型对缺陷检测位置进行分析,并通过声场分布模拟以及缺陷检测模拟优化实验方案,最后利用聚焦扫描对人工预置平底孔缺陷进行检测。检测结果表明:利用相控阵超声检测技术在叶轮内腔对叶根进行检测,缺陷信号明显,缺陷定位精度高,定位误差仅为0.19%。

  14. Application of Dry Coupling Ultrasonic Detecting Technology for the Rocket Engine Nozzle%干耦合超声检测技术在某火箭发动机喷管在役检测中的应用

    Institute of Scientific and Technical Information of China (English)

    穆洪彬; 吴朝军; 吴晨; 李剑

    2013-01-01

    应用干耦合超声检测方法对某火箭发动机喷管进行了在役检测试验,验证了干耦合超声检测技术对该火箭发动机喷管的在役检测能力.结果表明,干耦合超声检测方法能够有效地检测出该型号发动机喷管中φ 20 mm以上的脱粘缺陷,满足在役检测要求.自动与手动,两种检测方法的检测能力相当,但在操作方式和工作效率等方面各有优劣.%In order to study the feasibility of the in-service dry coupling ultrasonic test technology for rocket jet,the principle of the dry coupling ultrasonic testing was analyzed,and both the manual and automatic testing methods were applied to test the rocket jet specimen and the rocket jet parts in service.The results show that the debond defect,whose normal size is larger than 20mm,can be found using the two kinds of the dry coupling ultrasonic testing methods.It satisfies the quality request of the rocket jet being tested in service.It is the same to the manual testing and automatic testing in the ability of finding defect.And there is difference between the two testing methods in the operation and efficiency.The study is useful for testing rocket jet in service.

  15. Application of Ultrasonic Techniques for Brain Injury Diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Kasili, P.M.; Mobley, J.; Norton, S.J.; Vo-Dinh, T.

    1999-09-19

    In this work, we evaluate methods for detecting brain injury using ultrasound. We have used simulations of ultrasonic fields in the head to model the phase distortion of the skull. In addition we present experimental data from the crania of large animals. The experimental data help us understand and evaluate the performance of different transducers in acquiring the backscatter data from the brain through the skull. Both the simulations and acquired data illustrate the superiority of lower-frequency (<= 1 MHz) ultrasonic fields for transcranial acquisition of signals from inside the brain. Additionally, the experimental work shows that the higher-frequency (5 MHz) ultrasound can also be useful in acquiring clean nearfield data to help detect the position of the inner boundary of the skull.

  16. Residual stress profiling of an aluminum alloy by laser ultrasonics

    Institute of Scientific and Technical Information of China (English)

    PAN Yondong; QIAN Menglu; XU Weijiang; M. OURAK

    2004-01-01

    A residual-stress profile along the thickness of an aluminum alloy sheet is determined by laser-ultrasonic technique. Surface acoustic waves are generated by a Nd:YAG pulse laser and detected by a Heterodyne interferometer on a lateral free surface of the sheet. The distribution of residual stress is determined by measuring the relative variation of the wavevelocities at different location of the sample along its thickness. This technique is validated by three different residual stress profiles obtained experimentally.

  17. CFRP Structural Health Monitoring by Ultrasonic Phased Array Technique

    OpenAIRE

    Boychuk, A.S.; Generalov, A.S.; A.V. Stepanov

    2014-01-01

    International audience; The report deals with ultrasonic phased array (PA) application for high-loaded CFRP structural health monitoring in aviation. Principles of phased array technique and most dangerous types of damages are briefly described. High-performance inspection technology suitable for periodic plane structure check is suggested. The results of numerical estimation of detection probability for impact damages and delaminations by PA technique are presented. The experience of PA impl...

  18. Frogs Communicate by Means of Ultrasonic Sounds

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ People are always fascinated by ways that some members of mammalian species (such as dolphins, bats and some rodents) communicate using sounds that we cannot hear. But think twice if you say the capacity of producing and detecting ultrasounds (frequencies greater than 20kHz) is limited to mammalians. A study implemented by Prof. SHEN Junxian from the CAS Institute of Biophysics (IBP) and colleagues in CAS and abroad showed that a rare frog species in China should also be added to that list. It is the first documented case of a non-mammalian species being able to use ultrasonic communication. Their work was reported in the March 16 issue of the journal Nature.

  19. Recent modelling advances for ultrasonic TOFD inspections

    Energy Technology Data Exchange (ETDEWEB)

    Darmon, Michel; Ferrand, Adrien; Dorval, Vincent; Chatillon, Sylvain [CEA, LIST, Department of Imaging and Simulation for Non Destructive Testing, F-91191 Gif-sur-Yvette cedex (France); Lonné, Sébastien [EXTENDE, Le Bergson, 15 Avenue Emile Baudot, F-91300 MASSY (France)

    2015-03-31

    The ultrasonic TOFD (Time of Flight Diffraction) Technique is commonly used to detect and characterize disoriented cracks using their edge diffraction echoes. An overview of the models integrated in the CIVA software platform and devoted to TOFD simulation is presented. CIVA allows to predict diffraction echoes from complex 3D flaws using a PTD (Physical Theory of Diffraction) based model. Other dedicated developments have been added to simulate lateral waves in 3D on planar entry surfaces and in 2D on irregular surfaces by a ray approach. Calibration echoes from Side Drilled Holes (SDHs), specimen echoes and shadowing effects from flaws can also been modelled. Some examples of theoretical validation of the models are presented. In addition, experimental validations have been performed both on planar blocks containing calibration holes and various notches and also on a specimen with an irregular entry surface and allow to draw conclusions on the validity of all the developed models.

  20. The value and ultrasonic detection of renal artery stenosis in renovascular hypertensive canine%肾血管性高血压犬中肾动脉狭窄的超声检测及价值

    Institute of Scientific and Technical Information of China (English)

    田作军; 由天辉; 廖海星; 王晓明; 陈长兵; 沈粤春; 陈惠芬; 曾玲; 汤庆; 陆亚琴

    2012-01-01

    目的 研究肾血管性高血压犬中肾动脉狭窄的超声检测方法及其对模型建立的影响.方法 12只beagle犬按双侧肾动脉直径狭窄率分为>80%组、70%~80%组及假手术组,并以双肾双夹法(2k2c)建立肾血管性高血压犬模型.术后1周以彩超检测缩窄犬狭窄处及狭窄远段的肾动脉口径及血流收缩期峰值流速(PSV),并与假手术犬相对照计算肾动脉的狭窄率;在术前1天,术后第2天、4个月、8个月及12个月动态检测犬的尿素氮(BUN)及肌酐(Cr);术后1年比较缩窄犬及假手术犬的肾脏及颈动脉的病理结果.结果 实验早期,连续2只双侧肾动脉狭窄>80%犬在术后4天内因急性肾功能衰竭而死亡,该分组被放弃;5只双侧肾动脉缩窄70% ~80%犬均形成高血压;术后第7天彩超证实:左右两侧肾动脉的狭窄率分别为(73.9±4.2)%及(73.2±4.4)%,这和左右肾动脉狭窄处的PSV与假手术犬左右肾动脉的平均PSV的比率相一致;术后1年,病理切片发现缩窄犬部分肾组织透明样变性,颈动脉有明显斑块形成,BUN和Cr无明显改变.5只假手术犬术后血压无明显升高,术后1年肾组织及颈动脉无明显异常改变.结论 肾动脉缩窄到合适的程度是2k2c法建立肾血管性高血压犬模型的关键性技术;彩超能够准确检测肾血管性高血压犬肾动脉的狭窄程度,为实验做出指导.%Objective To investigate the ultrasonic detection method ant influence on model establishment of renal artery stenosis in renovascular hypertensive canine.Methods Twelve beagles in this experiment were assigned to stenosis rate > 80%,70% ~ 80% and sham-operated group according to the bilateral renal artery diameter stenosis,and induced renovascular hypertension by 2 kidney 2 clip (2k2c) method.One week after operation,the diameter on the stenosis site and the distal segment of renal artery and the corresponding peak systolic velocity (PSV) in

  1. Monitoring of polymeric membrane fouling in hollow fiber module using ultrasonic nondestructive testing

    Institute of Scientific and Technical Information of China (English)

    LIU Jing-xia; LI Jian-xin; CHEN Xue-mei; ZHANG Yu-zhong

    2006-01-01

    This study describes the development of novel protocols extending the real-time ultrasonic reflectometry(UTDR) for the detection of membrane fouling in hollow fiber module during ultrafiltration(UF) of oily water treatment. A specially designed acoustic sensor with a frequency of 2.5 MHz was used. The hollow fiber membranes used were polysulphone(PSf) UF membranes with MWCO 40 kDa. The wastewaters with three different oily concentrations of 100,500 and 1 000 mg/L were investigated. Diesel oil was utilized as the primary foulant. The results show that the permeate flux declines with operation time and its value becomes lower with the increase of the oily concentration in wastewater. It is found that ultrasonic measurement can detect the fouling and cleaning processes. A new signal analysis protocol-ultrasonic reflected energy was developed. Ultrasonic reflected energy obtained indicates the deposition of oily layer as a function of operation time and its removal after cleaning. The overall flux decline is reasonably correlated with the changes in ultrasonic reflected energy. This research provides the evidence that the ultrasonic reflectometry technique is capable of monitoring membrane fouling and cleaning in hollow fiber modules.

  2. Repeat scanning technology for laser ultrasonic propagation imaging

    Science.gov (United States)

    Lee, Jung-Ryul; Yenn Chong, See; Sunuwar, Nitam; Park, Chan Yik

    2013-08-01

    Laser ultrasonic scanning in combination with contact or non-contact sensors provides new paradigms in structural health management (SHM) and non-destructive in-process quality control (IPQC) for large composite structures. Wave propagation imaging technology based on laser ultrasonic scanning and fixed-point sensing shows remarkable advantages, such as minimal need for embedded sensors in SHM, minimum invasive defect visualization in IPQC and general capabilities of curved and complex target inspection, and temporal reference-free inspection. However, as with other SHM methods and non-destructive evaluation based on ultrasound, the signal-to-noise ratio (SNR) is a prevalent issue in real structural applications, especially with non-contact thin-composite sensing or with thick and heterogeneous composites. This study proposes a high-speed repeat scanning technique for laser ultrasonic propagation imaging (UPI) technology, which is realized with the scanning speed of 1 kHz of a Q-switched continuous wave laser, and precise control of the laser beam pulses for identical point scanning. As a result, the technique enables the achievement of significant improvement in the SNR to inspect real-world composite structures. The proposed technique provides enhanced results for impact damage detection in a 2 mm thick wing box made of carbon-fiber-reinforced plastic, despite the low sensitivity of non-contact laser ultrasonic sensing. A field-applicable pure laser UPI system has been developed using a laser Doppler vibrometer as the non-contact ultrasonic sensor. The proposed technique enables the visualization of the disbond defect in a 15 mm thick wind blade specimen made of glass-fiber-reinforced plastic, despite the high dissipation of ultrasound in the thick composite.

  3. Bruce Thompson: Adventures and advances in ultrasonic backscatter

    Science.gov (United States)

    Margetan, Frank J.

    2012-05-01

    Over the course of his professional career Dr. R. Bruce Thompson published several hundred articles on non-destructive evaluation, the majority dealing with topics in ultrasonics. One longtime research interest of Dr. Thompson, with applications both to microstructure characterization and defect detection, was backscattered grain noise in metals. Over a 20 year period he led a revolving team of staff members and graduate students investigating various aspects of ultrasonic backscatter. As a member of that team I had the privilege of working along side Dr. Thompson for many years, serving as a sort of Dr. Watson to Bruce's Sherlock Holmes. This article discusses Dr. Thompson's general approaches to modeling backscatter, the research topics he chose to explore to systematically elucidate a better understanding of the phenomena, and the many contributions to the field achieved under his leadership. The backscatter work began in earnest around 1990, motivated by a need to improve inspections of aircraft engine components. At that time Dr. Thompson launched two research efforts. The first led to the heuristic Independent Scatterer Model which could be used to estimate the average grain noise level that would be seen in any given ultrasonic inspection. There the contribution from the microstructure was contained in a measureable parameter known as the Figure-of-Merit or FOM. The second research effort, spearheaded by Dr. Jim Rose, led to a formal relationship between FOM and details of the metal microstructure. The combination of the Independent Scattering Model and Rose's formalism provided a powerful tool for investigating backscatter in metals. In this article model developments are briefly reviewed and several illustrative applications are discussed. These include: the determination of grain size and shape from ultrasonic backscatter; grain noise variability in engine-titanium billets and forgings; and the design of ultrasonic inspection systems to improve defect

  4. Ultrasonic waves scattering through dissimilar welds: application to characterisation of spurious echoes detected during inspection; Etude de la diffusion des ondes ultrasonores dans les soudures austeno-ferritiques: application a la caracterisation des echos de lignes observes lors du controle des soudures bimetalliques

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, F

    1999-07-01

    Ultrasonic testing of bimetallic welds can show the presence of structural echoes. In pulse echo mode inspections at oblique incidence, these echoes are detected close to the back-wall (surface opposite to the control). These echoes have a specific shape: the amplitude is distributed along lines parallel to the weld sides. Such echoes can disturb the inspection: they can be misinterpreted as provided by a defect, or they can mask a possible defect. The aim of this thesis is to explain this phenomenon with an interpretation based on the anisotropic property of the weld. In such a structure, specific mode conversions in the lasts welding pass arise. Mode converted waves can reflect normally on the back-wall and therefore back propagate to the transducer along the same wave path as the forward propagation. Some generalities of ultrasonic testing of bimetallic welds are given in a preliminary chapter. In the first chapter, various experiments showed that these structural echoes do not result from beam deflection in the weld and that this phenomenon occurs in the last millimeters under the back-wall. According to these results, an interpretation for these echoes based on the anisotropic and the inhomogeneous structure of the weld is given in the last welding pass, oblique compression waves may be converted into normal shear waves. The second chapter presented a theoretical analysis of these mode conversions phenomenon between two metallurgical structures with different dendrite orientations. The analysis of the welding passes metallography and a bibliographic study summarizes on the relevancy to use a orthotropic symmetry to describe the metallurgical structure of the material under test. The third chapter deals with experimental studies to confirm this hypothesis. Detection of shear waves in the last welding passes near the back-wall mock-up using a specific sensor, able to discriminate the polarisation wave at the reception, validate the mode conversion hypothesis

  5. Computer-controlled Sophisticated Ultrasonic Cleaner

    Directory of Open Access Journals (Sweden)

    H. Muthurajan

    2007-01-01

    Full Text Available The significant advantage of ultrasonic cleaning technique is the abilities to clean the delicateand complex shape materials without damaging their surfaces quickly. Ultrasonic cleaners havefound increasing applications in a variety of industries because these offer an environmentallygood alternative to ozone-depleting compounds and hazardous solvents. Also, ultrasonicvibration is one of the methods for chemical synthesis (chemical reaction and of yieldenhancement of chemical engineering process. Consequently, there is a need to developmultipurpose ultrasonic cleaner/vibrator using computer control, which can be used to set thevarious performance parameter of ultrasonic vibrator such as frequency, duty cycle, continuous/pulsed mode, duration of operation, and thermal profile of tank during the process. An ultrasoniccleaner was developed using an oscillator circuit and the duration of oscillator circuit functioningcan be set through the computer. Computerised ultrasonic cleaner using indigenously madepiezoceramic transducers and their advantages over the conventional ultrasonic cleaners are discussed.

  6. Ultrasonic Phased Array Nondestructive Detection Technique Based on Total Focusing Method%基于整体聚焦算法(TFM)的超声探测技术

    Institute of Scientific and Technical Information of China (English)

    马锐; 施未来

    2016-01-01

    Aiming at the problem of nondestructive testing of micro defects at mechanical workpiece surface and inter‐nal ,the total focusing method based on the ultrasonic phased array technology is used to provide an effective solution for mi‐cro defect localization and imaging .%针对具有不规则表面器件的内部微观缺陷的无损检测问题,以超声相控阵技术为基础,利用声场能量的整体聚焦法则,为器件内部微观缺陷的精确定位和成像提供有效的解决方案。

  7. Ultrasonic material hardness depth measurement

    Science.gov (United States)

    Good, Morris S.; Schuster, George J.; Skorpik, James R.

    1997-01-01

    The invention is an ultrasonic surface hardness depth measurement apparatus and method permitting rapid determination of hardness depth of shafts, rods, tubes and other cylindrical parts. The apparatus of the invention has a part handler, sensor, ultrasonic electronics component, computer, computer instruction sets, and may include a display screen. The part handler has a vessel filled with a couplant, and a part rotator for rotating a cylindrical metal part with respect to the sensor. The part handler further has a surface follower upon which the sensor is mounted, thereby maintaining a constant distance between the sensor and the exterior surface of the cylindrical metal part. The sensor is mounted so that a front surface of the sensor is within the vessel with couplant between the front surface of the sensor and the part.

  8. Integrated Ultrasonic-Photonic Devices

    DEFF Research Database (Denmark)

    Barretto, Elaine Cristina Saraiva

    This thesis deals with the modeling, design, fabrication and characterization of integrated ultrasonic-photonic devices, with particular focus on the use of standard semiconductor materials such as GaAs and silicon. The devices are based on the use of guided acoustic waves to modulate the light...... systems, all in search for paths to improve acousto-optic interaction. Some of the solutions proposed lead to enhancements of up to two orders of magnitude in the eciency of the device. The main aspects related to the design of the devices are discussed, including single-mode guidance, optical coupling......, integration and cost. The design proves to be robust towards fabrication and design tolerances. Several uses for this device are proposed, opening up a whole new group of applications for this class of integrated ultrasonic-photonic devices....

  9. Ultrasonic enhancement of battery diffusion.

    Science.gov (United States)

    Hilton, R; Dornbusch, D; Branson, K; Tekeei, A; Suppes, G J

    2014-03-01

    It has been demonstrated that sonic energy can be harnessed to enhance convection in Galvanic cells during cyclic voltammetry; however, the practical value of this approach is limited due to the lack of open volumes for convection patterns to develop in most batteries. This study evaluates the ability of ultrasonic waves to enhance diffusion in membrane separators commonly used in sandwich-architecture batteries. Studies include the measuring of open-circuit performance curves to interpret performances in terms of reductions in concentration overpotentials. The use of a 40 kHz sonicator bath can consistently increase the voltage of the battery and reduce overpotential losses up to 30%. This work demonstrates and quantifies battery enhancement due to enhanced diffusion made possible with ultrasonic energy.

  10. Ultrasonic attenuation in pearlitic steel.

    Science.gov (United States)

    Du, Hualong; Turner, Joseph A

    2014-03-01

    Expressions for the attenuation coefficients of longitudinal and transverse ultrasonic waves are developed for steel with pearlitic microstructure. This type of lamellar duplex microstructure influences attenuation because of the lamellar spacing. In addition, longitudinal attenuation measurements were conducted using an unfocused transducer with 10 MHz central frequency on the cross section of a quenched railroad wheel sample. The dependence of longitudinal attenuation on the pearlite microstructure is observed from the changes of longitudinal attenuation from the quenched tread surface to deeper locations. The results show that the attenuation value is lowest and relatively constant within the quench depth, then increases linearly. The experimental results demonstrate a reasonable agreement with results from the theoretical model. Ultrasonic attenuation provides an important non-destructive method to evaluate duplex microstructure within grains which can be implemented for quality control in conjunction with other manufacturing processes.

  11. Ultrasonic characterization of yogurt fermentation process

    OpenAIRE

    2012-01-01

    International audience; The objective of this work is to characterize the fermentation of yogurt based on an ultrasonic technique. Conventionally, the acidity of the yogurt is measured by a pH meter to determine the progress of fermentation. However, the pH meter should be cleaned and calibrated for each measurement and, therefore, this method is not practical. In this regard, ultrasonic techniques are fast, non-invasive and inexpensive. The measurement of ultrasonic parameters such as amplit...

  12. Littoral Subsonic Seismoacoustic Phenomena Ultrasonic Modeling

    Science.gov (United States)

    2016-06-07

    Littoral Subsonic Seismoacoustic Phenomena Ultrasonic Modeling Jacques R. Chamuel Sonoquest Advanced Ultrasonics Research P.O. Box 81153 Wellesley... variable water/air content, and benthic shelled animals leading to accurate acoustic modeling of littoral surficial layer and geophysical inversion...UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Sonoquest Advanced Ultrasonics Research ,P.O. Box 81153,Wellesley Hills,MA,02481-0001 8

  13. Studies on Ultrasonic Spray Dryer (1)

    OpenAIRE

    井上, 昌夫

    1981-01-01

    Author has initiated research and development activities for a epochal ultrasonic spray dryer in order to obtain large quantities of droplets in uniform diameters, from which a practically applicable ultrasonic spray dryer would possibly be developed. Since the time Wood, Loomis et al. reported their experiments on atomization of liquids by ultrasonic power, research in this field is now widely attempted in many countries. In Japan, this field is being investigated by Ohno et al. Chiba, and M...

  14. Analysis of the Rotary Ultrasonic Machining Mechanism

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Ultrasonic machining (USM) is considered as an effective method for machining hard and brittle materials such as glass, engineering ceramics, semiconductors, diamonds, metal composites and so on. However, the low material removal rate due to using abrasive slurry limits further application of USM. Rotary ultrasonic machining (rotary USM) superimposes rotational movement on the tool head that vibrates at ultrasonic frequency (20 kHz) simultaneously. The tool is made of mild steel coated or bonded with diamon...

  15. The Influence of the Ultrasonic Intensity on the Cleaning Efficacy of Passive Ultrasonic Irrigation

    NARCIS (Netherlands)

    Jiang, Lei-Meng; Verhaagen, Bram; Versluis, Michel; Langedijk, Jelmer; Wesselink, Paul; van der Sluis, Lucas W. M.

    2011-01-01

    Introduction: It is not clear whether increasing the ultrasonic intensity would enhance the cleaning efficacy of passive ultrasonic irrigation (PUI) inside a root canal. The aim of this study was to evaluate the effect of the ultrasonic intensity on PUI to remove dentin debris and whether there is a

  16. Microprocessor-controlled ultrasonic plethysmograph

    Science.gov (United States)

    Bhagat, P. K.; Wu, V. C.

    1981-01-01

    Safe, nonintrusive microprocessor system times ultrasonic pulses to measure limb cross-sectional area. Simple instrument requires no calibration and does not confine leg movement, making tests relating limb volume to activity level possible. Program considers more realistic geometries of human limb than circular cross-sections and monitors changes in area with great accuracy. Errors due to body temperature changes and timing roundoff are insignificant.

  17. Nonlinear ultrasonic phased array imaging.

    Science.gov (United States)

    Potter, J N; Croxford, A J; Wilcox, P D

    2014-10-03

    This Letter reports a technique for the imaging of acoustic nonlinearity. By contrasting the energy of the diffuse field produced through the focusing of an ultrasonic array by delayed parallel element transmission with that produced by postprocessing of sequential transmission data, acoustic nonlinearity local to the focal point is measured. Spatially isolated wave distortion is inferred without requiring interrogation of the wave at the inspection point, thereby allowing nonlinear imaging through depth.

  18. Nonlinear Ultrasonic Phased Array Imaging

    Science.gov (United States)

    Potter, J. N.; Croxford, A. J.; Wilcox, P. D.

    2014-10-01

    This Letter reports a technique for the imaging of acoustic nonlinearity. By contrasting the energy of the diffuse field produced through the focusing of an ultrasonic array by delayed parallel element transmission with that produced by postprocessing of sequential transmission data, acoustic nonlinearity local to the focal point is measured. Spatially isolated wave distortion is inferred without requiring interrogation of the wave at the inspection point, thereby allowing nonlinear imaging through depth.

  19. Nonlinear ultrasonic phased array imaging

    OpenAIRE

    Potter, J N; Croxford, A.J.; Wilcox, P. D.

    2014-01-01

    This Letter reports a technique for the imaging of acoustic nonlinearity. By contrasting the energy of the diffuse field produced through the focusing of an ultrasonic array by delayed parallel element transmission with that produced by postprocessing of sequential transmission data, acoustic nonlinearity local to the focal point is measured. Spatially isolated wave distortion is inferred without requiring interrogation of the wave at the inspection point, thereby allowing nonlinear imaging t...

  20. Ultrasonic Dynamic Vector Stress Sensor

    Science.gov (United States)

    Heyman, Joseph S.; Froggatt, Mark

    1992-01-01

    Stress inferred from measurements in specimens rather than in bonded gauges. Ultrasonic dynamic vector stress sensor (UDVSS) measures changes in dynamic directional stress occurring in material or structure at location touched by device when material or structure put under cyclic load. Includes phase-locked loop, synchronous amplifier, and contact probe. Useful among manufacturers of aerospace and automotive structures for stress testing and evaluation of designs.

  1. Ultrasonic Linear Motor with Anisotropic Composite

    Institute of Scientific and Technical Information of China (English)

    曾周末; 王新辉; 赵伯雷

    2004-01-01

    An idea to make up the vibrating body of ultrasonic motor with anisotropic composite is proposed and a linear piezoelectric motor is developed in this paper. Relative problems such as actuating mechanism, resonant frequency are discussed theoretically. According to the feature that impulse exists between the elastic body of composite ultrasonic linear motor and the base, an impulse analysis is presented to calculate the motor′s friction driving force and frictional conversion efficiency. The impulse analysis essentially explains the reason why the ultrasonic motor has great driving force, and can be applied to analyze the non-linear ultrasonic motor.

  2. Predictive simulation of nonlinear ultrasonics

    Science.gov (United States)

    Shen, Yanfeng; Giurgiutiu, Victor

    2012-04-01

    Most of the nonlinear ultrasonic studies to date have been experimental, but few theoretical predictive studies exist, especially for Lamb wave ultrasonic. Compared with nonlinear bulk waves and Rayleigh waves, nonlinear Lamb waves for structural health monitoring become more challenging due to their multi-mode dispersive features. In this paper, predictive study of nonlinear Lamb waves is done with finite element simulation. A pitch-catch method is used to interrogate a plate with a "breathing crack" which opens and closes under tension and compression. Piezoelectric wafer active sensors (PWAS) used as transmitter and receiver are modeled with coupled field elements. The "breathing crack" is simulated via "element birth and death" technique. The ultrasonic waves generated by the transmitter PWAS propagate into the structure, interact with the "breathing crack", acquire nonlinear features, and are picked up by the receiver PWAS. The features of the wave packets at the receiver PWAS are studied and discussed. The received signal is processed with Fast Fourier Transform to show the higher harmonics nonlinear characteristics. A baseline free damage index is introduced to assess the presence and the severity of the crack. The paper finishes with summary, conclusions, and suggestions for future work.

  3. Design and Development of an Ultrasonic Motion Detector

    CERN Document Server

    Zungeru, A M

    2013-01-01

    The ultrasonic motion detector devices emit ultrasonic sound energy into an area of interest (monitored area), and this further reacts to a change in the reflected energy pattern. The system uses a technique that is based on a frequency shift in reflected energy to detect a movement or change in position (motion). In this system, ultrasonic sound is transmitted from the transmitting device which is normally in the form of energy. The transmitted sound utilizes air as its medium and this travel in a wave type motion. The wave is reflected back from the surroundings in the room/hallway and the device hears a pitch characteristic of the protected environment. In this system, the wave pattern is disturbed and reflected back more quickly, thus increasing the pitch and signaling an alarm whenever motion is detected. The main contribution of this work is the design of a circuit that can sense motion through movement of anything, a low cost and portable motion detector, and the design of a circuit that can be used to...

  4. Full waveform inversion for ultrasonic flaw identification

    Science.gov (United States)

    Seidl, Robert; Rank, Ernst

    2017-02-01

    Ultrasonic Nondestructive Testing is concerned with detecting flaws inside components without causing physical damage. It is possible to detect flaws using ultrasound measurements but usually no additional details about the flaw like position, dimension or orientation are available. The information about these details is hidden in the recorded experimental signals. The idea of full waveform inversion is to adapt the parameters of an initial simulation model of the undamaged specimen by minimizing the discrepancy between these simulated signals and experimentally measured signals of the flawed specimen. Flaws in the structure are characterized by a change or deterioration in the material properties. Commonly, full waveform inversion is mostly applied in seismology on a larger scale to infer mechanical properties of the earth. We propose to use acoustic full waveform inversion for structural parameters to visualize the interior of the component. The method is adapted to US NDT by combining multiple similar experiments on the test component as the typical small amount of sensors is not sufficient for a successful imaging. It is shown that the combination of simulations and multiple experiments can be used to detect flaws and their position, dimension and orientation in emulated simulation cases.

  5. Phased annular array transducers for ultrasonic guided wave applications

    Science.gov (United States)

    Yan, Fei; Borigo, Cody; Liang, Yue; Koduru, Jaya P.; Rose, Joseph L.

    2011-04-01

    Mode and frequency control always plays an important role in ultrasonic guided wave applications. In this paper, theoretical understanding of guided wave excitations of axisymmetric sources on plate structures is established. It is shown that a wave number spectrum can be used to investigate the guided wave excitations of an axisymmetric source. The wave number spectrum is calculated from a Hankel transform of the axial source loading profile. On the basis of the theoretical understanding, phased annular array transducers are developed as a powerful tool for guided wave mode and frequency control. By applying appropriate time delays to phase the multiple elements of an annular array transducer, guided wave mode and frequency tuning can be achieved fully electronically. The phased annular array transducers have been successfully used for various applications. Example applications presented in this paper include phased annular arrays for guided wave beamforming and a novel ultrasonic vibration modal analysis technique for damage detection.

  6. Ultrasonic Phased Array Simulations of Welded Components at NASA

    Science.gov (United States)

    Roth, D. J.; Tokars, R. P.; Martin, R. E.; Rauser, R. W.; Aldrin, J. C.

    2009-01-01

    Comprehensive and accurate inspections of welded components have become of increasing importance as NASA develops new hardware such as Ares rocket segments for future exploration missions. Simulation and modeling will play an increasing role in the future for nondestructive evaluation in order to better understand the physics of the inspection process, to prove or disprove the feasibility for an inspection method or inspection scenario, for inspection optimization, for better understanding of experimental results, and for assessment of probability of detection. This study presents simulation and experimental results for an ultrasonic phased array inspection of a critical welded structure important for NASA future exploration vehicles. Keywords: nondestructive evaluation, computational simulation, ultrasonics, weld, modeling, phased array

  7. Strain Mapping in Metals Using Ultrasonic Array Speckle Images

    Science.gov (United States)

    Bowler, A. I.; Drinkwater, B. W.; Wilcox, P. D.

    2009-03-01

    The full-field non-destructive measurement of internal displacement and strain fields is of interest in many engineering applications. This paper describes an approach to measuring internal displacements and strains in metals which uses the correlation of ultrasonic speckle images of the internal structure of the material. This has the key advantage over optical surface displacement and strain measurement techniques in that internal information can be obtained. Experiments are described which use a 1-D ultrasonic array to map 2-D displacement fields for uniform translation and uniaxial tension of a metallic bar. The full matrix of transmit-receive signals from the array was post-processed to generate speckle images using a Fourier-domain imaging algorithm. Block-search cross-correlation was used to find the displacements of small sub-images corresponding to regions within the bar. Potential applications include characterising crack networks and creep damage detection.

  8. Study of ultrasonic phased array inspection imaging technology for NDT

    Institute of Scientific and Technical Information of China (English)

    Shan Baohua; Duan Zhongdong; Ou Jinping

    2006-01-01

    A research about the ultrasonic phased array imaging principle from A-scan signal to B-scan image for nondestructive testing (NDT) was conducted in this paper, the ultrasonic phased array inspection imaging system used in industrial field was developed and the experiment was performed on the steel testing block by the system with 64 elements, 5MHz phased array transducer.Experimental results show that the flaws could be accurately detected and the flaws size could be estimated from the B-scan images, and the B-scan images could clearly show the location of the flaws, but the quality of Bscan images needs to be enhanced by digital signal processing and controlling dynamic focusing for improving the image resolution.

  9. Improvement on the detection rate of Mycobacterium tuberculosis in fluorescence quantitation PCR by increasing sputum volume and modifying ultrasonic extraction procedure%通过增加痰液量和超声裂菌提高结核分枝杆菌荧光定量PCR检出率

    Institute of Scientific and Technical Information of China (English)

    张军; 王晓飞; 王瑞东; 韩敏; 景玲杰; 陈晋

    2014-01-01

    Objective To increase the detection rate of Mycobacterium tuberculosis(MTB)in real-time fluorescence quantitation polymerase chain reaction (PCR)by increasing sputum volume and modifying ultrasonic extraction of MTB DNA.Methods Sputum samples from 206 tuberculosis patients and 103 non-tuberculosis patients as controls were analyzed.Routine sputum MTB smear and liquid culture of MTB by American BD MAGIT960 system were performed.At least 5mL sputum was collected from each patient,and 2-3-fold volume of 4% NaOH solution was added to the sputum. After liquefaction,1 mL solution was used for the routine DNA extraction procedure,and the remaining part was used for the modified ultrasonic extraction procedure.Both of the extracted DNA were quantitated by real-time fluorescence quantitation PCR.Results By the modified ultrasonic extraction procedure,the MTB DNA positive detection rate increased from 87.5%(confidence interval 81.4%-93.6%)to 95.5%(confidence interval 91.7%-99.4%)(P<0.05)in the smear positive and culture positive tuberculosis patients,and the positive detection rate increased from 57.4%(confidence interval 47.5%-67.4%)to 83%(confidence interval 75.4%-90.6%)in the smear negative and culture positive tuberculosis patients (P<0.01 ).The quantity results of increasing sputum volume and modifying ultrasonic extraction procedure increased 14 folds in average by the modified ultrasonic extraction procedure.Conclusions The increasing sputum volume and modifying ultrasonic extraction procedure increase the positive detection rate of real-time fluorescence quantitation PCR for tuberculosis,which can be recommended for routine laboratory use.%目的:通过增加痰液量和超声破碎法提取痰液中的结核菌DNA,提高结核分枝杆菌实时荧光定量聚合酶链反应(PCR)的检出率。方法选择206例肺结核患者,以103例非结核患者作为对照组;肺结核患者同时进行结核菌涂片,并在美国BD公司的MAGIT960仪器上进

  10. Modular Air-Coupled Ultrasonic Multichannel System for Inline NDT

    Science.gov (United States)

    Bilcke, M.; Lust, P.; Naert, H.; Blomme, E.; Delrue, S.; Van Den Abeele, K.

    In many production processes it is important to detect in a very early stage basic errors in the fabricatedmaterial. If the errors are not visible from the exterior, ultrasonic inspection is a convenient technique,at least if the nature of the error influences the characteristics of sound passing through the material.Examples are local density variations in non-wovens, delaminations in composites, bad bondings inlaminates, inclusions, cracks or other artefacts in plastic or metal plates, etc. There are two major,difficult requirements imposed by industry to the used detection technique: the sensors shouldn't makephysical contact with the material and the speed of testing must be sufficiently high to enable testingin-line. The former requirement can be met by employing an air-coupled ultrasonic approach, the latterby using a multichannel system.We propose a modular air-coupled ultrasonic multichannel system. Each multichannel module contains12 air-coupled transducers and exists in a transmitter and a receiver version. The desired scan width isobtained by connecting several modules to each other. During the scanning all transducers are spatially fixed while the material is moving forward. This way, speeds up to 1m/s are possible, irrespective ofthe width of the material. To that purpose a FPGA based platform with parallel processing of largenumbers of data streams is implemented in the modules. This allows the implementation of all kind ofprocedures, going from point measurements to more sophisticated techniques. In spite of all measurements being performed in ambient air, the ultrasonic frequency is rather high(1 MHz), but lower frequencies are possible as well. The most obvious set-up of the modules is a through-transmission configuration. However the system can also be used in a pitch-catch configuration which isvery suitable for one-sided testing of thick materials. An examples established in the laboratory is shownto illustrate the performance.

  11. Ultrasonic imaging of foreign inclusions and blood vessels through thick skull bones.

    Science.gov (United States)

    Shapoori, Kiyanoosh; Sadler, Jeffrey; Ahmed, Zaki; Wydra, Adrian; Maeva, Elena; Malyarenko, Eugene; Maev, Roman

    2015-03-01

    We report a new progress in the development of a portable ultrasonic transcranial imaging system, which is expected to significantly improve the clinical utility of transcranial diagnostic ultrasound. When conventional ultrasonic phased array and Doppler techniques are applied through thick skull bones, the ultrasound field is attenuated, deflected, and defocused, leading to image distortion. To address these deficiencies, the ultrasonic transcranial imaging system implements two alternative ultrasonic methods. The first method improves detection of small foreign objects, such as bone fragments, pieces of shrapnel, or bullets, lodged in the brain tissue. Using adaptive beamforming, the method compensates for phase aberration induced by the skull and refocuses the distorted ultrasonic field at the desired location. The second method visualizes the blood flow through intact human skull using ultrasonic speckle reflections from the blood cells, platelets, or contrast agents. By analyzing these random temporal changes, it is possible to obtain 2D or 3D blood flow images, despite the adverse influence of the skull. Both methods were implemented on an advanced open platform phased array controller driving linear and matrix array probes. They were tested on realistic skull bone and head phantoms with foreign inclusions and blood vessel models.

  12. Assessment of fatigue damage in solid plates through the ultrasonic Lamb wave approach

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Changes(degradations) in the mechanical properties of solid plates induced by cyclic fatigue loading will influence the features of ultrasonic Lamb wave propagation,such as dispersion and attenuation.This paper has qualitatively analyzed the feasibility of using the amplitude-frequency characteristics and the stress wave factors(SWFs) of ultrasonic Lamb wave propagation to assess fatigue damage in solid plates.Liquid wedge transducers located on the surface of solid plates tested are used to generate and detect the Lamb wave signals.Based on the Ritec-SNAP ultrasonic measurement system,the experimental setup for assessing the degree of fatigue damage in solid plates using ultrasonic Lamb wave approach has been established.For several rolled aluminum sheets subjected to tension-tension cyclic loading,the experimental examinations have been performed for the relationships between the amplitude-frequency characteristics of ultrasonic Lamb wave propagation and the numbers of loading cycles(denoted by N),as well as the correlations between the Lamb wave SWFs and N.The experimental results show that the Lamb wave SWFs decrease monotonously and sensitively with the increment of cycles of fatigue loading.Based on the correlations between the Lamb wave SWFs and N,it is further verified that ultrasonic Lamb wave propagation combined with the Lamb wave SWFs can be used to effectively assess early fatigue damage in solid plates.

  13. Full matrix capture and the total focusing imaging algorithm using laser induced ultrasonic phased arrays

    Science.gov (United States)

    Stratoudaki, Theodosia; Clark, Matt; Wilcox, Paul D.

    2017-02-01

    Laser ultrasonics is a technique where lasers are used for the generation and detection of ultrasound instead of conventional piezoelectric transducers. The technique is broadband, non-contact, and couplant free, suitable for large stand-off distances, inspection of components of complex geometries and hazardous environments. In this paper, array imaging is presented by obtaining the full matrix of all possible laser generation, laser detection combinations in the array (Full Matrix Capture), at the nondestructive, thermoelastic regime. An advanced imaging technique developed for conventional ultrasonic transducers, the Total Focusing Method (TFM), is adapted for laser ultrasonics and then applied to the captured data, focusing at each point of the reconstruction area. In this way, the beamforming and steering of the ultrasound is done during the post processing. A 1-D laser induced ultrasonic phased array is synthesized with significantly improved spatial resolution and defect detectability. In this study, shear waves are used for the imaging, since they are more efficiently produced than longitudinal waves in the nondestructive, thermoelastic regime. Experimental results are presented from nondestructive, laser ultrasonic inspection of aluminum samples with side drilled holes and slots at depths varying between 5 and 20mm from the surface.

  14. Broadband, High-Temperature Ultrasonic Transducer

    Science.gov (United States)

    Parker, F. Raymond; Winfree, William P.; Barrows, Danny A.

    1995-01-01

    Materials chosen for endurance at high temperatures and acoustic coupling and damping. Acoustic transducer designed to exhibit broad frequency response and to survive temperatures close to melting points of brazing alloys. Attached directly and continuously to hot object monitored ultrasonically: for example, it can be attached to relatively cool spot on workpiece during brazing for taking ultrasonic quality-control measurements.

  15. Backward ray tracing for ultrasonic imaging

    NARCIS (Netherlands)

    Breeuwer, R.

    1990-01-01

    Focused ultrasonic beams frequently pass one or more media interfaces, strongly affecting the ultrasonic beamshape and focusing. A computer program, based on backward ray tracing was developed to compute the shape of a corrected focusing mirror. This shape is verified with another program; then the

  16. 21 CFR 870.2880 - Ultrasonic transducer.

    Science.gov (United States)

    2010-04-01

    ... structures. This device includes phased arrays and two-dimensional scanning transducers. (b) Classification... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ultrasonic transducer. 870.2880 Section 870.2880...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2880 Ultrasonic...

  17. Ultrasonic fingerprinting by phased array transducer

    Science.gov (United States)

    Sednev, D.; Kataeva, O.; Abramets, V.; Pushenko, P.; Tverdokhlebova, T.

    2016-06-01

    Increasing quantity of spent nuclear fuel that must be under national and international control requires a novel approach to safeguard techniques and equipment. One of the proposed approaches is utilize intrinsic features of casks with spent fuel. In this article an application of a phased array ultrasonic method is considered. This study describes an experimental results on ultrasonic fingerprinting of austenitic steel seam weld.

  18. Ultrasonic fingerprinting by phased array transducer

    OpenAIRE

    Sednev, Dmitry Andreevich; Kataeva, O.; Abramets, V.; Pushenko, P.; Tverdokhlebova, T.

    2016-01-01

    Increasing quantity of spent nuclear fuel that must be under national and international control requires a novel approach to safeguard techniques and equipment. One of the proposed approaches is utilize intrinsic features of casks with spent fuel. In this article an application of a phased array ultrasonic method is considered. This study describes an experimental results on ultrasonic fingerprinting of austenitic steel seam weld.

  19. Ultrasonic Testing Method of Quantitative Detection of Flaws in Concrete Filled Steel Tube%钢管混凝土缺陷定量的超声波检测方法

    Institute of Scientific and Technical Information of China (English)

    石世赛; 官权

    2011-01-01

    Cavity is a common defect in concrete filled steel tube(CFST) and it directly influences the durability and reliability of CFST. In order to find out the internal state of CFST, the empty thickness can be estimated by using ultrasonic inspection(UT) method. Based on combination of sound time from UT and test performance of insite drilling, the data was processed by line-fitting method, which could justify the flaws in the CFST accurately and quickly. This new method had practical application in engineering, and had certain reference value.%钢管混凝土脱空是一种常见的缺陷,脱空缺陷直接影响其耐久性和可靠性.为了探测钢管混凝土内部的情况,可以用超声检测方法估计脱空厚度.根据超声检测的声时和现场钻孔测试相结合,把数据进行直线回归拟合,可以快速准确地判断钢管混凝土拱肋的缺陷.在实际工程中具有实用价值.

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

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, Susan L.; Prowant, Matthew S.; Cinson, Anthony D.; Larche, Michael R.; Diaz, Aaron A.

    2014-08-01

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

  1. Feasibility of transparent flexible ultrasonic haptic actuator

    Science.gov (United States)

    Akther, Asma; Kafy, Abdullahil; Kim, Hyun Chan; Kim, Jaehwan

    2016-04-01

    Ultrasonic haptics actuator is a device that can create a haptic feedback to user's hand. The modulation of ultrasonic frequency can give different textures to the users. In this study, a feasibility of the ultrasonic haptic actuator made on a flexible piezoelectric substrate is investigated. As the piezoelectric substrate helps to propagate flexural waves, a pair of interdigital transducer (IDT) with reflectors can produce standing waves, which can increase the vibrational displacement of the actuator. A pair of IDT pattern was fabricated on a piezoelectric polymer substrate. A finite element analysis is at first performed to design the actuator. A sinusoidal excitation voltage is applied on IDT electrodes at ultrasonic frequencies and the displacement waveforms are found. The displacement waveforms clearly represent how ultrasonic waves propagate through the piezoelectric substrate.

  2. Ultrasonic vocalizations emitted by flying squirrels.

    Directory of Open Access Journals (Sweden)

    Meghan N Murrant

    Full Text Available Anecdotal reports of ultrasound use by flying squirrels have existed for decades, yet there has been little detailed analysis of their vocalizations. Here we demonstrate that two species of flying squirrel emit ultrasonic vocalizations. We recorded vocalizations from northern (Glaucomys sabrinus and southern (G. volans flying squirrels calling in both the laboratory and at a field site in central Ontario, Canada. We demonstrate that flying squirrels produce ultrasonic emissions through recorded bursts of broadband noise and time-frequency structured frequency modulated (FM vocalizations, some of which were purely ultrasonic. Squirrels emitted three types of ultrasonic calls in laboratory recordings and one type in the field. The variety of signals that were recorded suggest that flying squirrels may use ultrasonic vocalizations to transfer information. Thus, vocalizations may be an important, although still poorly understood, aspect of flying squirrel social biology.

  3. Ultrasonic assessment of oil quality during frying.

    Science.gov (United States)

    Benedito, Jose; Mulet, Antonio; Velasco, J; Dobarganes, M Carmen

    2002-07-31

    In this paper, changes in ultrasonic properties during thermoxidation of virgin olive oil were studied. Samples of virgin olive oil were heated over different periods of time from 2 to 16 h at 200 degrees C. Oil degradation was characterized by means of physical and chemical changes, i.e., viscosity, color, polar compounds, polymers, and polar fatty acids. Ultrasonic measurements were carried out while the oil sample was cooled from 35 to 25 degrees C. It was found that velocity and attenuation measurements were related to viscosity measurements through a classical equation for viscous liquids. The ultrasonic measurements were also related to the percentages of polar compounds and polymers, which shows the feasibility of using ultrasonic properties to monitor oil quality. Nevertheless, as long as the ultrasonic measurements are temperature dependent, this variable must be controlled in order to obtain repetitive and reliable measurements.

  4. Lase Ultrasonic Web Stiffness tester

    Energy Technology Data Exchange (ETDEWEB)

    Tim Patterson, Ph.D., IPST at Ga Tech

    2009-01-12

    The objective is to provide a sensor that uses non-contact, laser ultrasonics to measure the stiffness of paper during the manufacturing process. This will allow the manufacturer to adjust the production process in real time, increase filler content, modify fiber refining and as result produce a quality product using less energy. The sensor operates by moving back and forth across the paper web, at pre-selected locations firing a laser at the sheet, measuring the out-of-plane velocity of the sheet then using that measurement to calculate sheet stiffness.

  5. Calculations for Piezoelectric Ultrasonic Transducers

    DEFF Research Database (Denmark)

    Jensen, Henrik

    1986-01-01

    Analysis of piezoelectric ultrasonic transducers implies a solution of a boundary value problem, for a boay which consists of different materials, including a piezoelectric part. The problem is dynamic at frequencies, where a typical wavelength is somewhat less than the size of the body. Radiation...... and in particular the finite element method are considered. The finite element method is utilized for analysis of axisymmetric transducers. An explicit, fully piezoelectric, triangular ring element, with linear variations in displacememnt and electric potential is given. The influence of a fluid half-space is also...

  6. Passive wireless ultrasonic transducer systems

    Science.gov (United States)

    Zhong, C. H.; Croxford, A. J.; Wilcox, P. D.

    2014-02-01

    Inductive coupling and capacitive coupling both offer simple solutions to wirelessly probe ultrasonic transducers. This paper investigates the theory and feasibility of such system in the context of non-destructive evaluation (NDE) applications. Firstly, the physical principles and construction of an inductively coupled transducer system (ICTS) and a capacitively coupled transducer system (CCTS) are introduced. Then the development of a transmission line model with the measured impedance of a bonded piezoelectric ceramic disc representing a sensor attached to an arbitrary solid substrate for both systems is described. The models are validated experimentally. Several applications of CCTS are presented, such CCTS for the underwater and through-composite testing.

  7. Digital Phased Array Ultrasonic Inspection system with dynamic focusing

    Science.gov (United States)

    Hwang, J. S.; Shin, H. J.; Song, S. J.; Song, T. K.

    2000-05-01

    Enhancement of the ultrasonic flaw detection and characterization is expected through the development of a high performance PAULI (Phased Array Ultrasonic Inspection) system which can provide high resolution two-dimensional (sector scan: S-scan) images. The high-resolution S-scan image renders inspection results more readable compared to the conventional A-scan and B-scan results. Therefore, it can improve inspection efficiency and reliability. In this study, the ultrasonic imaging technologies developed in medical applications were adapted to develop a digital PAULI system for nondestructive testing. To provide real-time S-scan images, the PAULI system uses 64 independent transceiver channels controlled by proper delay laws for steering and focusing the ultrasound beams along each scan lines. The PAULI system employs a novel dynamic receive focusing technique in order to optimize the lateral resolution by focusing the ultrasound wave at all imaging points. The dynamic receive focusing is achieved in real-time by digital signal processing methods. The feasibility of PAULI system is demonstrated for the NDE of steel structures.

  8. Statistical ultrasonics: the influence of Robert F. Wagner

    Science.gov (United States)

    Insana, Michael F.

    2009-02-01

    An important ongoing question for higher education is how to successfully mentor the next generation of scientists and engineers. It has been my privilege to have been mentored by one of the best, Dr Robert F. Wagner and his colleagues at the CDRH/FDA during the mid 1980s. Bob introduced many of us in medical ultrasonics to statistical imaging techniques. These ideas continue to broadly influence studies on adaptive aperture management (beamforming, speckle suppression, compounding), tissue characterization (texture features, Rayleigh/Rician statistics, scatterer size and number density estimators), and fundamental questions about how limitations of the human eye-brain system for extracting information from textured images can motivate image processing. He adapted the classical techniques of signal detection theory to coherent imaging systems that, for the first time in ultrasonics, related common engineering metrics for image quality to task-based clinical performance. This talk summarizes my wonderfully-exciting three years with Bob as I watched him explore topics in statistical image analysis that formed a rational basis for many of the signal processing techniques used in commercial systems today. It is a story of an exciting time in medical ultrasonics, and of how a sparkling personality guided and motivated the development of junior scientists who flocked around him in admiration and amazement.

  9. FEATURE EXTRACTION OF BONES AND SKIN BASED ON ULTRASONIC SCANNING

    Institute of Scientific and Technical Information of China (English)

    Zheng Shuxian; Zhao Wanhua; Lu Bingheng; Zhao Zhao

    2005-01-01

    In the prosthetic socket design, aimed at the high cost and radiation deficiency caused by CT scanning which is a routine technique to obtain the cross-sectional image of the residual limb, a new ultrasonic scanning method is developed to acquire the bones and skin contours of the residual limb. Using a pig fore-leg as the scanning object, an overlapping algorithm is designed to reconstruct the 2D cross-sectional image, the contours of the bone and skin are extracted using edge detection algorithm and the 3D model of the pig fore-leg is reconstructed by using reverse engineering technology. The results of checking the accuracy of the image by scanning a cylinder work pieces show that the extracted contours of the cylinder are quite close to the standard circumference. So it is feasible to get the contours of bones and skin by ultrasonic scanning. The ultrasonic scanning system featuring no radiation and low cost is a kind of new means of cross section scanning for medical images.

  10. Ultrasonic wireless health monitoring

    Science.gov (United States)

    Petit, Lionel; Lefeuvre, Elie; Guyomar, Daniel; Richard, Claude; Guy, Philippe; Yuse, Kaori; Monnier, Thomas

    2006-03-01

    The integration of autonomous wireless elements in health monitoring network increases the reliability by suppressing power supplies and data transmission wiring. Micro-power piezoelectric generators are an attractive alternative to primary batteries which are limited by a finite amount of energy, a limited capacity retention and a short shelf life (few years). Our goal is to implement such an energy harvesting system for powering a single AWT (Autonomous Wireless Transmitter) using our SSH (Synchronized Switch Harvesting) method. Based on a non linear process of the piezoelement voltage, this SSH method optimizes the energy extraction from the mechanical vibrations. This AWT has two main functions : The generation of an identifier code by RF transmission to the central receiver and the Lamb wave generation for the health monitoring of the host structure. A damage index is derived from the variation between the transmitted wave spectrum and a reference spectrum. The same piezoelements are used for the energy harvesting function and the Lamb wave generation, thus reducing mass and cost. A micro-controller drives the energy balance and synchronizes the functions. Such an autonomous transmitter has been evaluated on a 300x50x2 mm 3 composite cantilever beam. Four 33x11x0.3 mm 3 piezoelements are used for the energy harvesting and for the wave lamb generation. A piezoelectric sensor is placed at the free end of the beam to track the transmitted Lamb wave. In this configuration, the needed energy for the RF emission is 0.1 mJ for a 1 byte-information and the Lamb wave emission requires less than 0.1mJ. The AWT can harvested an energy quantity of approximately 20 mJ (for a 1.5 Mpa lateral stress) with a 470 μF storage capacitor. This corresponds to a power density near to 6mW/cm 3. The experimental AWT energy abilities are presented and the damage detection process is discussed. Finally, some envisaged solutions are introduced for the implementation of the required data

  11. Radiation Tolerance Tests of Ultrasonic Oxygen Deficiency Sensors

    CERN Document Server

    Brodzinski, K; Gizicki, W; Jedrusyna, A; Ostropolski, W; Riddone, G

    2006-01-01

    The Large Hadron Collider (LHC), presently under construction at CERN, will contain about 96 tons of high-density helium (liquid and supercritical), mostly located in the underground components of the LHC machine. To detect a dangerous decrease of oxygen concentration in the atmosphere caused by a potential release of helium, the Oxygen Deficiency Hazard Detection system will be applied for the LHC operation in the tunnel and other selected areas. The oxygen concentration is derived on the assumption that the gas added to the air is helium alone. A novel concept of oxygen deficiency detection system, built at the Wroclaw University of Technology (WUT) in Poland, allows verifying the oxygen concentration in the air by means of sound velocity measurements. The paper describes the design and functionality of two prototypes of ultrasonic ODH detection system tested by the WUT. In order to qualify the systems to be used in the LHC tunnel, the stability of ultrasonic transducers and electronics has been checked und...

  12. Techniques of Spectrum and Correlation Characteristics for Ultrasonic Ranging System

    Directory of Open Access Journals (Sweden)

    Tao Gao

    2013-09-01

    Full Text Available Both the spectrum and correlation characteristics are important in constructing excitation sequences to realize the multichannel ultrasonic sensors working together. For LFM excitation sequence, there should not be too many simultaneously fired ultrasonic sensors, because of the limited available frequency band of the ultrasonic ranging system. The optimized CFM excitation sequences are proposed to trigger multiple-user ultrasonic sensors in this paper. Comparing with the CFM excitation sequences without optimization, the NSGA-II based optimization CFM excitation sequences are more spectrally matched to the ultrasonic ranging system. Moreover, the ultrasonic crosstalk among multichannel sensors of an ultrasonic ranging system can be eliminated. Real experiments using an ultrasonic ranging system consisting of eight-channel SensComp 600 series electrostatic sensors excited with optimized CFM excitation sequences validate the suitability of the proposed method. The idea of optimizing CFM excitation sequences can also be used for the ultrasonic ranging system which has more than eight ultrasonic sensors.  

  13. Dynamics of ultrasonic additive manufacturing.

    Science.gov (United States)

    Hehr, Adam; Dapino, Marcelo J

    2017-01-01

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

  14. Research on Phased Array Ultrasonic Damage Detection and Fuzzy Sets Based Image Enhancement%基于模糊集的相控阵超声监测成像图像增强研究

    Institute of Scientific and Technical Information of China (English)

    孙亚杰; 姜剑; 张永宏

    2014-01-01

    Ultrasonic signal processing techniques to get more accurate image monitoring. Dominate the beam orien-tation by controlling the signal time delay,in order to monitor the structural damage. Analysis of the characteristics of signal of structural damage cases does a favor to enhance the signal-to-noise ratio. Then the monitoring signal can be displayed in the way of gray level image according to the scanning angle. Because of the defect of the original im-age,dealing the image with the photographic enhancement which bases on fuzzy sets can improve the image recogni-tion. The method is analyzed in the aluminum sheet structure,validating the correctness and availability.%利用超声信号处理的方法,得到更准确的监测图像。通过控制阵元激发信号的时间延迟来控制波束的指向,进而实现结构中的损伤监测。分析结构损伤状况下接收到的信号,根据相控阵原理控制信号的延迟和聚焦,获得更高信噪比的信号。并将相应角度上的监测信号用图像的灰度级来表示。因为原始数据得到的图像并不清晰,所以采用模糊集的图像增强方法进行处理,提高图像的可识别度。该方法在铝板结构中进行实验分析,验证了方法的正确性和有效性。

  15. Time difference based measurement of ultrasonic cavitations in wastewater treatment

    Institute of Scientific and Technical Information of China (English)

    朱昌平

    2016-01-01

    Intensity of cavitation is significant in ultrasonic wastewater treatment, but is complicated to measure.A time difference based method of ultrasonic cavitation measurement is proposed.The time differences at different powers of 495kHz ultrasonic are measured in experiment in comparison with conductimetric method.Simulation results show that time difference and electrical conductivity are both approximately positive proportional to the ultrasonic power.The degradation of PNP solution verifies the availability in wastewater treatment by using ultrasonic.

  16. Detection of Micro-Crack by Ultrasonic Approach of One-Sided Pitch-Catch Method Based on Laser Assisted Heating%基于激光辅助加热的激光超声投捕法识别微裂纹

    Institute of Scientific and Technical Information of China (English)

    李加; 倪辰荫; 张宏超; 董利明; 沈中华

    2013-01-01

    Due to the geometry irregularities of specimens and the inhomogeneous of materials, micro-crack is usually generated by abrupt change of local stress. Traditional detecting techniques using ultrasound, such as pitch-catch method, are difficult to distinguish the micro-crack effectively, because the size of the cracks are so small that they are often hidden from ultrasonic detection by a stronger scattering from the very same structural imperfection, such as surface protuberance, surface grooves, corrosion pits, etc. The laser ultrasonic detecting system is built to detect the surface irregularities based on one-sided pitch-catch method. The laser line source is used to excite ultrasound and the optical deflection beam method is used to detect ultrasound. The traditional pitch-catch method, scanning laser source method and the scanning heating laser source method are used to detect the surface irregularities of specimen which contains a surface protuberance and a surface breaking micro-crack. The pitch-catch method requires high signal to noise ratio of signals and the reliability is poor. The scanning laser source method can detect both one but can not distinguish the crack from them. Based on the characteristics that the micro-crack can get closed partially after illuminated by heating laser, the scanning heating laser method can recognize it efficiently. The finite element method (FEM) is used to calculate the transmitted surface acoustic waves (SAW) which are influenced by different sizes of surface breaking cracks.%工件几何形状不规则或材料性质非均匀时,易发生局部应力突变,导致工件产生裂纹.利用传统的超声检测技术(如超声投捕法)对这种早期裂纹进行检测时,由于裂纹尺寸很小以及工件表面其他的散射物(如表面突起、凹槽和腐蚀坑等)对声波的影响,从而难以有效分辨微裂纹.搭建了基于激光超声投捕法的表面缺陷光学检测系统,超声信号由激光线源激

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

    Science.gov (United States)

    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.

  18. Damage Assessment in Composite Structures Based on Acousto-Ultrasonics - Evaluation of Performance

    NARCIS (Netherlands)

    Moix Bonet, M.; Wierach, P.; Loendersloot, R.; Bach, M.; Woelcken, P.C.; Papadopoulos, M.

    2015-01-01

    This work focuses on the damage detection and assessment of barely visible impact damages that occur after impacting a composite stiffened structure through the acousto-ultrasonics technique. Delaminations and debondings have been introduced in two stiffened panels and afterwards interrogated with a

  19. Phased array ultrasonic technology contribution to engineering critical assessment (ECA) of economizer piping welds

    Energy Technology Data Exchange (ETDEWEB)

    Ciorau, P.; Gray, D.; Daks, W. [Ontario Power Generation, Pickering, Ontario (Canada)]. E-mail: peter.ciorau@opg.com

    2006-09-15

    This paper describes the application of phased array ultrasonic technology for engineering critical assessment of economizer piping welds. The objective is to detect and size fatigue cracks in the counter bore area of carbon steel boiler feedwater piping welds of a thermal station. A size accuracy of {+-} 1 mm for the outer ligament was required.

  20. Evaluation of Ultrasonic Sensors for the Variable Rate Tree Liner Sprayer Development

    Science.gov (United States)

    Sensors functioning reliably under harsh field conditions are needed for the development of variable-rate sprayers to apply pest control agents for tree liners in ornamental nurseries. Two ultrasonic sensors were tested to determine how their durability and detection stability would be influenced by...

  1. Least-Squares Estimation of Imaging Parameters for an Ultrasonic Array Using Known Geometric Image Features

    NARCIS (Netherlands)

    Hunter, A.J.; Drinkwater, B.W.; Wilcox, P.D.

    2011-01-01

    Ultrasonic array images are adversely affected by errors in the assumed or measured imaging parameters. For non-destructive testing and evaluation, this can result in reduced defect detection and characterization performance. In this paper, an autofocus algorithm is presented for estimating and corr

  2. Testresults KROHNE 8-inch ultrasonic flowmeter

    Energy Technology Data Exchange (ETDEWEB)

    Boer, A.H.; Volmer, W.

    1997-07-01

    A new development in the field of ultrasonic liquid flowmeasurements has been achieved with the multichannel liquid ultrasonic flowmeter; the first for use in maintenance-free custody transfer applications. Although ultrasonic flowmeters are used for applications in the oil industry for many years, this new development will have a big impact on custody transfer flow measurement. Not only because of the compactness, but also because of the low investment and operating cost of this flowmeter. This paper describes the system and the method of operation as well as practical experiences and achieved test results of this flowmeter. (author)

  3. Fundamentals and applications of ultrasonic waves

    CERN Document Server

    Cheeke, J David N

    2002-01-01

    Ultrasonics. A subject with applications across all the basic sciences, engineering, medicine, and oceanography, yet even the broader topic of acoustics is now rarely offered at undergraduate levels. Ultrasonics is addressed primarily at the doctoral level, and texts appropriate for beginning graduate students or newcomers to the field are virtually nonexistent.Fundamentals and Applications of Ultrasonic Waves fills that void. Designed specifically for senior undergraduates, beginning graduate students, and those just entering the field, it begins with the fundamentals, but goes well beyond th

  4. Nondestructive Testing and Characterization of Residual Stress Field Using an Ultrasonic Method

    Institute of Scientific and Technical Information of China (English)

    SONG Wentao; XU Chunguang; PAN Qinxue; SONG Jianfeng

    2016-01-01

    To address the difficulty in testing and calibrating the stress gradient in the depth direction of mechanical components, a new technology of nondestructive testing and characterization of the residual stress gradient field by ultrasonic method is proposed based on acoustoelasticity theory. By carrying out theoretical analysis, the sensitivity coefficients of different types of ultrasonic are obtained by taking the low carbon steel(12%C) as a research object. By fixing the interval distance between sending and receiving transducers, the mathematical expressions of the change of stress and the variation of time are established. To design one sending-one receiving and oblique incidence ultrasonic detection probes, according to Snell law, the critically refracted longitudinal wave (LCR wave) is excited at a certain depth of the fixed distance of the tested components. Then, the relationship between the depth of LCR wave detection and the center frequency of the probe in Q235 steel is obtained through experimental study. To detect the stress gradient in the depth direction, a stress gradient LCR wave detection model is established, through which the stress gradient formula is derived by the relationship between center frequency and detecting depth. A C-shaped stress specimen of Q235 steel is designedto conduct stress loading tests, and the stress is measured with the five group probes at different center frequencies. The accuracy of ultrasonic testing is verified by X-ray stress analyzer. The stress value of each specific depth is calculated using the stress gradient formula. Accordingly, the ultrasonic characterization of residual stress field is realized. Characterization results show that the stress gradient distribution is consistent with the simulation in ANSYS. The new technology can be widely applied in the detection of the residual stress gradient field caused by mechanical processing, such as welding and shot peening.

  5. Nondestructive testing and characterization of residual stress field using an ultrasonic method

    Science.gov (United States)

    Song, Wentao; Xu, Chunguang; Pan, Qinxue; Song, Jianfeng

    2016-03-01

    To address the difficulty in testing and calibrating the stress gradient in the depth direction of mechanical components, a new technology of nondestructive testing and characterization of the residual stress gradient field by ultrasonic method is proposed based on acoustoelasticity theory. By carrying out theoretical analysis, the sensitivity coefficients of different types of ultrasonic are obtained by taking the low carbon steel(12%C) as a research object. By fixing the interval distance between sending and receiving transducers, the mathematical expressions of the change of stress and the variation of time are established. To design one sending-one receiving and oblique incidence ultrasonic detection probes, according to Snell law, the critically refracted longitudinal wave (LCR wave) is excited at a certain depth of the fixed distance of the tested components. Then, the relationship between the depth of LCR wave detection and the center frequency of the probe in Q235 steel is obtained through experimental study. To detect the stress gradient in the depth direction, a stress gradient LCR wave detection model is established, through which the stress gradient formula is derived by the relationship between center frequency and detecting depth. A C-shaped stress specimen of Q235 steel is designed to conduct stress loading tests, and the stress is measured with the five group probes at different center frequencies. The accuracy of ultrasonic testing is verified by X-ray stress analyzer. The stress value of each specific depth is calculated using the stress gradient formula. Accordingly, the ultrasonic characterization of residual stress field is realized. Characterization results show that the stress gradient distribution is consistent with the simulation in ANSYS. The new technology can be widely applied in the detection of the residual stress gradient field caused by mechanical processing, such as welding and shot peening.

  6. USING LASER ULTRASONICS FOR NONDESTRUCTIVE RESIDUAL STRESS EVALUATION

    Institute of Scientific and Technical Information of China (English)

    贺玲凤; Shoichi Kobayashi

    2002-01-01

    A non-contact measuring technique of ultrasonic waves velocity is proposed, in which Rayleigh waves are detected by a laser Doppler velocimeter and the velocity is measured precisely by means of a sing-around unit and a digital oscilloscope. With the proposed technique, the acoustoelastic coefficient of Rayleigh waves in mild steel SS41 is obtained, which is in good agreement with that obtained by the contact method. Furthermore the non-contact technique is applied to evaluate the residual stress in a butt-welded steel plate, the result is reasonable.

  7. Phased array ultrasonic inspection of Friction Stir Weldments

    Science.gov (United States)

    Lamarre, André; Moles, Michael; Lupien, Vincent

    2000-05-01

    Phased array ultrasonic inspection methods have been developed for the rapid inspection of Friction Stir Weldments (FSW) on Delta rocket cryogenic tanks. A comprehensive review was performed to identify NDE methods that are suitable for the detection of defects in this new welding process. The search included a review of traditional and advanced NDE methods that were capable of demonstrating both the sensitivity and inspection rates required for this examination. This paper will discuss the theory behind phased array techniques, fundamentals of several probe designs for FSW configurations, and the advantages of using phased arrays over conventional NDE methods for this applications.

  8. Ultrasonic Phased Array Inspection Simulations of Welded Components at NASA

    Science.gov (United States)

    Roth, D. J.; Tokars, R. P.; Martin, R. E.; Rauser, R. W.; Aldrin, J. C.; Schumacher, E. J.

    2009-01-01

    Comprehensive and accurate inspections of welded components have become of increasing importance as NASA develops new hardware such as Ares rocket segments for future exploration missions. Simulation and modeling will play an increased role in the future for nondestructive evaluation in order to better understand the physics of the inspection process and help explain the experimental results. It will also help to prove or disprove the feasibility for an inspection method or inspection scenario, help optimize inspections, and allow to a first approximation limits of detectability. This study presents simulation and experimental results for an ultrasonic phased array inspection of a critical welded structure important for NASA future exploration vehicles.

  9. Liquid level sensor using ultrasonic Lamb waves.

    Science.gov (United States)

    Sakharov, V E; Kuznetsov, S A; Zaitsev, B D; Kuznetsova, I E; Joshi, S G

    2003-06-01

    This paper describes a novel, noninvasive method for measurement of liquid level in closed metal tanks that are under high pressure. It is based on the use of ultrasonic Lamb waves propagating along the tank wall. Contact with liquid substantially changes the characteristics of these waves and this can be used as an indicator of liquid presence. Theoretical analysis shows that the symmetric and antisymmetric Lamb wave modes, both fundamental and higher order, are sensitive to presence of the liquid. The optimal wave frequency depends on the thickness of the tank wall and wall material. A prototype level sensor based on this principle has been developed. It uses two pairs of wedge transducers to generate and detect Lamb waves propagating along the circumference of the gas tank. An operating frequency of 100 kHz is found to be optimal for use with tanks having a wall thickness of 30-50 mm. Prototype sensors developed under this program have been used successfully in oil fields in the far northern region of Russia.

  10. Ultrasonic Signal Processing Algorithm for Crack Information Extraction on the Keyway of Turbine Rotor Disk

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hong Kyu; Seo, Won Chan; Park, Chan [Pukyong National University, Busan (Korea, Republic of); Lee, Jong O; Son, Young Ho [KIMM, Daejeon (Korea, Republic of)

    2009-10-15

    An ultrasonic signal processing algorithm was developed for extracting the information of cracks generated around the keyway of a turbine rotor disk. B-scan images were obtained by using keyway specimens and an ultrasonic scan system with x-y position controller. The B-scan images were used as input images for 2-Dimensional signal processing, and the algorithm was constructed with four processing stages of pre-processing, crack candidate region detection, crack region classification and crack information extraction. It is confirmed by experiments that the developed algorithm is effective for the quantitative evaluation of cracks generated around the keyway of turbine rotor disk

  11. Application of wavelet packet entropy flow manifold learning in bearing factory inspection using the ultrasonic technique.

    Science.gov (United States)

    Chen, Xiaoguang; Liu, Dan; Xu, Guanghua; Jiang, Kuosheng; Liang, Lin

    2014-12-26

    For decades, bearing factory quality evaluation has been a key problem and the methods used are always static tests. This paper investigates the use of piezoelectric ultrasonic transducers (PUT) as dynamic diagnostic tools and a relevant signal classification technique, wavelet packet entropy (WPEntropy) flow manifold learning, for the evaluation of bearing factory quality. The data were analyzed using wavelet packet entropy (WPEntropy) flow manifold learning. The results showed that the ultrasonic technique with WPEntropy flow manifold learning was able to detect different types of defects on the bearing components. The test method and the proposed technique are described and the different signals are analyzed and discussed.

  12. Perancangan Pemantau Kapasitas Tong Air Menggunakan Sensor Ultrasonic dengan Sms Gatewayberbasis Atmega 8535

    OpenAIRE

    Syuhada, Fajar

    2015-01-01

    The purpose of making this thesis is to apply the CodeVision AVR ATMEGA 8535 to process the data controller in the capacity of the tank using ultrasonic sensors. capacity values are processed in the microcontroller is a change in the water level in the sensor detection using ultrasonic sensors CodeVision AVR is a software to create a program based on the C language which is then inserted into the microcontroller. Programs that are compiled on CodeVision AVR, that is executed...

  13. Navigation control for mobile robot based on vision and ultrasonic sensors

    Science.gov (United States)

    Takahashi, Satoru; Nara, Shunsuke

    2007-10-01

    This paper treats the navigation problem of a mobile robot based on vision information and ultrasonic data. In our method, by calculating the optical flow on the images, the mobile robot can detect obstacles which exist ahead of it, further avoiding the area of obstacles, it can make the optimal trajectory to the final goal. Then, in order to generate the optimal trajectory, the distance between a mobile robot and obstacle is needed and then is obtained by evaluating a function with ultrasonic information. Through some experiments, we show how our proposed method is effective.

  14. Development of a Novel Ultrasonic Waveguide Transducer for Under-Sodium Viewing

    Science.gov (United States)

    Wang, K.; Chien, H. T.; Lawrence, W. P.; Engel, D.; Sheen, S. H.

    2011-06-01

    A novel ultrasonic waveguide transducer (UWT) has been developed for under-sodium inspection of sodium-cooled fast reactor (SFR). Its performance was evaluated and compared with other four types of waveguide designs. The signal transmission efficiency and detection sensitivity has been greatly improved. The preliminary results in molten sodium demonstrate that our novel ultrasonic waveguide transducer is able to achieve 1 mm lateral resolution and 0.5 mm vertical resolution in molten sodium with temperature ranged from 300 °F to 650 °F.

  15. Nondestructive Evaluation of Adhesive Bonds via Ultrasonic Phase Measurements

    Science.gov (United States)

    Haldren, Harold A.; Perey, Daniel F.; Yost, William T.; Cramer, K. Elliott; Gupta, Mool C.

    2016-01-01

    The use of advanced composites utilizing adhesively bonded structures offers advantages in weight and cost for both the aerospace and automotive industries. Conventional nondestructive evaluation (NDE) has proved unable to reliably detect weak bonds or bond deterioration during service life conditions. A new nondestructive technique for quantitatively measuring adhesive bond strength is demonstrated. In this paper, an ultrasonic technique employing constant frequency pulsed phased-locked loop (CFPPLL) circuitry to monitor the phase response of a bonded structure from change in thermal stress is discussed. Theoretical research suggests that the thermal response of a bonded interface relates well with the quality of the adhesive bond. In particular, the effective stiffness of the adhesive-adherent interface may be extracted from the thermal phase response of the structure. The sensitivity of the CFPPLL instrument allows detection of bond pathologies that have been previously difficult-to-detect. Theoretical results with this ultrasonic technique on single epoxy lap joint (SLJ) specimens are presented and discussed. This technique has the potential to advance the use of adhesive bonds - and by association, advanced composite structures - by providing a reliable method to measure adhesive bond strength, thus permitting more complex, lightweight, and safe designs.

  16. Compensating temperature-induced ultrasonic phase and amplitude changes

    Science.gov (United States)

    Gong, Peng; Hay, Thomas R.; Greve, David W.; Junker, Warren R.; Oppenheim, Irving J.

    2016-04-01

    In ultrasonic structural health monitoring (SHM), environmental and operational conditions, especially temperature, can significantly affect the propagation of ultrasonic waves and thus degrade damage detection. Typically, temperature effects are compensated using optimal baseline selection (OBS) or optimal signal stretch (OSS). The OSS method achieves compensation by adjusting phase shifts caused by temperature, but it does not fully compensate phase shifts and it does not compensate for accompanying signal amplitude changes. In this paper, we develop a new temperature compensation strategy to address both phase shifts and amplitude changes. In this strategy, OSS is first used to compensate some of the phase shifts and to quantify the temperature effects by stretching factors. Based on stretching factors, empirical adjusting factors for a damage indicator are then applied to compensate for the temperature induced remaining phase shifts and amplitude changes. The empirical adjusting factors can be trained from baseline data with temperature variations in the absence of incremental damage. We applied this temperature compensation approach to detect volume loss in a thick wall aluminum tube with multiple damage levels and temperature variations. Our specimen is a thick-walled short tube, with dimensions closely comparable to the outlet region of a frac iron elbow where flow-induced erosion produces the volume loss that governs the service life of that component, and our experimental sequence simulates the erosion process by removing material in small damage steps. Our results show that damage detection is greatly improved when this new temperature compensation strategy, termed modified-OSS, is implemented.

  17. Ultrasonic attenuation in cuprate superconductors

    Indian Academy of Sciences (India)

    T Gupta; D M Gaitonde

    2002-05-01

    We calculate the longitudinal ultrasonic attenuation rate (UAR) in clean d-wave superconductors in the Meissner and the mixed phases. In the Meissner phase we calculate the contribution of previously ignored processes involving the excitation of a pair of quasi-holes or quasi-particles. There is a contribution ∝ in the regime B ≪ F ≪ 0 and a contribution ∝ 1/ in the regime F ≪ B ≪ 0. We find that these contributions to the UAR are large and cannot be ignored. In the mixed phase, using a semi-classical description, we calculate the electronic quasi-particle contribution to the UAR which at very low , has a independent term proportional to $\\sqrt{H}$.

  18. Ultrasonic Characterization of Glass Beads

    Science.gov (United States)

    Lassila, I.; Siiriä, S.; Gates, F. K.; Hæggström, E.

    2008-02-01

    We report on the progress in developing a method for an in-line granule size measurement using ultrasonic through transmission method. The knowledge of granule size is important in the production of pharmaceutical dosage forms where the current optical and rheological methods have limitations such as fouling of the optical windows. The phase velocity of a wave propagated through interstitial air between glass balls of 1, 2 and 10 mm in diameter was 254±5 m/s, 261±3 m/s and 320±9 m/s, respectively. The power spectral density of the received signals showed that high frequencies were attenuated more in case of smaller beads due to increased scattering.

  19. A New Approach for Quantitative Evaluation of Ultrasonic Wave Attenuation in Composites

    Science.gov (United States)

    Ni, Qing-Qing; Li, Ran; Xia, Hong

    2017-02-01

    When ultrasonic waves propagate in composite materials, the propagation behaviors result from the combination effects of various factors, such as material anisotropy and viscoelastic property, internal microstructure and defects, incident wave characteristics and interface condition between composite components. It is essential to make it clear how these factors affect the ultrasonic wave propagation and attenuation characteristics, and how they mutually interact on each other. In the present paper, based on a newly developed time-domain finite element analysis code, PZflex, a unique approach for clarifying the detailed influence mechanism of aforementioned factors is proposed, in which each attenuation component can be extracted from the overall attenuation and analyzed respectively. By taking into consideration the interrelation between each individual attenuation component, the variation behaviors of each component and internal dynamic stress distribution against material anisotropy and matrix viscosity are separately and quantitatively evaluated. From the detailed analysis results of each attenuation component, the energy dissipation at interface is a major component in ultrasonic wave attenuation characteristics, which can provide a maximum contribution rate of 68.2 % to the overall attenuation, and each attenuation component is closely related to the material anisotropy and viscoelasticity. The results clarify the correlation between ultrasonic wave propagation characteristics and material viscoelastic properties, which will be useful in the further development of ultrasonic technology in defect detection.

  20. Comparison of ultrasonic wave speed measurements on wax at elevated temperatures to numerical method predictions

    Science.gov (United States)

    Moore, David G.; Stair, Sarah L.; Jack, David A.

    2017-02-01

    Ultrasonic stress wave amplitude and time-of-flight values may change as a media is heated. The measurement of relatively small variations in velocity and material attenuation can detect and quantify significant variations within a material's microstructure, such as a change in phase from solid to liquid. This paper discusses the experimental setup, ultrasonic wave speed tracking methods and signal analysis algorithms that are used in this study to document the changes within highly attenuative wax material as it is either being heated or cooled from 25°C to 90°C. The experimental set-up utilizes ultrasonic probes in a through-transmission configuration. The ultrasonic waveforms are recorded and analyzed during long duration thermal experiments. To complement the ultrasonic data, a Discontinuous-Galerkin Model (DGM) was also created, which uses unstructured meshes to determine how waves travel in this media and how the sound interacts with the prescribed boundary conditions. This numerical method solves particle motion travel using partial differential equations and outputs a wave trace per unit time. Both experimental and analytical data are presented and compared. The experimental and analytical data share some similarities; however, the differences between the two, including a high frequency component present in the analytical data that is not observed in the experimental data, are continuing to be studied and addressed in the model.

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

    Science.gov (United States)

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

    2014-12-01

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

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

    Science.gov (United States)

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

    2011-01-01

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

  3. A method to simulate grictional heating at defects in ultrasonic infrared thermography

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Won Jar; Choi, Man Yong; Park, Jeong Hak [Center for Safety Measurement, KRISS, Daejeon(Korea, Republic of)

    2015-12-15

    Ultrasonic infrared thermography is an active thermography methods. In this method, mechanical energy is introduced to a structure, it is converted into heat energy at the defects, and an infrared camera detects the heat for inspection. The heat generation mechanisms are dependent on many factors such as structure characteristics, defect type, excitation method and contact condition, which make it difficult to predict heat distribution in ultrasonic infrared thermography. In this paper, a method to simulate frictional heating, known to be one of the main heat generation mechanisms at the closed defects in metal structures, is proposed for ultrasonic infrared thermography. This method uses linear vibration analysis results without considering the contact boundary condition at the defect so that it is intuitive and simple to implement. Its advantages and disadvantages are also discussed. The simulation results show good agreement with the modal analysis and experiment result.

  4. Guided-wave tomography imaging plate defects by laser-based ultrasonic techniques

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jun Pil; Lim, Ju Young; Cho, Youn Ho [School of Mechanical Engineering, Pusan National University, Pusan (Korea, Republic of)

    2014-12-15

    Contact-guided-wave tests are impractical for investigating specimens with limited accessibility and rough surfaces or complex geometric features. A non-contact setup with a laser-ultrasonic transmitter and receiver is quite attractive for guided-wave inspection. In the present work, we developed a non-contact guided-wave tomography technique using the laser-ultrasonic technique in a plate. A method for Lamb-wave generation and detection in an aluminum plate with a pulsed laser-ultrasonic transmitter and Michelson-interferometer receiver was developed. The defect shape and area in the images obtained using laser scanning, showed good agreement with the actual defect. The proposed approach can be used as a non-contact online inspection and monitoring technique.

  5. A study on laser-based ultrasonic technique by the use of guided wave tomographic imaging

    Energy Technology Data Exchange (ETDEWEB)

    Park, Junpil, E-mail: jpp@pusan.ac.kr; Lim, Juyoung, E-mail: jpp@pusan.ac.kr [Graduate school, School of Mechanical Engineering, Pusan National University (Korea, Republic of); Cho, Younho [School of Mechanical Engineering, Pusan National University (Korea, Republic of); Krishnaswamy, Sridhar [Center for Quality Engineering and Failure Prevention, Northwestern University, Evanston, IL (United States)

    2015-03-31

    Guided wave tests are impractical for investigating specimens with limited accessibility and coarse surfaces or geometrically complicated features. A non-contact setup with a laser ultrasonic transmitter and receiver is the classic attractive for guided wave inspection. The present work was done to develop a non-contact guided-wave tomography technique by laser ultrasonic technique in a plate-like structure. A method for Lam wave generation and detection in an aluminum plate with a pulse laser ultrasonic transmitter and a Michelson interferometer receiver has been developed. In the images obtained by laser scanning, the defect shape and area showed good agreement with the actual defect. The proposed approach can be used as a non-contact-based online inspection and monitoring technique.

  6. Phase-delayed laser diode array allows ultrasonic guided wave mode selection and tuning

    Science.gov (United States)

    Karppinen, Pasi; Salmi, Ari; Moilanen, Petro; Karppinen, Timo; Zhao, Zuomin; Myllylä, Risto; Timonen, Jussi; Hæggström, Edward

    2013-04-01

    Selecting and tuning modes are useful in ultrasonic guided wave non-destructive testing (NDT) since certain modes at various center frequencies are sensitive to specific types of defects. Ideally one should be able to select both the mode and the center frequency of the launched waves. We demonstrated that an affordable laser diode array can selectively launch either the S0 or A0 ultrasonic wave mode at a chosen center frequency into a polymer plate. A fiber-coupled diode array (4 elements) illuminated a 2 mm thick acrylic plate. A predetermined time delay matching the selected mode and frequency was employed between the output of the elements. The generated ultrasound was detected by a 215 kHz piezo receiver. Our results imply that this array permits non-contacting guided wave ultrasonic NDT. The solution is small, affordable, and robust in comparison to conventional pulsed lasers. In addition, it does not require experienced operators.

  7. Standard guide for evaluating performance characteristics of phased-Array ultrasonic testing instruments and systems

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This guide describes procedures for evaluating some performance characteristics of phased-array ultrasonic examination instruments and systems. 1.2 Evaluation of these characteristics is intended to be used for comparing instruments and systems or, by periodic repetition, for detecting long-term changes in the characteristics of a given instrument or system that may be indicative of impending failure, and which, if beyond certain limits, will require corrective maintenance. Instrument characteristics measured in accordance with this guide are expressed in terms that relate to their potential usefulness for ultrasonic examinations. Other electronic instrument characteristics in phased-array units are similar to non-phased-array units and may be measured as described in E 1065 or E 1324. 1.3 Ultrasonic examination systems using pulsed-wave trains and A-scan presentation (rf or video) may be evaluated. 1.4 This guide establishes no performance limits for examination systems; if such acceptance criteria ar...

  8. Feasibility study of flexible phased array ultrasonic technology using irregular surface specimen

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Pyo; Moon, Yong Sik; Jung, Nam Du [NDE Performance Demonstration Team, Korea Hydro and Nuclear Power, Central Research Institute, Daejeon (Korea, Republic of)

    2015-02-15

    Nuclear power plant contain many dissimilar metal welds that connect carbon steel components with stainless steel pipes using alloy 600 welding materials. Primary water stress corrosion cracks at dissimilar metal welds have been continuously reported around the world. In periodic integrity evaluations, dissimilar metal welds are examined using a generic ultrasonic testing procedure, KPD-UT-10. In this procedure, the gap between the probe and examination surface is limited to 1/32 inch (0.8 mm). It is not easy to test some dissimilar metal welds in Korean plants applying ordinary technology because of their tapered shapes and irregular surface conditions. This paper introduces a method for applying a flexible phased array technology to improve the reliability of ultrasonic testing results for various shapes and surface conditions. The artificial flaws in specimens with irregular surfaces were completely detected using the flexible phased array ultrasonic technology. Therefore, it can be said that the technology is applicable to field examination.

  9. The effect of beam directivity on the inspection of anisotropic materials using ultrasonic arrays

    Science.gov (United States)

    Lane, C. J. L.; Wilcox, P. D.

    2012-05-01

    The beam directivity from an ultrasonic transducer in isotropic materials is well documented. However, beam directivities in elastically anisotropic materials and their effect on ultrasonic NDE inspection has been investigated far less extensively. In this paper, analytical and numerical finite element models are developed to predict the beam directivity in a single crystal nickel-based superalloy. This material is highly anisotropic and is used widely in the gas-turbine industry. The developed models are used to investigate the effect of the crystallographic orientation on the beam directivity. In turn, the effect of beam directivity on defect detection sensitivity and characterization capability using an ultrasonic array is demonstrated. It is shown that the effect is particularly important for the accurate sizing of small defects.

  10. Sensitivity Distribution Properties of a Phase-Shifted Fiber Bragg Grating Sensor to Ultrasonic Waves

    Directory of Open Access Journals (Sweden)

    Qi Wu

    2014-01-01

    Full Text Available In this research, the sensitivity distribution properties of a phase-shifted fiber Bragg grating (PS-FBG to ultrasonic waves were investigated employing the surface attachment method. A careful consideration was taken and examined by experimental results to explain that the distances and angles between the sensor and ultrasonic source influence not only the amplitudes, but also the initial phases, waveforms, and spectra of detected signals. Furthermore, factors, including the attachment method and the material’s geometric dimensions, were also discussed. Although these results were obtained based on PS-FBG, they are also applicable to a normal FBG sensor or even an optical fiber sensor, due to the identical physical changes induced by ultrasonic waves in all three. Thus, these results are useful for applications of optical fiber sensors in non-destructive testing and structural health monitoring.

  11. Sensitivity distribution properties of a phase-shifted fiber bragg grating sensor to ultrasonic waves.

    Science.gov (United States)

    Wu, Qi; Okabe, Yoji; Saito, Kazuya; Yu, Fengming

    2014-01-09

    In this research, the sensitivity distribution properties of a phase-shifted fiber Bragg grating (PS-FBG) to ultrasonic waves were investigated employing the surface attachment method. A careful consideration was taken and examined by experimental results to explain that the distances and angles between the sensor and ultrasonic source influence not only the amplitudes, but also the initial phases, waveforms, and spectra of detected signals. Furthermore, factors, including the attachment method and the material's geometric dimensions, were also discussed. Although these results were obtained based on PS-FBG, they are also applicable to a normal FBG sensor or even an optical fiber sensor, due to the identical physical changes induced by ultrasonic waves in all three. Thus, these results are useful for applications of optical fiber sensors in non-destructive testing and structural health monitoring.

  12. Extraction of antioxidants from plants using ultrasonic methods and their antioxidant capacity.

    Science.gov (United States)

    Adam, Martin; Dobiás, Petr; Eisner, Ales; Ventura, Karel

    2009-01-01

    The analytical method based on the HPLC coupled with UV detection (HPLC-UV) for the determination of selected antioxidants (i.e. esculetin, scopoletin, 7-hydroxycoumarine, rutin, xanthotoxin, 5-methoxypsoralen and quercetin) in plant material was developed. Two ultrasonic extraction methods for the isolation of these compounds from the plants such as Mentha longifolia L., Mentha spicata L., Ruta graveolens L., Achyllea millefolium L., Plantago lanceolata L. and Coriandrum sativum L. were used. Both of these methods, i.e. ultrasonic probe and ultrasonic bath, were optimised and compared to each other. For the proposed HPLC-UV method LOQ values in the range from 22.7 (xanthotoxin) up to 97.2 ng/mL (rutin) were obtained. For all extracts the antioxidant capacity based on the reduction of free 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical was also determined. Obtained results ranged from 10.11 up to 73.50% of DPPH radical inhibition.

  13. Ultrasonic Histotripsy for Tissue Therapy

    Science.gov (United States)

    Pahk, K. J.; Dhar, D. K.; Malago, M.; Saffari, N.

    2015-01-01

    Hepatocyte transplantation has been considered and investigated as a promising and alternative method to liver transplantation for treating liver-based metabolic disorder in newborns over the past two decades. Although some clinical trials have been conducted and shown clinical benefits and outcomes, it is difficult to deliver and achieve a desired level of integration and transplantation of hepatocytes in the liver parenchyma. To overcome this problem, this work introduces an alternative method to a portal-infused-hepatocyte cell transplantation. To improve the level of engraftment of transplantable hepatocytes, these are injected directly into cavities generated by ultrasonic histotripsy. Histotripsy is an extracorporeal noninvasive technique which has been recently developed using high intensity focused ultrasound (HIFU) for inducing tissue fractionation with no coagulative necrosis. The exact mechanisms for the tissue fractionation are not well understood yet; but the possible mechanisms are thought to be a combination of nonlinear wave propagation effect, explosive bubble growth and ultrasonic atomization. The main objectives of this work are to demonstrate the feasibility of this new cell therapy and evaluate and distinguish between the different types of cavitation activity for either a thermally or a mechanically induced lesion. In the present work, numerical studies on the bubble dynamics (the Gilmore-Akulichev bubble model coupled with the Khokhlov-Zabolotskaya-Kuznetsov equation) and both ex- and in vivo liver experiments are conducted with histological analysis (haematoxylin and eosin stain). The numerical and the experimental results suggest that (a) the acoustic emissions emitted during the thermal ablation and the histotripsy exposure can be distinguished both numerically and experimentally and (b) the proposed cell therapy may potentially form an effective and safe clinical treatment for replacing and correcting disordered hepatocytes, although the

  14. Introduction to Rheology for Ultrasonic Engineers

    Science.gov (United States)

    Ueda, Takanobu

    2008-05-01

    Here, I introduce the fundamental concept and methodology of rheology measurement especially to researchers in the field of ultrasonic engineering. Althogh we consider the material as fluid and characterize it in terms of viscosity accompanied by its complex part representing elasticity, ultrasonic spectroscopy regards the material as solid with elasticity, which determines ultrasonic velocity. Although these two research fields have contrary viewpoints, they share the purpose of the study, that is, to characterize the mechanical properties of the material as a function of frequency or shear rate and to reveal its mechanism and structure at the molecular level. In this paper, I show the basic methods of rheology measurement and analysis in relation to ultrasonic technology.

  15. Flexible Ultrasonic Phased-Array Probe

    Institute of Scientific and Technical Information of China (English)

    施克仁; 阙开良; 郭大勇

    2004-01-01

    In ultrasonic phased-array testing, most probes are rigid with fixed elements. However, when testing a cambered piece, a rigid probe cannot be used directly, but an ultrasonic chock or coupling media must be used, which adds cost and reduces the accuracy. The objective of this research was to improve the tests of cambered pieces. A flexible ultrasonic phased-array probe was developed to do the flexible phased-array testing. The key technologies in the flexible phased-array probe include the probe design and the phased-array control. A new method was developed to design the flexible probe according to the curvature of the piece and the test depth. The method includes the calculation of the element's height (he), the relative rotation angle ((e), the distance between the adjoining elements (de), and the element's effective testing range. A flexible ultrasonic phased-array probe has been developed using this method.

  16. Ultrasonically-assisted Thermal Stir Welding System

    Science.gov (United States)

    Ding, R. Jeffrey (Inventor)

    2014-01-01

    A welding head assembly has a work piece disposed between its containment plates' opposing surfaces with the work piece being maintained in a plastic state thereof at least in a vicinity of the welding head assembly's stir rod as the rod is rotated about its longitudinal axis. The welding head assembly and the work piece experience relative movement there between in a direction perpendicular to the rod's longitudinal axis as the work piece is subjected to a compressive force applied by the containment plates. A first source coupled to the first containment plate applies a first ultrasonic wave thereto such that the first ultrasonic wave propagates parallel to the direction of relative movement. A second source coupled to the second containment plate applies a second ultrasonic wave thereto such that the second ultrasonic wave propagates parallel to the direction of relative movement.propagates parallel to the direction of relative movement.

  17. Ultrasonic ranking of toughness of tungsten carbide

    Science.gov (United States)

    Vary, A.; Hull, D. R.

    1983-01-01

    The feasibility of using ultrasonic attenuation measurements to rank tungsten carbide alloys according to their fracture toughness was demonstrated. Six samples of cobalt-cemented tungsten carbide (WC-Co) were examined. These varied in cobalt content from approximately 2 to 16 weight percent. The toughness generally increased with increasing cobalt content. Toughness was first determined by the Palmqvist and short rod fracture toughness tests. Subsequently, ultrasonic attenuation measurements were correlated with both these mechanical test methods. It is shown that there is a strong increase in ultrasonic attenuation corresponding to increased toughness of the WC-Co alloys. A correlation between attenuation and toughness exists for a wide range of ultrasonic frequencies. However, the best correlation for the WC-Co alloys occurs when the attenuation coefficient measured in the vicinity of 100 megahertz is compared with toughness as determined by the Palmqvist technique.

  18. Ultrasonic intensification as a tool for enhanced microbial biofuel yields.

    Science.gov (United States)

    Naveena, Balakrishnan; Armshaw, Patricia; Tony Pembroke, J

    2015-01-01

    Ultrasonication has recently received attention as a novel bioprocessing tool for process intensification in many areas of downstream processing. Ultrasonic intensification (periodic ultrasonic treatment during the fermentation process) can result in a more effective homogenization of biomass and faster energy and mass transfer to biomass over short time periods which can result in enhanced microbial growth. Ultrasonic intensification can allow the rapid selective extraction of specific biomass components and can enhance product yields which can be of economic benefit. This review focuses on the role of ultrasonication in the extraction and yield enhancement of compounds from various microbial sources, specifically algal and cyanobacterial biomass with a focus on the production of biofuels. The operating principles associated with the process of ultrasonication and the influence of various operating conditions including ultrasonic frequency, power intensity, ultrasonic duration, reactor designs and kinetics applied for ultrasonic intensification are also described.

  19. Modeling and optimization of ultrasonic linear motors

    OpenAIRE

    Fernandez Lopez, José; Perriard, Yves

    2007-01-01

    Ultrasonic motors have received much attention these last years, in particular with regard to their modeling and their design principle. Their operating principle is based on piezoelectric ceramics that convert electrical energy into mechanical energy in the form of vibrations of an elastic body whose surface points perform an elliptic motion with a frequency in the ultrasonic range (≥ 20 kHz). The moving part, which is pressed against the vibrating body by a prestressing force, can move than...

  20. Fundamentals and Applications of Ultrasonic Waves

    CERN Document Server

    Cheeke, J David N

    2012-01-01

    Designed specifically for newcomers to the field, this fully updated second edition begins with fundamentals and quickly advances beyond general wave concepts into an in-depth treatment of ultrasonic waves in isotropic media. Focusing on the physics of acoustic waves, their propagation, technology, and applications, this accessible overview of ultrasonics includes accounts of viscoelasticity and multiple scattering. It examines new technologies, including atomic force acoustic microscopy, lasers, micro-acoustics, and nanotechnology. In addition, it highlights both direct and indirect applicati

  1. Carbon dioxide, but not isoflurane, elicits ultrasonic vocalizations in female rats.

    Science.gov (United States)

    Chisholm, J; De Rantere, D; Fernandez, N J; Krajacic, A; Pang, D S J

    2013-10-01

    Gradual filling of a chamber with carbon dioxide is currently listed by the Canadian Council on Animal Care guidelines as a conditionally acceptable method of euthanasia for rats. Behavioural evidence suggests, however, that exposure to carbon dioxide gas is aversive. Isoflurane is less aversive than carbon dioxide and may be a viable alternative, though objective data are lacking for the period leading up to loss of consciousness. It has been shown that during negative states, such as pain and distress, rats produce ultrasonic vocalizations. The objective of this study was to detect ultrasonic vocalizations during exposure to carbon dioxide gas or isoflurane as an indicator of a negative state. Specialized recording equipment, with a frequency detection range of 10 to 200 kHz, was used to register these calls during administration of each agent. Nine female Sprague-Dawley rats were exposed to either carbon dioxide or isoflurane on two different occasions. All rats vocalized in the ultrasonic range (30 to 70 kHz) during exposure to carbon dioxide. When exposed to isoflurane, no calls were detected from any of the animals. The frequent occurrence of ultrasonic vocalizations during carbon dioxide exposure suggests that the common practice of carbon dioxide euthanasia is aversive to rats and that isoflurane may be a preferable alternative.

  2. Remediation of Diesel Fuel Contaminated Sandy Soil using Ultrasonic Waves

    Directory of Open Access Journals (Sweden)

    Wulandari P.S.

    2010-01-01

    Full Text Available Ultrasonic cleaning has been used in industry for some time, but the application of ultrasonic cleaning in contaminated soil is just recently received considerable attention, it is a very new technique, especially in Indonesia. An ultrasonic cleaner works mostly by energy released from the collapse of millions of microscopic cavitations near the dirty surface. This paper investigates the use of ultrasonic wave to enhance remediation of diesel fuel contaminated sandy soil considering the ultrasonic power, soil particle size, soil density, water flow rate, and duration of ultrasonic waves application.

  3. Performance comparison of Infrared and Ultrasonic sensors for obstacles of different materials in vehicle/ robot navigation applications

    Science.gov (United States)

    Adarsh, S.; Kaleemuddin, S. Mohamed; Bose, Dinesh; Ramachandran, K. I.

    2016-09-01

    In robotics, Ultrasonic sensors and Infrared sensors are commonly used for distance measurement. These low-cost sensors fundamentally address majority of problems related to the obstacle detection and obstacle avoidance. In this paper, the performance comparison of ultrasonic and infrared measurement techniques across obstacles of different types of materials presented. The Vehicle model integrated with the sensors, moving with constant velocity towards different types of obstacles for capturing the distance parameter. Based on the data acquired from the sensors, correlation analysis of the measured distance with actual distance performed. This analysis will be very much useful, to select the right sensor - Ultrasonic sensor / Infrared sensor or a combination of both sensors, while developing the algorithm for addressing obstacle detection problems. The detection range and inherent properties of sensors (reflection/ absorption etc.) also were tested in this experiment.

  4. Laser induced ultrasonic phased array using Full Matrix Capture data acquisition and Total Focusing Method

    OpenAIRE

    Stratoudaki, Theodosia; Clark, Matt; Wilcox, Paul

    2015-01-01

    Laser based ultrasound is a technique where a short pulsed laser is used to generate ultrasound and optical interferometry is used in order to detect the signal. Since both generation and detection of ultrasound is based on optical means, the technique is broadband, non-contact, and couplant free, suitable for large stand-off distances, inspection of components of complex geometries and hazardous environments. A data collection method (Full Matrix Capture) developed for ultrasonic arrays, is ...

  5. High resolution ultrasonic monitoring of muscle dynamics and novel approach to modelling

    OpenAIRE

    Muhammad, Zakir Hossain

    2013-01-01

    The presented work is concerned with the development and application of an ultrasonic detection scheme suitable for the monitoring of muscle dynamics with high temporal - down to 5 µs - and spatial resolution - down to 0.78 µm. A differential detection scheme has been developed to monitor the variations of the velocity of longitudinal polarized ultrasound waves travelling in contracting and relaxing muscle, compensating for variations of the path length by referencing to a frame. The observed...

  6. Ultrasonic Periodontal Probing Based on the Dynamic Wavelet Fingerprint

    Directory of Open Access Journals (Sweden)

    Rose S Timothy

    2005-01-01

    Full Text Available Manual pocket depth probing has been widely used as a retrospective diagnosis method in periodontics. However, numerous studies have questioned its ability to accurately measure the anatomic pocket depth. In this paper, an ultrasonic periodontal probing method is described, which involves using a hollow water-filled probe to focus a narrow beam of ultrasound energy into and out of the periodontal pocket, followed by automatic processing of pulse-echo signals to obtain the periodontal pocket depth. The signal processing algorithm consists of three steps: peak detection/characterization, peak classification, and peak identification. A dynamic wavelet fingerprint (DWFP technique is first applied to detect suspected scatterers in the A-scan signal and generate a two-dimensional black and white pattern to characterize the local transient signal corresponding to each scatterer. These DWFP patterns are then classified by a two-dimensional FFT procedure and mapped to an inclination index curve. The location of the pocket bottom was identified as the third broad peak in the inclination index curve. The algorithm is tested on full-mouth probing data from two sequential visits of 14 patients. Its performance is evaluated by comparing ultrasonic probing results with that of full-mouth manual probing at the same sites, which is taken as the "gold standard."

  7. Effects of Ultrasonic Treatment on Residue Properties

    Institute of Scientific and Technical Information of China (English)

    Sun Yudong; Zhang Qiang; Shi Honghong; Wang Xue; Liu Bo

    2013-01-01

    The changes in properties and structural parameters of four vacuum residue samples before and after ultrasonic treatment were analyzed. Ultrasonic treatment could increase the carbon residue value, decrease the average molecular weight and viscosity, which can barely inlfuence the density of vacuum residue. Meanwhile the constitution of residue can be varied including the decrease in the content of saturates, aromatics and asphaltenes, while the increase in the content of resins can lead to an increase in the total content of asphaltenes and resins. Among the four kinds of residue samples, there is a common trend that the more the content of asphaltenes in feedstock is, the more the increase in the content of resins, the more signiifcant decrease in the aromatic content and the less decrease in the saturates content after ultrasonic treatment of residue would be. Changes in the structure and content of asphaltenes caused by ultrasonic treatment have a signiifcant impact on the changes in residue properties. Ultrasonic treatment has changed the structural parameters of residue such as decrease in the total carbon number of average molecule (CTotal), the total number of rings (RT), the aromatic carbon number (CA),the aromatic rings number (RA) and the naphthenic rings number (RN) , and increase of characterization factor (KH). The study has indicated that ultrasonic treatment of vacuum residue can change the average structure of residue, and the changes in the content and structure of asphaltenes are the main cause leading to property changes. The results of residue hydrotreat-ing revealed that coke yield decreased, whereas the gas and light oil yield and conversion increased after ultrasonic treat-ment of vacuum residue.

  8. Modeling of ultrasonic and terahertz radiations in defective tiles for condition monitoring of thermal protection systems

    Science.gov (United States)

    Kabiri Rahani, Ehsan

    Condition based monitoring of Thermal Protection Systems (TPS) is necessary for safe operations of space shuttles when quick turn-around time is desired. In the current research Terahertz radiation (T-ray) has been used to detect mechanical and heat induced damages in TPS tiles. Voids and cracks inside the foam tile are denoted as mechanical damage while property changes due to long and short term exposures of tiles to high heat are denoted as heat induced damage. Ultrasonic waves cannot detect cracks and voids inside the tile because the tile material (silica foam) has high attenuation for ultrasonic energy. Instead, electromagnetic terahertz radiation can easily penetrate into the foam material and detect the internal voids although this electromagnetic radiation finds it difficult to detect delaminations between the foam tile and the substrate plate. Thus these two technologies are complementary to each other for TPS inspection. Ultrasonic and T-ray field modeling in free and mounted tiles with different types of mechanical and thermal damages has been the focus of this research. Shortcomings and limitations of FEM method in modeling 3D problems especially at high-frequencies has been discussed and a newly developed semi-analytical technique called Distributed Point Source Method (DPSM) has been used for this purpose. A FORTRAN code called DPSM3D has been developed to model both ultrasonic and electromagnetic problems using the conventional DPSM method. This code is designed in a general form capable of modeling a variety of geometries. DPSM has been extended from ultrasonic applications to electromagnetic to model THz Gaussian beams, multilayered dielectrics and Gaussian beam-scatterer interaction problems. Since the conventional DPSM has some drawbacks, to overcome it two modification methods called G-DPSM and ESM have been proposed. The conventional DPSM in the past was only capable of solving time harmonic (frequency domain) problems. Time history was

  9. Application of laser ultrasonic non-destructive evaluation technique to additive manufacturing

    Science.gov (United States)

    Manzo, Anthony J.; Kenderian, Shant; Helvajian, Henry

    2016-04-01

    The change in properties of a propagating ultrasonic wave has been a mainstay characterization tool of the nondestructive evaluation (NDE) industry for identifying subsurface defects (e.g. damage). A variant of this concept could be applicable to 3D additive manufacturing where the existence of defects (e.g. pores) within a sub-layer could mark a product as non-qualifying. We have been exploring the utility of pulsed laser ultrasonic excitation coupled with CW laser heterodyne detection as an all optical scheme for characterizing sub surface layer properties. The all-optical approach permits a straight forward integration into a laser additive processing tool. To test the concept, we have developed an experimental system that generates pulsed ultrasonic waves (the probe) with high bandwidth (sensor that can capture the ultrasonic "return" signal with bandwidth close to 300 MHz. The use of high frequencies enables the detection of smaller defect sites. The technique is time resolved with the sensor and probe as point (>>30-200 microns) beams. Current tests include characterizing properties of spot weld joints between two thin stainless steel plates. The long term objective is to transition the technique into a laser additive manufacturing tool.

  10. Quantitative ultrasonic phased array imaging

    Science.gov (United States)

    Engle, Brady J.; Schmerr, Lester W., Jr.; Sedov, Alexander

    2014-02-01

    When imaging with ultrasonic phased arrays, what do we actually image? What quantitative information is contained in the image? Ad-hoc delay-and-sum methods such as the synthetic aperture focusing technique (SAFT) and the total focusing method (TFM) fail to answer these questions. We have shown that a new quantitative approach allows the formation of flaw images by explicitly inverting the Thompson-Gray measurement model. To examine the above questions, we have set up a software simulation test bed that considers a 2-D scalar scattering problem of a cylindrical inclusion with the method of separation of variables. It is shown that in SAFT types of imaging the only part of the flaw properly imaged is the front surface specular response of the flaw. Other responses (back surface reflections, creeping waves, etc.) are improperly imaged and form artifacts in the image. In the case of TFM-like imaging the quantity being properly imaged is an angular integration of the front surface reflectivity. The other, improperly imaged responses are also averaged, leading to a reduction in some of the artifacts present. Our results have strong implications for flaw sizing and flaw characterization with delay-and-sum images.

  11. Novel use of an ultrasonic cleaning device for fish reproductive studies

    Science.gov (United States)

    Barnes, L. M.; van der Meulen, D. E.; Orchard, B. A.; Gray, C. A.

    2013-02-01

    A major challenge commonly faced in reproductive studies of teleosts is to cost effectively and safely separate oocytes from one another and from surrounding ovarian tissue. This challenge is exacerbated when ovarian tissue has been chemically preserved. Using Platycephalus caeruleopunctatus, a platycephalid species found within oceanic waters along the east coast of Australia, as an example species, within this study we describe and assess the utility of an ultrasonic cleaning device to separate oocytes from preserved ovarian tissue. The ultrasonic cleaning device was observed to separate oocytes from the surrounding ovarian tissue within less than 80 min of treatment and had no deleterious effects on the number of oocytes present. Treatment within the ultrasonic cleaning device reduced oocyte diameters at a constant rate of 3.9 μm per hour among the samples tested. As the ultrasonic cleaning device was able to separate oocytes from connective tissue within 80 min, this observed rate of reduction in oocyte diameters is unlikely to be detected at the resolution at which oocytes are traditionally measured and is less than that reported to occur using alternate chemically derived methods to separate oocytes from preserved connective tissue. Following the assessment of using an ultrasonic cleaning device to separate oocytes from ovarian tissue for P. caeruleopunctatus, this technique has been successfully employed to separate oocytes from preserved ovarian tissue for a variety of other teleost species including Macquaria colonorum, Platycephalus longispinis and Ratabulus diversidens. The use of an ultrasonic cleaning device to separate oocytes from preserved ovarian tissue will increase the efficiency of future investigations into teleost reproductive biology and potentially in other fields of research where particle separation and analysis are required.

  12. Ultrasonic Cleaning of Nuclear Steam Generator by Micro Bubble

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Woo Tae [Korea Hydro and Nuclear Power Co., Daejeon (Korea, Republic of); Kim, Sang Tae; Yoon, Sang Jung [Sae-An Engineering Co., Seoul (Korea, Republic of)

    2012-05-15

    In this paper, we present ultrasonic cleaning technology for a nuclear steam generator using micro bubble. We could extend the boundary of ultrasonic cleaning by using micro bubbles in water. Ultrasonic energy measured was increased about 5 times after the generation of micro bubbles in water. Furthermore, ultrasound energy was measured to be strong enough to create cavitation even though the ultrasound sensor was about 2 meters away from the ultrasonic transducer

  13. Ultrasonic measurement models for imaging with phased arrays

    Science.gov (United States)

    Schmerr, Lester W., Jr.; Engle, Brady J.; Sedov, Alexander; Li, Xiongbing

    2014-02-01

    Ultrasonic imaging measurement models (IMMs) are developed that generate images of flaws by inversion of ultrasonic measurement models. These IMMs are generalizations of the synthetic aperture focusing technique (SAFT) and the total focusing method (TFM). A special case when the flaw is small is shown to generalize physical optics far field inverse scattering (POFFIS) images. The ultrasonic IMMs provide a rational basis for generating and understanding the ultrasonic images produced by delay-and-sum imaging methods.

  14. Separation of metal ions in nitrate solution by ultrasonic atomization

    Science.gov (United States)

    Sato, Masanori; Ikeno, Masayuki; Fujii, Toshitaka

    2004-11-01

    In the ultrasonic atomization of metal nitrate solutions, the molar ratio of metal ions is changed between solution and mist. Small molar metal ions tend to be transferred to mist by ultrasonic wave acceleration, while large molar ions tend to remain in solution. As a result, metal ions can be separated by ultrasonic atomization. We show experimental data and propose a conceptual mechanism for the ultrasonic separation of metal ions.

  15. Ultrasonic Dental Scaler Performance Assessment with an Innovative Cavitometer

    OpenAIRE

    Antonio H.A. Pereira; Camila Tirapelli; Lucimar A. Rodolpho

    2010-01-01

    Problem statement: There is no specific instrument to test ultrasonic dental scalers used in dentistry. Approach: The aim of this research was to develop and test an innovative cavitometer for quantitative and automatic performance assessments of Ultrasonic Dental Scalers (UDS) through the acoustic emission produced by cavitation induced by the tip of the UDS ultrasonic transducer when immersed in aqueous solution. Firstly, an optimized acoustic emission sensor specifically for UDS ultrasonic...

  16. Signal Separation in Ultrasonic Non-Destructive Testing

    OpenAIRE

    V. Matz; M. Kreidl; R. Šmíd

    2007-01-01

    In ultrasonic non-destructive testing the signals characterizing the material structure are commonly evaluated. The sensitivity and resolution of ultrasonic systems is limited by the backscattering and electronic noise level commonly contained in the acquired ultrasonic signals. For this reason, it is very important to use appropriate advanced signal processing methods for noise reduction and signal separation. This paper compares algorithms used for efficient noise reduction in ultrasonic si...

  17. 3D Ultrasonic Wave Simulations for Structural Health Monitoring

    Science.gov (United States)

    Campbell, Leckey Cara A/; Miler, Corey A.; Hinders, Mark K.

    2011-01-01

    Structural health monitoring (SHM) for the detection of damage in aerospace materials is an important area of research at NASA. Ultrasonic guided Lamb waves are a promising SHM damage detection technique since the waves can propagate long distances. For complicated flaw geometries experimental signals can be difficult to interpret. High performance computing can now handle full 3-dimensional (3D) simulations of elastic wave propagation in materials. We have developed and implemented parallel 3D elastodynamic finite integration technique (3D EFIT) code to investigate ultrasound scattering from flaws in materials. EFIT results have been compared to experimental data and the simulations provide unique insight into details of the wave behavior. This type of insight is useful for developing optimized experimental SHM techniques. 3D EFIT can also be expanded to model wave propagation and scattering in anisotropic composite materials.

  18. Ultrasonic photoacoustic spectroscopy of trace hazardous chemicals using quantum cascade laser

    Science.gov (United States)

    Kumar, Deepak; Ghai, Devinder Pal; Soni, R. K.

    2016-12-01

    We report an ultrasonic sensor based on open-cell photoacoustic spectroscopy method for the detection of explosive agents in traces. Experimentally, we recorded photoacoustic spectra of traces of hazardous explosives and molecules. Tunable mid-infrared quantum cascade lasers in the wavelength range 7.0-8.8 μm lying in the molecular fingerprint region are used as optical source. Samples of Pentaerylthirol Tetranitrate (PETN), Tetranitro-triazacyclohexane (RDX), Dinitrotoluene, p-Nitrobenzoic acid and other chemicals like Ibuprofen having quantity 1.0 mg were detected using a custom made photoacoustic cells in both open and closed configurations. The explosive traces were swiped using paper from contaminated surface and detected. Finite element mesh based simulation of photoacoustic cell is carried out for optimization of geometry at ultrasonic frequency (40 kHz). A point sensor based on above approach will be very effective for forensic applications and suspicious material screening.

  19. Ultrasonic echo signal fetures of dissimilar material bonding joints

    Institute of Scientific and Technical Information of China (English)

    GANG Tie(刚铁); Yasuo TAKAHASHI

    2004-01-01

    An ultrasonic evaluation method of echo feature of diffusion bond joint between two dissimilar materials is presented. The echo signal was acquired by an automatic ultrasonic C-scan test system. It is found that the intensity of echo and its phase can be used to evaluate the joint quality, and interface products of dissimilar materials bonding can be evaluated by ultrasonic method.

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

    Science.gov (United States)

    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...

  1. 21 CFR 884.2960 - Obstetric ultrasonic transducer and accessories.

    Science.gov (United States)

    2010-04-01

    ... energy from, the body in conjunction with an obstetric monitor or imager. The device converts electrical signals into ultrasonic energy, and vice versa, by means of an assembly distinct from an ultrasonic... type of device does not include devices used to generate the ultrasonic frequency electrical...

  2. Non-destructive detection for bending deformation of aluminum beams using ultrasonic Lamb waves%金属铝板弯折形变积累的超声兰姆波无损检测

    Institute of Scientific and Technical Information of China (English)

    李仕俊; 廖非易; 高敏; 张胤; 林媛

    2015-01-01

    The formation and growth of fatigue cracks in structural materials is a crucial factor affecting their service life. Thus, it is important to detect the formation of the fatigue crack at the beginning and monitor its growth. Through the bending deformation simulation experiment, an approach by using Lamb wave was developed to detect the process from the accumulation of fatigue damages to the fracture of materials. By analyzing the dispersion curves and particle motion amplitudes of Lamb waves and comparing the theoretical and the actual group velocities, the characteristic mode packets under the optimum excitation frequency can be distinguished to evaluate the accumulation of the fatigues. And fast Fourier transform was used to reveal the energy distribution in frequency domain to detect damage accumulation. It is found that during the bending process from the fatigue accumulation to the appearance of micro-crack, the amplitude of A0 wave packet decreases. Especially, before the failure of materials, the amplitude decreases significantly.%材料结构中疲劳微裂纹的产生和扩展是影响其寿命的重要因素,在疲劳裂纹产生初期就将其检测出来对于提高结构安全性至关重要。利用兰姆波探索了铝板反复弯折时判定材料疲劳积累到最终塑性形变断裂失效的方法。试验通过分析兰姆波各模式的频散曲线、振幅曲线和对比理论与实际的波包群速度,选定了在最佳激励频率下判定疲劳损伤积累的特征信号。还通过快速傅里叶变换分析频域的能量分布来判定疲劳累积。试验结果表明:在试样从弯折塑性形变积累到出现微裂纹的过程中,A0波包振幅有小幅度的减小,而在材料断裂失效前,该振幅幅度会急剧减小。

  3. Particle size characterization by ultrasonic attenuation spectra

    Institute of Scientific and Technical Information of China (English)

    Mingxu Su; Minghua Xue; Xiaoshu Cai; Zhitao Shang; Feng Xu

    2008-01-01

    This paper contributes to extracting information from signals of broadband ultrasonic attenuation spectrum for effective utilization in particle size characterization. The single particle scattering model and the coupled-phase model are formulated simultaneously, the relationship between particle size distribution and ultrasonic spectrum is established, and a convergence criterion for calculation is quantified. Demonsa'ation inversion by the optimum regularization factor method is carded out to yield typical numerical results for discussion. With the experimental set-up developed by the Institute of Particle and Two-Phase Flow Measurement (IPTFM) at the University of Shanghai for Science and Technology, sand sediment particle size is measured by attenuation spectrum and analyzed using the above inversion algorithm and theoretical models. To validate the proposed ultrasonic spectrum particle sizing method, results are compared with those obtained by microscopy.

  4. Ultrasonic Welding of Wires and Cables

    Science.gov (United States)

    Heinz, Stefan; Wagner, Guntram; Eifler, Dietmar

    2012-03-01

    In the automobile industry, ultrasonic metal welding is an established method. At the Institute of Materials Science and Engineering (WKK) at the University of Kaiserslautern, Germany, systematic investigations of the weldability of Al-wires and flat flexible copper cables were carried out. In the case of Al-wires, joints with cross-sectional area of up to 80 mm2 and tensile shear load of about 3500 N were finally realized. Furthermore, methods to reduce unintentional adherence between the sonotrode coupling face and the Al-wires were developed. To realize FFC joints, ultrasonic spot welding systems and ultrasonic torsion welding systems were used. A central purpose of these investigations is the development of a system to enable welding through the insulation of the FFC without weakening the base material.

  5. Ultrasonic filtration of industrial chemical solutions

    Science.gov (United States)

    Cosma, T.

    1974-01-01

    The practical results obtained as a result of filtering industrial chemical solutions under continuous flow conditions with the aid of an ultrasonic filter are presented. The main part of the assembly consists of an ultrasonic generator with an output power of about 400 W and the filtration assembly, in which there is a magnetostrictive amplifier constructed for 20.5 kHz. In addition to ensuring a continuous flow of filtered solution, ultrasonic filters can be replaced or cleaned at intervals of time that are 8-10 times greater than in the case of mechanical filters. They yield considerably better results as far as the size of the filtered particles is concerned. The parameters on which filtration quality depends are also presented.

  6. Process monitoring using ultrasonic sensor systems.

    Science.gov (United States)

    Henning, Bernd; Rautenberg, Jens

    2006-12-22

    Continuous in-line measurement of substance concentration in liquid mixtures is valuable in improving industrial processes in terms of material properties, energy efficiency and process safety. Ultrasonic sensor systems meet the practical requirements of a chemical sensor quite well. Currently ultrasonic sensor systems are widely used as acoustic chemical sensors to measure concentration of selected substances or to monitor the course of polymerisation, crystallisation or fermentation processes. Useable acoustic properties for the characterisation of liquid mixtures are sound velocity, sound absorption and acoustic impedance. This contribution will give a short overview of the state of the art and several trends for the use of ultrasonic sensor systems in process applications. Novel investigations show the very promising possibility to analyse liquid multi-phase mixtures like suspensions, emulsions and dispersions.

  7. Novel Applications of Power Ultrasonic Spray

    Science.gov (United States)

    Quan, Ke-Ming

    Atomization is a process where a liquid is dispersed into droplets in a gas. Ultrasonic atomization was discovered in the 1920s (Loomis and Woods, 1927). Since then, atomization has seen diversified applications in devices such as drug nebulizers, room humidifiers, and air refreshers, as well as in industrial processes such as combustion, prilling, and web coating. In contrast to conventional liquid atomizers, ultrasound atomizers generally handle lower flow rates, and atomization of the liquid is achieved not by pressure, but by the vibration of ultrasonic waves (Morgan, 1993). This latter feature decouples the requirement of orifice geometry and pressure from the flow rate, allowing the flow to be controlled independently. Typically, ultrasonic atomizers excel in accurately processing low flow rates and slurry without clogging issues.

  8. Ultrasonically-assisted Polymer Molding: An Evaluation

    Science.gov (United States)

    Moles, Matthew; Roy, Anish; Silberschmidt, Vadim

    Energy reduction in extrusion and injection molding processes can be achieved by the introduction of ultrasonic energy. Polymer flow can be enhanced on application of ultrasonic vibration, which can reduce the thermal and pressure input requirements to produce the same molding; higher productivity may also be achieved. In this paper, a design of an ultrasound-assisted injection mold machine is explored. An extrusion-die design was augmented with a commercial 1.5 kW ultrasonic transducer and sonotrode designed to resonate close to 20 kHz with up to 100 μm vibration amplitude. The design was evaluated with modal and thermal analysis using finite-element analysis software. The use of numerical techniques, including computational fluid dynamics, fluid-structure interaction and coupled Lagrangian-Eulerian method, to predict the effect of ultrasound on polymer flow was considered. A sonotrode design utilizing ceramic to enhance thermal isolation was also explored.

  9. Ultrasonic precision optical grinding technology

    Science.gov (United States)

    Cahill, Michael J.; Bechtold, Michael J.; Fess, Edward; Wolfs, Frank L.; Bechtold, Rob

    2015-10-01

    As optical geometries become more precise and complex and a wider range of materials are used, the processes used for manufacturing become more critical. As the preparatory stage for polishing, this is especially true for grinding. Slow processing speeds, accelerated tool wear, and poor surface quality are often detriments in manufacturing glass and hard ceramics. The quality of the ground surface greatly influences the polishing process and the resulting finished product. Through extensive research and development, OptiPro Systems has introduced an ultrasonic assisted grinding technology, OptiSonic, which has numerous advantages over traditional grinding processes. OptiSonic utilizes a custom tool holder designed to produce oscillations in line with the rotating spindle. A newly developed software package called IntelliSonic is integral to this platform. IntelliSonic automatically characterizes the tool and continuously optimizes the output frequency for optimal cutting while in contact with the part. This helps maintain a highly consistent process under changing load conditions for a more accurate surface. Utilizing a wide variety of instruments, test have proven to show a reduction in tool wear and increase in surface quality while allowing processing speeds to be increased. OptiSonic has proven to be an enabling technology to overcome the difficulties seen in grinding of glass and hard optical ceramics. OptiSonic has demonstrated numerous advantages over the standard CNC grinding process. Advantages are evident in reduced tool wear, better surface quality, and reduced cycle times due to increased feed rates. These benefits can be seen over numerous applications within the precision optics industry.

  10. Ultrasonic guided wave bondline evaluation of thick metallic structures with viscoelastic coatings and the demonstration of a novel mode sweep technique

    Science.gov (United States)

    Bostron, Jason

    Ultrasonic guided waves are becoming more widely used in nondestructive evaluation applications due to their efficiency in defect detection, ability to inspect hidden areas, and other reasons. This dissertation addresses two main topics: ultrasonic guided wave bond evaluation of thin and thick coatings on thick metallic structures, and the use of a novel phased array technique for optimal guided wave mode and frequency selection. (Abstract shortened by UMI.).

  11. Ultrasonic medical imaging: past, current, and future (Keynote Presentation)

    Science.gov (United States)

    Reid, John M.

    2005-04-01

    Ultrasonic imaging began, like life, in the sea, with the development of sonar for detecting submarines after World-War 1. However, to begin to image soft tissues the ranging time of ocean sonars needed to be reduced, and the electronics speeded up, by a factor of about the ratio between nautical miles and centimeters. This was only possible after the electronic developments made for radar in World-War 2. The rest of our technical history closely follows the developments in semiconductors and fabrication methods that led to modern electronics. This is a largely personal story of a recently graduated engineer with radar experience, who began with fabricating equipment to be used in the hospital to diagnose breast cancer, and continued with involvement the development of echocardiography and Doppler devices. Along the way many others have contributed to the field, including work in other countries that is not covered here. In future, ultrasonic imaging may hold the key to understanding some fundamental questions in human health if adopted for screening studies. It alone offers a relatively inexpensive imaging method that is free of known hazards.

  12. Inspection of additive manufactured parts using laser ultrasonics

    Science.gov (United States)

    Lévesque, D.; Bescond, C.; Lord, M.; Cao, X.; Wanjara, P.; Monchalin, J.-P.

    2016-02-01

    Additive manufacturing is a novel technology of high importance for global sustainability of resources. As additive manufacturing involves typically layer-by-layer fusion of the feedstock (wire or powder), an important characteristic of the fabricated metallic structural parts, such as those used in aero-engines, is the performance, which is highly related to the presence of defects, such as cracks, lack of fusion or bonding between layers, and porosity. For this purpose, laser ultrasonics is very attractive due to its non-contact nature and is especially suited for the analysis of parts of complex geometries. In addition, the technique is well adapted to online implementation and real-time measurement during the manufacturing process. The inspection can be performed from either the top deposited layer or the underside of the substrate and the defects can be visualized using laser ultrasonics combined with the synthetic aperture focusing technique (SAFT). In this work, a variety of results obtained off-line on INCONEL® 718 and Ti-6Al-4V coupons that were manufactured using laser powder, laser wire, or electron beam wire deposition are reported and most defects detected were further confirmed by X-ray micro-computed tomography.

  13. Ultrasonic wavefield imaging: Research tool or emerging NDE method?

    Science.gov (United States)

    Michaels, Jennifer E.

    2017-02-01

    Ultrasonic wavefield imaging refers to acquiring full waveform data over a region of interest for waves generated by a stationary source. Although various implementations of wavefield imaging have existed for many years, the widespread availability of laser Doppler vibrometers that can acquire signals in the high kHz and low MHz range has resulted in a rapid expansion of fundamental research utilizing full wavefield data. In addition, inspection methods based upon wavefield imaging have been proposed for standalone nondestructive evaluation (NDE) with most of these methods coming from the structural health monitoring (SHM) community and based upon guided waves. If transducers are already embedded in or mounted on the structure as part of an SHM system, then a wavefield-based inspection can potentially take place with very little required disassembly. A frequently-proposed paradigm for wavefield NDE is its application as a follow-up inspection method using embedded SHM transducers as guided wave sources if the in situ SHM system generates an alarm. Discussed here is the broad role of wavefield imaging as it relates to ultrasonic NDE, both as a research tool and as an emerging NDE method. Examples of current research are presented based upon both guided and bulk wavefield imaging in metals and composites, drawing primarily from the author's work. Progress towards wavefield NDE is discussed in the context of defect detection and characterization capabilities, scan times, data quality, and required data analysis. Recent research efforts are summarized that can potentially enable wavefield NDE.

  14. Update on Ultrasonic Thermometry Development at Idaho National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Joshua Daw; Joy Rempe; John Crepeau

    2012-07-01

    The Idaho National Laboratory (INL) has initiated an effort to evaluate the viability of using ultrasonic thermometry technology as an improved sensor for detecting temperature during irradiation testing of advanced fuels proposed within the Fuel Cycle Research and Development (FCR&D) program sponsored by the U.S. Department of Energy (US DOE). Ultrasonic thermometers (UTs) work on the principle that the speed at which sound travels through a material (acoustic velocity) is dependent on the temperature of the material. UTs have several advantages over other types of temperature sensors . UTs can be made very small, as the sensor consists only of a small diameter rod which may or may not require a sheath. Measurements may be made up to very high temperature (near the melting point of the sensor material) and, as no electrical insulation is required, shunting effects observed in traditional high temperature thermocouple applications are avoided. Most attractive, however, is the ability to introduce multiple acoustic discontinuities into the sensor, as this enables temperature profiling with a single sensor. The current paper presents initial results from FCR&D UT development efforts. These developments include improved methods for fabricating magnetostrictive transducers and joining them to waveguides, characterization of candidate sensor materials appropriate for use in FCR&D fuels irradiations (both ceramic fuels in inert gas and sodium bonded metallic fuels), enhanced signal processing techniques, and tests to determine potential accuracy and resolution.

  15. Linear System Models for Ultrasonic Imaging: Application to Signal Statistics

    Science.gov (United States)

    Zemp, Roger J.; Abbey, Craig K.; Insana, Michael F.

    2009-01-01

    Linear equations for modeling echo signals from shift-variant systems forming ultrasonic B-mode, Doppler, and strain images are analyzed and extended. The approach is based on a solution to the homogeneous wave equation for random inhomogeneous media. When the system is shift-variant, the spatial sensitivity function—defined as a spatial weighting function that determines the scattering volume for a fixed point of time—has advantages over the point-spread function traditionally used to analyze ultrasound systems. Spatial sensitivity functions are necessary for determining statistical moments in the context of rigorous image quality assessment, and they are time-reversed copies of point-spread functions for shift variant systems. A criterion is proposed to assess the validity of a local shift-invariance assumption. The analysis reveals realistic situations in which in-phase signals are correlated to the corresponding quadrature signals, which has strong implications for assessing lesion detectability. Also revealed is an opportunity to enhance near- and far-field spatial resolution by matched filtering unfocused beams. The analysis connects several well-known approaches to modeling ultrasonic echo signals. PMID:12839176

  16. Radiation-Force Assisted Targeting Facilitates Ultrasonic Molecular Imaging

    Directory of Open Access Journals (Sweden)

    Shukui Zhao

    2004-07-01

    Full Text Available Ultrasonic molecular imaging employs contrast agents, such as microbubbles, nanoparticles, or liposomes, coated with ligands specific for receptors expressed on cells at sites of angiogenesis, inflammation, or thrombus. Concentration of these highly echogenic contrast agents at a target site enhances the ultrasound signal received from that site, promoting ultrasonic detection and analysis of disease states. In this article, we show that acoustic radiation force can be used to displace targeted contrast agents to a vessel wall, greatly increasing the number of agents binding to available surface receptors. We provide a theoretical evaluation of the magnitude of acoustic radiation force and show that it is possible to displace micron-sized agents physiologically relevant distances. Following this, we show in a series of experiments that acoustic radiation force can enhance the binding of targeted agents: The number of biotinylated microbubbles adherent to a synthetic vessel coated with avidin increases as much as 20-fold when acoustic radiation force is applied; the adhesion of contrast agents targeted to αvβ3 expressed on human umbilical vein endothelial cells increases 27-fold within a mimetic vessel when radiation force is applied; and finally, the image signal-to-noise ratio in a phantom vessel increases up to 25 dB using a combination of radiation force and a targeted contrast agent, over use of a targeted contrast agent alone.

  17. Magnetic and ultrasonic investigations on magnetite nanofluids.

    Science.gov (United States)

    Nabeel Rashin, M; Hemalatha, J

    2012-12-01

    Magnetite nanofluids of various concentrations have been prepared through co-precipitation method. The structural and magnetic properties of the magnetic nanofluids have been analyzed which respectively revealed their face centered cubic crystal structure and super paramagnetic behavior. Ultrasonic investigations have been made for the nanofluids at different temperatures and magnetic fields. Open- and close-packed water structure is considered to explain the temperature effects. The inter particle interactions of surface modified nanomagnetite particle and the cluster formation are realized through the variations in ultrasonic parameters.

  18. Ultrasonic motors using piezoelectric ceramic multimode vibrators.

    Science.gov (United States)

    Takano, T; Tomikawa, Y; Ogasawara, T; Sugawara, S; Konno, M

    1990-01-01

    The development is reported of an ultrasonic motor using piezoelectric ceramic multimode vibrators consisting of circular or annular plates in which degenerate horizontal vibration modes of the same or different form are used. Two orthogonal nonaxisymmetric vibration modes were used in the same-form case, and the combination of a nonaxisymmetric vibration mode and a radial vibration mode was used in the different-forms case. Some details of the motor design and its experimental characteristics are presented. The ultrasonic motor presented here has a special advantage in its thin construction.

  19. Ultrasonic methods in solid state physics

    CERN Document Server

    Truell, John; Elbaum, Charles

    1969-01-01

    Ultrasonic Methods in Solid State Physics is devoted to studies of energy loss and velocity of ultrasonic waves which have a bearing on present-day problems in solid-state physics. The discussion is particularly concerned with the type of investigation that can be carried out in the megacycle range of frequencies from a few megacycles to kilomegacycles; it deals almost entirely with short-duration pulse methods rather than with standing-wave methods. The book opens with a chapter on a classical treatment of wave propagation in solids. This is followed by separate chapters on methods and techni

  20. Absorption and dispersion of ultrasonic waves

    CERN Document Server

    Herzfeld, Karl F; Massey, H S W; Brueckner, Keith A

    1959-01-01

    Absorption and Dispersion of Ultrasonic Waves focuses on the influence of ultrasonics on molecular processes in liquids and gases, including hydrodynamics, energy exchange, and chemical reactions. The book first offers information on the Stokes-Navier equations of hydrodynamics, as well as equations of motion, viscosity, formal introduction of volume viscosity, and linearized wave equation for a nonviscous fluid. The manuscript then ponders on energy exchange between internal and external degrees of freedom as relaxation phenomenon; effect of slow energy exchange on sound propagation; differe