WorldWideScience

Sample records for surface acoustical holography

  1. Acoustic Holography

    Science.gov (United States)

    Kim, Yang-Hann

    One of the subtle problems that make noise control difficult for engineers is the invisibility of noise or sound. A visual image of noise often helps to determine an appropriate means for noise control. There have been many attempts to fulfill this rather challenging objective. Theoretical (or numerical) means for visualizing the sound field have been attempted, and as a result, a great deal of progress has been made. However, most of these numerical methods are not quite ready for practical applications to noise control problems. In the meantime, rapid progress with instrumentation has made it possible to use multiple microphones and fast signal-processing systems. Although these systems are not perfect, they are useful. A state-of-the-art system has recently become available, but it still has many problematic issues; for example, how can one implement the visualized noise field. The constructed noise or sound picture always consists of bias and random errors, and consequently, it is often difficult to determine the origin of the noise and the spatial distribution of the noise field. Section 26.2 of this chapter introduces a brief history, which is associated with sound visualization, acoustic source identification methods and what has been accomplished with a line or surface array. Section 26.2.3 introduces difficulties and recent studies, including de-Dopplerization and de-re verberation methods, both essential for visualizing a moving noise source, such as occurs for cars or trains. This section also addresses what produces ambiguity in realizing real sound sources in a room or closed space. Another major issue associated with sound/noise visualization is whether or not we can distinguish between mutual dependencies of noise in space (Sect. 26.2.4); for example, we are asked to answer the question, Can we see two birds singing or one bird with two beaks?

  2. Application of holography in jet acoustic studies

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    was focussed on back projection of the sound field on to a cylindrical surface. A jet emanating from 5 mm convergent nozzle was used for the holography exper- iments, assuming axisymmetry. Experimental results were compared with results obtained from holography. Keywords. Acoustic noise; jet noise; source strength ...

  3. Surface and subsurface layers characterization in artworks using conoscopic laser holography and acoustic microscopy

    Science.gov (United States)

    Marchioro, Giacomo; Apostolidis, Georgios; Karagiannis, Georgios; Galeotti, Monica; Daffara, Claudia

    2017-07-01

    The characterization of the surface morphology and the material layers stratigraphy is a pivotal step in several stages of the conservation process of the artwork. Generally, optimal characterization of the surface cannot be achieved using a single technique but is not always possible to find techniques that can be coupled effectively. Surface maps were retrieved using acoustic microscopy and conoscopic laser holography over a set of reference samples. The surface maps compared for showing possible way to better characterize the surface morphology when their information is combined. The final data give us a more complete surface and subsurface digitalization while the results obtained are discussed highlighting the main pros and cons of the two techniques. Thus besides having insights on the effectiveness and on the performance of the processes, it is also evident that uncertainties associated with the measurement can be overcome and a single more accurate representation of the surface can be derived using both scanning methods.

  4. Error analysis by means of acoustic holography

    International Nuclear Information System (INIS)

    Kutzner, J.; Wuestenberg, H.

    1976-01-01

    The possilbilities to use the acoustical holography in nondestructive testing are discussed. Although compared to optical holography the image quality of acoustical holography is reduced this technique can give important informations about the shape of defects. Especially in nondestructive testing of thick walled components no alternative exists until now. (orig.) [de

  5. Acoustic emission linear pulse holography

    International Nuclear Information System (INIS)

    Collins, H.D.; Busse, L.J.; Lemon, D.K.

    1983-01-01

    This paper describes the emission linear pulse holography which produces a chronological linear holographic image of a flaw by utilizing the acoustic energy emitted during crack growth. A thirty two point sampling array is used to construct phase-only linear holograms of simulated acoustic emission sources on large metal plates. The concept behind the AE linear pulse holography is illustrated, and a block diagram of a data acquisition system to implement the concept is given. Array element spacing, synthetic frequency criteria, and lateral depth resolution are specified. A reference timing transducer positioned between the array and the inspection zone and which inititates the time-of-flight measurements is described. The results graphically illustrate the technique using a one-dimensional FFT computer algorithm (ie. linear backward wave) for an AE image reconstruction

  6. Acoustic emission linear pulse holography

    Science.gov (United States)

    Collins, H.D.; Busse, L.J.; Lemon, D.K.

    1983-10-25

    This device relates to the concept of and means for performing Acoustic Emission Linear Pulse Holography, which combines the advantages of linear holographic imaging and Acoustic Emission into a single non-destructive inspection system. This unique system produces a chronological, linear holographic image of a flaw by utilizing the acoustic energy emitted during crack growth. The innovation is the concept of utilizing the crack-generated acoustic emission energy to generate a chronological series of images of a growing crack by applying linear, pulse holographic processing to the acoustic emission data. The process is implemented by placing on a structure an array of piezoelectric sensors (typically 16 or 32 of them) near the defect location. A reference sensor is placed between the defect and the array.

  7. Experimental verification of transient nonlinear acoustical holography.

    Science.gov (United States)

    Jing, Yun; Cannata, Jonathan; Wang, Tianren

    2013-05-01

    This paper presents an experimental study on nonlinear transient acoustical holography. The validity and effectiveness of a recently proposed nonlinear transient acoustical holography algorithm is evaluated in the presence of noise. The acoustic field measured on a post-focal plane of a high-intensity focused transducer is backward projected to reconstruct the pressure distributions on the focal and a pre-focal plane, which are shown to be in good agreement with the measurement. In contrast, the conventional linear holography produces erroneous results in this case where the nonlinearity involved is strong. Forward acoustic field projection was also carried out to further verify the algorithm.

  8. Application of holography in jet acoustic studies

    Indian Academy of Sciences (India)

    Source strength distribution on a jet boundary was obtained from measurements using the principle of acoustic holography. Measurements were conducted in an open field. Measurement of acoustic pressure on a cylindrical twodimensional contour located close to the vibrating jet boundary was used to obtain the acoustic ...

  9. Application of holography in jet acoustic studies

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    MS received 4 February 2003; revised 30 April 2004. Abstract. Source strength distribution on a jet boundary was obtained from measurements using the principle of acoustic holography. Measurements were con- ducted in an open field. Measurement of acoustic pressure on a cylindrical two- dimensional contour located ...

  10. Near field acoustic holography with microphones on a rigid sphere

    DEFF Research Database (Denmark)

    Jacobsen, Finn; Moreno-Pescador, Guillermo; Fernandez Grande, Efren

    2011-01-01

    Spherical near field acoustic holography (spherical NAH) is a technique that makes it possible to reconstruct the sound field inside and just outside a spherical surface on which the sound pressure is measured with an array of microphones. This is potentially very useful for source identification...

  11. Patch near field acoustic holography based on particle velocity measurements

    DEFF Research Database (Denmark)

    Zhang, Yong-Bin; Jacobsen, Finn; Bi, Chuan-Xing

    2009-01-01

    Patch near field acoustic holography (PNAH) based on sound pressure measurements makes it possible to reconstruct the source field near a source by measuring the sound pressure at positions on a surface. that is comparable in size to the source region of concern. Particle velocity is an alternative...

  12. Supersonic acoustic intensity with statistically optimized near-field acoustic holography

    DEFF Research Database (Denmark)

    Fernandez Grande, Efren; Jacobsen, Finn

    2011-01-01

    to the information provided by the near-field acoustic holography technique. This study proposes a version of the supersonic acoustic intensity applied to statistically optimized near-field acoustic holography (SONAH). The theory, numerical results and an experimental study are presented. The possibility of using...

  13. Near field acoustic holography with microphones mounted on a rigid sphere

    DEFF Research Database (Denmark)

    Jacobsen, Finn; Moreno, Guillermo; Fernandez Grande, Efren

    2008-01-01

    Spherical near field acoustic holography (spherical NAH) is a technique that makes it pos-sible to reconstruct the sound field inside and just outside an acoustically transparent spherical surface on which the sound pressure is measured with an array of microphones with negligible scattering...

  14. Spherical near field acoustic holography with microphones on a rigid sphere

    DEFF Research Database (Denmark)

    Jacobsen, Finn; Hald, Jørgen; Fernandez Grande, Efren

    2008-01-01

    Spherical near field acoustic holography (SNAH) is a recently developed technique that makes it possible to reconstruct the sound field inside and just outside an acoustically transparent spherical surface on which the sound pressure is measured with an array of microphones with negligible...

  15. A study on the dimensioning of flaws by acoustical holography

    International Nuclear Information System (INIS)

    Yamamoto, Michio; Ando, Tomozumi; Enami, Koji; Yajima, Minoru; Fukui, Shigetaka.

    1978-01-01

    As a means of evaluating the safety of flawed pressure vessels and other structures against fracture, fracture mechanics has come to be applied. For the application of fracture mechanics it is necessary to get information concerning the sizes and shapes of flaws. The ultrasonic flaw detection method that is widely used as a nondestructive inspection method cannot measure the sizes and shapes of flaws accurately. Considering that acoustical holography is an useful means for the dimensioning of flaws, we performed basic tests on this method and obtained the following results: (1) The measured values of artificial flaws (flat bottom drilled holes: 5 - 36 mm) made on a steel plate of 150 mm thick showed a good linear relation with their actual sizes and scatter in the measured values was +-3 - 6 mm. (2) The measured values of fatigue cracks (length: 5 - 57 mm) introduced into a steel plate of 150 mm thick also showed a good linear relation with their actual sizes and scatter in the measured values was +-3 mm. (3) It was found that acoustical holography can also be applied to heavy section cast steels. (4) The method of correcting distortion caused by curved surface was investigated by computer-aided simulation and it was considered that such distortion can be corrected by radial scanning of a transducer. (author)

  16. Near field acoustic holography with particle velocity transducers

    DEFF Research Database (Denmark)

    Jacobsen, Finn; Liu, Yang

    2005-01-01

    Near field acoustic holography is usually based on measurement of the pressure. This paper describes an investigation of an alternative technique that involves measuring the normal component of the acoustic particle velocity. A simulation study shows that there is no appreciable difference between...... in a plane further away, high spatial frequency components are reduced by the reciprocal wave number ratio (k/kz). For the same reason holography based on the particle velocity is less sensitive to transducer mismatch than the conventional technique based on the pressure. These findings are confirmed...

  17. Surface Vibration Reconstruction using Inverse Numerical Acoustics

    Directory of Open Access Journals (Sweden)

    F. Martinus

    2003-05-01

    Full Text Available This paper explores the use of inverse numerical acoustics to reconstruct the surface vibration of a noise source. Inverse numerical acoustics is mainly used for source identification. This approach uses the measured sound pressure at a set of field points and the Helmholtz integral equation to reconstruct the normal surface velocity. The number of sound pressure measurements is considerably less than the number of surface vibration nodes. An overview of inverse numerical acoustics is presented and compared with other holography techniques such as nearfield acoustical holography and the Helmholtz equation least squares method. In order to obtain an acceptable reproduction of the surface vibration, several critical factors such as the field point selection and the effect of experimental errors have to be handled properly. Other practical considerations such as the use of few measured velocities and regularization techniques will also be presented. Examples will include a diesel engine, a transmission housing and an engine cover.

  18. A comparison of SONAH and IBEM for near-field acoustic holography

    DEFF Research Database (Denmark)

    Juhl, Peter Møller

    2008-01-01

    Among the popular techniques for acoustic source identification in complex environments are the Statistically Optimal Near Acoustic Holography (SONAH) and the Inverse Boundary Element Method (IBEM). These two methods are quite different regarding the underlying assumptions and the practical imple...

  19. A comparison of SONAH and IBEM for near-field acoustic holography

    DEFF Research Database (Denmark)

    Juhl, Peter Møller

    2008-01-01

    Among the popular techniques for acoustic source identification in complex environments are the Statistically Optimal Near Acoustic Holography (SONAH) and the Inverse Boundary Element Method (IBEM). These two methods are quite different regarding the underlying assumptions and the practical...

  20. A study on the acoustical holography

    International Nuclear Information System (INIS)

    Shin, S.H.; Lee, J.H.; Jang, M.S.

    1979-01-01

    Theoretical and experimental investigations of acoustical holograms, and the optical reconstruction of their images are described. Acoustical holograms are constructed through the use of sound waves of 14 KHz-16 KHz frequency range. The virtual images and conjugate images are reconstructed using He-Ne gas laser(Wavelength 6,328A) light. The effect on the reconstructed images of the wavelength of the sound waves and of the scanning plane are discussed. Furthermore, the three dimensional information memory in acoustical holograms is discussed. (author)

  1. A comparison of inverse boundary element method and near-field acoustical holography

    DEFF Research Database (Denmark)

    Schuhmacher, Andreas; Hald, Jørgen; Saemann, E.-U.

    1999-01-01

    An inverse boundary element method (IBEM) is used to estimate the surface velocity of a rolling tyre from measurements of the near-field pressure. Subsequently, the sound pressure is calculated over a finite plane surface next to the tyre from the reconstructed velocity field on the tyre surface........ In order to verify the reconstruction process, part of the measurement data is used together with Near-Field Acoustical Holography (NAH). Estimated distributions of sound pressure and particle velocity over a plane surface obtained from the two methods are compared....

  2. Pulsed TV holography measurement and digital reconstruction of compression acoustic wave fields: application to nondestructive testing of thick metallic samples

    International Nuclear Information System (INIS)

    Trillo, C; Doval, A F; Deán-Ben, X L; López-Vázquez, J C; Fernández, J L; Hernández-Montes, S

    2011-01-01

    This paper describes a technique that numerically reconstructs the complex acoustic amplitude (i.e. the acoustic amplitude and phase) of a compression acoustic wave in the interior volume of a specimen from a set of full-field optical measurements of the instantaneous displacement of the surface. The volume of a thick specimen is probed in transmission mode by short bursts of narrowband compression acoustic waves generated at one of its faces. The temporal evolution of the displacement field induced by the bursts emerging at the opposite surface is measured by pulsed digital holographic interferometry (pulsed TV holography). A spatio-temporal 3D Fourier transform processing of the measured data yields the complex acoustic amplitude at the plane of the surface as a sequence of 2D complex-valued maps. Finally, a numerical implementation of the Rayleigh–Sommerfeld diffraction formula is employed to reconstruct the complex acoustic amplitude at other planes in the interior volume of the specimen. The whole procedure can be regarded as a combination of optical digital holography and acoustical holography methods. The technique was successfully tested on aluminium specimens with and without an internal artificial defect and sample results are presented. In particular, information about the shape and position of the defect was retrieved in the experiment performed on the flawed specimen, which indicates the potential applicability of the technique for the nondestructive testing of materials

  3. How hummingbirds hum: Acoustic holography of hummingbirds during maneuvering flight

    Science.gov (United States)

    Hightower, Ben; Wijnings, Patrick; Ingersoll, Rivers; Chin, Diana; Scholte, Rick; Lentink, David

    2017-11-01

    Hummingbirds make a characteristic humming sound when they flap their wings. The physics and the biological significance of hummingbird aeroacoustics is still poorly understood. We used acoustic holography and high-speed cameras to determine the acoustic field of six hummingbirds while they either hovered stationary in front of a flower or maneuvered to track flower motion. We used a robotic flower that oscillated either laterally or longitudinally with a linear combination of 20 different frequencies between 0.2 and 20 Hz, a range that encompasses natural flower vibration frequencies in wind. We used high-speed marker tracking to dissect the transfer function between the moving flower, the head, and body of the bird. We also positioned four acoustic arrays equipped with 2176 microphones total above, below, and in front of the hummingbird. Acoustic data from the microphones were back-propagated to planes adjacent to the hummingbird to create the first real-time holograms of the pressure field a hummingbird generates in vivo. Integration of all this data offers insight into how hummingbirds modulate the acoustic field during hovering and maneuvering flight.

  4. Near-field acoustical holography of military jet aircraft noise

    Science.gov (United States)

    Wall, Alan T.; Gee, Kent L.; Neilsen, Tracianne; Krueger, David W.; Sommerfeldt, Scott D.; James, Michael M.

    2010-10-01

    Noise radiated from high-performance military jet aircraft poses a hearing-loss risk to personnel. Accurate characterization of jet noise can assist in noise prediction and noise reduction techniques. In this work, sound pressure measurements were made in the near field of an F-22 Raptor. With more than 6000 measurement points, this is the most extensive near-field measurement of a high-performance jet to date. A technique called near-field acoustical holography has been used to propagate the complex pressure from a two- dimensional plane to a three-dimensional region in the jet vicinity. Results will be shown and what they reveal about jet noise characteristics will be discussed.

  5. A study on the measurement of flaw sizes by acoustical holography

    International Nuclear Information System (INIS)

    Yamamoto, M.; Ando, T.; Enami, K.; Yajima, M.; Fukui, S.

    1978-01-01

    As a means of evaluating the safety of flawed pressure vessels and other structures against fracture, fracture mechanics has come to be applied. For the application of fracture mechanics it is necessary to get information concerning the sizes and shapes of flaws. The ultrasonic flaw detection method which is widely used as a nondestructive inspection method cannot measure the sizes and shapes of flaws accurately. Considering that acoustical holography is an useful means for the measurement of flaws, we performed basic tests on this method and obtained the following results: (1) The measured values of artificial flaws (flat bottom drilled holes: 5 -- 36 mm) made on a steel plate with a thickness of 150 mm showed a good linear relation with their actual sizes and scatter in the measured values was +-3 -- 6 mm. (2) The measured values of fatigue cracks (length: 5 -- 57 mm) introduced into a steel plate with thickness of 150 mm also showed a good linear relation with their actual sizes and scatter in the measured values was +-3 mm. (3) It was found that acoustical holography can also be applied to heavy section cast steels. (4) The method of correcting distortion caused by curved surface was investigated by computer-aided simulation and it was considered that such distortion can be corrected by radial scanning of a transducer. (auth.)

  6. Enhancing the beamforming map of spherical arrays at low frequencies using acoustic holography

    DEFF Research Database (Denmark)

    Tiana Roig, Elisabet; Torras Rosell, Antoni; Fernandez Grande, Efren

    2014-01-01

    Recent studies have shown that the localization of acoustic sources based on circular arrays can be improved at low frequencies by combining beamforming with acoustic holography. This paper extends this technique to the three dimensional case by making use of spherical arrays. The pressure captured...... by a rigid spherical array under free-field conditions is used to compute the expected pressure on a virtual and larger sphere by means of acoustic holography. Beamforming is then applied with the pressure predicted at the virtual array. Since the virtual array has a larger radius compared to the one...

  7. Responsive acoustic surfaces

    DEFF Research Database (Denmark)

    Peters, Brady; Tamke, Martin; Nielsen, Stig Anton

    2011-01-01

    Acoustic performance is defined by the parameter of reverberation time; however, this does not capture the acoustic experience in some types of open plan spaces. As many working and learning activities now take place in open plan spaces, it is important to be able to understand and design...... for the acoustic conditions of these spaces. This paper describes an experimental research project that studied the design processes necessary to design for sound. A responsive acoustic surface was designed, fabricated and tested. This acoustic surface was designed to create specific sonic effects. The design...... was simulated using custom integrated acoustic software and also using Odeon acoustic analysis software. The research demonstrates a method for designing space- and sound-defining surfaces, defines the concept of acoustic subspace, and suggests some new parameters for defining acoustic subspaces....

  8. Holography.

    Science.gov (United States)

    Klein, H. Arthur

    Holography is a process which numbers among its many applications the creation of holograms--unique three dimensional photographs that show spatial relations and shifts just as they exist in reality. This book recounts the history of holography, tracing its development from Euclid's theory of light rays through Huygens' theory of wave motion to…

  9. Application of acoustical holography for construction shadow images in ultrasonic testing

    International Nuclear Information System (INIS)

    Kutzner, J.; Zimpfer, J.

    1977-01-01

    The full-scale, three-dimensional presentation of material defects by means of acoustical holography is limited on the one hand by an insufficient resolving power in depth of the procedure and, on the other hand, by the fact that the defects of the material to be examined often reflect mirror-like. Examined is the possible range of reducing these limitations by means of constructing shadow images of defects in ultrasonic testing without - as it is usually done - reconstructing the sonic field reflected by the flow but reconstructing the sonic field diffracted at the flow by means of acoustical holography. It has been shown that acoustical holography, during which the amplitude information is always analyzed as well as - on principle - the phase information, improves the efficiency of ultrasonic testing to a large extent. (orig.) [de

  10. Responsive acoustic surfaces

    DEFF Research Database (Denmark)

    Peters, Brady; Tamke, Martin; Nielsen, Stig Anton

    2011-01-01

    Acoustic performance is defined by the parameter of reverberation time; however, this does not capture the acoustic experience in some types of open plan spaces. As many working and learning activities now take place in open plan spaces, it is important to be able to understand and design...... was simulated using custom integrated acoustic software and also using Odeon acoustic analysis software. The research demonstrates a method for designing space- and sound-defining surfaces, defines the concept of acoustic subspace, and suggests some new parameters for defining acoustic subspaces....

  11. Feasibility study of complex wavefield retrieval in off-axis acoustic holography employing an acousto-optic sensor.

    Science.gov (United States)

    Rodríguez, Guillermo López; Weber, Joshua; Sandhu, Jaswinder Singh; Anastasio, Mark A

    2011-12-01

    We propose and experimentally demonstrate a new method for complex-valued wavefield retrieval in off-axis acoustic holography. The method involves use of an intensity-sensitive acousto-optic (AO) sensor, optimized for use at 3.3 MHz, to record the acoustic hologram and a computational method for reconstruction of the object wavefield. The proposed method may circumvent limitations of conventional implementations of acoustic holography and may facilitate the development of acoustic-holography-based biomedical imaging methods. Copyright © 2011 Elsevier B.V. All rights reserved.

  12. A sparse equivalent source method for near-field acoustic holography

    DEFF Research Database (Denmark)

    Fernandez Grande, Efren; Xenaki, Angeliki; Gerstoft, Peter

    2017-01-01

    This study examines a near-field acoustic holography method consisting of a sparse formulation of the equivalent source method, based on the compressive sensing (CS) framework. The method, denoted Compressive–Equivalent Source Method (C-ESM), encourages spatially sparse solutions (based on the su......This study examines a near-field acoustic holography method consisting of a sparse formulation of the equivalent source method, based on the compressive sensing (CS) framework. The method, denoted Compressive–Equivalent Source Method (C-ESM), encourages spatially sparse solutions (based...

  13. Investigating the use of the acousto-optic effect for acoustic holography

    DEFF Research Database (Denmark)

    Torras Rosell, Antoni; Fernandez Grande, Efren; Jacobsen, Finn

    2012-01-01

    Recent studies have demonstrated that the acousto-optic effect, that is, the interaction between sound and light, can be used as a means to visualize acoustic fields in the audible frequency range. The changes of density caused by sound waves propagating in air induce phase shifts to a laser beam...... that travels through the acoustic field. This phenomenon can in practice be captured with a laser Doppler vibrometer (LDV), and the pressure distribution of the acoustic field can be reconstructed using tomography. The present work investigates the potential of the acousto-optic effect in acoustic holography....... Two different holographic methods are examined for this purpose. One method first reconstructs the hologram plane using acousto-optic tomography and then propagates it using conventional near-field acoustic holography (NAH). The other method exploits the so-called Fourier Slice Theorem and bases all...

  14. Localized Acoustic Surface Modes

    KAUST Repository

    Farhat, Mohamed

    2015-08-04

    We introduce the concept of localized acoustic surface modes (ASMs). We demonstrate that they are induced on a two-dimensional cylindrical rigid surface with subwavelength corrugations under excitation by an incident acoustic plane wave. Our results show that the corrugated rigid surface is acoustically equivalent to a cylindrical scatterer with uniform mass density that can be represented using a Drude-like model. This, indeed, suggests that plasmonic-like acoustic materials can be engineered with potential applications in various areas including sensing, imaging, and cloaking.

  15. Investigations of the efficiency of acoustical holography especially in comparison to focussed beams in NDT

    International Nuclear Information System (INIS)

    During the project, the basic knowledge for the practicable application of the linear acoustical holography has been developed. For the application and construction of focusing probes the most important parameters have been determined. The activities for the holography with numerical construction have been concentrated on the reconstruction procedure, the probes, the manipulation and the external controle of time gates. The optimal parameters for holographic scannings have been determined. Practical experiences are showing an acceptable agreement between reconstruction and real flaw sizes, depending on the kind and position of the flaws. The acoustical holography seems to be especially suited for the determination of flaw extensions in depth whereas focusing probes can be applied with more advantage for the extensions in length. (orig.) [de

  16. Near field acoustic holography based on the equivalent source method and pressure-velocity transducers

    DEFF Research Database (Denmark)

    Zhang, Y.-B.; Chen, X.-Z.; Jacobsen, Finn

    2009-01-01

    The advantage of using the normal component of the particle velocity rather than the sound pressure in the hologram plane as the input of conventional spatial Fourier transform based near field acoustic holography (NAH) and also as the input of the statistically optimized variant of NAH has...

  17. IDENTIFICATION AND MONITORING OF NOISE SOURCES OF CNC MACHINE TOOLS BY ACOUSTIC HOLOGRAPHY METHODS

    Directory of Open Access Journals (Sweden)

    Jerzy Józwik

    2016-06-01

    Full Text Available The paper presents the analysis of sound field emitted by selected CNC machine tools. The identification of noise sources and level was measured by acoustic holography for the 3-axis DMC 635eco machine tool and the 5-axis vertical machining centre DMU 65 monoBlock. The acoustic holography method allows precise identification and measurement of noise sources at different bandwidths of frequency. Detection of noise sources in tested objects allows diagnosis of their technical condition, as well as choice of effective means of noise reduction, which is highly significant from the perspective of minimising noise at the CNC machine operator workstation. Test results were presented as acoustic maps in various frequency ranges. Noise sources of the machine tool itself were identified, as well as the range of noise influence and the most frequent places of reflections and their span. The results of measurements were presented in figures and diagrams.

  18. Identification of Turbomachinery Noise Sources Using Acoustical Holography, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Evaluation and enhancement of the acoustical performance of turbomachinery requires knowledge of the acoustic sources. However, the noise generation mechanisms...

  19. Tomographic reconstruction of transient acoustic fields recorded by pulsed TV holography.

    Science.gov (United States)

    Gren, P; Schedin, S; Li, X

    1998-02-10

    Pulsed TV holography combined with computerized tomography (CT) are used to evaluate the three-dimensional distribution of transient acoustic fields in air. Experiments are performed with an electrical discharge between two electrodes as the sound source. Holograms from several directions of the acoustic field are recorded directly onto a CCD detector by use of a double-pulsed ruby laser as the light source. Phase maps, representing projections of the acoustic field, are evaluated quantitatively from the recorded holograms. The projections are used for the CT reconstruction to evaluate the pressure-field distribution in any cross section of the measured volume of air.

  20. Characterization of High-Power Rocket and Jet Noise Using Near-Field Acoustical Holography

    OpenAIRE

    Wall, Alan T.; Gee, Kent L.; Gardner, Michael D.; James, Michael M.

    2010-01-01

    Structural fatigue, hearing damage, and community disturbances are all consequences of rocket and jet noise, especially as they become more powerful. Noise-reduction schemes require accurate characterization of the noise sources within rocket plumes and jets. Nearfield acoustical holography (NAH) measurements were made to visualize the sound field in the jet exhaust region of an F-22 Raptor. This is one of the largest-scale applications of NAH since its development in the 1980s. A scan-based ...

  1. A New Method for Determining Optimal Regularization Parameter in Near-Field Acoustic Holography

    Directory of Open Access Journals (Sweden)

    Yue Xiao

    2018-01-01

    Full Text Available Tikhonov regularization method is effective in stabilizing reconstruction process of the near-field acoustic holography (NAH based on the equivalent source method (ESM, and the selection of the optimal regularization parameter is a key problem that determines the regularization effect. In this work, a new method for determining the optimal regularization parameter is proposed. The transfer matrix relating the source strengths of the equivalent sources to the measured pressures on the hologram surface is augmented by adding a fictitious point source with zero strength. The minimization of the norm of this fictitious point source strength is as the criterion for choosing the optimal regularization parameter since the reconstructed value should tend to zero. The original inverse problem in calculating the source strengths is converted into a univariate optimization problem which is solved by a one-dimensional search technique. Two numerical simulations with a point driven simply supported plate and a pulsating sphere are investigated to validate the performance of the proposed method by comparison with the L-curve method. The results demonstrate that the proposed method can determine the regularization parameter correctly and effectively for the reconstruction in NAH.

  2. Surface Acoustic Wave Devices

    DEFF Research Database (Denmark)

    Dühring, Maria Bayard

    application is modulation of optical waves in waveguides. This presentation elaborates on how a SAW is generated by interdigital transducers using a 2D model of a piezoelectric, inhomogeneous material implemented in the high-level programming language Comsol Multiphysics. The SAW is send through a model......The work of this project is concerned with the simulation of surface acoustic waves (SAW) and topology optimization of SAW devices. SAWs are elastic vibrations that propagate along a material surface and are extensively used in electromechanical filters and resonators in telecommunication. A new...

  3. Measurement of incident sound power using near field acoustic holography

    DEFF Research Database (Denmark)

    Jacobsen, Finn; Tiana Roig, Elisabet

    2009-01-01

    ; and it has always been regarded as impossible to measure the sound power that is incident on a wall directly. This paper examines a new method of determining this quantity from sound pressure measurements at positions on the wall using ‘statistically optimised near field acoustic holography’ (SONAH...

  4. Acoustic holography as a metrological tool for characterizing medical ultrasound sources and fields.

    Science.gov (United States)

    Sapozhnikov, Oleg A; Tsysar, Sergey A; Khokhlova, Vera A; Kreider, Wayne

    2015-09-01

    Acoustic holography is a powerful technique for characterizing ultrasound sources and the fields they radiate, with the ability to quantify source vibrations and reduce the number of required measurements. These capabilities are increasingly appealing for meeting measurement standards in medical ultrasound; however, associated uncertainties have not been investigated systematically. Here errors associated with holographic representations of a linear, continuous-wave ultrasound field are studied. To facilitate the analysis, error metrics are defined explicitly, and a detailed description of a holography formulation based on the Rayleigh integral is provided. Errors are evaluated both for simulations of a typical therapeutic ultrasound source and for physical experiments with three different ultrasound sources. Simulated experiments explore sampling errors introduced by the use of a finite number of measurements, geometric uncertainties in the actual positions of acquired measurements, and uncertainties in the properties of the propagation medium. Results demonstrate the theoretical feasibility of keeping errors less than about 1%. Typical errors in physical experiments were somewhat larger, on the order of a few percent; comparison with simulations provides specific guidelines for improving the experimental implementation to reduce these errors. Overall, results suggest that holography can be implemented successfully as a metrological tool with small, quantifiable errors.

  5. Designing an array for performing Near-field Acoustic Holography with a small number of p-u probes

    DEFF Research Database (Denmark)

    Fernandez Comesaña, Daniel; Wen, Junjie; Fernandez Grande, Efren

    2016-01-01

    Near-field acoustic holography (NAH) enables the reconstruction of an entire three-dimensional wave field using data acquired near the sources of sound. An array of sensors can be used in combination with NAH techniques for tackling both time-stationary and transient noise problems. However...

  6. Measurement of the sound power incident on the walls of a reverberation room with near field acoustic holography

    DEFF Research Database (Denmark)

    Jacobsen, Finn; Tiana Roig, Elisabet

    2010-01-01

    area; and it has always been regarded as impossible to measure the sound power that is incident on a wall directly. This paper examines a new method of determining this quantity from sound pressure measurements at positions on the wall using 'statistically optimised near field acoustic holography...

  7. Optimization of Fixed Microphone Array in High Speed Train Noises Identification Based on Far-Field Acoustic Holography

    Directory of Open Access Journals (Sweden)

    Rujia Wang

    2017-01-01

    Full Text Available Acoustical holography has been widely applied for noise sources location and sound field measurement. Performance of the microphones array directly determines the sound source recognition method. Therefore, research is very important to the performance of the microphone array, its array of applications, selection, and how to design instructive. In this paper, based on acoustic holography moving sound source identification theory, the optimization method is applied in design of the microphone array, we select the main side lobe ratio and the main lobe area as the optimization objective function and then put the optimization method use in the sound source identification based on holography, and finally we designed this paper to optimize microphone array and compare the original array of equally spaced array with optimization results; by analyzing the optimization results and objectives, we get that the array can be achieved which is optimized not only to reduce the microphone but also to change objective function results, while improving the far-field acoustic holography resolving effect. Validation experiments have showed that the optimization method is suitable for high speed trains sound source identification microphone array optimization.

  8. Tunable coupled surface acoustic cavities

    Science.gov (United States)

    de Lima, M. M.; Santos, P. V.; Kosevich, Yu. A.; Cantarero, A.

    2012-06-01

    We demonstrate the electric tuning of the acoustic field in acoustic microcavities (MCs) defined by a periodic arrangement of metal stripes within a surface acoustic delay line on LiNbO3 substrate. Interferometric measurements show the enhancement of the acoustic field distribution within a single MC, the presence of a "bonding" and "anti-bonding" modes for two strongly coupled MCs, as well as the positive dispersion of the "mini-bands" formed by five coupled MCs. The frequency and amplitude of the resonances can be controlled by the potential applied to the metal stripes.

  9. Analysis of the radiation from the violin f-holes using patch near field acoustical holography

    Science.gov (United States)

    Williams, Earl G.; Bissinger, George

    2003-04-01

    Although differential pressure measurements offer a direct means to understand the energy flow from the f-holes of the violin they have been performed only at discrete frequencies over relatively limited portions of the acoustic field, and none have ever covered an entire f-hole over a broad frequency region. Application of recently developed near field acoustical holography (NAH) patch processing techniques to 108-node planar rectangular grid microphone data provides a powerful tool to understand the flow of acoustic energy from the f-holes up to 4 kHz. The grid covered each f-hole as well as a small portion of the violin top-plate and provided the necessary spatial resolution to allow isolation of only f-hole aperture radiation in the NAH processing. The projected radiativity in the far field at 1.2 m from just the f-holes was compared with prior microphone measurements in an anechoic chamber over an entire sphere around the violin. As expected the lowest cavity mode A0 was the major radiator at the frequencies below all the corpus modes. Surprisingly the first corpus bending modes appear to radiate strongly through the f-holes also. [Work supported by ONR and NSF.

  10. Violin f-hole contribution to far-field radiation via patch near-field acoustical holography.

    Science.gov (United States)

    Bissinger, George; Williams, Earl G; Valdivia, Nicolas

    2007-06-01

    The violin radiates either from dual ports (f-holes) or via surface motion of the corpus (top+ribs+back), with no clear delineation between these sources. Combining "patch" near-field acoustical holography over just the f-hole region of a violin with far-field radiativity measurements over a sphere, it was possible to separate f-hole from surface motion contributions to the total radiation of the corpus below 2.6 kHz. A0, the Helmholtz-like lowest cavity resonance, radiated essentially entirely through the f-holes as expected while A1, the first longitudinal cavity mode with a node at the f-holes, had no significant f-hole radiation. The observed A1 radiation comes from an indirect radiation mechanism, induced corpus motion approximately mirroring the cavity pressure profile seen for violinlike bowed string instruments across a wide range of sizes. The first estimates of the fraction of radiation from the f-holes F(f) indicate that some low frequency corpus modes thought to radiate only via surface motion (notably the first corpus bending modes) had significant radiation through the f-holes, in agreement with net volume changes estimated from experimental modal analysis. F(f) generally trended lower with increasing frequency, following corpus mobility decreases. The f-hole directivity (top/back radiativity ratio) was generally higher than whole-violin directivity.

  11. Neutron holography

    International Nuclear Information System (INIS)

    Beynon, T.D.

    1986-01-01

    the paper concerns neutron holography, which allows an image to be constructed of the surfaces, as well as the interiors, of objects. The technique of neutron holography and its applications are described. Present and future use of the method is briefly outlined. (U.K.)

  12. Patch near-field acoustic holography: The influence of acoustic contributions from outside the source

    DEFF Research Database (Denmark)

    Fernandez Grande, Efren; Jacobsen, Finn; Zhang, Yong-Bin

    2009-01-01

    is of particular interest (known as the “patch” or “source patch”). The area of the source beyond this patch is not of interest in the analysis. However, its acoustic output may nevertheless contribute to the total sound field in the measurement plane, and influence the reconstruction of the field close...... to the patch. The purpose of this paper is to investigate how the acoustic radiation from outside the patch area influences the reconstruction of the sound field close to the source. The reconstruction is based on simulated measurements of sound pressure and particle velocity. The methods used in this paper...... that an acceptable reconstruction of the normal velocity can be achieved if the contributions from beyond the patch area are accounted for....

  13. Real-time nearfield acoustic holography in a uniformly moving medium

    Science.gov (United States)

    Dong, Bi-Chun; Bi, Chuan-Xing; Zhang, Xiao-Zheng; Zhang, Yong-Bin

    2017-12-01

    Real-time nearfield acoustic holography (RT-NAH) is an effective tool to identify nonstationary sound sources and predict the time-dependent sound field via a temporal convolution between the time-dependent wavenumber spectrum on the hologram plane and an impulse response. However, the conventional RT-NAH procedures are developed for sound sources situated in a static medium. As for sound sources located in a moving medium, the conventional RT-NAH procedures cannot be applied directly due to the fact that the impulse response will be changed by flow effects. In this paper, two analytical impulse responses in a uniformly moving medium, corresponding to two cases that the flow direction is parallel to and perpendicular to the hologram plane, are derived first with consideration of flow effects, and then RT-NAH is extended to realize forward and backward propagation of time-dependent signals in the moving medium. Numerical simulations are conducted to check the performances of the proposed method. The results show that the proposed method not only can be used to predict nonstationary sound fields but also can be utilized to identify nonstationary sources in a moving medium for both the parallel and perpendicular cases.

  14. Characterization of acoustically induced deformations of human tympanic membranes by digital holography and shearography

    Science.gov (United States)

    Flores-Moreno, J. M.; Furlong, Cosme; Cheng, Jeffrey T.; Rosowski, John J.; Merchant, S. N.

    2011-08-01

    Recently, we introduced a Digital Optoelectronic Holographic System (DOEHS) for measurement of acoustically induced deformations of the human tympanic membrane (TM) in order to study and diagnose pathologic conditions of the middle-ear. The DOEHS consists of laser-delivery illumination (IS), optical head (OH), image-processing computer (IP), and positioning arm (PS) subsystems. Holographic information is recorded by a CCD and numerically reconstructed by Fresnel approximation. Our holographic otoscope system is currently deployed in a clinic and is packaged in a custom design. Since digital holography is a high sensitivity measurement technique and the interfering light waves travel along different paths, it makes measurements acquired by DOEHS susceptible to external vibrations. In order to avoid this susceptibility, we are testing a shearography setup as OH. Shearography presents same advantages as holographic interferometry, but it is less susceptible to vibration and external noise, which is a characteristic needed for the use of our techniques in a clinical environment. In this paper we present work in progress in our development of a shearography technique based on a Mach-Zehnder configuration as OH and demonstrate its application by quantifying vibrations modes in thin membranes, including human TM. Results are compared with those obtained with DOEHS.

  15. Near-field acoustic holography using sparse regularization and compressive sampling principles.

    Science.gov (United States)

    Chardon, Gilles; Daudet, Laurent; Peillot, Antoine; Ollivier, François; Bertin, Nancy; Gribonval, Rémi

    2012-09-01

    Regularization of the inverse problem is a complex issue when using near-field acoustic holography (NAH) techniques to identify the vibrating sources. This paper shows that, for convex homogeneous plates with arbitrary boundary conditions, alternative regularization schemes can be developed based on the sparsity of the normal velocity of the plate in a well-designed basis, i.e., the possibility to approximate it as a weighted sum of few elementary basis functions. In particular, these techniques can handle discontinuities of the velocity field at the boundaries, which can be problematic with standard techniques. This comes at the cost of a higher computational complexity to solve the associated optimization problem, though it remains easily tractable with out-of-the-box software. Furthermore, this sparsity framework allows us to take advantage of the concept of compressive sampling; under some conditions on the sampling process (here, the design of a random array, which can be numerically and experimentally validated), it is possible to reconstruct the sparse signals with significantly less measurements (i.e., microphones) than classically required. After introducing the different concepts, this paper presents numerical and experimental results of NAH with two plate geometries, and compares the advantages and limitations of these sparsity-based techniques over standard Tikhonov regularization.

  16. Noise suppression in curved glass shells using macro-fiber-composite actuators studied by the means of digital holography and acoustic measurements

    Science.gov (United States)

    Mokrý, P.; Psota, P.; Steiger, K.; Václavík, J.; Doleček, R.; Lédl, V.; Šulc, M.

    2015-02-01

    The paper presents methods and experimental results of the semi-active control of noise transmission in a curved glass shell with attached piezoelectric macro fiber composite (MFC) actuators. The semi-active noise control is achieved via active elasticity control of piezoelectric actuators by connecting them to an active electric shunt circuit that has a negative effective capacitance. Using this approach, it is possible to suppress the vibration of the glass shell in the normal direction with respect to its surface and to increase the acoustic transmission loss of the piezoelectric MFC-glass composite structure. The effect of the MFC actuators connected to the negative capacitance shunt circuit on the surface distribution of the normal vibration amplitude is studied using frequency-shifted digital holography (FSDH). The principle of the used FSDH method is described in the paper. The frequency dependence of the acoustic transmission loss through the piezoelectric MFC-glass composite structure is estimated using measurements of the specific acoustic impedance of the curved glass shell. The specific acoustic impedance is measured using two microphones and a laser Doppler vibrometer (LDV). The results from the LDV measurements are compared with the FSDH data. The results of the experiments show that using this approach, the acoustic transmission loss in a glass shell can be increased by 36 dB in the frequency range around 247 Hz and by 25 dB in the frequency range around 258 Hz. The experiments indicate that FSDH measurements provide an efficient tool that can be used for fast and accurate measurements of the acoustic transmission loss in large planar structures.

  17. Noise suppression in curved glass shells using macro-fiber-composite actuators studied by the means of digital holography and acoustic measurements

    Directory of Open Access Journals (Sweden)

    P. Mokrý

    2015-02-01

    Full Text Available The paper presents methods and experimental results of the semi-active control of noise transmission in a curved glass shell with attached piezoelectric macro fiber composite (MFC actuators. The semi-active noise control is achieved via active elasticity control of piezoelectric actuators by connecting them to an active electric shunt circuit that has a negative effective capacitance. Using this approach, it is possible to suppress the vibration of the glass shell in the normal direction with respect to its surface and to increase the acoustic transmission loss of the piezoelectric MFC-glass composite structure. The effect of the MFC actuators connected to the negative capacitance shunt circuit on the surface distribution of the normal vibration amplitude is studied using frequency-shifted digital holography (FSDH. The principle of the used FSDH method is described in the paper. The frequency dependence of the acoustic transmission loss through the piezoelectric MFC-glass composite structure is estimated using measurements of the specific acoustic impedance of the curved glass shell. The specific acoustic impedance is measured using two microphones and a laser Doppler vibrometer (LDV. The results from the LDV measurements are compared with the FSDH data. The results of the experiments show that using this approach, the acoustic transmission loss in a glass shell can be increased by 36 dB in the frequency range around 247 Hz and by 25 dB in the frequency range around 258 Hz. The experiments indicate that FSDH measurements provide an efficient tool that can be used for fast and accurate measurements of the acoustic transmission loss in large planar structures.

  18. Seismic Holography of Solar Activity

    Science.gov (United States)

    Lindsey, Charles

    2000-01-01

    The basic goal of the project was to extend holographic seismic imaging techniques developed under a previous NASA contract, and to incorporate phase diagnostics. Phase-sensitive imaging gives us a powerful probe of local thermal and Doppler perturbations in active region subphotospheres, allowing us to map thermal structure and flows associated with "acoustic moats" and "acoustic glories". These remarkable features were discovered during our work, by applying simple acoustic power holography to active regions. Included in the original project statement was an effort to obtain the first seismic images of active regions on the Sun's far surface.

  19. A patch near-field acoustical holography procedure based on a generalized discrete Fourier series

    Science.gov (United States)

    Pasqual, A. M.

    2017-06-01

    Planar near-field acoustical holography (NAH) can be used to reconstruct a three-dimensional sound field from sound pressure data measured by a planar microphone array. The conventional planar NAH makes use of the discrete Fourier transform (DFT) to process the measured data, yielding a low computational cost. However, if the measurement aperture does not fully cover the sound source extension, the spatial windowing will lead to severe reconstruction errors. Many patch NAH methods have been proposed to allow measurement apertures smaller than the source size, such as the statistically optimized NAH (SONAH), which is not based on the DFT. These methods have proven to outperform the conventional NAH for small measurement apertures, but with an increased computation time and more complex implementation. This paper introduces an alternative patch procedure for planar NAH that replaces the DFT with a so-called "generalized discrete Fourier series" (GDFS). Unlike the DFT, the periods of the two-dimensional GDFS and the number of Fourier coefficients are made larger than the measurement aperture and the number of microphones, respectively. Then, the Fourier coefficients are evaluated in the least-norm sense. This reduces the spectral leakage due to the spatial windowing, improving the NAH results. As a numerical example, a simply supported plate driven by a point force is considered, and patches of the plate normal velocity are estimated from simulations of the radiated sound pressure on a small microphone array. It is shown that the GDFS-based method might lead to reconstructed velocity fields as accurate as SONAH, or even more accurate. However, unlike SONAH, the proposed method presents a low computational cost and a straightforward implementation. Therefore, it is a worthy alternative to the currently available patch procedures for planar NAH.

  20. Characterization of a multi-element clinical HIFU system using acoustic holography and nonlinear modeling.

    Science.gov (United States)

    Kreider, Wayne; Yuldashev, Petr V; Sapozhnikov, Oleg A; Farr, Navid; Partanen, Ari; Bailey, Michael R; Khokhlova, Vera A

    2013-08-01

    High-intensity focused ultrasound (HIFU) is a treatment modality that relies on the delivery of acoustic energy to remote tissue sites to induce thermal and/or mechanical tissue ablation. To ensure the safety and efficacy of this medical technology, standard approaches are needed for accurately characterizing the acoustic pressures generated by clinical ultrasound sources under operating conditions. Characterization of HIFU fields is complicated by nonlinear wave propagation and the complexity of phased-array transducers. Previous work has described aspects of an approach that combines measurements and modeling, and here we demonstrate this approach for a clinical phased-array transducer. First, low amplitude hydrophone measurements were performed in water over a scan plane between the array and the focus. Second, these measurements were used to holographically reconstruct the surface vibrations of the transducer and to set a boundary condition for a 3-D acoustic propagation model. Finally, nonlinear simulations of the acoustic field were carried out over a range of source power levels. Simulation results were compared with pressure waveforms measured directly by hydrophone at both low and high power levels, demonstrating that details of the acoustic field, including shock formation, are quantitatively predicted.

  1. A high-reflective surface measurement method based on conoscopic holography technology

    Science.gov (United States)

    Cheng, Xu; Li, ZhongWei; Shi, YuSheng; Zhao, HengShuang; Zhan, Guomin

    2014-11-01

    Measuring high-reflective surfaces using optical method is always a big challenging problem. This paper presents a high-reflective surface measurement method based on conoscopic holography technology using a 4D motion platform equipped with a conoscopic holography optical probe. There are two key problems needed to solve before the automate scan of the complex shape surface: the coordinate calibration and the path planning. To improve the calibration efficiency and accuracy, the coordinate calibration is divided into two parts: the rough calibration and the accurate registration. The path planning consists of two aspects including: the path points generation and the path points verification. In addition, by scanning the objects having high-reflective surfaces, such as the metal blades, coins and other work-pieces, the efficiency of the measurement method has been verified.

  2. Swimming using surface acoustic waves.

    Directory of Open Access Journals (Sweden)

    Yannyk Bourquin

    Full Text Available Microactuation of free standing objects in fluids is currently dominated by the rotary propeller, giving rise to a range of potential applications in the military, aeronautic and biomedical fields. Previously, surface acoustic waves (SAWs have been shown to be of increasing interest in the field of microfluidics, where the refraction of a SAW into a drop of fluid creates a convective flow, a phenomenon generally known as SAW streaming. We now show how SAWs, generated at microelectronic devices, can be used as an efficient method of propulsion actuated by localised fluid streaming. The direction of the force arising from such streaming is optimal when the devices are maintained at the Rayleigh angle. The technique provides propulsion without any moving parts, and, due to the inherent design of the SAW transducer, enables simple control of the direction of travel.

  3. Patch holography using a double layer microphone array

    DEFF Research Database (Denmark)

    Gomes, Jesper Skovhus

    In contrast to several techniques in Near-field Acoustical Holography, the Inverse Boundary Element Method (IBEM) can be used on arbitrary source geometries. In IBEM one must define a closed surface which confines/excludes all sources. This surface is subsequently discretized by an element mesh...

  4. Thermodynamic holography.

    Science.gov (United States)

    Wei, Bo-Bo; Jiang, Zhan-Feng; Liu, Ren-Bao

    2015-10-19

    The holographic principle states that the information about a volume of a system is encoded on the boundary surface of the volume. Holography appears in many branches of physics, such as optics, electromagnetism, many-body physics, quantum gravity, and string theory. Here we show that holography is also an underlying principle in thermodynamics, a most important foundation of physics. The thermodynamics of a system is fully determined by its partition function. We prove that the partition function of a finite but arbitrarily large system is an analytic function on the complex plane of physical parameters, and therefore the partition function in a region on the complex plane is uniquely determined by its values along the boundary. The thermodynamic holography has applications in studying thermodynamics of nano-scale systems (such as molecule engines, nano-generators and macromolecules) and provides a new approach to many-body physics.

  5. Thermodynamic holography

    Science.gov (United States)

    Wei, Bo-Bo; Jiang, Zhan-Feng; Liu, Ren-Bao

    2015-01-01

    The holographic principle states that the information about a volume of a system is encoded on the boundary surface of the volume. Holography appears in many branches of physics, such as optics, electromagnetism, many-body physics, quantum gravity, and string theory. Here we show that holography is also an underlying principle in thermodynamics, a most important foundation of physics. The thermodynamics of a system is fully determined by its partition function. We prove that the partition function of a finite but arbitrarily large system is an analytic function on the complex plane of physical parameters, and therefore the partition function in a region on the complex plane is uniquely determined by its values along the boundary. The thermodynamic holography has applications in studying thermodynamics of nano-scale systems (such as molecule engines, nano-generators and macromolecules) and provides a new approach to many-body physics. PMID:26478214

  6. Efficient Interior NSI based on Various BeamformingMethods for Overview and Conformal Mapping usingSONAH Holography for Details on Selected Panels

    DEFF Research Database (Denmark)

    Hald, Jørgen; Mørkholt, Jakob; Gomes, Jesper Skovhus

    of problematic areas is performed with a small planar single-layer or double-layer array in combination with SONAH holography. Using the SONAH algorithm for patch near-field acoustic holography, all sound field parameters can be estimated directly on the irregularly shaped panel surfaces. All the array...

  7. Development of a Digital Holography Diagnostic for Surface Characterization at ORNL

    Science.gov (United States)

    Biewer, T. M.; Thomas, C. E.

    2016-10-01

    The Fusion and Materials for Nuclear Systems Division (FMNSD) at Oak Ridge National Laboratory (ORNL), in collaboration with Third Dimension Technologies (TDT), proposes to develop a digital holography (DH) surface erosion/deposition diagnostic for imaging 3D plasma facing component (PFC) surfaces in real time. Digital holography is a technique that utilizes IR lasers reflected from a material surface to form a holographic interferogram, which carries information about the topology of the surface when reconstructed. The interrogated surface (at a distance of 3 m) is a region of 2.3 cm x 2.3 cm, and the surface feature resolution is 10 micron or better in depth, around 1 mm transverse to the beam. This is being accomplished in a multi-staged research program at ORNL: 1) establishment of a single-laser DH system ``on the bench,'' 2) establishment of a dual-laser DH system ``on the bench,'' and 3) implementation of the dual-laser DH system on the Proto-MPEX device. The status of the diagnostic development effort will be presented. This work was supported by the US. D.O.E. contract DE-AC05-00OR22725. Research sponsored by the Laboratory Directed Research and Development Program of ORNL, managed by UT Battelle, LLC, for the U.S. D.O.E.

  8. Holography In Japan

    Science.gov (United States)

    Tsujiuchi, Jumpei

    1985-08-01

    The present status of activities of research and application of holography in Japan is reviewed. The most active field is metrology, and many applications in automobile, aircraft, electronic industries as well as basic researches are found. Information processing and optical memory are still in laboratory level, and suitable applications are looked for. Optical elements are promising, and applications in POS scanning systems are already in practical use. Applications in 3-D image display are spreading among the public, and applications for medical purpose have started. Acoustical holography is applied in mechanical engineering, and electron holography becomes a very attractive tool for experimental physics.

  9. Acoustic imaging in application to reconstruction of rough rigid surface with airborne ultrasound waves

    Science.gov (United States)

    Krynkin, A.; Dolcetti, G.; Hunting, S.

    2017-02-01

    Accurate reconstruction of the surface roughness is of high importance to various areas of science and engineering. One important application of this technology is for remote monitoring of open channel flows through observing its dynamic surface roughness. In this paper a novel airborne acoustic method of roughness reconstruction is proposed and tested with a static rigid rough surface. This method is based on the acoustic holography principle and Kirchhoff approximation which make use of acoustic pressure data collected at multiple receiver points spread along an arch. The Tikhonov regularisation and generalised cross validation technique are used to solve the underdetermined system of equations for the acoustic pressures. The experimental data are collected above a roughness created with a 3D printer. For the given surface, it is shown that the proposed method works well with the various number of receiver positions. In this paper, the tested ratios between the number of surface points at which the surface elevation can be reconstructed and number of receiver positions are 2.5, 5, and 7.5. It is shown that, in a region comparable with the projected size of the main directivity lobe, the method is able to reconstruct the spatial spectrum density of the actual surface elevation with the accuracy of 20%.

  10. Reconfigurable Nano-Plasmonics Holography

    Science.gov (United States)

    2013-04-01

    30 Sept. 2012 4. TITLE AND SUBTITLE Reconfigurable Nano-Plasmonics Holography 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT...of plasmonic holography by Reconfigurable Surface Plasmon Phase Modulators from micro-electromechanical devices. High dielectric constant...Project Title: Reconfigurable Nano-Plasmonics Holography Award Number: FA9550-09-1-0698 Start Date: Sept. 30

  11. Digital holography on moving objects: multiwavelength height measurements on inclined surfaces

    Science.gov (United States)

    Schiller, Annelie; Beckmann, Tobias; Fratz, Markus; Belzer, Dominik; Bertz, Alexander; Carl, Daniel; Buse, Karsten

    2017-06-01

    Multiwavelength digital holography on moving objects enables fast and precise inline-measurements of surface pro files. Due to the use of multiple wavelengths, optically rough surfaces with structure heights in the micrometer range can be mapped unambiguously. In this work we explore the influence of the object velocity on height measurements on inclined surfaces. We show measurements using spatial-phase-shifting holography employing two wavelengths and object velocities of up to 90 mm/s with eye-safe cw-lasers with less than 1 mW of laser light. Despite motion blur exceeding the mean speckle size, reliable height measurements can be conducted at these velocities. The height map of a metal cone with two different slope angles (1° , 10° ) is measured at an exposure time of 2 ms. Using line shaped illumination, each frame yields a height map of approximately 2 x 17 mm2. The overlap between the frames allows averaging as the image is put together, improving data quality. The mean repeatability of the height information in the investigated setup is better than 4.5 µm at a synthetic wavelength of 214 µm.

  12. Entanglement entropy of singular surfaces under relevant deformations in holography

    Science.gov (United States)

    Ghasemi, Mostafa; Parvizi, Shahrokh

    2018-02-01

    In the vacuum state of a CFT, the entanglement entropy of singular surfaces contains a logarithmic universal term which is only due to the singularity of the entangling surface. We consider the relevant perturbation of a three dimensional CFT for singular entangling surface. We observe that in addition to the universal term due to the entangling surface, there is a new logarithmic term which corresponds to a relevant perturbation of the conformal field theory with a coefficient depending on the scaling dimension of the relevant operator. We also find a new power law divergence in the holographic entanglement entropy. In addition, we study the effect of a relevant perturbation in the Gauss-Bonnet gravity for a singular entangling surface. Again a logarithmic term shows up. This new term is proportional to both the dimension of the relevant operator and the Gauss-Bonnet coupling. We also introduce the renormalized entanglement entropy for a kink region which in the UV limit reduces to a universal positive finite term.

  13. A long standoff profilometer for surface inspection in adverse environments based on conoscopic holography

    Science.gov (United States)

    Enguita, Jose M.; Alvarez, Ignacio; Fraga, Cesar; Marina, Jorge; Fernandez, Yolanda; Sirat, Gabriel

    2005-06-01

    One of the more challenging applications of optical metrology is real-time dimensional control and surface inspection in industrial applications, where strong requirements of cost, setup and applicability in adverse environments, greatly limit the number of applicable technologies. This paper shows an optic profilometer developed specifically for this purpose. This device, based on Conoscopic holography, is able to obtain a distance profile of a target in a single-axis scan; works from long distances and still keeps good resolution with a very easy and reliable setup. The first part of the paper introduces the working principles of Conoscopic holography and shows the sensor set-up. Necessary algorithms for obtaining the distance information are presented and the whole process is illustrated with real captures of test objects. The second part focuses on a real example of this technology applied in an on-line inspection system in steel continuous casting funded by the European Committee for Steel and Carbon, and which is currently working in Aceralia LDA steelmaking factory in Asturias, Spain). The system is placed in the process line and performs on-line detection of surface defects over hot steel slabs from a distance of 1200 mm. 100% of the production can be inspected without interfering with the process and without adding any delay.

  14. Acoustic Impedance Measurement for Underground Surfaces.

    Science.gov (United States)

    Cockcroft, Paul William

    Available from UMI in association with The British Library. Requires signed TDF. This thesis investigates the measurement of acoustic impedance for surfaces likely to be found in underground coal mines. By introducing the concepts of industrial noise, the effects of noise on the ear and relevant legislation the need for the protection of workers can be appreciated. Representative acoustic impedance values are vital as input for existing computer models that predict sound levels in various underground environments. These enable the mining engineer to predict the noise level at any point within a mine in the vicinity of noisy machinery. The concepts of acoustic intensity and acoustic impedance are investigated and different acoustic impedance measurement techniques are detailed. The possible use of either an impedance tube or an intensity meter for these kinds of measurements are suggested. The problems with acoustic intensity and acoustic impedance measurements are discussed with reference to the restraints that an underground environment imposes on any measurement technique. The impedance tube method for work in an acoustics laboratory is shown and the theory explained, accompanied by a few representative results. The use of a Metravib intensity meter in a soundproof chamber to gain impedance values is explained in detail. The accompanying software for the analysis of the two measured pressure signals is shown as well as the actual results for a variety of test surfaces. The use of a Nagra IV-SJ tape recorder is investigated to determine the effect of recording on the measurement and subsequent analysis of the input signals, particularly with reference to the phase difference introduced between the two simultaneous pressure signals. The subsequent use of a Norwegian Electronic intensity meter, including a proposal for underground work, is shown along with results for tests completed with this piece of equipment. Finally, recommendations are made on how to link up

  15. Noninvasive conoscopic holography-based device for artworks surface acquisition

    Science.gov (United States)

    Carcagnì, P.; Cavallo, E.; Della Patria, A.; Gianfrate, G.; Pezzati, L.; Piccolo, R.; Pingi, P.

    2009-07-01

    Surface topography is very important for many applications. Today the most used techniques on artworks and stone artifacts require long acquisition times and invasive interventions. For this reason, here a non-contact device improved in portability is described. It can acquire wide areas in short times, so it is suitable for topography reconstruction with spatial resolution of some tens of micrometers. The starting point is a commercial conoscopic probe, the Optimet Conoline, that is able to reconstruct the depth profile of a surface line probed by a built-in laser. Its accuracy and acquisition speed are as high as to return wide measured areas in short times; its resolution permits fine details reproduction. Low interference with the artwork, high portability and low response to environmental noise are the ingredients for the instrumental setup.

  16. Quality investigation of surface mount technology using phase-shifting digital holography

    Science.gov (United States)

    Boonsri, Chantira; Buranasiri, Prathan

    2016-09-01

    Applying of a phase-shifting digital holography combined with compressive sensing to inspect the soldering quality of surface mount technology (SMT) which is a method for producing electronic circuits. In SMT, the components are mounted and connected with each other directly onto the surface of printed circuit boards (PCBs). By reconstructing the multidimensional images from a few samples of SMT, the results are solved by an optimization problem. In this paper, two problems have been concerned. The first one is to examine the devices and the soldering quality of connections between them, which are in micro-scaled. The second is to observe the effect of heat treatment of soldering material and devices on the surface mount board.

  17. Primary Beam and Dish Surface Characterization at the Allen Telescope Array by Radio Holography

    Science.gov (United States)

    Harp, G. R.; Ackermann, R. F.; Nadler, Z. J.; Blair, Samantha K.; Davis, M. M.; Wright, M. C. H.; Forster, J. R.; Deboer, D. R.; Welch, W. J.; Atkinson, Shannon; Backer, D. C.; Backus, P. R.; Barott, William; Bauermeister, Amber; Blitz, Leo; Bock, D. C.-J.; Bower, Geoffrey C.; Bradford, Tucker; Cheng, Calvin; Croft, Steve; Dexter, Matt; Dreher, John; Engargiola, Greg; Fields, E. D.; Heiles, Carl; Helfer, Tamara; Jordan, Jane; Jorgensen, Susan; Kilsdonk, Tom; Gutierrez-Kraybill, Colby; Keating, Garrett; Law, Casey; Lugten, John; MacMahon, D. H. E.; McMahon, Peter; Milgrome, Oren; Siemion, Andrew; Smolek, Ken; Thornton, Douglas; Pierson, Tom; Randall, Karen; Ross, John; Shostak, Seth; Tarter, J. C.; Urry, Lynn; Werthimer, Dan; Williams, Peter K. G.; Whysong, David

    2011-06-01

    The Allen Telescope Array (ATA) is a cm-wave interferometer in California, comprising 42 antenna elements with 6-m diameter dishes. We characterize the antenna optical accuracy using two-antenna interferometry and radio holography. The distortion of each telescope relative to the average is small, with RMS differences of 1% of beam peak value. Holography provides images of dish illumination, characterizing as-built mirror surfaces. Maximal distortions across ~ 2 meter lengths appear to result from mounting stresses or solar radiation. Experimental RMS errors are 0.7 mm at night and 3 mm under worst-case solar illumination. For frequencies 4, 10, and 15 GHz, the nighttime values indicate sensitivity losses of 1, 10 and 20%, respectively. ATA's wide-bandwidth receiver permits observations over a continuous range 0.5-11.2 GHz. We probe the antenna optical gain and beam pattern stability as a function of focus position and observation frequency, concluding that ATA can produce high fidelity images over a decade of simultaneous observation frequencies. We quantify solar heating effects on antenna sensitivity and pointing accuracy. We find that during the day, observations >=5 GHz will suffer some sensitivity loss and it may be necessary to make antenna pointing corrections on a 1-2 hourly basis.

  18. Investigating the use of the acousto-optic effect for acoustic holography

    DEFF Research Database (Denmark)

    Torras Rosell, Antoni; Fernandez Grande, Efren; Jacobsen, Finn

    2012-01-01

    Recent studies have demonstrated that the acousto-optic effect, that is, the interaction between sound and light, can be used as a means to visualize acoustic fields in the audible frequency range. The changes of density caused by sound waves propagating in air induce phase shifts to a laser beam...

  19. Active micromixer using surface acoustic wave streaming

    Science.gov (United States)

    Branch,; Darren W. , Meyer; Grant D. , Craighead; Harold, G [Ithaca, NY

    2011-05-17

    An active micromixer uses a surface acoustic wave, preferably a Rayleigh wave, propagating on a piezoelectric substrate to induce acoustic streaming in a fluid in a microfluidic channel. The surface acoustic wave can be generated by applying an RF excitation signal to at least one interdigital transducer on the piezoelectric substrate. The active micromixer can rapidly mix quiescent fluids or laminar streams in low Reynolds number flows. The active micromixer has no moving parts (other than the SAW transducer) and is, therefore, more reliable, less damaging to sensitive fluids, and less susceptible to fouling and channel clogging than other types of active and passive micromixers. The active micromixer is adaptable to a wide range of geometries, can be easily fabricated, and can be integrated in a microfluidic system, reducing dead volume. Finally, the active micromixer has on-demand on/off mixing capability and can be operated at low power.

  20. Resonant surface acoustic wave chemical detector

    Science.gov (United States)

    Brocato, Robert W.; Brocato, Terisse; Stotts, Larry G.

    2017-08-08

    Apparatus for chemical detection includes a pair of interdigitated transducers (IDTs) formed on a piezoelectric substrate. The apparatus includes a layer of adsorptive material deposited on a surface of the piezoelectric substrate between the IDTs, where each IDT is conformed, and is dimensioned in relation to an operating frequency and an acoustic velocity of the piezoelectric substrate, so as to function as a single-phase uni-directional transducer (SPUDT) at the operating frequency. Additionally, the apparatus includes the pair of IDTs is spaced apart along a propagation axis and mutually aligned relative to said propagation axis so as to define an acoustic cavity that is resonant to surface acoustic waves (SAWs) at the operating frequency, where a distance between each IDT of the pair of IDTs ranges from 100 wavelength of the operating frequency to 400 wavelength of the operating frequency.

  1. Acoustic tomography in the atmospheric surface layer

    Directory of Open Access Journals (Sweden)

    A. Ziemann

    Full Text Available Acoustic tomography is presented as a technique for remote monitoring of meteorological quantities. This method and a special algorithm of analysis can directly produce area-averaged values of meteorological parameters. As a result consistent data will be obtained for validation of numerical atmospheric micro-scale models. Such a measuring system can complement conventional point measurements over different surfaces. The procedure of acoustic tomography uses the horizontal propagation of sound waves in the atmospheric surface layer. Therefore, to provide a general overview of sound propagation under various atmospheric conditions a two-dimensional ray-tracing model according to a modified version of Snell's law is used. The state of the crossed atmosphere can be estimated from measurements of acoustic travel time between sources and receivers at different points. Derivation of area-averaged values of the sound speed and furthermore of air temperature results from the inversion of travel time values for all acoustic paths. Thereby, the applied straight ray two-dimensional tomographic model using SIRT (simultaneous iterative reconstruction technique is characterised as a method with small computational requirements, satisfactory convergence and stability properties as well as simple handling, especially, during online evaluation.

    Key words. Meteorology and atmospheric dynamics (turbulence; instruments and techniques.

  2. Statistically optimized near field acoustic holography using an array of pressure-velocity probes

    DEFF Research Database (Denmark)

    Jacobsen, Finn; Jaud, Virginie

    2007-01-01

    of a measurement aperture that extends well beyond the source can be relaxed. Both NAH and SONAH are based on the assumption that all sources are on one side of the measurement plane whereas the other side is source free. An extension of the SONAH procedure based on measurement with a double layer array...... of pressure microphones has been suggested. The double layer technique makes it possible to distinguish between sources on the two sides of the array and thus suppress the influence of extraneous noise coming from the “wrong” side. It has also recently been demonstrated that there are significant advantages...... in NAH based on an array of acoustic particle velocity transducers (in a single layer) compared with NAH based on an array of pressure microphones. This investigation combines the two ideas and examines SONAH based on an array of pressure-velocity intensity probes through computer simulations as well...

  3. Surface Acoustic Wave Transducer Study.

    Science.gov (United States)

    1978-05-01

    ment. — ISO Lir — ~.1 L ~~~~~~~~ ~ ~~~ L~~~I&jr ~~ —- — — —--- - - - - t - s’ rlr ~~T I O , 4 ) F ~ H I ’ ~~,! ~WI.ft ?).s. ~~~~MEPORT DOCUMENTAT I...multiplying the norma l stress components thus ensuring that the normal stress is zero at x 2 = 0. For the present , an open-circuit elec trical...boundary condition is assumed so that the norma l D-uield is zero at the surface. This is taken .5 into account in a similar manner with a step-function

  4. ConoSurf: Open-source 3D scanning system based on a conoscopic holography device for acquiring surgical surfaces.

    Science.gov (United States)

    Brudfors, Mikael; García-Vázquez, Verónica; Sesé-Lucio, Begoña; Marinetto, Eugenio; Desco, Manuel; Pascau, Javier

    2017-09-01

    A difficulty in computer-assisted interventions is acquiring the patient's anatomy intraoperatively. Standard modalities have several limitations: low image quality (ultrasound), radiation exposure (computed tomography) or high costs (magnetic resonance imaging). An alternative approach uses a tracked pointer; however, the pointer causes tissue deformation and requires sterilizing. Recent proposals, utilizing a tracked conoscopic holography device, have shown promising results without the previously mentioned drawbacks. We have developed an open-source software system that enables real-time surface scanning using a conoscopic holography device and a wide variety of tracking systems, integrated into pre-existing and well-supported software solutions. The mean target registration error of point measurements was 1.46 mm. For a quick guidance scan, surface reconstruction improved the surface registration error compared with point-set registration. We have presented a system enabling real-time surface scanning using a tracked conoscopic holography device. Results show that it can be useful for acquiring the patient's anatomy during surgery. © 2016 The Authors. The International Journal of Medical Robotics and Computer Assisted Surgery Published by John Wiley & Sons Ltd.

  5. ConoSurf: Open‐source 3D scanning system based on a conoscopic holography device for acquiring surgical surfaces

    Science.gov (United States)

    Brudfors, Mikael; García‐Vázquez, Verónica; Sesé‐Lucio, Begoña; Marinetto, Eugenio; Desco, Manuel

    2016-01-01

    Abstract Background A difficulty in computer‐assisted interventions is acquiring the patient's anatomy intraoperatively. Standard modalities have several limitations: low image quality (ultrasound), radiation exposure (computed tomography) or high costs (magnetic resonance imaging). An alternative approach uses a tracked pointer; however, the pointer causes tissue deformation and requires sterilizing. Recent proposals, utilizing a tracked conoscopic holography device, have shown promising results without the previously mentioned drawbacks. Methods We have developed an open‐source software system that enables real‐time surface scanning using a conoscopic holography device and a wide variety of tracking systems, integrated into pre‐existing and well‐supported software solutions. Results The mean target registration error of point measurements was 1.46 mm. For a quick guidance scan, surface reconstruction improved the surface registration error compared with point‐set registration. Conclusions We have presented a system enabling real‐time surface scanning using a tracked conoscopic holography device. Results show that it can be useful for acquiring the patient's anatomy during surgery. PMID:27868345

  6. The effects of two counterpropagating surface acoustic wave beams on single electron acoustic charge transport

    International Nuclear Information System (INIS)

    He Jianhong; Guo Huazhong; Song Li; Zhang Wei; Gao Jie; Lu Chuan

    2010-01-01

    We present a comprehensive study of the effects of two counterpropagating surface acoustic waves on the acoustoelectric current of single electron transport devices. A significant improvement in the accuracy of current quantization is achieved as a result of an additional surface acoustic wave beam. The experiments reveal the sinusoidally periodical modulation in the acoustoelectric current characteristic as a function of the relative phase of the two surface acoustic wave beams. Besides, by using standing surface acoustic waves, the acoustoelectric current is detected which we consider as the so-called anomalous acoustoelectric current produced by acoustic wave mechanical deformations. This kind current is contributed to one component of the acoustoelectric current in surface acoustic wave device, which could enable us to establish a more adequate description of acoustoelectric effects on single-electron acoustic charge transport.

  7. Surface acoustic wave actuated cell sorting (SAWACS).

    Science.gov (United States)

    Franke, T; Braunmüller, S; Schmid, L; Wixforth, A; Weitz, D A

    2010-03-21

    We describe a novel microfluidic cell sorter which operates in continuous flow at high sorting rates. The device is based on a surface acoustic wave cell-sorting scheme and combines many advantages of fluorescence activated cell sorting (FACS) and fluorescence activated droplet sorting (FADS) in microfluidic channels. It is fully integrated on a PDMS device, and allows fast electronic control of cell diversion. We direct cells by acoustic streaming excited by a surface acoustic wave which deflects the fluid independently of the contrast in material properties of deflected objects and the continuous phase; thus the device underlying principle works without additional enhancement of the sorting by prior labelling of the cells with responsive markers such as magnetic or polarizable beads. Single cells are sorted directly from bulk media at rates as fast as several kHz without prior encapsulation into liquid droplet compartments as in traditional FACS. We have successfully directed HaCaT cells (human keratinocytes), fibroblasts from mice and MV3 melanoma cells. The low shear forces of this sorting method ensure that cells survive after sorting.

  8. Quasi-two-dimensional holography

    International Nuclear Information System (INIS)

    Kutzner, J.; Erhard, A.; Wuestenberg, H.; Zimpfer, J.

    1980-01-01

    The acoustical holography with numerical reconstruction by area scanning is memory- and time-intensive. With the experiences by the linear holography we tried to derive a scanning for the evaluating of the two-dimensional flaw-sizes. In most practical cases it is sufficient to determine the exact depth extension of a flaw, whereas the accuracy of the length extension is less critical. For this reason the applicability of the so-called quasi-two-dimensional holography is appropriate. The used sound field given by special probes is divergent in the inclined plane and light focussed in the perpendicular plane using cylindrical lenses. (orig.) [de

  9. Development of a Dual-Laser Digital Holography Diagnostic for Surface Characterization at ORNL

    Science.gov (United States)

    Sawyer, J. C.; Biewer, T. M.; Thomas, C. E.; Zhang, Z.

    2017-10-01

    The Fusion and Materials for Nuclear Systems Division (FMNSD) at Oak Ridge National Laboratory (ORNL), in collaboration with The University of Tennessee, Knoxville and Third Dimension Technologies (TDT), presents continuing progress towards the development of a dual-laser digital holography (DH) technique for 3D imaging of plasma facing component (PFC) surfaces in real time. This update includes results from an ``on the bench'' single-laser DH demonstration. The dual-laser approach utilizes two CO2 lasers tuned to neighboring molecular CO2 lines to extend the 2 π ambiguity of holographic interferograms to 5 mm from the 10 μm wavelength. Reconstruction of the interferogram allows for measurement of changes in surface topology at rates of 2 mm/s. This status of a dual-laser DH system ``on the bench,'' demonstration and implementation on the Proto-MPEX device will be presented. This work was supported by The University of Tennessee JDRD program and the US. D.O.E. contract DE-AC05-00OR22725. Research sponsored by the Laboratory Directed Research and Development Program of ORNL, managed by UT Battelle, LLC, for the U.S. D.O.E.

  10. Acoustic surface transformation realized by acoustic-null materials using bilayer natural materials

    Science.gov (United States)

    Li, Borui; Sun, Fei; He, Sailing

    2017-11-01

    We propose a general method, known as acoustic surface transformation (AST), to design novel acoustic devices and study the realization of such devices by using naturally available materials in broadband acoustic frequencies. All devices designed by AST only need one anisotropic homogeneous acoustic-null material (ANM). We design the ANM by exploiting natural material-based metal-fluid structures and verify that by numerical simulation. Unlike traditional methods, no complicated mathematical calculations are needed. We only need to design the geometrical shapes of the input and output surfaces of the devices. The proposed method will pave a new road for future acoustic design.

  11. Polarization holography

    DEFF Research Database (Denmark)

    Nikolova, L.; Ramanujam, P.S.

    Current research into holography is concerned with applications in optically storing, retrieving, and processing information. Polarization holography has many unique properties compared to conventional holography. It gives results in high efficiency, achromaticity, and special polarization...... properties. This books reviews the research carried out in this field over the last 15 years. The authors provide basic concepts in polarization and the propagation of light through anisotropic materials, before presenting a sound theoretical basis for polarization holography. The fabrication...... and characterization of azobenzene based materials, which remain the most efficient for the purpose, is described in detail. This is followed by a description of other materials that are used in polarization holography. An in-depth description of various applications, including display holography and optical storage...

  12. Surface Acoustic Wave (SAW Vibration Sensors

    Directory of Open Access Journals (Sweden)

    Jerzy Filipiak

    2011-12-01

    Full Text Available In the paper a feasibility study on the use of surface acoustic wave (SAW vibration sensors for electronic warning systems is presented. The system is assembled from concatenated SAW vibration sensors based on a SAW delay line manufactured on a surface of a piezoelectric plate. Vibrations of the plate are transformed into electric signals that allow identification of the sensor and localization of a threat. The theoretical study of sensor vibrations leads us to the simple isotropic model with one degree of freedom. This model allowed an explicit description of the sensor plate movement and identification of the vibrating sensor. Analysis of frequency response of the ST-cut quartz sensor plate and a damping speed of its impulse response has been conducted. The analysis above was the basis to determine the ranges of parameters for vibrating plates to be useful in electronic warning systems. Generally, operation of electronic warning systems with SAW vibration sensors is based on the analysis of signal phase changes at the working frequency of delay line after being transmitted via two circuits of concatenated four-terminal networks. Frequencies of phase changes are equal to resonance frequencies of vibrating plates of sensors. The amplitude of these phase changes is proportional to the amplitude of vibrations of a sensor plate. Both pieces of information may be sent and recorded jointly by a simple electrical unit.

  13. High transmission acoustic focusing by impedance-matched acoustic meta-surfaces

    KAUST Repository

    Al Jahdali, Rasha

    2016-01-19

    Impedance is an important issue in the design of acoustic lenses because mismatched impedance is detrimental to real focusing applications. Here, we report two designs of acoustic lenses that focus acoustic waves in water and air, respectively. They are tailored by acoustic meta-surfaces, which are rigid thin plates decorated with periodically distributed sub-wavelength slits. Their respective building blocks are constructed from the coiling-up spaces in water and the layered structures in air. Analytic analysis based on coupled-mode theory and transfer matrix reveals that the impedances of the lenses are matched to those of the background media. With these impedance-matched acoustic lenses, we demonstrate the acoustic focusing effect by finite-element simulations.

  14. Surface acoustic wave devices for sensor applications

    Science.gov (United States)

    Bo, Liu; Xiao, Chen; Hualin, Cai; Mohammad, Mohammad Ali; Xiangguang, Tian; Luqi, Tao; Yi, Yang; Tianling, Ren

    2016-02-01

    Surface acoustic wave (SAW) devices have been widely used in different fields and will continue to be of great importance in the foreseeable future. These devices are compact, cost efficient, easy to fabricate, and have a high performance, among other advantages. SAW devices can work as filters, signal processing units, sensors and actuators. They can even work without batteries and operate under harsh environments. In this review, the operating principles of SAW sensors, including temperature sensors, pressure sensors, humidity sensors and biosensors, will be discussed. Several examples and related issues will be presented. Technological trends and future developments will also be discussed. Project supported by the National Natural Science Foundation of China (Nos. 60936002, 61025021, 61434001, 61574083), the State Key Development Program for Basic Research of China (No. 2015CB352100), the National Key Project of Science and Technology (No. 2011ZX02403-002) and the Special Fund for Agroscientific Research in the Public Interest of China (No. 201303107). M.A.M is additionally supported by the Postdoctoral Fellowship (PDF) program of the Natural Sciences and Engineering Research Council (NSERC) of Canada and the China Postdoctoral Science Foundation (CPSF).

  15. Surface acoustic wave electric field effect on acoustic streaming: Numerical analysis

    Science.gov (United States)

    Darinskii, A. N.; Weihnacht, M.; Schmidt, H.

    2018-01-01

    The paper numerically studies the contribution of the electric field accompanying the surface acoustic wave to the actuation of the acoustic streaming in microchannels. The finite element method is used. The results obtained as applied to the surface waves on 128° and 64°-rotated Y cuts of LiNbO3 demonstrate that the force created by the electric field is capable of accelerating appreciably the acoustic streaming. In particular, examples are given for the situations where the electric field increases the streaming velocity by a factor of about 2-3 and significantly changes the flow pattern as compared to predictions of computations ignoring the electric field.

  16. Surface Wave Focusing and Acoustic Communications in the Surf Zone

    National Research Council Canada - National Science Library

    Preisig, James

    2004-01-01

    The forward scattering of acoustic signals off of shoaling surface gravity waves in the surf zone results in a time-varying channel impulse response that is characterized by intense, rapidly fluctuating arrivals...

  17. CAMEX-3 JPL SURFACE ACOUSTIC WAVE (SAW) HYGROMETER V1

    Data.gov (United States)

    National Aeronautics and Space Administration — This CAMEX-3 Jet Propulsion Laboratory (JPL) Surface Acoustic Wave (SAW) Hygrometer dataset consists of dewpoint timeline measurements acquired during each DC-8...

  18. Estimating propagation velocity through a surface acoustic wave sensor

    Science.gov (United States)

    Xu, Wenyuan; Huizinga, John S.

    2010-03-16

    Techniques are described for estimating the propagation velocity through a surface acoustic wave sensor. In particular, techniques which measure and exploit a proper segment of phase frequency response of the surface acoustic wave sensor are described for use as a basis of bacterial detection by the sensor. As described, use of velocity estimation based on a proper segment of phase frequency response has advantages over conventional techniques that use phase shift as the basis for detection.

  19. Modulation of cavity-polaritons by surface acoustic waves

    DEFF Research Database (Denmark)

    de Lima, M. M.; Poel, Mike van der; Hey, R.

    2006-01-01

    We modulate cavity-polaritons using surface acoustic waves. The corresponding formation of a mini-Brillouin zone and band folding of the polariton dispersion is demonstrated for the first time. Results are in good agreement with model calculations.......We modulate cavity-polaritons using surface acoustic waves. The corresponding formation of a mini-Brillouin zone and band folding of the polariton dispersion is demonstrated for the first time. Results are in good agreement with model calculations....

  20. Characterization of microchannel anechoic corners formed by surface acoustic waves

    Science.gov (United States)

    Destgeer, Ghulam; Alam, Ashar; Ahmed, Husnain; Park, Jinsoo; Jung, Jin Ho; Park, Kwangseok; Sung, Hyung Jin

    2018-02-01

    Surface acoustic waves (SAWs) generated in a piezoelectric substrate couple with a liquid according to Snell's law such that a compressional acoustic wave propagates obliquely at a Rayleigh angle ( θ t) inside the microchannel to form a region devoid of a direct acoustic field, which is termed a microchannel anechoic corner (MAC). In the present study, we used microchannels with various heights and widths to characterize the width of the MAC region formed by a single travelling SAW. The attenuation of high-frequency SAWs produced a strong acoustic streaming flow that moved the particles in and out of the MAC region, whereas reflections of the acoustic waves within the microchannel resulted in standing acoustic waves that trapped particles at acoustic pressure nodes located within or outside of the MAC region. A range of actuation frequencies and particle diameters were used to investigate the effects of the acoustic streaming flow and the direct acoustic radiation forces by the travelling as well as standing waves on the particle motion with respect to the MAC region. The width of the MAC ( w c), measured experimentally by tracing the particles, increased with the height of the microchannel ( h m) according to a simple trigonometric equation w c = h m × tan ( θ t ).

  1. Particle separation by phase modulated surface acoustic waves.

    Science.gov (United States)

    Simon, Gergely; Andrade, Marco A B; Reboud, Julien; Marques-Hueso, Jose; Desmulliez, Marc P Y; Cooper, Jonathan M; Riehle, Mathis O; Bernassau, Anne L

    2017-09-01

    High efficiency isolation of cells or particles from a heterogeneous mixture is a critical processing step in lab-on-a-chip devices. Acoustic techniques offer contactless and label-free manipulation, preserve viability of biological cells, and provide versatility as the applied electrical signal can be adapted to various scenarios. Conventional acoustic separation methods use time-of-flight and achieve separation up to distances of quarter wavelength with limited separation power due to slow gradients in the force. The method proposed here allows separation by half of the wavelength and can be extended by repeating the modulation pattern and can ensure maximum force acting on the particles. In this work, we propose an optimised phase modulation scheme for particle separation in a surface acoustic wave microfluidic device. An expression for the acoustic radiation force arising from the interaction between acoustic waves in the fluid was derived. We demonstrated, for the first time, that the expression of the acoustic radiation force differs in surface acoustic wave and bulk devices, due to the presence of a geometric scaling factor. Two phase modulation schemes are investigated theoretically and experimentally. Theoretical findings were experimentally validated for different mixtures of polystyrene particles confirming that the method offers high selectivity. A Monte-Carlo simulation enabled us to assess performance in real situations, including the effects of particle size variation and non-uniform acoustic field on sorting efficiency and purity, validating the ability to separate particles with high purity and high resolution.

  2. Electron holography of biological samples.

    Science.gov (United States)

    Simon, P; Lichte, H; Formanek, P; Lehmann, M; Huhle, R; Carrillo-Cabrera, W; Harscher, A; Ehrlich, H

    2008-01-01

    In this paper, we summarise the development of off-axis electron holography on biological samples starting in 1986 with the first results on ferritin from the group of Tonomura. In the middle of the 1990s strong interest was evoked, but then stagnation took place because the results obtained at that stage did not reach the contrast and the resolution achieved by conventional electron microscopy. To date, there exist only a few ( approximately 12) publications on electron holography of biological objects, thus this topic is quite small and concise. The reason for this could be that holography is mostly established in materials science by physicists. Therefore, applications for off-axis holography were powerfully pushed forward in the area of imaging, e.g. electric or magnetic micro- and nanofields. Unstained biological systems investigated by means of off-axis electron holography up to now are ferritin, tobacco mosaic virus, a bacterial flagellum, T5 bacteriophage virus, hexagonal packed intermediate layer of bacteria and the Semliki Forest virus. New results of the authors on collagen fibres and surface layer of bacteria, the so-called S-layer 2D crystal lattice are presented in this review. For the sake of completeness, we will shortly discuss in-line holography of biological samples and off-axis holography of materials related to biological systems, such as biomaterial composites or magnetotactic bacteria.

  3. Single-exposure two-dimensional superresolution in digital holography using a vertical cavity surface-emitting laser source array.

    Science.gov (United States)

    Granero, Luis; Zalevsky, Zeev; Micó, Vicente

    2011-04-01

    We present a new implementation capable of producing two-dimensional (2D) superresolution (SR) imaging in a single exposure by aperture synthesis in digital lensless Fourier holography when using angular multiplexing provided by a vertical cavity surface-emitting laser source array. The system performs the recording in a single CCD snapshot of a multiplexed hologram coming from the incoherent addition of multiple subholograms, where each contains information about a different 2D spatial frequency band of the object's spectrum. Thus, a set of nonoverlapping bandpass images of the input object can be recovered by Fourier transformation (FT) of the multiplexed hologram. The SR is obtained by coherent addition of the information contained in each bandpass image while generating an enlarged synthetic aperture. Experimental results demonstrate improvement in resolution and image quality.

  4. A study on the theoretical and practical accuracy of conoscopic holography-based surface measurements: toward image registration in minimally invasive surgery†

    Science.gov (United States)

    Burgner, J.; Simpson, A. L.; Fitzpatrick, J. M.; Lathrop, R. A.; Herrell, S. D.; Miga, M. I.; Webster, R. J.

    2013-01-01

    Background Registered medical images can assist with surgical navigation and enable image-guided therapy delivery. In soft tissues, surface-based registration is often used and can be facilitated by laser surface scanning. Tracked conoscopic holography (which provides distance measurements) has been recently proposed as a minimally invasive way to obtain surface scans. Moving this technique from concept to clinical use requires a rigorous accuracy evaluation, which is the purpose of our paper. Methods We adapt recent non-homogeneous and anisotropic point-based registration results to provide a theoretical framework for predicting the accuracy of tracked distance measurement systems. Experiments are conducted a complex objects of defined geometry, an anthropomorphic kidney phantom and a human cadaver kidney. Results Experiments agree with model predictions, producing point RMS errors consistently holography is clinically viable; it enables minimally invasive surface scan accuracy comparable to current clinical methods that require open surgery. PMID:22761086

  5. A study on the theoretical and practical accuracy of conoscopic holography-based surface measurements: toward image registration in minimally invasive surgery.

    Science.gov (United States)

    Burgner, J; Simpson, A L; Fitzpatrick, J M; Lathrop, R A; Herrell, S D; Miga, M I; Webster, R J

    2013-06-01

    Registered medical images can assist with surgical navigation and enable image-guided therapy delivery. In soft tissues, surface-based registration is often used and can be facilitated by laser surface scanning. Tracked conoscopic holography (which provides distance measurements) has been recently proposed as a minimally invasive way to obtain surface scans. Moving this technique from concept to clinical use requires a rigorous accuracy evaluation, which is the purpose of our paper. We adapt recent non-homogeneous and anisotropic point-based registration results to provide a theoretical framework for predicting the accuracy of tracked distance measurement systems. Experiments are conducted a complex objects of defined geometry, an anthropomorphic kidney phantom and a human cadaver kidney. Experiments agree with model predictions, producing point RMS errors consistently holography is clinically viable; it enables minimally invasive surface scan accuracy comparable to current clinical methods that require open surgery. Copyright © 2012 John Wiley & Sons, Ltd.

  6. Homotopy based Surface Reconstruction with Application to Acoustic Signals

    DEFF Research Database (Denmark)

    Sharma, Ojaswa; Anton, François

    2011-01-01

    This work introduces a new algorithm for surface reconstruction in a"e(3) from spatially arranged one-dimensional cross sections embedded in a"e(3). This is generally the case with acoustic signals that pierce an object non-destructively. Continuous deformations (homotopies) that smoothly...... homotopies that can generate a C (2) surface. An algorithm to generate surface from acoustic sonar signals is presented with results. Reconstruction accuracies of the homotopies are compared by means of simulations performed on basic geometric primitives....

  7. Acoustic Sensors for Air and Surface Navigation Applications

    Directory of Open Access Journals (Sweden)

    Rohan Kapoor

    2018-02-01

    Full Text Available This paper presents the state-of-the-art and reviews the state-of-research of acoustic sensors used for a variety of navigation and guidance applications on air and surface vehicles. In particular, this paper focuses on echolocation, which is widely utilized in nature by certain mammals (e.g., cetaceans and bats. Although acoustic sensors have been extensively adopted in various engineering applications, their use in navigation and guidance systems is yet to be fully exploited. This technology has clear potential for applications in air and surface navigation/guidance for intelligent transport systems (ITS, especially considering air and surface operations indoors and in other environments where satellite positioning is not available. Propagation of sound in the atmosphere is discussed in detail, with all potential attenuation sources taken into account. The errors introduced in echolocation measurements due to Doppler, multipath and atmospheric effects are discussed, and an uncertainty analysis method is presented for ranging error budget prediction in acoustic navigation applications. Considering the design challenges associated with monostatic and multi-static sensor implementations and looking at the performance predictions for different possible configurations, acoustic sensors show clear promises in navigation, proximity sensing, as well as obstacle detection and tracking. The integration of acoustic sensors in multi-sensor navigation systems is also considered towards the end of the paper and a low Size, Weight and Power, and Cost (SWaP-C sensor integration architecture is presented for possible introduction in air and surface navigation systems.

  8. Acoustic Sensors for Air and Surface Navigation Applications.

    Science.gov (United States)

    Kapoor, Rohan; Ramasamy, Subramanian; Gardi, Alessandro; Schyndel, Ron Van; Sabatini, Roberto

    2018-02-07

    This paper presents the state-of-the-art and reviews the state-of-research of acoustic sensors used for a variety of navigation and guidance applications on air and surface vehicles. In particular, this paper focuses on echolocation, which is widely utilized in nature by certain mammals (e.g., cetaceans and bats). Although acoustic sensors have been extensively adopted in various engineering applications, their use in navigation and guidance systems is yet to be fully exploited. This technology has clear potential for applications in air and surface navigation/guidance for Intelligent Transport Systems (ITS), especially considering air and surface operations indoors and in other environments where satellite positioning is not available. Propagation of sound in the atmosphere is discussed in detail, with all potential attenuation sources taken into account. The errors introduced in echolocation measurements due to Doppler, multipath and atmospheric effects are discussed, and an uncertainty analysis method is presented for ranging error budget prediction in acoustic navigation applications. Considering the design challenges associated with monostatic and multi-static sensor implementations and looking at the performance predictions for different possible configurations, acoustic sensors show clear promises in navigation, proximity sensing, as well as obstacle detection and tracking. The integration of acoustic sensors in multi-sensor navigation systems is also considered towards the end of the paper and a low Size, Weight and Power, and Cost (SWaP-C) sensor integration architecture is presented for possible introduction in air and surface navigation systems.

  9. Surface Acoustic Wave Devices for Harsh Environment Wireless Sensing

    Directory of Open Access Journals (Sweden)

    David W. Greve

    2013-05-01

    Full Text Available Langasite surface acoustic wave devices can be used to implement harsh-environment wireless sensing of gas concentration and temperature. This paper reviews prior work on the development of langasite surface acoustic wave devices, followed by a report of recent progress toward the implementation of oxygen gas sensors. Resistive metal oxide films can be used as the oxygen sensing film, although development of an adherent barrier layer will be necessary with the sensing layers studied here to prevent interaction with the langasite substrate. Experimental results are presented for the performance of a langasite surface acoustic wave oxygen sensor with tin oxide sensing layer, and these experimental results are correlated with direct measurements of the sensing layer resistivity.

  10. Surface Modification on Acoustic Wave Biosensors for Enhanced Specificity

    Directory of Open Access Journals (Sweden)

    Nathan D. Gallant

    2012-09-01

    Full Text Available Changes in mass loading on the surface of acoustic biosensors result in output frequency shifts which provide precise measurements of analytes. Therefore, to detect a particular biomarker, the sensor delay path must be judiciously designed to maximize sensitivity and specificity. B-cell lymphoma 2 protein (Bcl-2 found in urine is under investigation as a biomarker for non-invasive early detection of ovarian cancer. In this study, surface chemistry and biofunctionalization approaches were evaluated for their effectiveness in presenting antibodies for Bcl-2 capture while minimizing non-specific protein adsorption. The optimal combination of sequentially adsorbing protein A/G, anti-Bcl-2 IgG and Pluronic F127 onto a hydrophobic surface provided the greatest signal-to-noise ratio and enabled the reliable detection of Bcl-2 concentrations below that previously identified for early stage ovarian cancer as characterized by a modified ELISA method. Finally, the optimal surface modification was applied to a prototype acoustic device and the frequency shift for a range of Bcl-2 concentration was quantified to demonstrate the effectiveness in surface acoustic wave (SAW-based detection applications. The surface functionalization approaches demonstrated here to specifically and sensitively detect Bcl-2 in a working ultrasonic MEMS biosensor prototype can easily be modified to detect additional biomarkers and enhance other acoustic biosensors.

  11. Bending and splitting of spoof surface acoustic waves through structured rigid surface

    Science.gov (United States)

    Xie, Sujun; Ouyang, Shiliang; He, Zhaojian; Wang, Xiaoyun; Deng, Ke; Zhao, Heping

    2018-03-01

    In this paper, we demonstrated that a 90°-bended imaging of spoof surface acoustic waves with subwavelength resolution of 0.316λ can be realized by a 45° prism-shaped surface phononic crystal (SPC), which is composed of borehole arrays with square lattice in a rigid plate. Furthermore, by combining two identical prism-shaped phononic crystal to form an interface (to form a line-defect), the excited spoof surface acoustic waves can be split into bended and transmitted parts. The power ratio between the bended and transmitted surface waves can be tuned arbitrarily by adjusting the defect size. This acoustic system is believed to have potential applications in various multifunctional acoustic solutions integrated by different acoustical devices.

  12. Acoustic shadows help gleaning bats find prey, but may be defeated by prey acoustic camouflage on rough surfaces.

    Science.gov (United States)

    Clare, Elizabeth L; Holderied, Marc W

    2015-09-01

    Perceptual abilities of animals, like echolocating bats, are difficult to study because they challenge our understanding of non-visual senses. We used novel acoustic tomography to convert echoes into visual representations and compare these cues to traditional echo measurements. We provide a new hypothesis for the echo-acoustic basis of prey detection on surfaces. We propose that bats perceive a change in depth profile and an 'acoustic shadow' cast by prey. The shadow is more salient than prey echoes and particularly strong on smooth surfaces. This may explain why bats look for prey on flat surfaces like leaves using scanning behaviour. We propose that rather than forming search images for prey, whose characteristics are unpredictable, predators may look for disruptions to the resting surface (acoustic shadows). The fact that the acoustic shadow is much fainter on rougher resting surfaces provides the first empirical evidence for 'acoustic camouflage' as an anti-predator defence mechanism.

  13. Black holes and holography

    International Nuclear Information System (INIS)

    Mathur, Samir D

    2012-01-01

    The idea of holography in gravity arose from the fact that the entropy of black holes is given by their surface area. The holography encountered in gauge/gravity duality has no such relation however; the boundary surface can be placed at an arbitrary location in AdS space and its area does not give the entropy of the bulk. The essential issues are also different between the two cases: in black holes we get Hawking radiation from the 'holographic surface' which leads to the information issue, while in gauge/gravity duality there is no such radiation. To resolve the information paradox we need to show that there are real degrees of freedom at the horizon of the hole; this is achieved by the fuzzball construction. In gauge/gravity duality we have instead a field theory defined on an abstract dual space; there are no gravitational degrees of freedom at the holographic boundary. It is important to understand the relations and differences between these two notions of holography to get a full understanding of the lessons from the information paradox.

  14. Topology optimization applied to room acoustic problems and surface acoustic wave devices

    DEFF Research Database (Denmark)

    Dühring, Maria Bayard; Sigmund, Ole; Jensen, Jakob Søndergaard

    of the project is concerned with simulation and optimization of surface acoustic wave (SAW) devices [4]. SAWs are for instance used in filters and resonators in mobile phones and to modulate light waves [5], and it is here essential to obtain waves with a high intensity, to direct the waves or to optimize...... of engineering fields such as mechanism design, fluid problems and photonic and phononic band-gap materials and structures [1,2]. In this project topology optimization is first applied to control acoustic properties in a room [3]. It is shown how the squared sound pressure amplitude in a certain part of a room...

  15. Influence of surface position along the working range of conoscopic holography sensors on dimensional verification of AISI 316 wire EDM machined surfaces.

    Science.gov (United States)

    Fernández, Pedro; Blanco, David; Rico, Carlos; Valiño, Gonzalo; Mateos, Sabino

    2014-03-06

    Conoscopic holography (CH) is a non-contact interferometric technique used for surface digitization which presents several advantages over other optical techniques such as laser triangulation. Among others, the ability for the reconstruction of high-sloped surfaces stands out, and so does its lower dependence on surface optical properties. Nevertheless, similarly to other optical systems, adjustment of CH sensors requires an adequate selection of configuration parameters for ensuring a high quality surface digitizing. This should be done on a surface located as close as possible to the stand-off distance by tuning frequency (F) and power (P) until the quality indicators Signal-to-Noise Ratio (SNR) and signal envelope (Total) meet proper values. However, not all the points of an actual surface are located at the stand-off distance, but they could be located throughout the whole working range (WR). Thus, the quality of a digitized surface may not be uniform. The present work analyses how the quality of a reconstructed surface is affected by its relative position within the WR under different combinations of the parameters F and P. Experiments have been conducted on AISI 316 wire EDM machined flat surfaces. The number of high-quality points digitized as well as distance measurements between different surfaces throughout the WR allowed for comparing the metrological behaviour of the CH sensor with respect to a touch probe (TP) on a CMM.

  16. Influence of Surface Position along the Working Range of Conoscopic Holography Sensors on Dimensional Verification of AISI 316 Wire EDM Machined Surfaces

    Directory of Open Access Journals (Sweden)

    Pedro Fernández

    2014-03-01

    Full Text Available Conoscopic holography (CH is a non-contact interferometric technique used for surface digitization which presents several advantages over other optical techniques such as laser triangulation. Among others, the ability for the reconstruction of high-sloped surfaces stands out, and so does its lower dependence on surface optical properties. Nevertheless, similarly to other optical systems, adjustment of CH sensors requires an adequate selection of configuration parameters for ensuring a high quality surface digitizing. This should be done on a surface located as close as possible to the stand-off distance by tuning frequency (F and power (P until the quality indicators Signal-to-Noise Ratio (SNR and signal envelope (Total meet proper values. However, not all the points of an actual surface are located at the stand-off distance, but they could be located throughout the whole working range (WR. Thus, the quality of a digitized surface may not be uniform. The present work analyses how the quality of a reconstructed surface is affected by its relative position within the WR under different combinations of the parameters F and P. Experiments have been conducted on AISI 316 wire EDM machined flat surfaces. The number of high-quality points digitized as well as distance measurements between different surfaces throughout the WR allowed for comparing the metrological behaviour of the CH sensor with respect to a touch probe (TP on a CMM.

  17. Standing surface acoustic wave (SSAW) based multichannel cell sorting.

    Science.gov (United States)

    Ding, Xiaoyun; Lin, Sz-Chin Steven; Lapsley, Michael Ian; Li, Sixing; Guo, Xiang; Chan, Chung Yu; Chiang, I-Kao; Wang, Lin; McCoy, J Philip; Huang, Tony Jun

    2012-11-07

    We introduce a novel microfluidic device for cell sorting in continuous flow using tunable standing surface acoustic waves. This method allows individual cells to be precisely directed into five different outlet channels in a single step. It is versatile, simple, label-free, non-invasive, and highly controllable.

  18. A versatile optical profilometer based on conoscopic holography sensors for acquisition of specular and diffusive surfaces in artworks

    Science.gov (United States)

    Gaburro, Nicola; Marchioro, Giacomo; Daffara, Claudia

    2017-07-01

    Surface metrology of artworks requires the design of suitable devices for in-situ non-destructive measurement together with reliable procedures for an effective analysis of such non-engineered variegate objects. To advance the state-of-the-art it has been implemented a versatile optical micro-profilometry taking advantage of the adapt- ability of conoscopic holography sensors, able to operate with irregular shapes and composite materials (diffusive, specular, and polychrome) of artworks. The scanning technique is used to obtain wide field and high spatially resolved areal profilometry. The prototype has a modular scheme based on a set of conoscopic sensors, extending the typical design based on a scanning stage and a single probe with a limited bandwidth, thus allowing the collection of heights data from surface with different scales and materials with variegate optical response. The system was optimized by characterizing the quality of the measurement with the probes triggered in continuous scanning modality. The results obtained on examples of cultural heritage objects (2D paintings, 3D height-relief) and materials (pictorial, metallic) demonstrate the versatility of the implemented device.

  19. Solar holography

    Science.gov (United States)

    Ludman, Jacques E.; Riccobono, Juanita R.; Caulfield, H. John; Upton, Timothy D.

    2002-07-01

    A solar photovoltaic energy collection system using a reflection hologram is described herein. The system uses a single-axis tracking system in conjunction with a spectral- splitting holographic element. The hologram accurately focuses the desired regions of the solar spectrum to match the bandgaps of two ro more different solar cells, while diverting unused IR wavelengths away. Other applications for solar holography include daylighting and greenhouses.

  20. Scattering from objects and surfaces in room acoustical simulations

    DEFF Research Database (Denmark)

    Marbjerg, Gerd Høy; Brunskog, Jonas; Jeong, Cheol-Ho

    2016-01-01

    In room acoustical simulations, scattering objects are often modeled as impenetrable boxes with high scattering coefficients assigned to the surfaces. In some cases, a cluster of objects is modeled as a virtual impenetrable box, such that no sound propagation can take place between the objects....... Thus, the scattering only takes place on the boundary surfaces of the box and the acoustic volume of the room is reduced. Another challenge with representing scattering objects by reflecting surfaces is that it increases the number of surfaces, which greatly increases the calculation complexity...... for methods such as the image source method. In this paper a modeling method where the scattering from objects takes place in certain parts of the room volume is proposed. In this method, sound can still travel through scattering objects, but be partly scattered. This volume scattering method has at present...

  1. Dental Holography

    Science.gov (United States)

    Dirtoft, Ingegerd

    1983-12-01

    Ten years have passed since the first articles appeared in this new field. The qualities of the laser light together with the need of contactless 3-D measurements for different dental purposes seemed to be extremely promising, but still just a few scientists have used the method and mostly for laboratory studies. For some reason there has been a preponderance for orthodontic measurements. This seems to be a bit peculiar from holographic view compared with measurements for engineering purposes, which usually are made on metals. So naturally holography can become a clinical tool for measurements in the field of fixed bridges, removable partial dentures and implants. One of the problems is that the need for holography in dental research must be fulfilled in collaboration with physicists. Only a two-way communication during an entire experiment can balance both technical and odontological demands and thus give practical and clinical important results. The need for an easy way of handling the evaluation to get all required information is another problem and of course the holographic equipment must be converted to a box easy to handle for everyone. At last the position of dental holography today is going to be carefully examined together with an attempt to look into the hopefully exciting and not to utopic future for this research field.

  2. Conoscopic holography

    Science.gov (United States)

    Sirat, Gabriel Y.; Paz, Freddy; Agronik, Gregory; Wilner, Kalman

    2005-08-01

    Based on crystal optics, Conoscopy is a unique implementation of polarized light interference process,. In the basic interference set-up a light beam is projected onto a diffusive object. The beam creates a light point on a target, which via reflection disperses the light in all directions. A complete solid angle of the diffused light is analyzed.. The measurement process corresponds to the retrieval of a distance of the light point from a fmed reference plane. Three dimensional measurement systems based on Conoscopic Holography are steadily gaining ground against conventional techniques. Conoscopic system have evolved from an exotic solution to the fist choice for all measurement problems not covered by triangulation techniques. Currently, they can be utilized on many applications such as quality control measurements, digitizing, reverse engineering and in-process inspection. A review of Conoscopic Holography principle will be presented in the first part of the paper. The exclusivity of Conoscopic Holography and its distinction from commonly used techniques will be reviewed.

  3. Optimizing surface acoustic wave sensors for trace chemical detection

    Energy Technology Data Exchange (ETDEWEB)

    Frye, G.C.; Kottenstette, R.J.; Heller, E.J. [and others

    1997-06-01

    This paper describes several recent advances for fabricating coated surface acoustic wave (SAW) sensors for applications requiring trace chemical detection. Specifically, we have demonstrated that high surface area microporous oxides can provide 100-fold improvements in SAW sensor responses compared with more typical polymeric coatings. In addition, we fabricated GaAs SAW devices with frequencies up to 500 MHz to provide greater sensitivity and an ideal substrate for integration with high-frequency electronics.

  4. Temperature Compensation of Surface Acoustic Waves on Berlinite

    Science.gov (United States)

    Searle, David Michael Marshall

    The surface acoustic wave properties of Berlinite (a-AlPO4) have been investigated theoretically and experimentally, for a variety of crystallographic orientations, to evaluate its possible use as a substrate material for temperature compensated surface acoustic wave devices. A computer program has been developed to calculate the surface wave properties of a material from its elastic, piezoelectric, dielectric and lattice constants and their temperature derivatives. The program calculates the temperature coefficient of delay, the velocity of the surface wave, the direction of power flow and a measure of the electro-mechanical coupling. These calculations have been performed for a large number of orientations using a modified form of the data given by Chang and Barsch for Berlinite and predict several new temperature compensated directions. Experimental measurements have been made of the frequency-temperature response of a surface acoustic wave oscillator on an 80° X axis boule cut which show it to be temperature compensated in qualitative agreement with the theoretical predictions. This orientation shows a cubic frequency-temperature dependence instead of the expected parabolic response. Measurements of the electro-mechanical coupling coefficient k gave a value lower than predicted. Similar measurements on a Y cut plate gave a value which is approximately twice that of ST cut quartz, but again lower than predicted. The surface wave velocity on both these cuts was measured to be slightly higher than predicted by the computer program. Experimental measurements of the lattice parameters a and c are also presented for a range of temperatures from 25°C to just above the alpha-beta transition at 584°C. These results are compared with the values obtained by Chang and Barsch. The results of this work indicate that Berlinite should become a useful substrate material for the construction of temperature compensated surface acoustic wave devices.

  5. Langasite Surface Acoustic Wave Sensors: Fabrication and Testing

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Peng; Greve, David W.; Oppenheim, Irving J.; Chin, Tao-Lun; Malone, Vanessa

    2012-02-01

    We report on the development of harsh-environment surface acoustic wave sensors for wired and wireless operation. Surface acoustic wave devices with an interdigitated transducer emitter and multiple reflectors were fabricated on langasite substrates. Both wired and wireless temperature sensing was demonstrated using radar-mode (pulse) detection. Temperature resolution of better than ±0.5°C was achieved between 200°C and 600°C. Oxygen sensing was achieved by depositing a layer of ZnO on the propagation path. Although the ZnO layer caused additional attenuation of the surface wave, oxygen sensing was accomplished at temperatures up to 700°C. The results indicate that langasite SAW devices are a potential solution for harsh-environment gas and temperature sensing.

  6. Acoustics and Surface Pressure Measurements from Tandem Cylinder Configurations

    Science.gov (United States)

    Hutcheson, Florence V.; Brooks, Thomas F.; Lockard, David P.; Choudhari, Meelan M.; Stead, Daniel J.

    2014-01-01

    Acoustic and unsteady surface pressure measurements from two cylinders in tandem configurations were acquired to study the effect of spacing, surface trip and freestream velocity on the radiated noise. The Reynolds number ranged from 1.15x10(exp 5) to 2.17x10(exp 5), and the cylinder spacing varied between 1.435 and 3.7 cylinder diameters. The acoustic and surface pressure spectral characteristics associated with the different flow regimes produced by the cylinders' wake interference were identified. The dependence of the Strouhal number, peak Sound Pressure Level and spanwise coherence on cylinder spacing and flow velocity was examined. Directivity measurements were performed to determine how well the dipole assumption for the radiation of vortex shedding noise holds for the largest and smallest cylinder spacing tested.

  7. Ultrasonic attenuation of surface acoustic waves in superconducting zinc

    International Nuclear Information System (INIS)

    Bailey, W.E.; Marshall, B.J.

    1979-01-01

    The attenuation of 90-MHz elastic surface waves propagating in both 3,000 and 10,000 A films of zinc has been measured as a function of temperature from 3 to 0.38 K. The surface acoustic waves were generated and detected by using a surface-acoustic-wave device interdigital transducers plated onto a Y-Z cut lithium-niobate substrate. Utilizing the experimental results, in the BCS theory, energy gaps of 2Δ (0) equal to 4.17 +- 0.20 and 3.81 +- 0.20 in units of k/sub B/T/sub c/ were calculated for the 3,000 and 10,000 A films, respectively. The transition temperatures for the 3,000 and 10,000 A films were 1.5 +- 0.01 and 1.31 +- 0.01 K, respectively

  8. New techniques in digital holography

    CERN Document Server

    Picart, Pascal

    2015-01-01

    A state of the art presentation of important advances in the field of digital holography, detailing advances related to fundamentals of digital holography, in-line holography applied to fluid mechanics, digital color holography, digital holographic microscopy, infrared holography, special techniques in full field vibrometry and inverse problems in digital holography

  9. DSN Microwave Antenna Holography

    Science.gov (United States)

    Rochblatt, D. J.; Seidel, B. L.

    1984-01-01

    The DSN microwave antenna holography project will obtain three-dimensional pictures of the large DSN antenna surfaces. These pictures must be of suffi icient resolution to allow adjustment of the reflector panels to an rms surface of 0.5 mm (0.25 mm, goal). The major parameters and equations needed to define a holographic measurement system are outlined and then the proof of concept demonstration measurement that was made at DSS-43 (Australia) that resulted in contour maps with spatial resolution of 7 m in the aperture plane and resolution orthogonal to the aperture plane of 0.7 mm was discussed.

  10. Circuit Design of Surface Acoustic Wave Based Micro Force Sensor

    OpenAIRE

    Yuanyuan Li; Wenke Lu; Changchun Zhu; Qinghong Liu; Haoxin Zhang; Chenchao Tang

    2014-01-01

    Pressure sensors are commonly used in industrial production and mechanical system. However, resistance strain, piezoresistive sensor, and ceramic capacitive pressure sensors possess limitations, especially in micro force measurement. A surface acoustic wave (SAW) based micro force sensor is designed in this paper, which is based on the theories of wavelet transform, SAW detection, and pierce oscillator circuits. Using lithium niobate as the basal material, a mathematical model is established ...

  11. Conoscopic interferometry of surface-acoustic-wave substrate crystals.

    Science.gov (United States)

    Ayräs, P H; Friberg, A T; Kaivola, M A; Salomaa, M M

    1999-09-01

    Conoscopic interferometry is applied for determining the crystal orientation of lithium niobate and other commonly employed substrate wafers for integrated-optic and surface-acoustic-wave devices. The method is particularly applicable for detecting the orientation of the optic axes of the strongly birefringent niobate but is less sensitive for lithium tantalate or quartz. Conoscopic interference is a low-cost and easy-to-use method that is especially suitable for laboratory usage.

  12. Monolithic GaAs surface acoustic wave chemical microsensor array

    Energy Technology Data Exchange (ETDEWEB)

    HIETALA,VINCENT M.; CASALNUOVO,STEPHEN A.; HELLER,EDWIN J.; WENDT,JOEL R.; FRYE-MASON,GREGORY CHARLES; BACA,ALBERT G.

    2000-03-09

    A four-channel surface acoustic wave (SAW) chemical sensor array with associated RF electronics is monolithically integrated onto one GaAs IC. The sensor operates at 690 MHz from an on-chip SAW based oscillator and provides simple DC voltage outputs by using integrated phase detectors. This sensor array represents a significant advance in microsensor technology offering miniaturization, increased chemical selectivity, simplified system assembly, improved sensitivity, and inherent temperature compensation.

  13. Surface acoustic wave probe implant for predicting epileptic seizures

    Science.gov (United States)

    Gopalsami, Nachappa [Naperville, IL; Kulikov, Stanislav [Sarov, RU; Osorio, Ivan [Leawood, KS; Raptis, Apostolos C [Downers Grove, IL

    2012-04-24

    A system and method for predicting and avoiding a seizure in a patient. The system and method includes use of an implanted surface acoustic wave probe and coupled RF antenna to monitor temperature of the patient's brain, critical changes in the temperature characteristic of a precursor to the seizure. The system can activate an implanted cooling unit which can avoid or minimize a seizure in the patient.

  14. Electron holography for polymer microscopy

    International Nuclear Information System (INIS)

    Joy, D.C.

    1992-01-01

    Electron holography provides a radically new approach to the problem of imaging objects such as macromolecules, which exhibit little or no contrast when viewed in the conventional transmission electron microscope (TEM). This is overcome in electron holography by using the macromolecule as a phase object. Computer reconstruction of the hologram then allows the phase to be viewed as an image, and amplified. Holography requires a TEM with a field emission gun, and with an electro-static biprism to produce the interference pattern. The hologram requires a similar radiation dose to conventional microscopy but many different images (e.g. a through focal series) can be extracted from the same hologram. Further developments of the technique promise to combine high contrast imaging of the bulk of the macromolecule together with high spatial resolution imaging of surface detail

  15. Acoustic modes propagating along the free surface of granular media.

    Science.gov (United States)

    Aleshin, V; Gusev, V; Tournat, V

    2007-05-01

    In unconsolidated granular materials under gravity there exist acoustical waves propagating along the surface with anomalously low sound velocity. The presented theory describes these guided surface acoustic modes (GSAM) confined between the surface of the granular materials and in-depth layers with increasing rigidity. The analysis is based on the obtained original analytical solution of the Helmholtz equation that has never been used both in classical and quantum mechanics. This solution is valid for a particular rigidity profile, whereas the general case of grains with or without adhesion has been analyzed numerically. In contrast to the Rayleigh wave polarized in the sagittal (vertical) plane, which is the unique localized mode in a homogeneous solid, an infinite number of modes with sagittal polarization as well as an infinite number of shear horizontal modes have been found. The difference in physical mechanisms of localization is discussed, and the transformation of the GSAMs into the Rayleigh wave at the increasing adhesion is demonstrated: The first sagittal mode transforms into the Rayleigh one, while the others delocalize. The theory explains the experimentally observed magnitude of velocity for the acoustic waves in sand elliptically polarized in the sagittal plane.

  16. Laser method of acoustical emission control from vibrating surfaces

    Science.gov (United States)

    Motyka, Zbigniew

    2013-01-01

    For limitation of the noise in environment, the necessity occurs of determining and location of sources of sounds emitted from surfaces of many machines and devices, assuring in effect the possibility of suitable constructional changes implementation, targeted at decreasing of their nuisance. In the paper, the results of tests and calculations are presented for plane surface sources emitting acoustic waves. The tests were realized with the use of scanning laser vibrometer which enabled remote registration and the spectral analysis of the surfaces vibrations. The known hybrid digital method developed for determination of sound wave emission from such surfaces divided into small finite elements was slightly modified by distinguishing the phase correlations between such vibrating elements. The final method being developed may find use in wide range of applications for different forms of vibrations of plane surfaces.

  17. Single Beam Holography.

    Science.gov (United States)

    Chen, Hsuan; Ruterbusch, Paul H.

    1979-01-01

    Discusses how holography can be used as part of undergraduate physics laboratories. The authors propose a single beam technique of holography, which will reduce the recording scheme as well as relax the isolation requirements. (HM)

  18. Acoustic building infiltration measurement system

    Energy Technology Data Exchange (ETDEWEB)

    Muehleisen, Ralph T.; Raman, Ganesh

    2018-04-10

    Systems and methods of detecting and identifying a leak from a container or building. Acoustic pressure and velocity are measured. Acoustic properties are acquired from the measured values. The acoustic properties are converted to infiltration/leakage information. Nearfield Acoustic Holography (NAH) may be one method to detect the leakages from a container by locating the noise sources.

  19. ConoSurf: Open‐source 3D scanning system based on a conoscopic holography device for acquiring surgical surfaces

    OpenAIRE

    Brudfors, Mikael; García‐Vázquez, Verónica; Sesé‐Lucio, Begoña; Marinetto, Eugenio; Desco, Manuel; Pascau, Javier

    2016-01-01

    Background. A difficulty in computer-assisted interventions is acquiring the patient's anatomy intraoperatively. Standard modalities have several limitations: low image quality (ultrasound), radiation exposure (computed tomography) or high costs (magnetic resonance imaging). An alternative approach uses a tracked pointer; however, the pointer causes tissue deformation and requires sterilizing. Recent proposals, utilizing a tracked conoscopic holography device, have shown promising results wit...

  20. Holography and tomography

    International Nuclear Information System (INIS)

    Howells, M.

    1997-01-01

    This session includes a collection of outlines of pertinent information, diagrams, graphs, electron micrographs, and color photographs pertaining to historical aspects and recent advances in the development of X-ray Gabor Holography. Many of the photographs feature or pertain to instrumentation used in holography, tomography, and cryo-holography

  1. Surface acoustic wave micromotor with arbitrary axis rotational capability

    Science.gov (United States)

    Tjeung, Ricky T.; Hughes, Mark S.; Yeo, Leslie Y.; Friend, James R.

    2011-11-01

    A surface acoustic wave (SAW) actuated rotary motor is reported here, consisting of a millimeter-sized spherical metal rotor placed on the surface of a lead zirconate titanate piezoelectric substrate upon which the SAW is made to propagate. At the design frequency of 3.2 MHz and with a fixed preload of 41.1 μN, the maximum rotational speed and torque achieved were approximately 1900 rpm and 5.37 μN-mm, respectively, producing a maximum output power of 1.19 μW. The surface vibrations were visualized using laser Doppler vibrometry and indicate that the rotational motion arises due to retrograde elliptical motions of the piezoelectric surface elements. Rotation about orthogonal axes in the plane of the substrate has been obtained by using orthogonally placed interdigital electrodes on the substrate to generate SAW impinging on the rotor, offering a means to generate rotation about an arbitrary axis in the plane of the substrate.

  2. Combined surface acoustic wave and surface plasmon resonance measurement of collagen and fibrinogen layer physical properties

    Directory of Open Access Journals (Sweden)

    J.-M. Friedt

    2016-12-01

    Full Text Available We use an instrument combining optical (surface plasmon resonance and acoustic (Love mode surface acoustic wave device real-time measurements on a same surface for the identification of water content in collagen and fibrinogen protein layers. After calibration of the surface acoustic wave device sensitivity by copper electrodeposition and surfactant adsorption, the bound mass and its physical properties – density and optical index – are extracted from the complementary measurement techniques and lead to thickness and water ratio values compatible with the observed signal shifts. Such results are especially usefully for protein layers with a high water content as shown here for collagen on an hydrophobic surface. We obtain the following results: collagen layers include 70±20% water and are 16±3 to 19±3 nm thick for bulk concentrations ranging from 30 to 300 μg/ml. Fibrinogen layers include 50±10% water for layer thicknesses in the 6±1.5 to 13±2 nm range when the bulk concentration is in the 46 to 460 μg/ml range. Keywords: surface acoustic wave, surface plasmon resonance, collagen, fibrinogen, density, thickness

  3. An efficient planar inverse acoustic method based on Toeplitz matrices

    NARCIS (Netherlands)

    Wind, Jelmer; de Boer, Andries; Ellenbroek, Marcellinus Hermannus Maria

    2011-01-01

    This article proposes a new, fast method to solve inverse acoustic problems for planar sources. This problem is often encountered in practice and methods such as planar nearfield acoustic holography (PNAH) and statistically optimised nearfield acoustic holography (SONAH) are widely used to solve it.

  4. Circuit Design of Surface Acoustic Wave Based Micro Force Sensor

    Directory of Open Access Journals (Sweden)

    Yuanyuan Li

    2014-01-01

    Full Text Available Pressure sensors are commonly used in industrial production and mechanical system. However, resistance strain, piezoresistive sensor, and ceramic capacitive pressure sensors possess limitations, especially in micro force measurement. A surface acoustic wave (SAW based micro force sensor is designed in this paper, which is based on the theories of wavelet transform, SAW detection, and pierce oscillator circuits. Using lithium niobate as the basal material, a mathematical model is established to analyze the frequency, and a peripheral circuit is designed to measure the micro force. The SAW based micro force sensor is tested to show the reasonable design of detection circuit and the stability of frequency and amplitude.

  5. Motion of the surface of the human tympanic membrane measured with stroboscopic holography

    Science.gov (United States)

    Cheng, Jeffrey Tao; Aarnisalo, Antti A.; Harrington, Ellery; Hernandez-Montes, Maria del Socorro; Furlong, Cosme; Merchant, Saumil N.; Rosowski, John J.

    2010-01-01

    Sound-induced motion of the surface of the human tympanic membrane (TM) was studied by stroboscopic holographic interferometery, which measures the amplitude and phase of the displacement at each of about 40000 points on the surface of the TM. Measurements were made with tonal stimuli of 0.5, 1, 4 and 8 kHz. The magnitude and phase of the sinusoidal displacement of the TM at each driven frequency were derived from the fundamental Fourier component of the raw displacement data computed from stroboscopic holograms of the TM recorded at eight stimulus phases. The correlation between the Fourier estimates and measured motion data was generally above 0.9 over the entire TM surface. We used three data presentations: (i) Plots of the phasic displacements along a single chord across the surface of the TM, (ii) Phasic surface maps of the displacement of the entire TM surface, and (iii) Plots of the Fourier derived amplitude and phase-angle of the surface displacement along four diameter lines that define and bisect each of the four quadrants of the TM. These displays led to some common conclusions: At 0.5 and 1 kHz, the entire TM moved roughly in-phase with some small phase delay apparent between local areas of maximal displacement in the posterior half of the TM. At 4 and 8 kHz, the motion of the TM became more complicated with multiple local displacement maxima arranged in rings around the manubrium. The displacements at most of these maxima were roughly in-phase, while some moved out-of-phase. Superposed on this in- and out-of-phase behavior were significant cyclic variations in phase with location of less than 0.2 cycles or occasionally rapid half-cycle step-like changes in phase. The high frequency displacement amplitude and phase maps discovered in this study can not be explained by any single wave motion, but are consistent with a combination of low and higher order modal motions plus some small traveling-wave-like components. The observations of the dynamics of TM

  6. Codimension-2 surfaces and their Hilbert spaces: low-energy clues for holography from general covariance

    Energy Technology Data Exchange (ETDEWEB)

    Neiman, Yakov, E-mail: yashula@gmail.co [Raymond and Beverly Sackler School of Physics and Astronomy, Tel-Aviv University, Tel-Aviv 69978 (Israel)

    2009-12-21

    We argue that the holographic principle may be hinted at already from low-energy considerations, assuming diffeomorphism invariance, quantum mechanics and Minkowski-like causality. We consider the states of finite spacelike hypersurfaces in a diffeomorphism-invariant QFT. A low-energy regularization is assumed. We note a natural dependence of the Hilbert space on a codimension-2 boundary surface. The Hilbert product is defined dynamically, in terms of transition amplitudes which are described by a path integral. We show that a canonical basis is incompatible with these assumptions, which opens the possibility for a smaller Hilbert-space dimension than canonically expected. We argue further that this dimension may decrease with surface area at constant volume, hinting at holographic area proportionality. We draw comparisons with other approaches and setups, and propose an interpretation for the non-holographic space of graviton states at asymptotically Minkowski null infinity.

  7. Surface/state correspondence and bulk local operators in pp-wave holography

    Directory of Open Access Journals (Sweden)

    Nakwoo Kim

    2015-12-01

    Full Text Available We apply the surface/state correspondence proposal of Miyaji et al. to IIB pp-waves and propose that the bulk local operators should be instantonic D-branes. In line with ordinary AdS/CFT correspondence, the bulk local operators in pp-waves also create a hole, or a boundary, in the dual gauge theory as pointed out by H. Verlinde, and by Y. Nakayama and H. Ooguri. We also present simple calculations which illustrate how to extract the spacetime metric of pp-waves from instantonic D-branes in boundary state formalism.

  8. The Impact of Very High Frequency Surface Reverberation on Coherent Acoustic Propagation and Modeling

    Science.gov (United States)

    2015-09-30

    on Coherent Acoustic Propagation and Modeling Grant B. Deane Marine Physical Laboratory , Scripps Institution of Oceanography UCSD La Jolla, CA...long-term science objective is to develop a physical model of high-frequency scattering of underwater acoustic signals from the sea surface under a... acoustic communications problem. The scattering of sound from the sea surface is important for the operation of underwater sonar and underwater

  9. Surface Acoustic Wave Vibration Sensors for Measuring Aircraft Flutter

    Science.gov (United States)

    Wilson, William C.; Moore, Jason P.; Juarez, Peter D.

    2016-01-01

    Under NASA's Advanced Air Vehicles Program the Advanced Air Transport Technology (AATT) Project is investigating flutter effects on aeroelastic wings. To support that work a new method for measuring vibrations due to flutter has been developed. The method employs low power Surface Acoustic Wave (SAW) sensors. To demonstrate the ability of the SAW sensor to detect flutter vibrations the sensors were attached to a Carbon fiber-reinforced polymer (CFRP) composite panel which was vibrated at six frequencies from 1Hz to 50Hz. The SAW data was compared to accelerometer data and was found to resemble sine waves and match each other closely. The SAW module design and results from the tests are presented here.

  10. Photon correlation holography.

    Science.gov (United States)

    Naik, Dinesh N; Singh, Rakesh Kumar; Ezawa, Takahiro; Miyamoto, Yoko; Takeda, Mitsuo

    2011-01-17

    Unconventional holography called photon correlation holography is proposed and experimentally demonstrated. Using photon correlation, i.e. intensity correlation or fourth order correlation of optical field, a 3-D image of the object recorded in a hologram is reconstructed stochastically with illumination through a random phase screen. Two different schemes for realizing photon correlation holography are examined by numerical simulations, and the experiment was performed for one of the reconstruction schemes suitable for the experimental proof of the principle. The technique of photon correlation holography provides a new insight into how the information is embedded in the spatial as well as temporal correlation of photons in the stochastic pseudo thermal light.

  11. Surface Acoustic Wave (SAW Resonators for Monitoring Conditioning Film Formation

    Directory of Open Access Journals (Sweden)

    Siegfried Hohmann

    2015-05-01

    Full Text Available We propose surface acoustic wave (SAW resonators as a complementary tool for conditioning film monitoring. Conditioning films are formed by adsorption of inorganic and organic substances on a substrate the moment this substrate comes into contact with a liquid phase. In the case of implant insertion, for instance, initial protein adsorption is required to start wound healing, but it will also trigger immune reactions leading to inflammatory responses. The control of the initial protein adsorption would allow to promote the healing process and to suppress adverse immune reactions. Methods to investigate these adsorption processes are available, but it remains difficult to translate measurement results into actual protein binding events. Biosensor transducers allow user-friendly investigation of protein adsorption on different surfaces. The combination of several transduction principles leads to complementary results, allowing a more comprehensive characterization of the adsorbing layer. We introduce SAW resonators as a novel complementary tool for time-resolved conditioning film monitoring. SAW resonators were coated with polymers. The adsorption of the plasma proteins human serum albumin (HSA and fibrinogen onto the polymer-coated surfaces were monitored. Frequency results were compared with quartz crystal microbalance (QCM sensor measurements, which confirmed the suitability of the SAW resonators for this application.

  12. Ultrasonic phased array with surface acoustic wave for imaging cracks

    Directory of Open Access Journals (Sweden)

    Yoshikazu Ohara

    2017-06-01

    Full Text Available To accurately measure crack lengths, we developed a real-time surface imaging method (SAW PA combining an ultrasonic phased array (PA with a surface acoustic wave (SAW. SAW PA using a Rayleigh wave with a high sensitivity to surface defects was implemented for contact testing using a wedge with the third critical angle that allows the Rayleigh wave to be generated. Here, to realize high sensitivity imaging, SAW PA was optimized in terms of the wedge and the imaging area. The improved SAW PA was experimentally demonstrated using a fatigue crack specimen made of an aluminum alloy. For further verification in more realistic specimens, SAW PA was applied to stainless-steel specimens with a fatigue crack and stress corrosion cracks (SCCs. The fatigue crack was visualized with a high signal-to-noise ratio (SNR and its length was measured with a high accuracy of better than 1 mm. The SCCs generated in the heat-affected zones (HAZs of a weld were successfully visualized with a satisfactory SNR, although responses at coarse grains appeared throughout the imaging area. The SCC lengths were accurately measured. The imaging results also precisely showed complicated distributions of SCCs, which were in excellent agreement with the optically observed distributions.

  13. Microwave antenna holography

    Science.gov (United States)

    Rochblatt, David J.; Seidel, Boris L.

    1992-01-01

    This microwave holography technique utilizes the Fourier transform relation between the complex far field radiation pattern of an antenna and the complex aperture field distribution. Resulting aperture phase and amplitude distribution data can be used to precisely characterize various crucial performance parameters, including panel alignment, panel shaping, subreflector position, antenna aperture illumination, directivity at various frequencies, and gravity deformation effects. The methodology of data processing presented here was successfully applied to the Deep Space Network (DSN) 34-m beam waveguide antennas. The antenna performance was improved at all operating frequencies by reducing the main reflector mechanical surface rms error to 0.43 mm. At Ka-band (32 GHz), the estimated improvement is 4.1 dB, resulting in an aperture efficiency of 52 percent. The performance improvement was verified by efficiency measurements and additional holographic measurements.

  14. Ghost Images in Helioseismic Holography? Toy Models in a Uniform Medium

    Science.gov (United States)

    Yang, Dan

    2018-02-01

    Helioseismic holography is a powerful technique used to probe the solar interior based on estimations of the 3D wavefield. The Porter-Bojarski holography, which is a well-established method used in acoustics to recover sources and scatterers in 3D, is also an estimation of the wavefield, and hence it has the potential of being applied to helioseismology. Here we present a proof-of-concept study, where we compare helioseismic holography and Porter-Bojarski holography under the assumption that the waves propagate in a homogeneous medium. We consider the problem of locating a point source of wave excitation inside a sphere. Under these assumptions, we find that the two imaging methods have the same capability of locating the source, with the exception that helioseismic holography suffers from "ghost images" ( i.e. artificial peaks away from the source location). We conclude that Porter-Bojarski holography may improve the method currently used in helioseismology.

  15. Integration of a conoscopic holography sensor on a CMM

    Science.gov (United States)

    Fernández, P.; Blanco, D.; Valiño, G.; Hoang, H.; Suárez, L.; Mateos, S.

    2012-04-01

    Conoscopic Holography is a non-contact digitizing technique used for verification and reverse engineering tasks. Conoscopic holography share some advantages with other non-contact digitizing techniques: surface digitizing from a secure distance and high point sampling rates. On the other hand, conoscopic holography owns some exclusive advantages: no occlusion problems, vision angles up to 85° and a higher robustness against variations in surface characteristics. The work presented here is part of a project that aims to evaluate conoscopic holography performance when used as an on-machine measurement system. Here, the scope is the integration of a conoscopic holography sensor onto a coordinates measuring machine. Special attention has been paid to calibration procedure, in order to achieve measurements with similar accuracy as those obtained with more common techniques, like laser triangulation sensors.

  16. Mix-and-match holography

    KAUST Repository

    Peng, Yifan

    2017-11-22

    Computational caustics and light steering displays offer a wide range of interesting applications, ranging from art works and architectural installations to energy efficient HDR projection. In this work we expand on this concept by encoding several target images into pairs of front and rear phase-distorting surfaces. Different target holograms can be decoded by mixing and matching different front and rear surfaces under specific geometric alignments. Our approach, which we call mix-and-match holography, is made possible by moving from a refractive caustic image formation process to a diffractive, holographic one. This provides the extra bandwidth that is required to multiplex several images into pairing surfaces.

  17. Artistic Representation with Pulsed Holography

    International Nuclear Information System (INIS)

    Ishii, S

    2013-01-01

    This thesis describes artistic representation through pulsed holography. One of the prevalent practical problems in making holograms is object movement. Any movement of the object or film, including movement caused by acoustic vibration, has the same fatal results. One way of reducing the chance of movement is by ensuring that the exposure is very quick; using a pulsed laser can fulfill this objective. The attractiveness of using pulsed laser is based on the variety of materials or objects that can be recorded (e.g., liquid material or instantaneous scene of a moving object). One of the most interesting points about pulsed holograms is that some reconstructed images present us with completely different views of the real world. For example, the holographic image of liquid material does not appear fluid; it looks like a piece of hard glass that would produce a sharp sound upon tapping. In everyday life, we are unfamiliar with such an instantaneous scene. On the other hand, soft-textured materials such as a feather or wool differ from liquids when observed through holography. Using a pulsed hologram, we can sense the soft touch of the object or material with the help of realistic three-dimensional (3-D) images. The images allow us to realize the sense of touch in a way that resembles touching real objects. I had the opportunity to use a pulsed ruby laser soon after I started to work in the field of holography in 1979. Since then, I have made pulsed holograms of activities, including pouring water, breaking eggs, blowing soap bubbles, and scattering feathers and popcorn. I have also created holographic art with materials and objects, such as silk fiber, fabric, balloons, glass, flowers, and even the human body. Whenever I create art, I like to present the spectator with a new experience in perception. Therefore, I would like to introduce my experimental artwork through those pulsed holograms.

  18. Artistic Representation with Pulsed Holography

    Science.gov (United States)

    Ishii, S.

    2013-02-01

    This thesis describes artistic representation through pulsed holography. One of the prevalent practical problems in making holograms is object movement. Any movement of the object or film, including movement caused by acoustic vibration, has the same fatal results. One way of reducing the chance of movement is by ensuring that the exposure is very quick; using a pulsed laser can fulfill this objective. The attractiveness of using pulsed laser is based on the variety of materials or objects that can be recorded (e.g., liquid material or instantaneous scene of a moving object). One of the most interesting points about pulsed holograms is that some reconstructed images present us with completely different views of the real world. For example, the holographic image of liquid material does not appear fluid; it looks like a piece of hard glass that would produce a sharp sound upon tapping. In everyday life, we are unfamiliar with such an instantaneous scene. On the other hand, soft-textured materials such as a feather or wool differ from liquids when observed through holography. Using a pulsed hologram, we can sense the soft touch of the object or material with the help of realistic three-dimensional (3-D) images. The images allow us to realize the sense of touch in a way that resembles touching real objects. I had the opportunity to use a pulsed ruby laser soon after I started to work in the field of holography in 1979. Since then, I have made pulsed holograms of activities, including pouring water, breaking eggs, blowing soap bubbles, and scattering feathers and popcorn. I have also created holographic art with materials and objects, such as silk fiber, fabric, balloons, glass, flowers, and even the human body. Whenever I create art, I like to present the spectator with a new experience in perception. Therefore, I would like to introduce my experimental artwork through those pulsed holograms.

  19. Simulation of an Underwater Acoustic Communication Channel Characterized by Wind-Generated Surface Waves and Bubbles

    NARCIS (Netherlands)

    Dol, H.S.; Colin, M.E.G.D.; Ainslie, M.A.; Walree, P.A. van; Janmaat, J.

    2013-01-01

    Abstract—Sea-surface scattering by wind-generated waves and bubbles is regarded to be the main nonplatform related cause of the time variability of shallow acoustic communication channels. Simulations for predicting the quality of acoustic communication links in such channels thus require adequate

  20. Simulation of an Underwater Acoustic Communication Channel Characterized by Wind-Generated Surface Waves and Bubbles

    NARCIS (Netherlands)

    Dol, H.S.; Ainslie, M.A.; Colin, M.E.G.D.; Janmaat, J.

    2012-01-01

    Sea surface scattering by wind-generated waves and bubbles is regarded to be the main nonplatform-related cause of the time variability of shallow acoustic communication channels. Simulations for predicting the quality of acoustic communication links in such channels thus require adequate modelling

  1. Contrast investigations of surface acoustic waves by stroboscopic topography. 1. Orientation contrast

    Energy Technology Data Exchange (ETDEWEB)

    Cerva, H.; Graeff, W.

    1984-03-16

    Surface acoustic waves are investigated by stroboscopic topography using synchrotron radiation from the storage ring DORIS. The observed contrast of the acoustic displacements of the lattice planes has the same periods as the acoustic wave. It is demonstrated that the major part of the contrast is due to orientation contrast of the curved net planes. Intensity maxima correspond to troughs of the acoustic wave, minima to crests. A numerical treatment yielding ray tracing maps, intensity curves as well as focusing conditions which are in quantitative agreement with the experimental data is presented.

  2. Contrast investigations of surface acoustic waves by stroboscopic topography. 2. Wavefield deviation contrast

    Energy Technology Data Exchange (ETDEWEB)

    Cerva, H.; Graeff, W. (Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany, F.R.))

    1985-02-16

    When imaging a surface acoustic wave by stroboscopic X-ray topography a contrast contribution exists which can be related to the deviation of X-ray beams in the deformation field of the acoustic wave. With narrow entrance slits this contribution can be separated from the surface reflected waves. Using a beam path theory of Bonse the beam trajectories inside the crystal and the intensity profiles at the surface are calculated. It is also demonstrated that this contrast which has two nearly equal peaks within the acoustic period turns to the orientation contrast with one peak per period when increasing the distance between sample and film.

  3. A surface acoustic wave ICP sensor with good temperature stability.

    Science.gov (United States)

    Zhang, Bing; Hu, Hong; Ye, Aipeng; Zhang, Peng

    2017-07-20

    Intracranial pressure (ICP) monitoring is very important for assessing and monitoring hydrocephalus, head trauma and hypertension patients, which could lead to elevated ICP or even devastating neurological damage. The mortality rate due to these diseases could be reduced through ICP monitoring, because precautions can be taken against the brain damage. This paper presents a surface acoustic wave (SAW) pressure sensor to realize ICP monitoring, which is capable of wireless and passive transmission with antenna attached. In order to improve the temperature stability of the sensor, two methods were adopted. First, the ST cut quartz was chosen as the sensor substrate due to its good temperature stability. Then, a differential temperature compensation method was proposed to reduce the effects of temperature. Two resonators were designed based on coupling of mode (COM) theory and the prototype was fabricated and verified using a system established for testing pressure and temperature. The experiment result shows that the sensor has a linearity of 2.63% and hysteresis of 1.77%. The temperature stability of the sensor has been greatly improved by using the differential compensation method, which validates the effectiveness of the proposed method.

  4. Calculation of surface acoustic waves in a multilayered piezoelectric structure

    International Nuclear Information System (INIS)

    Zhang Zuwei; Wen Zhiyu; Hu Jing

    2013-01-01

    The propagation properties of the surface acoustic waves (SAWs) in a ZnO—SiO 2 —Si multilayered piezoelectric structure are calculated by using the recursive asymptotic method. The phase velocities and the electromechanical coupling coefficients for the Rayleigh wave and the Love wave in the different ZnO—SiO 2 —Si structures are calculated and analyzed. The Love mode wave is found to be predominantly generated since the c-axis of the ZnO film is generally perpendicular to the substrate. In order to prove the calculated results, a Love mode SAW device based on the ZnO—SiO 2 —Si multilayered structure is fabricated by micromachining, and its frequency responses are detected. The experimental results are found to be mainly consistent with the calculated ones, except for the slightly larger velocities induced by the residual stresses produced in the fabrication process of the films. The deviation of the experimental results from the calculated ones is reduced by thermal annealing. (semiconductor physics)

  5. Holography as a measuring tool

    International Nuclear Information System (INIS)

    Tozer, B.A.; Webster, J.M.

    1981-01-01

    Holography has advantages over conventional photography for the recording and direct measurement of physical structures. The three-dimensional reconstruction carries information equivalent to almost a million photographs. Other advantages include the depth of field, resolution, wide angle of view and information storage density. A number of possible applications of holography have been identified within the CEGB and a proposal to apply it during the post-irradiation examination of nuclear fuel elements is now well advanced. Optical inspection of discharged fuel elements from Advanced-Gas-Cooled Reactors, whether undertaken in the irradiated-fuel disposal system at the station or at a post-irradiation-examination centre, can normally be performed remotely. Because of the very high radiation levels near the surfaces of the fuel element, viewing must be carried out through windows about 1.5 metres thick. Conventional photography is possible in the fuel-disposal system, but a specialised camera is required and only relatively low-resolution photographs of the top of the element can be obtained. At the post-irradiation centre, elements are dismantled and a detailed study can then be made, but it is very laborious and consumes expensive radiation- 'cave' time. Holography offers the possibility of recording a three-dimensional image of a complete element, which can then be studied at leisure to provide information on the condition of individual fuel pins. The present state of development of this work at Marchwood Engineering Laboratories is described. (author)

  6. Brillouin light scattering from surface acoustic waves in a subwavelength-diameter optical fibre.

    Science.gov (United States)

    Beugnot, Jean-Charles; Lebrun, Sylvie; Pauliat, Gilles; Maillotte, Hervé; Laude, Vincent; Sylvestre, Thibaut

    2014-10-24

    Brillouin scattering in optical fibres is a fundamental interaction between light and sound with important implications ranging from optical sensors to slow and fast light. In usual optical fibres, light both excites and feels shear and longitudinal bulk elastic waves, giving rise to forward-guided acoustic wave Brillouin scattering and backward-stimulated Brillouin scattering. In a subwavelength-diameter optical fibre, the situation changes dramatically, as we here report with the first experimental observation of Brillouin light scattering from surface acoustic waves. These Rayleigh-type surface waves travel the wire surface at a specific velocity of 3,400 m s(-1) and backscatter the light with a Doppler shift of about 6 GHz. As these acoustic resonances are sensitive to surface defects or features, surface acoustic wave Brillouin scattering opens new opportunities for various sensing applications, but also in other domains such as microwave photonics and nonlinear plasmonics.

  7. Influence of viscoelastic property on laser-generated surface acoustic waves in coating-substrate systems

    International Nuclear Information System (INIS)

    Sun Hongxiang; Zhang Shuyi; Xu Baiqiang

    2011-01-01

    Taking account of the viscoelasticity of materials, the pulsed laser generation of surface acoustic waves in coating-substrate systems has been investigated quantitatively by using the finite element method. The displacement spectra of the surface acoustic waves have been calculated in frequency domain for different coating-substrate systems, in which the viscoelastic properties of the coatings and substrates are considered separately. Meanwhile, the temporal displacement waveforms have been obtained by applying inverse fast Fourier transforms. The numerical results of the normal surface displacements are presented for different configurations: a single plate, a slow coating on a fast substrate, and a fast coating on a slow substrate. The influences of the viscoelastic properties of the coating and the substrate on the attenuation of the surface acoustic waves have been studied. In addition, the influence of the coating thickness on the attenuation of the surface acoustic waves has been also investigated in detail.

  8. Holography: art with light

    OpenAIRE

    Beléndez Vázquez, Augusto

    2015-01-01

    “It’s the intersection of art, science, and technology that makes holography so interesting,” stated Stephen Benton (1941-2003), a key figure in the development of modern holography not only on account of his scientific achievements (such as the holograms on credit cards) but also for his artistic talent. The fact is that in addition to innumerable scientific and technological applications, holography is one of the few scientific fields that have provided a medium for art. Stephen Benton firs...

  9. Surface Acoustic Analog of Bloch Oscillations, Wannier-Stark Ladders and Landau-Zener Tunneling

    Science.gov (United States)

    de Lima, M. M.; Kosevich, Yu. A.; Santos, P. V.; Cantarero, A.

    2011-12-01

    In this contribution, we discuss the recent experimental demonstration of Wannier-Stark ladders, Bloch Oscillations and Landau Zener tunneling in a solid by means of surface acoustic waves propagating through perturbed grating structures.

  10. Single-electron transport driven by surface acoustic waves: Moving quantum dots versus short barriers

    DEFF Research Database (Denmark)

    Utko, Pawel; Hansen, Jørn Bindslev; Lindelof, Poul Erik

    2007-01-01

    We have investigated the response of the acoustoelectric-current driven by a surface-acoustic wave through a quantum point contact in the closed-channel regime. Under proper conditions, the current develops plateaus at integer multiples of ef when the frequency f of the surface-acoustic wave...... or the gate voltage V-g of the point contact is varied. A pronounced 1.1 MHz beat period of the current indicates that the interference of the surface-acoustic wave with reflected waves matters. This is supported by the results obtained after a second independent beam of surface-acoustic wave was added......, though at different current values, as if they were superposed on each other. Their presence could result from two independent quantization mechanisms for the acoustoelectric-current. We point out that short potential barriers determining the properties of our nominally long constrictions could lead...

  11. Interface nano-confined acoustic waves in polymeric surface phononic crystals

    Energy Technology Data Exchange (ETDEWEB)

    Travagliati, Marco, E-mail: marco.travagliati@iit.it [Center for Nanotechnology Innovation@NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa (Italy); NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR, Piazza San Silvestro 12, 56127 Pisa (Italy); Nardi, Damiano [JILA and Department of Physics, University of Colorado, 440 UCB, Boulder, Colorado 80309 (United States); Giannetti, Claudio; Ferrini, Gabriele; Banfi, Francesco, E-mail: francesco.banfi@unicatt.it [i-LAMP and Dipartimento di Matematica e Fisica, Università Cattolica del Sacro Cuore, Via Musei 41, 25121 Brescia (Italy); Gusev, Vitalyi [LAUM, UMR-CNRS 6613, Université du Maine, av. O. Messiaen, 72085 Le Mans (France); Pingue, Pasqualantonio [NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR, Piazza San Silvestro 12, 56127 Pisa (Italy); Piazza, Vincenzo [Center for Nanotechnology Innovation@NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa (Italy)

    2015-01-12

    The impulsive acoustic dynamics of soft polymeric surface phononic crystals is investigated here in the hypersonic frequency range by near-IR time-resolved optical diffraction. The acoustic response is analysed by means of wavelet spectral methods and finite element modeling. An unprecedented class of acoustic modes propagating within the polymer surface phononic crystal and confined within 100 nm of the nano-patterned interface is revealed. The present finding opens the path to an alternative paradigm for characterizing the mechanical properties of soft polymers at interfaces and for sensing schemes exploiting polymers as embedding materials.

  12. Monitoring polymer properties using shear horizontal surface acoustic waves.

    Science.gov (United States)

    Gallimore, Dana Y; Millard, Paul J; Pereira da Cunha, Mauricio

    2009-10-01

    Real-time, nondestructive methods for monitoring polymer film properties are increasingly important in the development and fabrication of modern polymer-containing products. Online testing of industrial polymer films during preparation and conditioning is required to minimize material and energy consumption, improve the product quality, increase the production rate, and reduce the number of product rejects. It is well-known that shear horizontal surface acoustic wave (SH-SAW) propagation is sensitive to mass changes as well as to the mechanical properties of attached materials. In this work, the SH-SAW was used to monitor polymer property changes primarily dictated by variations in the viscoelasticity. The viscoelastic properties of a negative photoresist film were monitored throughout the ultraviolet (UV) light-induced polymer cross-linking process using SH-SAW delay line devices. Changes in the polymer film mass and viscoelasticity caused by UV exposure produced variations in the phase velocity and attenuation of the SH-SAW propagating in the structure. Based on measured polymer-coated delay line scattering transmission responses (S(21)) and the measured polymer layer thickness and density, the viscoelastic constants c(44) and eta(44) were extracted. The polymer thickness was found to decrease 0.6% during UV curing, while variations in the polymer density were determined to be insignificant. Changes of 6% in c(44) and 22% in eta(44) during the cross-linking process were observed, showing the sensitivity of the SH-SAW phase velocity and attenuation to changes in the polymer film viscoelasticity. These results indicate the potential for SH-SAW devices as online monitoring sensors for polymer film processing.

  13. Acoustics

    Science.gov (United States)

    Goodman, Jerry R.; Grosveld, Ferdinand

    2007-01-01

    The acoustics environment in space operations is important to maintain at manageable levels so that the crewperson can remain safe, functional, effective, and reasonably comfortable. High acoustic levels can produce temporary or permanent hearing loss, or cause other physiological symptoms such as auditory pain, headaches, discomfort, strain in the vocal cords, or fatigue. Noise is defined as undesirable sound. Excessive noise may result in psychological effects such as irritability, inability to concentrate, decrease in productivity, annoyance, errors in judgment, and distraction. A noisy environment can also result in the inability to sleep, or sleep well. Elevated noise levels can affect the ability to communicate, understand what is being said, hear what is going on in the environment, degrade crew performance and operations, and create habitability concerns. Superfluous noise emissions can also create the inability to hear alarms or other important auditory cues such as an equipment malfunctioning. Recent space flight experience, evaluations of the requirements in crew habitable areas, and lessons learned (Goodman 2003; Allen and Goodman 2003; Pilkinton 2003; Grosveld et al. 2003) show the importance of maintaining an acceptable acoustics environment. This is best accomplished by having a high-quality set of limits/requirements early in the program, the "designing in" of acoustics in the development of hardware and systems, and by monitoring, testing and verifying the levels to ensure that they are acceptable.

  14. Predictive Dynamic Digital Holography

    OpenAIRE

    Sulaiman, Sennan David

    2017-01-01

    Digital holography has received recent attention for many imaging and sensing applications, including imaging through turbulent and turbid media, adaptive optics, three-dimensional projective display technology and optical tweezing. It holds several advantages over conventional imaging and wavefront sensing, chief among these being significantly fewer and simpler optical components and the retrieval of complex field. A significant obstacle for digital holography in real-time applications, suc...

  15. X-ray holography

    CERN Document Server

    Faigel, G; Belakhovsky, M; Marchesini, S; Bortel, G

    2003-01-01

    In the last decade holographic methods using hard X-rays were developed. They are able to resolve atomic distances, and can give the 3D arrangement of atoms around a selected element. Therefore, hard X-ray holography has potential applications in chemistry, biology and physics. In this article we give a general description of these methods and discuss the developments in the experimental technique. The capabilities of hard X-ray holography are demonstrated by examples.

  16. X-ray holography

    International Nuclear Information System (INIS)

    Faigel, G.; Tegze, M.; Belakhovsky, M.; Marchesini, S.; Bortel, G.

    2003-01-01

    In the last decade holographic methods using hard X-rays were developed. They are able to resolve atomic distances, and can give the 3D arrangement of atoms around a selected element. Therefore, hard X-ray holography has potential applications in chemistry, biology and physics. In this article we give a general description of these methods and discuss the developments in the experimental technique. The capabilities of hard X-ray holography are demonstrated by examples

  17. Predictive Dynamic Digital Holography

    Science.gov (United States)

    Sulaiman, Sennan David

    Digital holography has received recent attention for many imaging and sensing applications, including imaging through turbulent and turbid media, adaptive optics, three-dimensional projective display technology and optical tweezing. It holds several advantages over conventional imaging and wavefront sensing, chief among these being significantly fewer and simpler optical components and the retrieval of complex field. A significant obstacle for digital holography in real-time applications, such as wavefront sensing for high-energy laser systems and high-speed imaging for target tracking, is the fact that digital holography is computationally intensive; it requires iterative virtual wavefront propagation and hill-climbing algorithms to optimize sharpness criteria. This research demonstrates real-time methods for digital holography based on approaches for optimal and adaptive identification, prediction, and control of optical wavefronts. The methods presented integrate minimum-variance wavefront prediction into dynamic digital holography schemes to accelerate the wavefront correction and image sharpening algorithms. Further gains in computational efficiency are demonstrated in this work with a variant of localized sharpening in conjunction with predictive dynamic digital holography for real-time applications. This "subspace correction" method optimizes sharpness of local regions in a detector plane by parallel independent wavefront correction on reduced-dimension subspaces of the complex field in a spectral plane.

  18. Amplification of surface acoustic waves by transverse electric current in piezoelectric semiconductors

    DEFF Research Database (Denmark)

    Gulyaev, Yuri V.

    1974-01-01

    It is shown that the principal characteristic feature of the surface acoustic waves in piezoelectrics—the presence of an alternating electric field transverse to the surface, which can be of the same order of magnitude as the longitudinal field—may not only give rise to the known transverse...... acoustoelectric effect but also lead to amplification of surface acoustic waves by electron drift perpendicular to the surface. For Love waves in a piezoelectric semiconductor film on a highly conducting substrate, the amplification coefficient is found and the conditions necessary for amplification...

  19. Noise suppression in curved glass shells using macro-fiber-composite actuators studied by the means of digital holography and acoustic measurements

    Czech Academy of Sciences Publication Activity Database

    Mokrý, P.; Psota, Pavel; Steiger, Kateřina; Václavík, J.; Doleček, Roman; Lédl, Vít; Šulc, Miroslav

    2015-01-01

    Roč. 5, č. 2 (2015), s. 27132-27132 ISSN 2158-3226 R&D Projects: GA MŠk(CZ) LO1206; GA ČR GA13-10365S Institutional support: RVO:61389021 Keywords : negative-capacitance circuits * piezoelectric polymer-films * double-glazed windows * elasticity control * active control * vibration analysis * feedback-control * system * transmission * membrane Subject RIV: BI - Acoustics Impact factor: 1.444, year: 2015 http://dx.doi.org/10.1063/1.4913624

  20. Multiharmonic Frequency-Chirped Transducers for Surface-Acoustic-Wave Optomechanics

    Science.gov (United States)

    Weiß, Matthias; Hörner, Andreas L.; Zallo, Eugenio; Atkinson, Paola; Rastelli, Armando; Schmidt, Oliver G.; Wixforth, Achim; Krenner, Hubert J.

    2018-01-01

    Wide-passband interdigital transducers are employed to establish a stable phase lock between a train of laser pulses emitted by a mode-locked laser and a surface acoustic wave generated electrically by the transducer. The transducer design is based on a multiharmonic split-finger architecture for the excitation of a fundamental surface acoustic wave and a discrete number of its overtones. Simply by introducing a variation of the transducer's periodicity p , a frequency chirp is added. This combination results in wide frequency bands for each harmonic. The transducer's conversion efficiency from the electrical to the acoustic domain is characterized optomechanically using single quantum dots acting as nanoscale pressure sensors. The ability to generate surface acoustic waves over a wide band of frequencies enables advanced acousto-optic spectroscopy using mode-locked lasers with fixed repetition rate. Stable phase locking between the electrically generated acoustic wave and the train of laser pulses is confirmed by performing stroboscopic spectroscopy on a single quantum dot at a frequency of 320 MHz. Finally, the dynamic spectral modulation of the quantum dot is directly monitored in the time domain combining stable phase-locked optical excitation and time-correlated single-photon counting. The demonstrated scheme will be particularly useful for the experimental implementation of surface-acoustic-wave-driven quantum gates of optically addressable qubits or collective quantum states or for multicomponent Fourier synthesis of tailored nanomechanical waveforms.

  1. Control of cavity acoustics by surface waviness in landing configurations

    CSIR Research Space (South Africa)

    Dala, L

    2014-08-01

    Full Text Available The aviation industry’s interest towards cavity control methods rose accordingly due to the acoustic attenuation potential of such methods. However cost effective control devices which are also efficient over a wide range aircraft operations are yet...

  2. An Introduction to Educational Holography.

    Science.gov (United States)

    Lloyd, R. Scott

    Holograms are capable of taking the two-dimensional ways of envisioning information to another dimension of presentation, representation, and conceptualization. Educational holography is joining display holography, holographic testing of materials, and holographic optical elements as a fourth major field in holography. Holograms are explored as…

  3. Environmental Acoustics and Intensity Vector Acoustics with Emphasis on Shallow Water Effects and the Sea Surface

    Science.gov (United States)

    2015-09-30

    single mode at 1000 Hz, based on depth of 19 m. 5 The waveguide supports 10 modes at this frequency and this mode -6, a...OBJECTIVES This year our objective has been to investigate properties of the acoustic vector field within a waveguide as they are influenced by the...meeting in May 2015 (Pittsburgh). A more finalized compendium of results is currently being worked on for a special issue on TREX13 to be published

  4. Photonic Mach-Zehnder modulators driven by surface acoustic waves in AlGaAs technology

    Science.gov (United States)

    Crespo-Poveda, A.; Gargallo, B.; Artundo, I.; Doménech, J. D.; Muñoz, P.; Hey, R.; Biermann, K.; Tahraoui, A.; Santos, P. V.; Cantarero, A.; de Lima, M. M.

    2014-03-01

    In this paper, photonic devices driven by surface acoustic waves and operating in the GHz frequency range are presented. The devices were designed and fabricated in (Al,Ga)As technology. In contrast to previously realized modulators, where part of the light transmission is lost due to destructive interference, in the present devices light only switches paths, avoiding losses. One of the devices presents two output channels with 180°-dephasing synchronization. Odd multiples of the fundamental driving frequency are enabled by adjusting the applied acoustic power. A second and more complex photonic integrated device, based on the acoustic modulation of tunable Arrayed Waveguide Gratings, is also proposed.

  5. Self-Similar Micron-Size and Nanosize Drops of Liquid Generated by Surface Acoustic Waves

    Science.gov (United States)

    Taller, Daniel; Go, David B.; Chang, Hsueh-Chia

    2012-11-01

    A planar surface acoustic wave on a solid substrate and its radiated sound into a static liquid drop produce time-averaged, exponentially decaying acoustic and electric Maxwell pressures near the contact line. These localized contact-line pressures are shown to generate two sequences of hemispherical satellite droplets at the tens of microns and submicron scales, both obeying self-similar exponential scaling but with distinct exponents that correspond to viscous dissipation and field leakage length scales, respectively. The acoustic pressure becomes dominant when the film thickness exceeds (1/4π) of the surface acoustic wave wavelength and it affects the shape and stability of the mother drop. The Maxwell pressure of the nanodrops, which exceeds ten atmospheres, is sensitive to the contact angle.

  6. Dynamic Response of X-37 Hot Structure Control Surfaces Exposed to Controlled Reverberant Acoustic Excitation

    Science.gov (United States)

    Grosveld, Ferdinand W.; Rizzi, Stephen A.; Rice, Chad E.

    2004-01-01

    This document represents a compilation of three informal reports from reverberant acoustic tests performed on X-37 hot structure control surfaces in the NASA Langley Research Center Structural Acoustics Loads and Transmission (SALT) facility. The first test was performed on a carbon-silicone carbide flaperon subcomponent on February 24, 2004. The second test was performed on a carbon-carbon ruddervator subcomponent on May 27, 2004. The third test was performed on a carbon-carbon flaperon subcomponent on June 30, 2004.

  7. Conventional and acoustic surface plasmons on noble metal surfaces: a time-dependent density functional theory study

    DEFF Research Database (Denmark)

    Yan, Jun; Jacobsen, Karsten W.; Thygesen, Kristian S.

    2012-01-01

    First-principles calculations of the conventional and acoustic surface plasmons (CSPs and ASPs) on the (111) surfaces of Cu, Ag, and Au are presented. The effect of s-d interband transitions on both types of plasmons is investigated by comparing results from the local density approximation...

  8. A Four-Quadrant PVDF Transducer for Surface Acoustic Wave Detection

    Directory of Open Access Journals (Sweden)

    Zhi Chen

    2012-08-01

    Full Text Available In this paper, a polyvinylidene fluoride (PVDF piezoelectric transducer was developed to detect laser-induced surface acoustic waves in a SiO2-thin film–Si-substrate structure. In order to solve the problems related to, firstly, the position of the probe, and secondly, the fact that signals at different points cannot be detected simultaneously during the detection process, a four-quadrant surface acoustic wave PVDF transducer was designed and constructed for the purpose of detecting surface acoustic waves excited by a pulse laser line source. The experimental results of the four-quadrant piezoelectric detection in comparison with the commercial nanoindentation technology were consistent, the relative error is 0.56%, and the system eliminates the piezoelectric surface wave detection direction deviation errors, improves the accuracy of the testing system by 1.30%, achieving the acquisition at the same time at different testing positions of the sample.

  9. Brillouin scattering study of surface acoustic waves in crystalline GaP

    Science.gov (United States)

    Zuk, J.; Kiefte, H.; Clouter, M. J.

    1992-10-01

    Surface acoustic modes in GaP crystals have been observed and identified using the technique of high-contrast Brillouin spectroscopy. Surface acoustic wave velocities were determined for (100) GaP in different directions of wave propagation. The values of the velocities are: 3250 m/s in the [010] direction and 3467 m/s in the [011] direction on the (100) GaP surface. These results are discussed and compared with theoretical calculations and with similar measurements in GaAs and Si.

  10. Microscale anechoic architecture: acoustic diffusers for ultra low power microparticle separation via traveling surface acoustic waves.

    Science.gov (United States)

    Behrens, Jan; Langelier, Sean; Rezk, Amgad R; Lindner, Gerhard; Yeo, Leslie Y; Friend, James R

    2015-01-07

    We present a versatile and very low-power traveling SAW microfluidic sorting device able to displace and separate particles of different diameter in aqueous suspension; the travelling wave propagates through the fluid bulk and diffuses via a Schröder diffuser, adapted from its typical use in concert hall acoustics to be the smallest such diffuser to be suitable for microfluidics. The effective operating power range is two to three orders of magnitude less than current SAW devices, uniquely eliminating the need for amplifiers, and by using traveling waves to impart forces directly upon suspended microparticles, they can be separated by size.

  11. Studies on a surface acoustic wave (SAW) dosimeter sensor for organophosphorous nerve agents

    NARCIS (Netherlands)

    Nieuwenhuizen, M.S.; Harteveld, J.L.N.

    1997-01-01

    As a follow-up of previous work on a Surface Acoustic Wave (SAW) sensor for nerve agents, irreversible response effects have been studied in more detail. Surface analytical studies indicated that degradation products are responsible for the effects observed. In addition it was tried to explore these

  12. Quality factor due to roughness scattering of shear horizontal surface acoustic waves in nanoresonators

    NARCIS (Netherlands)

    Palasantzas, G.

    2008-01-01

    In this work we study the quality factor associated with dissipation due to scattering of shear horizontal surface acoustic waves by random self-affine roughness. It is shown that the quality factor is strongly influenced by both the surface roughness exponent H and the roughness amplitude w to

  13. Dynamic Leidenfrost temperature on micro-textured surfaces: Acoustic wave absorption into thin vapor layer

    Science.gov (United States)

    Jerng, Dong Wook; Kim, Dong Eok

    2018-01-01

    The dynamic Leidenfrost phenomenon is governed by three types of pressure potentials induced via vapor hydrodynamics, liquid dynamic pressure, and the water hammer effect resulting from the generation of acoustic waves at the liquid-vapor interface. The prediction of the Leidenfrost temperature for a dynamic droplet needs quantitative evaluation and definition for each of the pressure fields. In particular, the textures on a heated surface can significantly affect the vapor hydrodynamics and the water hammer pressure. We present a quantitative model for evaluating the water hammer pressure on micro-textured surfaces taking into account the absorption of acoustic waves into the thin vapor layer. The model demonstrates that the strength of the acoustic flow into the liquid droplet, which directly contributes to the water hammer pressure, depends on the magnitude of the acoustic resistance (impedance) in the droplet and the vapor region. In consequence, the micro-textures of the surface and the increased spacing between them reduce the water hammer coefficient ( kh ) defined as the ratio of the acoustic flow into the droplet to total generated flow. Aided by numerical calculations that solve the laminar Navier-Stokes equation for the vapor flow, we also predict the dynamic Leidenfrost temperature on a micro-textured surface with reliable accuracy consistent with the experimental data.

  14. The Research of Phase Retrieval Holography Method Based on the Active Deformation of the Active Reflector Surface

    Science.gov (United States)

    Wang, Z. Q.; Chen, M. Z.; Pei, X.; Wang, J.

    2017-09-01

    The surface accuracy of a large reflector radio telescope is one of the important factors influencing the performance of the antenna. The effects of panel processing, installation, as well as gravity, temperature, and wind load, will greatly limit the observation efficiency of the antenna. Focused on the technology of active surface which is more accurately controllable than the minor reflector surface of six-ploe, the continuous distribution of active deformation phase factor described by Zernike polynomials is adopted for the first time. Only getting the far field amplitude through adjusting the active surface, the surface error can be detected. By building the models of numerical simulation, the retrieval error of arbitrary surface deformation is calculated, and the retrieval results of surface deformation in a variety of continuous active surface deformation is also studied. It is indicated that this method can stably and accurately detect surface deformation, and can also improve the efficiency of radio telescope observations effectively.

  15. Application of the complex cepstrum to the location of acoustic sources near reflective surfaces

    Science.gov (United States)

    Fuller, C. R.; Tavakkoli, S.; Elliott, K. B.; Hurst, C. J.; Obrien, W. F.

    1987-01-01

    The complex cepstrum is used to correct bearing estimations of acoustic sources in the presence of a reflective surface. An automated liftering procedure is used which zeros out a block portion of the cepstrum including the echo information. The problem of the resulting distortion is alleviated by applying a coherence criterion to the recovered direct signals at each microphone. Thus to a large degree the interactive nature of cepstral processing is overcome for this application. For the test signals and geometries considered the cepstrum is shown to accurately correct for bearing errors in acoustic signals contaminated with reflections from nearby surfaces.

  16. Different quantization mechanisms in single-electron pumps driven by surface acoustic waves

    DEFF Research Database (Denmark)

    Utko, P.; Gloos, K.; Hansen, Jørn Bindslev

    2006-01-01

    We have studied the acoustoelectric current in single-electron pumps driven by surface acoustic waves. We have found that in certain parameter ranges two different sets of quantized steps dominate the acoustoelectric current versus gate-voltage characteristics. In some cases, both types of quanti......We have studied the acoustoelectric current in single-electron pumps driven by surface acoustic waves. We have found that in certain parameter ranges two different sets of quantized steps dominate the acoustoelectric current versus gate-voltage characteristics. In some cases, both types...

  17. Scattering of X-rays on the surface acoustic wave in the case of grazing geometry

    CERN Document Server

    Mkrtchyan, A R; Petrosian, A

    2000-01-01

    The scattering of X-rays on a crystal is considered in grazing geometry when a surface acoustic wave is excited normal to the diffraction vector. The intensity of wave field at finite distance from crystal to detector is obtained. It is shown that in the presence of surface acoustic wave the magnitude of the main peak of specular reflected diffracted wave intensity decreases and intensity of satellites increases. The main peak of specular reflected diffracted wave intensity is split up as the grazing observation angle increases.

  18. Surface Acoustic Wave Monitor for Deposition and Analysis of Ultra-Thin Films

    Science.gov (United States)

    Hines, Jacqueline H. (Inventor)

    2015-01-01

    A surface acoustic wave (SAW) based thin film deposition monitor device and system for monitoring the deposition of ultra-thin films and nanomaterials and the analysis thereof is characterized by acoustic wave device embodiments that include differential delay line device designs, and which can optionally have integral reference devices fabricated on the same substrate as the sensing device, or on a separate device in thermal contact with the film monitoring/analysis device, in order to provide inherently temperature compensated measurements. These deposition monitor and analysis devices can include inherent temperature compensation, higher sensitivity to surface interactions than quartz crystal microbalance (QCM) devices, and the ability to operate at extreme temperatures.

  19. Imaging of Acoustic Waves in Sand

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-08-01

    There is considerable interest in detecting objects such as landmines shallowly buried in loose earth or sand. Various techniques involving microwave, acoustic, thermal and magnetic sensors have been used to detect such objects. Acoustic and microwave sensors have shown promise, especially if used together. In most cases, the sensor package is scanned over an area to eventually build up an image or map of anomalies. We are proposing an alternate, acoustic method that directly provides an image of acoustic waves in sand or soil, and their interaction with buried objects. The INEEL Laser Ultrasonic Camera utilizes dynamic holography within photorefractive recording materials. This permits one to image and demodulate acoustic waves on surfaces in real time, without scanning. A video image is produced where intensity is directly and linearly proportional to surface motion. Both specular and diffusely reflecting surfaces can be accomodated and surface motion as small as 0.1 nm can be quantitatively detected. This system was used to directly image acoustic surface waves in sand as well as in solid objects. Waves as frequencies of 16 kHz were generated using modified acoustic speakers. These waves were directed through sand toward partially buried objects. The sand container was not on a vibration isolation table, but sat on the lab floor. Interaction of wavefronts with buried objects showed reflection, diffraction and interference effects that could provide clues to location and characteristics of buried objects. Although results are preliminary, success in this effort suggests that this method could be applied to detection of buried landmines or other near-surface items such as pipes and tanks.

  20. Anisotropic surface acoustic waves in tungsten/lithium niobate phononic crystals

    Science.gov (United States)

    Sun, Jia-Hong; Yu, Yuan-Hai

    2018-02-01

    Phononic crystals (PnC) were known for acoustic band gaps for different acoustic waves. PnCs were already applied in surface acoustic wave (SAW) devices as reflective gratings based on the band gaps. In this paper, another important property of PnCs, the anisotropic propagation, was studied. PnCs made of circular tungsten films on a lithium niobate substrate were analyzed by finite element method. Dispersion curves and equal frequency contours of surface acoustic waves in PnCs of various dimensions were calculated to study the anisotropy. The non-circular equal frequency contours and negative refraction of group velocity were observed. Then PnC was applied as an acoustic lens based on the anisotropic propagation. Trajectory of SAW passing PnC lens was calculated and transmission of SAW was optimized by selecting proper layers of lens and applying tapered PnC. The result showed that PnC lens can suppress diffraction of surface waves effectively and improve the performance of SAW devices.

  1. Simultaneous measurement of surface tension and viscosity using freely decaying oscillations of acoustically levitated droplets

    Science.gov (United States)

    Kremer, J.; Kilzer, A.; Petermann, M.

    2018-01-01

    Oscillations of small liquid drops around a spherical shape have been of great interest to scientists measuring physical properties such as interfacial tension and viscosity, over the last few decades. A powerful tool for contactless positioning is acoustic levitation, which has been used to simultaneously determine the surface tension and viscosity of liquids at ambient pressure. In order to extend this acoustic levitation measurement method to high pressure systems, the method is first evaluated under ambient pressure. To measure surface tension and viscosity using acoustically levitated oscillating drops, an image analysis method has to be developed and factors which may affect measurement, such as sound field or oscillation amplitude, have to be analyzed. In this paper, we describe the simultaneous measurement of surface tension and viscosity using freely decaying shape oscillations of acoustically levitated droplets of different liquids (silicone oils AK 5 and AK 10, squalane, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol, and 1-octanol) in air. These liquids vary in viscosity from 2 to about 30 mPa s. An acoustic levitation system, including an optimized standing wave acoustic levitator and a high-speed camera, was used for this study. An image analysis was performed with a self-written Matlab® code. The frequency of oscillation and the damping constant, required for the determination of surface tension and viscosity, respectively, were calculated from the evolution of the equatorial and polar radii. The results and observations are compared to data from the literature in order to analyze the accuracy of surface tension and viscosity determination, as well as the effect of non-spherical drop shape or amplitude of oscillation on measurement.

  2. Simultaneous measurement of surface tension and viscosity using freely decaying oscillations of acoustically levitated droplets.

    Science.gov (United States)

    Kremer, J; Kilzer, A; Petermann, M

    2018-01-01

    Oscillations of small liquid drops around a spherical shape have been of great interest to scientists measuring physical properties such as interfacial tension and viscosity, over the last few decades. A powerful tool for contactless positioning is acoustic levitation, which has been used to simultaneously determine the surface tension and viscosity of liquids at ambient pressure. In order to extend this acoustic levitation measurement method to high pressure systems, the method is first evaluated under ambient pressure. To measure surface tension and viscosity using acoustically levitated oscillating drops, an image analysis method has to be developed and factors which may affect measurement, such as sound field or oscillation amplitude, have to be analyzed. In this paper, we describe the simultaneous measurement of surface tension and viscosity using freely decaying shape oscillations of acoustically levitated droplets of different liquids (silicone oils AK 5 and AK 10, squalane, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol, and 1-octanol) in air. These liquids vary in viscosity from 2 to about 30 mPa s. An acoustic levitation system, including an optimized standing wave acoustic levitator and a high-speed camera, was used for this study. An image analysis was performed with a self-written Matlab® code. The frequency of oscillation and the damping constant, required for the determination of surface tension and viscosity, respectively, were calculated from the evolution of the equatorial and polar radii. The results and observations are compared to data from the literature in order to analyze the accuracy of surface tension and viscosity determination, as well as the effect of non-spherical drop shape or amplitude of oscillation on measurement.

  3. Enhanced Sensitive Love Wave Surface Acoustic Wave Sensor Designed for Immunoassay Formats

    OpenAIRE

    Puiu, Mihaela; Gurban, Ana-Maria; Rotariu, Lucian; Brajnicov, Simona; Viespe, Cristian; Bala, Camelia

    2015-01-01

    We report a Love wave surface acoustic wave (LW-SAW) immunosensor designed for the detection of high molecular weight targets in liquid samples, amenable also for low molecular targets in surface competition assays. We implemented a label-free interaction protocol similar to other surface plasmon resonance bioassays having the advantage of requiring reduced time analysis. The fabricated LW-SAW sensor supports the detection of the target in the nanomolar range, and can be ultimately incorporat...

  4. Flexible Surface Acoustic Wave Device with AlN Film on Polymer Substrate

    Directory of Open Access Journals (Sweden)

    Jian Zhou

    2012-01-01

    Full Text Available Surface acoustic wave device with c-axis-oriented aluminum nitride (AlN piezoelectric thin films on polymer substrates can be potentially used for development of flexible sensors, flexible microfluidic applications, microsystems, and lab-on-chip systems. In this work, the AlN films have been successfully deposited on polymer substrates using the DC reactive magnetron-sputtering method at room temperature, and the XRD, SEM, and AFM methods reveal that low deposition pressure is beneficial to the highly c-axis-oriented AlN film on polymer substrates. Studies toward the development of AlN thin film-based flexible surface acoustic wave devices on the polymer substrates are initiated and the experimental and simulated results demonstrate the devices showing the acoustic wave velocity of 9000–10000 m/s, which indicate the AlN lamb wave.

  5. Acoustic techniques for studying soil-surface seals and crusts

    Science.gov (United States)

    The impact of raindrops on a soil surface during a rainstorm may cause soil-surface sealing and upon drying, soil crusting. Soil-surface sealing is a result of the clogging of interaggregate pores by smaller suspended particles in the water and by structural deformation of the soil fabric, which red...

  6. Characterization of Residual Stress in Shot Peened Al 7075 Alloy Using Surface Acoustic Wave

    International Nuclear Information System (INIS)

    Kim, Chung Seok; Kwun, Sook In; Kim, Yong Kwon; Park, Ik Keun

    2006-01-01

    The residual stress in shot-peened Al 7075 alloy was evaluated using surface acoustic wave (SAW). Shot peening was conducted to produce a variation in the residual stress with the depth below the surface under a shot velocity of 30 m/s. The SAW velocity was measured from the V(z) curve using a scanning acoustic microscopy (SAM). The Vickers hardness profile from the surface showed a significant work hardening near the surface layer with a thickness of about 0.25 mm. As the residual stress became more compressive, the SAW velocity increased, whereas as the residual stress became more tensile, the SAW velocity decreased. The variation in the SAW velocity through the shot peened surface layer was in good agreement with the distribution of the residual stress measured by X-ray diffraction technique

  7. Holography out of equilibrium

    NARCIS (Netherlands)

    Smolic, M.

    2013-01-01

    Using holography it is possible to write down the dissipative hydrodynamic behaviour of a boundary field theory which describes a non-conformal fluid. It is also possible to write down the evolution equations of the two-point correlators for the various field present within the cornerstone field

  8. Holography without Fuss.

    Science.gov (United States)

    Davies, Steve

    1989-01-01

    Outlines what a hologram is, the main types of holography, and how a simple system producing a white light reflection hologram can be set up in a school physics laboratory. Discusses the basic optics of the hologram and procedures and materials for making holograms in school. (YP)

  9. Marine Acoustic Sensor Assembly

    National Research Council Canada - National Science Library

    Ruffa, Anthony A

    2007-01-01

    A marine acoustic sensor assembly includes an acoustic panel having a forward surface and an after surface, a laser scanner oriented so as to project a laser beam onto the acoustic panel after surface...

  10. Spread-Spectrum Coherent Acoustic Communication Between a Submarine and a Surface Ship

    NARCIS (Netherlands)

    Walree, P.A. van

    2004-01-01

    This paper describes an underwater acoustic communication experiment executed in the North Sea near Norway. A submarine broadcast direct-sequence spread-spectrum signals with data rates of 167 and 33 bit/s. The receiver station was a surface ship with a towed hydrophone array. As the platforms

  11. Finite element analysis of surface acoustic waves in high aspect ratio electrodes

    DEFF Research Database (Denmark)

    Dühring, Maria Bayard; Laude, Vincent; Khelif, Abdelkrim

    2008-01-01

    This paper elaborates on how the finite element method is employed to model surface acoustic waves generated by high aspect ratio electrodes and their interaction with optical waves in a waveguide. With a periodic model it is shown that these electrodes act as a mechanical resonator which slows d...

  12. In situ characterization of local elastic properties of thin shape memory films by surface acoustic waves

    Czech Academy of Sciences Publication Activity Database

    Grabec, T.; Sedlák, Petr; Stoklasová, Pavla; Thomasová, M.; Shilo, D.; Kabla, M.; Seiner, Hanuš; Landa, Michal

    2016-01-01

    Roč. 25, č. 12 (2016), č. článku 127002. ISSN 0964-1726 R&D Projects: GA ČR GA14-15264S Institutional support: RVO:61388998 Keywords : thin films * shape memory alloys * surface acoustic waves Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.909, year: 2016

  13. Photonic integrated single-sideband modulator / frequency shifter based on surface acoustic waves

    DEFF Research Database (Denmark)

    Barretto, Elaine Cristina Saraiva; Hvam, Jørn Märcher

    2010-01-01

    Optical frequency shifters are essential components of many systems. In this paper, a compact integrated optical frequency shifter is designed making use of the combination of surface acoustic waves and Mach-Zehnder interferometers. It has a very simple operation setup and can be fabricated in st...

  14. Biosonar resolving power : echo-acoustic perception of surface structures in the submillimeter range

    NARCIS (Netherlands)

    Simon, Ralph; Knörnschild, Mirjam; Tschapka, Marco; Schneider, Annkathrin; Passauer, Nadine; Kalko, Elisabeth K V; von Helversen, Otto

    2014-01-01

    The minimum distance for which two points still can be separated from each other defines the resolving power of a visual system. In an echo-acoustic context, the resolving power is usually measured as the smallest perceivable distance of two reflecting surfaces on the range axis and is found to be

  15. Acoustic propagation within a surface duct in the western Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    PrasannaKumar, S.; Navelkar, G.S.; Murty, T.V.R.; Murty, C.S.

    Sound speed structure forms a surface duct in the upper 50 m layer in the western Bay of Bengal during late July. A range-dependent acoustic ray computation shows that some rays emanating from a source within the upper 30 m, get trapped within...

  16. Characterization Test Report for the Mnemonics-UCS Wireless Surface Acoustic Wave Sensor System

    Science.gov (United States)

    Duncan, Joshua J.; Youngquist, Robert C.

    2013-01-01

    The scope of this testing includes the Surface Acoustic Wave Sensor System delivered to KSC: two interrogator (transceiver) systems, four temperature sensors, with wooden mounting blocks, two antennas, two power supplies, network cables, and analysis software. Also included are a number of additional temperature sensors and newly-developed hydrogen sensors

  17. Exploration Technology Development including Surface Acoustic Wave RFID chips

    Data.gov (United States)

    National Aeronautics and Space Administration — This project is focused on maturing future surface exploration technologies and instrumentation and working towards flight instrumentation and systems to support...

  18. Recording medium based on the films of azobenzene copolymer with free surface and in sandwich-structures for polarization holography

    Science.gov (United States)

    Davidenko, N. A.; Davidenko, I. I.; Pavlov, V. A.; Chuprina, N. G.; Mokrinskaya, E. V.; Tarasenko, V. V.; Tonkopieva, L. S.; Kravchenko, V. V.

    2018-02-01

    Peculiarities of the polarization holographic recording in the samples with the films of copolymer poly[4-((2-nitrophenyl)diazenyl)phenylmethacrylate-co-octylmethacrylate] with free surface and in the sandwich-structures with solid covering layer are investigated. Time of the holographic recording and its storage is less in the sandwich-structures. It was concluded, that in the sandwich-structures, geometric relief of the film surface does not appear during the recording.

  19. Tunable arrayed waveguide grating driven by surface acoustic waves

    Science.gov (United States)

    Crespo-Poveda, Antonio; Hernández-Mínguez, Alberto; Biermann, Klaus; Tahraoui, Abbes; Gargallo, Bernardo; Muñoz, Pascual; Santos, Paulo V.; Cantarero, Andrés.; de Lima, Maurício M.

    2016-03-01

    We present a design approach for compact reconfigurable phased-array wavelength-division multiplexing (WDM) devices with N access waveguides (WGs) based on multimode interference (MMI) couplers. The proposed devices comprise two MMI couplers which are employed as power splitters and combiners, respectively, linked by an array of N single-mode WGs. First, passive devices are explored. Taking advantage of the transfer phases between the access ports of the MMI couplers, we derive very simple phase relations between the arms that provide wavelength dispersion at the output plane of the devices. When the effective refractive index of the WGs is modulated with the proper relative optical phase difference, each wavelength component can switch paths between the preset output channel and the remaining output WGs. Moreover, very simple phase relations between the modulated WGs that enable the reconfiguration of the output channel distribution when the appropriated coupling lengths of the MMI couplers are chosen are also derived. In this way, a very compact expression to calculate the channel assignment of the devices as a function of the applied phase shift is derived for the general case of N access WGs. Finally, the experimental results corresponding to an acoustically driven phased-array WDM device with five access WGs fabricated on (Al,Ga)As are shown.

  20. Energy storage and dispersion of surface acoustic waves trapped in a periodic array of mechanical resonators

    DEFF Research Database (Denmark)

    Dühring, Maria Bayard; Laude, Vincent; Khelif, Abdelkrim

    2009-01-01

    confined to the electrode as compared to the total mechanical energy is calculated and is found to be increasing for increasing aspect ratio and to tend to a definite limit for the two families of surface waves. This observation is in support of the interpretation that high aspect ratio electrodes act......It has been shown previously that surface acoustic waves can be efficiently trapped and slowed by steep ridges on a piezoelectric substrate, giving rise to two families of shear-horizontal and vertically polarized surface waves. The mechanisms of energy storage and dispersion are explored by using...... the finite element method to model surface acoustic waves generated by high aspect ratio electrodes. A periodic model is proposed including a perfectly matched layer to simulate radiation conditions away from the sources, from which the modal distributions are found. The ratio of the mechanical energy...

  1. Surface Generated Acoustic Wave Biosensors for the Detection of Pathogens: A Review

    Directory of Open Access Journals (Sweden)

    Antonio Arnau-Vives

    2009-07-01

    Full Text Available This review presents a deep insight into the Surface Generated Acoustic Wave (SGAW technology for biosensing applications, based on more than 40 years of technological and scientific developments. In the last 20 years, SGAWs have been attracting the attention of the biochemical scientific community, due to the fact that some of these devices - Shear Horizontal Surface Acoustic Wave (SH-SAW, Surface Transverse Wave (STW, Love Wave (LW, Flexural Plate Wave (FPW, Shear Horizontal Acoustic Plate Mode (SH-APM and Layered Guided Acoustic Plate Mode (LG-APM - have demonstrated a high sensitivity in the detection of biorelevant molecules in liquid media. In addition, complementary efforts to improve the sensing films have been done during these years. All these developments have been made with the aim of achieving, in a future, a highly sensitive, low cost, small size, multi-channel, portable, reliable and commercially established SGAW biosensor. A setup with these features could significantly contribute to future developments in the health, food and environmental industries. The second purpose of this work is to describe the state-of-the-art of SGAW biosensors for the detection of pathogens, being this topic an issue of extremely importance for the human health. Finally, the review discuses the commercial availability, trends and future challenges of the SGAW biosensors for such applications.

  2. High quality factor surface Fabry-Perot cavity of acoustic waves

    Science.gov (United States)

    Xu, Yuntao; Fu, Wei; Zou, Chang-ling; Shen, Zhen; Tang, Hong X.

    2018-02-01

    Surface acoustic wave (SAW) resonators are critical components in wireless communications and many sensing applications. They have also recently emerged as a subject of study in quantum acoustics at the single phonon level. Acoustic loss reduction and mode confinement are key performance factors in SAW resonators. Here, we report the design and experimental realization of high quality factor Fabry-Perot SAW resonators formed in between the tapered phononic crystal mirrors patterned on a GaN-on-sapphire material platform. The fabricated SAW resonators are characterized by both an electrical network analyzer and an optical heterodyne vibrometer. We observed standing Rayleigh waves inside the cavity, with an intrinsic quality factor exceeding 1.3 × 104 at ambient conditions.

  3. Acoustic propagation operators for pressure waves on an arbitrarily curved surface in a homogeneous medium

    Science.gov (United States)

    Sun, Yimin; Verschuur, Eric; van Borselen, Roald

    2018-03-01

    The Rayleigh integral solution of the acoustic Helmholtz equation in a homogeneous medium can only be applied when the integral surface is a planar surface, while in reality almost all surfaces where pressure waves are measured exhibit some curvature. In this paper we derive a theoretically rigorous way of building propagation operators for pressure waves on an arbitrarily curved surface. Our theory is still based upon the Rayleigh integral, but it resorts to matrix inversion to overcome the limitations faced by the Rayleigh integral. Three examples are used to demonstrate the correctness of our theory - propagation of pressure waves acquired on an arbitrarily curved surface to a planar surface, on an arbitrarily curved surface to another arbitrarily curved surface, and on a spherical cap to a planar surface, and results agree well with the analytical solutions. The generalization of our method for particle velocities and the calculation cost of our method are also discussed.

  4. Coupling a Surface Acoustic Wave to an Electron Spin in Diamond via a Dark State

    Directory of Open Access Journals (Sweden)

    D. Andrew Golter

    2016-12-01

    Full Text Available The emerging field of quantum acoustics explores interactions between acoustic waves and artificial atoms and their applications in quantum information processing. In this experimental study, we demonstrate the coupling between a surface acoustic wave (SAW and an electron spin in diamond by taking advantage of the strong strain coupling of the excited states of a nitrogen vacancy center while avoiding the short lifetime of these states. The SAW-spin coupling takes place through a Λ-type three-level system where two ground spin states couple to a common excited state through a phonon-assisted as well as a direct dipole optical transition. Both coherent population trapping and optically driven spin transitions have been realized. The coherent population trapping demonstrates the coupling between a SAW and an electron spin coherence through a dark state. The optically driven spin transitions, which resemble the sideband transitions in a trapped-ion system, can enable the quantum control of both spin and mechanical degrees of freedom and potentially a trapped-ion-like solid-state system for applications in quantum computing. These results establish an experimental platform for spin-based quantum acoustics, bridging the gap between spintronics and quantum acoustics.

  5. Control of single photon emitters in semiconductor nanowires by surface acoustic waves

    Science.gov (United States)

    Lazić, S.; Hernández-Mínguez, A.; Santos, P. V.

    2017-08-01

    We report on an experimental study into the effects of surface acoustic waves on the optical emission of dot-in-a-nanowire heterostructures in III-V material systems. Under direct optical excitation, the excitonic energy levels in III-nitride dot-in-a-nanowire heterostructures oscillate at the acoustic frequency, producing a characteristic splitting of the emission lines in the time-integrated photoluminescence spectra. This acoustically induced periodic tuning of the excitonic transition energies is combined with spectral detection filtering and employed as a tool to regulate the temporal output of anti-bunched photons emitted from these nanowire quantum dots. In addition, the acoustic transport of electrons and holes along a III-arsenide nanowire injects the electric charges into an ensemble of quantum dot-like recombination centers that are spatially separated from the optical excitation area. The acoustic population and depopulation mechanism determines the number of carrier recombination events taking place simultaneously in the ensemble, thus allowing control of the anti-bunching degree of the emitted photons. The results presented are relevant for the dynamic control of single photon emission in III-V semiconductor heterostructures.

  6. Acoustic emission-based in-process monitoring of surface generation in robot-assisted polishing

    DEFF Research Database (Denmark)

    Pilny, Lukas; Bissacco, Giuliano; De Chiffre, Leonardo

    2016-01-01

    The applicability of acoustic emission (AE) measurements for in-process monitoring of surface generation in the robot-assisted polishing (RAP) was investigated. Surface roughness measurements require interruption of the process, proper surface cleaning and measurements that sometimes necessitate......-process determination of the process endpoint. This makes it possible to reliably determine the right time for changing the polishing media to finer abrasive when applying a given set of parameters is no longer effective to create a smoother surface, thus improving the efficiency of the process. The findings enabling...

  7. Dependency of magnetic microwave absorption on surface architecture of Co20Ni80 hierarchical structures studied by electron holography.

    Science.gov (United States)

    Liu, Qinghe; Xu, Xianhui; Xia, Weixing; Che, Renchao; Chen, Chen; Cao, Qi; He, Jingang

    2015-02-07

    To design and fabricate rational surface architecture of individual particles is one of the key factors that affect their magnetic properties and microwave absorption capability, which is still a great challenge. Herein, a series of Co20Ni80 hierarchical structures with different surface morphologies, including flower-, urchin-, ball-, and chain-like morphologies, were obtained using structure-directing templates via a facile one-step solvothermal treatment. The microwave reflection loss (RL) of urchin-like Co20Ni80 hierarchical structures reaches as high as -33.5 dB at 3 GHz, with almost twice the RL intensity of the ball- and chain-like structures, and the absorption bandwidth (structures might become an effective path to achieve high-performance microwave absorption for electromagnetic shielding and stealth camouflage applications.

  8. Tuning Acoustic Wave Properties by Mechanical Resonators on a Surface

    DEFF Research Database (Denmark)

    Dühring, Maria Bayard; Laude, Vincent; Khelif, Abdelkrim

    Vibrations generated by high aspects ratio electrodes are studied by the finite element method. It is found that the modes are combined of a surface wave and vibration in the electrodes. For increasing aspect ratio most of the mechanical energy is confined to the electrodes which act as mechanical...

  9. Deconstruction and Holography

    CERN Document Server

    Jejjala, V; Minic, D; Jejjala, Vishnu; Leigh, Robert G.; Minic, Djordje

    2003-01-01

    It was recently pointed out that the physics of a single discrete gravitational extra dimension exhibits a peculiar UV/IR connection relating the UV scale to the radius of the effective extra dimension. Here we note that this non-locality is a manifestation of holography, encoding the correct scaling of the number of fundamental degrees of freedom of the UV theory. This in turn relates the Wilsonian RG flow in the UV theory to the effective gravitational dynamics in the extra dimension. The relevant holographic c-function is determined by the expression for the holographic bound. Holography in this context is a result of the requirements of unitarity and diffeomorphism invariance. We comment on the relevance of this observation for the cosmological constant problem.

  10. Multispectral hyperbolic incoherent holography

    Science.gov (United States)

    Srinuanjan, Keerayoot; Obara, Masaki; Yoshimori, Kyu

    2018-02-01

    This paper presents a new method of multispectral hyperbolic incoherent holography in which a hyperbolic volume interferogram was directly measured by an appropriate designed interferometer. This method enables to obtain a set of spectral components of three-dimensional images and continuous spectra for spatially incoherent, polychromatic objects. We introduced a calibration method of a phase aberration of the interferometer. The spectral resolution and spatial resolutions are investigated based on analytical solution of impulse response function of hyperbolic holography. From experimental results and theoretical predictions, the validity of the calibration method was confirmed. Experimental results agree with the theoretical ones. Consequently, the retrieved images obtained by the method are shown to demonstrate the performance of the method.

  11. Pre-holography

    International Nuclear Information System (INIS)

    Kay, Bernard S.; Larkin, Peter

    2008-01-01

    We construct a symplectic isomorphism h from classical Klein Gordon solutions of mass m on (d+1)-dimensional Lorentzian anti-de Sitter space (equipped with the usual symplectic form) to a certain symplectic space of functions on its conformal boundary (only) for all integer and half-integer Δ (=(d/2)+(1/2)(d 2 +4m 2 ) 1/2 ). h induces a large family of new examples of Rehren's algebraic holography in which the net of local quantum Klein Gordon algebras in AdS is seen to map to a suitably defined net of local algebras for the (generalized free) scalar conformal field with anomalous dimension Δ on d-dimensional Minkowski space (the AdS boundary). Relatedly, we show for these models that Bertola et al.'s boundary-limit holography becomes a quantum duality (only) if the test functions for boundary Wightman distributions are restricted in a particular way

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

    Science.gov (United States)

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

    2018-05-01

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

  13. On the formation of nanostructures on a CdTe surface, stimulated by surface acoustic waves under nanosecond laser irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Vlasenko, A. I.; Baidullaeva, A.; Veleschuk, V. P., E-mail: vvvit@ukr.net; Mozol, P. E.; Boiko, N. I.; Litvin, O. S. [National Academy of Sciences of Ukraine, Lashkaryov Institute of Semiconductors Physics (Ukraine)

    2015-02-15

    The formation of nanoscale structures in the unirradiated part of a p-CdTe crystal surface irradiated by a nanosecond ruby laser is revealed and investigated. It is shown that their formation is caused by the effect of the long-range action of a laser pulse with an intensity of I = 20 MW/cm{sup 2}. Nanoscale-structure formation is explained by the influence of the pressure gradient of the surface acoustic wave, in particular, within the “vacancy-pump” mechanism on the surface.

  14. Lifshitz symmetries and nonrelativistic holography

    NARCIS (Netherlands)

    Sybesma, Z.W.

    2017-01-01

    In this dissertation we cover topics within the main themes of Lifshitz symmetries and nonrelativistic holography. Nonrelativistic theories are typically less constrained than relativistic ones, which makes them often more cumbersome to work with. Via holography one can have acces to domains of a

  15. Applications and Fundamentals of Holography

    NARCIS (Netherlands)

    Betzios, P.|info:eu-repo/dai/nl/369185110

    2017-01-01

    In this thesis we explore the fascinating topic of Holography for various systems. The intuitive idea of Holography is that one has at hand two dual descriptions of the physical reality at different number of dimensions much like in the usual holograms, where one projects a three dimensional object

  16. Holography in the Junior High.

    Science.gov (United States)

    Tomaszkiewicz, Frank

    1988-01-01

    Examines the use of holography in the art technology program of a junior high school. Characterizing holography as a valuable artistic experience and discovery experience and stressing the importance of student interest and involvement, the author discusses the necessary equipment for the project and includes two diagrams of a holographic setup.…

  17. Surface Acoustic Wave Nebulisation Mass Spectrometry for the Fast and Highly Sensitive Characterisation of Synthetic Dyes in Textile Samples

    NARCIS (Netherlands)

    Astefanei, A.; van Bommel, M.; Corthals, G.L.

    2017-01-01

    Surface acoustic wave nebulisation (SAWN) mass spectrometry (MS) is a method to generate gaseous ions compatible with direct MS of minute samples at femtomole sensitivity. To perform SAWN, acoustic waves are propagated through a LiNbO3 sampling chip, and are conducted to the liquid sample, which

  18. Flow patterns and transport in Rayleigh surface acoustic wave streaming: combined finite element method and raytracing numerics versus experiments.

    Science.gov (United States)

    Frommelt, Thomas; Gogel, Daniel; Kostur, Marcin; Talkner, Peter; Hänggi, Peter; Wixforth, Achim

    2008-10-01

    This work presents an approach for determining the streaming patterns that are generated by Rayleigh surface acoustic waves in arbitrary 3-D geometries by finite element method (FEM) simulations. An efficient raytracing algorithm is applied on the acoustic subproblem to avoid the unbearable memory demands and computational time of a conventional FEM acoustics simulation in 3-D. The acoustic streaming interaction is modeled by a body force term in the Stokes equation. In comparisons between experiments and simulated flow patterns, we demonstrate the quality of the proposed technique.

  19. Seismo-acoustic location method for small-magnitude surface explosions

    Science.gov (United States)

    Che, I.-Y.; Shin, J. S.; Kang, I. B.

    2009-02-01

    The aims of this study were to develop an improved method using infrasound observations at multiple seismo-acoustic arrays for locating small-magnitude surface explosions at regional distances and to apply the method to ground-truth blasting events for validation. The location method is based on a nonlinear grid search using the travel times and back azimuths of infrasonic signals generated from the surface explosions and on seismic parameters that are independently determined by routine seismic monitoring systems. Specifically, the method utilizes wind-corrected infrasonic azimuths in grid searching to constrain the grids according to nearness to feasibly real observations. Ground-truth events were recorded by a seismo-acoustic station temporarily operated inside an open-pit mine and then used to investigate the improvement by the location method. The method improved the locating of ground-truth events by approximately 50% compared to the seismic location results. Surface explosions generating both seismic and infrasonic signals could be located independently by the seismic location, infrasonic-azimuth intersection, and seismo-acoustic location method, respectively. This method can be applied to automatic seismic/infrasonic monitoring systems as an additional location tool for explosion-induced seismic events, allowing for simultaneous monitoring for surface explosions and reduced risk of false location results.

  20. Incoherent Digital Holography: A Review

    Directory of Open Access Journals (Sweden)

    Jung-Ping Liu

    2018-01-01

    Full Text Available Digital holography (DH is a promising technique for modern three-dimensional (3D imaging. Coherent holography records the complex amplitude of a 3D object holographically, giving speckle noise upon reconstruction and presenting a serious drawback inherent in coherent optical systems. On the other hand, incoherent holography records the intensity distribution of the object, allowing a higher signal-to-noise ratio as compared to its coherent counterpart. Currently there are two incoherent digital holographic techniques: optical scanning holography (OSH and Fresnel incoherent correlation holography (FINCH. In this review, we first explain the principles of OSH and FINCH. We then compare, to some extent, the differences between OSH and FINCH. Finally, some of the recent applications of the two incoherent holographic techniques are reviewed.

  1. Analyzing panel acoustic contributions toward the sound field inside the passenger compartment of a full-size automobile.

    Science.gov (United States)

    Wu, Sean F; Moondra, Manmohan; Beniwal, Ravi

    2015-04-01

    The Helmholtz equation least squares (HELS)-based nearfield acoustical holography (NAH) is utilized to analyze panel acoustic contributions toward the acoustic field inside the interior region of an automobile. Specifically, the acoustic power flows from individual panels are reconstructed, and relative contributions to sound pressure level and spectrum at any point of interest are calculated. Results demonstrate that by correlating the acoustic power flows from individual panels to the field acoustic pressure, one can correctly locate the panel allowing the most acoustic energy transmission into the vehicle interior. The panel on which the surface acoustic pressure amplitude is the highest should not be used as indicative of the panel responsible for the sound field in the vehicle passenger compartment. Another significant advantage of this HELS-based NAH is that measurements of the input data only need to be taken once by using a conformal array of microphones in the near field, and ranking of panel acoustic contributions to any field point can be readily performed. The transfer functions between individual panels of any vibrating structure to the acoustic pressure anywhere in space are calculated not measured, thus significantly reducing the time and effort involved in panel acoustic contributions analyses.

  2. Enhanced sensitive love wave surface acoustic wave sensor designed for immunoassay formats.

    Science.gov (United States)

    Puiu, Mihaela; Gurban, Ana-Maria; Rotariu, Lucian; Brajnicov, Simona; Viespe, Cristian; Bala, Camelia

    2015-05-05

    We report a Love wave surface acoustic wave (LW-SAW) immunosensor designed for the detection of high molecular weight targets in liquid samples, amenable also for low molecular targets in surface competition assays. We implemented a label-free interaction protocol similar to other surface plasmon resonance bioassays having the advantage of requiring reduced time analysis. The fabricated LW-SAW sensor supports the detection of the target in the nanomolar range, and can be ultimately incorporated in portable devices, suitable for point-of-care testing (POCT) applications.

  3. Enhanced Sensitive Love Wave Surface Acoustic Wave Sensor Designed for Immunoassay Formats

    Directory of Open Access Journals (Sweden)

    Mihaela Puiu

    2015-05-01

    Full Text Available We report a Love wave surface acoustic wave (LW-SAW immunosensor designed for the detection of high molecular weight targets in liquid samples, amenable also for low molecular targets in surface competition assays. We implemented a label-free interaction protocol similar to other surface plasmon resonance bioassays having the advantage of requiring reduced time analysis. The fabricated LW-SAW sensor supports the detection of the target in the nanomolar range, and can be ultimately incorporated in portable devices, suitable for point-of-care testing (POCT applications.

  4. Conoscopic holography for image registration: a feasibility study

    Science.gov (United States)

    Lathrop, Ray A.; Cheng, Tiffany T.; Webster, Robert J., III

    2009-02-01

    Preoperative image data can facilitate intrasurgical guidance by revealing interior features of opaque tissues, provided image data can be accurately registered to the physical patient. Registration is challenging in organs that are deformable and lack features suitable for use as alignment fiducials (e.g. liver, kidneys, etc.). However, provided intraoperative sensing of surface contours can be accomplished, a variety of rigid and deformable 3D surface registration techniques become applicable. In this paper, we evaluate the feasibility of conoscopic holography as a new method to sense organ surface shape. We also describe potential advantages of conoscopic holography, including the promise of replacing open surgery with a laparoscopic approach. Our feasibility study investigated use of a tracked off-the-shelf conoscopic holography unit to perform a surface scans on several types of biological and synthetic phantom tissues. After first exploring baseline accuracy and repeatability of distance measurements, we performed a number of surface scan experiments on the phantom and ex vivo tissues with a variety of surface properties and shapes. These indicate that conoscopic holography is capable of generating surface point clouds of at least comparable (and perhaps eventually improved) accuracy in comparison to published experimental laser triangulation-based surface scanning results.

  5. High quality broadband spatial reflections of slow Rayleigh surface acoustic waves modulated by a graded grooved surface

    KAUST Repository

    Xu, Yanlong

    2015-01-21

    We report high quality broadband spatial reflections of Rayleigh surface acoustic waves (SAWs) through a graded grooved surface. High quality means that no wave is allowed to transmit and the incident wave is nearly all reflected to the input side. The graded grooved surface is structured by drilling one dimensional array of graded grooves with increased depths on a flat surface. We investigate SAW dispersion relations, wave field distribution at several typical SAW wavelengths, and time evolution of a Gaussian pulse through the graded grooved surface. Results show that the input broadband Rayleigh SAWs can be slowed, spatially enhanced and stopped, and finally reflected to the input side. The study suggests that engraving the flat surface can be used as an efficient and economical way to manipulate Rayleigh SAWs, which has potential application in novel SAW devices such as filters, reflectors, sensors, energy harvesters, and diodes.

  6. Development of a pressure based room acoustic model using impedance descriptions of surfaces

    DEFF Research Database (Denmark)

    Marbjerg, Gerd Høy; Brunskog, Jonas; Jeong, Cheol-Ho

    2013-01-01

    and acoustic radiosity will account for the diffuse reflections. This paper presents the motivation for the new model in the form of results in literature, which show the importance of retaining the angle dependence and phase information in reflections along with simple examples of angle dependent reflection......If a simulation tool is to be used for the optimization of absorbent ceilings, it is important that the simulation tool includes a good description of the surface. This study therefore aims at developing a model which can describe surfaces by their impedance values and not just by their statistical...... absorption coefficient, thus retaining the phase and the angle dependence. The approach of the proposed model will be to calculate the pressure impulse response using a combination of the image source method and acoustic radiosity. The image source method will account for the specular reflections...

  7. Structural characterisations of AlN/diamond structures used for surface acoustic wave device applications

    OpenAIRE

    MORTET, Vincent; Elmazria, O; NESLADEK, Milos; Elhakiki, M; VANHOYLAND, Geert; D'HAEN, Jan; D'OLIESLAEGER, Marc; Alnot, P

    2003-01-01

    Diamond based surface acoustic wave (SAW) devices are extremely versatile devices that are just beginning to realize their commercial potential for use from sensors till high frequency (HF) filters for wireless telecommunications. One of the most promising piezoelectric materials for diamond based HF-SAW devices is aluminium nitride (AlN) thin film. The ability of AlN and diamond to be used for SAW applications depends both on the piezoelectric AlN layer properties and the diamond substrate p...

  8. Propagation of surface acoustic waves in n-type GaAs films

    Science.gov (United States)

    Wu, Chhi-Chong; Tsai, Jensan

    1983-05-01

    The effect of nonparabolicity on the amplification of surface acoustic waves in n-type GaAs films is investigated quantum mechanically in the GHz frequency region. Numerical results show that the amplification coefficient for the nonparabolic band structure is enhanced due to the nonlinear nature of the energy band in semiconductors. Moreover, the amplification coefficients in semiconductors depend on the temperature, the electronic screening effect, the frequency of sound waves, the applied electric field, and the thickness of the semiconductor film.

  9. AlScN thin film based surface acoustic wave devices with enhanced microfluidic performance

    International Nuclear Information System (INIS)

    Wang, W B; Xuan, W P; Chen, J K; Wang, X Z; Luo, J K; Fu, Y Q; Chen, J J; Duan, P F; Mayrhofer, P; Bittner, A; Schmid, U

    2016-01-01

    This paper reports the characterization of scandium aluminum nitride (Al 1−xS c xN , x   =  27%) films and discusses surface acoustic wave (SAW) devices based on them. Both AlScN and AlN films were deposited on silicon by sputtering and possessed columnar microstructures with (0 0 0 2) crystal orientation. The AlScN/Si SAW devices showed improved electromechanical coupling coefficients ( K 2 , ∼2%) compared with pure AlN films (<0.5%). The performance of the two types of devices was also investigated and compared, using acoustofluidics as an example. The AlScN/Si SAW devices achieved much lower threshold powers for the acoustic streaming and pumping of liquid droplets, and the acoustic streaming and pumping velocities were 2  ×  and 3  ×  those of the AlN/Si SAW devices, respectively. Mechanical characterization showed that the Young’s modulus and hardness of the AlN film decreased significantly when Sc was doped, and this was responsible for the decreased acoustic velocity and resonant frequency, and the increased temperature coefficient of frequency, of the AlScN SAW devices. (paper)

  10. Detection of Volatile Organics Using a Surface Acoustic Wave Array System

    Energy Technology Data Exchange (ETDEWEB)

    ANDERSON, LAWRENCE F.; BARTHOLOMEW, JOHN W.; CERNOSEK, RICHARD W.; COLBURN, CHRISTOPHER W.; CROOKS, R.M.; MARTINEZ, R.F.; OSBOURN, GORDON C.; RICCO, A.J.; STATON, ALAN W.; YELTON, WILLIAM G.

    1999-10-14

    A chemical sensing system based on arrays of surface acoustic wave (SAW) delay lines has been developed for identification and quantification of volatile organic compounds (VOCs). The individual SAW chemical sensors consist of interdigital transducers patterned on the surface of an ST-cut quartz substrate to launch and detect the acoustic waves and a thin film coating in the SAW propagation path to perturb the acoustic wave velocity and attenuation during analyte sorption. A diverse set of material coatings gives the sensor arrays a degree of chemical sensitivity and selectivity. Materials examined for sensor application include the alkanethiol-based self-assembled monolayer, plasma-processed films, custom-synthesized conventional polymers, dendrimeric polymers, molecular recognition materials, electroplated metal thin films, and porous metal oxides. All of these materials target a specific chemical fi.mctionality and the enhancement of accessible film surface area. Since no one coating provides absolute analyte specificity, the array responses are further analyzed using a visual-empirical region-of-influence (VERI) pattern recognition algorithm. The chemical sensing system consists of a seven-element SAW array with accompanying drive and control electronics, sensor signal acquisition electronics, environmental vapor sampling hardware, and a notebook computer. Based on data gathered for individual sensor responses, greater than 93%-accurate identification can be achieved for any single analyte from a group of 17 VOCs and water.

  11. New trend in electron holography

    International Nuclear Information System (INIS)

    Tanigaki, Toshiaki; Akashi, Tetsuya; Takahashi, Yoshio; Sugawara, Akira; Harada, Ken; Niitsu, Kodai; Shindo, Daisuke; Murakami, Yasukazu

    2016-01-01

    Electron holography using a coherent electron wave is a promising technique for high-resolution visualization of electromagnetic fields in and around objects. The capability of electron holography has been enhanced by the development of new technologies and has thus become an even more powerful tool for exploring scientific frontiers. This review introduces these technologies including split-illumination electron holography and vector-field electron tomography. Split-illumination electron holography, which uses separated coherent waves, overcomes the limits imposed by the lateral coherence requirement for electron waves in electron holography. Areas that are difficult to observe using conventional electron holography are now observable. Exemplified applications include observing a singular magnetic domain wall in electrical steel sheets, local magnetizations at anti-phase boundaries, and electrostatic potentials in metal-oxide-semiconductor field-effect transistors. Vector-field electron tomography can be used to visualize magnetic vectors in three dimensions. Two components of the vectors are reconstructed using dual-axis tomography, and the remaining one is calculated using div B   =  0. A high-voltage electron microscope can be used to achieve precise magnetic reconstruction. For example, magnetic vortices have been visualized using a 1 MV holography electron microscope. (paper)

  12. Preliminary study of the effect of the turbulent flow field around complex surfaces on their acoustic characteristics

    Science.gov (United States)

    Olsen, W. A.; Boldman, D.

    1978-01-01

    Fairly extensive measurements have been conducted of the turbulent flow around various surfaces as a basis for a study of the acoustic characteristics involved. In the experiments the flow from a nozzle was directed upon various two-dimensional surface configurations such as the three-flap model. A turbulent flow field description is given and an estimate of the acoustic characteristics is provided. The developed equations are based upon fundamental theories for simple configurations having simple flows. Qualitative estimates are obtained regarding the radiation pattern and the velocity power law. The effect of geometry and turbulent flow distribution on the acoustic emission from simple configurations are discussed.

  13. Elastic properties of boron carbide films via surface acoustic waves measured by Brillouin light scattering

    Energy Technology Data Exchange (ETDEWEB)

    Salas, E.; Jimenez-Villacorta, F.; Jimenez Rioboo, R.J.; Prieto, C. [Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Cientificas, Cantoblanco, 28049 Madrid (Spain); Sanchez-Marcos, J. [Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Cientificas, Cantoblanco, 28049 Madrid (Spain); Departamento de Quimica-Fisica Aplicada, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Munoz-Martin, A.; Prieto, J.E.; Joco, V. [Centro de Microanalisis de Materiales, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain)

    2013-03-15

    Surface acoustic wave (SAW) velocity has been determined by high resolution Brillouin light scattering to study the mechano-elastic properties of boron carbide films prepared by radio frequency (RF) sputtering. The comparison of experimentally observed elastic behaviour with simulations made by considering film composition obtained from elastic recoil detection analysis-time of flight (ERDA-ToF) spectroscopy allows establishing that elastic properties are determined by that of crystalline boron carbide with a lessening of the SAW velocity values due to surface oxidation. (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  14. Efficient Solution of Three-Dimensional Problems of Acoustic and Electromagnetic Scattering by Open Surfaces

    Science.gov (United States)

    Turc, Catalin; Anand, Akash; Bruno, Oscar; Chaubell, Julian

    2011-01-01

    We present a computational methodology (a novel Nystrom approach based on use of a non-overlapping patch technique and Chebyshev discretizations) for efficient solution of problems of acoustic and electromagnetic scattering by open surfaces. Our integral equation formulations (1) Incorporate, as ansatz, the singular nature of open-surface integral-equation solutions, and (2) For the Electric Field Integral Equation (EFIE), use analytical regularizes that effectively reduce the number of iterations required by iterative linear-algebra solution based on Krylov-subspace iterative solvers.

  15. Holography with surface plasma waves

    Science.gov (United States)

    Cowan, J. J.

    1976-01-01

    New technique utilizes reflection-type diffraction grating of type generally used in grating spectrometers. Grating is coated with thin layer of high-resolution recording medium, having absorption coefficient low enough to prevent incident light absorption before it is reflected by metal layer.

  16. Effect of transverse electron drift on absorption of surface acoustic waves in CdS

    International Nuclear Information System (INIS)

    Kmita, A.M.; Medved', A.V.; Fedorets, V.N.

    1976-01-01

    The effect of the transverse electron drift on acousto-electron interaction in CdS has been studied. It has been revealed that the free electron drift only in the direction normal to the plane of propagation of surface acoustic waves may change the sound electron absorption coefficient in a wide range. In the case of metallization of the active part of a crystal surface a decrease in sound absorption has been observed both on the electron drift to a working crystal surface and on the opposite direction. Whereas in the case of a free crystal surface the transverse electron drift directed to the working plate surface causes an increase in sound absorption, and with the opposite drift electron absorption of the Rayleigh ultrasound waves is almost not observed. An explanation of the effects observed is proposed

  17. Particle Separation inside a Sessile Droplet with Variable Contact Angle Using Surface Acoustic Waves.

    Science.gov (United States)

    Destgeer, Ghulam; Jung, Jin Ho; Park, Jinsoo; Ahmed, Husnain; Sung, Hyung Jin

    2017-01-03

    A sessile droplet of water carrying polystyrene microparticles of different diameters was uniformly exposed to high frequency surface acoustic waves (SAWs) produced by an interdigitated transducer (IDT). We investigated the concentration behavior of the microparticles as the SAWs generated a strong acoustic streaming flow (ASF) inside the water droplet and exerted a direct acoustic radiation force (ARF) on the suspended particles, the magnitude of which depended upon the particle diameter. As a result of the ARF, the microparticles were concentrated according to their diameters at different positions inside the sessile droplet placed in the path of the SAW, right in front of the IDT. The microparticle concentration behavior changed as the sessile droplet contact angle with the substrate was varied by adding surfactant to the water or by gradually evaporating the water. The positions at which the smaller and larger microparticles were concentrated remained distinguishable, even at very different experimental conditions. The long-term exposure of the droplets to the SAWs was accompanied by the gradual evaporation of the carrier fluid, which dynamically changed the droplet contact angle as well as the concentration of particles. Complete evaporation of the fluid left behind several concentrated yet separated clusters of particles on the substrate surface. The effect of the droplet contact angle on particles' concentration behavior and consequent separation of particles has been uniquely studied in this SAW-based report.

  18. Split-illumination electron holography

    International Nuclear Information System (INIS)

    Tanigaki, Toshiaki; Aizawa, Shinji; Suzuki, Takahiro; Park, Hyun Soon; Inada, Yoshikatsu; Matsuda, Tsuyoshi; Taniyama, Akira; Shindo, Daisuke; Tonomura, Akira

    2012-01-01

    We developed a split-illumination electron holography that uses an electron biprism in the illuminating system and two biprisms (applicable to one biprism) in the imaging system, enabling holographic interference micrographs of regions far from the sample edge to be obtained. Using a condenser biprism, we split an electron wave into two coherent electron waves: one wave is to illuminate an observation area far from the sample edge in the sample plane and the other wave to pass through a vacuum space outside the sample. The split-illumination holography has the potential to greatly expand the breadth of applications of electron holography.

  19. Musique et holographie

    OpenAIRE

    Vach, Holger

    2010-01-01

    Introduction L’holographie est surtout connue pour son rendu esthétique dans l’enregistrement d’images en trois dimensions. Cependant, dans le contexte des mesures scientifiques, elle joue souvent le rôle d’un instrument à la fois précis et simple d’emploi, par exemple pour les mesures de tout petits déplacements, ou de changements d’index de réfraction, ou bien d’amplitudes de vibration. Dans ce dernier cas, l’hologramme d’un objet en vibration présente l’objet en trois dimensions superposé ...

  20. Holography gets smart

    Science.gov (United States)

    Lowe, Chris; Larbey, Cynthia

    2008-02-01

    At least 6% of world trade, amounting to some 200bn per year, involves counterfeit goods. But this figure would be even higher were it not for the humble hologram. Invented 50 years ago, holograms provide authentication tags to deter copying, and can be found everywhere from credit cards, passports and banknotes to consumer goods, cosmetics and pharmaceuticals. Holography also underpins supermarket scanners and CD players; it can even be used to store optical data in 3D. Now, however, holograms are making their mark as powerful yet cheap diagnostic tools, which could in particular have many applications in biomedicine.

  1. Adaptive Optical Scanning Holography

    Science.gov (United States)

    Tsang, P. W. M.; Poon, Ting-Chung; Liu, J.-P.

    2016-01-01

    Optical Scanning Holography (OSH) is a powerful technique that employs a single-pixel sensor and a row-by-row scanning mechanism to capture the hologram of a wide-view, three-dimensional object. However, the time required to acquire a hologram with OSH is rather lengthy. In this paper, we propose an enhanced framework, which is referred to as Adaptive OSH (AOSH), to shorten the holographic recording process. We have demonstrated that the AOSH method is capable of decreasing the acquisition time by up to an order of magnitude, while preserving the content of the hologram favorably. PMID:26916866

  2. Single-drop liquid phase microextraction accelerated by surface acoustic wave.

    Science.gov (United States)

    Zhang, Anliang; Zha, Yan

    2013-03-01

    A single-drop liquid phase microextraction method is presented, in which surface acoustic wave (SAW) is used for accelerating extraction speed. A pair of interdigital transducers with 27.5 MHz center frequency is fabricated on a 128° yx-LiNbO3 substrate. A radio frequency signal is applied to one of interdigital transducers to excite SAW. Plastic straw is filled with PDMS, leaving 1 mL for holding sample solution. Plastic straw with sample solution droplet is then dipping into extractant, into which SAW is radiated. Mass transportation from sample solution to extractant drop is accelerated due to acoustic streaming, and extraction time is decreased. An ionic liquid and an acid green-25 solution are used for extraction experiments. Results show that the extraction process is almost finished within 2 min, and extraction speed is increased with radio frequency signal power. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Estimating sub-surface dispersed oil concentration using acoustic backscatter response.

    Science.gov (United States)

    Fuller, Christopher B; Bonner, James S; Islam, Mohammad S; Page, Cheryl; Ojo, Temitope; Kirkey, William

    2013-05-15

    The recent Deepwater Horizon disaster resulted in a dispersed oil plume at an approximate depth of 1000 m. Several methods were used to characterize this plume with respect to concentration and spatial extent including surface supported sampling and autonomous underwater vehicles with in situ instrument payloads. Additionally, echo sounders were used to track the plume location, demonstrating the potential for remote detection using acoustic backscatter (ABS). This study evaluated use of an Acoustic Doppler Current Profiler (ADCP) to quantitatively detect oil-droplet suspensions from the ABS response in a controlled laboratory setting. Results from this study showed log-linear ABS responses to oil-droplet volume concentration. However, the inability to reproduce ABS response factors suggests the difficultly in developing meaningful calibration factors for quantitative field analysis. Evaluation of theoretical ABS intensity derived from the particle size distribution provided insight regarding method sensitivity in the presence of interfering ambient particles. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Computer holography as an application of computational optics

    Science.gov (United States)

    Matsushima, Kyoji; Nakahara, Sumio

    2015-09-01

    Several techniques are reviewed in high-definition computer holography. These techniques are based on numerical techniques in wave optics. For example, the polygon-based method based on propagation between tilted planes is used for calculating the field of polygonal surface sources of light. Numerical propagation of large-scaled field is also implemented by using the technique of off-axis propagation. The silhouette method for occlusion processing is based on the angular spectrum method for propagation between parallel planes. The relation between computer holography and computational optics are presented and several high-definition CGHs using these techniques are demonstrated for verifying the techniques.

  5. When is holography consistent?

    Directory of Open Access Journals (Sweden)

    Brett McInnes

    2015-09-01

    Full Text Available Holographic duality relates two radically different kinds of theory: one with gravity, one without. The very existence of such an equivalence imposes strong consistency conditions which are, in the nature of the case, hard to satisfy. Recently a particularly deep condition of this kind, relating the minimum of a probe brane action to a gravitational bulk action (in a Euclidean formulation, has been recognized; and the question arises as to the circumstances under which it, and its Lorentzian counterpart, is satisfied. We discuss the fact that there are physically interesting situations in which one or both versions might, in principle, not be satisfied. These arise in two distinct circumstances: first, when the bulk is not an Einstein manifold and, second, in the presence of angular momentum. Focusing on the application of holography to the quark–gluon plasma (of the various forms arising in the early Universe and in heavy-ion collisions, we find that these potential violations never actually occur. This suggests that the consistency condition is a “law of physics” expressing a particular aspect of holography.

  6. Holography of Little Inflation

    Directory of Open Access Journals (Sweden)

    Brett McInnes

    2015-05-01

    Full Text Available For several crucial microseconds of its early history, the Universe consisted of a Quark–Gluon Plasma. As it cooled during this era, it traced out a trajectory in the quark matter phase diagram. The form taken by this trajectory is not known with certainty, but is of great importance: it determines, for example, whether the cosmic plasma passed through a first-order phase change during the transition to the hadron era, as has recently been suggested by advocates of the “Little Inflation” model. Just before this transition, the plasma was strongly coupled and therefore can be studied by holographic techniques. We show that holography imposes a strong constraint (taking the form of a bound on the baryonic chemical potential relative to the temperature on the domain through which the cosmic plasma could pass as it cooled, with important consequences for Little Inflation. In fact, we find that holography applied to Little Inflation implies that the cosmic plasma must have passed quite close to the quark matter critical point, and might therefore have been affected by the associated fluctuation phenomena.

  7. Surface Acoustic Wave (SAW-Enhanced Chemical Functionalization of Gold Films

    Directory of Open Access Journals (Sweden)

    Gina Greco

    2017-10-01

    Full Text Available Surface chemical and biochemical functionalization is a fundamental process that is widely applied in many fields to add new functions, features, or capabilities to a material’s surface. Here, we demonstrate that surface acoustic waves (SAWs can enhance the chemical functionalization of gold films. This is shown by using an integrated biochip composed by a microfluidic channel coupled to a surface plasmon resonance (SPR readout system and by monitoring the adhesion of biotin-thiol on the gold SPR areas in different conditions. In the case of SAW-induced streaming, the functionalization efficiency is improved ≈ 5 times with respect to the case without SAWs. The technology here proposed can be easily applied to a wide variety of biological systems (e.g., proteins, nucleic acids and devices (e.g., sensors, devices for cell cultures.

  8. Nanostructure-Enhanced Surface Acoustic Waves Biosensor and Its Computational Modeling

    Directory of Open Access Journals (Sweden)

    Guigen Zhang

    2009-01-01

    Full Text Available Surface acoustic wave (SAW devices are considered to be very promising in providing a high-performance sensing platform with wireless and remote operational capabilities. In this review, the basic principles of SAW devices and Love-mode SAW-based biosensors are discussed first to illustrate the need for surface enhancement for the active area of a SAW sensor. Then some of the recent efforts made to incorporate nanostructures into SAW sensors are summarized. After that, a computational approach to elucidate the underlying mechanism for the operations of a Love-mode SAW biosensor with nanostructured active surface is discussed. Finally, a modeling example for a Love-mode SAW sensor with skyscraper nanopillars added to in its active surface along with some selected results is presented.

  9. Atomic imaging by x-ray-fluorescence holography and electron-emission holography: A comparative theoretical study

    International Nuclear Information System (INIS)

    Len, P.M.; Thevuthasan, S.; Fadley, C.S.; Kaduwela, A.P.; Van Hove, M.A.

    1994-01-01

    We consider from a theoretical viewpoint the direct imaging of atoms at and near the surfaces of solids by both x-ray-fluorescence holography (XFH) and electron-emission holography (EEH). The more ideal nature of x-ray scattering makes XFH images superior to those in single-energy EEH. The overlap of real and twin features for pairs of atoms at ±a can cause their XFH or EEH atomic images to cancel for certain combinations of wave vector and |a|. The relative merits of XFH and EEH for structure studies are considered

  10. Holography for fast reactor inspection

    International Nuclear Information System (INIS)

    Tozer, B.A.

    1980-01-01

    Holography, an optical process whereby an image of the original subject can be reconstructed in three dimensions, is being developed for use as an optical inspection tool. With a potential information storage density of 10 16 bits/m 2 , the ability to reconstruct in 3 dimensions, a depth of field of up to 8 metres, extremely wide angle of view, and potentially diffraction limited resolution, holography should be invaluable for the optical recording of fast reactors during construction, and the inspection of optically accessible regions during operation, or maintenance down-times. The photographic emulsions used for high resolution holography are fine-grained and fog only very slowly when subjected to γ-radiation, so that inspection of highly radio-active regions and components can be effected satisfactorily. Some of the practical limitations affecting holography are described and ways of overcoming them discussed. Some preliminary results are presented. (author)

  11. Holography Experiments on Optical Imaging.

    Science.gov (United States)

    Bonczak, B.; Dabrowski, J.

    1979-01-01

    Describes experiments intended to produce a better understanding of the holographic method of producing images and optical imaging by other optical systems. Application of holography to teaching physics courses is considered. (Author/SA)

  12. A Finite Element Model of a MEMS-based Surface Acoustic Wave Hydrogen Sensor

    Directory of Open Access Journals (Sweden)

    Walied A. Moussa

    2010-02-01

    Full Text Available Hydrogen plays a significant role in various industrial applications, but careful handling and continuous monitoring are crucial since it is explosive when mixed with air. Surface Acoustic Wave (SAW sensors provide desirable characteristics for hydrogen detection due to their small size, low fabrication cost, ease of integration and high sensitivity. In this paper a finite element model of a Surface Acoustic Wave sensor is developed using ANSYS12© and tested for hydrogen detection. The sensor consists of a YZ-lithium niobate substrate with interdigital electrodes (IDT patterned on the surface. A thin palladium (Pd film is added on the surface of the sensor due to its high affinity for hydrogen. With increased hydrogen absorption the palladium hydride structure undergoes a phase change due to the formation of the β-phase, which deteriorates the crystal structure. Therefore with increasing hydrogen concentration the stiffness and the density are significantly reduced. The values of the modulus of elasticity and the density at different hydrogen concentrations in palladium are utilized in the finite element model to determine the corresponding SAW sensor response. Results indicate that with increasing the hydrogen concentration the wave velocity decreases and the attenuation of the wave is reduced.

  13. Using the acoustic-pulse conservation law in estimating the energy of surface acoustic sources by remote sounding

    Science.gov (United States)

    Kulichkov, S. N.; Popov, O. Ye.; Mishenin, A. A.; Chunchuzov, I. P.; Chkhetiani, O. G.; Tsybulskaya, N. D.

    2017-11-01

    The atmospheric effect on the characteristics of infrasonic signals from explosions has been studied. New methods have been proposed to remotely estimate the energy of explosions using the data of infrasonic wave registration. One method is based on the law of conservation of acoustic pulse I, which is equal to the product of the wave profile area S/2 of the studied infrasonic signal and the distance to the source E I [kt] = 1.38 × 10-10 (I [kg/s])1.482. The second method is based on the relationship between the explosion energy and the dominant period T of the recorded signal, ET [kt] =1.02 × ( T [s]2/σ)3/2, where σ is a dimensionless distance used for determining the degree of manifestation of nonlinear effects in the propagation of sound along ray trajectories. When compared to the conventional E W (Whitaker's) relation, the advantage of the EI relation is that it can be used for pulsed sources located at an arbitrary height over the land surface and having an arbitrary form of the initial-pulse profile and for any type of infrasonic arrivals. A distinctive feature of the expression for E T is that the atmospheric effect on the characteristics of recorded infrasonic signals is explicitly taken into account. These methods have been tested using infrasonic data recorded at a distance of 322 km from the sources (30 explosions caused by a fire that occurred at the Pugachevo armory in Udmurtia on June 2, 2011). For the same explosion, empirical relations have been found between energy values obtained by different methods: E I = 1.107 × E W , E T = 2.201 × E I .

  14. An on-chip, multichannel droplet sorter using standing surface acoustic waves (SSAW)

    Science.gov (United States)

    Li, Sixing; Ding, Xiaoyun; Guo, Feng; Chen, Yuchao; Lapsley, Michael Ian; Lin, Sz-Chin Steven; Wang, Lin; McCoy, J. Philip; Cameron, Craig E.; Huang, Tony Jun

    2014-01-01

    The emerging field of droplet microfluidics requires effective on-chip handling and sorting of droplets. In this work, we demonstrate a microfluidic device that is capable of sorting picoliter water-in-oil droplets into multiple outputs using standing surface acoustic waves (SSAW). This device integrates a single-layer microfluidic channel with interdigital transducers (IDTs) to achieve on-chip droplet generation and sorting. Within the SSAW field, water-in-oil droplets experience an acoustic radiation force and are pushed towards the acoustic pressure node. As a result, by tuning the frequency of the SSAW excitation, the position of the pressure nodes can be changed and droplets can be sorted to different outlets at rates up to 222 droplets s−1. With its advantages in simplicity, controllability, versatility, non-invasiveness, and capability to be integrated with other on-chip components such as droplet manipulation and optical detection units, the technique presented here could be valuable for the development of droplet-based micro total analysis systems (μTAS). PMID:23647057

  15. An on-chip, multichannel droplet sorter using standing surface acoustic waves.

    Science.gov (United States)

    Li, Sixing; Ding, Xiaoyun; Guo, Feng; Chen, Yuchao; Lapsley, Michael Ian; Lin, Sz-Chin Steven; Wang, Lin; McCoy, J Philip; Cameron, Craig E; Huang, Tony Jun

    2013-06-04

    The emerging field of droplet microfluidics requires effective on-chip handling and sorting of droplets. In this work, we demonstrate a microfluidic device that is capable of sorting picoliter water-in-oil droplets into multiple outputs using standing surface acoustic waves (SSAW). This device integrates a single-layer microfluidic channel with interdigital transducers (IDTs) to achieve on-chip droplet generation and sorting. Within the SSAW field, water-in-oil droplets experience an acoustic radiation force and are pushed toward the acoustic pressure node. As a result, by tuning the frequency of the SSAW excitation, the position of the pressure nodes can be changed and droplets can be sorted to different outlets at rates up to 222 droplets s(-1). With its advantages in simplicity, controllability, versatility, noninvasiveness, and capability to be integrated with other on-chip components such as droplet manipulation and optical detection units, the technique presented here could be valuable for the development of droplet-based micro total analysis systems (μTAS).

  16. Surface Acoustic WaveAmmonia Sensors Based on ST-cut Quartz under Periodic Al Structure

    Directory of Open Access Journals (Sweden)

    Ming-Yau Su

    2009-02-01

    Full Text Available Surface acoustic wave (SAW devices are key components for sensing applications. SAW propagation under a periodic grating was investigated in this work. The theoretical method used here is the space harmonic method. We also applied the results of SAW propagation studied in this work to design a two-port resonator with an Al grating on ST-cut quartz. The measured frequency responses of the resonator were similar to the simulation ones. Then, the chemical interface of polyaniline/WO3 composites was coated on the SAW sensor for ammonia detection. The SAW sensor responded to ammonia gas and could be regenerated using dry nitrogen.

  17. Surface acoustic wave sensors with Graphene/PANI nanocomposites for nitric oxide detection

    Science.gov (United States)

    Wang, Beibei; Zheng, Lei; Zhou, Lingling

    2017-12-01

    Surface acoustic wave sensors with grapheme/PANI nanocomposite sensitive films for detecting nitric oxide (NO) were fabricated and experimentally studied. Morphological characterization and functionalization of the sensing material were explored using SEM and FTIR, respectively. The study of sensor response compared film sensitivity, response time, reversibility, and limit of detection for nanocomposite films, pure grapheme and pure PANI to the detection of NO. The response and recovery times were 40s and 20s when detecting 4ppm NO, respectively. The frequency response was discovered to be linear in the NO concentration range 1-50 ppm. The nanocomposite sensors had improved sensitivities compared to the polymer devices, and better response times.

  18. Surface acoustic wave opto-mechanical oscillator and frequency comb generator.

    Science.gov (United States)

    Savchenkov, A A; Matsko, A B; Ilchenko, V S; Seidel, D; Maleki, L

    2011-09-01

    We report on realization of an efficient triply resonant coupling between two long lived optical modes and a high frequency surface acoustic wave (SAW) mode of the same monolithic crystalline whispering gallery mode resonator. The coupling results in an opto-mechanical oscillation and generation of a monochromatic SAW. A strong nonlinear interaction of this mechanical mode with other equidistant SAW modes leads to mechanical hyperparametric oscillation and generation of a SAW pulse train and associated frequency comb in the resonator. We visualized the comb by observing the modulation of the light escaping the resonator.

  19. Laser-generated surface acoustic waves in a ring-shaped waveguide resonator.

    Science.gov (United States)

    Maznev, A A

    2009-01-01

    Surface acoustic wave (SAW) waveguide resonator is formed by a ring-shaped strip of copper 10 microm wide and approximately 130 microm in diameter embedded into a 0.8 microm thick layer of silica on a silicon wafer. SAWs are excited at one side of the copper ring by a short laser pulse focused into a spatially periodic pattern and detected via diffraction of the probe laser beam overlapped with the excitation spot. SAW wavepackets with central frequency 460 MHz travel around the ring and are detected each time they make a full circle and pass trough the probe spot. Potential applications of ring resonators for SAWs are discussed.

  20. AlScN thin film based surface acoustic wave devices with enhanced microfluidic performance

    OpenAIRE

    Wang, Wenbo; Fu, Yong Qing; Chen, Jinju; Xuan, Weipeng; Chen, Jinkai; Mayrhofer, Paul; Duan, Pengfei; Bittner, Elmar; Luo, Jikui

    2016-01-01

    This paper reports the characterization of scandium aluminum nitride (Al1−x Sc x N, x  =  27%) films and discusses surface acoustic wave (SAW) devices based on them. Both AlScN and AlN films were deposited on silicon by sputtering and possessed columnar microstructures with (0 0 0 2) crystal orientation. The AlScN/Si SAW devices showed improved electromechanical coupling coefficients (K 2, ~2%) compared with pure AlN films (

  1. Optimization of autonomous magnetic field sensor consisting of giant magnetoimpedance sensor and surface acoustic wave transducer

    KAUST Repository

    Li, Bodong

    2012-11-01

    This paper presents a novel autonomous thin film magnetic field sensor consisting of a tri-layer giant magnetoimpedance sensor and a surface acoustic wave transponder. Double and single electrode interdigital transducer (IDT) designs are employed and compared. The integrated sensor is fabricated using standard microfabrication technology. The results show the double electrode IDT has an advantage in terms of the sensitivity. In order to optimize the matching component, a simulation based on P-matrix is carried out. A maximum change of 2.4 dB of the reflection amplitude and a sensitivity of 0.34 dB/Oe are obtained experimentally. © 2012 IEEE.

  2. Biosonar resolving power: Echo-acoustic perception of surface structures in the submillimeter range

    Directory of Open Access Journals (Sweden)

    Ralph eSimon

    2014-02-01

    Full Text Available The minimum distance for which two points still can be separated from each other defines the resolving power of a visual system. In an echo-acoustic context, the resolving power is usually measured as the smallest perceivable distance of two reflecting surfaces on the range axis and is found to be around half a millimetre for bats employing frequency modulated echolocation calls. Only few studies measured such thresholds with physical objects, most often bats were trained on virtual echoes i.e. echoes generated and played back by a computer; moreover, bats were sitting while they received the stimuli. In these studies differences in structure depth between 200 µm and 340 µm were found. However, these low thresholds were never verified for free-flying bats and real physical objects. Here, we show behavioural evidence that the echo-acoustic resolving power for surface structures in fact can be as low as measured for computer generated echoes and even lower, sometimes below 100 µm. We found this exceptional fine discrimination ability only when one of the targets showed spectral interferences in the frequency range of the bats' echolocation call while the other target did not. This result indicates that surface structure is likely to be perceived as a spectral quality rather than being perceived strictly in the time domain. Further, it points out that sonar resolving power directly depends on the highest frequency/shortest wavelength of the signal employed.

  3. Medical Holography for Basic Anatomy Training

    Science.gov (United States)

    2013-12-01

    2.5D representation to a 3D representation within working memory. A unique technological solution to achieve this uses holography to present the...including the medical holography research and virtual patient research efforts. As a science and technology manager, he oversees these research efforts and...A unique technological solution to achieve this uses holography to present the medical content. Holography allows the user to view fully parallax

  4. Infrared beam-steering using acoustically modulated surface plasmons over a graphene monolayer

    KAUST Repository

    Chen, Paiyen

    2014-09-01

    We model and design a graphene-based infrared beamformer based on the concept of leaky-wave (fast traveling wave) antennas. The excitation of infrared surface plasmon polaritons (SPPs) over a \\'one-atom-thick\\' graphene monolayer is typically associated with intrinsically \\'slow light\\'. By modulating the graphene with elastic vibrations based on flexural waves, a dynamic diffraction grating can be formed on the graphene surface, converting propagating SPPs into fast surface waves, able to radiate directive infrared beams into the background medium. This scheme allows fast on-off switching of infrared emission and dynamic tuning of its radiation pattern, beam angle and frequency of operation, by simply varying the acoustic frequency that controls the effective grating period. We envision that this graphene beamformer may be integrated into reconfigurable transmitter/receiver modules, switches and detectors for THz and infrared wireless communication, sensing, imaging and actuation systems.

  5. Forward and inverse problems for surface acoustic waves in anisotropic media: A Ritz-Rayleigh method based approach

    Czech Academy of Sciences Publication Activity Database

    Stoklasová, Pavla; Sedlák, Petr; Seiner, Hanuš; Landa, Michal

    2015-01-01

    Roč. 56, February 2015 (2015), s. 381-389 ISSN 0041-624X R&D Projects: GA ČR GPP101/12/P428 Institutional support: RVO:61388998 Keywords : surface acoustic waves * anisotropic materials * Ritz-Rayleigh method * inverse problem Subject RIV: BI - Acoustics Impact factor: 1.954, year: 2015 http://www.sciencedirect.com/science/article/pii/S0041624X14002686

  6. Intraoperative brain tumor resection cavity characterization with conoscopic holography

    Science.gov (United States)

    Simpson, Amber L.; Burgner, Jessica; Chen, Ishita; Pheiffer, Thomas S.; Sun, Kay; Thompson, Reid C.; Webster, Robert J., III; Miga, Michael I.

    2012-02-01

    Brain shift compromises the accuracy of neurosurgical image-guided interventions if not corrected by either intraoperative imaging or computational modeling. The latter requires intraoperative sparse measurements for constraining and driving model-based compensation strategies. Conoscopic holography, an interferometric technique that measures the distance of a laser light illuminated surface point from a fixed laser source, was recently proposed for non-contact surface data acquisition in image-guided surgery and is used here for validation of our modeling strategies. In this contribution, we use this inexpensive, hand-held conoscopic holography device for intraoperative validation of our computational modeling approach to correcting for brain shift. Laser range scan, instrument swabbing, and conoscopic holography data sets were collected from two patients undergoing brain tumor resection therapy at Vanderbilt University Medical Center. The results of our study indicate that conoscopic holography is a promising method for surface acquisition since it requires no contact with delicate tissues and can characterize the extents of structures within confined spaces. We demonstrate that for two clinical cases, the acquired conoprobe points align with our model-updated images better than the uncorrected images lending further evidence that computational modeling approaches improve the accuracy of image-guided surgical interventions in the presence of soft tissue deformations.

  7. Surface Acoustic Bloch Oscillations, the Wannier-Stark Ladder, and Landau-Zener Tunneling in a Solid

    Science.gov (United States)

    de Lima, M. M., Jr.; Kosevich, Yu. A.; Santos, P. V.; Cantarero, A.

    2010-04-01

    We present the experimental observation of Bloch oscillations, the Wannier-Stark ladder, and Landau-Zener tunneling of surface acoustic waves in perturbed grating structures on a solid substrate. A model providing a quantitative description of our experimental observations, including multiple Landau-Zener transitions of the anticrossed surface acoustic Wannier-Stark states, is developed. The use of a planar geometry for the realization of the Bloch oscillations and Landau-Zener tunneling allows a direct access to the elastic field distribution. The vertical surface displacement has been measured by interferometry.

  8. Acoustic cloaking and transformation acoustics

    Energy Technology Data Exchange (ETDEWEB)

    Chen Huanyang [School of Physical Science and Technology, Soochow University, Suzhou, Jiangsu 215006 (China); Chan, C T, E-mail: kenyon@ust.h, E-mail: phchan@ust.h [Department of Physics and the William Mong Institute of NanoScience and Technology, The Hong Kong University of Science and Technology, Clear Water Bay (Hong Kong)

    2010-03-24

    In this review, we give a brief introduction to the application of the new technique of transformation acoustics, which draws on a correspondence between coordinate transformation and material properties. The technique is formulated for both acoustic waves and linear liquid surface waves. Some interesting conceptual devices can be designed for manipulating acoustic waves. For example, we can design acoustic cloaks that make an object invisible to acoustic waves, and the cloak can either encompass or lie outside the object to be concealed. Transformation acoustics, as an analog of transformation optics, can go beyond invisibility cloaking. As an illustration for manipulating linear liquid surface waves, we show that a liquid wave rotator can be designed and fabricated to rotate the wave front. The acoustic transformation media require acoustic materials which are anisotropic and inhomogeneous. Such materials are difficult to find in nature. However, composite materials with embedded sub-wavelength resonators can in principle be made and such 'acoustic metamaterials' can exhibit nearly arbitrary values of effective density and modulus tensors to satisfy the demanding material requirements in transformation acoustics. We introduce resonant sonic materials and Helmholtz resonators as examples of acoustic metamaterials that exhibit resonant behaviour in effective density and effective modulus. (topical review)

  9. Advanced Electron Holography Applied to Electromagnetic Field Study in Materials Science.

    Science.gov (United States)

    Shindo, Daisuke; Tanigaki, Toshiaki; Park, Hyun Soon

    2017-07-01

    Advances and applications of electron holography to the study of electromagnetic fields in various functional materials are presented. In particular, the development of split-illumination electron holography, which introduces a biprism in the illumination system of a holography electron microscope, enables highly accurate observations of electromagnetic fields and the expansion of the observable area. First, the charge distributions on insulating materials were studied by using split-illumination electron holography and including a mask in the illumination system. Second, the three-dimensional spin configurations of skyrmion lattices in a helimagnet were visualized by using a high-voltage holography electron microscope. Third, the pinning of the magnetic flux lines in a high-temperature superconductor YBa 2 Cu 3 O 7-y was analyzed by combining electron holography and scanning ion microscopy. Finally, the dynamic accumulation and collective motions of electrons around insulating biomaterial surfaces were observed by utilizing the amplitude reconstruction processes of electron holography. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Direct imaging of delayed magneto-dynamic modes induced by surface acoustic waves.

    Science.gov (United States)

    Foerster, Michael; Macià, Ferran; Statuto, Nahuel; Finizio, Simone; Hernández-Mínguez, Alberto; Lendínez, Sergi; Santos, Paulo V; Fontcuberta, Josep; Hernàndez, Joan Manel; Kläui, Mathias; Aballe, Lucia

    2017-09-01

    The magnetoelastic effect-the change of magnetic properties caused by the elastic deformation of a magnetic material-has been proposed as an alternative approach to magnetic fields for the low-power control of magnetization states of nanoelements since it avoids charge currents, which entail ohmic losses. Here, we have studied the effect of dynamic strain accompanying a surface acoustic wave on magnetic nanostructures in thermal equilibrium. We have developed an experimental technique based on stroboscopic X-ray microscopy that provides a pathway to the quantitative study of strain waves and magnetization at the nanoscale. We have simultaneously imaged the evolution of both strain and magnetization dynamics of nanostructures at the picosecond time scale and found that magnetization modes have a delayed response to the strain modes, adjustable by the magnetic domain configuration. Our results provide fundamental insight into magnetoelastic coupling in nanostructures and have implications for the design of strain-controlled magnetostrictive nano-devices.Understanding the effects of local dynamic strain on magnetization may help the development of magnetic devices. Foerster et al. demonstrate stroboscopic imaging that allows the observation of both strain and magnetization dynamics in nickel when surface acoustic waves are driven in the substrate.

  11. Passive wireless surface acoustic wave sensors for monitoring sequestration sites CO2 emission

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yizhong [Univ. of Pittsburgh, PA (United States); Chyu, Minking [Univ. of Pittsburgh, PA (United States); Wang, Qing-Ming [Univ. of Pittsburgh, PA (United States)

    2013-02-14

    University of Pittsburgh’s Transducer lab has teamed with the U.S. Department of Energy’s National Energy Technology Laboratory (DOE NETL) to conduct a comprehensive study to develop/evaluate low-cost, efficient CO2 measuring technologies for geological sequestration sites leakage monitoring. A passive wireless CO2 sensing system based on surface acoustic wave technology and carbon nanotube nanocomposite was developed. Surface acoustic wave device was studied to determine the optimum parameters. Delay line structure was adopted as basic sensor structure. CNT polymer nanocomposite was fabricated and tested under different temperature and strain condition for natural environment impact evaluation. Nanocomposite resistance increased for 5 times under pure strain, while the temperature dependence of resistance for CNT solely was -1375ppm/°C. The overall effect of temperature on nanocomposite resistance was -1000ppm/°C. The gas response of the nanocomposite was about 10% resistance increase under pure CO2 . The sensor frequency change was around 300ppm for pure CO2 . With paralyne packaging, the sensor frequency change from relative humidity of 0% to 100% at room temperature decreased from over 1000ppm to less than 100ppm. The lowest detection limit of the sensor is 1% gas concentration, with 36ppm frequency change. Wireless module was tested and showed over one foot transmission distance at preferred parallel orientation.

  12. A high-performance lab-on-a-chip liquid sensor employing surface acoustic wave resonance

    Science.gov (United States)

    Kustanovich, K.; Yantchev, V.; Kirejev, V.; Jeffries, G. D. M.; Lobovkina, T.; Jesorka, A.

    2017-11-01

    We demonstrate herein a new concept for lab-on-a-chip in-liquid sensing, through integration of surface acoustic wave resonance (SAR) in a one-port configuration with a soft polymer microfluidic delivery system. In this concept, the reflective gratings of a one-port surface acoustic wave (SAW) resonator are employed as mass loading-sensing elements, while the SAW transducer is protected from the measurement environment. We describe the design, fabrication, implementation, and characterization using liquid medium. The sensor operates at a frequency of 185 MHz and has demonstrated a comparable sensitivity to other SAW in-liquid sensors, while offering quality factor (Q) value in water of about 250, low impedance and fairly low susceptibility to viscous damping. For proof of principle, sensing performance was evaluated by means of binding 40 nm neutravidin-coated SiO2 nanoparticles to a biotin-labeled lipid bilayer deposited over the reflectors. Frequency shifts were determined for every step of the affinity assay. Demonstration of this integrated technology highlights the potential of SAR technology for in-liquid sensing.

  13. Interferometric Correlator for Acoustic Radiation & Underlying Structural Vibration (ICARUSV), Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Current methods for identification of aircraft noise sources, such as near-field acoustical holography and beam forming techniques, involve the use of pressure...

  14. Interferometric Correlator for Acoustic Radiation & Underlying Structural Vibration (ICARUSV), Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Current methods for identification of aircraft noise sources, such as near-field acoustical holography and beam forming techniques, involve the use of pressure...

  15. Ion-driven instabilities of surface dust ion-acoustic waves in bounded plasma devices

    Science.gov (United States)

    Lee, Myoung-Jae; Jung, Young-Dae

    2018-02-01

    The growth rates of the dust ion-acoustic surface wave in the plasma slab device containing ion streaming passing through the stationary electrons and dusty grains at the speed of wave phase velocity are derived and numerically analyzed. We have found that the growth rates for the resonant symmetric and antisymmetric waves are similar to the case of semi-bounded plasma when we have a thick slab. However, in the case of the symmetric wave, the growth rate moves towards the bulk wave as the slab thickness reduces. In the case of the antisymmetric wave, the growth rate increases fast as the slab thickness decreases. The growth rates of surface waves in a plasma slab are compared with those of semi-bounded and bulk waves.

  16. Acoustic Source Localization in Aircraft Interiors Using Microphone Array Technologies

    Science.gov (United States)

    Sklanka, Bernard J.; Tuss, Joel R.; Buehrle, Ralph D.; Klos, Jacob; Williams, Earl G.; Valdivia, Nicolas

    2006-01-01

    Using three microphone array configurations at two aircraft body stations on a Boeing 777-300ER flight test, the acoustic radiation characteristics of the sidewall and outboard floor system are investigated by experimental measurement. Analysis of the experimental data is performed using sound intensity calculations for closely spaced microphones, PATCH Inverse Boundary Element Nearfield Acoustic Holography, and Spherical Nearfield Acoustic Holography. Each method is compared assessing strengths and weaknesses, evaluating source identification capability for both broadband and narrowband sources, evaluating sources during transient and steady-state conditions, and quantifying field reconstruction continuity using multiple array positions.

  17. Ethereal presences in holography and photography

    Science.gov (United States)

    Richardson, M.; Byrne, Kay

    2007-02-01

    This paper examines the concept of the 'Presence of Absence' in post-mortem photography and holography, drawing upon both historical and lesser-known images as reference. To create a photographic negative one needs the presence of light to expose the light sensitive surface, be it glass, a polished plate or plastic. A hologram may also be created when a coherent light source, for example from a Laser, travels through a light sensitive material and falls upon the subject to be recorded. A holograph however, retains the optical qualities of both phase and amplitude, the memory of light. Both mediums recall, as it were, 'now absent moments', and confronts us with what is 'not there' as much as 'what is'. This paper examines the exploration of absence and presence in post-mortem photography and holography and it's a richly visceral visual language. A photonic syntax can interpret death as an elegant yet horrific aesthetic, the photograph may be beautify screened and yet obscene in its content. In essence one can be a voyeur, experiencing a mere visual whisper of the true nature of the subject. Our Victorian forefathers explored postmortem photography as an object of mourning, and at the close of the nineteenth century when Jack the Ripper had the inhabitants of White Chapel in a grip of fear, photography made its mark as a documentation of violent crime. Today, within contemporary photography, death is now presented within the confines of the 'Art Gallery', as a sensual, and at times, sensationalised art form. In exploring post-mortem imagery, both in holography and conventional photography, absence presents an aspect of death as startling in its unanimated form and detailed in its finite examination of mortality.

  18. Fast evaluation of the Rayleigh integral and applications to inverse acoustics

    NARCIS (Netherlands)

    Wind, Jelmer; Wijnant, Ysbrand H.; de Boer, Andries

    2006-01-01

    In this paper we present a fast evaluation of the Rayleigh integral, which leads to fast and robust solutions in inverse acoustics. The method commonly used to reconstruct acoustic sources on a plane in space is Planar Nearfield Acoustic Holography (PNAH). Some of the most important recent

  19. Simultaneous Conoscopic Holography and Raman Spectroscopy

    Science.gov (United States)

    Schramm, Harry F.; Kaiser, Bruce

    2005-01-01

    A new instrument was developed for chemical characterization of surfaces that combines the analytical power of Raman spectroscopy with the three-dimensional topographic information provided by conoscopic holography. The figure schematically depicts the proposed hybrid instrument. The output of the conoscopic holographic portion of the instrument is a topographical map of the surface; the output of the Raman portion of the instrument is hyperspectral Raman data, from which the chemical and/or biological composition of the surface would be deduced. By virtue of the basic principles of design and operation of the instrument, the hyperspectral image data would be inherently spatially registered with the topographical data. In conoscopic holography, the object and reference beams of classical holography are replaced by the ordinary and extraordinary components generated by a single beam traveling through a birefringent, uniaxial crystal. In the basic conoscopic configuration, a laser light is projected onto a specimen and the resulting illuminated spot becomes a point source of diffuse light that propagates in every direction. The laser beam is rasterscanned in two dimensions (x and y) perpendicular to the beam axis (z), and at each x,y location, the pattern of interference between the ordinary and extraordinary rays is recorded. The recorded interferogram constitutes the conoscopic hologram. Of particular significance for the proposed instrument is that the conoscopic hologram contains information on the z coordinate (height) of the illuminated surface spot. Hence, a topographical map of the specimen is constructed point-by-point by rastering the laser beam in the x and y directions and correlating the x and y coordinates with the z information obtained from the interferograms. Conoscopic imaging is an established method, and conoscopic laboratory instruments for surface metrology are commercially available. In Raman spectroscopy of a surface, one measures the spectrum

  20. Holography in small bubble chambers

    International Nuclear Information System (INIS)

    Lecoq, P.

    1984-01-01

    This chapter reports on an experiment to determine the total charm cross section at different incident momenta using the small, heavy liquid bubble chamber HOBC. Holography in liquid hydrogen is also tested using the holographic lexan bubble chamber HOLEBC with the aim of preparing a future holographic experiment in hydrogen. The high intensity tests show that more than 100 incident tracks per hologram do not cause a dramatic effect on the picture quality. Hydrogen is more favorable than freon as the bubble growth is much slower in hydrogen. An advantage of holography is to have the maximum resolution in the full volume of the bubble chamber, which allows a gain in sensitivity by a factor of 10 compared to classical optics as 100 tracks per hologram look reasonable. Holograms are not more difficult to analyze than classical optics high-resolution pictures. The results show that holography is a very powerful technique which can be used in very high resolution particle physics experiments

  1. The Characterization of Surface Acoustic Wave Devices Based on AlN-Metal Structures

    Directory of Open Access Journals (Sweden)

    Lin Shu

    2016-04-01

    Full Text Available We report in this paper on the study of surface acoustic wave (SAW resonators based on an AlN/titanium alloy (TC4 structure. The AlN/TC4 structure with different thicknesses of AlN films was simulated, and the acoustic propagating modes were discussed. Based on the simulation results, interdigital transducers with a periodic length of 24 μm were patterned by lift-off photolithography techniques on the AlN films/TC4 structure, while the AlN film thickness was in the range 1.5–3.5 μm. The device performances in terms of quality factor (Q-factor and electromechanical coupling coefficient (k2 were determined from the measure S11 parameters. The Q-factor and k2 were strongly dependent not only on the normalized AlN film thickness but also on the full-width at half-maximum (FWHM of AlN (002 peak. The dispersion curve of the SAW phase velocity was analyzed, and the experimental results showed a good agreement with simulations. The temperature behaviors of the devices were also presented and discussed. The prepared SAW resonators based on AlN/TC4 structure have potential applications in integrated micromechanical sensing systems.

  2. Surface Acoustic Wave (SAW) for Chemical Sensing Applications of Recognition Layers †

    Science.gov (United States)

    2017-01-01

    Surface acoustic wave (SAW) resonators represent some of the most prominent acoustic devices for chemical sensing applications. As their frequency ranges from several hundred MHz to GHz, therefore they can record remarkably diminutive frequency shifts resulting from exceptionally small mass loadings. Their miniaturized design, high thermal stability and possibility of wireless integration make these devices highly competitive. Owing to these special characteristics, they are widely accepted as smart transducers that can be combined with a variety of recognition layers based on host-guest interactions, metal oxide coatings, carbon nanotubes, graphene sheets, functional polymers and biological receptors. As a result of this, there is a broad spectrum of SAW sensors, i.e., having sensing applications ranging from small gas molecules to large bio-analytes or even whole cell structures. This review shall cover from the fundamentals to modern design developments in SAW devices with respect to interfacial receptor coatings for exemplary sensor applications. The related problems and their possible solutions shall also be covered, with a focus on emerging trends and future opportunities for making SAW as established sensing technology. PMID:29186771

  3. Surface Acoustic Wave (SAW for Chemical Sensing Applications of Recognition Layers

    Directory of Open Access Journals (Sweden)

    Adnan Mujahid

    2017-11-01

    Full Text Available Surface acoustic wave (SAW resonators represent some of the most prominent acoustic devices for chemical sensing applications. As their frequency ranges from several hundred MHz to GHz, therefore they can record remarkably diminutive frequency shifts resulting from exceptionally small mass loadings. Their miniaturized design, high thermal stability and possibility of wireless integration make these devices highly competitive. Owing to these special characteristics, they are widely accepted as smart transducers that can be combined with a variety of recognition layers based on host-guest interactions, metal oxide coatings, carbon nanotubes, graphene sheets, functional polymers and biological receptors. As a result of this, there is a broad spectrum of SAW sensors, i.e., having sensing applications ranging from small gas molecules to large bio-analytes or even whole cell structures. This review shall cover from the fundamentals to modern design developments in SAW devices with respect to interfacial receptor coatings for exemplary sensor applications. The related problems and their possible solutions shall also be covered, with a focus on emerging trends and future opportunities for making SAW as established sensing technology.

  4. Revised model for the radiation force exerted by standing surface acoustic waves on a rigid cylinder

    Science.gov (United States)

    Liang, Shen; Chaohui, Wang

    2018-03-01

    In this paper, a model for the radiation force exerted by standing surface acoustic waves (SSAWs) on a rigid cylinder in inviscid fluids is extended to account for the dependence on the Rayleigh angle. The conventional model for the radiation force used in the SSAW-based applications is developed in plane standing waves, which fails to predict the movement of the cylinder in the SSAW. Our revised model reveals that, in the direction normal to the piezoelectric substrate on which the SSAW is generated, acoustic radiation force can be large enough to drive the cylinder even in the long-wavelength limit. Furthermore, the force in this direction can not only push the cylinder away, but also pull it back toward the substrate. In the direction parallel to the substrate, the equilibrium positions for particles can be actively tuned by changing Rayleigh angle. As an example considered in the paper, with the reduction of Rayleigh angle the equilibrium positions for steel cylinders in water change from pressure nodes to pressure antinodes. The model can thus be used in the design of SSAWs for particle manipulations.

  5. Hybridization approach to in-line and off-axis (electron) holography for superior resolution and phase sensitivity

    Science.gov (United States)

    Ozsoy-Keskinbora, C.; Boothroyd, C. B.; Dunin-Borkowski, R. E.; van Aken, P. A.; Koch, C. T.

    2014-01-01

    Holography - originally developed for correcting spherical aberration in transmission electron microscopes - is now used in a wide range of disciplines that involve the propagation of waves, including light optics, electron microscopy, acoustics and seismology. In electron microscopy, the two primary modes of holography are Gabor's original in-line setup and an off-axis approach that was developed subsequently. These two techniques are highly complementary, offering superior phase sensitivity at high and low spatial resolution, respectively. All previous investigations have focused on improving each method individually. Here, we show how the two approaches can be combined in a synergetic fashion to provide phase information with excellent sensitivity across all spatial frequencies, low noise and an efficient use of electron dose. The principle is also expected to be widely to applications of holography in light optics, X-ray optics, acoustics, ultra-sound, terahertz imaging, etc. PMID:25387480

  6. A Urinary Bcl-2 Surface Acoustic Wave Biosensor for Early Ovarian Cancer Detection

    Directory of Open Access Journals (Sweden)

    Nathan D. Gallant

    2012-05-01

    Full Text Available In this study, the design, fabrication, surface functionalization and experimental characterization of an ultrasonic MEMS biosensor for urinary anti-apoptotic protein B-cell lymphoma 2 (Bcl-2 detection with sub ng/mL sensitivity is presented. It was previously shown that urinary Bcl-2 levels are reliably elevated during early and late stages of ovarian cancer. Our biosensor uses shear horizontal (SH surface acoustic waves (SAWs on surface functionalized ST-cut Quartz to quantify the mass loading change by protein adhesion to the delay path. SH-SAWs were generated and received by a pair of micro-fabricated interdigital transducers (IDTs separated by a judiciously designed delay path. The delay path was surface-functionalized with monoclonal antibodies, ODMS, Protein A/G and Pluronic F127 for optimal Bcl-2 capture with minimal non-specific adsorption. Bcl-2 concentrations were quantified by the resulting resonance frequency shift detected by a custom designed resonator circuit. The target sensitivity for diagnosis and identifying the stage of ovarian cancer was successfully achieved with demonstrated Bcl-2 detection capability of 500 pg/mL. It was also shown that resonance frequency shift increases linearly with increasing Bcl-2 concentration.

  7. Silence on Shangri-La: Attenuation of Huygens acoustic signals suggests surface volatiles

    Science.gov (United States)

    Lorenz, Ralph D.; Leese, Mark R.; Hathi, Brijen; Zarnecki, John C.; Hagermann, Axel; Rosenberg, Phil; Towner, Martin C.; Garry, James; Svedhem, Håkan

    2014-01-01

    Objective. Characterize and understand acoustic instrument performance on the surface of Titan. Methods. The Huygens probe measured the speed of sound in Titan's atmosphere with a 1 MHz pulse time-of-flight transducer pair near the bottom of the vehicle. We examine the fraction of pulses correctly received as a function of time. Results. This system returned good data from about 11 km altitude, where the atmosphere became thick enough to effectively transmit the sound, down to the surface just before landing: these data have been analyzed previously. After an initial transient at landing, the instrument operated nominally for about 10 min, recording pulses much as during descent. The fraction of pulses detected then declined and the transmitted sound ceased to be detected altogether, despite no indication of instrument or probe configuration changes. Conclusions. The most likely explanation appears to be absorption of the signal by polyatomic gases with relaxation losses at the instrument frequency, such as ethane, acetylene and carbon dioxide. These vapors, detected independently by the GCMS instrument, were evolved from the surface material by the warmth leaking from the probe, and confirm the nature of the surface materials as 'damp' with a cocktail of volatile compounds. Some suggestions for future missions are considered. Practice implications. None.

  8. A method for the frequency control in time-resolved two-dimensional gigahertz surface acoustic wave imaging

    Directory of Open Access Journals (Sweden)

    Shogo Kaneko

    2014-01-01

    Full Text Available We describe an extension of the time-resolved two-dimensional gigahertz surface acoustic wave imaging based on the optical pump-probe technique with periodic light source at a fixed repetition frequency. Usually such imaging measurement may generate and detect acoustic waves with their frequencies only at or near the integer multiples of the repetition frequency. Here we propose a method which utilizes the amplitude modulation of the excitation pulse train to modify the generation frequency free from the mentioned limitation, and allows for the first time the discrimination of the resulted upper- and lower-side-band frequency components in the detection. The validity of the method is demonstrated in a simple measurement on an isotropic glass plate covered by a metal thin film to extract the dispersion curves of the surface acoustic waves.

  9. A method for the frequency control in time-resolved two-dimensional gigahertz surface acoustic wave imaging

    Science.gov (United States)

    Kaneko, Shogo; Tomoda, Motonobu; Matsuda, Osamu

    2014-01-01

    We describe an extension of the time-resolved two-dimensional gigahertz surface acoustic wave imaging based on the optical pump-probe technique with periodic light source at a fixed repetition frequency. Usually such imaging measurement may generate and detect acoustic waves with their frequencies only at or near the integer multiples of the repetition frequency. Here we propose a method which utilizes the amplitude modulation of the excitation pulse train to modify the generation frequency free from the mentioned limitation, and allows for the first time the discrimination of the resulted upper- and lower-side-band frequency components in the detection. The validity of the method is demonstrated in a simple measurement on an isotropic glass plate covered by a metal thin film to extract the dispersion curves of the surface acoustic waves.

  10. Holography inspired stringy hadrons

    Science.gov (United States)

    Sonnenschein, Jacob

    2017-01-01

    Holography inspired stringy hadrons (HISH) is a set of models that describe hadrons: mesons, baryons and glueballs as strings in flat four dimensional space-time. The models are based on a "map" from stringy hadrons of holographic confining backgrounds. In this note we review the "derivation" of the models. We start with a brief reminder of the passage from the AdS5 ×S5 string theory to certain flavored confining holographic models. We then describe the string configurations in holographic backgrounds that correspond to a Wilson line, a meson, a baryon and a glueball. The key ingredients of the four dimensional picture of hadrons are the "string endpoint mass" and the "baryonic string vertex". We determine the classical trajectories of the HISH. We review the current understanding of the quantization of the hadronic strings. We end with a summary of the comparison of the outcome of the HISH models with the PDG data about mesons and baryons. We extract the values of the tension, masses and intercepts from best fits, write down certain predictions for higher excited hadrons and present attempts to identify glueballs.

  11. Strong Coupling Holography

    CERN Document Server

    Dvali, Gia

    2009-01-01

    We show that whenever a 4-dimensional theory with N particle species emerges as a consistent low energy description of a 3-brane embedded in an asymptotically-flat (4+d)-dimensional space, the holographic scale of high-dimensional gravity sets the strong coupling scale of the 4D theory. This connection persists in the limit in which gravity can be consistently decoupled. We demonstrate this effect for orbifold planes, as well as for the solitonic branes and string theoretic D-branes. In all cases the emergence of a 4D strong coupling scale from bulk holography is a persistent phenomenon. The effect turns out to be insensitive even to such extreme deformations of the brane action that seemingly shield 4D theory from the bulk gravity effects. A well understood example of such deformation is given by large 4D Einstein term in the 3-brane action, which is known to suppress the strength of 5D gravity at short distances and change the 5D Newton's law into the four-dimensional one. Nevertheless, we observe that the ...

  12. Electron Holography: phases matter.

    Science.gov (United States)

    Lichte, Hannes

    2013-06-01

    Essentially, all optics is wave optics, be it with light, X-rays, neutrons or electrons. The information transfer from the object to the image can only be understood in terms of waves given by amplitude and phase. However, phases are difficult to measure: for slowly oscillating waves such as sound or low-frequency electromagnetic waves, phases can be measured directly; for high frequencies this has to be done by heterodyne detection, i.e. superposition with a reference and averaging over time. In optics, this is called interferometry. Because interference is mostly very difficult to achieve, phases have often been considered 'hidden variables' seemingly pulling the strings from backstage, only visible by their action on the image intensity. This was almost the case in conventional Electron Microscopy with the phase differences introduced by an object. However, in the face of the urgent questions from solid state physics and materials science, these phases have to be determined precisely, because they encode the most dominant object properties, such as charge distributions and electromagnetic fields. After more than six decades of very patient advancement, electron interferometry and holography offer unprecedented analytical facilities down to an atomic scale. Akira Tonomura has prominently contributed to the present state.

  13. Pulse picker for synchrotron radiation driven by a surface acoustic wave.

    Science.gov (United States)

    Vadilonga, Simone; Zizak, Ivo; Roshchupkin, Dmitry; Petsiuk, Andrei; Dolbnya, Igor; Sawhney, Kawal; Erko, Alexei

    2017-05-15

    A functional test for a pulse picker for synchrotron radiation was performed at Diamond Light Source. The purpose of a pulse picker is to select which pulse from the synchrotron hybrid-mode bunch pattern reaches the experiment. In the present work, the Bragg reflection on a Si/B4C multilayer was modified using surface acoustic wave (SAW) trains. Diffraction on the SAW alters the direction of the x rays and it can be used to modulate the intensity of the x rays that reach the experimental chamber. Using electronic modulation of the SAW amplitude, it is possible to obtain different scattering conditions for different x-ray pulses. To isolate the single bunch, the state of the SAW must be changed in the short time gap between the pulses. To achieve the necessary time resolution, the measurements have been performed in conical diffraction geometry. The achieved time resolution was 120 ns.

  14. ZnO film for application in surface acoustic wave device

    International Nuclear Information System (INIS)

    Du, X Y; Fu, Y Q; Tan, S C; Luo, J K; Flewitt, A J; Maeng, S; Kim, S H; Choi, Y J; Lee, D S; Park, N M; Park, J; Milne, W I

    2007-01-01

    High quality, c-axis oriented zinc oxide (ZnO) thin films were grown on silicon substrate using RF magnetron sputtering. Surface acoustic wave (SAW) devices were fabricated with different thickness of ZnO ranging from 1.2 to 5.5 μmUm and the frequency responses were characterized using a network analyzer. Thick ZnO films produce the strongest transmission and reflection signals from the SAW devices. The SAW propagation velocity is also strongly dependent on ZnO film thickness. The performance of the ZnO SAW devices could be improved with addition of a SiO 2 layer, in name of reflection signal amplitude and phase velocity of Rayleigh wave

  15. Detection of bioagents using a shear horizontal surface acoustic wave biosensor

    Energy Technology Data Exchange (ETDEWEB)

    Larson, Richard S; Hjelle, Brian; Hall, Pam R; Brown, David C; Bisoffi, Marco; Brozik, Susan M; Branch, Darren W; Edwards, Thayne L; Wheeler, David

    2014-04-29

    A biosensor combining the sensitivity of surface acoustic waves (SAW) generated at a frequency of 325 MHz with the specificity provided by antibodies and other ligands for the detection of viral agents. In a preferred embodiment, a lithium tantalate based SAW transducer with silicon dioxide waveguide sensor platform featuring three test and one reference delay lines was used to adsorb antibodies directed against Coxsackie virus B4 or the negative-stranded category A bioagent Sin Nombre virus (SNV). Rapid detection of increasing concentrations of viral particles was linear over a range of order of magnitude for both viruses, and the sensor's selectivity for its target was not compromised by the presence of confounding Herpes Simplex virus type 1 The biosensor was able to delect SNV at doses lower than the load of virus typically found in a human patient suffering from hantavirus cardiopulmonary syndrome (HCPS).

  16. Detection of bioagents using a shear horizontal surface acoustic wave biosensor

    Science.gov (United States)

    Larson, Richard S; Hjelle, Brian; Hall, Pam R; Brown, David C; Bisoffi, Marco; Brozik, Susan M; Branch, Darren W; Edwards, Thayne L; Wheeler, David

    2014-04-29

    A biosensor combining the sensitivity of surface acoustic waves (SAW) generated at a frequency of 325 MHz with the specificity provided by antibodies and other ligands for the detection of viral agents. In a preferred embodiment, a lithium tantalate based SAW transducer with silicon dioxide waveguide sensor platform featuring three test and one reference delay lines was used to adsorb antibodies directed against Coxsackie virus B4 or the negative-stranded category A bioagent Sin Nombre virus (SNV). Rapid detection of increasing concentrations of viral particles was linear over a range of order of magnitude for both viruses, and the sensor's selectivity for its target was not compromised by the presence of confounding Herpes Simplex virus type 1 The biosensor was able to delect SNV at doses lower than the load of virus typically found in a human patient suffering from hantavirus cardiopulmonary syndrome (HCPS).

  17. Integration of thin film giant magnetoimpedance sensor and surface acoustic wave transponder

    KAUST Repository

    Li, Bodong

    2012-03-09

    Passive and remote sensing technology has many potential applications in implantable devices, automation, or structural monitoring. In this paper, a tri-layer thin film giant magnetoimpedance (GMI) sensor with the maximum sensitivity of 16%/Oe and GMI ratio of 44% was combined with a two-port surface acoustic wave(SAW) transponder on a common substrate using standard microfabrication technology resulting in a fully integrated sensor for passive and remote operation. The implementation of the two devices has been optimized by on-chip matching circuits. The measurement results clearly show a magnetic field response at the input port of the SAW transponder that reflects the impedance change of the GMI sensor.

  18. EDITORIAL: Optical tomography and digital holography

    Science.gov (United States)

    Coupland, Jeremy; Lobera, Julia

    2008-07-01

    terms the papers we present describe closely related holographic techniques that address application areas within the field of engineering. The application of digital holography to 3D fluid flow measurement is addressed by several authors. Salah et al demonstrate the simplicity of digital holography with an in-line multiple exposure holographic system using a low-cost laser diode. Soria and Atkinson discuss limitations of low NA holography in fluid velocimetry and demonstrate the potential of a multiple camera, in-line technique which they call Tomographic Digital Holographic Particle Image Velocimetry (Tomo-HPIV). Problems caused by the twin images (real and virtual) of in-line HPIV are described by Ooms et al. It is shown how sign ambiguity can be eliminated and bias errors suppressed by the application of a suitable threshold in piecewise correlation of the reconstructed field. Denis et al explain the problem of twin image removal as a deconvolution process and compare suppression algorithms based on wavelet decomposition. This process can be considered as an inverse problem and the benefits of this approach are discussed with reference to particulate holograms by Gire et al. Of course, the twin image problem can be solved by off-axis holographic geometries which, in effect, add a carrier modulation. Arroyo presents a comparison of carrier modulation strategies that have been presented in the literature and shows circumstances in which the information in each of the real and virtual images can be separated when the sensor resolution is less than that required by the NA of the objective. State-of-the-art digital holographic microscopy (DHM) is presented by Kühn et al. This paper uses an off-axis geometry that simultaneously records images at two wavelengths. The microscope allows the surface profile to be measured from a single recording and sub-nanometre axial resolution is demonstrated. Another interesting application of DHM is addressed by Grilli et al. They

  19. Graphene Surface Acoustic Wave Sensor for Simultaneous Detection of Charge and Mass.

    Science.gov (United States)

    Okuda, Satoshi; Ono, Takao; Kanai, Yasushi; Ikuta, Takashi; Shimatani, Masaaki; Ogawa, Shinpei; Maehashi, Kenzo; Inoue, Koichi; Matsumoto, Kazuhiko

    2018-01-26

    We have combined a graphene field-effect transistor (GFET) and a surface acoustic wave (SAW) sensor on a LiTaO 3 substrate to create a graphene surface acoustic wave (GSAW) sensor. When a SAW propagates in graphene, an acoustoelectric current (I A ) flows between two attached electrodes. This current has unique electrical characteristics, having both positive and negative peak values with respect to the electrolyte-gate voltage (V Eg ) in solution. We found that I A is controlled by V Eg and the amplitude of the SAW. It was also confirmed that the GSAW sensor detects changes of electrical charge in solution like conventional GFET sensors. Furthermore, the detection of amino-group-modified microbeads was performed by employing a GSAW sensor in a phthalate buffer solution at pH 4.1. The hole current peak shifted to the lower left in the I A -V Eg characteristics. The left shift was caused by charge detection by the GFET and can be explained by an increase of amino groups that have positive charges at pH 4.1. In contrast, the downward shift is thought to be due to a reduction in the amplitude of the propagating SAW because of an increase in the mass loading of microbeads. This mass loading was detected by the SAW sensor. Thus, we have demonstrated that the GSAW sensor is a transducer capable of the simultaneous detection of charge and mass, which indicates that it is an attractive platform for highly sensitive and multifunctional solution sensing.

  20. A portable pulmonary delivery system for nano engineered DNA vaccines driven by surface acoustic wave devices

    International Nuclear Information System (INIS)

    Rajapaksa, A.E.; Qi, Aisha; Yeo, L.; Friend, J.

    2010-01-01

    Full text: The increase in the need for effective delivery of potelll vaccines against infectious diseases, require robust yet straightforward pro duction of encapsulated DNA-laden aerosols. Aerosol delivery of drugs represents the next generation of vaccine delivery where the drug is deposited into the lung, which provides an ideal, non-invasive route. Moreover, several features of D A vaccines make them more attractive than conventional vaccines; thus, DNA vaccines have gained global interest for a variety of applications. However, several limitations such as ineffective cellular uptake and intracellular delivery, and degradation of DNA need to be overcome before clin ical applications. In this study, a novel and scalable engineered technique has been developed to create a biodegradable polymer system, which enables controlled delivery of a well designed DNA vaccine for immuno-therapeutics. Surface Acoustic Wave (SAW) atomisation has been found as useful mechanism for atomising fluid samples for medical and industrial devices. It is a straightforward method for synthesising un-agglomerated biodegradable nanoparti cles (<250 nm) in the absence of organic solvents which would represent a major breakthrough for biopharmaceutical encapsulation and delivery. Nano-scale polymer particles for DNA vaccines deliv ery were obtained through an evaporative process of the initial aerosol created by surface acoustic waves at 8-150 MHz, the final size of which could be controlled by modifying the initial polymer concen tration and solid contents. Thus, SAW atomiser represents a promising alternative for the development of a low power device for producing nano-engineered vaccines with a controlled and narrow size distribution as delivery system for genetic immuno-therapeutics.

  1. Eigenwave spectrum of surface acoustic waves on a rough self-affine fractal surface

    NARCIS (Netherlands)

    Palasantzas, George

    1994-01-01

    The propagation of a sound wave along a statistically rough solid-vacuum interface is investigated for the case of self-affine fractals. The wave-number relation ω=ω(k) is examined for the transverse polarized surface wave. The range of existence of this wave is analyzed as a function of the degree

  2. Near-surface viscosity measurements with a love acoustic wave device

    International Nuclear Information System (INIS)

    Collings, A.F.; Cooper, B.J.; Lappas, S.; Sor, J.A.

    1999-01-01

    Full text: In the last decade, considerable research effort has been directed towards interfacing piezoelectric transducers with biological detection systems to produce efficient and highly selective biosensors. Several types of piezoelectric or, more specifically, acoustic wave transducers have been investigated. Our group has developed Love wave (guided surface skimming wave) devices which are made by attaching a thin overlayer with the appropriate acoustic properties to the surface of a conventional surface horizontal mode device. An optimised layer concentrates most of the propagating wave energy in the guiding layer and can improve the device sensitivity in detecting gas-phase mass loading on the surface some 20- to 40-fold. Love wave devices used in liquid phase sensing will also respond to viscous, as well as mass, loading on the device surface. We have studied the propagation of viscous waves into liquid sitting on a Love wave device both theoretically and experimentally. Modelling of the effect of a viscous liquid layer on a Love wave propagating in a layered medium predicts the velocity profile in the solid substrate and in the adjoining liquid. This is a function of the thickness of the guiding layer, the elastic properties of the guiding layer and the piezoelectric substrate, and of the viscosity and density of the liquid layer. We report here on measurements of the viscosity of aqueous glycerine solutions made with a quartz Love wave device with a 5.5 μm SiO 2 guiding layer. The linear relationship between the decrease in the device frequency and the square root of the viscosity density product is accurately observed at Newtonian viscosities. At higher viscosities, there is an increase in damping, the insertion loss of the device saturates, Δf is no longer proportional to (ηp) l/2 and reaches a maximum. We also show results for the determination of the gelation time in protein and inorganic aqueous gels and for the rate of change of viscosity with

  3. Surface acoustic load sensing using a face-shear PIN-PMN-PT single-crystal resonator.

    Science.gov (United States)

    Kim, Kyungrim; Zhang, Shujun; Jiang, Xiaoning

    2012-11-01

    Pb(In(0.5)Nb(0.5))O(3)-Pb(Mg(1/3)Nb(2/3))O(3)-PbTiO(3) (PIN-PMN-PT) resonators for surface acoustic load sensing are presented in this paper. Different acoustic loads are applied to thickness mode, thickness-shear mode, and face-shear mode resonators, and the electrical impedances at resonance and anti-resonance frequencies are recorded. More than one order of magnitude higher sensitivity (ratio of electrical impedance change to surface acoustic impedance change) at the resonance is achieved for the face-shear-mode resonator compared with other resonators with the same dimensions. The Krimholtz, Leedom, and Matthaei (KLM) model is used to verify the surface acoustic loading effect on the electrical impedance spectrum of face-shear PIN-PMN-PT single-crystal resonators. The demonstrated high sensitivity of face-shear mode resonators to surface loads is promising for a broad range of applications, including artificial skin, biological and chemical sensors, touch screens, and other touch-based sensors.

  4. SH surface acoustic wave propagation in a cylindrically layered piezomagnetic/piezoelectric structure.

    Science.gov (United States)

    Du, Jianke; Xian, Kai; Wang, Ji

    2009-01-01

    SH surface acoustic wave (SH-SAW) propagation in a cylindrically layered magneto-electro-elastic structure is investigated analytically, where a piezomagnetic (or piezoelectric) material layer is bonded to a piezoelectric (or piezomagnetic) substrate. By means of transformation, the governing equations of the coupled waves are reduced to Bessel equation and Laplace equation. The boundary conditions imply that the displacements, shear stresses, electric potential, and electric displacements are continuous across the interface between the layer and the substrate together with the traction free at the surface of the layer. The magneto-electrically open and shorted conditions at cylindrical surface are taken to solve the problem. The phase velocity is numerically calculated for different thickness of the layer and wavenumber for piezomagnetic ceramics CoFe(2)O(4) and piezoelectric ceramics BaTiO(3). The effects of magnetic permeability on propagation properties of SH-SAW are discussed in detail. The distributions of displacement, magnetic potential and magneto-electromechanical coupling factor are also figured and discussed.

  5. Holography applications in recent China

    Science.gov (United States)

    Hsu, Dahsiung

    2000-10-01

    Reports on recent developments on holography applications in China are given in this paper, including the development of anti-counterfeiting Holograms from 1986-2000, China issued Banknotes in 1999 with holograms and OVIs, the developments in Machine Readable Holograms in China, the developments in Anti-counterfeiting Information Networks in China.

  6. X-ray absorption holography

    Czech Academy of Sciences Publication Activity Database

    Kopecký, Miloš; Lausi, A.; Bussetto, E.; Kub, Jiří; Savoia, A.

    2002-01-01

    Roč. 88, č. 18 (2002), s. 185503-1 - 185503-3 ISSN 0031-9007 R&D Projects: GA MŠk LN00A100 Institutional research plan: CEZ:AV0Z1010921 Keywords : x-ray holography Subject RIV: BH - Optics, Masers, Lasers Impact factor: 7.323, year: 2002

  7. Comparative study of binding constants from Love wave surface acoustic wave and surface plasmon resonance biosensors using kinetic analysis.

    Science.gov (United States)

    Lee, Sangdae; Kim, Yong-Il; Kim, Ki-Bok

    2013-11-01

    Biosensors are used in a variety of fields for early diagnosis of diseases, measurement of toxic contaminants, quick detection of pathogens, and separation of specific proteins or DNA. In this study, we fabricated and evaluated the capability of a high sensitivity Love wave surface acoustic wave (SAW) biosensor. The experimental setup was composed of the fabricated 155-MHz Love wave SAW biosensor, a signal measurement system, a liquid flow system, and a temperature-control system. Subsequently, we measured the lower limit of detection (LOD) of the 155-MHz Love wave SAW biosensor, and calculated the association and dissociation constants between protein G and anti-mouse IgG using kinetic analysis. We compared these results with those obtained using a commercial surface plasmon resonance (SPR) biosensor. We found that the LOD of the SAW biosensor for anti-mouse IgG and mouse IgG was 0.5 and 1 microg/ml, respectively, and the resultant equilibrium association and dissociation constants were similar to the corresponding values obtaining using the commercial SPR biosensor. Thus, we conclude that the fabricated 155-MHz Love wave SAW biosensor exhibited the high sensitivity of the commercial SPR biosensor and was able to analyze the binding properties of the ligand and receptor by kinetic analysis similarly to the commercial SPR biosensor.

  8. Measurements of the Characteristics of Transparent Material Using Digital Holography

    Directory of Open Access Journals (Sweden)

    Ding Yu

    2013-01-01

    Full Text Available Digital holography is applied to measure the characteristics of transparent material. A digital hologram recording system to measure the surface of transparent material was established, and the digital holograms of transparent object were obtained in high quality. For postprocessing of hologram, the least-squares phase unwrapping algorithm was used in phase unwrapping, and the phase reconstruction image of transparent object was obtained. The information of material surfaces was measured and the characteristic was presented in 3D visualization. The validation experiment was conducted by NanoMap 500LS system; the results of validation experiment are well satisfied with the measurement by digital holography, which proved the feasibility of digital holographic technology as a good measurement tool for transparent material.

  9. Digital holography for MEMS and microsystem metrology

    CERN Document Server

    Asundi, Anand

    2011-01-01

    Approaching the topic of digital holography from the practical perspective of industrial inspection, Digital Holography for MEMS and Microsystem Metrology describes the process of digital holography and its growing applications for MEMS characterization, residual stress measurement, design and evaluation, and device testing and inspection. Asundi also provides a thorough theoretical grounding that enables the reader to understand basic concepts and thus identify areas where this technique can be adopted. This combination of both practical and theoretical approach will ensure the

  10. Atom-resolving x-ray holography

    International Nuclear Information System (INIS)

    Adams, B.; Hiort, T.; Materlik, G.; Nishino, Y.; Novikov, D. V.

    2000-01-01

    The current state of atomic resolution x-ray holography is discussed on the basis of theory and experimental results. X-ray holography is theoretically described in quantum theory. Presently-used experimental implementations are shown together with the data analysis used. Reconstructions of experimental and simulated holograms are compared for a Cu 3 Au crystal structure. Rigorous experimental realizations of pure direct and reciprocal x-ray holography methods are demonstrated, and future developments and applications of the method are suggested

  11. Characterization of Zinc Oxide (ZnO piezoelectric properties for Surface Acoustic Wave (SAW device

    Directory of Open Access Journals (Sweden)

    Zakaria Mohd Rosydi

    2017-01-01

    Full Text Available In fabricating Surface Acoustic Wave (SAW biosensors device, the substrate is one of important factors that affected to performance device. there are many types of piezoelectric substrate in the markets and the cheapest is zinc Oxide substrate. Zinc Oxide (ZnO with its unique properties can be used as piezoelectric substrate along with SAW devices for detection of DNA in this research. In this project, ZnO thin film is deposited onto silicon oxide substrate using electron beam evaporation (E-beam and Sol-Gel technique. Different material structure is used to compare the roughness and best piezoelectric substrate of ZnO thin film. Two different structures of ZnO target which are pellet and granular are used for e-beam deposition and one sol-gel liquid were synthesize and compared. Parameter for thickness of ZnO e-beam deposition is fixed to a 0.1kÅ for both materials structure and sol-gel was coat using spin coat technique. After the process is done, samples are annealed at temperature of 500°C for 2 hours. The structural properties of effect of post annealing using different material structure of ZnO are studied using Atomic Force Microscopic (AFM for surface morphology and X-ray Diffraction (XRD for phase structure.

  12. Use of surface acoustic waves to reduce pain and discomfort related to indwelling nasogastric tube.

    Science.gov (United States)

    Schlager, A; Metzger, Y C; Adler, S N

    2010-12-01

    Nasogastric intubation, one of the most widely utilized therapeutic procedures in medical practice, is associated with trauma, pain, and discomfort, which can occur both at insertion and during the indwelling phase. Although lubricating jelly is useful during the insertion phase, insertion can still cause great discomfort. Furthermore, the jelly is rapidly absorbed and therefore is unable to decrease the friction between the tissues and the tube during the indwelling phase of the nasogastric tube. The aim of this study was to test a device, the NG-Shield, that generates surface acoustic waves on the surfaces of the nasogastric tube to reduce contact time and thus friction between the nasogastric tube and body tissues. Twenty-four healthy volunteers were enrolled in a single-center, crossover, blinded study, in which a nasogastric tube was inserted and left indwelling for 6 hours. Throughout the indwelling period the device was activated and deactivated alternately every hour, and the volunteers were questioned every hour about their pain and discomfort levels as well as grading pain and discomfort upon insertion and removal of the nasogastric tube. Pain and discomfort levels were compared between active and nonactive phases of the device. The activated NG-Shield was found to reduce both pain and discomfort significantly in both the nose and throat throughout the indwelling phase. The NG-Shield is a safe and effective device for reducing pain and discomfort associated with an indwelling nasogastric tube. © Georg Thieme Verlag KG Stuttgart · New York.

  13. Optical find of hypersonic surface acoustic waves in bulk transparent materials

    Science.gov (United States)

    Jiménez Riobóo, Rafael J.; Sánchez-Sánchez, Alberto; Prieto, Carlos

    2016-07-01

    It is shown that direct information from surface acoustic waves (SAWs) of bulk transparent materials can be obtained by using Brillouin light scattering (BLS). The study of surface phonons by means of an optical spectroscopy such as BLS has been historically constrained to nontransparent and highly reflecting bulk and film samples or even to very thin films deposited on reflecting substrates. Probably due to its low signal and to the narrow window in experimental conditions, it was assumed for years that bulk transparent samples were not suited for Brillouin spectroscopy in order to get information on SAWs, negating this optical technique in the search for SAW properties. The reported experiments on transparent glasses and single crystals (cubic MgO and trigonal sapphire) prove that there is no intrinsic physical reason not to collect SAW propagation velocity data from transparent bulk samples and opens a challenge to apply the Brillouin spectroscopy in a wider scenario to obtain direct information, in a nondestructive and contactless way, about SAWs in bulk materials.

  14. Analytical modelling of acoustic emission from buried or surface-breaking cracks under stress

    International Nuclear Information System (INIS)

    Ben Khalifa, W; Jezzine, K; Hello, G; Grondel, S

    2012-01-01

    Acoustic emission (AE) is a non-destructive testing method used in various industries (aerospace, petrochemical and pressure-vessel industries in general, power generation, civil engineering, mechanical engineering, etc...) for the examination of large structures subjected to various stresses (e.g. mechanical loading).The energy released by a defect under stress (the AE phenomenon) can propagate as guided waves in thin structures or as surface Rayleigh waves in thick ones. Sensors (possibly permanently) are positioned at various locations on the structure under examination and are assumed to be sensitive to these waves. Then, post-processing tools typically based on signal processing and triangulation algorithms can be used to inverse these data, allowing one to estimate the position of the defect from which emanates the waves measured. The French Atomic Energy Commission is engaged in the development of tools for simulating AE examinations. These tools are based on specific models for the AE sources, for the propagation of guided or Rayleigh waves and for the behaviour of AE sensors. Here, the coupling of a fracture mechanics based model for AE source and surface/guided wave propagation models is achieved through an integral formulation relying on the elastodynamic reciprocity principle. As a first approximation, a simple piston-like model is used to predict the sensitivity of AE sensors. Predictions computed by our simulation tool are compared to results from the literature for validation purpose.

  15. Investigation into Mass Loading Sensitivity of Sezawa Wave Mode-Based Surface Acoustic Wave Sensors

    Directory of Open Access Journals (Sweden)

    N. Ramakrishnan

    2013-02-01

    Full Text Available In this work mass loading sensitivity of a Sezawa wave mode based surface acoustic wave (SAW device is investigated through finite element method (FEM simulation and the prospects of these devices to function as highly sensitive SAW sensors is reported. A ZnO/Si layered SAW resonator is considered for the simulation study. Initially the occurrence of Sezawa wave mode and displacement amplitude of the Rayleigh and Sezawa wave mode is studied for lower ZnO film thickness. Further, a thin film made of an arbitrary material is coated over the ZnO surface and the resonance frequency shift caused by mass loading of the film is estimated. It was observed that Sezawa wave mode shows significant sensitivity to change in mass loading and has higher sensitivity (eight times higher than Rayleigh wave mode for the same device configuration. Further, the mass loading sensitivity was observed to be greater for a low ZnO film thickness to wavelength ratio. Accordingly, highly sensitive SAW sensors can be developed by coating a sensing medium over a layered SAW device and operating at Sezawa mode resonance frequency. The sensitivity can be increased by tuning the ZnO film thickness to wavelength ratio.

  16. Surface acoustic waves in two dimensional phononic crystal with anisotropic inclusions

    Directory of Open Access Journals (Sweden)

    Ketata H.

    2012-06-01

    Full Text Available An analysis is given to the band structure of the two dimensional solid phononic crystal considered as a semi infinite medium. The lattice includes an array of elastic anisotropic materials with different shapes embedded in a uniform matrix. For illustration two kinds of phononic materials are assumed. A particular attention is devoted to the computational procedure which is mainly based on the plane wave expansion (PWE method. It has been adapted to Matlab environment. Numerical calculations of the dispersion curves have been achieved by introducing particular functions which transform motion equations into an Eigen value problem. Significant improvements are obtained by increasing reasonably the number of Fourier components even when a large elastic mismatch is assumed. Such approach can be generalized to different types of symmetry and permit new physical properties as piezoelectricity to be added. The actual semi infinite phononic structure with a free surface has been shown to support surface acoustic waves (SAW. The obtained dispersion curves reveal band gaps in the SAW branches. It has been found that the influence, of the filling factor and anisotropy on their band gaps, is different from that of bulk waves.

  17. Characterization of Zinc Oxide (ZnO) piezoelectric properties for Surface Acoustic Wave (SAW) device

    Science.gov (United States)

    Rosydi Zakaria, Mohd; Johari, Shazlina; Hafiz Ismail, Mohd; Hashim, Uda

    2017-11-01

    In fabricating Surface Acoustic Wave (SAW) biosensors device, the substrate is one of important factors that affected to performance device. there are many types of piezoelectric substrate in the markets and the cheapest is zinc Oxide substrate. Zinc Oxide (ZnO) with its unique properties can be used as piezoelectric substrate along with SAW devices for detection of DNA in this research. In this project, ZnO thin film is deposited onto silicon oxide substrate using electron beam evaporation (E-beam) and Sol-Gel technique. Different material structure is used to compare the roughness and best piezoelectric substrate of ZnO thin film. Two different structures of ZnO target which are pellet and granular are used for e-beam deposition and one sol-gel liquid were synthesize and compared. Parameter for thickness of ZnO e-beam deposition is fixed to a 0.1kÅ for both materials structure and sol-gel was coat using spin coat technique. After the process is done, samples are annealed at temperature of 500°C for 2 hours. The structural properties of effect of post annealing using different material structure of ZnO are studied using Atomic Force Microscopic (AFM) for surface morphology and X-ray Diffraction (XRD) for phase structure.

  18. Acoustic VTI wavefield tomography of P-wave surface and VSP data

    KAUST Repository

    Li, Vladimir

    2017-08-17

    Transversely isotropic (TI) models have become standard in depth imaging and are often used in waveform inversion. Here, we develop a robust wave-equation-based tomographic algorithm for building acoustic VTI (transversely isotropic with a vertical symmetry axis) velocity models from P-wave surface reflection and vertical seismic profiling (VSP) data. Wavefield extrapolation is performed with an integral operator to avoid generating shear-wave artifacts. Focusing energy in extended images produced by reverse-time migration (RTM) makes it possible to update the zero-dip NMO velocity Vnmo and the anellipiticity parameter η. To constrain the anisotropy coefficient δ and improve the accuracy in Vnmo and η, we employ borehole information by introducing an additional objective-function term designed to fit VSP data. Image-guided smoothing is applied to both data- and image-domain gradients to steer the inversion towards geologically plausible solutions. Testing on the VTI Marmousi model shows that the joint inversion of surface and VSP data helps estimate all three relevant medium parameters.

  19. Radar, sonar, and holography an introduction

    CERN Document Server

    Kock, Winston E

    1974-01-01

    Radar, Sonar, and Holography: An Introduction provides an introduction to the technology of radar and sonar. Because the new science of holography is affecting both these fields quite strongly, the book includes an explanation of the fundamental principles underlying this new art (including the subjects of wave coherence, interference, and diffraction) and of the hologram process itself. Finally, numerous examples are discussed which show how holography is providing new horizons to radar and sonar systems. The book thus also provides a simple approach to the new technology of holography. The

  20. Conoscopic holography systematic error processing by means of gaussian filters

    OpenAIRE

    Zapico, Pablo; Patiño, Héctor; Fernández, Pedro; Valiño, Gonzalo; Rico, J.C. (José)

    2018-01-01

    This work analyses the directional effect shown by the point clouds when digitizing with a conoscopic holography (CH) sensor. The asymmetric shape of the laser spot for this sensor yields that directionality appears along the greatest spot length and it occurs repeatedly under different working conditions. To study this effect of the sensor, several tests were performed on a surface machined by EDM with a very uniform and isotropic finish, so that the directional effect should not appear actu...

  1. Mutual conversion of bulk and surface acoustic waves in gratings of finite length on half-infinite substrates. I. FE analysis of surface wave generation.

    Science.gov (United States)

    Darinskii, A N; Weihnacht, M; Schmidt, H

    2013-07-01

    A numerical study is carried out of the surface acoustic wave generation by a bulk acoustic wave in a half-infinite anisotropic half-space without piezoeffect. The efficient conversion of bulk waves into surface waves occurs due to a grating area created on the surface of the substrate. Our simulations are fully based on the finite element method. Given the incident bulk wave, we directly determine the amplitude of the surface wave and investigate its dependence on various parameters specifying the situation under consideration, such as the frequency and the polarization of the bulk wave, the length of the grating, the geometrical size of grooves or strips forming the grating. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Digital Holography Display (2)

    Science.gov (United States)

    Lee, Cheok Peng; Asundi, A.; Yu, Yang; Xiao, Zhen Zhong

    This paper describes the extension work from the last Digital Holography Projector System. From the developed works shows that, some unforeseen factors have created the difficulties for the system alignment. Such factors are the DMD frame rate, light source and diffractive zero order. It is really the challenging development works to achieve the virtual 3D model display on the high speed rotation screen. The three most key factors are emphasizing: 1) The display device's frame rate; 2) The light source orientation angle; and 3) The zero order filtering optic. 1) This device's is the digital micro mirror, in short is DMD. It is the high speed switching device has developed by the most recent technology. The switching frame rate can go up as high as 291fps. At first, the 8 bits depth file must be digitalized and stored for DMD onboard Ram. The digitalized data are transmitting from the PC USB to DMD onboard Ram. Instead of the data are downloading directly from the PC to DVI or VGA during display, this downloading method cause slower down the display speed, which is the common frame rate of 30 Hz. Next, the onboard Ram data then transfer to the DMD mirror's for display, at the 8 bits 291 fps speed. At this frame rate, the display 2D image can almost cover for 10 of out of the 360 0 in 1 revolution. 2) This laser light source must be installed such that free for orientated in any arbitrary angle from 220 to 450. Which is normalized to the DMD mirrors and the brief sketch show on figure (a). The purpose of orientated the light source is ensure that multi diffractive order would be reflected straight from the mirrors. (This multi diffractive order is the phenomenon of the digital micro mirror's characteristic). This mean, the reconstruct images would be followed the DMD normalized direction reflected up to fibre conduit. Moreover, this orientated method install of the laser light source is making space for other optical lenses or device driver/controller. Because, all

  3. Surpassing digital holography limits by lensless object scanning holography.

    Science.gov (United States)

    Micó, Vicente; Ferreira, Carlos; García, Javier

    2012-04-23

    We present lensless object scanning holography (LOSH) as a fully lensless method, capable of improving image quality in reflective digital Fourier holography, by means of an extremely simplified experimental setup. LOSH is based on the recording and digital post-processing of a set of digital lensless holograms and results in a synthetic image with improved resolution, field of view (FOV), signal-to-noise ratio (SNR), and depth of field (DOF). The superresolution (SR) effect arises from the generation of a synthetic aperture (SA) based on the linear movement of the inspected object. The same scanning principle enlarges the object FOV. SNR enhancement is achieved by speckle suppression and coherent artifacts averaging due to the coherent addition of the multiple partially overlapping bandpass images. And DOF extension is performed by digital refocusing to different object's sections. Experimental results showing an impressive image quality improvement are reported for a one-dimensional reflective resolution test target. © 2012 Optical Society of America

  4. X-ray interferometric Fourier holography

    International Nuclear Information System (INIS)

    Balyan, M.K.

    2016-01-01

    The X-ray interferometric Fourier holography is proposed and theoretically investigated. Fourier The X-ray interferometric Young fringes and object image reconstruction are investigated. It is shown that the interference pattern of two slits formed on the exit surface of the crystal-analyzer (the third plate of the interferometer) is the X-ray interferometric Young fringes. An expression for X-ray interferometric Young fringes period is obtained. The subsequent reconstruction of the slit image as an object is performed by means of Fourier transform of the intensity distribution on the hologram. Three methods of reconstruction of the amplitude transmission complex function of the object are presented: analytical - approximate method, method of iteration and step by step method. As an example the X-ray Fourier interferometric hologram recording and the complex amplitude transmission function reconstruction for a beryllium circular wire are considered

  5. Contact studies of weak adhesive interactions in water with membrane enhanced surface acoustic wave analysis

    Science.gov (United States)

    Brass, David Alan

    The measurement of weak adhesive energies has previously been difficult to obtain. To measure these energies, I designed a technique that uses the combined sensitivities of both a quartz crystal resonator and the inflation of an elastomeric polymer membrane. The surfaces of the quartz crystal and/or the membrane are modified with water swollen polymer brushes, which are used to eliminate nonspecific adhesion. These brushes are then end-modified with adhesive functional groups. An analysis is developed for the frequency response of a quartz crystal resonator as the membrane layer is placed in contact with the surface of these swollen brushes. The shear wave generated at the resonator surface couples into the membrane layer with an efficiency that is strongly dependent on the thickness of the swollen brush layer. The calculated shift decreases substantially for increases in the brush thickness of ten to twenty nanometers, giving a net frequency response that is extremely sensitive to the degree of swelling of the brush. An optimum capping layer thickness is determined by balancing the resonant frequency shift against dissipative effects that weaken the crystal resonance. Detailed calculations are presented for the specific case of poly(ethylene glycol) (PEG) brushes swollen by water and capped by a poly(styrene-ethylene/butene-styrene) (SEBS) elastomeric, water-permeable membrane. These calculations show that the method is sensitive to the properties of the brush layer. This surface acoustic wave technique was coupled with an inflation method that enabled quantification of the adhesion between the membrane and the brush coated surface. This adhesive interaction is obtained from the contact angle made between the quartz and membrane surfaces and the tension on the membrane. An analysis of the membrane profile based on the numerical solution of the axisymmetric Laplace equation is developed and used to investigate both adhesive and non-adhesive situations with both an

  6. A surface acoustic wave passive and wireless sensor for magnetic fields, temperature, and humidity

    KAUST Repository

    Li, Bodong

    2015-01-01

    In this paper, we report an integrated single-chip surface acoustic wave sensor with the capability of measuring magnetic field, temperature, and humidity. The sensor is fabricated using a thermally sensitive LiNbO3 substrate, a humidity sensitive hydrogel coating, and a magnetic field sensitive impedance load. The sensor response to individually and simultaneously changing magnetic field, temperature and humidity is characterized by connecting a network analyzer directly to the sensor. Analytical models for each measurand are derived and used to compensate noise due to cross sensitivities. The results show that all three measurands can be monitored in parallel with sensitivities of 75 ppm/°C, 0.13 dB/%R.H. (at 50%R.H.), 0.18 dB/Oe and resolutions of 0.1 °C, 0.4%R.H., 1 Oe for temperature, humidity and magnetic field, respectively. A passive wireless measurement is also conducted on a current line using, which shows the sensors capability to measure both temperature and current signals simultaneously.

  7. Hydrogen Gas Sensing Using Palladium-Graphene Nanocomposite Material Based on Surface Acoustic Wave

    Directory of Open Access Journals (Sweden)

    Nguyen Hai Ha

    2017-01-01

    Full Text Available We report the fabrication and characterization of surface acoustic wave (SAW hydrogen sensors using palladium-graphene (Pd-Gr nanocomposite as sensing material. The Pd-Gr nanocomposite as sensing layer was deposited onto SAW delay line sensor-based interdigitated electrodes (IDTs/aluminum nitride (AlN/silicon (Si structure. The Pd-Gr nanocomposite was synthesized by a chemical route and deposited onto SAW sensors by air-brush spraying. The SAW H2 sensor using Pd-Gr nanocomposite as a sensing layer shows a frequency shift of 25 kHz in 0.5% H2 concentration at room temperature with good repeatability and stability. Moreover, the sensor showed good linearity and fast response/recovery within ten seconds with various H2 concentrations from 0.25 to 1%. The specific interaction between graphene and SAW transfer inside AlN/Si structures yields a high sensitivity and fast response/recovery of SAW H2 sensor based on Pd-Gr/AlN/Si structure.

  8. The Separation of Blood Components Using Standing Surface Acoustic Waves (SSAWs Microfluidic Devices: Analysis and Simulation

    Directory of Open Access Journals (Sweden)

    Ahmed M. Soliman

    2017-03-01

    Full Text Available The separation of blood components (WBCs, RBCs, and platelets is important for medical applications. Recently, standing surface acoustic wave (SSAW microfluidic devices are used for the separation of particles. In this paper, the design analysis of SSAW microfluidics is presented. Also, the analysis of SSAW force with Rayleigh angle effect and its attenuation in liquid-loaded substrate, viscous drag force, hydrodynamic force, and diffusion force are explained and analyzed. The analyses are provided for selecting the piezoelectric material, width of the main microchannel, working area of SAW, wavelength, minimum input power required for the separation process, and widths of outlet collecting microchannels. The design analysis of SSAW microfluidics is provided for determining the minimum input power required for the separation process with appropriated the displacement contrast of the particles.The analyses are applied for simulation the separation of blood components. The piezoelectric material, width of the main microchannel, working area of SAW, wavelength, and minimum input power required for the separation process are selected as LiNbO3, 120 μm, 1.08 mm2, 300 μm, 371 mW. The results are compared to other published results. The results of these simulations achieve minimum power consumption, less complicated setup, and high collecting efficiency. All simulation programs are built by MATLAB.

  9. Enhanced Sensitivity of Surface Acoustic Wave-Based Rate Sensors Incorporating Metallic Dot Arrays

    Directory of Open Access Journals (Sweden)

    Wen Wang

    2014-02-01

    Full Text Available A new surface acoustic wave (SAW-based rate sensor pattern incorporating metallic dot arrays was developed in this paper. Two parallel SAW delay lines with a reverse direction and an operation frequency of 80 MHz on a same X-112°Y LiTaO3 wafer are fabricated as the feedback of two SAW oscillators, and mixed oscillation frequency was used to characterize the external rotation. To enhance the Coriolis force effect acting on the SAW propagation, a copper (Cu dot array was deposited along the SAW propagation path of the SAW devices. The approach of partial-wave analysis in layered media was referred to analyze the response mechanisms of the SAW based rate sensor, resulting in determination of the optimal design parameters. To improve the frequency stability of the oscillator, the single phase unidirectional transducers (SPUDTs and combed transducer were used to form the SAW device to minimize the insertion loss and accomplish the single mode selection, respectively. Excellent long-term (measured in hours frequency stability of 0.1 ppm/h was obtained. Using the rate table with high precision, the performance of the developed SAW rate sensor was evaluated experimentally; satisfactory detection sensitivity (16.7 Hz∙deg∙s−1 and good linearity were observed.

  10. Flexible surface acoustic wave respiration sensor for monitoring obstructive sleep apnea syndrome

    Science.gov (United States)

    Jin, Hao; Tao, Xiang; Dong, Shurong; Qin, Yiheng; Yu, Liyang; Luo, Jikui; Deen, M. Jamal

    2017-11-01

    Obstructive sleep apnea syndrome (OSAS) has received much attention in recent years due to its significant harm to human health and high morbidity rate. A respiration monitoring system is needed to detect OSAS, so that the patient can receive treatment in a timely manner. Wired and wireless OSAS monitoring systems have been developed, but they require a wire connection and batteries to operate, and they are bulky, heavy and not user-friendly. In this paper, we propose the use of a flexible surface acoustic wave (SAW) microsensor to detect and monitor OSAS by measuring the humidity change associated with the respiration of a person. SAW sensors on rigid 128° YX LiNbO3 substrate are also characterized for this application. Results show both types of SAW sensors are suitable for OSAS monitoring with good sensitivity, repeatability and reliability, and the response time and recovery time for the flexible SAW sensors are 1.125 and 0.75 s, respectively. Our work demonstrates the potential for an innovative flexible microsensor for the detection and monitoring of OSAS.

  11. A Novel Particulate Matter 2.5 Sensor Based on Surface Acoustic Wave Technology

    Directory of Open Access Journals (Sweden)

    Jiuling Liu

    2018-01-01

    Full Text Available Design, fabrication and experiments of a miniature particulate matter (PM 2.5 sensor based on the surface acoustic wave (SAW technology were proposed. The sensor contains a virtual impactor (VI for particle separation, a thermophoretic precipitator (TP for PM2.5 capture and a SAW sensor chip for PM2.5 mass detection. The separation performance of the VI was evaluated by using the finite element method (FEM model and the PM2.5 deposition characteristic in the TP was obtained by analyzing the thermophoretic theory. Employing the coupling-of-modes (COM model, a low loss and high-quality SAW resonator was designed. By virtue of the micro electro mechanical system (MEMS technology and semiconductor technology, the SAW based PM2.5 sensor detecting probe was fabricated. Then, combining a dual-port SAW oscillator and an air sampler, the experimental platform was set up. Exposing the PM2.5 sensor to the polystyrene latex (PSL particles in a chamber, the sensor performance was evaluated. The results show that by detecting the PSL particles with a certain diameter of 2 μm, the response of the SAW based PM2.5 sensor is linear, and in accordance with the response of the light scattering based PM2.5 monitor. The developed SAW based PM2.5 sensor has great potential for the application of airborne particle detection.

  12. Mass Sensitivity Optimization of a Surface Acoustic Wave Sensor Incorporating a Resonator Configuration

    Directory of Open Access Journals (Sweden)

    Wenchang Hao

    2016-04-01

    Full Text Available The effect of the sensitive area of the two-port resonator configuration on the mass sensitivity of a Rayleigh surface acoustic wave (R-SAW sensor was investigated theoretically, and verified in experiments. A theoretical model utilizing a 3-dimensional finite element method (FEM approach was established to extract the coupling-of-modes (COM parameters in the absence and presence of mass loading covering the electrode structures. The COM model was used to simulate the frequency response of an R-SAW resonator by a P-matrix cascading technique. Cascading the P-matrixes of unloaded areas with mass loaded areas, the sensitivity for different sensitive areas was obtained by analyzing the frequency shift. The performance of the sensitivity analysis was confirmed by the measured responses from the silicon dioxide (SiO2 deposited on different sensitive areas of R-SAW resonators. It is shown that the mass sensitivity varies strongly for different sensitive areas, and the optimal sensitive area lies towards the center of the device.

  13. A Synthetic Phased Array Surface Acoustic Wave Sensor for Quantifying Bolt Tension

    Directory of Open Access Journals (Sweden)

    Rasim Guldiken

    2012-09-01

    Full Text Available In this paper, we report our findings on implementing a synthetic phased array surface acoustic wave sensor to quantify bolt tension. Maintaining proper bolt tension is important in many fields such as for ensuring safe operation of civil infrastructures. Significant advantages of this relatively simple methodology is its capability to assess bolt tension without any contact with the bolt, thus enabling measurement at inaccessible locations, multiple bolt measurement capability at a time, not requiring data collection during the installation and no calibration requirements. We performed detailed experiments on a custom-built flexible bench-top experimental setup consisting of 1018 steel plate of 12.7 mm (½ in thickness, a 6.4 mm (¼ in grade 8 bolt and a stainless steel washer with 19 mm (¾ in of external diameter. Our results indicate that this method is not only capable of clearly distinguishing properly bolted joints from loosened joints but also capable of quantifying how loose the bolt actually is. We also conducted detailed signal-to-noise (SNR analysis and showed that the SNR value for the entire bolt tension range was sufficient for image reconstruction.

  14. Enabling practical surface acoustic wave nebulizer drug delivery via amplitude modulation.

    Science.gov (United States)

    Rajapaksa, Anushi; Qi, Aisha; Yeo, Leslie Y; Coppel, Ross; Friend, James R

    2014-06-07

    A practical, commercially viable microfluidic device relies upon the miniaturization and integration of all its components--including pumps, circuitry, and power supply--onto a chip-based platform. Surface acoustic waves (SAW) have become popular in microfluidic manipulation, in solving the problems of microfluidic manipulation, but practical applications employing SAW still require more power than available via a battery. Introducing amplitude modulation at 0.5-40 kHz in SAW nebulization, which requires the highest energy input levels of all known SAW microfluidic processes, halves the power required to 1.5 W even while including the power in the sidebands, suitable for small lithium ion batteries, and maintains the nebulization rate, size, and size distributions vital to drug inhalation therapeutics. This simple yet effective means to enable an integrated SAW microfluidics device for nebulization exploits the relatively slow hydrodynamics and is furthermore shown to deliver shear-sensitive biomolecules--plasmid DNA and antibodies as exemplars of future pulmonary gene and vaccination therapies--undamaged in the nebulized mist. Altogether, the approach demonstrates a means to offer truly micro-scale microfluidics devices in a handheld, battery powered SAW nebulization device.

  15. A surface acoustic wave response detection method for passive wireless torque sensor

    Science.gov (United States)

    Fan, Yanping; Kong, Ping; Qi, Hongli; Liu, Hongye; Ji, Xiaojun

    2018-01-01

    This paper presents an effective surface acoustic wave (SAW) response detection method for the passive wireless SAW torque sensor to improve the measurement accuracy. An analysis was conducted on the relationship between the response energy-entropy and the bandwidth of SAW resonator (SAWR). A self-correlation method was modified to suppress the blurred white noise and highlight the attenuation characteristic of wireless SAW response. The SAW response was detected according to both the variation and the duration of energy-entropy ascension of an acquired RF signal. Numerical simulation results showed that the SAW response can be detected even when the signal-to-noise ratio (SNR) is 6dB. The proposed SAW response detection method was evaluated with several experiments at different conditions. The SAW response can be well distinguished from the sinusoidal signal and the noise. The performance of the SAW torque measurement system incorporating the detection method was tested. The obtained repeatability error was 0.23% and the linearity was 0.9934, indicating the validity of the detection method.

  16. Simultaneous measurement of gas concentration and temperature by the ball surface acoustic wave sensor

    Science.gov (United States)

    Yamanaka, Kazushi; Akao, Shingo; Takeda, Nobuo; Tsuji, Toshihiro; Oizumi, Toru; Tsukahara, Yusuke

    2017-07-01

    We have developed a ball surface acoustic wave (SAW) trace moisture sensor with an amorphous silica sensitive film and realized wide-range measurement from 0.017 ppmv [a frost point (FP) of -99 °C] to 6.0 × 103 ppmv (0 °C FP). However, since the sensitivity of the sensor depends on the temperature, measurement results are disturbed when the temperature largely changes. To overcome this problem, we developed a method to simultaneously measure temperature and gas concentration using a ball SAW sensor. Temperature and concentration is derived by solving equations for the delay time change at two frequencies. When the temperature had a large jump, the delay time change was significantly disturbed, but the water concentration was almost correctly measured, by compensating the sensitivity change using measured temperature. The temperature measured by a ball SAW sensor will also be used to control the ball temperature. This method will make a ball SAW sensor reliable in environments of varying temperatures.

  17. A surface acoustic wave electric field strength meter for environmental studies of HV transmission lines

    International Nuclear Information System (INIS)

    Grandolfo, M.; Ranghiasci, C.; Verona, E.

    1988-01-01

    In recent years, there has been a significant increase in concern over the health and safety aspects of high voltage transmission lines (HVTL). The majority of research has focused on effects directly or indirectly involved with the central nervous system, including physiological, ultrastructural, and biochemical alterations, changes in blood composition, behaviour, reproduction, and development. Several recent epidemiological reports have presented preliminary data suggesting an increase in the incidence of cancer among children and adults exposed to magnetic fields through living close to various types of electrical power lines or devices. With the increase in environmental concerns there has been a concomitant consideration of biological effects and health implications related to presently existing HVTL and those planned in the future. It was concluded that the electric and magnetic field strengths and the electrical discharges are the most important electrophysical factors. Thus, it has been deemed necessary to develop measuring means to determine the field strengths in areas surrounding electric installations, in particular at ground level. In the present paper an electric field meter, based on the use of a surface acoustic wave (SAW) delay line, is presented and the experimental results obtained are discussed

  18. On the exploitation of mode localization in surface acoustic wave MEMS

    Science.gov (United States)

    Hanley, T. H.; Gallacher, B. J.; Grigg, H. T. D.

    2017-05-01

    Mode localization sensing has been recently introduced as an alternative resonant sensing protocol. It has been shown to exhibit several advantages over other resonant methods, in particular a potential for higher sensitivity and rejection of common mode noise. This paper expounds the principles of utilising surface acoustic waves (SAW) to create a mode localization sensor. A generalised geometry consisting of a pair of coupled resonant cavities is introduced and an analytical solution found for the displacement fields within the cavities. The solution is achieved by coupling the internal cavity solutions using a ray tracing method. The results of the analytical solution are compared to a numerical solution found using commercial finite element method (FEM) software; exact agreement is found between the two solutions. The insight gained from the analytical model enables the determination of critical design parameters. A brief analysis is presented showing analogous operation to previous examples of mode localization sensors. The sensitivity of the device is shown to depend nonlinearly on the number of periods in the array coupling the two cavities.

  19. Implementation of guiding layers of surface acoustic wave devices: A review.

    Science.gov (United States)

    Xu, Zhangliang; Yuan, Yong J

    2018-01-15

    The purpose of overviewing research and development status of dependable, efficient, and portable and miniaturized surface acoustic wave (SAW) is to propose practical devices for biosensing and medical diagnosis. SAW Love-mode sensors fortunately have a great deal of attention during last two decades. Several periodic structure models of SAW devices were reviewed, especially interdigital transducers (IDTs), wave guiding layers, patterned-ZnO. SAW devices based on such periodic wave guiding layers and patterned-ZnO were demonstrated with superior performance, much better than conventional SAW devices. Both 2D and 3D models of phononic-crystal-based SAW devices can be respectively fabricated by an array of periodic cylindrical holes and pillars, which allowed SAW devices to have both higher Q-factor and GHz-level frequency. Ring waveguide and spherical SAW devices would have potential applications and implementation in biosensing. ZnO is one of attractive guiding-layer materials. Its nanostructures, such as nanowires, nanorods and nanofibers provided with excellent properties, will make nanoscaled SAW devices contribute to be much more sensitive in biosensors. A range of applications based on SAW and ZnO guiding-layer would be therefore expected among of immunochemical analysis, in-situ virus or bacteria determination, microfluidic automation, and cell manipulation. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Development of a Magnetostrictive FeNi Coated Surface Acoustic Wave Current Sensor

    Directory of Open Access Journals (Sweden)

    Jie Tong

    2017-07-01

    Full Text Available A magnetostrictive FeNi-coated surface acoustic wave (SAW-based current sensor was proposed in this work. The weak remanence and hysteresis effect of the FeNi itself contributes to suppress the asymmetry in sensor response at increasing and decreasing current. The sensor response was simulated by solving the coupled electromechanical field equation in layered structure considering the magnetostrictive effect and an approach of effective dielectric constant. The effects from the aspect ratio and thickness of the FeNi film on sensor response were analyzed to determine the optimal design parameters. Differential oscillation structure was used to form the sensor, in which, the FeNi thin film was deposited along the SAW propagation of the sensor chip by using RF magnetron sputtering. The magnetostrictive effect of the FeNi coating induced by the magnetic loading generates the perturbation in SAW velocity, and corresponding oscillation frequency. High sensitivity of 10.7 KHz/A, good linearity and repeatability, lower hysteresis error of 0.97% were obtained from the developed prototype 150 MHz SAW FeNi coated current sensor.

  1. Método para Medir Indirectamente la Velocidad de Fase en Sensores Surface Acoustic Wave

    Directory of Open Access Journals (Sweden)

    Leonardo Andrés Pérez

    2015-10-01

    Full Text Available El sensor de temperatura Surface Acoustic Wave (SAW ofrece amplias posibilidades para ser utilizado en ambientes hostiles. En teoría, las mediciones del SAW se pueden leer inalámbricamente sin integrar circuitos electrónicos en su estructura, permitiendo funcionalidades en mediciones a muy altas temperaturas. La literatura reporta que las variaciones de temperatura del SAW ocasionan corrimientos en su frecuencia de sincronismo, efecto que se atribuye a la sensibilidad térmica de la velocidad de fase del substrato piezoeléctrico. Caracterizar  apropiadamente el SAW requiere una buena medición de la velocidad de fase. No obstante, medir esta velocidad con respecto a la temperatura no es posible con la instrumentación actual. Este artículo reporta un método indirecto para medir estas variaciones de velocidad a través de  simulaciones basadas en el Modelo de Mason y mediciones de la respuesta en frecuencia de un prototipo SAW. Identificar la velocidad de fase del SAW conlleva a graficar, con aceptable precisión, la curva de funcionamiento del sensor, la cual puede utilizarse posteriormente como curva de calibración.

  2. A Novel Rotation Speed Measurement Method Based on Surface Acoustic Wave

    Science.gov (United States)

    Fan, Yanping; Ji, Xiaojun

    2018-01-01

    This paper presents an original passive wireless rotation speed measurement method based on surface acoustic wave (SAW) technology. A theoretical analysis was conducted on the principle of SAW rotation speed measurement and a numerical analysis on the SAW response energy pulses with different rotation angles and resonance frequencies was performed. Numerical calculation results showed that when the distance and the effective length of the antenna connected to SAWR vary with the rotation angle, the energy of acquired SAW response varies periodically. The rotation speed was estimated by searching the crossing points of the SAW response energy pulses and its mean value line. The SAW rotation speed measurement system was set up and the high performance SAW resonators were fabricated on a quartz substrate. The proposed measurement system was tested with a maximum error of 0.6 rpm, indicating that the system is capable of measuring rotation speeds from 10 to 100 rpm. Experimental results verified the validity and feasibility of presented rotation speed measurement method.

  3. Temperature dependence of immunoreactions using shear horizontal surface acoustic wave immunosensors

    Science.gov (United States)

    Kogai, Takashi; Yatsuda, Hiromi; Kondoh, Jun

    2017-07-01

    In this paper, the temperature dependence of immunoreactions, which are antibody-antigen reactions, on a shear horizontal surface acoustic wave (SH-SAW) immunosensor is described. The immunosensor is based on a reflection-type delay line on a 36° Y-cut 90° X-propagation quartz substrate, where the delay line is composed of a floating electrode unidirectional transducer (FEUDT), a grating reflector, and a sensing area between them. In order to evaluate the temperature dependence of immunoreactions, human serum albumin (HSA) antigen-antibody reactions are investigated. The SH-SAW immunosensor chip is placed in a thermostatic chamber and the changes in the SH-SAW velocity resulting from the immunoreactions are measured at different temperatures. As a result, it is observed that the HSA immunoreactions are influenced by the ambient temperature and that higher temperatures provide more active reactions. In order to analyze the immunoreactions, an analytical approach using an exponential fitting method for changes in SH-SAW velocity is employed.

  4. X-ray fluorescence holography.

    Science.gov (United States)

    Hayashi, Kouichi; Happo, Naohisa; Hosokawa, Shinya; Hu, Wen; Matsushita, Tomohiro

    2012-03-07

    X-ray fluorescence holography (XFH) is a method of atomic resolution holography which utilizes fluorescing atoms as a wave source or a monitor of the interference field within a crystal sample. It provides three-dimensional atomic images around a specified element and has a range of up to a few nm in real space. Because of this feature, XFH is expected to be used for medium-range local structural analysis, which cannot be performed by x-ray diffraction or x-ray absorption fine structure analysis. In this article, we explain the theory of XFH including solutions to the twin-image problem, an advanced measuring system, and data processing for the reconstruction of atomic images. Then, we briefly introduce our recent applications of this technique to the analysis of local lattice distortions in mixed crystals and nanometer-size clusters appearing in the low-temperature phase of a shape-memory alloy.

  5. X-ray fluorescence holography

    International Nuclear Information System (INIS)

    Hayashi, Kouichi; Happo, Naohisa; Hosokawa, Shinya; Hu Wen; Matsushita, Tomohiro

    2012-01-01

    X-ray fluorescence holography (XFH) is a method of atomic resolution holography which utilizes fluorescing atoms as a wave source or a monitor of the interference field within a crystal sample. It provides three-dimensional atomic images around a specified element and has a range of up to a few nm in real space. Because of this feature, XFH is expected to be used for medium-range local structural analysis, which cannot be performed by x-ray diffraction or x-ray absorption fine structure analysis. In this article, we explain the theory of XFH including solutions to the twin-image problem, an advanced measuring system, and data processing for the reconstruction of atomic images. Then, we briefly introduce our recent applications of this technique to the analysis of local lattice distortions in mixed crystals and nanometer-size clusters appearing in the low-temperature phase of a shape-memory alloy. (topical review)

  6. Atomic-resolution neutron holography

    International Nuclear Information System (INIS)

    Cser, L.; Toeroek, Gy.; Krexner, G.

    2001-01-01

    Atomic-resolution neutron holography can be realised by two different schemes. In the frame of the first approach a point-like source of slow neutrons is produced inside the investigated crystal. Due to the extremely large value of the incoherent-scattering cross-section of the proton, hydrogen atoms imbedded in a metal single-crystal lattice may serve as point-like sources when the sample is irradiated by a monochromatic beam of slow neutrons. The second approach utilizes the registration of the interference between the incident and scattered waves by means of a point-like detector inserted in the lattice of the crystal under investigation. In addition, neutron-induced electron holography is considered. The feasibility of these ideas is discussed. (orig.)

  7. Axial-resolution in depth from focus digital holography

    Science.gov (United States)

    van Rooij, Joseph; Kalkman, Jeroen

    2017-06-01

    We use digital holography to quantify surface topography of rough objects in full-field. We calculate the variance of the intensity image as a focus metric over a set of reconstruction distances for each pixel, which results in a focus metric curve. The distance where the variance peaks is an estimate for the depth. First we analyze the lateral resolution of this method using the Talbot effect and argue that sub-mm axial resolution is feasible. Then, using a Michelson setup without magnifying optics or lateral scanning we experimentally demonstrate that sub-mm FWHM width of the focus curve can be achieved. This is significantly better than what was previously reported using digital holography and could make this technique useful for characterising objects in art and machine vision.

  8. Flat holography and Carrollian fluids arXiv

    CERN Document Server

    Ciambelli, Luca; Petkou, Anastasios C.; Petropoulos, P. Marios; Siampos, Konstantinos

    We show that a holographic description of four-dimensional asymptotically locally flat spacetimes is reached smoothly from the zero-cosmological-constant limit of anti-de Sitter holography. To this end, we use the derivative expansion of fluid/gravity correspondence. From the boundary perspective, the vanishing of the bulk cosmological constant appears as the zero velocity of light limit. This sets how Carrollian geometry emerges in flat holography. The new boundary data are a two-dimensional spatial surface, identified with the null infinity of the bulk Ricci-flat spacetime, accompanied with a Carrollian time and equipped with a Carrollian structure, plus the dynamical observables of a conformal Carrollian fluid. These are the energy, the viscous stress tensors and the heat currents, whereas the Carrollian geometry is gathered by a two-dimensional spatial metric, a frame connection and a scale factor. The reconstruction of Ricci-flat spacetimes from Carrollian boundary data is conducted with a flat derivativ...

  9. Importance of ultrasonic holography as imaging technique of material faults

    International Nuclear Information System (INIS)

    Schmitz, V.

    1978-01-01

    In ultra-sound testing of thick-wall components the reconstruction of shape and position of material faults stands in the foreground. Ultra-sound holography allows imaging of this kind. The principle of this technique is to completely measure the amount and phase of a sound field arising from the fault location on the surface of the material-piece. The quantity is measured as a complex quantity. To accomplish this, ultra-sound holography works with monochromatic burst-signals. The recording of phase and amplitude formation can be made optically by means of a film carrier as well as numerically in a computer. Corresponding to this fact the reconstruction takes place by means of a laser beam or by means of mathematical formalisms in the computer. Both the methods are realized today and are applied in destruction-free testing. (orig./DG) [de

  10. Multicolor Holography With Phase Shifting

    Science.gov (United States)

    Vikram, Chandra S.

    1996-01-01

    Prototype apparatus constructed to test feasibility of two-color holographic interferometric scheme in which data for reconstructing holographic wavefront obtained with help of phase-shifting technique. Provides two sets of data needed to solve equations for effects of temperature and concentration. Concept extended to holography at three or more wavelengths to measure three or more phenomena associated with significant variations in index of refraction

  11. Holography: childrens' window to relativity

    Science.gov (United States)

    MacShane, James E.

    1995-02-01

    This paper is concerned with the development of the concept of natural education. Psychology has discovered that all humans learn intuitively the cultural concepts of time from birth to eight and one-half to ten years of age. Einstein showed us that this must also be the natural time for the development of spatial concepts. The importance of this has been dramatized for me in the past eight years that I have been developing the Laser Arts and Holography Programs and Workshops. I have worked with over 100,000 students kindergarten through eighth grade. I have worked with 175 students age 8 to 10 in three hour and one half workshops specifically on the development of time and space concepts. The concepts developed are based upon the vast amount of psychological evidence related to the natural development of time and space understandings, Dr. Nils Abramson's 'Light in Flight' and subsequent work on the clarification of relativity through holography, and Maria Montessori's method of Scientific Education. The paper also demonstrates the natural method of teaching science to younger students is to teach scientifically. All of the research which has been done in the past 100 years has been used by the educational institutions to try to improve the system. What has not been done is changing the system to how humans learn. Because of the perceived hi-tech nature of the program I am able to dramatize the potential. An outline for a holography curriculum kindergarten through eighth grade is included.

  12. Application of Compressive Sensing to Digital Holography

    Science.gov (United States)

    2015-05-01

    AFRL-RY-WP-TR-2015-0071 APPLICATION OF COMPRESSIVE SENSING TO DIGITAL HOLOGRAPHY Mark Neifeld University of Arizona...LADAR Technology Branch LADAR Technology Branch Multispectral Sensing and Detection Division Multispectral Sensing and Detection Division...From - To) May 2015 Final 3 September 2013 – 27 February 2015 4. TITLE AND SUBTITLE APPLICATION OF COMPRESSIVE SENSING TO DIGITAL HOLOGRAPHY 5a

  13. Progress in industrial holography in France

    Science.gov (United States)

    Smigielski, Paul

    1992-01-01

    Industrial applications of holography in France are briefly reviewed. Particular attention is given to nondestructive testing of helicopter blades at Aerospatiale Central Laboratory, the use of holography at Renault for car-engine vibration study, vibration characterization of turbo-jet engine components at SNECMA, and vibration analysis of plates in an industrial hemodynamic tunnel.

  14. Nd:YAG laser for holography

    International Nuclear Information System (INIS)

    Bykovsky, Yu.A.; Evtihiev, N.N.; Larkin, A.I.

    1982-01-01

    Different possibilities to use photonics, holography and optical processing for nuclear physics has been investigated in our works. The paper presents the results of the study of time and spatial coherence of Nd:YAG laser and application in holography. (orig./HSI)

  15. Surface acoustic wave nebulization of peptides as a microfluidic interface for mass spectrometry.

    Science.gov (United States)

    Heron, Scott R; Wilson, Rab; Shaffer, Scott A; Goodlett, David R; Cooper, Jonathan M

    2010-05-15

    We describe the fabrication of a surface acoustic wave (SAW) device on a LiNbO(3) piezoelectric transducer for the transfer of nonvolatile analytes to the gas phase at atmospheric pressure (a process referred to as nebulization or atomization). We subsequently show how such a device can be used in the field of mass spectrometry (MS) detection, demonstrating that SAW nebulization (SAWN) can be performed either in a discontinuous or pulsed mode, similar to that for matrix assisted laser desorption ionization (MALDI) or in a continuous mode like electrospray ionization (ESI). We present data showing the transfer of peptides to the gas phase, where ions are detected by MS. These peptide ions were subsequently fragmented by collision-induced dissociation, from which the sequence was assigned. Unlike MALDI mass spectra, which are typically contaminated with matrix ions at low m/z, the SAWN generated spectra had no such interference. In continuous mode, the SAWN plume was sampled on a microsecond time scale by a linear ion trap mass spectrometer and produced multiply charged peptide precursor ions with a charge state distribution shifted to higher m/z compared to an identical sample analyzed by ESI. The SAWN technology also provides the opportunity to re-examine a sample from a flat surface, repeatedly. The process can be performed without the need for capillaries, which can clog, reservoirs, which dilute the sample, and electrodes, which when in direct contact with sample, cause unwanted electrochemical oxidation. In both continuous and pulsed sampling modes, the quality of precursor ion scans and tandem mass spectra of peptides was consistent across the plume's lifetime.

  16. Dynamic Rabi oscillations in a quantum dot embedded in a nanobridge in the presence of surface acoustic waves

    Science.gov (United States)

    Mourokh, L.; Wixforth, A.; Beil, F.; Bichler, M.; Wegscheider, W.; Blick, R. H.

    2017-10-01

    A quantum dot is created within a suspended nanobridge containing a two-dimensional electron gas. The electron current through this dot exhibits well-pronounced Coulomb blockade oscillations. When surface acoustic waves (SAW) are driven through the nanobridge, Coulomb blockade peaks are shifted. To explain this feature, we derive the expressions for the quantum dot level populations and electron currents through these levels and show that SAW-induced Rabi oscillations lead to the observed phenomenology.

  17. Continuous sheathless microparticle and cell patterning using CL-SSAWs (conductive liquid-based standing surface acoustic waves)

    OpenAIRE

    Jeonghun Nam; Jae Young Kim; Chae Seung Lim

    2017-01-01

    We present continuous, sheathless microparticle patterning using conductive liquid (CL)-based standing surface acoustic waves (SSAWs). Conventional metal electrodes patterned on a piezoelectric substrate were replaced with electrode channels filled with a CL. The device performance was evaluated with 5-μm fluorescent polystyrene particles at different flow rate and via phase shifting. In addition, our device was further applied to continuous concentration of malaria parasites at the sidewalls...

  18. Continuous sheathless microparticle and cell patterning using CL-SSAWs (conductive liquid-based standing surface acoustic waves

    Directory of Open Access Journals (Sweden)

    Jeonghun Nam

    2017-01-01

    Full Text Available We present continuous, sheathless microparticle patterning using conductive liquid (CL-based standing surface acoustic waves (SSAWs. Conventional metal electrodes patterned on a piezoelectric substrate were replaced with electrode channels filled with a CL. The device performance was evaluated with 5-μm fluorescent polystyrene particles at different flow rate and via phase shifting. In addition, our device was further applied to continuous concentration of malaria parasites at the sidewalls of the fluidic channel.

  19. Development of a passive and remote magnetic microsensor with thin-film giant magnetoimpedance element and surface acoustic wave transponder

    KAUST Repository

    Al Rowais, Hommood

    2011-01-01

    This paper presents the development of a wireless magnetic field sensor consisting of a three-layer thin-film giant magnetoimpedance sensor and a surface acoustic wave device on one substrate. The goal of this integration is a passive and remotely interrogated sensor that can be easily mass fabricated using standard microfabrication tools. The design parameters, fabrication process, and a model of the integrated sensor are presented together with experimental results of the sensor. © 2011 American Institute of Physics.

  20. Implementing wavelet inverse-transform processor with surface acoustic wave device.

    Science.gov (United States)

    Lu, Wenke; Zhu, Changchun; Liu, Qinghong; Zhang, Jingduan

    2013-02-01

    The objective of this research was to investigate the implementation schemes of the wavelet inverse-transform processor using surface acoustic wave (SAW) device, the length function of defining the electrodes, and the possibility of solving the load resistance and the internal resistance for the wavelet inverse-transform processor using SAW device. In this paper, we investigate the implementation schemes of the wavelet inverse-transform processor using SAW device. In the implementation scheme that the input interdigital transducer (IDT) and output IDT stand in a line, because the electrode-overlap envelope of the input IDT is identical with the one of the output IDT (i.e. the two transducers are identical), the product of the input IDT's frequency response and the output IDT's frequency response can be implemented, so that the wavelet inverse-transform processor can be fabricated. X-112(0)Y LiTaO(3) is used as a substrate material to fabricate the wavelet inverse-transform processor. The size of the wavelet inverse-transform processor using this implementation scheme is small, so its cost is low. First, according to the envelope function of the wavelet function, the length function of the electrodes is defined, then, the lengths of the electrodes can be calculated from the length function of the electrodes, finally, the input IDT and output IDT can be designed according to the lengths and widths for the electrodes. In this paper, we also present the load resistance and the internal resistance as the two problems of the wavelet inverse-transform processor using SAW devices. The solutions to these problems are achieved in this study. When the amplifiers are subjected to the input end and output end for the wavelet inverse-transform processor, they can eliminate the influence of the load resistance and the internal resistance on the output voltage of the wavelet inverse-transform processor using SAW device. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. Acoustic-gravity waves generated by atmospheric and near-surface sources

    Science.gov (United States)

    Kunitsyn, Viacheslav E.; Kholodov, Alexander S.; Krysanov, Boris Yu.; Andreeva, Elena S.; Nesterov, Ivan A.; Vorontsov, Artem M.

    2013-04-01

    Numerical simulation of the acoustic-gravity waves (AGW) generated by long-period oscillations of the Earth's (oceanic) surface, earthquakes, explosions, thermal heating, seiches, and tsunami is carried out. Wavelike disturbances are quite frequent phenomena in the atmosphere and ionosphere. These events can be caused by the impacts from space and atmosphere, by oscillations of the Earth'as surface and other near-surface events. These wavelike phenomena in the atmosphere and ionosphere appear as the alternating areas of enhanced and depleted density (in the atmosphere) or electron concentration (in the ionosphere). In the paper, AGW with typical frequencies of a few hertz - millihertz are analyzed. AGW are often observed after the atmospheric perturbations, during the earthquakes, and some time (a few days to hours) in advance of the earthquakes. Numerical simulation of the generation of AGW by long-period oscillations of the Earth's and oceanic surface, earthquakes, explosions, thermal heating, seiches, and tsunami is carried out. The AGW generated by the near-surface phenomena within a few hertz-millihertz frequency range build up at the mid-atmospheric and ionospheric altitudes, where they assume their typical spatial scales of the order of a few hundred kilometers. Oscillations of the ionospheric plasma within a few hertz-millihertz frequency range generate electromagnetic waves with corresponding frequencies as well as travelling ionospheric irregularities (TIDs). Such structures can be successfully monitored using satellite radio tomography (RT) techniques. For the purposes of RT diagnostics, 150/400 MHz transmissions from low-orbiting navigational satellites flying in polar orbits at the altitudes of about 1000 km as well as 1.2-1.5 GHz signals form high-orbiting (orbital altitudes about 20000 km) navigation systems like GPS/GLONASS are used. The results of experimental studies on generation of wavelike disturbances by particle precipitation are presented

  2. HoloNetwork: communicating science through holography

    Science.gov (United States)

    Pombo, Pedro; Santos, Emanuel; Magalhães, Carolina

    2017-03-01

    Since 1997 a program dedicated to holography has been developed and implemented in Portugal. This program started with focus on schools and science education. The HoloNetwork was created and it has been spread at a National level, involving a group of thirty schools and hundreds of students and teachers. In 2009 this network started to work to achieve a new target, the general public. With this goal, a larger program was developed with focus on science and society and on science communication through holography. For the implementation of this new program, special holography outreach activities were built, dedicated to informal learning and seven Science Centers around Portugal were add into the HoloNetwork. During last years, we have been working on holography, based on two main branches, one dedicated to schools and with the aimed to promote physics teaching and to teach how to make holograms, and another dedicated to society and with the aimed to promote holography and to increase scientific literacy. This paper would analyze the educational program, all holography outreach activities, exhibitions or events, all equipments, materials and setups used and it would present the holographic techniques explored with students or with the public. Finally, the results obtained in this work would be present and explored, with focus on students impact and outcomes, taking into account the public engagement on holography and its effect into scientific culture and analyzing the quality of holograms made by students and by the general public. subject.

  3. High-intensity x-ray holography: an approach to high-resolution snapshot imaging of biological specimens

    Energy Technology Data Exchange (ETDEWEB)

    Solem, J.C.

    1982-08-01

    The crucial physical and technological issues pertaining to the holographic imaging of biological structures with a short-pulse, high-intensity, high-quantum-energy laser were examined. The limitations of x-ray optics are discussed. Alternative holographic techniques were considered, and it was concluded that far-field Fresnel transform holography (Fraunhofer holography) using a photoresist recording surface is most tractable with near term technology. The hydrodynamic expansion of inhomogeneities within the specimen is discussed. It is shown that expansion is the major source of image blurring. Analytic expressions were derived for the explosion of protein concentrations in an x-ray transparent cytoplasm, compared with numerical calculations, and corrections derived to account for the competitive transport processes by which these inhomogeneities lose energy. It is concluded that for the near term Fresnel transform holography, particularly, far-field or Fraunhofer holography, is more practical than Fourier transform holography. Of the alternative fine grain recording media for use with Fresnel transform holography, a photo-resist is most attractive. For best resolution, exposure times must be limited to a few picoseconds, and this calls for investigation of mechanisms to shutter the laser or gate the recording surface. The best contrast ratio between the nitrogen-bearing polymers (protein and the nucleic acids) and water is between the K-edges of oxygen and nitrogen.

  4. On-line metrology with conoscopic holography: beyond triangulation.

    Science.gov (United States)

    Alvarez, Ignacio; Enguita, Jose M; Frade, María; Marina, Jorge; Ojea, Guillermo

    2009-01-01

    On-line non-contact surface inspection with high precision is still an open problem. Laser triangulation techniques are the most common solution for this kind of systems, but there exist fundamental limitations to their applicability when high precisions, long standoffs or large apertures are needed, and when there are difficult operating conditions. Other methods are, in general, not applicable in hostile environments or inadequate for on-line measurement. In this paper we review the latest research in Conoscopic Holography, an interferometric technique that has been applied successfully in this kind of applications, ranging from submicrometric roughness measurements, to long standoff sensors for surface defect detection in steel at high temperatures.

  5. Sound Visualization and Holography

    Science.gov (United States)

    Kock, Winston E.

    1975-01-01

    Describes liquid surface holograms including their application to medicine. Discusses interference and diffraction phenomena using sound wave scanning techniques. Compares focussing by zone plate to holographic image development. (GH)

  6. Acoustic streaming in a microfluidic channel with a reflector: Case of a standing wave generated by two counterpropagating leaky surface waves.

    Science.gov (United States)

    Doinikov, Alexander A; Thibault, Pierre; Marmottant, Philippe

    2017-07-01

    A theory is developed for the modeling of acoustic streaming in a microfluidic channel confined between an elastic solid wall and a rigid reflector. A situation is studied where the acoustic streaming is produced by two leaky surface waves that propagate towards each other in the solid wall and thus form a combined standing wave in the fluid. Full analytical solutions are found for both the linear acoustic field and the field of the acoustic streaming. A dispersion equation is derived that allows one to calculate the wave speed in the system under study. The obtained solutions are used to consider particular numerical examples and to reveal the structure of the acoustic streaming. It is shown that two systems of vortices are established along the boundaries of the microfluidic channel.

  7. Holography through optically active windows

    Science.gov (United States)

    Decker, A. J.

    1979-01-01

    By using two orthogonally polarized reference beams, holograms can be recorded through stressed windows and the reconstructed virtual image will show no stress pattern. As shown analytically, the stress-pattern-free hologram is recordable for any polarization state of the object illumination. Hence, the more efficient nondepolarizing diffuser can be used in performing holography through stressed windows if two reference beams are used. Results are presented for a pair of machined polysulfone windows intended for use in a holographic flow-visualization setup in a single-stage-compressor test rig.

  8. Simulation study and guidelines to generate Laser-induced Surface Acoustic Waves for human skin feature detection

    Science.gov (United States)

    Li, Tingting; Fu, Xing; Chen, Kun; Dorantes-Gonzalez, Dante J.; Li, Yanning; Wu, Sen; Hu, Xiaotang

    2015-12-01

    Despite the seriously increasing number of people contracting skin cancer every year, limited attention has been given to the investigation of human skin tissues. To this regard, Laser-induced Surface Acoustic Wave (LSAW) technology, with its accurate, non-invasive and rapid testing characteristics, has recently shown promising results in biological and biomedical tissues. In order to improve the measurement accuracy and efficiency of detecting important features in highly opaque and soft surfaces such as human skin, this paper identifies the most important parameters of a pulse laser source, as well as provides practical guidelines to recommended proper ranges to generate Surface Acoustic Waves (SAWs) for characterization purposes. Considering that melanoma is a serious type of skin cancer, we conducted a finite element simulation-based research on the generation and propagation of surface waves in human skin containing a melanoma-like feature, determine best pulse laser parameter ranges of variation, simulation mesh size and time step, working bandwidth, and minimal size of detectable melanoma.

  9. Elastic Characterization of Transparent and Opaque Films, Multilayers and Acoustic Resonators by Surface Brillouin Scattering: A Review

    Directory of Open Access Journals (Sweden)

    Giovanni Carlotti

    2018-01-01

    Full Text Available There is currently a renewed interest in the development of experimental methods to achieve the elastic characterization of thin films, multilayers and acoustic resonators operating in the GHz range of frequencies. The potentialities of surface Brillouin light scattering (surf-BLS for this aim are reviewed in this paper, addressing the various situations that may occur for the different types of structures. In particular, the experimental methodology and the amount of information that can be obtained depending on the transparency or opacity of the film material, as well as on the ratio between the film thickness and the light wavelength, are discussed. A generalization to the case of multilayered samples is also provided, together with an outlook on the capability of the recently developed micro-focused scanning version of the surf-BLS technique, which opens new opportunities for the imaging of the spatial profile of the acoustic field in acoustic resonators and in artificially patterned metamaterials, such as phononic crystals.

  10. Effect of fiber surface conditioning on the acoustic emission behavior of steel fiber reinforced concrete

    Science.gov (United States)

    Aggelis, D. G.; Soulioti, D. V.; Gatselou, E.; Barkoula, N. M.; Paipetis, A.; Matikas, T. E.

    2011-04-01

    The role of coating in preserving the bonding between steel fibers and concrete is investigated in this paper. Straight types of fibers with and without chemical coating are used in steel fiber reinforced concrete mixes. The specimens are tested in bending with concurrent monitoring of their acoustic emission activity throughout the failure process using two broadband sensors. The different stages of fracture (before, during and after main crack formation) exhibit different acoustic fingerprints, depending on the mechanisms that are active during failure (concrete matrix micro-cracking, macro-cracking and fiber pull out). Additionally, it was seen that the acoustic emission behaviour exhibits distinct characteristics between coated and uncoated fiber specimens. Specifically, the frequency of the emitted waves is much lower for uncoated fiber specimens, especially after the main fracture incident, during the fiber pull out stage of failure. Additionally, the duration and the rise time of the acquired waveforms are much higher for uncoated specimens. These indices are used to distinguish between tensile and shear fracture in concrete and suggest that friction is much stronger for the uncoated fibers. On the other hand, specimens with coated fibers exhibit more tensile characteristics, more likely due to the fact that the bond between fibers and concrete matrix is stronger. The fibers therefore, are not simply pulled out but also detach a small volume of the brittle concrete matrix surrounding them. It seems that the effect of chemical coating can be assessed by acoustic emission parameters additionally to the macroscopic measurements of ultimate toughness.

  11. Conoscopic holography: two-dimensional numerical reconstructions.

    Science.gov (United States)

    Mugnier, L M; Sirat, G Y; Charlot, D

    1993-01-01

    Conoscopic holography is an incoherent light holographic technique based on the properties of crystal optics. We present experimental results of the numerical reconstruction of a two-dimensional object from its conoscopic hologram.

  12. Holography: Art in an Ephemeral Medium.

    Science.gov (United States)

    Buterbaugh, James G.

    1979-01-01

    The science of holography provides an opportunity to see reality by illusion using laser light, lenses, and mirrors. To develop as holographic artists, students must first gain proficiency in using its techniques, equipment, and materials. (Author/CMV)

  13. General temperature field measurement by digital holography

    Czech Academy of Sciences Publication Activity Database

    Doleček, Roman; Psota, Pavel; Lédl, Vít; Vít, Tomáš; Václavík, Jan; Kopecký, V.

    2013-01-01

    Roč. 52, č. 1 (2013), A319-A325 ISSN 1559-128X Institutional support: RVO:61389021 Keywords : digital holography * temperature field measurement * tomography Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.649, year: 2013

  14. Holography as a Liberal Arts Physics Course

    Science.gov (United States)

    Huang, Jacob Wen-kuang

    1978-01-01

    Describes a liberal arts physics course for all majors interested in holography or to satisfy the general education requirements. An outline of the course and some experience of offering it are given. (Author/GA)

  15. Theoretical Study of the Effect of Enamel Parameters on Laser-Induced Surface Acoustic Waves in Human Incisor

    Science.gov (United States)

    Yuan, Ling; Sun, Kaihua; Shen, Zhonghua; Ni, Xiaowu; Lu, Jian

    2015-06-01

    The laser ultrasound technique has great potential for clinical diagnosis of teeth because of its many advantages. To study laser surface acoustic wave (LSAW) propagation in human teeth, two theoretical methods, the finite element method (FEM) and Laguerre polynomial extension method (LPEM), are presented. The full field temperature values and SAW displacements in an incisor can be obtained by the FEM. The SAW phase velocity in a healthy incisor and dental caries is obtained by the LPEM. The methods and results of this work can provide a theoretical basis for nondestructive evaluation of human teeth with LSAWs.

  16. Surface acoustic wave quasi-zero-temperature cuts in Ba2NaNb5O15

    International Nuclear Information System (INIS)

    Henaff, J.; Feldmann, M.

    1983-01-01

    Surface acoustic wave properties of Ba 2 NaNb 5 O 15 crystals are investigated in terms of electromechanical coupling coefficient k 2 and frequency temperature coefficients. A X-rotated cut and a Y-rotated cut are selected for their fair coupling. Experimental verifications on a Union Carbide Ba 2 NaNb 5 O 15 crystal proved excellent agreement for the coupling (1.2%) and markedly better results than computed for the frequency-temperature coefficient. The best value is measured to be as low as 1.5 ppm/K for cut, (101) propagation

  17. Analytical Model of the Nonlinear Dynamics of Cantilever Tip-Sample Surface Interactions for Various Acoustic-Atomic Force Microscopies

    Science.gov (United States)

    Cantrell, John H., Jr.; Cantrell, Sean A.

    2008-01-01

    A comprehensive analytical model of the interaction of the cantilever tip of the atomic force microscope (AFM) with the sample surface is developed that accounts for the nonlinearity of the tip-surface interaction force. The interaction is modeled as a nonlinear spring coupled at opposite ends to linear springs representing cantilever and sample surface oscillators. The model leads to a pair of coupled nonlinear differential equations that are solved analytically using a standard iteration procedure. Solutions are obtained for the phase and amplitude signals generated by various acoustic-atomic force microscope (A-AFM) techniques including force modulation microscopy, atomic force acoustic microscopy, ultrasonic force microscopy, heterodyne force microscopy, resonant difference-frequency atomic force ultrasonic microscopy (RDF-AFUM), and the commonly used intermittent contact mode (TappingMode) generally available on AFMs. The solutions are used to obtain a quantitative measure of image contrast resulting from variations in the Young modulus of the sample for the amplitude and phase images generated by the A-AFM techniques. Application of the model to RDF-AFUM and intermittent soft contact phase images of LaRC-cp2 polyimide polymer is discussed. The model predicts variations in the Young modulus of the material of 24 percent from the RDF-AFUM image and 18 percent from the intermittent soft contact image. Both predictions are in good agreement with the literature value of 21 percent obtained from independent, macroscopic measurements of sheet polymer material.

  18. Impulse excitation scanning acoustic microscopy for local quantification of Rayleigh surface wave velocity using B-scan analysis.

    Science.gov (United States)

    Cherry, M; Dierken, J; Boehnlein, T; Pilchak, A; Sathish, S; Grandhi, R

    2018-01-01

    A new technique for performing quantitative scanning acoustic microscopy imaging of Rayleigh surface wave (RSW) velocity was developed based on b-scan processing. In this technique, the focused acoustic beam is moved through many defocus distances over the sample and excited with an impulse excitation, and advanced algorithms based on frequency filtering and the Hilbert transform are used to post-process the b-scans to estimate the Rayleigh surface wave velocity. The new method was used to estimate the RSW velocity on an optically flat E6 glass sample, and the velocity was measured at ±2 m/s and the scanning time per point was on the order of 1.0 s, which are both improvement from the previous two-point defocus method. The new method was also applied to the analysis of two titanium samples, and the velocity was estimated with very low standard deviation in certain large grains on the sample. A new behavior was observed with the b-scan analysis technique where the amplitude of the surface wave decayed dramatically on certain crystallographic orientations. The new technique was also compared with previous results, and the new technique has been found to be much more reliable and to have higher contrast than previously possible with impulse excitation.

  19. Impulse excitation scanning acoustic microscopy for local quantification of Rayleigh surface wave velocity using B-scan analysis

    Science.gov (United States)

    Cherry, M.; Dierken, J.; Boehnlein, T.; Pilchak, A.; Sathish, S.; Grandhi, R.

    2018-01-01

    A new technique for performing quantitative scanning acoustic microscopy imaging of Rayleigh surface wave (RSW) velocity was developed based on b-scan processing. In this technique, the focused acoustic beam is moved through many defocus distances over the sample and excited with an impulse excitation, and advanced algorithms based on frequency filtering and the Hilbert transform are used to post-process the b-scans to estimate the Rayleigh surface wave velocity. The new method was used to estimate the RSW velocity on an optically flat E6 glass sample, and the velocity was measured at ±2 m/s and the scanning time per point was on the order of 1.0 s, which are both improvement from the previous two-point defocus method. The new method was also applied to the analysis of two titanium samples, and the velocity was estimated with very low standard deviation in certain large grains on the sample. A new behavior was observed with the b-scan analysis technique where the amplitude of the surface wave decayed dramatically on certain crystallographic orientations. The new technique was also compared with previous results, and the new technique has been found to be much more reliable and to have higher contrast than previously possible with impulse excitation.

  20. Pseudo - Color Reflection Holography - An Artist's Perspective

    Science.gov (United States)

    Crenshaw, M. M.

    1987-06-01

    A survey of display holography shows that an arbitrary use of color lends little to the overall success of the intention of an image. Often the lack of concern regarding color detracts from the hologram and its ability to effectively communicate ideas in a visual format. Creative opportunities offered by pseudo-color reflection techniques and their impact on display holography will be considered. A review of the current procedures for producing pseudo-color reflection holograms is presented.

  1. Line-focus probe excitation of Scholte acoustic waves at the liquid-loaded surfaces of periodic structures

    International Nuclear Information System (INIS)

    Every, A.G.; Vines, R.E.; Wolfe, J.P.

    1999-01-01

    A model is introduced to explain our observation of Scholte-like ultrasonic waves traveling at the water-loaded surfaces of solids with periodically varying properties. The observations pertain to two two-dimensional superlattices: a laminated solid of alternating 0.5-mm-thick layers of aluminum and a polymer, and a hexagonal array of polymer rods of lattice spacing 1 mm in an aluminum matrix. The surface waves are generated and detected by line focus acoustic lenses aligned parallel to each other, and separated by varying distances. The acoustic fields of these lenses may be considered a superposition of plain bulk waves with wave normals contained within the angular apertures of the lenses. For homogeneous solids, phase matching constraints do not allow the Scholte wave to be coupled into with an experimental configuration of this type. This is not true for a spatially periodic solid, where coupling between bulk waves and the Scholte surface wave takes place through Umklapp processes involving a change in the wave-vector component parallel to the surface by a reciprocal lattice vector. In the experiments, the source pulse is broadband, extending up to about 6 MHz, whereas the spectrum of the observed Scholte wave is peaked at around 4 and 4.5 MHz for the layered solid and hexagonal lattice, respectively. We attribute this to a resonance in the surface response of the solid, possibly associated with a critical point in the dispersion relation of the superlattice. On rotating the solid about its surface normal, the Scholte wave displays dramatic variation in phase arrival time and, to a lesser extent, also group arrival time. This variation is well accounted for by our model. copyright 1999 The American Physical Society

  2. Introduction to holography - theory - experimental equipment; Introduction a l'holographie - theorie - dispositifs experimentaux

    Energy Technology Data Exchange (ETDEWEB)

    Consoli, T.; Proca, G.; Slama, L. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-07-01

    This work presents the theory and the technic in the field of holography. It makes a synthesis of the present knowledge in that field. (authors) [French] Ce travail expose les theories et les techniques dans le domaine de l'holographie. Il fait la synthese des connaissances acquises a ce jour dans ce domaine en evolution rapide. (auteurs)

  3. Holography and optical computing: the ongoing entanglement

    Science.gov (United States)

    Caulfield, H. John

    2003-05-01

    Holography records not a 3D image but an encrypted wavefront. To determine what object must have caused that wavefront, we must solve the inverse problem. Most of the time, inverse problems are singular, but in certain very simple cases they are not and an optical computer does that very well. In others, it is disastrous. So, optical computing has been part of holography from its beginning in 1947. It was not until 1962 with VanderLugt's work on Fourier Optical pattern recognitiion that holography became part of optical computing. In this paper, I review both directions of that continuing intercourse between hologrpahy and optical computing. Neither requires the other, and both are sometimes best without the other. But there remain a few cases where the fit seems ideal. The processing and recording and modification of spectral-temporal patterns is the test case I will use to illustrate their constructive relationships. Here are some examples: Spectral recognition is best done in the optical domain by holography. Temporal pulse shaping is best done in the optical domain by holography. Temporal pulses are best recorded by holography.

  4. Shallow Water Acoustic Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Supports experimental research where high-frequency acoustic scattering and surface vibration measurements of fluid-loaded and non-fluid-loaded structures...

  5. Laboratory for Structural Acoustics

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Supports experimental research where acoustic radiation, scattering, and surface vibration measurements of fluid-loaded and non-fluid-loaded structures are...

  6. Effects of the Distance from a Diffusive Surface on the Objective and Perceptual Evaluation of the Sound Field in a Small Simulated Variable-Acoustics Hall

    Directory of Open Access Journals (Sweden)

    Louena Shtrepi

    2017-02-01

    Full Text Available Simulations of the acoustic effects that diffusive surfaces have on the objective acoustic parameters and on sound perception have not yet been fully understood. To this end, acoustic simulations have been performed in Odeon in the model of a variable-acoustic concert hall. This paper is presented as a follow-up study to a previous paper that dealt with in-field measurements only. As in measurements, a diffusive and a reflective condition of one of the lateral walls have been considered in the room models. Two modeling alternatives of the diffusive condition, that is, (a a flat surface with high scattering coefficient applied; and (b a triangular relief modeled including edge diffraction, have been investigated. Objective acoustic parameters, such as early decay time (EDT, reverberation time (T30, clarity (C80, definition (D50, and interaural cross correlation (IACC, have been compared between the two conditions. Moreover, an auditory experiment has been performed to determine the maximum distance from a diffusive surface at which the simulated acoustic scattering effects are still audible. Although the simulated objective results showed a good match with measured values, the subjective results showed that the differences between the diffuse and reflective conditions become significant when model (b is used.

  7. Non-leaky modes and bandgaps of surface acoustic waves in wrinkled stiff-film/compliant-substrate bilayers

    Science.gov (United States)

    Li, Guo-Yang; Xu, Guoqiang; Zheng, Yang; Cao, Yanping

    2018-03-01

    Surface acoustic wave (SAW) devices have found a wide variety of technical applications, including SAW filters, SAW resonators, microfluidic actuators, biosensors, flow measurement devices, and seismic wave shields. Stretchable/flexible electronic devices, such as sensory skins for robotics, structural health monitors, and wearable communication devices, have received considerable attention across different disciplines. Flexible SAW devices are essential building blocks for these applications, wherein piezoelectric films may need to be integrated with the compliant substrates. When piezoelectric films are much stiffer than soft substrates, SAWs are usually leaky and the devices incorporating them suffer from acoustic losses. In this study, the propagation of SAWs in a wrinkled bilayer system is investigated, and our analysis shows that non-leaky modes can be achieved by engineering stress patterns through surface wrinkles in the system. Our analysis also uncovers intriguing bandgaps (BGs) related to the SAWs in a wrinkled bilayer system; these are caused by periodic deformation patterns, which indicate that diverse wrinkling patterns could be used as metasurfaces for controlling the propagation of SAWs.

  8. Holography without strings?

    International Nuclear Information System (INIS)

    Marolf, Donald

    2014-01-01

    A defining feature of holographic dualities is that, along with the bulk equations of motion, boundary correlators at any given time t determine those of observables deep in the bulk. We argue that this property emerges from the bulk gravitational Gauss law together with bulk quantum entanglement as embodied in the Reeh–Schlieder theorem. Stringy bulk degrees of freedom are not required and play little role even when they exist. As an example we study a toy model whose matter sector is a free scalar field. The energy density ρ sources what we call a pseudo-Newtonian potential Φ through Poisson’s equation on each constant time surface, but there is no back-reaction of Φ on the matter. We show the Hamiltonian to be essentially self-adjoint on the domain generated from the vacuum by acting with boundary observables localized in an arbitrarily small neighborhood of the chosen time t. Since the Gauss law represents the Hamiltonian as a boundary term, the model is holographic in the sense stated above. (paper)

  9. Visualizing Breath using Digital Holography

    Science.gov (United States)

    Hobson, P. R.; Reid, I. D.; Wilton, J. B.

    2013-02-01

    Artist Jayne Wilton and physicists Peter Hobson and Ivan Reid of Brunel University are collaborating at Brunel University on a project which aims to use a range of techniques to make visible the normally invisible dynamics of the breath and the verbal and non-verbal communication it facilitates. The breath is a source of a wide range of chemical, auditory and physical exchanges with the direct environment. Digital Holography is being investigated to enable a visually stimulating articulation of the physical trajectory of the breath as it leaves the mouth. Initial findings of this research are presented. Real time digital hologram replay allows the audience to move through holographs of breath-born particles.

  10. Digital holography-based steganography.

    Science.gov (United States)

    Hamam, Habib

    2010-12-15

    A steganographic method offering a high hiding capacity is presented in which the techniques of digital holography are used to distribute information from a small secret image across the larger pixel field of a cover image. An iterative algorithm is used to design a phase-only or complex hologram from a padded version of the secret image, quantizing this data according to the carrier data bits that are available within the intended cover image. By introducing the hologram data only into low-order bits of larger amplitude cover pixels, the change in the cover image remains imperceptible to the casual observer, with a peak signal-to-noise ratio of >40 dB.

  11. A surface acoustic wave humidity sensor with high sensitivity based on electrospun MWCNT/Nafion nanofiber films

    International Nuclear Information System (INIS)

    Lei Sheng; Chen Dajing; Chen Yuquan

    2011-01-01

    Humidity detection has been widely used in a variety of fields. A humidity sensor with high sensitivity is reported in this paper. A surface acoustic wave resonator (SAWR) with high resonance frequency was fabricated as a basic sensitive component. Various nanotechnologies were used to improve the sensor's performance. A multi-walled carbon nanotube/Nafion (MWCNT/Nafion) composite material was prepared as humidity-sensitive films, deposited on the surface of an SAWR by the electrospinning method. The electrospun MWCNT/Nafion nanofiber films showed a three-dimensional (3D) porous structure, which was profitable for improving the sensor's performance. The new nano-water-channel model of Nafion was also applied in the humidity sensing process. Compared to other research, the present sensor showed excellent sensitivity (above 400 kHz/% relative humidity (RH) in the range from 10% RH to 80% RH), good linearity (R 2 > 0.98) and a short response time (∼3 s-63%).

  12. Holography And Holometry Applications In Dental Research

    Science.gov (United States)

    Willenborg, George C.

    1987-06-01

    The earliest reference to holographic applications appeared in the dental literature in 1972 when Wictorin, Bjelkhagen and Abramson described a method to study elastic deformation of defective gold solder joints in simulated fixed bridges. Their paper, published in the Swedish dental literature, offered a concise presentation of the interferometry technique which led to the development of other research applications of holographic interferometry(holometry) in dentistry. In this presentation, the development and application of the interferometry technique in the dental field will be discussed. Various interesting and potentially useful applications of holography have appeared in the dental literature over the past decade. Some of these, which will be discussed, include the use of holograms as a storage medium for dental study models, multiplexing of computer(CT) scan sections to form white light viewable holograms and the potential application of holographic training aids in the teaching of the basic courses of dental anatomy and restorative dentistry. In addition, some unique related applications will be mentioned including a laser reflection method for accurate non-contact measurement of tooth mobility/movement and a technique for contour mapping of occlusal surfaces to measure wear of restorative materials.

  13. Non-invasive thermal profiling of silicon wafer surface during RTP using acoustic and signal processing techniques

    Science.gov (United States)

    Syed, Ahmed Rashid

    Among the great physical challenges faced by the current front-end semiconductor equipment manufacturers is the accurate and repeatable surface temperature measurement of wafers during various fabrication steps. Close monitoring of temperature is essential in that it ensures desirable device characteristics to be reliably reproduced across various wafer lots. No where is the need to control temperature more pronounced than it is during Rapid Thermal Processing (RTP) which involves temperature ramp rates in excess of 200°C/s. This dissertation presents an elegant and practical approach to solve the wafer surface temperature estimation problem, in context of RTP, by deploying hardware that acquires the necessary data while preserving the integrity and purity of the wafer. In contrast to the widely used wafer-contacting (and hence contaminating) methods, such as bonded thermocouples, or environment sensitive schemes, such as light-pipes and infrared pyrometry, the proposed research explores the concept of utilizing Lamb (acoustic) waves to detect changes in wafer surface temperature, during RTP. Acoustic waves are transmitted to the wafer via an array of quartz rods that normally props the wafer inside an RTP chamber. These waves are generated using piezoelectric transducers affixed to the bases of the quartz rods. The group velocity of Lamb waves traversing the wafer surface undergoes a monotonic decrease with rise in wafer temperature. The correspondence of delay in phase of the received Lamb waves and the ambient temperature, along all direct paths between sending and receiving transducers, yields a psuedo real-time thermal image of the wafer. Although the custom built hardware-setup implements the above "proof-of-concept" scheme by transceiving acoustic signals at a single frequency, the real-world application will seek to enhance the data acquistion. rate (>1000 temperature measurements per seconds) by sending and receiving Lamb waves at multiple frequencies (by

  14. Surface Acoustic Wave Nebulisation Mass Spectrometry for the Fast and Highly Sensitive Characterisation of Synthetic Dyes in Textile Samples

    Science.gov (United States)

    Astefanei, Alina; van Bommel, Maarten; Corthals, Garry L.

    2017-10-01

    Surface acoustic wave nebulisation (SAWN) mass spectrometry (MS) is a method to generate gaseous ions compatible with direct MS of minute samples at femtomole sensitivity. To perform SAWN, acoustic waves are propagated through a LiNbO3 sampling chip, and are conducted to the liquid sample, which ultimately leads to the generation of a fine mist containing droplets of nanometre to micrometre diameter. Through fission and evaporation, the droplets undergo a phase change from liquid to gaseous analyte ions in a non-destructive manner. We have developed SAWN technology for the characterisation of organic colourants in textiles. It generates electrospray-ionisation-like ions in a non-destructive manner during ionisation, as can be observed by the unmodified chemical structure. The sample size is decreased by tenfold to 1000-fold when compared with currently used liquid chromatography-MS methods, with equal or better sensitivity. This work underscores SAWN-MS as an ideal tool for molecular analysis of art objects as it is non-destructive, is rapid, involves minimally invasive sampling and is more sensitive than current MS-based methods. [Figure not available: see fulltext.

  15. Frequency response improvement of a two-port surface acoustic wave device based on epitaxial AlN thin film

    Science.gov (United States)

    Gao, Junning; Hao, Zhibiao; Luo, Yi; Li, Guoqiang

    2018-01-01

    This paper presents an exploration on improving the frequency response of the symmetrical two-port AlN surface acoustic wave (SAW) device, using epitaxial AlN thin film on (0001) sapphire as the piezoelectric substrate. The devices were fabricated by lift-off processes with Ti/Al composite electrodes as interleaved digital transducers (IDT). The impact of DL and the number of the IDT finger pairs on the frequency response was carefully investigated. The overall properties of the device are found to be greatly improved with DL elongation, indicated by the reduced pass band ripple and increased stop band rejection ratio. The rejection increases by 8.3 dB when DL elongates from 15.5λ to 55.5λ and 4.4 dB further accompanying another 50λ elongation. This is because larger DL repels the stray acoustic energy out of the propagation path and provides a cleaner traveling channel for functional SAW, and at the same time restrains electromagnetic feedthrough. It is also found that proper addition of the IDT finger pairs is beneficial for the device response, indicated by the ripple reduction and the insertion loss drop.

  16. The Main Principles of Formation of the Transverse Modes in the Multilayered Waveguides of Surface Acoustic Waves

    Science.gov (United States)

    Sveshnikov, B. V.; Bagdasaryan, A. S.

    2016-07-01

    We develop a self-consistent model allowing one to analyze the properties of the interdigital transducer of the surface acoustic waves as a symmetric five-layered waveguide on a piezoelectric substrate with three possible values of the phase velocity of the acoustic-wave propagation along the longitudinal axis of the system. The transcendental dispersion relation for describing the waves in such a system is derived and the method for its instructive graphic analysis is proposed. The condition under which only the fundamental transverse mode is excited in the waveguide is formulated. The method for calculating the normalized power and the transverse distribution of the field of the continuous-spectrum waves radiated from the considered waveguide is described. It is shown that the characteristic spatial scale of the longitudinal damping of the amplitude of this field at the waveguide center can be a qualitative estimate of the transverse-mode formation length. The efficiency of a new method for suppressing the higher-order transverse waveguide modes is demonstrated.

  17. System and method for investigating sub-surface features of a rock formation using compressional acoustic sources

    Energy Technology Data Exchange (ETDEWEB)

    Vu, Cung Khac; Skelt, Christopher; Nihei, Kurt; Johnson, Paul A.; Guyer, Robert; Ten Cate, James A.; Le Bas, Pierre-Yves; Larmat, Carene S.

    2016-09-27

    A system and method for investigating rock formations outside a borehole are provided. The method includes generating a first compressional acoustic wave at a first frequency by a first acoustic source; and generating a second compressional acoustic wave at a second frequency by a second acoustic source. The first and the second acoustic sources are arranged within a localized area of the borehole. The first and the second acoustic waves intersect in an intersection volume outside the borehole. The method further includes receiving a third shear acoustic wave at a third frequency, the third shear acoustic wave returning to the borehole due to a non-linear mixing process in a non-linear mixing zone within the intersection volume at a receiver arranged in the borehole. The third frequency is equal to a difference between the first frequency and the second frequency.

  18. Nonlinear Acoustic Waves Generated by Surface Disturbances and Their Effects on Lower Thermospheric Composition

    Science.gov (United States)

    Pineyro, B.; Snively, J. B.

    2017-12-01

    Recent 1D and 2D nonlinear atmospheric models have provided important insight into acoustic waves generated by seismic events, which may steepen into shocks or saw-tooth trains while also dissipating strongly in the thermosphere [e.g., Chum et al., JGR, 121, 2016; Zettergren et al., JGR, 122, 2017]. Although they have yield results that agree with with observations of ionospheric perturbations, dynamical models for the diffusive and stratified lower thermosphere [e.g., Snively and Pasko, JGR, 113, 2008] often use single gas approximations with height-dependent physical properties (e.g. mean molecular weight, specific heats) that do not vary with time (fixed composition). This approximation is simpler and less computationally expensive than a true multi-fluid model, yet captures the important physical transition between molecular and atomic gases in the lower thermosphere. Models with time-dependent composition and properties have been shown to outperform commonly used models with fixed properties; these time-dependent effects have been included in a one-gas model by adding an advection equation for the molecular weight, finding closer agreement to a true binary-gas model [Walterscheid and Hickey, JGR, 106, 2001 and JGR, 117, 2012]. Here, a one-dimensional nonlinear mass fraction approach to multi-constituent gas modeling, motivated by the results of Walterscheid and Hickey [2001, 2012], is presented. The finite volume method of Bale et al. [SIAM JSC, 24, 2002] is implemented in Clawpack [http://www.clawpack.org; LeVeque, 2002] with a Riemann Solver to solve the Euler Equations including multiple species, defined by their mass fractions, as they undergo advection. Viscous dissipation and thermal conduction are applied via a fractional step method. The model is validated with shock tube problems for two species, and then applied to investigate propagating nonlinear acoustic waves from ground to thermosphere, such as following the 2011 Tohoku Earthquake [e

  19. Fabrication of Cheap Optical Transducers (CHOTs) on film carriers for in-situ application and generation of surface acoustic waves

    Science.gov (United States)

    Ageeva, V.; Stratoudaki, T.; Clark, M.; Somekh, M. G.

    2015-01-01

    Cheap optical transducers (CHOTs) are patterns on the surface of a component activated by lasers to generate and detect ultrasound. Excited optically, with minimal surface impact, and fully customizable, CHOTs provide a simple alternative to conventional piezoelectric transducers, offering wireless, remote operation. Of particular interest is application of CHOTs for in-situ ultrasonic inspection of hard-to reach and complex-geometry components such as those of aero-engines. A suitable fabrication method has been developed to allow in-situ application of CHOTs onto large size and curved components, as well as those already in service, challenging for current laboratory-based micro-patterning methods. This work describes the fabrication of a transferable g-CHOT for generation of ultrasound. The g- CHOT has been made on an SU8 carrier film using a sacrificial polystyrene layer, allowing the transducer to be transferred from the substrate and subsequently delivered and applied to the surface of the sample in-situ. The functionality of the fabricated transducer is demonstrated by detection of the Surface Acoustic Waves (SAW) generated by the g-CHOT transferred onto glass and aluminium samples.

  20. Distributed Acoustic Sensing for Seismic Monitoring of The Near Surface: A Traffic-Noise Interferometry Case Study.

    Science.gov (United States)

    Dou, Shan; Lindsey, Nate; Wagner, Anna M; Daley, Thomas M; Freifeld, Barry; Robertson, Michelle; Peterson, John; Ulrich, Craig; Martin, Eileen R; Ajo-Franklin, Jonathan B

    2017-09-14

    Ambient-noise-based seismic monitoring of the near surface often has limited spatiotemporal resolutions because dense seismic arrays are rarely sufficiently affordable for such applications. In recent years, however, distributed acoustic sensing (DAS) techniques have emerged to transform telecommunication fiber-optic cables into dense seismic arrays that are cost effective. With DAS enabling both high sensor counts ("large N") and long-term operations ("large T"), time-lapse imaging of shear-wave velocity (V S ) structures is now possible by combining ambient noise interferometry and multichannel analysis of surface waves (MASW). Here we report the first end-to-end study of time-lapse V S imaging that uses traffic noise continuously recorded on linear DAS arrays over a three-week period. Our results illustrate that for the top 20 meters the V S models that is well constrained by the data, we obtain time-lapse repeatability of about 2% in the model domain-a threshold that is low enough for observing subtle near-surface changes such as water content variations and permafrost alteration. This study demonstrates the efficacy of near-surface seismic monitoring using DAS-recorded ambient noise.

  1. Shear horizontal surface acoustic wave microsensor for Class A viral and bacterial detection.

    Energy Technology Data Exchange (ETDEWEB)

    Branch, Darren W.; Huber, Dale L.; Brozik, Susan Marie; Edwards, Thayne L.

    2008-10-01

    The rapid autonomous detection of pathogenic microorganisms and bioagents by field deployable platforms is critical to human health and safety. To achieve a high level of sensitivity for fluidic detection applications, we have developed a 330 MHz Love wave acoustic biosensor on 36{sup o} YX Lithium Tantalate (LTO). Each die has four delay-line detection channels, permitting simultaneous measurement of multiple analytes or for parallel detection of single analyte containing samples. Crucial to our biosensor was the development of a transducer that excites the shear horizontal (SH) mode, through optimization of the transducer, minimizing propagation losses and reducing undesirable modes. Detection was achieved by comparing the reference phase of an input signal to the phase shift from the biosensor using an integrated electronic multi-readout system connected to a laptop computer or PDA. The Love wave acoustic arrays were centered at 330 MHz, shifting to 325-328 MHz after application of the silicon dioxide waveguides. The insertion loss was -6 dB with an out-of-band rejection of 35 dB. The amplitude and phase ripple were 2.5 dB p-p and 2-3{sup o} p-p, respectively. Time-domain gating confirmed propagation of the SH mode while showing suppression of the triple transit. Antigen capture and mass detection experiments demonstrate a sensitivity of 7.19 {+-} 0.74{sup o} mm{sup 2}/ng with a detection limit of 6.7 {+-} 0.40 pg/mm{sup 2} for each channel.

  2. Advanced technology development multi-color holography

    Science.gov (United States)

    Vikram, Chandra S.

    1994-01-01

    Several key aspects of multi-color holography and some non-conventional ways to study the holographic reconstructions are considered. The error analysis of three-color holography is considered in detail with particular example of a typical triglycine sulfate crystal growth situation. For the numerical analysis of the fringe patterns, a new algorithm is introduced with experimental verification using sugar-water solution. The role of the phase difference among component holograms is also critically considered with examples of several two- and three-color situations. The status of experimentation on two-color holography and fabrication of a small breadboard system is also reported. Finally, some successful demonstrations of unconventional ways to study holographic reconstructions are described. These methods are deflectometry and confocal optical processing using some Spacelab III holograms.

  3. Atomic structure holography using thermal neutrons

    International Nuclear Information System (INIS)

    Sur, B.; Rogge, R.B.; Hammond, R.P.; Anghel, V.N.P.; Katsaras, J.

    2001-01-01

    The idea of atomic-resolution holography has its roots in the X-ray work of Bragg and in Gabor's electron interference microscope. Gabor's lensless microscope was not realized in his time, but over the past twelve years there has been a steady increase in the number of reports on atomic-resolution holography. All of this work involves the use of electrons or hard X-rays to produce the hologram. Neutrons are often unique among scattering probes in their interaction with materials: for example, the relative visibility of hydrogen and its isotopes is a great advantage in the study of polymers and biologically relevant materials. Recent work proposed that atomic-resolution holography could be achieved with thermal neutrons. Here we use monochromatic thermal neutrons, adopting the inside-source concept of Szoke, to image planes of oxygen atoms located above and below a single hydrogen atom in the oxide mineral Simpsonite. (author)

  4. An easy teaching tool for holography

    International Nuclear Information System (INIS)

    Voslion, T; Escarguel, A

    2012-01-01

    In the framework of scientific outreach at the Maison des Sciences of Aix-Marseilles University, we created a teaching kit for holography that can be packed into a small case. It includes all the equipment required to produce holograms almost anywhere and has a simple optical assembly and very good vibration tolerance. The fundamental principles of holography and several applications are illustrated through simple experiments: reflection Denisyuk holograms, angular multiplexing, notch filters, holographic interferometry and diffraction holographic gratings. It is possible to use this tool for several purposes: science outreach, teaching for undergraduate and graduate students and continuing education. In this paper, we explain the basis of holography, how the kit works and indicate some applications and results that can be performed and obtained with it. (paper)

  5. Ten years of x-ray holography

    International Nuclear Information System (INIS)

    Faigel, G.; Bortel, G.; Tegze, M.; Fadley, C.S.; Simionovici, A.S.

    2007-01-01

    With the appearance of nano-science the role of local methods has become more and more important. Hard x-ray holography based on the inside reference point concept is a local probe of the atomic order in solids. It gives the 3D real space image of atoms without the phase ambiguity inherent to diffraction methods. In this paper a brief description of the basics of hard x-ray holography is given. The last ten years' experimental and evaluation-related developments are reviewed. We also introduce different variants of the method, such as Bremsstrahlung and gamma ray holography (GRH). The power of the method is illustrated by examples. We outline new directions and future possibilities. (authors)

  6. Electron holography at atomic dimensions -- Present state

    International Nuclear Information System (INIS)

    Lehmann, M.; Lichte, H.

    1999-01-01

    An electron microscope is a wave optical instrument where the object information is carried by an electron wave. However, an important information, the phase of the electron wave, is lost, because only intensities can be recorded in a conventional electron micrograph. Off-axis electron holography solves this phase problem by encoding amplitude and phase information in an interference pattern, the so-called hologram. After reconstruction, a rather unrestricted wave optical analysis can be performed on a computer. The possibilities as well as the current limitations of off-axis electron holography at atomic dimensions are discussed, and they are illustrated at two applications of structure characterization of ε-NbN and YBCO-1237. Finally, an electron microscope equipped with a Cs-corrector, a monochromator, and a Moellenstedt biprism is outlined for subangstrom holography

  7. Prediction of the Strain Response of Poly-AlN/(100Si Surface Acoustic Wave Resonator and Experimental Analysis

    Directory of Open Access Journals (Sweden)

    Shuo Chen

    2016-04-01

    Full Text Available The strain sensitivity of the Aluminum Nitride (AlN/Silicon (Si surface acoustic wave resonator (SAWR is predicted based on a modeling method introduced in this work, and further compared with experimental results. The strain influence on both the period of the inter-digital transducer (IDT and the sound velocity is taken into consideration when modeling the strain response. From the modeling results, AlN and Si have opposite responses to strain; hence, for the AlN/Si-based SAWR, both a positive and a negative strain coefficient factor can be achieved by changing the thickness of the AlN layer, which is confirmed by strain response testing based on a silicon cantilever structure with two AlN configurations (1 μm and 3 μm in thickness, respectively.

  8. Prediction of the Strain Response of Poly-AlN/(100)Si Surface Acoustic Wave Resonator and Experimental Analysis.

    Science.gov (United States)

    Chen, Shuo; You, Zheng

    2016-04-27

    The strain sensitivity of the Aluminum Nitride (AlN)/Silicon (Si) surface acoustic wave resonator (SAWR) is predicted based on a modeling method introduced in this work, and further compared with experimental results. The strain influence on both the period of the inter-digital transducer (IDT) and the sound velocity is taken into consideration when modeling the strain response. From the modeling results, AlN and Si have opposite responses to strain; hence, for the AlN/Si-based SAWR, both a positive and a negative strain coefficient factor can be achieved by changing the thickness of the AlN layer, which is confirmed by strain response testing based on a silicon cantilever structure with two AlN configurations (1 μm and 3 μm in thickness, respectively).

  9. An S-FSCW Based Multi-Channel Reader System for Beamforming Applications using Surface Acoustic Wave Sensors

    Directory of Open Access Journals (Sweden)

    C. Pfeffer

    2011-12-01

    Full Text Available Interrogating multiple surface acoustic wave (SAW sensors located within the same radar beam require techniques to separate the multiple superposing SAW sensor responses. The presented multi-channel reader features four parallel transceiver channels, which are based on the switched frequency-stepped continuous-wave principle and high-speed parallelized baseband electronics. Thus classical beamforming applications including angle of arrival measurement of single SAW tags and the angular separation of multiple SAW sensors are presented and compared to a multiple-input multiple-output (MIMO approach. Due to the larger virtual array in the MIMO approach a larger aperture can be synthesized, which leads to significantly better angular separation results. The level analysis for the given system is verified by baseband-power measurements at different readout distances, considering the hardware parameters as well as the free-space propagation aspects. Finally measurements assess the maximum interrogation distance for the system.

  10. Study on generation mechanisms of second-order nonlinear signals in surface acoustic wave devices and their suppression

    Science.gov (United States)

    Nakagawa, Ryo; Kyoya, Haruki; Shimizu, Hiroshi; Kihara, Takashi; Hashimoto, Ken-ya

    2015-07-01

    In this study, we examine the generation mechanisms of the second-order nonlinear signals in surface acoustic wave resonators/duplexers fabricated on a 42°YX-LiTaO3 substrate. It is shown that the crystal asymmetry of the substrate can generate the second-order nonlinear signals. The following two mechanisms mainly contribute to their generation: (a) self-mixing of the electrostatic field and (b) mixing of the electrostatic field with the strain field associated with laterally propagating modes. Both of them occur at the gaps between the electrode tip and the dummy electrode. In addition, an interdigital transducer design that cancels this asymmetry is proposed. The design is applied to a one-port resonator and a duplexer, and the effectiveness of this technique is demonstrated.

  11. Titanium Dioxide-Based 64∘ YX LiNbO3 Surface Acoustic Wave Hydrogen Gas Sensors

    Directory of Open Access Journals (Sweden)

    A. Z. Sadek

    2008-01-01

    Full Text Available Amorphous titanium dioxide (TiO2 and gold (Au doped TiO2-based surface acoustic wave (SAW sensors have been investigated as hydrogen gas detectors. The nanocrystal-doped TiO2 films were synthesized through a sol-gel route, mixing a Ti-butoxide-based solution with diluted colloidal gold nanoparticles. The films were deposited via spin coating onto 64∘ YX LiNbO3 SAW transducers in a helium atmosphere. The SAW gas sensors were operated at various temperatures between 150 and 310∘C. It was found that gold doping on TiO2 increased the device sensitivity and reduced the optimum operating temperature.

  12. Mapping the Large Millimeter Telescope primary reflector using photogrammetry: a first comparison with 12 GHz holography

    Science.gov (United States)

    Gale, David M.; Leon-Huerta, Andrea; Cabrera Cuevas, Lizeth; Castro Santos, David; Hernández Ríos, Emilio; Lucero Álvarez, Maribel; Tecuapetla Sosa, Esteban; Tzile Torres, Carlos; Sánchez-Argüelles, David; Narayanan, Gopal; Schloerb, F. Peter; Wilson, Grant W.; Smith, David R.

    2016-07-01

    The Large Millimeter Telescope (LMT) makes extensive use of 12 GHz holography during maintenance periods to finetune the alignment of primary reflector segments to the best-fit design parabola. Tracker measurements have also been used for this task, however the technique is severely limited by environmental noise and large data collection times, on the order of many hours for a single map. In 2015 we started photogrammetry trials as a complimentary measurement technique. Photogrammetry can offer reduced mapping times compared with laser trackers, and like holography, allows maps to be made at arbitrary elevation angles. Depending on the placement of reflecting targets, the technique can also provide higher spatial resolution than currently achieved using our holography system. Accurate photogrammetry requires a robust strategy for the incorporation of multiple camera stations, a task complicated by the size of the antenna, obstructions of the surface by the sub-reflector and tetrapod legs, and the practicability of using the site tower crane as a moving camera platform. Image scaling is also a major consideration, since photogrammetry lacks any inherent distance reference. Therefore appropriate scale bars must be fabricated and located within the camera field of view. Additional considerations relate to the size and placement of reflective targets, and the optimization of camera settings. In this paper we present some initial comparisons of laser tracker, holography and photogrammetry measurements taken in 2015, showing clearly the status of alignment for distinct zones of the currently operating 32.5 m primary collecting area.

  13. THz holography in reflection using a high resolution microbolometer array.

    Science.gov (United States)

    Zolliker, Peter; Hack, Erwin

    2015-05-04

    We demonstrate a digital holographic setup for Terahertz imaging of surfaces in reflection. The set-up is based on a high-power continuous wave (CW) THz laser and a high-resolution (640 × 480 pixel) bolometer detector array. Wave propagation to non-parallel planes is used to reconstruct the object surface that is rotated relative to the detector plane. In addition we implement synthetic aperture methods for resolution enhancement and compare Fourier transform phase retrieval to phase stepping methods. A lateral resolution of 200 μm and a relative phase sensitivity of about 0.4 rad corresponding to a depth resolution of 6 μm are estimated from reconstructed images of two specially prepared test targets, respectively. We highlight the use of digital THz holography for surface profilometry as well as its potential for video-rate imaging.

  14. On generalized gravitational entropy, squashed cones and holography

    International Nuclear Information System (INIS)

    Bhattacharyya, Arpan; Sharma, Menika; Sinha, Aninda

    2014-01-01

    We consider generalized gravitational entropy in various higher derivative theories of gravity dual to four dimensional CFTs using the recently proposed regularization of squashed cones. We derive the universal terms in the entanglement entropy for spherical and cylindrical surfaces. This is achieved by constructing the Fefferman-Graham expansion for the leading order metrics for the bulk geometry and evaluating the generalized gravitational entropy. We further show that the Wald entropy evaluated in the bulk geometry constructed for the regularized squashed cones leads to the correct universal parts of the entanglement entropy for both spherical and cylindrical entangling surfaces. We comment on the relation with the Iyer-Wald formula for dynamical horizons relating entropy to a Noether charge. Finally we show how to derive the entangling surface equation in Gauss-Bonnet holography

  15. Enhancement of acousto-optical coupling in two-dimensional air-slot phoxonic crystal cavities by utilizing surface acoustic waves

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Tian-Xue [Institute of Engineering Mechanics, Beijing Jiaotong University, Beijing 100044 (China); Wang, Yue-Sheng, E-mail: yswang@bjtu.edu.cn [Institute of Engineering Mechanics, Beijing Jiaotong University, Beijing 100044 (China); Zhang, Chuanzeng [Department of Civil Engineering, University of Siegen, D-57068 Siegen (Germany)

    2017-01-30

    A phoxonic crystal is a periodically patterned material that can simultaneously localize optical and acoustic modes. The acousto-optical coupling in two-dimensional air-slot phoxonic crystal cavities is investigated numerically. The photons can be well confined in the slot owing to the large electric field discontinuity at the air/dielectric interfaces. Besides, the surface acoustic modes lead to the localization of the phonons near the air-slot. The high overlap of the photonic and phononic cavity modes near the slot results in a significant enhancement of the moving interface effect, and thus strengthens the total acousto-optical interaction. The results of two cavities with different slot widths show that the coupling strength is dependent on the slot width. It is expected to achieve a strong acousto-optical/optomechanical coupling in air-slot phoxonic crystal structures by utilizing surface acoustic modes. - Highlights: • Two-dimensional air-slot phoxonic crystal cavities which can confine simultaneously optical and acoustic waves are proposed. • The acoustic and optical waves are highly confined near/in the air-slot. • The high overlap of the photonic and phononic cavity modes significantly enhances the moving interface effect. • Different factors which affect the acousto-optical coupling are discussed.

  16. Holography - Application To Art: Curatorial Observations

    Science.gov (United States)

    Dinsmore, Sydney

    1987-06-01

    An exploration of the need to define a specific and critical language to describe the art of holography. Within any discussion of art, critical analysis must maintain an objective openess, particularily when the discourse concerns new media. To apply technological invention to art, new media is often without precedent on which to base criticism and bias. For this reason, holography falls prey to comparative rhetoric and established evaluation of other forms of imaging,as photography emulated the compositional romanticism of painting initially. Isolated and often misunderstood within the context of history, new media vascillates between legitimacy and curiosity in an attempt to create specific parameters to identify perceptual transition.

  17. Holography, Dimensional Reduction and the Bekenstein Bound

    Science.gov (United States)

    Bak, Dongsu; Yee, Ho-Ung

    2004-04-01

    We consider dimensional reduction of the lightlike holography of the covariant entropy bound from D+1 dimensional geometry of M × S1 to the D dimensional geometry M. With a warping factor, the local Bekenstein bound in D+1 dimensions leads to a more refined form of the bound from the D dimensional view point. With this new local Bekenstein bound, it is quite possible to saturate the lightlike holography even with nonvanishing expansion rate. With a Kaluza-Klein gauge field, the dimensional reduction implies a stronger bound where the energy momentum tensor contribution is replaced by the energy momentum tensor with the electromagnetic contribution subtracted.

  18. Holography on the Spacelab 3 mission

    Science.gov (United States)

    Owen, Robert B.; Kroes, R. L.

    1985-01-01

    Spacelab 3's Fluid Experiment System, in which triglycine sulfate crystals were produced by a low temperature solution-growth technique, employs holography as its primary data-gathering system. This use of holography allows optical techniques which would be difficult to apply in orbit to be used after the holographic data is returned to ground laboratories, using an analysis of the reconstructed holographic image. The system used allows both single- and double-exposure holograms to be obtained in two separate orthogonal configurations.

  19. Resolution in in-line digital holography

    International Nuclear Information System (INIS)

    Fournier, C; Denis, L; Fournel, T

    2010-01-01

    Digital in-line holography is a 3D imaging technique which has been widely developed during the last two decades. This technique achieves the 3D reconstruction of volume objects from a 2D image-hologram. It is a metrological tool and therefore the improvement of resolution is one of the current challenges. However the resolution depends on several experimental parameters and the experimenters have to choose the parameters which will lead to the best resolution. This paper presents the study of resolution in in-line digital holography from the asymptotical bounds of the covariance of estimators used in hologram reconstruction.

  20. Evaluation of a gas chromatograph with a novel surface acoustic wave detector (SAW GC) for screening of volatile organic compounds in Hanford waste tank samples

    International Nuclear Information System (INIS)

    Lockrem, L.L.

    1998-01-01

    A novel instrument, a gas chromatograph with a Surface Acoustic Wave Detector (SAW GC), was evaluated for the screening of organic compounds in Hanford tank headspace vapors. Calibration data were developed for the most common organic compounds, and the accuracy and precision were measured with a certified standard. The instrument was tested with headspace samples collected from seven Hanford waste tanks

  1. Holography with a Landau pole

    Science.gov (United States)

    Faedo, Antón F.; Mateos, David; Pantelidou, Christiana; Tarrío, Javier

    2017-02-01

    Holography for UV-incomplete gauge theories is important but poorly understood. A paradigmatic example is d = 4, N=4 super Yang-Mills coupled to N f quark flavors, which possesses a Landau pole at a UV scale ΛLP. The dual gravity solution exhibits a UV singularity at a finite proper distance along the holographic direction. Despite this, holographic renormalization can be fully implemented via analytic continuation to an AdS solution. The presence of a UV cut-off manifests itself in several interesting ways. At energies E ≪ ΛLP no pathologies appear, as expected from effective field theory. In contrast, at scales E ≲ ΛLP the gravitational potential becomes repulsive, and at temperatures T ≲ ΛLP the specific heat becomes negative. Although we focus on N=4 super Yang-Mills with flavor, our qualitative results apply to a much more general class of theories, since they only depend on the fact that the metric near the UV singularity is a hyper-scaling violating metric with exponent θ > d - 1.

  2. Holography with a Landau pole

    Energy Technology Data Exchange (ETDEWEB)

    Faedo, Antón F. [Departament de Física Quántica i Astrofísica and Institut de Ciències del Cosmos (ICC), Universitat de Barcelona, Martí i Franquès 1, ES-08028, Barcelona (Spain); Mateos, David [Departament de Física Quántica i Astrofísica and Institut de Ciències del Cosmos (ICC), Universitat de Barcelona, Martí i Franquès 1, ES-08028, Barcelona (Spain); Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys 23, ES-08010, Barcelona (Spain); Pantelidou, Christiana [Departament de Física Quántica i Astrofísica and Institut de Ciències del Cosmos (ICC), Universitat de Barcelona, Martí i Franquès 1, ES-08028, Barcelona (Spain); Tarrío, Javier [Physique Théorique et Mathématique, Université Libre de Bruxelles (ULB), and International Solvay Institutes, Campus de la Plaine CP 231, B-1050, Brussels (Belgium)

    2017-02-08

    Holography for UV-incomplete gauge theories is important but poorly understood. A paradigmatic example is d=4, N=4 super Yang-Mills coupled to N{sub f} quark flavors, which possesses a Landau pole at a UV scale Λ{sub LP}. The dual gravity solution exhibits a UV singularity at a finite proper distance along the holographic direction. Despite this, holographic renormalization can be fully implemented via analytic continuation to an AdS solution. The presence of a UV cut-off manifests itself in several interesting ways. At energies E≪Λ{sub LP} no pathologies appear, as expected from effective field theory. In contrast, at scales E≲Λ{sub LP} the gravitational potential becomes repulsive, and at temperatures T≲Λ{sub LP} the specific heat becomes negative. Although we focus on N=4 super Yang-Mills with flavor, our qualitative results apply to a much more general class of theories, since they only depend on the fact that the metric near the UV singularity is a hyper-scaling violating metric with exponent θ>d−1.

  3. Is holography ready for yet another life? or make holography great again

    Science.gov (United States)

    Trolinger, James D.

    2016-08-01

    Holographic metrology, unlike most other applications of holography, has always thrived and continues to thrive by continuously incorporating new supporting technologies that make it more powerful and useful. Successes, failures, lives, and deaths are examined and recognized as evolutionary steps that position the field where opportunities are as great and as many as ever. This is a story of that evolution. Comparisons and analogies with other applications of holography such as data storage, archiving, the arts, entertainment, advertising, and security and their evolution are interesting. Critical events, successes, mistakes, and coincidences represent milestones of abandonment or failure to deliver in many holography communities that followed a different evolutionary path. Events and new technical developments continue to emerge in supporting fields that can revive and expand all holography applications. New opportunities are described with encouragement to act on them and take some risks. Don't wait until all of the required technology and hardware are available, because good scientists always act before then. The paper is about "making holography great again" and your opportunity to be a part of the upcoming revolution. Although the discussion focuses on holographic metrology, the same principles should apply to other holography communities.

  4. Directionality and maneuvering effects on a surface ship underwater acoustic signature.

    Science.gov (United States)

    Trevorrow, Mark V; Vasiliev, Boris; Vagle, Svein

    2008-08-01

    This work examines underwater source spectra of a small (560 tons, 40 m length), single-screw oceanographic vessel, focusing on directionality and effects of maneuvers. The measurements utilized a set of four, self-contained buoys with GPS positioning, each recording two calibrated hydrophones with effective acoustic bandwidth from 150 Hz to 5 kHz. In straight, constant-speed runs at speeds up to 6.2 m s(-1), the ship source spectra showed spectral levels in reasonable agreement with reference spectra. The broadband source level was observed to increase as approximately speed to the fourth power over the range of 2.6-6.1 m s(-1), partially biased at low speeds by nonpropulsion machinery signals. Source directionality patterns were extracted from variations in source spectra while the ship transited past the buoy field. The observed spectral source levels exhibited a broadside maximum, with bow and stern aspect reduced by approximately 12-9 dB, respectively, independent of frequency. An empirical model is proposed assuming that spectral source levels exhibit simultaneous variations in aspect angle, speed, and turn rate. After correction for source directionality and speed during turning maneuvers, an excess of up to 18 dB in one-third octave source levels was observed.

  5. Inverse least-squares modeling of vapor descriptors using polymer-coated surface acoustic wave sensor array responses.

    Science.gov (United States)

    Grate, J W; Patrash, S J; Kaganovet, S N; Abraham, M H; Wise, B M; Gallagher, N B

    2001-11-01

    In previous work, it was shown that, in principle, vapor descriptors could be derived from the responses of an array of polymer-coated acoustic wave devices. This new chemometric classification approach was based on polymer/vapor interactions following the well-established linear solvation energy relationships (LSERs) and the surface acoustic wave (SAW) transducers being mass sensitive. Mathematical derivations were included and were supported by simulations. In this work, an experimental data set of polymer-coated SAW vapor sensors is investigated. The data set includes 20 diverse polymers tested against 18 diverse organic vapors. It is shown that interfacial adsorption can influence the response behavior of sensors with nonpolar polymers in response to hydrogen-bonding vapors; however, in general, most sensor responses are related to vapor interactions with the polymers. It is also shown that polymer-coated SAW sensor responses can be empirically modeled with LSERs, deriving an LSER for each individual sensor based on its responses to the 18 vapors. Inverse least-squares methods are used to develop models that correlate and predict vapor descriptors from sensor array responses. Successful correlations can be developed by multiple linear regression (MLR), principal components regression (PCR), and partial least-squares (PLS) regression. MLR yields the best fits to the training data, however cross-validation shows that prediction of vapor descriptors for vapors not in the training set is significantly more successful using PCR or PLS. In addition, the optimal dimension of the PCR and PLS models supports the dimensionality of the LSER formulation and SAW response models.

  6. Acoustic lenses

    International Nuclear Information System (INIS)

    Kittmer, C.A.

    1983-03-01

    Acoustic lenses focus ultrasound to produce pencil-like beams with reduced near fields. When fitted to conventional (flat-faced) transducers, such lenses greatly improve the ability to detect and size defects. This paper describes a program developed to design acoustic lenses for use in immersion or contact inspection, using normal or angle beam mode with flat or curved targets. Lens surfaces are circular in geometry to facilitate machining. For normal beam inspection of flat plate, spherical or cylindrical lenses are used. For angle beam or curved surface inspections, a compound lens is required to correct for the extra induced aberration. Such a lens is aspherical with one radius of curvature in the plane of incidence, and a different radius of curvature in the plane perpendicular to the incident plane. The resultant beam profile (i.e., location of the acoustic focus, beam diameter, 6 dB working range) depends on the degree of focusing and the transducer used. The operating frequency and bandwidth can be affected by the instrumentation used. Theoretical and measured beam profiles are in good agreement. Various applications, from zone focusing used for defect sizing in thick plate, to line focusing for pipe weld inspection, are discussed

  7. On-Line Metrology with Conoscopic Holography: Beyond Triangulation

    Directory of Open Access Journals (Sweden)

    Ignacio Álvarez

    2009-09-01

    Full Text Available On-line non-contact surface inspection with high precision is still an open problem. Laser triangulation techniques are the most common solution for this kind of systems, but there exist fundamental limitations to their applicability when high precisions, long standoffs or large apertures are needed, and when there are difficult operating conditions. Other methods are, in general, not applicable in hostile environments or inadequate for on-line measurement. In this paper we review the latest research in Conoscopic Holography, an interferometric technique that has been applied successfully in this kind of applications, ranging from submicrometric roughness measurements, to long standoff sensors for surface defect detection in steel at high temperatures.

  8. Precision holography for non-conformal branes

    NARCIS (Netherlands)

    Kanitscheider, I.; Skenderis, K.; Taylor, M.

    2008-01-01

    We set up precision holography for the non-conformal branes preserving 16 supersymmetries. The near-horizon limit of all such p-brane solutions with p <= 4, including the case of fundamental string solutions, is conformal to AdS(p+2) x S8-p with a linear dilaton. We develop holographic

  9. Electron Holography Image Simulation of Nanoparticles

    NARCIS (Netherlands)

    Keimpema, K.; Raedt, H. De; Hosson, J.Th.M. De

    We discuss a real-space and a Fourier-space technique to compute numerically, the phase images observed by electron holography of nanoscale particles. An assessment of the applicability and accuracy of these techniques is made by calculating numerical results for simple geometries for which

  10. Photopolymer for Optical Holography and Holographic Interferometry

    Czech Academy of Sciences Publication Activity Database

    Květoň, M.; Lédl, Vít; Havránek, A.; Fiala, P.

    2010-01-01

    Roč. 295, č. 1 (2010), s. 107-113 ISSN 1022-1360 Institutional research plan: CEZ:AV0Z20430508 Keywords : holographic interferometry * holography * photopolymerization * recording material * refractive index Subject RIV: BH - Optics, Masers, Lasers http://onlinelibrary.wiley.com/doi/10.1002/masy.200900093/pdf

  11. Synthetic optical holography for rapid nanoimaging.

    Science.gov (United States)

    Schnell, M; Carney, P S; Hillenbrand, R

    2014-03-20

    Holography has paved the way for phase imaging in a variety of wide-field techniques, including electron, X-ray and optical microscopy. In scanning optical microscopy, however, the serial fashion of image acquisition seems to challenge a direct implementation of traditional holography. Here we introduce synthetic optical holography (SOH) for quantitative phase-resolved imaging in scanning optical microscopy. It uniquely combines fast phase imaging, technical simplicity and simultaneous operation at visible and infrared frequencies with a single reference arm. We demonstrate SOH with a scattering-type scanning near-field optical microscope (s-SNOM) where it enables reliable quantitative phase-resolved near-field imaging with unprecedented speed. We apply these capabilities to nanoscale, non-invasive and rapid screening of grain boundaries in CVD-grown graphene, by recording 65 kilopixel near-field images in 26 s and 2.3 megapixel images in 13 min. Beyond s-SNOM, the SOH concept could boost the implementation of holography in other scanning imaging applications such as confocal microscopy.

  12. Nonreciprocity of spin waves in magnonic crystals created by surface acoustic waves in structures with yttrium iron garnet

    Energy Technology Data Exchange (ETDEWEB)

    Kryshtal, R.G.; Medved, A.V., E-mail: avm@ms.ire.rssi.ru

    2015-12-01

    Experimental results of investigations of nonreciprocity for surface magnetostatic spin waves (SMSW) in the magnonic crystal created by surface acoustic waves (SAW) in yttrium iron garnet films on a gallium gadolinium garnet substrate as without metallization and with aluminum films with different electrical conductivities (thicknesses) are presented. In structures without metallization, the frequency of magnonic gaps is dependent on mutual directions of propagation of the SAW and SMSW, showing nonreciprocal properties for SMSW in SAW – magnonic crystals even with the symmetrical dispersion characteristic. In metalized SAW – magnonic crystals the shift of the magnonic band gaps frequencies at the inversion of the biasing magnetic field was observed. The frequencies of magnonic band gaps as functions of SAW frequency are presented. Measured dependencies, showing the decrease of magnonic gaps frequency and the expansion of the magnonic band gap width with the decreasing of the metal film conductivity are given. Such nonreciprocal properties of the SAW – magnonic crystals are promising for signal processing in the GHz range. - Highlights: • Spin waves nonreciprocity in YIG magnonic crystals with SAW was studied. • SAW was shown to create nonreciprocity for spin waves in YIG–GGG even without metal. • Frequency and width of magnonic band gaps were measured versus metal conductivity. • Conductivity for practical use of spin waves in the structure YIG–metal was defined.

  13. A Comparative Study of the Monitoring of a Self Aligning Spherical Journal using Surface Vibration, Airborne Sound and Acoustic Emission

    International Nuclear Information System (INIS)

    Raharjo, P; Tesfa, B; Gu, F; Ball, A D

    2012-01-01

    A Self aligning spherical journal bearing is a plain bearing which has spherical surface contact that can be applied in high power industrial machinery. This type of bearing can accommodate a misalignment problem. The journal bearing faults degrade machine performance, decrease life time service and cause unexpected failure which are dangerous for safety issues. Non-intrusive measurements such as surface vibration (SV), airborne sound (AS) and acoustic emission (AE) measurement are appropriate monitoring methods for early stage journal bearing fault in low, medium and high frequency. This paper focuses on the performance comparison using SV, AS and AE measurements in monitoring a self aligning spherical journal bearing for normal and faulty (scratch) conditions. It examines the signals in the time domain and frequency domain and identifies the frequency ranges for each measurement in which significant changes are observed. The results of SV, AS and AE experiments indicate that the spectrum can be used to detect the differences between normal and faulty bearing. The statistic parameter shows that RMS value and peak value for faulty bearing is higher than normal bearing.

  14. Nonlinear spin waves in dynamic magnonic crystals created by surface acoustic waves in yttrium iron garnet films

    Science.gov (United States)

    Kryshtal, R. G.; Medved, A. V.

    2017-12-01

    Experimental results on the influence of the intensity of surface magnetostatic spin wave (SMSW) on its propagation in the dynamic magnonic crystals (MCs) created by surface acoustic waves (SAW) propagating in yttrium iron garnet (YIG) film on the gallium gadolinium garnet (GGG) substrate are presented. The shift of the resonant frequency of the SMSW reflections (frequency of the magnonic gap) and widening of the resonant reflection curves (increasing the width of the magnonic band gap) from their former meanings (3730 MHz and 5.25 MHz, respectively) were observed at 20 MHz SAW of 20 mW in biasing magnetic field of 640 Oe at input microwave power exceeding the threshold value of  ‑5 dBm. At the input power of 10 dBm, the deviations of the magnonic gap frequency and of the width of the SMSW resonant reflected curves reach the values of 5 MHz and 2 MHz, respectively. At a frequency of 3730 MHz, a decrease in the reflection coefficient of the SMSW was observed at the input powers above the threshold. These results may be useful in investigations of MC and for creating new nonlinear signal processing devices.

  15. Holography, Gravity and Condensed Matter

    Energy Technology Data Exchange (ETDEWEB)

    Hartnoll, Sean [Stanford Univ., CA (United States). Dept. of Physics

    2017-12-20

    Over the five years of funding from this grant, I produced 26 publications. These include a book-long monograph on "Holographic Quantum Matter" that is currently in press with MIT press. The remainder were mostly published in Physical Review Letters, the Journal of High Energy Physics, Nature Physics, Classical and Quantum Gravity and Physical Review B. Over this period, the field of holography applied to condensed matter physics developed from a promising theoretical approach to a mature conceptual and practical edifice, whose ideas were realized in experiments. My own work played a central role in this development. In particular, in the final year of this grant, I co-authored two experimental papers in which ideas that I had developed in earlier years were shown to usefully describe transport in strongly correlated materials — these papers were published in Science and in the Proceedings of the National Academy of Sciences (obviously my contribution to these papers was theoretical). My theoretical work in this period developed several new directions of research that have proven to be influential. These include (i) The construction of highly inhomogeneous black hole event horizons, realizing disordered fixed points and describing new regimes of classical gravity, (ii) The conjecture of a bound on diffusivities that could underpin transport in strongly interacting media — an idea which may be proven in the near future and has turned out to be intimately connected to studies of quantum chaos in black holes and strongly correlated media, (iii) The characterization of new forms of hydrodynamic transport, e.g. with phase-disordered order parameters. These studies pertain to key open questions in our understanding of how non-quasiparticle, intrinsically strongly interacting systems can behave. In addition to the interface between holography and strongly interacting condensed matter systems, I made several advances on understanding the role of entanglement in quantum

  16. Quantitative measurement of in-plane acoustic field components using surface-mounted fiber sensors

    Science.gov (United States)

    Claus, Richard O.; Dhawan, Rajat R.; Gunther, Michael F.; Murphy, Kent A.

    1993-01-01

    Extrinsic Fabry-Perot interferometric sensors have been used to obtain calibrated, quantitative measurements of the in-plane displacement components associated with the propagation of ultrasonic elastic stress waves on the surfaces of solids. The frequency response of the sensor is determined by the internal spacing between the two reflecting fiber endface surfaces which form the Fabry-Perot cavity, a distance which is easily controlled during fabrication. With knowledge of the material properties of the solid, the out-of-plane displacement component of the wave may also be determined, giving full field data.

  17. Simple optical setup implementation for digital Fourier transform holography

    International Nuclear Information System (INIS)

    De Oliveira, G N; Rodrigues, D M C; Dos Santos, P A M

    2011-01-01

    In the present work a simple implementation of Digital Fourier Transform Holography (DFTH) setup is discussed. This is obtained making a very simple modification in the classical setup arquiteture of the Fourier Transform holography. It is also demonstrated the easy and practical viability of the setup in an interferometric application for mechanical parameters determination. The work is also proposed as an interesting advanced introductory training for graduated students in digital holography.

  18. Extending the detection limit of dopants for focused ion beam prepared semiconductor specimens examined by off-axis electron holography

    DEFF Research Database (Denmark)

    Cooper, David; Rivallin, Pierrette; Hartmann, Jean-Michel

    2009-01-01

    Silicon specimens containing p-n junctions have been prepared for examination by off-axis electron holography using focused ion beam (FIB) milling. FIB milling modifies the surfaces of the specimens due to gallium implantation and the creation of defects which has the effect of reducing the active...

  19. Vibro-acoustics

    CERN Document Server

    Nilsson, Anders

    2015-01-01

    This three-volume book gives a thorough and comprehensive presentation of vibration and acoustic theories. Different from traditional textbooks which typically deal with some aspects of either acoustic or vibration problems, it is unique of this book to combine those two correlated subjects together. Moreover, it provides fundamental analysis and mathematical descriptions for several crucial phenomena of Vibro-Acoustics which are quite useful in noise reduction, including how structures are excited, energy flows from an excitation point to a sound radiating surface, and finally how a structure radiates noise to a surrounding fluid. Many measurement results included in the text make the reading interesting and informative. Problems/questions are listed at the end of each chapter and the solutions are provided. This will help the readers to understand the topics of Vibro-Acoustics more deeply. The book should be of interest to anyone interested in sound and vibration, vehicle acoustics, ship acoustics and inter...

  20. Measurement of the traction force of biological cells by digital holography

    Science.gov (United States)

    Yu, Xiao; Cross, Michael; Liu, Changgeng; Clark, David C.; Haynie, Donald T.; Kim, Myung K.

    2011-01-01

    The traction force produced by biological cells has been visualized as distortions in flexible substrata. We have utilized quantitative phase microscopy by digital holography (DH-QPM) to study the wrinkling of a silicone rubber film by motile fibroblasts. Surface deformation and the cellular traction force have been measured from phase profiles in a direct and straightforward manner. DH-QPM is shown to provide highly efficient and versatile means for quantitatively analyzing cellular motility. PMID:22254175

  1. Electron holography study of the charging effect in microfibrils of sciatic nerve tissues.

    Science.gov (United States)

    Kim, Ki Hyun; Akase, Zentaro; Shindo, Daisuke; Ohno, Nobuhiko; Fujii, Yasuhisa; Terada, Nobuo; Ohno, Shinichi

    2013-08-01

    The charging effects of microfibrils of sciatic nerve tissues due to electron irradiation are investigated using electron holography. The phenomenon that the charging effects are enhanced with an increase of electron intensity is visualized through direct observations of the electric potential distribution around the specimen. The electric potential at the surface of the specimen could be quantitatively evaluated by simulation, which takes into account the reference wave modulation due to the long-range electric field.

  2. Architectural acoustics

    National Research Council Canada - National Science Library

    Long, Marshall

    2014-01-01

    .... Beginning with a brief history, it reviews the fundamentals of acoustics, human perception and reaction to sound, acoustic noise measurements, noise metrics, and environmental noise characterization...

  3. Surface acoustic waves in finite slabs of three-dimensional phononic crystals

    OpenAIRE

    Sainidou, R.; Djafari-Rouhani, B.; Vasseur, J. O.

    2008-01-01

    We study theoretically, by means of layer-multiple-scattering techniques, the propagation of elastic waves through finite slabs of phononic crystals consisting of metallic spheres in a polyester matrix, embedded in air. In particular, we focus on the study of modes localized on the surfaces of the structure. Their origin and behavior, as well as the physical parameters that influence and determine their appearance, are investigated in detail. Our results reveal the existence of absolute phono...

  4. Scattering of acoustic waves from a surface in the presence of an anharmonic interface

    DEFF Research Database (Denmark)

    Kulak, A.; Lodziana, Zbigniew; Srokowski, T.

    2002-01-01

    Energy transfer coefficient (analogue of LDOS) and aperiodicity index are defined to characterise the nonlinear response and the surface resonances in a thin layer separated from the underlying bulk crystal by an anharmonic interface. Regions of periodic, aperiodic and intermittent motion of the ...... of the system are found by analysing the electric circuit obeying the same delayed differential equations. (C) 2002 Elsevier Science B.V. All rights reserved....

  5. Surface-induced errors in target strength and position estimates during horizontal acoustic surveys

    Czech Academy of Sciences Publication Activity Database

    Balk, Helge; Sovegjarto, B.S.; Tušer, Michal; Frouzová, Jaroslava; Muška, Milan; Draštík, Vladislav; Baran, Roman; Kubečka, Jan

    2017-01-01

    Roč. 188, APR (2017), s. 149-156 ISSN 0165-7836 R&D Projects: GA MŠk(CZ) EE2.3.20.0204; GA ČR GAP504/12/1186 Institutional support: RVO:60077344 Keywords : hydroacoustics * surface boundary * shallow water * horizontal beaming * simulations Subject RIV: GL - Fishing OBOR OECD: Fishery Impact factor: 2.185, year: 2016

  6. In situ biasing and off-axis electron holography of a ZnO nanowire

    Science.gov (United States)

    den Hertog, Martien; Donatini, Fabrice; McLeod, Robert; Monroy, Eva; Sartel, Corinne; Sallet, Vincent; Pernot, Julien

    2018-01-01

    Quantitative characterization of electrically active dopants and surface charges in nano-objects is challenging, since most characterization techniques using electrons [1-3], ions [4] or field ionization effects [5-7] study the chemical presence of dopants, which are not necessarily electrically active. We perform cathodoluminescence and voltage contrast experiments on a contacted and biased ZnO nanowire with a Schottky contact and measure the depletion length as a function of reverse bias. We compare these results with state-of-the-art off-axis electron holography in combination with electrical in situ biasing on the same nanowire. The extension of the depletion length under bias observed in scanning electron microscopy based techniques is unusual as it follows a linear rather than square root dependence, and is therefore difficult to model by bulk equations or finite element simulations. In contrast, the analysis of the axial depletion length observed by holography may be compared with three-dimensional simulations, which allows estimating an n-doping level of 1 × 1018 cm-3 and negative sidewall surface charge of 2.5 × 1012 cm-2 of the nanowire, resulting in a radial surface depletion to a depth of 36 nm. We found excellent agreement between the simulated diameter of the undepleted core and the active thickness observed in the experimental data. By combining TEM holography experiments and finite element simulation of the NW electrostatics, the bulk-like character of the nanowire core is revealed.

  7. Highly sensitive and ultrafast response surface acoustic wave humidity sensor based on electrospun polyaniline/poly(vinyl butyral) nanofibers

    International Nuclear Information System (INIS)

    Lin Qianqian; Li Yang; Yang Mujie

    2012-01-01

    Highlights: ► Polyanline/poly(vinyl butyral) nanofibers are prepared by electrospinning. ► Nanofiber-based SAW humidity sensor show high sensitivity and ultrafast response. ► The SAW sensor can detect very low humidity. - Abstract: Polyaniline (PANi) composite nanofibers were deposited on surface acoustic wave (SAW) resonator with a central frequency of 433 MHz to construct humidity sensors. Electrospun nanofibers of poly(methyl methacrylate), poly(vinyl pyrrolidone), poly(ethylene oxide), poly(vinylidene fluoride), poly(vinyl butyral) (PVB) were characterized by scanning electron microscopy, and humidity response of corresponding SAW humidity sensors were investigated. The results indicated that PVB was suitable as a matrix to form nanofibers with PANi by electrospinning (ES). Electrospun PANi/PVB nanofibers exhibited a core–sheath structure as revealed by transmittance electron microscopy. Effects of ES collection time on humidity response of SAW sensor based on PANi/PVB nanofibers were examined at room temperature. The composite nanofiber sensor exhibited very high sensitivity of ∼75 kHz/%RH from 20 to 90%RH, ultrafast response (1 s and 2 s for humidification and desiccation, respectively) and good sensing linearity. Furthermore, the sensor could detect humidity as low as 0.5%RH, suggesting its potentials for low humidity detection. Attempts were done to explain the attractive humidity sensing performance of the sensor by considering conductivity, hydrophilicity, viscoelasticity and morphology of the polymer composite nanofibers.

  8. Formation and properties of proton-exchanged and annealed $LiNbO_{3}$ waveguides for surface acoustic wave

    CERN Document Server

    Chien Chuan Cheng; Ying Chung Chen

    2001-01-01

    The proton-exchanged (PE) and annealed PE (APE) z-cut LiNbO/sub 3/ waveguides were fabricated using H/sub 4/P/sub 2/O/sub 7/. The positive strain, c-axis lattice constant change ( Delta c/c), was calculated to be about +0.43%, which was almost independent of the exchanged conditions. The penetration depth of H measured by secondary ion mass spectrometry (SIMS) exhibited a step-like profile, which was assumed to be equal to the waveguide depth (d). The surface acoustic wave (SAW) properties of PE and APE z-cut LiNbO/sub 3/ samples were investigated. The phase velocity (V/sub p/) and electromechanical coupling coefficient (K/sup 2/) of PE samples were significantly decreased by the increase of kd, where k was the wavenumber (2 pi / lambda ). The insertion loss (IL) of PE samples was increased by the increase of kd and became nearly constant at kd >0.064. The temperature coefficient of frequency (TCF) of PE samples allowed an apparent increase with kd, reaching a maximum at kd=0.292, then slightly decreased at h...

  9. A Dry Membrane Protection Technique to Allow Surface Acoustic Wave Biosensor Measurements of Biological Model Membrane Approaches

    Directory of Open Access Journals (Sweden)

    Marius Enachescu

    2013-09-01

    Full Text Available Model membrane approaches have attracted much attention in biomedical sciences to investigate and simulate biological processes. The application of model membrane systems for biosensor measurements is partly restricted by the fact that the integrity of membranes critically depends on the maintenance of an aqueous surrounding, while various biosensors require a preconditioning of dry sensors. This is for example true for the well-established surface acoustic wave (SAW biosensor SAM®5 blue. Here, a simple drying procedure of sensor-supported model membranes is introduced using the protective disaccharide trehalose. Highly reproducible model membranes were prepared by the Langmuir-Blodgett technique, transferred to SAW sensors and supplemented with a trehalose solution. Membrane rehydration after dry incorporation into the SAW device becomes immediately evident by phase changes. Reconstituted model membranes maintain their full functionality, as indicated by biotin/avidin binding experiments. Atomic force microscopy confirmed the morphological invariability of dried and rehydrated membranes. Approximating to more physiological recognition phenomena, the site-directed immobilization of the integrin VLA-4 into the reconstituted model membrane and subsequent VCAM-1 ligand binding with nanomolar affinity were illustrated. This simple drying procedure is a novel way to combine the model membrane generation by Langmuir-Blodgett technique with SAW biosensor measurements, which extends the applicability of SAM®5 blue in biomedical sciences.

  10. Theoretical analysis of surface acoustic wave propagating properties of Y-cut nano lithium niobate film on silicon dioxide

    Directory of Open Access Journals (Sweden)

    Jing Chen

    2015-08-01

    Full Text Available The surface acoustic wave (SAW propagating characteristics of Y-cut nano LiNbO3 (LN film on SiO2/LN substrate have been theoretically calculated. The simulated results showed a shear horizontal (SH SAW with enhanced electromechanical coupling factor K2 owing to a dimensional effect of the nanoscale LN film. However, a Rayleigh SAW and two other resonances related to thickness vibrations caused spurious responses for wideband SAW devices. These spurious waves could be fully suppressed by properly controlling structural parameters including the electrode layer height, thickness, and the Euler angle (θ of the LN thin film. Finally, a pure SH SAW was obtained with a wide θ range, from 0° to 5° and 165° to 180°. The largest K2 achieved for the pure SH SAW was about 35.1%. The calculated results demonstrate the promising application of nano LN film to the realization of ultra-wideband SAW devices.

  11. Theoretical analysis of surface acoustic wave propagating properties of Y-cut nano lithium niobate film on silicon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jing, E-mail: jingchen0408@hotmail.com; Zhang, Qiaozhen; Han, Tao; Zhou, Liu; Tang, Gongbin; Liu, Boquan; Ji, Xiaojun [Department of Instrument Science and Engineering, Shanghai Jiaotong University, Shanghai 200240 (China)

    2015-08-15

    The surface acoustic wave (SAW) propagating characteristics of Y-cut nano LiNbO{sub 3} (LN) film on SiO{sub 2}/LN substrate have been theoretically calculated. The simulated results showed a shear horizontal (SH) SAW with enhanced electromechanical coupling factor K{sup 2} owing to a dimensional effect of the nanoscale LN film. However, a Rayleigh SAW and two other resonances related to thickness vibrations caused spurious responses for wideband SAW devices. These spurious waves could be fully suppressed by properly controlling structural parameters including the electrode layer height, thickness, and the Euler angle (θ) of the LN thin film. Finally, a pure SH SAW was obtained with a wide θ range, from 0° to 5° and 165° to 180°. The largest K{sup 2} achieved for the pure SH SAW was about 35.1%. The calculated results demonstrate the promising application of nano LN film to the realization of ultra-wideband SAW devices.

  12. Extensional flow of low-viscosity fluids in capillary bridges formed by pulsed surface acoustic wave jetting

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharjee, P K; McDonnell, A G; Prabhakar, R; Yeo, L Y; Friend, J, E-mail: james.friend@monash.edu.au [MicroNanophysics Research Laboratory, Department of Mechanical and Aerospace Engineering, Monash University, Melbourne, VIC 3800 (Australia); Melbourne Centre for Nanofabrication, Melbourne, VIC 3800 (Australia)

    2011-02-15

    Forming capillary bridges of low-viscosity ({approx}<10 mPa s) fluids is difficult, making the study of their capillary-thinning behavior and the measurement of the fluid's extensional viscosity difficult as well. Current techniques require some time to form a liquid bridge from the stretching of a droplet. Rapidly stretching a liquid bridge using these methods can cause its breakup if the viscosity is too low. Stretching more slowly allows the bridge to thin and break up before a suitable bridge geometry can be established to provide reliable and accurate rheological data. Using a pulsed surface acoustic wave to eject a jet from a sessile droplet, a capillary bridge may be formed in about 7.5 ms, about seven times quicker than current methods. With this approach, capillary bridges may be formed from Newtonian and non-Newtonian fluids having much lower viscosities-water, 0.04% by weight solution of high-molecular-weight (7 MDa) polystyrene in dioctyl phthalate and 0.25% fibrinogen solution in demineralized water, for example. Details of the relatively simple system used to achieve these results are provided, as are experimental results indicating deviations from a Newtonian response by the low-viscosity non-Newtonian fluids used in our study.

  13. Development and experimental verification of a finite element method for accurate analysis of a surface acoustic wave device

    Science.gov (United States)

    Mohibul Kabir, K. M.; Matthews, Glenn I.; Sabri, Ylias M.; Russo, Salvy P.; Ippolito, Samuel J.; Bhargava, Suresh K.

    2016-03-01

    Accurate analysis of surface acoustic wave (SAW) devices is highly important due to their use in ever-growing applications in electronics, telecommunication and chemical sensing. In this study, a novel approach for analyzing the SAW devices was developed based on a series of two-dimensional finite element method (FEM) simulations, which has been experimentally verified. It was found that the frequency response of the two SAW device structures, each having slightly different bandwidth and center lobe characteristics, can be successfully obtained utilizing the current density of the electrodes via FEM simulations. The two SAW structures were based on XY Lithium Niobate (LiNbO3) substrates and had two and four electrode finger pairs in both of their interdigital transducers, respectively. Later, SAW devices were fabricated in accordance with the simulated models and their measured frequency responses were found to correlate well with the obtained simulations results. The results indicated that better match between calculated and measured frequency response can be obtained when one of the input electrode finger pairs was set at zero volts and all the current density components were taken into account when calculating the frequency response of the simulated SAW device structures.

  14. Chemical etching of Tungsten thin films for high-temperature surface acoustic wave-based sensor devices

    Energy Technology Data Exchange (ETDEWEB)

    Spindler, M., E-mail: m.spindler@ifw-dresden.de [IFW Dresden, SAWLab Saxony, P.O. Box 270116, D-01171 Dresden (Germany); Herold, S.; Acker, J. [BTU Cottbus – Senftenberg, Faculty of Sciences, P.O. Box 101548, 01968 Senftenberg (Germany); Brachmann, E.; Oswald, S.; Menzel, S.; Rane, G. [IFW Dresden, SAWLab Saxony, P.O. Box 270116, D-01171 Dresden (Germany)

    2016-08-01

    Surface acoustic wave devices are widely used as wireless sensors in different application fields. Recent developments aimed to utilize those devices as temperature sensors even in the high temperature range (T > 300 °C) and in harsh environmental conditions. Therefore, conventional materials, which are used for the substrate and for the interdigital transducer finger electrodes such as multilayers or alloys based on Al or Cu have to be exchanged by materials, which fulfill some important criteria regarding temperature related effects. Electron beam evaporation as a standard fabrication method is not well applicable for depositing high temperature stable electrode materials because of their very high melting points. Magnetron sputtering is an alternative deposition process but is also not applicable for lift-off structuring without any further improvement of the structuring process. Due to a relatively high Ar gas pressure of about 10{sup −1} Pa, the sidewalls of the photoresist line structures are also covered by the metallization, which subsequently prevents a successful lift-off process. In this study, we investigate the chemical etching of thin tungsten films as an intermediate step between magnetron sputtering deposition of thin tungsten finger electrodes and the lift-off process to remove sidewall covering for a successful patterning process of interdigital transducers. - Highlights: • We fabricated Tungsten SAW Electrodes by magnetron sputtering technology. • An etching process removes sidewall covering of photoresist, which allows lift-off. • Tungsten etching rates based on a hydrogen peroxide solutions were determined.

  15. Longitudinal-Type Leaky Surface Acoustic Wave on LiNbO3 with High-Velocity Thin Film

    Science.gov (United States)

    Matsukura, Fumiya; Uematsu, Masato; Hosaka, Keiko; Kakio, Shoji

    2013-07-01

    The loss reduction of a longitudinal-type leaky surface acoustic wave (LLSAW) by loading with a dielectric thin film with a higher velocity than the substrate is proposed. An aluminum nitride (AlN) thin film was adopted as a high-velocity thin film, and the propagation properties of an LLSAW on an X36°Y-LiNbO3 (LN) substrate were investigated. First, the elastic constants c11 and c44 of an amorphous AlN (a-AlN) thin film deposited by RF magnetron sputtering were determined from the measured phase velocities of two SAW modes with mutually perpendicular particle motion, and they were 78 and 96% of those of a single-crystal AlN thin film. Next, from the theoretical calculation for the LLSAW on X36°Y-LN using the determined constants, it was found that the LLSAW attenuation can be reduced to zero by loading with an a-AlN thin film. Then, the propagation properties of the LLSAW on X36°Y-LN were measured by using an interdigital transducer pair. It was found that the losses due to bulk wave radiation can be reduced by loading with an a-AlN thin film.

  16. Real-Time Characterization of Electrospun PVP Nanofibers as Sensitive Layer of a Surface Acoustic Wave Device for Gas Detection

    Directory of Open Access Journals (Sweden)

    D. Matatagui

    2014-01-01

    Full Text Available The goal of this work has been to study the polyvinylpyrrolidone (PVP fibers deposited by means of the electrospinning technique for using as sensitive layer in surface acoustic wave (SAW sensors to detect volatile organic compounds (VOCs. The electrospinning process of the fibers has been monitored and RF characterized in real time, and it has been shown that the diameters of the fibers depend mainly on two variables: the applied voltage and the distance between the needle and the collector, since all the electrospun fibers have been characterized by a scanning electron microscopy (SEM. Real-time measurement during the fiber coating process has shown that the depth of penetration of mechanical perturbation in the fiber layer has a limit. It has been demonstrated that once this saturation has been reached, the increase of the thickness of the fibers coating does not improve the sensitivity of the sensor. Finally, the parameters used to deposit the electrospun fibers of smaller diameters have been used to deposit fibers on a SAW device to obtain a sensor to measure different concentrations of toluene at room temperature. The present sensor exhibited excellent sensitivity, good linearity and repeatability, and high and fast response to toluene at room temperature.

  17. High performance AlScN thin film based surface acoustic wave devices with large electromechanical coupling coefficient

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wenbo; He, Xingli; Ye, Zhi, E-mail: yezhi@zju.edu.cn, E-mail: jl2@bolton.ac.uk; Wang, Xiaozhi [Department of Information Science and Electronic Engineering, Zhejiang University and Cyrus Tang Centre for Sensor Materials and Applications, 38 Zheda Road, Hangzhou 310027 (China); Mayrhofer, Patrick M.; Gillinger, Manuel; Bittner, Achim; Schmid, Ulrich [Institute of Sensor and Actuator Systems, Vienna University of Technology, Floragasse, 7/2/366-MST, A-1040 Vienna (Austria); Luo, J. K., E-mail: yezhi@zju.edu.cn, E-mail: jl2@bolton.ac.uk [Institute of Renewable Energy Environmental Technology, University of Bolton, Deane Road, Bolton BL3 5AB (United Kingdom); Department of Information Science and Electronic Engineering, Zhejiang University and Cyrus Tang Centre for Sensor Materials and Applications, 38 Zheda Road, Hangzhou 310027 (China)

    2014-09-29

    AlN and AlScN thin films with 27% scandium (Sc) were synthesized by DC magnetron sputtering deposition and used to fabricate surface acoustic wave (SAW) devices. Compared with AlN-based devices, the AlScN SAW devices exhibit much better transmission properties. Scandium doping results in electromechanical coupling coefficient, K{sup 2}, in the range of 2.0% ∼ 2.2% for a wide normalized thickness range, more than a 300% increase compared to that of AlN-based SAW devices, thus demonstrating the potential applications of AlScN in high frequency resonators, sensors, and high efficiency energy harvesting devices. The coupling coefficients of the present AlScN based SAW devices are much higher than that of the theoretical calculation based on some assumptions for AlScN piezoelectric material properties, implying there is a need for in-depth investigations on the material properties of AlScN.

  18. Rapid determination of floral aroma compounds of lilac blossom by fast gas chromatography combined with surface acoustic wave sensor.

    Science.gov (United States)

    Oh, Se Yeon; Shin, Hyun Du; Kim, Sung Jean; Hong, Jongki

    2008-03-07

    A novel analytical method using fast gas chromatography combined with surface acoustic wave sensor (GC/SAW) has been developed for the detection of volatile aroma compounds emanated from lilac blossom (Syringa species: Syringa vulgaris variginata and Syringa dilatata). GC/SAW could detect and quantify various fragrance emitted from lilac blossom, enabling to provide fragrance pattern analysis results. The fragrance pattern analysis could easily characterize the delicate differences in aromas caused by the substantial difference of chemical composition according to different color and shape of petals. Moreover, the method validation of GC/SAW was performed for the purpose of volatile floral actual aroma analysis, achieving a high reproducibility and excellent sensitivity. From the validation results, GC/SAW could serve as an alternative analytical technique for the analysis of volatile floral actual aroma of lilac. In addition, headspace solid-phase microextraction (HS-SPME) GC-MS was employed to further confirm the identification of fragrances emitted from lilac blossom and compared to GC/SAW.

  19. Surface integrity evaluation of brass CW614N after impact of acoustically\

    Czech Academy of Sciences Publication Activity Database

    Lehocká, D.; Klich, Jiří; Foldyna, Josef; Hloch, Sergej; Hvizdoš, P.; Fides, M.; Botko, F.; Cárach, J.

    2016-01-01

    Roč. 149, č. 149 (2016), s. 236-244 E-ISSN 1877-7058. [International Conference on Manufacturing Engineering and Materials, ICMEM 2016. Nový Smokovec, 06.06.2016-10.06.2016] R&D Projects: GA MŠk(CZ) LO1406; GA MŠk ED2.1.00/03.0082 Institutional support: RVO:68145535 Keywords : pulsating water jet * surface integrity * mass material removal * brass * nanoindentation Subject RIV: JQ - Machines ; Tools http://www.sciencedirect.com/science/article/pii/S1877705816311705

  20. Acoustic Telemetry Evaluation of Juvenile Salmonid Passage and Survival at John Day Dam with Emphasis on the Prototype Surface Flow Outlet, 2008

    Energy Technology Data Exchange (ETDEWEB)

    Weiland, Mark A.; Ploskey, Gene R.; Hughes, James S.; Deng, Zhiqun; Fu, Tao; Monter, Tyrell J.; Johnson, Gary E.; Khan, Fenton; Wilberding, Matthew C.; Cushing, Aaron W.; Zimmerman, Shon A.; Faber, Derrek M.; Durham, Robin E.; Townsend, Richard L.; Skalski, John R.; Kim, Jina; Fischer, Eric S.; Meyer, Matthew M.

    2009-12-01

    The main purpose of the study was to evaluate the performance of Top Spill Weirs installed at two spillbays at John Day Dam and evaluate the effectiveness of these surface flow outlets at attracting juvenile salmon away from the powerhouse and reducing turbine passage. The Juvenile Salmonid Acoustic Telemetry System (JSATS) was used to estimate survival of juvenile salmonids passing the dam and also for calculating performance metrics used to evaluate the efficiency and effectiveness of the dam at passing juvenile salmonids.

  1. Holography at x-ray wavelengths

    International Nuclear Information System (INIS)

    Solem, T.C.; Baldwin, G.C.; Chapline, G.F.

    1981-01-01

    We discuss alternative holographic techniques for imaging microscopic structures with a short-pulse, high intensity, high-quantum-energy laser. We find that Fresnel transform holography using a photoresist for registration of the hologram is most likely to be within the scope of near term technology. Although it has advantages in time gating, using an in-line electron microscope for hologram registration has an unacceptable tradeoff between quantum efficiency and resolution. Fourier transform holography using a reflector to generate the reference beam might be a reasonable alternative using low resolution film, but is necessarily more complicated. We discuss the dependence of the required laser intensity on the resolution sought and on the elastic and absorption cross sections. We conclude that resonant scattering must be used to obtain holograms at reasonable intensities

  2. Mutual conversion of bulk and surface acoustic waves in gratings of finite length on half-infinite substrates. II. FE analysis of bulk wave generation.

    Science.gov (United States)

    Darinskii, A N; Weihnacht, M; Schmidt, H

    2013-07-01

    The paper studies numerically the bulk acoustic wave generation by the surface acoustic wave propagating across a grating created on the surface of an elastically anisotropic half-infinite substrate. The computations are fully based on the finite element method. Applying the discrete Fourier transformation to the displacement field found inside the substrate and using an orthogonality relation valid for plane modes we determine separately the spatial spectrum of the quasi longitudinal and the quasi transverse bulk waves, that is, the dependence of the amplitudes of these waves on the tangential component of the wave vector. The dependence is investigated of the central spectral peak height and shape on the frequency of the incident surface wave as well as on the thickness, the width, and the number of strips forming the grating. In particular, it is found that under certain conditions the central peak can be approximated fairly precisely by the central peak of a sinc-function describing the spectrum of the bounded acoustic beam of rectangular shape and of width equal to the length of the grating. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Real Time Cascade Impactor Based On Surface Acoustic Wave Delay Lines for PM10 and PM2.5 Mass Concentration Measurement.

    Science.gov (United States)

    Djoumi, Lyes; Vanotti, Meddy; Blondeau-Patissier, Virginie

    2018-01-16

    In this research, Surface Acoustic Wave (SAW) sensors are combined with a cascade impactor to perform real time PM10 and PM2.5 mass concentration measurements. The SAW sensors consist of 125 MHz delay lines based on Love waves propagating on an AT-cut quartz substrate. The Love waves are guided on the substrate's surface using a silica layer. SAW sensors themselves are not capable to discriminate particles by their size, therefore, particle separation based on aerodynamic diameter is achieved using a 3 Lpm dedicated cascade impactor. The latter was designed to integrate the SAW sensors which are monitored using a phase shift measurement. The collected particles impact on the acoustic sensor's surface inducing a gravimetric effect that modifies the acoustic wave propagation conditions. The resulted phase shift allows the measurement of the mass deposited on the sensitive zone. The novel cascade impactor with SAW sensors as particle collecting stages is exposed to different aerosols in the 0-150 μg/m³ concentration range and proved to be able to detect and differentiate particles based on their size in real time. The system's response was compared to a commercial optical counter based on light scattering technology and was found to be in good agreement with it.

  4. Investigation of ionospheric irregularities by radio holography

    Science.gov (United States)

    Tereshchenko, E. D.; Popov, A. A.; Tereshchenko, A. D.; Khudukon, B. Z.

    Methodological aspects of the design of a radio-holography experiment for the investigation of ionospheric irregularities are considered on the basis of a theoretical examination of the formation of a diffraction field by two coherent satellite signals. The equipment needed to implement such an experiment is described, and results of first observations performed at high latitudes (in the Murmansk region) on February 8, 1978 are examined.

  5. Review of digital holography reconstruction methods

    Science.gov (United States)

    Dovhaliuk, Rostyslav Yu.

    2018-01-01

    Development of digital holography opened new ways of both transparent and opaque objects non-destructive study. In this paper, a digital hologram reconstruction process is investigated. The advantages and limitations of common wave propagation methods are discussed. The details of a software implementation of a digital hologram reconstruction methods are presented. Finally, the performance of each wave propagation method is evaluated, and recommendations about possible use cases for each of them are given.

  6. Digital holography from shadowgraphic phase estimates.

    Science.gov (United States)

    Eilenberger, Falk; Minardi, Stefano; Pliakis, Dimitris; Pertsch, Thomas

    2012-02-15

    We show experimentally that the recently proposed iterative shadowgraphic method can be applied to in-line digital holography, provided a suitable regularization step is introduced. We show that the method correctly solves the "twin-image" problem using just two samples of the intensity field scattered by a phase object. Field retrieval accuracy is significantly improved when compared to a reconstruction obtained with the defocusing variation algorithms.

  7. Holography and noncommutative yang-mills theory

    Science.gov (United States)

    Li; Wu

    2000-03-06

    In this Letter a recently proposed gravity dual of noncommutative Yang-Mills theory is derived from the relations between closed string moduli and open string moduli recently suggested by Seiberg and Witten. The only new input one needs is a simple form of the running string tension as a function of energy. This derivation provides convincing evidence that string theory integrates with the holographical principle and demonstrates a direct link between noncommutative Yang-Mills theory and holography.

  8. Chaos in AdS_{2} Holography.

    Science.gov (United States)

    Jensen, Kristan

    2016-09-09

    We revisit two-dimensional holography with the Sachdev-Ye-Kitaev models in mind. Our main result is to rewrite a generic theory of gravity near a two-dimensional anti-de Sitter spacetime throat as a novel hydrodynamics coupled to the correlation functions of a conformal quantum mechanics. This gives a prescription for the computation of n-point functions in the dual quantum mechanics. We thereby find that the dual is maximally chaotic.

  9. Analyses of Sea Surface Height, Bottom Pressure and Acoustic Travel Time in the Japan/East Sea

    National Research Council Canada - National Science Library

    Xu, Yongsheng

    2006-01-01

    ...) was deployed in the southwestern JES for two years, from June 1999 to July 2001. The PIESs recorded hourly vertical acoustic travel time and pressure, which are respectively good proxies of baroclinic and barotropic sea level variability...

  10. The relationship between the acoustic behaviour and surface activity of killer whales (Orcinus orca) that feed on herring (Clupea harengus)

    DEFF Research Database (Denmark)

    Simon, Malene Juul; McGregor, Peter K.; Ugarte, Fernando

    2007-01-01

    We describe the acoustic behaviour of piscivorous killer whales in Norwegian and Icelandic waters. Whales were assigned to one of three activities (feeding, travelling or other), and sound recordings were made in their proximity with a single hydrophone and a digital audiotape (DAT) recorder....... A quantitative analysis of the production of pulsed calls, whistles and echolocation clicks in the three activities revealed that there was a significant effect of activity on the production of these sound types. Both killer whales in Icelandic and Norwegian waters produced high rates of clicks and calls during...... feeding and low rates of click, calls and whistles during travelling. The differences can be used as acoustical markers and provides new possibilities for acoustic monitoring of killer whales in these areas. Based on the similarity between their prey choice, hunting strategies, phenotype and acoustic...

  11. Ultrarealistic imaging: the future of display holography

    Science.gov (United States)

    Bjelkhagen, Hans I.; Brotherton-Ratcliffe, David

    2014-11-01

    Ultrarealistic imaging is the science of producing images that faithfully recreate the light field surrounding an object, such that the unaided eye of a human observer cannot distinguish the difference between the original and the image. Recent technology improvements are now set to transform the fields of both analog and digital display holography, permitting both techniques to operate in the ultrarealistic regime. In particular, ultrarealistic analog holograms have now heralded the serious use of holography in such areas as museum display and cultural heritage protection. These full-color holograms are characterized by a substantially lower noise and a greater spectral fidelity. New recording systems, based on recent diode-pumped solid-state and semiconductor lasers combined with recording materials and processing, have been behind these improvements. Progress in illumination technology, however, has also led to a major reduction in display noise and to a significant increase in the clear image depth and brightness of holograms. Recent progress in one-step direct-write digital holography (DWDH) is now also opening the way to the creation of a new type of ultrarealistic display: the high virtual volume display. This is a large format full-parallax DWDH reflection hologram having a fundamentally larger clear image depth.

  12. Laser Holography. High Tech with High Potential for Learning Activities.

    Science.gov (United States)

    Schlegel, Ronald D.

    1986-01-01

    This article discusses the procedure, historical development, and applications of holography, and discusses the feasibility and value of implementing a unit or course of study of laser holography into an existing photography laboratory and curriculum. An equipment and supplies list, giving supplies and cost, is included. (CT)

  13. Application of Denisyuk pulsed holography to material testing

    NARCIS (Netherlands)

    Renesse, R.L. van; Burgmeijer, J.W.

    1983-01-01

    When holography is applied outside the laboratory, some well known problems are experienced: vibrations, rigid body motion, stray daylight. Pulse holography can overcome the difficulties with vibrations, but the other problems are less easily solved. When the object area to be holographically tested

  14. System and method for investigating sub-surface features of a rock formation with acoustic sources generating conical broadcast signals

    Science.gov (United States)

    Vu, Cung Khac; Skelt, Christopher; Nihei, Kurt; Johnson, Paul A.; Guyer, Robert; Ten Cate, James A.; Le Bas, Pierre -Yves; Larmat, Carene S.

    2015-08-18

    A method of interrogating a formation includes generating a conical acoustic signal, at a first frequency--a second conical acoustic signal at a second frequency each in the between approximately 500 Hz and 500 kHz such that the signals intersect in a desired intersection volume outside the borehole. The method further includes receiving, a difference signal returning to the borehole resulting from a non-linear mixing of the signals in a mixing zone within the intersection volume.

  15. The Application of the Theory of Synthesis of a Delay Line with a Surface Acoustic Wave for a Single-Mode Oscillator of Electric Signals in Some Sensors of Non-Electrical Quantities

    Directory of Open Access Journals (Sweden)

    Šimko Milan

    2017-09-01

    Full Text Available The paper deals with the issue of constructing delay lines on the basis of surface acoustic waves and their application to single-mode oscillators. As a result of a theoretical analysis concrete delay lines are proposed.

  16. Terahertz acoustic phonon detection from a compact surface layer of spherical nanoparticles powder mixture of aluminum, alumina and multi-walled carbon nanotube

    Science.gov (United States)

    Abouelsayed, A.; Ebrahim, M. R.; El hotaby, W.; Hassan, S. A.; Al-Ashkar, Emad

    2017-10-01

    We present terahertz spectroscopy study on spherical nanoparticles powder mixture of aluminum, alumina, and MWCNTs induced by surface mechanical attrition treatment (SMAT) of aluminum substrates. Surface alloying of AL, Al2O3 0.95% and MWCNTs 0.05% powder mixture was produced during SMAT process, where a compact surface layer of about 200 μm due to ball bombardment was produced from the mixture. Al2O3 alumina powder played a significant role in MWCNTs distribution on surface, those were held in deformation surface cites of micro-cavities due to SMAT process of Al. The benefits are the effects on resulted optical properties of the surface studied at the terahertz frequency range due to electrical isolation confinement effects and electronic resonance disturbances exerted on Al electronic resonance at the same range of frequencies. THz acoustic phonon around 0.53-0.6 THz (17-20 cm-1) were observed at ambient conditions for the spherical nanoparticles powder mixture of Al, Al2O3 and MWCNTs. These results suggested that the presence of Al2O3 and MWCNTs during SMAT process leads to the optically detection of such acoustic phonon in the THz frequency range.

  17. Molecularly imprinted surface acoustic wave sensors: The synergy of electrochemical and gravimetric transductions in chemical recognition processes

    International Nuclear Information System (INIS)

    Lattach, Youssef; Fourati, Najla; Zerrouki, Chouki; Fougnion, Jean-Marie; Garnier, Francis; Pernelle, Christine; Remita, Samy

    2012-01-01

    Chemical sensor based on molecularly imprinted conducting polymers (MICP) is described. Polythiophenes – acetic acid thiophene MICP films with different thicknesses have been electrosynthesized over the sensing area of an original electrochemical surface acoustic wave sensor (ESAW). To investigate the sensing properties of the developed sensor, electrochemical and gravimetric combined transductions have been applied to atrazine (ATZ) detection. Films of poly(3,4-ethylenedioxythiophene) noted PEDOT as well as non imprinted conducting polymers (NICP), were also prepared, in order to lead a comparative study. The structure of all films was investigated by IR spectroscopy (ATR-FTIR) and atomic force microscopy (AFM). Films growth and their doping/undoping processes were investigated by simultaneous gravimetric/electrochemical transduction. Real time measurements highlighted difference between the two polymers electrosynthesis kinetics. MICP and NICP films grow linearly with time, whereas PEDOT film thickness presents a limit value of 1 μm in the implied conditions. Considering ESAW sensor response towards charge “transfer”, a linear relationship between sensor phase variations and charges density have been found for PEDOT film, with a sensitivity of about 470 ° C −1 cm 2 . The same sensitivity can also be considered for MICP and NICP films up to 200 mC cm −2 . Beyond this value, saturation has been observed. This divergence have been attributed to difference in films thicknesses, which led to values of weight ratio MICP (NICP)/PEDOT included between 3 and 4.6 for electropolymerization duration going from 10 s to 30 s. Combined use of electrochemical and gravimetric transductions, using MICP as sensitive layer, have also been considered to highlight the ability of the developed ESAW sensor to detect the specific recognition of polymer functional cavities towards ATZ molecules.

  18. Application and exploration of fast gas chromatography-surface acoustic wave sensor to the analysis of thymus species.

    Science.gov (United States)

    Oh, Se Yeon; Ko, Jae Won; Jeong, Seo-Young; Hong, Jongki

    2008-09-26

    Fast gas chromatography combined with surface acoustic wave sensor (GC/SAW) has been applied for the detection of volatile aroma compounds emanated from thymus medicinal plants such as T. quinquecostotus (Jeju and Mt. Gaya in South Korea), T. quinquecostotus var. japonica (Ulreung island in South Korea), T. mongolicus (Northeastern Asia), and T. serpyllum (Europe). The GC/SAW involving the fragrance pattern analysis provides a novel analytical method with a very fast separation and characterization of aromas caused by the delicate difference of chemical composition according to botanical and geographical origin. On the comparison of experiments, the characteristic components and analytical tendency for air-dried thymus species detected by GC/SAW appear to be quite similar to those obtained by headspace solid-phase microextraction (HS-SPME)-GC-MS, but the abundance ratios between these two methods are different. In addition to that, the discrimination of various thymus species by using VaporPrint image based on GC/SAW provides a quite reliable result. On the basis of principal component analysis (PCA) results, the ability for classification among species of completely different chemotypes by HS-SPME-GC-MS is good enough, but the classification of same chemotypes species which are from different geographical origin in same country, original species and its variety, an air-drying term for 13 days and 16 months appear much lower than GC/SAW. Interestingly, the present experiment reveals that the air-drying term influences the aroma composition: the concentration of the pharmacologically active species, monoterpene phenol (thymol), reaches its highest concentrations after it was dried for 5 days or 13 days, which is much higher than in fresh or over-dried for a long times.

  19. Using Nano-mechanics and Surface Acoustic Wave (SAW) for Disease Monitoring and Diagnostics at a Cellular Level in Red Blood Cells

    Science.gov (United States)

    Sivanantha, Ninnuja; Ma, Charles; Collins, David J.; Sesen, Muhsincan; Brenker, Jason; Coppel, Ross L.; Neild, Adrian; Alan, Tuncay

    A popular approach to monitoring diseases and their diagnosis is through biological, pathological or immunological characterization. However, at a cellular level progression of certain diseases manifests itself through mechanical effects as well. Here, we present a method which exploits localised flow; surface acoustic wave (SAW) induced acoustic streaming in a 9 μL droplet to characterize the adhesive properties of red blood cells (healthy, gluteraldehyde treated and malaria infected) in approximately 50 seconds. Our results show a 79% difference in cell mobilization between healthy malaria infected RBCs (and a 39% difference between healthy and treated ones), indicating that the method can serve as a platform for rapid clinical diagnosis; where separation of two or more different cell populations in a mixed solution is desirable. It can also act as a key biomarker for monitoring some diseases offering quantitative measures of disease progression and response to therapy.

  20. Modeling, design, packing and experimental analysis of liquid-phase shear-horizontal surface acoustic wave sensors

    Science.gov (United States)

    Pollard, Thomas B

    Recent advances in microbiology, computational capabilities, and microelectromechanical-system fabrication techniques permit modeling, design, and fabrication of low-cost, miniature, sensitive and selective liquid-phase sensors and lab-on-a-chip systems. Such devices are expected to replace expensive, time-consuming, and bulky laboratory-based testing equipment. Potential applications for devices include: fluid characterization for material science and industry; chemical analysis in medicine and pharmacology; study of biological processes; food analysis; chemical kinetics analysis; and environmental monitoring. When combined with liquid-phase packaging, sensors based on surface-acoustic-wave (SAW) technology are considered strong candidates. For this reason such devices are focused on in this work; emphasis placed on device modeling and packaging for liquid-phase operation. Regarding modeling, topics considered include mode excitation efficiency of transducers; mode sensitivity based on guiding structure materials/geometries; and use of new piezoelectric materials. On packaging, topics considered include package interfacing with SAW devices, and minimization of packaging effects on device performance. In this work novel numerical models are theoretically developed and implemented to study propagation and transduction characteristics of sensor designs using wave/constitutive equations, Green's functions, and boundary/finite element methods. Using developed simulation tools that consider finite-thickness of all device electrodes, transduction efficiency for SAW transducers with neighboring uniform or periodic guiding electrodes is reported for the first time. Results indicate finite electrode thickness strongly affects efficiency. Using dense electrodes, efficiency is shown to approach 92% and 100% for uniform and periodic electrode guiding, respectively; yielding improved sensor detection limits. A numerical sensitivity analysis is presented targeting viscosity