bluuebunny/crossref_metadata_2025 huggingface dataset:
Babesia canis vogeli,Ehrlichia canis, and Anaplasma platys infection in a dog
Authors: Al Izzi Salah , Martin Donald S. , Chan Roxanne Y.Y. , Leutenegger Christian M.
Published: October 2013

A 12‐month‐old male neutered mixed breed dog was presented with a history of diarrhea, lethargy, emaciation, polydypsia, and sniffling. Physical examination findings included pale mucous membranes, increased heart and respiratory rates, and normal rectal temperature (38°C). Hematologic abnormalities included anemia and thrombocytopenia. Biochemical abnormalities included hypoalbuminemia, hyperbilirubinemia, and elevated ALP and ALT activities. A SNAP 4Dx test result was positive for Ehrlichia canis. Babesia canis vogeli organisms were found in the peripheral blood films, while morulae of E canis were not seen. Real‐time polymerase chain reaction testing confirmed the presence of both B c vogeli and E canis organisms, and also was positive for Anaplasma platys infection. The dog recovered following treatment with doxycycline and imidocarb dipropionate, with normal hematology and biochemical profiles.
Closed-Loop System Identification Based on Data Correlation
Authors: Jammoussi Hassene , Franchek Matthew , Grigoriadis Karolos , Books Martin
Published: October 2013

A closed-loop system identification method is developed to estimate the parameters of a single input single output (SISO) linear time invariant system (LTI) operating within a feedback loop. The method uses the reference command in addition to the input–output data and establishes a correlation framework to structure the system. The correlation-based method is capable of delivering consistent estimates provided that the specific conditions on the signals are met. The method parallels the instrumental variables four step algorithm (IV4) and is comprised of three steps. First a model is estimated using cross correlation calculations between the reference input signal and the control and measured output signals. In the second step, a prefilter is identified to reduce estimation bias. In the final step, the prefilter, the instrumental variables and the measured signals are employed to estimate the final model. A consistency proof is provided for the proposed estimation process. The method is demonstrated on two examples. The first uses data collected from a diesel engine operation, and an open-loop model relating fueling to engine speed is sought. The identification process is complicated by the presence of nonmeasurable external torque disturbances and stochastic sensor noise. The second example uses data obtained from a time domain simulation of a closed-loop system where high levels of nonmeasured noise and disturbances were considered and a comparison with existing methods is made.
Physical properties of epitaxial ZrN/MgO(001) layers grown by reactive magnetron sputtering
Authors: Mei A. B. , Howe B. M. , Zhang C. , Sardela M. , Eckstein J. N. , Hultman L. , Rockett A. , Petrov I. , Greene J. E.
Published: October 2013

Single-crystal ZrN films, 830 nm thick, are grown on MgO(001) at 450 °C by magnetically unbalanced reactive magnetron sputtering. The combination of high-resolution x-ray diffraction reciprocal lattice maps, high-resolution cross-sectional transmission electron microscopy, and selected-area electron diffraction shows that ZrN grows epitaxially on MgO(001) with a cube-on-cube orientational relationship, (001)ZrN‖(001)MgO and [100]ZrN‖[100]MgO. The layers are essentially fully relaxed with a lattice parameter of 0.4575 nm, in good agreement with reported results for bulk ZrN crystals. X-ray reflectivity results reveal that the films are completely dense with smooth surfaces (roughness = 1.3 nm, consistent with atomic-force microscopy analyses). Based on temperature-dependent electronic transport measurements, epitaxial ZrN/MgO(001) layers have a room-temperature resistivity ρ300K of 12.0 μΩ-cm, a temperature coefficient of resistivity between 100 and 300 K of 5.6 × 10−8 Ω-cm K−1, a residual resistivity ρo below 30 K of 0.78 μΩ-cm (corresponding to a residual resistivity ratio ρ300Κ/ρ15K = 15), and the layers exhibit a superconducting transition temperature of 10.4 K. The relatively high residual resistivity ratio, combined with long in-plane and out-of-plane x-ray coherence lengths, ξ‖ = 18 nm and ξ⊥ = 161 nm, indicates high crystalline quality with low mosaicity. The reflectance of ZrN(001), as determined by variable-angle spectroscopic ellipsometry, decreases slowly from 95% at 1 eV to 90% at 2 eV with a reflectance edge at 3.04 eV. Interband transitions dominate the dielectric response above 2 eV. The ZrN(001) nanoindentation hardness and modulus are 22.7 ± 1.7 and 450 ± 25 GPa.
Comparison of ultrasound scattering behavior of optison and a liquid perflourocarbon nanoparticle contrast agent
Authors: Hughes Michael , Marsh Jon , Furhop Ralph , Chinen Lori , Wickline Sam , Lanza Greg
Published: October 2013

Useful ultrasound contrast enhancement has been obtained using liquid emulsion contrast agents developed in our laboratory [Evaluation of liquid perflourocarbon nanoparticles as a blood pool contrast agent utilizing power Doppler harmonic imaging, IEEE Ultrason. Symp. 00CH37121, 1931–1934 (2000)]. While the physical basis for enhancement is unknown, it is reproducible, in vivo and in vitro. It is hypothesized that microbubble formation is not a significant factor in the acoustic behavior of these contrast agents; attenuation and backscatter (measured in a water bath at 37°C) are uneffected by changes in hydrostatic pressure (from −50 to 200 mm Hg), acoustic pressure (0.038–3.0 MPa), and show no evidence of scattering agent destruction with ultrasound exposure time (2–80 s). The microbubble agent attenuation coefficient exhibits a single peak between 1 and 2 MHz. The exact peak location, height and width vary significantly with experimental conditions. In contrast, the emulsion does not exhibit any of these effects, which makes it appear very unlikely that microbubble formation through perflourocarbon phase conversion contributes in a measurable manner to the acoustic properties of the liquid perflourocarbon nanoparticle contrast agent over the range of experimental parameters in this study. [Work supported in part by HL-59865, N01-C0-07013-32.]
Ultrasonic time reversal, basic principles
Authors: Cassereau Didier , Fink Mathias
Published: October 2013

For about 10 years now, time reversal methods have been widely developed in the laboratory and applied to various domains of acoustics like medical imaging/therapy and nondestructive evaluation. Many experiments and theoretical works have shown the robustness of this approach in multiple conditions (inhomogeneous and multiscattering media, solid layers, submarine acoustics,...). This paper will first present an overview of the basic theoretical principles which govern the time reversal approach. It will be shown how the concept of closed time reversal cavity yields theoretical predictions of the intrinsic limitations of the process. Starting from the closed time reversal cavity, the discussion will migrate in direction of (i) time reversal mirrors and (ii) time reversal arrays of final aperture. It will be shown how the general performances of the system are degraded. Then the presentation will focus on the time reversal methods applied to ultrasonic waves in solids. It will be shown how the time reversal technology takes advantage of longitudinal and transverse propagation modes in order to increase the focusing efficiency. These results will be illustrated by an experiment carried out with an aluminum plate partially immersed in water and excited by a laser impact.
Nonadiabatic travel time and time series synthesis in range dependent waveguides
Authors: LePage Kevin D.
Published: October 2013

A WKB approximation for the range dependent modal group slownesses and dispersions in a range dependent waveguide is derived. The resulting slownesses can be used to synthesize time series in a narrow band or over broader bandwidths by adding narrow band results together coherently. The slownesses themselves are also highly useful intermediate products which help give insight into the speeds with which the modes of a range dependent waveguide propagate. The range dependent modal group slownesses are compared to their adiabatic approximations and conclusions are drawn regarding the relative accuracy of these two approximations for time series synthesis.
Concert hall acoustics—2001
Authors: Beranek Leo L.
Published: October 2013

A brief summary is made of major factors encountered in today’s acoustical design of concert halls, including preferred reverberation times, loudness, lateral reflections, seat absorption, suspended panels, need for irregular surfaces to create sound diffusion and eliminate acoustical ‘‘glare,’’ and objective measurement techniques developed from laboratory experiments that can be used to estimate subjective acoustical quality. Objective measurements of these factors have been made in over 70 halls. The results are plotted versus subjective rank-orderings of acoustical quality for these halls. The rank-orderings were obtained from interviews and questionnaires involving conductors, music critics, and music aficionados. The objective quantities plotted are reverberation time, early decay time, spaciousness, lateral fraction, interaural cross-correlation coefficient, initial-time-delay gap, strength factor (sound level), bass ratio, 125-Hz level, and surface diffusivity index.
How worship space acoustics helped to shape western history
Authors: Lubman David
Published: October 2013

Acoustical communication is a vital element in the co-evolution of worship space architecture and liturgy. Acoustical communication in worship spaces is bound by scientific verities. Information theory holds that for any communication channel there exists an optimum coding of transmitted information. Speech and music are alternative informational codings. Speech coding is efficient for small, dry indoor spaces and well suited to the spoken liturgies of synagogues, early Christian house churches, and other small pre-Constantinian churches. The historic and fateful change from a spoken to a musical liturgy beginning with Constantine (ca. 313) was likely driven by the highly reverberant acoustics of large basilicas that rendered speech unintelligible. Such highly reverberant spaces are well suited for specific types of musical communication. Gregorian chant is shown to be an ingenious coding for reverberant spaces and an early use of frequency diversity coding. The historic return to spoken liturgies beginning with the reformation and counter-reformation of the 15th century was accompanied by reductions in church reverberation. The Protestant acoustic also engendered a need for music suited to less reverberant spaces, e.g., simple melodies with rapidly changing chordal harmonies. Electronics is a new element driving the evolution of worship space architecture and liturgical form.
A combined auralization and visualization system for noise prediction in enclosures
Authors: Zeng Xiangyang , Ning Fangli , Chen Ke’an , Sun Jincai
Published: October 2013

A combined auralization and visualization system was devised for the research on internoise control. For any individual point in an enclosure, a hybrid geometric method was used to simulate the impulse response at high frequency and the finite element method was used to model that at low frequency. Then the two parts were joined. Acoustical indexes such as SPL(A) can be calculated based on this complete impulse response. For binaural simulation, the impulse responses of two points, each of which was 0.08 m away from the receiving point were considered as the binaural impulse response. They were then convoluted with any anechoic signal in time domain using the fast Fourier transform algorithm. This subsystem of auralization was tested on real acoustical spaces to compare real sound signals and the corresponding reproduced ones. The subsystem of visualization was designed to build an interface for data input and output and to show the structure of the enclosure and status of sound sources and receivers. By using computer language C++ these two subsystems were combined, therefore the complete system can be conveniently used on a personal computer. [Project supported by the Doctorate Foundation of Northwestern Polytechnical University.]
Measurement of guided ultrasonic waves in the human tibia and radius
Authors: Nicholson Patrick H. , Cheng Sulin , Karkkainen Tommi , Moilanen Petro , Timonen Jussi
Published: October 2013

The use of guided ultrasonic waves to characterize human long bones may offer advantages over existing approaches based on lateral wave velocity measurement alone. To investigate this possibility, a pulse transmission system consisting of low frequency transducers orientated perpendicularly to the limb was used to measure the tibia and radius of healthy and osteoporotic subjects. At least two wave components were consistently observed: a fast wave traveling at 3600–4500 m/s, and a slower wave propagating at 1200–1900 m/s. Satisfactory excitation of the slower mode was dependent on adequate transducer contact pressure. Analytical and numerical models, combined with phantom measurements, were used to confirm the nature of the two waves. The fast wave behaved as expected for a lateral wave, while the slower wave was consistent with the lowest order antisymmetric guided mode. In pilot studies, the relative velocity difference in the tibia between healthy and osteoporotic women was greater for the guided wave (18%) compared to the lateral wave (2%), suggesting that the guided wave is a better discriminant of osteoporosis. These preliminary results indicate guided wave analysis to be a promising adjunct to conventional axial ultrasound measurements in bone.
Investigation of guided ultrasonic waves in bone phantoms using an axial transmission method
Authors: Moilanen Petro , Timonen Jussi , Karkkainen Tommi , Nicholson Patrick H. , Cheng Sulin
Published: October 2013

Human long bones are effectively hollow tubes of irregular cross-section which potentially allow the propagation of guided modes in addition to the lateral or ‘‘head’’ wave measured by existing clinical devices. Guided modes are attractive because they propagate throughout the bone thickness, are less attenuated with distance, and may yield a more complete picture of the bone material and geometrical properties. A low-frequency pulse transmission technique was used in bone phantoms consisting of acrylic plates with thicknesses ranging from 2 to 25 mm. The receiving transducer was moved automatically, producing (r,t) plots which allowed different wave fronts to be visualized and measured. Two distinct wave components were observed. The faster wave front behaved as predicted for the lateral wave, propagating at the longitudinal velocity (2700 m/s) in thick plates. However, in plates thinner than 5 mm this velocity decreased nonlinearly with thickness toward that of the lowest-order symmetric guided wave (2400 m/s). The second component was consistent with the lowest-order antisymmetric guided wave, propagating at the Rayleigh velocity (1300 m/s) in the thickest plates and exhibiting a strong nonlinear velocity decrease at thicknesses below 10 mm. These results provide a useful framework for applying similar measurements in real bones.
Music Technology at Northeastern University
Authors: De Ritis Anthony
Published: October 2013

Inititated in 1998 by Professors Dennis Miller and Anthony De Ritis, the Music Technology program at Northeastern University requires all students to take private lessons in music composition. During the first two years, emphasis is on acoustic instruments only. Acoustics and psychoacoustics play an important role in this process. Music Technology students are required to take embedded learning modlues, or ELMOs, introducing concepts in the physics and perception of sound in a hands-on laboratory environment. We believe ELMOs shorten the learning curve students require for the acquisiton of advanced orchestration skills and serves to heighten their awareness in sound design. Core courses include Interactive Real-Time Performance (using the MAX programming language), Composition for Electronic Insturments, Advanced Music Systems (including Kyma and C-Sound), and Sound Design, which includes the production of an entire radio drama for its final exam. At the end of their sophomore year, students have the option to apply for the Multimedia Studies Dual Major, grouping majors in music technology, animation, graphic design and digital imaging in multimedia-based projects. The Music Technology program is a leader in Education Technology at Northeastern, and was recently awarded a $25000 grant to develop an internet-based course called Computer Literacy for Musicians.
Music synthesis program at Berklee College of Music
Authors: Rhea Thomas L.
Published: October 2013

A description is given of the Music Synthesis Department of the Music Technology Division of Berklee College of Music in Boston, MA. A ‘‘virtual tour’’ of facilities will be provided, as well as a brief exposition of the teaching and support infrastructures. The session will comprise examples of Music Synthesis Department (undergraduate) student compositions, soundscapes, web page designs, and multi-media productions, and research projects in acoustics and psychoacoustics completed as final projects required for graduation. Questions from any educators interested in logistics for this type of program will be answered.
A review of elastic constant measurements with resonant ultrasound spectroscopy
Authors: So Jin H. , Gladden J. R. , Maynard J. D.
Published: October 2013

Measurements of elastic constants in new materials are crucial because the elastic constants, being directly related to atomic and electronic configurations, carry important information about the mechanical and electronic properties and phase transitions. A conventional method for measuring elastic constants, the pulse-echo technique, suffers from a number of problems, such as transducer-sample coupling, parallelism of sample faces, the necessity of remounting transducers, etc. Such problems are avoided in resonant ultrasound spectroscopy (RUS), a relatively new method which can determine all elastic constants in a single measurement. Currently a number of research groups, e.g., UCLA, Los Alamos, Colorado State, University of Wisconsin, University of Nevada, NIST, and laboratories in Europe and Asia are using the RUS technique to study a wide variety of systems, and these will be reviewed in this talk. In our own research, the RUS technique has been extended for studies of very small samples (less than 100 μg) and for measuring the elastic constants in thin film (200 nm) samples. Studies include thin films of magnetic materials involving colossal magnetoresistance (candidates for high density digital data storage media) and films of carbon nanotubes, which have unique mechanical properties. [Research supported by ONR.]
Radiation from nonhomogeneous structures using SEA
Authors: Manning Jerome E.
Published: October 2013

Prediction of the acoustic radiation from vibrating structures at high frequencies can be accomplished using statistical energy analysis models. However, the basic formulations of radiation efficiency used in these models are often based on assumptions regarding boundary conditions and structural homogeneity that are not valid. Recent work carried out for nonhomogeneous structures with realistic boundary conditions is presented. An impedance approach is used that allows the radiation to be defined in terms of the forces acting on the structure from boundaries and added components. Examples are used to demonstrate the changes in radiation efficiency resulting from realistic boundaries, frame stiffeners, and added components.
Provided the modal overlap parameters exceed a threshold, statistical energy analysis (SEA) is not challenged by energy analysis (EA)
Authors: Maidanik G. , Becker K. J.
Published: October 2013

A structural complex is modeled by an externally driven master oscillator that is coupled to a set of satellite oscillators. In this model the satellite oscillators are not coupled to one another and the resonance frequencies of the satellite oscillators centrally span that of the master oscillator. The response of the model is cast in terms of the modal coupling strength ζ(y). This quantity is the ratio of the energy typically stored in a satellite oscillator to the energy stored in the master oscillator, (y) is the normalized frequency (ω/ω0) and (ω0) is the resonance frequency of the master oscillator. The modal coupling strength ζ(y) determined via the statistical energy analysis (SEA) is invariably less than unity; ζ(y)<1. This quantity determined via the energy analysis (EA) is not necessarily so restricted. Indeed, the (EA) ζ(y) can be maintained below unity only if a typical modal overlap parameter (bs) of the satellite oscillators exceeds a threshold (bt); bt<bs. This threshold is required if the validation of SEA is not to be challenged by EA. Cited is a reasonable complex with strong couplings; e.g., satellite oscillators as sprung-masses, for which (bt) exceeds unity. Therefore, to validate the SEA, modal overlap in this set must prevail.
Application of the mode isolation algorithm for experimental modal analysis to a system with close natural frequencies
Authors: Ginsberg Jerry H. , Zaki Bassem R.
Published: October 2013

Experimental modal analysis techniques in current use have difficulty with modes whose natural frequencies are very close or whose drive point mobility is very low. How well these issues are addressed by the Mode Isolation Algorithm (MIA), see M. V. Drexel and J. H. Ginsberg, ‘‘Modal parameter isolation using state space mode isolation,’’ in Proceedings of the 19th International Modal Analysis Conference, Orlando, Florida, February 5–8, 2001, is the topic of this presentation. MIA is an iterative procedure that employs frequency domain response data. The application of MIA to a system consisting of a beam with three suspended spring-mass-dashpot subsystems is described. Judicious choice of the system parameters leads to two modes having close natural frequencies, and two other modes in which impulse excitation at the free end of the beam results essentially in vibration of the subsystems away from the end. Synthetic impulse response data for the analysis is contaminating with white noise. It is shown that MIA accurately identifies all natural frequencies and modal damping ratios if the frequency resolution of the response data is sufficiently fine. Furthermore, the two normal mode shapes associated with the proximate natural frequencies are correctly identified, but the two with low drive point mobility are not. [Work supported by the National Science Foundation, Grant No. CMS-0098539.]
Results from a shallow water propagation experiment on the Malta Plateau
Authors: Williams Neil J. , DeFerrari Harry A. , Nguyen Hien B. , Metzger Kurt , Ensign Thomas H. , Zets Gary A.
Published: October 2013

A shallow water propagation experiment was performed in conjunction with a Saclant Undersea Research Center project known as the Malta Plateau Experiment (or MAPEX 2000) in early March 2000. A small, inexpensive, prototype 800-Hz source broadcasting 128-digit M-sequences was deployed off the southern coast of Sicily in approximately 135 m of water at a distance of 5 km from a fixed 64-element vertical array of hydrophones. This array relayed received signals to the R/V Alliance via radio telemetry. The Alliance then deployed a 256-element towed array and proceeded away from the source at a speed of 5 kts for about 3 h. The experiment was repeated once more using a second prototype with a different length M-sequence. The maximum distance from source to receiver was 30 km. The data were processed to remove Doppler and channel pulse responses were generated. The data will be compared with model results and the utility of the new projector will be discussed. [Work supported by ONR Code 321SS.]
Validity conditions for the Markov approximation in theories for internal wave effects on propagation
Authors: Henyey Frank S. , Ewart Terry E.
Published: October 2013

There are two conditions that, if satisfied, guarantee the validity of the Markov approximation as usually imposed [see, for example, B. J. Uscinski The Elements of Wave Propagation in Random Media (McGraw-Hill, New York, 1977)]. One condition is that the scattering angle be small compared to the anisotropy of the medium, and the second is that there be less than one radian of phase shift in a correlation length. For the MATE experiment on acoustic propagation through oceanic internal waves, the second condition is violated, yet theories based on the Markov approximation work well. In this talk, it is shown that this second condition is much too pessimistic, by explicit construction of the next-order correction in an example that neglects sound channel effects over a correlation length. There is a strong cancellation among terms for the correction, each of which is of the order of the second expansion parameter squared. This cancellation occurs because the horizontal wave number is insensitive to the vertical wave number at small angles and that most of the phase shift comes from large-scale internal waves. With this cancellation, Markov approximation theories should correctly predict the MATE results—as they do. [Work supported by ONR.]
Shallow water impact acoustics
Authors: Deveau David M.
Published: October 2013

During a series of impact detection and tracking accuracy tests near Wallops Island, Maryland, an analysis was conducted on the acoustic impacts themselves. Since the impact area was very shallow (<60 ft.), the acoustic signature traveled unscathed between the 1000 yard baseline sensors. The initial goal was to implement deep water impact tracking algorithms in the shallow environment. Initially the in-water tracking system computed positions that were close to those which were laser sighted—but not close enough. Since the transient acoustic signature was very evident, hence a stable timing mark, an investigation into the acoustics surrounding the impact was undertaken. A review of the data showed small transients which occurred distinctly before the large transient detection which had routinely been considered as the impact itself. Using a threshold detection scheme, a relative set of timing marks were generated based on these early transients and were found to produce a more accurate placement of the projectile impact. A further analysis consisted of reviews of controlled historical experiments that supported the experimental data and yielded a more precise impact detection scheme through a knowledge of the physical acoustics.
Chorus behavior ecology in warm temperature sciaenid (Pisces: Sciaenidae) within a warm–temperate to tropical coastal lagoon
Authors: Gilmore R. Grant
Published: October 2013

Individual sound production and aggregative choral behaviors in sciaenid fishes of the Indian River Lagoon system of east central Florida have been under study since 1977. Long term studies of sonifery augmented with equally long term life history research has allowed classification of their call behaviors relative to their ecology. Five sciaenid species, silver perch, Bairdiella chrysoura, spotted seatrout, Cynoscion nebulosus, black drum, Pogonias cromis, red drum, Sciaenops ocellata, and weakfish, Cynoscion regalis can be divided into temporal, spatial, morphological, and vocal guilds. These guilds reveal partitioning of estuarine resources not only for habitat, food, and predation avoidance, but also for reproductive biology, sonifery, and larval-juvenile ecology. Variation in call type is significant between these species further presenting implications for co-evolved mating strategies under syntopic conditions within confined lagoonal ecosystems.
Psychoacoustics of ultrasound detection in clupeids
Authors: Mann David A. , Tavolga William N. , Higgs Dennis M. , Popper Arthur N.
Published: October 2013

Recent behavioral and physiological studies have shown that some clupeid fishes are able to detect ultrasonic signals up to 180 kHz. Fishes in the subfamily Alosinae, including the American shad (Alosa sapidissima) and the gulf menhaden (Brevoortia patronus) are able to detect ultrasound. Yet other clupeids, including the scaled sardine (Harengula jaguana), Spanish sardine (Sardinella aurita), and the bay anchovy (Anchoa mitchilli), are not able to detect ultrasound. In this paper we review the ability of clupeids to detect ultrasound, and investigate the psychoacoustics of ultrasound detection, including frequency discrimination and masking by low-frequency and high-frequency sounds. [Work supported by NSF and NIH.]
The measurement of flow and turbulence levels using acoustical scintillation analysis
Authors: Di Iorio Daniela
Published: October 2013

For acoustical propagation in the coastal environment, small scale fluctuations in the temperature/salinity and flow velocity distorts the spherically spreading phase fronts which result in amplitude and phase fluctuations (scintillation). As the fine structure variability in the medium has a natural coherence time, it will be transported by the current. Detection of pattern motion is an essential concept exploited in acoustical scintillation and has been demonstrated in a variety of coastal channels. Important features of this approach are that the measurement is path averaged, is of the flow component perpendicular to the acoustic path and is sensitive to the Fresnel scale size which is chosen to lie within the inertial subrange of the turbulent random medium. Analysis of the signals goes beyond measurement of flow speed, and has included detection of turbulent velocity and scalar levels and turbulent anisotropy. For one-way propagation the turbulent kinetic energy dissipation rate is derived from the variance of the log-amplitude signal which is dependent on the level of the Kolmogorov spectrum dominated by current fluctuations. From reciprocal propagation, scalar and velocity turbulence levels are derived from accurate phase fluctuations. Detection of turbulent anisotropy is based on horizontal and vertical angle of arrival correlations using a square array with 1 m sides and thus sensitive to turbulent scale sizes approximately a few meters.
Laboratory measurements of acoustic scattering from a temperature and salinity gradient
Authors: Warren Joseph D. , Lavery Andone C. , Schmitt Ray W. , Stanton Timothy K.
Published: October 2013

Recently developed theoretical scattering models predict that acoustic scattering from temperature and salinity microstructure at high frequencies (10 kHz–1 MHz) can be significant under certain oceanographic conditions. The results of this theoretical work suggest that it may be possible to use acoustic scattering techniques, in combination with the scattering models, to estimate oceanographic parameters, such as the dissipation rate of turbulent kinetic energy. In addition, quantification of the scattering contributions from temperature and salinity microstructure can play an important role in correctly interpreting acoustic surveys of marine life, since recent field data indicate that the acoustic returns from zooplankton and microstructure can be of similar strength. Acoustic backscatter from a sharp temperature and salinity gradient was measured in a tank capable of generating, and sustaining, a thin double-diffusive layer (1–2 cm thick) between two water masses (cold, fresh residing above warm, salty water). Vertical shear, temperature, and salinity profiles were measured during the experiment to provide input to the acoustic scattering models. Backscatter was measured at frequencies between 24 kHz and 500 kHz, and as a function of range from the sharp interface as part of a program to measure the backscattering from microstructure. a)Currently at Southwest Fisheries Science Center, La Jolla, CA 92037.
MRI guided focused ultrasound opening of blood brain barrier
Authors: Hynynen K. , McDannold N. , Vykhodtseva N. , Sheikov N. , Jolesz F.
Published: October 2013

Previously, we demonstrated that focused ultrasound can focally open the blood brain barrier (BBB) reversibly without damage to the neurons. In this study, we varied the ultrasound pulse parameters to investigate their influence on BBB opening and any resulting tissue damage. Under magnetic resonance imaging (MRI) guidance, a series of targeted ultrasound bursts (1.5 MHz, burst duration: 5 cycles to 100 ms, repetition frequency: 1 Hz–1 kHz) were delivered into rabbit brains at low pressure levels (up to approximately 5 MPa) after intravenous administration of a commercially available ultrasound contrast agent containing preformed gas bubbles. Focal MRI signal intensity changes were observed during the deposition of acoustic energy. BBB opening at the correct target was confirmed by detecting the localized uptake of an MRI contrast agent. In some animals Trypan Blue was injected intravenously after the sonications. The animals were sacrificed at time intervals ranging from 2 h to 7 days. Light and electron microscopy evaluation was performed. No neuronal damage was observed at the lowest power levels that produced BBB opening. No neuronal damage was observed at the lowest power levels that produced BBB opening. Correlation of focal MRI signal changes to the uptake of a large molecular size contrast agent was observed demonstrating the potential of image guided drug delivery.
SonablateTM 500: A novel ultrasound platform for transrectal image-guided treatment of prostate diseases
Authors: Sanghvi Narendra T. , Calson Roy F. , Seip Ralf , Tavakkoli Jahangir , Dines Kris A. , Gardner Thomas A. , Uchida Toyoaki
Published: October 2013

The SonablateTM system for transrectal image-guided high intensity focused ultrasound (TR-HIFU) treatment of prostate diseases has been in clinical use since 1992. Recently, we developed the third generation of the system, call SonablateTM 500, with major improvements aimed specifically toward localized prostate cancer treatment. Salient features of the SonablateTM 500 include: (1) PC-based digital technology, (2) multifocal lengths probe with split beam transducer to cover a wide range of tissue depths (2.5–4.5 cm), (3) an upgraded treatment planning and control software with safety features such as reflectivity index measurement (RIMTM) and transducer tissue measurement (TTMTM); and (4) 3-D volume image rendering of the prostate. The SonablateTM 500 platform was tested in an in vivo canine experimental study in which the entire prostate was ablated. The prostate ultrasound images before and post HIFU treatment show very good correlation to the planned lesion. Histology delineated that the entire prostate was contiguously ablated without affecting surrounding tissues. Long-term canine survival studies as well as human prostate cancer studies under the FDA’s IDE (Investigational Device Exemption) approval are in progress. [We would like to thank the engineering and clinical staff of Focus Surgery, Inc. who made this project possible.]
Measurement of particulate densities in air
Authors: Beniwal Ravinder , Wu Sean
Published: October 2013

Clean air is one of the most important issues that govern the health of all live forms. However, presently there are not many quick and simple methods for measuring impurities like particulates in air. These impurities have an enormous diversity in their physical and chemical structure. They may be unburned carbon particles from a diesel engine exhaust and chimney, pollen grains in the spring air, or asbestos in a factory. This paper shows that changes in the composition of the air cause a change in the speed of sound. Therefore by measuring the change in the speed of sound, it is possible to monitor the density of particulates in the air. Preliminary tests are conducted on various smoke–air mixtures. The results demonstrate that this methodology is very sensitive to any changes in the composition of the air. Its implementation is very simple and efficient, and costs much less than the conventional method currently used in the auto industry. This technique will be used to calculate the mass density of the particulates resulting from a diesel engine, and results thus obtained will be compared with those calculated using other methods.
Capacitive micromachined interdigital transducers
Authors: Yaralioglu Goksen G. , Badi Mohammed H. , Khuri-Yakub Butrus T.
Published: October 2013

Capacitive Micromachined Ultrasonic Transducers (CMUTs) have become very popular for medical imaging and sonar applications during the last decade. They can compete with piezoelectric transducers in terms of efficiency and bandwidth. Recently, it has been noticed that these devices couple energy into silicon wafer in addition to the immersion medium. By placing the CMUTs on a substrate in an interdigitated configuration, Lamb wave or Rayleigh wave modes can be excited with very high efficiency without a need for any piezoelectric material. In this study, the acoustic power coupled into the silicon substrate as well as the acoustic impedance of the CMUT membrane are calculated by using finite element analysis. Normal mode theory is used to find the distribution of the acoustic power among different Lamb wave modes. For low frequency (1 MHz) devices, the lowest order antisymmetric (A0) mode Lamb wave is the dominant mode in the substrate. For high frequency devices (100 MHz), interdigital CMUTs excite Rayleigh wave with efficiencies comparable to piezoelectric surface acoustic wave (SAW) devices. Experimental results for Lamb wave devices in the vicinity of 1 MHz will also be presented. [Work supported by ONR.]
Shape optimization techniques for musical instrument design
Authors: Henrique Luis , Antunes José , Soeiro de Carvalho João
Published: October 2013

The design of musical instruments is still mostly based on empirical knowledge and costly experimentation. One interesting improvement is the shape optimization of resonating components, given a number of constraints (allowed parameter ranges, shape smoothness, etc.), so that vibrations occur at specified modal frequencies. Each admissible geometrical configuration generates an error between computed eigenfrequencies and the target set. Typically, error surfaces present many local minima, corresponding to suboptimal designs. This difficulty can be overcome using global optimization techniques, such as simulated annealing. However these methods are greedy, concerning the number of function evaluations required. Thus, computational times can be unacceptable if complex problems, such as bell optimization, are tackled. Those issues are addressed in this paper, and a method for improving optimization procedures is proposed. Instead of using the (local) parameters Pf(r) as searched variables, the system geometry is modeled in terms of truncated series of orthogonal space-functions Pj(r)=∑najnψjn(r), and optimization is performed on the (global) coefficients ajn. Fourier series and orthogonal polynomials are typical functions ψjn(r). This technique reduces considerably the number of search variables, and has a potential for significant computational savings in complex problems. It is illustrated by optimizing the shapes of both current and uncommon marimba bars.
On the acoustics of organ reed pipes
Authors: Cox Eric , Rossing Thomas D.
Published: October 2013

In most lingual organ pipes, the reed vibrates against a fixed shallot and modulates the flow of air passing through the shallot into the resonator. In an earlier paper [T. D. Rossing, J. Angster, and A. Miklos, paper 2pMU6, 136th meeting, Acoustical Society, 1998] we described distinct regimes of oscillation observed in a Trompette pipe. Using a laser vibrometer, we have now observed similar phenomena in two pipes of quite different design: a Rankett and a Krummhorn. Without the resonator the reed frequency in each pipe varies smoothly with reed length, but the resonator lowers the frequency of the reed and also produces distinct regimes of sound, separated by discontinuities, as the system jumps from one regime to the next one. Changing the wind pressure has a modest effect on sound output but little effect on sounding frequency, within limits.
Experiences with acoustical renovation of classrooms in a public school
Authors: Wallace Robert
Published: October 2013

The Harbor Science and Arts Charter School is a small, public elementary school with children in grades 1 through 7 located in the East Harlem section of New York City. A hallmark of our curriculum is that we encourage students to work on group projects and to make many oral presentations of the results of their work. We noticed that when children were engaged in group work and oral presentations, it was often difficult to understand everything that was said. One of our fourth grade teachers had a friend who was an acoustical designer who arranged a sound analysis of the teacher’s room that confirmed that our high ceilings, concrete block walls, and window air conditioners were creating some of the problems we were experiencing. Using the room as a test case, Armstrong Industries donated materials for modifications to the room. They subsidized lowering the ceiling with acoustical tiles. We installed new bulletin boards and purchased new air conditioners. The results were extraordinary. Students and teachers who used the classroom were amazed at the improvements. We have used what we have learned to modify all of the classrooms as well as the cafeteria. These relatively simple modifications have made a significant improvement in the quality of life in our school.
The Future of Schools, Inside and Out: TV documentary
Authors: Greene Debra , Edgington Crystal
Published: October 2013

‘‘The Future of Schools, Inside and Out’’ is an information-rich and colorful 1 hour documentary designed to entertain and inform viewers about America’s schools. Areas of interest include acoustics, building safety, energy efficiency, day lighting, and more. The episode explores the connection between our nation’s school facilities and the quality of a child’s education. This program travels out in the field to school locations from rural areas to the inner city to the suburbs to help tell the story. Several top experts not only point out the problems and challenges but also offer solutions to help give the children of America every possible advantage in their learning environment.
Numerical simulation of viscous losses in resonators
Authors: Morris Philip J. , Boluriaan Said
Published: October 2013

Thermoacoustic devices consist of resonators that contain high amplitude standing or traveling waves. They depend on the interaction between the high amplitude acoustic waves with surfaces in the resonator, such as a stack, to either transport heat or extract power. However, this same interaction results in losses. These losses may be in the form of viscous dissipation or from the conversion of acoustic energy into vorticity. The latter occurs at sudden changes in the cross sectional area of the resonator where the unsteady flow produces a jet- and sinklike behavior in one period of the oscillation. Numerical simulations are performed on a parallel cluster of PC’s for the unsteady flow generated at such a sudden change of area. Results are presented for the instantaneous and averaged flow field and the thermodynamic properties. The pressure drop across the sudden change in area is calculated and the physical processes that result in this pressure difference are examined. Estimates are given of the total losses in the resonator and the relative contributions of viscous dissipation in the wall boundary layers and the conversion of acoustic energy into vorticity are given. [Research supported by ONR.]
Simulation of streaming in a tapered resonator
Authors: Tuttle Brian C. , Sparrow Victor W.
Published: October 2013

In 1997, Olson and Swift [Cryogenics 37, 769–776 (1997)] investigated acoustic streaming in conical tubes of varying taper angle of a pulse tube refrigerator to increase the efficiency. They found that an optimal taper angle existed that would minimize Rayleigh streaming in the tube. The present research is aimed at numerically simulating this taper effect on the Rayleigh streaming. The two-dimensional (2-D) nonlinear acoustic numerical approach of Sparrow and Raspet [J. Acoust. Soc. Am. 90, 2683–2691 (1991)] is modified for tapered geometries matching those of Olson and Swift. The method for grid generation and stretching will be discussed. Results of this numerical simulation will be compared to the published experimental results and will aid in a deeper understanding of acoustic streaming. [Work supported by ONR.]
Application of a stream-function numerical approach to Rayleigh streaming
Authors: Sastrapradja Debbie , Sparrow Victor W.
Published: October 2013

In 1995 Kamakura et al. [J. Acoust. Soc. Am. 97 (5, Pt. 1), 2740–2746] showed how an incompressible, viscous fluid stream-function vorticity formulation could be applied to model the time dependent build up of acoustic streaming in and around the focal area of an ultrasonic transducer in water. They found excellent qualitative agreement between their numerical results and experimental findings available in the literature. The purpose of the present research is to apply this numerical method to the Rayleigh streaming encountered in resonator tubes of thermoacoustic devices. A new code has been written from scratch and benchmarked against the published results of Kamakura et al. with excellent agreement. An overview of both the algorithm and application method to the Rayleigh streaming problem briefly will be provided. Initial results and comparisons to recent analytical solutions will be given. While not as flexible as high-resolution computational fluid dynamics calculations on large parallel computers for the study of acoustic streaming, the present formulation is much faster and can run on a desktop machine. [Work supported by ONR.]
Relative timing of oral and laryngeal motions in voiceless consonant production: A comparison of single and geminate consonants in Japanese
Authors: Fujino Akinori , Kaburagi Tokihiko , Honda Masaaki , Murano Emi Z. , Niimi Seiji
Published: October 2013

It is known that temporal coordination of oral and laryngeal articulations is important in voiceless consonant production. In this study, the relative timing of oral constriction and glottal opening is investigated for single and geminate voiceless consonants in Japanese. The motions of the jaw, lips, tongue, and larynx of three male speakers were examined using EMA (electromagnetic articulograph), PGG (photoglottograph), and EGG (electroglottograph) techniques. A set of /iie eCe desu/ and /iie eQCe desu/ sentences, containing voiceless consonants /s, t, φ, p/, was used for the test utterances. /QC/ in the sentence shows a geminate form in Japanese. The experiment data showed that the interval between the peak of glottal opening and oral release onset for geminates was longer than for singles and that consonant duration was also longer. For each form, the longer the consonant duration was, the longer the interval became. These temporal relations were found for all speakers, although the ratio of the two intervals was different for each speaker. The results suggest that, for both single and geminate consonants, articulators are controlled based on the consonant duration dependence of the oral-glottal timing. [Work supported by CREST, JST.]