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Sample records for acoustic resonant bar

  1. Split Hopkinson Resonant Bar Test for Sonic-Frequency Acoustic Velocity and Attenuation Measurements of Small, Isotropic Geologic Samples

    SciTech Connect

    Nakagawa, S.

    2011-04-01

    Mechanical properties (seismic velocities and attenuation) of geological materials are often frequency dependent, which necessitates measurements of the properties at frequencies relevant to a problem at hand. Conventional acoustic resonant bar tests allow measuring seismic properties of rocks and sediments at sonic frequencies (several kilohertz) that are close to the frequencies employed for geophysical exploration of oil and gas resources. However, the tests require a long, slender sample, which is often difficult to obtain from the deep subsurface or from weak and fractured geological formations. In this paper, an alternative measurement technique to conventional resonant bar tests is presented. This technique uses only a small, jacketed rock or sediment core sample mediating a pair of long, metal extension bars with attached seismic source and receiver - the same geometry as the split Hopkinson pressure bar test for large-strain, dynamic impact experiments. Because of the length and mass added to the sample, the resonance frequency of the entire system can be lowered significantly, compared to the sample alone. The experiment can be conducted under elevated confining pressures up to tens of MPa and temperatures above 100 C, and concurrently with x-ray CT imaging. The described Split Hopkinson Resonant Bar (SHRB) test is applied in two steps. First, extension and torsion-mode resonance frequencies and attenuation of the entire system are measured. Next, numerical inversions for the complex Young's and shear moduli of the sample are performed. One particularly important step is the correction of the inverted Young's moduli for the effect of sample-rod interfaces. Examples of the application are given for homogeneous, isotropic polymer samples and a natural rock sample.

  2. Acoustic metasurface with hybrid resonances.

    PubMed

    Ma, Guancong; Yang, Min; Xiao, Songwen; Yang, Zhiyu; Sheng, Ping

    2014-09-01

    An impedance-matched surface has the property that an incident wave generates no reflection. Here we demonstrate that by using a simple construction, an acoustically reflecting surface can acquire hybrid resonances and becomes impedance-matched to airborne sound at tunable frequencies, such that no reflection is generated. Each resonant cell of the metasurface is deep-subwavelength in all its spatial dimensions, with its thickness less than the peak absorption wavelength by two orders of magnitude. As there can be no transmission, the impedance-matched acoustic wave is hence either completely absorbed at one or multiple frequencies, or converted into other form(s) of energy, such as an electrical current. A high acoustic-electrical energy conversion efficiency of 23% is achieved. PMID:24880731

  3. Contour mode resonators with acoustic reflectors

    DOEpatents

    Olsson, Roy H.; Fleming, James G.; Tuck, Melanie R.

    2008-06-10

    A microelectromechanical (MEM) resonator is disclosed which has a linear or ring-shaped acoustic resonator suspended above a substrate by an acoustic reflector. The acoustic resonator can be formed with a piezoelectric material (e.g. aluminum nitride, zinc oxide or PZT), or using an electrostatically-actuated material. The acoustic reflector (also termed an acoustic mirror) uses alternating sections of a relatively low acoustic impedance Z.sub.L material and a relatively high acoustic impedance Z.sub.H material to isolate the acoustic resonator from the substrate. The MEM resonator, which can be formed on a silicon substrate with conventional CMOS circuitry, has applications for forming oscillators, rf filters, and acoustic sensors.

  4. Miniature Sapphire Acoustic Resonator - MSAR

    NASA Technical Reports Server (NTRS)

    Wang, Rabi T.; Tjoelker, Robert L.

    2011-01-01

    A room temperature sapphire acoustics resonator incorporated into an oscillator represents a possible opportunity to improve on quartz ultrastable oscillator (USO) performance, which has been a staple for NASA missions since the inception of spaceflight. Where quartz technology is very mature and shows a performance improvement of perhaps 1 dB/decade, these sapphire acoustic resonators when integrated with matured quartz electronics could achieve a frequency stability improvement of 10 dB or more. As quartz oscillators are an essential element of nearly all types of frequency standards and reference systems, the success of MSAR would advance the development of frequency standards and systems for both groundbased and flight-based projects. Current quartz oscillator technology is limited by quartz mechanical Q. With a possible improvement of more than x 10 Q with sapphire acoustic modes, the stability limit of current quartz oscillators may be improved tenfold, to 10(exp -14) at 1 second. The electromagnetic modes of sapphire that were previously developed at JPL require cryogenic temperatures to achieve the high Q levels needed to achieve this stability level. However sapphire fs acoustic modes, which have not been used before in a high-stability oscillator, indicate the required Q values (as high as Q = 10(exp 8)) may be achieved at room temperature in the kHz range. Even though sapphire is not piezoelectric, such a high Q should allow electrostatic excitation of the acoustic modes with a combination of DC and AC voltages across a small sapphire disk (approximately equal to l mm thick). The first evaluations under this task will test predictions of an estimated input impedance of 10 kilohms at Q = 10(exp 8), and explore the Q values that can be realized in a smaller resonator, which has not been previously tested for acoustic modes. This initial Q measurement and excitation demonstration can be viewed similar to a transducer converting electrical energy to

  5. Acoustic resonance frequency locked photoacoustic spectrometer

    DOEpatents

    Pilgrim, Jeffrey S.; Bomse, David S.; Silver, Joel A.

    2003-09-09

    A photoacoustic spectroscopy method and apparatus for maintaining an acoustic source frequency on a sample cell resonance frequency comprising: providing an acoustic source to the sample cell, the acoustic source having a source frequency; repeatedly and continuously sweeping the source frequency across the resonance frequency at a sweep rate; and employing an odd-harmonic of the source frequency sweep rate to maintain the source frequency sweep centered on the resonance frequency.

  6. Acoustic resonance techniques for quality control

    SciTech Connect

    Sinha, D.N.

    1992-09-01

    Acoustic resonance based nondestructive techniques are described that can be used for both process and quality control in manufacturing. The Acoustic Resonance Spectroscopy (AS) technique is highlighted for its capability in fluid property (flow, density, viscosity, and speed of sound) monitoring. Possible applications of these noninvasive techniques for textile manufacturing are pointed out.

  7. Acoustic resonance techniques for quality control

    SciTech Connect

    Sinha, D.N.

    1992-01-01

    Acoustic resonance based nondestructive techniques are described that can be used for both process and quality control in manufacturing. The Acoustic Resonance Spectroscopy (AS) technique is highlighted for its capability in fluid property (flow, density, viscosity, and speed of sound) monitoring. Possible applications of these noninvasive techniques for textile manufacturing are pointed out.

  8. Acoustic resonance phase locked photoacoustic spectrometer

    DOEpatents

    Pilgrim, Jeffrey S.; Bomse, David S.; Silver, Joel A.

    2003-08-19

    A photoacoustic spectroscopy method and apparatus for maintaining an acoustic source frequency on a sample cell resonance frequency comprising: providing an acoustic source to the sample cell to generate a photoacoustic signal, the acoustic source having a source frequency; continuously measuring detection phase of the photoacoustic signal with respect to source frequency or a harmonic thereof; and employing the measured detection phase to provide magnitude and direction for correcting the source frequency to the resonance frequency.

  9. Acoustic resonance for nonmetallic mine detection

    SciTech Connect

    Kercel, S.W.

    1998-04-01

    The feasibility of acoustic resonance for detection of plastic mines was investigated by researchers at the Oak Ridge National Laboratory`s Instrumentation and Controls Division under an internally funded program. The data reported in this paper suggest that acoustic resonance is not a practical method for mine detection. Representative small plastic anti-personnel mines were tested, and were found to not exhibit detectable acoustic resonances. Also, non-metal objects known to have strong acoustic resonances were tested with a variety of excitation techniques, and no practical non-contact method of exciting a consistently detectable resonance in a buried object was discovered. Some of the experimental data developed in this work may be useful to other researchers seeking a method to detect buried plastic mines. A number of excitation methods and their pitfalls are discussed. Excitation methods that were investigated include swept acoustic, chopped acoustic, wavelet acoustic, and mechanical shaking. Under very contrived conditions, a weak response that could be attributed to acoustic resonance was observed, but it does not appear to be practical as a mine detection feature. Transfer properties of soil were investigated. Impulse responses of several representative plastic mines were investigated. Acoustic leakage coupling, and its implications as a disruptive mechanism were investigated.

  10. Measuring the acoustic response of Helmholtz resonators

    NASA Astrophysics Data System (ADS)

    Monteiro, Martín; Marti, Arturo C.; Vogt, Patrik; Kasper, Lutz; Quarthal, Dominik

    2015-04-01

    Many experiments have been proposed to investigate acoustic phenomena in college and early undergraduate levels, in particular the speed of sound,1-9 by means of different methods, such as time of flight, transit time, or resonance in tubes. In this paper we propose to measure the acoustic response curves of a glass beaker filled with different gases, used as an acoustic resonator. We show that these curves expose many interesting peaks and features, one of which matches the resonance peak predicted for a Helmholtz resonator fairly well, and gives a decent estimate for the speed of sound in some cases. The measures are obtained thanks to the capabilities of smartphones.

  11. Humanitarian mine detection by acoustic resonance

    SciTech Connect

    Kercel, S.W.

    1998-03-01

    The JASON Committee at MITRE Corp. was tasked by DARPA to inquire into suitable technologies for humanitarian mine detection. Acoustic resonance was one of the very few technologies that the JASONs determined might be promising for the task, but was as yet unexplored at the time that they conducted their inquiry. The objective of this Seed Money investigation into acoustic resonance was to determine if it would be feasible to use acoustic resonance to provide an improvement to present methods for humanitarian mine detection. As detailed in this report, acoustic resonance methods do not appear to be feasible for this task. Although acoustic resonant responses are relatively easy to detect when they exist, they are very difficult to excite by the non-contact means that must be used for buried objects. Despite many different attempts, this research did not discover any practical means of using sound to excite resonant responses in objects known to have strong resonances. The shaker table experiments did see an effect that might be attributable to the resonance of the object under test, but the effect was weak, and exploited the a priori knowledge of the resonant frequency of the object under test to distinguish it from the background. If experiments that used objects known to have strong acoustic resonances produced such marginal results, this does not seem to be a practical method to detect objects with weak resonances or non-existent resonances. The results of this work contribute to the ORNL countermine initiative. ORNL is exploring several unconventional mine detection technologies, and is proposed to explore others. Since this research has discovered some major pitfalls in non-metallic mine detection, this experience will add realism to other strategies proposed for mine detection technologies. The experiment provided hands-on experience with inert plastic mines under field conditions, and gives ORNL additional insight into the problems of developing practical

  12. High Q Miniature Sapphire Acoustic Resonator

    NASA Technical Reports Server (NTRS)

    Wang, Rabi T.; Tjoelker, R. L.

    2010-01-01

    We have demonstrated high Q measurements in a room temperature Miniature Sapphire Acoustic Resonator (MSAR). Initial measurements of bulk acoustic modes in room temperature sapphire at 39 MHz have demonstrated a Q of 8.8 x 10(exp 6). The long term goal of this work is to integrate such a high Q resonator with small, low noise quartz oscillator electronics, providing a fractional frequency stability better than 1 x 10(exp -14) @ 1s.

  13. Optically selective, acoustically resonant gas detecting transducer

    NASA Technical Reports Server (NTRS)

    Dimeff, J. (Inventor)

    1977-01-01

    A gas analyzer is disclosed which responds to the resonant absorption or emission spectrum of a specific gas by producing an acoustic resonance in a chamber containing a sample of that gas, and which measures the amount of that emission or absorption by measuring the strength of that acoustic resonance, e.g., the maximum periodic pressure, velocity or density achieved. In the preferred embodiment, a light beam is modulated periodically at the acoustical resonance frequency of a closed chamber which contains an optically dense sample of the gas of interest. Periodic heating of the absorbing gas by the light beam causes a cyclic expansion, movement, and pressure within the gas. An amplitude is reached where the increased losses were the cyclic radiation energy received. A transducing system is inclined for converting the pressure variations of the resonant gas into electronic readout signals.

  14. Convert Acoustic Resonances to Orbital Angular Momentum

    NASA Astrophysics Data System (ADS)

    Jiang, Xue; Li, Yong; Liang, Bin; Cheng, Jian-chun; Zhang, Likun

    2016-07-01

    We use acoustic resonances in a planar layer of half-wavelength thickness to twist wave vectors of an in-coming plane wave into a spiral phase dislocation of an outgoing vortex beam with orbital angular momentum (OAM). The mechanism is numerically and experimentally demonstrated by producing an airborne Bessel-like vortex beam. Our acoustic resonance-based OAM production differs from existing means for OAM production by enormous phased spiral sources or by elaborate spiral profiles. Our study can advance the capability of generating phase dislocated wave fields for further applications of acoustic OAM.

  15. Convert Acoustic Resonances to Orbital Angular Momentum.

    PubMed

    Jiang, Xue; Li, Yong; Liang, Bin; Cheng, Jian-Chun; Zhang, Likun

    2016-07-15

    We use acoustic resonances in a planar layer of half-wavelength thickness to twist wave vectors of an in-coming plane wave into a spiral phase dislocation of an outgoing vortex beam with orbital angular momentum (OAM). The mechanism is numerically and experimentally demonstrated by producing an airborne Bessel-like vortex beam. Our acoustic resonance-based OAM production differs from existing means for OAM production by enormous phased spiral sources or by elaborate spiral profiles. Our study can advance the capability of generating phase dislocated wave fields for further applications of acoustic OAM. PMID:27472113

  16. Acoustic spin pumping in magnetoelectric bulk acoustic wave resonator

    NASA Astrophysics Data System (ADS)

    Polzikova, N. I.; Alekseev, S. G.; Pyataikin, I. I.; Kotelyanskii, I. M.; Luzanov, V. A.; Orlov, A. P.

    2016-05-01

    We present the generation and detection of spin currents by using magnetoelastic resonance excitation in a magnetoelectric composite high overtone bulk acoustic wave (BAW) resonator (HBAR) formed by a Al-ZnO-Al-GGG-YIG-Pt structure. Transversal BAW drives magnetization oscillations in YIG film at a given resonant magnetic field, and the resonant magneto-elastic coupling establishes the spin-current generation at the Pt/YIG interface. Due to the inverse spin Hall effect (ISHE) this BAW-driven spin current is converted to a dc voltage in the Pt layer. The dependence of the measured voltage both on magnetic field and frequency has a resonant character. The voltage is determined by the acoustic power in HBAR and changes its sign upon magnetic field reversal. We compare the experimentally observed amplitudes of the ISHE electrical field achieved by our method and other approaches to spin current generation that use surface acoustic waves and microwave resonators for ferromagnetic resonance excitation, with the theoretically expected values.

  17. Extraordinary acoustic transmission mediated by Helmholtz resonators

    SciTech Connect

    Koju, Vijay; Rowe, Ebony; Robertson, William M.

    2014-07-15

    We demonstrate perfect transmission of sound through a rigid barrier embedded with Helmholtz resonators. The resonators are confined within a waveguide and they are oriented such that one neck protrudes onto each side of the barrier. Perfect sound transmission occurs even though the open area of the necks is less than 3% of the barrier area. Maximum transmission occurs at the resonant frequency of the Helmholtz resonator. Because the dimensions of the Helmholtz resonators are much smaller than the resonant wavelength, the transmission is independent of the direction of sound on the barrier and of the relative placement of the necks. Further, we show that the transmitted sound experiences a continuous phase transition of π radians as a function of frequency through resonance. In simulations of adjacent resonators with slightly offset resonance frequencies, the phase difference leads to destructive interference. By expanding the simulation to a linear array of tuned Helmholtz resonators we show that it is possible to create an acoustic lens. The ability of Helmholtz resonator arrays to manipulate the phase of a plane acoustic wave enables a new class of sonic beam-forming devices analogous to diffractive optics.

  18. Acoustic Resonator Optimisation for Airborne Particle Manipulation

    NASA Astrophysics Data System (ADS)

    Devendran, Citsabehsan; Billson, Duncan R.; Hutchins, David A.; Alan, Tuncay; Neild, Adrian

    Advances in micro-electromechanical systems (MEMS) technology and biomedical research necessitate micro-machined manipulators to capture, handle and position delicate micron-sized particles. To this end, a parallel plate acoustic resonator system has been investigated for the purposes of manipulation and entrapment of micron sized particles in air. Numerical and finite element modelling was performed to optimise the design of the layered acoustic resonator. To obtain an optimised resonator design, careful considerations of the effect of thickness and material properties are required. Furthermore, the effect of acoustic attenuation which is dependent on frequency is also considered within this study, leading to an optimum operational frequency range. Finally, experimental results demonstrated good particle levitation and capture of various particle properties and sizes ranging to as small as 14.8 μm.

  19. Formation of q{bar q} resonances in the {bar N}N system

    SciTech Connect

    Ivanov, N.Ya.

    1995-11-01

    The formation of q{bar q} resonances lying on the leading Regge trajectories in the {bar N}N system is studied in the quark-gluon string model. The model predicts strong suppression of the decays of q{bar q} states into {bar N}N pairs in relation to two-meson modes. The author`s analysis shows that the contributions of the resonances f{sub 4}(2050) (I{sup G}J{sup PC}= 0{sup +}4{sup ++}), {rho}{sub 5}(2240) (I{sup G}J{sup PC} = 1{sup +}5{sup {minus}{minus}}), and f{sub 6}(2510) (I{sup G}J{sup PC} = 0{sup +}6{sup ++}) to the processes of two-meson {bar N}N annihilation ({bar p}p {yields} {pi}{pi}, {bar K}K, {hor_ellipsis}) are about 1% of the corresponding experimental integrated cross sections. 30 refs., 2 figs., 1 tab.

  20. Acoustofluidics 5: Building microfluidic acoustic resonators.

    PubMed

    Lenshof, A; Evander, M; Laurell, T; Nilsson, J

    2012-02-21

    Acoustophoresis is getting more attention as an effective and gentle non-contact method of manipulating cells and particles in microfluidic systems. A key to a successful assembly of an acoustophoresis system is a proper design of the acoustic resonator where aspects of fabrication techniques, material choice, thickness matching of involved components, as well as strategies of actuation, all have to be considered. This tutorial covers some of the basics in designing and building microfluidic acoustic resonators and will hopefully be a comprehensive and advisory document to assist the interested reader in creating a successful acoustophoretic device. PMID:22246532

  1. Wave Phenomena in an Acoustic Resonant Chamber

    ERIC Educational Resources Information Center

    Smith, Mary E.; And Others

    1974-01-01

    Discusses the design and operation of a high Q acoustical resonant chamber which can be used to demonstrate wave phenomena such as three-dimensional normal modes, Q values, densities of states, changes in the speed of sound, Fourier decomposition, damped harmonic oscillations, sound-absorbing properties, and perturbation and scattering problems.…

  2. Acoustic resonator and method of making same

    DOEpatents

    Kline, Gerald R.; Lakin, Kenneth M.

    1985-03-05

    A method of fabricating an acoustic wave resonator wherein all processing steps are accomplished from a single side of said substrate. The method involves deposition of a multi-layered Al/AlN structure on a GaAs substrate followed by a series of fabrication steps to define a resonator from said composite. The resulting resonator comprises an AlN layer between two Al layers and another layer of AlN on an exterior of one of said Al layers.

  3. Acoustic resonator and method of making same

    DOEpatents

    Kline, G.R.; Lakin, K.M.

    1983-10-13

    A method of fabricating an acoustic wave resonator wherein all processing steps are accomplished from a single side of said substrate. The method involves deposition of a multi-layered Al/AlN structure on a GaAs substrate followed by a series of fabrication steps to define a resonator from said composite. The resulting resonator comprises an AlN layer between two Al layers and another layer of AlN on an exterior of one of said Al layers.

  4. Acoustic resonator and method of making same

    DOEpatents

    Kline, G.R.; Lakin, K.M.

    1985-03-05

    A method is disclosed of fabricating an acoustic wave resonator wherein all processing steps are accomplished from a single side of said substrate. The method involves deposition of a multi-layered Al/AlN structure on a GaAs substrate followed by a series of fabrication steps to define a resonator from said composite. The resulting resonator comprises an AlN layer between two Al layers and another layer of AlN on an exterior of one of said Al layers. 4 figs.

  5. Magnetic resonance acoustic radiation force imaging

    PubMed Central

    McDannold, Nathan; Maier, Stephan E.

    2008-01-01

    Acoustic radiation force impulse imaging is an elastography method developed for ultrasound imaging that maps displacements produced by focused ultrasound pulses systematically applied to different locations. The resulting images are “stiffness weighted” and yield information about local mechanical tissue properties. Here, the feasibility of magnetic resonance acoustic radiation force imaging (MR-ARFI) was tested. Quasistatic MR elastography was used to measure focal displacements using a one-dimensional MRI pulse sequence. A 1.63 or 1.5 MHz transducer supplied ultrasound pulses which were triggered by the magnetic resonance imaging hardware to occur before a displacement-encoding gradient. Displacements in and around the focus were mapped in a tissue-mimicking phantom and in an ex vivo bovine kidney. They were readily observed and increased linearly with acoustic power in the phantom (R2=0.99). At higher acoustic power levels, the displacement substantially increased and was associated with irreversible changes in the phantom. At these levels, transverse displacement components could also be detected. Displacements in the kidney were also observed and increased after thermal ablation. While the measurements need validation, the authors have demonstrated the feasibility of detecting small displacements induced by low-power ultrasound pulses using an efficient magnetic resonance imaging pulse sequence that is compatible with tracking of a dynamically steered ultrasound focal spot, and that the displacement increases with acoustic power. MR-ARFI has potential for elastography or to guide ultrasound therapies that use low-power pulsed ultrasound exposures, such as drug delivery. PMID:18777934

  6. Power absorption in acoustically driven ferromagnetic resonance

    NASA Astrophysics Data System (ADS)

    Labanowski, D.; Jung, A.; Salahuddin, S.

    2016-01-01

    Surface acoustic waves (SAWs) have recently been used to drive ferromagnetic resonance by exploiting the coupling between strain and magnetization in magnetostrictive materials in a technique called acoustically driven ferromagnetic resonance (ADFMR). In this work, we quantitatively examine the power absorbed by the magnetic elements in such systems. We find that power absorption scales exponentially with the length of the magnetic element in the direction of SAW propagation, with the rate of scaling set by the thickness of magnetic material. In addition, we find that ADFMR behaves consistently across a wide range of input power values (>65 dB). Our results indicate that devices such as filters, oscillators, and sensors can be designed that operate with very low power, yet provide high tunability.

  7. Porous silicon bulk acoustic wave resonator with integrated transducer

    PubMed Central

    2012-01-01

    We report that porous silicon acoustic Bragg reflectors and AlN-based transducers can be successfully combined and processed in a commercial solidly mounted resonator production line. The resulting device takes advantage of the unique acoustic properties of porous silicon in order to form a monolithically integrated bulk acoustic wave resonator. PMID:22776697

  8. Conversion acoustic resonances in orthorhombic crystals

    NASA Astrophysics Data System (ADS)

    Lyubimov, V. N.; Bessonov, D. A.; Alshits, V. I.

    2016-05-01

    A classification of acoustic-beam reflection resonances in orthorhombic crystals under conditions where a proximity to conversion is implemented in the vicinity of total internal reflection is proposed. In this case, the energy from the incident pump beam falls almost entirely into a narrow intense reflected beam propagating at a small angle with respect to the surface. The crystal boundary is parallel to one of the elastic symmetry planes, and the excited beam propagates near one of axes 2 in this plane. Depending on the relations between the elastic moduli and the chosen propagation geometry, 18 types of resonances may occur, but no more than three in each crystal. The developed theory combines an approximate analytical description and accurate computer analysis. The relations between the elastic moduli providing minimum energy loss over the parasite reflected wave are determined. Some crystals with resonant excitation very close to conversion are revealed.

  9. Recent developments of film bulk acoustic resonators

    NASA Astrophysics Data System (ADS)

    Gao, Junning; Liu, Guorong; Li, Jie; Li, Guoqiang

    2016-06-01

    Film bulk acoustic wave resonator (FBAR) experienced skyrocketing development in the past 15 years, owing to the explosive development of mobile communication. It stands out in acoustic filters mainly because of high quality factor, which enables low insertion loss and sharp roll off. Except for the massive application in wireless communication, FBARs are also promising sensors because of the high sensitivity and readily integration ability to miniaturize circuits. On the ground of summarizing FBAR’s application in wireless communication as filters and in sensors including electronic nose, bio field, and pressure sensing, this paper review the main challenges of each application faced. The number of filters installed in the mobile phone has being grown explosively, which leads to overcrowded bands and put harsh requirements on component size and power consumption control for each unit. Data flow and rate are becoming increasingly demanding as well. This paper discusses three promising technical strategies addressing these issues. Among which coupled resonator filter is given intense attention because it is able to vigorously reduce the filter size by stacking two or more resonators together, and it is a great technique to increase data flow and rate. Temperature compensation methods are discussed considering their vital influence on frequency stability. Finally, materials improvement and novel materials exploration for band width modulation, tunable band acquisition, and quality factor improvement are discussed. The authors appeal attention of the academic society to bring AlN epitaxial thin film into the FBAR fabrication and have proposed a configuration to implement this idea.

  10. Optical motion sensor for resonant-bar gravitational wave antennas.

    PubMed

    Richard, J P; Pang, Y; Hamilton, J J

    1992-04-01

    An experiment is described in which an optical method was used to measure fluctuations in the separation between two mirrors of a Fabry-Perot sensor cavity. Noise measurements were made to determine the sensitivity of this device to vibration amplitudes in the frequency range 1.1-2.1 kHz, which is of interestfor resonant-bar gravitational wave antennas. The rms spectral noise density for length fluctuations inthis range was 3.7 x 10(15-) m/Hz((1/2)) and can be related to electronic noise of the circuitry plus vibrationalnoise from the environment. The cavity finesse was relatively low at 117, and the power dissipated in the mirrors was estimated to be 1.9 muW. On a multimode gravitational wave detector, the sensor cavity would be formed by one reference mirror and by one mirror mounted on the last resonator. For a 1200-kg bar, 1.2-g last resonator system operating at 1600 Hz, the sensor described here would exhibit a noise temperature of 18 muK; the resolution in h in the case of negligible thermal noise from the mechanical system would be 3.7 x 10(-18)/Hz((1/2)). Improvements in the sensitivity in a quiet antenna-like environment should be possible with higher finesse mirrors. PMID:20720800

  11. Resonant capacitive MEMS acoustic emission transducers

    NASA Astrophysics Data System (ADS)

    Ozevin, D.; Greve, D. W.; Oppenheim, I. J.; Pessiki, S. P.

    2006-12-01

    We describe resonant capacitive MEMS transducers developed for use as acoustic emission (AE) detectors, fabricated in the commercial three-layer polysilicon surface micromachining process (MUMPs). The 1 cm square device contains six independent transducers in the frequency range between 100 and 500 kHz, and a seventh transducer at 1 MHz. Each transducer is a parallel plate capacitor with one plate free to vibrate, thereby causing a capacitance change which creates an output signal in the form of a current under a dc bias voltage. With the geometric proportions we employed, each transducer responds with two distinct resonant frequencies. In our design the etch hole spacing was chosen to limit squeeze film damping and thereby produce an underdamped vibration when operated at atmospheric pressure. Characterization experiments obtained by capacitance and admittance measurements are presented, and transducer responses to physically simulated AE source are discussed. Finally, we report our use of the device to detect acoustic emissions associated with crack initiation and growth in weld metal.

  12. Passive separation control by acoustic resonance

    NASA Astrophysics Data System (ADS)

    Yang, S. L.; Spedding, G. R.

    2013-10-01

    At transitional Reynolds numbers, the laminar boundary layer separation and possible reattachment on a smooth airfoil, or wing section, are notoriously sensitive to small variations in geometry or in the fluid environment. We report here on the results of a pilot study that adds to this list of sensitivities. The presence of small holes in the suction surface of an Eppler 387 wing has a transformative effect upon the aerodynamics, by changing the mean chordwise separation line location. These changes are not simply a consequence of the presence of the small cavities, which by themselves have no effect. Acoustic resonance in the backing cavities generates tones that interact with intrinsic flow instabilities. Possible consequences for passive flow control strategies are discussed together with potential problems in measurements through pressure taps in such flow regimes.

  13. Wax Point Determinations Using Acoustic Resonance Spectroscopy

    SciTech Connect

    Jubin, R.T.

    2002-04-08

    The thermodynamic characterization of the wax point of a given crude is essential in order to maintain flow conditions that prevent plugging of undersea pipelines. This report summarizes the efforts made towards applying an Acoustic Cavity Resonance Spectrometer (ACRS) to the determination of pressures and temperatures at which wax precipitates from crude. Phillips Petroleum Company, Inc., the CRADA participant, supplied the ACRS. The instrumentation was shipped to Dr. Thomas Schmidt of ORNL, the CRADA contractor, in May 2000 after preliminary software development performed under the guidance of Dr. Samuel Colgate and Dr. Evan House of the University of Florida, Gainesville, FL. Upon receipt it became apparent that a number of modifications still needed to be made before the ACRS could be precisely and safely used for wax point measurements. This report reviews the sequence of alterations made to the ACRS, as well as defines the possible applications of the instrumentation once the modifications have been completed.

  14. Characterization of energy trapping in a bulk acoustic wave resonator

    NASA Astrophysics Data System (ADS)

    Kokkonen, Kimmo; Meltaus, Johanna; Pensala, Tuomas; Kaivola, Matti

    2010-12-01

    Acoustic wave fields both within the active electrode area of a solidly mounted 1.8 GHz bulk acoustic wave resonator, and around it in the surrounding region, are measured using a heterodyne laser interferometer. Plate-wave dispersion diagrams for both regions are extracted from the measurement data. The experimental dispersion data reveal the cutoff frequencies of the acoustic vibration modes in the region surrounding the resonator, and, therefore, the energy trapping range of the resonator can readily be determined. The measured dispersion properties of the surrounding region, together with the abruptly diminishing amplitude of the dispersion curves in the resonator, signal the onset of acoustic leakage from the resonator. This information is important for verifying and further developing the simulation tools used for the design of the resonators. Experimental wave field images, dispersion diagrams for both regions, and the threshold for energy leakage are discussed.

  15. Acoustic subwavelength imaging of subsurface objects with acoustic resonant metalens

    SciTech Connect

    Cheng, Ying; Liu, XiaoJun; Zhou, Chen; Wei, Qi; Wu, DaJian

    2013-11-25

    Early research into acoustic metamaterials has shown the possibility of achieving subwavelength near-field acoustic imaging. However, a major restriction of acoustic metamaterials is that the imaging objects must be placed in close vicinity of the devices. Here, we present an approach for acoustic imaging of subsurface objects far below the diffraction limit. An acoustic metalens made of holey-structured metamaterials is used to magnify evanescent waves, which can rebuild an image at the central plane. Without changing the physical structure of the metalens, our proposed approach can image objects located at certain distances from the input surface, which provides subsurface signatures of the objects with subwavelength spatial resolution.

  16. Numerical Investigations of High Pressure Acoustic Waves in Resonators

    NASA Technical Reports Server (NTRS)

    Athavale, Mahesh; Pindera, Maciej; Daniels, Christopher C.; Steinetz, Bruce M.

    2004-01-01

    This presentation presents work on numerical investigations of nonlinear acoustic phenomena in resonators that can generate high-pressure waves using acoustic forcing of the flow. Time-accurate simulations of the flow in a closed cone resonator were performed at different oscillation frequencies and amplitudes, and the numerical results for the resonance frequency and fluid pressure increase match the GRC experimental data well. Work on cone resonator assembly simulations has started and will involve calculations of the flow through the resonator assembly with and without acoustic excitation. A new technique for direct calculation of resonance frequency of complex shaped resonators is also being investigated. Script-driven command procedures will also be developed for optimization of the resonator shape for maximum pressure increase.

  17. Resonant Acoustic Determination of Complex Elastic Moduli

    NASA Technical Reports Server (NTRS)

    Brown, David A.; Garrett, Steven L.

    1991-01-01

    A simple, inexpensive, yet accurate method for measuring the dynamic complex modulus of elasticity is described. Using a 'free-free' bar selectively excited in three independent vibrational modes, the shear modulus is obtained by measuring the frequency of the torsional resonant mode and the Young's modulus is determined from measurement of either the longitudinal or flexural mode. The damping properties are obtained by measuring the quality factor (Q) for each mode. The Q is inversely proportional to the loss tangent. The viscoelastic behavior of the sample can be obtained by tracking a particular resonant mode (and thus a particular modulus) using a phase locked loop (PLL) and by changing the temperature of the sample. The change in the damping properties is obtained by measuring the in-phase amplitude of the PLL which is proportional to the Q of the material. The real and imaginary parts or the complex modulus can be obtained continuously as a function of parameters such as temperature, pressure, or humidity. For homogeneous and isotropic samples only two independent moduli are needed in order to characterize the complete set of elastic constants, thus, values can be obtained for the dynamic Poisson's ratio, bulk modulus, Lame constants, etc.

  18. Tuning Coler Magnetic Current Apparatus with Magneto-Acoustic Resonance

    NASA Astrophysics Data System (ADS)

    Ludwig, Thorsten

    An attempt was made to tune the Coler magnetic current apparatus with the magneto acoustic resonance of the magnetic rods. Measurements with a replica of the famous Coler "Magnetstromapparat" were conducted. In order to tune the acoustic, magnetic and electric resonance circuits of the Coler device the magneto-acoustic resonance was measured with a frequency scan through a function generator and a lock-in amplifier. The frequency generator was powering a driving coil, while the lock-in was connected to a pickup coil. Both coils were placed on a magnetic rod. Resonances were observed up to the 17th harmonic. The quality Q of the observed resonances was 270. To study the magneto-acoustic resonance in the time domain a pair of Permendur rods were employed. The magneto-acoustic resonances of the Permendur rods were observed with an oscilloscope. Spectra of the magneto acoustic resonance were measured for the Permendur rods and for a Coler replica magnet in the frequency range from 25 kHz to 380 kHz. The next step was to bring the resonances of the Permendur rods close together so that they overlap. The 10thharmonic was chosen because it was close to the 180 kHz that Hans Coler related to ferromagnetism. Further more magneto-acoustic coupling between the Permendur rods was studied. Finally the question was explored if Hans Coler converted vacuum fluctuations via magnetic and acoustic resonance into electricity. There is a strong connection between magnetism and quantum field zero point energy (ZPE). An outlook is given on next steps in the experiments to unveil the working mechanism of the Coler magnetic current apparatus.

  19. The e{sup +}e{sup -}{yields}J/{psi}DD-bar, J/{psi}DD-bar* reactions with dynamically generated resonances

    SciTech Connect

    Gamermann, D.; Oset, E.

    2008-08-31

    In two recent reactions by Belle producing DD-bar and DD-bar* meson pairs, peaks above threshold have been measured in the differential cross sections, possibly indicating new resonances in these channels. We want to study such reactions from the point of view that the D meson pairs are produced from already known or predicted resonances below threshold. Our study shows that the peak in the DD-bar* production is not likely to be caused by the X(3872) resonance, but the peak seen in DD-bar invariant mass can be well described if the DD-bar pair comes from the already predicted scalar X(3700) resonance.

  20. Acoustic noise during functional magnetic resonance imaginga)

    PubMed Central

    Ravicz, Michael E.; Melcher, Jennifer R.; Kiang, Nelson Y.-S.

    2007-01-01

    Functional magnetic resonance imaging (fMRI) enables sites of brain activation to be localized in human subjects. For studies of the auditory system, acoustic noise generated during fMRI can interfere with assessments of this activation by introducing uncontrolled extraneous sounds. As a first step toward reducing the noise during fMRI, this paper describes the temporal and spectral characteristics of the noise present under typical fMRI study conditions for two imagers with different static magnetic field strengths. Peak noise levels were 123 and 138 dB re 20 μPa in a 1.5-tesla (T) and a 3-T imager, respectively. The noise spectrum (calculated over a 10-ms window coinciding with the highest-amplitude noise) showed a prominent maximum at 1 kHz for the 1.5-T imager (115 dB SPL) and at 1.4 kHz for the 3-T imager (131 dB SPL). The frequency content and timing of the most intense noise components indicated that the noise was primarily attributable to the readout gradients in the imaging pulse sequence. The noise persisted above background levels for 300-500 ms after gradient activity ceased, indicating that resonating structures in the imager or noise reverberating in the imager room were also factors. The gradient noise waveform was highly repeatable. In addition, the coolant pump for the imager’s permanent magnet and the room air handling system were sources of ongoing noise lower in both level and frequency than gradient coil noise. Knowledge of the sources and characteristics of the noise enabled the examination of general approaches to noise control that could be applied to reduce the unwanted noise during fMRI sessions. PMID:11051496

  1. Coupled resonator filter with single-layer acoustic coupler.

    PubMed

    Jamneala, Tiberiu; Small, Martha; Ruby, Rich; Larson, John D

    2008-10-01

    We discuss the operation of novel coupled-resonator filters with single-layer acoustic couplers. Our analysis employs the physical Mason model for acoustic resonators. Their simpler fabrication process is counterbalanced by the high acoustic attenuation of suitable coupler materials. At high levels of attenuation, both the phase and the acoustic impedance must be treated as complex quantities to accurately predict the filter insertion loss. We demonstrate that the typically poor near-band rejection of coupled resonator filters can be improved at the die level by connecting a small capacitance between the input and output of the filter to produce a pair of tunable transmission minima. We make use of these theoretical findings to fabricate coupled resonators filters operating at 2.45 GHz. PMID:18986880

  2. Resonant acoustic transducer system for a well drilling string

    DOEpatents

    Kent, William H.; Mitchell, Peter G.

    1981-01-01

    For use in transmitting acoustic waves propagated along a well drilling string, a piezoelectric transducer is provided operating in the relatively low loss acoustic propagation range of the well drilling string. The efficiently coupled transmitting transducer incorporates a mass-spring-piezoelectric transmitter combination permitting resonant operation in the desired low frequency range.

  3. Resonant acoustic transducer system for a well drilling string

    DOEpatents

    Nardi, Anthony P.

    1981-01-01

    For use in transmitting acoustic waves propated along a well drilling string, a piezoelectric transducer is provided operating in the relatively low loss acoustic propagation range of the well drilling string. The efficiently coupled transmitting transducer incorporates a mass-spring-piezoelectric transmitter combination permitting a resonant operation in the desired low frequency range.

  4. Experimental realization of extraordinary acoustic transmission using Helmholtz resonators

    SciTech Connect

    Crow, Brian C.; Cullen, Jordan M.; McKenzie, William W.; Koju, Vijay; Robertson, William M.

    2015-02-15

    The phenomenon of extraordinary acoustic transmission through a solid barrier with an embedded Helmholtz resonator (HR) is demonstrated. The Helmholtz resonator consists of an embedded cavity and two necks that protrude, one on each side of the barrier. Extraordinary transmission occurs for a narrow spectral range encompassing the resonant frequency of the Helmholtz resonator. We show that an amplitude transmission of 97.5% is achieved through a resonator whose neck creates an open area of 6.25% of the total barrier area. In addition to the enhanced transmission, we show that there is a smooth, continuous phase transition in the transmitted sound as a function of frequency. The frequency dependent phase transition is used to experimentally realize slow wave propagation for a narrow-band Gaussian wave packet centered at the maximum transmission frequency. The use of parallel pairs of Helmholtz resonators tuned to different resonant frequencies is experimentally explored as a means of increasing the transmission bandwidth. These experiments show that because of the phase transition, there is always a frequency between the two Helmholtz resonant frequencies at which destructive interference occurs whether the resonances are close or far apart. Finally, we explain how the phase transition associated with Helmholtz-resonator-mediated extraordinary acoustic transmission can be exploited to produce diffractive acoustic components including sub-wavelength thickness acoustic lenses.

  5. Preliminary investigation of acoustic bar codes for short-range underwater communications

    NASA Astrophysics Data System (ADS)

    Jones, Dennis F.

    2005-09-01

    In March 2005, underwater acoustic communications experiments were carried out from the DRDC Atlantic research vessel CFAV QUEST. A battery-operated BATS20 transmitter and a broadband barrel-stave flextensional transducer were used to broadcast noise containing acoustic bar code (ABC) information. The ABCs are silent frequency bands of fixed duration that resemble retail bar codes when viewed in a spectrogram. Two sites were selected for the experiments. The first was a shallow-water area west of the Berry Islands in the Bahamas, and the second was a deep-water site south of the Western Bank on the Scotian Shelf. Two receiver systems were deployed; autonomous, variable-buoyancy Stealth Buoys resting on the bottom at the shallow site, and drifting AN/SSQ-53F sonobuoys fitted with GPS at the deep site. Results from these experiments will be presented and future work will be discussed.

  6. Review on Acoustic Transducers for Resonant Ultrasound Spectroscopy

    NASA Astrophysics Data System (ADS)

    Nakamura, N.; Ogi, H.; Hirao, M.

    2015-08-01

    Determination of elastic constants using resonant ultrasound spectroscopy requires transducers that can measure resonance frequencies accurately and identify the vibrational mode of each resonance frequency. We developed three transducers, namely an electromagnetic acoustic transducer, a tripod piezoelectric transducer coupled with a laser Doppler interferometer, and an antenna transmission transducer, for use with various materials and in different measurement circumstances. Their capability in resonant ultrasound spectroscopy and their applications are described.

  7. Acoustically induced transparency using Fano resonant periodic arrays

    NASA Astrophysics Data System (ADS)

    Amin, M.; Elayouch, A.; Farhat, M.; Addouche, M.; Khelif, A.; Baǧcı, H.

    2015-10-01

    A three-dimensional acoustic device, which supports Fano resonance and induced transparency in its response to an incident sound wave, is designed and fabricated. These effects are generated from the destructive interference of closely coupled one broad- and one narrow-band acoustic modes. The proposed design ensures excitation and interference of two spectrally close modes by locating a small pipe inside a wider and longer one. Indeed, numerical simulations and experiments demonstrate that this simple-to-fabricate structure can be used to generate Fano resonance as well as acoustically induced transparency with promising applications in sensing, cloaking, and imaging.

  8. Acoustic control in enclosures using optimally designed Helmholtz resonators

    NASA Astrophysics Data System (ADS)

    Driesch, Patricia Lynne

    A virtual design methodology is developed to minimize the noise in enclosures with optimally designed, passive, acoustic absorbers (Helmholtz resonators). A series expansion of eigen functions is used to represent the acoustic absorbers as external volume velocities, eliminating the need for a solution of large matrix eigen value problems. A determination of this type (efficient model/reevaluation approach) significantly increases the design possibilities when optimization techniques are implemented. As a benchmarking exercise, this novel methodology was experimentally validated for a narrowband acoustic assessment of two optimally designed Helmholtz resonators coupled to a 2D enclosure. The resonators were tuned to the two lowest resonance frequencies of a 30.5 by 40.6 by 2.5 cm (12 x 16 x 1 inch) cavity with the resonator volume occupying only 2% of the enclosure volume. A maximum potential energy reduction of 12.4 dB was obtained at the second resonance of the cavity. As a full-scale demonstration of the efficacy of the proposed design method, the acoustic response from 90--190 Hz of a John Deere 7000 Ten series tractor cabin was investigated. The lowest cabin mode, referred to as a "boom" mode, proposes a significant challenge to a noise control engineer since its anti-node is located near the head of the operator and often generates unacceptable sound pressure levels. Exploiting the low frequency capability of Helmholtz resonators, lumped parameter models of these resonators were coupled to the enclosure via an experimentally determined acoustic model of the tractor cabin. The virtual design methodology uses gradient optimization techniques as a post processor for the modeling and analysis of the unmodified acoustic interior to determine optimal resonator characteristics. Using two optimally designed Helmholtz resonators; potential energy was experimentally reduced by 3.4 and 10.3 dB at 117 and 167 Hz, respectively.

  9. Acoustic metamaterials: From local resonances to broad horizons.

    PubMed

    Ma, Guancong; Sheng, Ping

    2016-02-01

    Within a time span of 15 years, acoustic metamaterials have emerged from academic curiosity to become an active field driven by scientific discoveries and diverse application potentials. This review traces the development of acoustic metamaterials from the initial findings of mass density and bulk modulus frequency dispersions in locally resonant structures to the diverse functionalities afforded by the perspective of negative constitutive parameter values, and their implications for acoustic wave behaviors. We survey the more recent developments, which include compact phase manipulation structures, superabsorption, and actively controllable metamaterials as well as the new directions on acoustic wave transport in moving fluid, elastic, and mechanical metamaterials, graphene-inspired metamaterials, and structures whose characteristics are best delineated by non-Hermitian Hamiltonians. Many of the novel acoustic metamaterial structures have transcended the original definition of metamaterials as arising from the collective manifestations of constituent resonating units, but they continue to extend wave manipulation functionalities beyond those found in nature. PMID:26933692

  10. Acoustic resonant spectroscopy for characterization of thin polymer films

    NASA Astrophysics Data System (ADS)

    Tohmyoh, Hironori; Imaizumi, Takuya; Saka, Masumi

    2006-10-01

    An acoustic resonant spectroscopy technique for measuring the acoustic impedance, ultrasonic velocity, and density of micron-scale polymer films is developed. The method, which is based on spectral analysis, observes the acoustic resonance between water, the film, and a tungsten plate with high acoustic impedance in the frequency range of 20-70MHz. The interface between the film being examined and the plate is vacuum sealed, enabling us to characterize the low-density polyethylene film with acoustic impedances as low as about 1.9MNm-3s and the poly(vinyl chloride) film as thin as about 8μm. The error in the film density measurements is found to be less than 1%, and the validity of the technique is verified.

  11. Acoustic metamaterials: From local resonances to broad horizons

    PubMed Central

    Ma, Guancong; Sheng, Ping

    2016-01-01

    Within a time span of 15 years, acoustic metamaterials have emerged from academic curiosity to become an active field driven by scientific discoveries and diverse application potentials. This review traces the development of acoustic metamaterials from the initial findings of mass density and bulk modulus frequency dispersions in locally resonant structures to the diverse functionalities afforded by the perspective of negative constitutive parameter values, and their implications for acoustic wave behaviors. We survey the more recent developments, which include compact phase manipulation structures, superabsorption, and actively controllable metamaterials as well as the new directions on acoustic wave transport in moving fluid, elastic, and mechanical metamaterials, graphene-inspired metamaterials, and structures whose characteristics are best delineated by non-Hermitian Hamiltonians. Many of the novel acoustic metamaterial structures have transcended the original definition of metamaterials as arising from the collective manifestations of constituent resonating units, but they continue to extend wave manipulation functionalities beyond those found in nature. PMID:26933692

  12. Acoustic resonances in cylinder bundles oscillating in a compressibile fluid

    SciTech Connect

    Lin, W.H.; Raptis, A.C.

    1984-12-01

    This paper deals with an analytical study on acoustic resonances of elastic oscillations of a group of parallel, circular, thin cylinders in an unbounded volume of barotropic, compressible, inviscid fluid. The perturbed motion of the fluid is assumed due entirely to the flexural oscillations of the cylinders. The motion of the fluid disturbances is first formulated in a three-dimensional wave form and then casted into a two-dimensional Helmholtz equation for the harmonic motion in time and in axial space. The acoustic motion in the fluid and the elastic motion in the cylinders are solved simultaneously. Acoustic resonances were approximately determined from the secular (eigenvalue) equation by the method of successive iteration with the use of digital computers for a given set of the fluid properties and the cylinders' geometry and properties. Effects of the flexural wavenumber and the configuration of and the spacing between the cylinders on the acoustic resonances were thoroughly investigated.

  13. Wax Point Determinations Using Acoustic Resonance Spectroscopy

    SciTech Connect

    Bostick, D.T.; Jubin, R.T.; Schmidt, T.W.

    2001-06-01

    The thermodynamic characterization of the wax point of a given crude is essential in order to maintain flow conditions that prevent plugging of undersea pipelines. This report summarizes the efforts made towards applying an Acoustic Cavity Resonance Spectrometer (ACRS) to the determination of pressures and temperatures at which wax precipitates from crude. Phillips Petroleum Company, Inc., the CRADA participant, supplied the ACRS. The instrumentation was shipped to Dr. Thomas Schmidt of ORNL, the CRADA contractor, in May 2000 after preliminary software development performed under the guidance of Dr. Samuel Colgate and Dr. Evan House of the University of Florida, Gainesville, Fl. Upon receipt it became apparent that a number of modifications still needed to be made before the ACRS could be precisely and safely used for wax point measurements. This report reviews the sequence of alterations made to the ACRS, as well as defines the possible applications of the instrumentation once the modifications have been completed. The purpose of this Cooperative Research and Development Agreement (CRADA) between Phillips Petroleum Company, Inc. (Participant) and Lockheed Martin Energy Research Corporation (Contractor) was the measurement of the formation of solids in crude oils and petroleum products that are commonly transported through pipelines. This information is essential in the proper design, operation and maintenance of the petroleum pipeline system in the United States. Recently, new petroleum discoveries in the Gulf of Mexico have shown that there is a potential for plugging of undersea pipeline because of the precipitation of wax. It is important that the wax points of the expected crude oils be well characterized so that the production facilities for these new wells are capable of properly transporting the expected production. The goal of this work is to perform measurements of solids formation in crude oils and petroleum products supplied by the Participant. It is

  14. Resonant bar detector constraints on macro dark matter

    NASA Astrophysics Data System (ADS)

    Jacobs, David M.; Weltman, Amanda; Starkman, Glenn D.

    2015-06-01

    The current standard model of cosmology, Λ CDM , requires dark matter to make up around 25% of the total energy budget of the Universe. Yet, quite puzzlingly, there appears to be no candidate particle in the current Standard Model of particle physics. Assuming the validity of the cold dark matter (CDM) paradigm, dark matter has evaded detection thus far either because it is intrinsically a weakly interacting substance or because its interactions are suppressed by its high constituent mass and low number density. Most approaches to explain dark matter to date assume the former and therefore require beyond-the-Standard-Model particles that have yet to be observed directly or indirectly. Given the dearth of evidence for this class of candidates it is timely to consider the latter possibility, which allows for candidates that may or may not arise from the Standard Model. In this work we extend a recent study of this general class of so-called macro dark matter—candidates with characteristic masses of grams and geometric cross sections of cm2. We consider new bounds that can be set using existing data from the resonant bar gravitational wave detectors NAUTILUS and EXPLORER.

  15. Acoustic detection of electron spin resonance

    NASA Astrophysics Data System (ADS)

    Coufal, H.

    1981-07-01

    The ESR-signal of DPPH was recorded by detecting the modulation of the absorbed microwave power with a gas-coupled microphone. This photo-acoustic detection scheme is compared with conventional ESR-detection. Applications of the acoustical detection method to other modulation spectroscopic techniques, particularly NMR, are discussed.

  16. Effects of specimen resonances on acoustic-ultrasonic testing

    NASA Technical Reports Server (NTRS)

    Williams, J. H., Jr.; Kahn, E. B.; Lee, S. S.

    1983-01-01

    The effects of specimen resonances on acoustic ultrasonic (AU) nondestructive testing were investigated. Selected resonant frequencies and the corresponding normal mode nodal patterns of the aluminum block are measured up to 75.64 kHz. Prominent peaks in the pencil lead fracture and sphere impact spectra from the two transducer locations corresponded exactly to resonant frequencies of the block. It is established that the resonant frequencies of the block dominated the spectral content of the output signal. The spectral content of the output signals is further influenced by the transducer location relative to the resonant frequency nodal lines. Implications of the results are discussed in relation to AU parameters and measurements.

  17. Acoustic resonance in the combustion conduits of a steam locomotive

    SciTech Connect

    Ziada, S.; Oengoeren, A.; Vogel, H.H.

    1996-12-01

    The sound emission of a modern, oil fired steam rack locomotive increased sharply when the locomotive speed exceeded the design value of 12 km/hr. The results of pressure and noise measurements, together with an acoustical model of the combustion conduits indicated that the acoustic resonance modes of the combustion conduits are excited by the pressure pulsations generated by the exhaust from the steam cylinders at multiples of the piston frequency. Additionally, when the acoustic resonance is initiated, the resulting pulsations trigger the flame instability of the oil burners which, in turn, enhances the resonance. By means of the acoustical model, a Helmholtz resonator has been designed and optimized to reduce the acoustic response such that it does not excite the flame instability. A second set of measurements, after installing the resonator, has shown a reduction in the noise level by an amount exceeding 21 dBA. The paper focuses upon the identification of the excitation source and the implementation of the countermeasure which are of interest to other applications involving combustion oscillations.

  18. Lateral acoustic wave resonator comprising a suspended membrane of low damping resonator material

    DOEpatents

    Olsson, Roy H.; El-Kady; , Ihab F.; Ziaei-Moayyed, Maryam; Branch; , Darren W.; Su; Mehmet F.,; Reinke; Charles M.,

    2013-09-03

    A very high-Q, low insertion loss resonator can be achieved by storing many overtone cycles of a lateral acoustic wave (i.e., Lamb wave) in a lithographically defined suspended membrane comprising a low damping resonator material, such as silicon carbide. The high-Q resonator can sets up a Fabry-Perot cavity in a low-damping resonator material using high-reflectivity acoustic end mirrors, which can comprise phononic crystals. The lateral overtone acoustic wave resonator can be electrically transduced by piezoelectric couplers. The resonator Q can be increased without increasing the impedance or insertion loss by storing many cycles or wavelengths in the high-Q resonator material, with much lower damping than the piezoelectric transducer material.

  19. Pyrotechnic shock simulation using the controlled response of a resonating bar fixture

    NASA Astrophysics Data System (ADS)

    Davie, N. T.

    Test laboratories frequently simulate pyrotechnic shock by mounting test items on various bar or plate fixtures which are excited into resonance by mechanical impact. A method for controlling the longitudinal response of a bar fixture is described. Masses clamped along the bar allow one to select which of the bar's natural frequencies will dominate its response upon impact. A test item mounted on one end of the bar thus experiences a controlled shock environment. This method ultimately provides a predictive means for controlling the shock spectrum shape produced by the simulated pyrotechnic shock. Control of the shock spectrum shape eliminates much of the trial and error usually required to tailor a shock test to satisfy the test requirement. A simple analytical model is described which derives the propagation and reflection of strain waves in the bar fixture. Bar responses predicted by this model agree with actual measurements.

  20. Pyrotechnic shock simulation using the controlled response of a resonating bar fixture

    NASA Astrophysics Data System (ADS)

    Davis, N. T.

    Test laboratories frequently simulate pyrotechnic shock by mounting test items on various bar or plate fixtures which are excited into resonance by mechanical impact. A method for controlling the longitudinal response of a bar fixture is described. Masses clamped along the bar allow one to select which of the bar's natural frequencies will dominate its response upon impact. A test item mounted on one end of the bar thus experiences a controlled shock environment. This method ultimately provides a predictive means for controlling the shock spectrum shape produced by the simulated pyrotechnic shock. Control of the shock spectrum shape eliminates much of the trial and error usually required to tailor a shock test to satisfy the test requirement. A simple analytical model which describes the propagation and reflection of strain waves in the bar fixture is also derived. Bar responses predicted by this model agree with actual measurements.

  1. Pyrotechnic shock simulation using the controlled response of a resonating bar fixture

    SciTech Connect

    Davie, N.T.

    1985-01-01

    Test laboratories frequently simulate pyrotechnic shock by mounting test items on various bar or plate fixtures which are excited into resonance by mechanical impact. The author describes a method for controlling the longitudinal response of a bar fixture. Masses clamped along the bar allow one to select which of the bar's natural frequencies will dominate its response upon impact. A test item mounted on one end of the bar thus experiences a controlled shock environment. This method ultimately provides a predictive means for controlling the shock spectrum shape produced by the simulated pyrotechnic shock. Control of the shock spectrum shape eliminates much of the trial and error usually required to tailor a shock test to satisfy the test requirement. The author also derives a simple analytical model which describes the propagation and reflection of strain waves in the bar fixture. Bar responses predicted by this model agree with actual measurements.

  2. New Resonances and Meson Spectroscopy at BaBar and Belle

    SciTech Connect

    Poireau, Vincent; /Annecy, LAPP

    2007-06-06

    We present a short review on the recent progresses that have been made in meson spectroscopy. We discuss the experimental discoveries made at the BaBar and Belle experiments, as well as the possible interpretations of the new resonances.

  3. Particle manipulation by a non-resonant acoustic levitator

    SciTech Connect

    Andrade, Marco A. B.; Pérez, Nicolás; Adamowski, Julio C.

    2015-01-05

    We present the analysis of a non-resonant acoustic levitator, formed by an ultrasonic transducer and a concave reflector. In contrast to traditional levitators, the geometry presented herein does not require the separation distance between the transducer and the reflector to be a multiple of half wavelength. The levitator behavior is numerically predicted by applying a numerical model to calculate the acoustic pressure distribution and the Gor'kov theory to obtain the potential of the acoustic radiation force that acts on a levitated particle. We also demonstrate that levitating particles can be manipulated by controlling the reflector position while maintaining the transducer in a fixed position.

  4. Particle manipulation by a non-resonant acoustic levitator

    NASA Astrophysics Data System (ADS)

    Andrade, Marco A. B.; Pérez, Nicolás; Adamowski, Julio C.

    2015-01-01

    We present the analysis of a non-resonant acoustic levitator, formed by an ultrasonic transducer and a concave reflector. In contrast to traditional levitators, the geometry presented herein does not require the separation distance between the transducer and the reflector to be a multiple of half wavelength. The levitator behavior is numerically predicted by applying a numerical model to calculate the acoustic pressure distribution and the Gor'kov theory to obtain the potential of the acoustic radiation force that acts on a levitated particle. We also demonstrate that levitating particles can be manipulated by controlling the reflector position while maintaining the transducer in a fixed position.

  5. Acoustic emission monitoring of hot functional testing: Watts Bar Unit 1 Nuclear Reactor

    SciTech Connect

    Hutton, P.H.; Dawson, J.F.; Friesel, M.A.; Harris, J.C.; Pappas, R.A.

    1984-06-01

    Acoustic emission (AE) monitoring of selected pressure boundary areas at TVA's Watts Bar, Unit 1 Nuclear Power Plant during hot functional preservice testing is described in this report. The report deals with background, methodology, and results. The work discussed here is a major milestone in a program supported by NRC to develop and demonstrate application of AE monitoring for continuous surveillance of reactor pressure boundaries to detect and evaluate growing flaws. The subject work demonstrated that anticipated problem areas can be overcome. Work is continuing toward AE monitoring during reactor operation.

  6. Modeling Nonlinear Acoustic Standing Waves in Resonators: Theory and Experiments

    NASA Technical Reports Server (NTRS)

    Raman, Ganesh; Li, Xiaofan; Finkbeiner, Joshua

    2004-01-01

    The overall goal of the cooperative research with NASA Glenn is to fundamentally understand, computationally model, and experimentally validate non-linear acoustic waves in enclosures with the ultimate goal of developing a non-contact acoustic seal. The longer term goal is to transition the Glenn acoustic seal innovation to a prototype sealing device. Lucas and coworkers are credited with pioneering work in Resonant Macrosonic Synthesis (RMS). Several Patents and publications have successfully illustrated the concept of Resonant Macrosonic Synthesis. To utilize this concept in practical application one needs to have an understanding of the details of the phenomenon and a predictive tool that can examine the waveforms produced within resonators of complex shapes. With appropriately shaped resonators one can produce un-shocked waveforms of high amplitude that would result in very high pressures in certain regions. Our goal is to control the waveforms and exploit the high pressures to produce an acoustic seal. Note that shock formation critically limits peak-to-peak pressure amplitudes and also causes excessive energy dissipation. Proper shaping of the resonator is thus critical to the use of this innovation.

  7. Triad Resonance in the Gravity-Acoustic Family

    NASA Astrophysics Data System (ADS)

    Kadri, U.

    2015-12-01

    Resonance interactions of waves play a prominent role in energy share among the different wave types involved. Such interactions may significantly contribute, among others, to the evolution of the ocean energy spectrum by exchanging energy between surface-gravity waves; surface and internal gravity waves; or even surface and compression-type waves, that can transfer energy from the upper ocean through the whole water column reaching down to the seafloor. A resonant triad occurs among a triplet of waves, usually involving interaction of nonlinear terms of second order perturbed equations. Until recently, it has been believed that in a homogeneous fluid a resonant triad is possible only when tension forces are included, or at the limit of a shallow water, and that when the compressibility of water is considered, no resonant triads can occur within the family of gravity-acoustic waves. However, more recently it has been proved that, under some circumstances, resonant triads comprising two opposing surface-gravity waves of similar periods (though not identical) and a much longer acoustic-gravity wave, of almost double the frequency, exist [Kadri and Stiassnie 2013, J. Fluid Mech.735 R6]. Here, I report on a new resonant triad involving a gravity wave and two acoustic waves of almost double the length. Interestingly, the two acoustic waves propagate in the same direction with similar wavelengths, that are almost double of that of the gravity wave. The evolution of the wave triad amplitudes is periodic and it is derived analytically, in terms of Jacobian elliptic functions and elliptic integrals. The physical importance of this type of triad interactions is the modulation of pertinent acoustic signals, leading to inaccurate signal perceptions. Enclosed figure: presents an example spatio-temporal evolution of the wave triad amplitudes. The gravity wave (top) remains almost unaltered, while the envelope slowly displaces to the left. However, the prescribed acoustic

  8. Acoustic superlens using Helmholtz-resonator-based metamaterials

    SciTech Connect

    Yang, Xishan; Yin, Jing; Yu, Gaokun Peng, Linhui; Wang, Ning

    2015-11-09

    Acoustic superlens provides a way to overcome the diffraction limit with respect to the wavelength of the bulk wave in air. However, the operating frequency range of subwavelength imaging is quite narrow. Here, an acoustic superlens is designed using Helmholtz-resonator-based metamaterials to broaden the bandwidth of super-resolution. An experiment is carried out to verify subwavelength imaging of double slits, the imaging of which can be well resolved in the frequency range from 570 to 650 Hz. Different from previous works based on the Fabry-Pérot resonance, the corresponding mechanism of subwavelength imaging is the Fano resonance, and the strong coupling between the neighbouring Helmholtz resonators separated at the subwavelength interval leads to the enhanced sound transmission over a relatively wide frequency range.

  9. Validation of an Acoustic Impedance Prediction Model for Skewed Resonators

    NASA Technical Reports Server (NTRS)

    Howerton, Brian M.; Parrott, Tony L.

    2009-01-01

    An impedance prediction model was validated experimentally to determine the composite impedance of a series of high-aspect ratio slot resonators incorporating channel skew and sharp bends. Such structures are useful for packaging acoustic liners into constrained spaces for turbofan noise control applications. A formulation of the Zwikker-Kosten Transmission Line (ZKTL) model, incorporating the Richards correction for rectangular channels, is used to calculate the composite normalized impedance of a series of six multi-slot resonator arrays with constant channel length. Experimentally, acoustic data was acquired in the NASA Langley Normal Incidence Tube over the frequency range of 500 to 3500 Hz at 120 and 140 dB OASPL. Normalized impedance was reduced using the Two-Microphone Method for the various combinations of channel skew and sharp 90o and 180o bends. Results show that the presence of skew and/or sharp bends does not significantly alter the impedance of a slot resonator as compared to a straight resonator of the same total channel length. ZKTL predicts the impedance of such resonators very well over the frequency range of interest. The model can be used to design arrays of slot resonators that can be packaged into complex geometries heretofore unsuitable for effective acoustic treatment.

  10. Nonlinear Resonant Oscillations of Gas in Optimized Acoustical Resonators and the Effect of Central Blockage

    NASA Technical Reports Server (NTRS)

    Li, Xiaofan; Finkbeiner, Joshua; Raman, Ganesh; Daniels, Christopher; Steinetz, Bruce M.

    2003-01-01

    Optimizing resonator shapes for maximizing the ratio of maximum to minimum gas pressure at an end of the resonator is investigated numerically. It is well known that the resonant frequencies and the nonlinear standing waveform in an acoustical resonator strongly depend on the resonator geometry. A quasi-Newton type scheme was used to find optimized axisymmetric resonator shapes achieving the maximum pressure compression ratio with an acceleration of constant amplitude. The acoustical field was solved using a one-dimensional model, and the resonance frequency shift and hysteresis effects were obtained through an automation scheme based on continuation method. Results are presented for optimizing three types of geometry: a cone, a horn-cone and a half cosine-shape. For each type, different optimized shapes were found when starting with different initial guesses. Further, the one-dimensional model was modified to study the effect of an axisymmetric central blockage on the nonlinear standing wave.

  11. Nonlinear Resonant Oscillations of Gas in Optimized Acoustical Resonators and the Effect of Central Blockage

    NASA Technical Reports Server (NTRS)

    Li, Xiao-Fan; Finkbeiner, Joshua; Raman, Ganesh; Daniels, Christopher; Steinetz, Bruce M.

    2003-01-01

    Optimizing resonator shapes for maximizing the ratio of maximum to minimum gas pressure at an end of the resonator is investigated numerically. It is well known that the resonant frequencies and the nonlinear standing waveform in an acoustical resonator strongly depend on the resonator geometry. A quasi-Newton type scheme was used to find optimized axisymmetric resonator shapes achieving the maximum pressure compression ratio with an acceleration of constant amplitude. The acoustical field was solved using a one-dimensional model, and the resonance frequency shift and hysteresis effects were obtained through an automation scheme based on continuation method. Results are presented for optimizing three types of geometry: a cone, a horn-cone and a half cosine- shape. For each type, different optimized shapes were found when starting with different initial guesses. Further, the one-dimensional model was modified to study the effect of an axisymmetric central blockage on the nonlinear standing wave.

  12. Quantitative Determination of Lateral Mode Dispersion in Film Bulk Acoustic Resonators through Laser Acoustic Imaging

    SciTech Connect

    Ken Telschow; John D. Larson III

    2006-10-01

    Film Bulk Acoustic Resonators are useful for many signal processing applications. Detailed knowledge of their operation properties are needed to optimize their design for specific applications. The finite size of these resonators precludes their use in single acoustic modes; rather, multiple wave modes, such as, lateral wave modes are always excited concurrently. In order to determine the contributions of these modes, we have been using a newly developed full-field laser acoustic imaging approach to directly measure their amplitude and phase throughout the resonator. This paper describes new results comparing modeling of both elastic and piezoelectric effects in the active material with imaging measurement of all excited modes. Fourier transformation of the acoustic amplitude and phase displacement images provides a quantitative determination of excited mode amplitude and wavenumber at any frequency. Images combined at several frequencies form a direct visualization of lateral mode excitation and dispersion for the device under test allowing mode identification and comparison with predicted operational properties. Discussion and analysis are presented for modes near the first longitudinal thickness resonance (~900 MHz) in an AlN thin film resonator. Plate wave modeling, taking account of material crystalline orientation, elastic and piezoelectric properties and overlayer metallic films, will be discussed in relation to direct image measurements.

  13. Subwavelength total acoustic absorption with degenerate resonators

    NASA Astrophysics Data System (ADS)

    Yang, Min; Meng, Chong; Fu, Caixing; Li, Yong; Yang, Zhiyu; Sheng, Ping

    2015-09-01

    We report the experimental realization of perfect sound absorption by sub-wavelength monopole and dipole resonators that exhibit degenerate resonant frequencies. This is achieved through the destructive interference of two resonators' transmission responses, while the matching of their averaged impedances to that of air implies no backscattering, thereby leading to total absorption. Two examples, both using decorated membrane resonators (DMRs) as the basic units, are presented. The first is a flat panel comprising a DMR and a pair of coupled DMRs, while the second one is a ventilated short tube containing a DMR in conjunction with a sidewall DMR backed by a cavity. In both examples, near perfect absorption, up to 99.7%, has been observed with the airborne wavelength up to 1.2 m, which is at least an order of magnitude larger than the composite absorber. Excellent agreement between theory and experiment is obtained.

  14. Modeling the acoustic excitation of a resonator

    NASA Astrophysics Data System (ADS)

    Mandre, Shreyas; Mahadevan, Lakshminarayanan

    2007-11-01

    The sounding of a beverage bottle when blown on is a familiar but very little understood phenomenon. A very similar mechanism is used by musical wind instruments, like organ pipes and flutes, for sound production. This phenomenon falls under the general umbrella of flow induced oscillations and is representative of a more generic mechanism. The modeling of this phenomenon essentially involves two components. The first is the resonator, which bears the oscillations and this component is very well understood. The resonator, however, needs an external energy input to sustain the oscillations, which is provided by the jet of air blown. The dynamics of the jet and its interaction with the resonator is the primary focus of this talk. In particular, we provide a linearized model based on first principles to explain the feedback of energy from the jet to the resonator and compare the predictions with experimental results.

  15. Search for tt-bar-Resonances in the Lepton+Jets Final State

    SciTech Connect

    Schliephake, Thorsten

    2008-11-23

    A search for a narrow-width heavy resonance decaying into top quark pairs (X{yields}tt-bar) in pp-bar collisions at {radical}(s) = 1.96 TeV has been performed using data collected with the DOe detector at the Fermilab Tevatron Collider. This analysis considers tt-bar candidate events in the lepton+jets channel using a neural network tagger to identify b-jets and the tt-bar invariant mass distribution to search for evidence of resonant production. The analyzed dataset corresponds to an integrated luminosity of approximately 2.1 fb{sup -1}. We find no evidence for a narrow resonance X decaying to tt-bar. Therefore, we set upper limits on {sigma}{sub X}{center_dot}B(X{yields}tt-bar) for different hypothesized resonance masses using a Bayesian approach. Within a topcolor-assisted technicolor model, the existence of a leptophobic Z' boson with mass M{sub Z'}<760 GeV and width {gamma}{sub Z'} = 0.012M{sub Z'} can be excluded at 95% C.L.

  16. Acoustically driven programmable liquid motion using resonance cavities

    PubMed Central

    Langelier, Sean M.; Chang, Dustin S.; Zeitoun, Ramsey I.; Burns, Mark A.

    2009-01-01

    Performance and utility of microfluidic systems are often overshadowed by the difficulties and costs associated with operation and control. As a step toward the development of a more efficient platform for microfluidic control, we present a distributed pressure generation scheme whereby independently tunable pressure sources can be simultaneously controlled by using a single acoustic source. We demonstrate how this scheme can be used to perform precise droplet positioning as well as merging, splitting, and sorting within open microfluidic networks. We further show how this scheme can be implemented for control of continuous-flow systems, specifically for generation of acoustically tunable liquid gradients. Device operation hinges on a resonance-decoding and rectification mechanism by which the frequency content in a composite acoustic input is decomposed into multiple independently buffered output pressures. The device consists of a bank of 4 uniquely tuned resonance cavities (404, 484, 532, and 654 Hz), each being responsible for the actuation of a single droplet, 4 identical flow-rectification structures, and a single acoustic source. Cavities selectively amplify resonant tones in the input signal, resulting in highly elevated local cavity pressures. Fluidic-rectification structures then serve to convert the elevated oscillating cavity pressures into unidirectional flows. The resulting pressure gradients, which are used to manipulate fluids in a microdevice, are tunable over a range of ≈0–200 Pa with a control resolution of 10 Pa. PMID:19620719

  17. Laser Acoustic Imaging of Film Bulk Acoustic Resonator (FBAR) Lateral Mode Dispersion

    SciTech Connect

    Ken L. Telschow

    2004-07-01

    A laser acoustic imaging microscope has been developed that measures acoustic motion with high spatial resolution without scanning. Images are recorded at normal video frame rates and heterodyne principles are used to allow operation at any frequency from Hz to GHz. Fourier transformation of the acoustic amplitude and phase displacement images provides a direct quantitative determination of excited mode wavenumbers at any frequency. Results are presented at frequencies near the first longitudinal thickness mode (~ 900 MHz) demonstrating simultaneous excitation of lateral modes with nonzero wavenumbers in an electrically driven AlN thin film acoustic resonator. Images combined at several frequencies form a direct visualization of lateral mode dispersion relations for the device under test allowing mode identification and a direct measure of specific lateral mode properties. Discussion and analysis of the results are presented in comparison with plate wave modeling of these devices taking account for material anisotropy and multilayer films.

  18. Magnetic resonance imaging of acoustic streaming: absorption coefficient and acoustic field shape estimation.

    PubMed

    Madelin, Guillaume; Grucker, Daniel; Franconi, Jean-Michel; Thiaudiere, Eric

    2006-07-01

    In this study, magnetic resonance imaging (MRI) is used to visualize acoustic streaming in liquids. A single-shot spin echo sequence (HASTE) with a saturation band perpendicular to the acoustic beam permits the acquisition of an instantaneous image of the flow due to the application of ultrasound. An average acoustic streaming velocity can be estimated from the MR images, from which the ultrasonic absorption coefficient and the bulk viscosity of different glycerol-water mixtures can be deduced. In the same way, this MRI method could be used to assess the acoustic field and time-average power of ultrasonic transducers in water (or other liquids with known physical properties), after calibration of a geometrical parameter that is dependent on the experimental setup. PMID:16650447

  19. Simulation and fabrication of thin film bulk acoustic wave resonator

    NASA Astrophysics Data System (ADS)

    Xixi, Han; Yi, Ou; Zhigang, Li; Wen, Ou; Dapeng, Chen; Tianchun, Ye

    2016-07-01

    In this paper, we present the simulation and fabrication of a thin film bulk acoustic resonator (FBAR). In order to improve the accuracy of simulation, an improved Mason model was introduced to design the resonator by taking the coupling effect between electrode and substrate into consideration. The resonators were fabricated by the eight inch CMOS process, and the measurements show that the improved Mason model is more accurate than a simple Mason model. The Q s (Q at series resonance), Q p (Q at parallel resonance), Q max and k t 2 of the FBAR were measured to be 695, 814, 1049, and 7.01% respectively, showing better performance than previous reports. Project supported by the National Natural Science Foundation of China (Nos. 61274119, 61306141, 61335008) and the Natural Science Foundation of Jiangsu Province (No. BK20131099).

  20. Investigation of acoustically dead materials for resonant ultrasound spectroscopy

    NASA Astrophysics Data System (ADS)

    Betts, Jonathan; Maiorov, Boris; Ramshaw, Brad; Shehter, Arkady; Migliori, Albert

    2015-03-01

    Resonant Ultrasound Spectroscopy is used to excite mechanical resonances in solid samples. By precisely knowing the resonant frequency the complete elastic tensor of the sample can be calculated. In practice unwanted resonances are also created in the sample holder structure, these resonances are not related to the sample and can often confuse the measurement. To reduce this problem we have investigated the use of acoustically ``dead'' materials. We present data from various natural and synthetic materials. We also present RUS sample holder designs that can be used from <4K up to 700K and in magnet fields up to 45T. The elastic tensor of poly-crystal beryllium will be presented as a demonstration of the system performance.

  1. Acoustic swimbladder resonance spectroscopy: Fundamentals in scattering theory

    NASA Astrophysics Data System (ADS)

    Francis, David T. I.; Foote, Kenneth G.

    2003-04-01

    A history of the physics of acoustic resonance is given. The primary, low-frequency, resonant scattering model for air bubbles in water [Minnaert (1933)] is reviewed. Subsequent applications to swimbladdered fish, including models by Andreeva (1964), Love (1978), and Feuillade and Nero (1998), among others, are developed. Reference is made to exemplary measurements of backscattering by Holliday (1972) and Loevik and Hovem (1979), and of forward scattering, or absorption, by Weston (1967) and Diachok (2000), among others. High-frequency resonances are also described, with presentation of both analytical and numerical results for the immersed air bubble. Comparison of these validates the numerical, boundary-element method (BEM). The BEM allows high-frequency resonances to be studied for swimbladders of realistic shapes under pressure and for typical wave-number-swimbladder length products of order 10-40. Implications of high-frequency swimbladder resonance for auditory function in fish are mentioned. [Work supported by ONR.

  2. Acoustic wave flow sensor using quartz thickness shear mode resonator.

    PubMed

    Qin, Lifeng; Zeng, Zijing; Cheng, Hongbin; Wang, Qing-Ming

    2009-09-01

    A quartz thickness shear mode (TSM) bulk acoustic wave resonator was used for in situ and real-time detection of liquid flow rate in this study. A special flow chamber made of 2 parallel acrylic plates was designed for flow measurement. The flow chamber has a rectangular flow channel, 2 flow reservoirs for stabilizing the fluid flow, a sensor mounting port for resonator holding, one inlet port, and one outlet port for pipe connection. A 5-MHz TSM quartz resonator was edge-bonded to the sensor mounting port with one side exposed to the flowing liquid and other side exposed to air. The electrical impedance spectra of the quartz resonator at different volumetric flow rate conditions were measured by an impedance analyzer for the extraction of the resonant frequency through a data-fitting method. The fundamental, 3rd, 5th, 7th, and 9th resonant frequency shifts were found to be around 920, 3572, 5947, 8228, and 10,300 Hz for flow rate variation from 0 to 3000 mL/min, which had a corresponding Reynolds number change from 0 to 822. The resonant frequency shifts of different modes are found to be quadratic with flow rate, which is attributed to the nonlinear effect of quartz resonator due to the effective normal pressure imposing on the resonator sensor by the flowing fluid. The results indicate that quartz TSM resonators can be used for flow sensors with characteristics of simplicity, fast response, and good repeatability. PMID:19811997

  3. Energy Dependence of $\\bar{K}N$ Interactions and Resonance Pole of Strange Dibaryons

    SciTech Connect

    Ikeda, Y.; Kamano, H.; Sato, T.

    2010-09-01

    We study the resonance energy of the strange dibaryons using two models with the energy-independent and energy-dependent potentials for the s-wave $\\bar{K}N$ interaction, both of which are derived by certain reductions from the leading order term of the effective chiral Lagrangian. These potential models produce rather different off-shell behaviors of the two-body $\\bar{K}N$ - $\\pi\\Sigma$ amplitudes in $I=0$ channel, i.e., the model with energy-independent (energy-dependent) potential predicts one (two) resonance pole in the $\\Lambda(1405)$ region, while they describe the available data equally well. We find that the energy-independent potential model predicts one resonance pole of the strange dibaryons, whereas the energy-dependent potential model predicts two resonance poles: one is the shallow quasi-bound state of the $\\bar{K}NN$, and another is the resonance of the $\\pi Y N$ with large width. An investigation of the binding energy of the strange dibaryons will make a significant contribution to clarify resonance structure of s-wave $\\bar{K}N$ -$\\pi\\Sigma$ around the $\\Lambda(1405)$ region.

  4. Flow-excited acoustic resonance of a Helmholtz resonator: Discrete vortex model compared to experiments

    SciTech Connect

    Dai, Xiwen; Jing, Xiaodong Sun, Xiaofeng

    2015-05-15

    The acoustic resonance in a Helmholtz resonator excited by a low Mach number grazing flow is studied theoretically. The nonlinear numerical model is established by coupling the vortical motion at the cavity opening with the cavity acoustic mode through an explicit force balancing relation between the two sides of the opening. The vortical motion is modeled in the potential flow framework, in which the oscillating motion of the thin shear layer is described by an array of convected point vortices, and the unsteady vortex shedding is determined by the Kutta condition. The cavity acoustic mode is obtained from the one-dimensional acoustic propagation model, the time-domain equivalent of which is given by means of a broadband time-domain impedance model. The acoustic resistances due to radiation and viscous loss at the opening are also taken into account. The physical processes of the self-excited oscillations, at both resonance and off-resonance states, are simulated directly in the time domain. Results show that the shear layer exhibits a weak flapping motion at the off-resonance state, whereas it rolls up into large-scale vortex cores when resonances occur. Single and dual-vortex patterns are observed corresponding to the first and second hydrodynamic modes. The simulation also reveals different trajectories of the two vortices across the opening when the first and second hydrodynamic modes co-exist. The strong modulation of the shed vorticity by the acoustic feedback at the resonance state is demonstrated. The model overestimates the pressure pulsation amplitude by a factor 2, which is expected to be due to the turbulence of the flow which is not taken into account. The model neglects vortex shedding at the downstream and side edges of the cavity. This will also result in an overestimation of the pulsation amplitude.

  5. Flow-excited acoustic resonance of a Helmholtz resonator: Discrete vortex model compared to experiments

    NASA Astrophysics Data System (ADS)

    Dai, Xiwen; Jing, Xiaodong; Sun, Xiaofeng

    2015-05-01

    The acoustic resonance in a Helmholtz resonator excited by a low Mach number grazing flow is studied theoretically. The nonlinear numerical model is established by coupling the vortical motion at the cavity opening with the cavity acoustic mode through an explicit force balancing relation between the two sides of the opening. The vortical motion is modeled in the potential flow framework, in which the oscillating motion of the thin shear layer is described by an array of convected point vortices, and the unsteady vortex shedding is determined by the Kutta condition. The cavity acoustic mode is obtained from the one-dimensional acoustic propagation model, the time-domain equivalent of which is given by means of a broadband time-domain impedance model. The acoustic resistances due to radiation and viscous loss at the opening are also taken into account. The physical processes of the self-excited oscillations, at both resonance and off-resonance states, are simulated directly in the time domain. Results show that the shear layer exhibits a weak flapping motion at the off-resonance state, whereas it rolls up into large-scale vortex cores when resonances occur. Single and dual-vortex patterns are observed corresponding to the first and second hydrodynamic modes. The simulation also reveals different trajectories of the two vortices across the opening when the first and second hydrodynamic modes co-exist. The strong modulation of the shed vorticity by the acoustic feedback at the resonance state is demonstrated. The model overestimates the pressure pulsation amplitude by a factor 2, which is expected to be due to the turbulence of the flow which is not taken into account. The model neglects vortex shedding at the downstream and side edges of the cavity. This will also result in an overestimation of the pulsation amplitude.

  6. EM localization for resonance frequency of pre-Cantor bar of higher stages

    NASA Astrophysics Data System (ADS)

    Kaino, K.; Obata, T.; Sonoda, J.; Kojo, J.

    2013-02-01

    Using the transmission-line theory, we investigate properties of wave propagation and resonance in a pre-Cantor multilayer called pre-Cantor bars whose interval is [0,L]. When the stage number n increases, the pre-Cantor bar will not transmit almost anywhere for ɛr2 > 1 where ɛr2 is the ratio of dielectric constants of two kinds of layers. For resonance frequencies of the n-th pre-Cantor bar, the largest amplitude of voltage at the midpoint of the bar, V(L/2), increases double-exponentially because of the inequality |V(L/2)|≤ɛr22n-2. For such a resonance frequency, the amplitude of the voltage at the midpoint of an interval [L/3k+1,2L/3k+1] is given by |V(L/2ṡ3k)|≤ɛr22n-k-2 where k = 1,2, ..., n - 1. Because the voltage |V(x)| is localized around x = L/2, the electro-magnetic wave (EM) localization occurs for the resonance frequencies of the pre-Cantor bar of the higher stages. Using a microstripline of the 3rd stage Cantor structure we will show that the measured transmission spectrum is consistent with the ideal one if the dissipation factor of the substrate is tan δ = 0.023 that is a typical value for the substrate of glassy epoxy resin in microwave frequencies.

  7. Using Resonant Bars and Interferometers to Search for Stochastic Gravitational Waves

    NASA Astrophysics Data System (ADS)

    Whelan, John T.

    2002-10-01

    A stochastic background of gravitational waves (SBGW) may result from gravitational waves emitted in the early universe (e.g., during inflation) or from a superposition of many unresolved astrophysical sources. Pairs of resonant bar detectors, as well as pairs of prototype interferometers, have been used to set limits on SBGW strength by looking for correlations between the random signals in the two detectors, and data from the two LIGO interferometers are being analyzed right now for this purpose. I will describe a parallel analysis being carried out to look for SBGW-induced correlations between the LIGO detector in Livingston, LA and the ALLEGRO resonant bar detector in Baton Rouge, LA.

  8. Acoustic resonance in MEMS scale cylindrical tubes with side branches

    NASA Astrophysics Data System (ADS)

    Schill, John F.; Holthoff, Ellen L.; Pellegrino, Paul M.; Marcus, Logan S.

    2014-05-01

    Photoacoustic spectroscopy (PAS) is a useful monitoring technique that is well suited for trace gas detection. This method routinely exhibits detection limits at the parts-per-million (ppm) or parts-per-billion (ppb) level for gaseous samples. PAS also possesses favorable detection characteristics when the system dimensions are scaled to a microelectromechanical system (MEMS) design. One of the central issues related to sensor miniaturization is optimization of the photoacoustic cell geometry, especially in relationship to high acoustical amplification and reduced system noise. Previous work relied on a multiphysics approach to analyze the resonance structures of the MEMS scale photo acoustic cell. This technique was unable to provide an accurate model of the acoustic structure. In this paper we describe a method that relies on techniques developed from musical instrument theory and electronic transmission line matrix methods to describe cylindrical acoustic resonant cells with side branches of various configurations. Experimental results are presented that demonstrate the ease and accuracy of this method. All experimental results were within 2% of those predicted by this theory.

  9. Active Cancellation of Acoustical Resonances with an FPGA FIR Filter

    NASA Astrophysics Data System (ADS)

    Ryou, Albert; Simon, Jonathan

    2016-05-01

    We demonstrate a novel approach to enhancing the closed-loop bandwidth of a feedback-controlled mechanical system by digitally cancelling its acoustical resonances and antiresonances with an FPGA FIR filter. By performing a real-time convolution of the feedback error signal with an arbitrary filter, we can suppress arbitrarily many poles and zeros below 100 kHz, each with a linewidth as small as 10 Hz. We demonstrate the efficacy of this technique by cancelling the six largest resonances and antiresonances of a high-finesse optical resonator piezomechanical transfer function, thereby enhancing the unity gain frequency by more than an order of magnitude. More broadly, this approach is applicable to stabilization of optical resonators, external cavity diode lasers, and scanning tunneling microscopes.

  10. Subwavelength acoustic focusing by surface-wave-resonance enhanced transmission in doubly negative acoustic metamaterials

    SciTech Connect

    Zhou, Xiaoming; Badreddine Assouar, M. Oudich, Mourad

    2014-11-21

    We present analytical and numerical analyses of a yet unseen lensing paradigm that is based on a solid metamaterial slab in which the wave excitation source is attached. We propose and demonstrate sub-diffraction-limited acoustic focusing induced by surface resonant states in doubly negative metamaterials. The enhancement of evanescent waves across the metamaterial slab produced by their resonant coupling to surface waves is evidenced and quantitatively determined. The effect of metamaterial parameters on surface states, transmission, and wavenumber bandwidth is clearly identified. Based on this concept consisting of a wave source attached on the metamaterial, a high resolution of λ/28.4 is obtained with the optimum effective physical parameters, opening then an exciting way to design acoustic metamaterials for ultrasonic focused imaging.

  11. Monitoring accelerated carbonation on standard Portland cement mortar by nonlinear resonance acoustic test

    NASA Astrophysics Data System (ADS)

    Eiras, J. N.; Kundu, T.; Popovics, J. S.; Monzó, J.; Borrachero, M. V.; Payá, J.

    2015-03-01

    Carbonation is an important deleterious process for concrete structures. Carbonation begins when carbon dioxide (CO2) present in the atmosphere reacts with portlandite producing calcium carbonate (CaCO3). In severe carbonation conditions, C-S-H gel is decomposed into silica gel (SiO2.nH2O) and CaCO3. As a result, concrete pore water pH decreases (usually below 10) and eventually steel reinforcing bars become unprotected from corrosion agents. Usually, the carbonation of the cementing matrix reduces the porosity, because CaCO3 crystals (calcite and vaterite) occupy more volume than portlandite. In this study, an accelerated carbonation-ageing process is conducted on Portland cement mortar samples with water to cement ratio of 0.5. The evolution of the carbonation process on mortar is monitored at different levels of ageing until the mortar is almost fully carbonated. A nondestructive technique based on nonlinear acoustic resonance is used to monitor the variation of the constitutive properties upon carbonation. At selected levels of ageing, the compressive strength is obtained. From fractured surfaces the depth of carbonation is determined with phenolphthalein solution. An image analysis of the fractured surfaces is used to quantify the depth of carbonation. The results from resonant acoustic tests revealed a progressive increase of stiffness and a decrease of material nonlinearity.

  12. A new model for film bulk acoustic wave resonators

    NASA Astrophysics Data System (ADS)

    Li, Yu-Jin; Yuan, Xiu-Hua

    2014-11-01

    Based on cavity resonance and sandwich composite plate theory, this paper presents a universal three-dimensional (3D) theoretical model for frequency dispersion characterization and displacement profile shapes of the film bulk acoustic resonator (FBARs). This model provides results of FBAR excited thickness-extensional and flexure modes, and the result of frequency dispersion is proposed in which the thicknesses and impedance of the electrodes and the piezoelectric material are taken into consideration; its further simplification shows good agreement with the modified Butterworth—Van-Dyke (MBVD) model. The displacement profile reflects the vibration stress distribution of electrode shapes and the lateral resonance effect, which depends on the axis ratio of the electrode shapes a/b. The results are consistent with the 3D finite element method modeling and laser interferometry measurement in general.

  13. Microwave bulk-acoustic-wave reflection-grating resonators.

    PubMed

    Oates, D E; Pan, J Y

    1988-01-01

    A technique for fabrication of bulk-acoustic-wave (BAW) resonators operating at fundamental frequencies between 1 and 10 GHz is presented. The resonators utilize a reflection grating made by optical holographic methods in iron-doped lithium niobate. Q factors of 30000 at 1 GHz have been demonstrated. Extension to Q of 10000 at 10 GHz appears feasible. Projected limitations to performance are discussed. The high Q at the high fundamental frequency directly results in low-phase noise. Phase-noise measurements of BAW resonator-stabilized oscillators operating at 1.14 GHz are presented. The single-sideband noise floor of <-140 dBc/Hz is shown to be in agreement with an analytical model. Projected improvements in the devices and circuits promise performance of <-160 dBc/Hz. PMID:18290157

  14. Dispersion and mirror transmission characteristics of bulk acoustic wave resonators.

    PubMed

    Kokkonen, Kimmo; Pensala, Tuomas; Kaivola, Matti

    2011-01-01

    A heterodyne laser interferometer is used for a detailed study of the acoustic wave fields excited in a 932-MHz solidly mounted ZnO thin-film BAW resonator. The sample is manufactured on a glass substrate, which also allows direct measurement of the vibration fields from the bottom of the acoustic mirror. Vibration fields are measured both on top of the resonator and at the mirror-substrate interface in a frequency range of 350 to 1200 MHz. Plate wave dispersion diagrams are calculated from the experimental data in both cases and the transmission characteristics of the acoustic mirror are determined as a function of both frequency and lateral wave number. The experimental data are compared with 1-D and 2-D simulations to evaluate the validity of the modeling tools commonly used in mirror design. All the major features observed in the 1-D model are identified in the measured dispersion diagrams, and the mirror transmission characteristics predicted for the longitudinal waves, by both the 1-D and the 2-D models, match the measured values well. PMID:21244989

  15. A sound absorptive element comprising an acoustic resonance nanofibrous membrane.

    PubMed

    Kalinova, Klara

    2015-01-01

    As absorption of sound of lower frequencies is quite problematic with fibrous material made up of coarser fibers, development of highly efficient sound absorption material is called for. This is why this work deals with the development of new high sound absorption material. To absorb the low frequencies, especially the structures based on resonance principle of nanofibrous layers are used, when through resonance of some elements the acoustic energy is transferred into thermal energy. The goal of the invention is achieved by a sound absorbing means which contains resonance membrane formed by a layer of polymeric nanofibers, which is attached to a frame. For production of nanofibrous membranes, the cord electrospinning was used. The resonance membrane was then, upon impact of sound waves of low frequency, brought into forced vibrations, whereby the kinetic energy of the membrane was converted into thermal energy by friction of individual nanofibers, by the friction of the membrane with ambient air and possibly with other layers of material arranged in its proximity, and some of the energy was also transmitted to the frame, through which the vibrations of the resonance membrane were damped. The density and shape of the mesh of frame formations determine the resonance frequency of the acoustic means. The goal of the invention is therefore to eliminate or at least reduce the disadvantages of the present state of the art and to propose sound absorbing means that would be capable of absorbing, with good results sounds in as broadest frequency range as possible. Here, we also discussed some patents relevant to the topic. PMID:25986230

  16. Resonant Acoustic Measurement of Vapor Phase Transport Phenomenon

    NASA Astrophysics Data System (ADS)

    Schuhmann, R. J.; Garrett, S. L.; Matson, J. V.

    2002-12-01

    A major impediment to accurate non steady-state diffusion measurements is the ability to accurately measure and track a rapidly changing gas concentration without disturbing the system. Non-destructive methods that do not interfere with system dynamics have been developed in the past. These methods, however, have tended to be cumbersome or inaccurate at low concentrations. A new experimental approach has been developed to measure gaseous diffusion in free air and through porous materials. The method combines the traditional non steady-state laboratory methodology with resonant acoustic gas analysis. A phase-locked-loop (PLL) resonance frequency tracker is combined with a thermally insulated copper resonator. A piston sealed with a metal bellows excites the fundamental standing wave resonance of the resonator. The PLL maintains a constant phase difference (typically 90§) between the accelerometer mounted on the piston and a microphone near the piston to track the resonance frequency in real time. A capillary or glass bead filled core is fitted into an o-ring sealed opening at the end of the resonator opposite the bellows. The rate at which the tracer gas is replaced by air within the resonator is controlled by the diffusion coefficient of the gas in free air through the capillary (DA) or by the effective diffusion coefficient of the gas through the core (De). The mean molecular weight of the gas mixture in the resonator is directly determined six times each minute from the ratio of the absolute temperature to the square of the fundamental acoustic resonance frequency. Average system stability (temperature divided by frequency squared) is better than 350 ppm. DA values for a 0.3-inch diameter capillary were in excellent agreement with published values. De values for porous media samples (0.5 mm glass beads) of four different lengths (1 through 4 inches) using three different tracer gases (He, CH4, Kr) will be reported. Comments will be offered regarding tracer gas

  17. Search for a Narrow $t\\bar{t}$ Resonance in $p\\bar{p}$ Collisions at $\\sqrt{s}=1.96$ TeV

    SciTech Connect

    Abazov, Victor Mukhamedovich; Abbott, Braden Keim; Acharya, Bannanje Sripath; Adams, Mark Raymond; Adams, Todd; Alexeev, Guennadi D.; Alkhazov, Georgiy D.; Alton, Andrew K.; Alverson, George O.; Alves, Gilvan Augusto; Aoki, Masato; /Fermilab /Florida State U.

    2011-11-01

    We report a search for a narrow t{bar t} resonance that decays into a lepton+jets final state based on an integrated luminosity of 5.3 fb{sup -1} of proton-antiproton collisions at {radical}s = 1.96 TeV collected by the D0 Collaboration at the Fermilab Tevatron Collider. We set upper limits on the production cross section of such a resonance multiplied by its branching fraction to t{bar t} which we compare to predictions for a leptophobic topcolor Z' boson. We exclude such a resonance at the 95% confidence level for masses below 835 GeV.

  18. Acoustic agglomeration of fine particles based on a high intensity acoustical resonator

    NASA Astrophysics Data System (ADS)

    Zhao, Yun; Zeng, Xinwu; Tian, Zhangfu

    2015-10-01

    Acoustic agglomeration (AA) is considered to be a promising method for reducing the air pollution caused by fine aerosol particles. Removal efficiency and energy consuming are primary parameters and generally have a conflict with each other for the industry applications. It was proved that removal efficiency is increased with sound intensity and optimal frequency is presented for certain polydisperse aerosol. As a result, a high efficiency and low energy cost removal system was constructed using acoustical resonance. High intensity standing wave is generated by a tube system with abrupt section driven by four loudspeakers. Numerical model of the tube system was built base on the finite element method, and the resonance condition and SPL increase were confirmd. Extensive tests were carried out to investigate the acoustic field in the agglomeration chamber. Removal efficiency of fine particles was tested by the comparison of filter paper mass and particle size distribution at different operating conditions including sound pressure level (SPL), and frequency. The experimental study has demonstrated that agglomeration increases with sound pressure level. Sound pressure level in the agglomeration chamber is between 145 dB and 165 dB from 500 Hz to 2 kHz. The resonance frequency can be predicted with the quarter tube theory. Sound pressure level gain of more than 10 dB is gained at resonance frequency. With the help of high intensity sound waves, fine particles are reduced greatly, and the AA effect is enhanced at high SPL condition. The optimal frequency is 1.1kHz for aerosol generated by coal ash. In the resonace tube, higher resonance frequencies are not the integral multiplies of the first one. As a result, Strong nonlinearity is avoided by the dissonant characteristic and shock wave is not found in the testing results. The mechanism and testing system can be used effectively in industrial processes in the future.

  19. Resonance compression of an acoustic beam in a crystal

    NASA Astrophysics Data System (ADS)

    Alshits, V. I.; Bessonov, D. A.; Lyubimov, V. N.

    2016-04-01

    The resonance excitation of an intense acoustic beam in a crystal is described for a special geometry of pump-wave reflection from the crystal surface. The resonance appears in the vicinity of the total internal reflection angle under the condition that the wave field in a compressed reflected beam propagating almost parallel to the surface is close to the volume eigenmode satisfying the free boundary condition. Criteria for the existence of such modes are considered in detail. Conversion conditions are analyzed under which a "parasitic" reflected wave of the same branch as the incident wave is absent and entire energy from the incident wave falls within a narrow intense acoustic beam of another branch. It is shown that, when the surface is chosen parallel to the crystal symmetry plane, the conversion criterion is reduced to the sole condition on the elastic moduli of the medium. Analysis is performed by analytic and numerical methods for skew cuts of monoclinic, rhombic, trigonal, and hexagonal crystals, when the boundary is the symmetry plane, while the sagittal plane has no symmetry. A number of crystals are found in which resonance excitation is very close to conversion.

  20. Helmholtz Resonator for Lead Zirconate Titanate Acoustic Energy Harvester

    NASA Astrophysics Data System (ADS)

    Matsuda, Tomohiro; Tomii, Kazuki; Hagiwara, Saori; Miyake, Shuntaro; Hasegawa, Yuichi; Sato, Takamitsu; Kaneko, Yuta; Nishioka, Yasushiro

    2013-12-01

    Acoustic energy harvesters that function in environments where sound pressure is extremely high (~150 dB), such as in engine rooms of aircrafts, are expected to be capable of powering wireless health monitoring systems. This paper presents the power generation performances of a lead-zirconate-titanate (PZT) acoustic energy harvester with a vibrating PZT diaphragm. The diaphragm had a diameter of 2 mm, consisting of Al(0.1 μm)/PZT(1 μm)/Pt(0.1 μm)/Ti(0.1 μm)/SiO2(1.5 μm). The harvester generated a power of 1.7×10-13 W under a sound pressure level of 110 dB at the first resonance frequency of 6.28 kHz. It was found that the generated power was increased to 6.8×10-13 W using a sound-collecting Helmholtz resonator cone with the height of 60 mm. The cone provided a Helmholtz resonance at 5.8 kHz, and the generated power increased from 3.4×10-14 W to 1.4×10-13 W at this frequency. The cone was also effective in increasing the bandwidth of the energy harvester.

  1. Activation of immobilized enzymes by acoustic wave resonance oscillation.

    PubMed

    Nishiyama, Hiroshi; Watanabe, Tomoya; Inoue, Yasunobu

    2014-12-01

    Acoustic wave resonance oscillation has been used successfully in the development of methods to activate immobilized enzyme catalysts. In this study, resonance oscillation effects were demonstrated for enzyme reactions on galactose oxidase (GAD), D-amino acid oxidase (DAAO), and L-amino acid oxidase (LAAO), all of which were immobilized covalently on a ferroelectric lead zirconate titanate (PZT) device that could generate thickness-extensional resonance oscillations (TERO) of acoustic waves. For galactose oxidation on immobilized GAD in a microreactor, TERO generation immediately increased enzyme activity 2- to 3-fold. Eliminating TERO caused a slight decrease in the activity, with ∼90% of the enhanced activity retained while the reaction proceeded. Contact of the enhanced enzyme with a galactose-free solution caused almost complete reversion of the activity to the original low level before TERO generation, indicating that, not only TERO-induced GAD activation, but also preservation of the increased activity, required a galactose substrate. Similar activity changes with TERO were observed for enzyme reactions on DAAO and LAAO. Kinetic analysis demonstrated that TERO helped strengthen the interactions of the immobilized enzyme with the reactant substrate and promoted formation of an activation complex. PMID:25442945

  2. Soft resonator of omnidirectional resonance for acoustic metamaterials with a negative bulk modulus

    NASA Astrophysics Data System (ADS)

    Jing, Xiaodong; Meng, Yang; Sun, Xiaofeng

    2015-11-01

    Monopolar resonance is of fundamental importance in the acoustic field. Here, we present the realization of a monopolar resonance that goes beyond the concept of Helmholtz resonators. The balloon-like soft resonator (SR) oscillates omnidirectionally and radiates from all parts of its spherical surface, eliminating the need for a hard wall for the cavity and baffle effects. For airborne sound, such a low-modulus resonator can be made extremely lightweight. Deep subwavelength resonance is achieved when the SR is tuned by adjusting the shell thickness, benefiting from the large density contrast between the shell material and the encapsulated gas. The SR resonates with near-perfect monopole symmetry, as demonstrated by the theoretical and experimental results, which are in excellent agreement. For a lattice of SRs, a band gap occurs and blocks near-total transmission, and the effective bulk modulus exhibits a prominent negative band, while the effective mass density remains unchanged. Our study shows that the SR is suitable for building 3D acoustic metamaterials and provides a basis for constructing left-handed materials as a new means of creating a negative bulk modulus.

  3. Soft resonator of omnidirectional resonance for acoustic metamaterials with a negative bulk modulus.

    PubMed

    Jing, Xiaodong; Meng, Yang; Sun, Xiaofeng

    2015-01-01

    Monopolar resonance is of fundamental importance in the acoustic field. Here, we present the realization of a monopolar resonance that goes beyond the concept of Helmholtz resonators. The balloon-like soft resonator (SR) oscillates omnidirectionally and radiates from all parts of its spherical surface, eliminating the need for a hard wall for the cavity and baffle effects. For airborne sound, such a low-modulus resonator can be made extremely lightweight. Deep subwavelength resonance is achieved when the SR is tuned by adjusting the shell thickness, benefiting from the large density contrast between the shell material and the encapsulated gas. The SR resonates with near-perfect monopole symmetry, as demonstrated by the theoretical and experimental results, which are in excellent agreement. For a lattice of SRs, a band gap occurs and blocks near-total transmission, and the effective bulk modulus exhibits a prominent negative band, while the effective mass density remains unchanged. Our study shows that the SR is suitable for building 3D acoustic metamaterials and provides a basis for constructing left-handed materials as a new means of creating a negative bulk modulus. PMID:26538085

  4. Soft resonator of omnidirectional resonance for acoustic metamaterials with a negative bulk modulus

    PubMed Central

    Jing, Xiaodong; Meng, Yang; Sun, Xiaofeng

    2015-01-01

    Monopolar resonance is of fundamental importance in the acoustic field. Here, we present the realization of a monopolar resonance that goes beyond the concept of Helmholtz resonators. The balloon-like soft resonator (SR) oscillates omnidirectionally and radiates from all parts of its spherical surface, eliminating the need for a hard wall for the cavity and baffle effects. For airborne sound, such a low-modulus resonator can be made extremely lightweight. Deep subwavelength resonance is achieved when the SR is tuned by adjusting the shell thickness, benefiting from the large density contrast between the shell material and the encapsulated gas. The SR resonates with near-perfect monopole symmetry, as demonstrated by the theoretical and experimental results, which are in excellent agreement. For a lattice of SRs, a band gap occurs and blocks near-total transmission, and the effective bulk modulus exhibits a prominent negative band, while the effective mass density remains unchanged. Our study shows that the SR is suitable for building 3D acoustic metamaterials and provides a basis for constructing left-handed materials as a new means of creating a negative bulk modulus. PMID:26538085

  5. Micro acoustic resonant chambers for heating/agitating/mixing (MARCHAM)

    NASA Astrophysics Data System (ADS)

    Sherrit, Stewart; Noell, Aaron C.; Fisher, Anita M.; Takano, Nobuyuki; Grunthaner, Frank

    2016-04-01

    A variety of applications require the mixing and/or heating of a slurry made from a powder/fluid mixture. One of these applications, Sub Critical Water Extraction (SCWE), is a process where water and an environmental powder sample (sieved soil, drill cuttings, etc.) are heated in a sealed chamber to temperatures greater than 200 degrees Celsius by allowing the pressure to increase, but without reaching the critical point of water. At these temperatures, the ability of water to extract organics from solid particulate increases drastically. This paper describes the modeling and experimentation on the use of an acoustic resonant chamber which is part of an amino acid detection instrument called Astrobionibbler [Noell et al. 2014, 2015]. In this instrument we use acoustics to excite a fluid- solid fines mixture in different frequency/amplitude regimes to accomplish a variety of sample processing tasks. Driving the acoustic resonant chamber at lower frequencies can create circulation patterns in the fluid and mixes the liquid and fines, while driving the chamber at higher frequencies one can agitate the fluid and powder and create a suspension. If one then drives the chamber at high amplitude at resonance heating of the slurry occurs. In the mixing and agitating cell the particle levitation force depends on the relative densities and compressibility's of the particulate and fluid and on the kinetic and potential energy densities associated with the velocity and pressure fields [Glynne-Jones, Boltryk and Hill 2012] in the cell. When heating, the piezoelectric transducer and chamber is driven at high power in resonance where the solid/fines region is modelled as an acoustic transmission line with a large loss component. In this regime, heat is pumped into the solution/fines mixture and rapidly heats the sample. We have modeled the piezoelectric transducer/chamber/ sample using Mason's equivalent circuit. In order to assess the validity of the model we have built and

  6. 2-D modeling of laterally acoustically coupled thin film bulk acoustic wave resonator filters.

    PubMed

    Pensala, Tuomas; Meltaus, Johanna; Kokkonen, Kimmo; Ylilammi, Markku

    2010-11-01

    A 2-D model is developed for calculating lateral acoustical coupling between adjacent thin film BAW resonators forming an electrical N-port. The model is based on solution and superposition of lateral eigenmodes and eigenfrequencies in a structure consisting of adjacent regions with known plate wave dispersion properties. Mechanical and electrical response of the device are calculated as a superposition of eigenmodes according to voltage drive at one electrical port at a time while extracting current induced in the other ports, leading to a full Y-parameter description of the device. Exemplary cases are simulated to show the usefulness of the model in the study of the basic design rules of laterally coupled thin film BAW resonator filters. Model predictions are compared to an experimental 1.9-GHz band-pass filter based on aluminum nitride thin film technology and lateral acoustical coupling. Good agreement is obtained in prediction of passband behavior. The eigenmode-based model forms a useful tool for fast simulation of laterally coupled acoustic devices. It allows one to gain insight into basic device physics in a very intuitive fashion compared with more detailed but heavier finite element method. Shortcomings of this model and possible improvements are discussed. PMID:21041141

  7. Cryogenic resonant acoustic spectroscopy of bulk materials (CRA spectroscopy).

    PubMed

    Zimmer, Anja; Nawrodt, Ronny; Koettig, Torsten; Neubert, Ralf; Thürk, Matthias; Vodel, Wolfgang; Seidel, Paul; Tünnermann, Andreas

    2007-06-01

    The capability to measure Q factors at cryogenic temperatures enhances the ability to study relaxation processes in solids. Here we present a high-precision cryogenic setup with the ability to measure Q factors of at least 10(9). This level of sensitivity offers new potential for analyzing relaxation processes in solids and for correlating mode shape and relaxation strength. Our improved method of mechanical spectroscopy, cryogenic resonant acoustic spectroscopy of bulk materials, is verified by identifying relaxation processes in low-loss quartz crystals. For the first time, we observe additional damping peaks. The mechanical Q factors of different modes of cylindrical crystalline quartz substrates were measured from 300 down to 6 K. Resonant modes with frequencies between 10 and 325 kHz were excited without contact to the substrates and the ring down of the amplitudes was recorded using an interferometric vibration readout. PMID:17614624

  8. Parallel Helmholtz resonators for a planar acoustic notch filter

    NASA Astrophysics Data System (ADS)

    Isozaki, Akihiro; Takahashi, Hidetoshi; Tamura, Hiroto; Takahata, Tomoyuki; Matsumoto, Kiyoshi; Shimoyama, Isao

    2014-12-01

    This paper reports on an acoustic planar notch filter with a sub-wavelength thickness at the notch frequency. The developed notch filter consists of a number of spherical Helmholtz resonators (HRs) connected to a hole created in a plate. The HRs were placed at the in-plane vertices of a regular polygon. A simulated pressure distribution revealed that this uniform arrangement of HRs improves the silencing effect because the uniform applied waves emitted from the HRs act as canceling waves to the cross-section of the short hole (in this case, the length of the hole is sub-wavelength). The total pressure emitted from the HRs is equal regardless of the number of HRs connected to the hole. Therefore, the arrangement of HRs is essential for realizing a planar notch filter. Simulated transmittance spectra showed that the depth of the dip in the transmittance increased with the number of uniformly arranged HRs. We confirmed that the experimental transmittance spectra of fabricated notch filters, which consisted of between one and six HRs, agreed with the simulated transmittance spectra. The design of the acoustic filter presented in this study and the corresponding analysis should motivate further development of thin acoustic filters.

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

    PubMed

    Hohmann, Siegfried; Kögel, Svea; Brunner, Yvonne; Schmieg, Barbara; Ewald, Christina; Kirschhöfer, Frank; Brenner-Weiß, Gerald; Länge, Kerstin

    2015-01-01

    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. PMID:26007735

  10. Random acoustic metamaterial with a subwavelength dipolar resonance.

    PubMed

    Duranteau, Mickaël; Valier-Brasier, Tony; Conoir, Jean-Marc; Wunenburger, Régis

    2016-06-01

    The effective velocity and attenuation of longitudinal waves through random dispersions of rigid, tungsten-carbide beads in an elastic matrix made of epoxy resin in the range of beads volume fraction 2%-10% are determined experimentally. The multiple scattering model proposed by Luppé, Conoir, and Norris [J. Acoust. Soc. Am. 131(2), 1113-1120 (2012)], which fully takes into account the elastic nature of the matrix and the associated mode conversions, accurately describes the measurements. Theoretical calculations show that the rigid particles display a local, dipolar resonance which shares several features with Minnaert resonance of bubbly liquids and with the dipolar resonance of core-shell particles. Moreover, for the samples under study, the main cause of smoothing of the dipolar resonance of the scatterers and the associated variations of the effective mass density of the dispersions is elastic relaxation, i.e., the finite time required for the shear stresses associated to the translational motion of the scatterers to propagate through the matrix. It is shown that its influence is governed solely by the value of the particle to matrix mass density contrast. PMID:27369160

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

    PubMed Central

    Hohmann, Siegfried; Kögel, Svea; Brunner, Yvonne; Schmieg, Barbara; Ewald, Christina; Kirschhöfer, Frank; Brenner-Weiß, Gerald; Länge, Kerstin

    2015-01-01

    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. PMID:26007735

  12. A study of acoustic resonance in a low-speed multistage compressor

    SciTech Connect

    Camp, T.R.

    1999-01-01

    Measurements are presented of a resonant acoustic phenomenon occurring in a low-speed multistage compressor. The results show that this phenomenon shares many characteristics with acoustic resonance as measured in high-speed compressors. These similarities include a rotating pressure field, several acoustic frequencies corresponding to different circumferential modes, step changes in frequency as the flow rate is increased, and acoustic frequencies that are independent of flow coefficient, shaft speed, and the axial length of the compression system. The paper includes measurements of the helical structure of the rotating pressure field and of the variation in amplitude of the acoustic signal over a stator exit plane.

  13. Barred galaxy resonance rings: analytically explaining morphology and predicting dissipative misalignment

    NASA Astrophysics Data System (ADS)

    Byrd, Gene G.; Ousley, Derrick; dalla Piazza, Chris

    1998-07-01

    Many barred disc galaxies show rings of gas clouds and young stars thought to be in periodic orbits near the two-fold inner and outer Lindblad resonances (ILR and OLR) plus a four-fold ultraharmonic resonance (UHR) of the turning bar with oscillations about the disc orbital motion. To confirm and extend simulations by Schwarz and by Byrd et al. of resonance ring formation, we present an analytical formulation of the clouds' orbital motion which includes dissipative damping of oscillations relative to the local interstellar medium plus the rotation curve, bar pattern speed, and strength. Observed ring morphology matches our plots of periodic orbits where the density is enhanced but clouds do not collide violently. Pairs of `outer rings' bracket the OLR. Dimpled outer rings like that of ESO 507-16 can be matched by plots with strong bars. Slightly dimpled outer rings like that of ESO 509-98 can be matched by weak bar plots. For flat rotation curves, a pair of two-fold rings bracket the ILR; the smaller can be identified with the tiny `nuclear rings'. We find narrow UHR rings just outside this pair as well as just inside the OLR pair. We confirm the identification of the larger ILR ring and the inner UHR ring with `inner rings'. Disagreeing with the common identification, we associate the dimpled outer rings with the UHR just inside the OLR. See ESO 507-16 as an example. We predict that damping can misalign the ILR and OLR rings relative to the bar as seen in our match to ESO 507-16. We find that for weak bars, if the linearly rising portion of the rotation curve is a significant fraction of the corotation radius, nuclear and inner rings are absent with outer rings still present. We show this in a match to ESO 509-98. Success of the matches to ESO 507-16 and 509-98 shows how the analytic formulation can be used to estimate disc orientation and pattern speed if rotation curve observations are available.

  14. Resonant interaction of acoustic waves with subaqueous bedforms: Sand dunes in the South China Sea.

    PubMed

    Chiu, Linus Y S; Chang, Andrea Y Y; Reeder, D Benjamin

    2015-12-01

    The large subaqueous sand dunes in the South China Sea are expected to produce the coupling of energy between acoustic normal modes. In this letter, resonant interaction between acoustic propagating modes and subaqueous bedforms are numerically investigated as a function of bedform wavelength, acoustic frequency and bedform packet length. The results demonstrate that bedform wavelength impacts acoustic mode coupling behavior, with the principal transfer of energy occurring between acoustic modes whose eigenvalue difference is equal to the peak value in the bedform wavenumber spectrum. The observed effect of wavelength is greater than that of acoustic frequency and bedform packet length. PMID:26723360

  15. Acoustic solitons in waveguides with Helmholtz resonators: transmission line approach.

    PubMed

    Achilleos, V; Richoux, O; Theocharis, G; Frantzeskakis, D J

    2015-02-01

    We report experimental results and study theoretically soliton formation and propagation in an air-filled acoustic waveguide side loaded with Helmholtz resonators. We propose a theoretical modeling of the system, which relies on a transmission-line approach, leading to a nonlinear dynamical lattice model. The latter allows for an analytical description of the various soliton solutions for the pressure, which are found by means of dynamical systems and multiscale expansion techniques. These solutions include Boussinesq-like and Korteweg-de Vries pulse-shaped solitons that are observed in the experiment, as well as nonlinear Schrödinger envelope solitons, that are predicted theoretically. The analytical predictions are in excellent agreement with direct numerical simulations and in qualitative agreement with the experimental observations. PMID:25768623

  16. Monaural sound localization based on structure-induced acoustic resonance.

    PubMed

    Kim, Keonwook; Kim, Youngwoong

    2015-01-01

    A physical structure such as a cylindrical pipe controls the propagated sound spectrum in a predictable way that can be used to localize the sound source. This paper designs a monaural sound localization system based on multiple pyramidal horns around a single microphone. The acoustic resonance within the horn provides a periodicity in the spectral domain known as the fundamental frequency which is inversely proportional to the radial horn length. Once the system accurately estimates the fundamental frequency, the horn length and corresponding angle can be derived by the relationship. The modified Cepstrum algorithm is employed to evaluate the fundamental frequency. In an anechoic chamber, localization experiments over azimuthal configuration show that up to 61% of the proper signal is recognized correctly with 30% misfire. With a speculated detection threshold, the system estimates direction 52% in positive-to-positive and 34% in negative-to-positive decision rate, on average. PMID:25668214

  17. Monaural Sound Localization Based on Structure-Induced Acoustic Resonance

    PubMed Central

    Kim, Keonwook; Kim, Youngwoong

    2015-01-01

    A physical structure such as a cylindrical pipe controls the propagated sound spectrum in a predictable way that can be used to localize the sound source. This paper designs a monaural sound localization system based on multiple pyramidal horns around a single microphone. The acoustic resonance within the horn provides a periodicity in the spectral domain known as the fundamental frequency which is inversely proportional to the radial horn length. Once the system accurately estimates the fundamental frequency, the horn length and corresponding angle can be derived by the relationship. The modified Cepstrum algorithm is employed to evaluate the fundamental frequency. In an anechoic chamber, localization experiments over azimuthal configuration show that up to 61% of the proper signal is recognized correctly with 30% misfire. With a speculated detection threshold, the system estimates direction 52% in positive-to-positive and 34% in negative-to-positive decision rate, on average. PMID:25668214

  18. Evaluation of the applicability of Helmholtz resonators for low frequency acoustic liners

    NASA Astrophysics Data System (ADS)

    Vanderwal, J. M. M.

    1988-09-01

    A literature study was performed on the acoustic behavior of those Helmholtz resonator type liners which are most promising for low frequency sound absorption in aero-engine applications. The equations for the acoustic impedance of various types of Helmholtz resonators were analyzed as well as the conditions for the validity of these equations. An experimental program is defined for a further analysis of various types of resonators.

  19. Effects of acoustic wave resonance oscillation on immobilized enzyme

    NASA Astrophysics Data System (ADS)

    Nishiyama, Hiroshi; Watanabe, Tomoya; Inoue, Yasunobu

    2014-03-01

    In aiming at developing a new method to artificially activate enzyme catalysts immobilized on surface, the effects of resonance oscillation of bulk acoustic waves were studied. Glucose oxidase (GOD) was immobilized by a covalent coupling method on a ferroelectric lead zirconate titanate (PZT) device that was able to generate thickness-extensional resonance oscillation (TERO). Glucose oxidation by the GOD enzyme was studied in a microreactor. The generation of TERO immediately increased the catalytic activity of immobilized GOD by a factor of 2-3. With turn-off of TERO, no significant activity decrease occurred, and 80-90% of the enhanced activity was maintained while the reaction proceeded. The almost complete reversion of the activity to the original low level before TERO generation was observed when the immobilized GOD was exposed to a glucose substrate-free solution. These results indicated that the presence of glucose substrate was essential for TERO-induced GOD activation and preservation of the increased activity level. The influences of reaction temperature, glucose concentration, pH, and rf electric power on the TERO activation showed that TERO strengthened the interactions of the immobilized enzyme with glucose substrate and hence promoted the formation of an activation complex.

  20. Precise rainbow trapping for low-frequency acoustic waves with micro Mie resonance-based structures

    NASA Astrophysics Data System (ADS)

    Zhou, Chen; Yuan, Baoguo; Cheng, Ying; Liu, Xiaojun

    2016-02-01

    We have realized the acoustic rainbow trapping in the low frequency region (200-500 Hz) through micro Mie resonance-based structures. The structure has eight channels with a high refractive index obtained by coiling space, that can excite strong interactions with incident waves and support various orders of multipoles due to the Mie resonances of the microstructure. By utilizing the structure, the precise spatial modulation of the acoustic wave is demonstrated both theoretically and experimentally. The effect of trapping broadband acoustic waves and spatially separating different frequency components are ascribed to the monopolar Mie resonances of the structures. The trapping frequency is derived and the trapping positions can be tuned arbitrarily. With enhanced wave-structure interactions and tailored frequency responses, such micro structures show precise spectral-spatial control of acoustic waves and open a diverse venue for high performance acoustic wave detection, sensing, filtering, and a nondestructive test.

  1. Resonant acoustic transducer and driver system for a well drilling string communication system

    DOEpatents

    Chanson, Gary J.; Nicolson, Alexander M.

    1981-01-01

    The acoustic data communication system includes an acoustic transmitter and receiver wherein low frequency acoustic waves, propagating in relatively loss free manner in well drilling string piping, are efficiently coupled to the drill string and propagate at levels competitive with the levels of noise generated by drilling machinery also present in the drill string. The transmitting transducer incorporates a mass-spring piezoelectric transmitter and amplifier combination that permits self-oscillating resonant operation in the desired low frequency range.

  2. Search for a narrow t(t)over-bar resonance in p(p)over-bar collisions at root s=1.96 TeV

    SciTech Connect

    Abazov V. M.; Abbott B.; Acharya B. S.; Adams M.; Adams T.; Alexeev G. D.; Alkhazov G.; Alton A.; Alverson G.; Alves G. A.; Aoki M.; Askew A.; Asman B.; Atkins S.; Atramentov O.; Augsten K.; Avila C.; BackusMayes J.; Badaud F.; Bagby L.; Baldin B.; Bandurin D. V.; Banerjee S.; Barberis E.; Baringer P.; Barreto J.; Bartlett J. F.; Bassler U.; Bazterra V.; Bean A.; Begalli M.; Belanger-Champagne C.; Bellantoni L.; Beri S. B.; Bernardi G.; Bernhard R.; Bertram I.; Besancon M.; Beuselinck R.; Bezzubov V. A.; Bhat P. C.; Bhatnagar V.; Blazey G.; Blessing S.; Bloom K.; Boehnlein A.; Boline D.; Boos E. E.; Borissov G.; Bose T.; Brandt A.; Brandt O.; Brock R.; Brooijmans G.; Bross A.; Brown D.; Brown J.; Bu X. B.; Buehler M.; Buescher V.; Bunichev V.; Burdin S.; Burnett T. H.; Buszello C. P.; Calpas B.; Camacho-Perez E.; Carrasco-Lizarraga M. A.; Casey B. C. K.; Castilla-Valdez H.; Chakrabarti S.; Chakraborty D.; Chan K. M.; Chandra A.; Chapon E.; Chen G.; Chevalier-Thery S.; Cho D. K.; Cho S. W.; Choi S.; Choudhary B.; Cihangir S.; Claes D.; Clutter J.; Cooke M.; Cooper W. E.; Corcoran M.; Couderc F.; Cousinou M-C; Croc A.; Cutts D.; Das A.; Davies G.; De K.; de Jong S. J.; De La Cruz-Burelo E.; Deliot F.; Demina R.; Denisov D.; Denisov S. P.; Desai S.; Deterre C.; DeVaughan K.; Diehl H. T.; Diesburg M.; Ding P. F.; Dominguez A.; Dorland T.; Dubey A.; Dudko L. V.; Duggan D.; Duperrin A.; Dutt S.; Dyshkant A.; Eads M.; Edmunds D.; Ellison J.; Elvira V. D.; Enari Y.; Evans H.; Evdokimov A.; Evdokimov V. N.; Facini G.; Ferbel T.; Fiedler F.; Filthaut F.; Fisher W.; Fisk H. E.; Fortner M.; Fox H.; Fuess S.; Garcia-Bellido A.; Garcia-Guerra G. A.; Gavrilov V.; Gay P.; Geng W.; Gerbaudo D.; Gerber C. E.; Gershtein Y.; Ginther G.; Golovanov G.; Goussiou A.; Grannis P. D.; Greder S.; Greenlee H.; Greenwood Z. D.; Gregores E. M.; Grenier G.; Gris Ph; Grivaz J-F; Grohsjean A.; Gruenendahl S.; Gruenewald M. W.; Guillemin T.; Gutierrez G.; Gutierrez P.; Haas A.; Hagopian S.; Haley J.; Han L.; Harder K.; Harel A.; Hauptman J. M.; Hays J.; Head T.; Hebbeker T.; Hedin D.; Hegab H.; Heinson A. P.; Heintz U.; Hensel C.; Heredia-De La Cruz I.; Herner K.; Hesketh G.; Hildreth M. D.; Hirosky R.; Hoang T.; Hobbs J. D.; Hoeneisen B.; Hohlfeld M.; Hubacek Z.; Hynek V.; Iashvili I.; Ilchenko Y.; Illingworth R.; Ito A. S.; Jabeen S.; Jaffre M.; Jamin D.; Jayasinghe A.; Jesik R.; Johns K.; Johnson M.; Jonckheere A.; Jonsson P.; Joshi J.; Jung A. W.; Juste A.; Kaadze K.; Kajfasz E.; Karmanov D.; Kasper P. A.; Katsanos I.; Kehoe R.; Kermiche S.; Khalatyan N.; Khanov A.; Kharchilava A.; Kharzheev Y. N.; Kohli J. M.; Kozelov A. V.; Kraus J.; Kulikov S.; Kumar A.; Kupco A.; Kurca T.; Kuzmin V. A.; Kvita J.; Lammers S.; Landsberg G.; Lebrun P.; Lee H. S.; Lee S. W.; Lee W. M.; Lellouch J.; Li L.; Li Q. Z.; Lietti S. M.; Lim J. K.; Lincoln D.; Linnemann J.; Lipaev V. V.; Lipton R.; Liu Y.; Lobodenko A.; Lokajicek M.; de Sa R. Lopes; Lubatti H. J.; Luna-Garcia R.; Lyon A. L.; Maciel A. K. A.; Mackin D.; Madar R.; Magana-Villalba R.; Malik S.; Malyshev V. L.; Maravin Y.; Martinez-Ortega J.; McCarthy R.; McGivern C. L.; Meijer M. M.; Melnitchouk A.; Menezes D.; Mercadante P. G.; Merkin M.; Meyer A.; Meyer J.; et al.

    2012-03-14

    We report a search for a narrow t{bar t} resonance that decays into a lepton+jets final state based on an integrated luminosity of 5.3 fb{sup -1} of proton-antiproton collisions at {radical}s = 1.96 TeV collected by the D0 Collaboration at the Fermilab Tevatron Collider. We set upper limits on the production cross section of such a resonance multiplied by its branching fraction to t{bar t}. We exclude a leptophobic topcolor Z' at the 95% confidence level for masses below 835 GeV (940 GeV) if its width is 1.2% (3%) of its mass. We also exclude color octet vector bosons (colorons) with masses below 775 GeV.

  3. Acoustic resonance in tube bundles -- Comparison of full scale and laboratory test results

    SciTech Connect

    Eisinger, F.L.

    1995-12-01

    Full scale operational data from steam generator tube bundles exposed to hot gases in crossflow are compared with small scale laboratory test results with cold air. Vibration thresholds based on input energy, acoustic particle velocity and effective damping are evaluated and compared. It is shown that these parameters play an important role in the development, or suppression of acoustic resonance.

  4. Apparatus and method for comparing corresponding acoustic resonances in liquids

    DOEpatents

    Sinha, D.N.

    1999-03-23

    Apparatus and method are disclosed for comparing corresponding acoustic resonances in liquids. The present invention permits the measurement of certain characteristics of liquids which affect the speed of sound therein. For example, a direct correlation between the octane rating of gasoline and the speed of sound in a gasoline sample has been experimentally observed. Therefore, changes in the speed of sound therein can be utilized as a sensitive parameter for determining changes in composition of a liquid sample. The present apparatus establishes interference patterns inside of a liquid without requiring the use of very thin, rigorously parallel ceramic discs, but rather uses readily available piezoelectric transducers attached to the outside surface of the usual container for the liquid and located on the same side thereof in the vicinity of one another. That is, various receptacle geometries may be employed, and the driving and receiving transducers may be located on the same side of the receptacle. The cell may also be constructed of any material that is inert to the liquid under investigation. A single-transducer embodiment, where the same transducer provides the excitation to the sample container and receives signals impressed therein, is also described. 5 figs.

  5. Apparatus and method for comparing corresponding acoustic resonances in liquids

    DOEpatents

    Sinha, Dipen N.

    1999-01-01

    Apparatus and method for comparing corresponding acoustic resonances in liquids. The present invention permits the measurement of certain characteristics of liquids which affect the speed of sound therein. For example, a direct correlation between the octane rating of gasoline and the speed of sound in a gasoline sample has been experimentally observed. Therefore, changes in the speed of sound therein can be utilized as a sensitive parameter for determining changes in composition of a liquid sample. The present apparatus establishes interference patterns inside of a liquid without requiring the use of very thin, rigorously parallel ceramic discs, but rather uses readily available piezoelectric transducers attached to the outside surface of the usual container for the liquid and located on the same side thereof in the vicinity of one another. That is, various receptacle geometries may be employed, and the driving and receiving transducers may be located on the same side of the receptacle. The cell may also be constructed of any material that is inert to the liquid under investigation. A single-transducer embodiment, where the same transducer provides the excitation to the sample container and receives signals impressed therein, is also described.

  6. Coupling of Acoustic Vibrations to Plasmon Resonances in Metal Nanoparticles

    NASA Astrophysics Data System (ADS)

    Ahmed, Aftab; Pelton, Matthew; Guest, Jeffrey

    Measurements of acoustic vibrations in nanoparticles provide a unique opportunity to study mechanical phenomena at nanometer length scales and picosecond time scales. Phonon vibrations of plasmonic nanoparticles are of particular interest, due to their large extinction efficiencies, and high sensitivity to surrounding medium. There are two mechanisms that transduce the mechanical oscillations into plasmon resonance shift: (1) changes in polarizability; and (2) changes in electron density. These mechanisms have been used to explain qualitatively the origin of the transient-absorption signals, however, a quantitative connection has not yet been made except for simple geometries. Here, we present a method to quantitatively determine the coupling between vibrational modes and plasmon modes in noble-metal nanoparticles including spheres, shells, rods and cubes. We separately determine the parts of the optical response that are due to shape changes and to changes in electron density, and we relate the optical signals to the symmetries of the vibrational and plasmon modes. These results clarify reported experimental results, and should help guide the optimization of future experiments.

  7. Towards optimal design of locally resonant acoustic metamaterials

    NASA Astrophysics Data System (ADS)

    Krushynska, A. O.; Kouznetsova, V. G.; Geers, M. G. D.

    2014-11-01

    The paper presents an in-depth analysis of solid locally resonant acoustic metamaterials (LRAMs) consisting of rubber-coated inclusions. Dispersion properties of two-dimensional LRAMs are studied by means of finite-element modal analysis. For an incompressible rubber, only one practically important spectral band gap is found for in-plane modes in a low-frequency range. This result is in striking contrast with the compressible coating case, previously studied in the literature. For inclusions with a circular cross-section, the lower bound of the band gap can be evaluated exactly by means of the derived analytical solution, which is also valid for compressible coatings and can therefore be used to determine lower bounds of higher band gaps as well. The influence of geometric and material parameters, filling fraction and inclusion shape on the width of the lowest band gap is investigated in detail. Based on the results of this analysis, an optimal microstructure of LRAMs yielding the widest low-frequency band gap is proposed. To achieve the band gap at the lowest possible frequencies in LRAMs suitable for practical applications, the use of the tungsten core material is advised, as a safe and economically viable alternative to commonly considered lead and gold. Two configurations of LRAM with various sizes of coated tungsten cylindrical inclusions with circular cross-section are considered. The evolution of dispersion spectra due to the presence of different inclusions is investigated, and the parameters for optimal design of LRAMs are determined.

  8. NGC 3081 - Surface photometry and kinematics of a classic resonance ring barred galaxy

    NASA Astrophysics Data System (ADS)

    Buta, R.; Purcell, Guy B.

    1998-02-01

    This paper presents a detailed photometric and kinematic study of the well-known Seyfert 2 galaxy NGC 3081, one of the best examples of a resonance ring barred galaxy in the sky. Improved optical images compared to previous studies reveal that NGC 3081 is a classic R1R'2 galaxy, a type that shows a distinctive outer ring/pseudoring pattern at large radii that can be linked to orbit families at the outer Lindblad resonance (OLR). Together with an exceptionally strong inner ring and a blue nuclear ring, NGC 3081 has the rare distinction of having all four of the main types of resonance rings that have been predicted by test-particle models of barred spirals. NIR imaging of NGC 3081 reveals clear old rings connected to the inner ring and the R1 outer ring. Objective comparison of the B- and H-band positions of the inner ring indicates no significant difference in shape, major-axis position angle, or major-axis radius between the two passbands, in spite of the different stellar populations each band emphasizes. Imaging Fabry-Perot interferometry provides an intriguing picture of star formation in the galaxy and of the dynamics of the system. H-alpha emission is strong in the inner ring and is confined to a bounded elliptical annulus of diffuse emission whose ellipticity increases from the inner edge to the outer edge. A few H II regions are connected to the strong R1-type outer ring, particularly just off the major axis of the inner ring where 'dimples', typical of the R1 morphology, are found.

  9. An intermode-coupled thin-film micro-acoustic resonator

    NASA Astrophysics Data System (ADS)

    Arapan, Lilia; Katardjiev, Ilia; Yantchev, Ventsislav

    2012-08-01

    A novel concept for the development of thin-film micro-acoustic resonators based on the coupling between different plate acoustic modes is demonstrated. The basic principles for the design and fabrication of intermode-coupled plate acoustic wave resonators on c-textured thin aluminum nitride films are presented. More specifically, the lowest order symmetric S0 Lamb wave is excited and then coupled to the fundamental thickness shear bulk resonance by means of a metal strip grating with specific periodicity. The experimental results demonstrate that the grating-assisted intermode coupling can be employed in high-frequency resonators inheriting the low dispersive nature of the S0 mode in combination with the energy localization in the plate bulk typical for the fundamental thickness shear resonance.

  10. Acoustofluidics 9: Modelling and applications of planar resonant devices for acoustic particle manipulation.

    PubMed

    Glynne-Jones, Peter; Boltryk, Rosemary J; Hill, Martyn

    2012-04-21

    This article introduces the design, construction and applications of planar resonant devices for particle and cell manipulation. These systems rely on the pistonic action of a piezoelectric layer to generate a one dimensional axial variation in acoustic pressure through a system of acoustically tuned layers. The resulting acoustic standing wave is dominated by planar variations in pressure causing particles to migrate to planar pressure nodes (or antinodes depending on particle and fluid properties). The consequences of lateral variations in the fields are discussed, and rules for designing resonators with high energy density within the appropriate layer for a given drive voltage presented. PMID:22402608

  11. Numerical derivation of forces on particles and agglomerates in a resonant acoustic field

    NASA Astrophysics Data System (ADS)

    Knoop, Claas; Fritsching, Udo

    2013-10-01

    Particles and agglomerates are investigated in gaseous acoustic flow fields. Acoustic fields exert forces on solid objects, which can influence the shape of the exposed bodies, even to the point of breakage of the structures. Motivated by experimentally observed breakage of agglomerates in an acoustic levitator (f = 20 kHz), a numerical study is presented that derives the acoustic forces on a complex model agglomerate from the pressure and velocity fields of a resonant standing ultrasound wave, calculated by computational fluid dynamics (CFD). It is distinguished between the drag and lift/lateral forces on the overall agglomerate and on the different primary particles of the model.

  12. Grazing incidence modeling of a metamaterial-inspired dual-resonance acoustic liner

    NASA Astrophysics Data System (ADS)

    Beck, Benjamin S.

    2014-03-01

    To reduce the noise emitted by commercial aircraft turbofan engines, the inlet and aft nacelle ducts are lined with acoustic absorbing structures called acoustic liners. Traditionally, these structures consist of a perforated facesheet bonded on top of a honeycomb core. These traditional perforate over honeycomb core (POHC) liners create an absorption spectra where the maximum absorption occurs at a frequency that is dictated by the depth of the honeycomb core; which acts as a quarter-wave resonator. Recent advances in turbofan engine design have increased the need for thin acoustic liners that are effective at low frequencies. One design that has been developed uses an acoustic metamaterial architecture to improve the low frequency absorption. Specifically, the liner consists of an array of Helmholtz resonators separated by quarter-wave volumes to create a dual-resonance acoustic liner. While previous work investigated the acoustic behavior under normal incidence, this paper outlines the modeling and predicted transmission loss and absorption of a dual-resonance acoustic metamaterial when subjected to grazing incidence sound.

  13. Coherent acoustic phonon oscillation accompanied with backward acoustic pulse below exciton resonance in a ZnO epifilm on oxide-buffered Si(1 1 1)

    NASA Astrophysics Data System (ADS)

    Lin, Ja-Hon; Shen, Yu-Kai; Liu, Wei-Rein; Lu, Chia-Hui; Chen, Yao-Hui; Chang, Chun-peng; Lee, Wei-Chin; Hong, Minghwei; Kwo, Jueinai-Raynien; Hsu, Chia-Hung; Hsieh, Wen-Feng

    2016-08-01

    Unlike coherent acoustic phonons (CAPs) generated from heat induced thermal stress by the coated Au film, we demonstrated the oscillation from c-ZnO epitaxial film on oxide buffered Si through a degenerate pump–probe technique. As the excited photon energy was set below the exciton resonance, the electronic stress that resulted from defect resonance was used to induce acoustic wave. The damped oscillation revealed a superposition of a high frequency and long decay CAP signal with a backward propagating acoustic pulse which was generated by the absorption of the penetrated pump beam at the Si surface and selected by the ZnO layer as the acoustic resonator.

  14. Condition of resonant break-up of gas bubbles by an acoustic wave in liquid

    NASA Astrophysics Data System (ADS)

    Vanovskiy, V. V.; Petrov, A. G.

    2016-07-01

    The linear theory of damping of radial vibrations of a bubble in a liquid is constructed by taking into account the key dissipative mechanisms: thermal, viscous, and acoustic. The basic approximation of homobaricity made helps to obtain the results in a convenient and simple form. The results obtained for damping are used further in the description of the forced resonant oscillations of a bubble in an acoustic wave with the frequency equal to the eigenfrequency of the radial oscillation mode and twice as high as the frequency of the deformation oscillation mode (resonance 2:2:1). It is shown that the amplitude of deformation oscillations, which is reasonably large for breaking, is developed at a relatively small pressure amplitude of the exciting acoustic wave, and subharmonics arise in the acoustic-emission spectrum. The condition of bubble break-up is obtained for a fast and slow start of the acoustic wave.

  15. Application of the Split Hopkinson Resonant Bar Test for Seismic Property Characterization of Hydrate-bearing Sand Undergoing Water Saturation

    SciTech Connect

    Nakagawa, S.; Kneafsey, T.J.

    2011-05-03

    Conventional resonant bar tests allow the measurement of seismic properties of rocks and sediments at low frequencies (several kilohertz). However, the tests require a long, slender sample which is often difficult to obtain from the deep subsurface and weak and fractured formations. We present an alternative low-frequency measurement technique to the conventional resonant bar tests. This technique involves a jacketed core sample placed between a pair of long, metal extension rods with attached seismic source and receiver—the same geometry as the split Hopkinson pressure bar test for large-strain, dynamic impact experiments. Because of the added length and mass to the sample, the resonance frequency of the entire system can be lowered significantly, compared to the sample alone. The proposed “Split Hopkinson Resonant Bar (SHRB)” test is applied in two steps. In the first step, extension and torsion-mode resonance frequencies and attenuation of the system are measured. Then, numerical inversions for the compressional and shear wave velocities and attenuation are performed. We initially applied the SHRB test to synthetic materials (plastics) for testing its accuracy, then used it for measuring the seismic velocities and attenuation of a rock core containing supercritical CO{sub 2}, and a sediment core while methane hydrate formed in the pore space.

  16. Acoustic Resonance Spectroscopy (ARS) Munition Classification System enhancements. Final report

    SciTech Connect

    Vela, O.A.; Huggard, J.C.

    1997-09-18

    Acoustic Resonance Spectroscopy (ARS) is a non-destructive evaluation technology developed at the Los Alamos National Laboratory (LANL). This technology has resulted in three generations of instrumentation, funded by the Defense Special Weapons Agency (DSWA), specifically designed for field identification of chemical weapon (CW) munitions. Each generation of ARS instrumentation was developed with a specific user in mind. The ARS1OO was built for use by the U.N. Inspection Teams going into Iraq immediately after the Persian Gulf War. The ARS200 was built for use in the US-Russia Bilateral Chemical Weapons Treaty (the primary users for this system are the US Onsite Inspection Agency (OSIA) and their Russian counterparts). The ARS300 was built with the requirements of the Organization for the Prohibition of Chemical Weapons (OPCW) in mind. Each successive system is an improved version of the previous system based on learning the weaknesses of each and, coincidentally, on the fact that more time was available to do a requirements analysis and the necessary engineering development. The ARS300 is at a level of development that warrants transferring the technology to a commercial vendor. Since LANL will supply the computer software to the selected vendor, it is possible for LANL to continue to improve the decision algorithms, add features where necessary, and adjust the user interface before the final transfer occurs. This paper describes the current system, ARS system enhancements, and software enhancements. Appendices contain the Operations Manual (software Version 3.01), and two earlier reports on enhancements.

  17. Passive control of flow-excited acoustic resonance in rectangular cavities using upstream mounted blocks

    NASA Astrophysics Data System (ADS)

    Shaaban, Mahmoud; Mohany, Atef

    2015-04-01

    A passive method for controlling the flow-excited acoustic resonance resulting from subsonic flows over rectangular cavities in channels is investigated. A cavity with length to depth ratio of is tested in air flow of Mach number up to 0.45. When the acoustic resonance is excited, the sound pressure level in the cavity reaches 162 dB. Square blocks are attached to the surface of the channel and centred upstream of the cavity leading edge to suppress the flow-excited acoustic resonance in the cavity. Six blocks of different widths are tested at three different upstream distances. The results show that significant attenuation of up to 30 dB of the excited sound pressure level is achieved using a block with a width to height ratio of 3, while blocks that fill the whole width of the channel amplify the pressure of the excited acoustic resonance. Moreover, it is found that placing the block upstream of the cavity causes the onset of the acoustic resonance to occur at higher flow velocities. In order to investigate the nature of the interactions that lead to suppression of the acoustic resonance and to identify the changes in flow patterns due to the placement of the block, 2D measurements of turbulence intensity in the shear layer and the block wake region are performed. The location of the flow reattachment point downstream of the block relative to the shear layer separation point has a major influence on the suppression level of the excited acoustic resonance. Furthermore, higher attenuation of noise is related to lower span-wise correlation of the shear-layer perturbation.

  18. Study of the onset of the acoustic streaming in parallel plate resonators with pulse ultrasound.

    PubMed

    Castro, Angelica; Hoyos, Mauricio

    2016-03-01

    In a previous study, we introduced pulse mode ultrasound as a new method for reducing and controlling the acoustic streaming in parallel plate resonators (Hoyos and Castro, 2013). Here, by modifying other parameters such as the resonator geometry and the particle size, we have found a threshold for particle manipulation with ultrasonic standing waves in confined resonators without the influence of the acoustic streaming. We demonstrate that pulse mode ultrasound open the possibility of manipulating particles smaller than 1 μm size. PMID:26705604

  19. Enhanced acoustoelectric coupling in acoustic energy harvester using dual Helmholtz resonators.

    PubMed

    Peng, Xiao; Wen, Yumei; Li, Ping; Yang, Aichao; Bai, Xiaoling

    2013-10-01

    In this paper, enhanced acoustoelectric transduction in an acoustic energy harvester using dual Helmholtz resonators has been reported. The harvester uses a pair of cavities mechanically coupled with a compliant perforated plate to enhance the acoustic coupling between the cavity and the plate. The experimental results show that the volume optimization of the second cavity can significantly increase the generated electric voltage up to 400% and raise the output power to 16 times as large as that of a harvester using a single Helmholtz resonator at resonant frequencies primarily related to the plate. PMID:24081260

  20. Investigations of High Pressure Acoustic Waves in Resonators with Seal-Like Features

    NASA Technical Reports Server (NTRS)

    Daniels, Christopher C.; Steinetz, Bruce M.; Finkbeiner, Joshua R.; Li, Xiao-Fan; Raman, Ganesh

    2004-01-01

    1) Standing waves with maximum pressures of 188 kPa have been produced in resonators containing ambient pressure air; 2) Addition of structures inside the resonator shifts the fundamental frequency and decreases the amplitude of the generated pressure waves; 3) Addition of holes to the resonator does reduce the magnitude of the acoustic waves produced, but their addition does not prohibit the generation of large magnitude non-linear standing waves; 4) The feasibility of reducing leakage using non-linear acoustics has been confirmed.

  1. Intrinsically tunable bulk acoustic wave resonators based on sol-gel grown PMN-PT films

    NASA Astrophysics Data System (ADS)

    Vorobiev, A.; Spreitzer, M.; Veber, A.; Suvorov, D.; Gevorgian, S.

    2014-08-01

    Intrinsically tunable bulk acoustic wave resonators, based on sol-gel 0.70Pb(Mg1/3Nb2/3)O3-0.30PbTiO3 (PMN-PT) thin films, with high effective electromechanical coupling coefficient of 13% and tunability of the series resonance frequency up to 4.0% are fabricated and characterized. The enhanced electroacoustic properties of the PMN-PT resonators are attributed to the mechanism of polarization rotation occurring in the region of the morphotropic phase boundary. Electroacoustic performance of the PMN-PT resonators is analyzed using the theory of dc field-induced piezoelectric effect in ferroelectrics. Extrinsic acoustic loss in the PMN-PT resonators is analyzed using the model of the wave scattering at reflections from rough interfaces. Mechanical Q-factor of the resonators is up to 70 at 4.1 GHz and limited mainly by losses in the PMN-PT film.

  2. Optimal shaping of acoustic resonators for the generation of high-amplitude standing waves.

    PubMed

    Červenka, Milan; Šoltés, Martin; Bednařík, Michal

    2014-09-01

    Within this paper, optimal shaping of acoustic resonators for the generation of high-amplitude standing waves through the use of evolutionary algorithms is discussed. The resonator shapes are described using sets of control points interconnected with cubic-splines. Positions of the control points are calculated by means of an evolutionary algorithm in order to maximize acoustic pressure amplitude at a given point of the resonator cavity. As an objective function for the optimization procedure, numerical solution of one-dimensional linear wave equation taking into account boundary-layer dissipation is used. Resonator shapes maximizing acoustic pressure amplitude are found in case of a piston, shaker, or loudspeaker driving. It is shown that the optimum resonator shapes depend on the method of driving. In all the cases, acoustic field attains higher amplitude in the optimized resonators than in simple-shaped non-optimized resonators of similar dimensions. Theoretical results are compared with experimental data in the case of a loudspeaker driving, good agreement of which is achieved. PMID:25190376

  3. Can X(5568) be described as a Bsπ, B K bar resonant state?

    NASA Astrophysics Data System (ADS)

    Albaladejo, Miguel; Nieves, Juan; Oset, Eulogio; Sun, Zhi-Feng; Liu, Xiang

    2016-06-01

    The D0 Collaboration has recently seen a resonant-like peak in the Bs π invariant mass spectrum, claimed to be a new state called X (5568). Using a Bs π- B K bar coupled channel analysis, implementing unitarity, and with the interaction derived from Heavy Meson Chiral Perturbation Theory, we are able to reproduce the reported spectrum, with a pole that can be associated to the claimed X (5568) state, and with mass and width in agreement with the ones reported in the experimental analysis. However, if the T-matrix regularization is performed by means of a momentum cutoff, the value for the latter needed to reproduce the spectrum is Λ = 2.80 ± 0.04GeV, which is much larger than a "natural" value Λ ≃ 1GeV. In view of this, it is difficult to interpret the nature of this new state. This state would not qualify as a resonance dynamically generated by the unitarity loops. Assuming the observed peak to correspond to a physical state, we make predictions for partners in the D, D*, and B* sectors. Their observation (or lack thereof) would shed light into this issue.

  4. Acoustic control in a tractor cabin using two optimally designed Helmholtz resonators

    NASA Astrophysics Data System (ADS)

    Driesch, Patricia L.; Koopmann, Gary H.

    2003-10-01

    A virtual design methodology is developed to minimize the noise in enclosures with optimally designed, passive, 20 acoustic absorbers (Helmholtz resonators). A series expansion of eigenfunctions is used to represent the acoustic=20 absorbers as external volume velocities, eliminating the need for a solution of large matrix eigenvalue problems. A determination of this type (efficient model/reevaluation approach) significantly increases the design possibilities when optimization techniques are implemented. As a full-scale demonstration, the acoustic response from 90-190 Hz of a tractor cabin was investigated. The lowest cabin mode proposes a significant challenge to a noise control engineer since its anti-node is located near the head of the operator and often generates unacceptable sound-pressure levels. Exploiting the low-frequency capability of Helmholtz resonators, lumped parameter models of these resonators were coupled to the enclosure via an experimentally determined acoustic model of the tractor cabin. The virtual design methodology uses gradient optimization techniques as a post-processor for the modeling and analysis of the unmodified acoustic interior to determine optimal resonator characteristics. Using two optimally designed Helmholtz resonators, potential energy was experimentally reduced by 3.4 and 10.3 dB at 117 and 167 Hz, respectively.

  5. Positive-energy D-bar method for acoustic tomography: a computational study

    NASA Astrophysics Data System (ADS)

    de Hoop, M. V.; Lassas, M.; Santacesaria, M.; Siltanen, S.; Tamminen, J. P.

    2016-02-01

    A new computational method for reconstructing a potential from the Dirichlet-to-Neumann (DN) map at positive energy is developed. The method is based on D-bar techniques and it works in absence of exceptional points—in particular, if the potential is small enough compared to the energy. Numerical tests reveal exceptional points for perturbed, radial potentials. Reconstructions for several potentials are computed using simulated DN maps with and without added noise. The new reconstruction method is shown to work well for energy values between 10-5 and 5, smaller values giving better results.

  6. Tracheo-bronchial soft tissue and cartilage resonances in the subglottal acoustic input impedance.

    PubMed

    Lulich, Steven M; Arsikere, Harish

    2015-06-01

    This paper offers a re-evaluation of the mechanical properties of the tracheo-bronchial soft tissues and cartilage and uses a model to examine their effects on the subglottal acoustic input impedance. It is shown that the values for soft tissue elastance and cartilage viscosity typically used in models of subglottal acoustics during phonation are not accurate, and corrected values are proposed. The calculated subglottal acoustic input impedance using these corrected values reveals clusters of weak resonances due to soft tissues (SgT) and cartilage (SgC) lining the walls of the trachea and large bronchi, which can be observed empirically in subglottal acoustic spectra. The model predicts that individuals may exhibit SgT and SgC resonances to variable degrees, depending on a number of factors including tissue mechanical properties and the dimensions of the trachea and large bronchi. Potential implications for voice production and large pulmonary airway tissue diseases are also discussed. PMID:26093432

  7. A numerically efficient damping model for acoustic resonances in microfluidic cavities

    NASA Astrophysics Data System (ADS)

    Hahn, P.; Dual, J.

    2015-06-01

    Bulk acoustic wave devices are typically operated in a resonant state to achieve enhanced acoustic amplitudes and high acoustofluidic forces for the manipulation of microparticles. Among other loss mechanisms related to the structural parts of acoustofluidic devices, damping in the fluidic cavity is a crucial factor that limits the attainable acoustic amplitudes. In the analytical part of this study, we quantify all relevant loss mechanisms related to the fluid inside acoustofluidic micro-devices. Subsequently, a numerical analysis of the time-harmonic visco-acoustic and thermo-visco-acoustic equations is carried out to verify the analytical results for 2D and 3D examples. The damping results are fitted into the framework of classical linear acoustics to set up a numerically efficient device model. For this purpose, all damping effects are combined into an acoustofluidic loss factor. Since some components of the acoustofluidic loss factor depend on the acoustic mode shape in the fluid cavity, we propose a two-step simulation procedure. In the first step, the loss factors are deduced from the simulated mode shape. Subsequently, a second simulation is invoked, taking all losses into account. Owing to its computational efficiency, the presented numerical device model is of great relevance for the simulation of acoustofluidic particle manipulation by means of acoustic radiation forces or acoustic streaming. For the first time, accurate 3D simulations of realistic micro-devices for the quantitative prediction of pressure amplitudes and the related acoustofluidic forces become feasible.

  8. A numerically efficient damping model for acoustic resonances in microfluidic cavities

    SciTech Connect

    Hahn, P. Dual, J.

    2015-06-15

    Bulk acoustic wave devices are typically operated in a resonant state to achieve enhanced acoustic amplitudes and high acoustofluidic forces for the manipulation of microparticles. Among other loss mechanisms related to the structural parts of acoustofluidic devices, damping in the fluidic cavity is a crucial factor that limits the attainable acoustic amplitudes. In the analytical part of this study, we quantify all relevant loss mechanisms related to the fluid inside acoustofluidic micro-devices. Subsequently, a numerical analysis of the time-harmonic visco-acoustic and thermo-visco-acoustic equations is carried out to verify the analytical results for 2D and 3D examples. The damping results are fitted into the framework of classical linear acoustics to set up a numerically efficient device model. For this purpose, all damping effects are combined into an acoustofluidic loss factor. Since some components of the acoustofluidic loss factor depend on the acoustic mode shape in the fluid cavity, we propose a two-step simulation procedure. In the first step, the loss factors are deduced from the simulated mode shape. Subsequently, a second simulation is invoked, taking all losses into account. Owing to its computational efficiency, the presented numerical device model is of great relevance for the simulation of acoustofluidic particle manipulation by means of acoustic radiation forces or acoustic streaming. For the first time, accurate 3D simulations of realistic micro-devices for the quantitative prediction of pressure amplitudes and the related acoustofluidic forces become feasible.

  9. Effects of relevant parameters on the bandgaps of acoustic metamaterials with multi-resonators

    NASA Astrophysics Data System (ADS)

    Zhou, Xiaoqin; Wang, Jun; Wang, Rongqi; Lin, Jieqiong

    2016-04-01

    Locally resonant acoustic metamaterials with multi-resonators are generally regarded as a fine trend for managing the bandgaps, the different effects of relevant structural parameters on the bandgaps, which will be numerically investigated in this paper. A two-step homogenization method is extended to achieve the effective mass of multi-resonators metamaterial in the lattice system. As comparison, the dispersive wave propagation in lattice system and continuum model is studied. Then, the different effects of relevant parameters on the center frequencies and bandwidth of bandgaps are perfectly revealed, and the steady-state responses in the continuum models with purposed relevant parameters are additionally clarified. The related results can well confirm that the bandgaps exist around the undamped natural frequencies of internal resonators, and also their bandwidth can be efficiently controlled with the ensured center frequencies. Moreover, the design of purposed multi-resonators acoustic metamaterial in vibration control is presented and discussed by an example.

  10. Resonant attenuation of surface acoustic waves by a disordered monolayer of microspheres

    NASA Astrophysics Data System (ADS)

    Eliason, J. K.; Vega-Flick, A.; Hiraiwa, M.; Khanolkar, A.; Gan, T.; Boechler, N.; Fang, N.; Nelson, K. A.; Maznev, A. A.

    2016-02-01

    Attenuation of surface acoustic waves (SAWs) by a disordered monolayer of polystyrene microspheres is investigated. Surface acoustic wave packets are generated by a pair of crossed laser pulses in a glass substrate coated with a thin aluminum film and detected via the diffraction of a probe laser beam. When a 170 μm-wide strip of micron-sized spheres is placed on the substrate between the excitation and detection spots, strong resonant attenuation of SAWs near 240 MHz is observed. The attenuation is caused by the interaction of SAWs with a contact resonance of the microspheres, as confirmed by acoustic dispersion measurements on the microsphere-coated area. Frequency-selective attenuation of SAWs by such a locally resonant metamaterial may lead to reconfigurable SAW devices and sensors, which can be easily manufactured via self-assembly techniques.

  11. Micro- and Macro-Fluid Dynamics and Acoustics of Resonant Liners

    NASA Technical Reports Server (NTRS)

    Tam, Christopher K. W.; Watson, Willie (Technical Monitor)

    2002-01-01

    The objectives of this project are to perform direct numerical simulation of the micro-fluid and acoustic fields of a resonant acoustic liner and to investigate the physical processes by which incident sound waves are damped by the acoustic liner. We would like to report that our research work and results have fulfilled both objectives of the grant. The following is a summary of the important accomplishments: (1) Two dimensional direct numerical simulation of the flow and acoustic field around the cavity of resonant liner were successfully carried out; (2) The simulations of (1) were extended to include a laminar grazing flow; (3) The numerical simulations provided strong evidence that there are two principal mechanisms by which a resonant liner damps out an incident acoustic wave; (4) A validation test was performed by comparing the computed dissipation coefficients (not impedance) with impedance tube measurements done at GTRI; and (5) Some resources of this grant were used to support the development of new CAA methods. (Our work on numerical simulation of acoustic liners has benefited by the availability of these improved methods).

  12. Vortex shedding and acoustic resonance of single and tandem finned cylinders

    NASA Astrophysics Data System (ADS)

    Eid, M.; Ziada, S.

    2011-10-01

    The effect of fins on vortex shedding and acoustic resonance is investigated for isolated and two tandem cylinders exposed to cross-flow in a rectangular duct. Three spacing ratios between the tandem cylinders ( S/D e =1.5, 2 and 3) are tested for a Reynolds number range from 1.6×10 4 to 1.1×10 5 . Measurements of sound pressure as well as mean and fluctuating velocities are performed for bare and finned cylinders with three different fin densities. The effect of fins on the sound pressure generated before the onset of acoustic resonance as well as during the pre-coincidence and coincidence resonance is found to be rather complex and depends on the spacing ratio between cylinders, the fin density and the nature of the flow-sound interaction mechanism. For isolated cylinders, the fins reduce the strength of vortex shedding only slightly, but strongly attenuate the radiated sound before and during the occurrence of acoustic resonance. This suggests that the influence of the fins on correlation length is stronger than on velocity fluctuations. In contrast to isolated cylinders, the fins in the tandem cylinder case enhance the vortex shedding process at off-resonant conditions, except for the large spacing case which exhibits a reversed effect at high Reynolds numbers. Regarding the acoustic resonance of the tandem cylinders, the fins promote the onset of the coincidence resonance, but increasing the fin density drastically weakens the intensity of this resonance. The fins are also found to suppress the pre-coincidence resonance for the tandem cylinders with small spacing ratios ( S/D e =1.5, 2 and 2), but for the largest spacing case ( S/D e =3), they are found to have minor effects on the sound pressure and the lock-in range of the pre-coincidence resonance.

  13. Method for determining the octane rating of gasoline samples by observing corresponding acoustic resonances therein

    DOEpatents

    Sinha, Dipen N.; Anthony, Brian W.

    1997-01-01

    A method for determining the octane rating of gasoline samples by observing corresponding acoustic resonances therein. A direct correlation between the octane rating of gasoline and the frequency of corresponding acoustic resonances therein has been experimentally observed. Therefore, the octane rating of a gasoline sample can be directly determined through speed of sound measurements instead of by the cumbersome process of quantifying the knocking quality of the gasoline. Various receptacle geometries and construction materials may be employed. Moreover, it is anticipated that the measurements can be performed on flowing samples in pipes, thereby rendering the present method useful in refineries and distilleries.

  14. Method for determining the octane rating of gasoline samples by observing corresponding acoustic resonances therein

    DOEpatents

    Sinha, D.N.; Anthony, B.W.

    1997-02-25

    A method is described for determining the octane rating of gasoline samples by observing corresponding acoustic resonances therein. A direct correlation between the octane rating of gasoline and the frequency of corresponding acoustic resonances therein has been experimentally observed. Therefore, the octane rating of a gasoline sample can be directly determined through speed of sound measurements instead of by the cumbersome process of quantifying the knocking quality of the gasoline. Various receptacle geometries and construction materials may be employed. Moreover, it is anticipated that the measurements can be performed on flowing samples in pipes, thereby rendering the present method useful in refineries and distilleries. 3 figs.

  15. An acoustic dual filter in the audio frequencies with two local resonant systems

    NASA Astrophysics Data System (ADS)

    Liu, Zhao-qun; Zhang, Hui; Zhang, Shu-yi; Fan, Li

    2014-08-01

    We report an acoustic dual filter to realize the sound regulation in the audio frequency range, in which resonant vibrations of two membrane-air and metal-elastomer systems generate two sound transmission peaks and a sound blocking below 3000 Hz. The local vibrational profiles manifest that the transmission peak at lower frequency is mainly dependent on the resonant vibration of the membrane-air system, and the coupling vibrations of two systems generate the blocking frequency and transmission peak at higher frequency. Importantly, two transmission peaks can be controlled independently. It is feasible to realize the acoustic device in sound shield and dual filters.

  16. Acoustic resonance in centrifugal compressors induced by interaction between rotor and stator

    NASA Astrophysics Data System (ADS)

    Kurzin, V. B.; Izmailov, R. A.; Okulov, V. L.

    An experimental investigation is conducted of acoustic resonance phenomena generated in centrifugal compressors by the interaction between rotor and stator, with a view to the theoretical characterization of the conditions under which the excitation of resonance occurs. The theoretical model used assumes that the velocity of a basic stationary airflow representing the spiral flow is comparatively low, that the airfoils in question are thin, and that the sources of acoustic disturbances are absent outside the outer cascade radius. Good agreement is obtained between computational and experimental results.

  17. Extremely high Q-factor mechanical modes in quartz bulk acoustic wave resonators at millikelvin temperature

    SciTech Connect

    Goryachev, M.; Creedon, D. L.; Ivanov, E. N.; Tobar, M. E.; Galliou, S.; Bourquin, R.

    2014-12-04

    We demonstrate that Bulk Acoustic Wave (BAW) quartz resonator cooled down to millikelvin temperatures are excellent building blocks for hybrid quantum systems with extremely long coherence times. Two overtones of the longitudinal mode at frequencies of 15.6 and 65.4 MHz demonstrate a maximum f.Q product of 7.8×10{sup 16} Hz. With this result, the Q-factor in such devices near the quantum ground state can be four orders of magnitude better than previously attained in other mechanical systems. Tested quartz resonators possess the ultra low acoustic losses crucial for electromagnetic cooling to the phonon ground state.

  18. A Study of Standing Pressure Waves Within Open and Closed Acoustic Resonators

    NASA Technical Reports Server (NTRS)

    Daniels, C.; Steinetz, B.; Finkbeiner, J.; Raman, G.; Li, X.

    2002-01-01

    The first section of the results presented herein was conducted on an axisymmetric resonator configured with open ventilation ports on either end of the resonator, but otherwise closed and free from obstruction. The remaining section presents the results of a similar resonator shape that was closed, but contained an axisymmetric blockage centrally located through the axis of the resonator. Ambient air was used as the working fluid. In each of the studies, the resonator was oscillated at the resonant frequency of the fluid contained within the cavity while the dynamic pressure, static pressure, and temperature of the fluid were recorded at both ends of the resonator. The baseline results showed a marked reduction in the amplitude of the dynamic pressure waveforms over previous studies due to the use of air instead of refrigerant as the working fluid. A sharp reduction in the amplitude of the acoustic pressure waves was expected and recorded when the configuration of the resonators was modified from closed to open. A change in the resonant frequency was recorded when blockages of differing geometries were used in the closed resonator, while acoustic pressure amplitudes varied little from baseline measurements.

  19. Equivalent circuit of a composite acoustic resonator for microwave radioelectronic devices

    NASA Astrophysics Data System (ADS)

    Mansfel'D, G. D.; Alekseev, S. G.; Polzikova, N. I.

    2008-07-01

    On the basis of analyzing the expression for the input electric impedance of a composite microwave acoustic resonator, its equivalent electric circuit is constructed. It is shown that, for high-order harmonics, the difference between the antiresonance and resonance frequencies is determined not only by the electromechanical coupling coefficient, but also by the loss in the structure. The conditions under which this difference corresponds to the bandwidth of the equivalent parallel electric oscillatory circuit are formulated. Expressions for the resonance and antiresonance frequencies are derived. The procedures of determining the Q factor and the electromechanical coupling coefficient from the measured resonance and antiresonance frequencies of the structure are justified.

  20. Hyperon AND Hyperon Resonance Properties From Charm Baryon Decays At BaBar

    SciTech Connect

    Ziegler, Veronique; /Iowa U.

    2007-07-03

    This report describes studies of hyperons and hyperon resonances produced in charm baryon decays at BABAR. Using two-body decays of the {Xi}{sub c}{sup 0} and {Omega}{sub c}{sup 0}, it is shown, for the first time, that the spin of the {omega}{sup -} is 3/2. The {Omega}{sup -} analysis procedures are extended to three-body final states and properties of the {Xi}(1690){sup 0} are extracted from a detailed isobar model analysis of the {Lambda}{sub c}{sup +} {yields} {Lambda}{bar K}{sup 0}K{sup +} Dalitz plot. The mass and width values of the {Xi}(1690){sup 0} are measured with much greater precision than attained previously. The hypothesis that the spin of the {Xi}(1690) resonance is 1/2 yields an excellent description of the data, while spin values 3/2 and 5/2 are disfavored. The {Lambda}a{sub 0}(980){sup +} decay mode of the {Lambda}{sub c}{sup +} is observed for the first time. Similar techniques are then used to study {Xi}(1530){sup 0} production in {Lambda}{sub c}{sup +} decay. The spin of the {Xi}(1530) is established for the first time to be 3/2. The existence of an S-wave amplitude in the {Xi}{sup -}{pi}{sup +} system is shown, and its interference with the {Xi}(1530){sup 0} amplitude provides the first clear demonstration of the Breit-Wigner phase motion expected for the {Xi}(1530). The {Xi}{sup -}{pi}{sup +} mass distribution in the vicinity of the {Xi}(1690){sup 0} exhibits interesting structure which may be interpreted as indicating that the {Xi}(1690) has negative parity.

  1. Analysis of underwater decoupling properties of a locally resonant acoustic metamaterial coating

    NASA Astrophysics Data System (ADS)

    Ling-Zhi, Huang; Yong, Xiao; Ji-Hong, Wen; Hai-Bin, Yang; Xi-Sen, Wen

    2016-02-01

    This paper presents a semi-analytical solution for the vibration and sound radiation of a semi-infinite plate covered by a decoupling layer consisting of locally resonant acoustic metamaterial. Formulations are derived based on a combination use of effective medium theory and the theory of elasticity for the decoupling material. Theoretical results show good agreements between the method developed in this paper and the conventional finite element method (FEM), but the method of this paper is more efficient than FEM. Numerical results also show that system with acoustic metamaterial decoupling layer exhibits significant noise reduction performance at the local resonance frequency of the acoustic metamaterial, and such performance can be ascribed to the vibration suppression of the base plate. It is demonstrated that the effective density of acoustic metamaterial decoupling layer has a great influence on the mechanical impedance of the system. Furthermore, the resonance frequency of locally resonant structure can be effectively predicted by a simple model, and it can be significantly affected by the material properties of the locally resonant structure. Project supported by the National Natural Science Foundation of China (Grant Nos. 51305448 and 51275519).

  2. Flow-excited acoustic resonance of two tandem cylinders in cross-flow

    NASA Astrophysics Data System (ADS)

    Mohany, A.; Ziada, S.

    2005-11-01

    The aeroacoustic response of two tandem cylinders in cross-flow is investigated experimentally. Eleven spacing ratios between the cylinders, in the range of L/D=1.2 4.5, have been tested to investigate the effect of the gap between the cylinders on the excitation mechanism of acoustic resonance. During the tests, the acoustic cross-modes of the duct housing the cylinders are self-excited. Similar tests are performed on isolated cylinders. The aeroacoustic response of the tandem cylinders is found to be considerably different from that of isolated cylinders. For isolated cylinders, acoustic resonance of a given mode occurs over a single range of flow velocity and is excited by the natural vortex shedding process observed in the absence of acoustic resonance. In the case of tandem cylinders with a spacing ratio inside the proximity region, L/D is less than 3.5, the resonance occurs over two different ranges of flow velocity. One of these ranges is similar to that observed for isolated cylinders and the other occurs at much lower flow velocities. The latter resonance range seems to be triggered by the instability of the separated flow in the gap between the cylinders. Outside the proximity region, the aeroacoustic response of the two tandem cylinders is similar to that of isolated cylinder.

  3. Experimental and numerical investigations of resonant acoustic waves in near-critical carbon dioxide.

    PubMed

    Hasan, Nusair; Farouk, Bakhtier

    2015-10-01

    Flow and transport induced by resonant acoustic waves in a near-critical fluid filled cylindrical enclosure is investigated both experimentally and numerically. Supercritical carbon dioxide (near the critical or the pseudo-critical states) in a confined resonator is subjected to acoustic field created by an electro-mechanical acoustic transducer and the induced pressure waves are measured by a fast response pressure field microphone. The frequency of the acoustic transducer is chosen such that the lowest acoustic mode propagates along the enclosure. For numerical simulations, a real-fluid computational fluid dynamics model representing the thermo-physical and transport properties of the supercritical fluid is considered. The simulated acoustic field in the resonator is compared with measurements. The formation of acoustic streaming structures in the highly compressible medium is revealed by time-averaging the numerical solutions over a given period. Due to diverging thermo-physical properties of supercritical fluid near the critical point, large scale oscillations are generated even for small sound field intensity. The strength of the acoustic wave field is found to be in direct relation with the thermodynamic state of the fluid. The effects of near-critical property variations and the operating pressure on the formation process of the streaming structures are also investigated. Irregular streaming patterns with significantly higher streaming velocities are observed for near-pseudo-critical states at operating pressures close to the critical pressure. However, these structures quickly re-orient to the typical Rayleigh streaming patterns with the increase operating pressure. PMID:26520322

  4. Opto-acoustic phenomena in whispering gallery mode resonators

    NASA Astrophysics Data System (ADS)

    Lin, Guoping; Chembo, Yanne K.

    2016-01-01

    Optical whispering gallery mode resonators are important platforms to enhance and study various nonlinear frequency conversion processes. Stimulated Brillouin scattering is one of the strongest nonlinear effects, and can be successfully investigated using these platforms. In this article, we study the phenomenon of stimulated Brillouin scattering using a crystalline disk resonator. A fast scanning ringdown spectroscopy technique is used to characterize the optical modes featuring quality factors of the order of one billion at telecom wavelengths. The mW scale threshold power in a centimeter disk resonator is observed and found to be strongly dependent on the gap between the resonator and the prism coupler.

  5. Streptavidin Modified ZnO Film Bulk Acoustic Resonator for Detection of Tumor Marker Mucin 1.

    PubMed

    Zheng, Dan; Guo, Peng; Xiong, Juan; Wang, Shengfu

    2016-12-01

    A ZnO-based film bulk acoustic resonator has been fabricated using a magnetron sputtering technology, which was employed as a biosensor for detection of mucin 1. The resonant frequency of the thin-film bulk acoustic resonator was located near at 1503.3 MHz. The average electromechanical coupling factor [Formula: see text] and quality factor Q were 2.39 % and 224, respectively. Using the specific binding system of avidin-biotin, the streptavidin was self-assembled on the top gold electrode as the sensitive layer to indirectly test the MUC1 molecules. The resonant frequency of the biosensor decreases in response to the mass loading in range of 20-500 nM. The sensor modified with the streptavidin exhibits a high sensitivity of 4642.6 Hz/nM and a good selectivity. PMID:27624339

  6. Acoustical “transparency” induced by local resonance in Bragg bandgaps

    SciTech Connect

    Yu, Gaokun; Wang, Xinlong

    2014-01-28

    We show that sound waves can resonantly transmit through Bragg bandgaps in an acoustical duct periodically attached with an array of Helmholtz resonators, forming within the normally forbidden band a transparency window with group velocity smaller than the normal speed of sound. The transparency occurs for the locally resonant frequency so much close to the Bragg one that both the local-resonance-induced bandgap and the Bragg one heavily overlap with each other. The phenomenon seems an acoustical analog of the well-known electromagnetically induced transparency by quantum interference. Different from the Fano-like interference explanation, we also provide a mechanism for the transparency window phenomenon which makes it possible to extend the phenomenon in general.

  7. Cryogenic acoustic loss of pure and alloyed titanium

    NASA Astrophysics Data System (ADS)

    Matacz, A. L.; Veitch, P. J.; Blair, D. G.

    Low acoustic loss, high yield strength cryogenic materials are required for various high precision experiments, resonant-bar gravitational radiation antennae in particular. We report here acoustic loss measurements of commerically pure and alloyed titanium samples between 4.2 and 300 K. It is shown that machining damage of the surface significantly increased the acoustic loss of pure titanium, particularly below 100 K, and that the high strength alloy Ti-6AI-4V had significantly greater acoustic loss than pure titanium.

  8. Resonant-type MEMS transducers excited by two acoustic emission simulation techniques

    NASA Astrophysics Data System (ADS)

    Ozevin, Didem; Greve, David W.; Oppenheim, Irving J.; Pessiki, Stephen

    2004-07-01

    Acoustic emission testing is a passive nondestructive testing technique used to identify the onset and characteristics of damage through the detection and analysis of transient stress waves. Successful detection and implementation of acoustic emission requires good coupling, high transducer sensitivity and ability to discriminate noise from real signals. We report here detection of simulated acoustic emission signals using a MEMS chip fabricated in the multi-user polysilicon surface micromachining (MUMPs) process. The chip includes 18 different transducers with 10 different resonant frequencies in the range of 100 kHz to 1 MHz. It was excited by two different source simulation techniques; pencil lead break and impact loading. The former simulation was accomplished by breaking 0.5 mm lead on the ceramic package. Four transducer outputs were collected simultaneously using a multi-channel oscilloscope. The impact loading was repeated for five different diameter ball bearings. Traditional acoustic emission waveform analysis methods were applied to both data sets to illustrate the identification of different source mechanisms. In addition, a sliding window Fourier transform was performed to differentiate frequencies in time-frequency-amplitude domain. The arrival and energy contents of each resonant frequency were investigated in time-magnitude plots. The advantages of the simultaneous excitation of resonant transducers on one chip are discussed and compared with broadband acoustic emission transducers.

  9. Self-heating study of bulk acoustic wave resonators under high RF power.

    PubMed

    Ivira, Brice; Fillit, René-Yves; Ndagijimana, Fabien; Benech, Philippe; Parat, Guy; Ancey, Pascal

    2008-01-01

    The present work first provides an experimental technique to study self-heating of bulk acoustic wave (BAW) resonators under high RF power in the gigahertz range. This study is specially focused on film bulk acoustic wave resonators and solidly mounted resonators processed onto silicon wafers and designed for wireless systems. Precisely, the reflection coefficient of a one-port device is measured while up to several watts are applied and power leads to electrical drifts of impedances. In the following, we describe how absorbed power can be determined from the incident one in real time. Therefore, an infrared camera held over the radio frequency micro electromechanical system (RF-MEMS) surface with an exceptional spatial resolution reaching up to 2 microm/pixels gives accurate temperature mapping of resonators after emissivity correction. From theoretical point of view, accurate three-dimensional (3-D) structures for finite-element modeling analyses are carried out to know the best materials and architectures to use for enhancing power handling. In both experimental and theoretical investigations, comparison is made between film bulk acoustic wave resonators and solidly mounted resonators. Thus, the trend in term of material, architecture, and size of device for power application such as in transmission path of a transceiver is clearly identified. PMID:18334320

  10. Tunneling effects in resonant acoustic scattering of an air bubble in unbounded water.

    PubMed

    Simão, André G; Guimarães, Luiz G

    2016-01-01

    The problem of acoustic scattering of a gaseous spherical bubble immersed within unbounded liquid surrounding is considered in this work. The theory of partial wave expansion related to this problem is revisited. A physical model based on the analogy between acoustic scattering and potential scattering in quantum mechanics is proposed to describe and interpret the acoustical natural oscillation modes of the bubble, namely, the resonances. In this context, a physical model is devised in order to describe the air water interface and the implications of the high density contrast on the various regimes of the scattering resonances. The main results are presented in terms of resonance lifetime periods and quality factors. The explicit numerical calculations are undertaken through an asymptotic analysis considering typical bubble dimensions and underwater sound wavelengths. It is shown that the resonance periods are scaled according to the Minnaert's period, which is the short lived resonance mode, called breathing mode of the bubble. As expected, resonances with longer lifetimes lead to impressive cavity quality Q-factor ranging from 1010 to 105. The present theoretical findings lead to a better understanding of the energy storage mechanism in a bubbly medium. PMID:27331803

  11. Mode-locking of acoustic resonators and its application to vibration cancellation in acoustic heat engines

    SciTech Connect

    Spoor, P.S.; Swift, G.W. )

    1999-09-01

    Vibration induced in engine hardware by a working fluid can be very significant in high-power, high-amplitude acoustic heat engines, and is a serious impediment to their practical use. This vibration can cause fatigue and destruction of engine components as well as fuel lines, cooling lines, and sensor wires. The forces involved make anchoring such an engine to an [open quotes]immovable[close quotes] object impractical. Rigidly attaching two such engines together, and acoustically coupling them with a duct of such a length and diameter that the two engines mode-lock in antiphase (thus canceling the longitudinal vibration) appears to be an inexpensive, viable solution. This paper describes in detail experiments demonstrating the feasibility of this idea, and the underlying theory. [copyright] [ital 1999 Acoustical Society of America.] < --[HEB] -->

  12. Subterahertz acoustical pumping of electronic charge in a resonant tunneling device.

    PubMed

    Young, E S K; Akimov, A V; Henini, M; Eaves, L; Kent, A J

    2012-06-01

    We demonstrate that controlled subnanosecond bursts of electronic charge can be transferred through a resonant tunneling diode by successive picosecond acoustic pulses. The effect exploits the nonlinear current-voltage characteristics of the device and its asymmetric response to the compressive and tensile components of the strain pulse. This acoustoelectronic pump opens new possibilities for the control of quantum phenomena in nanostructures. PMID:23003634

  13. Improvements to the methods used to measure bubble attenuation using an underwater acoustical resonator.

    PubMed

    Czerski, Helen; Vagle, Svein; Farmer, David M; Hall-Patch, Nick

    2011-11-01

    Active acoustic techniques are commonly used to measure oceanic bubble size distributions, by inverting the bulk acoustical properties of the water (usually the attenuation) to infer the bubble population. Acoustical resonators have previously been used to determine attenuation over a wide range of frequencies (10-200 kHz) in a single measurement, corresponding to the simultaneous measurement of a wide range of bubble sizes (20-300 μm radii). However, there is now also considerable interest in acquiring measurements of bubbles with radii smaller than 16 μm, since these are thought to be important for ocean optics and as tracers for near-surface flow. To extend the bubble population measurement to smaller radii, it is necessary to extend the attenuation measurements to higher frequencies. Although the principles of resonator operation do not change as the frequency increases, the assumptions previously made during the spectral analysis may no longer be valid. In order to improve the methods used to calculate attenuation from acoustical resonator outputs, a more complete analysis of the resonator operation is presented here than has been published previously. This approach allows for robust attenuation measurements over a much wider frequency range and enables accurate measurements from lower-quality spectral peaks. PMID:22088016

  14. Acoustic resonance determination of the effect of light hydrocarbons on wax appearance points in a Njord well fluid

    SciTech Connect

    Colgate, S.O.; Sivaraman, A.

    1996-01-01

    Wax formation and deposition in pipelines and process equipment pose severe problems for petroleum companies, especially during transportation of crude oil in offshore environments. The light hydrocarbons present in the crude oil can play an important role in the shift of wax appearance points by increasing the solubilities of the heavier components. The following work was undertaken to study the effect of light hydrocarbons on wax appearance points in a Njord well fluid for Norsk Hydro, Norway. An automated high-pressure spherical acoustic resonator (50.8-mm-diameter) assembly designed and fabricated for that purpose has been used to measure resonance frequencies in a Njord well fluid (stabilized oil sample) provided by Norsk Hydro and blended with the appropriate amount of a synthetically prepared gaseous mixture containing six light hydrocarbons (Cl to C6), at pressures from 2 to 107 bar and temperatures in the range 35 to 50{degrees}C. Results on the present method to locate the wax appearance points in the Njord well fluid are presented. A figure showing experimental wax appearance points as a function of pressure is presented. The results are compared with those predicted by the Norsk Hydro model.

  15. Full-Field Imaging of GHz Film Bulk Acoustic Resonator Motion

    SciTech Connect

    Telschow, Kenneth Louis; Deason, Vance Albert; Cottle, David Lynn; Larson III, J. D.

    2003-10-01

    A full-field view laser ultrasonic imaging method has been developed that measures acoustic motion at a surface without scanning. Images are recorded at normal video frame rates by using dynamic holography with photorefractive interferometric detection. By extending the approach to ultra high frequencies, an acoustic microscope has been developed that is capable of operation at gigahertz frequency and micron length scales. Both acoustic amplitude and phase are recorded, allowing full calibration and determination of phases to within a single arbitrary constant. Results are presented of measurements at frequencies of 800-900 MHz, illustrating a multitude of normal mode behavior in electrically driven thin film acoustic resonators. Coupled with microwave electrical impedance measurements, this imaging mode provides an exceptionally fast method for evaluation of electric-to-acoustic coupling of these devices and their performance. Images of 256 /spl times/ 240 pixels are recorded at 18 fps rates synchronized to obtain both in-phase and quadrature detection of the acoustic motion. Simple averaging provides sensitivity to the subnanometer level at each pixel calibrated over the image using interferometry. Identification of specific acoustic modes and their relationship to electrical impedance characteristics show the advantages and overall high speed of the technique.

  16. Resonant coupling of ionization waves and acoustic gravity waves in the presence of a magnetic field

    NASA Technical Reports Server (NTRS)

    Eun, H.; Gross, S. H.

    1976-01-01

    The nature of the two resonant directions that occur for a single frequency in the presence of a magnetic field is demonstrated, along with the manner in which the resonances change with the dip angle and the angle of propagation from the meridian plane. The conditions under which acoustic branch resonances may occur are outlined. It is found that the calculated frequencies and directions for resonance are in the range of observed values for TID's obtained from ground and satellite measurements. This result is indicative of a possible connection between TID's and the resonance phenomenon. It is shown that a strong resonance type of response may be possible in the F region at a particular frequency from a region that can be as great as 100 km in altitude.

  17. On the contribution of circumferential resonance modes in acoustic radiation force experienced by cylindrical shells

    NASA Astrophysics Data System (ADS)

    Rajabi, Majid; Behzad, Mehdi

    2014-10-01

    A body insonified by a constant (time-varying) intensity sound field is known to experience a steady (oscillatory) force that is called the steady-state (dynamic) acoustic radiation force. Using the classical resonance scattering theorem (RST) which suggests the scattered field as a superposition of a resonance field and a background (non-resonance) component, we show that the radiation force acting on a cylindrical shell may be synthesized as a composition of three components: background part, resonance part and their interaction. The background component reveals the pure geometrical reflection effects and illustrates a regular behavior with respect to frequency, while the others demonstrate a singular behavior near the resonance frequencies. The results illustrate that the resonance effects associated to partial waves can be isolated by the subtraction of the background component from the total (steady-state or dynamic) radiation force function (i.e., residue component). In the case of steady-state radiation force, the components are exerted on the body as static forces. For the case of oscillatory amplitude excitation, the components are exerted at the modulation frequency with frequency-dependant phase shifts. The results demonstrate the dominant contribution of the non-resonance component of dynamic radiation force at high frequencies with respect to the residue component, which offers the potential application of ultrasound stimulated vibro-acoustic spectroscopy technique in low frequency resonance spectroscopy purposes. Furthermore, the proposed formulation may be useful essentially due to its intrinsic value in physical acoustics. In addition, it may unveil the contribution of resonance modes in the dynamic radiation force experienced by the cylindrical objects and its underlying physics.

  18. Note: A frequency modulated wireless interrogation system exploiting narrowband acoustic resonator for remote physical quantity measurement

    NASA Astrophysics Data System (ADS)

    Droit, C.; Martin, G.; Ballandras, S.; Friedt, J.-M.

    2010-05-01

    We demonstrate the wireless conversion of frequency modulation to amplitude modulation by radio frequency resonators as means of accurately determining the resonance frequency of passive acoustoelectronic sensors. The emitted frequency modulated radio frequency pulses are generated by a pulsed radar for probing a surface acoustic wave based sensor. The sharp sign transition of the amplitude modulated received signal provides a signal on which a feedback loop is locked to monitor the resonance signal. The strategy is demonstrated using a full software implementation on a generic hardware, resulting in 2 Hz resolution at 1 s integration time limited by the proportional feedback loop.

  19. NGC 3124: A Resonance Ring Disk Galaxy with a Skewed Bar

    NASA Astrophysics Data System (ADS)

    Treuthardt, P.; Seigar, M. S.; Salo, H.; Kennefick, D.; Kennefick, J.; Lacy, C. H. S.

    2014-03-01

    NGC 3124 is a highly regular SB(r)bc galaxy harboring a skewed bar that appears to be a very open spiral, counter-winding relative to the outer spiral arms. We investigate whether such bar morphology can be due to secular processes or if a more violent interaction is necessary. We find that the dust morphology observed in the bar region has the same sense of winding as the outer spiral arms. We also find that the gas kinematics are consistent across the galaxy. Finally, we attempt to recreate the observed stellar morphology by simulating the behavior of a large number of stellar test particles in a rigidly rotating gravitational potential. We are able to reproduce the skewed stellar bar but find that it is transient in nature. This evidence is a strong indication that secular processes are responsible for this unusual bar morphology.

  20. Phonon-Electron Interactions in Piezoelectric Semiconductor Bulk Acoustic Wave Resonators

    PubMed Central

    Gokhale, Vikrant J.; Rais-Zadeh, Mina

    2014-01-01

    This work presents the first comprehensive investigation of phonon-electron interactions in bulk acoustic standing wave (BAW) resonators made from piezoelectric semiconductor (PS) materials. We show that these interactions constitute a significant energy loss mechanism and can set practical loss limits lower than anharmonic phonon scattering limits or thermoelastic damping limits. Secondly, we theoretically and experimentally demonstrate that phonon-electron interactions, under appropriate conditions, can result in a significant acoustic gain manifested as an improved quality factor (Q). Measurements on GaN resonators are consistent with the presented interaction model and demonstrate up to 35% dynamic improvement in Q. The strong dependencies of electron-mediated acoustic loss/gain on resonance frequency and material properties are investigated. Piezoelectric semiconductors are an extremely important class of electromechanical materials, and this work provides crucial insights for material choice, material properties, and device design to achieve low-loss PS-BAW resonators along with the unprecedented ability to dynamically tune resonator Q. PMID:25001100

  1. All-fiber photoacoustic gas sensor with graphene nano-mechanical resonator as the acoustic detector

    NASA Astrophysics Data System (ADS)

    Yanzhen, Tan; Fan, Yang; Jun, Ma; Hoi Lut, Ho; Wei, Jin

    2015-09-01

    We demonstrate an all-optical-fiber photoacoustic (PA) spectrometric gas sensor with a graphene nano-mechanical resonator as the acoustic detector. The acoustic detection is performed by a miniature ferrule-top nano-mechanical resonator with a ˜100-nm-thick, 2.5-mm-diameter multilayer graphene diaphragm. Experimental investigation showed that the performance of the PA gas sensor can be significantly enhanced by operating at the resonance of the grapheme diaphragm where a lower detection limit of 153 parts-per-billion (ppb) acetylene is achieved. The all-fiber PA sensor which is immune to electromagnetic interference and safe in explosive environments is ideally suited for real-world remote, space-limited applications and for multipoint detection in a multiplexed fiber optic sensor network.

  2. Nondestructive evaluation of explosively welded clad rods by resonance acoustic spectroscopy.

    PubMed

    Fan, Y; Tysoe, B; Sim, J; Mirkhani, K; Sinclair, A N; Honarvar, F; Sildva, Harry; Szecket, Alexander; Hardwick, Roy

    2003-07-01

    A resonance acoustic spectroscopy technique is assessed for nondestructive evaluation of explosively welded clad rods. Each rod is modeled as a two-layered cylinder with a spring-mass system to represent a thin interfacial layer containing the weld. A range of interfacial profiles is generated in a set of experimental samples by varying the speed of the explosion that drives the copper cladding into the aluminum core. Excellent agreement is achieved between measured and calculated values of the resonant frequencies of the system, through appropriate adjustment of the interfacial mass and spring constants used in the wave scattering calculations. Destructive analysis of the interface in the experimental specimens confirms that key features of the interfacial profile may be inferred from resonance acoustic spectroscopy analysis applied to ultrasonic measurements. PMID:12788219

  3. Film bulk acoustic resonators integrated on arbitrary substrates using a polymer support layer

    NASA Astrophysics Data System (ADS)

    Chen, Guohao; Zhao, Xinru; Wang, Xiaozhi; Jin, Hao; Li, Shijian; Dong, Shurong; Flewitt, A. J.; Milne, W. I.; Luo, J. K.

    2015-03-01

    The film bulk acoustic resonator (FBAR) is a widely-used MEMS device which can be used as a filter, or as a gravimetric sensor for biochemical or physical sensing. Current device architectures require the use of an acoustic mirror or a freestanding membrane and are fabricated as discrete components. A new architecture is demonstrated which permits fabrication and integration of FBARs on arbitrary substrates. Wave confinement is achieved by fabricating the resonator on a polyimide support layer. Results show when the polymer thickness is greater than a critical value, d, the FBARs have similar performance to devices using alternative architectures. For ZnO FBARs operating at 1.3-2.2 GHz, d is ~9 μm, and the devices have a Q-factor of 470, comparable to 493 for the membrane architecture devices. The polymer support makes the resonators insensitive to the underlying substrate. Yields over 95% have been achieved on roughened silicon, copper and glass.

  4. Effects of Acoustic and Fluid Dynamic Interactions in Resonators: Applications in Thermoacoustic Refrigeration

    NASA Astrophysics Data System (ADS)

    Antao, Dion Savio

    Thermoacoustic refrigeration systems have gained increased importance in cryogenic cooling technologies and improvements are needed to increase the efficiency and effectiveness of the current cryogenic refrigeration devices. These improvements in performance require a re-examination of the fundamental acoustic and fluid dynamic interactions in the acoustic resonators that comprise a thermoacoustic refrigerator. A comprehensive research program of the pulse tube thermoacoustic refrigerator (PTR) and arbitrarily shaped, circular cross-section acoustic resonators was undertaken to develop robust computational models to design and predict the transport processes in these systems. This effort was divided into three main focus areas: (a) studying the acoustic and fluid dynamic interactions in consonant and dissonant acoustic resonators, (b) experimentally investigating thermoacoustic refrigeration systems attaining cryogenic levels and (c) computationally studying the transport processes and energy conversion through fluid-solid interactions in thermoacoustic pulse tube refrigeration devices. To investigate acoustic-fluid dynamic interactions in resonators, a high fidelity computational fluid dynamic model was developed and used to simulate the flow, pressure and temperature fields generated in consonant cylindrical and dissonant conical resonators. Excitation of the acoustic resonators produced high-amplitude standing waves in the conical resonator. The generated peak acoustic overpressures exceeded the initial undisturbed pressure by two to three times. The harmonic response in the conical resonator system was observed to be dependent on the piston amplitude. The resultant strong acoustic streaming structures in the cone resonator highlighted its potential over a cylindrical resonator as an efficient mixer. Two pulse tube cryogenic refrigeration (PTR) devices driven by a linear motor (a pressure wave generator) were designed, fabricated and tested. The characterization

  5. Sound Transmission Loss Through a Corrugated-Core Sandwich Panel with Integrated Acoustic Resonators

    NASA Technical Reports Server (NTRS)

    Schiller, Noah H.; Allen, Albert R.; Zalewski, Bart F; Beck, Benjamin S.

    2014-01-01

    The goal of this study is to better understand the effect of structurally integrated resonators on the transmission loss of a sandwich panel. The sandwich panel has facesheets over a corrugated core, which creates long aligned chambers that run parallel to the facesheets. When ports are introduced through the facesheet, the long chambers within the core can be used as low-frequency acoustic resonators. By integrating the resonators within the structure they contribute to the static load bearing capability of the panel while also attenuating noise. An analytical model of a panel with embedded resonators is derived and compared with numerical simulations. Predictions show that acoustic resonators can significantly improve the transmission loss of the sandwich panel around the natural frequency of the resonators. In one configuration with 0.813 m long internal chambers, the diffuse field transmission loss is improved by more than 22 dB around 104 Hz. The benefit is achieved with no added mass or volume relative to the baseline structure. The embedded resonators are effective because they radiate sound out-of-phase with the structure. This results in destructive interference, which leads to less transmitted sound power.

  6. Electro-thermo-mechanical model for bulk acoustic wave resonators.

    PubMed

    Rocas, Eduard; Collado, Carlos; Mateu, Jordi; Orloff, Nathan D; Aigner, Robert; Booth, James C

    2013-11-01

    We present the electro-thermo-mechanical constitutive relations, expanded up to the third order, for a BAW resonator. The relations obtained are implemented into a circuit model, which is validated with extensive linear and nonlinear measurements. The mathematical analysis, along with the modeling, allows us to identify the dominant terms, which are the material temperature derivatives and two intrinsic nonlinear terms, and explain, for the first time, all observable effects in a BAW resonator by use of a unified physical description. Moreover, the terms that are responsible for the second-harmonic generation and the frequency shift with dc voltage are shown to be the same. PMID:24158294

  7. Flow-excited acoustic resonances of coaxial side-branches in an annular duct

    NASA Astrophysics Data System (ADS)

    Arthurs, D.; Ziada, S.

    2009-01-01

    This paper investigates the aeroacoustic response of an annular duct with closed coaxial side-branches, and examines the effect of several passive countermeasures on the resonance intensity. The investigated geometry is inspired by the design of the Roll-Posts in the Rolls-Royce LiftSystem® engine, which is currently being developed for the Lockheed Martin Joint Strike Fighter (JSF®) aircraft. The effects of design parameters, such as diameter ratio, branch length ratio and thickness of the annular flow on the frequency and resonance intensity of the first acoustic mode are studied experimentally. Numerical simulations of the acoustic mode shapes and frequencies are also performed. The annular flow has been found to excite several acoustic modes, the strongest in all cases being the first acoustic mode, which consists of a quarter wavelength along the length of each branch. The ratios of the branch length and diameter, with respect to the main duct diameter, have been found to have strong effects on the frequency of the acoustic modes.

  8. Acoustic Eigenvalues of a Quasispherical Resonator: Second Order Shape Perturbation Theory for Arbitrary Modes

    PubMed Central

    Mehl, James B.

    2007-01-01

    The boundary-shape formalism of Morse and Ingard is applied to the acoustic modes of a deformed spherical resonator (quasisphere) with rigid boundaries. For boundary shapes described by r = a [1 − ε ℱ(θ, ϕ)], where ε is a small scale parameter and ℱ is a function of order unity, the frequency perturbation is calculated to order ε2. The formal results apply to acoustic modes whose angular dependence is designated by the indices ℓ and m. Specific examples are worked out for the radial (ℓ = 0) and triplet (ℓ = 1) modes, for prolate and oblate spheroids, and for triaxial ellipsoids. The exact eigenvalues for the spheroids, and eigenvalue determined with finite-element calculations, are shown to agree with perturbation theory through terms of order ε2. This work is an extension of the author’s previous papers on the acoustic eigenfrequencies of deformed spherical resonators, which were limited to the second-order perturbation for radial modes [J. Acoust. Soc. Am. 71, 1109-1113 (1982)] and the first order-perturbation for arbitrary modes [J. Acoust. Soc. Am. 79, 278–285 (1986)]. PMID:27110463

  9. Acoustic Seal

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M. (Inventor)

    2006-01-01

    The invention relates to a sealing device having an acoustic resonator. The acoustic resonator is adapted to create acoustic waveforms to generate a sealing pressure barrier blocking fluid flow from a high pressure area to a lower pressure area. The sealing device permits noncontacting sealing operation. The sealing device may include a resonant-macrosonic-synthesis (RMS) resonator.

  10. Acoustic seal

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M. (Inventor)

    2006-01-01

    The invention relates to a sealing device having an acoustic resonator. The acoustic resonator is adapted to create acoustic waveforms to generate a sealing pressure barrier blocking fluid flow from a high pressure area to a lower pressure area. The sealing device permits noncontacting sealing operation. The sealing device may include a resonant-macrosonic-synthesis (RMS) resonator.

  11. Low frequency acoustic energy harvesting using PZT piezoelectric plates in a straight tube resonator

    NASA Astrophysics Data System (ADS)

    Li, Bin; You, Jeong Ho; Kim, Yong-Joe

    2013-05-01

    A novel and practical acoustic energy harvesting mechanism to harvest traveling sound at low audible frequency is introduced and studied both experimentally and numerically. The acoustic energy harvester in this study contains a quarter-wavelength straight tube resonator with lead zirconate titanate (PZT) piezoelectric cantilever plates placed inside the tube. When the tube resonator is excited by an incident sound at its acoustic resonance frequency, the amplified acoustic pressure inside the tube drives the vibration motions of piezoelectric plates, resulting in the generation of electricity. To increase the total voltage and power, multiple PZT plates were placed inside the tube. The number of PZT plates to maximize the voltage and power is limited due to the interruption of air particle motion by the plates. It has been found to be more beneficial to place the piezoelectric plates in the first half of the tube rather than along the entire tube. With an incident sound pressure level of 100 dB, an output voltage of 5.089 V was measured. The output voltage increases linearly with the incident sound pressure. With an incident sound pressure of 110 dB, an output voltage of 15.689 V and a power of 12.697 mW were obtained. The corresponding areal and volume power densities are 0.635 mW cm-2 and 15.115 μW cm-3, respectively.

  12. Particle acoustic detection in gravitational wave aluminum resonant antennas

    NASA Astrophysics Data System (ADS)

    Buonomo, B.; Coccia, E.; D'Antonio, S.; Monache, G. Delle; Gioacchino, D. Di; Fafone, V.; Ligi, C.; Marini, A.; Mazzitelli, G.; Modestino, G.; Panella, S.; Pizzella, G.; Quintieri, L.; Roccella, S.; Ronga, F.; Tripodi, P.; Valente, P.

    2005-09-01

    The results on cosmic rays detected by the gravitational antenna NAUTILUS have motivated an experiment (RAP) based on a suspended cylindrical bar, which is made of the same aluminum alloy as NAUTILUS and is exposed to a high energy electron beam. Mechanical vibrations originate from the local thermal expansion caused by warming up due to the energy lost by particles crossing the material. The aim of the experiment is to measure the amplitude of the fundamental longitudinal vibration at different temperatures. We report on the results obtained down to a temperature of about 4 K, which agree at the level of ˜10% with the predictions of the model describing the underlying physical process.

  13. Numerical and experimental investigation of a low-frequency measurement technique: differential acoustic resonance spectroscopy

    NASA Astrophysics Data System (ADS)

    Yin, Hanjun; Zhao, Jianguo; Tang, Genyang; Ma, Xiaoyi; Wang, Shangxu

    2016-06-01

    Differential acoustic resonance spectroscopy (DARS) has been developed to determine the elastic properties of saturated rocks within the kHz frequency range. This laboratory technique is based on considerations from perturbation theory, wherein the resonance frequencies of the resonant cavity with and without a perturbation sample are used to estimate the acoustic properties of the test sample. In order to better understand the operating mechanism of DARS and therefore optimize the procedure, it is important to develop an accurate and efficient numerical model. Accordingly, this study presents a new multiphysics model by coupling together considerations from acoustics, solid mechanics, and electrostatics. The numerical results reveal that the newly developed model can successfully simulate the acoustic pressure field at different resonance modes, and that it can accurately reflect the measurement process. Based on the understanding of the DARS system afforded by the numerical simulation, we refine the system configuration by utilizing cavities of different lengths and appropriate radii to broaden the frequency bandwidth and ensure testing accuracy. Four synthetic samples are measured to test the performance of the optimized DARS system, in conjunction with ultrasonic and static measurements. For nonporous samples, the estimated bulk moduli are shown to be independent of the different measurement methods (i.e. DARS or ultrasonic techniques). In contrast, for sealed porous samples, the differences in bulk moduli between the low- and high-frequency techniques can be clearly observed; this discrepancy is attributed to frequency dispersion. In summary, the optimized DARS system with an extended frequency range of 500–2000 Hz demonstrates considerable utility in investigating the frequency dependence of the acoustic properties of reservoir rocks.

  14. A Methodology to Integrate Magnetic Resonance and Acoustic Measurements for Reservoir Characterization

    SciTech Connect

    Parra, J.O.

    2001-01-26

    The objective of this project was to develop an advanced imaging method, including pore scale imaging, to integrate magnetic resonance (MR) techniques and acoustic measurements to improve predictability of the pay zone in two hydrocarbon reservoirs. This was accomplished by extracting the fluid property parameters using MR laboratory measurements and the elastic parameters of the rock matrix from acoustic measurements to create poroelastic models of different parts of the reservoir. Laboratory measurements were compared with petrographic analysis results to determine the relative roles of petrographic elements such as porosity type, mineralogy, texture, and distribution of clay and cement in creating permeability heterogeneity.

  15. A Methodology to Integrate Magnetic Resonance and Acoustic Measurements for Reservoir Characterization

    SciTech Connect

    Parra, Ph.D., Jorge O.

    2002-06-10

    The objective of the project was to develop an advanced imaging method, including pore scale imaging, to integrate nuclear magnetic resonance (NMR) techniques and acoustic measurements to improve predictability of the pay zone in hydrocarbon reservoirs. This will be accomplished by extracting the fluid property parameters using NMR laboratory measurements and the elastic parameters of the rock matrix from acoustic measurements to create poroelastic models of different parts of the reservoir. Laboratory measurement techniques and core imaging were linked with a balanced petrographical analysis of cores and theoretical modeling.

  16. Stratospheric Observatory for Infrared Astronomy (SOFIA) Acoustical Resonance Technical Assessment Report

    NASA Technical Reports Server (NTRS)

    Gilbert, Michael G.; Kehoe, Michael W.; Gupta, Kajal K.; Kegerise, Michael A.; Ginsberg, Jerry H.; Kolar, Ramesh

    2009-01-01

    A request was submitted on September 2, 2004 concerning the uncertainties regarding the acoustic environment within the Stratospheric Observatory for Infrared Astronomy (SOFIA) cavity, and the potential for structural damage from acoustical resonance or tones, especially if they occur at or near a structural mode. The requestor asked for an independent expert opinion on the approach taken by the SOFIA project to determine if the project's analysis, structural design and proposed approach to flight test were sound and conservative. The findings from this assessment are recorded in this document.

  17. Confinement and transverse standing acoustic resonances in free-standing membranes

    NASA Astrophysics Data System (ADS)

    Zhang, X.; Sooryakumar, R.; Bussmann, K.

    2003-09-01

    Brillouin light scattering (BLS) reveal standing wave acoustic resonances in unsupported 100 and 200 nm thick, SiN membranes. In contrast to supported thin films where discrete high frequency (GHz) longitudinal standing wave excitations were recently reported, transverse standing resonances are observed by light scattering in an unsupported laminar structure. Due to the boundary conditions imposed by the free upper and lower surfaces, the standing wave resonances are quantized in frequency. The resonances provide for a direct, nondestructive, measure of all principal elastic constants (C11,C44) that completely characterize the mechanical properties of the membrane. In addition, the two lowest order Lamb waves (dilational and flexural modes) of the membrane are observed. The results are compared to BLS performed on nitride films atop a Si underlayer when it is found that all standing resonances transform to leaky modes leading to featureless light scattering spectra.

  18. Linear and Nonlinear Acoustic Measurements of Buried Landmines: Detection Schemes Near Resonance

    NASA Astrophysics Data System (ADS)

    Sabatier, James M.

    2003-03-01

    Measurements of the acoustic impedance of an anti-personnel and anti-tank plastic, blast-hardened landmines reveal resonances in the frequency range between 100 and 1000 Hz. The top surface resonances are due to its complicated mechanical structure vibrating in air. The lowest mode results from the blast hardened design of the landmine. Typically, a portion or cavity of the landmine is designed to absorb the shock from an explosion that is intended to detonate the landmine but still allow the landmine to trigger its explosive device when a slow steady pressure is applied. The mechanical design of the blast hardened aspects results in a high Q simple harmonic oscillator resonance of the top surface. At higher frequencies the top surface behaves like thin circular plate acoustic modes. When these landmines are buried in soils, the modes are mass loaded. Resonances from measurements of the normal component of the acoustically induced soil surface particle velocity are used for detection schemes. Since the interface between the top plate and the soil responds to pressure fluctuations nonlinearly, characteristics of landmines, the soil, and the interface are rich in nonlinear physics and allow for new methods of landmine detection not previously exploited.

  19. Nonlinear acoustic resonances to probe a threaded interface

    NASA Astrophysics Data System (ADS)

    Rivière, Jacques; Renaud, Guillaume; Haupert, Sylvain; Talmant, Maryline; Laugier, Pascal; Johnson, Paul A.

    2010-06-01

    We evaluate the sensitivity of multimodal nonlinear resonance spectroscopy to torque changes in a threaded interface. Our system is comprised of a bolt progressively tightened in an aluminum plate. Different modes of the system are studied in the range 1-25 kHz, which correspond primarily to bending modes of the plate. Nonlinear parameters expressing the importance of resonance frequency and damping variations are extracted and compared to linear ones. The influence of each mode shape on the sensitivity of nonlinear parameters is discussed. Results suggest that a multimodal measurement is an appropriate and sensitive method for monitoring bolt tightening. Further, we show that the nonlinear components provide new information regarding the interface, which can be linked to different friction theories. This work has import to study of friction and to nondestructive evaluation of interfaces for widespread application and basic research.

  20. Cylindrical Acoustic Resonator for the Re-determination of the Boltzmann Constant

    NASA Astrophysics Data System (ADS)

    Zhang, J. T.; Lin, H.; Sun, J. P.; Feng, X. J.; Gillis, K. A.; Moldover, M. R.

    2010-07-01

    The progress towards re-determining the Boltzmann constant k B using two fixed-path, gas-filled, cylindrical, acoustic cavity resonators is described. The difference in the lengths of the cavities is measured using optical interferometry. Thus, a literature value for the density of mercury is not used, in contrast with the presently accepted determination of k B. The longitudinal acoustic resonance modes of a cylindrical cavity have lower quality factors Q than the radial modes of gas-filled, spherical cavities, of equal volume. The lower Qs result in lower signal-to-noise ratios and wider, asymmetric resonances. To improve signal-to-noise ratios, conventional capacitance microphones were replaced with 6.3 mm diameter piezoelectric transducers (PZTs) installed on the outer surfaces of each resonator and coupled to the cavity by diaphragms. This arrangement preserved the shape of the cylindrical cavity, prevented contamination of the gas inside the cavity, and enabled us to measure the longitudinal resonance frequencies with a relative standard uncertainty of 0.2 × 10-6. The lengths of the cavities and the modes studied will be chosen to reduce the acoustic perturbations due to non-zero boundary admittances at the endplates, e.g., from endplate bending and ducts and/or transducers installed in the endplates. Alternatively, the acoustic perturbations generated by the viscous and thermal boundary layers at the gas-solid boundary can be reduced. Using the techniques outlined here, k B can be re-determined with an estimated relative standard uncertainty of 1.5 × 10-6.

  1. Resonant excitation of intense acoustic waves in crystals

    SciTech Connect

    Alshits, V. I. Bessonov, D. A.; Lyubimov, V. N.

    2013-06-15

    The resonant excitation of an intense elastic wave through nonspecular reflection of a special pump wave in a crystal is described. The choice of the plane and angle of incidence is dictated by the requirement that the excited reflected wave be close to the bulk eigenmode with its energy flow along a free boundary. The resonance parameters have been found for a medium with an arbitrary anisotropy. General relations are concretized for monoclinic, rhombic, and hexagonal systems. A criterion is formulated for an optimal selection of crystals in which the resonant reflection is close to the conversion one, when almost all of the energy from the incident beam of the pump wave falls into the near-surface narrow high-intensity reflected beam. Estimates and illustrations are given for such crystals as an example. The intensity of the reflected beam increases with its narrowing, but its diffraction divergence also increases with this narrowing. Nevertheless, the intensity of the beam can be increased by a factor of 5-10 at sufficiently high frequencies while keeping its divergence at an acceptable level. Amplification by two orders of magnitude can be achieved by compressing the beam in two dimensions through its double reflection.

  2. Visualization of subsurface nanoparticles in a polymer matrix using resonance tracking atomic force acoustic microscopy and contact resonance spectroscopy.

    PubMed

    Kimura, Kuniko; Kobayashi, Kei; Yao, Atsushi; Yamada, Hirofumi

    2016-10-14

    A visualization technique of subsurface features with a nanometer-scale spatial resolution is strongly demanded. Some research groups have demonstrated the visualization of subsurface features using various techniques based on atomic force microscopy. However, the imaging mechanisms have not yet been fully understood. In this study, we demonstrated the visualization of subsurface Au nanoparticles buried in a polymer matrix 900 nm from the surface using two techniques; i.e., resonance tracking atomic force acoustic microscopy and contact resonance spectroscopy. It was clarified that the subsurface features were visualized by the two techniques as the area with a higher contact resonance frequency and a higher Q-factor than those in the surrounding area, which suggests that the visualization is realized by the variation of the contact stiffness and damping of the polymer matrix due to the existence of the buried nanoparticles. PMID:27607548

  3. Noise control using a plate radiator and an acoustic resonator

    NASA Technical Reports Server (NTRS)

    Pla, Frederic G. (Inventor)

    1996-01-01

    An active noise control subassembly for reducing noise caused by a source (such as an aircraft engine) independent of the subassembly. A noise radiating panel is bendably vibratable to generate a panel noise canceling at least a portion of the source noise. A piezoceramic actuator plate is connected to the panel. A front plate is spaced apart from the panel and the first plate, is positioned generally between the source noise and the panel, and has a sound exit port. A first pair of spaced-apart side walls each generally abut the panel and the front plate so as to generally enclose a front cavity to define a resonator.

  4. Highly mass-sensitive thin film plate acoustic resonators (FPAR).

    PubMed

    Arapan, Lilia; Alexieva, Gergana; Avramov, Ivan D; Radeva, Ekaterina; Strashilov, Vesseline; Katardjiev, Ilia; Yantchev, Ventsislav

    2011-01-01

    The mass sensitivity of thin aluminum nitride (AlN) film S0 Lamb wave resonators is theoretically and experimentally studied. Theoretical predictions based on modal and finite elements method analysis are experimentally verified. Here, two-port 888 MHz synchronous FPARs are micromachined and subsequently coated with hexamethyl-disiloxane(HMDSO)-plasma-polymerized thin films of various thicknesses. Systematic data on frequency shift and insertion loss versus film thickness are presented. FPARs demonstrate high mass-loading sensitivity as well as good tolerance towards the HMDSO viscous losses. Initial measurements in gas phase environment are further presented. PMID:22163994

  5. Interaction of reed and acoustic resonator in clarinetlike systems.

    PubMed

    Silva, Fabrice; Kergomard, Jean; Vergez, Christophe; Gilbert, Joël

    2008-11-01

    Sound emergence in clarinetlike instruments is investigated in terms of instability of the static regime. Various models of reed-bore coupling are considered, from the pioneering work of Wilson and Beavers ["Operating modes of the clarinet," J. Acoust. Soc. Am. 56, 653-658 (1974)] to more recent modeling including viscothermal bore losses and vena contracta at the reed inlet. The pressure threshold above which these models may oscillate as well as the frequency of oscillation at threshold are calculated. In addition to Wilson and Beavers' previous conclusions concerning the role of the reed damping in the selection of the register the instrument will play on, the influence of the reed motion induced flow is also emphasized, particularly its effect on playing frequencies, contributing to reduce discrepancies between Wilson and Beavers' experimental results and theory, despite discrepancies still remain concerning the pressure threshold. Finally, analytical approximations of the oscillating solution based on Fourier series expansion are obtained in the vicinity of the threshold of oscillation. This allows to emphasize the conditions which determine the nature of the bifurcation (direct or inverse) through which the note may emerge, with therefore important consequences on the musical playing performances. PMID:19045811

  6. Dynamics of a Coagulating Polydisperse Gas Suspension in the Nonlinear Wave Field of an Acoustic Resonator

    NASA Astrophysics Data System (ADS)

    Tukmakov, A. L.

    2015-01-01

    A model of a multivelocity multitemperature polydisperse gas suspension has been constructed with account taken of coagulation. Calculations of the dynamics of an aerosol of a polydisperse composition in an acoustic resonator have been done and the derived regularities have been described. A system of Navier-Stokes equations for a compressible heat-conducting gas was used to describe the motion of a carrier medium. The dynamics of dispersed fractions is described by a system of equations including continuity, momentum, and internal-energy equations. The equations of motion of the carrier medium and dispersed fractions have been written with account of the interphase exchange of momentum and energy. The Lagrangian model has been used to describe the process of coagulation. The change in the dispersity of the gas suspension in the nonlinear field of an acoustic resonator has been analyzed.

  7. Electromagnetic Acoustic Resonance to Assess Creep Damage in Cr-Mo-V Steel

    NASA Astrophysics Data System (ADS)

    Ohtani, Toshihiro; Ogi, Hirotsugu; Hirao, Masahiko

    2006-05-01

    Electromagnetic acoustic resonance (EMAR) is a contactless resonance method using an electromagnetic acoustic transducer (EMAT). In this study, EMAR was applied to detect the creep damage process in Cr-Mo-V steel, which is an important structural material for thermal energy plants. The material was exposed to temperatures up to 923 K at various stresses. Two types of EMAT were used: bulk-wave EMAT for plate samples and axial-shear-wave EMAT for cylindrical samples. We measured ultrasonic attenuation in the frequency range between 1 and 7 MHz as creep progressed. Attenuation coefficient exhibits a much larger sensitivity to damage accumulation than velocity. It shows a maximum peak at approximately 30% and a minimum peak at 50% of the creep life, independent of the applied stress and the type of EMAT used. EMAR has the potential for assessing damage progress and for predicting the creep life of metals.

  8. Effect of flow on the acoustic resonances of an open-ended duct

    NASA Technical Reports Server (NTRS)

    Ingard, U.; Singhal, V. K.

    1975-01-01

    The effect of flow on the acoustic resonances of an open-ended, hard-walled duct is analyzed. The flow produces acoustic losses both in the interior of the duct and at the ends. Unless the duct is very long, typically 100 times the diameter, the losses at the ends dominate. At flow Mach numbers in excess of 0.4 the losses are so large that axial duct resonances are almost completely suppressed. The plane-wave Green's function for the duct with flow is expressed in terms of the (experimentally determined) pressure reflection coefficients at the ends of the duct, and the flow dependence of the complex eigenfrequencies of the duct is obtained. Some observations concerning the noise produced by the flow in the duct are also reported.

  9. Chirp resonance spectroscopy of single lipid-coated microbubbles using an "acoustical camera".

    PubMed

    Renaud, G; Bosch, J G; van der Steen, A F W; de Jong, N

    2012-12-01

    An acoustical method was developed to study the resonance of single lipid-coated microbubbles. The response of 127 SonoVue microbubbles to a swept sine excitation between 0.5 and 5.5 MHz with a peak acoustic pressure amplitude of 70 kPa was measured by means of a 25 MHz probing wave. The relative amplitude modulation in the signal scattered in response to the probing wave is approximately equal to the radial strain induced by the swept sine excitation. An average damping coefficient of 0.33 and an average resonance frequency of 2.5 MHz were measured. Microbubbles experienced an average peak radial strain of 20%. PMID:23231210

  10. Resonant transmission and mode modulation of acoustic waves in H-shaped metallic gratings

    SciTech Connect

    Deng, Yu-Qiang; Fan, Ren-Hao; Zhang, Kun; Peng, Ru-Wen E-mail: dongxiang87@gmail.com; Qi, Dong-Xiang E-mail: dongxiang87@gmail.com

    2015-04-15

    In this work, we demonstrate that resonant full transmission of acoustic waves exists in subwavelength H-shaped metallic gratings, and transmission peaks can be efficiently tuned by adjusting the grating geometry. We investigate this phenomenon through both numerical simulations and theoretical calculations based on rigorous-coupled wave analysis. The transmission peaks are originated from Fabry-Perot resonances together with the couplings between the diffractive wave on the surface and the multiple guided modes in the slits. Moreover, the transmission modes can be efficiently tuned by adjusting the cavity geometry, without changing the grating thickness. The mechanism is analyzed based on an equivalent circuit model and verified by both the theoretical calculations and the numerical simulations. This research has potential application in acoustic-device miniaturization over a wide range of wavelengths.

  11. Sub-optical wavelength acoustic wave modulation of integrated photonic resonators at microwave frequencies.

    PubMed

    Tadesse, Semere Ayalew; Li, Mo

    2014-01-01

    Light-sound interactions have long been exploited in various acousto-optic devices based on bulk crystalline materials. Conventionally, these devices operate in megahertz frequency range where the acoustic wavelength is much longer than the optical wavelength and a long interaction length is required to attain significant coupling. With nanoscale transducers, acoustic waves with sub-optical wavelengths can now be excited to induce strong acousto-optic coupling in nanophotonic devices. Here we demonstrate microwave frequency surface acoustic wave transducers co-integrated with nanophotonic resonators on piezoelectric aluminum nitride substrates. Acousto-optic modulation of the resonance modes at above 10 GHz with the acoustic wavelength significantly below the optical wavelength is achieved. The phase and modal matching conditions in this scheme are investigated for efficient modulation. The new acousto-optic platform can lead to novel optical devices based on nonlinear Brillouin processes and provides a direct, wideband link between optical and microwave photons for microwave photonics and quantum optomechanics. PMID:25400144

  12. Test of a virtual cylindrical acoustic resonator for determining the Boltzmann constant

    NASA Astrophysics Data System (ADS)

    Feng, X. J.; Lin, H.; Gillis, K. A.; Moldover, M. R.; Zhang, J. T.

    2015-10-01

    We report progress toward determining the Boltzmann constant kB using the concept of a virtual acoustic resonator, a hypothetical resonator that is mathematically equivalent to a cylindrical cavity with periodic boundary conditions. We derived the virtual resonator by combining the measured frequencies of the longitudinal acoustic modes of two argon-filled, cylindrical cavity resonators in such a way to minimize the effects of the cavities’ ends, including transducers and ducts attached to the ends. The cavities had lengths of 80 mm and 160 mm and were operated in their longitudinal (ℓ,0,0) modes. We explored virtual resonators that combine modes of the two resonators that have nearly the same frequencies. The virtual resonator formed from the (2,0,0) mode of the 80 mm resonator combined with the (4,0,0) mode of the 160 mm resonator yielded a value for kB that is, fractionally, only (0.2  ±  1.5)  ×  10-6 larger than the 2010 CODATA-recommended value of kB. (The estimated uncertainty is one standard uncertainty corresponding to a 68% confidence level.) The same virtual resonator yielded values of the pressure derivatives of the speed of sound c in argon, (∂c2/∂p)T and (∂c2/∂p2)T, that differed from literature values by 1% and 2%, respectively. By comparison, when each cavity was considered separately, the values of kB, (∂c2/∂p)T, and (∂c2/∂p2)T differed from literature values by up to 7 ppm, 10%, and 5%, respectively. However, combining the results from the (3,0,0) or (4,0,0) modes of shorter resonator with the results from the (6,0,0) or (8,0,0) modes of the longer resonator yielded incorrect values of kB that varied from run-to-run. We speculate that these puzzling results originated in an unmodeled coupling, either between the two cavities (that resonated at nearly identical resonance frequencies in the same pressure vessel) or between the cavities and modes of the pressure vessel.

  13. Using Combined X-ray Computed Tomography and Acoustic Resonance to Understand Supercritical CO2 Behavior in Fractured Sandstone

    NASA Astrophysics Data System (ADS)

    Kneafsey, T. J.; Nakagawa, S.

    2015-12-01

    Distribution of supercritical (sc) CO2 has a large impact on its flow behavior as well as on the properties of seismic waves used for monitoring. Simultaneous imaging of scCO2 distribution in a rock core using X-ray computed tomography (CT) and measurements of seismic waves in the laboratory can help understand how the distribution evolves as scCO2 invades through rock, and the resulting seismic signatures. To this end, we performed a series of laboratory scCO2 core-flood experiments in intact and fractured anisotropic Carbon Tan sandstone samples. In these experiments, we monitored changes in the CO2 saturation distribution and sonic-frequency acoustic resonances (yielding both seismic velocity and attenuation) over the course of the floods. A short-core resonant bar test system (Split-Hopkinson Resonant Bar Apparatus) custom fit into a long X-ray transparent pressure vessel was used for the seismic measurements, and a modified General Electric medical CT scanner was used to acquire X-ray CT data from which scCO2 saturation distributions were determined. The focus of the experiments was on the impact of single fractures on the scCO2 distribution and the seismic properties. For this reason, we examined several cases including 1. intact, 2. a closely mated fracture along the core axis, 3. a sheared fracture along the core axis (both vertical and horizontal for examining the buoyancy effect), and 4. a sheared fracture perpendicular to the core axis. For the intact and closely mated fractured cores, Young's modulus declined with increasing CO2 saturation, and attenuation increased up to about 15% CO2 saturation after which attenuation declined. For cores having wide axial fractures, the Young's modulus was lower than for the intact and closely mated cases, however did not change much with CO2 pore saturation. Much lower CO2 pore saturations were achieved in these cases. Attenuation increased more rapidly however than for the intact sample. For the core

  14. Acoustic resonance spectroscopy (ARS): ARS300 operations manual, software version 2.01

    SciTech Connect

    1996-07-25

    Acoustic Resonance Spectroscopy (ARS) is a nondestructive evaluation technology developed at the Los Alamos National Laboratory. The ARS technique is a fast, safe, and nonintrusive technique that is particularly useful when a large number of objects need to be tested. Any physical object, whether solid, hollow, or fluid filled, has many modes of vibration. These modes of vibration, commonly referred to as the natural resonant modes or resonant frequencies, are determined by the object`s shape, size, and physical properties, such as elastic moduli, speed of sound, and density. If the object is mechanically excited at frequencies corresponding to its characteristic natural vibrational modes, a resonance effect can be observed when small excitation energies produce large amplitude vibrations in the object. At other excitation frequencies, i.e., vibrational response of the object is minimal.

  15. Properties of ultrasonic acoustic resonances for exploitation in comb construction by social hornets and honeybees

    NASA Astrophysics Data System (ADS)

    Kadmon, Jonathan; Ishay, Jacob S.; Bergman, David J.

    2009-06-01

    Physical and mathematical considerations are presented in support of the suggestion that social hornets and bees, which construct brood combs with large arrays of cells in a honeycomb structure, exploit ultrasonic acoustic resonances in those cells in order to achieve the great accuracy of the hexagonal symmetry exhibited by these honeycomb-structured arrays. We present a numerical calculation of those resonances for the case of a perfect-hexagon duct utilizing a Bloch-Floquet-type theorem. We calculate the rate of energy dissipation in those resonances and use that, along with other considerations, to identify the resonance that is best suited for the suggested use by bees and hornets. Previously recorded ultrasonic data on social hornets and honeybees are cited which agree with some of our predictions and thus provide support for the above-mentioned suggestion.

  16. Vibration optimization of ZnO thin film bulk acoustic resonator with ring electrodes

    NASA Astrophysics Data System (ADS)

    Zhao, Zinan; Qian, Zhenghua; Wang, Bin

    2016-04-01

    A rectangular ZnO thin film bulk acoustic resonator with ring electrodes is presented in this paper to demonstrate the existence of a nearly uniform displacement distribution at the central part of this typical resonator. The variational formulation based on two-dimensional scalar differential equations provides a theoretical foundation for the Ritz method adopted in our analysis. The resonant frequencies and vibration distributions for the thickness-extensional modes of this ring electrode resonator are obtained. The structural parameters are optimized to achieve a more uniform displacement distribution and therefore a uniform mass sensitivity, which guarantee the high accuracy and repeatable measurement for sensor detection in an air or a liquid environment. These results provide a fundamental reference for the design and optimization of the high quality sensor.

  17. Profiles of Material Properties in Induction-Hardened Steel Determined through Inversion of Resonant Acoustic Measurements

    SciTech Connect

    Johnson, W.L.; Kim, S.A.; Norton, S.J.

    2005-04-09

    Electromagnetic-acoustic measurements of resonant frequencies of induction-hardened steel shafts were used in an inverse calculation to determine parameters of the radial variations in the shear constant and density, including the effects of material variations and residual stress. Parameters determined for the profile of the shear constant were consistent with independent measurements on cut specimens and estimates of the acoustoelastic contribution. The profiles determined for material variations were close to those of the measured hardness.

  18. Varying the agglomeration position of particles in a micro-channel using Acoustic Radiation Force beyond the resonance condition.

    PubMed

    Dron, Olivier; Aider, Jean-Luc

    2013-09-01

    It is well-known that particles can be focused at mid-height of a micro-channel using Acoustic Radiation Force (ARF) tuned at the resonance frequency (h=λ/2). The resonance condition is a strong limitation to the use of acoustophoresis (particles manipulation using acoustic force) in many applications. In this study we show that it is possible to focus the particles anywhere along the height of a micro-channel just by varying the acoustic frequency, in contradiction with the resonance condition. This result has been thoroughly checked experimentally. The different physical properties as well as wall materials have been changed. The wall materials is finally the only critical parameters. One of the specificity of the micro-channel is the thickness of the carrier and reflector layer. A preliminary analysis of the experimental results suggests that the acoustic focusing beyond the classic resonance condition can be explained in the framework of the multilayered resonator proposed by Hill [1]. Nevertheless, further numerical studies are needed in order to confirm and fully understand how the acoustic pressure node can be moved over the entire height of the micro channel by varying the acoustic frequency. Despite some uncertainties about the origin of the phenomenon, it is robust and can be used for improved acoustic sorting or manipulation of particles or biological cells in confined set-ups. PMID:23628114

  19. Temperature and velocity determination of shock-heated flows with non-resonant heterodyne laser-induced thermal acoustics

    NASA Astrophysics Data System (ADS)

    Förster, F. J.; Baab, S.; Lamanna, G.; Weigand, B.

    2015-12-01

    Non-resonant laser-induced thermal acoustics (LITA), a four-wave mixing technique, was applied to post-shock flows within a shock tube. Simultaneous single-shot determination of temperature, speed of sound and flow velocity behind incident and reflected shock waves at different pressure and temperature levels are presented. Measurements were performed non-intrusively and without any seeding. The paper describes the technique and outlines its advantages compared to more established laser-based methods with respect to the challenges of shock tube experiments. The experiments include argon and nitrogen as test gas at temperatures of up to 1000 K and pressures of up to 43 bar. The experimental data are compared to calculated values based on inviscid one-dimensional shock wave theory. The single-shot uncertainty of the technique is investigated for worst-case test conditions resulting in relative standard deviations of 1, 1.7 and 3.4 % for Mach number, speed of sound and temperature, respectively. For all further experimental conditions, calculated values stay well within the 95 % confidence intervals of the LITA measurement.

  20. Effect of acoustic resonance on the dynamic lift forces acting on two tandem cylinders in cross-flow

    NASA Astrophysics Data System (ADS)

    Mohany, A.; Ziada, S.

    2009-04-01

    Direct measurements of the dynamic lift force acting on two tandem cylinders in cross-flow are performed in the presence and absence of acoustic resonance. The dynamic lift force is measured because it represents the integrated effect of the unsteady wake and therefore it is directly related to the dipole sound source generated by vortex shedding from the cylinder. Three spacing ratios inside the proximity interference region, L/D=1.75, 2.5 and 3 are considered. During the tests, the first transverse acoustic mode of the duct housing the cylinders is self-excited. In the absence of acoustic resonance, the measured dynamic lift coefficients agree with those reported in the literature. When the acoustic resonance is initiated, a drastic increase in the dynamic lift coefficient is observed, especially for the downstream cylinder. This can be associated with abrupt changes in the phase between the lift forces and the acoustic pressure. The dynamic lift forces on both cylinders are also decomposed into in-phase and out-of-phase components, with respect to the resonant sound pressure. The lift force components for the downstream cylinder are found to be dominant. Moreover, the out-of-phase component of the lift force on the downstream cylinder is found to become negative over two different ranges of flow velocity and to virtually vanish between these two ranges. Acoustic resonance of the first mode is therefore excited over two ranges of flow velocity separated by a non-resonant range near the velocity of frequency coincidence. It is therefore concluded that the occurrence of acoustic resonance is controlled by the out-of-phase lift component of the downstream cylinder, whereas the effect of the in-phase lift component is confined to causing small changes in the acoustic resonance frequency.

  1. Acoustic add-drop filters based on phononic crystal ring resonators

    NASA Astrophysics Data System (ADS)

    Rostami-Dogolsara, Babak; Moravvej-Farshi, Mohammad Kazem; Nazari, Fakhroddin

    2016-01-01

    We report the design procedure for an acoustic add-drop filter (ADF) composed of two line-defect waveguides coupled through a ring resonator cavity (RRC) all based on a phononic crystal (PnC) platform. Using finite difference time domain and plane wave expansion methods, we study the propagation of acoustic waves through the PnC based ADF structures. Numerical results show that the quality factor for the ADF with a quasisquare ring resonator with a frequency band of 95 Hz centered about 75.21 kHz is Q ˜ 800. We show that the addition of an appropriate scatterer at each RRC corner can reduce the scattering loss, enhancing the quality factor and the transmission efficiency. Moreover, it is also shown that by increasing the coupling gaps between the RRC and waveguides the quality factor can be increased by ˜25 times, at the expense of a significant reduction in the transmission efficiency this is attributed to the enhanced selectivity in expense of weakened coupling. Finally, by varying the effective path length of the acoustic wave in the RRC, via selectively varying the inclusions physical and geometrical properties, we show how one can ultra-fine and fine-tune the resonant frequency of the ADF.

  2. Fabrication of capacitive acoustic resonators combining 3D printing and 2D inkjet printing techniques.

    PubMed

    Haque, Rubaiyet Iftekharul; Ogam, Erick; Loussert, Christophe; Benaben, Patrick; Boddaert, Xavier

    2015-01-01

    A capacitive acoustic resonator developed by combining three-dimensional (3D) printing and two-dimensional (2D) printed electronics technique is described. During this work, a patterned bottom structure with rigid backplate and cavity is fabricated directly by a 3D printing method, and then a direct write inkjet printing technique has been employed to print a silver conductive layer. A novel approach has been used to fabricate a diaphragm for the acoustic sensor as well, where the conductive layer is inkjet-printed on a pre-stressed thin organic film. After assembly, the resulting structure contains an electrically conductive diaphragm positioned at a distance from a fixed bottom electrode separated by a spacer. Measurements confirm that the transducer acts as capacitor. The deflection of the diaphragm in response to the incident acoustic single was observed by a laser Doppler vibrometer and the corresponding change of capacitance has been calculated, which is then compared with the numerical result. Observation confirms that the device performs as a resonator and provides adequate sensitivity and selectivity at its resonance frequency. PMID:26473878

  3. Fabrication of Capacitive Acoustic Resonators Combining 3D Printing and 2D Inkjet Printing Techniques

    PubMed Central

    Haque, Rubaiyet Iftekharul; Ogam, Erick; Loussert, Christophe; Benaben, Patrick; Boddaert, Xavier

    2015-01-01

    A capacitive acoustic resonator developed by combining three-dimensional (3D) printing and two-dimensional (2D) printed electronics technique is described. During this work, a patterned bottom structure with rigid backplate and cavity is fabricated directly by a 3D printing method, and then a direct write inkjet printing technique has been employed to print a silver conductive layer. A novel approach has been used to fabricate a diaphragm for the acoustic sensor as well, where the conductive layer is inkjet-printed on a pre-stressed thin organic film. After assembly, the resulting structure contains an electrically conductive diaphragm positioned at a distance from a fixed bottom electrode separated by a spacer. Measurements confirm that the transducer acts as capacitor. The deflection of the diaphragm in response to the incident acoustic single was observed by a laser Doppler vibrometer and the corresponding change of capacitance has been calculated, which is then compared with the numerical result. Observation confirms that the device performs as a resonator and provides adequate sensitivity and selectivity at its resonance frequency. PMID:26473878

  4. Acoustic resonances and sound scattering by a shear layer

    NASA Technical Reports Server (NTRS)

    Koutsoyannis, S. P.; Karamcheti, K.; Galant, D. C.

    1979-01-01

    The energy reflection coefficient is evaluated numerically for plane waves incident on a plane shear layer having a linear velocity profile. The shear layer is found to exhibit no resonances and no Brewster angles. The behavior of the reflection coefficient depends crucially on the parameter tau, a nondimensional measure of the disturbance Strouhal number with respect to the disturbance Mach number in the mean flow direction. For moderate values of tau, the amplified reflection regime degenerates into the total reflection one, whereas in the ordinary reflection regime the variation of the reflection coefficient with tau depends on whether or not the corresponding vortex sheet has a Brewster angle. The results indicate that caution should be exercised in uncritically modeling a finite thickness shear layer by a corresponding vortex sheet.

  5. Switchable and tunable film bulk acoustic resonator fabricated using barium strontium titanate active layer and Ta2O5/SiO2 acoustic reflector

    NASA Astrophysics Data System (ADS)

    Sbrockey, N. M.; Kalkur, T. S.; Mansour, A.; Khassaf, H.; Yu, H.; Aindow, M.; Alpay, S. P.; Tompa, G. S.

    2016-08-01

    A solidly mounted acoustic resonator was fabricated using a Ba0.60Sr0.40TiO3 (BST) film deposited by metal organic chemical vapor deposition. The device was acoustically isolated from the substrate using a Bragg reflector consisting of three pairs of Ta2O5/SiO2 layers deposited by chemical solution deposition. Transmission electron microscopy verified that the Bragg reflector was not affected by the high temperatures and oxidizing conditions necessary to process high quality BST films. Electrical characterization of the resonator demonstrated a quality factor (Q) of 320 and an electromechanical coupling coefficient (Kt2) of 7.0% at 11 V.

  6. Investigation of the Influence of the Clearance of Linear Alternator on Thermo-acoustic Electricity Generator without Resonator

    NASA Astrophysics Data System (ADS)

    Wang, Yufang; Li, Zhengyu; Li, Qing

    This paper proposes a thermo-acoustic electricity generator without resonator, which is realized by a looped-tube traveling-wave thermo-acoustic engine coupled with two linear alternators. A linear alternator is the resonating element of the thermo-acoustic engine, so its impedance determines the operating status and the clearance exerts a direct influence on it. A test bed is set to measure the clearance. An exact formula is determined after the analysis of data processing. This conclusion is used in the simulation of the influence of clearance and damping based on DeltaEC. At last, a series of experiments have been done to compare with the simulation.

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

    PubMed

    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. PMID:23192819

  8. A simple model for coupled acoustic-structure resonance in Stratospheric Observatory for Infrared Astronomy

    NASA Astrophysics Data System (ADS)

    Ginsberg, Jerry H.

    2005-04-01

    The Stratospheric Observatory For Infrared Astronomy (SOFIA) is a joint project of NASA and the Deutsches Zentrum fur Luft- und Raumfahrt that has mounted a 2.5 m, 20 000 kg infrared telescope on a bulkhead of a specially modified Boeing 747-SP. A large sliding door will expose the observation bay to the exterior flow field at Mach 0.85 and 13 km altitude. In the open configuration the interaction of turbulence vortices generated at the leading and trailing edges of the opening has the possibility of inducing a strong acoustic signal. A concern has been raised that the peak frequencies of such a signal might coincide with the cavity resonances. The present work examines the transfer function for a known source in order to identify the cavity resonances. Simplistic reasoning argues that the worst case would occur if the cavity resonant frequencies are close to structural resonances. However, the structure's impedance is very low at its resonances, which means that the cavity resonant frequencies are shifted from their nominal values. The present work uses a simple one-dimensional waveguide model, in which one end is terminated by a damped single-degree-of-freedom oscillator, to explain the coupled-fluid structure resonance. The characteristic equation and formulas for the pressure and displacement transfer functions are derived. Analysis of these results leads to some surprising insights regarding the role of a structure's stiffness and mass. [Work supported by the NASA.

  9. Optical and acoustic sensing using Fano-like resonances in dual phononic and photonic crystal plate

    NASA Astrophysics Data System (ADS)

    Amoudache, Samira; Moiseyenko, Rayisa; Pennec, Yan; Rouhani, Bahram Djafari; Khater, Antoine; Lucklum, Ralf; Tigrine, Rachid

    2016-03-01

    We perform a theoretical study based on the transmissions of optical and acoustic waves normally impinging to a periodic perforated silicon plate when the embedded medium is a liquid and show the existence of Fano-like resonances in both cases. The signature of the resonances appears as well-defined asymmetric peaks in the phononic and photonic transmission spectra. We show that the origin of the Fano-like resonances is different with respect to the nature of the wave. In photonic, the origin comes from guided modes in the photonic plate while in phononic we show that it comes from the excitation of standing waves confined inside the cavity coming from the deformation of the water/silicon edges of the cylindrical inclusion. We finally use these features for sensing and show ultra-sensitivity to the light and sound velocities for different concentrations of analytes.

  10. Efficient Structure Resonance Energy Transfer from Microwaves to Confined Acoustic Vibrations in Viruses

    NASA Astrophysics Data System (ADS)

    Yang, Szu-Chi; Lin, Huan-Chun; Liu, Tzu-Ming; Lu, Jen-Tang; Hung, Wan-Ting; Huang, Yu-Ru; Tsai, Yi-Chun; Kao, Chuan-Liang; Chen, Shih-Yuan; Sun, Chi-Kuang

    2015-12-01

    Virus is known to resonate in the confined-acoustic dipolar mode with microwave of the same frequency. However this effect was not considered in previous virus-microwave interaction studies and microwave-based virus epidemic prevention. Here we show that this structure-resonant energy transfer effect from microwaves to virus can be efficient enough so that airborne virus was inactivated with reasonable microwave power density safe for the open public. We demonstrate this effect by measuring the residual viral infectivity of influenza A virus after illuminating microwaves with different frequencies and powers. We also established a theoretical model to estimate the microwaves power threshold for virus inactivation and good agreement with experiments was obtained. Such structure-resonant energy transfer induced inactivation is mainly through physically fracturing the virus structure, which was confirmed by real-time reverse transcription polymerase chain reaction. These results provide a pathway toward establishing a new epidemic prevention strategy in open public for airborne virus.

  11. Acoustic properties of multiple cavity resonance liner for absorbing higher-order duct modes.

    PubMed

    Zhou, Di; Wang, Xiaoyu; Jing, Xiaodong; Sun, Xiaofeng

    2016-08-01

    This paper describes analytical and experimental studies conducted to investigate the acoustic properties of axially non-uniform multiple cavity resonance liner for absorbing higher-order duct modes. A three-dimensional analytical model is proposed based upon transfer element method. The model is assessed by making a comparison with results of a liner performance experiment concerning higher-order modes propagation, and the agreement is good. According to the present results, it is found that the performance of multiple cavity resonance liner is related to the incident sound waves. Moreover, an analysis of the corresponding response of liner perforated panel-cavity system is performed, in which the features of resonance frequency and dissipation of the system under grazing or oblique incidence condition are revealed. The conclusions can be extended to typical non-locally reacting liners with single large back-cavity, and it would be beneficial for future non-locally reacting liner design to some extent. PMID:27586753

  12. Protein-modified shear mode film bulk acoustic resonator for bio-sensing applications

    NASA Astrophysics Data System (ADS)

    Wang, Jingjing; Liu, Weihui; Xu, Yan; Chen, Da; Li, Dehua; Zhang, Luyin

    2014-09-01

    In this paper, we present a shear mode film bulk acoustic biosensor based on micro-electromechanical technology. The film bulk acoustic biosensor is a diaphragmatic structure consisting of a lateral field excited ZnO piezoelectric film piezoelectric stack built on an Si3N4 membrane. The device works at near 1.6 GHz with Q factors of 579 in water and 428 in glycerol. A frequency shift of 5.4 MHz and a small decline in the amplitude are found for the measurements in glycerol compared with those in water because of the viscous damping derived from the adjacent glycerol. For bio-sensing demonstration, the resonator was modified with biotin molecule to detect protein-ligand interactions in real-time and in situ. The resonant frequency of the biotin-modified device drops rapidly and gradually reaches equilibrium when exposed to the streptavidin solution due to the biotin-streptavidin interaction. The proposed film bulk acoustic biosensor shows promising applications for disease diagnostics, prognosis, and drug discovery.

  13. Blend uniformity analysis of pharmaceutical products by Broadband Acoustic Resonance Dissolution Spectroscopy (BARDS).

    PubMed

    Fitzpatrick, Dara; Scanlon, Eoin; Krüse, Jacob; Vos, Bastiaan; Evans-Hurson, Rachel; Fitzpatrick, Eileen; McSweeney, Seán

    2012-11-15

    Blend uniformity analysis (BUA) is a routine and highly regulated aspect of pharmaceutical production. In most instances, it involves quantitative determination of individual components of a blend in order to ascertain the mixture ratio. This approach often entails the use of costly and sophisticated instrumentation and complex statistical methods. In this study, a new and simple qualitative blend confirmatory test is introduced based on a well known acoustic phenomenon. Several over the counter (OTC) product powder blends are analysed and it is shown that each product has a unique and highly reproducible acoustic signature. The acoustic frequency responses generated during the dissolution of the product are measured and recorded in real time. It is shown that intra-batch and inter-batch variation for each product is either insignificant or non-existent when measured in triplicate. This study demonstrates that Broadband Acoustic Resonance Dissolution Spectroscopy or BARDS can be used successfully to determine inter-batch variability, stability and uniformity of powder blends. This is just one application of a wide range of BARDS applications which are more cost effective and time efficient than current methods. PMID:22884840

  14. Acoustic resonances of fluid-immersed elastic cylinders and spheroids: Theory and experiment

    NASA Astrophysics Data System (ADS)

    Niemiec, Jan; Überall, Herbert; Bao, X. L.

    2002-05-01

    Frequency resonances in the scattering of acoustic waves from a target object are caused by the phase matching of surface waves repeatedly encircling the object. This is exemplified here by considering elastic finite cylinders and spheroids, and the phase-matching condition provides a means of calculating the complex resonance frequencies of such objects. Tank experiments carried out at Catholic University, or at the University of Le Havre, France by G. Maze and J. Ripoche, have been interpreted using this approach. The experiments employed sound pulses to measure arrival times, which allowed identification of the surface paths taken by the surface waves, thus giving rise to resonances in the scattering amplitude. A calculation of the resonance frequencies using the T-matrix approach showed satisfactory agreement with the experimental resonance frequencies that were either measured directly (as at Le Havre), or that were obtained by the interpretation of measured arrival times (at Catholic University) using calculated surface wave paths, and the extraction of resonance frequencies therefrom, on the basis of the phase-matching condition. Results for hemispherically endcapped, evacuated steel cylinders obtained in a lake experiment carried out by the NSWC were interpreted in the same fashion.

  15. Note: High-efficiency broadband acoustic energy harvesting using Helmholtz resonator and dual piezoelectric cantilever beams

    SciTech Connect

    Yang, Aichao; Li, Ping Wen, Yumei; Lu, Caijiang; Peng, Xiao; He, Wei; Zhang, Jitao; Wang, Decai; Yang, Feng

    2014-06-15

    A high-efficiency broadband acoustic energy harvester consisting of a compliant-top-plate Helmholtz resonator (HR) and dual piezoelectric cantilever beams is proposed. Due to the high mechanical quality factor of beams and the strong multimode coupling of HR cavity, top plate and beams, the high efficiency in a broad bandwidth is obtained. Experiment exhibits that the proposed harvester at 170–206 Hz has 28–188 times higher efficiency than the conventional harvester using a HR with a piezoelectric composite diaphragm. For input acoustic pressure of 2.0 Pa, the proposed harvester exhibits 0.137–1.43 mW output power corresponding to 0.035–0.36 μW cm{sup −3} volume power density at 170–206 Hz.

  16. Note: High-efficiency broadband acoustic energy harvesting using Helmholtz resonator and dual piezoelectric cantilever beams.

    PubMed

    Yang, Aichao; Li, Ping; Wen, Yumei; Lu, Caijiang; Peng, Xiao; He, Wei; Zhang, Jitao; Wang, Decai; Yang, Feng

    2014-06-01

    A high-efficiency broadband acoustic energy harvester consisting of a compliant-top-plate Helmholtz resonator (HR) and dual piezoelectric cantilever beams is proposed. Due to the high mechanical quality factor of beams and the strong multimode coupling of HR cavity, top plate and beams, the high efficiency in a broad bandwidth is obtained. Experiment exhibits that the proposed harvester at 170-206 Hz has 28-188 times higher efficiency than the conventional harvester using a HR with a piezoelectric composite diaphragm. For input acoustic pressure of 2.0 Pa, the proposed harvester exhibits 0.137-1.43 mW output power corresponding to 0.035-0.36 μW cm(-3) volume power density at 170-206 Hz. PMID:24985867

  17. Note: High-efficiency broadband acoustic energy harvesting using Helmholtz resonator and dual piezoelectric cantilever beams

    NASA Astrophysics Data System (ADS)

    Yang, Aichao; Li, Ping; Wen, Yumei; Lu, Caijiang; Peng, Xiao; He, Wei; Zhang, Jitao; Wang, Decai; Yang, Feng

    2014-06-01

    A high-efficiency broadband acoustic energy harvester consisting of a compliant-top-plate Helmholtz resonator (HR) and dual piezoelectric cantilever beams is proposed. Due to the high mechanical quality factor of beams and the strong multimode coupling of HR cavity, top plate and beams, the high efficiency in a broad bandwidth is obtained. Experiment exhibits that the proposed harvester at 170-206 Hz has 28-188 times higher efficiency than the conventional harvester using a HR with a piezoelectric composite diaphragm. For input acoustic pressure of 2.0 Pa, the proposed harvester exhibits 0.137-1.43 mW output power corresponding to 0.035-0.36 μW cm-3 volume power density at 170-206 Hz.

  18. Traveling surface spin-wave resonance spectroscopy using surface acoustic waves

    NASA Astrophysics Data System (ADS)

    Gowtham, P. G.; Moriyama, T.; Ralph, D. C.; Buhrman, R. A.

    2015-12-01

    Coherent gigahertz-frequency surface acoustic waves (SAWs) traveling on the surface of a piezoelectric crystal can, via the magnetoelastic interaction, resonantly excite traveling surface spin waves in an adjacent thin-film ferromagnet. These excited surface spin waves, traveling with a definite in-plane wave-vector q ∥ enforced by the SAW, can be detected by measuring changes in the electro-acoustical transmission of a SAW delay line. Here, we provide a demonstration that such measurements constitute a precise and quantitative technique for spin-wave spectroscopy, providing a means to determine both isotropic and anisotropic contributions to the spin-wave dispersion and damping. We demonstrate the effectiveness of this spectroscopic technique by measuring the spin-wave properties of a Ni thin film for a large range of wave vectors, | q ∥ | = 2.5 × 104-8 × 104 cm-1, over which anisotropic dipolar interactions vary from being negligible to quite significant.

  19. A wireless interrogation system exploiting narrowband acoustic resonator for remote physical quantity measurement

    NASA Astrophysics Data System (ADS)

    Friedt, J.-M.; Droit, C.; Martin, G.; Ballandras, S.

    2010-01-01

    Monitoring physical quantities using acoustic wave devices can be advantageously achieved using the wave characteristic dependence to various parametric perturbations (temperature, stress, and pressure). Surface acoustic wave (SAW) resonators are particularly well suited to such applications as their resonance frequency is directly influenced by these perturbations, modifying both the phase velocity and resonance conditions. Moreover, the intrinsic radio frequency (rf) nature of these devices makes them ideal for wireless applications, mainly exploiting antennas reciprocity and piezoelectric reversibility. In this paper, we present a wireless SAW sensor interrogation unit operating in the 434 MHz centered ISM band—selected as a tradeoff between antenna dimensions and electromagnetic wave penetration in dielectric media—based on the principles of a frequency sweep network analyzer. We particularly focus on the compliance with the ISM standard which reveals complicated by the need for switching from emission to reception modes similarly to radar operation. In this matter, we propose a fully digital rf synthesis chain to develop various interrogation strategies to overcome the corresponding difficulties and comply with the above-mentioned standard. We finally assess the reader interrogation range, accuracy, and dynamics.

  20. Electrostatic Generation of Bulk Acoustic Waves and Electrical Parameters of Si-MEMS Resonators.

    PubMed

    Dulmet, Bernard; Ivan, Mihaela Eugenia; Ballandras, Sylvain

    2016-02-01

    This paper proposes an analytical approach to model the generation of bulk acoustic waves in an electrostatically excited silicon MEMS structure, as well as its electromechanical response in terms of static and dynamic displacements, electromechanical coupling, and motional current. The analysis pertains to the single-port electrostatic drive of trapped-energy thickness-extensional (TE) modes in thin plates. Both asymmetric single-side and symmetric double-side electrostatic gap configurations are modeled. Green's function is used to describe the characteristic of the static displacement of the driven surface of the structure versus the dc bias voltage, which allows us to determine the electrical response of the resonator. Optical and electrical characterizations have been performed on resonator samples operating at 10.3 MHz on the fundamental of TE mode under single-side electrostatic excitation. The various figures of merit depend on the dc bias voltage. Typical values of 9000 for the Q-factor, and of 10(-5) for the electromechanical coupling factor k(2) have been obtained with [Formula: see text] for [Formula: see text]-thick gaps. Here-considered modes have a typical temperature coefficients of frequency (TCF) close to -30 ppm/(°)C. We conclude that the practical usability of such electrostatically excited bulk acoustic waves (BAW) resonators essentially depends on the efficiency of the compensation of feed-through capacitance. PMID:26642450

  1. Film bulk acoustic resonators integrated on arbitrary substrates using a polymer support layer.

    PubMed

    Chen, Guohao; Zhao, Xinru; Wang, Xiaozhi; Jin, Hao; Li, Shijian; Dong, Shurong; Flewitt, A J; Milne, W I; Luo, J K

    2015-01-01

    The film bulk acoustic resonator (FBAR) is a widely-used MEMS device which can be used as a filter, or as a gravimetric sensor for biochemical or physical sensing. Current device architectures require the use of an acoustic mirror or a freestanding membrane and are fabricated as discrete components. A new architecture is demonstrated which permits fabrication and integration of FBARs on arbitrary substrates. Wave confinement is achieved by fabricating the resonator on a polyimide support layer. Results show when the polymer thickness is greater than a critical value, d, the FBARs have similar performance to devices using alternative architectures. For ZnO FBARs operating at 1.3-2.2 GHz, d is ~9 μm, and the devices have a Q-factor of 470, comparable to 493 for the membrane architecture devices. The polymer support makes the resonators insensitive to the underlying substrate. Yields over 95% have been achieved on roughened silicon, copper and glass. PMID:25824706

  2. Film bulk acoustic resonators integrated on arbitrary substrates using a polymer support layer

    PubMed Central

    Chen, Guohao; Zhao, Xinru; Wang, Xiaozhi; Jin, Hao; Li, Shijian; Dong, Shurong; Flewitt, A. J.; Milne, W. I.; Luo, J. K.

    2015-01-01

    The film bulk acoustic resonator (FBAR) is a widely-used MEMS device which can be used as a filter, or as a gravimetric sensor for biochemical or physical sensing. Current device architectures require the use of an acoustic mirror or a freestanding membrane and are fabricated as discrete components. A new architecture is demonstrated which permits fabrication and integration of FBARs on arbitrary substrates. Wave confinement is achieved by fabricating the resonator on a polyimide support layer. Results show when the polymer thickness is greater than a critical value, d, the FBARs have similar performance to devices using alternative architectures. For ZnO FBARs operating at 1.3–2.2 GHz, d is ~9 μm, and the devices have a Q-factor of 470, comparable to 493 for the membrane architecture devices. The polymer support makes the resonators insensitive to the underlying substrate. Yields over 95% have been achieved on roughened silicon, copper and glass. PMID:25824706

  3. Time-domain analysis of resonant acoustic nonlinearity arising from cracks in multilayer ceramic capacitors

    NASA Astrophysics Data System (ADS)

    Johnson, Ward L.; Kim, Sudook A.; White, Grady S.; Herzberger, Jaemi; Peterson, Kirsten L.; Heyliger, Paul R.

    2016-02-01

    Acoustic nonlinearity of cracked and uncracked multilayer ceramic capacitors (MLCCs) was characterized through time-domain analysis of resonant waveforms following tone-burst excitation. A phase-sensitive receiver was employed to measure the phase, relative to a reference sinusoid, of decaying oscillations of a resonant mode near 1 MHz that was excited through ferroelectric coupling within the barium-titanate-based ceramic of the MLCC. Amplitude dependence of the resonant frequency during decay of the oscillations was characterized through measurements of changes in the resonant phase versus time. Waveforms were analyzed by fitting the recorded RF amplitude versus time to a decaying exponential and inserting the parameters of this fit into a second function to fit the time-dependent phase, with amplitude dependence of the resonant frequency incorporated in the second function. The measurements and analyses were performed on unmounted type-1210 MLCCs before and after quenching in ice water from elevated temperatures. This thermal treatment generated surface-breaking cracks in a fraction of the specimens. Measurements of a nonlinear parameter B of the capacitors before quenching were used to set a range corresponding to plus and minus three standard deviations (±3σ) relative to the mean of a Gaussian fit to the distribution of this parameter. 93 % of the values of B determined for heat-treated MLCCs with cracks were outside of this ±3σ range of the as-received MLCCs, while only 10 % of the values of B for heat-treated MLCCs without visible cracks were outside this range. These results indicate that time-domain nonlinear measurements with tone-burst excitation are a promising approach for rapid nondestructive detection of cracks that have no significant initial effect on the electrical characteristics of an MLCC but can evolve into conductive pathways during service and lead to electrical-device failure. They also illustrate the potential of this approach for

  4. Investigating the emotional response to room acoustics: A functional magnetic resonance imaging study.

    PubMed

    Lawless, M S; Vigeant, M C

    2015-10-01

    While previous research has demonstrated the powerful influence of pleasant and unpleasant music on emotions, the present study utilizes functional magnetic resonance imaging (fMRI) to assess the positive and negative emotional responses as demonstrated in the brain when listening to music convolved with varying room acoustic conditions. During fMRI scans, subjects rated auralizations created in a simulated concert hall with varying reverberation times. The analysis detected activations in the dorsal striatum, a region associated with anticipation of reward, for two individuals for the highest rated stimulus, though no activations were found for regions associated with negative emotions in any subject. PMID:26520354

  5. Experimental Study of Highly Sensitive Sensor Using a Surface Acoustic Wave Resonator for Wireless Strain Detection

    NASA Astrophysics Data System (ADS)

    Bao; Zhongqing; Hara, Motoaki; Mitsui, Misato; Sano, Koji; Nagasawa, Sumito; Kuwano, Hiroki

    2012-07-01

    We developed a highly sensitive strain sensor employing a surface acoustic wave (SAW) resonator for a wireless sensing system. The aim of this study is to monitor the distribution of the strain in the earth crust or giant infrastructures, such as bridges, skyscrapers and power plants, for disaster prevention. A SAW strain sensor was fabricated using LiNbO3 and a quartz substrate, and applied in a tensile test by attaching the steel specimen based on Japanese Industrial Standards (JIS Z2441-1). The results confirmed that the developed sensor could detect a strain of 10-6 order with linearity.

  6. Resonant acoustic spectroscopy of soft tissues using embedded magnetomotive nanotransducers and optical coherence tomography

    PubMed Central

    Oldenburg, Amy L

    2010-01-01

    We present a new method for performing dynamic elastography of soft tissue samples. By sensing nanoscale displacements with optical coherence tomography, a chirped, modulated force is applied to acquire the mechanical spectrum of a tissue sample within a few seconds. This modulated force is applied via magnetic nanoparticles, named ‘nanotransducers’, which are diffused into the tissue, and which contribute negligible inertia to the soft tissue mechanical system. Using this novel system, we observed that excised tissues exhibit mechanical resonance modes which are well described by a linear damped harmonic oscillator. Results are validated by using cylindrical tissue phantoms of agarose in which resonant frequencies (30–400 Hz) are consistent with longitudinal modes and the sample boundary conditions. We furthermore show that the Young’s modulus can be computed from their measured resonance frequencies, analogous to resonant ultrasound spectroscopy for stiff material analysis. Using this new technique, named magnetomotive resonant acoustic spectroscopy (MRAS), we monitored the relative stiffening of an excised rat liver during a chemical fixation process. PMID:20124653

  7. Asymptotic solutions for shocked resonant acoustic oscillations between concentric spheres and coaxial cylinders

    NASA Astrophysics Data System (ADS)

    Seymour, Brian R.; Mortell, Michael P.; Amundsen, David E.

    2012-02-01

    For resonant oscillations of a gas in a straight tube with a closed end, shocks form and all harmonics are generated, see Chester ["Resonant oscillations in a closed tube," J. Fluid Mech. 18, 44 (1964)], 10.1017/S0022112064000040. When the gas is confined between two concentric spheres or coaxial cylinders, the radially symmetric resonant oscillations may be continuous or shocked. For a fixed small Mach number of the input, the flow is continuous for sufficiently small L, defined as the ratio of the inner radius to the difference of the radii, see Seymour et al. ["Resonant oscillations of an inhomogeneous gas between concentric spheres," Proc. R. Soc. London, Ser. A 467, 2149 (2011)], 10.1098/rspa.2010.0576. However, shocks appear in the resonant flow for either larger values of L or larger input Mach number. A nonlinear geometric acoustics approximation is used to analyse the shocked motion of the gas when L ≫ 1. This approximation and the exact numerical solution are compared for the shocked wave profiles and shock strengths, and the approximation is valid for surprisingly small values of L. The flow in the plane wave case for a straight tube is recovered in the limit L → ∞ for both the spherical and cylindrical cases, providing a check on the results. The shocked solutions given here complement those continuous solutions previously derived from a dominant first mode approximation.

  8. Resonant modal group theory of membrane-type acoustical metamaterials for low-frequency sound attenuation

    NASA Astrophysics Data System (ADS)

    Ma, Fuyin; Wu, Jiu Hui; Huang, Meng

    2015-09-01

    In order to overcome the influence of the structural resonance on the continuous structures and obtain a lightweight thin-layer structure which can effectively isolate the low-frequency noises, an elastic membrane structure was proposed. In the low-frequency range below 500 Hz, the sound transmission loss (STL) of this membrane type structure is greatly higher than that of the current sound insulation material EVA (ethylene-vinyl acetate copo) of vehicle, so it is possible to replace the EVA by the membrane-type metamaterial structure in practice engineering. Based on the band structure, modal shapes, as well as the sound transmission simulation, the sound insulation mechanism of the designed membrane-type acoustic metamaterials was analyzed from a new perspective, which had been validated experimentally. It is suggested that in the frequency range above 200 Hz for this membrane-mass type structure, the sound insulation effect was principally not due to the low-level locally resonant mode of the mass block, but the continuous vertical resonant modes of the localized membrane. So based on such a physical property, a resonant modal group theory is initially proposed in this paper. In addition, the sound insulation mechanism of the membrane-type structure and thin plate structure were combined by the membrane/plate resonant theory.

  9. 3.4 GHz composite thin film bulk acoustic wave resonator for miniaturized atomic clocks

    SciTech Connect

    Artieda, Alvaro; Muralt, Paul

    2011-06-27

    Triple layer SiO{sub 2}/AlN/SiO{sub 2} composite thin film bulk acoustic wave resonators (TFBARs) were studied for applications in atomic clocks. The TFBAR's were tuned to 3.4 GHz, corresponding to half the hyperfine splitting of the ground state of rubidium {sup 87}Rb atoms. The quality factor (Q) was equal to 2300 and the temperature coefficient of the resonance frequency f{sub r} amounted to 1.5 ppm/K. A figure of merit Qf{sub r} of {approx} 0.8 x 10{sup 13} Hz and a thickness mode coupling factor of 1% were reached. Such figures are ideal for frequency sources in an oscillator circuit that tracks the optical signal in atomic clocks.

  10. General band gap condition in one-dimensional resonator-based acoustic metamaterial

    NASA Astrophysics Data System (ADS)

    Liu, Yafei; Hou, Zhilin; Fu, Xiujun

    2016-03-01

    A one-dimensional model for resonator-based acoustic metamaterials is introduced. The condition for band gap in such kind of structure is obtained. According to this condition, the dispersion relation is in general a result of the scattering phase and propagating phase. The phenomenon that the band gap is less dependent on lattice structure appears only in the special system in which the coupling between the resonators and the host medium is weak enough. For strong coupled systems, the dispersion of wave can be significantly adjusted by the propagating phase. Based on the understanding, a general guide for band gap optimization is given and the mechanism for structures with the defect states at subwavelength scale is revealed.

  11. Measuring Gas Composition and Pressure Within Sealed Containers Using Acoustic Resonance Spectroscopy

    SciTech Connect

    Veirs, D.K.; Heiple, C.R.; Rosenblatt, G.M.; Baiardo, J.P.

    1997-05-19

    Interim and long-term storage of carefully prepared plutonium material within hermetically sealed containers may generate dangerous gas pressures and compositions. The authors have been investigating the application of acoustic resonance spectroscopy to non-intrusively monitor changes in these parameters within sealed containers. In this approach a drum-like gas cavity is formed within the storage container which is excited using a piezoelectric transducer mounted on the outside of the container. The frequency response spectrum contains a series of peaks whose positions and widths are determined by the composition of the gas and the geometry of the cylindrical resonator; the intensities are related to the gas pressure. Comparing observed gas frequencies with theory gives excellent agreement. Small changes in gas composition, better than 1:1000, are readily measurable.

  12. Control of acoustic absorption in one-dimensional scattering by resonant scatterers

    NASA Astrophysics Data System (ADS)

    Merkel, A.; Theocharis, G.; Richoux, O.; Romero-García, V.; Pagneux, V.

    2015-12-01

    We experimentally report perfect acoustic absorption through the interplay of the inherent losses and transparent modes with high Q factor. These modes are generated in a two-port, one-dimensional waveguide, which is side-loaded by isolated resonators of moderate Q factor. In symmetric structures, we show that in the presence of small inherent losses, these modes lead to coherent perfect absorption associated with one-sided absorption slightly larger than 0.5. In asymmetric structures, near perfect one-sided absorption is possible (96%) with a deep sub-wavelength sample ( λ / 28 , where λ is the wavelength of the sound wave in the air). The control of strong absorption by the proper tuning of the radiation leakage of few resonators with weak losses will open possibilities in various wave-control devices.

  13. Absorption of acoustic waves by sunspots. II - Resonance absorption in axisymmetric fibril models

    NASA Technical Reports Server (NTRS)

    Rosenthal, C. S.

    1992-01-01

    Analytical calculations of acoustic waves scattered by sunspots which concentrate on the absorption at the magnetohydrodynamic Alfven resonance are extended to the case of a flux-tube embedded in a uniform atmosphere. The model is based on a flux-tubes of varying radius that are highly structured, translationally invariant, and axisymmetric. The absorbed fractional energy is determined for different flux-densities and subphotospheric locations with attention given to the effects of twist. When the flux is highly concentrated into annuli efficient absorption is possible even when the mean magnetic flux density is low. The model demonstrates low absorption at low azimuthal orders even in the presence of twist which generally increases the range of wave numbers over which efficient absorption can occur. Resonance absorption is concluded to be an efficient mechanism in monolithic sunspots, fibril sunspots, and plage fields.

  14. Characterization of irradiated and temperature-compensated gallium nitride surface acoustic wave resonators

    NASA Astrophysics Data System (ADS)

    Shankar, Ashwin; Angadi, Chetan; Bhattacharya, Sharmila; Lin, Chih-Ming; Senesky, Debbie G.

    2014-06-01

    Conventional electronic components are prone to failure and drift when exposed to space environments, which contain harsh conditions, such as extreme variation in temperature and radiation exposure. As a result, electronic components are often shielded with heavy and complex packaging. New material platforms that leverage the radiation and temperature tolerance of wide bandgap materials can be used to develop robust electronic components without complex packaging. One such component that is vital for communication, navigation and signal processing on space exploration systems is the on-board timing reference, which is conventionally provided by a quartz crystal resonator and is prone to damage from radiation and temperature fluctuations. As a possible alternative, this paper presents the characterization of microfabricated and wide bandgap gallium nitride (GaN) surface acoustic wave (SAW) resonators in radiation environments. Ultimately, in combination with the two-dimensional gas (2DEG) layer at the AlGaN/GaN interface, high electron mobility transistor (HEMT) structures can provide a monolithic solution for timing electronics on board space systems. One-port SAW resonators are microfabricated on a GaN-on-sapphire substrate are used to explore the impact of irradiation on the device performance. The GaN-based SAW resonator was subjected to extreme temperature conditions to study the change in resonance frequency. Thermal characterization of the resonator has revealed a self-compensating property at cryogenic temperatures. In addition, GaN-on-sapphire samples were irradiated using a Cs-137 source up to 55 krads of total ionizing dose (TID). The measured frequency response and Raman spectroscopy of the GaN/sapphire SAW resonators microfabricated from the irradiated samples are presented.

  15. A portable blood plasma clot micro-elastometry device based on resonant acoustic spectroscopy

    NASA Astrophysics Data System (ADS)

    Krebs, C. R.; Li, Ling; Wolberg, Alisa S.; Oldenburg, Amy L.

    2015-07-01

    Abnormal blood clot stiffness is an important indicator of coagulation disorders arising from a variety of cardiovascular diseases and drug treatments. Here, we present a portable instrument for elastometry of microliter volume blood samples based upon the principle of resonant acoustic spectroscopy, where a sample of well-defined dimensions exhibits a fundamental longitudinal resonance mode proportional to the square root of the Young's modulus. In contrast to commercial thromboelastography, the resonant acoustic method offers improved repeatability and accuracy due to the high signal-to-noise ratio of the resonant vibration. We review the measurement principles and the design of a magnetically actuated microbead force transducer applying between 23 pN and 6.7 nN, providing a wide dynamic range of elastic moduli (3 Pa-27 kPa) appropriate for measurement of clot elastic modulus (CEM). An automated and portable device, the CEMport, is introduced and implemented using a 2 nm resolution displacement sensor with demonstrated accuracy and precision of 3% and 2%, respectively, of CEM in biogels. Importantly, the small strains (<0.13%) and low strain rates (<1/s) employed by the CEMport maintain a linear stress-to-strain relationship which provides a perturbative measurement of the Young's modulus. Measurements of blood plasma CEM versus heparin concentration show that CEMport is sensitive to heparin levels below 0.050 U/ml, which suggests future applications in sensing heparin levels of post-surgical cardiopulmonary bypass patients. The portability, high accuracy, and high precision of this device enable new clinical and animal studies for associating CEM with blood coagulation disorders, potentially leading to improved diagnostics and therapeutic monitoring.

  16. A portable blood plasma clot micro-elastometry device based on resonant acoustic spectroscopy

    PubMed Central

    Krebs, C. R.; Li, Ling; Wolberg, Alisa S.; Oldenburg, Amy L.

    2015-01-01

    Abnormal blood clot stiffness is an important indicator of coagulation disorders arising from a variety of cardiovascular diseases and drug treatments. Here, we present a portable instrument for elastometry of microliter volume blood samples based upon the principle of resonant acoustic spectroscopy, where a sample of well-defined dimensions exhibits a fundamental longitudinal resonance mode proportional to the square root of the Young’s modulus. In contrast to commercial thromboelastography, the resonant acoustic method offers improved repeatability and accuracy due to the high signal-to-noise ratio of the resonant vibration. We review the measurement principles and the design of a magnetically actuated microbead force transducer applying between 23 pN and 6.7 nN, providing a wide dynamic range of elastic moduli (3 Pa–27 kPa) appropriate for measurement of clot elastic modulus (CEM). An automated and portable device, the CEMport, is introduced and implemented using a 2 nm resolution displacement sensor with demonstrated accuracy and precision of 3% and 2%, respectively, of CEM in biogels. Importantly, the small strains (<0.13%) and low strain rates (<1/s) employed by the CEMport maintain a linear stress-to-strain relationship which provides a perturbative measurement of the Young’s modulus. Measurements of blood plasma CEM versus heparin concentration show that CEMport is sensitive to heparin levels below 0.050 U/ml, which suggests future applications in sensing heparin levels of post-surgical cardiopulmonary bypass patients. The portability, high accuracy, and high precision of this device enable new clinical and animal studies for associating CEM with blood coagulation disorders, potentially leading to improved diagnostics and therapeutic monitoring. PMID:26233406

  17. A portable blood plasma clot micro-elastometry device based on resonant acoustic spectroscopy.

    PubMed

    Krebs, C R; Li, Ling; Wolberg, Alisa S; Oldenburg, Amy L

    2015-07-01

    Abnormal blood clot stiffness is an important indicator of coagulation disorders arising from a variety of cardiovascular diseases and drug treatments. Here, we present a portable instrument for elastometry of microliter volume blood samples based upon the principle of resonant acoustic spectroscopy, where a sample of well-defined dimensions exhibits a fundamental longitudinal resonance mode proportional to the square root of the Young's modulus. In contrast to commercial thromboelastography, the resonant acoustic method offers improved repeatability and accuracy due to the high signal-to-noise ratio of the resonant vibration. We review the measurement principles and the design of a magnetically actuated microbead force transducer applying between 23 pN and 6.7 nN, providing a wide dynamic range of elastic moduli (3 Pa-27 kPa) appropriate for measurement of clot elastic modulus (CEM). An automated and portable device, the CEMport, is introduced and implemented using a 2 nm resolution displacement sensor with demonstrated accuracy and precision of 3% and 2%, respectively, of CEM in biogels. Importantly, the small strains (<0.13%) and low strain rates (<1/s) employed by the CEMport maintain a linear stress-to-strain relationship which provides a perturbative measurement of the Young's modulus. Measurements of blood plasma CEM versus heparin concentration show that CEMport is sensitive to heparin levels below 0.050 U/ml, which suggests future applications in sensing heparin levels of post-surgical cardiopulmonary bypass patients. The portability, high accuracy, and high precision of this device enable new clinical and animal studies for associating CEM with blood coagulation disorders, potentially leading to improved diagnostics and therapeutic monitoring. PMID:26233406

  18. A magnetic resonance imaging study on the articulatory and acoustic speech parameters of Malay vowels

    PubMed Central

    2014-01-01

    The phonetic properties of six Malay vowels are investigated using magnetic resonance imaging (MRI) to visualize the vocal tract in order to obtain dynamic articulatory parameters during speech production. To resolve image blurring due to the tongue movement during the scanning process, a method based on active contour extraction is used to track tongue contours. The proposed method efficiently tracks tongue contours despite the partial blurring of MRI images. Consequently, the articulatory parameters that are effectively measured as tongue movement is observed, and the specific shape of the tongue and its position for all six uttered Malay vowels are determined. Speech rehabilitation procedure demands some kind of visual perceivable prototype of speech articulation. To investigate the validity of the measured articulatory parameters based on acoustic theory of speech production, an acoustic analysis based on the uttered vowels by subjects has been performed. As the acoustic speech and articulatory parameters of uttered speech were examined, a correlation between formant frequencies and articulatory parameters was observed. The experiments reported a positive correlation between the constriction location of the tongue body and the first formant frequency, as well as a negative correlation between the constriction location of the tongue tip and the second formant frequency. The results demonstrate that the proposed method is an effective tool for the dynamic study of speech production. PMID:25060583

  19. Acoustics

    NASA Astrophysics Data System (ADS)

    The acoustics research activities of the DLR fluid-mechanics department (Forschungsbereich Stroemungsmechanik) during 1988 are surveyed and illustrated with extensive diagrams, drawings, graphs, and photographs. Particular attention is given to studies of helicopter rotor noise (high-speed impulsive noise, blade/vortex interaction noise, and main/tail-rotor interaction noise), propeller noise (temperature, angle-of-attack, and nonuniform-flow effects), noise certification, and industrial acoustics (road-vehicle flow noise and airport noise-control installations).

  20. Response to "Comment on 'Resonant acoustic scattering by swimbladder-bearing fish'" [J. Acoust. Soc. Am. 64, 571-580 (1978)].

    PubMed

    Love, Richard H

    2013-11-01

    In the 1970s a model of resonant scattering from a swimbladder-bearing fish was developed. The fish was modeled as an air bubble, representing a swimbladder, encased in a viscous spherical shell, representing the fish flesh. This model has been used successfully to correlate acoustic scattering data with fish information in a number of ocean locations. Recently, questions have arisen about viscous damping of the flesh and the thickness of the shell [K. Baik, J. Acoust. Soc. Am. 133, 5-8 (2013)]. This Letter responds to those questions and provides practical insight into the model's use. PMID:24180749

  1. Slow bars in spiral galaxies

    NASA Astrophysics Data System (ADS)

    Fridman, A. M.; Khoruzhii, O. V.

    2000-11-01

    Here we put forward some arguments in favour of the existence of slow bars. More then a half of spiral galaxies have in their central regions a bar - a structure in the form of triaxial ellipsoid. Historically two models of the bar were developed - those of the so called ``slow'' and ``fast'' bars. In both cases the bar is in some resonance with the galactic disc region near the bar ends - it is the corotation resonance for a fast bar and the inner Lindblad resonance for a slow bar. For the same angular velocity the fast bar would be larger then the slow bar. Alternatively, for the same size the fast bar would have much higher angular velocity, that being the reason for the terminology used. Up till now, the direct measurement of angular velocity of a bar has been an open problem. This is why all arguments on the nature of bar observed in some particular galaxy are inevitably indirect. Despite the fact that the model of slow bars was developed slightly earlier, the main part of attention was focused on the fast bars. Presently many researchers believe in the existence of the fast bars in real galaxies, while discussions on the existence of the slow bars continue so far. In this Letter we demonstrate that the bar detected in the grand design spiral galaxy NGC 157 is the slow bar.

  2. Acoustic resonance excitation of turbulent heat transfer and flow reattachment downstream of a fence

    NASA Astrophysics Data System (ADS)

    Selcan, Claudio; Cukurel, Beni; Shashank, Judah

    2015-12-01

    The current work investigates the aero-thermal impact of standing sound waves, excited in a straight channel geometry, on turbulent, separating and reattaching flow over a fence. Effects of distinct frequency resonant forcing (ReH = 10,050 and f = 122 Hz) are quantified by wall static pressure measurements and detailed convective heat transfer distributions via liquid crystal thermometry. Acoustic boundary conditions are numerically predicted and the computed longitudinal resonance mode shapes are experimentally verified by surface microphone measurements. Findings indicate the presence of a resonant sound field to exert strong influence on local heat transfer downstream of the fence, whereas the boundary layer upstream of the obstacle remains notable unaffected. Upstream shift of the maximum heat transfer location and an earlier pressure recovery indicate a reduction in time averaged flow reattachment length of up to 37 %. Although the streamwise peak Nusselt increased by only 5 %, the heat transfer level in the vicinity of the unexcited reattachment zone was locally enhanced up to 25 %. Despite prominent impact of resonant forcing on the fence wake flow, the total pressure drop penalty remained invariant. Observations demonstrate the significant aero-thermal implications of shear layer excitation by standing sound waves superimposed on the channel flow field.

  3. Acoustic scattering by elastic cylinders of elliptical cross-section and splitting up of resonances

    SciTech Connect

    Ancey, S. Bazzali, E. Gabrielli, P. Mercier, M.

    2014-05-21

    The scattering of a plane acoustic wave by an infinite elastic cylinder of elliptical cross section is studied from a modal formalism by emphasizing the role of the symmetries. More precisely, as the symmetry is broken in the transition from the infinite circular cylinder to the elliptical one, the splitting up of resonances is observed both theoretically and experimentally. This phenomenon can be interpreted using group theory. The main difficulty stands in the application of this theory within the framework of the vectorial formalism in elastodynamics. This method significantly simplifies the numerical treatment of the problem, provides a full classification of the resonances, and gives a physical interpretation of the splitting up in terms of symmetry breaking. An experimental part based on ultrasonic spectroscopy complements the theoretical study. A series of tank experiments is carried out in the case of aluminium elliptical cylinders immersed in water, in the frequency range 0 ≤ kr ≤ 50, where kr is the reduced wave number in the fluid. The symmetry is broken by selecting various cylinders of increasing eccentricity. More precisely, the greater the eccentricity, the higher the splitting up of resonances is accentuated. The experimental results provide a very good agreement with the theoretical ones, the splitting up is observed on experimental form functions, and the split resonant modes are identified on angular diagrams.

  4. Super-resolution imaging by resonant tunneling in anisotropic acoustic metamaterials.

    PubMed

    Liu, Aiping; Zhou, Xiaoming; Huang, Guoliang; Hu, Gengkai

    2012-10-01

    The resonant tunneling effects that could result in complete transmission of evanescent waves are examined in acoustic metamaterials of anisotropic effective mass. The tunneling conditions are first derived for the metamaterials composed of classical mass-in-mass structures. It is found that the tunneling transmission occurs when the total length of metamaterials is an integral number of half-wavelengths of the periodic Bloch wave. Due to the local resonance of building units of metamaterials, the Bloch waves are spatially modulated within the periodic structures, leading to the resonant tunneling occurring in the low-frequency region. The metamaterial slab lens with anisotropic effective mass is designed by which the physics of resonant tunneling and the features for evanescent field manipulations are examined. The designed lens interacts with evanescent waves in the way of the propagating wavenumber weakly dependent on the spatial frequency of evanescent waves. Full-wave simulations validate the imaging performance of the proposed lens with the spatial resolution beyond the diffraction limit. PMID:23039546

  5. Complex Contact-Based Dynamics of Microsphere Monolayers Revealed by Resonant Attenuation of Surface Acoustic Waves.

    PubMed

    Hiraiwa, M; Abi Ghanem, M; Wallen, S P; Khanolkar, A; Maznev, A A; Boechler, N

    2016-05-13

    Contact-based vibrations play an essential role in the dynamics of granular materials. Significant insights into vibrational granular dynamics have previously been obtained with reduced-dimensional systems containing macroscale particles. We study contact-based vibrations of a two-dimensional monolayer of micron-sized spheres on a solid substrate that forms a microscale granular crystal. Measurements of the resonant attenuation of laser-generated surface acoustic waves reveal three collective vibrational modes that involve displacements and rotations of the microspheres, as well as interparticle and particle-substrate interactions. To identify the modes, we tune the interparticle stiffness, which shifts the frequency of the horizontal-rotational resonances while leaving the vertical resonance unaffected. From the measured contact resonance frequencies we determine both particle-substrate and interparticle contact stiffnesses and find that the former is an order of magnitude larger than the latter. This study paves the way for investigating complex contact-based dynamics of microscale granular crystals and yields a new approach to studying micro- to nanoscale contact mechanics in multiparticle networks. PMID:27232047

  6. Complex Contact-Based Dynamics of Microsphere Monolayers Revealed by Resonant Attenuation of Surface Acoustic Waves

    NASA Astrophysics Data System (ADS)

    Hiraiwa, M.; Abi Ghanem, M.; Wallen, S. P.; Khanolkar, A.; Maznev, A. A.; Boechler, N.

    2016-05-01

    Contact-based vibrations play an essential role in the dynamics of granular materials. Significant insights into vibrational granular dynamics have previously been obtained with reduced-dimensional systems containing macroscale particles. We study contact-based vibrations of a two-dimensional monolayer of micron-sized spheres on a solid substrate that forms a microscale granular crystal. Measurements of the resonant attenuation of laser-generated surface acoustic waves reveal three collective vibrational modes that involve displacements and rotations of the microspheres, as well as interparticle and particle-substrate interactions. To identify the modes, we tune the interparticle stiffness, which shifts the frequency of the horizontal-rotational resonances while leaving the vertical resonance unaffected. From the measured contact resonance frequencies we determine both particle-substrate and interparticle contact stiffnesses and find that the former is an order of magnitude larger than the latter. This study paves the way for investigating complex contact-based dynamics of microscale granular crystals and yields a new approach to studying micro- to nanoscale contact mechanics in multiparticle networks.

  7. Outcome of resonant voice therapy for female teachers with voice disorders: perceptual, physiological, acoustic, aerodynamic, and functional measurements.

    PubMed

    Chen, Sheng Hwa; Hsiao, Tzu-Yu; Hsiao, Li-Chun; Chung, Yu-Mei; Chiang, Shu-Chiung

    2007-07-01

    Teachers have a high percentage of voice problems. For voice disordered teachers, resonant voice therapy is hypothesized to reduce voice problems. No research has been done on the physiological, acoustic, and aerodynamic effects of resonant voice therapy for school teachers. The purpose of this study is to investigate resonant voice therapy outcome from perceptual, physiological, acoustic, aerodynamic, and functional aspects for female teachers with voice disorders. A prospective study was designed for this research. The research subjects were 24 female teachers in Taipei. All subjects received resonant voice therapy in groups of 4 subjects, 90 minutes per session, and 1 session per week for 8 weeks. The outcome of resonant voice therapy was assessed from auditory perceptual judgment, videostroboscopic examination, acoustic measurements, aerodynamic measurements, and functional measurements before and after therapy. After therapy the severity of roughness, strain, monotone, resonance, hard attack, and glottal fry in auditory perceptual judgments, the severity of vocal fold pathology, mucosal wave, amplitude, and vocal fold closure in videostroboscopic examinations, phonation threshold pressure, and the score of physical scale in the Voice Handicap Index were significantly reduced. The speaking Fo, maximum range of speaking Fo, and maximum range of speaking intensity were significantly increased after therapy. No significant change was found in perturbation and breathiness measurements after therapy. Resonant voice therapy is effective for school teachers and is suggested as one of the therapy approaches in clinics for this population. PMID:16581227

  8. Validation study toward measuring the mechanical properties of blood clots using resonant acoustic spectroscopy with optical vibrometry

    NASA Astrophysics Data System (ADS)

    Wu, Gongting; Wolberg, Alisa S.; Oldenburg, Amy L.

    2012-03-01

    Clot elastic modulus (CEM) has recently been shown to correlate with various hemostatic and thrombotic disorders and may be an important diagnostic parameter in cardiovascular diseases. Current methods of CEM measurement lack repeatability and require large sample volume. We present a novel method named resonant acoustic spectroscopy with optical vibrometry (RASOV) that has the potential to assess CEM with higher accuracy and speed, and lower sample volume. To validate RASOV, we measured the acoustic spectrum of agarose gel with varied concentrations in openfaced rectangular wells. Results showed a linear relationship between the natural resonant frequency and agarose content within a concentration range of 4 to 12 mg/mL. Furthermore, we observed that the resonant frequencies decrease with increasing transducer mass. As a highly accurate, resonance-based method, RASOV has great potential for biomechanical properties measurement, especially for human blood.

  9. Development and testing of cabin sidewall acoustic resonators for the reduction of cabin tone levels in propfan-powered aircraft

    NASA Technical Reports Server (NTRS)

    Kuntz, H. L.; Gatineau, R. J.; Prydz, R. A.; Balena, F. J.

    1991-01-01

    The use of Helmholtz resonators to increase the sidewall transmission loss (TL) in aircraft cabin sidewalls is evaluated. Development, construction, and test of an aircraft cabin acoustic enclosure, built in support of the Propfan Test Assessment (PTA) program, is described. Laboratory and flight test results are discussed. Resonators (448) were located between the enclosure trim panels and the fuselage shell. In addition, 152 resonators were placed between the enclosure and aircraft floors. The 600 resonators were each tuned to a propfan fundamental blade passage frequency (235 Hz). After flight testing on the PTA aircraft, noise reduction (NR) tests were performed with the enclosure in the Kelly Johnson Research and Development Center Acoustics Laboratory. Broadband and tonal excitations were used in the laboratory. Tonal excitation simulated the propfan flight test excitation. The resonators increase the NR of the cabin walls around the resonance frequency of the resonator array. Increases in NR of up to 11 dB were measured. The effects of flanking, sidewall absorption, cabin absorption, resonator loading of trim panels, and panel vibrations are presented. Resonator and sidewall panel design and test are discussed.

  10. Acoustic resonance scattering from a multilayered cylindrical shell with imperfect bonding.

    PubMed

    Rajabi, M; Hasheminejad, Seyyed M

    2009-12-01

    The method of wave function expansion is adopted to study the three dimensional scattering of a time-harmonic plane progressive sound field obliquely incident upon a multi-layered hollow cylinder with interlaminar bonding imperfection. For the generality of solution, each layer is assumed to be cylindrically orthotropic. An approximate laminate model in the context of the modal state equations with variable coefficients along with the classical T-matrix solution technique is set up for each layer to solve for the unknown modal scattering and transmission coefficients. A linear spring model is used to describe the interlaminar adhesive bonding whose effects are incorporated into the global transfer matrix by introduction of proper interfacial transfer matrices. Following the classic acoustic resonance scattering theory (RST), the scattered field and response to surface waves are determined by constructing the partial waves and obtaining the non-resonance (backgrounds) and resonance components. The solution is first used to investigate the effect of interlayer imperfection of an air-filled and water submerged bilaminate aluminium cylindrical shell on the resonances associated with various modes of wave propagation (i.e., symmetric/asymmetric Lamb waves, fluid-borne A-type waves, Rayleigh and Whispering Gallery waves) appearing in the backscattered spectrum, according to their polarization and state of stress. An illustrative numerical example is also given for a multi-layered (five-layered) cylindrical shell for which the stiffness of the adhesive interlayers is artificially varied. The sensitivity of resonance frequencies associated with higher mode numbers to the stiffness coefficients is demonstrated to be a good measure of the bonding strength. Limiting cases are considered and fair agreements with solutions available in the literature are established. PMID:19586650

  11. Gaseous Absorption and Dispersion of Sound in a Resonant Cylindrical Cavity: AN Acoustic and Photoacoustic Study

    NASA Astrophysics Data System (ADS)

    Beckwith, Clyfe Gordon

    This research investigated the feasibility of accurately measuring Virial coefficients in an acoustically resonant cylindrical cavity. Gases studied were: Argon, Helium, Nitrogen, Carbon Dioxide, and Methane. Parameters considered were: resonant frequencies (f_ {rm r}- also a measure of speed of sound), quality factors (Q), and signal amplitudes. We studied the longitudinal modes smaller than 2000 Hz, at room temperature and at pressures of 200, 500, and 800 mm of Hg. The choice of the longitudinal modes was predetermined by our wish to compare acoustic and photoacoustic resonance techniques of the same mode. The acoustic excitation is limited to the longitudinal modes and is achieved by placing a loudspeaker close to one end of the cavity. Photoacoustically we excite a small concentration of molecular Iodine, mixed in with the buffer gases, by a periodically interrupted Xenon light beam. By increasing the length of the cavity we could decrease the space between the modes of frequency. Our observations focused on the behaviors that (a) f_{rm r} shifted with pressure, (b) the f_{rm r} deviated from the simple laws of harmonics, and (c) the amplitudes for the two techniques varied differently with frequency. Effect (a) is due to the fact that the gases are not "ideal", and due to the presence of boundary layers caused by thermal conduction and viscosity gradients. Effect (b) arises because of the f_{rm r}'s mode dependence, caused by the wave scattering due to imperfect geometrical symmetries. Effect (c) is governed by the coupling factors. All measurements could theoretically be justified to within instrumental error, the only noted discrepancy is the lack of a theoretical mode dependence. We conclude that it is feasible to study the accuracy of Virial coefficients of simple gases provided that the boundary layer loss effects and the mode dependent wave scattering can be quantified; in regions of high pressures and high frequencies the Virial effects dominate the

  12. Acoustics

    NASA Technical Reports Server (NTRS)

    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.

  13. Conformational Changes of Calmodulin on Calcium and Peptide Binding Monitored by Film Bulk Acoustic Resonators

    PubMed Central

    Nirschl, Martin; Ottl, Johannes; Vörös, Janos

    2011-01-01

    Film bulk acoustic resonators (FBAR) are mass sensitive, label-free biosensors that allow monitoring of the interaction between biomolecules. In this paper we use the FBAR to measure the binding of calcium and the CaMKII peptide to calmodulin. Because the mass of the calcium is too small to be detected, the conformational change caused by the binding process is measured by monitoring the resonant frequency and the motional resistance of the FBAR. The resonant frequency is a measure for the amount of mass coupled to the sensor while the motional resistance is influenced by the viscoelastic properties of the adsorbent. The measured frequency shift during the calcium adsorptions was found to be strongly dependent on the surface concentration of the immobilized calmodulin, which indicates that the measured signal is significantly influenced by the amount of water inside the calmodulin layer. By plotting the measured motional resistance against the frequency shift, a mass adsorption can be distinguished from processes involving measurable conformational changes. With this method three serial processes were identified during the peptide binding. The results show that the FBAR is a promising technology for the label-free measurement of conformational changes. PMID:25585566

  14. Efficient Structure Resonance Energy Transfer from Microwaves to Confined Acoustic Vibrations in Viruses

    PubMed Central

    Yang, Szu-Chi; Lin, Huan-Chun; Liu, Tzu-Ming; Lu, Jen-Tang; Hung, Wan-Ting; Huang, Yu-Ru; Tsai, Yi-Chun; Kao, Chuan-Liang; Chen, Shih-Yuan; Sun, Chi-Kuang

    2015-01-01

    Virus is known to resonate in the confined-acoustic dipolar mode with microwave of the same frequency. However this effect was not considered in previous virus-microwave interaction studies and microwave-based virus epidemic prevention. Here we show that this structure-resonant energy transfer effect from microwaves to virus can be efficient enough so that airborne virus was inactivated with reasonable microwave power density safe for the open public. We demonstrate this effect by measuring the residual viral infectivity of influenza A virus after illuminating microwaves with different frequencies and powers. We also established a theoretical model to estimate the microwaves power threshold for virus inactivation and good agreement with experiments was obtained. Such structure-resonant energy transfer induced inactivation is mainly through physically fracturing the virus structure, which was confirmed by real-time reverse transcription polymerase chain reaction. These results provide a pathway toward establishing a new epidemic prevention strategy in open public for airborne virus. PMID:26647655

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

    PubMed Central

    Hao, Wenchang; Liu, Jiuling; Liu, Minghua; Liang, Yong; He, Shitang

    2016-01-01

    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. PMID:27104540

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

    PubMed

    Hao, Wenchang; Liu, Jiuling; Liu, Minghua; Liang, Yong; He, Shitang

    2016-01-01

    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. PMID:27104540

  17. Efficient Structure Resonance Energy Transfer from Microwaves to Confined Acoustic Vibrations in Viruses.

    PubMed

    Yang, Szu-Chi; Lin, Huan-Chun; Liu, Tzu-Ming; Lu, Jen-Tang; Hung, Wan-Ting; Huang, Yu-Ru; Tsai, Yi-Chun; Kao, Chuan-Liang; Chen, Shih-Yuan; Sun, Chi-Kuang

    2015-01-01

    Virus is known to resonate in the confined-acoustic dipolar mode with microwave of the same frequency. However this effect was not considered in previous virus-microwave interaction studies and microwave-based virus epidemic prevention. Here we show that this structure-resonant energy transfer effect from microwaves to virus can be efficient enough so that airborne virus was inactivated with reasonable microwave power density safe for the open public. We demonstrate this effect by measuring the residual viral infectivity of influenza A virus after illuminating microwaves with different frequencies and powers. We also established a theoretical model to estimate the microwaves power threshold for virus inactivation and good agreement with experiments was obtained. Such structure-resonant energy transfer induced inactivation is mainly through physically fracturing the virus structure, which was confirmed by real-time reverse transcription polymerase chain reaction. These results provide a pathway toward establishing a new epidemic prevention strategy in open public for airborne virus. PMID:26647655

  18. Eliminating paranasal sinus resonance and its effects on acoustic properties of the nasal tract.

    PubMed

    Havel, Miriam; Kornes, Tanja; Weitzberg, Eddie; Lundberg, Jon O; Sundberg, Johan

    2016-01-01

    The significance of nasal resonance and anti-resonance to voice production is a classical issue in vocal pedagogy and voice research. The complex structure of the nasal tract produces a complex frequency response. This complexity must be heavily influenced by the morphology of the paranasal cavities, but their contributions are far from being entirely understood. Detailed analyses of these cavities are difficult because of their limited accessibility. Here we test different methods aiming at documenting the acoustical properties of the paranasal tract. The first set of experiments was performed under in vivo conditions, where the middle meatus was occluded by means of targeted application of a maltodextrin mass under endoscopic control. The efficiency of this occlusion method was verified by measuring the nasal nitric oxide (NO) output during humming. In another experiment the frequency responses to sine sweep excitation of an epoxy mould of a nasal cavity were measured, with and without elimination of paranasal sinuses. The third experiment was conducted in a cadaveric situs, with and without maltodextrin occlusion of the middle meatus and the sphenoidal ostia. The results show that some nasal tract resonances were unaffected by the manipulation of the paranasal cavities. Providing access to a maxillary sinus resulted in marked dips in the response curve while access to the sphenoidal ostium caused only minor effects. PMID:25327481

  19. Fissile and Non-Fissile Material Detection using Nuclear Acoustic Resonance Signatures

    SciTech Connect

    Herberg, J; Maxwell, R; Tittmann, B R; Lenahan, P M; Yerkes, S; Jayaraman, S

    2005-10-04

    This report reviews progress made on NA22 project LL251DP to develop a novel technique, Nuclear Acoustic Resonance (NAR), for remote, non-destructive, nonradiation-based detection of materials of interest to Nonproliferation Programs, including {sup 235}U and {sup 239}Pu. We have met all milestones and deliverables for FY05, as shown in Table 1. In short, we have developed a magnetic shield chamber and magnetic field, develop a digital lock-in amplifier computer to integrate both the ultrasound radiation with the detector, developed strain measurements, and begin to perform initial measurements to obtain a NAR signal from aluminum at room temperature and near the earth's magnetic field. The results obtained in FY05 further support the feasibility of successful demonstration of an NAR experiment for remote, non-destructive, non-radiation-based detection of materials of interest to Nonproliferation Programs.

  20. Benchmarking and Qualification of PAC-Femlab for Resonant Acoustic Chamber Design

    SciTech Connect

    Taleyarkhan, R.P.

    2006-07-01

    The design of high-powered resonant acoustic systems capable of inducing large pressure oscillations in the 10{sup 5} Hz to 10{sup 6} Hz range requires a validated simulation platform, one that includes complexities of multi-dimensional fluid-structure interactions. Past efforts at designing such systems have relied mainly on time-consuming, trial-error based heuristic approaches (West et al., 1967; Taleyarkhan et al., 2002; 2004). A robust design-cum-simulation platform is required to enable rapid strides and motivated this study for which the PAC-Femlab model was developed and successfully qualified against detailed experiment data as well as against data from a second independent experiment conducted elsewhere (Cancelos et al., 2004). (author)

  1. The mass load effect on the resonant acoustic frequencies of colloidal semiconductor nanoplatelets.

    PubMed

    Girard, Adrien; Saviot, Lucien; Pedetti, Silvia; Tessier, Mickaël D; Margueritat, Jérémie; Gehan, Hélène; Mahler, Benoit; Dubertret, Benoit; Mermet, Alain

    2016-07-01

    Resonant acoustic modes of ultrathin CdS and CdSe colloidal nanoplatelets (NPLs) with varying thicknesses were probed using low frequency Raman scattering. The spectra are dominated by an intense band ascribed to the thickness breathing mode of the 2D nanostructures. The measured Raman frequencies show strong deviations with respect to the values expected for simple bare plates, all the more so as the thickness is reduced. The deviation is shown to arise from the additional mass of the organic ligands that are bound to the free surfaces of the nanoplatelets. The calculated eigen frequencies of vibrating platelets weighed down by the mass of the organic ligands are in very good agreement with the observed experimental behaviours. This finding opens up a new possibility of nanomechanical sensing such as nanobalances. PMID:27334524

  2. The dependence of acoustic properties of a crack on the resonance mode and geometry

    USGS Publications Warehouse

    Kumagai, H.; Chouet, B.A.

    2001-01-01

    We examine the dependence of the acoustic properties of a crack containing magmatic or hydrothermal fluids on the resonance mode and geometry to quantify the source properties of long-period (LP) events observed in volcanic areas. Our results, based on spectral analyses of synthetic waveforms generated with a fluid-driven crack model, indicate that the basic features of the dimensionless frequency (??) and quality factor (Qr) for a crack containing various types of fluids are not strongly affected by the choice of mode, although the actual ranges of Q?? and ?? both depend on the mode. The dimensionless complex frequency systematically varies with changes in the crack geometry, showing increases in both Qr and ?? as the crack length to aperture ratio decreases. The present results may be useful for the interpretation of spatial and temporal variations in the observed complex frequencies of LP events.

  3. Fissile and Non-Fissile Material Detection using Nuclear Acoustic Resonance Signatures: Final Report

    SciTech Connect

    Herberg, J; Maxwell, R; Tittmann, B R; Lenahan, P M; Yerkes, S; Jayaraman, S B

    2006-11-02

    This is final report on NA-22 project LL251DP, where the goal was to develop a novel technique, Nuclear Acoustic Resonance (NAR), for remote, non-destructive, nonradiation-based detection of materials of interest to Nonproliferation Programs, including {sup 235}U and {sup 239}Pu. In short, we have developed a magnetic shield chamber and magnetic field, develop a digital lock-in amplifier computer to integrate both the ultrasound radiation with the detector, developed strain measurements, and begun to perform initial measurements to obtain a NAR signal from aluminum at room temperature and near the earth's magnetic field. Since our funding was cut in FY06, I will discuss where this project can go in the future with this technology.

  4. Elastic relaxations associated with the Pm3m-R3c transition in LaA103 III: superattenuation of acoustic resonances

    SciTech Connect

    Darling, Timothy W; Carpenter, M A; Buckley, A; Taylor, P A; Mcknight, R E A

    2009-01-01

    Resonant Ultrasound Spectroscopy has been used to characterize elastic softening and a variety of new acoustic dissipation processes associated with the Pm{bar 3}m {leftrightarrow} R{bar 3}c transition in single crystal and ceramic samples of LaAlO{sub 3}. Softening of the cubic structure ahead of the transition point is not accompanied by an increase in dissipation but follows different temperature dependences for the bulk modulus, 1/3(C{sub 11} + 2C{sub 12}), and the shear components 1/2(C{sub 11}-C{sub 12}) and C{sub 44} as if the tilting instability contains two slightly different critical temperatures. The transition itself is marked by the complete disappearance of resonance peaks (superattenuation), which then reappear below {approx}700 K in spectra from single crystals. Comparison with low frequency, high stress data from the literature indicate that the dissipation is not due to macroscopic displacement of needle twins. An alternative mechanism, local bowing of twin walls under low dynamic stress, is proposed. Pinning of the walls with respect to this displacement process occurs below {approx}350 K. Anelasticity maps, analogous to plastic deformation mechanism maps, are proposed to display dispersion relations and temperature/frequency/stress fields for different twin wall related dissipation mechanisms. An additional dissipation process, with an activation energy of 43 {+-} 6 kJ.mole{sup -1}, occurs in the vicinity of 250 K. The mechanism for this is not known, but it is associated with C{sub 44} and therefore appears to be related in some way to the cubic {leftrightarrow} rhombohedral transition at {approx}817 K. Slight softening in the temperature interval {approx}220 {yields} 70 K of resonance peaks determined by shear elastic constants hints at an incipient E{sub g} ferroelastic instability in LaAlO{sub 3}. The softening interval ends with a further dissipation peak at {approx} 60 K, the origin of which is discussed in terms of freezing of atomic

  5. Optimization of Capacitive Acoustic Resonant Sensor Using Numerical Simulation and Design of Experiment

    PubMed Central

    Haque, Rubaiyet Iftekharul; Loussert, Christophe; Sergent, Michelle; Benaben, Patrick; Boddaert, Xavier

    2015-01-01

    Optimization of the acoustic resonant sensor requires a clear understanding of how the output responses of the sensor are affected by the variation of different factors. During this work, output responses of a capacitive acoustic transducer, such as membrane displacement, quality factor, and capacitance variation, are considered to evaluate the sensor design. The six device parameters taken into consideration are membrane radius, backplate radius, cavity height, air gap, membrane tension, and membrane thickness. The effects of factors on the output responses of the transducer are investigated using an integrated methodology that combines numerical simulation and design of experiments (DOE). A series of numerical experiments are conducted to obtain output responses for different combinations of device parameters using finite element methods (FEM). Response surface method is used to identify the significant factors and to develop the empirical models for the output responses. Finally, these results are utilized to calculate the optimum device parameters using multi-criteria optimization with desirability function. Thereafter, the validating experiments are designed and deployed using the numerical simulation to crosscheck the responses. PMID:25894937

  6. Resonant raman scattering and dispersion of polar optical and acoustic phonons in hexagonal inn

    SciTech Connect

    Davydov, V. Yu. Klochikhin, A. A.; Smirnov, A. N.; Strashkova, I. Yu.; Krylov, A. S.; Lu Hai; Schaff, William J.; Lee, H.-M.; Hong, Y.-L.; Gwo, S.

    2010-02-15

    It is shown that a study of the dependence of impurity-related resonant first-order Raman scattering on the frequency of excitation light makes it possible to observe the dispersion of polar optical and acoustic branches of vibrational spectrum in hexagonal InN within a wide range of wave vectors. It is established that the wave vectors of excited phonons are uniquely related to the energy of excitation photon. Frequencies of longitudinal optical phonons E{sub 1}(LO) and A{sub 1}(LO) in hexagonal InN were measured in the range of excitation-photon energies from 2.81 to 1.17 eV and the frequencies of longitudinal acoustic phonons were measured in the range 2.81-1.83 eV of excitation-photon energies. The obtained dependences made it possible to extrapolate the dispersion of phonons A{sub 1}(LO) and E{sub 1}(LO) to as far as the point {Gamma} in the Brillouin zone and estimate the center-band energies of these phonons (these energies have not been uniquely determined so far).

  7. Near resonance acoustic scattering from organized schools of juvenile Atlantic bluefin tuna (Thunnus thynnus).

    PubMed

    Weber, Thomas C; Lutcavage, Molly E; Schroth-Miller, Madeline L

    2013-06-01

    Schools of Atlantic bluefin tuna (Thunnus thynnus) can exhibit highly organized spatial structure within the school. This structure was quantified for dome shaped schools using both aerial imagery collected from a commercial spotter plane and 400 kHz multibeam echo sounder data collected on a fishing vessel in 2009 in Cape Cod Bay, MA. Observations from one school, containing an estimated 263 fish within an approximately ellipsoidal volume of 1900 m(3), were used to seed an acoustic model that estimated the school target strength at frequencies between 10 and 2000 Hz. The fish's swimbladder resonance was estimated to occur at approximately 50 Hz. The acoustic model examined single and multiple scattering solutions and also a completely incoherent summation of scattering responses from the fish. Three levels of structure within the school were examined, starting with fish locations that were constrained by the school boundaries but placed according to a Poisson process, then incorporating a constraint on the distance to the nearest neighbor, and finally adding a constraint on the bearing to the nearest neighbor. Results suggest that both multiple scattering and spatial organization within the school should be considered when estimating the target strength of schools similar to the ones considered here. PMID:23742334

  8. Optimization of capacitive acoustic resonant sensor using numerical simulation and design of experiment.

    PubMed

    Haque, Rubaiyet Iftekharul; Loussert, Christophe; Sergent, Michelle; Benaben, Patrick; Boddaert, Xavier

    2015-01-01

    Optimization of the acoustic resonant sensor requires a clear understanding of how the output responses of the sensor are affected by the variation of different factors. During this work, output responses of a capacitive acoustic transducer, such as membrane displacement, quality factor, and capacitance variation, are considered to evaluate the sensor design. The six device parameters taken into consideration are membrane radius, backplate radius, cavity height, air gap, membrane tension, and membrane thickness. The effects of factors on the output responses of the transducer are investigated using an integrated methodology that combines numerical simulation and design of experiments (DOE). A series of numerical experiments are conducted to obtain output responses for different combinations of device parameters using finite element methods (FEM). Response surface method is used to identify the significant factors and to develop the empirical models for the output responses. Finally, these results are utilized to calculate the optimum device parameters using multi-criteria optimization with desirability function. Thereafter, the validating experiments are designed and deployed using the numerical simulation to crosscheck the responses. PMID:25894937

  9. The mass load effect on the resonant acoustic frequencies of colloidal semiconductor nanoplatelets

    NASA Astrophysics Data System (ADS)

    Girard, Adrien; Saviot, Lucien; Pedetti, Silvia; Tessier, Mickaël D.; Margueritat, Jérémie; Gehan, Hélène; Mahler, Benoit; Dubertret, Benoit; Mermet, Alain

    2016-07-01

    Resonant acoustic modes of ultrathin CdS and CdSe colloidal nanoplatelets (NPLs) with varying thicknesses were probed using low frequency Raman scattering. The spectra are dominated by an intense band ascribed to the thickness breathing mode of the 2D nanostructures. The measured Raman frequencies show strong deviations with respect to the values expected for simple bare plates, all the more so as the thickness is reduced. The deviation is shown to arise from the additional mass of the organic ligands that are bound to the free surfaces of the nanoplatelets. The calculated eigen frequencies of vibrating platelets weighed down by the mass of the organic ligands are in very good agreement with the observed experimental behaviours. This finding opens up a new possibility of nanomechanical sensing such as nanobalances.Resonant acoustic modes of ultrathin CdS and CdSe colloidal nanoplatelets (NPLs) with varying thicknesses were probed using low frequency Raman scattering. The spectra are dominated by an intense band ascribed to the thickness breathing mode of the 2D nanostructures. The measured Raman frequencies show strong deviations with respect to the values expected for simple bare plates, all the more so as the thickness is reduced. The deviation is shown to arise from the additional mass of the organic ligands that are bound to the free surfaces of the nanoplatelets. The calculated eigen frequencies of vibrating platelets weighed down by the mass of the organic ligands are in very good agreement with the observed experimental behaviours. This finding opens up a new possibility of nanomechanical sensing such as nanobalances. Electronic supplementary information (ESI) available. See DOI: 10.1039/C5NR07383A

  10. First Search for Multijet Resonances in $\\sqrt{s} = 1.96$ TeV $ p\\bar{p}$ Collisions

    SciTech Connect

    Aaltonen, T.

    2011-07-22

    We present the first model independent search for three-jet hadronic resonances within multijet events in $\\sqrt{s} = 1.96$ TeV $ p\\bar{p}$ collisions at the Fermilab Tevatron using the CDF II detector. Pair production of supersymmetric gluinos and squarks with hadronic R-parity violating decays is employed as an example of a new physics benchmark for this signature. Selection criteria based on the kinetmatic properties of an ensemble of jet combinations within each event help to extract signal from copious QCD background. Our background estimates include all-hadronic t{anti t} decays that have a signature similar to the signal. No significant excess outside the top quark mass window is observed in data with an integrated luminosity of 3.2 fb{sup -1}. We place 95% confidence level limits on the production cross section {sigma}(p{anti p} {yields} X X') x BR ((tilde gg) {yields} 3 jet + 3 jet) where X, X' = {tilde g}, {tilde q}, or {tilde {anti q}}, with {tilde q}, {tilde {anti q}} {yields} {tilde g} + jet, as a function of gluino mass, in the range of 77 GeV/c{sup 2} to 240 GeV/c{sup 2}.

  11. First Search for Multijet Resonances in $$\\sqrt{s} = 1.96$$ TeV $$ p\\bar{p}$$ Collisions

    DOE PAGESBeta

    Aaltonen, T.

    2011-07-22

    We present the first model independent search for three-jet hadronic resonances within multijet events inmore » $$\\sqrt{s} = 1.96$$ TeV $$ p\\bar{p}$$ collisions at the Fermilab Tevatron using the CDF II detector. Pair production of supersymmetric gluinos and squarks with hadronic R-parity violating decays is employed as an example of a new physics benchmark for this signature. Selection criteria based on the kinetmatic properties of an ensemble of jet combinations within each event help to extract signal from copious QCD background. Our background estimates include all-hadronic t{anti t} decays that have a signature similar to the signal. No significant excess outside the top quark mass window is observed in data with an integrated luminosity of 3.2 fb{sup -1}. We place 95% confidence level limits on the production cross section {sigma}(p{anti p} {yields} X X') x BR ((tilde gg) {yields} 3 jet + 3 jet) where X, X' = {tilde g}, {tilde q}, or {tilde {anti q}}, with {tilde q}, {tilde {anti q}} {yields} {tilde g} + jet, as a function of gluino mass, in the range of 77 GeV/c{sup 2} to 240 GeV/c{sup 2}.« less

  12. First cross-correlation analysis of interferometric and resonant-bar gravitational-wave data for stochastic backgrounds

    NASA Astrophysics Data System (ADS)

    Abbott, B.; Abbott, R.; Adhikari, R.; Agresti, J.; Ajith, P.; Allen, B.; Amin, R.; Anderson, S. B.; Anderson, W. G.; Arain, M.; Araya, M.; Armandula, H.; Ashley, M.; Aston, S.; Aufmuth, P.; Aulbert, C.; Babak, S.; Ballmer, S.; Bantilan, H.; Barish, B. C.; Barker, C.; Barker, D.; Barr, B.; Barriga, P.; Barton, M. A.; Bayer, K.; Belczynski, K.; Betzwieser, J.; Beyersdorf, P. T.; Bhawal, B.; Bilenko, I. A.; Billingsley, G.; Biswas, R.; Black, E.; Blackburn, K.; Blackburn, L.; Blair, D.; Bland, B.; Bogenstahl, J.; Bogue, L.; Bork, R.; Boschi, V.; Bose, S.; Brady, P. R.; Braginsky, V. B.; Brau, J. E.; Brinkmann, M.; Brooks, A.; Brown, D. A.; Bullington, A.; Bunkowski, A.; Buonanno, A.; Burgamy, M.; Burmeister, O.; Busby, D.; Byer, R. L.; Cadonati, L.; Cagnoli, G.; Camp, J. B.; Cannizzo, J.; Cannon, K.; Cantley, C. A.; Cao, J.; Cardenas, L.; Casey, M. M.; Castaldi, G.; Cepeda, C.; Chalkey, E.; Charlton, P.; Chatterji, S.; Chelkowski, S.; Chen, Y.; Chiadini, F.; Chin, D.; Chin, E.; Chow, J.; Christensen, N.; Clark, J.; Cochrane, P.; Cokelaer, T.; Colacino, C. N.; Coldwell, R.; Conte, R.; Cook, D.; Corbitt, T.; Coward, D.; Coyne, D.; Creighton, J. D. E.; Creighton, T. D.; Croce, R. P.; Crooks, D. R. M.; Cruise, A. M.; Cumming, A.; Dalrymple, J.; D'Ambrosio, E.; Danzmann, K.; Davies, G.; Debra, D.; Degallaix, J.; Degree, M.; Demma, T.; Dergachev, V.; Desai, S.; Desalvo, R.; Dhurandhar, S.; Díaz, M.; Dickson, J.; di Credico, A.; Diederichs, G.; Dietz, A.; Doomes, E. E.; Drever, R. W. P.; Dumas, J.-C.; Dupuis, R. J.; Dwyer, J. G.; Ehrens, P.; Espinoza, E.; Etzel, T.; Evans, M.; Evans, T.; Fairhurst, S.; Fan, Y.; Fazi, D.; Fejer, M. M.; Finn, L. S.; Fiumara, V.; Fotopoulos, N.; Franzen, A.; Franzen, K. Y.; Freise, A.; Frey, R.; Fricke, T.; Fritschel, P.; Frolov, V. V.; Fyffe, M.; Galdi, V.; Garofoli, J.; Gholami, I.; Giaime, J. A.; Giampanis, S.; Giardina, K. D.; Goda, K.; Goetz, E.; Goggin, L.; González, G.; Gossler, S.; Grant, A.; Gras, S.; Gray, C.; Gray, M.; Greenhalgh, J.; Gretarsson, A. M.; Grosso, R.; Grote, H.; Grunewald, S.; Guenther, M.; Gustafson, R.; Hage, B.; Hamilton, W. O.; Hammer, D.; Hanna, C.; Hanson, J.; Harms, J.; Harry, G.; Harstad, E.; Hayler, T.; Heefner, J.; Heng, I. S.; Heptonstall, A.; Heurs, M.; Hewitson, M.; Hild, S.; Hirose, E.; Hoak, D.; Hosken, D.; Hough, J.; Howell, E.; Hoyland, D.; Huttner, S. H.; Ingram, D.; Innerhofer, E.; Ito, M.; Itoh, Y.; Ivanov, A.; Jackrel, D.; Johnson, B.; Johnson, W. W.; Jones, D. I.; Jones, G.; Jones, R.; Ju, L.; Kalmus, P.; Kalogera, V.; Kasprzyk, D.; Katsavounidis, E.; Kawabe, K.; Kawamura, S.; Kawazoe, F.; Kells, W.; Keppel, D. G.; Khalili, F. Ya.; Kim, C.; King, P.; Kissel, J. S.; Klimenko, S.; Kokeyama, K.; Kondrashov, V.; Kopparapu, R. K.; Kozak, D.; Krishnan, B.; Kwee, P.; Lam, P. K.; Landry, M.; Lantz, B.; Lazzarini, A.; Lee, B.; Lei, M.; Leiner, J.; Leonhardt, V.; Leonor, I.; Libbrecht, K.; Lindquist, P.; Lockerbie, N. A.; Longo, M.; Lormand, M.; Lubiński, M.; Lück, H.; Machenschalk, B.; Macinnis, M.; Mageswaran, M.; Mailand, K.; Malec, M.; Mandic, V.; Marano, S.; Márka, S.; Markowitz, J.; Maros, E.; Martin, I.; Marx, J. N.; Mason, K.; Matone, L.; Matta, V.; Mavalvala, N.; McCarthy, R.; McCaulley, B. J.; McClelland, D. E.; McGuire, S. C.; McHugh, M.; McKenzie, K.; McNabb, J. W. C.; McWilliams, S.; Meier, T.; Melissinos, A.; Mendell, G.; Mercer, R. A.; Meshkov, S.; Messaritaki, E.; Messenger, C. J.; Meyers, D.; Mikhailov, E.; Miller, P.; Mitra, S.; Mitrofanov, V. P.; Mitselmakher, G.; Mittleman, R.; Miyakawa, O.; Mohanty, S.; Moody, V.; Moreno, G.; Mossavi, K.; Mowlowry, C.; Moylan, A.; Mudge, D.; Mueller, G.; Mukherjee, S.; Müller-Ebhardt, H.; Munch, J.; Murray, P.; Myers, E.; Myers, J.; Nash, T.; Nettles, D.; Newton, G.; Nishizawa, A.; Numata, K.; O'Reilly, B.; O'Shaughnessy, R.; Ottaway, D. J.; Overmier, H.; Owen, B. J.; Paik, H.-J.; Pan, Y.; Papa, M. A.; Parameshwaraiah, V.; Patel, P.; Pedraza, M.; Penn, S.; Pierro, V.; Pinto, I. M.; Pitkin, M.; Pletsch, H.; Plissi, M. V.; Postiglione, F.; Prix, R.; Quetschke, V.; Raab, F.; Rabeling, D.; Radkins, H.; Rahkola, R.; Rainer, N.; Rakhmanov, M.; Ramsunder, M.; Rawlins, K.; Ray-Majumder, S.; Re, V.; Rehbein, H.; Reid, S.; Reitze, D. H.; Ribichini, L.; Riesen, R.; Riles, K.; Rivera, B.; Robertson, N. A.; Robinson, C.; Robinson, E. L.; Roddy, S.; Rodriguez, A.; Rogan, A. M.; Rollins, J.; Romano, J. D.; Romie, J.; Route, R.; Rowan, S.; Rüdiger, A.; Ruet, L.; Russell, P.; Ryan, K.; Sakata, S.; Samidi, M.; Sancho de La Jordana, L.; Sandberg, V.; Sannibale, V.; Saraf, S.; Sarin, P.; Sathyaprakash, B. S.; Sato, S.; Saulson, P. R.; Savage, R.; Savov, P.; Schediwy, S.; Schilling, R.; Schnabel, R.; Schofield, R.; Schutz, B. F.; Schwinberg, P.; Scott, S. M.; Searle, A. C.; Sears, B.; Seifert, F.; Sellers, D.; Sengupta, A. S.; Shawhan, P.; Shoemaker, D. H.; Sibley, A.; Sidles, J. A.; Siemens, X.; Sigg, D.; Sinha, S.; Sintes, A. M.; Slagmolen, B. J. J.; Slutsky, J.; Smith, J. R.; Smith, M. R.; Somiya, K.; Strain, K. A.; Strom, D. M.; Stuver, A.; Summerscales, T. Z.; Sun, K.-X.; Sung, M.; Sutton, P. J.; Takahashi, H.; Tanner, D. B.; Tarallo, M.; Taylor, R.; Taylor, R.; Thacker, J.; Thorne, K. A.; Thorne, K. S.; Thüring, A.; Tokmakov, K. V.; Torres, C.; Torrie, C.; Traylor, G.; Trias, M.; Tyler, W.; Ugolini, D.; Ungarelli, C.; Urbanek, K.; Vahlbruch, H.; Vallisneri, M.; van den Broeck, C.; Varvella, M.; Vass, S.; Vecchio, A.; Veitch, J.; Veitch, P.; Villar, A.; Vorvick, C.; Vyachanin, S. P.; Waldman, S. J.; Wallace, L.; Ward, H.; Ward, R.; Watts, K.; Weaver, J.; Webber, D.; Weber, A.; Weidner, A.; Weinert, M.; Weinstein, A.; Weiss, R.; Wen, S.; Wette, K.; Whelan, J. T.; Whitbeck, D. M.; Whitcomb, S. E.; Whiting, B. F.; Wilkinson, C.; Willems, P. A.; Williams, L.; Willke, B.; Wilmut, I.; Winkler, W.; Wipf, C. C.; Wise, S.; Wiseman, A. G.; Woan, G.; Woods, D.; Wooley, R.; Worden, J.; Wu, W.; Yakushin, I.; Yamamoto, H.; Yan, Z.; Yoshida, S.; Yunes, N.; Zanolin, M.; Zhang, J.; Zhang, L.; Zhang, P.; Zhao, C.; Zotov, N.; Zucker, M.; Zur Mühlen, H.; Zweizig, J.

    2007-07-01

    Data from the LIGO Livingston interferometer and the ALLEGRO resonant-bar detector, taken during LIGO’s fourth science run, were examined for cross correlations indicative of a stochastic gravitational-wave background in the frequency range 850 950 Hz, with most of the sensitivity arising between 905 and 925 Hz. ALLEGRO was operated in three different orientations during the experiment to modulate the relative sign of gravitational-wave and environmental correlations. No statistically significant correlations were seen in any of the orientations, and the results were used to set a Bayesian 90% confidence level upper limit of Ωgw(f)≤1.02, which corresponds to a gravitational-wave strain at 915 Hz of 1.5×10-23Hz-1/2. In the traditional units of h1002Ωgw(f), this is a limit of 0.53, 2 orders of magnitude better than the previous direct limit at these frequencies. The method was also validated with successful extraction of simulated signals injected in hardware and software.

  13. Acoustic resonator with Al electrodes on an AlN layer and using a GaAs substrate

    DOEpatents

    Kline, Gerald R.; Lakin, Kenneth M.

    1985-12-03

    A method of fabricating an acoustic wave resonator wherein all processing steps are accomplished from a single side of said substrate. The method involves deposition of a multi-layered Al/AlN structure on a GaAs substrate followed by a series of fabrication steps to define a resonator from said composite. The resulting resonator comprises an AlN layer between two Al layers and another layer of AlN on an exterior of one of said Al layers.

  14. High-Q cross-plate phononic crystal resonator for enhanced acoustic wave localization and energy harvesting

    NASA Astrophysics Data System (ADS)

    Yang, Aichao; Li, Ping; Wen, Yumei; Yang, Chao; Wang, Decai; Zhang, Feng; Zhang, Jiajia

    2015-05-01

    A high-Q cross-plate phononic crystal resonator (Cr-PCR) coupled with an electromechanical Helmholtz resonator (EMHR) is proposed to improve acoustic wave localization and energy harvesting. Owing to the strongly directional wave-scattering effect of the cross-plate corners, strong confinement of acoustic waves emerges. Consequently, the proposed Cr-PCR structure exhibits ∼353.5 times higher Q value and ∼6.1 times greater maximum pressure amplification than the phononic crystal resonator (Cy-PCR) (consisting of cylindrical scatterers) of the same size. Furthermore, the harvester using the proposed Cr-PCR and the EMHR has ∼22 times greater maximum output-power volume density than the previous harvester using Cy-PCR and EMHR structures.

  15. Detecting leaks in gas-filled pressure vessels using acoustic resonances

    NASA Astrophysics Data System (ADS)

    Gillis, K. A.; Moldover, M. R.; Mehl, J. B.

    2016-05-01

    We demonstrate that a leak from a large, unthermostatted pressure vessel into ambient air can be detected an order of magnitude more effectively by measuring the time dependence of the ratio p/f2 than by measuring the ratio p/T. Here f is the resonance frequency of an acoustic mode of the gas inside the pressure vessel, p is the pressure of the gas, and T is the kelvin temperature measured at one point in the gas. In general, the resonance frequencies are determined by a mode-dependent, weighted average of the square of the speed-of-sound throughout the volume of the gas. However, the weighting usually has a weak dependence on likely temperature gradients in the gas inside a large pressure vessel. Using the ratio p/f2, we measured a gas leak (dM/dt)/M ≈ - 1.3 × 10-5 h-1 = - 0.11 yr-1 from a 300-liter pressure vessel filled with argon at 450 kPa that was exposed to sunshine-driven temperature and pressure fluctuations as large as (dT/dt)/T ≈ (dp/dt)/p ≈ 5 × 10-2 h-1 using a 24-hour data record. This leak could not be detected in a 72-hour record of p/T. (Here M is the mass of the gas in the vessel and t is the time.)

  16. Acoustic beam scattering and excitation of sphere resonance: Bessel beam example.

    PubMed

    Marston, Philip L

    2007-07-01

    The exact partial wave series for the scattering by a sphere centered on an ideal Bessel beam was recently given by Marston ["Scattering of a Bessel beam by a sphere," J. Acoust. Soc. Am. 121, 753-758 (2007)]. That series is applied here to solid elastic spheres in water and to an empty spherical shell in water. The examples are selected to illustrate the effect of varying the beam's conical angle so as to modify the coupling to specific resonances in the response of each type of sphere considered. The backscattering may be reduced or increased depending on properties of the resonance and of the specular contribution. Changing the conical angle is equivalent to changing the beamwidth. Some applications of the Van de Hulst localization principle to the interpretation of the partial wave series and to the interpretation of the scattering dependence on the beam's conical angle are discussed. Some potential applications to the analysis of the scattering by spheres of more general axisymmetric beams are noted. PMID:17614484

  17. Kiwi fruit (Actinidia chinensis) quality determination based on surface acoustic wave resonator combined with electronic nose.

    PubMed

    Wei, Liu; Guohua, Hui

    2015-01-01

    In this study, electronic nose (EN) combined with a 433 MHz surface acoustic wave resonator (SAWR) was used to determine Kiwi fruit quality under 12-day storage. EN responses to Kiwi samples were measured and analyzed by principal component analysis (PCA) and stochastic resonance (SR) methods. SAWR frequency eigen values were also measured to predict freshness. Kiwi fruit sample's weight loss index and human sensory evaluation were examined to characteristic its quality and freshness. Kiwi fruit's quality predictive models based on EN, SAWR, and EN combined with SAWR were developed, respectively. Weight loss and human sensory evaluation results demonstrated that Kiwi fruit's quality decline and overall acceptance decrease during the storage. Experiment result indicated that the PCA method could qualitatively discriminate all Kiwi fruit samples with different storage time. Both SR and SAWR frequency analysis methods could successfully discriminate samples with high regression coefficients (R = 0.98093 and R = 0.99014, respectively). The validation experiment results showed that the mixed predictive model developed using EN combined with SAWR present higher quality prediction accuracy than the model developed either by EN or by SAWR. This method exhibits some advantages including high accuracy, non-destructive, low cost, etc. It provides an effective way for fruit quality rapid analysis. PMID:25551334

  18. Kiwi fruit (Actinidia chinensis) quality determination based on surface acoustic wave resonator combined with electronic nose

    PubMed Central

    Wei, Liu; Guohua, Hui

    2015-01-01

    In this study, electronic nose (EN) combined with a 433 MHz surface acoustic wave resonator (SAWR) was used to determine Kiwi fruit quality under 12-day storage. EN responses to Kiwi samples were measured and analyzed by principal component analysis (PCA) and stochastic resonance (SR) methods. SAWR frequency eigen values were also measured to predict freshness. Kiwi fruit sample's weight loss index and human sensory evaluation were examined to characteristic its quality and freshness. Kiwi fruit's quality predictive models based on EN, SAWR, and EN combined with SAWR were developed, respectively. Weight loss and human sensory evaluation results demonstrated that Kiwi fruit's quality decline and overall acceptance decrease during the storage. Experiment result indicated that the PCA method could qualitatively discriminate all Kiwi fruit samples with different storage time. Both SR and SAWR frequency analysis methods could successfully discriminate samples with high regression coefficients (R = 0.98093 and R = 0.99014, respectively). The validation experiment results showed that the mixed predictive model developed using EN combined with SAWR present higher quality prediction accuracy than the model developed either by EN or by SAWR. This method exhibits some advantages including high accuracy, non-destructive, low cost, etc. It provides an effective way for fruit quality rapid analysis. PMID:25551334

  19. Detecting leaks in gas-filled pressure vessels using acoustic resonances.

    PubMed

    Gillis, K A; Moldover, M R; Mehl, J B

    2016-05-01

    We demonstrate that a leak from a large, unthermostatted pressure vessel into ambient air can be detected an order of magnitude more effectively by measuring the time dependence of the ratio p/f(2) than by measuring the ratio p/T. Here f is the resonance frequency of an acoustic mode of the gas inside the pressure vessel, p is the pressure of the gas, and T is the kelvin temperature measured at one point in the gas. In general, the resonance frequencies are determined by a mode-dependent, weighted average of the square of the speed-of-sound throughout the volume of the gas. However, the weighting usually has a weak dependence on likely temperature gradients in the gas inside a large pressure vessel. Using the ratio p/f(2), we measured a gas leak (dM/dt)/M ≈ - 1.3 × 10(-5) h(-1) = - 0.11 yr(-1) from a 300-liter pressure vessel filled with argon at 450 kPa that was exposed to sunshine-driven temperature and pressure fluctuations as large as (dT/dt)/T ≈ (dp/dt)/p ≈ 5 × 10(-2) h(-1) using a 24-hour data record. This leak could not be detected in a 72-hour record of p/T. (Here M is the mass of the gas in the vessel and t is the time.). PMID:27250456

  20. Search for High Mass Resonances Decaying to Muon Pairs in $\\sqrt{s}=1.96$ TeV $p\\bar{p}$ Collisions

    SciTech Connect

    Aaltonen, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J.A.; Apresyan, A.; Arisawa, T.; /Waseda U. /Dubna, JINR

    2011-01-01

    We present a search for a new narrow, spin-1, high mass resonance decaying to {mu}{sup +}{mu}{sup -} + X, using a matrix element based likelihood and a simultaneous measurement of the resonance mass and production rate. In data with 4.6 fb{sup -1} of integrated luminosity collected by the CDF detector in p{bar p} collisions at {radical}s = 1960 GeV, the most likely signal cross section is consistent with zero at 16% confidence level. We therefore do not observe evidence for a high mass resonance, and place limits on models predicting spin-1 resonances, including M > 1071 GeV/c{sup 2} at 95% confidence level for a Z{prime} boson with the same couplings to fermions as the Z boson.

  1. Perceptual identification and acoustic measures of the resonant voice based on "Lessac's Y-Buzz"--a preliminary study with actors.

    PubMed

    Barrichelo, Viviane M O; Behlau, Mara

    2007-01-01

    This study aimed to verify whether the resonant voice based on Lessac's Y-Buzz can be perceived by listeners as resonant and different from habitual voice and to compare them to determine whether this sound exploration improves the vocal production. Nine newly graduated actors, six men and three women without voice complaints, were the subjects. They received a session of Lessac's Y-Buzz training from the primary investigator. Before training, they were asked to sustain the vowel /i/ at comfortable frequency and habitual loudness. After training, they were requested to sustain the Y-Buzz they had learned at a comfortable frequency and habitual loudness. Three speech-language pathologists (SLP) trained in voice developed an auditory-perceptive analysis. The pre- and posttraining voice samples were randomly spliced together, edited, and presented in pairs to perceptual judges who were asked to identify the most resonant of the pair. The voice samples were also acoustically compared through the Hoarseness Diagram and acoustic measures using the VoxMetria Software (CTS, version 2.0s, Brazil). The Y-Buzz trials were identified as resonant voice in 74% of the comparisons. The acoustic measures showed a statistically significant decrease of irregularity (P = 0.002) and shimmer (P = 0.38). The Hoarseness Diagram demonstrated how the resonant voice moved toward the normality for irregularity and noise components. The results showed that the resonant voice based on the Y-Buzz can be identified as resonant and different from normal voicing in the same subject, and it apparently implies a better vocal production demonstrating a significant decrease of shimmer and irregularity through the Hoarseness Diagram evaluation. PMID:16458480

  2. The ionization instability and resonant acoustic modes suppression by charge space effects in a dusty plasma

    SciTech Connect

    Conde, L.

    2006-03-15

    The large wavenumber suppression of unstable modes by space charge effects of the ionization instability in a weakly ionized and unmagnetized dusty plasma is investigated. The charge losses in the initial equilibrium state are balanced by electron impact ionizations originated by both the thermal electron populations and an additional monoenergetic electron beam. The multifluid dimensionless equations are deduced by using the time and length scales for elastic collisions between ions and neutral atoms and the Poisson equation relates the plasma potential fluctuations with charged particle densities instead of the quasineutral approximation. A general dimensionless dispersion relation is obtained from the linearized transport equations, where the ratios between the characteristic velocities, as the dust ion acoustic (IA), dust acoustic (DA), ion sound, and thermal speeds permits us to evaluate the weight of the different terms. In the long wavelength limit the results obtained using the quasineutral approximation are recovered. The differences found between roots of both dispersion equations are discussed, as well as those of previous models. The unstable mode of the linear ionization instability is originated by the imbalance between ion and electron densities in the rest state caused by the negative charging of dust grains. Contrary to dust free plasmas, the unstable mode exists, even in the absence of the ionizing electron beam. The numerical calculations of the roots of the full dispersion equation present a maximum unstable wavenumber not predicted by the quasineutral approximation, which is related with the minimum allowed length for space charge fluctuations within a fluid model. This upper limit of unstable wave numbers hinders the predicted resonant coupling in the long wavenumber regime between the DA and DIA waves.

  3. Acoustic evaluation of the Helmholtz resonator treatment in the NASA Lewis 8- by 6-foot supersonic wind tunnel

    NASA Technical Reports Server (NTRS)

    Heidelberg, Laurence J.; Gordon, Elliot B.

    1989-01-01

    The acoustic consequences of sealing the Helmholtz resonators of the NASA Lewis 8- by 6-Foot Supersonic Wind Tunnel (8x6 SWT) were experimentally evaluated. This resonator sealing was proposed in order to avoid entrapment of hydrogen during tests of advanced hydrogen-fueled engines. The resonators were designed to absorb energy in the 4- to 20-Hz range; thus, this investigation is primarily concerned with infrasound. Limited internal and external noise measurements were made at tunnel Mach numbers ranging from 0.5 to 2.0. Although the resonators were part of the acoustic treatment installed because of a community noise problem their sealing did not seem to indicate a reoccurrence of the problem would result. Two factors were key to this conclusion: (1) A large bulk treatment muffler downstream of the resonators was able to make up for much of the attenuation originally provided by the resonators, and (2) there was no noise source in the tunnel test section. The previous community noise problem occurred when a large ramjet was tested in an open-loop tunnel configuration. If a propulsion system producing high noise levels at frequencies of less than 10 Hz were tested, the conclusion on community noise would have to be reevaluated.

  4. Development of a combined surface plasmon resonance/surface acoustic wave device for the characterization of biomolecules

    NASA Astrophysics Data System (ADS)

    Bender, Florian; Roach, Paul; Tsortos, Achilleas; Papadakis, George; Newton, Michael I.; McHale, Glen; Gizeli, Electra

    2009-12-01

    It is known that acoustic sensor devices, if operated in liquid phase, are sensitive not just to the mass of the analyte but also to various other parameters, such as size, shape, charge and elastic constants of the analyte as well as bound and viscously entrained water. This can be used to extract valuable information about a biomolecule, particularly if the acoustic device is combined with another sensor element which is sensitive to the mass or amount of analyte only. The latter is true in good approximation for various optical sensor techniques. This work reports on the development of a combined surface plasmon resonance/surface acoustic wave sensor system which is designed for the investigation of biomolecules such as proteins or DNA. Results for the deposition of neutravidin and DNA are reported.

  5. Focusing of the lowest-order antisymmetric Lamb mode behind a gradient-index acoustic metalens with local resonators

    NASA Astrophysics Data System (ADS)

    Zhao, Jinfeng; Bonello, Bernard; Boyko, Olga

    2016-05-01

    We have investigated the focusing of the lowest-order antisymmetric Lamb mode (A0) behind a positive gradient-index (GRIN) acoustic metalens consisting of air holes drilled in a silicon plate with silicon pillars erected on one face of the lens. We have analyzed the focusing in the near field as the result of the coupling between the flexural resonant mode of the pillars and the vibration mode of the air/silicon phononic crystal. We highlight the role played by the polarization coherence between the resonant mode and the vibration of the plate. We demonstrate both numerically and experimentally the focusing behind the lens over a spot less than half a wavelength, paving a way for performance of acoustic lenses beyond the diffraction limit. Our findings can be easily extended to other types of elastic wave.

  6. Dual-mode resonant instabilities of the surface dust-acoustic wave in a Lorentzian plasma slab

    SciTech Connect

    Lee, Myoung-Jae; Jung, Young-Dae

    2015-08-15

    The dual-mode resonant instabilities of the dust-acoustic surface wave propagating at the plasma-vacuum interfaces of the generalized Lorentzian dusty plasma slab are kinetically investigated. The dispersion relation is derived for the two propagation modes: symmetric and anti-symmetric waves. We have found that the temporal growth rate of the resonant instability increases with an increase of the slab thickness for both modes. Especially, the nonthermality of plasmas enhances the growth rate of the anti-symmetric resonant wave, and the nonthermal effect is enhanced as the slab thickness is increased. It is also found that the growth rate increases with increasing angular frequency of the rotating dust grain due to the enhanced resonant energy exchange.

  7. Investigation of the scaling rules determining the performance of film bulk acoustic resonators operating as mass sensors.

    PubMed

    Weber, Jan; Link, Mathias; Primig, Robert; Pitzer, Dana; Wersing, Wolfram; Schreiter, Matthias

    2007-02-01

    Solidly mounted (SMR-type) thin film bulk acoustic resonators operating at 2.2, 4.1, and 8.0 GHz and with lateral extents from 30 to 500 microm were fabricated and their performance as mass sensors was evaluated theoretically as well as experimentally. It was found that increasing the frequency leads to a principally improved performance of these devices. Problems arising for the horizontal as well as the vertical dimension and structure are investigated. PMID:17328337

  8. A process to control light in a micro resonator through a coupling modulation by surface acoustic waves

    PubMed Central

    Fan, Guofang; Li, Yuan; Hu, Chunguang; Lei, Lihua; Guo, Yanchuan

    2016-01-01

    A novel process to control light through the coupling modulation by surface acoustic wave (SAW) is presented in an optical micro resonator. An optical waveguide modulator of a racetrack resonator on silicon-on-insulator (SOI) technology is took as an example to explore the mechanism. A finite-difference time-domain (FDTD) is developed to simulate the acousto-optical (AO) modulator using the mechanism. An analytical method is presented to verify our proposal. The results show that the process can work well as an optical modulator by SAW. PMID:27485470

  9. A process to control light in a micro resonator through a coupling modulation by surface acoustic waves

    NASA Astrophysics Data System (ADS)

    Fan, Guofang; Li, Yuan; Hu, Chunguang; Lei, Lihua; Guo, Yanchuan

    2016-08-01

    A novel process to control light through the coupling modulation by surface acoustic wave (SAW) is presented in an optical micro resonator. An optical waveguide modulator of a racetrack resonator on silicon-on-insulator (SOI) technology is took as an example to explore the mechanism. A finite-difference time-domain (FDTD) is developed to simulate the acousto-optical (AO) modulator using the mechanism. An analytical method is presented to verify our proposal. The results show that the process can work well as an optical modulator by SAW.

  10. A process to control light in a micro resonator through a coupling modulation by surface acoustic waves.

    PubMed

    Fan, Guofang; Li, Yuan; Hu, Chunguang; Lei, Lihua; Guo, Yanchuan

    2016-01-01

    A novel process to control light through the coupling modulation by surface acoustic wave (SAW) is presented in an optical micro resonator. An optical waveguide modulator of a racetrack resonator on silicon-on-insulator (SOI) technology is took as an example to explore the mechanism. A finite-difference time-domain (FDTD) is developed to simulate the acousto-optical (AO) modulator using the mechanism. An analytical method is presented to verify our proposal. The results show that the process can work well as an optical modulator by SAW. PMID:27485470

  11. Emergence of colour symmetry in free-vibration acoustic resonance of a nonlinear hyperelastic material

    PubMed Central

    Tarumi, Ryuichi

    2013-01-01

    We investigated free-vibration acoustic resonance (FVAR) of two-dimensional St Venant–Kirchhoff-type hyperelastic materials and revealed the existence and structure of colour symmetry embedded therein. The hyperelastic material is isotropic and frame indifferent and includes geometrical nonlinearity in its constitutive equation. The FVAR state is formulated using the principle of stationary action with a subsidiary condition. Numerical analysis based on the Ritz method revealed the existence of four types of nonlinear FVAR modes associated with the irreducible representations of a linearized system. Projection operation revealed that the FVAR modes can be classified on the basis of a single colour (black or white) and three types of bicolour (black and white) magnetic point groups: , , and . These results demonstrate that colour symmetry naturally arises in the finite amplitude nonlinear FVAR modes, and its vibrational symmetries are explained in terms of magnetic point groups rather than the irreducible representations that have been used for linearized systems. We also predicted a grey colour nonlinear FVAR mode which cannot be derived from a linearized system. PMID:24204182

  12. Wave propagation in piezoelectric layered structures of film bulk acoustic resonators.

    PubMed

    Zhu, Feng; Qian, Zheng-hua; Wang, Bin

    2016-04-01

    In this paper, we studied the wave propagation in a piezoelectric layered plate consisting of a piezoelectric thin film on an electroded elastic substrate with or without a driving electrode. Both plane-strain and anti-plane waves were taken into account for the sake of completeness. Numerical results on dispersion relations, cut-off frequencies and vibration distributions of selected modes were given. The effects of mass ratio of driving electrode layer to film layer on the dispersion curve patterns and cut-off frequencies of the plane-strain waves were discussed in detail. Results show that the mass ratio does not change the trend of dispersion curves but larger mass ratio lowers corresponding frequency at a fixed wave number and may extend the frequency range for energy trapping. Those results are of fundamental importance and can be used as a reference to develop effective two-dimensional plate equations for structural analysis and design of film bulk acoustic resonators. PMID:26812132

  13. An experimental study on resonance of oscillating air/vapor bubbles in water using a two-frequency acoustic apparatus

    NASA Astrophysics Data System (ADS)

    Ohsaka, K.

    2003-05-01

    A two-frequency acoustic apparatus is employed to study the growth behavior of vapor-saturated bubbles driven in a volumetric mode. A unique feature of the apparatus is its capability of trapping a bubble by an ultrasonic standing wave while independently driving it into oscillations by a second lower-frequency acoustic wave. It is observed that the growing vapor bubbles exhibit a periodic shape transition between the volumetric and shape modes due to resonant coupling. In order to explain this observation, we performed an experimental investigation on resonant coupling of air bubbles and obtained the following results: First, the induced shape oscillations are actually a mixed mode that contains the volume component, thus, vapor bubbles can grow while they exhibit shape oscillations. Second, the acoustically levitated bubbles are deformed and therefore, degeneracy in resonant frequency is partially removed. As a result, the vapor bubbles exhibit the shape oscillations in both the axisymmetric mode and asymmetric (three-dimensional) modes. Nonlinear effects in addition to the frequency shift and split due to deformation creates overlapping of the coupling ranges for different modes, which leads to the continuous shape oscillations above a certain bubble radius as the bubble grows.

  14. Search for high-mass resonances decaying into $ZZ$ in p$\\bar{p}$ collisions at $\\sqrt{s}=1.96$\\,TeV

    SciTech Connect

    Aaltonen, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J.A.; Arisawa, T.; Artikov, A.; /Dubna, JINR /Texas A-M

    2011-11-01

    The authors search for high-mass resonances decaying into Z boson pairs using data corresponding to 6 fb{sup -1} collected by the CDF experiment in p{bar p} collisions at {radical}s = 1.96 TeV. The search is performed in three distinct final states: ZZ {yields} {ell}{sup +}{ell}{sup -}{ell}{sup +}{ell}{sup -}, ZZ {yields} {ell}{sup +}{ell}{sup -}{nu}{nu}, and ZZ {yields} {ell}{sup +}{ell}{sup -}jj. For a Randall-Sundrum graviton G*, the 95% CL upper limits on the production cross section times branching ratio to ZZ, {sigma}(p{bar p} {yields} G* {yields} ZZ), vary between 0.26 pb and 0.045 pb in the mass range 300 < M{sub G*} < 1000 GeV/c{sup 2}.

  15. Variable ultrasound trigger delay for improved magnetic resonance acoustic radiation force imaging

    NASA Astrophysics Data System (ADS)

    Mougenot, Charles; Waspe, Adam; Looi, Thomas; Drake, James M.

    2016-01-01

    Magnetic resonance acoustic radiation force imaging (MR-ARFI) allows the quantification of microscopic displacements induced by ultrasound pulses, which are proportional to the local acoustic intensity. This study describes a new method to acquire MR-ARFI maps, which reduces the measurement noise in the quantification of displacement as well as improving its robustness in the presence of motion. Two MR-ARFI sequences were compared in this study. The first sequence ‘variable MSG’ involves switching the polarity of the motion sensitive gradient (MSG) between odd and even image frames. The second sequence named ‘static MSG’ involves a variable ultrasound trigger delay to sonicate during the first or second MSG for odd and even image frames, respectively. As previously published, the data acquired with a variable MSG required the use of reference data acquired prior to any sonication to process displacement maps. In contrary, data acquired with a static MSG were converted to displacement maps without using reference data acquired prior to the sonication. Displacement maps acquired with both sequences were compared by performing sonications for three different conditions: in a polyacrylamide phantom, in the leg muscle of a freely breathing pig and in the leg muscle of pig under apnea. The comparison of images acquired at even image frames and odd image frames indicates that the sequence with a static MSG provides a significantly better steady state (p  <  0.001 based on a Student’s t-test) than the images acquired with a variable MSG. In addition no reference data prior to sonication were required to process displacement maps for data acquired with a static MSG. The absence of reference data prior to sonication provided a 41% reduction of the spatial distribution of noise (p  <  0.001 based on a Student’s t-test) and reduced the sensitivity to motion for displacements acquired with a static MSG. No significant differences were expected and

  16. Effect of grazing flow on the acoustic impedance of Helmholtz resonators consisting of single and clustered orifices

    NASA Technical Reports Server (NTRS)

    Hersch, A. S.; Walker, B.

    1979-01-01

    A semiempirical fluid mechanical model is derived for the acoustic behavior of thin-walled single orifice Helmholtz resonators in a grazing flow environment. The incident and cavity sound fields are connected in terms of an orifice discharge coefficient whose values are determined experimentally using the two-microphone method. Measurements show that at high grazing flow speeds, acoustical resistance is almost linearly proportional to the grazing flow speed and almost independent of incident sound pressure. The corresponding values of reactance are much smaller and tend towards zero. For thicker-walled orifice plates, resistance and reactance were observed to be less sensitive to grazing flow as the ratio of plate thickness to orifice diameter increased. Loud tones were observed to radiate from a single orifice Helmholtz resonator due to interaction between the grazing flow shear layer and the resonator cavity. Measurements showed that the tones radiated at a Strouhal number equal to 0.26. The effects of grazing flow on the impedance of Helmholtz resonators consisting of clusters of orifices was also studied. In general, both resistance and reaction were found to be virtually independent of orifice relative spacing and number. These findings are valid with and without grazing flow.

  17. Wave propagation characteristics of helically orthotropic cylindrical shells and resonance emergence in scattered acoustic field. Part 1. Formulations

    NASA Astrophysics Data System (ADS)

    Rajabi, Majid

    2016-05-01

    The method of wave function expansion is adopted to study the three dimensional scattering of a plane progressive harmonic acoustic wave incident upon an arbitrarily thick-walled helically filament-wound composite cylindrical shell submerged in and filled with compressible ideal fluids. An approximate laminate model in the context of the so-called state-space formulation is employed for the construction of T-matrix solution to solve for the unknown modal scattering coefficients. Considering the nonaxisymmetric wave propagation phenomenon in anisotropic cylindrical components and following the resonance scattering theory which determines the resonance and background scattering fields, the stimulated resonance frequencies of the shell are isolated and classified due to their fundamental mode of excitation, overtone and style of propagation along the cylindrical axis (i.e., clockwise or anticlockwise propagation around the shell) and are identified as the helically circumnavigating waves.

  18. Contactless transport of matter in the first five resonance modes of a line-focused acoustic manipulator.

    PubMed

    Foresti, Daniele; Nabavi, Majid; Poulikakos, Dimos

    2012-02-01

    The first five resonance modes for transport of matter in a line-focused acoustic levitation system are investigated. Contactless transport was achieved by varying the height between the radiating plate and the reflector. Transport and levitation of droplets in particular involve two limits of the acoustic forces. The lower limit corresponds to the minimum force required to overcome the gravitational force. The upper limit corresponds to the maximum acoustic pressure beyond which atomization of the droplet occurs. As the droplet size increases, the lower limit increases and the upper limit decreases. Therefore to have large droplets levitated, relatively flat radiation pressure amplitude during the translation is needed. In this study, using a finite element model, the Gor'kov potential was calculated for different heights between the reflector and the radiating plate. The application of the Gor'kov potential was extended to study the range of droplet sizes for which the droplets can be levitated and transported without atomization. It was found that the third resonant mode (H(3)-mode) represents the best compromise between high levitation force and smooth pattern transition, and water droplets of millimeter radius can be levitated and transported. The H(3)-mode also allows for three translation lines in parallel. PMID:22352478

  19. Search for High-Mass \\boldmath$e^+e^-$ Resonances in \\boldmath$p\\bar{p}$ Collisions at \\boldmath$\\sqrt{s}=$1.96 TeV

    SciTech Connect

    Aaltonen, T.; Adelman, J.; Akimoto, T.; Albrow, Michael G.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, Dante E.; Anastassov, A.; Annovi, Alberto; Antos, J.; Apollinari, G.; /Fermilab /Purdue U.

    2008-10-01

    A search for high-mass resonances in the e{sup +}e{sup -} final state is presented based on {radical}s =1.96 TeV p{bar p} collision data from the CDF II detector at the Fermilab Tevatron from an integrated luminosity of 2.5 fb{sup -1}. The largest excess over the standard model prediction is at an e{sup +}e{sup -} invariant mass of 240 GeV/c{sup 2}. The probability of observing such an excess arising from fluctuations in the standard model anywhere in the mass range of 150-1,000 GeV/c{sup 2} is 0.6% (equivalent to 2.5 {sigma}). We set Bayesian upper limits on {sigma}(p{bar p} {yields} X) {center_dot} {Beta}(X {yields} e{sup +}e{sup -}) at the 95% credibility level, where X is a spin 1 or spin 2 particle, and we exclude the standard model coupling Z{prime} and the Randall-Sundrum graviton for {kappa}/{bar M}{sub Pl} = 0.1 with masses below 963 and 848 GeV/c{sup 2}, respectively.

  20. The condition of the resonant break-up of a gas bubble subjected to an acoustic wave in liquid

    NASA Astrophysics Data System (ADS)

    Vanovskiy, V. V.; Petrov, A. G.

    2015-12-01

    The problem of a gas bubble break-up in liquid is considered in the conditions of the frequencies resonance of the radial and nth axially symmetric deformational mode 2:1. The nonlinear energy transfer between the modes is described using an efficient Krylov-Bogolyubov averaging technique. It is shown that the deformational mode magnitude can be some orders larger than the radial mode magnitude which is damped by the thermal, viscous and acoustic dissipation. The estimative criterion of bubble break-up is obtained in the cases of slow and fast acoustic wave start. The obtained pressure magnitudes in the wave for break-up are very small and the mechanism can have strong medical and technical applications.

  1. Digital data-acquisition system for measuring the free decay of acoustical standing waves in a resonant tube

    NASA Technical Reports Server (NTRS)

    Meredith, R. W.; Zuckerwar, A. J.

    1984-01-01

    A low-cost digital system based on an 8-bit Apple II microcomputer has been designed to provide on-line control, data acquisition, and evaluation of sound absorption measurements in gases. The measurements are conducted in a resonant tube, in which an acoustical standing wave is excited, the excitation removed, and the sound absorption evaluated from the free decay envelope. The free decay is initiated from the computer keyboard after the standing wave is established, and the microphone response signal is the source of the analog signal for the A/D converter. The acquisition software is written in ASSEMBLY language and the evaluation software in BASIC. This paper describes the acoustical measurement, hardware, software, and system performance and presents measurements of sound absorption in air as an example.

  2. Advanced numerical technique for analysis of surface and bulk acoustic waves in resonators using periodic metal gratings

    NASA Astrophysics Data System (ADS)

    Naumenko, Natalya F.

    2014-09-01

    A numerical technique characterized by a unified approach for the analysis of different types of acoustic waves utilized in resonators in which a periodic metal grating is used for excitation and reflection of such waves is described. The combination of the Finite Element Method analysis of the electrode domain with the Spectral Domain Analysis (SDA) applied to the adjacent upper and lower semi-infinite regions, which may be multilayered and include air as a special case of a dielectric material, enables rigorous simulation of the admittance in resonators using surface acoustic waves, Love waves, plate modes including Lamb waves, Stonely waves, and other waves propagating along the interface between two media, and waves with transient structure between the mentioned types. The matrix formalism with improved convergence incorporated into SDA provides fast and robust simulation for multilayered structures with arbitrary thickness of each layer. The described technique is illustrated by a few examples of its application to various combinations of LiNbO3, isotropic silicon dioxide and silicon with a periodic array of Cu electrodes. The wave characteristics extracted from the admittance functions change continuously with the variation of the film and plate thicknesses over wide ranges, even when the wave nature changes. The transformation of the wave nature with the variation of the layer thicknesses is illustrated by diagrams and contour plots of the displacements calculated at resonant frequencies.

  3. Realization of cavitation fields based on the acoustic resonance modes in an immersion-type sonochemical reactor.

    PubMed

    Wang, Yi-Chun; Yao, Ming-Chung

    2013-01-01

    Different modes of cavitation zones in an immersion-type sonochemical reactor have been realized based on the concept of acoustic resonance fields. The reactor contains three main components, namely a Langevin-type piezoelectric transducer (20 kHz), a metal horn, and a circular cylindrical sonicated cell filled with tap water. In order to diminish the generation of cavitation bubbles near the horn-tip, an enlarged cone-shaped horn is designed to reduce the ultrasonic intensity at the irradiating surface and to get better distribution of energy in the sonicated cell. It is demonstrated both numerically and experimentally that the cell geometry and the horn position have prominent effects on the pressure distribution of the ultrasound in the cell. With appropriate choices of these parameters, the whole reactor works at a resonant state. Several acoustic resonance modes observed in the simulation are realized experimentally to generate a large volume of cavitation zones using a very low ultrasonic power. PMID:22959558

  4. Biotin-Streptavidin Binding Interactions of Dielectric Filled Silicon Bulk Acoustic Resonators for Smart Label-Free Biochemical Sensor Applications

    PubMed Central

    Heidari, Amir; Yoon, Yong-Jin; Park, Woo-Tae; Su, Pei-Chen; Miao, Jianmin; Lin, Julius Tsai Ming; Park, Mi Kyoung

    2014-01-01

    Sensor performance of a dielectric filled silicon bulk acoustic resonator type label-free biosensor is verified with biotin-streptavidin binding interactions as a model system. The mass sensor is a micromachined silicon square plate with a dielectric filled capacitive excitation mechanism. The resonance frequency of the biotin modified resonator decreased 315 ppm when exposed to streptavidin solution for 15 min with a concentration of 10−7 M, corresponding to an added mass of 3.43 ng on the resonator surface. An additional control is added by exposing a bovine serum albumin (BSA)-covered device to streptavidin in the absence of the attached biotin. No resonance frequency shift was observed in the control experiment, which confirms the specificity of the detection. The sensor-to-sensor variability is also measured to be 4.3%. Consequently, the developed sensor can be used to observe in biotin-streptavidin interaction without the use of labelling or molecular tags. In addition, biosensor can be used in a variety of different immunoassay tests. PMID:24608003

  5. Biotin-streptavidin binding interactions of dielectric filled silicon bulk acoustic resonators for smart label-free biochemical sensor applications.

    PubMed

    Heidari, Amir; Yoon, Yong-Jin; Park, Woo-Tae; Su, Pei-Chen; Miao, Jianmin; Lin, Julius Tsai Ming; Park, Mi Kyoung

    2014-01-01

    Sensor performance of a dielectric filled silicon bulk acoustic resonator type label-free biosensor is verified with biotin-streptavidin binding interactions as a model system. The mass sensor is a micromachined silicon square plate with a dielectric filled capacitive excitation mechanism. The resonance frequency of the biotin modified resonator decreased 315 ppm when exposed to streptavidin solution for 15 min with a concentration of 10(-7) M, corresponding to an added mass of 3.43 ng on the resonator surface. An additional control is added by exposing a bovine serum albumin (BSA)-covered device to streptavidin in the absence of the attached biotin. No resonance frequency shift was observed in the control experiment, which confirms the specificity of the detection. The sensor-to-sensor variability is also measured to be 4.3%. Consequently, the developed sensor can be used to observe in biotin-streptavidin interaction without the use of labelling or molecular tags. In addition, biosensor can be used in a variety of different immunoassay tests. PMID:24608003

  6. Barometric and magnetic observations of vertical acoustic resonance and resultant generation of field-aligned current associated with earthquakes

    NASA Astrophysics Data System (ADS)

    Iyemori, Toshihiko; Tanaka, Yoshikazu; Odagi, Yoko; Sano, Yasuharu; Takeda, Masahiko; Nose, Masahito; Utsugi, Mitsuru; Rosales, Domingo; Choque, Edwin; Ishitsuka, Jose; Yamanaka, Sadato; Nakanishi, Kunihito; Matsumura, Mitsuru; Shinagawa, Hiroyuki

    2013-08-01

    Three rare occasions are introduced, where the excitation of vertical acoustic resonance between the ground and the ionosphere, and the resultant generation of a field-aligned current, just after earthquakes are observationally confirmed. In the case of two inland earthquakes, barometric observations very close to the epicenters (i.e., only 30 km apart) were available, and they showed a sharp spectral peak which appeared within one hour after the origin time and lasted a few hours. The observed periods of the spectral peaks around 260 seconds are close to the period of the theoretically-expected fundamental mode of the resonance. On the other hand, magnetic observations on the ground showed a dominant period at 220-230 seconds which corresponds to the first overtone among theoretically-expected major resonance peaks. In the third case, i.e., during the 2010 Chile earthquake, a long-period magnetic oscillation in the east-west direction, which has two major resonance periods at 265 and 190-195 seconds, was observed on the night-side magnetic dip equator in Peru, where the distance is more than 2600 km from the epicenter, under a very quiet geomagnetic condition. The oscillation was interpreted as the effect of field-aligned current generated through a dynamo process in the ionosphere over the epicenter caused by the resonance.

  7. A rapid magnetic resonance acoustic radiation force imaging sequence for ultrasonic refocusing

    NASA Astrophysics Data System (ADS)

    Mougenot, Charles; Pichardo, Samuel; Engler, Steven; Waspe, Adam; Constanciel Colas, Elodie; Drake, James M.

    2016-08-01

    Magnetic resonance guided acoustic radiation force imaging (MR-ARFI) is being used to correct for aberrations induced by tissue heterogeneities when using high intensity focusing ultrasound (HIFU). A compromise between published MR-ARFI adaptive solutions is proposed to achieve efficient refocusing of the ultrasound beam in under 10 min. In addition, an ARFI sequence based on an EPI gradient echo sequence was used to simultaneously monitor displacement and temperature with a large SNR and low distortion. This study was conducted inside an Achieva 3T clinical MRI using a Philips Sonalleve MR-HIFU system to emit a 1 ms pulsed sonication with duty cycle of 2.3% at 300 Wac inside a polymer phantom. Virtual elements defined by a Hadamard array with sonication patterns composed of 6 phase steps were used to characterize 64 groups of 4 elements to find the optimal phase of the 256 elements of the transducer. The 384 sonication patterns were acquired in 580 s to identify the set of phases that maximize the displacement at the focal point. Three aberrators (neonatal skull, 8 year old skull and a checkered pattern) were added to each sonication pattern to evaluate the performance of this refocusing algorithm (n  =  4). These aberrators reduced the relative intensities to 95.3%, 69.6% and 25.5% for the neonatal skull, 8 year old skull, and checkered pattern virtual aberrators respectively. Using a 10 min refocusing algorithm, relative intensities of 101.6%, 91.3% and 93.3% were obtained. Better relative intensities of 103.9%, 94.3% and 101% were achieved using a 25 min refocusing algorithm. An average temperature increase of 4.2 °C per refocusing test was induced for the 10 min refocusing algorithm, resulting in a negligible thermal dose of 2 EM. A rapid refocusing of the beam can be achieved while keeping thermal effects to a minimum.

  8. A rapid magnetic resonance acoustic radiation force imaging sequence for ultrasonic refocusing.

    PubMed

    Mougenot, Charles; Pichardo, Samuel; Engler, Steven; Waspe, Adam; Colas, Elodie Constanciel; Drake, James M

    2016-08-01

    Magnetic resonance guided acoustic radiation force imaging (MR-ARFI) is being used to correct for aberrations induced by tissue heterogeneities when using high intensity focusing ultrasound (HIFU). A compromise between published MR-ARFI adaptive solutions is proposed to achieve efficient refocusing of the ultrasound beam in under 10 min. In addition, an ARFI sequence based on an EPI gradient echo sequence was used to simultaneously monitor displacement and temperature with a large SNR and low distortion. This study was conducted inside an Achieva 3T clinical MRI using a Philips Sonalleve MR-HIFU system to emit a 1 ms pulsed sonication with duty cycle of 2.3% at 300 Wac inside a polymer phantom. Virtual elements defined by a Hadamard array with sonication patterns composed of 6 phase steps were used to characterize 64 groups of 4 elements to find the optimal phase of the 256 elements of the transducer. The 384 sonication patterns were acquired in 580 s to identify the set of phases that maximize the displacement at the focal point. Three aberrators (neonatal skull, 8 year old skull and a checkered pattern) were added to each sonication pattern to evaluate the performance of this refocusing algorithm (n  =  4). These aberrators reduced the relative intensities to 95.3%, 69.6% and 25.5% for the neonatal skull, 8 year old skull, and checkered pattern virtual aberrators respectively. Using a 10 min refocusing algorithm, relative intensities of 101.6%, 91.3% and 93.3% were obtained. Better relative intensities of 103.9%, 94.3% and 101% were achieved using a 25 min refocusing algorithm. An average temperature increase of 4.2 °C per refocusing test was induced for the 10 min refocusing algorithm, resulting in a negligible thermal dose of 2 EM. A rapid refocusing of the beam can be achieved while keeping thermal effects to a minimum. PMID:27401452

  9. A METHODOLOGY TO INTEGRATE MAGNETIC RESONANCE AND ACOUSTIC MEASUREMENTS FOR RESERVOIR CHARACTERIZATION

    SciTech Connect

    Jorge O. Parra; Chris L. Hackert; Lorna L. Wilson

    2002-09-20

    The work reported herein represents the third year of development efforts on a methodology to interpret magnetic resonance and acoustic measurements for reservoir characterization. In this last phase of the project we characterize a vuggy carbonate aquifer in the Hillsboro Basin, Palm Beach County, South Florida, using two data sets--the first generated by velocity tomography and the second generated by reflection tomography. First, we integrate optical macroscopic (OM), scanning electron microscope (SEM) and x-ray computed tomography (CT) images, as well as petrography, as a first step in characterizing the aquifer pore system. This pore scale integration provides information with which to evaluate nuclear magnetic resonance (NMR) well log signatures for NMR well log calibration, interpret ultrasonic data, and characterize flow units at the field scale between two wells in the aquifer. Saturated and desaturated NMR core measurements estimate the irreducible water in the rock and the variable T{sub 2} cut-offs for the NMR well log calibration. These measurements establish empirical equations to extract permeability from NMR well logs. Velocity and NMR-derived permeability and porosity relationships integrated with velocity tomography (based on crosswell seismic measurements recorded between two wells 100 m apart) capture two flow units that are supported with pore scale integration results. Next, we establish a more detailed picture of the complex aquifer pore structures and the critical role they play in water movement, which aids in our ability to characterize not only carbonate aquifers, but reservoirs in general. We analyze petrography and cores to reveal relationships between the rock physical properties that control the compressional and shear wave velocities of the formation. A digital thin section analysis provides the pore size distributions of the rock matrix, which allows us to relate pore structure to permeability and to characterize flow units at the

  10. Pulsed-laser excitation of acoustic modes in open high-Q photoacoustic resonators for trace gas monitoring: results for C2H4

    NASA Astrophysics Data System (ADS)

    Brand, Christian; Winkler, Andreas; Hess, Peter; Miklós, András; Bozóki, Zoltán; Sneider, János

    1995-06-01

    The pulsed excitation of acoustic resonances was studied with a continuously monitoring photoacoustic detector system. Acoustic waves were generated in C2H4/N 2 gas mixtures by light absorption of the pulses from a transversely excited atmospheric CO2 laser. The photoacoustic part consisted of high-Q cylindrical resonators (Q factor 820 for the first radial mode in N2) and two adjoining variable acoustic filter systems. The time-resolved signal was Fourier transformed to a frequency spectrum of high resolution. For the first radial mode a Lorentzian profile was fitted to the measured data. The outside noise suppression and the signal-to-noise ratio were investigated in a normal laboratory environment in the flow-through mode. The acoustic and electric filter system combined with the

  11. Non-linear Alfvén wave interaction leading to resonant excitation of an acoustic mode in the laboratorya)

    NASA Astrophysics Data System (ADS)

    Dorfman, S.; Carter, T. A.

    2015-05-01

    The nonlinear three-wave interaction process at the heart of the parametric decay process is studied by launching counter-propagating Alfvén waves from antennas placed at either end of the Large Plasma Device [W. Gekelman et al., Rev. Sci. Instrum. 62, 2875 (1991)]. A resonance in the beat wave response produced by the two launched Alfvén waves is observed and is identified as a damped ion acoustic mode based on the measured dispersion relation. Other properties of the interaction including the spatial profile of the beat mode and response amplitude are also consistent with theoretical predictions for a three-wave interaction driven by a nonlinear ponderomotive force. A simple damped, driven oscillator model making use of the MHD equations well-predicts most of the observations, but the width of the resonance curve is still under investigation.

  12. Non-linear Alfvén wave interaction leading to resonant excitation of an acoustic mode in the laboratory

    SciTech Connect

    Dorfman, S.; Carter, T. A.

    2015-05-15

    The nonlinear three-wave interaction process at the heart of the parametric decay process is studied by launching counter-propagating Alfvén waves from antennas placed at either end of the Large Plasma Device [W. Gekelman et al., Rev. Sci. Instrum. 62, 2875 (1991)]. A resonance in the beat wave response produced by the two launched Alfvén waves is observed and is identified as a damped ion acoustic mode based on the measured dispersion relation. Other properties of the interaction including the spatial profile of the beat mode and response amplitude are also consistent with theoretical predictions for a three-wave interaction driven by a nonlinear ponderomotive force. A simple damped, driven oscillator model making use of the MHD equations well-predicts most of the observations, but the width of the resonance curve is still under investigation.

  13. Resonance searches with the t$\\bar{t}$ invariant mass distribution measured with the DØ experiment at √s=1.96 TeV

    SciTech Connect

    Schliephake, Thorsten Dirk

    2010-06-01

    masses are therefore presumed to be a window to test the SM for deviations caused by new physics. The heaviest fundamental particle which is in our reach is the top quark. Its mass is almost as large as that of a complete tungsten atom. It is so heavy, that it decays faster than it can hadronize. It seems the perfect probe to study new physics at the moment. In this analysis the top quark is used as a probe to search for a new resonance, whose properties are similar to a SM Z boson but is much more massive. This analysis will study t{bar t} decays to search for an excess in the invariant mass distribution of the t$\\bar{t}$ pairs. Resonant states are suggested for massive Z-like bosons in extended gauge theories, Kaluza Klein states of the gluon or Z, axigluons, topcolor, and other beyond the Standard Model theories. Independent of the exact model a resonant production mechanism should be visible in the t$\\bar{t}$ invariant mass distribution. In this thesis a model-independent search for a narrow-width heavy resonance X decaying into t$\\bar{t}$ is performed. In the SM, the top quark decays into a W boson and a b quark nearly 100% of the time, which has been proven experimentally, too. The t$\\bar{t}$ event signature is fully determined by the W boson decay modes. In this analysis, only the lepton+jets final state, which results from the leptonic decay of one of the W bosons and the hadronic decay of the other, is considered. The event signature is an isolated electron or muon with high transverse momentum, large transverse energy imbalance due to the undetected neutrino, and at least three jets, two of which result from the hadronization of b quarks.

  14. Mechanical back-action of a spin-wave resonance in a magnetoelastic thin film on a surface acoustic wave

    NASA Astrophysics Data System (ADS)

    Gowtham, P. G.; Labanowski, D.; Salahuddin, S.

    2016-07-01

    Surface acoustic waves (SAWs) traveling on the surface of a piezoelectric crystal can, through the magnetoelastic interaction, excite traveling spin-wave resonance in a magnetic film deposited on the substrate. This spin-wave resonance in the magnetic film creates a time-ynamic surface stress of magnetoelastic origin that acts back on the surface of the piezoelectric and modifies the SAW propagation. Unlike previous analyses that treat the excitation as a magnon-phonon polariton, here the magnetoelastic film is treated as a perturbation modifying boundary conditions on the SAW. We use acoustical perturbation theory to find closed-form expressions for the back-action surface stress and strain fields and the resultant SAW velocity shifts and attenuation. We demonstrate that the shear stres fields associated with this spin-wave back-action also generate effective surface currents on the piezoelectric both in phase and out of phase with the driving SAW potential. Characterization of these surface currents and their applications in determination of the magnetoelastic coupling are discussed. The perturbative calculation is carried out explicitly to first order (a regime corresponding to many experimental situations of current interest) and we provide a sketch of the implications of the theory at higher order.

  15. Measured and calculated acoustic attenuation rates of tuned resonator arrays for two surface impedance distribution models with flow

    NASA Technical Reports Server (NTRS)

    Parrott, Tony L.; Abrahamson, A. Louis; Jones, Michael G.

    1988-01-01

    An experiment was performed to validate two analytical models for predicting low frequency attenuation of duct liner configurations built from an array of seven resonators that could be individually tuned via adjustable cavity depths. These analytical models had previously been developed for high frequency aero-engine inlet duct liner design. In the low frequency application, the liner surface impedance distribution is unavoidably spatially varying by virtue of available fabrication techniques. The characteristic length of this spatial variation may be a significant fraction of the acoustic wavelength. Comparison of measured and predicted attenuation rates and transmission losses for both modal decomposition and finite element propagation models were in good to excellent agreement for a test frequency range that included the first and second cavity resonance frequencies. This was true for either of two surface impedance distribution modeling procedures used to simplify the impedance boundary conditions. In the presence of mean flow, measurements revealed a fine scale structure of acoustic hot spots in the attenuation and phase profiles. These details were accurately predicted by the finite element model. Since no impedance changes due to mean flow were assumed, it is concluded that this fine scale structure was due to convective effects of the mean flow interacting with the surface impedance nonuniformities.

  16. Apparatus and method for non-contact, acoustic resonance determination of intraocular pressure

    DOEpatents

    Sinha, Dipen N.; Wray, William O.

    1994-01-01

    Apparatus and method for measuring intraocular pressure changes in an eye under investigation by detection of vibrational resonances therein. An ultrasonic transducer operating at its resonant frequency is amplitude modulated and swept over a range of audio frequencies in which human eyes will resonate. The output therefrom is focused onto the eye under investigation, and the resonant vibrations of the eye observed using a fiber-optic reflection vibration sensor. Since the resonant frequency of the eye is dependent on the pressure therein, changes in intraocular pressure may readily be determined after a baseline pressure is established.

  17. Apparatus and method for non-contact, acoustic resonance determination of intraocular pressure

    DOEpatents

    Sinha, D.N.; Wray, W.O.

    1994-12-27

    The apparatus and method for measuring intraocular pressure changes in an eye under investigation by detection of vibrational resonances therein. An ultrasonic transducer operating at its resonant frequency is amplitude modulated and swept over a range of audio frequencies in which human eyes will resonate. The output therefrom is focused onto the eye under investigation, and the resonant vibrations of the eye observed using a fiber-optic reflection vibration sensor. Since the resonant frequency of the eye is dependent on the pressure therein, changes in intraocular pressure may readily be determined after a baseline pressure is established. 3 figures.

  18. Inclusive π±, K± and(p,bar p) differential cross-sections at the Z resonance

    NASA Astrophysics Data System (ADS)

    Buskulic, D.; Casper, D.; de Bonis, I.; Decamp, D.; Ghez, P.; Goy, C.; Lees, J.-P.; Minard, M.-N.; Odier, P.; Pietrzyk, B.; Ariztizabal, F.; Chmeissani, M.; Crespo, J. M.; Efthymiopoulos, I.; Fernandez, E.; Fernandez-Bosman, M.; Gaitan, V.; Garrido, L. I.; Martinez, M.; Orteu, S.; Pacheco, A.; Padilla, C.; Palla, F.; Pascual, A.; Perlas, J. A.; Sanchez, F.; Teubert, F.; Creanza, D.; de Palma, M.; Farilla, A.; Iaselli, G.; Maggi, G.; Marinelli, N.; Natali, S.; Nuzzo, S.; Ranieri, A.; Raso, G.; Romano, F.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Zito, G.; Huang, X.; Lin, J.; Ouyang, Q.; Wang, T.; Xie, Y.; Xu, R.; Xue, S.; Zhang, J.; Zhang, L.; Zhao, W.; Bonvicini, G.; Cattaneo, M.; Comas, P.; Coyle, P.; Drevermann, H.; Engelhardt, A.; Forty, R. W.; Frank, M.; Ganis, G.; Gay, C.; Girone, M.; Hagelberg, R.; Harvey, J.; Jacobsen, R.; Jost, B.; Knobloch, J.; Lehraus, I.; Maggi, M.; Markou, C.; Martin, E. B.; Mato, P.; Meinhard, H.; Minten, A.; Miquel, R.; Palazzi, P.; Pater, J. R.; Perrodo, P.; Pusztaszeri, J.-F.; Ranjard, F.; Rolandi, L.; Schlatter, D.; Schmelling, M.; Tejessy, W.; Tomalin, I. R.; Veenhof, R.; Venturi, A.; Wachsmuth, H.; Wiedenmann, W.; Witzeling, W.; Wotschack, J.; Ajaltouni, Z.; Bardadin-Otwinowska, M.; Barres, A.; Boyer, C.; Falvard, A.; Gay, P.; Guicheney, C.; Henrard, P.; Jousset, J.; Michel, B.; Monteil, S.; Montret, J.-C.; Pallin, D.; Perret, P.; Podlyski, F.; Proriol, J.; Rossignol, J.-M.; Saadi, F.; Fearnley, T.; Hansen, J. B.; Hansen, J. D.; Hansen, J. R.; Hansen, P. H.; Johnson, S. D.; Nilsson, B. S.; Kyriakis, A.; Simopoulou, E.; Siotis, I.; Vayaki, A.; Zachariadou, K.; Blondel, A.; Bonneaud, G.; Brient, J. C.; Bourdon, P.; Passalacqua, L.; Rougé, A.; Rumpf, M.; Tanaka, R.; Valassi, A.; Verderi, M.; Videau, H.; Candlin, D. J.; Parsons, M. I.; Veitch, E.; Focardi, E.; Parrini, G.; Corden, M.; Delfino, M.; Georgiopoulos, C.; Jaffe, D. E.; Antonelli, A.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Cerutti, F.; Chiarella, V.; Felici, G.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G. P.; Pepe-Altarelli, M.; Salomone, S.; Colrain, P.; Ten Have, I.; Knowles, I. G.; Lynch, J. G.; Maitland, W.; Morton, W. T.; Raine, C.; Scarr, J. M.; Smith, K.; Smith, M. G.; Thompson, A. S.; Thorn, S.; Turnbull, R. M.; Becker, U.; Braun, O.; Geweniger, C.; Graefe, G.; Hanke, P.; Hepp, V.; Kluge, E. E.; Putzer, A.; Rensch, B.; Schmidt, M.; Sommer, J.; Stenzel, H.; Tittel, K.; Wunsch, M.; Beuselinck, R.; Binnie, D. M.; Cameron, W.; Colling, D. J.; Dornan, P. J.; Konstantinidis, N.; Moneta, L.; Moutoussi, A.; Nash, J.; San Martin, G.; Sedgbeer, J. K.; Stacey, A. M.; Dissertori, G.; Girtler, P.; Kneringer, E.; Kuhn, D.; Rudolph, G.; Bowdery, C. K.; Brodbeck, T. J.; Finch, A. J.; Foster, F.; Hughes, G.; Jackson, D.; Keemer, N. R.; Nuttall, M.; Patel, A.; Sloan, T.; Snow, S. W.; Whelan, E. P.; Galla, A.; Greene, A. M.; Kleinknecht, K.; Raab, J.; Renk, B.; Sander, H.-G.; Schmidt, H.; Walther, S. M.; Wanke, R.; Wolf, B.; Aubert, J. J.; Bencheikh, A. M.; Benchouk, C.; Bonissent, A.; Bujosa, G.; Calvet, D.; Carr, J.; Diaconu, C.; Etienne, F.; Thulasidas, M.; Nicod, D.; Payre, P.; Rousseau, D.; Talby, M.; Abt, I.; Assmann, R.; Bauer, C.; Blum, W.; Brown, D.; Dietl, H.; Dydak, F.; Gotzhein, C.; Halley, A. W.; Jakobs, K.; Kroha, H.; Lütjens, G.; Lutz, G.; Männer, W.; Moser, H.-G.; Richter, R.; Rosado-Schlosser, A.; Schwarz, A. S.; Settles, R.; Seywerd, H.; Stierlin, U.; St. Denis, R.; Wolf, G.; Alemany, R.; Boucrot, J.; Callot, O.; Cordier, A.; Courault, F.; Davier, M.; Duflot, L.; Grivaz, J.-F.; Heusse, Ph.; Jacquet, M.; Panot, P.; Kim, D. W.; Le Diberder, F.; Lefrançois, J.; Lutz, A.-M.; Musolino, G.; Nikolic, I.; Park, H. J.; Park, I. C.; Schune, M.-H.; Simion, S.; Veillet, J.-J.; Videau, I.; Abbaneo, D.; Bagliesi, G.; Batignani, G.; Bettarini, S.; Bottigli, U.; Bozzi, C.; Calderini, G.; Carpinelli, M.; Ciocci, M. A.; Ciulli, V.; Dell'Orso, R.; Ferrante, I.; Fidecaro, F.; Foa, L.; Forti, F.; Giassi, A.; Giorgi, M. A.; Gregorio, A.; Ligabue, F.; Lusiani, A.; Marrocchesi, P. S.; Messineo, A.; Rizzo, G.; Sanguinetti, G.; Sciabà, A.; Spagnolo, P.; Steinberger, J.; Tenchini, R.; Tonelli, G.; Triggiani, G.; Vannini, C.; Verdini, P. G.; Walsh, J.; Betteridge, A. P.; Blair, G. A.; Bryant, L. M.; Gao, Y.; Green, M. G.; Johnson, D. L.; Medcalf, T.; Mir, Ll. M.; Strong, J. A.; Bertin, V.; Botterill, D. R.; Clifft, R. W.; Edgecock, T. R.; Haywood, S.; Edwards, M.; Maley, P.; Norton, P. R.; Thompson, J. C.; Bloch-Devaux, B.; Colas, P.; Duarte, H.; Emery, S.; Kozanecki, W.; Lançon, E.; Lemaire, M. C.; Locci, E.; Marx, B.; Perez, P.; Rander, J.; Renardy, J.-F.; Rosowsky, A.; Roussarie, A.; Schuller, J.-P.; Schwindling, J.; Si Mohand, D.; Trabelsi, A.; Vallage, B.; Johnson, R. P.; Litke, A. M.; Taylor, G.; Wear, J.; Beddall, A.; Booth, C. N.; Boswell, R.; Cartwright, S.; Combley, F.; Dawson, I.; Koksal, A.; Letho, M.; Newton, W. M.; Rankin, C.; Reeves, P.; Thompson, L. F.; Böhrer, A.; Brandt, S.; Cowan, G.; Feigl, E.; Grupen, C.; Lutters, G.; Minguet-Rodriguez, J.; Rivera, F.; Saraiva, P.; Schäfer, U.; Smolik, L.; Bosisio, L.; Della Marina, R.; Giannini, G.; Gobbo, B.; Pitis, L.; Ragusa, F.; Kim, H.; Rothberg, J.; Wasserbaech, S.; Armstrong, S. R.; Bellantoni, L.; Conway, J. S.; Elmer, P.; Feng, Z.; Ferguson, D. P. S.; Gao, Y. S.; Gonzáles, S.; Grahl, J.; Harton, J. L.; Hayes, O. J.; Hu, H.; McNamara, P. A.; Nachtman, J. M.; Orejudos, W.; Pan, Y. B.; Saadi, Y.; Schmitt, M.; Scott, I. J.; Sharma, V.; Turk, J. D.; Walsh, A. M.; Weber, F. V.; Wildish, T.; Wu, Sau Lan; Wu, X.; Yamartino, J. M.; Zheng, M.; Zobernig, G.

    1995-09-01

    Inclusive π±, K± and(p,bar p) differential cross-sections in hadronic decays of the Z have been measured as a function of z= P hadron/ P beam, the scaled momentum. The results are based on approximately 520 000 events measured by the ALEPH detector at LEP during 1992. Charged particles are identified by their rate of ionization energy loss in the ALEPH Time Projection Chamber. The position, ξ*, of the peak in the ln(1/ z) distribution is determined, and the evolution of the peak position with centre-of-mass energy is compared with the prediction of QCD.

  19. A Methodology to Integrate Magnetic Resonance and Acoustic Measurements for Reservoir Characterization

    SciTech Connect

    Parra, Jorge O.; Hackert, Chris L.; Collier, Hughbert A.; Bennett, Michael

    2002-01-29

    The objective of this project was to develop an advanced imaging method, including pore scale imaging, to integrate NMR techniques and acoustic measurements to improve predictability of the pay zone in hydrocarbon reservoirs. This is accomplished by extracting the fluid property parameters using NMR laboratory measurements and the elastic parameters of the rock matrix from acoustic measurements to create poroelastic models of different parts of the reservoir. Laboratory measurement techniques and core imaging are being linked with a balanced petrographical analysis of the core and theoretical model.

  20. Spurious resonance suppression in gigahertz-range ZnO thin-film bulk acoustic wave resonators by the boundary frame method: modeling and experiment.

    PubMed

    Pensala, Tuomas; Ylilammi, Markku

    2009-08-01

    Zinc-oxide-based thin-film bulk acoustic wave (BAW) resonators operating at 932 MHz are investigated with respect to variation of dimensions of a boundary frame spurious mode suppression structure. A plate wave dispersion-based semi-2-D model and a 2-D finite element method are used to predict the eigenmode spectrum of the resonators to explain the detailed behavior. The models show how the boundary frame method changes the eigenmodes and their coupling to the driving electrical field via the modification of the mechanical boundary condition and leads to emergence of a flat-amplitude piston mode and suppression of spurious modes. Narrow band suppression of a single mode with a nonoptimal boundary frame is observed. Reduction of the effective electromechanical coupling coefficient k2eff as a function of the boundary width is observed and predicted by both models. The simple semi-2-D plate model is shown to predict the device behavior very well, and the 2-D finite element method results are shown to coincide with them with some additional effects. Breaking the resonator behavior down to eigenmodes, which are not directly observable in measurements, by the models, yields insight into the physics of the device operation. PMID:19686989

  1. Analysis of contributions of nonlinear material constants to temperature-induced velocity shifts of quartz surface acoustic wave resonators.

    PubMed

    Zhang, Haifeng; Kosinski, John A; Zuo, Lei

    2016-09-01

    In this paper, we examine the significance of the various higher-order effects regarding calculating temperature behavior from a set of material constants and their temperature coefficients. Temperature-induced velocity shifts have been calculated for quartz surface acoustic wave (SAW) resonators and the contributions of different groups of nonlinear material constants (third-order elastic constants (TOE), third-order piezoelectric constants (TOP), third-order dielectric constants (TOD) and electrostrictive constants (EL)) to the temperature-induced velocity shifts have been analyzed. The analytical methodology has been verified through the comparison of experimental and analytical results for quartz resonators. In general, the third-order elastic constants were found to contribute most significantly to the temperature-induced shifts in the SAW velocity. The contributions from the third-order dielectric constants and electrostrictive constants were found to be negligible. For some specific cases, the third-order piezoelectric constants were found to make a significant contribution to the temperature-induced shifts. The significance of each third-order elastic constant as a contributor to the temperature-velocity effect was analyzed by applying a 10% variation to each of the third-order elastic constants separately. Additionally, we have considered the issues arising from the commonly used thermoelastic expansions that provide a good but not exact description of the temperature effects on frequency in piezoelectric resonators as these commonly used expansions do not include the effects of higher-order material constants. PMID:27392205

  2. UV sensing using film bulk acoustic resonators based on Au/n-ZnO/piezoelectric-ZnO/Al structure

    PubMed Central

    Bian, Xiaolei; Jin, Hao; Wang, Xiaozhi; Dong, Shurong; Chen, Guohao; Luo, J. K.; Deen, M. Jamal; Qi, Bensheng

    2015-01-01

    A new type of ultraviolet (UV) light sensor based on film bulk acoustic wave resonator (FBAR) is proposed. The new sensor uses gold and a thin n-type ZnO layer deposited on the top of piezoelectric layer of FBAR to form a Schottky barrier. The Schottky barrier's capacitance can be changed with UV light, resulting in an enhanced shift in the entire FBAR's resonant frequency. The fabricated UV sensor has a 50 nm thick n-ZnO semiconductor layer with a carrier concentration of ~ 1017 cm−3. A large frequency downshift is observed when UV light irradiates the FBAR. With 365 nm UV light of intensity 1.7 mW/cm2, the FBAR with n-ZnO/Au Schottky diode has 250 kHz frequency downshift, much larger than the 60 kHz frequency downshift in a conventional FBAR without the n-ZnO layer. The shift in the new FBAR's resonant frequency is due to the junction formed between Au and n-ZnO semiconductor and its properties changes with UV light. The experimental results are in agreement with the theoretical analysis using an equivalent circuit model of the new FBAR structure. PMID:25773146

  3. Quantitative Interferometry in the Severe Acoustic Environment of Resonant Supersonic Jets

    NASA Technical Reports Server (NTRS)

    Mercer, Carolyn R.; Raman, Ganesh

    1999-01-01

    Understanding fundamental fluidic dynamic and acoustic processes in high-speed jets requires quantitative velocity, density and temperature measurements. In this paper we demonstrate a new, robust Liquid Crystal Point Diffraction Interferometer (LCPDI) that includes phase stepping and can provide accurate data even in the presence of intense acoustic fields. This novel common path interferometer (LCPDI) was developed to overcome difficulties with the Mach Zehnder interferometer in vibratory environments and is applied here to the case of a supersonic shock- containing jet. The environmentally insensitive LCPDI that is easy to align and capable of measuring optical wavefronts with high accuracy is briefly described, then integrated line of sight density data from the LCPDI for two underexpanded jets are presented.

  4. Improvement of Temperature Characteristics of Boundary Acoustic Wave Resonators Using Multilayered Electrodes

    NASA Astrophysics Data System (ADS)

    Mimura, Masakazu; Tamazaki, Daisuke; Yamane, Takashi; Kando, Hajime

    2012-07-01

    In this paper, we describe a new boundary acoustic wave structure employing multilayered metal electrodes with a high-density metal and a low-density metal. By using this structure, such as Pt/Al/Pt, the electromechanical coupling coefficient (k2) and temperature coefficient of frequency (TCF) of the boundary acoustic wave can be changed. We theoretically studied the dependence of the energy distribution of the boundary wave on the position of the total electrode gravity center when the electrode layer structure is changed. It was experimentally confirmed that k2 and TCF can be changed simultaneously. By using this structure, we developed a novel filter with good electrical characteristics, and a very small variation of the filter characteristic with temperature (almost zero TCF) was successfully realized.

  5. Microwave bandpass filters based on thin-film acoustic resonators: theory and experiment

    NASA Astrophysics Data System (ADS)

    Dvoesherstov, M. Yu.; Cherednik, V. I.

    2015-11-01

    We theoretically and experimentally analyze microwave thin-film acoustoelectronic bandpass ladder filters built on AlN-based thin-film acoustoelectronic microwave resonators operating in the frequency range 4.6-5 GHz and describe the technology of their fabrication. We demonstrate that the parameters of filters are mainly determined by the characteristics of resonators that make up the filter and show that the characteristics of a three-section ladder filter can be significantly improved by optimizing the areas of the upper electrodes of the series and parallel resonators contained in it.

  6. Structural Properties of Barred Galaxies

    NASA Astrophysics Data System (ADS)

    Kim, Taehyun; Gadotti, D. A.; Sheth, K.; Lee, M.; S4G Team

    2014-01-01

    We have performed two-dimensional multicomponent decomposition of 144 local barred spiral galaxies using 3.6 micron images from the Spitzer Survey of Stellar Structure in Galaxies. Our model fit includes up to four components (bulge, disk, bar, and a point source) and, most importantly, takes into account disk breaks. We present that ignoring the disk break and using a single disk scale length in the model fit for Type II (down- bending) disk galaxies can lead to differences of 40% in the disk scale length, 10% in bulge-to-total luminosity ratio (B/T), and 25% in bar-to-total luminosity ratios. We show that for galaxies with B/T > 0.1, the break radius to bar radius, r_br/R_bar, varies between 1 and 3, but as a function of B/T the ratio remains roughly constant. This suggests that in bulge-dominated galaxies the disk break is likely related to the outer Lindblad Resonance (OLR) of the bar, and thus the OLR also moves outwards at the same rate as the bar grows. For galaxies with B/T < 0.1, r_br/R_bar, spans a wide range from 1 to 6. This suggests that the mechanism that produces the break in these galaxies may be different from that in galaxies with more massive bulges. Consistent with previous studies, we conclude that disk breaks in galaxies with small bulges may originate from bar resonances that may be also coupled with the spiral arms, or be related to star formation thresholds. We quantifiy shapes of bar radial surface brightness profiles by measuring their Sersic indices and show that bars in higher B/T galaxies have flatter radial surface brightness profile than bulgeless galaxies do. In particular, bulgeless galaxies mostly have bars with steep profiles. We show that the normalized bar length is correlated with B/T, which is consistent with bars growing longer with time.

  7. Prediction of the Strain Response of Poly-AlN/(100)Si Surface Acoustic Wave Resonator and Experimental Analysis

    PubMed Central

    Chen, Shuo; You, Zheng

    2016-01-01

    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). PMID:27128922

  8. A surface acoustic wave (SAW)-enhanced grating-coupling phase-interrogation surface plasmon resonance (SPR) microfluidic biosensor.

    PubMed

    Sonato, A; Agostini, M; Ruffato, G; Gazzola, E; Liuni, D; Greco, G; Travagliati, M; Cecchini, M; Romanato, F

    2016-03-23

    A surface acoustic wave (SAW)-enhanced, surface plasmon resonance (SPR) microfluidic biosensor in which SAW-induced mixing and phase-interrogation grating-coupling SPR are combined in a single lithium niobate lab-on-a-chip is demonstrated. Thiol-polyethylene glycol adsorption and avidin/biotin binding kinetics were monitored by exploiting the high sensitivity of grating-coupling SPR under azimuthal control. A time saturation binding kinetics reduction of 82% and 24% for polyethylene and avidin adsorption was obtained, respectively, due to the fluid mixing enhancement by means of the SAW-generated chaotic advection. These results represent the first implementation of a nanostructured SAW-SPR microfluidic biochip capable of significantly improving the molecule binding kinetics on a single, portable device. In addition, the biochip here proposed is suitable for a great variety of biosensing applications. PMID:26932784

  9. Prediction of the Strain Response of Poly-AlN/(100)Si Surface Acoustic Wave Resonator and Experimental Analysis.

    PubMed

    Chen, Shuo; You, Zheng

    2016-01-01

    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). PMID:27128922

  10. Comparison of temporal and spectral scattering methods using acoustically large breast models derived from magnetic resonance images

    PubMed Central

    Hesford, Andrew J.; Tillett, Jason C.; Astheimer, Jeffrey P.; Waag, Robert C.

    2014-01-01

    Accurate and efficient modeling of ultrasound propagation through realistic tissue models is important to many aspects of clinical ultrasound imaging. Simplified problems with known solutions are often used to study and validate numerical methods. Greater confidence in a time-domain k-space method and a frequency-domain fast multipole method is established in this paper by analyzing results for realistic models of the human breast. Models of breast tissue were produced by segmenting magnetic resonance images of ex vivo specimens into seven distinct tissue types. After confirming with histologic analysis by pathologists that the model structures mimicked in vivo breast, the tissue types were mapped to variations in sound speed and acoustic absorption. Calculations of acoustic scattering by the resulting model were performed on massively parallel supercomputer clusters using parallel implementations of the k-space method and the fast multipole method. The efficient use of these resources was confirmed by parallel efficiency and scalability studies using large-scale, realistic tissue models. Comparisons between the temporal and spectral results were performed in representative planes by Fourier transforming the temporal results. An RMS field error less than 3% throughout the model volume confirms the accuracy of the methods for modeling ultrasound propagation through human breast. PMID:25096103

  11. Comparison of temporal and spectral scattering methods using acoustically large breast models derived from magnetic resonance images.

    PubMed

    Hesford, Andrew J; Tillett, Jason C; Astheimer, Jeffrey P; Waag, Robert C

    2014-08-01

    Accurate and efficient modeling of ultrasound propagation through realistic tissue models is important to many aspects of clinical ultrasound imaging. Simplified problems with known solutions are often used to study and validate numerical methods. Greater confidence in a time-domain k-space method and a frequency-domain fast multipole method is established in this paper by analyzing results for realistic models of the human breast. Models of breast tissue were produced by segmenting magnetic resonance images of ex vivo specimens into seven distinct tissue types. After confirming with histologic analysis by pathologists that the model structures mimicked in vivo breast, the tissue types were mapped to variations in sound speed and acoustic absorption. Calculations of acoustic scattering by the resulting model were performed on massively parallel supercomputer clusters using parallel implementations of the k-space method and the fast multipole method. The efficient use of these resources was confirmed by parallel efficiency and scalability studies using large-scale, realistic tissue models. Comparisons between the temporal and spectral results were performed in representative planes by Fourier transforming the temporal results. An RMS field error less than 3% throughout the model volume confirms the accuracy of the methods for modeling ultrasound propagation through human breast. PMID:25096103

  12. Acoustic waves from mechanical impulses due to fluorescence resonant energy (Förster) transfer: Blowing a whistle with light

    NASA Astrophysics Data System (ADS)

    Zurita-Sánchez, J. R.; Henkel, C.

    2012-02-01

    We present a momentum transfer mechanism mediated by electromagnetic fields that originates in a system of two nearby molecules: one excited (donor D*) and the other in ground state (acceptor A). An intermolecular force related to fluorescence resonant energy or Förster transfer (FRET) arises in the unstable D*A molecular system, which differs from the equilibrium van der Waals interaction. Due to the its finite lifetime, a mechanical impulse is imparted to the relative motion in the system. We analyze the FRET impulse when the molecules are embedded in free space and find that its magnitude can be much greater than the single recoil photon momentum, getting comparable with the thermal momentum (Maxwell-Boltzmann distribution) at room temperature. In addition, we propose that this FRET impulse can be exploited in the generation of acoustic waves inside a film containing layers of donor and acceptor molecules, when a picosecond laser pulse excites the donors. This acoustic transient is distinguishable from that produced by thermal stress due to laser absorption, and may therefore play a role in photoacoustic spectroscopy. The effect can be seen as exciting a vibrating system like a string or organ pipe with light; it may be used as an opto-mechanical transducer.

  13. Flexible surface acoustic wave resonators built on disposable plastic film for electronics and lab-on-a-chip applications

    PubMed Central

    Jin, Hao; Zhou, Jian; He, Xingli; Wang, Wenbo; Guo, Hongwei; Dong, Shurong; Wang, Demiao; Xu, Yang; Geng, Junfeng; Luo, J. K.; Milne, W. I.

    2013-01-01

    Flexible electronics are a very promising technology for various applications. Several types of flexible devices have been developed, but there has been limited research on flexible electromechanical systems (MEMS). Surface acoustic wave (SAW) devices are not only an essential electronic device, but also are the building blocks for sensors and MEMS. Here we report a method of making flexible SAW devices using ZnO nanocrystals deposited on a cheap and bendable plastic film. The flexible SAW devices exhibit two wave modes - the Rayleigh and Lamb waves with resonant frequencies of 198.1 MHz and 447.0 MHz respectively, and signal amplitudes of 18 dB. The flexible devices have a high temperature coefficient of frequency, and are thus useful as sensitive temperature sensors. Moreover, strong acoustic streaming with a velocity of 3.4 cm/s and particle concentration using the SAW have been achieved, demonstrating the great potential for applications in electronics and MEMS. PMID:23828169

  14. Arbitrary shaped, liquid filled reverberators with non-resonant transducers for broadband focusing of ultrasound using Time Reversed Acoustics.

    PubMed

    Sarvazyan, A; Fillinger, L

    2009-03-01

    The ability to generate short focused ultrasonic pulses with duration on the order of one period of carrier frequency depends on the bandwidth of the transmitter as the pulse duration is inversely proportional to the bandwidth. Conventional focusing arrays used for focusing ultrasound have limited bandwidth due to the resonant nature of the piezoelements generating ultrasound. Theoretically it is possible to build a broadband phased array composed of "non-resonant" elements: wedge-shaped or flat-concave piezotransducers, though there are numerous technical difficulties in designing arrays with hundreds of elements of complex shape. This task is much easier to realize in an alternative technique of ultrasound focusing based on the principles of Time Reversed Acoustics (TRA) because in TRA systems, effective focusing can be achieved with just a few, or even one, transducers. The goal of this study is to demonstrate the possibility of broadband focusing of ultrasonic waves using a TRA system with non-resonant transducers and to explore the factors affecting the performance of such a system. A new type of TRA reverberators, such as water-filled thin-wall plastic vessels, which can be used with the submersible piezotransducers fixed internally in the reverberator, are proposed and tested. The experiments are conducted in a water tank with the walls and bottom covered by a sound absorbing lining. A needle hydrophone mounted on a 3D positioning system is used as a beacon for the TRA focusing and then for measuring the spatial distribution of the focused ultrasound field. The bandwidth and spatial distribution of the signal focused by the TRA system using a single channel with the resonant versus non-resonant transducers have been analyzed. Two types of non-resonant transducers were tested: a flat-concave transducer with a diameter of 30 mm, and a thickness varying from 2 mm in the center to 11 mm at the edge, and a specially designed submersible transducer having an

  15. Hydro-acoustic resonance behavior in presence of a precessing vortex rope: observation of a lock-in phenomenon at part load Francis turbine operation

    NASA Astrophysics Data System (ADS)

    Favrel, A.; Landry, C.; Müller, A.; Yamamoto, K.; Avellan, F.

    2014-03-01

    Francis turbines operating at part load condition experience the development of a cavitating helical vortex rope in the draft tube cone at the runner outlet. The precession movement of this vortex rope induces local convective pressure fluctuations and a synchronous pressure pulsation acting as a forced excitation for the hydraulic system, propagating in the entire system. In the draft tube, synchronous pressure fluctuations with a frequency different to the precession frequency may also be observed in presence of cavitation. In the case of a matching between the precession frequency and the synchronous surge frequency, hydro-acoustic resonance occurs in the draft tube inducing high pressure fluctuations throughout the entire hydraulic system, causing torque and power pulsations. The risk of such resonances limits the possible extension of the Francis turbine operating range. A more precise knowledge of the phenomenon occurring at such resonance conditions and prediction capabilities of the induced pressure pulsations needs therefore to be developed. This paper proposes a detailed study of the occurrence of hydro-acoustic resonance for one particular part load operating point featuring a well-developed precessing vortex rope and corresponding to 64% of the BEP. It focuses particularly on the evolution of the local interaction between the pressure fluctuations at the precession frequency and the synchronous surge mode passing through the resonance condition. For this purpose, an experimental investigation is performed on a reduced scale model of a Francis turbine, including pressure fluctuation measurements in the draft tube and in the upstream piping system. Changing the pressure level in the draft tube, resonance occurrences are highlighted for different Froude numbers. The evolution of the hydro-acoustic response of the system suggests that a lock-in effect between the excitation frequency and the natural frequency may occur at low Froude number, inducing a hydro-acoustic

  16. Perfect and broadband acoustic absorption by critically coupled sub-wavelength resonators.

    PubMed

    Romero-García, V; Theocharis, G; Richoux, O; Merkel, A; Tournat, V; Pagneux, V

    2016-01-01

    Perfect absorption is an interdisciplinary topic with a large number of applications, the challenge of which consists of broadening its inherently narrow frequency-band performance. We experimentally and analytically report perfect and broadband absorption for audible sound, by the mechanism of critical coupling, with a sub-wavelength multi-resonant scatterer (SMRS) made of a plate-resonator/closed waveguide structure. In order to introduce the role of the key parameters, we first present the case of a single resonant scatterer (SRS) made of a Helmholtz resonator/closed waveguide structure. In both cases the controlled balance between the energy leakage of the several resonances and the inherent losses of the system leads to perfect absorption peaks. In the case of the SMRS we show that systems with large inherent losses can be critically coupled using resonances with large leakage. In particular, we show that in the SMRS system, with a thickness of λ/12 and diameter of λ/7, several perfect absorption peaks overlap to produce absorption bigger than 93% for frequencies that extend over a factor of 2 in audible frequencies. The reported concepts and methodology provide guidelines for the design of broadband perfect absorbers which could contribute to solve the major issue of noise reduction. PMID:26781863

  17. Perfect and broadband acoustic absorption by critically coupled sub-wavelength resonators

    NASA Astrophysics Data System (ADS)

    Romero-García, V.; Theocharis, G.; Richoux, O.; Merkel, A.; Tournat, V.; Pagneux, V.

    2016-01-01

    Perfect absorption is an interdisciplinary topic with a large number of applications, the challenge of which consists of broadening its inherently narrow frequency-band performance. We experimentally and analytically report perfect and broadband absorption for audible sound, by the mechanism of critical coupling, with a sub-wavelength multi-resonant scatterer (SMRS) made of a plate-resonator/closed waveguide structure. In order to introduce the role of the key parameters, we first present the case of a single resonant scatterer (SRS) made of a Helmholtz resonator/closed waveguide structure. In both cases the controlled balance between the energy leakage of the several resonances and the inherent losses of the system leads to perfect absorption peaks. In the case of the SMRS we show that systems with large inherent losses can be critically coupled using resonances with large leakage. In particular, we show that in the SMRS system, with a thickness of λ/12 and diameter of λ/7, several perfect absorption peaks overlap to produce absorption bigger than 93% for frequencies that extend over a factor of 2 in audible frequencies. The reported concepts and methodology provide guidelines for the design of broadband perfect absorbers which could contribute to solve the major issue of noise reduction.

  18. Perfect and broadband acoustic absorption by critically coupled sub-wavelength resonators

    PubMed Central

    Romero-García, V.; Theocharis, G.; Richoux, O.; Merkel, A.; Tournat, V.; Pagneux, V.

    2016-01-01

    Perfect absorption is an interdisciplinary topic with a large number of applications, the challenge of which consists of broadening its inherently narrow frequency-band performance. We experimentally and analytically report perfect and broadband absorption for audible sound, by the mechanism of critical coupling, with a sub-wavelength multi-resonant scatterer (SMRS) made of a plate-resonator/closed waveguide structure. In order to introduce the role of the key parameters, we first present the case of a single resonant scatterer (SRS) made of a Helmholtz resonator/closed waveguide structure. In both cases the controlled balance between the energy leakage of the several resonances and the inherent losses of the system leads to perfect absorption peaks. In the case of the SMRS we show that systems with large inherent losses can be critically coupled using resonances with large leakage. In particular, we show that in the SMRS system, with a thickness of λ/12 and diameter of λ/7, several perfect absorption peaks overlap to produce absorption bigger than 93% for frequencies that extend over a factor of 2 in audible frequencies. The reported concepts and methodology provide guidelines for the design of broadband perfect absorbers which could contribute to solve the major issue of noise reduction. PMID:26781863

  19. Acoustic field in a thermoacoustic Stirling engine having a looped tube and resonator

    NASA Astrophysics Data System (ADS)

    Ueda, Yuki; Biwa, Tetsushi; Mizutani, Uichiro; Yazaki, Taichi

    2002-12-01

    S. Backhaus and G. W. Swift [Nature 399, 335(1999)] have built a prototype thermoacoustic Stirling engine based on traveling wave energy conversions, and demonstrated that its efficiency reached above 40% of the Carnot efficiency. We experimentally investigate an acoustic field in the engine through simultaneous measurements of velocity U and pressure P. By focusing on the phase lead Φ of U relative to P in its regenerator, we find that the engine can achieve such a high efficiency by the negative Φ about -20° rather than a traveling wave phase (Φ=0).

  20. Negative effective mass density of acoustic metamaterial plate decorated with low frequency resonant pillars

    NASA Astrophysics Data System (ADS)

    Oudich, Mourad; Djafari-Rouhani, Bahram; Pennec, Yan; Assouar, M. Badreddine; Bonello, Bernard

    2014-11-01

    We investigate the elastic wave dispersion by a phononic metamaterial plate containing low frequency resonator stubs arranged periodically over the plate. We show that this system not only provides stop bands for wavelengths much larger than the periodicity but also displays negative behavior of its effective mass density under the homogenization assumption. A numerical method is used to calculate the plate's effective dynamic mass density as function of the frequency where the metamaterial is considered as homogeneous plate for these large wavelengths. Strong anisotropy of the effective mass density matrix is observed around the resonance frequencies where the gaps are opened. In these regions, we demonstrate that the effective matrix density components take negative values. For each of these components, the negative behavior is studied by taking into account the polarization of the involved resonant modes as well as their associated partial band gaps opened for each specific Lamb symmetry modes. We found that coupling between Lamb waves and resonant modes strongly affects the effective density of the whole plate especially in the coupling frequency regions of the gaps.

  1. 1/f noise in etched groove surface acoustic wave (SAW) resonators.

    PubMed

    Parker, T E; Andres, D; Greer, J A; Montress, G K

    1994-01-01

    Measurements of 1/f (or flicker) frequency fluctuations in SAW resonators fabricated with etched groove reflectors on single crystal quartz have shown that the observed noise levels vary inversely with device size. These measurements were made on sixteen 450 MHz resonators of four different sizes. The 1/f noise levels were also evaluated on twenty-eight other SAW resonators ranging in frequency from 401 to 915 MHz. This additional data provides valuable information on the dependence of the flicker noise levels on resonator frequency. A model based an localized, independent velocity fluctuations in the quartz is proposed which correctly fits the observed size and frequency dependence of the measured 1/f noise levels. This model suggests that the velocity fluctuations originate in small regions (much less than ~5 mum in diameter) randomly distributed throughout the quartz with an average separation of about 5 mum between independent (incoherent) sources. The magnitude of the localized fractional velocity fluctuations, Deltav/v, averaged over a 5 micron cube is on the order of 1x10 (-9). PMID:18263275

  2. Acoustic fatigue life prediction for nonlinear structures with multiple resonant modes

    NASA Technical Reports Server (NTRS)

    Miles, R. N.

    1992-01-01

    This report documents an effort to develop practical and accurate methods for estimating the fatigue lives of complex aerospace structures subjected to intense random excitations. The emphasis of the current program is to construct analytical schemes for performing fatigue life estimates for structures that exhibit nonlinear vibration behavior and that have numerous resonant modes contributing to the response.

  3. A Methodology to Integrate Magnetic Resonance and Acoustic Measurements for Reservoir Characterization

    SciTech Connect

    Parra, Jorge O.; Hackert, Chris L.; Ni, Qingwen; Collier, Hughbert A.

    2000-09-22

    This report contains eight sections. Some individual subsections contain lists of references as well as figures and conclusions when appropriate. The first section includes the introduction and summary of the first-year project efforts. The next section describes the results of the project tasks: (1) implementation of theoretical relations between effect dispersion and the stochastic medium, (2) imaging analyses using core and well log data, (3) construction of dispersion and attenuation models at the core and borehole scales in poroelastic media, (4) petrophysics and a catalog of core and well log data from Siberia Ridge field, (5) acoustic/geotechnical measurements and CT imaging of core samples from Florida carbonates, and (6) development of an algorithm to predict pore size distribution from NMR core data. The last section includes a summary of accomplishments, technology transfer activities and follow-on work for Phase II.

  4. Evaluation of an acoustic resonance temperature sensor for transformers: Final report

    SciTech Connect

    Benke, F.; Dell, T.; Gannon, G.; Geil, F.; Nomm, M.; Thompson, J.; Wright, L.; Yannucci, D.

    1987-08-01

    This report covers the development of a system for measuring power transformer hottest spot at high voltage under load. An acoustic sensor previously used in oceanic research was miniaturized and placed in contact with the coil. An insulating waveguide system was developed for voltage isolation; and the electronic system designed and built for readout and relay operation. The system was successfully demonstrated on one commercial order at high overloads. As much as 15/sup 0/ difference was shown between the presently available simulated device and the new system which measured actual hottest spot. Manufacturing cost of the sensor due to a high fallout rate as a result of sealing and waveguide attachment problems, and damage sustained after installation on the heavy coils during subsequent coil manufacture handling, preclude the use of this system at this time. 60 figs.

  5. Equilibrium shape and location of a liquid drop acoustically positioned in a resonant rectangular chamber

    NASA Technical Reports Server (NTRS)

    Jackson, H. W.; Barmatz, M.; Shipley, C.

    1988-01-01

    The effect of a standing wave field in a rectangular chamber on the shape and location of an acoustically positioned drop or bubble is calculated. The sample deformation and equilibrium position are obtained from an analysis of the spherical harmonic projections of the total surface stress tensor. The method of calculation relies on the assumed condition that the sample is only slightly distorted from a spherical form. The equilibrium location of a levitated drop is combined with a formula introduced by Hasegawa (1979) to calcualte the ka dependence of the radiation force function. The present theory is valid for large as well as small ka values. Calculations in the small ka limit agree with previous theories and experimental results. Examples are presented for nonplane-wave modes as well as plane-wave rectangular modes.

  6. Resonant photo-acoustic detection of carbon monoxide with UV Laser at 213 nm

    NASA Astrophysics Data System (ADS)

    Khalil, A. A. I.; Gondal, M. A.; Al-Suliman, N.

    2011-05-01

    A trace-gas sensor for carbon monoxide based on Pulsed Laser-Induced Photo-Acoustic Spectroscopy (PLIPAS) in conjunction with laser excitation wavelength of 213 nm was designed, fabricated and tested for the first time. PLIPAS-based sensor with different cell geometry was employed to enhance the sensitivity down to 58 ppbV level. The parametric dependence of the PLIPAS signals on CO gas concentration, buffer gas (Ar, O2 and He) concentration, laser pulse energy was studied and Ar proved to be better than O2 and He in terms of enhancing the sensitivity of the system. The signal-to-noise ratio and limit of detection have been quantified for different experimental conditions. This study proves that PLIPAS-based CO gas sensor is a reliable gas-leak detection system with high sensitivity and selectivity. Hence this sensor can be employed for pollution monitoring and detection of CO in a noisy environment.

  7. Fissile and Non-Fissile Material Detection Using Nuclear Acoustic Resonance Signatures

    SciTech Connect

    Bernhard R. Tittmann; P.M. Lenahan; David Spears; Rhys Williams

    2008-11-25

    The objective of this project is to develop anovel technique for remote, non-destructive, non-radiation-based detection of materials of interest to Nonproliferation Programs. We propse the development of a detection system based on magnetic resonance principles (NAR), which would work where radiation detection is not possible. The approach would be non-intrusive, penetrating, applicable to many materials of interest for Nonproliferation, and be able to identify the nuclear samples under investigation.

  8. Acoustic Resonance of a Two-Dimensional Isotropic Medium Studied Using Airy Stress Function

    NASA Astrophysics Data System (ADS)

    Tarumi, Ryuichi; Yamada, Shinpei; Shibutani, Yoji

    2012-07-01

    We have developed a theory that determines a complete set of stress field, σij, in a freely vibrating two-dimensional isotropic medium within the framework of the calculus of variation. Our formulation is based on the Airy stress function φ and the minimization of the complementary strain energy under the constrain condition || φ|| 2L2 =const. By the Ritz method, the constrained variational problem becomes a linear eigenvalue problem. Numerical analysis yields 36 types of the stress functions φi. Unlike the stress fields determined from the conventional resonant ultrasound spectroscopy theory, the stress fields derived from the stress functions φi explicitly satisfy the stress-free natural boundary condition and the equilibrium equation. It is also confirmed that the 36 resonant modes can be classified into four groups according to the parity of the coefficient of the basis function. Furthermore, the stress functions φi are orthogonal in the sense of the L2 inner product. These features are similar to those of the conventional resonant ultrasound spectroscopy (RUS) theory.

  9. Coupling of Helmholtz resonators to improve acoustic liners for turbofan engines at low frequency

    NASA Technical Reports Server (NTRS)

    Dean, L. W.

    1975-01-01

    An analytical and test program was conducted to evaluate means for increasing the effectiveness of low frequency sound absorbing liners for aircraft turbine engines. Three schemes for coupling low frequency absorber elements were considered. These schemes were analytically modeled and their impedance was predicted over a frequency range of 50 to 1,000 Hz. An optimum and two off-optimum designs of the most promising, a parallel coupled scheme, were fabricated and tested in a flow duct facility. Impedance measurements were in good agreement with predicted values and validated the procedure used to transform modeled parameters to hardware designs. Measurements of attenuation for panels of coupled resonators were consistent with predictions based on measured impedance. All coupled resonator panels tested showed an increase in peak attenuation of about 50% and an increase in attenuation bandwidth of one one-third octave band over that measured for an uncoupled panel. These attenuation characteristics equate to about 35% greater reduction in source perceived noise level (PNL), relative to the uncoupled panel, or a reduction in treatment length of about 24% for constant PNL reduction. The increased effectiveness of the coupled resonator concept for attenuation of low frequency broad spectrum noise is demonstrated.

  10. Acoustic Suppression Systems and Related Methods

    NASA Technical Reports Server (NTRS)

    Kolaini, Ali R. (Inventor); Kern, Dennis L. (Inventor)

    2013-01-01

    An acoustic suppression system for absorbing and/or scattering acoustic energy comprising a plurality of acoustic targets in a containment is described, the acoustic targets configured to have resonance frequencies allowing the targets to be excited by incoming acoustic waves, the resonance frequencies being adjustable to suppress acoustic energy in a set frequency range. Methods for fabricating and implementing the acoustic suppression system are also provided.

  11. Theoretical interpretation of a case study: Acoustic resonance in an archaeological site

    NASA Astrophysics Data System (ADS)

    Carrera, Jorge; Beristain, Sergio

    2002-11-01

    It is well-known that the stairways of some Mexican archaeological sites, like Chichen-Itza or Teotihuacan, present an interesting sound reflection and resonance phenomenon which causes a special audible effect. In this paper, mathematical modeling of this situation is presented, and the practical phenomenon is discussed from a theoretical standpoint. More than an end in itself, the idea is, once this validated model is obtained, to use the results for the analysis of a more extensive architectural environment in order to establish whether this kind of phenomenon would have been purposely introduced in the design of the site. This will be presented in future publications.

  12. Acoustic resonance at the dawn of life: musical fundamentals of the psychoanalytic relationship.

    PubMed

    Pickering, Judith

    2015-11-01

    This paper uses a case vignette to show how musical elements of speech are a crucial source of information regarding the patient's emotional states and associated memory systems that are activated at a given moment in the analytic field. There are specific psychoacoustic markers associated with different memory systems which indicate whether a patient is immersed in a state of creative intersubjective relatedness related to autobiographical memory, or has been triggered into a traumatic memory system. When a patient feels immersed in an atmosphere of intersubjective mutuality, dialogue features a rhythmical and tuneful form of speech featuring improvized reciprocal imitation, theme and variation. When the patient is catapulted into a traumatic memory system, speech becomes monotone and disjointed. Awareness of such acoustic features of the traumatic memory system helps to alert the analyst that such a shift has taken place informing appropriate responses and interventions. Communicative musicality (Malloch & Trevarthen 2009) originates in the earliest non-verbal vocal communication between infant and care-giver, states of primary intersubjectivity. Such musicality continues to be the primary vehicle for transmitting emotional meaning and for integrating right and left hemispheres. This enables communication that expresses emotional significance, personal value as well as conceptual reasoning. PMID:26499296

  13. Bar-spheroid interaction in galaxies

    NASA Technical Reports Server (NTRS)

    Hernquist, Lars; Weinberg, Martin D.

    1992-01-01

    N-body simulation and linear analysis is employed to investigate the secular evolution of barred galaxies, with emphasis on the interaction between bars and spheroidal components of galaxies. This interaction is argued to drive secular transfer of angular momentum from bars to spheroids, primarily through resonant coupling. A moderately strong bar, having mass within corotation about 0.3 times the enclosed spheroid mass, is predicted to shed all its angular momentum typically in less than about 10 exp 9 yr. Even shorter depletion time scales are found for relatively more massive bars. It is suggested either that spheroids around barred galaxies are structured so as to inhibit strong coupling with bars, or that bars can form by unknown processes long after disks are established. The present models reinforce the notion that bars can drive secular evolution in galaxies.

  14. Analytical and experimental study of the acoustics and the flow field characteristics of cavitating self-resonating water jets

    SciTech Connect

    Chahine, G.L.; Genoux, P.F.; Johnson, V.E. Jr.; Frederick, G.S.

    1984-09-01

    Waterjet nozzles (STRATOJETS) have been developed which achieve passive structuring of cavitating submerged jets into discrete ring vortices, and which possess cavitation incipient numbers six times higher than obtained with conventional cavitating jet nozzles. In this study we developed analytical and numerical techniques and conducted experimental work to gain an understanding of the basic phenomena involved. The achievements are: (1) a thorough analysis of the acoustic dynamics of the feed pipe to the nozzle; (2) a theory for bubble ring growth and collapse; (3) a numerical model for jet simulation; (4) an experimental observation and analysis of candidate second-generation low-sigma STRATOJETS. From this study we can conclude that intensification of bubble ring collapse and design of highly resonant feed tubes can lead to improved drilling rates. The models here described are excellent tools to analyze the various parameters needed for STRATOJET optimizations. Further analysis is needed to introduce such important factors as viscosity, nozzle-jet interaction, and ring-target interaction, and to develop the jet simulation model to describe the important fine details of the flow field at the nozzle exit.

  15. Monolithic integrated system with an electrowetting-on-dielectric actuator and a film-bulk-acoustic-resonator sensor

    NASA Astrophysics Data System (ADS)

    Zhang, Menglun; Cui, Weiwei; Chen, Xuejiao; Wang, Chao; Pang, Wei; Duan, Xuexin; Zhang, Daihua; Zhang, Hao

    2015-02-01

    Although digital microfluidics has shown great potential in a wide range of applications, a lab-on-a-chip with integrated digital droplet actuators and powerful biochemical sensors is still lacking. To address the demand, a fully integrated chip with electrowetting-on-dielectric (EWOD) and a film bulk acoustic resonator (FBAR) sensor is introduced, where an EWOD actuator manipulates digital droplets and the FBAR sensor detects the presence of substances in the droplets, respectively. The piezoelectric layer of the FBAR sensor and the dielectric layer of the EWOD share the same aluminum nitride (AlN) thin film, which is a key factor to achieve the full integration of the two completely different devices. The liquid droplets are reliably managed by the EWOD actuator to sit on or move off the FBAR sensor precisely. Sessile drop experiments and limit of detection (LOD) experiments are carried out to characterize the EWOD actuator and the FBAR sensor, respectively. Taking advantage of the digital droplet operation, a ‘dry sensing mode’ of the FBAR sensor in the lab-on-a-chip microsystem is proposed, which has a much higher signal to noise ratio than the conventional ‘wet sensing mode’. Hg2+ droplets with various concentrations are transported and sensed to demonstrate the capability of the integrated system. The EWOD-FBAR chip is expected to play an important role in many complex lab-on-a-chip applications.

  16. Effects of Magnetic Fields on Bar Substructures in Barred Galaxies

    NASA Astrophysics Data System (ADS)

    Kim, Woong-Tae

    2015-03-01

    To study the effects of magnetic fields on the properties of bar substructures, we run two-dimensional, ideal MHD simulations of barred galaxies under the influence of a non-axisymmetric bar potential. In the bar regions, magnetic fields reduce density compression in the dust-lane shocks, while removing angular momentum further from the gas at the shocks. This evidently results in a smaller and more distributed ring, and a larger mass inflows rate to the galaxy center in models with stronger magnetic fields. In the outer regions, an MHD dynamo due to the combined action of the bar potential and background shear operates, amplifying magnetic fields near the corotation resonance. In the absence of spiral arms, the amplified fields naturally shape into trailing magnetic arms with strong fields and low density. The reader is refereed to Kim & Stone (2012) for a detailed presentation of the simulation outcomes.

  17. Barred beaches

    NASA Astrophysics Data System (ADS)

    Wijnberg, Kathelijne M.; Kroon, Aart

    2002-11-01

    Seven different bar types are distinguished to provide a framework for comparing morphodynamic studies conducted in different areas. Five types occur in semiprotected or open coast settings, of which two are intertidal and three are subtidal. Two types occur in highly protected settings. The occurrence of a certain bar type is generally determined by the wave energy and tidal range, although the nearshore slope may also be a differentiating boundary condition. The theory behind the generation, evolution and decay of bars has evolved most for the subtidal bars in the semiprotected and open coast settings, for which three types of competing mechanisms have been formulated (breakpoint, infragravity waves, self-organisational). Most research has focused on these processes on the time scale of storm events and post-storm recovery. However, to understand the longer-term behavior of bar systems, knowledge of the role of relaxation time and morphologic feedback is needed as well. At present, such knowledge is very limited. We think it can best be obtained from the analysis of long time series of morphology and forcing conditions, rather than from intensive field experiments. In case of a feedback-dominated response (self-organisational), we expect to find no correlation between the time series of external forcing and the morphologic response. In case of a relaxation time-dominated response, we do expect to find such a correlation, albeit filtered. This discussion is illustrated by a case study of the Dutch coast.

  18. Study of high-overtone bulk acoustic resonators based on the Me1/AlN/Me2/(100) diamond piezoelectric layered structure

    NASA Astrophysics Data System (ADS)

    Sorokin, B. P.; Kvashnin, G. M.; Telichko, A. V.; Gordeev, G. I.; Burkov, S. I.; Blank, V. D.

    2015-07-01

    The Me1/AlN/Me2/(100) diamond structure has been theoretically analyzed and experimentally investigated in the range 0.5-10 GHz using high-overtone bulk acoustic resonators with different electrodes topologies based on the Al/AlN/Mo/(100) diamond structure. The maximum quality parameter Q × f ≈ 1014 Hz was obtained at f = 9.5 GHz. The layered structure has been analyzed using the developed HBAR software v. 2.3. It is demonstrated that the features in the frequency dependences of the parameters of such resonators are related to the behavior of a loaded thin-film piezoelectric transducer. The calculation results are in good agreement with the experiment. The frequency dependences of the equivalent parameters of the resonators have been calculated. It is shown that the synthetic type IIa diamond single crystal in combination with aluminum nitride is promising for implementation of high-Q acoustoelectronic microwave devices.

  19. Acoustic biosensors

    PubMed Central

    Fogel, Ronen; Seshia, Ashwin A.

    2016-01-01

    Resonant and acoustic wave devices have been researched for several decades for application in the gravimetric sensing of a variety of biological and chemical analytes. These devices operate by coupling the measurand (e.g. analyte adsorption) as a modulation in the physical properties of the acoustic wave (e.g. resonant frequency, acoustic velocity, dissipation) that can then be correlated with the amount of adsorbed analyte. These devices can also be miniaturized with advantages in terms of cost, size and scalability, as well as potential additional features including integration with microfluidics and electronics, scaled sensitivities associated with smaller dimensions and higher operational frequencies, the ability to multiplex detection across arrays of hundreds of devices embedded in a single chip, increased throughput and the ability to interrogate a wider range of modes including within the same device. Additionally, device fabrication is often compatible with semiconductor volume batch manufacturing techniques enabling cost scalability and a high degree of precision and reproducibility in the manufacturing process. Integration with microfluidics handling also enables suitable sample pre-processing/separation/purification/amplification steps that could improve selectivity and the overall signal-to-noise ratio. Three device types are reviewed here: (i) bulk acoustic wave sensors, (ii) surface acoustic wave sensors, and (iii) micro/nano-electromechanical system (MEMS/NEMS) sensors. PMID:27365040

  20. Acoustic biosensors.

    PubMed

    Fogel, Ronen; Limson, Janice; Seshia, Ashwin A

    2016-06-30

    Resonant and acoustic wave devices have been researched for several decades for application in the gravimetric sensing of a variety of biological and chemical analytes. These devices operate by coupling the measurand (e.g. analyte adsorption) as a modulation in the physical properties of the acoustic wave (e.g. resonant frequency, acoustic velocity, dissipation) that can then be correlated with the amount of adsorbed analyte. These devices can also be miniaturized with advantages in terms of cost, size and scalability, as well as potential additional features including integration with microfluidics and electronics, scaled sensitivities associated with smaller dimensions and higher operational frequencies, the ability to multiplex detection across arrays of hundreds of devices embedded in a single chip, increased throughput and the ability to interrogate a wider range of modes including within the same device. Additionally, device fabrication is often compatible with semiconductor volume batch manufacturing techniques enabling cost scalability and a high degree of precision and reproducibility in the manufacturing process. Integration with microfluidics handling also enables suitable sample pre-processing/separation/purification/amplification steps that could improve selectivity and the overall signal-to-noise ratio. Three device types are reviewed here: (i) bulk acoustic wave sensors, (ii) surface acoustic wave sensors, and (iii) micro/nano-electromechanical system (MEMS/NEMS) sensors. PMID:27365040

  1. GASEOUS STRUCTURES IN BARRED GALAXIES: EFFECTS OF THE BAR STRENGTH

    SciTech Connect

    Kim, Woong-Tae; Seo, Woo-Young; Kim, Yonghwi

    2012-10-10

    Using hydrodynamic simulations, we investigate the physical properties of gaseous substructures in barred galaxies and their relationships with the bar strength. The gaseous medium is assumed to be isothermal and unmagnetized. The bar potential is modeled as a Ferrers prolate with index n. To explore situations with differing bar strength, we vary the bar mass f{sub bar} relative to the spheroidal component as well as its aspect ratio R. We derive expressions as functions of f{sub bar} and R for the bar strength Q{sub b} and the radius r(Q{sub b} ) where the maximum bar torque occurs. When applied to observations, these expressions suggest that bars in real galaxies are most likely to have f{sub bar} {approx} 0.25-0.50 and n {approx}< 1. Dust lanes approximately follow one of the x{sub 1}-orbits and tend to be straighter under a stronger and more elongated bar, but are insensitive to the presence of self-gravity. A nuclear ring of a conventional x{sub 2} type forms only when the bar is not so massive or elongated. The radius of an x{sub 2}-type ring is generally smaller than the inner Lindblad resonance, decreases systematically with increasing Q{sub b} , and is slightly larger when self-gravity is included. This is evidence that the ring position is not determined by the resonance, but instead by the amount of angular momentum loss at dust-lane shocks. Nuclear spirals exist only when the ring is of the x{sub 2} type and is sufficiently large in size. Unlike the other features, nuclear spirals are transient in that they start out being tightly wound and weak, and then, due to the nonlinear effect, unwind and become stronger until they turn into shocks, with an unwinding rate that is higher for larger Q{sub b} . The mass inflow rate to the galaxy center is found to be less than 0.01 M{sub Sun} yr{sup -1} for models with Q{sub b} {approx}< 0.2, while becoming larger than 0.1 M{sub Sun} yr{sup -1} when Q{sub b} {approx}> 0.2 and self-gravity is included.

  2. Electromechanical acoustic liner

    NASA Technical Reports Server (NTRS)

    Sheplak, Mark (Inventor); Cattafesta, III, Louis N. (Inventor); Nishida, Toshikazu (Inventor); Horowitz, Stephen Brian (Inventor)

    2007-01-01

    A multi-resonator-based system responsive to acoustic waves includes at least two resonators, each including a bottom plate, side walls secured to the bottom plate, and a top plate disposed on top of the side walls. The top plate includes an orifice so that a portion of an incident acoustical wave compresses gas in the resonators. The bottom plate or the side walls include at least one compliant portion. A reciprocal electromechanical transducer coupled to the compliant portion of each of the resonators forms a first and second transducer/compliant composite. An electrical network is disposed between the reciprocal electromechanical transducer of the first and second resonator.

  3. Polarity-inverted ScAlN film growth by ion beam irradiation and application to overtone acoustic wave (000-1)/(0001) film resonators

    SciTech Connect

    Suzuki, Masashi; Yanagitani, Takahiko; Odagawa, Hiroyuki

    2014-04-28

    Polarity inversion in wurtzite film is generally achieved by the epitaxial growth on a specific under-layer. We demonstrate polarity inversion of c-axis oriented ScAlN films by substrate ion beam irradiation without using buffer layer. Substrate ion beam irradiation was induced by either sputtering a small amount of oxide (as a negative ion source) onto the cathode or by applying a RF bias to the substrate. Polarity of the films was determined by a press test and nonlinear dielectric measurement. Second overtone thickness extensional mode acoustic resonance and suppression of fundamental mode resonance, indicating complete polarity inversion, were clearly observed in bilayer highly oriented (000-1)/(0001) ScAlN film.

  4. Adventures of a tidally induced bar

    NASA Astrophysics Data System (ADS)

    Łokas, E. L.; Athanassoula, E.; Debattista, V. P.; Valluri, M.; Pino, A. del; Semczuk, M.; Gajda, G.; Kowalczyk, K.

    2014-12-01

    Using N-body simulations, we study the properties of a bar induced in a discy dwarf galaxy as a result of tidal interaction with the Milky Way. The bar forms at the first pericentre passage and survives until the end of the evolution at 10 Gyr. Fourier decomposition of the bar reveals that only even modes are significant and preserve a hierarchy so that the bar mode is always the strongest. They show a characteristic profile with a maximum, similar to simulated bars forming in isolated galaxies and observed bars in real galaxies. We adopt the maximum of the bar mode as a measure of the bar strength and we estimate the bar length by comparing the density profiles along the bar and perpendicular to it. The bar strength and the bar length decrease with time, mainly at pericentres, as a result of tidal torques acting at those times and not to secular evolution. The pattern speed of the bar varies significantly on a time-scale of 1 Gyr and is controlled by the orientation of the tidal torque from the Milky Way. The bar is never tidally locked, but we discover a hint of a 5/2 orbital resonance between the third and fourth pericentre passage. The speed of the bar decreases in the long run so that the bar changes from initially rather fast to slow in the later stages. The boxy/peanut shape is present for some time and its occurrence is preceded by a short period of buckling instability.

  5. Acoustic cooling engine

    DOEpatents

    Hofler, Thomas J.; Wheatley, John C.; Swift, Gregory W.; Migliori, Albert

    1988-01-01

    An acoustic cooling engine with improved thermal performance and reduced internal losses comprises a compressible fluid contained in a resonant pressure vessel. The fluid has a substantial thermal expansion coefficient and is capable of supporting an acoustic standing wave. A thermodynamic element has first and second ends and is located in the resonant pressure vessel in thermal communication with the fluid. The thermal response of the thermodynamic element to the acoustic standing wave pumps heat from the second end to the first end. The thermodynamic element permits substantial flow of the fluid through the thermodynamic element. An acoustic driver cyclically drives the fluid with an acoustic standing wave. The driver is at a location of maximum acoustic impedance in the resonant pressure vessel and proximate the first end of the thermodynamic element. A hot heat exchanger is adjacent to and in thermal communication with the first end of the thermodynamic element. The hot heat exchanger conducts heat from the first end to portions of the resonant pressure vessel proximate the hot heat exchanger. The hot heat exchanger permits substantial flow of the fluid through the hot heat exchanger. The resonant pressure vessel can include a housing less than one quarter wavelength in length coupled to a reservoir. The housing can include a reduced diameter portion communicating with the reservoir. The frequency of the acoustic driver can be continuously controlled so as to maintain resonance.

  6. Measurement of Branching Fractions and Resonance Contributions for B0 -> D0bar K+ pi- and Search for B0 -> D0 K+ pi- Decays

    SciTech Connect

    Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Tisserand, V.; Zghiche, A.; Grauges, E.; Palano, A.; Pappagallo, M.; Pompili, A.; Chen, J.C.; Qi, N.D.; Rong, G.; Wang, P.; Zhu, Y.S.; Eigen, G.; Ofte, I.; Stugu, B. /Bergen U. /LBL, Berkeley /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /Bristol U. /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UCLA /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Rossendorf, Forschungszentrum /Ecole Polytechnique /Edinburgh U. /Ferrara U. /INFN, Ferrara /Frascati /Genoa U. /INFN, Genoa /Harvard U. /Heidelberg U. /Imperial Coll., London /Iowa U. /Iowa State U. /Karlsruhe U., EKP /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT, LNS /McGill U. /Milan U. /INFN, Milan /Mississippi U. /Montreal U. /Mt. Holyoke Coll. /Naples U. /INFN, Naples /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /Padua U. /INFN, Padua /Paris U., VI-VII /Pennsylvania U. /Perugia U. /INFN, Perugia /Pisa U. /Pisa, Scuola Normale Superiore /INFN, Pisa /Prairie View A-M /Princeton U. /Rome U. /INFN, Rome /Rostock U. /Rutherford /DSM, DAPNIA, Saclay /South Carolina U. /SLAC /Stanford U., Phys. Dept. /SUNY, Albany /Tennessee U. /Texas U. /Texas U., Dallas /Turin U. /INFN, Turin /Trieste U. /INFN, Trieste /Valencia U., IFIC /Vanderbilt U. /Victoria U. /Warwick U. /Wisconsin U., Madison /Yale U.

    2005-09-30

    Using 226 million {Upsilon}(4S) {yields} B{bar B} events collected with the BABAR detector at the PEp-II e{sup +}e{sup -} storage ring at the Stanford Linear Accelerator Center, they measure the branching fraction for B{sup 0} {yields} {bar D}{sup 0}K{sup +}{pi}{sup -}, excluding B{sup 0} {yields} D*{sup -}K{sup +}, to be {Beta}(B{sup 0} {yields} {bar D}{sup 0}K{sup +}{pi}{sup -}) = 88 {+-} 15 {+-} 9 x 10{sup -6}. They observe B{sup 0} {yields} {bar D}{sup 0}K*(892){sup 0} and B{sup 0} {yields} D*{sub 2}(2460){sup -}K{sup +} contributions. The ratio of branching fractions {Beta}(B{sup 0} {yields} D*{sup -} K{sup +})/{Beta}(B{sup 0} {yields} D*{sup -}{pi}{sup +}) = (7.76 {+-} 0.34 {+-} 0.29)% is measured separately. The branching fraction for the suppressed mode B{sup 0} {yields} D{sup 0}K{sup +}{pi}{sup -} is {Beta}(B{sup 0} {yields} D{sup 0}K{sup +}{pi}{sup -}) < 19 x 10{sup -6} at the 90% confidence level.

  7. Magnetohydrodynamic Simulations of Barred Galaxies

    NASA Astrophysics Data System (ADS)

    Kim, W.-T.

    2013-04-01

    Magnetic fields are pervasive in barred galaxies, especially in gaseous substructures such as dust lanes and nuclear rings. To explore the effects of magnetic fields on the formation of the substructures as well as on the mass inflow rates to the galaxy center, we run two-dimensional, ideal magnetohydrodynamic simulations. We use a modified version of the Athena code whose numerical magnetic diffusivity is shown to be of third order in space. In the bar regions, magnetic fields are compressed and abruptly bent around the dust-lane shocks. The associated magnetic stress not only reduces the peak density of the dust-lane shocks but also removes angular momentum further from the gas that is moving radially in. Nuclear rings that form at the location of centrifugal barrier rather than resonance with the bar are smaller and more radially distributed, and the mass flow rate to the galaxy center is correspondingly larger in models with stronger magnetic fields. Outside the bar regions, the bar potential and strong shear conspire to amplify the field strength near the corotation resonance. The amplified fields transport angular momentum outward, producing trailing magnetic arms with strong fields and low density. The base of the magnetic arms are found to be unstable to a tearing-mode instability of magnetic reconnection. This produces numerous magnetic islands that eventually make the outer regions highly chaotic.

  8. Sub-Poissonian phonon statistics in an acoustical resonator coupled to a pumped two-level emitter

    SciTech Connect

    Ceban, V. Macovei, M. A.

    2015-11-15

    The concept of an acoustical analog of the optical laser has been developed recently in both theoretical and experimental works. We here discuss a model of a coherent phonon generator with a direct signature of the quantum properties of sound vibrations. The considered setup is made of a laser-driven quantum dot embedded in an acoustical nanocavity. The system dynamics is solved for a single phonon mode in the steady-state and in the strong quantum dot—phonon coupling regime beyond the secular approximation. We demonstrate that the phonon statistics exhibits quantum features, i.e., is sub-Poissonian.

  9. Acoustic Treatment Design Scaling Methods. Volume 4; Numerical Simulation of the Nonlinear Acoustic Impedance of a Perforated Plate Single-Degree-of-Freedom Resonator Using a Time-Domain Finite Difference Method

    NASA Technical Reports Server (NTRS)

    Kraft, R. E.

    1999-01-01

    Single-degree-of-freedom resonators consisting of honeycomb cells covered by perforated facesheets are widely used as acoustic noise suppression liners in aircraft engine ducts. The acoustic resistance and mass reactance of such liners are known to vary with the intensity of the sound incident upon the panel. Since the pressure drop across a perforated liner facesheet increases quadratically with the flow velocity through the facesheet, this is known as the nonlinear resistance effect. In the past, two different empirical frequency domain models have been used to predict the Sound Pressure Level effect of the incident wave on the perforated liner impedance, one that uses the incident particle velocity in isolated narrowbands, and one that models the particle velocity as the overall velocity. In the absence of grazing flow, neither frequency domain model is entirely accurate in predicting the nonlinear effect that is measured for typical perforated sheets. The time domain model is developed in an attempt to understand and improve the model for the effect of spectral shape and amplitude of multi-frequency incident sound pressure on the liner impedance. A computer code for the time-domain finite difference model is developed and predictions using the models are compared to current frequency-domain models.

  10. Bar dimensions and bar shapes in estuaries

    NASA Astrophysics Data System (ADS)

    Leuven, Jasper; Kleinhans, Maarten; Weisscher, Steven; van der Vegt, Maarten

    2016-04-01

    Estuaries cause fascinating patterns of dynamic channels and shoals. Intertidal sandbars are valuable habitats, whilst channels provide access to harbors. We still lack a full explanation and classification scheme for the shapes and dimensions of bar patterns in natural estuaries, in contrast with bars in rivers. Analytical physics-based models suggest that bar length in estuaries increases with flow velocity, tidal excursion length or estuary width, depending on which model. However, these hypotheses were never validated for lack of data and experiments. We present a large dataset and determine the controls on bar shape and dimensions in estuaries, spanning bar lengths from centimeters (experiments) to 10s of kilometers length. First, we visually identified and classified 190 bars, measured their dimensions (width, length, height) and local braiding index. Data on estuarine geometry and tidal characteristics were obtained from governmental databases and literature on case studies. We found that many complex bars can be seen as simple elongated bars partly cut by mutually evasive ebb- and flood-dominated channels. Data analysis shows that bar dimensions scale with estuary dimensions, in particular estuary width. Breaking up the complex bars in simple bars greatly reduced scatter. Analytical bar theory overpredicts bar dimensions by an order of magnitude in case of small estuarine systems. Likewise, braiding index depends on local width-to-depth ratio, as was previously found for river systems. Our results suggest that estuary dimensions determine the order of magnitude of bar dimensions, while tidal characteristics modify this. We will continue to model bars numerically and experimentally. Our dataset on tidal bars enables future studies on the sedimentary architecture of geologically complex tidal deposits and enables studying effects of man-induced perturbations such as dredging and dumping on bar and channel patterns and habitats.

  11. Reduction of Transverse Surface Acoustic Wave Leakage in Resonator on Al/42° YX-LiTaO3 Substrate for High-Frequency Applications

    NASA Astrophysics Data System (ADS)

    Komatsu, Tomoya; Nakamura, Hiroyuki; Nakanishi, Hidekazu; Turunari, Tetsuya; Fujiwara, Joji

    2013-07-01

    In this paper, we propose a new structure for reducing the extent of transverse surface acoustic wave (SAW) leakage for the SAW resonator on a 42° YX-LiTaO3 substrate. Such leakage occurs from the interdigital region toward the busbar region in the SAW resonators. The new structure has a Ta2O5 film outside the interdigital region. This structure can make the SAW velocity in the busbar region lower than the velocity in the interdigital region. Therefore, the new structure could reduce the extent of leakage, and contribute to confine the SAW energy in the interdigital region. This structure was applied in SAW resonators and ladder-type SAW filters fabricated on a 42° YX-LiTaO3 substrate. The insertion loss could be improved by suppressing transverse SAW leakage. This technique could be applied to the fabrication of the filters and duplexers using leaky SAW on a 42° YX-LiTaO3 substrate, and the SAW devices could exhibit excellent performance.

  12. Characterization of condenser microphones under different environmental conditions for accurate speed of sound measurements with acoustic resonators.

    PubMed

    Guianvarc'h, Cécile; Gavioso, Roberto M; Benedetto, Giuliana; Pitre, Laurent; Bruneau, Michel

    2009-07-01

    Condenser microphones are more commonly used and have been extensively modeled and characterized in air at ambient temperature and static pressure. However, several applications of interest for metrology and physical acoustics require to use these transducers in significantly different environmental conditions. Particularly, the extremely accurate determination of the speed of sound in monoatomic gases, which is pursued for a determination of the Boltzmann constant k by an acoustic method, entails the use of condenser microphones mounted within a spherical cavity, over a wide range of static pressures, at the temperature of the triple point of water (273.16 K). To further increase the accuracy achievable in this application, the microphone frequency response and its acoustic input impedance need to be precisely determined over the same static pressure and temperature range. Few previous works examined the influence of static pressure, temperature, and gas composition on the microphone's sensitivity. In this work, the results of relative calibrations of 1/4 in. condenser microphones obtained using an electrostatic actuator technique are presented. The calibrations are performed in pure helium and argon gas at temperatures near 273 K and in the pressure range between 10 and 600 kPa. These experimental results are compared with the predictions of a realistic model available in the literature, finding a remarkable good agreement. The model provides an estimate of the acoustic impedance of 1/4 in. condenser microphones as a function of frequency and static pressure and is used to calculate the corresponding frequency perturbations induced on the normal modes of a spherical cavity when this is filled with helium or argon gas. PMID:19655971

  13. Acoustic Translation of an Acoustically Levitated Sample

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Allen, J. L.

    1986-01-01

    Acoustic-levitation apparatus uses only one acoustic mode to move sample from one region of chamber to another. Sample heated and cooled quickly by translation between hot and cold regions of levitation chamber. Levitated sample is raised into furnace region by raising plunger. Frequency of sound produced by transducers adjusted by feedback system to maintain (102) resonant mode, which levitates sample midway between transducers and plunger regardless of plunger position.

  14. High-performance surface acoustic wave resonators in the 1 to 3 GHz range using a ScAlN/6H-SiC structure.

    PubMed

    Hashimoto, Ken-ya; Sato, Shuhei; Teshigahara, Akihiko; Nakamura, Takuya; Kano, Kazuhiko

    2013-03-01

    This paper describes application of Sc-doped AlN (ScAlN) to wideband SAW devices in the 1 to 3 GHz range. First, it is shown theoretically that large SAW velocity and electromechanical coupling factor are simultaneously achievable when the ScAlN film is combined with a base substrate with extremely high acoustic wave velocities, such as diamond and SiC. Next, SAW delay lines are fabricated on the ScAlN/6H-SiC structure, and reasonable agreement between the theory and experiment is obtained. Finally, one-port SAW resonators are fabricated on the structure, and it is shown that high-performance is achievable in the 1 to 3 GHz range by use of the structure. PMID:23475930

  15. Acoustic neuroma

    MedlinePlus

    Vestibular schwannoma; Tumor - acoustic; Cerebellopontine angle tumor; Angle tumor ... Acoustic neuromas have been linked with the genetic disorder neurofibromatosis type 2 (NF2). Acoustic neuromas are uncommon.

  16. Comparison of three lines of broiler breeders differing in ascites susceptibility or growth rate. 1. Relationship between acoustic resonance data and embryonic or hatching parameters.

    PubMed

    Tona, K; Kemps, B; Bruggeman, V; Bamelis, F; De Smit, L; Onagbesan, O; De Baerdemaeker, J; Decuypere, E

    2005-09-01

    Ascites is a prevalent cardiovascular disease among modern broilers with negative impacts on production and animal welfare. The peak of mortality due to ascites occurs at the end of the growing period, but the etiology of this problem may start during embryonic development. A few recent reports have demonstrated that the signs of ascites susceptibility are manifested during the late stages of incubation. In the current study, we used a nondestructive method based on egg acoustic resonance parameters [resonant frequency (RF) and damping] to establish a relationship between embryo physiological events during early development in broiler eggs and susceptibility to ascites. The hatching eggs of 3 broiler lines differing in ascites susceptibility were used for this study: ascites-resistant dam line (DAR), ascites-sensitive dam line (DAS), and ascites-sensitive sire line (SASL). These lines were selected on the basis of fast growth, high breast meat yield, and ascites induction at low temperatures such that the order of ascites susceptibility in terms of mortality was SASL > DAS > DAR. Eggs were incubated under standard conditions in forced-draft incubators. We measured egg weights at setting, albumen pH, Haugh units (HU) at setting, and embryo weights at d 11 and 18, at internal pipping (IP), and at hatch. The durations of IP, external pipping (EP), and hatching were also determined. At 2 hourly periods during incubation, egg RF and damping were also measured. There were differences in egg weights between DAR and SASL vs. DAS, but albumen HU, albumen pH, and the ratio of yolk weight to egg weight were similar. There were differences in RF, damping, embryonic growth rates, and hatching events. Changes in resonant frequency and damping, which certainly suggest eggshell differences among lines, were not totally related to variations in physiological events during early and late embryonic development. A comparison between DAR and DAS, between DAS and SASL, or DAR and SASL

  17. Spectroscopic Study of Hyperon Resonances below bar{K}N Threshold via the ≤ft( K - ,n right) Reaction on Deuteron

    NASA Astrophysics Data System (ADS)

    Yamaga, T.; Ajimura, S.; Beer, G.; Bhang, H.; Bragadireanu, M.; Buehler, P.; Busso, L.; Cargnelli, M.; Choi, S.; Curceanu, C.; Enomoto, S.; Faso, D.; Fujioka, H.; Fujiwara, Y.; Fukuda, T.; Guaraldo, C.; Hashimoto, T.; Hayano, R. S.; Hiraiwa, T.; Iio, M.; Iliescu, M.; Inoue, K.; Ishiguro, Y.; Ishikawa, T.; Ishimoto, S.; Ishiwatari, T.; Itahashi, K.; Iwai, M.; Iwasaki, M.; Kato, Y.; Kawasaki, S.; Kienle, P.; Kou, H.; Ma, Y.; Marton, J.; Matsuda, Y.; Mizoi, Y.; Morra, O.; Nagae, T.; Noumi, H.; Ohnishi, H.; Okada, S.; Outa, H.; Piscicchia, K.; Poli Lener, M.; Romero Vidal, A.; Sada, Y.; Sakaguchi, A.; Sakuma, F.; Sato, M.; Scordo, Al; Sekimoto, M.; Shi, H.; Shirotori, K.; Sirghi, D.; Sirghi, F.; Suzuki, K.; Suzuki, S.; Suzuki, T.; Tanida, T.; Tatsuno, H.; Tokuda, M.; Tomono, D.; Toyoda, A.; Tsukada, K.; Vazquez Doce, O.; Widmann, E.; Wuenschek, B. K.; Yamazaki, T.; Yim, H.; Zhang, Q.; Zmeskal, J.

    We are planning to carry out an experimental study of hyperon resonance via the d≤ft( K - ,n right) reaction using kaon beam which has momentum of 1 GeV/c at the J-PARC hadron experimental facility. In the presented reaction, Λ (1405) can be produced dynamically from meson-baryon resonant state. The performance of the counters was tested at the previous beam time of the J-PARC. The counters worked as expected. The preparation of experimental setup had been done.

  18. Resonance

    NASA Astrophysics Data System (ADS)

    Perozzi, E.; Murdin, P.

    2000-11-01

    A resonance in CELESTIAL MECHANICS occurs when some of the quantities characterizing the motion of two or more celestial bodies can be considered as commensurable, i.e. their ratio is close to an integer fraction. In a simplified form, this can be expressed as ...

  19. Nano-structural Characteristics of N-doped ZnO Thin Films and Fabrication of Film Bulk Acoustic Resonator Devices

    SciTech Connect

    Lee, E. J.; Zhang, R. R.; Yoon, G. W.; Park, J. D.

    2011-12-23

    N-doped ZnO thin films (ZnO:N) with c-axis preferred orientation were prepared on p-Si(100) wafers, using an RF magnetron sputter deposition. For ZnO deposition, N{sub 2}O gas was employed as a dopant source and various deposition conditions such as N{sub 2}O gas fraction and RF power were applied. In addition, the film bulk acoustic resonator (FBAR) devices with three kinds of top electrodes patterns were fabricated by using the N-doped ZnO thin films as the piezoelectric layers. The depth profiles of the nitrogen [N] atoms incorporated into the ZnO thin films were investigated by an Auger Electron Spectroscopy (AES) and the nano-scale structural characteristics of the N-doped ZnO (ZnO:N) thin films were also investigated by a scanning electron microscope (SEM) technique. The fabricated resonators were evaluated by measuring the return loss (S{sub 11}) characteristics using a probe station and E8361A PNA Network Analyzer.

  20. Effect of grazing flow on the acoustic impedance of Helmholtz resonators consisting of single and clustered orifices

    NASA Technical Reports Server (NTRS)

    Hersh, A. S.; Walker, B.; Bucka, M.

    1978-01-01

    A semiempirical fluid mechanical model is presented which predicts impedance of a Helmholtz resonator consisting of a single cavity-backed orifice as a function of grazing flow speed, boundary-layer thickness, incident sound amplitude and frequency, and resonator geometry. The incident and cavity sound fields are connected in terms of an orifice discharge coefficient. The effect of multiple orifices was studied experimentally. Interaction between orifices is important only for orifices aligned parallel to the grazing flow. Resistance was virtually independent of both orifice relative spacing and number. Reactance was found to be quite dependent upon orifice spacing but insensitive to the number of orifices.

  1. Acoustic behavior of a rigidly backed poroelastic layer with periodic resonant inclusions by a multiple scattering approach.

    PubMed

    Weisser, Thomas; Groby, Jean-Philippe; Dazel, Olivier; Gaultier, François; Deckers, Elke; Futatsugi, Sideto; Monteiro, Luciana

    2016-02-01

    The acoustic response of a rigidly backed poroelastic layer with a periodic set of elastic cylindrical inclusions embedded is studied. A semi-analytical approach is presented, based on Biot's 1956 theory to account for the deformation of the skeleton, coupling mode matching technique, Bloch wave representation, and multiple scattering theory. This model is validated by comparing the derived absorption coefficients to finite element simulations. Numerical results are further exposed to investigate the influence of the properties of the inclusions (type, material properties, size) of this structure, while a modal analysis is performed to characterize the dynamic behaviors leading to high acoustic absorption. Particularly, in the case of thin viscoelastic membranes, an absorption coefficient larger than 0.8 is observed on a wide frequency band. This property is found to be due to the coupling between the first volume mode of the inclusion and the trapped mode induced by the periodic array and the rigid backing, for a wavelength in the air smaller than 11 times the material thickness. PMID:26936546

  2. Effects of core position of locally resonant scatterers on low-frequency acoustic absorption in viscoelastic panel

    NASA Astrophysics Data System (ADS)

    Zhong, Jie; Wen, Ji-Hong; Zhao, Hong-Gang; Yin, Jian-Fei; Yang, Hai-Bin

    2015-08-01

    Locally resonant sonic materials, due to their ability to control the propagation of low-frequency elastic waves, have become a promising option for underwater sound absorption materials. In this paper, the finite element method is used to investigate the absorption characteristics of a viscoelastic panel periodically embedded with a type of infinite-long non-coaxially cylindrical locally resonant scatterers (LRSs). The effect of the core position in the coating layer of the LRS on the low-frequency (500 Hz-3000 Hz) sound absorption property is investigated. With increasing the longitudinal core eccentricity e, there occur few changes in the absorptance at the frequencies below 1500 Hz, however, the absorptance above 1500 Hz becomes gradually better and the valid absorption (with absorptance above 0.8) frequency band (VAFB) of the viscoelastic panel becomes accordingly broader. The absorption mechanism is revealed by using the displacement field maps of the viscoelastic panel and the steel slab. The results show two typical resonance modes. One is the overall resonance mode (ORM) caused by steel backing, and the other is the core resonance mode (CRM) caused by LRS. The absorptance of the viscoelastic panel by ORM is induced mainly by the vibration of the steel slab and affected little by core position. On the contrary, with increasing the core eccentricity, the CRM shifts toward high frequency band and decouples with the ORM, leading to two separate absorption peaks and the broadened VAFB of the panel. Project supported by the National Natural Science Foundation of China (Grant No. 51275519).

  3. A high-overtone bulk acoustic wave resonator-oscillator-based 4.596 GHz frequency source: Application to a coherent population trapping Cs vapor cell atomic clock

    SciTech Connect

    Daugey, Thomas; Friedt, Jean-Michel; Martin, Gilles; Boudot, Rodolphe

    2015-11-15

    This article reports on the design and characterization of a high-overtone bulk acoustic wave resonator (HBAR)-oscillator-based 4.596 GHz frequency source. A 2.298 GHz signal, generated by an oscillator constructed around a thermally controlled two-port aluminum nitride-sapphire HBAR resonator with a Q-factor of 24 000 at 68 °C, is frequency multiplied by 2–4.596 GHz, half of the Cs atom clock frequency. The temperature coefficient of frequency of the HBAR is measured to be −23 ppm/ °C at 2.298 GHz. The measured phase noise of the 4.596 GHz source is −105 dB rad{sup 2}/Hz at 1 kHz offset and −150 dB rad{sup 2}/Hz at 100 kHz offset. The 4.596 GHz output signal is used as a local oscillator in a laboratory-prototype Cs microcell-based coherent population trapping atomic clock. The signal is stabilized onto the atomic transition frequency by tuning finely a voltage-controlled phase shifter implemented in the 2.298 GHz HBAR-oscillator loop, preventing the need for a high-power-consuming direct digital synthesis. The short-term fractional frequency stability of the free-running oscillator is 1.8 × 10{sup −9} at one second integration time. In locked regime, the latter is improved in a preliminary proof-of-concept experiment at the level of 6.6 × 10{sup −11} τ{sup −1/2} up to a few seconds and found to be limited by the signal-to-noise ratio of the detected CPT resonance.

  4. Search for t bar{{t}} resonances in semileptonic final states at √{{s}}=8 TeV with the CMS detector

    NASA Astrophysics Data System (ADS)

    Missiroli, M.; CMS Collaboration

    2015-01-01

    We present a search for heavy resonances decaying to a top quark-antiquark pair with the Compact Muon Solenoid (CMS) detector in pp collisions at √{s}=8 TeV. The analysis is performed in the semileptonic channel and corresponds to the combination of two dedicated searches, one designed for the reconstruction of top decays with well-separated decay products, the other optimized to probe the production of two high-pT top quarks, whose decay can potentially lead to the presence of merged jets and non-isolated leptons at the reconstruction level. No excess is observed in data with respect to the background expectation and 95% CL limits are set on the production cross section of resonances in the mass range from 500GeV/c2 to 3TeV/c2 for several benchmark models.

  5. Double resonance spectroscopy of the D {}^1 \\Pi _u^+ and B^{\\prime \\prime }\\barB^1\\Sigma ^+_u states near the third dissociation threshold of H2

    NASA Astrophysics Data System (ADS)

    Ekey, R. C.; Cordova, A. E.; Duan, W.; Chartrand, A. M.; McCormack, E. F.

    2013-12-01

    Double-resonance laser spectroscopy via the E,F {}^1 \\Sigma _g^+, v^{\\prime }=6, J^{\\prime } state was used to probe the energy region below the third dissociation limit of molecular hydrogen. Resonantly enhanced multi-photon ionization spectra were recorded by detecting ion production as a function of energy using a time-of-flight mass spectrometer. Energies and line widths for the v = 14-17 levels of the D{}^1 \\Pi _u^+ state of H2 are reported and compared to experimental data obtained by using VUV synchrotron light excitation (Dickenson et al 2010 J. Chem. Phys. 133 144317) and fully ab initio non-adiabatic calculations of D {}^1 \\Pi _u^+ state energies and line widths (Glass-Maujean et al 2012 Phys. Rev. A 86 052507). Several high vibrational levels of the B^{\\prime \\prime }\\bar{B}^1\\Sigma ^+_u state were also observed in this region. Term energies and rotational constants for the v = 67-69 vibrational levels are reported and compared to highly accurate ro-vibrational energy level predictions from fully ab initio non-adiabatic calculations of the first six {}^1 \\Sigma _u^+ levels of H2 (Wolniewicz et al 2006 J. Mol. Spectrosc. 238 118). While additional observed transitions can be assigned to other states, several unassigned features in the spectra highlight the need for a fully integrated theoretical treatment of dissociation and ionization to understand the complex pattern of highly vibrationally excited states expected in this region.

  6. Discussion about generation mechanisms of third-order nonlinear signals in surface acoustic wave resonators based on simulation

    NASA Astrophysics Data System (ADS)

    Nakagawa, Ryo; Suzuki, Takanao; Shimizu, Hiroshi; Kyoya, Haruki; Nako, Katsuhiro; Hashimoto, Ken-ya

    2016-07-01

    In this paper, we discuss the generation mechanisms of third-order nonlinearity in surface acoustic wave (SAW) devices on the basis of simulation results, which are obtained by a proposed method for this discussion. First, eight nonlinear terms are introduced to the piezoelectric constitutive equations, and nonlinear stress and electric flux fields are estimated using linear strain and electric fields calculated by a linear analysis, i.e., the coupling of mode simulation. Then, their contributions are embedded as voltage and current sources, respectively, in an equivalent circuit model, and nonlinear signals appearing at external ports are estimated. It is shown that eight coefficients of the nonlinear terms can be determined from a series of experiments carried out at various driving and resulting frequencies. This is because the effect of each nonlinear term on the nonlinear signal outputs changes markedly with the conditions. When the coefficients are determined properly, the simulations agree well with some measurement results under various conditions.

  7. Infragravity waves over a natural barred profile

    USGS Publications Warehouse

    Sallenger, A.H., Jr.; Holman, R.A.

    1987-01-01

    Measurements of cross-shore flow were made across the surf zone during a storm as a nearshore bar became better developed and migrated offshore. Measured infragravity band spectra were compared to synthetic spectra calculated numerically over the natural barred profile assuming a white run-up spectrum of leaky mode or high-mode edge waves. The dominant wave observed early in the storm was consistent with Symond and Bowen's (1984) theoretical prediction of resonant amplification of discrete frequencies over a barred profile. -from Authors

  8. Design and Characterization of a High-power Laser-induced Acoustic Desorption (LIAD) Probe Coupled with a Fourier-transform Ion Cyclotron Resonance Mass Spectrometer

    PubMed Central

    Shea, Ryan C.; Habicht, Steven C.; Vaughn, Weldon E.; Kenttämaa, Hilkka I.

    2008-01-01

    We report here the construction and characterization of a high-power laser-induced acoustic desorption (LIAD) probe designed for Fourier-transform ion cyclotron resonance (FT-ICR) mass spectrometers to facilitate analysis of non-volatile, thermally labile compounds. This “next generation” LIAD probe offers significant improvements in sensitivity and desorption efficiency for analytes with larger molecular weights via the use of higher laser irradiances. Unlike the previous probes which utilized a power limiting optical fiber to transmit the laser pulses through the probe, this probe employs a set of mirrors and a focusing lens. At the end of the probe, the energy from the laser pulses propagates through a thin metal foil as an acoustic wave, resulting in desorption of neutral molecules from the opposite side of the foil. Following desorption, the molecules can be ionized by electron impact or chemical ionization. Almost an order of magnitude greater power density (up to 5.0 × 109 W/cm2) is achievable on the backside of the foil with the high-power LIAD probe compared to the earlier LIAD probes (maximum power density ~9.0 × 108 W/cm2). The use of higher laser irradiances is demonstrated not to cause fragmentation of the analyte. The use of higher laser irradiances increases sensitivity since it results in the evaporation of a greater number of molecules per laser pulse. Measurement of the average velocities of LIAD evaporated molecules demonstrates that higher laser irradiances do not correlate with higher velocities of the gaseous analyte molecules. PMID:17319645

  9. Exotic and qq-bar resonances in the pi+pi-pi- system produced in pi-p collisions at 18 GeV/c

    SciTech Connect

    S. U. Chung; K. Danyo; R. W. Hackenburg; C. Olchanski; J. S. Suh; H. J. Willutzki; S. P. Denisov; V. Dorofeev; V. V. Lipaev; A. V. Popov; D. I. Ryabchikov; Z. Bar-Yam; J. P. Dowd; P. Eugenio; M. Hayek; W. Kern; E. King; N. Shenhav; V. A. Bodyagin; O. L. Kodolova; V. L. Korotkikh; M. A. Kostin; A. I. Ostrovidov; L. I. Sarycheva; I. N. Vardanyan; A. A. Yershov; D. S. Brown; X. L. Fan; D. Joffe; T. K. Pedlar; K. K. Seth; A. Tomaradze; T. Adams; J. M. Bishop; N. M. Cason; E. I. Ivanov; J. M. LoSecco; J. J. Manak; W. D. Shephard; D. L. Stienike; S. A. Taegar; G. S. Adams; J. P. Cummings; J. Hu; J. Kuhn; M. Lu; J. Napolitano; D. B. White; M. Witkowski; M. Nozar; X. Shen; D. P. Weygand

    2002-03-01

    A partial-wave analysis of the reaction pi{sup -}p-->pi{sup +}pi{sup -}pi{sup -}p at 18 GeV/c has been performed on a data sample of 250 000 events obtained in the Brookhaven experiment E852. The well-known a{sub 1}(1260), a{sub 2}(1320) and pi{sub 2}(1670) resonant states are observed. The existence of the pi(1800), a{sub 1}(1700) and a{sub 4}(2040) states is confirmed. The a{sub 3}(1874) state is also observed. The exotic 1{sup -+} pi{sub 1}(1600) state produced in the natural parity exchange process is found to decay in the rho(770)pi{sup -} channel. A mass-dependent fit results in a resonance mass of 1593{+-}8{sub -47}{sup +29} MeV/c{sup 2} and a width of 168{+-}20{sub -12}{sup +150} MeV/c{sup 2}.

  10. Micro acoustic spectrum analyzer

    DOEpatents

    Schubert, W. Kent; Butler, Michael A.; Adkins, Douglas R.; Anderson, Larry F.

    2004-11-23

    A micro acoustic spectrum analyzer for determining the frequency components of a fluctuating sound signal comprises a microphone to pick up the fluctuating sound signal and produce an alternating current electrical signal; at least one microfabricated resonator, each resonator having a different resonant frequency, that vibrate in response to the alternating current electrical signal; and at least one detector to detect the vibration of the microfabricated resonators. The micro acoustic spectrum analyzer can further comprise a mixer to mix a reference signal with the alternating current electrical signal from the microphone to shift the frequency spectrum to a frequency range that is a better matched to the resonant frequencies of the microfabricated resonators. The micro acoustic spectrum analyzer can be designed specifically for portability, size, cost, accuracy, speed, power requirements, and use in a harsh environment. The micro acoustic spectrum analyzer is particularly suited for applications where size, accessibility, and power requirements are limited, such as the monitoring of industrial equipment and processes, detection of security intrusions, or evaluation of military threats.

  11. Cochlear bionic acoustic metamaterials

    NASA Astrophysics Data System (ADS)

    Ma, Fuyin; Wu, Jiu Hui; Huang, Meng; Fu, Gang; Bai, Changan

    2014-11-01

    A design of bionic acoustic metamaterial and acoustic functional devices was proposed by employing the mammalian cochlear as a prototype. First, combined with the experimental data in previous literatures, it is pointed out that the cochlear hair cells and stereocilia cluster are a kind of natural biological acoustic metamaterials with the negative stiffness characteristics. Then, to design the acoustic functional devices conveniently in engineering application, a simplified parametric helical structure was proposed to replace actual irregular cochlea for bionic design, and based on the computational results of such a bionic parametric helical structure, it is suggested that the overall cochlear is a local resonant system with the negative dynamic effective mass characteristics. There are many potential applications in the bandboard energy recovery device, cochlear implant, and acoustic black hole.

  12. Acoustic, piezoelectric, and dielectric nonlinearities of AlN in coupled resonator filters for high RF power levels.

    PubMed

    Sahyoun, Walaa; Duchamp, Jean-Marc; Benech, Philippe

    2011-10-01

    Coupled resonator filters (CRFs) are the new generation of BAW filters recently designed for the front-end modules of mobile transmission systems. Looking for designers' requirements, CRF devices have been characterized and modeled. The model based on equivalent circuits relies on material constants such as stiffness and electro-coupling coefficients, and works only for linear-mode propagation. Because of their positions between antennas and power amplifiers, they often work under high RF power, inducing nonlinear response in the AlN piezoelectric layer. In this work, we analyze for the first time the nonlinear behavior of AlN material particularly for coupled BAW resonators. To characterize the nonlinear effects in CRFs, we measure the 1-dB gain compression point (P1dB) and the intercept point (IP(3)). Then, we develop a nonlinear model of CRFs using harmonic balance (HB) simulation in commercially available software. The HB environment allows fitting simulations to measurements in terms of P(1dB) and IP(3). We find that a high RF power induces nonlinear changes in the material constants' real parts: elastic stiffness c(33) (4.9%), piezoelectric e(33) (17.4%), and permittivity ϵ(33) (5.2%). These nonlinear variations of material constants describe the nonlinear behavior of CRF devices using the same deposit process for AlN material. PMID:21989879

  13. Small-scale field-aligned currents and ionospheric disturbances induced by vertical acoustic resonance during the 2015 eruption of Chile's Calbuco volcano

    NASA Astrophysics Data System (ADS)

    Aoyama, T.; Iyemori, T.; Nakanishi, K.; Nishioka, M.

    2015-12-01

    Wave packet structure of small-scale magnetic fluctuations were observed by SWARM satellites just above the volcano and it's magnetic conjugate point after the eruption of Chile's Calbuco volcano on April 22, 2015. These magnetic fluctuations in low and middle latitudes generated by small-scale field aligned currents (FACs), and have about 10-30 seconds period along the satellites' orbit [Nakanishi et al., 2014] and about 200 (340) seconds temporal scale for meridional (longitudinal) magnetic components [Iyemori et al., 2015]. We also observed ionospheric disturbances and ground geomagnetic fluctuations just after the eruption. The 4-min period oscillations of total electron content (TEC) were observed by GPS receivers near the volcano. The 260 and 215 seconds spectral peaks in D component of ground based geomagnetic observation were found. Such oscillations and spectral peaks didn't exist before the eruption. All of these observations may have the same origin, i.e., vertical acoustic resonance between the ionosphere and the ground. In this presentation, we estimate the propagation velocity of the TEC oscillations and the spatial scale of the disturbance region in the E-layer where the FACs are generated by the ionospheric dynamo.

  14. Experimental investigations of the internal energy of molecules evaporated via laser-induced acoustic desorption into a Fourier transform ion cyclotron resonance mass spectrometer.

    PubMed

    Shea, Ryan C; Petzold, Christopher J; Liu, Ji-Ang; Kenttämaa, Hilkka I

    2007-03-01

    The internal energy of neutral gas-phase organic and biomolecules, evaporated by means of laser-induced acoustic desorption (LIAD) into a Fourier transform ion cyclotron resonance mass spectrometer, was investigated through several experimental approaches. The desorbed molecules were demonstrated not to undergo degradation during the desorption process by collecting LIAD-evaporated molecules and subjecting them to analysis by electrospray ionization/quadrupole ion trap mass spectrometry. Previously established gas-phase basicity values were remeasured for LIAD-evaporated organic molecules and biomolecules with the use of the bracketing method. No endothermic reactions were observed. The remeasured basicity values are in close agreement with the values reported in the literature. The amount of internal energy deposited during LIAD is concluded to be less than a few kilocalories per mole. Chemical ionization with a series of proton-transfer reagents was employed to obtain a breakdown curve for a protonated dipeptide, Val-Pro, evaporated by LIAD. Comparison of this breakdown curve with a previously published analogous curve obtained by using substrate-assisted laser desorption (SALD) to evaporate the peptide suggests that the molecules evaporated via LIAD have a similar internal energy as those evaporated via SALD. PMID:17263513

  15. Acoustic bubble removal method

    NASA Technical Reports Server (NTRS)

    Trinh, E. H.; Elleman, D. D.; Wang, T. G. (Inventor)

    1983-01-01

    A method is described for removing bubbles from a liquid bath such as a bath of molten glass to be used for optical elements. Larger bubbles are first removed by applying acoustic energy resonant to a bath dimension to drive the larger bubbles toward a pressure well where the bubbles can coalesce and then be more easily removed. Thereafter, submillimeter bubbles are removed by applying acoustic energy of frequencies resonant to the small bubbles to oscillate them and thereby stir liquid immediately about the bubbles to facilitate their breakup and absorption into the liquid.

  16. Cryogenic oxygen jet response to transverse acoustic excitation with the first transverse and the first combined longitudinal-transverse modes

    NASA Astrophysics Data System (ADS)

    Hardi, J. S.; Oschwald, M.

    2016-07-01

    The intact length of the dense oxygen core from an oxygen-hydrogen shear coaxial rocket injector was measured. The measurements were made in a rectangular rocket combustor with optical access and acoustic forcing. The combustor was operated at chamber pressures of 40 and 60 bar, with either ambient temperature or cryogenic hydrogen. The multielement injection spray is subjected to forced transverse gas oscillations of two different acoustic resonance modes; the first transverse (1T) mode at 4200 Hz and the first combined longitudinal-transverse (1L1T) at 5500 Hz. Intact core length is measured from high-speed shadowgraph imaging. The dependence of intact core length with increasing acoustic amplitude is compared for the two modes of excitation.

  17. Dual-resonance converse magnetoelectric and voltage step-up effects in laminated composite of long-type 0.71Pb(Mg1/3Nb2/3)O3-0.29PbTiO3 piezoelectric single-crystal transformer and Tb0.3Dy0.7Fe1.92 magnetostrictive alloy bars

    NASA Astrophysics Data System (ADS)

    Ming Leung, Chung; Wing Or, Siu; Wang, Feifei; Ho, S. L.

    2011-05-01

    We report a dual-resonance converse magnetoelectric effect and a dual-resonance voltage step-up effect in a laminated composite made by sandwiching the output (or secondary) section of a long-type 0.71Pb(Mg1/3Nb2/3)O3-0.29PbTiO3 (PMN-PT) piezoelectric single-crystal transformer having a longitudinal-longitudinal polarization between two Tb0.3Dy0.7Fe1.92 (Terfenol-D) magnetostrictive alloy bars having a longitudinal magnetization. The reported converse magnetoelectric effect originates from the mechanically mediated resonance converse piezoelectric effect in the PMN-PT transformer and resonance converse magnetostrictive effect in the Terfenol-D bars. The additional voltage step-up effect results from the mechanically mediated resonance converse and direct piezoelectric effects in the PMN-PT transformer. The composite shows two sharp resonance peaks of 0.39 and 0.54 G/V in converse magnetoelectric coefficient (αB = dB/dVin) and of 1.4 and 2.1 in voltage step-up ratio (Vout/Vin) at about 54 and 120 kHz, corresponding to the half- and full-wavelength longitudinal mode resonances, respectively. The measured magnetic induction (B) exhibits good linear relationships to the applied ac voltage (Vin) with amplitude varying from 10 to 100 V in both resonance and nonresonance conditions. These dual-resonance effects make the composite great promise for coil-free electromagnetic device applications.

  18. The four bars problem

    NASA Astrophysics Data System (ADS)

    Mauroy, Alexandre; Taslakian, Perouz; Langerman, Stefan; Jungers, Raphaël

    2016-09-01

    A four-bar linkage is a mechanism consisting of four rigid bars which are joined by their endpoints in a polygonal chain and which can rotate freely at the joints (or vertices). We assume that the linkage lies in the 2-dimensional plane so that one of the bars is held horizontally fixed. In this paper we consider the problem of reconfiguring a four-bar linkage using an operation called a pop. Given a four-bar linkage, a pop reflects a vertex across the line defined by its two adjacent vertices along the polygonal chain. Our main result shows that for certain conditions on the lengths of the bars, the neighborhood of any configuration that can be reached by smooth motion can also be reached by pops. The proof relies on the fact that pops are described by a map on the circle with an irrational number of rotation.

  19. Predictions for the $$\\bar{B}^{0}\\rightarrow \\bar{K}^{\\ast 0}$$ X(YZ) and $$\\bar{B}^{0}_{s}\\rightarrow\\phi$$ X(YZ) with X(4160), Y(3940), Z(3930)

    DOE PAGESBeta

    Liang, Wei -Hong; Molina, R.; Xie, Ju -Jun; Doring, M.; Oset, E.

    2015-05-22

    We investigate the decay ofmore » $$\\bar B^0 \\to \\bar K^{*0} R$$ and $$\\bar B^0_s \\to \\phi R$$ with $R$ being the $X(4160)$, $Y(3940)$, $Z(3930)$ resonances. Under the assumption that these states are dynamically generated from the vector-vector interaction, as has been concluded from several theoretical studies, we use a reaction mechanism of quark production at the elementary level, followed by hadronization of one final $$q \\bar q$$ pair into two vectors and posterior final state interaction of this pair of vector mesons to produce the resonances. With this procedure we are able to predict five ratios for these decays, which are closely linked to the dynamical nature of these states, and also predict the order of magnitude of the branching ratios which we find of the order of $$10^{-4}$$, well within the present measurable range. In order to further test the dynamical nature of these resonances we study the $$\\bar B^0_s \\to \\phi D^* \\bar D^*$$ and $$\\bar B^0_s \\to \\phi D_s^* \\bar D_s^*$$ decays close to the $$D^* \\bar D^*$$ and $$D_s^* \\bar D_s^*$$ thresholds and make predictions for the ratio of the mass distributions in these decays and the $$\\bar B^0_s \\to \\phi R$$ decay widths. In conclusion, the measurement of these decays rates can help unravel the nature of these resonances.« less

  20. Predictions for the $\\bar{B}^{0}\\rightarrow \\bar{K}^{\\ast 0}$ X(YZ) and $\\bar{B}^{0}_{s}\\rightarrow\\phi$ X(YZ) with X(4160), Y(3940), Z(3930)

    SciTech Connect

    Liang, Wei -Hong; Molina, R.; Xie, Ju -Jun; Doring, M.; Oset, E.

    2015-05-22

    We investigate the decay of $\\bar B^0 \\to \\bar K^{*0} R$ and $\\bar B^0_s \\to \\phi R$ with $R$ being the $X(4160)$, $Y(3940)$, $Z(3930)$ resonances. Under the assumption that these states are dynamically generated from the vector-vector interaction, as has been concluded from several theoretical studies, we use a reaction mechanism of quark production at the elementary level, followed by hadronization of one final $q \\bar q$ pair into two vectors and posterior final state interaction of this pair of vector mesons to produce the resonances. With this procedure we are able to predict five ratios for these decays, which are closely linked to the dynamical nature of these states, and also predict the order of magnitude of the branching ratios which we find of the order of $10^{-4}$, well within the present measurable range. In order to further test the dynamical nature of these resonances we study the $\\bar B^0_s \\to \\phi D^* \\bar D^*$ and $\\bar B^0_s \\to \\phi D_s^* \\bar D_s^*$ decays close to the $D^* \\bar D^*$ and $D_s^* \\bar D_s^*$ thresholds and make predictions for the ratio of the mass distributions in these decays and the $\\bar B^0_s \\to \\phi R$ decay widths. In conclusion, the measurement of these decays rates can help unravel the nature of these resonances.

  1. Bar Code Labels

    NASA Technical Reports Server (NTRS)

    1988-01-01

    American Bar Codes, Inc. developed special bar code labels for inventory control of space shuttle parts and other space system components. ABC labels are made in a company-developed anodizing aluminum process and consecutively marketed with bar code symbology and human readable numbers. They offer extreme abrasion resistance and indefinite resistance to ultraviolet radiation, capable of withstanding 700 degree temperatures without deterioration and up to 1400 degrees with special designs. They offer high resistance to salt spray, cleaning fluids and mild acids. ABC is now producing these bar code labels commercially or industrial customers who also need labels to resist harsh environments.

  2. Latticed pentamode acoustic cloak

    PubMed Central

    Chen, Yi; Liu, Xiaoning; Hu, Gengkai

    2015-01-01

    We report in this work a practical design of pentamode acoustic cloak with microstructure. The proposed cloak is assembled by pentamode lattice made of a single-phase solid material. The function of rerouting acoustic wave round an obstacle has been demonstrated numerically. It is also revealed that shear related resonance due to weak shear resistance in practical pentamode lattices punctures broadband feature predicted based on ideal pentamode cloak. As a consequence, the latticed pentamode cloak can only conceal the obstacle in segmented frequency ranges. We have also shown that the shear resonance can be largely reduced by introducing material damping, and an improved broadband performance can be achieved. These works pave the way for experimental demonstration of pentamode acoustic cloak. PMID:26503821

  3. Compact acoustic refrigerator

    DOEpatents

    Bennett, Gloria A.

    1992-01-01

    A compact acoustic refrigeration system actively cools components, e.g., electrical circuits (22), in a borehole environment. An acoustic engine (12, 14) includes first thermodynamic elements (12) for generating a standing acoustic wave in a selected medium. An acoustic refrigerator (16, 26, 28) includes second thermodynamic elements (16) located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements (16) and a relatively hot temperature at a second end of the second thermodynamic elements (16). A resonator volume (18) cooperates with the first and second thermodynamic elements (12, 16) to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements (12, 16), first heat pipes (24, 26) transfer heat from the heat load (22) to the second thermodynamic elements (16) and second heat pipes (28, 32) transfer heat from first and second thermodynamic elements (12, 16) to the borehole environment.

  4. Compact acoustic refrigerator

    SciTech Connect

    Bennett, G.A.

    1991-12-31

    This invention is comprised of a compact acoustic refrigeration system that actively cools components, e.g., electrical circuits, in a borehole environment. An acoustic engine includes first thermodynamic elements for generating a standing acoustic wave in a selected medium. An acoustic refrigerator includes second thermodynamic elements located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements and a relatively hot temperature at a second end of the second thermodynamic elements. A resonator volume cooperates with the first and second thermodynamic elements to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements, first heat pipes transfer heat from the heat load to the second thermodynamic elements and second heat pipes transfer heat from first and second thermodynamic elements to the borehole environment.

  5. Compact acoustic refrigerator

    DOEpatents

    Bennett, G.A.

    1992-11-24

    A compact acoustic refrigeration system actively cools components, e.g., electrical circuits, in a borehole environment. An acoustic engine includes first thermodynamic elements for generating a standing acoustic wave in a selected medium. An acoustic refrigerator includes second thermodynamic elements located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements and a relatively hot temperature at a second end of the second thermodynamic elements. A resonator volume cooperates with the first and second thermodynamic elements to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements, first heat pipes transfer heat from the heat load to the second thermodynamic elements and second heat pipes transfer heat from first and second thermodynamic elements to the borehole environment. 18 figs.

  6. Multipacting Analysis of the Superconducting Parallel-bar Cavity

    SciTech Connect

    S.U. De Silva, J.R. Delayen,

    2011-03-01

    The superconducting parallel-bar cavity is a deflecting/crabbing cavity with attractive properties, compared to other conventional designs, that is being considered for a number of applications. Multipacting can be a limiting factor to the performance of in any superconducting structure. In the parallel-bar cavity the main contribution to the deflection is due to the transverse deflecting voltage, between the parallel bars, making the design potentially prone to multipacting. This paper presents the results of analytical calculations and numerical simulations of multipacting in the parallel-bar cavity with resonant voltage, impact energies and corresponding particle trajectories.

  7. Analysis of D0 -> K+ pi- pi0 Decays: Search for D0-D0bar Mixing, and Measurements of the Doubly Cabibbo-Suppressed Decay Rate and Resonance Contributions

    SciTech Connect

    Wilson, Michael Galante

    2005-12-13

    Analyzing D{sup 0} {yields} K{sup +}{pi}{sup -}{pi}{sup 0} decays, herein are presented the methods and results of a search for D{sup 0}-{bar D}{sup 0} mixing, a measurement of the branching ratio R {equivalent_to} {Lambda}(D{sup 0} {yields} K{sup +}{pi}{sup -}{pi}{sup 0})/{Lambda}(D{sup 0} {yields} K{sup -}{pi}{sup +}{pi}{sup 0}), and measurements of the contributions from D{sup 0} {yields} K{sup +}{rho}{sup -}, K*{sup +}{pi}{sup -}, K*{sup 0}{pi}{sup 0}; 230.4 fb{sup -1} of data collected from the BABAR detector at the PEP-II collider during 2000-2004 (Runs 1-4) are analyzed. An event-level tagging technique is developed, which facilitates the accurate determination of doubly Cabibbo-suppressed resonance contributions by suppressing background from Cabibbo-favored decays. The branching ratio is measured as R = (0.214 {+-} 0.008 (stat) {+-} 0.008 (syst))%, with (46.1 {+-} 3.3 (stat) {+-} 2.9 (syst))% of D{sup 0} {yields} K{sup +}{pi}{sup -}{pi}{sup 0} decays proceeding through the channel D{sup 0} {yields} K*{sup +}{pi}{sup -}. The data are consistent with the null-D-mixing hypothesis at a confidence level of 10%, and the expected value of {+-} {radical}(x{sup 2} + y{sup 2}) is measured as -0.013 {+-} 0.010 (stat), indicating negative interference between mixing and doubly Cabibbo-suppressed decay. The expected value of the integrated mixing rate is (x{sup 2} + y{sup 2})/2 = (0.013 {+-} 0.013 (stat))%.

  8. Bar-biting

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bar biting is regarded as a stereotypic behavior in which the animal carries out repetitive mouthing and biting of the metal bars in its environmental enclosure. It is commonly seen in sows housed in close confinement, in barren environments, and with restricted access to food. However, it has also ...

  9. Acoustic energy harvesting based on a planar acoustic metamaterial

    NASA Astrophysics Data System (ADS)

    Qi, Shuibao; Oudich, Mourad; Li, Yong; Assouar, Badreddine

    2016-06-01

    We theoretically report on an innovative and practical acoustic energy harvester based on a defected acoustic metamaterial (AMM) with piezoelectric material. The idea is to create suitable resonant defects in an AMM to confine the strain energy originating from an acoustic incidence. This scavenged energy is converted into electrical energy by attaching a structured piezoelectric material into the defect area of the AMM. We show an acoustic energy harvester based on a meta-structure capable of producing electrical power from an acoustic pressure. Numerical simulations are provided to analyze and elucidate the principles and the performances of the proposed system. A maximum output voltage of 1.3 V and a power density of 0.54 μW/cm3 are obtained at a frequency of 2257.5 Hz. The proposed concept should have broad applications on energy harvesting as well as on low-frequency sound isolation, since this system acts as both acoustic insulator and energy harvester.

  10. On the bar formation mechanism in galaxies with cuspy bulges

    NASA Astrophysics Data System (ADS)

    Polyachenko, E. V.; Berczik, P.; Just, A.

    2016-08-01

    We show by numerical simulations that a purely stellar dynamical model composed of an exponential disc, a cuspy bulge, and an NFW halo with parameters relevant to the Milky Way Galaxy is subject to bar formation. Taking into account the finite disc thickness, the bar formation can be explained by the usual bar instability, in spite of the presence of an inner Lindblad resonance, that is believed to damp any global modes. The effect of replacing the live halo and bulge by a fixed external axisymmetric potential (rigid models) is studied. It is shown that while the e-folding time of bar instability increases significantly (from 250 to 500 Myr), the bar pattern speed remains almost the same. For the latter, our average value of 55 km/s/kpc agrees with the assumption that the Hercules stream in the solar neighbourhood is an imprint of the bar-disc interaction at the outer Lindblad resonance of the bar. Vertical averaging of the radial force in the central disc region comparable to the characteristic scale length allows us to reproduce the bar pattern speed and the growth rate of the rigid models, using normal mode analysis of linear perturbation theory in a razor thin disc. The strong increase of the e-folding time with decreasing disc mass predicted by the mode analysis suggests that bars in galaxies similar to the Milky Way have formed only recently.

  11. Optical Helmholtz resonators

    NASA Astrophysics Data System (ADS)

    Chevalier, Paul; Bouchon, Patrick; Haïdar, Riad; Pardo, Fabrice

    2014-08-01

    Helmholtz resonators are widely used acoustic components able to select a single frequency. Here, based on an analogy between acoustics and electromagnetism wave equations, we present an electromagnetic 2D Helmholtz resonator made of a metallic slit-box structure. At the resonance, the light is funneled in the λ/800 apertures, and is subsequently absorbed in the cavity. As in acoustics, there is no higher order of resonance, which is an appealing feature for applications such as photodetection or thermal emission. Eventually, we demonstrate that the slit is of capacitive nature while the box behaves inductively. We derive an analytical formula for the resonance wavelength, which does not rely on wave propagation and therefore does not depend on the permittivity of the material filling the box. Besides, in contrast with half-wavelength resonators, the resonance wavelength can be engineered by both the slit aspect ratio and the box area.

  12. Scalar mesons in. pi pi. and K-barK: Results of a unitary amplitude analysis

    SciTech Connect

    Wicklund, A.B.; Ayres, D.S.; Cohen, D.; Diebold, R.; Pawlicki, A.J.

    1980-11-03

    The ..pi pi -->..K-barK S wave has been extracted from an amplitude analysis of K-barK production. With use of unitarity constraints, evidence has been found for a resonance in ..pi pi -->..K-barK at 1425 +- 14 MeV/c/sup 2/ having a width 160 +- 30 MeV/c/sup 2/; this state is a likely candidate for the QQ-bar, J/sup P/C=0/sup + +/ nonet. It is shown that the S*(980), which is a background to this resonance, must be a very broad effect and is likely a K-barK virtual bound state.

  13. Acoustic Neuroma

    MedlinePlus

    An acoustic neuroma is a benign tumor that develops on the nerve that connects the ear to the brain. ... can press against the brain, becoming life-threatening. Acoustic neuroma can be difficult to diagnose, because the ...

  14. Acoustic and electromagnetic waves

    NASA Astrophysics Data System (ADS)

    Jones, Douglas Samuel

    Theoretical models of EM and acoustic wave propagation are presented in an introductory text intended for intermediate-level science and engineering students. Chapters are devoted to the mathematical representation of acoustic and EM fields, the special theory of relativity, radiation, resonators, waveguide theory, refraction, surface waves, scattering by smooth objects, diffraction by edges, and transient waves. The mathematical tools required for the analysis (Bessel, Legendre, Mathieu, parabolic-cylinder, and spheroidal functions; tensor calculus; and the asymptotic evaluation of integrals) are covered in appendices.

  15. An experimentally validated contactless acoustic energy transfer model with resistive-reactive electrical loading

    NASA Astrophysics Data System (ADS)

    Shahab, S.; Gray, M.; Erturk, A.

    2015-04-01

    This paper investigates analytical modeling and experimental validation of Ultrasonic Acoustic Energy Transfer (UAET) for low-power electricity transfer to exploit in wireless applications ranging from medical implants to underwater sensor systems. A piezoelectric receiver bar is excited by incident acoustic waves originating from a source of known strength located at a specific distance from the receiver. The receiver is a free-free piezoelectric cylinder operating in the 33- mode of piezoelectricity with a fundamental resonance frequency above the audible frequency range. In order to extract the electrical power output, the piezoelectric receiver bar is shunted to a generalized resistive-reactive circuit. The goal is to quantify the electrical power delivered to the load (connected to the receiver) in terms of the source strength. Experimental validations are presented along with parameter optimization studies. Sensitivity of the electrical power output to the excitation frequency in the neighborhood of the receiver's underwater resonance frequency, source-to-receiver distance, and source-strength level are reported. Resistive and resistive-reactive electrical loading cases are discussed for performance enhancement and frequency-wise robustness. Simulations and experiments reveal that the presented multiphysics analytical model for UAET can be used to predict the coupled system dynamics with very good accuracy.

  16. Perturbation measurement of waveguides for acoustic thermometry

    NASA Astrophysics Data System (ADS)

    Lin, H.; Feng, X. J.; Zhang, J. T.

    2013-09-01

    Acoustic thermometers normally embed small acoustic transducers in the wall bounding a gas-filled cavity resonator. At high temperature, insulators of transducers loss electrical insulation and degrade the signal-to-noise ratio. One essential solution to this technical trouble is to couple sound by acoustic waveguides between resonator and transducers. But waveguide will break the ideal acoustic surface and bring perturbations(Δf+ig) to the ideal resonance frequency. The perturbation model for waveguides was developed based on the first-order acoustic theory in this paper. The frequency shift Δf and half-width change g caused by the position, length and radius of waveguides were analyzed using this model. Six different length of waveguides (52˜1763 mm) were settled on the cylinder resonator and the perturbation (Δf+ig) were measured at T=332 K and p=250˜500 kPa. The experiment results agreed with the theoretical prediction very well.

  17. Mass modeling for bars

    NASA Technical Reports Server (NTRS)

    Butler, Thomas G.

    1987-01-01

    Methods of modeling mass for bars are surveyed. A method for extending John Archer's concept of consistent mass beyond just translational inertia effects is included. Recommendations are given for various types of modeling situations.

  18. Acoustic positioning and orientation prediction

    NASA Technical Reports Server (NTRS)

    Barmatz, Martin B. (Inventor); Aveni, Glenn (Inventor); Putterman, Seth (Inventor); Rudnick, Joseph (Inventor)

    1990-01-01

    A method is described for use with an acoustic positioner, which enables a determination of the equilibrium position and orientation which an object assumes in a zero gravity environment, as well as restoring forces and torques of an object in an acoustic standing wave field. An acoustic standing wave field is established in the chamber, and the object is held at several different positions near the expected equilibrium position. While the object is held at each position, the center resonant frequency of the chamber is determined, by noting which frequency results in the greatest pressure of the acoustic field. The object position which results in the lowest center resonant frequency is the equilibrium position. The orientation of a nonspherical object is similarly determined, by holding the object in a plurality of different orientations at its equilibrium position, and noting the center resonant frequency for each orientation. The orientation which results in the lowest center resonant frequency is the equilibrium orientation. Where the acoustic frequency is constant, but the chamber length is variable, the equilibrium position or orientation is that which results in the greatest chamber length at the center resonant frequency.

  19. Effect of granular media on the vibrational response of a resonant structure: theory and experiment.

    PubMed

    Valenza, John J; Hsu, Chaur-Jian; Johnson, David Linton

    2010-11-01

    The acoustic response of a structure that contains a cavity filled with a loose granular material is analyzed. The inputs to the theory are the effective masses of each subsystem: that of the empty-cavity resonating structure and that of the granular medium within the cavity. This theory accurately predicts the frequencies, widths, and relative amplitudes of the various flexural mode resonances observed with rectangular bars, each having a cavity filled with loose tungsten granules. Inasmuch as the dominant mechanism for damping is due to adsorbed water at the grain-grain contacts, the significant effects of humidity on both the effective mass of the granular medium as well as on the response of the grain-loaded bars are monitored. Here, depending upon the humidity and the preparation protocol, it is possible to observe one, two, or three distinct resonances in a wide frequency range (1-5 kHz) over which the empty bar has but one resonance. These effects are understood in terms of the theoretical framework, which may simplify in terms of perturbation theories. PMID:21110572

  20. Low-Loss Wide-Band Floating Electrode Type Unidirectional Transducer Filters and Ladder-Type Resonator Filters Using High-Temperature-Stable High Electromechanical Coupling Surface Acoustic Wave Substrates

    NASA Astrophysics Data System (ADS)

    Yamanouchi, Kazuhiko; Ishii, Toru

    2003-05-01

    The important properties required for surface acoustic wave (SAW) substrates are large electromechanical coupling coefficients (k2), small temperature coefficient of frequency (TCF), low propagation loss, among other. LiNbO3 is a good SAW substrate because of its good properties and large size. We developed SiO2/rotated Y-cut, X-propagating LiNbO3 leaky SAW substrates with a large k2 (over 0.2) and zero TCF at a small thickness of SiO2 of H/λ=0.2 (H: SiO2 film thickness, λ: SAW wave-length) compared to those of other substrates and zero propagation attenuation in the case of metalized surface. In this paper, the theoretical and experimental results for SAW filters, resonators and resonator filters are described. The low-loss filters using floating electrode type unidirectional transducer (FEUDT) showed an insertion loss of below 1 dB at a center frequency of 400 MHz and bandwidth of 20 MHz. Also, the resonator showed the wide-band characteristics and resonator filters showed a bandwidth of 80 MHz at a center frequency of 500 MHz.

  1. Dependence of SAW resonator 1/f noise on device size.

    PubMed

    Parker, T E

    1993-01-01

    Experiments were conducted with eight 450-MHz surface acoustic wave (SAW) resonators which demonstrate that a resonator's 1/f noise depends approximately inversely on the active acoustic area of the device. This observation is consistent with a proposed theory that 1/f noise in acoustic resonators is caused by localized velocity or dimensional fluctuations. PMID:18263254

  2. Determining Equilibrium Position For Acoustical Levitation

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Aveni, G.; Putterman, S.; Rudnick, J.

    1989-01-01

    Equilibrium position and orientation of acoustically-levitated weightless object determined by calibration technique on Earth. From calibration data, possible to calculate equilibrium position and orientation in presence of Earth gravitation. Sample not levitated acoustically during calibration. Technique relies on Boltzmann-Ehrenfest adiabatic-invariance principle. One converts resonant-frequency-shift data into data on normalized acoustical potential energy. Minimum of energy occurs at equilibrium point. From gradients of acoustical potential energy, one calculates acoustical restoring force or torque on objects as function of deviation from equilibrium position or orientation.

  3. Stable And Oscillating Acoustic Levitation

    NASA Technical Reports Server (NTRS)

    Barmatz, Martin B.; Garrett, Steven L.

    1988-01-01

    Sample stability or instability determined by levitating frequency. Degree of oscillation of acoustically levitated object along axis of levitation chamber controlled by varying frequency of acoustic driver for axis above or below frequency of corresponding chamber resonance. Stabilization/oscillation technique applied in normal Earth gravity, or in absence of gravity to bring object quickly to rest at nominal levitation position or make object oscillate in desired range about that position.

  4. Cylindrical acoustic levitator/concentrator

    DOEpatents

    Kaduchak, Gregory; Sinha, Dipen N.

    2002-01-01

    A low-power, inexpensive acoustic apparatus for levitation and/or concentration of aerosols and small liquid/solid samples having particulates up to several millimeters in diameter in air or other fluids is described. It is constructed from a commercially available, hollow cylindrical piezoelectric crystal which has been modified to tune the resonance frequency of the breathing mode resonance of the crystal to that of the interior cavity of the cylinder. When the resonance frequency of the interior cylindrical cavity is matched to the breathing mode resonance of the cylindrical piezoelectric transducer, the acoustic efficiency for establishing a standing wave pattern in the cavity is high. The cylinder does not require accurate alignment of a resonant cavity. Water droplets having diameters greater than 1 mm have been levitated against the force of gravity using; less than 1 W of input electrical power. Concentration of aerosol particles in air is also demonstrated.

  5. Topological Acoustics

    NASA Astrophysics Data System (ADS)

    Yang, Zhaoju; Gao, Fei; Shi, Xihang; Lin, Xiao; Gao, Zhen; Chong, Yidong; Zhang, Baile

    2015-03-01

    The manipulation of acoustic wave propagation in fluids has numerous applications, including some in everyday life. Acoustic technologies frequently develop in tandem with optics, using shared concepts such as waveguiding and metamedia. It is thus noteworthy that an entirely novel class of electromagnetic waves, known as "topological edge states," has recently been demonstrated. These are inspired by the electronic edge states occurring in topological insulators, and possess a striking and technologically promising property: the ability to travel in a single direction along a surface without backscattering, regardless of the existence of defects or disorder. Here, we develop an analogous theory of topological fluid acoustics, and propose a scheme for realizing topological edge states in an acoustic structure containing circulating fluids. The phenomenon of disorder-free one-way sound propagation, which does not occur in ordinary acoustic devices, may have novel applications for acoustic isolators, modulators, and transducers.

  6. Topological acoustics.

    PubMed

    Yang, Zhaoju; Gao, Fei; Shi, Xihang; Lin, Xiao; Gao, Zhen; Chong, Yidong; Zhang, Baile

    2015-03-20

    The manipulation of acoustic wave propagation in fluids has numerous applications, including some in everyday life. Acoustic technologies frequently develop in tandem with optics, using shared concepts such as waveguiding and metamedia. It is thus noteworthy that an entirely novel class of electromagnetic waves, known as "topological edge states," has recently been demonstrated. These are inspired by the electronic edge states occurring in topological insulators, and possess a striking and technologically promising property: the ability to travel in a single direction along a surface without backscattering, regardless of the existence of defects or disorder. Here, we develop an analogous theory of topological fluid acoustics, and propose a scheme for realizing topological edge states in an acoustic structure containing circulating fluids. The phenomenon of disorder-free one-way sound propagation, which does not occur in ordinary acoustic devices, may have novel applications for acoustic isolators, modulators, and transducers. PMID:25839273

  7. Acoustic neuroma

    MedlinePlus

    Vestibular schwannoma; Tumor - acoustic; Cerebellopontine angle tumor; Angle tumor ... 177. Battista RA. Gamma knife radiosurgery for vestibular schwannoma. Otolaryngol Clin North Am . 2009;42:635-654. ...

  8. Size Dependence of Ferromagnetic Resonance Frequency in Submicron Patterned Magnet

    NASA Astrophysics Data System (ADS)

    Manago, Takashi; Yamanoi, Kazuto; Yakata, Satoshi; Kimura, Takashi

    2013-05-01

    We investigated the size effect on ferromagnetic resonance (FMR) in a submicron-wide single permalloy bar. The resonant frequency markedly increased with decreasing bar width to less than 1 µm, since the demagnetizing field is effectively modified by changing the bar width even in thin films. The resonant frequency difference between 100- and 1000-nm-wide bars was over 4 GHz in the absence of a magnetic field. This characteristic is promising for practical microwave devices because the desired resonant frequency can be obtained simply by varying the width of narrow ferromagnetic bars so that it is not necessary to change the material or magnetic field.

  9. BARS/SSC/SPHINX

    SciTech Connect

    Herrmann, W. )

    1993-06-06

    BARS is a program which allows retrieval of information from suitable bibliographic databases. Two databases are included, SSC and SPHINX, which together list bibliographic information for some 12,000 references related to the fields of shock compression of condensed media, high rate deformation of solids, and detonation.

  10. BARS/SSC/SPHINX

    SciTech Connect

    Herrmann, W. )

    1993-06-06

    BARS is a program which allows retrieval of information from suitable bibliographic databases. Two databases are included, SSC and SPHINX, which together list bibliographic information for some 12,000 references related to the fields of shoch compression of condensed media, high rate deformation of solids, and detonation.

  11. Toll Bar on Sea

    ERIC Educational Resources Information Center

    Hunter, Dave

    2008-01-01

    In the summer of 2007 the United Kingdom experienced some of the heaviest rainfall since records began. Toll Bar in South Yorkshire featured prominently in media coverage as the village and the homes surrounding it began to flood. Many people lost everything: their homes, their furniture, their possessions. In an effort to come to terms with what…

  12. Musical Acoustics

    NASA Astrophysics Data System (ADS)

    Gough, Colin

    This chapter provides an introduction to the physical and psycho-acoustic principles underlying the production and perception of the sounds of musical instruments. The first section introduces generic aspects of musical acoustics and the perception of musical sounds, followed by separate sections on string, wind and percussion instruments.

  13. Baffling or Baffled: Improve Your Acoustics.

    ERIC Educational Resources Information Center

    Abdoo, Frank B.

    1981-01-01

    Presents techniques for evaluating the acoustics (reverberation time, and standing waves and resonance phenomena) of a band performance room. Gives instructions for building and placing inexpensive baffles (free-standing, portable sound barriers) to correct room defects. (SJL)

  14. Traveling wave type ultrasonic linear motor using twin bending bars

    NASA Astrophysics Data System (ADS)

    Kondo, Shuichi; Yamaura, Hiroshi; Koyama, Daisuke; Nakamura, Kentaro

    2010-01-01

    Ultrasonic linear motors with a small body are highly demanded since efficiency does not decrease very much with downsizing. In this study, we aim at realizing ultrasonic linear motor with the diameter less than 10 mm as an alternative to small air cylinder actuators. We propose a new stator structure using two PZT elements between two parallel bending bars. The PZT elements are bonded at the position of several mm from the bar end. In this structure, both bar ends vibrate resonantly in a bending mode, and high vibration displacement amplitude can be obtained along the bars. The length between the PZT element and the bar end determines the optimum driving frequency. The slider simply consists of three metal plates, which sandwich the bending bars, and the preload can be controlled by springs. The conditions in which the traveling wave can be generated along the bars were investigated. When the bars vibrate in a symmetric mode and traveling waves are generated, the slider moves in the direction to the opposite of traveling wave. Traveling wave could be generated by controlling the driving phase difference between the two PZT elements. It was found that the phase differences depend on the distance between the two PZT elements. We experimentally achieved the stroke of 10 mm and the thrust of 78 mN at 23 kHz.

  15. Advanced Technology Development for Active Acoustic Liners

    NASA Technical Reports Server (NTRS)

    Sheplak, Mark; Cattafesta, Louis N., III; Nishida, Toshikazu; Kurdila, Andrew J.

    2001-01-01

    Objectives include: (1) Develop electro-mechanical/acoustic models of a Helmholtz resonator possessing a compliant diaphragm coupled to a piezoelectric device; (2) Design and fabricate the energy reclamation module and active Helmholtz resonator; (3) Develop and build appropriate energy reclamation/storage circuit; (4) Develop and fabricate appropriate piezoelectric shunt circuit to tune the compliance of the active Helmholtz resonator via a variable capacitor; (5) Quantify energy reclamation module efficiency in a grazing-flow plane wave tube possessing known acoustic energy input; and (6) Quantify actively tuned Helmholtz resonator performance in grazing-flow plane wave tube for a white-noise input

  16. Bar formation and evolution in disc galaxies with gas and a triaxial halo: morphology, bar strength and halo properties

    NASA Astrophysics Data System (ADS)

    Athanassoula, E.; Machado, Rubens E. G.; Rodionov, S. A.

    2013-03-01

    We follow the formation and evolution of bars in N-body simulations of disc galaxies with gas and/or a triaxial halo. We find that both the relative gas fraction and the halo shape play a major role in the formation and evolution of the bar. In gas-rich simulations, the disc stays near-axisymmetric much longer than in gas-poor ones, and, when the bar starts growing, it does so at a much slower rate. Because of these two effects combined, large-scale bars form much later in gas-rich than in gas-poor discs. This can explain the observation that bars are in place earlier in massive red disc galaxies than in blue spirals. We also find that the morphological characteristics in the bar region are strongly influenced by the gas fraction. In particular, the bar at the end of the simulation is much weaker in gas-rich cases. The quality of our simulations is such as to allow us to discuss the question of bar longevity because the resonances are well resolved and the number of gas particles is sufficient to describe the gas flow adequately. In no case did we find a bar which was destroyed. Halo triaxiality has a dual influence on bar strength. In the very early stages of the simulation it induces bar formation to start earlier. On the other hand, during the later, secular evolution phase, triaxial haloes lead to considerably less increase of the bar strength than spherical ones. The shape of the halo evolves considerably with time. We confirm previous results of gas-less simulations that find that the inner part of an initially spherical halo can become elongated and develop a halo bar. However we also show that, on the contrary, in gas-rich simulations, the inner parts of an initially triaxial halo can become rounder with time. The main body of initially triaxial haloes evolves towards sphericity, but in initially strongly triaxial cases it stops well short of becoming spherical. Part of the angular momentum absorbed by the halo generates considerable rotation of the halo

  17. Measurements of vertical bar Vcb vertical bar and vertical bar Vub vertical bar at BaBar

    SciTech Connect

    Rotondo, M.

    2005-10-12

    We report results from the BABAR Collaboration on the semileptonic B decays, highlighting the measurements of the magnitude of the Cabibbo-Kobayashi-Maskawa matrix elements Vub and Vcb. We describe the techniques used to obtain the matrix element |Vcb| using the measurement of the inclusive B {yields} Xclv process and a large sample of exclusive B {yields} D*lv decays. The vertical bar Vub vertical bar matrix elements has been measured studying different kinematic variables of the B {yields} Xulv process, and also with the exclusive reconstruction of B {yields} {pi}({rho})lv decays.

  18. Arctic acoustics ultrasonic modeling studies

    NASA Astrophysics Data System (ADS)

    Chamuel, Jacques R.

    1990-03-01

    A unique collection of laboratory ultrasonic modeling results are presented revealing and characterizing hidden pulsed seismoacoustic wave phenomena from 3-D range dependent liquid/solid boundaries. The research succeeded in isolating and identifying low frequency (10 to 500 Hz) transmission loss mechanisms and provided physical insight into Arctic acoustic problems generally beyond the state-of-the-art of theoretical and numerical analysis. The ultrasonic modeling studies dealt with controversial issues and existing discrepancies on seismo-acoustic waves at water/ice interface, sea ice thickness determination, low frequency transmission loss, and bottom leaky Rayleigh waves. The areas investigated include leaky Rayleigh waves at water/ice interface, leaky flexural waves in floating ice plates, effects of dry/wet cracks in sea ice on plate waves and near grazing acoustic waves, edge waves in floating plates, low frequency backscatter from ice keel width resonances, conversion of underwater acoustic waves into plate waves by keels, nondispersive flexural wave along apex of small angle solid wedge, Scholte and leaky Rayleigh waves along apex of immersed 90 ice wedge, backscatter from trailing edge of floes, floating plate resonances associated with near-grazing underwater acoustic waves, acoustic coupling between adjacent floes, and multiple bottom leaky Rayleigh wave components in water layer over solid bottom.

  19. Acoustic Mechanical Feedthroughs

    NASA Technical Reports Server (NTRS)

    Sherrit, Stewart; Walkemeyer, Phillip; Bao, Xiaoqi; Bar-Cohen, Yoseph; Badescu, Mircea

    2013-01-01

    Electromagnetic motors can have problems when operating in extreme environments. In addition, if one needs to do mechanical work outside a structure, electrical feedthroughs are required to transport the electric power to drive the motor. In this paper, we present designs for driving rotary and linear motors by pumping stress waves across a structure or barrier. We accomplish this by designing a piezoelectric actuator on one side of the structure and a resonance structure that is matched to the piezoelectric resonance of the actuator on the other side. Typically, piezoelectric motors can be designed with high torques and lower speeds without the need for gears. One can also use other actuation materials such as electrostrictive, or magnetostrictive materials in a benign environment and transmit the power in acoustic form as a stress wave and actuate mechanisms that are external to the benign environment. This technology removes the need to perforate a structure and allows work to be done directly on the other side of a structure without the use of electrical feedthroughs, which can weaken the structure, pipe, or vessel. Acoustic energy is pumped as a stress wave at a set frequency or range of frequencies to produce rotary or linear motion in a structure. This method of transferring useful mechanical work across solid barriers by pumping acoustic energy through a resonant structure features the ability to transfer work (rotary or linear motion) across pressure or thermal barriers, or in a sterile environment, without generating contaminants. Reflectors in the wall of barriers can be designed to enhance the efficiency of the energy/power transmission. The method features the ability to produce a bi-directional driving mechanism using higher-mode resonances. There are a variety of applications where the presence of a motor is complicated by thermal or chemical environments that would be hostile to the motor components and reduce life and, in some instances, not be

  20. Exclusive Initial-State-Radiation Production of the DDbar,D*Dbar, and D*D*bar Systems

    SciTech Connect

    Aubert, B.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Lopez, L.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Sun, L.; Battaglia, M.; Brown, D.N.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; /LBL, Berkeley /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UCLA /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT, LNS /McGill U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /Mt. Holyoke Coll. /INFN, Naples /Naples U. /INFN, Naples /INFN, Naples /Naples U. /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /Pennsylvania U. /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /Rostock U. /Rutherford /DSM, DAPNIA, Saclay /South Carolina U. /SLAC /Stanford U., Phys. Dept. /SUNY, Albany /Tennessee U. /Texas U. /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U., IFIC /Victoria U. /Warwick U. /Wisconsin U., Madison

    2009-06-19

    We perform a study of the exclusive production of D{bar D}, D*{bar D}, and D*{bar D}* in initial-state-radiation events, from e{sup +}e{sup -} annihilations at a center-of-mass energy near 10.58 GeV, to search for charmonium and possible new resonances. The data sample corresponds to an integrated luminosity of 384 fb{sup -1} and was recorded by the BABAR experiment at the PEP-II storage rings. The D{bar D}, D*{bar D}, and D*{bar D}* mass spectra show clear evidence of several {psi} resonances. However, there is no evidence for Y(4260) {yields} D*{bar D} or Y(4260) {yields} D*{bar D}*.

  1. Dark Matter Trapping by Stellar Bars: The Shadow Bar

    NASA Astrophysics Data System (ADS)

    Petersen, Michael S.; Weinberg, Martin D.; Katz, Neal

    2016-09-01

    We investigate the complex interactions between the stellar disc and the dark-matter halo during bar formation and evolution using N-body simulations with fine temporal resolution and optimally chosen spatial resolution. We find that the forming stellar bar traps dark matter in the vicinity of the stellar bar into bar-supporting orbits. We call this feature the shadow bar. The shadow bar modifies both the location and magnitude of the angular momentum transfer between the disc and dark matter halo and adds 10 per cent to the mass of the stellar bar over 4 Gyr. The shadow bar is potentially observable by its density and velocity signature in spheroid stars and by direct dark matter detection experiments. Numerical tests demonstrate that the shadow bar can diminish the rate of angular momentum transport from the bar to the dark matter halo by more than a factor of three over the rate predicted by dynamical friction with an untrapped dark halo, and thus provides a possible physical explanation for the observed prevalence of fast bars in nature.

  2. Breaking through the Bar

    ERIC Educational Resources Information Center

    Gray, Katti

    2011-01-01

    Howard University School of Law had a problem, and school officials knew it. Over a 20-year period, 40 percent of its graduates who took the Maryland bar exam failed it on their first try. During the next 24 months--the time frame required to determine its "eventual pass rate"--almost 90 percent of the students did pass. What they did not know was…

  3. Bar coded retroreflective target

    DOEpatents

    Vann, Charles S.

    2000-01-01

    This small, inexpensive, non-contact laser sensor can detect the location of a retroreflective target in a relatively large volume and up to six degrees of position. The tracker's laser beam is formed into a plane of light which is swept across the space of interest. When the beam illuminates the retroreflector, some of the light returns to the tracker. The intensity, angle, and time of the return beam is measured to calculate the three dimensional location of the target. With three retroreflectors on the target, the locations of three points on the target are measured, enabling the calculation of all six degrees of target position. Until now, devices for three-dimensional tracking of objects in a large volume have been heavy, large, and very expensive. Because of the simplicity and unique characteristics of this tracker, it is capable of three-dimensional tracking of one to several objects in a large volume, yet it is compact, light-weight, and relatively inexpensive. Alternatively, a tracker produces a diverging laser beam which is directed towards a fixed position, and senses when a retroreflective target enters the fixed field of view. An optically bar coded target can be read by the tracker to provide information about the target. The target can be formed of a ball lens with a bar code on one end. As the target moves through the field, the ball lens causes the laser beam to scan across the bar code.

  4. LLNL`s acoustic spectrometer

    SciTech Connect

    Baker, J.

    1997-03-17

    This paper describes the development of a frequency sensitive acoustic transducer that operates in the 10 Hz to 10 kHz regime. This device uses modem silicon microfabrication techniques to form mechanical tines that resonate at specified frequencies. This high-sensitivity device is intended for low-power battery powered applications.

  5. Acoustic agglomeration methods and apparatus

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B. (Inventor)

    1984-01-01

    Methods are described for using acoustic energy to agglomerate fine particles on the order of one micron diameter that are suspended in gas, to provide agglomerates large enough for efficient removal by other techniques. The gas with suspended particles, is passed through the length of a chamber while acoustic energy at a resonant chamber mode is applied to set up one or more acoustic standing wave patterns that vibrate the suspended particles to bring them together so they agglomerate. Several widely different frequencies can be applied to efficiently vibrate particles of widely differing sizes. The standing wave pattern can be applied along directions transversed to the flow of the gas. The particles can be made to move in circles by applying acoustic energy in perpendicular directions with the energy in both directions being of the same wavelength but 90 deg out of phase.

  6. Room Acoustics

    NASA Astrophysics Data System (ADS)

    Kuttruff, Heinrich; Mommertz, Eckard

    The traditional task of room acoustics is to create or formulate conditions which ensure the best possible propagation of sound in a room from a sound source to a listener. Thus, objects of room acoustics are in particular assembly halls of all kinds, such as auditoria and lecture halls, conference rooms, theaters, concert halls or churches. Already at this point, it has to be pointed out that these conditions essentially depend on the question if speech or music should be transmitted; in the first case, the criterion for transmission quality is good speech intelligibility, in the other case, however, the success of room-acoustical efforts depends on other factors that cannot be quantified that easily, not least it also depends on the hearing habits of the listeners. In any case, absolutely "good acoustics" of a room do not exist.

  7. Acoustic Neuroma

    MedlinePlus

    ... slow growing tumor which arise primarily from the vestibular portion of the VIII cranial nerve and lie ... you have a "brain tumor" called acoustic neuroma (vestibular schwannoma). You think you are the only one ...

  8. Underwater Acoustics

    NASA Astrophysics Data System (ADS)

    Kuperman, William A.; Roux, Philippe

    It is well underwater established that sound waves, compared to electromagnetic waves, propagate long distances in the ocean. Hence, in the ocean as opposed to air or a vacuum, one uses sound navigation and ranging (SONAR) instead navigation and ranging (SONAR) of radar, acoustic communication instead of radio, and acoustic imaging and tomography instead of microwave or optical imaging or X-ray tomography. Underwater acoustics is the science of sound in water (most commonly in the ocean) and encompasses not only the study of sound propagation, but also the masking of sound signals by interfering phenomenon and signal processing for extracting these signals from interference. This chapter we will present the basics physics of ocean acoustics and then discuss applications.

  9. Reusable acoustic tweezers for disposable devices

    PubMed Central

    Guo, Feng; Xie, Yuliang; Li, Sixing; Lata, James; Ren, Liqiang; Mao, Zhangming; Ren, Baiyang; Wu, Mengxi; Ozcelik, Adem

    2015-01-01

    We demonstrate acoustic tweezers used for disposable devices. Rather than forming an acoustic resonance, we locally transmitted standing surface acoustic waves into a removable, independent polydimethylsiloxane (PDMS)-glass hybridized microfluidic superstrate device for micromanipulation. By configuring and regulating the displacement nodes on a piezoelectric substrate, cells and particles were effectively patterned and transported into said superstrate, accordingly. With the label-free and contactless nature of acoustic waves, the presented technology could offer a simple, accurate, low-cost, biocompatible, and disposable method for applications in the fields of point-of-care diagnostics and fundamental biomedical studies. PMID:26507411

  10. Hercules and Wolf 630 stellar streams and galactic bar kinematics

    NASA Astrophysics Data System (ADS)

    Bobylev, V. V.; Bajkova, A. T.

    2016-04-01

    We have identified the four most significant features in the UV velocity distribution of solarneighborhood stars: H1, H2 in the Hercules stream and W1, W2 in the Wolf 630 stream. We have formulated the problemof determining several characteristics of the centralGalactic bar independently from each of the identified features by assuming that the Hercules and Wolf 630 streams are of a bar-induced dynamical nature. The problem has been solved by constructing 2: 1 resonant orbits in the rotating bar frame for each star in these streams. Analysis of the resonant orbits found has shown that the bar pattern speed is 45-55 km s-1 kpc-1, while the bar angle lies within the range 40°-60°. The results obtained are consistent with the view that the Hercules andWolf 630 streams could be formed by a long-term influence of the Galactic bar leading to a characteristic bimodal splitting of the UV velocity plane.

  11. Transverse-Mode Spurious Suppression Technique for Surface Acoustic Wave Resonator with Zero Temperature Coefficient of Frequency on a SiO2/Al/LiNbO3 Structure

    NASA Astrophysics Data System (ADS)

    Nakanishi, Hidekazu; Nakamura, Hiroyuki; Tsurunari, Tetsuya; Fujiwara, Joji; Hamaoka, Yosuke; Hashimoto, Ken-ya

    2012-07-01

    In this paper, we describe a suppression technique of transverse-mode spurious responses for a surface acoustic wave (SAW) resonator with a near zero temperature coefficient of frequency (TCF) on a SiO2/Al/LiNbO3 structure. We investigated the thinning of SiO2 on the dummy electrode region and studied how the transverse-mode responses change with remaining SiO2 thickness h on the dummy electrode region. As the results, we clarified that the remaining SiO2 thickness h on the dummy electrode region has an optimum value and could suppress the transverse-mode spurious responses completely when H and h are set at 0.35 λ and 0.20 λ, respectively. It was demonstrated that the selective SiO2 removal technique is effective to suppress transverse-mode spurious responses for SAW resonators employing the SiO2/Al/LiNbO3 structure for a wide range of SiO2 thicknesses, provided that the SiO2 thickness at the dummy electrode region is adjusted properly.

  12. Analysis of Rayleigh-Mode Spurious Response Using Finite Element Method/Spectrum Domain Analysis for Surface Acoustic Wave Resonator on Nonflat SiO2/Al/LiNbO3 Structure

    NASA Astrophysics Data System (ADS)

    Nakamura, Hiroyuki; Nakanishi, Hidekazu; Goto, Rei; Hashimoto, Ken-ya; Yamaguchi, Masatsune

    2010-07-01

    Because of their low insertion loss, high out-of-band rejection, and high power durability, miniature surface acoustic wave (SAW) duplexers are widely used in mobile phones. Substrate materials substantially limit and determine the performance of SAW duplexers; for their applications to Band I and Band IV systems with large pass-band widths and wide frequency separations between the transmitting and receiving frequency bands, a larger coupling coefficient (K2) is of primary importance. We have developed a shape-controlled SiO2 film/Al electrode/LiNbO3 substrate structure for their applications. It could lead to a large K2 and suppression of Rayleigh-mode spurious response. In this paper, we report the analysis using finite element method/spectrum domain analysis (FEM/SDA) for the SAW resonator on a nonflat SiO2 film/Al electrode/LiNbO3 structure. It was clarified that the shape-controlled SiO2 was effective in terms of achieving a large K2 for the SAW resonator with suppressed Rayleigh-mode spurious responses and bulk wave radiation. Furthermore, the experiment results showed a good agreement with the analysis results.

  13. Acoustic levitation in the presence of gravity

    NASA Technical Reports Server (NTRS)

    Collas, P.; Barmatz, M.; Shipley, C.

    1989-01-01

    The method of Gor'kov (1961) has been applied to derive general expressions for the total potential and force on a small spherical object in a resonant chamber in the presence of both acoustic and gravitational force fields. The levitation position is also determined in rectangular resonators for the simultaneous excitation of up to three acoustic modes, and the results are applied to the triple-axis acoustic levitator. The analysis is applied to rectangular, spherical, and cylindrical single-mode levitators that are arbitrarily oriented relative to the gravitational force field. Criteria are determined for isotropic force fields in rectangular and cylindrical resonators. It is demonstrated that an object will be situated within a volume of possible levitation positions at a point determined by the relative strength of the acoustic and gravitational fields and the orientation of the chamber relative to gravity.

  14. Shepherding Tidal Debris with the Galactic Bar: The Ophiuchus Stream

    NASA Astrophysics Data System (ADS)

    Hattori, Kohei; Erkal, Denis; Sanders, Jason L.

    2016-04-01

    The dynamics of stellar streams in rotating barred potentials is explained for the first time. Naturally, neighbouring stream stars reach pericentre at slightly different times. In the presence of a rotating bar, these neighbouring stream stars experience different bar orientations during pericentric passage and hence each star receives a different torque from the bar. These differing torques reshape the angular momentum and energy distribution of stars in the stream, which in turn changes the growth rate of the stream. For a progenitor orbiting in the same sense as the bar's rotation and satisfying a resonance condition, the resultant stream can be substantially shorter or longer than expected, depending on whether the pericentric passages of the progenitor occur along the bar's minor or major axis respectively. We present a full discussion of this phenomenon focusing mainly on streams confined to the Galactic plane. In stark contrast with the evolution in static potentials, which give rise to streams that grow steadily in time, rotating barred potentials can produce dynamically old, short streams. This challenges the traditional viewpoint that the inner halo necessarily consists of well phase-mixed material whilst the tidally-disrupted structures in the outer halo are more spatially coherent. We argue that this mechanism may play an important role in explaining the mysteriously short Ophiuchus stream that was recently discovered near the bulge region of the Milky Way.

  15. Shepherding tidal debris with the Galactic bar: the Ophiuchus stream

    NASA Astrophysics Data System (ADS)

    Hattori, Kohei; Erkal, Denis; Sanders, Jason L.

    2016-07-01

    The dynamics of stellar streams in rotating barred potentials is explained for the first time. Naturally, neighbouring stream stars reach pericentre at slightly different times. In the presence of a rotating bar, these neighbouring stream stars experience different bar orientations during pericentric passage and hence each star receives a different torque from the bar. These differing torques reshape the angular momentum and energy distribution of stars in the stream, which in turn changes the growth rate of the stream. For a progenitor orbiting in the same sense as the bar's rotation and satisfying a resonance condition, the resultant stream can be substantially shorter or longer than expected, depending on whether the pericentric passages of the progenitor occur along the bar's minor or major axis, respectively. We present a full discussion of this phenomenon focusing mainly on streams confined to the Galactic plane. In stark contrast with the evolution in static potentials, which give rise to streams that grow steadily in time, rotating barred potentials can produce dynamically old, short streams. This challenges the traditional viewpoint that the inner halo necessarily consists of well phase-mixed material whilst the tidally disrupted structures in the outer halo are more spatially coherent. We argue that this mechanism may play an important role in explaining the mysteriously short Ophiuchus stream that was recently discovered near the bulge region of the Milky Way.

  16. Does an infrasonic acoustic shock wave resonance of the manganese 3+ loaded/copper depleted prion protein initiate the pathogenesis of TSE?

    PubMed

    Purdey, Mark

    2003-06-01

    Intensive exposures to natural and artificial sources of infrasonic acoustic shock (tectonic disturbances, supersonic aeroplanes, etc.) have been observed in ecosystems supporting mammalian populations that are blighted by clusters of traditional and new variant strains of transmissible spongiform encephalopathy (TSE). But TSEs will only emerge in those 'infrasound-rich' environments which are simultaneously influenced by eco-factors that induce a high manganese (Mn)/low copper (Cu)-zinc (Zn) ratio in brains of local mammalian populations. Since cellular prion protein (PrPc) is a cupro-protein expressed throughout the circadian mediated pathways of the body, it is proposed that PrP's Cu component performs a role in the conduction and distribution of endogenous electromagnetic energy; energy that has been transduced from incoming ultraviolet, acoustic, geomagnetic radiations. TSE pathogenesis is initiated once Mn substitutes at the vacant Cu domain on PrPc and forms a nonpathogenic, protease resistant, 'sleeping' prion. A second stage of pathogenesis comes into play once a low frequency wave of infrasonic shock metamorphoses the piezoelectric atomic structure of the Mn 3+ component of the prion, thereby 'priming' the sleeping prion into its fully fledged, pathogenic TSE isoform - where the paramagnetic status of the Mn 3+ atom is transformed into a stable ferrimagnetic lattice work, due to the strong electron-phonon coupling resulting from the dynamic 'Jahn-Teller' type distortions of the oxygen octahedra specific to the trivalent Mn species. The so called 'infectivity' of the prion is a misnomer and should be correctly defined as the contagious field inducing capacity of the ferrimagnetic Mn 3+ component of the prion; which remains pathogenic at all temperatures below the 'curie point'. A progressive domino-like 'metal to ligand to metal' ferrimagnetic corruption of the conduits of electromagnetic superexchange is initiated. The TSE diseased brain can be likened to

  17. Acoustic stabilization of electric arc instabilities in nontransferred plasma torches

    SciTech Connect

    Rat, V.; Coudert, J. F.

    2010-03-08

    Electric arc instabilities in dc plasma torches lead to nonhomogeneous treatments of nanosized solid particles or liquids injected within thermal plasma jets. This paper shows that an additional acoustic resonator mounted on the cathode cavity allows reaching a significant damping of these instabilities, particularly the Helmholtz mode of arc oscillations. The acoustic resonator is coupled with the Helmholtz resonator of the plasma torch limiting the amplitude of arc voltage variations. It is also highlighted that this damping is dependent on friction effects in the acoustic resonator.

  18. Acoustic transmitters for underwater neutrino telescopes.

    PubMed

    Ardid, Miguel; Martínez-Mora, Juan A; Bou-Cabo, Manuel; Larosa, Giuseppina; Adrián-Martínez, Silvia; Llorens, Carlos D

    2012-01-01

    In this paper acoustic transmitters that were developed for use in underwater neutrino telescopes are presented. Firstly, an acoustic transceiver has been developed as part of the acoustic positioning system of neutrino telescopes. These infrastructures are not completely rigid and require a positioning system in order to monitor the position of the optical sensors which move due to sea currents. To guarantee a reliable and versatile system, the transceiver has the requirements of reduced cost, low power consumption, high pressure withstanding (up to 500 bars), high intensity for emission, low intrinsic noise, arbitrary signals for emission and the capacity of acquiring and processing received signals. Secondly, a compact acoustic transmitter array has been developed for the calibration of acoustic neutrino detection systems. The array is able to mimic the signature of ultra-high-energy neutrino interaction in emission directivity and signal shape. The technique of parametric acoustic sources has been used to achieve the proposed aim. The developed compact array has practical features such as easy manageability and operation. The prototype designs and the results of different tests are described. The techniques applied for these two acoustic systems are so powerful and versatile that may be of interest in other marine applications using acoustic transmitters. PMID:22666022

  19. Acoustic Transmitters for Underwater Neutrino Telescopes

    PubMed Central

    Ardid, Miguel; Martínez-Mora, Juan A.; Bou-Cabo, Manuel; Larosa, Giuseppina; Adrián-Martínez, Silvia; Llorens, Carlos D.

    2012-01-01

    In this paper acoustic transmitters that were developed for use in underwater neutrino telescopes are presented. Firstly, an acoustic transceiver has been developed as part of the acoustic positioning system of neutrino telescopes. These infrastructures are not completely rigid and require a positioning system in order to monitor the position of the optical sensors which move due to sea currents. To guarantee a reliable and versatile system, the transceiver has the requirements of reduced cost, low power consumption, high pressure withstanding (up to 500 bars), high intensity for emission, low intrinsic noise, arbitrary signals for emission and the capacity of acquiring and processing received signals. Secondly, a compact acoustic transmitter array has been developed for the calibration of acoustic neutrino detection systems. The array is able to mimic the signature of ultra-high-energy neutrino interaction in emission directivity and signal shape. The technique of parametric acoustic sources has been used to achieve the proposed aim. The developed compact array has practical features such as easy manageability and operation. The prototype designs and the results of different tests are described. The techniques applied for these two acoustic systems are so powerful and versatile that may be of interest in other marine applications using acoustic transmitters. PMID:22666022

  20. Techniques for Primary Acoustic Thermometry to 800 K

    NASA Astrophysics Data System (ADS)

    Ripple, D. C.; Defibaugh, D. R.; Moldover, M. R.; Strouse, G. F.

    2003-09-01

    The NIST Primary Acoustic Thermometer will measure the difference between the International Temperature Scale of 1990 and the Kelvin Thermodynamic Scale throughout the range 273 K to 800 K with uncertainties of only a few millikelvins. The acoustic thermometer determines the frequencies of the acoustic resonances of pure argon gas contained within a spherical cavity with uncertainties approaching one part in 106. To achieve this small uncertainty at these elevated temperatures we developed new acoustic transducers and new techniques for the maintenance of gas purity and for temperature control. The new electro-acoustic transducers are based on the capacitance between a flexible silicon wafer and a rigid backing plate. Without the damping usually provided by polymers, mechanical vibrations caused unstable, spurious acoustic signals. We describe our techniques for suppression of these vibrations. Our acoustic thermometer allows the argon to be continuously flushed through the resonator, thereby preventing the build up of hydrogen that evolves from the stainless-steel resonator. We describe how the argon pressure is stabilized while flushing. The argon exiting from the resonator is analyzed with a customized gas chromatograph. Because the acoustic resonator was so large—it has an outer diameter of 20 cm—a sophisticated furnace, based on surrounding the resonator with three concentric aluminum shells, was designed to maintain thermal uniformity and stability of the resonator at a level of 1 mK. We describe the design, modeling, and operational characteristics of the furnace.

  1. Prospects for X(3872) Detection at P-barANDA

    SciTech Connect

    Lange, Jens Soeren; Galuska, Martin; Gessler, Thomas; Kuehn, Wolfgang; Kuenze, Stephanie; Liang, Yutie; Muenchow, David; Spruck, Bjoern; Ullrich, Matthias; Werner, Marcel

    2011-10-24

    Monte-Carlo simulations for a resonance scan of the charmonium-like state X(3872) at P-barANDA are performed. Final state radiation hadronic background reactions are taken into account. The signal reconstruction uses a realistic pattern recognition (track finder and track fitter) and electron/pion discrimination.

  2. Use of Strain Measurements from Acoustic Bench Tests of the Battleship Flowliner Test Articles To Link Analytical Model Results to In-Service Resonant Response

    NASA Technical Reports Server (NTRS)

    Frady, Greg; Smaolloey, Kurt; LaVerde, Bruce; Bishop, Jim

    2004-01-01

    The paper will discuss practical and analytical findings of a test program conducted to assist engineers in determining which analytical strain fields are most appropriate to describe the crack initiating and crack propagating stresses in thin walled cylindrical hardware that serves as part of the Space Shuttle Main Engine's fuel system. In service the hardware is excited by fluctuating dynamic pressures in a cryogenic fuel that arise from turbulent flow/pump cavitation. A bench test using a simplified system was conducted using acoustic energy in air to excite the test articles. Strain measurements were used to reveal response characteristics of two Flowliner test articles that are assembled as a pair when installed in the engine feed system.

  3. Observation of the baryonic B-decay B0bar -> LambdaC antiproton K- pi

    SciTech Connect

    Aubert, B.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Martinelli, M.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Sun, L.; Battaglia, M.; Brown, D.N.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; /LBL, Berkeley /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT, LNS /McGill U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /Mt. Holyoke Coll. /INFN, Naples /Naples U. /INFN, Naples /INFN, Naples /Naples U. /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /Pennsylvania U. /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas U. /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U., IFIC /Victoria U. /Warwick U. /Wisconsin U., Madison

    2009-10-20

    The authors report the observation of the baryonic B-decay {bar B}{sup 0} {yields} {Lambda}{sub c}{sup +}{bar p}K{sup -}{pi}{sup +}, excluding contributions from the decay {bar B}{sup 0} {yields} {Lambda}{sub c}{sup +}{bar {Lambda}}K{sup -}. Using a data sample of 467 million B{bar B} pairs collected with the BABAR detector at the PEP-II storage ring at SLAC, the measured branching fraction is (4.33 {+-} 0.82){sub stat} {+-} 0.33{sub syst} {+-} 1.13{sub {Lambda}{sub c}{sup +}} x 10{sup -5}. In addition they find evidence for the resonant decay {bar B}{sup 0} {yields} {Sigma}{sub c}(2455){sup ++}{bar p}K{sup -} and determine its branching fraction to be (1.11 {+-} 0.30{sub stat} {+-} 0.09{sub syst} {+-} 0.29{sub {Lambda}{sub c}{sup +}}) x 10{sup -5}. The errors are statistical, systematic, and due to the uncertainty in the {Lambda}{sub c}{sup +} branching fraction. For the resonant decay {bar B}{sup 0} {yields} {Lambda}{sub c}{sup +}{bar p}{bar K}*{sup 0} we obtain an upper limit of 2.42 x 10{sup -5} at 90% confidence level.

  4. Acoustically-Induced Electrical Signals

    NASA Astrophysics Data System (ADS)

    Brown, S. R.

    2014-12-01

    We have observed electrical signals excited by and moving along with an acoustic pulse propagating in a sandstone sample. Using resonance we are now studying the characteristics of this acousto-electric signal and determining its origin and the controlling physical parameters. Four rock samples with a range of porosities, permeabilities, and mineralogies were chosen: Berea, Boise, and Colton sandstones and Austin Chalk. Pore water salinity was varied from deionized water to sea water. Ag-AgCl electrodes were attached to the sample and were interfaced to a 4-wire electrical resistivity system. Under computer control, the acoustic signals were excited and the electrical response was recorded. We see strong acoustically-induced electrical signals in all samples, with the magnitude of the effect for each rock getting stronger as we move from the 1st to the 3rd harmonics in resonance. Given a particular fluid salinity, each rock has its own distinct sensitivity in the induced electrical effect. For example at the 2nd harmonic, Berea Sandstone produces the largest electrical signal per acoustic power input even though Austin Chalk and Boise Sandstone tend to resonate with much larger amplitudes at the same harmonic. Two effects are potentially responsible for this acoustically-induced electrical response: one the co-seismic seismo-electric effect and the other a strain-induced resistivity change known as the acousto-electric effect. We have designed experimental tests to separate these mechanisms. The tests show that the seismo-electric effect is dominant in our studies. We note that these experiments are in a fluid viscosity dominated seismo-electric regime, leading to a simple interpretation of the signals where the electric potential developed is proportional to the local acceleration of the rock. Toward a test of this theory we have measured the local time-varying acoustic strain in our samples using a laser vibrometer.

  5. Leptonic B Decays at BaBar

    SciTech Connect

    Baracchini, Elisabetta; /Rome U. /INFN, Rome

    2011-11-10

    We will present the most recent results on leptonic B decays B{sup {+-}(0)} {yields} K*{sup {+-}(0)}{nu}{bar {nu}} and B{sup {+-}} {yields} {mu}{sup {+-}}{nu}, based on the data collected by the BaBar detector at PEP-II, an asymmetric e{sup +}e{sup -} collider at the center of mass energy of the {Upsilon}(4S) resonance. Rare B decays have always been a standard probe for New Physics (NP) searches. The very low Standard Model (SM) rate of these decays often make them unaccessible with the present experimental datasets, unless NP effects enhance the rate up to the current experimental sensitivity. Moreover, as NP effects can modify the decay kinematic, particular attention must be paid in order to perform a model independent analysis. A B-Factory provides an unique environment to investigate these processes. The high number of B{bar B} pairs produced by a B-Factory often allows to approach the needed experimental sensitivity. Moreover, the clean environment and the closed kinematic of the initial state enable to obtaining a very pure sample where to look for these decays.

  6. Leptonic B Decays at BaBar

    SciTech Connect

    Monorchio, Diego; /INFN, Naples /Naples U.

    2011-09-13

    The authors will present the most recent results on leptonic B decays B{sup {+-}(0)} {yields} K*{sup {+-}(0)} {nu}{bar {nu}} and B{sup {+-}} {yields} {mu}{sup {+-}}{nu}, based on the data collected by the BaBar detector at PEP-II, an asymmetric e{sup +}e{sup -} collider at the center of mass energy of the {Upsilon}(4S) resonance. Rare B decays have always been a standard probe for New Physics (NP) searches. The very low Standard Model (SM) rate of these decays often make them unaccessible with the present experimental datasets, unless NP effects enhance the rate up to the current experimental sensitivity. Moreover, as NP effects can modify the decay kinematic, particular attention must be payed in order to perform a model independent analysis. A B-Factory provides an unique environment where to investigate these processes. The high number of B{bar B} pairs produced by a B-Factory often allows to approach the needed experimental sensitivity. Moreover, the clean environment and the closed kinematic of the initial state enable to obtaining a very pure sample where to look for these decays.

  7. Bar-Code-Scribing Tool

    NASA Technical Reports Server (NTRS)

    Badinger, Michael A.; Drouant, George J.

    1991-01-01

    Proposed hand-held tool applies indelible bar code to small parts. Possible to identify parts for management of inventory without tags or labels. Microprocessor supplies bar-code data to impact-printer-like device. Device drives replaceable scribe, which cuts bar code on surface of part. Used to mark serially controlled parts for military and aerospace equipment. Also adapts for discrete marking of bulk items used in food and pharmaceutical processing.

  8. Ladder supported ring bar circuit

    NASA Technical Reports Server (NTRS)

    Kosmahl, H. G. (Inventor)

    1983-01-01

    An improved slow wave circuit especially useful in backward wave oscillators includes a slow wave circuit in a waveguide. The slow wave circuit is comprised of rings disposed between and attached to respective stubs. The stubs are attached to opposing sidewalls of the waveguide. To the end that opposed, interacting magnetic fields will be established to provide a very high coupling impedance for the slow wave structure, axially orientated bars are connected between rings in alternate spaces and adjacent to the attachment points of stubs. Similarly, axial bars are connected between rings in the spaces which do not include bars and at points adjacent to the attachment of bars.

  9. A new type of glucose biosensor based on surface acoustic wave resonator using Mn-doped ZnO multilayer structure.

    PubMed

    Luo, Jingting; Luo, Pingxiang; Xie, Min; Du, Ke; Zhao, Bixia; Pan, Feng; Fan, Ping; Zeng, Fei; Zhang, Dongping; Zheng, Zhuanghao; Liang, Guangxing

    2013-11-15

    This work reports a high-performance Mn-doped ZnO multilayer structure Love mode surface acoustic wave (SAW) biosensor for the detection of blood sugar. The biosensor was functionalized via immobilizing glucose oxidase onto a pH-sensitive polymer which was attached on Mn-doped ZnO biosensor. The fabricated SAW glucose biosensor is highly sensitive, accurate and fast with good anti-interference. The sensitivity of the SAW glucose biosensor is 7.184 MHz/mM and the accuracy is 6.96 × 10(-3)mM, which is sensitive and accurate enough for glucose monitoring. A good degree of reversibility and stability of the glucose sensor is also demonstrated, which keeps a constant differential frequency shift up to 32 days. Concerning the time response to human serum, the glucose sensor shows a value of 4.6 ± 0.4 min when increasing glucose concentrations and 7.1 ± 0.6 min when decreasing, which is less than 10 min and reach the fast response requirement for medical applications. The Mn-doped ZnO Love mode SAW biosensor can be fully integrated with CMOS Si chips and developed as a portable, passive and wireless real time detection system for blood sugar monitoring in human serum. PMID:23816847

  10. Improvement of Shape Factor and Loss of Surface Acoustic Wave Resonator Filter Composed of SiO2/High-Density-Electrode/LiTaO3

    NASA Astrophysics Data System (ADS)

    Murata, Takaki; Kadota, Michio; Nakao, Takeshi; Matsuda, Kenji; Hashimoto, Ken-ya

    2009-07-01

    Radio frequency (RF) filters in high frequencies using surface acoustic waves (SAWs), such as MediaFLOTM, time division synchronous code division multiple access (TD-SCDMA) in China's handy phone system, and the global positioning system (GPS) in cars, require a narrow bandwidth. Thus, the SAW substrates for their RF filters also require an excellent temperature coefficient of frequency (TCF) and an optimum electromechanical coupling factor. The authors reported an RF SAW filter for MediaFLOTM using a shear horizontal (SH) leaky SAW (LSAW) on a flattened SiO2 film/high-density metal electrode/36-48°Y·X-LiTaO3 substrate. Although it had a good TCF and a large attenuation out of the pass band, it had a slightly large loss at the pass band only at room temperature compared with that of the conventional Al-electrode/42°Y·X-LiTaO3 in the previous report. In this study, calculation using the coupling-of-modes (COM) theory showed the effect of a new phase inverse method of obtaining a steep slope at the right side of the filter frequency characteristic, although the previous paper showed only the measured frequency characteristics. In addition, an RF SAW filter with a lower loss at the pass band and a better TCF than that of the previous report has been realized.

  11. Tunable acoustic waveguide based on vibro-acoustic metamaterials with shunted piezoelectric unit cells

    NASA Astrophysics Data System (ADS)

    Kwon, Byung-Jin; Jung, Jin-Young; Lee, Dooho; Park, Kwang-Chun; Oh, Il-Kwon

    2015-10-01

    We propose a new class of acoustic waveguides with tunable bandgaps (TBs) by using vibro-acoustic metamaterials with shunted periodic piezoelectric unit cells. The unit metamaterial cells that consist of a single crystal piezoelectric transducer and an electrical shunt circuit are designed to induce a strong vibro-acousto-electrical coupling, resulting in a tunable acoustic bandgap as well as local structural resonance and Bragg scattering bandgaps. The present results show that the TB frequency can be actively controlled and the transmission loss of the acoustic wave can be greatly improved by simply changing the inductance values in the shunt circuit.

  12. Extraordinary acoustic transmission through annuluses in air and its applications in acoustic beam splitter and concentrator

    NASA Astrophysics Data System (ADS)

    Ge, Yong; Sun, Hong-xiang; Liu, Shu-sen; Yuan, Shou-qi; Xia, Jian-ping; Guan, Yi-jun; Zhang, Shu-yi

    2016-08-01

    We report an extraordinary acoustic transmission through two layer annuluses made of metal cylinders in air both numerically and experimentally. The effect arises from the enhancement and reconstruction of the incident source induced by different Mie-resonance modes of the annuluses. The proposed system takes advantages of the consistency in the waveform between the input and output waves, the high amplitude amplification of output waves, and the easy adjustment of structure. More interestingly, we investigate the applications of the extraordinary acoustic transmission in the acoustic beam splitter and acoustic concentrator. Our finding should have an impact on ultrasonic applications.

  13. Extraordinary acoustic transmission through annuluses in air and its applications in acoustic beam splitter and concentrator.

    PubMed

    Ge, Yong; Sun, Hong-Xiang; Liu, Shu-Sen; Yuan, Shou-Qi; Xia, Jian-Ping; Guan, Yi-Jun; Zhang, Shu-Yi

    2016-08-01

    We report an extraordinary acoustic transmission through two layer annuluses made of metal cylinders in air both numerically and experimentally. The effect arises from the enhancement and reconstruction of the incident source induced by different Mie-resonance modes of the annuluses. The proposed system takes advantages of the consistency in the waveform between the input and output waves, the high amplitude amplification of output waves, and the easy adjustment of structure. More interestingly, we investigate the applications of the extraordinary acoustic transmission in the acoustic beam splitter and acoustic concentrator. Our finding should have an impact on ultrasonic applications. PMID:27587144

  14. Physics of Sports: Resonances

    NASA Astrophysics Data System (ADS)

    Browning, David

    2000-04-01

    When force is applied by an athlete to sports equipment resonances can occur. Just a few examples are: the ringing of a spiked volleyball, the strumming of a golf club shaft during a swing, and multiple modes induced in an aluminum baseball bat when striking a ball. Resonances produce acoustic waves which, if conditions are favorable, can be detected off the playing field. This can provide a means to evaluate athletic performance during game conditions. Results are given from the use of a simple hand-held acoustic detector - by a spectator sitting in the stands - to determine how hard volleyballs were spiked during college and high school games.

  15. Introducing passive acoustic filter in acoustic based condition monitoring: Motor bike piston-bore fault identification

    NASA Astrophysics Data System (ADS)

    Jena, D. P.; Panigrahi, S. N.

    2016-03-01

    Requirement of designing a sophisticated digital band-pass filter in acoustic based condition monitoring has been eliminated by introducing a passive acoustic filter in the present work. So far, no one has attempted to explore the possibility of implementing passive acoustic filters in acoustic based condition monitoring as a pre-conditioner. In order to enhance the acoustic based condition monitoring, a passive acoustic band-pass filter has been designed and deployed. Towards achieving an efficient band-pass acoustic filter, a generalized design methodology has been proposed to design and optimize the desired acoustic filter using multiple filter components in series. An appropriate objective function has been identified for genetic algorithm (GA) based optimization technique with multiple design constraints. In addition, the sturdiness of the proposed method has been demonstrated in designing a band-pass filter by using an n-branch Quincke tube, a high pass filter and multiple Helmholtz resonators. The performance of the designed acoustic band-pass filter has been shown by investigating the piston-bore defect of a motor-bike using engine noise signature. On the introducing a passive acoustic filter in acoustic based condition monitoring reveals the enhancement in machine learning based fault identification practice significantly. This is also a first attempt of its own kind.

  16. Tungsten Oxide Layers of High Acoustic Impedance for Fully Insulating Acoustic Reflectors.

    PubMed

    DeMiguel-Ramos, M; Diaz-Duran, Barbara; Munir, Junaid; Clement, Marta; Mirea, Teona; Olivares, Jimena; Iborra, Enrique

    2016-07-01

    Gravimetric sensors based on solidly mounted resonators require fully insulating acoustic reflectors to avoid parasitics when operating in liquid media. In this work, we propose a new high-acoustic impedance material, tungsten oxide ([Formula: see text]), for acoustic reflectors. We have optimized the sputtering conditions of [Formula: see text] to obtain nonconductive layers with mass density around [Formula: see text] and acoustic velocities for the shear and the longitudinal modes up to 2700 and 4500 m/s, respectively. Compared to other conventionally used high impedance layers, [Formula: see text] films display several manufacture advantages, such as high deposition rates, great reproducibility, and good adhesion to underlying substrates. We have demonstrated the applicability of [Formula: see text] in practical shear mode bulk acoustic wave resonators that display good performance in liquid environments. PMID:26571521

  17. Implementation of viscoelastic Hopkinson bars

    NASA Astrophysics Data System (ADS)

    Curry, R.; Cloete, T.; Govender, R.

    2012-08-01

    Knowledge of the properties of soft, viscoelastic materials at high strain rates are important in furthering our understanding of their role during blast or impact events. Testing these low impedance materials using a metallic split Hopkinson pressure bar setup results in poor signal to noise ratios due to impedance mismatching. These difficulties are overcome by using polymeric Hopkinson bars. Conventional Hopkinson bar analysis cannot be used on the polymeric bars due to the viscoelastic nature of the bar material. Implementing polymeric Hopkinson bars requires characterization of the viscoelastic properties of the material used. In this paper, 30 mm diameter Polymethyl Methacrylate bars are used as Hopkinson pressure bars. This testing technique is applied to polymeric foam called Divinycell H80 and H200. Although there is a large body of of literature containing compressive data, this rarely deals with strain rates above 250s-1 which becomes increasingly important when looking at the design of composite structures where energy absorption during impact events is high on the list of priorities. Testing of polymeric foams at high strain rates allows for the development of better constitutive models.

  18. Experimental Investigations of the Internal Energy of Molecules Evaporated via Laser-induced Acoustic Desorption into a Fourier-transform Ion Cyclotron Resonance Mass Spectrometer (LIAD/FT-ICR)

    PubMed Central

    Shea, Ryan C.; Petzold, Christopher J.; Liu, Ji-ang; Kenttämaa, Hilkka I.

    2008-01-01

    The internal energy of neutral gas-phase organic and biomolecules, evaporated by means of laser-induced acoustic desorption (LIAD) into a Fourier-transform ion cyclotron resonance mass spectrometer (FT-ICR), was investigated through several experimental approaches. The desorbed molecules were demonstrated not to undergo degradation during the desorption process by collecting LIAD-evaporated molecules and subjecting them to analysis by electrospray ionization/quadrupole ion trap mass spectrometry. Previously established gas-phase basicity (GB) values were remeasured for LIAD-evaporated organic molecules and biomolecules with the use of the bracketing method. No endothermic reactions were observed. The remeasured basicity values are in close agreement with the values reported in the literature. The amount of internal energy deposited during LIAD is concluded to be less than a few kcal/mol. Chemical ionization with a series of proton transfer reagents was employed to obtain a breakdown curve for a protonated dipeptide, val-pro, evaporated by LIAD. Comparison of this breakdown curve with a previously published analogous curve obtained by using substrate-assisted laser desorption (SALD) to evaporate the peptide suggests that the molecules evaporated via LIAD have less internal energy than those evaporated via SALD. PMID:17263513

  19. Galaxy Zoo: CANDELS barred discs and bar fractions

    NASA Astrophysics Data System (ADS)

    Simmons, B. D.; Melvin, Thomas; Lintott, Chris; Masters, Karen L.; Willett, Kyle W.; Keel, William C.; Smethurst, R. J.; Cheung, Edmond; Nichol, Robert C.; Schawinski, Kevin; Rutkowski, Michael; Kartaltepe, Jeyhan S.; Bell, Eric F.; Casteels, Kevin R. V.; Conselice, Christopher J.; Almaini, Omar; Ferguson, Henry C.; Fortson, Lucy; Hartley, William; Kocevski, Dale; Koekemoer, Anton M.; McIntosh, Daniel H.; Mortlock, Alice; Newman, Jeffrey A.; Ownsworth, Jamie; Bamford, Steven; Dahlen, Tomas; Faber, Sandra M.; Finkelstein, Steven L.; Fontana, Adriano; Galametz, Audrey; Grogin, N. A.; Grützbauch, Ruth; Guo, Yicheng; Häußler, Boris; Jek, Kian J.; Kaviraj, Sugata; Lucas, Ray A.; Peth, Michael; Salvato, Mara; Wiklind, Tommy; Wuyts, Stijn

    2014-12-01

    The formation of bars in disc galaxies is a tracer of the dynamical maturity of the population. Previous studies have found that the incidence of bars in discs decreases from the local Universe to z ˜ 1, and by z > 1 simulations predict that bar features in dynamically mature discs should be extremely rare. Here, we report the discovery of strong barred structures in massive disc galaxies at z ˜ 1.5 in deep rest-frame optical images from the Cosmic Assembly Near-Infrared Deep Extragalactic Legacy Survey. From within a sample of 876 disc galaxies identified by visual classification in Galaxy Zoo, we identify 123 barred galaxies. Selecting a subsample within the same region of the evolving galaxy luminosity function (brighter than L*), we find that the bar fraction across the redshift range 0.5 ≤ z ≤ 2 ( f_{bar} = 10.7^{+6.3}_{-3.5} per cent after correcting for incompleteness) does not significantly evolve. We discuss the implications of this discovery in the context of existing simulations and our current understanding of the way disc galaxies have evolved over the last 11 billion years.

  20. Acoustic transducer for acoustic microscopy

    DOEpatents

    Khuri-Yakub, Butrus T.; Chou, Ching H.

    1990-01-01

    A shear acoustic transducer-lens system in which a shear polarized piezoelectric material excites shear polarized waves at one end of a buffer rod having a lens at the other end which excites longitudinal waves in a coupling medium by mode conversion at selected locations on the lens.