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Sample records for acoustic stimulation eas

  1. The advantages of sound localization and speech perception of bilateral electric acoustic stimulation

    PubMed Central

    Moteki, Hideaki; Kitoh, Ryosuke; Tsukada, Keita; Iwasaki, Satoshi; Nishio, Shin-Ya

    2015-01-01

    Conclusion: Bilateral electric acoustic stimulation (EAS) effectively improved speech perception in noise and sound localization in patients with high-frequency hearing loss. Objective: To evaluate bilateral EAS efficacy of sound localization detection and speech perception in noise in two cases of high-frequency hearing loss. Methods: Two female patients, aged 38 and 45 years, respectively, received bilateral EAS sequentially. Pure-tone audiometry was performed preoperatively and postoperatively to evaluate the hearing preservation in the lower frequencies. Speech perception outcomes in quiet and noise and sound localization were assessed with unilateral and bilateral EAS. Results: Residual hearing in the lower frequencies was well preserved after insertion of a FLEX24 electrode (24 mm) using the round window approach. After bilateral EAS, speech perception improved in quiet and even more so in noise. In addition, the sound localization ability of both cases with bilateral EAS improved remarkably. PMID:25423260

  2. A partial hearing animal model for chronic electro-acoustic stimulation

    NASA Astrophysics Data System (ADS)

    Irving, S.; Wise, A. K.; Millard, R. E.; Shepherd, R. K.; Fallon, J. B.

    2014-08-01

    Objective. Cochlear implants (CIs) have provided some auditory function to hundreds of thousands of people around the world. Although traditionally carried out only in profoundly deaf patients, the eligibility criteria for implantation have recently been relaxed to include many partially-deaf patients with useful levels of hearing. These patients receive both electrical stimulation from their implant and acoustic stimulation via their residual hearing (electro-acoustic stimulation; EAS) and perform very well. It is unclear how EAS improves speech perception over electrical stimulation alone, and little evidence exists about the nature of the interactions between electric and acoustic stimuli. Furthermore, clinical results suggest that some patients that undergo cochlear implantation lose some, if not all, of their residual hearing, reducing the advantages of EAS over electrical stimulation alone. A reliable animal model with clinically-relevant partial deafness combined with clinical CIs is important to enable these issues to be studied. This paper outlines such a model that has been successfully used in our laboratory. Approach. This paper outlines a battery of techniques used in our laboratory to generate, validate and examine an animal model of partial deafness and chronic CI use. Main results. Ototoxic deafening produced bilaterally symmetrical hearing thresholds in neonatal and adult animals. Electrical activation of the auditory system was confirmed, and all animals were chronically stimulated via adapted clinical CIs. Acoustic compound action potentials (CAPs) were obtained from partially-hearing cochleae, using the CI amplifier. Immunohistochemical analysis allows the effects of deafness and electrical stimulation on cell survival to be studied. Significance. This animal model has applications in EAS research, including investigating the functional interactions between electric and acoustic stimulation, and the development of techniques to maintain residual

  3. Effects of contextual cues on speech recognition in simulated electric-acoustic stimulation.

    PubMed

    Kong, Ying-Yee; Donaldson, Gail; Somarowthu, Ala

    2015-05-01

    Low-frequency acoustic cues have shown to improve speech perception in cochlear-implant listeners. However, the mechanisms underlying this benefit are still not well understood. This study investigated the extent to which low-frequency cues can facilitate listeners' use of linguistic knowledge in simulated electric-acoustic stimulation (EAS). Experiment 1 examined differences in the magnitude of EAS benefit at the phoneme, word, and sentence levels. Speech materials were processed via noise-channel vocoding and lowpass (LP) filtering. The amount of spectral degradation in the vocoder speech was varied by applying different numbers of vocoder channels. Normal-hearing listeners were tested on vocoder-alone, LP-alone, and vocoder + LP conditions. Experiment 2 further examined factors that underlie the context effect on EAS benefit at the sentence level by limiting the low-frequency cues to temporal envelope and periodicity (AM + FM). Results showed that EAS benefit was greater for higher-context than for lower-context speech materials even when the LP ear received only low-frequency AM + FM cues. Possible explanations for the greater EAS benefit observed with higher-context materials may lie in the interplay between perceptual and expectation-driven processes for EAS speech recognition, and/or the band-importance functions for different types of speech materials. PMID:25994712

  4. Effects of contextual cues on speech recognition in simulated electric-acoustic stimulation

    PubMed Central

    Kong, Ying-Yee; Donaldson, Gail; Somarowthu, Ala

    2015-01-01

    Low-frequency acoustic cues have shown to improve speech perception in cochlear-implant listeners. However, the mechanisms underlying this benefit are still not well understood. This study investigated the extent to which low-frequency cues can facilitate listeners' use of linguistic knowledge in simulated electric-acoustic stimulation (EAS). Experiment 1 examined differences in the magnitude of EAS benefit at the phoneme, word, and sentence levels. Speech materials were processed via noise-channel vocoding and lowpass (LP) filtering. The amount of spectral degradation in the vocoder speech was varied by applying different numbers of vocoder channels. Normal-hearing listeners were tested on vocoder-alone, LP-alone, and vocoder + LP conditions. Experiment 2 further examined factors that underlie the context effect on EAS benefit at the sentence level by limiting the low-frequency cues to temporal envelope and periodicity (AM + FM). Results showed that EAS benefit was greater for higher-context than for lower-context speech materials even when the LP ear received only low-frequency AM + FM cues. Possible explanations for the greater EAS benefit observed with higher-context materials may lie in the interplay between perceptual and expectation-driven processes for EAS speech recognition, and/or the band-importance functions for different types of speech materials. PMID:25994712

  5. A simulation study of harmonics regeneration in noise reduction for electric and acoustic stimulation.

    PubMed

    Hu, Yi

    2010-05-01

    Recent research results show that combined electric and acoustic stimulation (EAS) significantly improves speech recognition in noise, and it is generally established that access to the improved F0 representation of target speech, along with the glimpse cues, provide the EAS benefits. Under noisy listening conditions, noise signals degrade these important cues by introducing undesired temporal-frequency components and corrupting harmonics structure. In this study, the potential of combining noise reduction and harmonics regeneration techniques was investigated to further improve speech intelligibility in noise by providing improved beneficial cues for EAS. Three hypotheses were tested: (1) noise reduction methods can improve speech intelligibility in noise for EAS; (2) harmonics regeneration after noise reduction can further improve speech intelligibility in noise for EAS; and (3) harmonics sideband constraints in frequency domain (or equivalently, amplitude modulation in temporal domain), even deterministic ones, can provide additional benefits. Test results demonstrate that combining noise reduction and harmonics regeneration can significantly improve speech recognition in noise for EAS, and it is also beneficial to preserve the harmonics sidebands under adverse listening conditions. This finding warrants further work into the development of algorithms that regenerate harmonics and the related sidebands for EAS processing under noisy conditions.

  6. Assessment of a direct acoustic cochlear stimulator.

    PubMed

    Chatzimichalis, Michail; Sim, Jae Hoon; Huber, Alexander M

    2012-01-01

    This study aimed to assess the functional results of a new, active, acoustic-mechanical hearing implant, the Direct Acoustic Cochlear Stimulation Partial Implant (DACS PI), in a preclinical study. The DACS PI is an electromagnetic device fixed to the mastoid by screws and coupled to a standard stapes prosthesis by an artificial incus (AI). The function of the DACS PI-aided reconstruction was assessed by determining: (1) the maximum equivalent sound pressure level (SPL) of the implant, which was obtained from measurements of the volume displacement at the round window in normal and implanted ears, and (2) the quality at the coupling interface between the AI of the DACS and the stapes prosthesis, which was quantified from measurements of relative motions between the AI and the prosthesis. Both measurements were performed with fresh temporal bones using a scanning laser Doppler interferometry system. The expected maximum equivalent SPL with a typical driving voltage of 0.3 V was about 115-125 dB SPL up to 1.5 kHz in reconstruction with the DACS PI, and decreased with a roll-off slope of about 65 dB/decade, reaching 90 dB SPL at 8 kHz. The large roll-off relative to a normal ear was presumed to be a relatively high inductive impedance of the coil of the DACS PI actuator at higher frequencies. Good coupling quality between the AI and the prosthesis was achieved below the resonance (∼1.5 kHz) of the DACS PI for all tested stapes prostheses. Above the resonance, the SMart Piston, which is composed of a shape-memory alloy, had the best coupling quality.

  7. Cochlear Implant Electrode Effect on Sound Energy Transfer within the Cochlea during Acoustic Stimulation

    PubMed Central

    Greene, Nathaniel T.; Mattingly, Jameson K.; Jenkins, Herman A.; Tollin, Daniel J.; Easter, James R.; Cass, Stephen P.

    2015-01-01

    Hypothesis Cochlear implants (CI) designed for hearing preservation will not alter mechanical properties of the middle and inner ear as measured by intracochlear pressure (PIC) and stapes velocity (Vstap). Background CIs designed to provide combined electrical and acoustic stimulation (EAS) are now available. To maintain functional acoustic hearing, it is important to know if a CI electrode can alter middle or inner ear mechanics, as any alteration could contribute to elevated low-frequency thresholds in EAS patients. Methods Seven human cadaveric temporal bones were prepared, and pure-tone stimuli from 120Hz–10kHz were presented at a range of intensities up to 110 dB SPL. PIC in the scala vestibuli (PSV) and tympani (PST) were measured with fiber-optic pressure sensors concurrently with VStap using laser Doppler vibrometry. Five CI electrodes from two different manufacturers, with varying dimensions were inserted via a round window approach at six different depths (16–25 mm). Results The responses of PIC and VStap to acoustic stimulation were assessed as a function of stimulus frequency, normalized to SPL in the external auditory canal (EAC), in baseline and electrode inserted conditions. Responses measured with electrodes inserted were generally within ~5 dB of baseline, indicating little effect of cochlear implant electrode insertion on PIC and VStap. Overall, mean differences across conditions were small for all responses, and no substantial differences were consistently visible across electrode types. Conclusions Results suggest that the influence of a CI electrode on middle and inner ear mechanics is minimal, despite variation in electrode lengths and configurations. PMID:26333018

  8. Acoustic Wave Stimulated Enhanced Oil Recovery

    NASA Astrophysics Data System (ADS)

    Reichmann, Sven; Giese, Rüdiger; Amro, Mohammed

    2013-04-01

    High demand and the finite oil deposits will be a problem in the future. To temper the impact of a shortage in crude oil, a lot of research in the field of enhanced oil recovery (EOR) is worldwide ongoing. Using seismic waves to stimulate recovery of oil is known as seismic-EOR. The development of a stimulation procedure using seismic sources and the evaluation of the obtained data in a real oil field is the aim of the project WAVE.O.R. The project is funded by the German scientific society for oil, gas and coal (DGMK). The Technical University of Freiberg (TUBAF) and the German Research Center for Geosciences (GFZ) in Potsdam developed a flooding cell connected with magnetostrictive actuators as sources for seismic energy. This device is eligible to survey the impact of different seismic stimulation parameter like frequency, alignment, amplitude and rock characteristics on oil recovery. The obtained laboratory data of flooding experiments using seismic waves were analyzed for key features like water breakthrough point, oil recovery and oil fraction. New approach has been developed, which consists of the connection of a principal component analysis with a clustering algorithm. This new technique allows us a better understanding and thus prediction of the recovery behavior of oil bearing sediments. The experiments show promising possibilities to enhance oil recovery with seismic stimulation. Especially the combination of different frequencies between 100 Hz and 4000 Hz had a positive impact on oil recovery. The responsible mechanisms were identified and discussed. Data obtained with the laboratory device will be applied in a field test using a borehole device developed by the GFZ in the project "Seismic Prediction While Drilling" (SPWD). For this purpose experiments are conducted to obtain the radiation pattern of the seismic sources used by the SPWD device in a borehole. In addition, the development of a control setup for the 1-D actuator array is an aim of the

  9. Direct Intracochlear Acoustic Stimulation Using a PZT Microactuator.

    PubMed

    Luo, Chuan; Omelchenko, Irina; Manson, Robert; Robbins, Carol; Oesterle, Elizabeth C; Cao, Guo Zhong; Shen, I Y; Hume, Clifford R

    2015-01-01

    Combined electric and acoustic stimulation has proven to be an effective strategy to improve hearing in some cochlear implant users. We describe an acoustic microactuator to directly deliver stimuli to the perilymph in the scala tympani. The 800 µm by 800 µm actuator has a silicon diaphragm driven by a piezoelectric thin film (e.g., lead-zirconium-titanium oxide or PZT). This device could also be used as a component of a bimodal acoustic-electric electrode array. In the current study, we established a guinea pig model to test the actuator for its ability to deliver auditory signals to the cochlea in vivo. The actuator was placed through the round window of the cochlea. Auditory brainstem response (ABR) thresholds, peak latencies, and amplitude growth were calculated for an ear canal speaker versus the intracochlear actuator for tone burst stimuli at 4, 8, 16, and 24 kHz. An ABR was obtained after removal of the probe to assess loss of hearing related to the procedure. In some animals, the temporal bone was harvested for histologic analysis of cochlear damage. We show that the device is capable of stimulating ABRs in vivo with latencies and growth functions comparable to stimulation in the ear canal. Further experiments will be necessary to evaluate the efficiency and safety of this modality in long-term auditory stimulation and its ability to be integrated with conventional cochlear implant arrays. PMID:26631107

  10. Direct Intracochlear Acoustic Stimulation Using a PZT Microactuator

    PubMed Central

    Luo, Chuan; Omelchenko, Irina; Manson, Robert; Robbins, Carol; Oesterle, Elizabeth C.; Cao, Guo Zhong; Hume, Clifford R.

    2015-01-01

    Combined electric and acoustic stimulation has proven to be an effective strategy to improve hearing in some cochlear implant users. We describe an acoustic microactuator to directly deliver stimuli to the perilymph in the scala tympani. The 800 µm by 800 µm actuator has a silicon diaphragm driven by a piezoelectric thin film (e.g., lead-zirconium-titanium oxide or PZT). This device could also be used as a component of a bimodal acoustic-electric electrode array. In the current study, we established a guinea pig model to test the actuator for its ability to deliver auditory signals to the cochlea in vivo. The actuator was placed through the round window of the cochlea. Auditory brainstem response (ABR) thresholds, peak latencies, and amplitude growth were calculated for an ear canal speaker versus the intracochlear actuator for tone burst stimuli at 4, 8, 16, and 24 kHz. An ABR was obtained after removal of the probe to assess loss of hearing related to the procedure. In some animals, the temporal bone was harvested for histologic analysis of cochlear damage. We show that the device is capable of stimulating ABRs in vivo with latencies and growth functions comparable to stimulation in the ear canal. Further experiments will be necessary to evaluate the efficiency and safety of this modality in long-term auditory stimulation and its ability to be integrated with conventional cochlear implant arrays. PMID:26631107

  11. Klamath Falls: High-Power Acoustic Well Stimulation Technology

    SciTech Connect

    Black, Brian

    2006-07-24

    Acoustic well stimulation (AWS) technology uses high-power sonic waves from specific frequency spectra in an attempt to stimulate production in a damaged or low-production wellbore. AWS technology is one of the most promising technologies in the oil and gas industry, but it has proven difficult for the industry to develop an effective downhole prototype. This collaboration between Klamath Falls Inc. and the Rocky Mountain Oilfield Testing Center (RMOTC) included a series of tests using high-power ultrasonic tools to stimulate oil and gas production. Phase I testing was designed and implemented to verify tool functionality, power requirements, and capacity of high-power AWS tools. The purpose of Phase II testing was to validate the production response of wells with marginal production rates to AWS stimulation and to capture and identify any changes in the downhole environment after tool deployment. This final report presents methodology and results.

  12. A systematic review of electric-acoustic stimulation: device fitting ranges, outcomes, and clinical fitting practices.

    PubMed

    Incerti, Paola V; Ching, Teresa Y C; Cowan, Robert

    2013-03-01

    Cochlear implant systems that combine electric and acoustic stimulation in the same ear are now commercially available and the number of patients using these devices is steadily increasing. In particular, electric-acoustic stimulation is an option for patients with severe, high frequency sensorineural hearing impairment. There have been a range of approaches to combining electric stimulation and acoustic hearing in the same ear. To develop a better understanding of fitting practices for devices that combine electric and acoustic stimulation, we conducted a systematic review addressing three clinical questions: what is the range of acoustic hearing in the implanted ear that can be effectively preserved for an electric-acoustic fitting?; what benefits are provided by combining acoustic stimulation with electric stimulation?; and what clinical fitting practices have been developed for devices that combine electric and acoustic stimulation? A search of the literature was conducted and 27 articles that met the strict evaluation criteria adopted for the review were identified for detailed analysis. The range of auditory thresholds in the implanted ear that can be successfully used for an electric-acoustic application is quite broad. The effectiveness of combined electric and acoustic stimulation as compared with electric stimulation alone was consistently demonstrated, highlighting the potential value of preservation and utilization of low frequency hearing in the implanted ear. However, clinical procedures for best fitting of electric-acoustic devices were varied. This clearly identified a need for further investigation of fitting procedures aimed at maximizing outcomes for recipients of electric-acoustic devices. PMID:23539259

  13. The facilitation of motor actions by acoustic and electric stimulation.

    PubMed

    Marinovic, Welber; Milford, Magdalene; Carroll, Timothy; Riek, Stephan

    2015-12-01

    The presentation of a loud acoustic stimulus during the preparation of motor actions can both speed movement initiation and increase response vigor. Several recent studies have explored this phenomenon as a means to investigate the mechanisms and neural correlates of movement preparation. Here, we sought to determine the generality of this effect across sensory modalities, and in particular whether unexpected somatosensory stimulation can facilitate movements in a manner similar to loud sounds. We show that electric and acoustic stimuli can be similarly effective in inducing the early release of motor actions, in both reaction time and anticipatory timing tasks. Consistent with recent response activation models of motor preparation, we also demonstrate that increasing the intensity of electric stimuli induces both progressive decreases in reaction time and increases in response vigor. Additionally, we show that the early release of motor actions can be induced by electric stimuli targeting predominantly either muscle afferents or skin afferents. Finally, we show that simultaneous acoustic and electric stimulation leads to earlier releases of anticipatory actions than either unimodal stimulus. These findings may lead to new avenues for experimental and clinical exploitation of the effects of accessory sensory information on movement preparation and initiation. PMID:26338375

  14. Investigating the interaction between acoustically stimulated microbubbles and fibrin clots

    NASA Astrophysics Data System (ADS)

    Acconcia, Christopher; Leung, Ben; Hynynen, Kullervo; Goertz, David

    2012-11-01

    While it is well established that ultrasound stimulated microbubbles can potentiate thrombolysis, the mechanisms of action are poorly understood. The objective of this work was to gain a more fundamental understanding of how acoustically stimulated microbubbles interact with and potentially degrade fibrin clots. Owing to their optical transparency, the use of fibrin clots allowed to optically observe microbubbles interacting with the clot boundary and any resultant disruption of the fluorescently tagged fibrin network. It was found that microbubbles could readily penetrate into fibrin clots with velocities up to 0.2 m/s and to depths related to the number of pulses applied. At lower pressures (0.2-0.55 MPa), microbubbles as small as 3μm were observed to penetrate, whereas higher pressures (>0.9 MPa) caused the penetration of larger microbubbles (10-30μm), formed by coalescence prior to entry. In some cases, patent 'tunnels' remained along the path taken by penetrating microbubbles. Tunnel diameters ranged between 9-35μm depending largely on pressure and pulse duration. Two-photon microscopy indicated either patent tunnels or paths of disrupted fibers consistent with collapsed tunnel. Fluid flow within the clot was observed to accompany penetrating microbubbles, which may have implications for lytic enzyme penetration.

  15. A new brain stimulation method: Noninvasive transcranial magneto-acoustical stimulation

    NASA Astrophysics Data System (ADS)

    Yuan, Yi; Chen, Yu-Dong; Li, Xiao-Li

    2016-08-01

    We investigate transcranial magneto-acoustical stimulation (TMAS) for noninvasive brain neuromodulation in vivo. TMAS as a novel technique uses an ultrasound wave to induce an electric current in the brain tissue in the static magnetic field. It has the advantage of high spatial resolution and penetration depth. The mechanism of TMAS onto a neuron is analyzed by combining the TMAS principle and Hodgkin-Huxley neuron model. The anesthetized rats are stimulated by TMAS, resulting in the local field potentials which are recorded and analyzed. The simulation results show that TMAS can induce neuronal action potential. The experimental results indicate that TMAS can not only increase the amplitude of local field potentials but also enhance the effect of focused ultrasound stimulation on the neuromodulation. In summary, TMAS can accomplish brain neuromodulation, suggesting a potentially powerful noninvasive stimulation method to interfere with brain rhythms for diagnostic and therapeutic purposes. Project supported by the National Natural Science Foundation of China (Grant Nos. 61503321 and 61273063) and the Natural Science Foundation of Hebei Province, China (Grant No. F2014203161).

  16. A new brain stimulation method: Noninvasive transcranial magneto–acoustical stimulation

    NASA Astrophysics Data System (ADS)

    Yuan, Yi; Chen, Yu-Dong; Li, Xiao-Li

    2016-08-01

    We investigate transcranial magneto–acoustical stimulation (TMAS) for noninvasive brain neuromodulation in vivo. TMAS as a novel technique uses an ultrasound wave to induce an electric current in the brain tissue in the static magnetic field. It has the advantage of high spatial resolution and penetration depth. The mechanism of TMAS onto a neuron is analyzed by combining the TMAS principle and Hodgkin–Huxley neuron model. The anesthetized rats are stimulated by TMAS, resulting in the local field potentials which are recorded and analyzed. The simulation results show that TMAS can induce neuronal action potential. The experimental results indicate that TMAS can not only increase the amplitude of local field potentials but also enhance the effect of focused ultrasound stimulation on the neuromodulation. In summary, TMAS can accomplish brain neuromodulation, suggesting a potentially powerful noninvasive stimulation method to interfere with brain rhythms for diagnostic and therapeutic purposes. Project supported by the National Natural Science Foundation of China (Grant Nos. 61503321 and 61273063) and the Natural Science Foundation of Hebei Province, China (Grant No. F2014203161).

  17. Acoustic stimulation promotes DNA fragmentation in the Guinea pig cochlea.

    PubMed

    Kamio, Tomonobu; Watanabe, Ken-Ichi; Okubo, Kimihiro

    2012-01-01

    Apoptosis can be described as programmed cell death. Apoptosis regulates cell turnover and is involved in various pathological conditions. The characteristic features of apoptosis are shrinkage of the cell body, chromatin condensation, and nucleic acid fragmentation. During apoptosis, double-stranded DNA is broken down into single-stranded DNA (ssDNA) by proteases. Acoustic trauma is commonly encountered in otorhinolaryngology clinics. Intense noise can cause inner ear damage, such as hearing disturbance, tinnitus, ear fullness, and decreased speech discrimination. In this study, we used immunohistochemical and electrophysiological methods to examine the fragmentation of DNA in the cochleas of guinea pigs that had been exposed to intense noise. Twenty-four guinea pigs weighing 250 to 350 g were used. The animals were divided into 4 groups: (I) a control group (n=6), (II) a group that was exposed to noise for 2 hours (n=6), (III) a group that was exposed to noise for 5 hours (n=6), and (IV) a group that was exposed to noise for 20 hours. The stimulus was a pure tone delivered at a frequency of 2 kHz. The sound pressure level was 120 dBSPL. No threshold shifts were apparent in group I. Group II showed a significant elevation of the hearing threshold (ANOVA, p<0.05(*)). The ABR threshold level was also significantly elevated immediately after the acoustic stimulation in groups III and IV (ANOVA, p<0.01(**)). In groups I, II, and IV, the lateral wall of the ear did not show immunoreactivity to ssDNA but did in group III. No immunoreactivity was apparent in the organ of Corti in group I or II. However, the supporting cells and outer hair cells in groups III and IV showed reactions for ssDNA. The fine structure of the organ of Corti had been destroyed in group IV. The lateral wall showed immunoreactivity for ssDNA only in group III, whereas the organ of Corti showed reactions for ssDNA in groups III and IV. Our study suggests that apoptotic changes occur in patients that

  18. Acoustic stimulation promotes DNA fragmentation in the Guinea pig cochlea.

    PubMed

    Kamio, Tomonobu; Watanabe, Ken-Ichi; Okubo, Kimihiro

    2012-01-01

    Apoptosis can be described as programmed cell death. Apoptosis regulates cell turnover and is involved in various pathological conditions. The characteristic features of apoptosis are shrinkage of the cell body, chromatin condensation, and nucleic acid fragmentation. During apoptosis, double-stranded DNA is broken down into single-stranded DNA (ssDNA) by proteases. Acoustic trauma is commonly encountered in otorhinolaryngology clinics. Intense noise can cause inner ear damage, such as hearing disturbance, tinnitus, ear fullness, and decreased speech discrimination. In this study, we used immunohistochemical and electrophysiological methods to examine the fragmentation of DNA in the cochleas of guinea pigs that had been exposed to intense noise. Twenty-four guinea pigs weighing 250 to 350 g were used. The animals were divided into 4 groups: (I) a control group (n=6), (II) a group that was exposed to noise for 2 hours (n=6), (III) a group that was exposed to noise for 5 hours (n=6), and (IV) a group that was exposed to noise for 20 hours. The stimulus was a pure tone delivered at a frequency of 2 kHz. The sound pressure level was 120 dBSPL. No threshold shifts were apparent in group I. Group II showed a significant elevation of the hearing threshold (ANOVA, p<0.05(*)). The ABR threshold level was also significantly elevated immediately after the acoustic stimulation in groups III and IV (ANOVA, p<0.01(**)). In groups I, II, and IV, the lateral wall of the ear did not show immunoreactivity to ssDNA but did in group III. No immunoreactivity was apparent in the organ of Corti in group I or II. However, the supporting cells and outer hair cells in groups III and IV showed reactions for ssDNA. The fine structure of the organ of Corti had been destroyed in group IV. The lateral wall showed immunoreactivity for ssDNA only in group III, whereas the organ of Corti showed reactions for ssDNA in groups III and IV. Our study suggests that apoptotic changes occur in patients that

  19. Using acoustics to study and stimulate the coalescence of oil drops surrounded by water

    SciTech Connect

    Gardner, E.A.; Apfel, R.E. . Dept. of Mechanical Engineering)

    1993-08-01

    The coalescence of oil drops in water is studied using acoustic levitation and stimulated with acoustic cavitation. Unlike most earlier studies, which investigate the coalescence of a single drop with an initially planar interface, the use of acoustic radiation forces allows two drops to be brought into contact and allowed to coalesce. The acoustic technique has the advantage over other drop-drop coalescence systems in that the drops remain in contact until they coalesce without the use of solid supports to control them. Additionally, acoustic cavitation is observed to deposit sufficient energy in the oil-water interface to trigger the coalescence of a pair of 2-mm-diameter drops. This stimulation mechanism could have application to emulsion breaking. Some of the factors that affect spontaneous and stimulated coalescence are investigated.

  20. The effect of static force on round window stimulation with the direct acoustic cochlea stimulator.

    PubMed

    Maier, Hannes; Salcher, Rolf; Schwab, Burkard; Lenarz, Thomas

    2013-07-01

    The Direct Acoustic Cochlea Stimulator Partial Implant (DACS PI, Phonak Acoustic Implants SA, Switzerland) is intended to stimulate the cochlea by a conventional stapedotomy piston that is crimped onto the DACS PI artificial incus. An alternative approach to the round window (RW) is successfully done with other devices, having the advantage of being also independent of the existence of middle ear structure (e.g. ossicles). Here the possibility of stimulating the RW with the DACS actuator is investigated including the impact of static force on sound transmission to the cochlea. The maximum equivalent sound pressure output with RW stimulation was determined experimentally in fresh human temporal bones. Experiments were performed in analogy to the ASTM standard (F2504.24930-1) method for the output determination of implantable middle ear hearing devices (IMEHDs) in human cadaveric temporal bones (TBs). ASTM compliant temporal bones were stimulated with a prosthesis having a spherical tip (∅0.5 mm) attached to the actuator. The stimulation was performed perpendicular to the round window membrane (RWM) at varying position relative to the RW and the resulting static force on the RW membrane was determined. At each position the displacement output of the DACS PI actuator and the stapes footplate (SFP) vibration in response to actuator stimulation was measured with a Laser Doppler Velocimeter (LDV). By comparison of the achieved output at the stapes footplate in response to sound and transducer stimulation the equivalent sound pressure level at the tympanic membrane at 1Vrms input voltage was calculated assuming that the SFP displacement in both conditions is a measure of perceived loudness, as it is done in the ASTM standard. Ten TB preparations within the acceptance range of the ASTM standard were used for analysis. The actuator driven stapes footplate displacement amplitude as well as the resulting equivalent sound pressure level was highly dependent on the static

  1. Plasticity in Human Pitch Perception Induced by Tonotopically Mismatched Electro-Acoustic Stimulation

    PubMed Central

    Reiss, Lina A.J.; Turner, Christopher W.; Karsten, Sue A.; Gantz, Bruce J.

    2013-01-01

    Under normal conditions, the acoustic pitch percept of a pure tone is determined mainly by the tonotopic place of the stimulation along the cochlea. Unlike acoustic stimulation, electric stimulation of a cochlear implant (CI) allows for the direct manipulation of the place of stimulation in human subjects. CI sound processors analyze the range of frequencies needed for speech perception and allocate portions of this range to the small number of electrodes distributed in the cochlea. Because the allocation is assigned independently of the original resonant frequency of the basilar membrane associated with the location of each electrode, CI users who have access to residual hearing in either or both ears often have tonotopic mismatches between the acoustic and electric stimulation. Here we demonstrate plasticity of place pitch representations of up to 3 octaves in Hybrid CI users after experience with combined electro-acoustic stimulation. The pitch percept evoked by single CI electrodes, measured relative to acoustic tones presented to the non-implanted ear, changed over time in directions that reduced the electro-acoustic pitch mismatch introduced by the CI programming. This trend was particularly apparent when the allocations of stimulus frequencies to electrodes were changed over time, with pitch changes even reversing direction in some subjects. These findings show that pitch plasticity can occur more rapidly and on a greater scale in the mature auditory system than previously thought possible. Overall, the results suggest that the adult auditory system can impose perceptual order on disordered arrays of inputs. PMID:24157931

  2. Acoustic build-up in on-chip stimulated Brillouin scattering

    PubMed Central

    Wolff, C.; Steel, M. J.; Eggleton, B. J.; Poulton, C. G.

    2015-01-01

    We investigate the role of the spatial evolution of the acoustic field in stimulated Brillouin scattering processes in short high-gain structures. When the gain is strong enough that the gain length becomes comparable to the acoustic wave decay length of order 100 microns, standard approximations treating the acoustic field as a local response no longer apply. Treating the acoustic evolution more accurately, we find that the backward SBS gain of sub-millimetre long waveguides is significantly reduced from the value obtained by the conventional treatment because the acoustic mode requires several decay lengths to build up to its nominal value. In addition, the corresponding resonance line is broadened with the development of side bands. In contrast, we argue that intra-mode forward SBS is not expected to show these effects. Our results have implications for several recent proposals and experiments on high-gain stimulated Brillouin scattering in short semiconductor waveguides. PMID:26338720

  3. Suppression and facilitation of auditory neurons through coordinated acoustic and midbrain stimulation: investigating a deep brain stimulator for tinnitus

    NASA Astrophysics Data System (ADS)

    Offutt, Sarah J.; Ryan, Kellie J.; Konop, Alexander E.; Lim, Hubert H.

    2014-12-01

    Objective. The inferior colliculus (IC) is the primary processing center of auditory information in the midbrain and is one site of tinnitus-related activity. One potential option for suppressing the tinnitus percept is through deep brain stimulation via the auditory midbrain implant (AMI), which is designed for hearing restoration and is already being implanted in deaf patients who also have tinnitus. However, to assess the feasibility of AMI stimulation for tinnitus treatment we first need to characterize the functional connectivity within the IC. Previous studies have suggested modulatory projections from the dorsal cortex of the IC (ICD) to the central nucleus of the IC (ICC), though the functional properties of these projections need to be determined. Approach. In this study, we investigated the effects of electrical stimulation of the ICD on acoustic-driven activity within the ICC in ketamine-anesthetized guinea pigs. Main Results. We observed ICD stimulation induces both suppressive and facilitatory changes across ICC that can occur immediately during stimulation and remain after stimulation. Additionally, ICD stimulation paired with broadband noise stimulation at a specific delay can induce greater suppressive than facilitatory effects, especially when stimulating in more rostral and medial ICD locations. Significance. These findings demonstrate that ICD stimulation can induce specific types of plastic changes in ICC activity, which may be relevant for treating tinnitus. By using the AMI with electrode sites positioned with the ICD and the ICC, the modulatory effects of ICD stimulation can be tested directly in tinnitus patients.

  4. Mandarin Speech Perception in Combined Electric and Acoustic Stimulation

    PubMed Central

    Li, Yongxin; Zhang, Guoping; Galvin, John J.; Fu, Qian-Jie

    2014-01-01

    For deaf individuals with residual low-frequency acoustic hearing, combined use of a cochlear implant (CI) and hearing aid (HA) typically provides better speech understanding than with either device alone. Because of coarse spectral resolution, CIs do not provide fundamental frequency (F0) information that contributes to understanding of tonal languages such as Mandarin Chinese. The HA can provide good representation of F0 and, depending on the range of aided acoustic hearing, first and second formant (F1 and F2) information. In this study, Mandarin tone, vowel, and consonant recognition in quiet and noise was measured in 12 adult Mandarin-speaking bimodal listeners with the CI-only and with the CI+HA. Tone recognition was significantly better with the CI+HA in noise, but not in quiet. Vowel recognition was significantly better with the CI+HA in quiet, but not in noise. There was no significant difference in consonant recognition between the CI-only and the CI+HA in quiet or in noise. There was a wide range in bimodal benefit, with improvements often greater than 20 percentage points in some tests and conditions. The bimodal benefit was compared to CI subjects’ HA-aided pure-tone average (PTA) thresholds between 250 and 2000 Hz; subjects were divided into two groups: “better” PTA (<50 dB HL) or “poorer” PTA (>50 dB HL). The bimodal benefit differed significantly between groups only for consonant recognition. The bimodal benefit for tone recognition in quiet was significantly correlated with CI experience, suggesting that bimodal CI users learn to better combine low-frequency spectro-temporal information from acoustic hearing with temporal envelope information from electric hearing. Given the small number of subjects in this study (n = 12), further research with Chinese bimodal listeners may provide more information regarding the contribution of acoustic and electric hearing to tonal language perception. PMID:25386962

  5. Perturbation and Nonlinear Dynamic Analysis of Acoustic Phonatory Signal in Parkinsonian Patients Receiving Deep Brain Stimulation

    ERIC Educational Resources Information Center

    Lee, Victoria S.; Zhou, Xiao Ping; Rahn, Douglas A., III; Wang, Emily Q.; Jiang, Jack J.

    2008-01-01

    Nineteen PD patients who received deep brain stimulation (DBS), 10 non-surgical (control) PD patients, and 11 non-pathologic age- and gender-matched subjects performed sustained vowel phonations. The following acoustic measures were obtained on the sustained vowel phonations: correlation dimension (D[subscript 2]), percent jitter, percent shimmer,…

  6. Morphological Correlates of Hearing Loss after Cochlear Implantation and Electro-Acoustic Stimulation in a Hearing-Impaired Guinea Pig Model

    PubMed Central

    Reiss, Lina A.J.; Stark, Gemaine; Nguyen-Huynh, Anh T.; Spear, Kayce A.; Zhang, Hongzheng; Tanaka, Chiemi; Li, Hongzhe

    2016-01-01

    Hybrid or electro-acoustic stimulation (EAS) cochlear implants (CIs) are designed to provide high-frequency electric hearing together with residual low-frequency acoustic hearing. However, 30-50% of EAS CI recipients lose residual hearing after implantation. The objective of this study was to determine the mechanisms of EAS-induced hearing loss in an animal model with high-frequency hearing loss. Guinea pigs were exposed to 24 hours of noise (12-24 kHz at 116 dB) to induce a high-frequency hearing loss. After recovery, two groups of animals were implanted (n=6 per group), with one group receiving chronic acoustic and electric stimulation for 10 weeks, and the other group receiving no stimulation during this time frame. A third group (n=6) was not implanted, but received chronic acoustic stimulation. Auditory brainstem responses were recorded biweekly to monitor changes in hearing. The organ of Corti was immunolabeled with phalloidin, anti-CtBP2, and anti-GluR2 to quantify hair cells, ribbons and post-synaptic receptors. The lateral wall was immunolabeled with phalloidin and lectin to quantify stria vascularis capillary diameters. Bimodal or trimodal diameter distributions were observed; the number and location of peaks were objectively determined using the Aikake Information Criterion and Expectation Maximization algorithm. Noise exposure led to immediate hearing loss at 16-32 kHz for all groups. Cochlear implantation led to additional hearing loss at 4-8 kHz; this hearing loss was negatively and positively correlated with minimum and maximum peaks of the bimodal or trimodal distributions of stria vascularis capillary diameters, respectively. After chronic stimulation, no significant group changes in thresholds were seen; however, elevated thresholds at 1 kHz in implanted, stimulated animals were significantly correlated with decreased presynaptic ribbon and postsynaptic receptor counts. Inner and outer hair cell counts did not differ between groups and were not

  7. Morphological correlates of hearing loss after cochlear implantation and electro-acoustic stimulation in a hearing-impaired Guinea pig model.

    PubMed

    Reiss, Lina A J; Stark, Gemaine; Nguyen-Huynh, Anh T; Spear, Kayce A; Zhang, Hongzheng; Tanaka, Chiemi; Li, Hongzhe

    2015-09-01

    Hybrid or electro-acoustic stimulation (EAS) cochlear implants (CIs) are designed to provide high-frequency electric hearing together with residual low-frequency acoustic hearing. However, 30-50% of EAS CI recipients lose residual hearing after implantation. The objective of this study was to determine the mechanisms of EAS-induced hearing loss in an animal model with high-frequency hearing loss. Guinea pigs were exposed to 24 h of noise (12-24 kHz at 116 dB) to induce a high-frequency hearing loss. After recovery, two groups of animals were implanted (n = 6 per group), with one group receiving chronic acoustic and electric stimulation for 10 weeks, and the other group receiving no stimulation during this time frame. A third group (n = 6) was not implanted, but received chronic acoustic stimulation. Auditory brainstem responses were recorded biweekly to monitor changes in hearing. The organ of Corti was immunolabeled with phalloidin, anti-CtBP2, and anti-GluR2 to quantify hair cells, ribbons and post-synaptic receptors. The lateral wall was immunolabeled with phalloidin and lectin to quantify stria vascularis capillary diameters. Bimodal or trimodal diameter distributions were observed; the number and location of peaks were objectively determined using the Aikake Information Criterion and Expectation Maximization algorithm. Noise exposure led to immediate hearing loss at 16-32 kHz for all groups. Cochlear implantation led to additional hearing loss at 4-8 kHz; this hearing loss was negatively and positively correlated with minimum and maximum peaks of the bimodal or trimodal distributions of stria vascularis capillary diameters, respectively. After chronic stimulation, no significant group changes in thresholds were seen; however, elevated thresholds at 1 kHz in implanted, stimulated animals were significantly correlated with decreased presynaptic ribbon and postsynaptic receptor counts. Inner and outer hair cell counts did not differ between groups and

  8. The influence of acoustic and tactile stimulation on vegetative parameters and EEG in persistent vegetative state.

    PubMed

    Keller, Ingo; Hülsdunk, Angelika; Müller, Friedemann

    2007-01-01

    In the present study, we investigated whether different kinds of stimulation in the persistent vegetative state (PVS) lead to specific patterns of physiological reactions. In addition, a possible effect of stimulating drugs was explored by comparing recordings with and without pharmacological stimulation. Eighteen patients in the PVS were submitted to tactile or acoustic stimulation. The latter consisted of white noise and of the voices of close relatives delivered via a digital voice recorder. Additionally, half of the patients were pharmacologically stimulated with amantadine, L-dopa or amphetamine. The effect of stimulation was assessed by recording the electroencephalogram (EEG), electromyogram (EMG), skin conductance response (SCR) and heart rate (HR). Tactile stimulation was associated with statistically significant increases in EEG and EMG parameters, SCR and HR. White noise stimulation led to significant increases in SCR and EMG parameters. The physiological responses to relatives? voices did not differ from baseline activity. Pharmacological stimulation increased the baseline level of activation, but showed no interaction with sensory stimulation. The data presented indicate that the level of arousal in patients in the PVS can be adequately monitored by measuring SCR, HR and EMG parameters.

  9. Acoustic Energy: An Innovative Technology for Stimulating Oil Wells

    SciTech Connect

    Edgar, Dorland E.; Peters, Robert W.; Johnson, Donald O.; Paulsen, P. David; Roberts, Wayne

    2006-04-30

    The objective of this investigation was to demonstrate the effectiveness of sonication in reducing the viscosity of heavy crude oils. Sonication is the use of acoustic or sound energy to produce physical and/or chemical changes in materials, usually fluids. The goal of the first project phase was to demonstrate a proof of concept for the project objective. Batch tests of three commercially available, single-weight oils (30-, 90-, and 120-wt) were performed in the laboratory. Several observations and conclusions were made from this series of experiments. These include the following: (1) In general, the lower the acoustic frequency, the greater the efficiency in reducing the viscosity of the oils; (2) Sonication treatment of the three oils resulted in reductions in viscosity that ranged from a low of 31% to a high of 75%; and (3) The results of the first phase of the project successfully demonstrated that sonication could reduce the viscosity of oils of differing viscosity. The goal of the second project phase was to demonstrate the ability of sonication to reduce the viscosity of three crude oils ranging from a light crude to a heavy crude. The experiments also were designed to examine the benefits of two proprietary chemical additives used in conjunction with sonication. Acoustic frequencies ranging from 800 Hz to 1.6 kHz were used in these tests, and a reactor chamber was designed for flow-through operation with a capacity of one gallon (3.8 liters). The three crude oils selected for use in the testing program were: (1) a heavy crude from California with a viscosity of approximately 65,000 cP (API gravity about 12{sup o}), (2) a crude from Alabama with a significant water content and a viscosity of approximately 6,000 cP (API gravity about 22 {sup o}), and (3) a light crude from the Middle East with a viscosity of approximately 700 cP (API gravity about 32{sup o}). The principal conclusions derived from the second project phase include the following: (1) The

  10. Prenatal features of Pena-Shokeir sequence with atypical response to acoustic stimulation.

    PubMed

    Pittyanont, Sirida; Jatavan, Phudit; Suwansirikul, Songkiat; Tongsong, Theera

    2016-09-01

    A fetal sonographic screening examination performed at 23 weeks showed polyhydramnios, micrognathia, fixed postures of all long bones, but no movement and no breathing. The fetus showed fetal heart rate acceleration but no movement when acoustic stimulation was applied with artificial larynx. All these findings persisted on serial examinations. The neonate was stillborn at 37 weeks and a final diagnosis of Pena-Shokeir sequence was made. In addition to typical sonographic features of Pena-Shokeir sequence, fetal heart rate accelerations with no movement in response to acoustic stimulation suggests that peripheral myopathy may possibly play an important role in the pathogenesis of the disease. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 44:459-462, 2016. PMID:27312123

  11. Improving survival of disassociated human embryonic stem cells by mechanical stimulation using acoustic tweezing cytometry.

    PubMed

    Chen, Di; Sun, Yubing; Deng, Cheri X; Fu, Jianping

    2015-03-24

    Dissociation-induced apoptosis of human embryonic stem cells (hESCs) hampers their large-scale culture. Herein we leveraged the mechanosensitivity of hESCs and employed, to our knowledge, a novel technique, acoustic tweezing cytometry (ATC), for subcellular mechanical stimulation of disassociated single hESCs to improve their survival. By acoustically actuating integrin-bound microbubbles (MBs) to live cells, ATC increased the survival rate and cloning efficiency of hESCs by threefold. A positive correlation was observed between the increased hESC survival rate and total accumulative displacement of integrin-anchored MBs during ATC stimulation. ATC may serve as a promising biocompatible tool to improve hESC culture.

  12. Effect of repetitive transcranial magnetic stimulation on auditory function following acoustic trauma.

    PubMed

    Yang, Haidi; Xiong, Hao; Ou, Yongkang; Xu, Yaodong; Pang, Jiaqi; Lai, Lan; Zheng, Yiqing

    2016-09-01

    Repetitive transcranial magnetic stimulation (rTMS) is one form of non-invasive brain stimulation and increasingly shows neuroprotection in multiple neurological disorders. However, the potential of rTMS for protective action on auditory function following acoustic trauma has not been investigated. Here, we examined effect of TMS on hearing conservation, neurons survival and brain-derived neurotrophin factor (BDNF) expression in the cochlea and auditory cortex following acoustic trauma in rats. Wistar rats were exposed to intense pure tone noise (10 kHz, 120 dB SPL for 2 h) followed by rTMS treatment or sham treatment (handling control) daily for 14 days. Auditory brainstem response revealed there was no significant difference in hearing threshold shifts between rTMS- and sham-treated rats, although rTMS-treated rats showed less neuron loss in the auditory cortex in comparison with sham rats. Additionally, acoustic trauma increased BDNF expression in the cochlea and auditory cortex, and this elevation could be attenuated by rTMS treatment. Our results suggest present regiment of rTMS does not protect hearing against acoustic trauma, but maybe have implications for tinnitus treatment. PMID:27230393

  13. Chronic detachable headphones for acoustic stimulation in freely moving animals.

    PubMed

    Nodal, Fernando R; Keating, Peter; King, Andrew J

    2010-05-30

    A growing number of studies of auditory processing are being carried out in awake, behaving animals, creating a need for precisely controlled sound delivery without restricting head movements. We have designed a system for closed-field stimulus presentation in freely moving ferrets, which comprises lightweight, adjustable headphones that can be consistently positioned over the ears via a small, skull-mounted implant. The invasiveness of the implant was minimized by simplifying its construction and using dental adhesive only for attaching it to the skull, thereby reducing the surgery required and avoiding the use of screws or other anchoring devices. Attaching the headphones to a chronic implant also reduced the amount of contact they had with the head and ears, increasing the willingness of the animals to wear them. We validated sound stimulation via the headphones in ferrets trained previously in a free-field task to localize stimuli presented from one of two loudspeakers. Noise bursts were delivered binaurally over the headphones and interaural level differences (ILDs) were introduced to allow the sound to be lateralized. Animals rapidly transferred from the free-field task to indicate the perceived location of the stimulus presented over headphones. They showed near perfect lateralization with a 5 dB ILD, matching the scores achieved in the free-field task. As expected, the ferrets' performance declined when the ILD was reduced in value. This closed-field system can easily be adapted for use in other species, and provides a reliable means of presenting closed-field stimuli whilst monitoring behavioral responses in freely moving animals.

  14. Chronic detachable headphones for acoustic stimulation in freely moving animals

    PubMed Central

    Nodal, Fernando R.; Keating, Peter; King, Andrew J.

    2010-01-01

    A growing number of studies of auditory processing are being carried out in awake, behaving animals, creating a need for precisely controlled sound delivery without restricting head movements. We have designed a system for closed-field stimulus presentation in freely moving ferrets, which comprises lightweight, adjustable headphones that can be consistently positioned over the ears via a small, skull-mounted implant. The invasiveness of the implant was minimized by simplifying its construction and using dental adhesive only for attaching it to the skull, thereby reducing the surgery required and avoiding the use of screws or other anchoring devices. Attaching the headphones to a chronic implant also reduced the amount of contact they had with the head and ears, increasing the willingness of the animals to wear them. We validated sound stimulation via the headphones in ferrets trained previously in a free-field task to localize stimuli presented from one of two loudspeakers. Noise bursts were delivered binaurally over the headphones and interaural level differences (ILDs) were introduced to allow the sound to be lateralized. Animals rapidly transferred from the free-field task to indicate the perceived location of the stimulus presented over headphones. They showed near perfect lateralization with a 5 dB ILD, matching the scores achieved in the free-field task. As expected, the ferrets’ performance declined when the ILD was reduced in value. This closed-field system can easily be adapted for use in other species, and provides a reliable means of presenting closed-field stimuli whilst monitoring behavioral responses in freely moving animals. PMID:20346981

  15. Direct Acoustic Stimulation at the Lateral Canal: An Alternative Route to the Inner Ear?

    PubMed Central

    Walraevens, Joris; Desloovere, Christian; Wouters, Jan; Gérard, Jean-Marc

    2016-01-01

    Severe to profound mixed hearing loss is associated with hearing rehabilitation difficulties. Recently, promising results for speech understanding were obtained with a direct acoustic cochlear implant (DACI). The surgical implantation of a DACI with standard coupling through a stapedotomy can however be regarded as challenging. Therefore, in this experimental study, the feasibility of direct acoustic stimulation was investigated at an anatomically and surgically more accessible inner ear site. DACI stimulation of the intact, blue-lined and opened lateral semicircular canal (LC) was investigated and compared with standard oval window (OW) coupling. Additionally, stapes footplate fixation was induced. Round window (RW) velocity, as a measure of the performance of the device and its coupling efficiency, was determined in fresh-frozen human cadaver heads. Using single point laser Doppler vibrometry, RW velocity could reliably be measured in low and middle frequency range, and equivalent sound pressure level (LE) output was calculated. Results for the different conditions obtained in five heads were analyzed in subsequent frequency ranges. Comparing the difference in RW membrane velocity showed higher LE in the LC opened condition [mean: 103 equivalent dB SPL], than in LC intact or blue-lined conditions [63 and 74 equivalent dB SPL, respectively]. No difference was observed between the LC opened and the standard OW condition. Inducing stapes fixation, however, led to a difference in the low frequency range of LE compared to LC opened. In conclusion, this feasibility study showed promising results for direct acoustic stimulation at this specific anatomically and surgically more accessible inner ear site. Future studies are needed to address the impact of LC stimulation on cochlear micromechanics and on the vestibular system like dizziness and risks of hearing loss. PMID:27500399

  16. Two-bubble acoustic tweezing cytometry for biomechanical probing and stimulation of cells.

    PubMed

    Chen, Di; Sun, Yubing; Gudur, Madhu S R; Hsiao, Yi-Sing; Wu, Ziqi; Fu, Jianping; Deng, Cheri X

    2015-01-01

    The study of mechanotransduction relies on tools that are capable of applying mechanical forces to elicit and assess cellular responses. Here we report a new (to our knowledge) technique, called two-bubble acoustic tweezing cytometry (TB-ATC), for generating spatiotemporally controlled subcellular mechanical forces on live cells by acoustic actuation of paired microbubbles targeted to the cell adhesion receptor integrin. By measuring the ultrasound-induced activities of cell-bound microbubbles and the actin cytoskeleton contractile force responses, we determine that TB-ATC elicits mechanoresponsive cellular changes via cyclic, paired displacements of integrin-bound microbubbles driven by the attractive secondary acoustic radiation force (sARF) between the bubbles in an ultrasound field. We demonstrate the feasibility of dual-mode TB-ATC for both subcellular probing and mechanical stimulation. By exploiting the robust and unique interaction of ultrasound with microbubbles, TB-ATC provides distinct advantages for experimentation and quantification of applied forces and cellular responses for biomechanical probing and stimulation of cells.

  17. Two-Bubble Acoustic Tweezing Cytometry for Biomechanical Probing and Stimulation of Cells

    PubMed Central

    Chen, Di; Sun, Yubing; Gudur, Madhu S.R.; Hsiao, Yi-Sing; Wu, Ziqi; Fu, Jianping; Deng, Cheri X.

    2015-01-01

    The study of mechanotransduction relies on tools that are capable of applying mechanical forces to elicit and assess cellular responses. Here we report a new (to our knowledge) technique, called two-bubble acoustic tweezing cytometry (TB-ATC), for generating spatiotemporally controlled subcellular mechanical forces on live cells by acoustic actuation of paired microbubbles targeted to the cell adhesion receptor integrin. By measuring the ultrasound-induced activities of cell-bound microbubbles and the actin cytoskeleton contractile force responses, we determine that TB-ATC elicits mechanoresponsive cellular changes via cyclic, paired displacements of integrin-bound microbubbles driven by the attractive secondary acoustic radiation force (sARF) between the bubbles in an ultrasound field. We demonstrate the feasibility of dual-mode TB-ATC for both subcellular probing and mechanical stimulation. By exploiting the robust and unique interaction of ultrasound with microbubbles, TB-ATC provides distinct advantages for experimentation and quantification of applied forces and cellular responses for biomechanical probing and stimulation of cells. PMID:25564850

  18. A measure of acoustic noise generated from transcranial magnetic stimulation coils.

    PubMed

    Dhamne, Sameer C; Kothare, Raveena S; Yu, Camilla; Hsieh, Tsung-Hsun; Anastasio, Elana M; Oberman, Lindsay; Pascual-Leone, Alvaro; Rotenberg, Alexander

    2014-01-01

    The intensity of sound emanating from the discharge of magnetic coils used in repetitive transcranial magnetic stimulation (rTMS) can potentially cause acoustic trauma. Per Occupational Safety and Health Administration (OSHA) standards for safety of noise exposure, hearing protection is recommended beyond restricted levels of noise and time limits. We measured the sound pressure levels (SPLs) from four rTMS coils with the goal of assessing if the acoustic artifact levels are of sufficient amplitude to warrant protection from acoustic trauma per OSHA standards. We studied the SPLs at two frequencies (5 and 10 Hz), three machine outputs (MO) (60, 80 and 100%), and two distances from the coil (5 and 10 cm). We found that the SPLs were louder at closer proximity from the coil and directly dependent on the MO. We also found that in all studied conditions, SPLs were lower than the OSHA permissible thresholds for short (<15 min) acoustic exposure, but at extremes of use, may generate sufficient noise to warrant ear protection with prolonged (>8 h) exposure.

  19. Spatio-temporal source modeling of evoked potentials to acoustic and cochlear implant stimulation.

    PubMed

    Ponton, C W; Don, M; Waring, M D; Eggermont, J J; Masuda, A

    1993-01-01

    Spatio-temporal source modeling (STSM) of event-related potentials was used to estimate the loci and characteristics of cortical activity evoked by acoustic stimulation in normal hearing subjects and by electrical stimulation in cochlear implant (CI) subjects. In both groups of subjects, source solutions obtained for the N1/P2 complex were located in the superior half of the temporal lobe in the head model. Results indicate that it may be possible to determine whether stimulation of different implant channels activates different regions of cochleotopically organized auditory cortex. Auditory system activation can be assessed further by examining the characteristics of the source wave forms. For example, subjects whose cochlear implants provided auditory sensations and normal hearing subjects had similar source activity. In contrast, a subject in whom implant activation evoked eyelid movements exhibited different source wave forms. STSM analysis may provide an electrophysiological technique for guiding rehabilitation programs based on the capabilities of the individual implant user and for disentangling the complex response patterns to electrical stimulation of the brain.

  20. Investigation of Balance Function Using Dynamic Posturography under Electrical-Acoustic Stimulation in Cochlear Implant Recipients.

    PubMed

    Schwab, B; Durisin, M; Kontorinis, G

    2010-01-01

    Introduction. The purpose of the present study is to investigate the effect of electrical-acoustic stimulation on vestibular function in CI patients by using the EquiTest and to help answer the question of whether electrically stimulating the inner ear using a cochlear implant influences the balance system in any way. Material and Methods. A test population (n = 50) was selected at random from among the cochlear implant recipients. Dynamic posturography (using the EquiTest) was performed with the device switched off an switched on. Results. In summary, it can be said that an activated cochlear implant affects the function of the vestibular system and may, to an extent, even lead to a stabilization of balance function under the static conditions of dynamic posturography, but nevertheless also to a significant destabilization. Significant improvements in vestibular function were seen mainly in equilibrium scores under conditions 4 and 5, the composite equilibrium score, and the vestibular components as revealed by sensory analysis. Conclusions. Only under the static conditions are significantly poorer scores achieved when stimulation is applied. It may be that the explanation for any symptoms of dizziness lies precisely in the fact that they occur in supposedly noncritical situations, since, when the cochlear implant makes increased demands on the balance system, induced disturbances can be centrally suppressed. PMID:20671908

  1. Investigation of Balance Function Using Dynamic Posturography under Electrical-Acoustic Stimulation in Cochlear Implant Recipients

    PubMed Central

    Schwab, B.; Durisin, M.; Kontorinis, G.

    2010-01-01

    Introduction. The purpose of the present study is to investigate the effect of electrical-acoustic stimulation on vestibular function in CI patients by using the EquiTest and to help answer the question of whether electrically stimulating the inner ear using a cochlear implant influences the balance system in any way. Material and Methods. A test population (n = 50) was selected at random from among the cochlear implant recipients. Dynamic posturography (using the EquiTest) was performed with the device switched off an switched on. Results. In summary, it can be said that an activated cochlear implant affects the function of the vestibular system and may, to an extent, even lead to a stabilization of balance function under the static conditions of dynamic posturography, but nevertheless also to a significant destabilization. Significant improvements in vestibular function were seen mainly in equilibrium scores under conditions 4 and 5, the composite equilibrium score, and the vestibular components as revealed by sensory analysis. Conclusions. Only under the static conditions are significantly poorer scores achieved when stimulation is applied. It may be that the explanation for any symptoms of dizziness lies precisely in the fact that they occur in supposedly noncritical situations, since, when the cochlear implant makes increased demands on the balance system, induced disturbances can be centrally suppressed. PMID:20671908

  2. Ultrasound-Stimulated Acoustic Emission in Thermal Image-Guided HIFU Therapy: A Phantom Study

    SciTech Connect

    Jiang, C. P.; Lin, W. T.; Chen, W. S.

    2006-05-08

    Magnetic resonance image (MRI) is a promising monitoring tool for non-invasive real-time thermal guidance in high intensity focused ultrasound (HIFU) during thermal ablation surgery. However, this approach has two main drawbacks: 1) majority of components need to be redesigned to be MR compatible in order to avoid effecting MR images, and 2) the cost of operating MRI facilities is high. Alternately, ultrasound-stimulated acoustic emission (USAE) method has been applied for detecting thermal variations in tissues. An optical transparent phantom, made from polyacrylamide, containing thermal sensitive indicator protein (Bovine Serum Albumin), was prepared for observing the HIFU-induced denaturalization. A thermal-couple was set up for validation of temperature distribution. Experimental results show that thermal image can be captured clearly under stationary conditions.

  3. [Quantification and improvement of speech transmission performance using headphones in acoustic stimulated functional magnetic resonance imaging].

    PubMed

    Yamamura, Ken ichiro; Takatsu, Yasuo; Miyati, Tosiaki; Kimura, Tetsuya

    2014-10-01

    Functional magnetic resonance imaging (fMRI) has made a major contribution to the understanding of higher brain function, but fMRI with auditory stimulation, used in the planning of brain tumor surgery, is often inaccurate because there is a risk that the sounds used in the trial may not be correctly transmitted to the subjects due to acoustic noise. This prompted us to devise a method of digitizing sound transmission ability from the accuracy rate of 67 syllables, classified into three types. We evaluated this with and without acoustic noise during imaging. We also improved the structure of the headphones and compared their sound transmission ability with that of conventional headphones attached to an MRI device (a GE Signa HDxt 3.0 T). We calculated and compared the sound transmission ability of the conventional headphones with that of the improved model. The 95 percent upper confidence limit (UCL) was used as the threshold for accuracy rate of hearing for both headphone models. There was a statistically significant difference between the conventional model and the improved model during imaging (p < 0.01). The rate of accuracy of the improved model was 16 percent higher. 29 and 22 syllables were accurate at a 95% UCL in the improved model and the conventional model, respectively. This study revealed the evaluation system used in this study to be useful for correctly identifying syllables during fMRI.

  4. Development of a loudness normalisation strategy for combined cochlear implant and acoustic stimulation.

    PubMed

    Francart, Tom; McDermott, Hugh J

    2012-12-01

    Users of a cochlear implant together with a hearing aid in the non-implanted ear currently use devices that were developed separately and are often fitted separately. This results in very different growth of loudness with level in the two ears, potentially leading to decreased wearing comfort and suboptimal perception of interaural level differences. A loudness equalisation strategy, named 'SCORE bimodal', is proposed. It equalises loudness growth for the two modalities using existing models of loudness for acoustic and electric stimulation, and is suitable for implementation in wearable devices. Loudness balancing experiments were performed with six bimodal listeners to validate the strategy. In a first set of experiments, the function of each loudness model used was validated by balancing the loudness of four harmonic complexes of different bandwidths, ranging from 200 Hz to 1000 Hz, separately for each ear. Both the electric and acoustic loudness models predicted the data well. In a second set of experiments, binaural balancing was done for the same stimuli. It was found that SCORE significantly improved binaural balance.

  5. Stimulated scattering of a whistler wave off ion-cyclotron and ion-acoustic modes in a dusty plasma

    SciTech Connect

    Annou, R.; Tripathi, V.K.

    1998-01-01

    A whistler wave propagating through a magnetized dusty plasma undergoes stimulated Brillioun scattering off ion-cyclotron and ion-acoustic modes. The dust has little effect on nonlinear coupling. However, it reduces the growth rate by introducing linear damping on the low-frequency modes. {copyright} {ital 1998 American Institute of Physics.}

  6. Theoretical Analysis of Transcranial Magneto-Acoustical Stimulation with Hodgkin-Huxley Neuron Model.

    PubMed

    Yuan, Yi; Chen, Yudong; Li, Xiaoli

    2016-01-01

    Transcranial magneto-acoustical stimulation (TMAS) is a novel stimulation technology in which an ultrasonic wave within a magnetostatic field generates an electric current in an area of interest in the brain to modulate neuronal activities. As a key part of the neural network, neurons transmit information in the nervous system. However, the effect of TMAS on the neuronal firing pattern remains unknown. To address this problem, we investigated the stimulatory mechanism of TMAS on neurons, by using a Hodgkin-Huxley neuron model. The simulation results indicated that the magnetostatic field intensity and ultrasonic power affect the amplitude and interspike interval of neuronal action potential under a continuous wave ultrasound. The simulation results also showed that the ultrasonic power, duty cycle and repetition frequency can alter the firing pattern of neural action potential under pulsed wave ultrasound. This study may help to reveal and explain the biological mechanism of TMAS and to provide a theoretical basis for TMAS in the treatment or rehabilitation of neuropsychiatric disorders.

  7. Theoretical Analysis of Transcranial Magneto-Acoustical Stimulation with Hodgkin-Huxley Neuron Model.

    PubMed

    Yuan, Yi; Chen, Yudong; Li, Xiaoli

    2016-01-01

    Transcranial magneto-acoustical stimulation (TMAS) is a novel stimulation technology in which an ultrasonic wave within a magnetostatic field generates an electric current in an area of interest in the brain to modulate neuronal activities. As a key part of the neural network, neurons transmit information in the nervous system. However, the effect of TMAS on the neuronal firing pattern remains unknown. To address this problem, we investigated the stimulatory mechanism of TMAS on neurons, by using a Hodgkin-Huxley neuron model. The simulation results indicated that the magnetostatic field intensity and ultrasonic power affect the amplitude and interspike interval of neuronal action potential under a continuous wave ultrasound. The simulation results also showed that the ultrasonic power, duty cycle and repetition frequency can alter the firing pattern of neural action potential under pulsed wave ultrasound. This study may help to reveal and explain the biological mechanism of TMAS and to provide a theoretical basis for TMAS in the treatment or rehabilitation of neuropsychiatric disorders. PMID:27148032

  8. Theoretical Analysis of Transcranial Magneto-Acoustical Stimulation with Hodgkin-Huxley Neuron Model

    PubMed Central

    Yuan, Yi; Chen, Yudong; Li, Xiaoli

    2016-01-01

    Transcranial magneto-acoustical stimulation (TMAS) is a novel stimulation technology in which an ultrasonic wave within a magnetostatic field generates an electric current in an area of interest in the brain to modulate neuronal activities. As a key part of the neural network, neurons transmit information in the nervous system. However, the effect of TMAS on the neuronal firing pattern remains unknown. To address this problem, we investigated the stimulatory mechanism of TMAS on neurons, by using a Hodgkin-Huxley neuron model. The simulation results indicated that the magnetostatic field intensity and ultrasonic power affect the amplitude and interspike interval of neuronal action potential under a continuous wave ultrasound. The simulation results also showed that the ultrasonic power, duty cycle and repetition frequency can alter the firing pattern of neural action potential under pulsed wave ultrasound. This study may help to reveal and explain the biological mechanism of TMAS and to provide a theoretical basis for TMAS in the treatment or rehabilitation of neuropsychiatric disorders. PMID:27148032

  9. Simultaneous stimulated Raman, Brillouin, and electron-acoustic scattering reveals a potential saturation mechanism in Raman plasma amplifiers

    SciTech Connect

    Turnbull, D.; Li, S.; Morozov, A.; Suckewer, S.

    2012-08-15

    In a Raman plasma amplifier, the aim is to create plasma conditions in which Raman backscattering is the fastest growing instability, outrunning all competing effects so that it is possible to amplify and compress a laser beam to unprecedented unfocused intensities by utilizing that instability. However, achieving high efficiencies via this scheme has proven very difficult experimentally. Recent data show the simultaneous occurrence of stimulated Raman scattering (SRS), stimulated Brillouin scattering (SBS), and stimulated electron-acoustic scattering (SEAS). The appearance of SEAS is indicative of strong particle trapping, the existence of which is hard to justify without highlighting the interplay between SRS and SBS.

  10. Stimulation-dependent recruitment of cytosolic phospholipase A2-alpha to EA.hy.926 endothelial cell membranes leads to calcium-independent association.

    PubMed

    Grewal, Seema; Smith, Jennifer; Ponnambalam, Sreenivasan; Walker, John

    2004-01-01

    Cytosolic phospholipase A2-alpha (cPLA2-alpha) is a calcium-activated enzyme involved in agonist-induced arachidonic acid release. In endothelial cells, free arachidonic acid is predominantly converted into prostacyclin, a potent vasodilator and inhibitor of platelet activation. As the rate-limiting step in prostacyclin production is the generation of free arachidonic acid by cPLA2-alpha, this enzyme has become an attractive pharmacological target and the focus of many studies. Following stimulation with calcium-mobilizing agonists, cPLA2-alpha translocates to intracellular phospholipid membranes via its C2 domain. In this study, the calcium-induced association of cPLA2-alpha with EA.hy.926 endothelial cell membranes was investigated. Subcellular fractionation and immunofluorescence studies showed that following stimulation with histamine, thrombin or the calcium ionophore A23187, cPLA2-alpha relocated to intracellular membranes. Treatment of A23187-stimulated cells with EGTA or BAPTA-AM demonstrated that a substantial pool of cPLA2-alpha remained associated with membrane fractions in a calcium-independent manner. Furthermore, immunofluorescence microscopy studies revealed that cells stimulated for periods of greater than 10 min showed a high proportion of calcium-independent membrane-associated cPLA2-alpha. Calcium-independent membrane association of cPLA2-alpha was not due to hydrophobic or cytoskeletal interactions. Finally, the recombinant C2 domain of cPLA2-alpha exhibited calcium-independent membrane binding to membranes isolated from A23187-stimulated cells but not those isolated from nonstimulated cells. These findings suggest that novel mechanisms involving accessory proteins at the target membrane play a role in the regulation of cPLA2-alpha. Such regulatory associations could enable the cell to discriminate between the varying levels of cytosolic calcium induced by different stimuli.

  11. Contralateral acoustic stimulation induces a phase advance in evoked otoacoustic emissions in humans.

    PubMed

    Giraud, A L; Perrin, E; Chéry-Croze, S; Chays, A; Collet, L

    1996-05-01

    In 28 normal-hearing human subjects, the medial olivocochlear efferent system was activated by contralateral acoustic stimulation which is able to mimic the inhibitory effects of electrical stimulation of the crossed olivocochlear bundle. A first experiment on 16 subjects demonstrated that a contralateral white noise of 35 dB SL was able to induce temporal changes on transiently evoked otoacoustic emissions in response to clicks of 63 dB SPL. These temporal changes consisted of an advance of click-evoked otoacoustic signals in 87% of cases and is referred to as phase-shift effect. The phase advance, quantified using two signal processing methods in both time and frequency domains, was found to be mainly associated with lower frequencies, with a maximal effect at 1.5 kHz and minimal effects around 3.5 and 4 kHz. In a second experiment, carried out on 12 subjects, a negative relationship was found to exist between the ipsilateral stimulation level (level of clicks ranging from 57 to 69 dB SPL) and the phase-shift effect (PSE). Specifically in the range of levels tested (25-45 dB SL), a linear relationship presenting no obvious saturation effect was observed between the contralateral level and the PSE. The PSE was examined in 6 additional subjects exhibiting pathological symptoms; 2 of 3 individuals, who had no contralateral stapedial reflexes unilaterally, showed the PSE whereas this response was reduced or absent in 3 other subjects in the ear with severed efferents associated with a vestibular neurotomy. The integrity of olivocochlear efferents was, therefore, necessary to obtain a full effect, but the absence of stapedial reflex did not prevent the effect from occurring. PMID:8789811

  12. Stimulated acoustic emission: pseudo-Doppler shifts seen during the destruction of nonmoving microbubbles.

    PubMed

    Tiemann, K; Pohl, C; Schlosser, T; Goenechea, J; Bruce, M; Veltmann, C; Kuntz, S; Bangard, M; Becher, H

    2000-09-01

    The purpose of this study was to evaluate the appearance and the characteristics of stimulated acoustic emission (SAE) as an echo contrast-specific color Doppler phenomenon with impact on myocardial contrast echocardiography (MCE). Stationary microbubbles of the new contrast agent SH-U 563A (Schering AG) were embedded within a tissue-mimicking gel material. Harmonic power Doppler imaging (H-PDI), color Doppler and pulse-wave Doppler data were acquired using an HDI-5000 equipped with a phased-array transducer (1.67/3.3 MHz). In color Doppler mode, bubble destruction resulted in random noise like Doppler signals. PW-Doppler revealed short "pseudo-Doppler" shifts with a broadband frequency spectrum. Quantification of SAE events by H-PDI demonstrated an exponential decay of signal intensities over successive frames. A strong linear relationship was found between bubble concentration and the square root of the linearized H-PDI signal for a range of concentrations of more than two orders of magnitude (R = 0.993, p < 0.0001). Intensity of the H-PDI signals correlated well with emission power (R = 0.96, p = 0.0014). SAE results from disintegration of microbubbles and can be demonstrated by all Doppler imaging modalities, including H-PDI. Intensity of SAE signals is influenced by the applied acoustic power and correlates highly with the concentration of microbubbles. Because intensity of SAE signals correlates highly with echo contrast concentrations, analysis of SAE signals might be used for quantitative MCE. PMID:11053751

  13. Electroacoustic Stimulation: Now and into the Future

    PubMed Central

    Irving, S.; Gillespie, L.; Richardson, R.; Rowe, D.; Fallon, J. B.; Wise, A. K.

    2014-01-01

    Cochlear implants have provided hearing to hundreds of thousands of profoundly deaf people around the world. Recently, the eligibility criteria for cochlear implantation have been relaxed to include individuals who have some useful residual hearing. These recipients receive inputs from both electric and acoustic stimulation (EAS). Implant recipients who can combine these hearing modalities demonstrate pronounced benefit in speech perception, listening in background noise, and music appreciation over implant recipients that rely on electrical stimulation alone. The mechanisms bestowing this benefit are unknown, but it is likely that interaction of the electric and acoustic signals in the auditory pathway plays a role. Protection of residual hearing both during and following cochlear implantation is critical for EAS. A number of surgical refinements have been implemented to protect residual hearing, and the development of hearing-protective drug and gene therapies is promising for EAS recipients. This review outlines the current field of EAS, with a focus on interactions that are observed between these modalities in animal models. It also outlines current trends in EAS surgery and gives an overview of the drug and gene therapies that are clinically translatable and may one day provide protection of residual hearing for cochlear implant recipients. PMID:25276779

  14. Angular characteristics of the stimulated-Brillouin-scattering spectrum from a laser plasma with strong acoustic-wave damping

    SciTech Connect

    Saikia, P.

    1981-07-01

    The spectrum of stimulated Brillouin scattering from an inhomogeneous moving laser plasma is analyzed. The damping of acoustic waves and scattered electromagnetic waves is taken into account. Spectra are derived for various scattering angles and for various radii of the laser beam. For all observation angles the center of the spectral line is at an unshifted frequency. As the observation angle increases, the width of the red wing in the spectrum increases. The intensity of the scattered light is very anisotropic.

  15. Detection of dead regions in the cochlea: relevance for combined electric and acoustic stimulation.

    PubMed

    Moore, Brian C J; Glasberg, Brian; Schlueter, Anne

    2010-01-01

    A dead region is a region in the cochlea where the inner hair cells and/or the auditory neurones are functioning very poorly, if at all. People who are being considered for a combination of a cochlear implant and a hearing aid typically have a dead region in the parts of the cochlea that normally respond to medium and high frequencies, but have some functional hearing at lower frequencies. For such people, it may be useful to determine the edge frequency, f(e), of any dead region. This may be relevant to choosing the most appropriate insertion depth of the electrode array, and to the way that frequencies in the input signal are mapped to acoustic and electric stimulation. It may also be helpful in interpreting the results of research studies. This paper reviews methods for diagnosing dead regions and defining the value of f(e). It is argued that the value of f(e) cannot be determined reliably from the audiogram, although a dead region is likely to be present at a given frequency when the hearing loss at that frequency is 70 dB or more. When a sinusoidal signal is reported as sounding highly distorted or noise-like, a dead region may be present at the signal frequency, but again this is not a reliable indicator. The TEN test is a simple clinical method for diagnosis of dead regions. Where this test gives a positive diagnosis, it is recommended that psychophysical tuning curves be measured to define the value of f(e) more precisely. PMID:19955720

  16. 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.

  17. Comparing the effects of reverberation and of noise on speech recognition in simulated electric-acoustic listening

    PubMed Central

    Helms Tillery, Kate; Brown, Christopher A.; Bacon, Sid P.

    2012-01-01

    Cochlear implant users report difficulty understanding speech in both noisy and reverberant environments. Electric-acoustic stimulation (EAS) is known to improve speech intelligibility in noise. However, little is known about the potential benefits of EAS in reverberation, or about how such benefits relate to those observed in noise. The present study used EAS simulations to examine these questions. Sentences were convolved with impulse responses from a model of a room whose estimated reverberation times were varied from 0 to 1 sec. These reverberated stimuli were then vocoded to simulate electric stimulation, or presented as a combination of vocoder plus low-pass filtered speech to simulate EAS. Monaural sentence recognition scores were measured in two conditions: reverberated speech and speech in a reverberated noise. The long-term spectrum and amplitude modulations of the noise were equated to the reverberant energy, allowing a comparison of the effects of the interferer (speech vs noise). Results indicate that, at least in simulation, (1) EAS provides significant benefit in reverberation; (2) the benefits of EAS in reverberation may be underestimated by those in a comparable noise; and (3) the EAS benefit in reverberation likely arises from partially preserved cues in this background accessible via the low-frequency acoustic component. PMID:22280603

  18. Perception of power modulation of light in conjunction with acoustic stimulation

    NASA Astrophysics Data System (ADS)

    Hahlweg, Cornelius F.; Weyer, Cornelia; Gercke-Hahn, Harald; Gutzmann, Holger L.; Brahmann, Andre; Rothe, Hendrik

    2013-09-01

    The present paper is derived from an ongoing study on the human perception of combined optical and acoustical periodical stimuli. Originating from problems of occupational medicine concerning artificial illumination and certain machinery with coherent optical and acoustical emissions there are effects which are interesting in the context of Optics and Music. Because of the difficulties in evaluation of physical and psychological effects of such coherent stimuli in a first step we questioned if such coherence is perceivable at all. Concept, experimental set-up and first results are discussed in short.

  19. Sympathetic skin response following thermal, electrical, acoustic, and inspiratory gasp stimulation in familial dysautonomia patients and healthy persons.

    PubMed

    Hilz, M J; Azelrod, F B; Schweibold, G; Kolodny, E H

    1999-08-01

    To determine whether sympathetic skin response (SSR) testing evaluates afferent small or efferent sympathetic nerve fiber dysfunction, we studied SSR in patients with familial dysautonomia (FD) in whom both afferent small and efferent sympathetic fibers are largely reduced. We analyzed whether the response pattern to a combination of stimuli specific for large or small fiber activation allows differentiation between afferent and efferent small fiber dysfunction. In 52 volunteers and 13 FD patients, SSR was studied at palms and soles after warm, cold and heat as well as electrical, acoustic, and inspiratory gasp stimulation. In addition, thermal thresholds were assessed at four body sites using a Thermotest device (Somedic; Stockholm, Sweden). In volunteers, any stimulus induced reproducible SSRs. Only cold failed to evoke SSR in two volunteers. In all FD patients, electrical SSR was present, but amplitudes were reduced. Five patients had no acoustic SSR, four had no inspiratory SSR. Thermal SSR was absent in 10 patients with abnormal thermal perception and present in one patient with preserved thermal sensation. In two patients, thermal SSR was present only when skin areas with preserved temperature perception were stimulated. In patients with FD, preserved electrical SSR demonstrated the overall integrity of the SSR reflex but amplitude reduction suggested impaired sudomotor activation. SSR responses were dependent on the perception of the stimulus. In the presence of preserved electrical SSR, absent thermal SSR reflects afferent small fiber dysfunction. A combination of SSR stimulus types allows differentiation between afferent small or efferent sympathetic nerve fiber dysfunction. PMID:10574280

  20. Pre- and post-stimulation characterization of geothermal well GRT-1, Rittershoffen, France: insights from acoustic image logs of hard fractured rock

    NASA Astrophysics Data System (ADS)

    Vidal, Jeanne; Genter, Albert; Schmittbuhl, Jean

    2016-08-01

    Geothermal well GRT-1 (Rittershoffen, Alsace) was drilled in 2012. Its open-hole section (extending down to a depth of 2.6 km) penetrated fractured sandstones and granite. In 2013, the well was subjected to Thermal, Chemical and Hydraulic (TCH) stimulation, which improved the injectivity index fivefold. The goal of the study was to assess the impact of the stimulation by comparing pre- and post-stimulation well-logging (acoustic and temperature [T] logs) and mud-logging data. This comparison revealed modifications of almost all the natural fractures. However, not all of these fractures are associated with permeability enhancement, and the post-stimulation T logs are important for characterizing this enhancement. Chemical alteration due to mechanical erosion at the tops and bottoms of the fractures was observed in the sandstones. These zones display indications of very small new permeability after the TCH stimulation. Because a major fault zone caved extensively where it crosses the borehole, it was not imaged in the acoustic logs. However, this originally permeable zone was enhanced as demonstrated by the T logs. Based on the natural injectivity of this fault zone, hydraulic erosion and thermal microcracking of its internal quartz veins are associated with this permeability enhancement. Although local changes in the borehole wall observed in the acoustic images cannot be directly linked to the improved injectivity index, the comparison of the acoustic image logs allows for identification of fracture zones impacted by the TCH stimulation.

  1. Stimulants

    MedlinePlus

    Stimulants are drugs that increase your heart rate, breathing rate, and brain function. Some stimulants affect only a specific organ, such as the heart, lungs, brain, or nervous system. Epinephrine is a stimulant. It ...

  2. Sea Cucumber Saponin Echinoside A (EA) Stimulates Hepatic Fatty Acid β-Oxidation and Suppresses Fatty Acid Biosynthesis Coupling in a Diurnal Pattern.

    PubMed

    Wen, Min; Fu, Xueyuan; Han, Xiuqing; Hu, Xiaoqian; Dong, Ping; Xu, Jie; Xue, Yong; Wang, Jingfeng; Xue, Changhu; Wang, Yuming

    2016-01-01

    Circadian rhythms control aspects of physiological events, including lipid metabolism, showing rhythmic fluctuation over 24 h. Therefore, it is not sufficient to evaluate thoroughly how dietary components regulate lipid metabolism with a single time-point assay. In the present study, a time-course study was performed to analyze the effect of sea cucumber saponin echinoside A (EA) on lipid metabolism over 24 h. Results showed that EA lowered the levels of TC and TG in both serum and liver at most time-points during the 24 h. Activities of hepatic lipogenic enzymes and lipolytic enzymes were inhibited and elevated respectively by EA to varied degrees at different time-points. Meanwhile, parallel variation trends of gene expression involved in fatty acid synthesis and β-oxidation were observed accordingly. The interaction between EA and lipid metabolism showed a time-dependent effect. Overall, EA impaired fatty acid synthesis and enhanced mitochondrial fatty acid β-oxidation in ad libitum feeding over 24 h. PMID:27465723

  3. The effects of bilateral electric and bimodal electric--acoustic stimulation on language development.

    PubMed

    Nittrouer, Susan; Chapman, Christopher

    2009-09-01

    There is no doubt that cochlear implants have improved the spoken language abilities of children with hearing loss, but delays persist. Consequently, it is imperative that new treatment options be explored. This study evaluated one aspect of treatment that might be modified, that having to do with bilateral implants and bimodal stimulation. A total of 58 children with at least one implant were tested at 42 months of age on four language measures spanning a continuum from basic to generative in nature. When children were grouped by the kind of stimulation they had at 42 months (one implant, bilateral implants, or bimodal stimulation), no differences across groups were observed. This was true even when groups were constrained to only children who had at least 12 months to acclimatize to their stimulation configuration. However, when children were grouped according to whether or not they had spent any time with bimodal stimulation (either consistently since their first implant or as an interlude to receiving a second) advantages were found for children who had some bimodal experience, but those advantages were restricted to language abilities that are generative in nature. Thus, previously reported benefits of simultaneous bilateral implantation early in a child's life may not extend to generative language. In fact, children may benefit from a period of bimodal stimulation early in childhood because low-frequency speech signals provide prosody and serve as an aid in learning how to perceptually organize the signal that is received through a cochlear implant. PMID:19713210

  4. The effects of bilateral electric and bimodal electric--acoustic stimulation on language development.

    PubMed

    Nittrouer, Susan; Chapman, Christopher

    2009-09-01

    There is no doubt that cochlear implants have improved the spoken language abilities of children with hearing loss, but delays persist. Consequently, it is imperative that new treatment options be explored. This study evaluated one aspect of treatment that might be modified, that having to do with bilateral implants and bimodal stimulation. A total of 58 children with at least one implant were tested at 42 months of age on four language measures spanning a continuum from basic to generative in nature. When children were grouped by the kind of stimulation they had at 42 months (one implant, bilateral implants, or bimodal stimulation), no differences across groups were observed. This was true even when groups were constrained to only children who had at least 12 months to acclimatize to their stimulation configuration. However, when children were grouped according to whether or not they had spent any time with bimodal stimulation (either consistently since their first implant or as an interlude to receiving a second) advantages were found for children who had some bimodal experience, but those advantages were restricted to language abilities that are generative in nature. Thus, previously reported benefits of simultaneous bilateral implantation early in a child's life may not extend to generative language. In fact, children may benefit from a period of bimodal stimulation early in childhood because low-frequency speech signals provide prosody and serve as an aid in learning how to perceptually organize the signal that is received through a cochlear implant.

  5. Numerical investigation on buffer performance based on acoustic excitation by stimulated Brillouin scattering in an As 2Se 3 fiber

    NASA Astrophysics Data System (ADS)

    Zhang, Zhiyao; Zhou, Xiaojun; Liang, Rui; Qin, Zujun; Liu, Yong

    2009-07-01

    Buffer performance of a 2.5 Gb/s bit stream with non-return-to-zero format is investigated based on acoustic excitation by stimulated Brillouin scattering in an As 2Se 3 fiber. The storage process and the retrieval process of the bit stream are separately controlled by a "Write" pulse and a "Read" pulse. The research results show that the output signal-to-noise ratio and the readout efficiency of the buffer are agreeable, and the pulse distortion is low, if both the "Write" and the "Read" pulses are with high enough peak power and spectrum wider than that of the signal pulse. Buffering of a consecutive 10-bit-long 2.5 Gb/s NRZ bit stream has also been demonstrated in the As 2Se 3 fiber with length of only 0.5 m. The storage of a long bit stream, such as the data packet containing about 1000 bits in the telecommunications, is limited by the high loss in the As 2Se 3 fiber. However, the development of the special optical fiber with high Brillouin gain coefficient, long acoustic lifetime and low loss can make this technology applicable for all-optical buffering in high speed optical networks.

  6. Effects of contralateral white noise stimulation on transitory evoked otoacoustic emissions in patients with acoustic neuroma.

    PubMed

    Maurer, J; Hinni, M; Beck, A; Mann, W

    1995-03-01

    Transitory evoked otoacoustic emissions are normal phenomena observed in most persons with hearing levels greater than 35 dB. Further, masking of the contralateral ear produces amplitude reductions in the transitory evoked otoacoustic emissions. We have undertaken a study of transitory evoked otoacoustic emissions in 20 patients with acoustic neuroma. All patients were assessed for transitory evoked otoacoustic emissions bilaterally, with and without contralateral masking with white band noise at 40, 50, and 60 dB. We found that transitory evoked otoacoustic emissions were present in 30% of ears with tumor and that the presence of transitory evoked otoacoustic emissions is associated with improved preoperative hearing levels, but that tumor size is not associated with the presence or absence of transitory evoked otoacoustic emissions. The amplitude of transitory evoked otoacoustic emissions from ears with tumor, when present, is decreased when compared with normal ears of normal patients. Further, with contralateral masking little of the amplitude reduction observed in normal patients is observed in the ears with acoustic neuroma. However, with masking of the contralateral ear, the ear without tumor demonstrated significantly greater amplitude reductions than normal ears from normal patients (p = 0.0006). Pertinent anatomy and possible explanations for these findings are discussed. PMID:7870435

  7. Low-frequency speech cues and simulated electric-acoustic hearing

    PubMed Central

    Brown, Christopher A.; Bacon, Sid P.

    2009-01-01

    The addition of low-frequency acoustic information to real or simulated electric stimulation (so-called electric-acoustic stimulation or EAS) often results in large improvements in intelligibility, particularly in competing backgrounds. This may reflect the availability of fundamental frequency (F0) information in the acoustic region. The contributions of F0 and the amplitude envelope (as well as voicing) of speech to simulated EAS was examined by replacing the low-frequency speech with a tone that was modulated in frequency to track the F0 of the speech, in amplitude with the envelope of the low-frequency speech, or both. A four-channel vocoder simulated electric hearing. Significant benefit over vocoder alone was observed with the addition of a tone carrying F0 or envelope cues, and both cues combined typically provided significantly more benefit than either alone. The intelligibility improvement over vocoder was between 24 and 57 percentage points, and was unaffected by the presence of a tone carrying these cues from a background talker. These results confirm the importance of the F0 of target speech for EAS (in simulation). They indicate that significant benefit can be provided by a tone carrying F0 and amplitude envelope cues. The results support a glimpsing account of EAS and argue against segregation. PMID:19275323

  8. Massively Parallel DNA Sequencing Successfully Identifies New Causative Mutations in Deafness Genes in Patients with Cochlear Implantation and EAS

    PubMed Central

    Miyagawa, Maiko; Nishio, Shin-ya; Ikeda, Takuo; Fukushima, Kunihiro; Usami, Shin-ichi

    2013-01-01

    Genetic factors, the most common etiology in severe to profound hearing loss, are one of the key determinants of Cochlear Implantation (CI) and Electric Acoustic Stimulation (EAS) outcomes. Satisfactory auditory performance after receiving a CI/EAS in patients with certain deafness gene mutations indicates that genetic testing would be helpful in predicting CI/EAS outcomes and deciding treatment choices. However, because of the extreme genetic heterogeneity of deafness, clinical application of genetic information still entails difficulties. Target exon sequencing using massively parallel DNA sequencing is a new powerful strategy to discover rare causative genes in Mendelian disorders such as deafness. We used massive sequencing of the exons of 58 target candidate genes to analyze 8 (4 early-onset, 4 late-onset) Japanese CI/EAS patients, who did not have mutations in commonly found genes including GJB2, SLC26A4, or mitochondrial 1555A>G or 3243A>G mutations. We successfully identified four rare causative mutations in the MYO15A, TECTA, TMPRSS3, and ACTG1 genes in four patients who showed relatively good auditory performance with CI including EAS, suggesting that genetic testing may be able to predict the performance after implantation. PMID:24130743

  9. Robustness against distortion of fundamental frequency cues in simulated electro-acoustic hearing.

    PubMed

    Vermeulen, Arthur; Verschuur, Carl

    2016-07-01

    Speech recognition by cochlear implant users can be improved by adding an audible low frequency acoustic signal to electrical hearing; the resulting improvement is deemed "electro-acoustic stimulation (EAS) benefit." However, a crucial low frequency cue, fundamental frequency (F0), can be distorted via the impaired auditory system. In order to understand how F0 distortions may affect EAS benefit, normal-hearing listeners were presented monaurally with vocoded speech (frequencies >250 Hz) and an acoustical signal (frequencies <250 Hz) with differing manipulations of the F0 signal, specifically: a pure tone with the correct mean F0 but with smaller variations around this mean, or a narrowband of white noise centered around F0, at varying bandwidths; a pure tone down-shifted in frequency by 50 Hz but keeping overall frequency modulations. Speech-recognition thresholds improved when tones with reduced frequency modulation were presented, and improved significantly for noise bands maintaining F0 information. A down-shifted tone, or only a tone to indicate voicing, showed no EAS benefit. These results confirm that the presence of the target's F0 is beneficial for EAS hearing in a noisy environment, and they indicate that the benefit is robust to F0 distortion, as long as the mean F0 and frequency modulations of F0 are preserved. PMID:27475149

  10. Stronger efferent suppression of cochlear neural potentials by contralateral acoustic stimulation in awake than in anesthetized chinchilla

    PubMed Central

    Aedo, Cristian; Tapia, Eduardo; Pavez, Elizabeth; Elgueda, Diego; Delano, Paul H.; Robles, Luis

    2015-01-01

    There are two types of sensory cells in the mammalian cochlea, inner hair cells, which make synaptic contact with auditory-nerve afferent fibers, and outer hair cells that are innervated by crossed and uncrossed medial olivocochlear (MOC) efferent fibers. Contralateral acoustic stimulation activates the uncrossed efferent MOC fibers reducing cochlear neural responses, thus modifying the input to the central auditory system. The chinchilla, among all studied mammals, displays the lowest percentage of uncrossed MOC fibers raising questions about the strength and frequency distribution of the contralateral-sound effect in this species. On the other hand, MOC effects on cochlear sensitivity have been mainly studied in anesthetized animals and since the MOC-neuron activity depends on the level of anesthesia, it is important to assess the influence of anesthesia in the strength of efferent effects. Seven adult chinchillas (Chinchilla laniger) were chronically implanted with round-window electrodes in both cochleae. We compared the effect of contralateral sound in awake and anesthetized condition. Compound action potentials (CAP) and cochlear microphonics (CM) were measured in the ipsilateral cochlea in response to tones in absence and presence of contralateral sound. Control measurements performed after middle-ear muscles section in one animal discarded any possible middle-ear reflex activation. Contralateral sound produced CAP amplitude reductions in all chinchillas, with suppression effects greater by about 1–3 dB in awake than in anesthetized animals. In contrast, CM amplitude increases of up to 1.9 dB were found in only three awake chinchillas. In both conditions the strongest efferent effects were produced by contralateral tones at frequencies equal or close to those of ipsilateral tones. Contralateral CAP suppressions for 1–6 kHz ipsilateral tones corresponded to a span of uncrossed MOC fiber innervation reaching at least the central third of the chinchilla

  11. Stronger efferent suppression of cochlear neural potentials by contralateral acoustic stimulation in awake than in anesthetized chinchilla.

    PubMed

    Aedo, Cristian; Tapia, Eduardo; Pavez, Elizabeth; Elgueda, Diego; Delano, Paul H; Robles, Luis

    2015-01-01

    There are two types of sensory cells in the mammalian cochlea, inner hair cells, which make synaptic contact with auditory-nerve afferent fibers, and outer hair cells that are innervated by crossed and uncrossed medial olivocochlear (MOC) efferent fibers. Contralateral acoustic stimulation activates the uncrossed efferent MOC fibers reducing cochlear neural responses, thus modifying the input to the central auditory system. The chinchilla, among all studied mammals, displays the lowest percentage of uncrossed MOC fibers raising questions about the strength and frequency distribution of the contralateral-sound effect in this species. On the other hand, MOC effects on cochlear sensitivity have been mainly studied in anesthetized animals and since the MOC-neuron activity depends on the level of anesthesia, it is important to assess the influence of anesthesia in the strength of efferent effects. Seven adult chinchillas (Chinchilla laniger) were chronically implanted with round-window electrodes in both cochleae. We compared the effect of contralateral sound in awake and anesthetized condition. Compound action potentials (CAP) and cochlear microphonics (CM) were measured in the ipsilateral cochlea in response to tones in absence and presence of contralateral sound. Control measurements performed after middle-ear muscles section in one animal discarded any possible middle-ear reflex activation. Contralateral sound produced CAP amplitude reductions in all chinchillas, with suppression effects greater by about 1-3 dB in awake than in anesthetized animals. In contrast, CM amplitude increases of up to 1.9 dB were found in only three awake chinchillas. In both conditions the strongest efferent effects were produced by contralateral tones at frequencies equal or close to those of ipsilateral tones. Contralateral CAP suppressions for 1-6 kHz ipsilateral tones corresponded to a span of uncrossed MOC fiber innervation reaching at least the central third of the chinchilla cochlea.

  12. Stronger efferent suppression of cochlear neural potentials by contralateral acoustic stimulation in awake than in anesthetized chinchilla.

    PubMed

    Aedo, Cristian; Tapia, Eduardo; Pavez, Elizabeth; Elgueda, Diego; Delano, Paul H; Robles, Luis

    2015-01-01

    There are two types of sensory cells in the mammalian cochlea, inner hair cells, which make synaptic contact with auditory-nerve afferent fibers, and outer hair cells that are innervated by crossed and uncrossed medial olivocochlear (MOC) efferent fibers. Contralateral acoustic stimulation activates the uncrossed efferent MOC fibers reducing cochlear neural responses, thus modifying the input to the central auditory system. The chinchilla, among all studied mammals, displays the lowest percentage of uncrossed MOC fibers raising questions about the strength and frequency distribution of the contralateral-sound effect in this species. On the other hand, MOC effects on cochlear sensitivity have been mainly studied in anesthetized animals and since the MOC-neuron activity depends on the level of anesthesia, it is important to assess the influence of anesthesia in the strength of efferent effects. Seven adult chinchillas (Chinchilla laniger) were chronically implanted with round-window electrodes in both cochleae. We compared the effect of contralateral sound in awake and anesthetized condition. Compound action potentials (CAP) and cochlear microphonics (CM) were measured in the ipsilateral cochlea in response to tones in absence and presence of contralateral sound. Control measurements performed after middle-ear muscles section in one animal discarded any possible middle-ear reflex activation. Contralateral sound produced CAP amplitude reductions in all chinchillas, with suppression effects greater by about 1-3 dB in awake than in anesthetized animals. In contrast, CM amplitude increases of up to 1.9 dB were found in only three awake chinchillas. In both conditions the strongest efferent effects were produced by contralateral tones at frequencies equal or close to those of ipsilateral tones. Contralateral CAP suppressions for 1-6 kHz ipsilateral tones corresponded to a span of uncrossed MOC fiber innervation reaching at least the central third of the chinchilla cochlea

  13. Inhibitory effect of A10 dopaminergic neurons of the ventral tegmental area on the orienting response evoked by acoustic stimulation in the cat.

    PubMed

    Crescimanno, G; Sorbera, F; Emmi, A; Amato, G

    1998-01-01

    The effect of bilateral electric stimulation of A10 dopaminergic neurons of the ventral tegmental area (80-300 microA, 20-50 Hz, 0.1-0.5 ms, 2 s duration) on latency and duration of the orienting response, evoked by acoustic stimuli (4500-8000 Hz, 2 s), was studied in the cat. A10 neuron stimulation, simultaneous with the acoustic one, was performed with threshold parameters inducing minimal behavioral signs (head searching movement, sniffing, increase in alertness). By means of a videoanalysis system, a statistically significant increase, both of latency and duration of the response, was observed. The possible role of dopamine was studied administrating sulpiride (20 mg/kg i.p.), a dopaminergic antagonist prevalently acting on the mesolimbic-mesocortical system. In this condition, the disappearance of A10 neuron effect occurred. Sulpiride injection did not affect the parameters of the orienting response to acoustic stimulus alone, suggesting a direct effect on A10 dopaminergic neurons. Moreover, when saline administration was carried out, no significant modification of the effects, obtained following A10 neuron activation, was observed. The data suggest that A10 dopaminergic neurons, origin of the mesolimbic-mesocortical system, may be involved in the control of the response to sensory stimuli, likely by influencing sensorimotor integration processes. An involvement in the inhibitory regulation of the switching of attention is also discussed. PMID:9434203

  14. Evolution of elastic and thermal properties during TMOS-gel formation determined by ringing bottle acoustic resonance spectroscopy, impulsive stimulated scattering, photopyroelectric spectroscopy and the hot ball method

    NASA Astrophysics Data System (ADS)

    Xu, Xiaodong; Agustin Flores Cuautle, Jose Jesus; Kouyate, Mansour; Bernardus Roozen, Nicolaas; Goossens, Jozefien; Menon, Preethy; Kuriakose Malayil, Maju; Salenbien, Robbe; Nair Rajesh, Ravindran; Glorieux, Christ; Griesmar, Pascal; Martinez, Loïc; Serfaty, Stéphane

    2016-03-01

    The evolution of the elastic and thermal properties of a tetramethylorthosilicate (TMOS)-based gel that exhibits an extraordinary ringing effect when enclosed in a bottle is investigated during the sol-gel transition. The results demonstrate the feasibility of three proposed experimental methods for monitoring of gels during their formation. The shear stiffening evolution during gelation is monitored by ringing bottle, resonant acoustic spectroscopy and by an ultrasonic technique using piezo electric excitation and detection. The evolution of the longitudinal modulus and the thermal diffusivity of the gel during stiffening are simultaneously determined by a combined photoacoustic and photothermal method based on heterodyne diffraction detection of impulsive stimulated scattering by, respectively, a propagating acoustic wave grating and a decaying thermal expansion grating that were both thermo elastically generated using a pulsed laser. Also, the feasibility of an inverse photopyroelectric method and a hot ball technique to monitor the thermal transport efficiency and thermal impedance of a forming gel by tracking the thermal conductivity, the thermal diffusivity, and the thermal effusivity is demonstrated. The network polymerization and stiffening during the sol-gel transition in TMOS-gel corresponds with substantial changes in the shear acoustic velocity and in all thermal properties, while the longitudinal acoustic velocity is only weakly affected.

  15. Education in acoustics in Argentina

    NASA Astrophysics Data System (ADS)

    Miyara, Federico

    2002-11-01

    Over the last decades, education in acoustics (EA) in Argentina has experienced ups and downs due to economic and political issues interfering with long term projects. Unlike other countries, like Chile, where EA has reached maturity in spite of the acoustical industry having shown little development, Argentina has several well-established manufacturers of acoustic materials and equipment but no specific career with a major in acoustics. At the university level, acoustics is taught as a complementary--often elective--course for careers such as architecture, communication engineering, or music. In spite of this there are several research centers with programs covering environmental and community noise, effects of noise on man, acoustic signal processing, musical acoustics and acoustic emission, and several national and international meetings are held each year in which results are communicated and discussed. Several books on a variety of topics such as sound system, architectural acoustics, and noise control have been published as well. Another chapter in EA is technical and vocational education, ranging between secondary and postsecondary levels, with technical training on sound system operation or design. Over the last years there have been several attempts to implement master degrees in acoustics or audio engineering, with little or no success.

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

    SciTech Connect

    Vlasenko, A. I.; Baidullaeva, A.; Veleschuk, V. P. Mozol, P. E.; Boiko, N. I.; Litvin, O. S.

    2015-02-15

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

  17. Large-scale investigation of plaster detachments in historical murals by acoustic stimulation and video-holographic detection

    NASA Astrophysics Data System (ADS)

    Guelker, Gerd; Hinsch, Klaus D.; Joost, Holger

    2001-10-01

    In the conservation of historical murals an important issue is the detection of plaster or paint layers that detach from the supporting material and thus threaten to fall off. Commonly, walls are inspected by the acoustic response to a gentle finger-tapping (percussion method). Since this is a costly and cumbersome technique there is need for a metrological instrument serving the same purpose. In the last few years we have shown, that a time-average version of electronic speckle pattern interferometry (ESPI) with increased sensitivity in combination with acoustic excitation of the object can be a powerful tool for monitoring of loose areas. It offers full-field, video real time capability and has the advantage of non-contact and remote operation which, for example, is extremely useful in large buildings. Recently, a fully computer-based evaluation and control system was added to the system to assist in the introduction of the method as a generally approved tool in artwork monitoring. Principles of the method and instrumental features of the equipment are presented and some results and their interpretation obtained with the computerized system in the church and chapel at St. John's convent at Mnstair, Switzerland are demonstrated.

  18. 47 CFR 11.33 - EAS Decoder.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false EAS Decoder. 11.33 Section 11.33 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL EMERGENCY ALERT SYSTEM (EAS) Equipment Requirements § 11.33 EAS Decoder. (a) An EAS Decoder must at a minimum be capable of decoding the EAS protocol described in § 11.31, provide the EAS...

  19. A dynamic pressure view cell for acoustic stimulation of fluids—Micro-bubble generation and fluid movement in porous media

    NASA Astrophysics Data System (ADS)

    Stewart, Robert A.; Shaw, J. M.

    2015-09-01

    The development and baseline operation of an acoustic view cell for observing fluids, and fluid-fluid and fluid-solid interfaces in porous media over the frequency range of 10-5000 Hz is described. This range includes the industrially relevant frequency range 500-5000 Hz that is not covered by existing devices. Pressure waveforms of arbitrary shape are generated in a 17.46 mm ID by 200 mm and 690.5 mm long glass tubes at flow rates up to 200 ml/min using a syringe pump. Peak-to-peak amplitudes exceeding 80 kPa are readily realized at frequencies from 10 to 5000 Hz in bubble free fluids when actuated with 20 Vpp as exemplified using castor oil. At resonant frequencies, peak-to-peak pressure amplitudes exceeding 500 kPa were obtained (castor oil at 2100 Hz when actuated with 20 Vpp). Impacts of vibration on macroscopic liquid-liquid and liquid-vapour interfaces and interface movement are illustrated. Pressure wave transmission and attenuation in a fluid saturated porous medium, randomly packed 250-330 μm spherical silica beads, is also demonstrated. Attenuation differences and frequency shifts in resonant peaks are used to detect the presence and generation of dispersed micro-bubbles (<180 μm diameter), and bubbles within porous media that are not readily visualized. Envisioned applications include assessment of the impacts of vibration on reaction, mass transfer, and flow/flow pattern outcomes. This knowledge will inform laboratory and pilot scale process studies, where nuisance vibrations may affect the interpretation of process outcomes, and large scale or in situ processes in aquifers or hydrocarbon reservoirs where imposed vibration may be deployed to improve aspects of process performance. Future work will include miscible interface observation and quantitative measurements in the bulk and in porous media where the roles of micro-bubbles comprise subjects of special interest.

  20. A dynamic pressure view cell for acoustic stimulation of fluids--Micro-bubble generation and fluid movement in porous media.

    PubMed

    Stewart, Robert A; Shaw, J M

    2015-09-01

    The development and baseline operation of an acoustic view cell for observing fluids, and fluid-fluid and fluid-solid interfaces in porous media over the frequency range of 10-5000 Hz is described. This range includes the industrially relevant frequency range 500-5000 Hz that is not covered by existing devices. Pressure waveforms of arbitrary shape are generated in a 17.46 mm ID by 200 mm and 690.5 mm long glass tubes at flow rates up to 200 ml/min using a syringe pump. Peak-to-peak amplitudes exceeding 80 kPa are readily realized at frequencies from 10 to 5000 Hz in bubble free fluids when actuated with 20 Vpp as exemplified using castor oil. At resonant frequencies, peak-to-peak pressure amplitudes exceeding 500 kPa were obtained (castor oil at 2100 Hz when actuated with 20 Vpp). Impacts of vibration on macroscopic liquid-liquid and liquid-vapour interfaces and interface movement are illustrated. Pressure wave transmission and attenuation in a fluid saturated porous medium, randomly packed 250-330 μm spherical silica beads, is also demonstrated. Attenuation differences and frequency shifts in resonant peaks are used to detect the presence and generation of dispersed micro-bubbles (<180 μm diameter), and bubbles within porous media that are not readily visualized. Envisioned applications include assessment of the impacts of vibration on reaction, mass transfer, and flow/flow pattern outcomes. This knowledge will inform laboratory and pilot scale process studies, where nuisance vibrations may affect the interpretation of process outcomes, and large scale or in situ processes in aquifers or hydrocarbon reservoirs where imposed vibration may be deployed to improve aspects of process performance. Future work will include miscible interface observation and quantitative measurements in the bulk and in porous media where the roles of micro-bubbles comprise subjects of special interest.

  1. Ovarian blood flow responses to electroacupuncture stimulation depend on estrous cycle and on site and frequency of stimulation in anesthetized rats.

    PubMed

    Stener-Victorin, Elisabet; Fujisawa, Shigeko; Kurosawa, Mieko

    2006-07-01

    Electroacupuncture (EA) applied to the abdomen and hindlimb modulates the ovarian blood flow (OBF) response. The present study aimed to further elucidate the role of the site and the frequency of short-term EA stimulation and the influence of the estrous cycle on the OBF response using anesthetized rats. EA stimulation was applied to the abdominal or the hindlimb muscles at three different frequencies (2, 10, and 80 Hz) during the estrus or diestrus phase. Involvement of spinal and supraspinal reflexes in OBF responses to EA stimulation was investigated by spinal cord transection. Abdominal EA stimulation at 10 Hz increased the OBF response, whereas hindlimb EA stimulation at 10 Hz and abdominal and hindlimb stimulation at 80 Hz decreased the OBF response; 2-Hz EA caused no OBF response. The OBF response to abdominal EA was more pronounced in the estrus than the diestrus phase. The OBF response to abdominal and hindlimb EA stimulation at both 10 and 80 Hz was almost abolished, both after severance of the sympathetic nerves and after spinal cord transection. In conclusion, the OBF response to both abdominal and hindlimb EA stimulation was mediated as a reflex response via the ovarian sympathetic nerves, and the response was controlled via supraspinal pathways. Furthermore, the OBF response to segmental abdominal EA stimulation was frequency dependent and amplified in the estrous phase.

  2. [The effect of electrical and acoustic stimulation in early ontogeny on the characteristics of higher nervous activity and on the nucleic acid content of the tissues in chum salmon fry].

    PubMed

    Tikhomirov, A M; Vitvitskaia, L V

    1991-01-01

    Stimulation of salmon larvae by electric current led further to unstable character of reactions in the open field. Acoustic stimulation both by tonal and musical signals favourably influenced the behaviour in the open field and the ability to elaborate conditioned reflexes. Changes of the content of nucleic acids were not found in the brain tissue but were found in the muscles, where they correlated with the growth speed and motor activity of the experimental fishes. The obtained data show the possibility of elaboration of applied methods of the control of CNS development and behaviour of young fishes at fishing plants.

  3. [The effect of electrical and acoustic stimulation in early ontogeny on the characteristics of higher nervous activity and on the nucleic acid content of the tissues in chum salmon fry].

    PubMed

    Tikhomirov, A M; Vitvitskaia, L V

    1991-01-01

    Stimulation of salmon larvae by electric current led further to unstable character of reactions in the open field. Acoustic stimulation both by tonal and musical signals favourably influenced the behaviour in the open field and the ability to elaborate conditioned reflexes. Changes of the content of nucleic acids were not found in the brain tissue but were found in the muscles, where they correlated with the growth speed and motor activity of the experimental fishes. The obtained data show the possibility of elaboration of applied methods of the control of CNS development and behaviour of young fishes at fishing plants. PMID:1714672

  4. Different sensitivity of pain-related chemosensory potentials evoked by stimulation with CO2, tooth pulp event-related potentials, and acoustic event-related potentials to the tranquilizer diazepam.

    PubMed

    Thürauf, N; Ditterich, W; Kobal, G

    1994-12-01

    1. The aim of this study was to investigate the sensitivity of pain-related potentials used in experimental pain models to the non-specific effects of the tranquilizer diazepam. Pain-related potentials were recorded after painful stimulation of the nasal mucosa with CO2 and after painful stimulation of the tooth pulp. Acoustically evoked potentials were measured in order to compare their sensitivity to the tranquilizer diazepam with the sensitivity of the pain-related potentials. 2. Twenty volunteers participated in this randomised, double-blind, three-fold crossover study. Measurements were obtained before and 20 min after the administration of the drug. Event-related potentials were recorded after painful stimulation of the nasal mucosa with CO2 (two stimulus intensities: 60% v/v and 70% v/v CO2), after painful stimulation of the tooth pulp (two stimulus intensities: 2.2 x and 3.3 x detection threshold), and after non-painful acoustical stimulation of the right ear. The subjects rated the perceived intensity of the painful stimuli by means of a visual analogue scale. In addition the spontaneous EEG was analysed in the frequency domain and the vigilance of the subjects was assessed in a tracking task. 3. Diazepam reduced significantly the amplitudes of the event-related potentials after painful stimulation of the tooth pulp and after acoustical stimulation. In contrast only a small, statistically non-significant reduction could be found after painful stimulation with CO2. The pain ratings of the painful stimuli were not affected by diazepam. Diazepam reduced the performance of the tracking task. A decrease of arousal could be found in the alpha 2-range, whereas in the beta 2 and the theta-range the power density increased under diazepam. 4. We demonstrated that event-related potentials after painful stimulation of the nasal mucosa with CO2 are less affected by the nonspecific effects of the tranquilizer diazepam than event-related potentials after painful

  5. 47 CFR 11.33 - EAS Decoder.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false EAS Decoder. 11.33 Section 11.33 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL EMERGENCY ALERT SYSTEM (EAS) Equipment Requirements § 11.33 EAS Decoder. (a) An EAS Decoder must at a minimum be capable of providing the EAS monitoring functions described in § 11.52, decoding...

  6. 47 CFR 11.33 - EAS Decoder.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false EAS Decoder. 11.33 Section 11.33 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL EMERGENCY ALERT SYSTEM (EAS) Equipment Requirements § 11.33 EAS Decoder. (a) An EAS Decoder must at a minimum be capable of providing the EAS monitoring functions described in § 11.52, decoding...

  7. Study of envelope electron acoustic solitary waves under transverse perturbations having kappa distributed hot electrons

    SciTech Connect

    Bedi, Chanchal; Gill, T. S.

    2012-06-15

    As is well known, the envelope electron acoustic (EA) nonlinear waves are expressed by nonlinear Schroedinger equation. In this paper, we find that under transverse perturbations, this kind of nonlinear waves can be described by Davey-Stewartson equation. In this work, modulational properties of EA wave and its stability regions in two-dimensional plasma have been studied.

  8. EA Shuttle Document Retention Effort

    NASA Technical Reports Server (NTRS)

    Wagner, Howard A.

    2010-01-01

    This slide presentation reviews the effort of code EA at Johnson Space Center (JSC) to identify and acquire databases and documents from the space shuttle program that are adjudged important for retention after the retirement of the space shuttle.

  9. Acoustical standards in engineering acoustics

    NASA Astrophysics Data System (ADS)

    Burkhard, Mahlon D.

    2001-05-01

    The Engineering Acoustics Technical Committee is concerned with the evolution and improvement of acoustical techniques and apparatus, and with the promotion of new applications of acoustics. As cited in the Membership Directory and Handbook (2002), the interest areas include transducers and arrays; underwater acoustic systems; acoustical instrumentation and monitoring; applied sonics, promotion of useful effects, information gathering and transmission; audio engineering; acoustic holography and acoustic imaging; acoustic signal processing (equipment and techniques); and ultrasound and infrasound. Evident connections between engineering and standards are needs for calibration, consistent terminology, uniform presentation of data, reference levels, or design targets for product development. Thus for the acoustical engineer standards are both a tool for practices, for communication, and for comparison of his efforts with those of others. Development of many standards depends on knowledge of the way products are put together for the market place and acoustical engineers provide important input to the development of standards. Acoustical engineers and members of the Engineering Acoustics arm of the Society both benefit from and contribute to the Acoustical Standards of the Acoustical Society.

  10. 32 CFR 651.34 - EA components.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true EA components. 651.34 Section 651.34 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) ENVIRONMENTAL QUALITY ENVIRONMENTAL ANALYSIS OF ARMY ACTIONS (AR 200-2) Environmental Assessment § 651.34 EA components. EAs should...

  11. 32 CFR 651.34 - EA components.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 4 2012-07-01 2011-07-01 true EA components. 651.34 Section 651.34 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) ENVIRONMENTAL QUALITY ENVIRONMENTAL ANALYSIS OF ARMY ACTIONS (AR 200-2) Environmental Assessment § 651.34 EA components. EAs should...

  12. 32 CFR 651.34 - EA components.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 4 2014-07-01 2013-07-01 true EA components. 651.34 Section 651.34 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) ENVIRONMENTAL QUALITY ENVIRONMENTAL ANALYSIS OF ARMY ACTIONS (AR 200-2) Environmental Assessment § 651.34 EA components. EAs should...

  13. 32 CFR 651.34 - EA components.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 4 2013-07-01 2013-07-01 false EA components. 651.34 Section 651.34 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) ENVIRONMENTAL QUALITY ENVIRONMENTAL ANALYSIS OF ARMY ACTIONS (AR 200-2) Environmental Assessment § 651.34 EA components. EAs should...

  14. 32 CFR 651.34 - EA components.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 4 2011-07-01 2011-07-01 false EA components. 651.34 Section 651.34 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) ENVIRONMENTAL QUALITY ENVIRONMENTAL ANALYSIS OF ARMY ACTIONS (AR 200-2) Environmental Assessment § 651.34 EA components. EAs should...

  15. Acoustic Neuroma

    MedlinePlus

    An acoustic neuroma is a benign tumor that develops on the nerve that connects the ear to the brain. The tumor ... press against the brain, becoming life-threatening. Acoustic neuroma can be difficult to diagnose, because the symptoms ...

  16. [Reactions of neurons in the dental projection area of the rabbit sensomotor cortex to photic, acoustic and painful stimulation of the dental pulp].

    PubMed

    Samko, Iu N

    1979-04-01

    In experiments on unrestrained rabbits interactions of sound (tone, click), light and pain excitation occurring during stimulation of the dental pulp in the neurons of the cortical sensomotor zone, in the area of representation of the dental afferents were studied by the microelectrode method. It was shown that bi- and polysensor convergence of excitation is realized in the cells of this area. It is suggested that convergence of excitation underlies the mechanisms of formation of the integral systemic pain reaction during stimulation of the dental receptors.

  17. 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.

  18. 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.

  19. Molecular regulation of auditory hair cell death and approaches to protect sensory receptor cells and/or stimulate repair following acoustic trauma

    PubMed Central

    Dinh, Christine T.; Goncalves, Stefania; Bas, Esperanza; Van De Water, Thomas R.; Zine, Azel

    2015-01-01

    Loss of auditory sensory hair cells (HCs) is the most common cause of hearing loss. This review addresses the signaling pathways that are involved in the programmed and necrotic cell death of auditory HCs that occur in response to ototoxic and traumatic stressor events. The roles of inflammatory processes, oxidative stress, mitochondrial damage, cell death receptors, members of the mitogen-activated protein kinase (MAPK) signal pathway and pro- and anti-cell death members of the Bcl-2 family are explored. The molecular interaction of these signal pathways that initiates the loss of auditory HCs following acoustic trauma is covered and possible therapeutic interventions that may protect these sensory HCs from loss via apoptotic or non-apoptotic cell death are explored. PMID:25873860

  20. Twisted electron-acoustic waves in plasmas

    NASA Astrophysics Data System (ADS)

    Aman-ur-Rehman, Ali, S.; Khan, S. A.; Shahzad, K.

    2016-08-01

    In the paraxial limit, a twisted electron-acoustic (EA) wave is studied in a collisionless unmagnetized plasma, whose constituents are the dynamical cold electrons and Boltzmannian hot electrons in the background of static positive ions. The analytical and numerical solutions of the plasma kinetic equation suggest that EA waves with finite amount of orbital angular momentum exhibit a twist in its behavior. The twisted wave particle resonance is also taken into consideration that has been appeared through the effective wave number qeff accounting for Laguerre-Gaussian mode profiles attributed to helical phase structures. Consequently, the dispersion relation and the damping rate of the EA waves are significantly modified with the twisted parameter η, and for η → ∞, the results coincide with the straight propagating plane EA waves. Numerically, new features of twisted EA waves are identified by considering various regimes of wavelength and the results might be useful for transport and trapping of plasma particles in a two-electron component plasma.

  1. 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.

  2. 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.

  3. 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.

  4. Acoustic metafluids.

    PubMed

    Norris, Andrew N

    2009-02-01

    Acoustic metafluids are defined as the class of fluids that allow one domain of fluid to acoustically mimic another, as exemplified by acoustic cloaks. It is shown that the most general class of acoustic metafluids are materials with anisotropic inertia and the elastic properties of what are known as pentamode materials. The derivation uses the notion of finite deformation to define the transformation of one region to another. The main result is found by considering energy density in the original and transformed regions. Properties of acoustic metafluids are discussed, and general conditions are found which ensure that the mapped fluid has isotropic inertia, which potentially opens up the possibility of achieving broadband cloaking. PMID:19206861

  5. 47 CFR 11.18 - EAS Designations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... source of EAS Local Area messages. An LP source is responsible for coordinating the carriage of common... as specified in its EAS Local Area Plan. If it is unable to carry out this function, other LP sources in the Local Area may be assigned the responsibility as indicated in State and Local Area Plans....

  6. 47 CFR 11.18 - EAS Designations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Designations. (a) National Primary (NP) is a source of EAS Presidential messages. (b) Local Primary (LP) is a source of EAS Local Area messages. An LP source is responsible for coordinating the carriage of common emergency messages from sources such as the National Weather Service or local emergency management...

  7. Acoustic trauma

    MedlinePlus

    Acoustic trauma is a common cause of sensory hearing loss . Damage to the hearing mechanisms within the inner ... Symptoms include: Partial hearing loss that most often involves ... The hearing loss may slowly get worse. Noises, ringing in ...

  8. 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 ...

  9. Underwater Acoustics.

    ERIC Educational Resources Information Center

    Creasey, D. J.

    1981-01-01

    Summarizes the history of underwater acoustics and describes related research studies and teaching activities at the University of Birmingham (England). Also includes research studies on transducer design and mathematical techniques. (SK)

  10. 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.

  11. 47 CFR 11.46 - EAS public service announcements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false EAS public service announcements. 11.46 Section...) Organization § 11.46 EAS public service announcements. EAS Participants may use Public Service Announcements or obtain commercial sponsors for announcements, infomercials, or programs explaining the EAS to the...

  12. 47 CFR 11.46 - EAS public service announcements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false EAS public service announcements. 11.46 Section...) Organization § 11.46 EAS public service announcements. EAS Participants may use Public Service Announcements or obtain commercial sponsors for announcements, infomercials, or programs explaining the EAS to the...

  13. 7 CFR 1794.71 - Adoption of an EA.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 12 2013-01-01 2013-01-01 false Adoption of an EA. 1794.71 Section 1794.71... AGRICULTURE (CONTINUED) ENVIRONMENTAL POLICIES AND PROCEDURES Adoption of Environmental Documents § 1794.71 Adoption of an EA. RUS may adopt a Federal EA or EIS or a portion thereof as its EA. RUS shall make the...

  14. 7 CFR 1794.71 - Adoption of an EA.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 12 2010-01-01 2010-01-01 false Adoption of an EA. 1794.71 Section 1794.71... AGRICULTURE (CONTINUED) ENVIRONMENTAL POLICIES AND PROCEDURES Adoption of Environmental Documents § 1794.71 Adoption of an EA. RUS may adopt a Federal EA or EIS or a portion thereof as its EA. RUS shall make the...

  15. 7 CFR 1794.71 - Adoption of an EA.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 12 2012-01-01 2012-01-01 false Adoption of an EA. 1794.71 Section 1794.71... AGRICULTURE (CONTINUED) ENVIRONMENTAL POLICIES AND PROCEDURES Adoption of Environmental Documents § 1794.71 Adoption of an EA. RUS may adopt a Federal EA or EIS or a portion thereof as its EA. RUS shall make the...

  16. 7 CFR 1794.71 - Adoption of an EA.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 12 2011-01-01 2011-01-01 false Adoption of an EA. 1794.71 Section 1794.71... AGRICULTURE (CONTINUED) ENVIRONMENTAL POLICIES AND PROCEDURES Adoption of Environmental Documents § 1794.71 Adoption of an EA. RUS may adopt a Federal EA or EIS or a portion thereof as its EA. RUS shall make the...

  17. 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

  18. 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

  19. Registration of Neutrons Within 2 Milliseconds after EAS

    NASA Astrophysics Data System (ADS)

    JȨDRZEJCZAK, K.; Karczmarczyk, J.; Kasztelan, M.; Petrochenkov, S. A.; Polański, A.; Swarzyński, J.; Szabelski, J.; Wibig, T.

    We register an excess of signals from neutron detectors within a few milliseconds after passage of EAS front in Łódź EAS array. The most probable explanation is that neutrons are produced in EAS hadron interactions with lead block of muon detector. These neutrons diffuse and are thermalized before the detection. We present experimental data and results of simulations using MCNP code. This "new EAS observable" can be used as inexpensive hadron detector in EAS.

  20. Electric-acoustic interactions in the hearing cochlea: single fiber recordings.

    PubMed

    Tillein, J; Hartmann, R; Kral, A

    2015-04-01

    The present study investigates interactions of simultaneous electric and acoustic stimulation in single auditory nerve fibers in normal hearing cats. First, the auditory nerve was accessed with a microelectrode and response areas of single nerve fibers were determined for acoustic stimulation. Second, response thresholds to extracochlear sinusoidal electric stimulation using ball electrodes positioned at the round window were measured. Third, interactions that occurred with combined electric-acoustic stimulation were investigated in two areas: (1) the spectral domain (frequency response areas) and (2) the temporal domain (phase-locking to each stimulus) at moderate stimulus intensities (electric: 6 dB re threshold, acoustic: 20-40 dB re threshold at the characteristic frequency, CF). For fibers responding to both modalities responses to both electric and acoustic stimulation could be clearly identified. CFs, thresholds, and bandwidth (Q10dB) of acoustic responses were not significantly affected by simultaneous electric stimulation. Phase-locking of electric responses decreased in the presence of acoustic stimulation. Indication for electric stimulation of inner hair cells with 125 and 250 Hz were observed. However, these did not disturb the acoustic receptive fields of auditory nerve fibers. There was a trade-off between these responses when the intensities of the stimulation were varied: Relatively more intense stimulation dominated less intense stimulation. The scarcity of interaction between the different stimulus modalities demonstrates the ability of electric-acoustic stimulation to transfer useful information through both stimulation channels at the same time despite cochlear electrophonic effects. Application of 30 Hz electric stimulation resulted in a strong suppression of acoustic activity in the anodic phase of the stimulus. An electric stimulation like this might thus be used to control acoustic responses. This article is part of a Special Issue

  1. Advances In Atmospheric Acoustic Sounding

    NASA Astrophysics Data System (ADS)

    Bradley, S. G.; von Hunerbein, S.

    Acoustic sounders (SODAR) have developed as a useful and reliable operational tool for atmospheric boundary layer studies. This means that the effort in SODAR design can now be directed toward extended range, more compact design, use in more dif- ficult environments, and into extracting more information content from the scattered signals. We describe leading-edge developments and approaches in each of these ar- eas, but particularly with reference to the work by the Salford UK team. Specifically, we discuss: new hardware implementations using pulse-coding; progress and the pro- jected use of a suitcase-SODAR; baffle/beam requirements for use in urban environ- ments; multi-frequency methods of separating observables; use of multiple-SODAR arrays; multi-phase precipitation measurements; and inverse-method techniques for systematic optimization of data retrievals.

  2. The identification of gamma ray induced EAS

    NASA Technical Reports Server (NTRS)

    Blake, P. R.; Nash, W. F.

    1985-01-01

    Some of the penetrating particles in gamma-induced EAS from Cygnus X-3 observed by a single layer of flash-bulbs under 880 g cm/2 concrete, may be punched through photons rather than muons. An analysis of the shielded flash-tube response detected from EAS is presented. The penetration of the electro-magnetic component through 20 cm of Pb is observed at core distances approx. 10 m.

  3. Acoustic transducer for acoustic microscopy

    DOEpatents

    Khuri-Yakub, B.T.; Chou, C.H.

    1990-03-20

    A shear acoustic transducer-lens system is described 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. 9 figs.

  4. 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.

  5. Medical Acoustics

    NASA Astrophysics Data System (ADS)

    Beach, Kirk W.; Dunmire, Barbrina

    Medical acoustics can be subdivided into diagnostics and therapy. Diagnostics are further separated into auditory and ultrasonic methods, and both employ low amplitudes. Therapy (excluding medical advice) uses ultrasound for heating, cooking, permeablizing, activating and fracturing tissues and structures within the body, usually at much higher amplitudes than in diagnostics. Because ultrasound is a wave, linear wave physics are generally applicable, but recently nonlinear effects have become more important, even in low-intensity diagnostic applications.

  6. Wideband Acoustic Immittance: Normative Study and Test-Retest Reliability of Tympanometric Measurements in Adults

    ERIC Educational Resources Information Center

    Sun, Xiao-Ming

    2016-01-01

    Purpose: The purpose of this study was to present normative data of tympanometric measurements of wideband acoustic immittance and to characterize wideband tympanograms. Method: Data were collected in 84 young adults with strictly defined normal hearing and middle ear status. Energy absorbance (EA) was measured using clicks for 1/12-octave…

  7. The Samarkand EAS installation and experimental results

    NASA Astrophysics Data System (ADS)

    Makhmudov, B. M.; Sirodzhev, N. S.; Alimov, T. A.; Aliev, N. A.; Kakhkharov, M. K.; Khamikov, N. Kh.; Vernov, S. N.; Khristiansen, G. B.

    1982-09-01

    The Samarkand University extensive-air-shower installation is briefly described, and experimental results obtained at this installation are discussed. It is shown that the spatial distribution of EAS Cerenkov emission at distances of 10-100 m from the EAS axis with respect to shape and absolute value given a purely protonic composition of the primary radiation can be made compatible with the scaling model only under the assumption of an anomalously sharp increase with energy of the cross section of the inelastic interactions of hadrons with atomic air nuclei. In addition, it is shown that the Xmax(E0) relationship (Xmax is the position of the maximum of an individual EAS) obtained at E0 exceeding 10 to the 17th eV on the basis of Yakutsk data does not contradict Samarkand data at E0 = 10 to the 16th eV.

  8. Acoustic Tooth Cleaner

    NASA Technical Reports Server (NTRS)

    Heyman, J. S.

    1984-01-01

    Acoustically-energized water jet aids in plaque breakdown. Acoustic Wand includes acoustic transducer 1/4 wave plate, and tapered cone. Together elements energize solution of water containing mild abrasive injected into mouth to help prevent calculous buildup.

  9. Study of EAS neutron component temporal structure

    NASA Astrophysics Data System (ADS)

    Gromushkin, D. M.; Petrukhin, A. A.; Stenkin, Yu. V.; Yashin, I. I.

    2011-04-01

    The neutron component of Extensive Air Showers (EAS) carries information about the primary cosmic ray flux as well as about parameters of hadronic interactions at ultra-high energies. We present here the data obtained with the "Neutron" array which is a prototype of a novel type EAS array PRISMA (Stenkin, 2009). The prototype consists of 5 large area scintillator detectors (0.75 m2 each) placed in the corners and in the center of 5 m side square. The scintillator consisting of an alloy of ZnS(Ag) and 6LiF is shaped as a thin layer of grains covered with thin transparent plastic film.

  10. 47 CFR 11.41 - Participation in EAS.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Participation in EAS. 11.41 Section 11.41 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL EMERGENCY ALERT SYSTEM (EAS) Organization § 11.41... sources, including NN, must have immediate access to an EAS Operating Handbook....

  11. Electroacupuncture increased cerebral blood flow and reduced ischemic brain injury: dependence on stimulation intensity and frequency

    PubMed Central

    Zhou, Fei; Guo, Jingchun; Cheng, Jieshi; Wu, Gencheng

    2011-01-01

    Stroke causes ischemic brain injury and is a leading cause of neurological disability and death. There is, however, no promising therapy to protect the brain from ischemic stress to date. Here we show an exciting finding that optimal electroacupuncture (EA) effectively protects the brain from ischemic injury. The experiments were performed on rats subjected to middle cerebral artery occlusion (MCAO) with continuous monitoring of cerebral blood flow. EA was delivered to acupoints of “Shuigou” (Du 26) and “Baihui” (Du 20) with different intensities and frequencies to optimize the stimulation parameters. The results showed that 1) EA at 1.0–1.2 mA and 5–20 Hz remarkably reduced ischemic infarction, neurological deficit, and death rate; 2) the EA treatment increased the blood flow by >100%, which appeared immediately after the initiation of EA and disappeared after the cessation of EA; 3) the EA treatment promoted the recovery of the blood flow after MCAO; 4) “nonoptimal” parameters of EA (e.g., <0.6 mA or >40 Hz) could not improve the blood flow or reduce ischemic injury; and 5) the same EA treatment with optimal parameters could not increase the blood flow in naive brains. These novel observations suggest that appropriate EA treatment protects the brain from cerebral ischemia by increasing blood flow to the ischemic brain region via a rapid regulation. Our findings have far-reaching impacts on the prevention and treatment of ischemic encephalopathy, and the optimized EA parameters may potentially be a useful clue for the clinical application of EA. PMID:21836043

  12. Performance comparisons between PCA-EA-LBG and PCA-LBG-EA approaches in VQ codebook generation for image compression

    NASA Astrophysics Data System (ADS)

    Tsai, Jinn-Tsong; Chou, Ping-Yi; Chou, Jyh-Horng

    2015-11-01

    The aim of this study is to generate vector quantisation (VQ) codebooks by integrating principle component analysis (PCA) algorithm, Linde-Buzo-Gray (LBG) algorithm, and evolutionary algorithms (EAs). The EAs include genetic algorithm (GA), particle swarm optimisation (PSO), honey bee mating optimisation (HBMO), and firefly algorithm (FF). The study is to provide performance comparisons between PCA-EA-LBG and PCA-LBG-EA approaches. The PCA-EA-LBG approaches contain PCA-GA-LBG, PCA-PSO-LBG, PCA-HBMO-LBG, and PCA-FF-LBG, while the PCA-LBG-EA approaches contain PCA-LBG, PCA-LBG-GA, PCA-LBG-PSO, PCA-LBG-HBMO, and PCA-LBG-FF. All training vectors of test images are grouped according to PCA. The PCA-EA-LBG used the vectors grouped by PCA as initial individuals, and the best solution gained by the EAs was given for LBG to discover a codebook. The PCA-LBG approach is to use the PCA to select vectors as initial individuals for LBG to find a codebook. The PCA-LBG-EA used the final result of PCA-LBG as an initial individual for EAs to find a codebook. The search schemes in PCA-EA-LBG first used global search and then applied local search skill, while in PCA-LBG-EA first used local search and then employed global search skill. The results verify that the PCA-EA-LBG indeed gain superior results compared to the PCA-LBG-EA, because the PCA-EA-LBG explores a global area to find a solution, and then exploits a better one from the local area of the solution. Furthermore the proposed PCA-EA-LBG approaches in designing VQ codebooks outperform existing approaches shown in the literature.

  13. Acoustic transducer

    DOEpatents

    Drumheller, D.S.

    1997-12-30

    An acoustic transducer is described comprising a one-piece hollow mandrel into the outer surface of which is formed a recess with sides perpendicular to the central axis of the mandrel and separated by a first distance and with a bottom parallel to the central axis and within which recess are a plurality of washer-shaped discs of a piezoelectric material and at least one disc of a temperature-compensating material with the discs being captured between the sides of the recess in a pre-stressed interference fit, typically at 2,000 psi of compressive stress. The transducer also includes a power supply and means to connect to a measurement device. The transducer is intended to be used for telemetry between a measurement device located downhole in an oil or gas well and the surface. The transducer is of an construction that is stronger with fewer joints that could leak fluids into the recess holding the piezoelectric elements than is found in previous acoustic transducers. 4 figs.

  14. Acoustic transducer

    DOEpatents

    Drumheller, Douglas S.

    1997-01-01

    An acoustic transducer comprising a one-piece hollow mandrel into the outer surface of which is formed a recess with sides perpendicular to the central axis of the mandrel and separated by a first distance and with a bottom parallel to the central axis and within which recess are a plurality of washer-shaped discs of a piezoelectric material and at least one disc of a temperature-compensating material with the discs being captured between the sides of the recess in a pre-stressed interference fit, typically at 2000 psi of compressive stress. The transducer also includes a power supply and means to connect to a measurement device. The transducer is intended to be used for telemetry between a measurement device located downhole in an oil or gas well and the surface. The transducer is of an construction that is stronger with fewer joints that could leak fluids into the recess holding the piezoelectric elements than is found in previous acoustic transducers.

  15. TRANSPORT PROPERTY MEASUREMENTS OF HFC-236EA

    EPA Science Inventory

    The report gives results of an evaluation of transport properties of 1,1,1,2,3,3,-hexafluoropropane (HFC-236ea), with liquid viscosity and thermal conductivity being the two main transport properties of interest. In addition, the specific heat and density of refrigerant/lubrican...

  16. 47 CFR 11.33 - EAS Decoder.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., satellite, public switched telephone network, or any other source that uses the EAS protocol. (2) Valid..., either internally or externally, at least two minutes of audio or text messages. A decoder manufactured... messages which still have valid time periods must be stored for comparison with the incoming valid...

  17. 24 CFR 50.31 - The EA.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false The EA. 50.31 Section 50.31 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development PROTECTION... form to be used for analysis and documentation by HUD for projects and activities under subpart E....

  18. 24 CFR 50.31 - The EA.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 1 2013-04-01 2013-04-01 false The EA. 50.31 Section 50.31 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development PROTECTION AND ENHANCEMENT OF ENVIRONMENTAL QUALITY Environmental Assessments and Related Reviews § 50.31 The...

  19. 24 CFR 50.31 - The EA.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 1 2012-04-01 2012-04-01 false The EA. 50.31 Section 50.31 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development PROTECTION AND ENHANCEMENT OF ENVIRONMENTAL QUALITY Environmental Assessments and Related Reviews § 50.31 The...

  20. 24 CFR 50.31 - The EA.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 1 2014-04-01 2014-04-01 false The EA. 50.31 Section 50.31 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development PROTECTION AND ENHANCEMENT OF ENVIRONMENTAL QUALITY Environmental Assessments and Related Reviews § 50.31 The...

  1. 24 CFR 50.31 - The EA.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 1 2011-04-01 2011-04-01 false The EA. 50.31 Section 50.31 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development PROTECTION AND ENHANCEMENT OF ENVIRONMENTAL QUALITY Environmental Assessments and Related Reviews § 50.31 The...

  2. 47 CFR 11.33 - EAS Decoder.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... satisfied via an Intermediary Device, as specified in § 11.56(b), provided that all other requirements set...: (1) Inputs. Decoders must have the capability to receive at least two audio inputs from EAS monitoring assignments, and at least one data input. The data input(s) may be used to monitor...

  3. Acoustic emission descriptors

    NASA Astrophysics Data System (ADS)

    Witos, Franciszek; Malecki, Ignacy

    The authors present selected problems associated with acoustic emission interpreted as a physical phenomenon and as a measurement technique. The authors examine point sources of acoustic emission in isotropic, homogeneous linearly elastic media of different shapes. In the case of an unbounded medium the authors give the analytical form of the stress field and the wave shift field of the acoustic emission. In the case of a medium which is unbounded plate the authors give a form for the equations which is suitable for numerical calculation of the changes over time of selected acoustic emission values. For acoustic emission as a measurement technique, the authors represent the output signal as the resultant of a mechanical input value which describes the source, the transient function of the medium, and the transient function of specific components of the measurement loop. As an effect of this notation, the authors introduce the distinction between an acoustic measurement signal and an acoustic measurement impulse. The authors define the basic parameters of an arbitrary impulse. The authors extensively discuss the signal functions of acoustic emission impulses and acoustic emission signals defined in this article as acoustic emission descriptors (or signal functions of acoustic emission impulses) and advanced acoustic emission descriptors (which are either descriptors associated with acoustic emission applications or the signal functions of acoustic emission signals). The article also contains the results of experimental research on three different problems in which acoustic emission descriptors associated with acoustic emission pulses, acoustic emission applications, and acoustic emission signals are used. These problems are respectively: a problem of the amplitude-load characteristics of acoustic emission pulses in carbon samples subjected to compound uniaxial compression, the use of acoustic emission to predict the durability characteristics of conveyor belts, and

  4. Acoustic transducer

    DOEpatents

    Drumheller, Douglas S.

    2000-01-01

    An active acoustic transducer tool for use down-hole applications. The tool includes a single cylindrical mandrel including a shoulder defining the boundary of a narrowed portion over which is placed a sandwich-style piezoelectric tranducer assembly. The piezoelectric transducer assembly is prestressed by being placed in a thermal interference fit between the shoulder of the mandrel and the base of an anvil which is likewise positioned over the narrower portion of the mandrel. In the preferred embodiment, assembly of the tool is accomplished using a hydraulic jack to stretch the mandrel prior to emplacement of the cylindrical sandwich-style piezoelectric transducer assembly and anvil. After those elements are positioned and secured, the stretched mandrel is allowed to return substantially to its original (pre-stretch) dimensions with the result that the piezoelectric transducer elements are compressed between the anvil and the shoulder of the mandrel.

  5. Acoustic cryocooler

    DOEpatents

    Swift, Gregory W.; Martin, Richard A.; Radenbaugh, Ray

    1990-01-01

    An acoustic cryocooler with no moving parts is formed from a thermoacoustic driver (TAD) driving a pulse tube refrigerator (PTR) through a standing wave tube. Thermoacoustic elements in the TAD are spaced apart a distance effective to accommodate the increased thermal penetration length arising from the relatively low TAD operating frequency in the range of 15-60 Hz. At these low operating frequencies, a long tube is required to support the standing wave. The tube may be coiled to reduce the overall length of the cryocooler. One or two PTR's are located on the standing wave tube adjacent antinodes in the standing wave to be driven by the standing wave pressure oscillations. It is predicted that a heat input of 1000 W at 1000 K will maintian a cooling load of 5 W at 80 K.

  6. Acoustic telemetry.

    SciTech Connect

    Drumheller, Douglas Schaeffer; Kuszmaul, Scott S.

    2003-08-01

    Broadcasting messages through the earth is a daunting task. Indeed, broadcasting a normal telephone conversion through the earth by wireless means is impossible with todays technology. Most of us don't care, but some do. Industries that drill into the earth need wireless communication to broadcast navigation parameters. This allows them to steer their drill bits. They also need information about the natural formation that they are drilling. Measurements of parameters such as pressure, temperature, and gamma radiation levels can tell them if they have found a valuable resource such as a geothermal reservoir or a stratum bearing natural gas. Wireless communication methods are available to the drilling industry. Information is broadcast via either pressure waves in the drilling fluid or electromagnetic waves in the earth and well tubing. Data transmission can only travel one way at rates around a few baud. Given that normal Internet telephone modems operate near 20,000 baud, these data rates are truly very slow. Moreover, communication is often interrupted or permanently blocked by drilling conditions or natural formation properties. Here we describe a tool that communicates with stress waves traveling through the steel drill pipe and production tubing in the well. It's based on an old idea called Acoustic Telemetry. But what we present here is more than an idea. This tool exists, it's drilled several wells, and it works. Currently, it's the first and only acoustic telemetry tool that can withstand the drilling environment. It broadcasts one way over a limited range at much faster rates than existing methods, but we also know how build a system that can communicate both up and down wells of indefinite length.

  7. A wirelessly powered electro-acupuncture based on adaptive pulsewidth monophase stimulation.

    PubMed

    Kiseok Song; Long Yan; Seulki Lee; Yoo, Jerald; Hoi-Jun Yoo

    2011-04-01

    A wirelessly powered electro-acupuncture (EA) system with adaptive-pulsewidth (APW) monophase stimulation is presented for convenient invasive medicine. The proposed system removes cumbersome wires connected between EA nodes and an EA controller in order to realize both patients' convenience and remedial values simultaneously. An ultra-low-power stimulator integrated circuit (IC) that is integrated on the flexible-printed-circuit board (F-PCB) is attached to the tip of a needle electrode. Combined with a conductive yarn helical antenna wound around the needle electrode, the EA node receives wireless power from the EA controller using 433 MHz with the maximum loss of 6 dB. A zero-Vth nMOS rectifier harvests a supply voltage of 1.0 V from a -16-dBm incoming power signal with 32% efficiency. To deal with a body impedance variation (BIV) in the range of 100-200 kΩ , the proposed APW stimulator IC, fabricated in a 0.18-μm 1P6M complementary metal-oxide semiconductor CMOS process and occupying 1.56 mm(2), enables constant charge injection of 80-nC/stimulation. To ensure the patients' safety, the EA node (a pair of EAs) shares ground and clock wires to operate in alternate monophase (AMP) fashion for neutralizing the injected charge. The proposed wirelessly powered EA node was verified by applying it to a chunk of pork as a body model with the wireless power supplied from an RF signal generator (output power of 10 dBm and located 30 cm away).

  8. A wirelessly powered electro-acupuncture based on adaptive pulsewidth monophase stimulation.

    PubMed

    Kiseok Song; Long Yan; Seulki Lee; Yoo, Jerald; Hoi-Jun Yoo

    2011-04-01

    A wirelessly powered electro-acupuncture (EA) system with adaptive-pulsewidth (APW) monophase stimulation is presented for convenient invasive medicine. The proposed system removes cumbersome wires connected between EA nodes and an EA controller in order to realize both patients' convenience and remedial values simultaneously. An ultra-low-power stimulator integrated circuit (IC) that is integrated on the flexible-printed-circuit board (F-PCB) is attached to the tip of a needle electrode. Combined with a conductive yarn helical antenna wound around the needle electrode, the EA node receives wireless power from the EA controller using 433 MHz with the maximum loss of 6 dB. A zero-Vth nMOS rectifier harvests a supply voltage of 1.0 V from a -16-dBm incoming power signal with 32% efficiency. To deal with a body impedance variation (BIV) in the range of 100-200 kΩ , the proposed APW stimulator IC, fabricated in a 0.18-μm 1P6M complementary metal-oxide semiconductor CMOS process and occupying 1.56 mm(2), enables constant charge injection of 80-nC/stimulation. To ensure the patients' safety, the EA node (a pair of EAs) shares ground and clock wires to operate in alternate monophase (AMP) fashion for neutralizing the injected charge. The proposed wirelessly powered EA node was verified by applying it to a chunk of pork as a body model with the wireless power supplied from an RF signal generator (output power of 10 dBm and located 30 cm away). PMID:23851202

  9. Acoustic hemostasis

    NASA Astrophysics Data System (ADS)

    Crum, Lawrence; Beach, Kirk; Carter, Stephen; Chandler, Wayne; Curra, Francesco; Kaczkowski, Peter; Keilman, George; Khokhlova, Vera; Martin, Roy; Mourad, Pierre; Vaezy, Shahram

    2000-07-01

    In cases of severe injury, physicians speak of a "golden hour"—a brief grace period in which quickly applied, proper therapy can save the life of the patient. Much of this mortality results from exsanguination, i.e., bleeding to death—often from internal hemorrhage. The inability of a paramedic to treat breaches in the vascular system deep within the body or to stem the loss of blood from internal organs is a major reason for the high level of mortality associated with blunt trauma. We have undertaken an extensive research program to treat the problem of internal bleeding. Our approach is as follows: (a) We use scanning ultrasound to identify internal bleeding and hemorrhage, (b) we use ultrasound imaging to locate specific breaches in the vascular system, both from damaged vessels and gross damage to the capillary bed, and (c) we use High Intensity Focused Ultrasound (HIFU) to treat the damaged region and to induce hemostasis. We present a general review of this research with some emphasis on the role of nonlinear acoustics.

  10. 47 CFR 11.55 - EAS operation during a State or Local Area emergency.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false EAS operation during a State or Local Area... SYSTEM (EAS) Emergency Operations § 11.55 EAS operation during a State or Local Area emergency. (a) The EAS may be activated at the State and Local Area levels by EAS Participants at their discretion...

  11. Acoustic source for generating an acoustic beam

    DOEpatents

    Vu, Cung Khac; Sinha, Dipen N.; Pantea, Cristian

    2016-05-31

    An acoustic source for generating an acoustic beam includes a housing; a plurality of spaced apart piezo-electric layers disposed within the housing; and a non-linear medium filling between the plurality of layers. Each of the plurality of piezoelectric layers is configured to generate an acoustic wave. The non-linear medium and the plurality of piezo-electric material layers have a matching impedance so as to enhance a transmission of the acoustic wave generated by each of plurality of layers through the remaining plurality of layers.

  12. A model-based analysis of the "combined-stimulation advantage".

    PubMed

    Seldran, Fabien; Micheyl, Christophe; Truy, Eric; Berger-Vachon, Christian; Thai-Van, Hung; Gallego, Stéphane

    2011-12-01

    Improvements in speech-recognition performance resulting from the addition of low-frequency information to electric (or vocoded) signals have attracted considerable interest in recent years. An important question is whether these improvements reflect a form of constructive perceptual interaction-whereby acoustic cues enhance the perception of electric or vocoded signals-or whether they can be explained without assuming any interaction. To address this question, speech-recognition performance was measured in 24 normal-hearing listeners using lowpass-filtered, vocoded, and "combined" (lowpass + vocoded) words presented either in quiet or in a realistic background (cafeteria noise), for different signal-to-noise ratios, different lowpass-filter cutoff frequencies, and different numbers of vocoder bands. The results of these measures were then compared to the predictions of three models of cue combination, including a "probability-summation" model and two Gaussian signal detection theory (SDT) models-one (the "independent-noises" model) involving pre-combination noises, and the other (the "late-noise" model) involving post-combination noise. Consistent with previous findings, speech-recognition performance with combined stimulation was significantly higher than performance with vocoded or lowpass stimuli alone, and it was also higher than predicted by the probability-summation model. The two Gaussian-SDT models could account quantitatively for the data. Moreover, a Bayesian model-comparison procedure demonstrated that, given the data, these two models were far more likely than the probability-summation model. Since these models do not involve any constructive-interaction mechanism, this demonstrates that constructive interactions are not needed to explain the combined-stimulation benefits measured in this study. It will be important for future studies to investigate whether this conclusion generalizes to other test conditions, including real EAS, and to further test

  13. Phyiscal associated companion of E+A Galaxies

    NASA Astrophysics Data System (ADS)

    Yamauchi, Chisato; Goto, Tomotsugu; Yagi, Masafumi

    2005-08-01

    The subject of this proposal is to identify physically associated companions of E+A galaxies, and to obtain basic spectroscopic features of bright companions in order to understand the evolution of E+A system. E+A galaxies have been understood as post-starburst galaxies based on their strong Balmer absorption lines and the absence of [OII] or H(alpha) emission lines. Their origin has remained unknown for more than 20 years since E+A galaxies are very rare. To rectify the situation, Goto (2003,2005) has selected large & uniform E+A sample using the Sloan Digital Sky Survey (SDSS) data. Goto (2003) found that there is an excess in number of accompanying galaxies of E+As in the SDSS imaging data, and suggest that the origin of E+As is dynamical merger/interaction with companion galaxies. The merger/interaction origin scenario also implies that E+As can be progenitors of early-type galaxies and play important roles in galaxy evolution. The discussion of Goto (2003) was based on the imaging data. The accompanying galaxies are not spectroscopically observed in SDSS, and it is unknown which galaxy is the real companion of E+A. We therefore propose spectroscopic observation to identify physically associated companions, and to construct companion catalog without any contamination of fore/background overlapping galaxies. The correlation between properties of E+A and those of companions would give us great hints for understanding the evolution of E+A system, and set constraints on the theoretical models of E+A formation.

  14. Physically associated companion of E+A Galaxies - III

    NASA Astrophysics Data System (ADS)

    Yamauchi, Chisato; Goto, Tomotsugu; Yagi, Masafumi

    2007-02-01

    The subject of this proposal is to identify physically associated companions of E+A galaxies, and to obtain basic spectroscopic features of bright companions in order to understand the evolution of E+A system. E+A galaxies have been understood as post-starburst galaxies based on their strong Balmer absorption lines and the absence of [OII] or H(alpha) emission lines. Their origin has remained unknown for more than 20 years since E+A galaxies are very rare. To rectify the situation, Goto (2003,2005) has selected large & uniform E+A sample using the Sloan Digital Sky Survey (SDSS) data. Goto (2003) found that there is an excess in number of accompanying galaxies of E+As in the SDSS imaging data, and suggest that the origin of E+As is dynamical merger/interaction with companion galaxies. The merger/interaction origin scenario also implies that E+As can be progenitors of early-type galaxies and play important roles in galaxy evolution. The discussion of Goto (2003) was based on the imaging data. The accompanying galaxies are not spectroscopically observed in the SDSS, and therefore it is unknown which galaxy is a real companion of E+A. We therefore propose spectroscopic observation to identify physically associated companions, and to construct a companion catalog without any contamination of fore/background overlapping galaxies. The correlation between properties of E+A and those of companions would give us great hints for understanding the evolution of the E+A system, and set constraints on the theoretical models of the E+A formation.

  15. Canonical Acoustics and Its Application to Surface Acoustic Wave on Acoustic Metamaterials

    NASA Astrophysics Data System (ADS)

    Shen, Jian Qi

    2016-08-01

    In a conventional formalism of acoustics, acoustic pressure p and velocity field u are used for characterizing acoustic waves propagating inside elastic/acoustic materials. We shall treat some fundamental problems relevant to acoustic wave propagation alternatively by using canonical acoustics (a more concise and compact formalism of acoustic dynamics), in which an acoustic scalar potential and an acoustic vector potential (Φ ,V), instead of the conventional acoustic field quantities such as acoustic pressure and velocity field (p,u) for characterizing acoustic waves, have been defined as the fundamental variables. The canonical formalism of the acoustic energy-momentum tensor is derived in terms of the acoustic potentials. Both the acoustic Hamiltonian density and the acoustic Lagrangian density have been defined, and based on this formulation, the acoustic wave quantization in a fluid is also developed. Such a formalism of acoustic potentials is employed to the problem of negative-mass-density assisted surface acoustic wave that is a highly localized surface bound state (an eigenstate of the acoustic wave equations). Since such a surface acoustic wave can be strongly confined to an interface between an acoustic metamaterial (e.g., fluid-solid composite structures with a negative dynamical mass density) and an ordinary material (with a positive mass density), it will give rise to an effect of acoustic field enhancement on the acoustic interface, and would have potential applications in acoustic device design for acoustic wave control.

  16. What Is an Acoustic Neuroma

    MedlinePlus

    ... Acoustic Neuroma An acoustic neuroma, also called a vestibular schwannoma, is a rare benign tumor of the ... Acoustic Neuroma? An acoustic neuroma, known as a vestibular schwannoma, is a benign (non-cancerous) growth that ...

  17. Acoustic (loudspeaker) facial EMG monitoring: II. Use of evoked EMG activity during acoustic neuroma resection.

    PubMed

    Prass, R L; Kinney, S E; Hardy, R W; Hahn, J F; Lüders, H

    1987-12-01

    Facial electromyographic (EMG) activity was continuously monitored via loudspeaker during eleven translabyrinthine and nine suboccipital consecutive unselected acoustic neuroma resections. Ipsilateral facial EMG activity was synchronously recorded on the audio channels of operative videotapes, which were retrospectively reviewed in order to allow detailed evaluation of the potential benefit of various acoustic EMG patterns in the performance of specific aspects of acoustic neuroma resection. The use of evoked facial EMG activity was classified and described. Direct local mechanical (surgical) stimulation and direct electrical stimulation were of benefit in the localization and/or delineation of the facial nerve contour. Burst and train acoustic patterns of EMG activity appeared to indicate surgical trauma to the facial nerve that would not have been appreciated otherwise. Early results of postoperative facial function of monitored patients are presented, and the possible value of burst and train acoustic EMG activity patterns in the intraoperative assessment of facial nerve function is discussed. Acoustic facial EMG monitoring appears to provide a potentially powerful surgical tool for delineation of the facial nerve contour, the ongoing use of which may lead to continued improvement in facial nerve function preservation through modification of dissection strategy.

  18. 47 CFR 11.44 - EAS message priorities.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Messages; second, State Messages; and third, National Information Center (NIC) Messages. (c) Key EAS... distribution of Presidential Messages. NIC messages received from national networks which are not broadcast...

  19. Ovarian blood flow responses to electro-acupuncture stimulation at different frequencies and intensities in anaesthetized rats.

    PubMed

    Stener-Victorin, Elisabet; Kobayashi, Rie; Kurosawa, Mieko

    2003-10-31

    The purpose of the present study was to investigate changes in ovarian blood flow (OBF) in response to electro-acupuncture (EA) stimulation at different frequencies and intensities in anaesthetized rats. Whether the ovarian sympathetic nerves were involved in OBF responses was elucidated by severance of the ovarian sympathetic nerves. In addition, how changes in the systemic circulation affected OBF was evaluated by continuously recording blood pressure. OBF was measured on the surface of the left ovary using laser Doppler flowmeter. Acupuncture needles with a diameter of 0.3 mm were inserted bilaterally into the abdominal and the hindlimb muscles and connected to an electrical stimulator. Two frequencies-2 Hz (low) and 80 Hz (high)-with three different intensities-1.5, 3, and 6 mA-were applied for 35 s. Both low- and high-frequency EA at 1.5 mA and high-frequency EA at 3 mA had no effect on OBF or mean arterial blood pressure (MAP). Low-frequency EA at 3 and 6 mA elicited significant increases in OBF. In contrast, high-frequency EA with an intensity of 6 mA evoked significant decreases in OBF, followed by decreases in MAP. After severance of the ovarian sympathetic nerves, the increases in the OBF responses to low-frequency EA at 3 and 6 mA were totally abolished, and the responses at 6 mA showed a tendency to decrease, probably because of concomitant decreases in MAP. The decreased OBF and MAP responses to high-frequency EA at 6 mA remained after the ovarian sympathectomy, and the difference in the responses before and after ovarian sympathectomy was nonsignificant. In conclusion, the present study showed that low-frequency EA stimulation increases OBF as a reflex response via the ovarian sympathetic nerves, whereas high-frequency EA stimulation decreases OBF as a passive response following systemic circulatory changes.

  20. Infrared neural stimulation in the cochlea

    PubMed Central

    Richter, Claus-Peter; Rajguru, Suhrud; Bendett, Mark

    2014-01-01

    The application of photonics to manipulate and stimulate neurons and to study neural networks has gained momentum over the last decade. Two general methods have been used: the genetic expression of light or temperature sensitive ion channels in the plasma membrane of neurons (Optogenetics and Thermogenetics) and the direct stimulation of neurons using infrared radiation (Infrared Neural Stimulation, INS). Both approaches have their strengths and challenges, which are well understood with a profound understanding of the light tissue interaction(s). This paper compares the opportunities of the methods for the use in cochlear prostheses. Ample data are already available on the stimulation of the cochlea with INS. The data show that the stimulation is selective, feasible at rates that would be sufficient to encode acoustic information and may be beneficial over conventional pulsed electrical stimulation. A third approach, using lasers in stress confinement to generate pressure waves and to stimulate the functional cochlea mechanically will also be discussed. PMID:25075260

  1. Infrared neural stimulation in the cochlea.

    PubMed

    Richter, Claus-Peter; Rajguru, Suhrud; Bendett, Mark

    2013-03-01

    The application of photonics to manipulate and stimulate neurons and to study neural networks has gained momentum over the last decade. Two general methods have been used: the genetic expression of light or temperature sensitive ion channels in the plasma membrane of neurons (Optogenetics and Thermogenetics) and the direct stimulation of neurons using infrared radiation (Infrared Neural Stimulation, INS). Both approaches have their strengths and challenges, which are well understood with a profound understanding of the light tissue interaction(s). This paper compares the opportunities of the methods for the use in cochlear prostheses. Ample data are already available on the stimulation of the cochlea with INS. The data show that the stimulation is selective, feasible at rates that would be sufficient to encode acoustic information and may be beneficial over conventional pulsed electrical stimulation. A third approach, using lasers in stress confinement to generate pressure waves and to stimulate the functional cochlea mechanically will also be discussed. PMID:25075260

  2. Effects of Ion-Ion Collisions and Inhomogeneity in Two-Dimensional Kinetic Ion Simulations of Stimulated Brillouin Backscattering

    SciTech Connect

    Cohen, B I; Divol, L; Langdon, A B; Williams, E A

    2005-10-17

    Two-dimensional simulations with the BZOHAR [B.I. Cohen, B.F. Lasinski, A.B. Langdon, and E.A. Williams, Phys. Plasmas 4, 956 (1997)] hybrid code (kinetic particle ions and Boltzmann fluid electrons) have been used to investigate the saturation of stimulated Brillouin backscatter (SBBS) instability including the effects of ion-ion collisions and inhomogeneity. Ion-ion collisions tend to increase ion-wave dissipation, which decreases the gain exponent for stimulated Brillouin backscattering; and the peak Brillouin backscatter reflectivities tend to decrease with increasing collisionality in the simulations. Two types of Langevin-operator, ion-ion collision models were implemented in the simulations. In both models used the collisions are functions of the local ion temperature and density, but the collisions have no velocity dependence in the first model. In the second model, the collisions are also functions of the energy of the ion that is being scattered so as to represent a Fokker-Planck collision operator. Collisions decorrelate the ions from the acoustic waves in SBS, which disrupts ion trapping in the acoustic wave. Nevertheless, ion trapping leading to a hot ion tail and two-dimensional physics that allows the SBS ion waves to nonlinearly scatter remain robust saturation mechanisms for SBBS in a high-gain limit over a range of ion collisionality. SBS backscatter in the presence of a spatially nonuniform plasma flow is also investigated. Simulations show that depending on the sign of the spatial gradient of the flow relative to the backscatter, ion trapping effects that produce a nonlinear frequency shift can enhance (auto-resonance) or decrease (anti-auto-resonance) reflectivities in agreement with theoretical arguments.

  3. Symptoms of Acoustic Neuroma

    MedlinePlus

    ... Watch and Wait Radiation Microsurgery Acoustic Neuroma Decision Tree Questions for Your Physician Questions to Ask Yourself ... Watch and Wait Radiation Microsurgery Acoustic Neuroma Decision Tree Questions for Your Physician Questions to Ask Yourself ...

  4. Acoustic Neuroma Educational Video

    MedlinePlus

    ... Watch and Wait Radiation Microsurgery Acoustic Neuroma Decision Tree Questions for Your Physician Questions to Ask Yourself ... Watch and Wait Radiation Microsurgery Acoustic Neuroma Decision Tree Questions for Your Physician Questions to Ask Yourself ...

  5. Acoustic emission frequency discrimination

    NASA Technical Reports Server (NTRS)

    Sugg, Frank E. (Inventor); Graham, Lloyd J. (Inventor)

    1988-01-01

    In acoustic emission nondestructive testing, broadband frequency noise is distinguished from narrow banded acoustic emission signals, since the latter are valid events indicative of structural flaws in the material being examined. This is accomplished by separating out those signals which contain frequency components both within and beyond (either above or below) the range of valid acoustic emission events. Application to acoustic emission monitoring during nondestructive bond verification and proof loading of undensified tiles on the Space Shuttle Orbiter is considered.

  6. Tutorial on architectural acoustics

    NASA Astrophysics Data System (ADS)

    Shaw, Neil; Talaske, Rick; Bistafa, Sylvio

    2002-11-01

    This tutorial is intended to provide an overview of current knowledge and practice in architectural acoustics. Topics covered will include basic concepts and history, acoustics of small rooms (small rooms for speech such as classrooms and meeting rooms, music studios, small critical listening spaces such as home theatres) and the acoustics of large rooms (larger assembly halls, auditoria, and performance halls).

  7. Relation between gamma-ray family and EAS core: Monte-Carlo simulation of EAS core

    NASA Technical Reports Server (NTRS)

    Yanagita, T.

    1985-01-01

    Preliminary results of Monte-Carlo simulation on Extensive Air Showers (EAS) (Ne=100,000) core is reported. For the first collision at the top of the atmosphere, high multiplicity (high rapidity, density) and a large Pt (1.5GeV average) model is assumed. Most of the simulated cores show a complicated structure.

  8. 7 CFR 1794.23 - Proposals normally requiring an EA.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... water and waste programs. An EA shall be prepared for applications for financial assistance for all... classification are: (1) Construction of fuel cell, combustion turbine, combined cycle, or diesel generating... be covered in the EA; (2) Construction of fuel cell, combustion turbine, combined cycle, or...

  9. 7 CFR 1794.23 - Proposals normally requiring an EA.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... water and waste programs. An EA shall be prepared for applications for financial assistance for all... classification are: (1) Construction of fuel cell, combustion turbine, combined cycle, or diesel generating... be covered in the EA; (2) Construction of fuel cell, combustion turbine, combined cycle, or...

  10. 47 CFR 90.761 - EA and Regional licenses.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... MOBILE RADIO SERVICES Regulations Governing Licensing and Use of Frequencies in the 220-222 MHz Band... Regional licenses. (a) EA licenses for spectrum blocks listed in Table 2 of § 90.721(b) are available in 175 Economic Areas (EAs) as defined in § 90.7. (b) Regional licenses for spectrum blocks listed...

  11. 47 CFR 90.761 - EA and Regional licenses.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... MOBILE RADIO SERVICES Regulations Governing Licensing and Use of Frequencies in the 220-222 MHz Band... Regional licenses. (a) EA licenses for spectrum blocks listed in Table 2 of § 90.721(b) are available in 175 Economic Areas (EAs) as defined in § 90.7. (b) Regional licenses for spectrum blocks listed...

  12. 47 CFR 90.761 - EA and Regional licenses.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... MOBILE RADIO SERVICES Regulations Governing Licensing and Use of Frequencies in the 220-222 MHz Band... Regional licenses. (a) EA licenses for spectrum blocks listed in Table 2 of § 90.721(b) are available in 175 Economic Areas (EAs) as defined in § 90.7. (b) Regional licenses for spectrum blocks listed...

  13. 47 CFR 90.761 - EA and Regional licenses.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... MOBILE RADIO SERVICES Regulations Governing Licensing and Use of Frequencies in the 220-222 MHz Band... Regional licenses. (a) EA licenses for spectrum blocks listed in Table 2 of § 90.721(b) are available in 175 Economic Areas (EAs) as defined in § 90.7. (b) Regional licenses for spectrum blocks listed...

  14. 47 CFR 90.761 - EA and Regional licenses.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... MOBILE RADIO SERVICES Regulations Governing Licensing and Use of Frequencies in the 220-222 MHz Band... Regional licenses. (a) EA licenses for spectrum blocks listed in Table 2 of § 90.721(b) are available in 175 Economic Areas (EAs) as defined in § 90.7. (b) Regional licenses for spectrum blocks listed...

  15. Draft Genome Sequence of Rice Isolate Pseudomonas chlororaphis EA105

    PubMed Central

    McCully, Lucy M.; Bitzer, Adam S.; Spence, Carla A.; Bais, Harsh P.

    2014-01-01

    Pseudomonas chlororaphis EA105, a strain isolated from rice rhizosphere, has shown antagonistic activities against a rice fungal pathogen, and could be important in defense against rice blast. We report the draft genome sequence of EA105, which is an estimated size of 6.6 Mb. PMID:25540352

  16. 47 CFR 11.15 - EAS Operating Handbook.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false EAS Operating Handbook. 11.15 Section 11.15... Operating Handbook. The EAS Operating Handbook states in summary form the actions to be taken by personnel.... It is issued by the FCC and contains instructions for the above situations. A copy of the...

  17. 47 CFR 11.15 - EAS Operating Handbook.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false EAS Operating Handbook. 11.15 Section 11.15... Operating Handbook. The EAS Operating Handbook states in summary form the actions to be taken by personnel.... It is issued by the FCC and contains instructions for the above situations. A copy of the...

  18. 36 CFR 1010.11 - Preparation of an EA.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... prepare or require an EA at any time to assist planning and decision-making. (b) Content and format. An EA... impacts, including cumulative impacts, on those resources that are specifically relevant to the particular proposal. Those impacts should be addressed in as much detail as is necessary to allow an analysis of...

  19. ACOUSTICAL STANDARDS NEWS.

    PubMed

    Stremmel, Neil; Struck, Christopher J

    2016-07-01

    American National Standards (ANSI Standards) developed by Accredited Standards Committees S1, S2, S3, S3/SC 1, and S12 in the areas of acoustics, mechanical vibration and shock, bioacoustics, animal bioacoustics, and noise, respectively, are published by the Acoustical Society of America (ASA). In addition to these standards, ASA publishes a catalog of Acoustical American National Standards. To receive a copy of the latest Standards catalog, please contact Neil Stremmel.Comments are welcomed on all material in Acoustical Standards News.This Acoustical Standards News section in JASA, as well as the National Catalog of Acoustical Standards and other information on the Standards Program of the Acoustical Society of America, are available via the ASA home page: http://acousticalsociety.org. PMID:27475185

  20. Research on transport properties of HFC-227ea

    NASA Astrophysics Data System (ADS)

    Shi, Lin; Liu, Xiaojun; Duan, Yuanyuan; Han, Lizhong; Zhu, Mingshan

    2001-10-01

    HFC-227ea(1,1,1,2,3,3,3-heptafluoropropane) is considered as a promising refrigerant alternative, especially as a component in mixtures, to replace to CFC-12, HCFC-22 and R502. But reliable transport properties data for HFC-227ea are very limited. In this paper, experimental data of viscosity along the saturation line and gaseous thermal conductivity of HFC-227ea are given. The viscosity of HFC-227ea was measured with a capillary viscometer at temperatures between 263.15 K and 333.15 K along the saturation line and its uncertainty of the results is estimated to be no more than ±3%. The thermal conductivity of gaseous HFC-227ea was also measured with a transient hot-wire instrument at temperatures between 259.28 K and 341.75 K and pressures up to 1.289MPa, and its uncertainty of the results is estimated to be less than ±1%.

  1. Assessment of Microelastic Properties of Bone Using Scanning Acoustic Microscopy: A Face-to-Face Comparison with Nanoindentation

    NASA Astrophysics Data System (ADS)

    Rupin, Fabienne; Saïed, Amena; Dalmas, Davy; Peyrin, Françoise; Haupert, Sylvain; Raum, Kay; Barthel, Etienne; Boivin, Georges; Laugier, Pascal

    2009-07-01

    The current work aimed at comparing, on site-matched cortical bone tissue, the micron-level elastic modulus Ea derived from 200 MHz-scanning acoustic microscopy (SAM) acoustic impedance (Z) combined with bone mineral density (assessed by synchrotron radiation microcomputed tomography, SR-µCT) to nanoindentation modulus En. A good correlation was observed between En and Z (R2=0.67, p<0.0001, root mean square error RMSE=1.9 GPa). The acoustical elastic modulus Ea derived from Z showed higher values of E compared to nanoindentation moduli. We assumed that the discrepancy between Ea and En values may likely be due to the fixed assumed value of Poisson's ratio while values comprised between 0.15 and 0.45 have been reported in the literature. Despite these differences, a highly significant correlation between Ea and En was found (R2=0.66, p<0.001, RMSE=1.8 GPa) suggesting that SAM can reliably be used as a modality to quantitatively map the local variations of tissue-level bone elasticity.

  2. Electroacupuncture at the Zusanli (ST-36) Acupoint Induces a Hypoglycemic Effect by Stimulating the Cholinergic Nerve in a Rat Model of Streptozotocine-Induced Insulin-Dependent Diabetes Mellitus

    PubMed Central

    Lee, Yu-Chen; Li, Te-Mao; Tzeng, Chung-Yuh; Chen, Ying-I; Ho, Wai-Jane; Lin, Jaung-Geng; Chang, Shih-Liang

    2011-01-01

    Animal studies have shown that electroacupuncture (EA) at Zusanli (ST-36) and Zhongwan (CV-12) acupoints reduces plasma glucose concentrations in rats with type II diabetes. However, whether EA reduces plasma glucose levels in type I diabetes is still unknown. In this study, we explore the various non-insulin-dependent pathways involved in EA-induced lowering of plasma glucose. Streptozotocin (STZ) (60 mg kg−1, i.v.) was administered via the femoral vein to induce insulin-dependent diabetes in non-adrenalectomized and in adrenalectomomized rats. EA (15 Hz) was applied for 30 min to bilateral ST-36 acupoints after administration of Atropine (0.1 mg kg−1 i.p.), Eserine (0.01 mg kg−1 i.p.), or Hemicholinium-3 (5 μg kg−1 i.p.) in non-adrenalectomized rats. Rats administered acetylcholine (0.01 mg kg−1 i.v.) did not undergo EA. Adrenalectomized rats underwent EA at bilateral ST-36 acupoints without further treatment. Blood samples were drawn from all rats before and after EA to measure changes in plasma glucose levels. Expression of insulin signaling proteins (IRS1, AKT2) in atropine-exposed rats before and after EA was measured by western blot. Atropine and hemicholinium-3 completely blocked the plasma glucose lowering effects of EA, whereas eserine led to a significant hypoglycemic response. In addition, plasma glucose levels after administration of acetylcholine were significantly lower than the fasting glucose levels. In STZ-adrenalectomized rats, EA did not induce a hypoglycemic response. EA stimulated the expression of IRS1 and AKT2 and atropine treatment blocked the EA-induced expression of those insulin signaling proteins. Taken together, EA at the ST-36 acupoint reduces plasma glucose concentrations by stimulating the cholinergic nerves. PMID:21799686

  3. Electroacupuncture at the Zusanli (ST-36) Acupoint Induces a Hypoglycemic Effect by Stimulating the Cholinergic Nerve in a Rat Model of Streptozotocine-Induced Insulin-Dependent Diabetes Mellitus.

    PubMed

    Lee, Yu-Chen; Li, Te-Mao; Tzeng, Chung-Yuh; Chen, Ying-I; Ho, Wai-Jane; Lin, Jaung-Geng; Chang, Shih-Liang

    2011-01-01

    Animal studies have shown that electroacupuncture (EA) at Zusanli (ST-36) and Zhongwan (CV-12) acupoints reduces plasma glucose concentrations in rats with type II diabetes. However, whether EA reduces plasma glucose levels in type I diabetes is still unknown. In this study, we explore the various non-insulin-dependent pathways involved in EA-induced lowering of plasma glucose. Streptozotocin (STZ) (60 mg kg(-1), i.v.) was administered via the femoral vein to induce insulin-dependent diabetes in non-adrenalectomized and in adrenalectomomized rats. EA (15 Hz) was applied for 30 min to bilateral ST-36 acupoints after administration of Atropine (0.1 mg kg(-1) i.p.), Eserine (0.01 mg kg(-1) i.p.), or Hemicholinium-3 (5 μg kg(-1) i.p.) in non-adrenalectomized rats. Rats administered acetylcholine (0.01 mg kg(-1) i.v.) did not undergo EA. Adrenalectomized rats underwent EA at bilateral ST-36 acupoints without further treatment. Blood samples were drawn from all rats before and after EA to measure changes in plasma glucose levels. Expression of insulin signaling proteins (IRS1, AKT2) in atropine-exposed rats before and after EA was measured by western blot. Atropine and hemicholinium-3 completely blocked the plasma glucose lowering effects of EA, whereas eserine led to a significant hypoglycemic response. In addition, plasma glucose levels after administration of acetylcholine were significantly lower than the fasting glucose levels. In STZ-adrenalectomized rats, EA did not induce a hypoglycemic response. EA stimulated the expression of IRS1 and AKT2 and atropine treatment blocked the EA-induced expression of those insulin signaling proteins. Taken together, EA at the ST-36 acupoint reduces plasma glucose concentrations by stimulating the cholinergic nerves. PMID:21799686

  4. AST Launch Vehicle Acoustics

    NASA Technical Reports Server (NTRS)

    Houston, Janice; Counter, D.; Giacomoni, D.

    2015-01-01

    The liftoff phase induces acoustic loading over a broad frequency range for a launch vehicle. These external acoustic environments are then used in the prediction of internal vibration responses of the vehicle and components which result in the qualification levels. Thus, predicting these liftoff acoustic (LOA) environments is critical to the design requirements of any launch vehicle. If there is a significant amount of uncertainty in the predictions or if acoustic mitigation options must be implemented, a subscale acoustic test is a feasible pre-launch test option to verify the LOA environments. The NASA Space Launch System (SLS) program initiated the Scale Model Acoustic Test (SMAT) to verify the predicted SLS LOA environments and to determine the acoustic reduction with an above deck water sound suppression system. The SMAT was conducted at Marshall Space Flight Center and the test article included a 5% scale SLS vehicle model, tower and Mobile Launcher. Acoustic and pressure data were measured by approximately 250 instruments. The SMAT liftoff acoustic results are presented, findings are discussed and a comparison is shown to the Ares I Scale Model Acoustic Test (ASMAT) results.

  5. 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.

  6. Vaccenic and elaidic acid modify plasma and splenocyte membrane phospholipids and mitogen-stimulated cytokine production in obese insulin resistant JCR: LA-cp rats.

    PubMed

    Ruth, Megan R; Wang, Ye; Yu, Howe-Ming; Goruk, Susan; Reaney, Martin J; Proctor, Spencer D; Vine, Donna F; Field, Catherine J

    2010-02-01

    This study assessed the long-term effects of dietary vaccenic acid (VA) and elaidic acid (EA) on plasma and splenocyte phospholipid (PL) composition and related changes in inflammation and splenocyte phenotypes and cytokine responses in obese/insulin resistant JCR:LA-cp rats. Relative to lean control (Ctl), obese Ctl rats had higher serum haptoglobin and impaired T-cell-stimulated cytokine responses. VA and EA diets improved T-cell-stimulated cytokine production; but, only VA normalized serum haptoglobin. However, EA- and VA-fed rats had enhanced LPS-stimulated cytokine responses. The changes elicited by VA were likely due changes in essential fatty acid composition in PL; whereas EA-induced changes may due to direct incorporation into membrane PL.

  7. Automatic detection of unattended changes in room acoustics.

    PubMed

    Frey, Johannes Daniel; Wendt, Mike; Jacobsen, Thomas

    2015-01-01

    Previous research has shown that the human auditory system continuously monitors its acoustic environment, detecting a variety of irregularities (e.g., deviance from prior stimulation regularity in pitch, loudness, duration, and (perceived) sound source location). Detection of irregularities can be inferred from a component of the event-related brain potential (ERP), referred to as the mismatch negativity (MMN), even in conditions in which participants are instructed to ignore the auditory stimulation. The current study extends previous findings by demonstrating that auditory irregularities brought about by a change in room acoustics elicit a MMN in a passive oddball protocol (acoustic stimuli with differing room acoustics, that were otherwise identical, were employed as standard and deviant stimuli), in which participants watched a fiction movie (silent with subtitles). While the majority of participants reported no awareness for any changes in the auditory stimulation, only one out of 14 participants reported to have become aware of changing room acoustics or sound source location. Together, these findings suggest automatic monitoring of room acoustics.

  8. Controllable optical transparency using an acoustic standing-wave device

    NASA Astrophysics Data System (ADS)

    Moradi, Kamran; El-Zahab, Bilal

    2015-09-01

    In this paper, a suspended-particle device with controllable light transmittance was developed based on acoustic stimuli. Using a glass compartment and carbon particle suspension in an organic solvent, the device responded to acoustic stimulation by alignment of particles. The alignment of light-absorbing carbon particles afforded an increase in light transmittance as high as 84.5% and was controllable based on the control of the frequency and amplitude of the acoustic waves. The device also demonstrated alignment memory rendering it energy-efficient.

  9. Liquid Helium Acoustic Microscope.

    NASA Astrophysics Data System (ADS)

    Steer, Andrew Paul

    Available from UMI in association with The British Library. In an acoustic microscope, images are generated by monitoring the intensity of the ultrasonic reflection, or echo, from the surface of a sample. In order to achieve this a pulse of acoustic energy is produced by the excitation of a thin film transducer. The pulse thus generated propagates through a crystal and is incident upon the acoustic lens surface, which is the boundary between the crystal and an acoustic coupling liquid. The acoustic lens is a converging element, and brings the ultrasonic beam to a focus within the liquid. A sample, placed at the focus, can act as a reflector, and the returned pulse then contains information regarding the acoustic reflectivity of this specimen. Acoustic pulses are repeatedly launched and detected while the acoustic lens is scanned over the surface of the sample. In this manner an acoustic image is constructed. Acoustic losses in room temperature liquid coupling media represent a considerable source of difficulty in the recovery of acoustic echo signals. At the frequencies of operation required in a microscope which is capable of high resolution, the ultrasonic attenuation is not only large but increases with the square of frequency. In superfluid liquid helium at temperatures below 0.1 K, however, the ultrasonic attenuation becomes negligible. Furthermore, the low sound velocity in liquid helium results in an increase in resolution, since the acoustic wavelength is proportional to velocity. A liquid helium acoustic microscope has been designed and constructed. Details of the various possible detection methods are given, and comparisons are made between them. Measurements of the performance of the system that was adopted are reported. The development of a cooled preamplifier is also described. The variation of reflected signal with object distance has been measured and compared with theoretical predictions. This variation is important in the analysis of acoustic

  10. Efficient PCA-driven EAs and metamodel-assisted EAs, with applications in turbomachinery

    NASA Astrophysics Data System (ADS)

    Kyriacou, Stylianos A.; Asouti, Varvara G.; Giannakoglou, Kyriakos C.

    2014-07-01

    This article presents methods to enhance the efficiency of Evolutionary Algorithms (EAs), particularly those assisted by surrogate evaluation models or metamodels. The gain in efficiency becomes important in applications related to industrial optimization problems with a great number of design variables. The development is based on the principal components analysis of the elite members of the evolving EA population, the outcome of which is used to guide the application of evolution operators and/or train dependable metamodels/artificial neural networks by reducing the number of sensory units. Regarding the latter, the metamodels are trained with less computing cost and yield more relevant objective function predictions. The proposed methods are applied to constrained, single- and two-objective optimization of thermal and hydraulic turbomachines.

  11. Nonlinear Acoustics in Fluids

    NASA Astrophysics Data System (ADS)

    Lauterborn, Werner; Kurz, Thomas; Akhatov, Iskander

    At high sound intensities or long propagation distances at in fluids sufficiently low damping acoustic phenomena become nonlinear. This chapter focuses on nonlinear acoustic wave properties in gases and liquids. The origin of nonlinearity, equations of state, simple nonlinear waves, nonlinear acoustic wave equations, shock-wave formation, and interaction of waves are presented and discussed. Tables are given for the nonlinearity parameter B/A for water and a range of organic liquids, liquid metals and gases. Acoustic cavitation with its nonlinear bubble oscillations, pattern formation and sonoluminescence (light from sound) are modern examples of nonlinear acoustics. The language of nonlinear dynamics needed for understanding chaotic dynamics and acoustic chaotic systems is introduced.

  12. 47 CFR 11.52 - EAS code and Attention Signal Monitoring requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false EAS code and Attention Signal Monitoring... SYSTEM (EAS) Emergency Operations § 11.52 EAS code and Attention Signal Monitoring requirements. (a) EAS Participants must be capable of receiving the Attention Signal required by § 11.32(a)(9) and emergency...

  13. 47 CFR 11.52 - EAS code and Attention Signal Monitoring requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false EAS code and Attention Signal Monitoring... SYSTEM (EAS) Emergency Operations § 11.52 EAS code and Attention Signal Monitoring requirements. (a) EAS Participants must be capable of receiving the Attention Signal required by § 11.31(a)(2) and emergency...

  14. 47 CFR 11.52 - EAS code and Attention Signal Monitoring requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false EAS code and Attention Signal Monitoring... SYSTEM (EAS) Emergency Operations § 11.52 EAS code and Attention Signal Monitoring requirements. (a) EAS Participants must be capable of receiving the Attention Signal required by § 11.31(a)(2) and emergency...

  15. Acoustic Levitator Maintains Resonance

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Gaspar, M. S.

    1986-01-01

    Transducer loading characteristics allow resonance tracked at high temperature. Acoustic-levitation chamber length automatically adjusted to maintain resonance at constant acoustic frequency as temperature changes. Developed for containerless processing of materials at high temperatures, system does not rely on microphones as resonance sensors, since microphones are difficult to fabricate for use at temperatures above 500 degrees C. Instead, system uses acoustic transducer itself as sensor.

  16. EAS-BUAP: Lateral Distribution and Performance

    NASA Astrophysics Data System (ADS)

    Salazar, H.; Martinez, O.; Cotzomi, J.; Moreno, E.; Aguilar, S.; Villaseñor, L.

    2003-07-01

    We describe the operation and performance of the first stage of the EAS-UAP extensive air shower array, as a detector of very high energy cosmic rays (Eo > 1014eV) after one year of operation. The array is located at the Campus of Puebla University, 2200 m above sea level. It consists of 10 liquid scintillator detectors, each with an active surface of 1 m2 and a detector spacing of 20 m in a square grid. One Auger Water Cherenkov detector is also included as part of the array. In this report we discuss the stability, the calibration and lateral distribution function reconstruction capabilities of the detector array. We also present the analysis of the shower size spectrum. In addition, the main characteristics of this array allow us to use it as an educational and training facility.

  17. Acoustic metamaterial design and applications

    NASA Astrophysics Data System (ADS)

    Zhang, Shu

    The explosion of interest in metamaterials is due to the dramatically increased manipulation ability over light as well as sound waves. This material research was stimulated by the opportunity to develop an artificial media with negative refractive index and the application in superlens which allows super-resolution imaging. High-resolution acoustic imaging techniques are the essential tools for nondestructive testing and medical screening. However, the spatial resolution of the conventional acoustic imaging methods is restricted by the incident wavelength of ultrasound. This is due to the quickly fading evanescent fields which carry the subwavelength features of objects. By focusing the propagating wave and recovering the evanescent field, a flat lens with negative-index can potentially overcome the diffraction limit. We present the first experimental demonstration of focusing ultrasound waves through a flat acoustic metamaterial lens composed of a planar network of subwavelength Helmholtz resonators. We observed a tight focus of half-wavelength in width at 60.5 KHz by imaging a point source. This result is in excellent agreement with the numerical simulation by transmission line model in which we derived the effective mass density and compressibility. This metamaterial lens also displays variable focal length at different frequencies. Our experiment shows the promise of designing compact and light-weight ultrasound imaging elements. Moreover, the concept of metamaterial extends far beyond negative refraction, rather giving enormous choice of material parameters for different applications. One of the most interesting examples these years is the invisible cloak. Such a device is proposed to render the hidden object undetectable under the flow of light or sound, by guiding and controlling the wave path through an engineered space surrounding the object. However, the cloak designed by transformation optics usually calls for a highly anisotropic metamaterial, which

  18. Acoustic dispersive prism

    PubMed Central

    Esfahlani, Hussein; Karkar, Sami; Lissek, Herve; Mosig, Juan R.

    2016-01-01

    The optical dispersive prism is a well-studied element, which allows separating white light into its constituent spectral colors, and stands in nature as water droplets. In analogy to this definition, the acoustic dispersive prism should be an acoustic device with capability of splitting a broadband acoustic wave into its constituent Fourier components. However, due to the acoustical nature of materials as well as the design and fabrication difficulties, there is neither any natural acoustic counterpart of the optical prism, nor any artificial design reported so far exhibiting an equivalent acoustic behaviour. Here, based on exotic properties of the acoustic transmission-line metamaterials and exploiting unique physical behaviour of acoustic leaky-wave radiation, we report the first acoustic dispersive prism, effective within the audible frequency range 800 Hz–1300 Hz. The dispersive nature, and consequently the frequency-dependent refractive index of the metamaterial are exploited to split the sound waves towards different and frequency-dependent directions. Meanwhile, the leaky-wave nature of the structure facilitates the sound wave radiation into the ambient medium. PMID:26739504

  19. Localized acoustic surface modes

    NASA Astrophysics Data System (ADS)

    Farhat, Mohamed; Chen, Pai-Yen; Bağcı, Hakan

    2016-04-01

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

  20. Low frequency acoustic microscope

    DOEpatents

    Khuri-Yakub, Butrus T.

    1986-11-04

    A scanning acoustic microscope is disclosed for the detection and location of near surface flaws, inclusions or voids in a solid sample material. A focused beam of acoustic energy is directed at the sample with its focal plane at the subsurface flaw, inclusion or void location. The sample is scanned with the beam. Detected acoustic energy specularly reflected and mode converted at the surface of the sample and acoustic energy reflected by subsurface flaws, inclusions or voids at the focal plane are used for generating an interference signal which is processed and forms a signal indicative of the subsurface flaws, inclusions or voids.

  1. Acoustic Levitation With Less Equipment

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Jacobi, N.

    1983-01-01

    Certain chamber shapes require fewer than three acoustic drivers. Levitation at center of spherical chamber attained using only one acoustic driver. Exitation of lowest spherical mode produces asymmetric acoustic potential well.

  2. Combined Electric and Contralateral Acoustic Hearing: Word and Sentence Recognition with Bimodal Hearing

    ERIC Educational Resources Information Center

    Gifford, Rene H.; Dorman, Michael F.; McKarns, Sharon A.; Spahr, Anthony J.

    2007-01-01

    Purpose: The authors assessed whether (a) a full-insertion cochlear implant would provide a higher level of speech understanding than bilateral low-frequency acoustic hearing, (b) contralateral acoustic hearing would add to the speech understanding provided by the implant, and (c) the level of performance achieved with electric stimulation plus…

  3. Microbial-Induced Heterogeneity in the Acoustic Properties of Porous Media

    EPA Science Inventory

    Acoustic wave data were acquired over a two-dimensional region of a microbial-stimulated sand column and an unstimulated sand column to assess the spatiotemporal changes in a porous medium caused by microbial growth and biofilm formation. The acoustic signals from the unstimulate...

  4. Optogenetic stimulation of the auditory pathway

    PubMed Central

    Hernandez, Victor H.; Gehrt, Anna; Reuter, Kirsten; Jing, Zhizi; Jeschke, Marcus; Mendoza Schulz, Alejandro; Hoch, Gerhard; Bartels, Matthias; Vogt, Gerhard; Garnham, Carolyn W.; Yawo, Hiromu; Fukazawa, Yugo; Augustine, George J.; Bamberg, Ernst; Kügler, Sebastian; Salditt, Tim; de Hoz, Livia; Strenzke, Nicola; Moser, Tobias

    2014-01-01

    Auditory prostheses can partially restore speech comprehension when hearing fails. Sound coding with current prostheses is based on electrical stimulation of auditory neurons and has limited frequency resolution due to broad current spread within the cochlea. In contrast, optical stimulation can be spatially confined, which may improve frequency resolution. Here, we used animal models to characterize optogenetic stimulation, which is the optical stimulation of neurons genetically engineered to express the light-gated ion channel channelrhodopsin-2 (ChR2). Optogenetic stimulation of spiral ganglion neurons (SGNs) activated the auditory pathway, as demonstrated by recordings of single neuron and neuronal population responses. Furthermore, optogenetic stimulation of SGNs restored auditory activity in deaf mice. Approximation of the spatial spread of cochlear excitation by recording local field potentials (LFPs) in the inferior colliculus in response to suprathreshold optical, acoustic, and electrical stimuli indicated that optogenetic stimulation achieves better frequency resolution than monopolar electrical stimulation. Virus-mediated expression of a ChR2 variant with greater light sensitivity in SGNs reduced the amount of light required for responses and allowed neuronal spiking following stimulation up to 60 Hz. Our study demonstrates a strategy for optogenetic stimulation of the auditory pathway in rodents and lays the groundwork for future applications of cochlear optogenetics in auditory research and prosthetics. PMID:24509078

  5. The arrival time distribution of EAS at Taro

    NASA Astrophysics Data System (ADS)

    Maeda, T.; Kuramochi, H.; Ono, S.; Sakuyama, H.; Suzuki, N.

    The arrival time distribution of EAS has been observed since 1995 at Taro cosmicray laboratory (200m above sea level). The EAS arrays consist of 1m2 and 0.25m2 scintillation detectors, 0.25m2 fast timing counters and ultra fast Cherenkov detectors (UFC). 169 0.25m2 scintillation detectors are arranged in alattice configuration with a unit distance of 1.5m. UFC is placed at 20m from the center of lattice array. The arrival time distribution has been analyzed with distance from EAS core (r=10-60m). One of the results shows that the radius of corvature increases as shower size (Ne), near to the EAS core.

  6. 33 CFR 230.10 - Environmental Assessments (EA).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... determining whether to prepare an EIS or a FONSI (40 CFR 1508.9). The district commander is responsible for making this determination and for keeping the public informed of the availability of the EA and FONSI....

  7. 33 CFR 230.10 - Environmental Assessments (EA).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... determining whether to prepare an EIS or a FONSI (40 CFR 1508.9). The district commander is responsible for making this determination and for keeping the public informed of the availability of the EA and FONSI....

  8. 33 CFR 230.10 - Environmental Assessments (EA).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... determining whether to prepare an EIS or a FONSI (40 CFR 1508.9). The district commander is responsible for making this determination and for keeping the public informed of the availability of the EA and FONSI....

  9. 33 CFR 230.10 - Environmental Assessments (EA).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... determining whether to prepare an EIS or a FONSI (40 CFR 1508.9). The district commander is responsible for making this determination and for keeping the public informed of the availability of the EA and FONSI....

  10. 33 CFR 230.10 - Environmental Assessments (EA).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... determining whether to prepare an EIS or a FONSI (40 CFR 1508.9). The district commander is responsible for making this determination and for keeping the public informed of the availability of the EA and FONSI....

  11. Acoustics Critical Readiness Review

    NASA Technical Reports Server (NTRS)

    Ballard, Kenny

    2010-01-01

    This presentation reviews the status of the acoustic equipment from the medical operations perspective. Included is information about the acoustic dosimeters, sound level meter, and headphones that are planned for use while on orbit. Finally there is information about on-orbit hearing assessments.

  12. Introduction to acoustic emission

    NASA Technical Reports Server (NTRS)

    Possa, G.

    1983-01-01

    Typical acoustic emission signal characteristics are described and techniques which localize the signal source by processing the acoustic delay data from multiple sensors are discussed. The instrumentation, which includes sensors, amplifiers, pulse counters, a minicomputer and output devices is examined. Applications are reviewed.

  13. 47 CFR 11.11 - The Emergency Alert System (EAS).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., including digital AM, FM, and Low-power FM stations; Class A television (CA) and Low-power TV (LPTV... Direct to Home providers); and SDARS, as defined in § 25.201 of this chapter. These entities are referred... DTV Analog &digital class A TV Analog &digital LPTV EAS decoder 1 Y Y Y Y Y Y Y EAS encoder Y Y N N...

  14. 47 CFR 11.11 - The Emergency Alert System (EAS).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., including digital AM, FM, and Low-power FM stations; Class A television (CA) and Low-power TV (LPTV... Direct to Home providers); and SDARS, as defined in § 25.201 of this chapter. These entities are referred... DTV Analog &digital class A TV Analog &digital LPTV EAS decoder 1 Y Y Y Y Y Y Y EAS encoder Y Y N N...

  15. 47 CFR 11.11 - The Emergency Alert System (EAS).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., including digital AM, FM, and Low-power FM stations; Class A television (CA) and Low-power TV (LPTV... Direct to Home providers); and SDARS, as defined in § 25.201 of this chapter. These entities are referred... DTV Analog &digital class A TV Analog &digital LPTV EAS decoder 1 Y Y Y Y Y Y Y EAS encoder Y Y N N...

  16. Analysis of the hadron component in E.A.S.

    NASA Technical Reports Server (NTRS)

    Procureur, J.; Stamenov, J. N.; Stavrev, P. V.; Ushev, S. Z.

    1985-01-01

    Hadrons in extensive air showers (E.A.S.) provide direct information about high energy interactions. As a rule the biases pertaining to different shower array arrangements have a relative large influence for the basic phenomenological characteristics of the E.A.S. hadron component. In this situation, the problem of the correct comparison between model calculated and experimental characteristics is of great importance for the reliability of the derived conclusions about the high energy interaction characteristics.

  17. Virtual acoustics displays

    NASA Technical Reports Server (NTRS)

    Wenzel, Elizabeth M.; Fisher, Scott S.; Stone, Philip K.; Foster, Scott H.

    1991-01-01

    The real time acoustic display capabilities are described which were developed for the Virtual Environment Workstation (VIEW) Project at NASA-Ames. The acoustic display is capable of generating localized acoustic cues in real time over headphones. An auditory symbology, a related collection of representational auditory 'objects' or 'icons', can be designed using ACE (Auditory Cue Editor), which links both discrete and continuously varying acoustic parameters with information or events in the display. During a given display scenario, the symbology can be dynamically coordinated in real time with 3-D visual objects, speech, and gestural displays. The types of displays feasible with the system range from simple warnings and alarms to the acoustic representation of multidimensional data or events.

  18. Acoustic ground impedance meter

    NASA Technical Reports Server (NTRS)

    Zuckerwar, A. J. (Inventor)

    1984-01-01

    A method and apparatus are presented for measuring the acoustic impedance of a surface in which the surface is used to enclose one end of the chamber of a Helmholz resonator. Acoustic waves are generated in the neck of the resonator by a piston driven by a variable speed motor through a cam assembly. The acoustic waves are measured in the chamber and the frequency of the generated acoustic waves is measured by an optical device. These measurements are used to compute the compliance and conductance of the chamber and surface combined. The same procedure is followed with a calibration plate having infinite acoustic impedance enclosing the chamber of the resonator to compute the compliance and conductance of the chamber alone. Then by subtracting, the compliance and conductance for the surface is obtained.

  19. Ocean acoustic hurricane classification.

    PubMed

    Wilson, Joshua D; Makris, Nicholas C

    2006-01-01

    Theoretical and empirical evidence are combined to show that underwater acoustic sensing techniques may be valuable for measuring the wind speed and determining the destructive power of a hurricane. This is done by first developing a model for the acoustic intensity and mutual intensity in an ocean waveguide due to a hurricane and then determining the relationship between local wind speed and underwater acoustic intensity. From this it is shown that it should be feasible to accurately measure the local wind speed and classify the destructive power of a hurricane if its eye wall passes directly over a single underwater acoustic sensor. The potential advantages and disadvantages of the proposed acoustic method are weighed against those of currently employed techniques. PMID:16454274

  20. Ocean acoustic hurricane classification.

    PubMed

    Wilson, Joshua D; Makris, Nicholas C

    2006-01-01

    Theoretical and empirical evidence are combined to show that underwater acoustic sensing techniques may be valuable for measuring the wind speed and determining the destructive power of a hurricane. This is done by first developing a model for the acoustic intensity and mutual intensity in an ocean waveguide due to a hurricane and then determining the relationship between local wind speed and underwater acoustic intensity. From this it is shown that it should be feasible to accurately measure the local wind speed and classify the destructive power of a hurricane if its eye wall passes directly over a single underwater acoustic sensor. The potential advantages and disadvantages of the proposed acoustic method are weighed against those of currently employed techniques.

  1. 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.

  2. Acoustic Remote Sensing

    NASA Astrophysics Data System (ADS)

    Dowling, David R.; Sabra, Karim G.

    2015-01-01

    Acoustic waves carry information about their source and collect information about their environment as they propagate. This article reviews how these information-carrying and -collecting features of acoustic waves that travel through fluids can be exploited for remote sensing. In nearly all cases, modern acoustic remote sensing involves array-recorded sounds and array signal processing to recover multidimensional results. The application realm for acoustic remote sensing spans an impressive range of signal frequencies (10-2 to 107 Hz) and distances (10-2 to 107 m) and involves biomedical ultrasound imaging, nondestructive evaluation, oil and gas exploration, military systems, and Nuclear Test Ban Treaty monitoring. In the past two decades, approaches have been developed to robustly localize remote sources; remove noise and multipath distortion from recorded signals; and determine the acoustic characteristics of the environment through which the sound waves have traveled, even when the recorded sounds originate from uncooperative sources or are merely ambient noise.

  3. Acoustic suspension system

    NASA Technical Reports Server (NTRS)

    Lee, M. C.; Wang, T. G. (Inventor)

    1983-01-01

    An acoustic levitation system is described, with single acoustic source and a small reflector to stably levitate a small object while the object is processed as by coating or heating it. The system includes a concave acoustic source which has locations on opposite sides of its axis that vibrate towards and away from a focal point to generate a converging acoustic field. A small reflector is located near the focal point, and preferably slightly beyond it, to create an intense acoustic field that stably supports a small object near the reflector. The reflector is located about one-half wavelength from the focal point and is concavely curved to a radius of curvature (L) of about one-half the wavelength, to stably support an object one-quarter wavelength (N) from the reflector.

  4. Acoustic integrated extinction

    PubMed Central

    Norris, Andrew N.

    2015-01-01

    The integrated extinction (IE) is defined as the integral of the scattering cross section as a function of wavelength. Sohl et al. (2007 J. Acoust. Soc. Am. 122, 3206–3210. (doi:10.1121/1.2801546)) derived an IE expression for acoustic scattering that is causal, i.e. the scattered wavefront in the forward direction arrives later than the incident plane wave in the background medium. The IE formula was based on electromagnetic results, for which scattering is causal by default. Here, we derive a formula for the acoustic IE that is valid for causal and non-causal scattering. The general result is expressed as an integral of the time-dependent forward scattering function. The IE reduces to a finite integral for scatterers with zero long-wavelength monopole and dipole amplitudes. Implications for acoustic cloaking are discussed and a new metric is proposed for broadband acoustic transparency. PMID:27547100

  5. On the determination of the depth of EAS development maximum using the lateral distribution of Cerenkov light at distances 150 m from EAS axis

    NASA Technical Reports Server (NTRS)

    Aliev, N.; Alimov, T.; Kakhkharov, M.; Makhmudov, B. M.; Rakhimova, N.; Tashpulatov, R.; Kalmykov, N. N.; Khristiansen, G. B.; Prosin, V. V.

    1985-01-01

    The Samarkand extensive air showers (EAS) array was used to measure the mean and individual lateral distribution functions (LDF) of EAS Cerenkov light. The analysis of the individual parameters b showed that the mean depth of EAS maximum and the variance of the depth distribution of maxima of EAS with energies of approx. 2x10 to the 15th power eV can properly be described in terms of Kaidalov-Martirosyan quark-gluon string model (QGSM).

  6. Acoustic sniper localization system

    NASA Astrophysics Data System (ADS)

    Prado, Gervasio; Dhaliwal, Hardave; Martel, Philip O.

    1997-02-01

    Technologies for sniper localization have received increased attention in recent months as American forces have been deployed to various trouble spots around the world. Among the technologies considered for this task acoustics is a natural choice for various reasons. The acoustic signatures of gunshots are loud and distinctive, making them easy to detect even in high noise background environments. Acoustics provides a passive sensing technology with excellent range and non line of sight capabilities. Last but not least, an acoustic sniper location system can be built at a low cost with off the shelf components. Despite its many advantages, the performance of acoustic sensors can degrade under adverse propagation conditions. Localization accuracy, although good, is usually not accurate enough to pinpoint a sniper's location in some scenarios (for example which widow in a building or behind which tree in a grove). For these more demanding missions, the acoustic sensor can be used in conjunction with an infra red imaging system that detects the muzzle blast of the gun. The acoustic system can be used to cue the pointing system of the IR camera in the direction of the shot's source.

  7. 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.

  8. Acoustic mapping velocimetry

    NASA Astrophysics Data System (ADS)

    Muste, M.; Baranya, S.; Tsubaki, R.; Kim, D.; Ho, H.; Tsai, H.; Law, D.

    2016-05-01

    Knowledge of sediment dynamics in rivers is of great importance for various practical purposes. Despite its high relevance in riverine environment processes, the monitoring of sediment rates remains a major and challenging task for both suspended and bed load estimation. While the measurement of suspended load is currently an active area of testing with nonintrusive technologies (optical and acoustic), bed load measurement does not mark a similar progress. This paper describes an innovative combination of measurement techniques and analysis protocols that establishes the proof-of-concept for a promising technique, labeled herein Acoustic Mapping Velocimetry (AMV). The technique estimates bed load rates in rivers developing bed forms using a nonintrusive measurements approach. The raw information for AMV is collected with acoustic multibeam technology that in turn provides maps of the bathymetry over longitudinal swaths. As long as the acoustic maps can be acquired relatively quickly and the repetition rate for the mapping is commensurate with the movement of the bed forms, successive acoustic maps capture the progression of the bed form movement. Two-dimensional velocity maps associated with the bed form migration are obtained by implementing algorithms typically used in particle image velocimetry to acoustic maps converted in gray-level images. Furthermore, use of the obtained acoustic and velocity maps in conjunction with analytical formulations (e.g., Exner equation) enables estimation of multidirectional bed load rates over the whole imaged area. This paper presents a validation study of the AMV technique using a set of laboratory experiments.

  9. Rapid decompression in the EA-6B.

    PubMed

    Hudson, S J; Todd, J S

    1998-08-01

    A Grumman EA-6B aircraft experienced a rapid pressurization failure at 27,000 feet. All four crew members had removed their oxygen masks and were breathing cabin air pressurized to 8,000 feet before the incident. Although none of the crew members developed signs or symptoms of decompression sickness, the potential for adversity was realized by all. Altitude decompression sickness (DCS) and pulmonary overinflation syndrome (POIS) represent potentially fatal complications of rapid decompression or uncontrolled ascent in aircraft. The signs and symptoms of DCS range from mild joint pain to eventual cardiopulmonary collapse and death. The symptoms of POIS are usually more abrupt and lethal. The medical management of DCS and POIS includes (1) maintenance of airway and cardiopulmonary resuscitation if necessary: (2) administration of 100% oxygen; (3) descent as per Naval Aviation Training and Operating Procedures Standardization guidelines; (4) horizontal body position; (5) maintenance of fluid intake; and (6) early medical evaluation by a flight surgeon or other physician qualified in the management of DCS. Symptoms of DCS may appear up to 24 hours after decompression, and continued monitoring or grounding of exposed individuals during this time is essential. Many controllable factors may predispose to DCS/POIS, and preventive measures should be taken to ensure maximum reduction of risk.

  10. Calibration of acoustic transients.

    PubMed

    Burkard, Robert

    2006-05-26

    This article reviews the appropriate stimulus parameters (click duration, toneburst envelope) that should be used when eliciting auditory brainstem responses from mice. Equipment specifications required to calibrate these acoustic transients are discussed. Several methods of calibrating the level of acoustic transients are presented, including the measurement of peak equivalent sound pressure level (peSPL) and peak sound pressure level (pSPL). It is hoped that those who collect auditory brainstem response thresholds in mice will begin to use standardized methods of acoustic calibration, so that hearing thresholds across mouse strains obtained in different laboratories can more readily be compared.

  11. Acoustical heat pumping engine

    DOEpatents

    Wheatley, John C.; Swift, Gregory W.; Migliori, Albert

    1983-08-16

    The disclosure is directed to an acoustical heat pumping engine without moving seals. A tubular housing holds a compressible fluid capable of supporting an acoustical standing wave. An acoustical driver is disposed at one end of the housing and the other end is capped. A second thermodynamic medium is disposed in the housing near to but spaced from the capped end. Heat is pumped along the second thermodynamic medium toward the capped end as a consequence both of the pressure oscillation due to the driver and imperfect thermal contact between the fluid and the second thermodynamic medium.

  12. PRSEUS Acoustic Panel Fabrication

    NASA Technical Reports Server (NTRS)

    Nicolette, Velicki; Yovanof, Nicolette P.; Baraja, Jaime; Mathur, Gopal; Thrash, Patrick; Pickell, Robert

    2011-01-01

    This report describes the development of a novel structural concept, Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS), that addresses the demanding fuselage loading requirements for the Hybrid Wing or Blended Wing Body (BWB) airplane configuration with regards to acoustic response. A PRSEUS panel was designed and fabricated and provided to NASA-LaRC for acoustic response testing in the Structural Acoustics Loads and Transmission (SALT) facility). Preliminary assessments of the sound transmission characteristics of a PRSEUS panel subjected to a representative Hybrid Wing Body (HWB) operating environment were completed for the NASA Environmentally Responsible Aviation (ERA) Program.

  13. Acoustic rotation control

    NASA Technical Reports Server (NTRS)

    Elleman, D. D.; Croonquist, A. P.; Wang, T. G. (Inventor)

    1983-01-01

    A system is described for acoustically controlled rotation of a levitated object, which avoids deformation of a levitated liquid object. Acoustic waves of the same wavelength are directed along perpendicular directions across the object, and with the relative phases of the acoustic waves repeatedly switched so that one wave alternately leads and lags the other by 90 deg. The amount of torque for rotating the object, and the direction of rotation, are controlled by controlling the proportion of time one wave leads the other and selecting which wave leads the other most of the time.

  14. Acoustical heat pumping engine

    DOEpatents

    Wheatley, J.C.; Swift, G.W.; Migliori, A.

    1983-08-16

    The disclosure is directed to an acoustical heat pumping engine without moving seals. A tubular housing holds a compressible fluid capable of supporting an acoustical standing wave. An acoustical driver is disposed at one end of the housing and the other end is capped. A second thermodynamic medium is disposed in the housing near to but spaced from the capped end. Heat is pumped along the second thermodynamic medium toward the capped end as a consequence both of the pressure oscillation due to the driver and imperfect thermal contact between the fluid and the second thermodynamic medium. 2 figs.

  15. Acoustic well cleaner

    DOEpatents

    Maki, Jr., Voldi E.; Sharma, Mukul M.

    1997-01-21

    A method and apparatus are disclosed for cleaning the wellbore and the near wellbore region. A sonde is provided which is adapted to be lowered into a borehole and which includes a plurality of acoustic transducers arranged around the sonde. Electrical power provided by a cable is converted to acoustic energy. The high intensity acoustic energy directed to the borehole wall and into the near wellbore region, redissolves or resuspends the material which is reducing the permeability of the formation and/or restricting flow in the wellbore.

  16. Underwater acoustic omnidirectional absorber

    NASA Astrophysics Data System (ADS)

    Naify, Christina J.; Martin, Theodore P.; Layman, Christopher N.; Nicholas, Michael; Thangawng, Abel L.; Calvo, David C.; Orris, Gregory J.

    2014-02-01

    Gradient index media, which are designed by varying local element properties in given geometry, have been utilized to manipulate acoustic waves for a variety of devices. This study presents a cylindrical, two-dimensional acoustic "black hole" design that functions as an omnidirectional absorber for underwater applications. The design features a metamaterial shell that focuses acoustic energy into the shell's core. Multiple scattering theory was used to design layers of rubber cylinders with varying filling fractions to produce a linearly graded sound speed profile through the structure. Measured pressure intensity agreed with predicted results over a range of frequencies within the homogenization limit.

  17. Stimulated Brillouin scatter in a magnetized ionospheric plasma.

    PubMed

    Bernhardt, P A; Selcher, C A; Lehmberg, R H; Rodriguez, S P; Thomason, J F; Groves, K M; McCarrick, M J; Frazer, G J

    2010-04-23

    High power electromagnetic waves transmitted from the HAARP facility in Alaska can excite low-frequency electrostatic waves by magnetized stimulated Brillouin scatter. Either an ion-acoustic wave with a frequency less than the ion cyclotron frequency (f(CI)) or an electrostatic ion cyclotron (EIC) wave just above f(CI) can be produced. The coupled equations describing the magnetized stimulated Brillouin scatter instability show that the production of both ion-acoustic and EIC waves is strongly influenced by the wave propagation relative to the background magnetic field. Experimental observations of stimulated electromagnetic emissions using the HAARP transmitter have confirmed that only ion-acoustic waves are excited for propagation along the magnetic zenith and that EIC waves can only be detected with oblique propagation angles. The ion composition can be obtained from the measured EIC frequency. PMID:20482059

  18. Stimulated Brillouin Scatter in a Magnetized Ionospheric Plasma

    SciTech Connect

    Bernhardt, P. A.; Selcher, C. A.; Lehmberg, R. H.; Rodriguez, S. P.; Thomason, J. F.; Groves, K. M.; McCarrick, M. J.; Frazer, G. J.

    2010-04-23

    High power electromagnetic waves transmitted from the HAARP facility in Alaska can excite low-frequency electrostatic waves by magnetized stimulated Brillouin scatter. Either an ion-acoustic wave with a frequency less than the ion cyclotron frequency (f{sub CI}) or an electrostatic ion cyclotron (EIC) wave just above f{sub CI} can be produced. The coupled equations describing the magnetized stimulated Brillouin scatter instability show that the production of both ion-acoustic and EIC waves is strongly influenced by the wave propagation relative to the background magnetic field. Experimental observations of stimulated electromagnetic emissions using the HAARP transmitter have confirmed that only ion-acoustic waves are excited for propagation along the magnetic zenith and that EIC waves can only be detected with oblique propagation angles. The ion composition can be obtained from the measured EIC frequency.

  19. Psychophysics, fitting, and signal processing for combined hearing aid and cochlear implant stimulation.

    PubMed

    Francart, Tom; McDermott, Hugh J

    2013-01-01

    The addition of acoustic stimulation to electric stimulation via a cochlear implant has been shown to be advantageous for speech perception in noise, sound quality, music perception, and sound source localization. However, the signal processing and fitting procedures of current cochlear implants and hearing aids were developed independently, precluding several potential advantages of bimodal stimulation, such as improved sound source localization and binaural unmasking of speech in noise. While there is a large and increasing population of implantees who use a hearing aid, there are currently no generally accepted fitting methods for this configuration. It is not practical to fit current commercial devices to achieve optimal binaural loudness balance or optimal binaural cue transmission for arbitrary signals and levels. There are several promising experimental signal processing systems specifically designed for bimodal stimulation. In this article, basic psychophysical studies with electric acoustic stimulation are reviewed, along with the current state of the art in fitting, and experimental signal processing techniques for electric acoustic stimulation.

  20. Kinetic Enhancement of Raman Backscatter, and Electron Acoustic Thomson Scatter

    SciTech Connect

    Strozzi, D J; Williams, E A; Langdon, A B; Bers, A

    2006-09-01

    1-D Eulerian Vlasov-Maxwell simulations are presented which show kinetic enhancement of stimulated Raman backscatter (SRBS) due to electron trapping in regimes of heavy linear Landau damping. The conventional Raman Langmuir wave is transformed into a set of beam acoustic modes [L. Yin et al., Phys. Rev. E 73, 025401 (2006)]. For the first time, a low phase velocity electron acoustic wave (EAW) is seen developing from the self-consistent Raman physics. Backscatter of the pump laser off the EAW fluctuations is reported and referred to as electron acoustic Thomson scatter. This light is similar in wavelength to, although much lower in amplitude than, the reflected light between the pump and SRBS wavelengths observed in single hot spot experiments, and previously interpreted as stimulated electron acoustic scatter [D. S. Montgomery et al., Phys. Rev. Lett. 87, 155001 (2001)]. The EAW observed in our simulations is strongest well below the phase-matched frequency for electron acoustic scatter, and therefore the EAW is not produced by it. The beating of different beam acoustic modes is proposed as the EAW excitation mechanism, and is called beam acoustic decay. Supporting evidence for this process, including bispectral analysis, is presented. The linear electrostatic modes, found by projecting the numerical distribution function onto a Gauss-Hermite basis, include beam acoustic modes (some of which are unstable even without parametric coupling to light waves) and a strongly-damped EAW similar to the observed one. This linear EAW results from non-Maxwellian features in the electron distribution, rather than nonlinearity due to electron trapping.

  1. 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.

  2. Acoustics lecturing in Mexico

    NASA Astrophysics Data System (ADS)

    Beristain, Sergio

    2002-11-01

    Some thirty years ago acoustics lecturing started in Mexico at the National Polytechnic Institute in Mexico City, as part of the Bachelor of Science degree in Communications and Electronics Engineering curricula, including the widest program on this field in the whole country. This program has been producing acoustics specialists ever since. Nowadays many universities and superior education institutions around the country are teaching students at the B.Sc. level and postgraduate level many topics related to acoustics, such as Architectural Acoustics, Seismology, Mechanical Vibrations, Noise Control, Audio, Audiology, Music, etc. Also many institutions have started research programs in related fields, with participation of medical doctors, psychologists, musicians, engineers, etc. Details will be given on particular topics and development.

  3. 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.

  4. Acoustic imaging system

    DOEpatents

    Smith, Richard W.

    1979-01-01

    An acoustic imaging system for displaying an object viewed by a moving array of transducers as the array is pivoted about a fixed point within a given plane. A plurality of transducers are fixedly positioned and equally spaced within a laterally extending array and operatively directed to transmit and receive acoustic signals along substantially parallel transmission paths. The transducers are sequentially activated along the array to transmit and receive acoustic signals according to a preestablished sequence. Means are provided for generating output voltages for each reception of an acoustic signal, corresponding to the coordinate position of the object viewed as the array is pivoted. Receptions from each of the transducers are presented on the same display at coordinates corresponding to the actual position of the object viewed to form a plane view of the object scanned.

  5. Acoustic Neuroma Association

    MedlinePlus

    ... Platinum Sponsors More from this sponsor... Platinum Sponsor Gold Sponsor University of Colorado Acoustic Neuroma Program Rocky Mountain Gamma Knife Center Gold Sponsor NYU Langone Medical Center Departments of Neurosurgery ...

  6. Acoustic-Levitation Chamber

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Granett, D.; Lee, M. C.

    1984-01-01

    Uncontaminated environments for highly-pure material processing provided within completely sealed levitation chamber that suspends particles by acoustic excitation. Technique ideally suited for material processing in low gravity environment of space.

  7. Multimode Acoustic Research

    NASA Technical Reports Server (NTRS)

    Barmatz, M.

    1985-01-01

    There is a need for high temperature containerless processing facilities that can efficiently position and manipulate molten samples in the reduced gravity environment of space. The goal of the research is to develop sophisticated high temperature manipulation capabilities such as selection of arbitrary axes rotation and rapid sample cooling. This program will investigate new classes of acoustic levitation in rectangular, cylindrical and spherical geometries. The program tasks include calculating theoretical expressions of the acoustic forces in these geometries for the excitation of up to three acoustic modes (multimodes). These calculations are used to: (1) determine those acoustic modes that produce stable levitation, (2) isolate the levitation and rotation capabilities to produce more than one axis of rotation, and (3) develop methods to translate samples down long tube cylindrical chambers. Experimental levitators will then be constructed to verify the stable levitation and rotation predictions of the models.

  8. 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.

  9. Numerical Techniques in Acoustics

    NASA Technical Reports Server (NTRS)

    Baumeister, K. J. (Compiler)

    1985-01-01

    This is the compilation of abstracts of the Numerical Techniques in Acoustics Forum held at the ASME's Winter Annual Meeting. This forum was for informal presentation and information exchange of ongoing acoustic work in finite elements, finite difference, boundary elements and other numerical approaches. As part of this forum, it was intended to allow the participants time to raise questions on unresolved problems and to generate discussions on possible approaches and methods of solution.

  10. Wavefront modulation and subwavelength diffractive acoustics with an acoustic metasurface

    NASA Astrophysics Data System (ADS)

    Xie, Yangbo; Wang, Wenqi; Chen, Huanyang; Konneker, Adam; Popa, Bogdan-Ioan; Cummer, Steven A.

    2014-11-01

    Metasurfaces are a family of novel wavefront-shaping devices with planar profile and subwavelength thickness. Acoustic metasurfaces with ultralow profile yet extraordinary wave manipulating properties would be highly desirable for improving the performance of many acoustic wave-based applications. However, designing acoustic metasurfaces with similar functionality to their electromagnetic counterparts remains challenging with traditional metamaterial design approaches. Here we present a design and realization of an acoustic metasurface based on tapered labyrinthine metamaterials. The demonstrated metasurface can not only steer an acoustic beam as expected from the generalized Snell’s law, but also exhibits various unique properties such as conversion from propagating wave to surface mode, extraordinary beam-steering and apparent negative refraction through higher-order diffraction. Such designer acoustic metasurfaces provide a new design methodology for acoustic signal modulation devices and may be useful for applications such as acoustic imaging, beam steering, ultrasound lens design and acoustic surface wave-based applications.

  11. Wavefront modulation and subwavelength diffractive acoustics with an acoustic metasurface.

    PubMed

    Xie, Yangbo; Wang, Wenqi; Chen, Huanyang; Konneker, Adam; Popa, Bogdan-Ioan; Cummer, Steven A

    2014-11-24

    Metasurfaces are a family of novel wavefront-shaping devices with planar profile and subwavelength thickness. Acoustic metasurfaces with ultralow profile yet extraordinary wave manipulating properties would be highly desirable for improving the performance of many acoustic wave-based applications. However, designing acoustic metasurfaces with similar functionality to their electromagnetic counterparts remains challenging with traditional metamaterial design approaches. Here we present a design and realization of an acoustic metasurface based on tapered labyrinthine metamaterials. The demonstrated metasurface can not only steer an acoustic beam as expected from the generalized Snell's law, but also exhibits various unique properties such as conversion from propagating wave to surface mode, extraordinary beam-steering and apparent negative refraction through higher-order diffraction. Such designer acoustic metasurfaces provide a new design methodology for acoustic signal modulation devices and may be useful for applications such as acoustic imaging, beam steering, ultrasound lens design and acoustic surface wave-based applications.

  12. Acoustic detection of pneumothorax

    NASA Astrophysics Data System (ADS)

    Mansy, Hansen A.; Royston, Thomas J.; Balk, Robert A.; Sandler, Richard H.

    2003-04-01

    This study aims at investigating the feasibility of using low-frequency (<2000 Hz) acoustic methods for medical diagnosis. Several candidate methods of pneumothorax detection were tested in dogs. In the first approach, broadband acoustic signals were introduced into the trachea during end-expiration and transmitted waves were measured at the chest surface. Pneumothorax was found to consistently decrease pulmonary acoustic transmission in the 200-1200-Hz frequency band, while less change was observed at lower frequencies (p<0.0001). The ratio of acoustic energy between low (<220 Hz) and mid (550-770 Hz) frequency bands was significantly different in the control (healthy) and pneumothorax states (p<0.0001). The second approach measured breath sounds in the absence of an external acoustic input. Pneumothorax was found to be associated with a preferential reduction of sound amplitude in the 200- to 700-Hz range, and a decrease of sound amplitude variation (in the 300 to 600-Hz band) during the respiration cycle (p<0.01 for each). Finally, chest percussion was implemented. Pneumothorax changed the frequency and decay rate of percussive sounds. These results imply that certain medical conditions may be reliably detected using appropriate acoustic measurements and analysis. [Work supported by NIH/NHLBI #R44HL61108.

  13. Ocean acoustic reverberation tomography.

    PubMed

    Dunn, Robert A

    2015-12-01

    Seismic wide-angle imaging using ship-towed acoustic sources and networks of ocean bottom seismographs is a common technique for exploring earth structure beneath the oceans. In these studies, the recorded data are dominated by acoustic waves propagating as reverberations in the water column. For surveys with a small receiver spacing (e.g., <10 km), the acoustic wave field densely samples properties of the water column over the width of the receiver array. A method, referred to as ocean acoustic reverberation tomography, is developed that uses the travel times of direct and reflected waves to image ocean acoustic structure. Reverberation tomography offers an alternative approach for determining the structure of the oceans and advancing the understanding of ocean heat content and mixing processes. The technique has the potential for revealing small-scale ocean thermal structure over the entire vertical height of the water column and along long survey profiles or across three-dimensional volumes of the ocean. For realistic experimental geometries and data noise levels, the method can produce images of ocean sound speed on a smaller scale than traditional acoustic tomography. PMID:26723303

  14. Ocean acoustic reverberation tomography.

    PubMed

    Dunn, Robert A

    2015-12-01

    Seismic wide-angle imaging using ship-towed acoustic sources and networks of ocean bottom seismographs is a common technique for exploring earth structure beneath the oceans. In these studies, the recorded data are dominated by acoustic waves propagating as reverberations in the water column. For surveys with a small receiver spacing (e.g., <10 km), the acoustic wave field densely samples properties of the water column over the width of the receiver array. A method, referred to as ocean acoustic reverberation tomography, is developed that uses the travel times of direct and reflected waves to image ocean acoustic structure. Reverberation tomography offers an alternative approach for determining the structure of the oceans and advancing the understanding of ocean heat content and mixing processes. The technique has the potential for revealing small-scale ocean thermal structure over the entire vertical height of the water column and along long survey profiles or across three-dimensional volumes of the ocean. For realistic experimental geometries and data noise levels, the method can produce images of ocean sound speed on a smaller scale than traditional acoustic tomography.

  15. A compact acoustic recorder

    NASA Astrophysics Data System (ADS)

    Stein, Ronald

    1989-09-01

    The design and operation of a portable compact acoustic recorder is discussed. Designed to be used in arctic conditions for applications that require portable equipment, the device is configured to fit into a lightweight briefcase. It will operate for eight hours at -40 F with heat provided by a hot water bottle. It has proven to be an effective scientific tool in the measurement of underwater acoustic signals in arctic experiments. It has also been used successfully in warmer climates, e.g., in recording acoustic signals from small boats with no ac power. The acoustic recorder's cost is moderate since it is based on a Sony Walkman Professional (WM-D6C) tape recorder playback unit. A speaker and battery assembly and a hydrophone interface electronic assembly complete the system electronics. The interface assembly supplies a number of functions, including a calibration tone generator, an audio amplifier, and a hydrophone interface. Calibrated acoustic recordings can be made by comparing the calibration tone amplitude with the acoustic signal amplitude. The distortion of the recording is minimized by using a high quality, consumer tape recorder.

  16. Acoustic communication by ants

    NASA Astrophysics Data System (ADS)

    Hickling, Robert

    2002-05-01

    Many ant species communicate acoustically by stridulating, i.e., running a scraper over a washboard-like set of ridges. Ants appear to be insensitive to airborne sound. Consequently, myrmecologists have concluded that the stridulatory signals are transmitted through the substrate. This has tended to diminish the importance of acoustic communication, and it is currently believed that ant communication is based almost exclusively on pheromones, with acoustic communication assigned an almost nonexistent role. However, it can be shown that acoustic communication between ants is effective only if the medium is air and not the substrate. How, then, is it possible for ants to appear deaf to airborne sound and yet communicate through the air? An explanation is provided in a paper [R. Hickling and R. L. Brown, ``Analysis of acoustic communication by ants,'' J. Acoust. Soc. Am. 108, 1920-1929 (2000)]. Ants are small relative to the wavelengths they generate. Hence, they create a near field, which is characterized by a major increase in sound velocity (particle velocity of sound) in the vicinity of the source. Hair sensilla on the ants' antennae respond to sound velocity. Thus, ants are able to detect near-field sound from other ants and to exclude extraneous airborne sound.

  17. Registration of neutrons within 2 milliseconds after EAS impact

    NASA Astrophysics Data System (ADS)

    Jȩdrzejczak, K.; Karczmarczyk, J.; Kasztelan, M.; Petrochenkov, S. A.; Polański, A.; Swarzyński, J.; Szabelski, J.; Wibig, T.

    2006-01-01

    We register an excess of signals from neutron detectors within a few milliseconds after passage of EAS front in Lodz EAS array. The most probable explanation is that neutrons are produced in EAS hadron interactions with lead block of muon detector. These neutrons diffuse and are thermalized before the detection in the Geiger-Müller counters, the boron counter and other detectors registering time structure of the impulses (10 MHz FADC, 8-bit converters, 32 kB memory). We performed computer simulations of neutron diffusion in the vicinity of the array. We used MCNP program and introduced the detailed geometry of the array and its surroundings. Simulated neutrons started their diffusion in the lead block or in the ground near the detector. The obtained time distributions of slow neutrons are consistent with the registrations in the boron counter. The only problem is the requirement of a great number of neutrons produced at the shower arrival. This "new EAS observable" can be used as inexpensive hadron detector in EAS.

  18. Effect of electroacupuncture stimulation at Zusanli acupoint (ST36) on gastric motility: possible through PKC and MAPK signal transduction pathways

    PubMed Central

    2014-01-01

    Background Electroacupuncture (EA) stimulation has been shown to have a great therapeutic potential for treating gastrointestinal motility disorders. However, no evidence has clarified the mechanisms contributing to the effects of EA stimulation at the Zusanli acupoint (ST.36). This study was designed to investigate the regulative effect of EA stimulation at the ST.36 on gastric motility and to explore its possible mechanisms. Methods Thirty Sprague-Dawley rats were randomly divided into three groups: the ST.36 group, the non-acupoint group, and the control group. EA stimulation was set at 2 Hz, continuous mode, and 1 V for 30 min. The frequency and average peak amplitude of gastric motility were measured by electrogastrography. The protein kinase C (PKC) and mitogen-activated protein kinase (MAPK) signaling pathways were assessed using real-time polymerase chain reactions. Caldesmon (CaD) and calponin (CaP) protein expression in the gastric antrum were detected on Western blots. A Computed Video Processing System was used to evaluate morphological changes in smooth muscle cells (SMCs) from the gastric antrum. Results EA stimulation at ST.36 had a dual effect on the frequency and average peak amplitude. Additionally, EA stimulation at ST.36 regulated the expression of some genes in the PKC and MAPK signaling pathways, and it regulated the expression of the CaD and CaP proteins. EA serum induced SMC contractility. Promotion of gastric motility may correlate with up-regulation of MAPK6 (ERK3), MAPK13, and Prostaglandin-endoperoxide synthase 2 (PTGS2) gene expression, and the down-regulation of the collagen, type I, alpha 1 (COL1A1) gene and CaD and CaP protein expression. Inhibition of gastric motility may correlate with down-regulation of the Interleukin-1 receptor type 2 (IL1R2) and Matrix metalloproteinase-9 (MMP9) genes, and up-regulation of CaD and CaP protein expression. Conclusions EA stimulation at ST.36 regulated gastric motility, and the effects were

  19. Observation of EAS using a large water tank

    NASA Technical Reports Server (NTRS)

    Inoue, K.; Sakuyama, H.; Suzuki, N.; Suzuki, T.

    1985-01-01

    Using a large water tank (30 m in diameter, 4.5 m in depth) transition of extensive air showers (EAS) was investigated at Taro (200 m above sea level). There are set 150,0.4 sq m proportional counters on the bottom of the water tank. A conventional EAS array of 25 plastic scintillation detectors was arranged within several tens meter from the water tank. A proportional counter (10x10x200 cc x2) is made of a square shaped pipe of iron. Tungsten wire (100 mu m phi) is stretched tight in the center of the counter. A gas mixture of 90% argon and 10% methane is used at 760 mmHg. About 3000 EAS were obtained through 1 m of water since 1984.

  20. Observation of EAS using a large water tank

    NASA Astrophysics Data System (ADS)

    Inoue, K.; Sakuyama, H.; Suzuki, N.; Suzuki, T.

    1985-08-01

    Using a large water tank (30 m in diameter, 4.5 m in depth) transition of extensive air showers (EAS) was investigated at Taro (200 m above sea level). There are set 150,0.4 sq m proportional counters on the bottom of the water tank. A conventional EAS array of 25 plastic scintillation detectors was arranged within several tens meter from the water tank. A proportional counter (10x10x200 cc x2) is made of a square shaped pipe of iron. Tungsten wire (100 mu m phi) is stretched tight in the center of the counter. A gas mixture of 90% argon and 10% methane is used at 760 mmHg. About 3000 EAS were obtained through 1 m of water since 1984.

  1. Chemosensory stimulation during sleep - Arousal responses to gustatory stimulation.

    PubMed

    Stuck, B A; Moutsis, T T; Bingel, U; Sommer, J U

    2016-05-13

    The processing of nociceptive, visual, vibrotactile, thermal and acoustic stimuli during sleep has been extensively investigated in the past. Recently, interest has focused on the impact of olfactory stimulation on sleep. In contrast to all other sensory systems, olfactory stimulation does not lead to an increased arousal frequency, regardless of hedonicity and concentration. The impact of the second chemosensory system, gustation, on sleep however has not been investigated to date. Twenty-one normosmic and normogeusic volunteers of both genders, aged 19-33 years, participated in the trial. Stimulation was performed with a gustometer using the following aqueous solutions: saccharose 20% (sweet), sodium chloride (NaCl) 7.5% (salty), citrate 5% (sour), and quinine 0.02% (bitter). A tasteless solution was used as negative control. Capsaicin, a strong trigeminal stimulus, served as positive control. Primary outcome was arousal frequency per stimulus in each sleep stage, as assessed with polysomnography. The frequency of arousals decreased in deeper sleep stages (N1: 211 arousals of 333 stimuli=63%, N2: 676/2728=25%, N3: 43/1378=3%, REM: 57/1010=6%). Statistically significant differences in terms of arousal frequency were found in N2 between the negative control and NaCl 100 μl (p<0.001), saccharose 100 μl, citrate 50 μl & 100 μl, and quinine 100 μl (p<0.05). Capsaicin led to complete awakenings in 94% of stimuli (30/32). These results demonstrate that gustatory stimulation during sleep induces arousals depending on stimulus intensity and sleep stage, which is different to olfactory stimulation and may be related to differences in central processing of the two chemosensory systems. PMID:26921652

  2. Cocaine: effects on acoustic startle and startle elicited electrically from the cochlear nucleus.

    PubMed

    Harty, T P; Davis, M

    1985-01-01

    Startle-like responses can be elicited by single pulse electrical stimulation of nuclei within the acoustic startle pathway. Compared with acoustically-elicited startle, this technique provides a method for localizing the ultimate sites of action of a drug that affects the acoustic startle response. Strychnine (1 mg/kg) increased both acoustically-elicited startle and startle elicited from the ventral cochlear nucleus (VCN), the first central nucleus in the acoustic startle pathway. In contrast, cocaine (10 mg/kg) increased acoustically-elicited startle but depressed VCN-elicited startle. These results suggest that cocaine increases startle by acting on sensory rather than final motor systems and are discussed in relation to the putative effect of cocaine on dopamine neurotransmission and the involvement of dopamine in sensorimotor reactivity. PMID:3001807

  3. Measuring acoustic habitats

    PubMed Central

    Merchant, Nathan D; Fristrup, Kurt M; Johnson, Mark P; Tyack, Peter L; Witt, Matthew J; Blondel, Philippe; Parks, Susan E

    2015-01-01

    1. Many organisms depend on sound for communication, predator/prey detection and navigation. The acoustic environment can therefore play an important role in ecosystem dynamics and evolution. A growing number of studies are documenting acoustic habitats and their influences on animal development, behaviour, physiology and spatial ecology, which has led to increasing demand for passive acoustic monitoring (PAM) expertise in the life sciences. However, as yet, there has been no synthesis of data processing methods for acoustic habitat monitoring, which presents an unnecessary obstacle to would-be PAM analysts. 2. Here, we review the signal processing techniques needed to produce calibrated measurements of terrestrial and aquatic acoustic habitats. We include a supplemental tutorial and template computer codes in matlab and r, which give detailed guidance on how to produce calibrated spectrograms and statistical analyses of sound levels. Key metrics and terminology for the characterisation of biotic, abiotic and anthropogenic sound are covered, and their application to relevant monitoring scenarios is illustrated through example data sets. To inform study design and hardware selection, we also include an up-to-date overview of terrestrial and aquatic PAM instruments. 3. Monitoring of acoustic habitats at large spatiotemporal scales is becoming possible through recent advances in PAM technology. This will enhance our understanding of the role of sound in the spatial ecology of acoustically sensitive species and inform spatial planning to mitigate the rising influence of anthropogenic noise in these ecosystems. As we demonstrate in this work, progress in these areas will depend upon the application of consistent and appropriate PAM methodologies. PMID:25954500

  4. Acoustic neuromodulation from a basic science prospective.

    PubMed

    Sassaroli, Elisabetta; Vykhodtseva, Natalia

    2016-01-01

    We present here biophysical models to gain deeper insights into how an acoustic stimulus might influence or modulate neuronal activity. There is clear evidence that neural activity is not only associated with electrical and chemical changes but that an electro-mechanical coupling is also involved. Currently, there is no theory that unifies the electrical, chemical, and mechanical aspects of neuronal activity. Here, we discuss biophysical models and hypotheses that can explain some of the mechanical aspects associated with neuronal activity: the soliton model, the neuronal intramembrane cavitation excitation model, and the flexoelectricity hypothesis. We analyze these models and discuss their implications on stimulation and modulation of neuronal activity by ultrasound. PMID:27213044

  5. Measurements of the thermal neutrons flux near the EAS core

    NASA Astrophysics Data System (ADS)

    Dzhappuev, D. D.; Volchenko, V. I.; Kudzhaev, A. U.; Mikhailova, O. I.; Petkov, V. B.; Stenkin, Yu V.; Tsyabuk, A. L.

    2013-02-01

    The characteristics of the thermal neutrons flux have been measured near the EAS core at the "Carpet-2" EAS array. The thermal neutron detectors were placed on the floor of the tunnel of the Muon Detector (MD) and showers with a core near the MD were selected. Thermal neutrons multiplicity spectrum has been obtained for these showers. Measurements of the lateral distribution function of thermal neutrons at distances of 1-16 m from the shower axis have been performed. The mean number of the recorded thermal neutrons as a function of the number of hadrons crossing the MD has been measured.

  6. 77 FR 1676 - EasTrans, LLC; Notice Granting Extension of Time

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-11

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission EasTrans, LLC; Notice Granting Extension of Time On December 16, 2011, Eas... an extension of time for EasTrans to file its section 284.123 rate petition is granted to...

  7. 47 CFR 11.54 - EAS operation during a National Level emergency.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false EAS operation during a National Level emergency. 11.54 Section 11.54 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL EMERGENCY ALERT SYSTEM (EAS) Emergency Operations § 11.54 EAS operation during a National Level emergency. (a) Immediately upon receipt of an EAN message,...

  8. 47 CFR 11.54 - EAS operation during a National Level emergency.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false EAS operation during a National Level emergency. 11.54 Section 11.54 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL EMERGENCY ALERT SYSTEM (EAS) Emergency Operations § 11.54 EAS operation during a National Level emergency. (a) Immediately upon receipt of an EAN message,...

  9. 47 CFR 11.54 - EAS operation during a National Level emergency.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... licensees and DBS providers may choose their two EAS sources, one of which must be a PEP station. (2... Script is in the EAS Operating Handbook's section for Participating sources. (5) Analog and digital TV... and aurally as specified in § 11.51(g) and (h). (7) DBS providers shall transmit all EAS...

  10. 47 CFR 11.51 - EAS code and Attention Signal Transmission requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... programming of a broadcast station carrying news or weather related emergency information with state and local... weather related emergency information with state and local EAS messages based on a written agreement... control location may be used to override the transmission of an EAS alert. EAS Participants may...

  11. Acoustic Imaging in Helioseismology

    NASA Astrophysics Data System (ADS)

    Chou, Dean-Yi; Chang, Hsiang-Kuang; Sun, Ming-Tsung; LaBonte, Barry; Chen, Huei-Ru; Yeh, Sheng-Jen; Team, The TON

    1999-04-01

    The time-variant acoustic signal at a point in the solar interior can be constructed from observations at the surface, based on the knowledge of how acoustic waves travel in the Sun: the time-distance relation of the p-modes. The basic principle and properties of this imaging technique are discussed in detail. The helioseismic data used in this study were taken with the Taiwan Oscillation Network (TON). The time series of observed acoustic signals on the solar surface is treated as a phased array. The time-distance relation provides the phase information among the phased array elements. The signal at any location at any time can be reconstructed by summing the observed signal at array elements in phase and with a proper normalization. The time series of the constructed acoustic signal contains information on frequency, phase, and intensity. We use the constructed intensity to obtain three-dimensional acoustic absorption images. The features in the absorption images correlate with the magnetic field in the active region. The vertical extension of absorption features in the active region is smaller in images constructed with shorter wavelengths. This indicates that the vertical resolution of the three-dimensional images depends on the range of modes used in constructing the signal. The actual depths of the absorption features in the active region may be smaller than those shown in the three-dimensional images.

  12. [Acoustic characteristics of classrooms].

    PubMed

    Koszarny, Zbigniew; Chyla, Andrzej

    2003-01-01

    Quality and usefulness of school rooms for transmission of verbal information depends on the two basic parameters: form and quantity of the reverberation time, and profitable line measurements of school rooms from the acoustic point of view. An analysis of the above-mentioned parameters in 48 class rooms and two gymnasiums in schools, which were built in different periods, shows that the most important problem is connected with too long reverberation time and inappropriate acoustic proportions. In schools built in the 1970s, the length of reverberation time is mostly within a low frequency band, while in schools built contemporarily, the maximum length of disappearance time takes place in a quite wide band of 250-2000 Hz. This exceeds optimal values for that kind of rooms at least twice, and five times in the newly built school. A long reverberation time is connected with a low acoustic absorption of school rooms. Moreover, school rooms are characterised by inappropriate acoustic proportions. The classrooms, in their relation to the height, are too long and too wide. It is connected with deterioration of the transmission of verbal information. The data show that this transmission is unequal. Automatically, it leads to a speech disturbance and difficulties with understanding. There is the need for adaptation of school rooms through increase of an acoustic absorption.

  13. Acoustic emission monitoring system

    DOEpatents

    Romrell, Delwin M.

    1977-07-05

    Methods and apparatus for identifying the source location of acoustic emissions generated within an acoustically conductive medium. A plurality of acoustic receivers are communicably coupled to the surface of the medium at a corresponding number of spaced locations. The differences in the reception time of the respective sensors in response to a given acoustic event are measured among various sensor combinations prescribed by the monitoring mode employed. Acoustic reception response encountered subsequent to the reception by a predetermined number of the prescribed sensor combinations are inhibited from being communicated to the processing circuitry, while the time measurements obtained from the prescribed sensor combinations are translated into a position measurement representative of the location on the surface most proximate the source of the emission. The apparatus is programmable to function in six separate and five distinct operating modes employing either two, three or four sensory locations. In its preferred arrangement the apparatus of this invention will re-initiate a monitoring interval if the predetermined number of sensors do not respond to a particular emission within a given time period.

  14. ACOUSTICS IN ARCHITECTURAL DESIGN, AN ANNOTATED BIBLIOGRAPHY ON ARCHITECTURAL ACOUSTICS.

    ERIC Educational Resources Information Center

    DOELLE, LESLIE L.

    THE PURPOSE OF THIS ANNOTATED BIBLIOGRAPHY ON ARCHITECTURAL ACOUSTICS WAS--(1) TO COMPILE A CLASSIFIED BIBLIOGRAPHY, INCLUDING MOST OF THOSE PUBLICATIONS ON ARCHITECTURAL ACOUSTICS, PUBLISHED IN ENGLISH, FRENCH, AND GERMAN WHICH CAN SUPPLY A USEFUL AND UP-TO-DATE SOURCE OF INFORMATION FOR THOSE ENCOUNTERING ANY ARCHITECTURAL-ACOUSTIC DESIGN…

  15. Surface Acoustic Wave Microfluidics

    NASA Astrophysics Data System (ADS)

    Yeo, Leslie Y.; Friend, James R.

    2014-01-01

    Fluid manipulations at the microscale and beyond are powerfully enabled through the use of 10-1,000-MHz acoustic waves. A superior alternative in many cases to other microfluidic actuation techniques, such high-frequency acoustics is almost universally produced by surface acoustic wave devices that employ electromechanical transduction in wafer-scale or thin-film piezoelectric media to generate the kinetic energy needed to transport and manipulate fluids placed in adjacent microfluidic structures. These waves are responsible for a diverse range of complex fluid transport phenomena - from interfacial fluid vibration and drop and confined fluid transport to jetting and atomization - underlying a flourishing research literature spanning fundamental fluid physics to chip-scale engineering applications. We highlight some of this literature to provide the reader with a historical basis, routes for more detailed study, and an impression of the field's future directions.

  16. Acoustic particle separation

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Stoneburner, J. D.; Jacobi, N.; Wang, T. (Inventor)

    1985-01-01

    A method is described which uses acoustic energy to separate particles of different sizes, densities, or the like. The method includes applying acoustic energy resonant to a chamber containing a liquid of gaseous medium to set up a standing wave pattern that includes a force potential well wherein particles within the well are urged towards the center, or position of minimum force potential. A group of particles to be separated is placed in the chamber, while a non-acoustic force such as gravity is applied, so that the particles separate with the larger or denser particles moving away from the center of the well to a position near its edge and progressively smaller lighter particles moving progressively closer to the center of the well. Particles are removed from different positions within the well, so that particles are separated according to the positions they occupy in the well.

  17. Acoustic Levitation Containerless Processing

    NASA Technical Reports Server (NTRS)

    Whymark, R. R.; Rey, C. A.

    1985-01-01

    This research program consists of the development of acoustic containerless processing systems with applications in the areas of research in material sciences, as well as the production of new materials, solid forms with novel and unusual microstructures, fusion target spheres, and improved optical fibers. Efforts have been focused on the containerless processing at high temperatures for producing new kinds of glasses. Also, some development has occurred in the areas of containerlessly supporting liquids at room temperature, with applications in studies of fluid dynamics, potential undercooling of liquids, etc. The high temperature area holds the greatest promise for producing new kinds of glasses and ceramics, new alloys, and possibly unusual structural shapes, such as very uniform hollow glass shells for fusion target applications. High temperature acoustic levitation required for containerless processing has been demonstrated in low-g environments as well as in ground-based experiments. Future activities include continued development of the signals axis acoustic levitator.

  18. Acoustic energy shaping

    NASA Technical Reports Server (NTRS)

    Wang, T. G.; Elleman, D. D. (Inventor)

    1977-01-01

    A suspended mass is shaped by melting all or a selected portion of the mass and applying acoustic energy in varying amounts to different portions of the mass. In one technique for forming an optical waveguide slug, a mass of oval section is suspended and only a portion along the middle of the cross-section is heated to a largely fluid consistency. Acoustic energy is applied to opposite edges of the oval mass to press the unheated opposite edge portions together so as to form bulges at the middle of the mass. In another technique for forming a ribbon of silicon for constructing solar cells, a cylindrical thread of silicon is drawn from a molten mass of silicon, and acoustic energy is applied to opposite sides of the molten thread to flatten it into a ribbon.

  19. Passive broadband acoustic thermometry

    NASA Astrophysics Data System (ADS)

    Anosov, A. A.; Belyaev, R. V.; Klin'shov, V. V.; Mansfel'd, A. D.; Subochev, P. V.

    2016-04-01

    The 1D internal (core) temperature profiles for the model object (plasticine) and the human hand are reconstructed using the passive acoustothermometric broadband probing data. Thermal acoustic radiation is detected by a broadband (0.8-3.5 MHz) acoustic radiometer. The temperature distribution is reconstructed using a priori information corresponding to the experimental conditions. The temperature distribution for the heated model object is assumed to be monotonic. For the hand, we assume that the temperature distribution satisfies the heat-conduction equation taking into account the blood flow. The average error of reconstruction determined for plasticine from the results of independent temperature measurements is 0.6 K for a measuring time of 25 s. The reconstructed value of the core temperature of the hand (36°C) generally corresponds to physiological data. The obtained results make it possible to use passive broadband acoustic probing for measuring the core temperatures in medical procedures associated with heating of human organism tissues.

  20. Latticed pentamode acoustic cloak.

    PubMed

    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

  1. 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

  2. Treatment of iatrogenic Cushing's syndrome in dogs with electroacupuncture stimulation of stomach 36.

    PubMed

    Lin, J H; Su, H L; Chang, S H; Shien, Y S; Wu, L S

    1991-01-01

    This study was conducted to evaluate the effectiveness of electroacupuncture (EA) on the recovery of adrenocortical function from Iatrogenic Cushings Syndrome (ICS) in dogs. Experiment I: Selection of the most effective Acupuncture point to treat ICS--Six healthy adult female dogs were treated bilaterally with EA for 15 minutes at loci BL22 + BL23 + BL24, ST36, or a non-locus control point on M. brachialis. Each dog was tested at all three sites in rotation. Blood samples were collected before and 0, 15 and 60 minutes after EA, and the serum cortisol levels were measured by radioimmunoassay. The data showed that EA at ST36 resulted in the highest response of serum cortisol levels among the three treatments. Experiment II: Evaluation of the effectiveness of EA ST36 in the treatment of ICS in dogs--Eight healthy adult female dogs were given prednisolone acetate 2mg/kg/day IM for 3 weeks. They were then randomly divided into ST36 and control groups of 4 dogs each. In the ST36 group, ST36 was treated bilaterally with EA for 30 minutes, 3 times per week, for 3 consecutive weeks. For the control, a non-locus point on M. brachialis was treated bilaterally with the same protocol. After the first week of EA, the serum cortisol levels of the ST36 and control groups were 0.9 +/- 0.1 and 0.5 +/- 0.1 micrograms/dl (P less than 0.005) baseline and 2.5 +/- 0.2 and 1.4 +/- 0.4 micrograms/dl (p less than 0.05) and after ACTH stimulation test, respectively. After the third week of EA treatment, the results were 1.0 +/- 0.1 and 0.6 +/- 0.2 micrograms/dl (p less than 0.05) baseline and 4.0 +/- 0.5 and 1.7 +/- 0.5 micrograms/dl (p less than 0.001) after ACTH stimulation respectively. These data indicated that EA at ST36 could restore the adrenocortical hypofunction resulting from ICS in dogs.

  3. A New Wave of Acoustics.

    ERIC Educational Resources Information Center

    Beyer, Robert

    1981-01-01

    Surveys 50 years of acoustical studies by discussing selected topics including the ear, nonlinear representations, underwater sound, acoustical diagnostics, absorption, electrolytes, phonons, magnetic interaction, and superfluidity and the five sounds. (JN)

  4. 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.

  5. Acoustic emission intrusion detector

    DOEpatents

    Carver, Donald W.; Whittaker, Jerry W.

    1980-01-01

    An intrusion detector is provided for detecting a forcible entry into a secured structure while minimizing false alarms. The detector uses a piezoelectric crystal transducer to sense acoustic emissions. The transducer output is amplified by a selectable gain amplifier to control the sensitivity. The rectified output of the amplifier is applied to a Schmitt trigger circuit having a preselected threshold level to provide amplitude discrimination. Timing circuitry is provided which is activated by successive pulses from the Schmitt trigger which lie within a selected time frame for frequency discrimination. Detected signals having proper amplitude and frequency trigger an alarm within the first complete cycle time of a detected acoustical disturbance signal.

  6. 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.

  7. Acoustic tooth cleaner

    NASA Technical Reports Server (NTRS)

    Heyman, J. S. (Inventor)

    1982-01-01

    An acoustic oral hygiene unit is described that uses acoustic energy to oscillate mild abrasive particles in a water suspension which is then directed in a low pressure stream onto the teeth. The oscillating abrasives scrub the teeth clean removing food particles, plaque, calculous, and other foreign material from tooth surfaces, interproximal areas, and tooth-gingiva interface more effectively than any previous technique. The relatively low power output and the basic design makes the invention safe and convenient for everyday use in the home without special training. This invention replaces all former means of home dental prophylaxis, and requires no augmentation to fulfill all requirements for daily oral hygienic care.

  8. Densitometry By Acoustic Levitation

    NASA Technical Reports Server (NTRS)

    Trinh, Eugene H.

    1989-01-01

    "Static" and "dynamic" methods developed for measuring mass density of acoustically levitated solid particle or liquid drop. "Static" method, unknown density of sample found by comparison with another sample of known density. "Dynamic" method practiced with or without gravitational field. Advantages over conventional density-measuring techniques: sample does not have to make contact with container or other solid surface, size and shape of samples do not affect measurement significantly, sound field does not have to be know in detail, and sample can be smaller than microliter. Detailed knowledge of acoustic field not necessary.

  9. Acoustically Induced Vibration of Structures: Reverberant Vs. Direct Acoustic Testing

    NASA Technical Reports Server (NTRS)

    Kolaini, Ali R.; O'Connell, Michael R.; Tsoi, Wan B.

    2009-01-01

    Large reverberant chambers have been used for several decades in the aerospace industry to test larger structures such as solar arrays and reflectors to qualify and to detect faults in the design and fabrication of spacecraft and satellites. In the past decade some companies have begun using direct near field acoustic testing, employing speakers, for qualifying larger structures. A limited test data set obtained from recent acoustic tests of the same hardware exposed to both direct and reverberant acoustic field testing has indicated some differences in the resulting structural responses. In reverberant acoustic testing, higher vibration responses were observed at lower frequencies when compared with the direct acoustic testing. In the case of direct near field acoustic testing higher vibration responses appeared to occur at higher frequencies as well. In reverberant chamber testing and direct acoustic testing, standing acoustic modes of the reverberant chamber or the speakers and spacecraft parallel surfaces can strongly couple with the fundamental structural modes of the test hardware. In this paper data from recent acoustic testing of flight hardware, that yielded evidence of acoustic standing wave coupling with structural responses, are discussed in some detail. Convincing evidence of the acoustic standing wave/structural coupling phenomenon will be discussed, citing observations from acoustic testing of a simple aluminum plate. The implications of such acoustic coupling to testing of sensitive flight hardware will be discussed. The results discussed in this paper reveal issues with over or under testing of flight hardware that could pose unanticipated structural and flight qualification issues. Therefore, it is of paramount importance to understand the structural modal coupling with standing acoustic waves that has been observed in both methods of acoustic testing. This study will assist the community to choose an appropriate testing method and test setup in

  10. 47 CFR 101.1311 - Initial EA license authorization.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Initial EA license authorization. 101.1311 Section 101.1311 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Multiple Address Systems System License Requirements § 101.1311...

  11. 7 CFR 1794.71 - Adoption of an EA.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 12 2014-01-01 2013-01-01 true Adoption of an EA. 1794.71 Section 1794.71 Agriculture Regulations of the Department of Agriculture (Continued) RURAL UTILITIES SERVICE, DEPARTMENT OF AGRICULTURE (CONTINUED) ENVIRONMENTAL POLICIES AND PROCEDURES Adoption of Environmental Documents § 1794.71 Adoption...

  12. 7 CFR 1794.23 - Proposals normally requiring an EA.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... classification are: (1) Construction of fuel cell, combustion turbine, combined cycle, or diesel generating... be covered in the EA; (2) Construction of fuel cell, combustion turbine, combined cycle, or diesel...) at a fossil-fueled generating station where the existing fuel combustion technology of the...

  13. 47 CFR 11.61 - Tests of EAS procedures.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...) Effective May 31, 2007, DBS providers must comply with this section by monitoring a state or local primary... provider), with channels tested varying from month to month, so that over the course of a given year, 100... and digital AM, FM, and TV broadcast stations must conduct tests of the EAS header and EOM codes...

  14. 47 CFR 11.61 - Tests of EAS procedures.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...) Effective May 31, 2007, DBS providers must comply with this section by monitoring a state or local primary... provider), with channels tested varying from month to month, so that over the course of a given year, 100... and digital AM, FM, and TV broadcast stations must conduct tests of the EAS header and EOM codes...

  15. 47 CFR 11.61 - Tests of EAS procedures.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...) Effective May 31, 2007, DBS providers must comply with this section by monitoring a state or local primary... provider), with channels tested varying from month to month, so that over the course of a given year, 100... and digital AM, FM, and TV broadcast stations must conduct tests of the EAS header and EOM codes...

  16. Mechanical properties of Hysol EA-9394 structural adhesive

    SciTech Connect

    Guess, T.R.; Reedy, E.D.; Stavig, M.E.

    1995-02-01

    Dextor`s Hysol EA-9394 is a room temperature curable paste adhesive representative of the adhesives used in wind turbine blade joints. A mechanical testing program has been performed to characterize this adhesive. Tension, compression stress relaxation, flexural, butt tensile, and fracture toughness test results are reported.

  17. 7 CFR 1794.23 - Proposals normally requiring an EA.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... classification are: (1) Construction of fuel cell, combustion turbine, combined cycle, or diesel generating... be covered in the EA; (2) Construction of fuel cell, combustion turbine, combined cycle, or diesel...) at a fossil-fueled generating station where the existing fuel combustion technology of the...

  18. 7 CFR 1794.23 - Proposals normally requiring an EA.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... classification are: (1) Construction of fuel cell, combustion turbine, combined cycle, or diesel generating... be covered in the EA; (2) Construction of fuel cell, combustion turbine, combined cycle, or diesel...) at a fossil-fueled generating station where the existing fuel combustion technology of the...

  19. 32 CFR 651.33 - Actions normally requiring an EA.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... wildlife habitat, or wild and scenic rivers. (f) Actions proposed during the life cycle of a weapon system... normally requiring an EA during the life cycle include, but are not limited to, testing, production... on Army land of a nature or magnitude not within the annual installation training cycle...

  20. 32 CFR 651.24 - Supplemental EAs and supplemental EISs.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) ENVIRONMENTAL QUALITY ENVIRONMENTAL ANALYSIS OF ARMY ACTIONS (AR 200-2) Records and Documents § 651.24 Supplemental EAs and supplemental EISs. As detailed in § 651.5(g) and in 40 CFR 1502.9(c), proposed actions...

  1. 32 CFR 651.24 - Supplemental EAs and supplemental EISs.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) ENVIRONMENTAL QUALITY ENVIRONMENTAL ANALYSIS OF ARMY ACTIONS (AR 200-2) Records and Documents § 651.24 Supplemental EAs and supplemental EISs. As detailed in § 651.5(g) and in 40 CFR 1502.9(c), proposed actions...

  2. 32 CFR 651.24 - Supplemental EAs and supplemental EISs.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) ENVIRONMENTAL QUALITY ENVIRONMENTAL ANALYSIS OF ARMY ACTIONS (AR 200-2) Records and Documents § 651.24 Supplemental EAs and supplemental EISs. As detailed in § 651.5(g) and in 40 CFR 1502.9(c), proposed actions...

  3. 32 CFR 651.24 - Supplemental EAs and supplemental EISs.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) ENVIRONMENTAL QUALITY ENVIRONMENTAL ANALYSIS OF ARMY ACTIONS (AR 200-2) Records and Documents § 651.24 Supplemental EAs and supplemental EISs. As detailed in § 651.5(g) and in 40 CFR 1502.9(c), proposed actions...

  4. 32 CFR 651.24 - Supplemental EAs and supplemental EISs.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) ENVIRONMENTAL QUALITY ENVIRONMENTAL ANALYSIS OF ARMY ACTIONS (AR 200-2) Records and Documents § 651.24 Supplemental EAs and supplemental EISs. As detailed in § 651.5(g) and in 40 CFR 1502.9(c), proposed actions...

  5. Post Treatment of Acoustic Neuroma

    MedlinePlus

    Home What is an AN What is an Acoustic Neuroma? Identifying an AN Symptoms Acoustic Neuroma Keywords Educational Video Pre-Treatment Treatment Options Summary Treatment Options Watch and Wait Radiation Microsurgery Acoustic Neuroma Decision Tree Questions for Your Physician Questions ...

  6. Variable-Position Acoustic Levitation

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Stoneburner, J. D.; Jacobi, N.; Wang, T. G.

    1983-01-01

    Method of acoustic levitation supports objects at positions other than acoustic nodes. Acoustic force is varied so it balances gravitational (or other) force, thereby maintaining object at any position within equilibrium range. Levitation method applicable to containerless processing. Such objects as table-tennis balls, hollow plastic spheres, and balsa-wood spheres levitated in laboratory by new method.

  7. Fundamentals of Acoustics. Psychoacoustics and Hearing. Acoustical Measurements

    NASA Technical Reports Server (NTRS)

    Begault, Durand R.; Ahumada, Al (Technical Monitor)

    1997-01-01

    These are 3 chapters that will appear in a book titled "Building Acoustical Design", edited by Charles Salter. They are designed to introduce the reader to fundamental concepts of acoustics, particularly as they relate to the built environment. "Fundamentals of Acoustics" reviews basic concepts of sound waveform frequency, pressure, and phase. "Psychoacoustics and Hearing" discusses the human interpretation sound pressure as loudness, particularly as a function of frequency. "Acoustic Measurements" gives a simple overview of the time and frequency weightings for sound pressure measurements that are used in acoustical work.

  8. 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.

  9. Multidimensional scaling between acoustic and electric stimuli in cochlear implant users with contralateral hearing

    PubMed Central

    Vermeire, Katrien; Landsberger, David M.; Schleich, Peter; Van de Heyning, Paul H.

    2013-01-01

    This study investigated the perceptual relationship between acoustic and electric stimuli presented to CI users with functional contralateral hearing. Fourteen subjects with unilateral profound deafness implanted with a MED-EL CI scaled the perceptual differences between pure tones presented to the acoustic hearing ear and electric biphasic pulse trains presented to the implanted ear. The differences were analyzed with a multidimensional scaling (MDS) analysis. Additionally, speech performance in noise was tested using sentence material presented in different spatial configurations while patients listened with both their acoustic hearing and implanted ears. Results of alternating least squares scaling (ALSCAL) analysis consistently demonstrate that a change in place of stimulation is in the same perceptual dimension as a change in acoustic frequency. However, the relative perceptual differences between the acoustic and the electric stimuli varied greatly across subjects. A degree of perceptual separation between acoustic and electric stimulation (quantified by relative dimensional weightings from an INDSCAL analysis) was hypothesized that would indicate a change in perceptual quality, but also be predictive of performance with combined acoustic and electric hearing. Perceptual separation between acoustic and electric stimuli was observed for some subjects. However, no relationship between the degree of perceptual separation and performance was found. PMID:24055624

  10. A new paradigm for Environmental Assessment (EA) in Korea

    SciTech Connect

    Song, Young-Il; Glasson, John

    2010-02-15

    Over the last 30 years, Environmental Impact Assessment (EIA) in Korea has played an important role in decision-making processes particularly for environmentally sensitive projects. However, the EIA system alone has sometimes not been effective enough to ensure the successful resolution of environmental concerns. In order to compensate for the limitations of the EIA system, a new assessment system called Prior Environmental Review System (PERS), which is relevant to Strategic Environmental Assessment (SEA) in some aspects, was introduced in 1993. PERS aims to balance development and preservation by identifying possible environmental impacts of some administrative plans mainly related to development projects in the early stages of planning. However, PERS still appeared to have some weak points such as a limited range of subjects to be assessed, and weakness of tiering (or vertical integration) from PERS to EIA. Therefore, the necessity for reform of the Korean Environmental Assessment (EA) system, including PERS, was raised. In response, the Korean government sought to establish its policy direction for implementing SEA by enhancing the objectivity and expertise of PERS. The policy was approved by the National Assembly in May 2005, and went into effect in June 2006. The introduction of SEA, by enhancing PERS, provides a framework for a system of EA from the strategic level, including PPPs, to the project level. Yet, despite such improvements, some managerial and technical problems associated with subsequent EA implementation remain. This paper critically reviews the evolution of the EA system in Korea and suggests essential improvements for the current EA system based on experiences of implementation of both EIA and SEA since June 2006, in the context of international good practice.

  11. The effects of acoustic vibration on fibroblast cell migration.

    PubMed

    Mohammed, Taybia; Murphy, Mark F; Lilley, Francis; Burton, David R; Bezombes, Frederic

    2016-12-01

    Cells are known to interact and respond to external mechanical cues and recent work has shown that application of mechanical stimulation, delivered via acoustic vibration, can be used to control complex cell behaviours. Fibroblast cells are known to respond to physical cues generated in the extracellular matrix and it is thought that such cues are important regulators of the wound healing process. Many conditions are associated with poor wound healing, so there is need for treatments/interventions, which can help accelerate the wound healing process. The primary aim of this research was to investigate the effects of mechanical stimulation upon the migratory and morphological properties of two different fibroblast cells namely; human lung fibroblast cells (LL24) and subcutaneous areolar/adipose mouse fibroblast cells (L929). Using a speaker-based system, the effects of mechanical stimulation (0-1600Hz for 5min) on the mean cell migration distance (μm) and actin organisation was investigated. The results show that 100Hz acoustic vibration enhanced cell migration for both cell lines whereas acoustic vibration above 100Hz was found to decrease cell migration in a frequency dependent manner. Mechanical stimulation was also found to promote changes to the morphology of both cell lines, particularly the formation of lamellipodia and filopodia. Overall lamellipodia was the most prominent actin structure displayed by the lung cell (LL24), whereas filopodia was the most prominent actin feature displayed by the fibroblast derived from subcutaneous areolar/adipose tissue. Mechanical stimulation at all the frequencies used here was found not to affect cell viability. These results suggest that low-frequency acoustic vibration may be used as a tool to manipulate the mechanosensitivity of cells to promote cell migration. PMID:27612824

  12. Acoustic analog of a free-electron laser

    SciTech Connect

    Zavtrak, S.T.

    1995-12-31

    As well known, at the present time there are many types of laser the operation of which is based on the stimulated emission of light by an active medium. Lasers are generators of coherent electromagnetic waves in the range from ultraviolet to submillimeters. But acoustic analogs of such devices have not been created up to now in spite of the progress in laser technology. Meanwhile, an acoustic laser could have a lot of interesting applications. Recently a theoretical scheme for an acoustic laser was proposed by the present author. A liquid dielectric with dispersed particles was considered as an active medium. The pumping was created by an oscillating electric field deforming dispersed particle volumes. Different types of oils or distilled water can serve as a liquid dielectric with gas bubbles as dispersed particles. Gas bubbles in water can be created by an electrolysis. The phase bunching of the initially incoherent emitters (gas bubbles) was realized by acoustic radiation forces. This scheme is an analog of the free-electron laser (FEL). It was shown that two types of losses must be overcome for the beginning of a generation. The first type results from the energy dissipation in the active medium and the second one is caused by radiation losses at the boundaries of the resonator. The purposes of this report are: (1) to discuss the analogies between the acoustic laser and FEL; (2) to propose an effective scheme of an acoustic laser with a mechanical pumping (by a piezoelectric emitter of the piston type); (3) to consider the schemes of acoustic lasers with the different types of the resonators (rectangular and cylindrical); (4) to discuss the possibility of the creation of an impact acoustic laser (5) to discuss the experimental works which are planned to be carried out in cooperation with prof. L.A. Crum.

  13. Acoustics in Schools.

    ERIC Educational Resources Information Center

    Singer, Miriam J.

    This paper explores the issues associated with poor acoustics within schools. Additionally, it suggests remedies for existing buildings and those under renovation, as well as concerns for new construction. The paper discusses the effects of unwanted noise on students in terms of physiological, motivational, and cognitive influences. Issues are…

  14. Improved acoustic levitation apparatus

    NASA Technical Reports Server (NTRS)

    Berge, L. H.; Johnson, J. L.; Oran, W. A.; Reiss, D. A.

    1980-01-01

    Concave driver and reflector enhance and shape levitation forces in acoustic resonance system. Single-mode standing-wave pattern is focused by ring element situated between driver and reflector. Concave surfaces increase levitating forces up to factor of 6 as opposed to conventional flat surfaces, making it possible to suspend heavier objects.

  15. Intelligent Engine Systems: Acoustics

    NASA Technical Reports Server (NTRS)

    Wojno, John; Martens, Steve; Simpson, Benjamin

    2008-01-01

    An extensive study of new fan exhaust nozzle technologies was performed. Three new uniform chevron nozzles were designed, based on extensive CFD analysis. Two new azimuthally varying variants were defined. All five were tested, along with two existing nozzles, on a representative model-scale, medium BPR exhaust nozzle. Substantial acoustic benefits were obtained from the uniform chevron nozzle designs, the best benefit being provided by an existing design. However, one of the azimuthally varying nozzle designs exhibited even better performance than any of the uniform chevron nozzles. In addition to the fan chevron nozzles, a new technology was demonstrated, using devices that enhance mixing when applied to an exhaust nozzle. The acoustic benefits from these devices applied to medium BPR nozzles were similar, and in some cases superior to, those obtained from conventional uniform chevron nozzles. However, none of the low noise technologies provided equivalent acoustic benefits on a model-scale high BPR exhaust nozzle, similar to current large commercial applications. New technologies must be identified to improve the acoustics of state-of-the-art high BPR jet engines.

  16. Acoustic leak detection system

    SciTech Connect

    Peacock, M.J.

    1993-08-03

    An acoustic leak detection system is described for determining the location of leaks in storage tanks, comprising: (a) sensor means for detecting a leak signal; (b) data acquisition means for digitizing and storing leak signals meeting preset criterion; and (c) analysis means for analyzing the digitized signals and computing the location of the source of the leak signals.

  17. 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.

  18. Teaching acoustics online

    NASA Astrophysics Data System (ADS)

    Morrison, Andrew; Rossing, Thomas D.

    2003-10-01

    We teach an introductory course in musical acoustics using a Blackboard. Students in this course can access audio and video materials as well as printed materials on our course website. All homework is submitted online, as are tests and examinations. The students also have the opportunity to use synchronous and asynchronous chat rooms to discuss the course with each other or with the instructors.

  19. Acupuncture with manual and electrical stimulation for labour pain: a longitudinal randomised controlled trial

    PubMed Central

    2014-01-01

    Background Acupuncture is commonly used to reduce pain during labour despite contradictory results. The aim of this study is to evaluate the effectiveness of acupuncture with manual stimulation and acupuncture with combined manual and electrical stimulation (electro-acupuncture) compared with standard care in reducing labour pain. Our hypothesis was that both acupuncture stimulation techniques were more effective than standard care, and that electro-acupuncture was most effective. Methods A longitudinal randomised controlled trial. The recruitment of participants took place at the admission to the labour ward between November 2008 and October 2011 at two Swedish hospitals . 303 nulliparous women with normal pregnancies were randomised to: 40 minutes of manual acupuncture (MA), electro-acupuncture (EA), or standard care without acupuncture (SC). Primary outcome: labour pain, assessed by Visual Analogue Scale (VAS). Secondary outcomes: relaxation, use of obstetric pain relief during labour and post-partum assessments of labour pain. The sample size calculation was based on the primary outcome and a difference of 15 mm on VAS was regarded as clinically relevant, this gave 101 in each group, including a total of 303 women. Results Mean estimated pain scores on VAS (SC: 69.0, MA: 66.4 and EA: 68.5), adjusted for: treatment, age, education, and time from baseline, with no interactions did not differ between the groups (SC vs MA: mean difference 2.6, 95% confidence interval [CI] -1.7-6.9 and SC vs EA: mean difference 0.6 [95% CI] -3.6-4.8). Fewer number of women in the EA group used epidural analgesia (46%) than women in the MA group (61%) and SC group (70%) (EA vs SC: odds ratio [OR] 0.35; [95% CI] 0.19-0.67). Conclusions Acupuncture does not reduce women’s experience of labour pain, neither with manual stimulation nor with combined manual and electrical stimulation. However, fewer women in the EA group used epidural analgesia thus indicating that the effect of

  20. Acoustics- Version 1.0

    2012-09-13

    This package contains modules that model acoustic sensors and acoustic sources (hearable) in Umbra. It is typically used to represent hearing in characters within Umbra. Typically, the acoustic sensors detect acoustic sources at a given point; however, it also contains the capability to detect bullet cracks by detecting the sound along the bullet path that is closest to the sensor. A memory module, acoustic memory, represents remembered sounds within a given character. Over time, themore » sounds are removed, as a character forgets what it has heard.« less

  1. Acoustics- Version 1.0

    SciTech Connect

    2012-09-13

    This package contains modules that model acoustic sensors and acoustic sources (hearable) in Umbra. It is typically used to represent hearing in characters within Umbra. Typically, the acoustic sensors detect acoustic sources at a given point; however, it also contains the capability to detect bullet cracks by detecting the sound along the bullet path that is closest to the sensor. A memory module, acoustic memory, represents remembered sounds within a given character. Over time, the sounds are removed, as a character forgets what it has heard.

  2. Holograms for acoustics.

    PubMed

    Melde, Kai; Mark, Andrew G; Qiu, Tian; Fischer, Peer

    2016-01-01

    Holographic techniques are fundamental to applications such as volumetric displays, high-density data storage and optical tweezers that require spatial control of intricate optical or acoustic fields within a three-dimensional volume. The basis of holography is spatial storage of the phase and/or amplitude profile of the desired wavefront in a manner that allows that wavefront to be reconstructed by interference when the hologram is illuminated with a suitable coherent source. Modern computer-generated holography skips the process of recording a hologram from a physical scene, and instead calculates the required phase profile before rendering it for reconstruction. In ultrasound applications, the phase profile is typically generated by discrete and independently driven ultrasound sources; however, these can only be used in small numbers, which limits the complexity or degrees of freedom that can be attained in the wavefront. Here we introduce monolithic acoustic holograms, which can reconstruct diffraction-limited acoustic pressure fields and thus arbitrary ultrasound beams. We use rapid fabrication to craft the holograms and achieve reconstruction degrees of freedom two orders of magnitude higher than commercial phased array sources. The technique is inexpensive, appropriate for both transmission and reflection elements, and scales well to higher information content, larger aperture size and higher power. The complex three-dimensional pressure and phase distributions produced by these acoustic holograms allow us to demonstrate new approaches to controlled ultrasonic manipulation of solids in water, and of liquids and solids in air. We expect that acoustic holograms will enable new capabilities in beam-steering and the contactless transfer of power, improve medical imaging, and drive new applications of ultrasound. PMID:27652563

  3. Holograms for acoustics

    NASA Astrophysics Data System (ADS)

    Melde, Kai; Mark, Andrew G.; Qiu, Tian; Fischer, Peer

    2016-09-01

    Holographic techniques are fundamental to applications such as volumetric displays, high-density data storage and optical tweezers that require spatial control of intricate optical or acoustic fields within a three-dimensional volume. The basis of holography is spatial storage of the phase and/or amplitude profile of the desired wavefront in a manner that allows that wavefront to be reconstructed by interference when the hologram is illuminated with a suitable coherent source. Modern computer-generated holography skips the process of recording a hologram from a physical scene, and instead calculates the required phase profile before rendering it for reconstruction. In ultrasound applications, the phase profile is typically generated by discrete and independently driven ultrasound sources; however, these can only be used in small numbers, which limits the complexity or degrees of freedom that can be attained in the wavefront. Here we introduce monolithic acoustic holograms, which can reconstruct diffraction-limited acoustic pressure fields and thus arbitrary ultrasound beams. We use rapid fabrication to craft the holograms and achieve reconstruction degrees of freedom two orders of magnitude higher than commercial phased array sources. The technique is inexpensive, appropriate for both transmission and reflection elements, and scales well to higher information content, larger aperture size and higher power. The complex three-dimensional pressure and phase distributions produced by these acoustic holograms allow us to demonstrate new approaches to controlled ultrasonic manipulation of solids in water, and of liquids and solids in air. We expect that acoustic holograms will enable new capabilities in beam-steering and the contactless transfer of power, improve medical imaging, and drive new applications of ultrasound.

  4. 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.

  5. Optical Heterodyne Investigation of the Microwave Frequency Acoustic Properties of Liquids.

    NASA Astrophysics Data System (ADS)

    Bonney, Rob

    An optical heterodyne interferometer with a state -of-the-art microwave frequency acoustic transducer was used to measure the acoustic properties of liquids and solutions at frequencies up to 1.5 GHz. Heterodyne detection with a strong optical local oscillator was used to detect a weak optical signal beam produced by Bragg deflection from an acoustic wave coupled into a liquid sample. The acoustic transducer had a frequency range of 0.2-1.5 GHz. Several liquid mixtures were measured for the first time, including aqueous dimethyl sulfoxide, and ethyl acetate in carbon disulphide. In some cases, previously unknown dispersions were characterized. A thermodynamic model (valid in the low frequency limit) involving the heat of mixing was used successfully to predict the variation of velocity with composition of liquid mixtures. With this model as a guide, an attempt was made to identify a liquid mixture which would make a superior medium for the acoustic microscope. The search produced results which supported theoretical predictions, but no superior medium was found. Solutions of biomolecules were also investigated due to interest in possible resonant acoustic modes in DNA. No dispersions or resonances were found in solutions of polyglycines, and results for DNA solutions were inconclusive. Applications of this work include general studies in liquid acoustics at very high frequencies, acoustic studies of DNA solutions, and characterization of media for such technological applications as acoustic microscopy or phase conjugation using stimulated Brillouin scattering.

  6. Speech Recognition and Acoustic Features in Combined Electric and Acoustic Stimulation

    ERIC Educational Resources Information Center

    Yoon, Yang-soo; Li, Yongxin; Fu, Qian-Jie

    2012-01-01

    Purpose: In this study, the authors aimed to identify speech information processed by a hearing aid (HA) that is additive to information processed by a cochlear implant (CI) as a function of signal-to-noise ratio (SNR). Method: Speech recognition was measured with CI alone, HA alone, and CI + HA. Ten participants were separated into 2 groups; good…

  7. Manipulate acoustic waves by impedance matched acoustic metasurfaces

    NASA Astrophysics Data System (ADS)

    Wu, Ying; Mei, Jun; Aljahdali, Rasha

    We design a type of acoustic metasurface, which is composed of carefully designed slits in a rigid thin plate. The effective refractive indices of different slits are different but the impedances are kept the same as that of the host medium. Numerical simulations show that such a metasurface can redirect or reflect a normally incident wave at different frequencies, even though it is impedance matched to the host medium. We show that the underlying mechanisms can be understood by using the generalized Snell's law, and a unified analytic model based on mode-coupling theory. We demonstrate some simple realization of such acoustic metasurface with real materials. The principle is also extended to the design of planar acoustic lens which can focus acoustic waves. Manipulate acoustic waves by impedance matched acoustic metasurfaces.

  8. 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.

  9. Large-conductance Ca²⁺-activated potassium channel in mitochondria of endothelial EA.hy926 cells.

    PubMed

    Bednarczyk, Piotr; Koziel, Agnieszka; Jarmuszkiewicz, Wieslawa; Szewczyk, Adam

    2013-06-01

    In the present study, we describe the existence of a large-conductance Ca²⁺-activated potassium (BKCa) channel in the mitochondria of the human endothelial cell line EA.hy926. A single-channel current was recorded from endothelial mitoplasts (i.e., inner mitochondrial membrane) using the patch-clamp technique in the mitoplast-attached mode. A potassium-selective current was recorded with a mean conductance equal to 270 ± 10 pS in a symmetrical 150/150 mM KCl isotonic solution. The channel activity, which was determined as the open probability, increased with the addition of calcium ions and the potassium channel opener NS1619. Conversely, the activity of the channel was irreversibly blocked by paxilline and iberiotoxin, BKCa channel inhibitors. The open-state probability was found to be voltage dependent. The substances known to modulate BKCa channel activity influenced the bioenergetics of mitochondria isolated from human endothelial EA.hy926 cells. In isolated mitochondria, 100 μM Ca²⁺, 10 μM NS1619, and 0.5 μM NS11021 depolarized the mitochondrial membrane potential and stimulated nonphosphorylating respiration. These effects were blocked by iberiotoxin and paxilline in a potassium-dependent manner. Under phosphorylating conditions, NS1619-induced, iberiotoxin-sensitive uncoupling diverted energy from ATP synthesis during the phosphorylating respiration of the endothelial mitochondria. Immunological analysis with antibodies raised against proteins of the plasma membrane BKCa channel identified a pore-forming α-subunit and an auxiliary β₂-subunit of the channel in the endothelial mitochondrial inner membrane. In conclusion, we show for the first time that the inner mitochondrial membrane in human endothelial EA.hy926 cells contains a large-conductance calcium-dependent potassium channel with properties similar to those of the surface membrane BKCa channel.

  10. Structural Acoustics and Vibrations

    NASA Astrophysics Data System (ADS)

    Chaigne, Antoine

    This structural chapter is devoted to vibrations of structures and to their coupling with the acoustic field. Depending on the context, the radiated sound can be judged as desirable, as is mostly the case for musical instruments, or undesirable, like noise generated by machinery. In architectural acoustics, one main goal is to limit the transmission of sound through walls. In the automobile industry, the engineers have to control the noise generated inside and outside the passenger compartment. This can be achieved by means of passive or active damping. In general, there is a strong need for quieter products and better sound quality generated by the structures in our daily environment.

  11. Radiosurgery of acoustic neurinomas

    SciTech Connect

    Flickinger, J.C.; Lunsford, L.D.; Coffey, R.J.; Linskey, M.E.; Bissonette, D.J.; Maitz, A.H.; Kondziolka, D. )

    1991-01-15

    Eighty-five patients with acoustic neurinomas underwent stereotactic radiosurgery with the gamma unit at the University of Pittsburgh (Pittsburgh, PA) during its first 30 months of operation. Neuroimaging studies performed in 40 patients with more than 1 year follow-up showed that tumors were smaller in 22 (55%), unchanged in 17 (43%), and larger in one (2%). The 2-year actuarial rates for preservation of useful hearing and any hearing were 46% and 62%, respectively. Previously undetected neuropathies of the trigeminal (n = 12) and facial nerves (n = 14) occurred 1 week to 1 year after radiosurgery (median, 7 and 6 months, respectively), and improved at median intervals of 13 and 8 months, respectively, after onset. Hearing loss was significantly associated with increasing average tumor diameter (P = 0.04). No deterioration of any cranial nerve function has yet developed in seven patients with average tumor diameters less than 10 mm. Radiosurgery is an important treatment alternative for selected acoustic neurinoma patients.

  12. A Martian acoustic anemometer.

    PubMed

    Banfield, Don; Schindel, David W; Tarr, Steve; Dissly, Richard W

    2016-08-01

    An acoustic anemometer for use on Mars has been developed. To understand the processes that control the interaction between surface and atmosphere on Mars, not only the mean winds, but also the turbulent boundary layer, the fluxes of momentum, heat and molecular constituents between surface and atmosphere must be measured. Terrestrially this is done with acoustic anemometers, but the low density atmosphere on Mars makes it challenging to adapt such an instrument for use on Mars. This has been achieved using capacitive transducers and pulse compression, and was successfully demonstrated on a stratospheric balloon (simulating the Martian environment) and in a dedicated Mars Wind Tunnel facility. This instrument achieves a measurement accuracy of ∼5 cm/s with an update rate of >20 Hz under Martian conditions. PMID:27586767

  13. Acoustic tractor beam.

    PubMed

    Démoré, Christine E M; Dahl, Patrick M; Yang, Zhengyi; Glynne-Jones, Peter; Melzer, Andreas; Cochran, Sandy; MacDonald, Michael P; Spalding, Gabriel C

    2014-05-01

    Negative radiation forces act opposite to the direction of propagation, or net momentum, of a beam but have previously been challenging to definitively demonstrate. We report an experimental acoustic tractor beam generated by an ultrasonic array operating on macroscopic targets (>1 cm) to demonstrate the negative radiation forces and to map out regimes over which they dominate, which we compare to simulations. The result and the geometrically simple configuration show that the effect is due to nonconservative forces, produced by redirection of a momentum flux from the angled sides of a target and not by conservative forces from a potential energy gradient. Use of a simple acoustic setup provides an easily understood illustration of the negative radiation pressure concept for tractor beams and demonstrates continuous attraction towards the source, against a net momentum flux in the system. PMID:24836252

  14. Acoustic Tractor Beam

    NASA Astrophysics Data System (ADS)

    Démoré, Christine E. M.; Dahl, Patrick M.; Yang, Zhengyi; Glynne-Jones, Peter; Melzer, Andreas; Cochran, Sandy; MacDonald, Michael P.; Spalding, Gabriel C.

    2014-05-01

    Negative radiation forces act opposite to the direction of propagation, or net momentum, of a beam but have previously been challenging to definitively demonstrate. We report an experimental acoustic tractor beam generated by an ultrasonic array operating on macroscopic targets (>1 cm) to demonstrate the negative radiation forces and to map out regimes over which they dominate, which we compare to simulations. The result and the geometrically simple configuration show that the effect is due to nonconservative forces, produced by redirection of a momentum flux from the angled sides of a target and not by conservative forces from a potential energy gradient. Use of a simple acoustic setup provides an easily understood illustration of the negative radiation pressure concept for tractor beams and demonstrates continuous attraction towards the source, against a net momentum flux in the system.

  15. Acoustics Discipline Overview

    NASA Technical Reports Server (NTRS)

    Envia, Edmane; Thomas, Russell

    2007-01-01

    As part of the Fundamental Aeronautics Program Annual Review, a summary of the progress made in 2007 in acoustics research under the Subsonic Fixed Wing project is given. The presentation describes highlights from in-house and external activities including partnerships and NRA-funded research with industry and academia. Brief progress reports from all acoustics Phase 1 NRAs are also included as are outlines of the planned activities for 2008 and all Phase 2 NRAs. N+1 and N+2 technology paths outlined for Subsonic Fixed Wing noise targets. NRA Round 1 progressing with focus on prediction method advancement. NRA Round 2 initiating work focused on N+2 technology, prediction methods, and validation. Excellent partnerships in progress supporting N+1 technology targets and providing key data sets.

  16. Acoustic methodology review

    NASA Technical Reports Server (NTRS)

    Schlegel, R. G.

    1982-01-01

    It is important for industry and NASA to assess the status of acoustic design technology for predicting and controlling helicopter external noise in order for a meaningful research program to be formulated which will address this problem. The prediction methodologies available to the designer and the acoustic engineer are three-fold. First is what has been described as a first principle analysis. This analysis approach attempts to remove any empiricism from the analysis process and deals with a theoretical mechanism approach to predicting the noise. The second approach attempts to combine first principle methodology (when available) with empirical data to formulate source predictors which can be combined to predict vehicle levels. The third is an empirical analysis, which attempts to generalize measured trends into a vehicle noise prediction method. This paper will briefly address each.

  17. Theoretical Analysis of Shear Wave Interference Patterns by Means of Dynamic Acoustic Radiation Forces.

    PubMed

    Hoyt, Kenneth

    2011-03-01

    Acoustic radiation forces associated with high intensity focused ultrasound stimulate shear wave propagation allowing shear wave speed and shear viscosity estimation of tissue structures. As wave speeds are meters per second, real time displacement tracking over an extend field-of-view using ultrasound is problematic due to very high frame rate requirements. However, two spatially separated dynamic external sources can stimulate shear wave motion leading to shear wave interference patterns. Advantages are shear waves can be imaged at lower frame rates and local interference pattern spatial properties reflect tissue's viscoelastic properties. Here a theoretical analysis of shear wave interference patterns by means of dynamic acoustic radiation forces is detailed. Using a viscoelastic Green's function analysis, tissue motion due to a pair of focused ultrasound beams and associated radiation forces are presented. Overall, this paper theoretically demonstrates shear wave interference patterns can be stimulated using dynamic acoustic radiation forces and tracked using conventional ultrasound imaging.

  18. Thermal neutron flux produced by EAS at various altitudes

    NASA Astrophysics Data System (ADS)

    Stenkin, V. Yu.; Alekseenko, V. V.; Gromushkin, D. M.; Liu, Ye; Ma, Xin-Hua; Zhao, Jing

    2013-01-01

    The results of Monte-Carlo simulations of extensive air showers are presented to show the difference of the hadronic component content at various altitudes with the aim to choose an optimal altitude for a PRISMA-like experiment. The CORSIKA program for EAS simulations with QGSJET and GHEISHA models was used to calculate the number of hadrons reaching the observational level inside a circle of 50 m radius around the EAS axis. Then the number of neutrons produced by the hadronic component was calculated using an empirical relationship between the two components. We have tested the results with the ProtoPRISMA array at sea level, and recorded the neutrons which are consistent with the simulation results.

  19. Acoustic velocity meter systems

    USGS Publications Warehouse

    Laenen, Antonius

    1985-01-01

    Acoustic velocity meter (AVM) systems operate on the principles that the point-to-point upstream traveltime of an acoustic pulse is longer than the downstream traveltime and that this difference in traveltime can be accurately measured by electronic devices. An AVM system is capable of recording water velocity (and discharge) under a wide range of conditions, but some constraints apply: 1. Accuracy is reduced and performance is degraded if the acoustic path is not a continuous straight line. The path can be bent by reflection if it is too close to a stream boundary or by refraction if it passes through density gradients resulting from variations in either water temperature or salinity. For paths of less than 100 m, a temperature gradient of 0.1' per meter causes signal bending less than 0.6 meter at midchannel, and satisfactory velocity results can be obtained. Reflection from stream boundaries can cause signal cancellation if boundaries are too close to signal path. 2. Signal strength is attenuated by particles or bubbles that absorb, spread, or scatter sound. The concentration of particles or bubbles that can be tolerated is a function of the path length and frequency of the acoustic signal. 3. Changes in streamline orientation can affect system accuracy if the variability is random. 4. Errors relating to signal resolution are much larger for a single threshold detection scheme than for multiple threshold schemes. This report provides methods for computing the effect of various conditions on the accuracy of a record obtained from an AVM. The equipment must be adapted to the site. Field reconnaissance and preinstallation analysis to detect possible problems are critical for proper installation and operation of an AVM system.

  20. Structures and Acoustics Division

    NASA Technical Reports Server (NTRS)

    Acquaviva, Cynthia S.

    1999-01-01

    The Structures and Acoustics Division of NASA Glenn Research Center is an international leader in rotating structures, mechanical components, fatigue and fracture, and structural aeroacoustics. Included are disciplines related to life prediction and reliability, nondestructive evaluation, and mechanical drive systems. Reported are a synopsis of the work and accomplishments reported by the Division during the 1996 calendar year. A bibliography containing 42 citations is provided.

  1. Structures and Acoustics Division

    NASA Technical Reports Server (NTRS)

    Acquaviva, Cynthia S.

    2001-01-01

    The Structures and Acoustics Division of the NASA Glenn Research Center is an international leader in rotating structures, mechanical components, fatigue and fracture, and structural aeroacoustics. Included in this report are disciplines related to life prediction and reliability, nondestructive evaluation, and mechanical drive systems. Reported is a synopsis of the work and accomplishments completed by the Division during the 1997, 1998, and 1999 calendar years. A bibliography containing 93 citations is provided.

  2. Acoustic paramagnetic logging tool

    DOEpatents

    Vail, III, William B.

    1988-01-01

    New methods and apparatus are disclosed which allow measurement of the presence of oil and water in geological formations using a new physical effect called the Acoustic Paramagnetic Logging Effect (APLE). The presence of petroleum in formation causes a slight increase in the earth's magnetic field in the vicinity of the reservoir. This is the phenomena of paramagnetism. Application of an acoustic source to a geological formation at the Larmor frequency of the nucleons present causes the paramagnetism of the formation to disappear. This results in a decrease in the earth3 s magnetic field in the vicinity of the oil bearing formation. Repetitively frequency sweeping the acoustic source through the Larmor frequency of the nucleons present (approx. 2 kHz) causes an amplitude modulation of the earth's magnetic field which is a consequence of the APLE. The amplitude modulation of the earth's magnetic field is measured with an induction coil gradiometer and provides a direct measure of the amount of oil and water in the excitation zone of the formation . The phase of the signal is used to infer the longitudinal relaxation times of the fluids present, which results in the ability in general to separate oil and water and to measure the viscosity of the oil present. Such measurements may be preformed in open boreholes and in cased well bores.

  3. Fast wideband acoustical holography.

    PubMed

    Hald, Jørgen

    2016-04-01

    Patch near-field acoustical holography methods like statistically optimized near-field acoustical holography and equivalent source method are limited to relatively low frequencies, where the average array-element spacing is less than half of the acoustic wavelength, while beamforming provides useful resolution only at medium-to-high frequencies. With adequate array design, both methods can be used with the same array. But for holography to provide good low-frequency resolution, a small measurement distance is needed, whereas beamforming requires a larger distance to limit sidelobe issues. The wideband holography method of the present paper was developed to overcome that practical conflict. Only a single measurement is needed at a relatively short distance and a single result is obtained covering the full frequency range. The method uses the principles of compressed sensing: A sparse sound field representation is assumed with a chosen set of basis functions, a measurement is taken with an irregular array, and the inverse problem is solved with a method that enforces sparsity in the coefficient vector. Instead of using regularization based on the 1-norm of the coefficient vector, an iterative solution procedure is used that promotes sparsity. The iterative method is shown to provide very similar results in most cases and to be computationally much more efficient. PMID:27106299

  4. Virtual acoustic prototyping

    NASA Astrophysics Data System (ADS)

    Johnson, Marty

    2003-10-01

    In this paper the re-creation of 3-D sound fields so the full psycho-acoustic impact of sound sources can be assessed before the manufacture of a product or environment is examined. Using head related transfer functions (HRTFs) coupled with a head tracked set of headphones the sound field at the left and right ears of a listener can be re-created for a set of sound sources. However, the HRTFs require that sources have a defined location and this is not the typical output from numerical codes which describe the sound field as a set of distributed modes. In this paper a method of creating a set of equivalent sources is described such that the standard set of HRTFs can be applied in real time. A structural-acoustic model of a cylinder driving an enclosed acoustic field will be used as an example. It will be shown that equivalent sources can be used to recreate all of the reverberation of the enclosed space. An efficient singular value decomposition technique allows the large number of sources required to be simulated in real time. An introduction to the requirements necessary for 3-D virtual prototyping using high frequency Statistical Energy Analysis models will be presented. [Work supported by AuSim and NASA.

  5. Acoustics, computers and measurements

    NASA Astrophysics Data System (ADS)

    Truchard, James J.

    2003-10-01

    The human ear has created a high standard for the requirements of acoustical measurements. The transient nature of most acoustical signals has limited the success of traditional volt meters. Professor Hixson's pioneering work in electroacoustical measurements at ARL and The University of Texas helped set the stage for modern computer-based measurements. The tremendous performance of modern PCs and extensive libraries of signal processing functions in virtual instrumentation application software has revolutionized the way acoustical measurements are made. Today's analog to digital converters have up to 24 bits of resolution with a dynamic range of over 120 dB and a single PC processor can process 112 channels of FFTs at 4 kHz in real time. Wavelet technology further extends the capabilities for analyzing transients. The tools available for measurements in speech, electroacoustics, noise, and vibration represent some of the most advanced measurement tools available. During the last 50 years, Professor Hixson has helped drive this revolution from simple oscilloscope measurements to the modern high performance computer-based measurements.

  6. Acoustic Force Density Acting on Inhomogeneous Fluids in Acoustic Fields.

    PubMed

    Karlsen, Jonas T; Augustsson, Per; Bruus, Henrik

    2016-09-01

    We present a theory for the acoustic force density acting on inhomogeneous fluids in acoustic fields on time scales that are slow compared to the acoustic oscillation period. The acoustic force density depends on gradients in the density and compressibility of the fluid. For microfluidic systems, the theory predicts a relocation of the inhomogeneities into stable field-dependent configurations, which are qualitatively different from the horizontally layered configurations due to gravity. Experimental validation is obtained by confocal imaging of aqueous solutions in a glass-silicon microchip. PMID:27661695

  7. Acoustic Force Density Acting on Inhomogeneous Fluids in Acoustic Fields.

    PubMed

    Karlsen, Jonas T; Augustsson, Per; Bruus, Henrik

    2016-09-01

    We present a theory for the acoustic force density acting on inhomogeneous fluids in acoustic fields on time scales that are slow compared to the acoustic oscillation period. The acoustic force density depends on gradients in the density and compressibility of the fluid. For microfluidic systems, the theory predicts a relocation of the inhomogeneities into stable field-dependent configurations, which are qualitatively different from the horizontally layered configurations due to gravity. Experimental validation is obtained by confocal imaging of aqueous solutions in a glass-silicon microchip.

  8. A Low-redshift Sample of E+A Galaxies

    NASA Astrophysics Data System (ADS)

    Walker, K. M.; Bergmann, M. P.; Turner, J.

    2004-12-01

    We present the results of a low-redshift survey for E+A galaxies. These galaxies are spectroscopically classified as having strong Balmer and metallic absorption with the absence of any emission. The absorption lines indicate an abundance of A-type stars as well as an old stellar population, while the absence of emission, especially {O ii}, denotes the lack of current star formation. Essential in determining the evolution of early-type galaxies, a low-redshift sample will allow easier morphology observations and further spectroscopic study. Fourteen low-redshift E+A galaxies were found using the Sloan Digital Sky Survey Data Release One following similar criteria as the H-delta strong survey of Goto (2003), except that only galaxies with a redshift lower than z=0.05 were selected. Two of these E+A galaxies were observed with the Cerro Tololo Inter-American Observatory 1.5-m telescope and confirmed to have no emission anywhere along the longslit, including outside the 3" region sampled by the SDSS fibers. This work was supported by the NSF through the CTIO REU program.

  9. Wireless Acoustic Measurement System

    NASA Technical Reports Server (NTRS)

    Anderson, Paul D.; Dorland, Wade D.; Jolly, Ronald L.

    2007-01-01

    A prototype wireless acoustic measurement system (WAMS) is one of two main subsystems of the Acoustic Prediction/ Measurement Tool, which comprises software, acoustic instrumentation, and electronic hardware combined to afford integrated capabilities for predicting and measuring noise emitted by rocket and jet engines. The other main subsystem is described in the article on page 8. The WAMS includes analog acoustic measurement instrumentation and analog and digital electronic circuitry combined with computer wireless local-area networking to enable (1) measurement of sound-pressure levels at multiple locations in the sound field of an engine under test and (2) recording and processing of the measurement data. At each field location, the measurements are taken by a portable unit, denoted a field station. There are ten field stations, each of which can take two channels of measurements. Each field station is equipped with two instrumentation microphones, a micro- ATX computer, a wireless network adapter, an environmental enclosure, a directional radio antenna, and a battery power supply. The environmental enclosure shields the computer from weather and from extreme acoustically induced vibrations. The power supply is based on a marine-service lead-acid storage battery that has enough capacity to support operation for as long as 10 hours. A desktop computer serves as a control server for the WAMS. The server is connected to a wireless router for communication with the field stations via a wireless local-area network that complies with wireless-network standard 802.11b of the Institute of Electrical and Electronics Engineers. The router and the wireless network adapters are controlled by use of Linux-compatible driver software. The server runs custom Linux software for synchronizing the recording of measurement data in the field stations. The software includes a module that provides an intuitive graphical user interface through which an operator at the control server

  10. Wireless Acoustic Measurement System

    NASA Technical Reports Server (NTRS)

    Anderson, Paul D.; Dorland, Wade D.

    2005-01-01

    A prototype wireless acoustic measurement system (WAMS) is one of two main subsystems of the Acoustic Prediction/Measurement Tool, which comprises software, acoustic instrumentation, and electronic hardware combined to afford integrated capabilities for predicting and measuring noise emitted by rocket and jet engines. The other main subsystem is described in "Predicting Rocket or Jet Noise in Real Time" (SSC-00215-1), which appears elsewhere in this issue of NASA Tech Briefs. The WAMS includes analog acoustic measurement instrumentation and analog and digital electronic circuitry combined with computer wireless local-area networking to enable (1) measurement of sound-pressure levels at multiple locations in the sound field of an engine under test and (2) recording and processing of the measurement data. At each field location, the measurements are taken by a portable unit, denoted a field station. There are ten field stations, each of which can take two channels of measurements. Each field station is equipped with two instrumentation microphones, a micro-ATX computer, a wireless network adapter, an environmental enclosure, a directional radio antenna, and a battery power supply. The environmental enclosure shields the computer from weather and from extreme acoustically induced vibrations. The power supply is based on a marine-service lead-acid storage battery that has enough capacity to support operation for as long as 10 hours. A desktop computer serves as a control server for the WAMS. The server is connected to a wireless router for communication with the field stations via a wireless local-area network that complies with wireless-network standard 802.11b of the Institute of Electrical and Electronics Engineers. The router and the wireless network adapters are controlled by use of Linux-compatible driver software. The server runs custom Linux software for synchronizing the recording of measurement data in the field stations. The software includes a module that

  11. Spacecraft Internal Acoustic Environment Modeling

    NASA Technical Reports Server (NTRS)

    Chu, S. Reynold; Allen, Chris

    2009-01-01

    The objective of the project is to develop an acoustic modeling capability, based on commercial off-the-shelf software, to be used as a tool for oversight of the future manned Constellation vehicles. The use of such a model will help ensure compliance with acoustic requirements. Also, this project includes modeling validation and development feedback via building physical mockups and conducting acoustic measurements to compare with the predictions.

  12. Guided acoustic wave inspection system

    DOEpatents

    Chinn, Diane J.

    2004-10-05

    A system for inspecting a conduit for undesirable characteristics. A transducer system induces guided acoustic waves onto said conduit. The transducer system detects the undesirable characteristics of the conduit by receiving guided acoustic waves that contain information about the undesirable characteristics. The conduit has at least two sides and the transducer system utilizes flexural modes of propagation to provide inspection using access from only the one side of the conduit. Cracking is detected with pulse-echo testing using one transducer to both send and receive the guided acoustic waves. Thinning is detected in through-transmission testing where one transducer sends and another transducer receives the guided acoustic waves.

  13. Transition section for acoustic waveguides

    DOEpatents

    Karplus, H.H.B.

    1975-10-28

    A means of facilitating the transmission of acoustic waves with minimal reflection between two regions having different specific acoustic impedances is described comprising a region exhibiting a constant product of cross-sectional area and specific acoustic impedance at each cross-sectional plane along the axis of the transition region. A variety of structures that exhibit this feature is disclosed, the preferred embodiment comprising a nested structure of doubly reentrant cones. This structure is useful for monitoring the operation of nuclear reactors in which random acoustic signals are generated in the course of operation.

  14. Truck acoustic data analyzer system

    DOEpatents

    Haynes, Howard D.; Akerman, Alfred; Ayers, Curtis W.

    2006-07-04

    A passive vehicle acoustic data analyzer system having at least one microphone disposed in the acoustic field of a moving vehicle and a computer in electronic communication the microphone(s). The computer detects and measures the frequency shift in the acoustic signature emitted by the vehicle as it approaches and passes the microphone(s). The acoustic signature of a truck driving by a microphone can provide enough information to estimate the truck speed in miles-per-hour (mph), engine speed in rotations-per-minute (RPM), turbocharger speed in RPM, and vehicle weight.

  15. 47 CFR 90.683 - EA-based SMR system operations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 806-824, 851-869, 896-901, and 935-940 MHz Bands Policies Governing the Licensing and Use of Ea-Based Smr Systems in the 809-824/851-869 Mhz Band § 90.683 EA-based SMR system operations. (a) EA-based licensees authorized in the 809-824/854-869 MHz band pursuant to § 90.681 of this part may construct...

  16. 47 CFR 90.683 - EA-based SMR system operations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 806-824, 851-869, 896-901, and 935-940 MHz Bands Policies Governing the Licensing and Use of Ea-Based Smr Systems in the 809-824/851-869 Mhz Band § 90.683 EA-based SMR system operations. (a) EA-based licensees authorized in the 809-824/854-869 MHz band pursuant to § 90.681 of this part may construct...

  17. 47 CFR 90.681 - EA-based SMR service areas.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., 851-869, 896-901, and 935-940 MHz Bands Policies Governing the Licensing and Use of Ea-Based Smr Systems in the 809-824/851-869 Mhz Band § 90.681 EA-based SMR service areas. EA licenses in for channels 711 through 830 and Spectrum Blocks A through V listed in Tables 4 and 5 of § 90.617 are available...

  18. 47 CFR 90.681 - EA-based SMR service areas.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., 851-869, 896-901, and 935-940 MHz Bands Policies Governing the Licensing and Use of Ea-Based Smr Systems in the 809-824/851-869 Mhz Band § 90.681 EA-based SMR service areas. EA licenses in for channels 711 through 830 and Spectrum Blocks A through V listed in Tables 4 and 5 of § 90.617 are available...

  19. 47 CFR 90.683 - EA-based SMR system operations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 806-824, 851-869, 896-901, and 935-940 MHz Bands Policies Governing the Licensing and Use of Ea-Based Smr Systems in the 809-824/851-869 Mhz Band § 90.683 EA-based SMR system operations. (a) EA-based licensees authorized in the 809-824/854-869 MHz band pursuant to § 90.681 of this part may construct...

  20. 47 CFR 90.681 - EA-based SMR service areas.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., 851-869, 896-901, and 935-940 MHz Bands Policies Governing the Licensing and Use of Ea-Based Smr Systems in the 809-824/851-869 Mhz Band § 90.681 EA-based SMR service areas. EA licenses in for channels 711 through 830 and Spectrum Blocks A through V listed in Tables 4 and 5 of § 90.617 are available...

  1. 47 CFR 90.681 - EA-based SMR service areas.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., 851-869, 896-901, and 935-940 MHz Bands Policies Governing the Licensing and Use of Ea-Based Smr Systems in the 809-824/851-869 Mhz Band § 90.681 EA-based SMR service areas. EA licenses in for channels 711 through 830 and Spectrum Blocks A through V listed in Tables 4 and 5 of § 90.617 are available...

  2. 47 CFR 90.681 - EA-based SMR service areas.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., 851-869, 896-901, and 935-940 MHz Bands Policies Governing the Licensing and Use of Ea-Based Smr Systems in the 809-824/851-869 Mhz Band § 90.681 EA-based SMR service areas. EA licenses in for channels 711 through 830 and Spectrum Blocks A through V listed in Tables 4 and 5 of § 90.617 are available...

  3. 47 CFR 90.683 - EA-based SMR system operations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 806-824, 851-869, 896-901, and 935-940 MHz Bands Policies Governing the Licensing and Use of Ea-Based Smr Systems in the 809-824/851-869 Mhz Band § 90.683 EA-based SMR system operations. (a) EA-based licensees authorized in the 809-824/854-869 MHz band pursuant to § 90.681 of this part may construct...

  4. Powered-Lift Aerodynamics and Acoustics. [conferences

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Powered lift technology is reviewed. Topics covered include: (1) high lift aerodynamics; (2) high speed and cruise aerodynamics; (3) acoustics; (4) propulsion aerodynamics and acoustics; (5) aerodynamic and acoustic loads; and (6) full-scale and flight research.

  5. Stimulated Brillouin scatter and stimulated ion Bernstein scatter during electron gyroharmonic heating experiments

    NASA Astrophysics Data System (ADS)

    Fu, H.; Scales, W. A.; Bernhardt, P. A.; Samimi, A.; Mahmoudian, A.; Briczinski, S. J.; McCarrick, M. J.

    2013-09-01

    Results of secondary radiation, Stimulated Electromagnetic Emission (SEE), produced during ionospheric modification experiments using ground-based high-power radio waves are reported. These results obtained at the High Frequency Active Auroral Research Program (HAARP) facility specifically considered the generation of Magnetized Stimulated Brillouin Scatter (MSBS) and Stimulated Ion Bernstein Scatter (SIBS) lines in the SEE spectrum when the transmitter frequency is near harmonics of the electron gyrofrequency. The heater antenna beam angle effect was investigated on MSBS in detail and shows a new spectral line postulated to be generated near the upper hybrid resonance region due to ion acoustic wave interaction. Frequency sweeping experiments near the electron gyroharmonics show for the first time the transition from MSBS to SIBS lines as the heater pump frequency approaches the gyroharmonic. Significantly far from the gyroharmonic, MSBS lines dominate, while close to the gyroharmonic, SIBS lines strengthen while MSBS lines weaken. New possibilities for diagnostic information are discussed in light of these new observations.

  6. Ares I Scale Model Acoustic Test Lift-Off Acoustics

    NASA Technical Reports Server (NTRS)

    Counter, Douglas D.; Houston, Janie D.

    2011-01-01

    The lift-off acoustic (LOA) environment is an important design factor for any launch vehicle. For the Ares I vehicle, the LOA environments were derived by scaling flight data from other launch vehicles. The Ares I LOA predicted environments are compared to the Ares I Scale Model Acoustic Test (ASMAT) preliminary results.

  7. Optical Stimulation of Neurons

    PubMed Central

    Thompson, Alexander C.; Stoddart, Paul R.; Jansen, E. Duco

    2014-01-01

    Our capacity to interface with the nervous system remains overwhelmingly reliant on electrical stimulation devices, such as electrode arrays and cuff electrodes that can stimulate both central and peripheral nervous systems. However, electrical stimulation has to deal with multiple challenges, including selectivity, spatial resolution, mechanical stability, implant-induced injury and the subsequent inflammatory response. Optical stimulation techniques may avoid some of these challenges by providing more selective stimulation, higher spatial resolution and reduced invasiveness of the device, while also avoiding the electrical artefacts that complicate recordings of electrically stimulated neuronal activity. This review explores the current status of optical stimulation techniques, including optogenetic methods, photoactive molecule approaches and infrared neural stimulation, together with emerging techniques such as hybrid optical-electrical stimulation, nanoparticle enhanced stimulation and optoelectric methods. Infrared neural stimulation is particularly emphasised, due to the potential for direct activation of neural tissue by infrared light, as opposed to techniques that rely on the introduction of exogenous light responsive materials. However, infrared neural stimulation remains imperfectly understood, and techniques for accurately delivering light are still under development. While the various techniques reviewed here confirm the overall feasibility of optical stimulation, a number of challenges remain to be overcome before they can deliver their full potential. PMID:26322269

  8. 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

  9. Frequency steerable acoustic transducers

    NASA Astrophysics Data System (ADS)

    Senesi, Matteo

    Structural health monitoring (SHM) is an active research area devoted to the assessment of the structural integrity of critical components of aerospace, civil and mechanical systems. Guided wave methods have been proposed for SHM of plate-like structures using permanently attached piezoelectric transducers, which generate and sense waves to evaluate the presence of damage. Effective interrogation of structural health is often facilitated by sensors and actuators with the ability to perform electronic, i.e. phased array, scanning. The objective of this research is to design an innovative directional piezoelectric transducer to be employed for the localization of broadband acoustic events, or for the generation of Lamb waves for active interrogation of structural health. The proposed Frequency Steerable Acoustic Transducers (FSATs) are characterized by a spatial arrangement of active material which leads to directional characteristics varying with frequency. Thus FSATs can be employed both for directional sensing and generation of guided waves without relying on phasing and control of a large number of channels. The analytical expression of the shape of the FSATs is obtained through a theoretical formulation for continuously distributed active material as part of a shaped piezoelectric device. The FSAT configurations analyzed in this work are a quadrilateral array and a geometry which corresponds to a spiral in the wavenumber domain. The quadrilateral array is experimentally validated, confirming the concept of frequency-dependent directionality. Its limited directivity is improved by the Wavenumber Spiral FSAT (WS-FSAT), which, instead, is characterized by a continuous frequency dependent directionality. Preliminary validations of the WS-FSAT, using a laser doppler vibrometer, are followed by the implementation of the WS-FSAT as a properly shaped piezo transducer. The prototype is first used for localization of acoustic broadband sources. Signal processing

  10. Acoustics and its relation to language: The influence of Dick Bolt

    NASA Astrophysics Data System (ADS)

    Stevens, Kenneth N.

    2003-04-01

    Under the mentoring of Dick Bolt, and the stimulation he provided in the Acoustics Laboratory at MIT, many students were exposed to a range of topics in acoustics, including mechanisms of sound generation, radiation, and propagation, noise control, acoustics of resonators and rooms, human responses to sound, and speech perception under various adverse conditions. As someone who became interested in speech communication, I have recognized that this kind of quantitative background in acoustics is an important requirement for developing models of how humans produce speech, how they perceive and understand speech, and how children acquire these skills. Speech production involves sound sources produced by a nonlinear mechanical system and by noise arising from turbulent airflow. Sound is propagated in a vocal tract with yielding walls, and acoustic coupling is introduced by lossy resonators attached to the vocal tract, including the trachea and the nasal cavity. These acoustic principles of sound generation create an inventory of sound types that give rise to distinctive responses in the ears and brains of listeners. The solid grounding in acoustics provided by Dick Bolt and his leadership have helped in the formation of this linkage between acoustics, speech physiology, linguistics, and human perception.

  11. The acoustics of snoring.

    PubMed

    Pevernagie, Dirk; Aarts, Ronald M; De Meyer, Micheline

    2010-04-01

    Snoring is a prevalent disorder affecting 20-40% of the general population. The mechanism of snoring is vibration of anatomical structures in the pharyngeal airway. Flutter of the soft palate accounts for the harsh aspect of the snoring sound. Natural or drug-induced sleep is required for its appearance. Snoring is subject to many influences such as body position, sleep stage, route of breathing and the presence or absence of sleep-disordered breathing. Its presentation may be variable within or between nights. While snoring is generally perceived as a social nuisance, rating of its noisiness is subjective and, therefore, inconsistent. Objective assessment of snoring is important to evaluate the effect of treatment interventions. Moreover, snoring carries information relating to the site and degree of obstruction of the upper airway. If evidence for monolevel snoring at the site of the soft palate is provided, the patient may benefit from palatal surgery. These considerations have inspired researchers to scrutinize the acoustic characteristics of snoring events. Similarly to speech, snoring is produced in the vocal tract. Because of this analogy, existing techniques for speech analysis have been applied to evaluate snoring sounds. It appears that the pitch of the snoring sound is in the low-frequency range (<500 Hz) and corresponds to a fundamental frequency with associated harmonics. The pitch of snoring is determined by vibration of the soft palate, while nonpalatal snoring is more 'noise-like', and has scattered energy content in the higher spectral sub-bands (>500 Hz). To evaluate acoustic properties of snoring, sleep nasendoscopy is often performed. Recent evidence suggests that the acoustic quality of snoring is markedly different in drug-induced sleep as compared with natural sleep. Most often, palatal surgery alters sound characteristics of snoring, but is no cure for this disorder. It is uncertain whether the perceived improvement after palatal surgery, as

  12. Dynamic acoustic tractor beams

    NASA Astrophysics Data System (ADS)

    Mitri, F. G.

    2015-03-01

    Pulling a sphere and vibrating it around an equilibrium position by amplitude-modulation in the near-field of a single finite circular piston transducer is theoretically demonstrated. Conditions are found where a fluid hexane sphere (with arbitrary radius) chosen as an example, centered on the axis of progressive propagating waves and submerged in non-viscous water, experiences an attractive (steady) force pulling it towards the transducer, as well as an oscillatory force forcing it to vibrate back-and-forth. Numerical predictions for the dynamic force illustrate the theory and suggest an innovative method in designing dynamic acoustical tractor beams.

  13. Coffee roasting acoustics.

    PubMed

    Wilson, Preston S

    2014-06-01

    Cracking sounds emitted by coffee beans during the roasting process were recorded and analyzed to investigate the potential of using the sounds as the basis for an automated roast monitoring technique. Three parameters were found that could be exploited. Near the end of the roasting process, sounds known as "first crack" exhibit a higher acoustic amplitude than sounds emitted later, known as "second crack." First crack emits more low frequency energy than second crack. Finally, the rate of cracks appearing in the second crack chorus is higher than the rate in the first crack chorus.

  14. Numerical predictions in acoustics

    NASA Technical Reports Server (NTRS)

    Hardin, Jay C.

    1992-01-01

    Computational Aeroacoustics (CAA) involves the calculation of the sound produced by a flow as well as the underlying flowfield itself from first principles. This paper describes the numerical challenges of CAA and recent research efforts to overcome these challenges. In addition, it includes the benefits of CAA in removing restrictions of linearity, single frequency, constant parameters, low Mach numbers, etc. found in standard acoustic analyses as well as means for evaluating the validity of these numerical approaches. Finally, numerous applications of CAA to both classical as well as modern problems of concern to the aerospace industry are presented.

  15. Wind turbine acoustics

    NASA Technical Reports Server (NTRS)

    Hubbard, Harvey H.; Shepherd, Kevin P.

    1990-01-01

    Available information on the physical characteristics of the noise generated by wind turbines is summarized, with example sound pressure time histories, narrow- and broadband frequency spectra, and noise radiation patterns. Reviewed are noise measurement standards, analysis technology, and a method of characterizing wind turbine noise. Prediction methods are given for both low-frequency rotational harmonics and broadband noise components. Also included are atmospheric propagation data showing the effects of distance and refraction by wind shear. Human perception thresholds, based on laboratory and field tests, are given. Building vibration analysis methods are summarized. The bibliography of this report lists technical publications on all aspects of wind turbine acoustics.

  16. Quantum positron acoustic waves

    SciTech Connect

    Metref, Hassina; Tribeche, Mouloud

    2014-12-15

    Nonlinear quantum positron-acoustic (QPA) waves are investigated for the first time, within the theoretical framework of the quantum hydrodynamic model. In the small but finite amplitude limit, both deformed Korteweg-de Vries and generalized Korteweg-de Vries equations governing, respectively, the dynamics of QPA solitary waves and double-layers are derived. Moreover, a full finite amplitude analysis is undertaken, and a numerical integration of the obtained highly nonlinear equations is carried out. The results complement our previously published results on this problem.

  17. Standoff photo acoustic spectroscopy

    SciTech Connect

    Van Neste, Charles W; Senesac, Larry R; Thundat, Thomas George

    2008-01-01

    Here, we demonstrate a variation of photoacoustic spectroscopy that can be used for obtaining spectroscopic information of surface adsorbed chemicals in a standoff fashion. Pulsed light scattered from a target excites an acoustic resonator and the variation of the resonance amplitude as a function of illumination wavelength yields a representation of the absorption spectrum of the target. We report sensitive and selective detection of surface adsorbed compounds such as tributyl phosphate and residues of explosives such as trinitrotoluene at standoff distances ranging from 0.5-20 m, with a detection limit on the order of 100 ng/cm{sup 2}.

  18. Dynamic acoustic tractor beams

    SciTech Connect

    Mitri, F. G.

    2015-03-07

    Pulling a sphere and vibrating it around an equilibrium position by amplitude-modulation in the near-field of a single finite circular piston transducer is theoretically demonstrated. Conditions are found where a fluid hexane sphere (with arbitrary radius) chosen as an example, centered on the axis of progressive propagating waves and submerged in non-viscous water, experiences an attractive (steady) force pulling it towards the transducer, as well as an oscillatory force forcing it to vibrate back-and-forth. Numerical predictions for the dynamic force illustrate the theory and suggest an innovative method in designing dynamic acoustical tractor beams.

  19. Numerical predictions in acoustics

    NASA Astrophysics Data System (ADS)

    Hardin, Jay C.

    Computational Aeroacoustics (CAA) involves the calculation of the sound produced by a flow as well as the underlying flowfield itself from first principles. This paper describes the numerical challenges of CAA and recent research efforts to overcome these challenges. In addition, it includes the benefits of CAA in removing restrictions of linearity, single frequency, constant parameters, low Mach numbers, etc. found in standard acoustic analyses as well as means for evaluating the validity of these numerical approaches. Finally, numerous applications of CAA to both classical as well as modern problems of concern to the aerospace industry are presented.

  20. Electrophysiological channel interactions using focused multipolar stimulation for cochlear implants

    NASA Astrophysics Data System (ADS)

    George, Shefin S.; Shivdasani, Mohit N.; Wise, Andrew K.; Shepherd, Robert K.; Fallon, James B.

    2015-12-01

    Objective. Speech intelligibility with existing multichannel cochlear implants (CIs) is thought to be limited by poor spatial selectivity and interactions between CI channels caused by overlapping activation with monopolar (MP) stimulation. Our previous studies have shown that focused multipolar (FMP) and tripolar (TP) stimulation produce more restricted neural activation in the inferior colliculus (IC), compared to MP stimulation. Approach. This study explored interactions in the IC produced by simultaneous stimulation of two CI channels. We recorded multi-unit neural activity in the IC of anaesthetized cats with normal and severely degenerated spiral ganglion neuron populations in response to FMP, TP and MP stimulation from a 14 channel CI. Stimuli were applied to a ‘fixed’ CI channel, chosen toward the middle of the cochlear electrode array, and the effects of simultaneously stimulating a more apical ‘test’ CI channel were measured as a function of spatial separation between the two stimulation channels and stimulus level of the fixed channel. Channel interactions were quantified by changes in neural responses and IC threshold (i.e., threshold shift) elicited by simultaneous stimulation of two CI channels, compared to stimulation of the test channel alone. Main results. Channel interactions were significantly lower for FMP and TP than for MP stimulation (p < 0.001), whereas no significant difference was observed between FMP and TP stimulation. With MP stimulation, threshold shifts increased with decreased inter-electrode spacing and increased stimulus levels of the fixed channel. For FMP and TP stimulation, channel interactions were found to be similar for different inter-electrode spacing and stimulus levels of the fixed channel. Significance. The present study demonstrates how the degree of channel interactions in a CI can be controlled using stimulation configurations such as FMP and TP; such knowledge is essential in enhancing CI function in complex

  1. Acoustical Environment for Academic Buildings.

    ERIC Educational Resources Information Center

    Lortie, L.J.

    Discussion of the parameters governing noise control and room acoustics are followed by a demonstration on how to achieve a good acoustical environment. Topics emphasized include--(1) design and control objectives, (2) noise sources and propagation, (3) reverberation parameters, (4) noise control factors and parameters, and (5) sound systems. Also…

  2. Improving Acoustics in American Schools.

    ERIC Educational Resources Information Center

    Nelson, Peggy B.

    2000-01-01

    This introductory article to a clinical forum describes the following seven articles that discuss the problem of noisy classrooms and resulting reduction in learning, basic principles of noise and reverberation measurements in classrooms, solutions to the problem of poor classroom acoustics, and the development of a classroom acoustics standard.…

  3. Piano acoustics-A review

    NASA Astrophysics Data System (ADS)

    Askenfelt, Anders

    2003-10-01

    The design of the piano as we know it today dates back to the second half of the 19th century. The history of studies of the acoustics of the piano begins during the same period. In this talk, known facts and unanswered questions about the acoustics of the piano are reviewed.

  4. Digital Controller For Acoustic Levitation

    NASA Technical Reports Server (NTRS)

    Tarver, D. Kent

    1989-01-01

    Acoustic driver digitally controls sound fields along three axes. Allows computerized acoustic levitation and manipulation of small objects for such purposes as containerless processing and nuclear-fusion power experiments. Also used for controlling motion of vibration-testing tables in three dimensions.

  5. The electron geodesic acoustic mode

    SciTech Connect

    Chakrabarti, N.; Kaw, P. K.

    2012-09-15

    In this report, a novel new mode, named the electron geodesic acoustic mode, is presented. This mode can occur in toroidal plasmas like the conventional geodesic acoustic mode (GAM). The frequency of this new mode is much larger than that of the conventional GAM by a factor equal to the square root of the ion to electron mass ratio.

  6. Acoustic Emissions Reveal Combustion Conditions

    NASA Technical Reports Server (NTRS)

    Ramohalli, D. N. R.; Seshan, P. K.

    1983-01-01

    Turbulent-flame acoustic emissions change with air/fuel ratio variations. Acoustic emissions sensed and processed to detect inefficient operation; control system responds by adjusting fuel/air mixture for greater efficiency. Useful for diagnosis of combustion processes and fuel/air control.

  7. Acoustic Levitation With One Driver

    NASA Technical Reports Server (NTRS)

    Wang, T. G.; Rudnick, I.; Elleman, D. D.; Stoneburner, J. D.

    1985-01-01

    Report discusses acoustic levitation in rectangular chamber using one driver mounted at corner. Placement of driver at corner enables it to couple effectively to acoustic modes along all three axes. Use of single driver reduces cost, complexity and weight of levitation system below those of three driver system.

  8. Acoustic Levitation With One Transducer

    NASA Technical Reports Server (NTRS)

    Barmatz, Martin B.

    1987-01-01

    Higher resonator modes enables simplification of equipment. Experimental acoustic levitator for high-temperature containerless processing has round cylindrical levitation chamber and only one acoustic transducer. Stable levitation of solid particle or liquid drop achieved by exciting sound in chamber to higher-order resonant mode that makes potential well for levitated particle or drop at some point within chamber.

  9. Acoustic Similarity and Dichotic Listening.

    ERIC Educational Resources Information Center

    Benson, Peter

    1978-01-01

    An experiment tests conjectures that right ear advantage (REA) has an auditory origin in competition or interference between acoustically similar stimuli and that feature-sharing effect (FSE) has its origin in assignment of features of phonetically similar stimuli. No effect on the REA for acoustic similarity, and a clear effect of acoustic…

  10. Electronic dummy for acoustical testing

    NASA Technical Reports Server (NTRS)

    Bauer, B. B.; Di Mattia, A. L.; Rosencheck, A. J.; Stern, M.; Torick, E. L.

    1967-01-01

    Electronic Dummy /ED/ used for acoustical testing represents the average male torso from the Xiphoid process upward and includes an acoustic replica of the human head. This head simulates natural flesh, and has an artificial voice and artificial ears that measure sound pressures at the eardrum or the entrance to the ear canal.

  11. Sound Advice on Classroom Acoustics.

    ERIC Educational Resources Information Center

    Sturgeon, Julie

    2003-01-01

    Discusses the importance of acoustic standards in classroom design, presenting an interview with the Acoustical Society of America's (ASA's) standards manager which focuses on reasons for the new ASA standards, the standards document (which was written for K-12 classroom but applies to college classrooms), the need to avoid echo and be able to…

  12. Array for measurement of the EAS pulse temporal structure at distances R>500 m

    NASA Astrophysics Data System (ADS)

    Fernandez, Arturo

    Indications of the existence of temporal structure in the signals of Extensive Air Showers (EAS) of energies 10 greater than 17 eV at core distances of about 500 m (Atrashkevich et al ,1997, J.Phys.G, Nucl. Part. Phys., v.23,p. 237 and papers cited there) and the preliminary analysis of the Auger Water Cherenkov Detector (WCD) signal traces (Fernandez et al, this conference) stimulated us to intensify the temporal signal studies. For this aim we started to construct a hybrid array of one WCD plus an array of seven Air Cherenkov Detectors (ACD) one near the WCD and six in a regular hexagonal network centered on the WCD. Separation between ACDs is of about 750 m. The correlation in the temporal structure of the WCD signals and the position of the maximum obtained from the ACD array is studied. This hybrid array is located at the campus of the University of Puebla which is inside the city. Evidence that such an array can be successfully used to detect EASs with 10 primary energies above 16 eV in conditions of moderate to heavy light pollution environment such as the city of Puebla is presented.

  13. Acoustic emission linear pulse holography

    DOEpatents

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

    1983-10-25

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

  14. Acoustic Absorption in Porous Materials

    NASA Technical Reports Server (NTRS)

    Kuczmarski, Maria A.; Johnston, James C.

    2011-01-01

    An understanding of both the areas of materials science and acoustics is necessary to successfully develop materials for acoustic absorption applications. This paper presents the basic knowledge and approaches for determining the acoustic performance of porous materials in a manner that will help materials researchers new to this area gain the understanding and skills necessary to make meaningful contributions to this field of study. Beginning with the basics and making as few assumptions as possible, this paper reviews relevant topics in the acoustic performance of porous materials, which are often used to make acoustic bulk absorbers, moving from the physics of sound wave interactions with porous materials to measurement techniques for flow resistivity, characteristic impedance, and wavenumber.

  15. Acoustic controlled rotation and orientation

    NASA Technical Reports Server (NTRS)

    Barmatz, Martin B. (Inventor); Allen, James L. (Inventor)

    1989-01-01

    Acoustic energy is applied to a pair of locations spaced about a chamber, to control rotation of an object levitated in the chamber. Two acoustic transducers applying energy of a single acoustic mode, one at each location, can (one or both) serve to levitate the object in three dimensions as well as control its rotation. Slow rotation is achieved by initially establishing a large phase difference and/or pressure ratio of the acoustic waves, which is sufficient to turn the object by more than 45 deg, which is immediately followed by reducing the phase difference and/or pressure ratio to maintain slow rotation. A small phase difference and/or pressure ratio enables control of the angular orientation of the object without rotating it. The sphericity of an object can be measured by its response to the acoustic energy.

  16. Bubble nonlinear dynamics and stimulated scattering process

    NASA Astrophysics Data System (ADS)

    Jie, Shi; De-Sen, Yang; Sheng-Guo, Shi; Bo, Hu; Hao-Yang, Zhang; Shi-Yong, Hu

    2016-02-01

    A complete understanding of the bubble dynamics is deemed necessary in order to achieve their full potential applications in industry and medicine. For this purpose it is first needed to expand our knowledge of a single bubble behavior under different possible conditions including the frequency and pressure variations of the sound field. In addition, stimulated scattering of sound on a bubble is a special effect in sound field, and its characteristics are associated with bubble oscillation mode. A bubble in liquid can be considered as a representative example of nonlinear dynamical system theory with its resonance, and its dynamics characteristics can be described by the Keller-Miksis equation. The nonlinear dynamics of an acoustically excited gas bubble in water is investigated by using theoretical and numerical analysis methods. Our results show its strongly nonlinear behavior with respect to the pressure amplitude and excitation frequency as the control parameters, and give an intuitive insight into stimulated sound scattering on a bubble. It is seen that the stimulated sound scattering is different from common dynamical behaviors, such as bifurcation and chaos, which is the result of the nonlinear resonance of a bubble under the excitation of a high amplitude acoustic sound wave essentially. The numerical analysis results show that the threshold of stimulated sound scattering is smaller than those of bifurcation and chaos in the common condition. Project supported by the Program for Changjiang Scholars and Innovative Research Team in University, China (Grant No. IRT1228) and the Young Scientists Fund of the National Natural Science Foundation of China (Grant Nos. 11204050 and 11204049).

  17. MEMS Based Acoustic Array

    NASA Technical Reports Server (NTRS)

    Sheplak, Mark (Inventor); Nishida, Toshikaza (Inventor); Humphreys, William M. (Inventor); Arnold, David P. (Inventor)

    2006-01-01

    Embodiments of the present invention described and shown in the specification aid drawings include a combination responsive to an acoustic wave that can be utilized as a dynamic pressure sensor. In one embodiment of the present invention, the combination has a substrate having a first surface and an opposite second surface, a microphone positioned on the first surface of the substrate and having an input and a first output and a second output, wherein the input receives a biased voltage, and the microphone generates an output signal responsive to the acoustic wave between the first output and the second output. The combination further has an amplifier positioned on the first surface of the substrate and having a first input and a second input and an output, wherein the first input of the amplifier is electrically coupled to the first output of the microphone and the second input of the amplifier is electrically coupled to the second output of the microphone for receiving the output sinual from the microphone. The amplifier is spaced from the microphone with a separation smaller than 0.5 mm.

  18. Opto-acoustic thrombolysis

    DOEpatents

    Celliers, Peter; Da Silva, Luiz; Glinsky, Michael; London, Richard; Maitland, Duncan; Matthews, Dennis; Fitch, Pat

    2000-01-01

    This invention is a catheter-based device for generating an ultrasound excitation in biological tissue. Pulsed laser light is guided through an optical fiber to provide the energy for producing the acoustic vibrations. The optical energy is deposited in a water-based absorbing fluid, e.g. saline, thrombolytic agent, blood or thrombus, and generates an acoustic impulse in the fluid through thermoelastic and/or thermodynamic mechanisms. By pulsing the laser at a repetition rate (which may vary from 10 Hz to 100 kHz) an ultrasonic radiation field can be established locally in the medium. This method of producing ultrasonic vibrations can be used in vivo for the treatment of stroke-related conditions in humans, particularly for dissolving thrombus or treating vasospasm. The catheter can also incorporate thrombolytic drug treatments as an adjunct therapy and it can be operated in conjunction with ultrasonic detection equipment for imaging and feedback control and with optical sensors for characterization of thrombus type and consistency.

  19. ChEAS Data: The Chequamegon Ecosystem Atmosphere Study

    DOE Data Explorer

    Davis, Kenneth J. [Penn State

    The Chequamegon Ecosystem-Atmosphere Study (ChEAS) is a multi-organizational research effort studying biosphere/atmosphere interactions within a northern mixed forest in Northern Wisconsin. A primary goal is to understand the processes controlling forest-atmosphere exchange of carbon dioxide and the response of these processes to climate change. Another primary goal is to bridge the gap between canopy-scale flux measurements and the global CO2 flask sampling network. The ChEAS flux towers participate in AmeriFlux, and the region is an EOS-validation site. The WLEF tower is a NOAA-CMDL CO2 sampling site. ChEAS sites are primarily located within or near the Chequamegon-Nicolet National Forest in northern Wisconsin, with one site in the Ottawa National Forest in the upper peninsula of Michigan. Current studies observe forest/atmosphere exchange of carbon dioxide at canopy and regional scales, forest floor respiration, photosynthesis and transpiration at the leaf level and use models to scale to canopy and regional levels. EOS-validation studies quantitatively assess the land cover of the area using remote sensing and conduct extensive ground truthing of new remote sensing data (i.e. ASTER and MODIS). Atmospheric remote sensing work is aimed at understanding atmospheric boundary layer dynamics, the role of entrainment in regulating the carbon dioxide mixing ratio profiles through the lower troposphere, and feedback between boundary layer dynamics and vegetation (especially via the hydrologic cycle). Airborne studies have included include balloon, kite and aircraft observations of the CO2 profile in the troposphere.

  20. On Linsley Effect and Electromagnetic Radiation from Large EAS

    NASA Astrophysics Data System (ADS)

    Deb, Manab Jyoti

    The aim of the present work was to study the following aspects of EAS : i) Detection and determination of air showers parameters by measuring the particle densities. ii) Measurement of inclination of shower axis by recording arrival time distribution of shower front particles. iii) Measurement of FWHM of pulses photographed and study of Linsley effect. iv) Characteristics of Cherenkov radiation from air showers. v) Characteristics of low frequency (120 KHz) radio signal from showers. The experiments based on the above investigations were carried out at the Cosmic Ray Research Laboratory, Gauhati University, India, since September 91 to March, 1994. Electromagnetic radiation both optical Cherenkov radiation and radio frequency (120 KHz) as well as pulses associated with extensive air showers (EAS) of energy ranging from 1.5 X 1015ev to 2.1 X 10 18ev and zenith angles 15° < 0 < 60° were selected for the present analysis. The lateral distribution of Cherenkov pulses were assumed to have an exponential form fitted with an exponential law with an exponent reflecting the depth of shower maxima (Xm). The variation of rise time (FWHM) with core distance (R) was studied from pulses photographed. The high field associated with low frequency radio signal (120KHz) and its variation with primary energy (Ep), core distance and zenith angle (0) were observed. The thesis consists of the following five chapters: 1. INTRODUCTION - This chapter contains a brief history of cosmic rays, its composition, development of EAS, emission of electromagnetic radiation from EAS, a brief introduction to the present work including review of the earlier works and aim of the experiment. 2. THEORY - This chapter mainly reviews the theories and numerical calculations. 3. EXPERIMENTAL SET-UP - This chapter describes in detail the instrumentation developed, working principle, calibration etc. 4. DATA COLLECTION AND ANALYSIS - This chapter includes data collection, selection of data for required

  1. Acoustic whispering gallery modes within the theory of elasticity

    NASA Astrophysics Data System (ADS)

    Sturman, Boris; Breunig, Ingo

    2015-07-01

    Investigations of nonlinear phenomena in optical whispering gallery mode (WGM) microresonators are booming because of rich physics and applications. Stimulated Brillouin scattering is one of the strongest processes in these devices. Here, the optical WGMs interact with acoustic counterparts. The acoustic WGMs are well known for resonators based on liquids and gases, where the sound waves are longitudinal. The situation with solid-state resonators is different because of the presence of the longitudinal (l) and transverse (t) sound waves with substantially different velocities v l , t . Moreover, the l- and t-parts of the acoustic displacement are coupled at the resonator surface breaking the separation of modes into longitudinal and transverse. Investigation of the acoustic WGMs is of high priority. Here, analytically and numerically we investigate the resonant frequencies and the eigenfunctions (displacement vector distributions) for acoustic WGMs in microresonators made of isotropic solid-state materials. Cylindrical and spherical resonators are considered. Each mode has the azimuth, radial, and orbital (for sphere) numbers m, q, and ℓ; its properties are controlled also by the ratio v l / v t . All modes are either transverse (t) or hybrid transverse-longitudinal (tl). Pure l-modes, providing the strongest interaction with optical modes in fibers and bulk crystals, are absent. The tl-modes include distorted Rayleigh waves, the modes with q ˜ 1 and dominating t-part, and pseudo-longitudinal modes with q ≫ 1 , closely spaced frequencies, and weakly localized t-part. They have no analogies to the optical WGMs and are of high relevance for Brillouin lasing in optical microresonators. The actual values of ℓ and m are 10 2 - 10 5 , and the lasing thresholds lie in the μW range. Our findings include exact dispersion equations for acoustic WGMs, which can be solved numerically for ℓ , m ≲ 10 4 , asymptotic tools for ℓ , m ≳ 10 3 , and particular

  2. MISCIBILITY, SOLUBILITY, VISCOSITY, AND DENSITY MEASUREMENTS FOR R-236EA WITH FOUR DIFFERENT EXXON LUBRICANTS

    EPA Science Inventory

    The report discusses miscibility, solubility, viscosity, and density data for the refrigerant hydrofluorocarbon (HFC)-236ea (or R-236ea) and four lubricants supplied by Exxon Corporation. Such data are needed to determine the suitability of refrigerant/lubricant combinations for ...

  3. 36 CFR 1010.6 - Determination of requirement for EA or EIS.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Determination of requirement for EA or EIS. 1010.6 Section 1010.6 Parks, Forests, and Public Property PRESIDIO TRUST ENVIRONMENTAL QUALITY § 1010.6 Determination of requirement for EA or EIS. In deciding whether to require...

  4. 36 CFR 1010.10 - Actions that normally require an EA.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... an EA. 1010.10 Section 1010.10 Parks, Forests, and Public Property PRESIDIO TRUST ENVIRONMENTAL QUALITY § 1010.10 Actions that normally require an EA. (a) General procedure. If a proposal or action is not one that normally requires an EIS, and does not qualify for a categorical exclusion under §...

  5. 76 FR 80366 - Availability of an Environmental Assessment (EA) and Finding of No Significant Impact (FONSI)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-23

    ... effective on June 30, 2008 (see 74 FR 40338) and will expire on February 15, 2012. The proposed action... issues and reasonable alternatives to be addressed in the EA. 76 FR 22882. The environmental review... AGENCY Availability of an Environmental Assessment (EA) and Finding of No Significant Impact...

  6. MODELING AND DESIGN STUDY USING HFC-236EA AS AN ALTERNATIVE REFRIGERANT IN A CENTRIFUGAL COMPRESSOR

    EPA Science Inventory

    The report gives results of an investigation of the operation of a centrifugal compressor--part of a chlorofluorocarbon (CFC)-114 chiller installation--with the new refrigerant hydrofluorocarbon (HFC)-236ea, a proposed alternative to CFC-114. A large set of CFC-236ea operating da...

  7. 47 CFR 11.51 - EAS code and Attention Signal Transmission requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... manually. (1) Automatic interrupt of programming and transmission of EAS messages are required when facilities are unattended. Automatic transmissions must include a permanent record that contains at a minimum... 47 Telecommunication 1 2011-10-01 2011-10-01 false EAS code and Attention Signal...

  8. 47 CFR 73.4097 - EBS (now EAS) attention signals on automated programing systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false EBS (now EAS) attention signals on automated programing systems. 73.4097 Section 73.4097 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED... (now EAS) attention signals on automated programing systems. See Public Notice dated March 1, 1979....

  9. 47 CFR 11.51 - EAS code and Attention Signal Transmission requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Notification (EAN), Emergency Action Termination (EAT), and Required Monthly Test (RMT), and when the... messages and required tests by sending the EAS header codes, Attention Signal, emergency message and End of... EAS codes will become the minimum signaling requirement for National level messages and tests....

  10. 47 CFR 11.55 - EAS operation during a State or Local Area emergency.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    .... At that time begin transmitting the common emergency message received from the above sources. (6...-level and geographically targeted EAS messages, as aggregated and delivered by the state governor or his... providers shall pass through all EAS messages aired on local television broadcast stations carried by...

  11. 47 CFR 11.55 - EAS operation during a State or Local Area emergency.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... EAS Participants within a state (excepting SDARs and DBS providers) must receive and transmit state... providers shall pass through all EAS messages aired on local television broadcast stations carried by DBS providers under the Commission's broadcast signal carriage rules to subscribers receiving those channels....

  12. 47 CFR 11.55 - EAS operation during a State or Local Area emergency.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... disorders. (1) DBS providers shall pass through all EAS messages aired on local television broadcast stations carried by DBS providers under the Commission's broadcast signal carriage rules to subscribers receiving those channels. (2) SDARS licensees and DBS providers may participate in EAS at the state...

  13. 47 CFR 11.55 - EAS operation during a State or Local Area emergency.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... disorders. (1) DBS providers shall pass through all EAS messages aired on local television broadcast stations carried by DBS providers under the Commission's broadcast signal carriage rules to subscribers receiving those channels. (2) SDARS licensees and DBS providers may participate in EAS at the state...

  14. Legislative Writing: A Case of Neglect in EA/OLP Courses.

    ERIC Educational Resources Information Center

    Bhatia, V. K.

    1989-01-01

    An overview of the English for Academic/Occupational Purposes (EA/OLP) situation focuses on the recent preoccupation with using simplified, abridged versions of legal cases in many of the available EA/OLP programs to the neglect of legislative use of language. The neglect or overemphasis of either approach will decrease learners' legal language…

  15. 47 CFR 76.1711 - Emergency alert system (EAS) tests and activation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Emergency alert system (EAS) tests and activation. 76.1711 Section 76.1711 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST... pursuant to the requirement of part 11 of this chapter and the EAS Operating Handbook. These records...

  16. 47 CFR 73.4097 - EBS (now EAS) attention signals on automated programing systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 4 2012-10-01 2012-10-01 false EBS (now EAS) attention signals on automated programing systems. 73.4097 Section 73.4097 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED... (now EAS) attention signals on automated programing systems. See Public Notice dated March 1, 1979....

  17. 47 CFR 73.4097 - EBS (now EAS) attention signals on automated programing systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 4 2014-10-01 2014-10-01 false EBS (now EAS) attention signals on automated programing systems. 73.4097 Section 73.4097 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED... (now EAS) attention signals on automated programing systems. See Public Notice dated March 1, 1979....

  18. 47 CFR 73.4097 - EBS (now EAS) attention signals on automated programing systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 4 2013-10-01 2013-10-01 false EBS (now EAS) attention signals on automated programing systems. 73.4097 Section 73.4097 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED... (now EAS) attention signals on automated programing systems. See Public Notice dated March 1, 1979....

  19. 47 CFR 73.4097 - EBS (now EAS) attention signals on automated programing systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 4 2011-10-01 2011-10-01 false EBS (now EAS) attention signals on automated programing systems. 73.4097 Section 73.4097 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED... (now EAS) attention signals on automated programing systems. See Public Notice dated March 1, 1979....

  20. Multimaterial Acoustic Fibers

    NASA Astrophysics Data System (ADS)

    Chocat, Noemie

    The emergence of multimaterial fibers that combine a multiplicity of solid materials with disparate electrical, optical, and mechanical properties into a single fiber presents new opportunities for extending fiber applications well beyond optical transmission. Fiber reflectors, thermal detectors, photodetectors, chemical sensors, surface-emitting fiber lasers, fiber diodes, and other functional fiber devices have been demonstrated with this approach. Yet, throughout this development and indeed the development of fibers in general, a key premise has remained unchanged : that fibers are essentially static devices incapable of controllably changing their properties at high frequencies. Unique opportunities would arise if a rapid, electrically-driven mechanism for changing fiber properties existed. A wide spectrum of hitherto passive fiber devices could at once become active with applications spanning electronics, mechanics, acoustics, and optics, with the benefits of large surface-area, structural robustness, and mechanical flexibility. This thesis addresses the challenges and opportunities associated with the realization of electromechanical transduction in fibers through the integration of internal piezoelectric and electrostrictive domains. The fundamental challenges related to the fabrication of piezoelectric devices in fiber form are analyzed from a materials perspective, and candidate materials and geometries are selected that are compatible with the thermal drawing process. The first realization of a thermally drawn piezoelectric fiber device is reported and its piezoelectric response is established over a wide range of frequencies. The acoustic properties of piezoelectric fiber devices are characterized and related to their mechanical and geometric properties. Collective effects in multi-fiber constructs are discussed and demonstrated by the realization of a linear phased array of piezoelectric fibers capable of acoustic beam steering. High strain actuation

  1. Human T cell activation. III. Induction of an early activation antigen, EA 1 by TPA, mitogens and antigens

    SciTech Connect

    Hara, T.; Jung, L.K.L.; FU, S.M.

    1986-03-01

    With human T cells activated for 12 hours by 12-o-tetradecanoyl phorbol-13-acetate (TPA) as immunogen, an IgG/sub 2a/ monoclonal antibody, mAb Ea 1, has been generated to a 60KD phosphorylated protein with 32KD and 28KD subunits. The antigen, Ea 1, is readily detected on 60% of isolated thymocytes by indirect immunofluorescence. A low level of Ea 1 expression is detectable on 2-6% of blood lymphocytes. Isolated T cells have been induced to express Ea 1 by TPA, mitogens and anitgens. TPA activated T cells express Ea 1 as early as 1 hour after activation. By 4 hours, greater than 95% of the T cells stain with mAb Ea 1. About 50% of the PHA or Con A activated T cells express Ea 1 with a similar kinetics. Ea 1 expression proceeds that of IL-2 receptor in these activation processes. T cells activated by soluble antigens (tetanus toxoid and PPD) and alloantigens in MLR also express Ea 1 after a long incubation. About 20% of the T cells stain for Ea 1 at day 6. Ea 1 expression is not limited to activated T cells. B cells activated by TPA or anti-IgM Ab plus B cell growth factor express Ea 1. The kinetics of Ea 1 expression is slower and the staining is less intense. Repeated attempts to detect Ea 1 on resting and activated monocytes and granulocytes have not been successful. Ea 1 expression is due to de novo synthesis for its induction is blocked by cycloheximide and actinomycin D. Ea 1 is the earliest activation antigen detectable to-date.

  2. Controlling sound with acoustic metamaterials

    NASA Astrophysics Data System (ADS)

    Cummer, Steven A.; Christensen, Johan; Alù, Andrea

    2016-03-01

    Acoustic metamaterials can manipulate and control sound waves in ways that are not possible in conventional materials. Metamaterials with zero, or even negative, refractive index for sound offer new possibilities for acoustic imaging and for the control of sound at subwavelength scales. The combination of transformation acoustics theory and highly anisotropic acoustic metamaterials enables precise control over the deformation of sound fields, which can be used, for example, to hide or cloak objects from incident acoustic energy. Active acoustic metamaterials use external control to create effective material properties that are not possible with passive structures and have led to the development of dynamically reconfigurable, loss-compensating and parity-time-symmetric materials for sound manipulation. Challenges remain, including the development of efficient techniques for fabricating large-scale metamaterial structures and converting laboratory experiments into useful devices. In this Review, we outline the designs and properties of materials with unusual acoustic parameters (for example, negative refractive index), discuss examples of extreme manipulation of sound and, finally, provide an overview of future directions in the field.

  3. PORTABLE ACOUSTIC MONITORING PACKAGE (PAMP)

    SciTech Connect

    John L. Loth; Gary J. Morris; George M. Palmer; Richard Guiler; Patrick Browning

    2004-07-20

    The Portable Acoustic Monitoring Package (PAMP) has been designed to record and monitor the acoustic signal in natural gas transmission lines. In particular the three acoustic signals associated with a line leak. The system is portable ({approx}30 lbs) and is designed for line pressures up to 1000 psi. It has become apparent that cataloging of the various background acoustic signals in natural gas transmission line is very important if a system to identify leak signals is to be developed. The low-pressure (0-200 psig) laboratory test phase has been completed and a number of field trials have been conducted. Before the cataloging phase could begin, a few problems identified in field trials identified had to be corrected such as: (1) Decreased microphone sensitivity at line pressures above 250 psig. (2) The inability to deal with large data sets collected when cataloging the variety of signals in a transmission line. (3) The lack of an available online acoustic calibration system. These problems have been solved and the WVU PAMP is now fully functional over the entire pressure range found in the Natural Gas transmission lines in this region. Field portability and reliability have been greatly improved. Data collection and storage have also improved to the point were the full acoustic spectrum of acoustic signals can be accurately cataloged, recorded and described.

  4. Turbofan Acoustic Propagation and Radiation

    NASA Technical Reports Server (NTRS)

    Eversman, Walter

    2000-01-01

    This document describes progress in the development of finite element codes for the prediction of near and far field acoustic radiation from the inlet and aft fan ducts of turbofan engines. The report consists of nine papers which have appeared in archival journals and conference proceedings, or are presently in review for publication. Topics included are: 1. Aft Fan Duct Acoustic Radiation; 2. Mapped Infinite Wave Envelope Elements for Acoustic Radiation in a Uniformly Moving Medium; 3. A Reflection Free Boundary Condition for Propagation in Uniform Flow Using Mapped Infinite Wave Envelope Elements; 4. A Numerical Comparison Between Multiple-Scales and FEM Solution for Sound Propagation in Lined Flow Ducts; 5. Acoustic Propagation at High Frequencies in Ducts; 6. The Boundary Condition at an Impedance Wall in a Nonuniform Duct with Potential Flow; 7. A Reverse Flow Theorem and Acoustic Reciprocity in Compressible Potential Flows; 8. Reciprocity and Acoustics Power in One Dimensional Compressible Potential Flows; and 9. Numerical Experiments on Acoustic Reciprocity in Compressible Potential Flows.

  5. EA follow-up in the Ghanaian mining sector: Challenges and opportunities

    SciTech Connect

    Appiah-Opoku, Seth; Bryan, Hobson C.

    2013-07-15

    Environmental assessment (EA) follow-up provides a means for monitoring and evaluating the implementation of environmental impact studies. It is integral to the success or failure of a project or program. In spite of its importance, very little attention is given to the need for follow-up programs in most jurisdictions in Africa. Using a case study in the Ghanaian mining sector, this paper explores the challenges and opportunities within the country's EA process for an effective follow-up program. The paper is based on informal interviews, content analysis of relevant publications, official EA documents, and internet searches. The authors suggest a standard EA follow-up program to be formalized as an integral part of Ghana's environmental assessment policy. They also propose a follow-up process that harnesses existing opportunities within the country's EA system. This approach can be replicated in other African countries.

  6. [Labelling of nif-plasmid pEA9 from Enterobacter agglomerans 339].

    PubMed

    Liu, Cheng-jun; Klingmüller, Walter

    2002-07-01

    The authors describe the in vivo labelling of the plasmid pEA9 in Enterobacter agglomerans 339 with a kanamycin resistance gene. For labelling purposes the donor plasmid pST5 was constructed. This plasmid contains the nif ENX region from pEA9,in which a kanamycin resistance gene is cloned.pST5 was transformed into E.a.339 and subsequently cured from the host. Curing was achieved with AP medium. Fourty strains that had lost pST5,but retained the kanamycin resistance, could be isolated. It showed that none of these clones contained co-integrates of pST5 and pEA9. This is evident that in all clones the kanamycin resistance gene was integrated into pEA9 by homologous recombination.

  7. Acoustic sensors using microstructures tunable with energy other than acoustic energy

    DOEpatents

    Datskos, Panagiotis G.

    2003-11-25

    A sensor for detecting acoustic energy includes a microstructure tuned to a predetermined acoustic frequency and a device for detecting movement of the microstructure. A display device is operatively linked to the movement detecting device. When acoustic energy strikes the acoustic sensor, acoustic energy having a predetermined frequency moves the microstructure, where the movement is detected by the movement detecting device.

  8. Acoustic sensors using microstructures tunable with energy other than acoustic energy

    DOEpatents

    Datskos, Panagiotis G.

    2005-06-07

    A sensor for detecting acoustic energy includes a microstructure tuned to a predetermined acoustic frequency and a device for detecting movement of the microstructure. A display device is operatively linked to the movement detecting device. When acoustic energy strikes the acoustic sensor, acoustic energy having a predetermined frequency moves the microstructure, where the movement is detected by the movement detecting device.

  9. Acoustic fault injection tool (AFIT)

    NASA Astrophysics Data System (ADS)

    Schoess, Jeffrey N.

    1999-05-01

    On September 18, 1997, Honeywell Technology Center (HTC) successfully completed a three-week flight test of its rotor acoustic monitoring system (RAMS) at Patuxent River Flight Test Center. This flight test was the culmination of an ambitious 38-month proof-of-concept effort directed at demonstrating the feasibility of detecting crack propagation in helicopter rotor components. The program was funded as part of the U.S. Navy's Air Vehicle Diagnostic Systems (AVDS) program. Reductions in Navy maintenance budgets and available personnel have dictated the need to transition from time-based to 'condition-based' maintenance. Achieving this will require new enabling diagnostic technologies. The application of acoustic emission for the early detection of helicopter rotor head dynamic component faults has proven the feasibility of the technology. The flight-test results demonstrated that stress-wave acoustic emission technology can detect signals equivalent to small fatigue cracks in rotor head components and can do so across the rotating articulated rotor head joints and in the presence of other background acoustic noise generated during flight operation. During the RAMS flight test, 12 test flights were flown from which 25 Gbyte of digital acoustic data and about 15 hours of analog flight data recorder (FDR) data were collected from the eight on-rotor acoustic sensors. The focus of this paper is to describe the CH-46 flight-test configuration and present design details about a new innovative machinery diagnostic technology called acoustic fault injection. This technology involves the injection of acoustic sound into machinery to assess health and characterize operational status. The paper will also address the development of the Acoustic Fault Injection Tool (AFIT), which was successfully demonstrated during the CH-46 flight tests.

  10. Acoustic cavitation movies

    NASA Astrophysics Data System (ADS)

    Crum, Lawrence A.

    2003-04-01

    Acoustic cavitation is a phenomenon that occurs on microsecond time scales and micron length scales, yet, it has many macroscopic manifestations. Accordingly, it is often difficult, at least for the author, to form realistic physical descriptions of the specific mechanisms through which it expresses itself in our macroscopic world. For example, there are still many who believe that cavitation erosion is due to the shock wave that is emitted by bubble implosion, rather than the liquid jet created on asymmetric collapse...and they may be right. Over the years, the author has accumulated a number of movies and high-speed photographs of cavitation activity, which he uses to form his own visual references. In the time allotted, he will show a number of these movies and photographs and discuss their relevance to existing technological problems. A limited number of CDs containing the presented materials will be available to interested individuals. [Work supported in part by the NIH, USAMRMC, and the ONR.

  11. Wind turbine acoustic standards

    NASA Technical Reports Server (NTRS)

    Stephens, D. G.; Shepherd, K. P.; Grosveld, F.

    1981-01-01

    A program is being conducted to develop noise standards for wind turbines which minimize annoyance and which can be used to design specifications. The approach consists of presenting wind turbine noise stimuli to test subjects in a laboratory listening chamber. The responses of the subjects are recorded for a range of stimuli which encompass the designs, operating conditions, and ambient noise levels of current and future installations. Results to date have established the threshold of detectability for a range of impulsive stimuli of the type associated with blade/tower wake interactions. The status of the ongoing psychoacoustic tests, the subjective data, and the approach to the development of acoustic criteria/standards are described.

  12. Electromagnetic acoustic transducer

    DOEpatents

    Alers, George A.; Burns, Jr., Leigh R.; MacLauchlan, Daniel T.

    1988-01-01

    A noncontact ultrasonic transducer for studying the acoustic properties of a metal workpiece includes a generally planar magnetizing coil positioned above the surface of the workpiece, and a generally planar eddy current coil between the magnetizing coil and the workpiece. When a large current is passed through the magnetizing coil, a large magnetic field is applied to the near-surface regions of the workpiece. The eddy current coil can then be operated as a transmitter by passing an alternating current therethrough to excite ultrasonic waves in the surface of the workpiece, or operated as a passive receiver to sense ultrasonic waves in the surface by measuring the output signal. The geometries of the two coils can be varied widely to be effective for different types of ultrasonic waves. The coils are preferably packaged in a housing which does not interfere with their operation, but protects them from a variety of adverse environmental conditions.

  13. Target structures in the cochlea for infrared neural stimulation (INS)

    NASA Astrophysics Data System (ADS)

    Young, Hunter; Tan, Xiaodong; Richter, Claus-Peter

    2014-03-01

    Spatial selective infrared neural stimulation has potential to improve neural prostheses, including cochlear implants. The heating of a confined target volume depolarizes the cell membrane and results in an action potential. Tissue heating may also result in the generation of a stress relaxation wave causing mechanical stimulation of hair cells in the cochlea, creating an optoacoustic response. Data are presented that quantify the effect of an acoustical stimulus (noise masker) on the response obtained with INS in normal hearing, and chronic deaf animals. While in normal hearing animals an acoustic masker can reduce the response to INS, in chronic deaf animals this effect has not been detected. The responses to INS remain stable following the different degrees of cochlear damage.

  14. DETECTING BARYON ACOUSTIC OSCILLATIONS

    SciTech Connect

    Labatie, A.; Starck, J. L.

    2012-02-20

    Baryon acoustic oscillations (BAOs) are a feature imprinted in the galaxy distribution by acoustic waves traveling in the plasma of the early universe. Their detection at the expected scale in large-scale structures strongly supports current cosmological models with a nearly linear evolution from redshift z Almost-Equal-To 1000 and the existence of dark energy. In addition, BAOs provide a standard ruler for studying cosmic expansion. In this paper, we focus on methods for BAO detection using the correlation function measurement {xi}-hat. For each method, we want to understand the tested hypothesis (the hypothesis H{sub 0} to be rejected) and the underlying assumptions. We first present wavelet methods which are mildly model-dependent and mostly sensitive to the BAO feature. Then we turn to fully model-dependent methods. We present the method used most often based on the {chi}{sup 2} statistic, but we find that it has limitations. In general the assumptions of the {chi}{sup 2} method are not verified, and it only gives a rough estimate of the significance. The estimate can become very wrong when considering more realistic hypotheses, where the covariance matrix of {xi}-hat depends on cosmological parameters. Instead, we propose to use the {Delta}l method based on two modifications: we modify the procedure for computing the significance and make it rigorous, and we modify the statistic to obtain better results in the case of varying covariance matrix. We verify with simulations that correct significances are different from the ones obtained using the classical {chi}{sup 2} procedure. We also test a simple example of varying covariance matrix. In this case we find that our modified statistic outperforms the classical {chi}{sup 2} statistic when both significances are correctly computed. Finally, we find that taking into account variations of the covariance matrix can change both BAO detection levels and cosmological parameter constraints.

  15. Weapons bay acoustic environment

    NASA Astrophysics Data System (ADS)

    Shaw, L. L.; Shimovetz, R. M.

    1994-09-01

    An aircraft weapons bay exposed to freestream flow experiences an intense aeroacoustic environment in and around the bay. Experience has taught that the intensity of this environment can be severe enough to result in damage to a store, its internal equipment, or the structure of the weapons bay itself. To ensure that stores and sensitive internal equipment can withstand this hazardous environment and successfully complete the mission, they must be qualified to the most severe sound pressure levels anticipated for the mission. If the qualification test levels are too high, the store and its internal equipment will be over designed, resulting in unnecessary costs and possible performance penalties. If the qualification levels are below those experienced in flight, the store or its internal equipment may catastrophically fail during performance of the mission. Thus, it is desirable that the expected levels in weapons bays be accurately predicted. A large number of research efforts have been directed toward understanding flow-induced cavity oscillations. However, the phenomena are still not adequately understood to allow one to predict the fluctuating pressure levels for various configurations and flow conditions. This is especially true at supersonic flow speeds, where only a small amount of data are available. This paper will give a background of flow induced cavity oscillations and discuss predictions, control and suppression, and the future of weapons bay acoustic environments. A large number of research efforts have been directed toward understanding flow-induced cavity oscillations. However, the phenomena are still not adequately understood to allow one to predict the fluctuating pressure levels for various configurations and flow conditions. This is especially true at supersonic flow speeds, where only a small amount of data are available. This paper will give a background of flow induced cavity oscillations and discuss predictions, control and suppression, and

  16. 77 FR 67862 - Notice of Availability of the Final Environmental Assessment (EA) and Finding of No Significant...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-14

    ... Finding of No Significant Impact/Record of Decision (FONSI/ROD) for the Aberdeen Regional Airport in... of a Final EA and FONSI/ROD. SUMMARY: The FAA has issued the final EA final Environmental Assessment (EA) for the Aberdeen Regional Airport Updates and FONSI/ROD for the proposed decoupling of runways...

  17. 78 FR 78943 - Notice of Availability (NOA) of an Environmental Assessment (EA) for the Temporary Storage of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-27

    ...The Defense Logistics Agency (DLA) announces the availability of an environmental assessment (EA) for the potential environmental impacts associated with the proposed action to temporarily store wheeled tactical vehicles at Defense Supply Center Richmond, Virginia. The EA has been prepared as required under the National Environmental Policy Act (NEPA) (1969). In addition, the EA complies with......

  18. Soldier detection using unattended acoustic and seismic sensors

    NASA Astrophysics Data System (ADS)

    Naz, P.; Hengy, S.; Hamery, P.

    2012-06-01

    During recent military conflicts, as well as for security interventions, the urban zone has taken a preponderant place. Studies have been initiated in national and in international programs to stimulate the technical innovations for these specific scenarios. For example joint field experiments have been organized by the NATO group SET-142 to evaluate the capability for the detection and localization of snipers, mortars or artillery guns using acoustic devices. Another important operational need corresponds to the protection of military sites or buildings. In this context, unattended acoustic and seismic sensors are envisaged to contribute to the survey of specific points by the detection of approaching enemy soldiers. This paper describes some measurements done in an anechoic chamber and in free field to characterize typical sounds generated by the soldier activities (walking, crawling, weapon handling, radio communication, clothing noises...). Footstep, speech and some specific impulsive sounds are detectable at various distances from the source. Such detection algorithms may be easily merged with the existing weapon firing detection algorithms to provide a more generic "battlefield acoustic" early warning system. Results obtained in various conditions (grassy terrain, gravel path, road, forest) will be presented. A method to extrapolate the distances of detection has been developed, based on an acoustic propagation model and applied to the laboratory measurements.

  19. Deformation of red blood cells using acoustic radiation forces

    PubMed Central

    Mishra, Puja; Hill, Martyn; Glynne-Jones, Peter

    2014-01-01

    Acoustic radiation forces have been used to manipulate cells and bacteria in a number of recent microfluidic applications. The net force on a cell has been subject to careful investigation over a number of decades. We demonstrate that the radiation forces also act to deform cells. An ultrasonic standing wave field is created in a 0.1 mm glass capillary at a frequency of 7.9 MHz. Using osmotically swollen red-blood cells, we show observable deformations up to an aspect ratio of 1.35, comparable to deformations created by optical tweezing. In contrast to optical technologies, ultrasonic devices are potentially capable of deforming thousands of cells simultaneously. We create a finite element model that includes both the acoustic environment of the cell, and a model of the cell membrane subject to forces resulting from the non-linear aspects of the acoustic field. The model is found to give reasonable agreement with the experimental results, and shows that the deformation is the result of variation in an acoustic force that is directed outwards at all points on the cell membrane. We foresee applications in diagnostic devices, and in the possibility of mechanically stimulating cells to promote differentiation and physiological effects. PMID:25379070

  20. Recent Langley helicopter acoustics contributions

    NASA Technical Reports Server (NTRS)

    Morgan, Homer G.; Pao, S. P.; Powell, C. A.

    1988-01-01

    The helicopter acoustics program at NASA Langley has included technology for elements of noise control ranging from sources of noise to receivers of noise. The scope of Langley contributions for about the last decade is discussed. Specifically, the resolution of two certification noise quantification issues by subjective acoustics research, the development status of the helicopter system noise prediction program ROTONET are reviewed and the highlights from research on blade rotational, broadband, and blade vortex interaction noise sources are presented. Finally, research contributions on helicopter cabin (or interior) noise control are presented. A bibliography of publications from the Langley helicopter acoustics program for the past 10 years is included.

  1. An asymptotic model in acoustics: acoustic drift equations.

    PubMed

    Vladimirov, Vladimir A; Ilin, Konstantin

    2013-11-01

    A rigorous asymptotic procedure with the Mach number as a small parameter is used to derive the equations of mean flows which coexist and are affected by the background acoustic waves in the limit of very high Reynolds number.

  2. Acoustic Responses after Total Destruction of the Cochlear Receptor: Brainstem and Auditory Cortex

    NASA Astrophysics Data System (ADS)

    Cazals, Yves; Aran, Jean-Marie; Erre, Jean-Paul; Guilhaume, Anne

    1980-10-01

    Acoustically evoked neural activity has been recorded from the brainstem and auditory cortex of guinea pigs after complete destruction of the organ of Corti by the aminoglycosidic antibiotic amikacin. These responses to sound differ in important respects from the evoked potentials normally recorded from the auditory pathways. At the brainstem level they resemble the potentials reported by others after stimulation of the vestibular nerve.

  3. Probing Acoustic Nonlinearity by Mixing Surface Acoustic Waves

    SciTech Connect

    Hurley, David Howard; Telschow, Kenneth Louis

    2000-07-01

    Measurement methods aimed at determining material properties through nonlinear wave propagation are sensitive to artifacts caused by background nonlinearities inherent in the ultrasonic generation and detection methods. The focus of this paper is to describe our investigation of nonlinear mixing of surface acoustic waves (SAWs) as a means to decrease sensitivity to background nonlinearity and increase spatial sensitivity to acoustic nonlinearity induced by material microstructure.

  4. A Reconstruction Algorithm of Magnetoacoustic Tomography with Magnetic Induction for Acoustically Inhomogeneous Tissue

    PubMed Central

    Zhou, Lian; Zhu, Shanan

    2014-01-01

    Magnetoacoustic tomography with Magnetic Induction (MAT-MI) is a noninvasive electrical conductivity imaging approach that measures ultrasound wave induced by magnetic stimulation, for reconstructing the distribution of electrical impedance in biological tissue. Existing reconstruction algorithms for MAT-MI are based on the assumption that the acoustic properties in the tissue are homogeneous. However, the tissue in most parts of human body, has heterogeneous acoustic properties, which leads to potential distortion and blurring of small buried objects in the impedance images. In the present study, we proposed a new algorithm for MAT-MI to image the impedance distribution in tissues with inhomogeneous acoustic speed distributions. With a computer head model constructed from MR images of a human subject, a series of numerical simulation experiments were conducted. The present results indicate that the inhomogeneous acoustic properties of tissues in terms of speed variation can be incorporated in MAT-MI imaging. PMID:24845284

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

    PubMed Central

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

    2014-01-01

    Brillouin scattering in optical fibres is a fundamental interaction between light and sound with important implications ranging from optical sensors to slow and fast light. In usual optical fibres, light both excites and feels shear and longitudinal bulk elastic waves, giving rise to forward-guided acoustic wave Brillouin scattering and backward-stimulated Brillouin scattering. In a subwavelength-diameter optical fibre, the situation changes dramatically, as we here report with the first experimental observation of Brillouin light scattering from surface acoustic waves. These Rayleigh-type surface waves travel the wire surface at a specific velocity of 3,400 m s−1 and backscatter the light with a Doppler shift of about 6 GHz. As these acoustic resonances are sensitive to surface defects or features, surface acoustic wave Brillouin scattering opens new opportunities for various sensing applications, but also in other domains such as microwave photonics and nonlinear plasmonics. PMID:25341638

  6. Echo-acoustic flow dynamically modifies the cortical map of target range in bats.

    PubMed

    Bartenstein, Sophia K; Gerstenberg, Nadine; Vanderelst, Dieter; Peremans, Herbert; Firzlaff, Uwe

    2014-01-01

    Echolocating bats use the delay between their sonar emissions and the reflected echoes to measure target range, a crucial parameter for avoiding collisions or capturing prey. In many bat species, target range is represented as an orderly organized map of echo delay in the auditory cortex. Here we show that the map of target range in bats is dynamically modified by the continuously changing flow of acoustic information perceived during flight ('echo-acoustic flow'). Combining dynamic acoustic stimulation in virtual space with extracellular recordings, we found that neurons in the auditory cortex of the bat Phyllostomus discolor encode echo-acoustic flow information on the geometric relation between targets and the bat's flight trajectory, rather than echo delay per se. Specifically, the cortical representation of close-range targets is enlarged when the lateral passing distance of the target decreases. This flow-dependent enlargement of target representation may trigger adaptive behaviours such as vocal control or flight manoeuvres. PMID:25131175

  7. Echo-acoustic flow dynamically modifies the cortical map of target range in bats.

    PubMed

    Bartenstein, Sophia K; Gerstenberg, Nadine; Vanderelst, Dieter; Peremans, Herbert; Firzlaff, Uwe

    2014-01-01

    Echolocating bats use the delay between their sonar emissions and the reflected echoes to measure target range, a crucial parameter for avoiding collisions or capturing prey. In many bat species, target range is represented as an orderly organized map of echo delay in the auditory cortex. Here we show that the map of target range in bats is dynamically modified by the continuously changing flow of acoustic information perceived during flight ('echo-acoustic flow'). Combining dynamic acoustic stimulation in virtual space with extracellular recordings, we found that neurons in the auditory cortex of the bat Phyllostomus discolor encode echo-acoustic flow information on the geometric relation between targets and the bat's flight trajectory, rather than echo delay per se. Specifically, the cortical representation of close-range targets is enlarged when the lateral passing distance of the target decreases. This flow-dependent enlargement of target representation may trigger adaptive behaviours such as vocal control or flight manoeuvres.

  8. Stimulated Brillouin scattering in a two-level system

    NASA Astrophysics Data System (ADS)

    Postan, A.; Rai, Jagdish; Bowden, Charles M.

    1992-03-01

    Resonances in the interaction of a saturable two-level system with stimulated Brillouin scattering are discussed. These resonances appear due to the coupling between the two-level system and the resonant acoustic waves that are excited in the host substance by a coherent electromagnetic field of two mutually detuned, counterpropagating laser beams. Results for sodium vapor mixed with nitrogen buffer gas are presented.

  9. Effects of subsampling of passive acoustic recordings on acoustic metrics.

    PubMed

    Thomisch, Karolin; Boebel, Olaf; Zitterbart, Daniel P; Samaran, Flore; Van Parijs, Sofie; Van Opzeeland, Ilse

    2015-07-01

    Passive acoustic monitoring is an important tool in marine mammal studies. However, logistics and finances frequently constrain the number and servicing schedules of acoustic recorders, requiring a trade-off between deployment periods and sampling continuity, i.e., the implementation of a subsampling scheme. Optimizing such schemes to each project's specific research questions is desirable. This study investigates the impact of subsampling on the accuracy of two common metrics, acoustic presence and call rate, for different vocalization patterns (regimes) of baleen whales: (1) variable vocal activity, (2) vocalizations organized in song bouts, and (3) vocal activity with diel patterns. To this end, above metrics are compared for continuous and subsampled data subject to different sampling strategies, covering duty cycles between 50% and 2%. The results show that a reduction of the duty cycle impacts negatively on the accuracy of both acoustic presence and call rate estimates. For a given duty cycle, frequent short listening periods improve accuracy of daily acoustic presence estimates over few long listening periods. Overall, subsampling effects are most pronounced for low and/or temporally clustered vocal activity. These findings illustrate the importance of informed decisions when applying subsampling strategies to passive acoustic recordings or analyses for a given target species.

  10. Effects of subsampling of passive acoustic recordings on acoustic metrics.

    PubMed

    Thomisch, Karolin; Boebel, Olaf; Zitterbart, Daniel P; Samaran, Flore; Van Parijs, Sofie; Van Opzeeland, Ilse

    2015-07-01

    Passive acoustic monitoring is an important tool in marine mammal studies. However, logistics and finances frequently constrain the number and servicing schedules of acoustic recorders, requiring a trade-off between deployment periods and sampling continuity, i.e., the implementation of a subsampling scheme. Optimizing such schemes to each project's specific research questions is desirable. This study investigates the impact of subsampling on the accuracy of two common metrics, acoustic presence and call rate, for different vocalization patterns (regimes) of baleen whales: (1) variable vocal activity, (2) vocalizations organized in song bouts, and (3) vocal activity with diel patterns. To this end, above metrics are compared for continuous and subsampled data subject to different sampling strategies, covering duty cycles between 50% and 2%. The results show that a reduction of the duty cycle impacts negatively on the accuracy of both acoustic presence and call rate estimates. For a given duty cycle, frequent short listening periods improve accuracy of daily acoustic presence estimates over few long listening periods. Overall, subsampling effects are most pronounced for low and/or temporally clustered vocal activity. These findings illustrate the importance of informed decisions when applying subsampling strategies to passive acoustic recordings or analyses for a given target species. PMID:26233026

  11. Peripheral nerve stimulation: definition.

    PubMed

    Abejón, David; Pérez-Cajaraville, Juan

    2011-01-01

    Recently, there has been a tremendous evolution in the field of neurostimulation, both from the technological point of view and from development of the new and different indications. In some areas, such as peripheral nerve stimulation, there has been a boom in recent years due to the variations in the surgical technique and the improved results documented by in multiple published papers. All this makes imperative the need to classify and define the different types of stimulation that are used today. The confusion arises when attempting to describe peripheral nerve stimulation and subcutaneous stimulation. Peripheral nerve stimulation, in its pure definition, involves implanting a lead on a nerve, with the aim to produce paresthesia along the entire trajectory of the stimulated nerve.

  12. Hybrid optical and acoustic force based sorting

    NASA Astrophysics Data System (ADS)

    O'Mahoney, Paul; Brodie, Graham W.; Wang, Han; Demore, Christine E. M.; Cochran, Sandy; Spalding, Gabriel C.; MacDonald, Michael P.

    2014-09-01

    We report the combined use of optical sorting and acoustic levitation to give particle sorting. Differing sizes of microparticles are sorted optically both with and without the aid of acoustic levitation, and the results compared to show that the use of acoustic trapping can increase sorting efficiency. The use of a transparent ultrasonic transducer is also shown to streamline the integration of optics and acoustics. We also demonstrate the balance of optical radiation pressure and acoustic levitation to achieve vertical sorting.

  13. The effective acoustic environment of helicopter crewmen

    NASA Technical Reports Server (NTRS)

    Camp, R. T., Jr.; Mozo, B. T.

    1978-01-01

    Methods of measuring the composite acoustic environment of helicopters in order to quantify the effective acoustic environment of the crewmen and to assess the real acoustic hazards of the personnel are examined. It is indicated that the attenuation characteristics of the helmets and hearing protectors and the variables of the physiology of the human ear be accounted for in determining the effective acoustic environment of Army helicopter crewmen as well as the acoustic hazards of voice communications systems noise.

  14. PC and PVC Acoustics Demonstrations.

    ERIC Educational Resources Information Center

    Luzader, Stephen

    1990-01-01

    Described are four musical instruments constructed from polyvinyl chloride (PVC) pipe. The use of computerized synthesizers to play scales and chords is discussed. Suggestions for other illustrations of acoustics are included. (CW)

  15. Acoustics: Motion controlled by sound

    NASA Astrophysics Data System (ADS)

    Neild, Adrian

    2016-09-01

    A simple technique has been developed that produces holograms made of sound waves. These acoustic landscapes are used to manipulate microscale objects, and offer great potential in medical imaging and selective heating. See Letter p.518

  16. Acoustic Characterization of Mesoscale Objects

    SciTech Connect

    Chinn, D; Huber, R; Chambers, D; Cole, G; Balogun, O; Spicer, J; Murray, T

    2007-03-13

    This report describes the science and engineering performed to provide state-of-the-art acoustic capabilities for nondestructively characterizing mesoscale (millimeter-sized) objects--allowing micrometer resolution over the objects entire volume. Materials and structures used in mesoscale objects necessitate the use of (1) GHz acoustic frequencies and (2) non-contacting laser generation and detection of acoustic waves. This effort demonstrated that acoustic methods at gigahertz frequencies have the necessary penetration depth and spatial resolution to effectively detect density discontinuities, gaps, and delaminations. A prototype laser-based ultrasonic system was designed and built. The system uses a micro-chip laser for excitation of broadband ultrasonic waves with frequency components reaching 1.0 GHz, and a path-stabilized Michelson interferometer for detection. The proof-of-concept for mesoscale characterization is demonstrated by imaging a micro-fabricated etched pattern in a 70 {micro}m thick silicon wafer.

  17. Stimulant Use Disorders.

    PubMed

    Park, Taryn M; Haning, William F

    2016-07-01

    Compared with other illicit substances, stimulants are not commonly used by adolescents; however, they represent a serious concern regarding substance use among youths. This article uses methamphetamine as a model for stimulant use in adolescents; cocaine and prescription stimulants are also mentioned. Methamphetamine use among adolescents and young adults is a serious health concern with potentially long-term physical, cognitive, and psychiatric consequences. Brain development and the effects of misusing stimulants align such that usage in adolescents can more dangerous than during adulthood. It seems helpful to keep in mind the differences between adolescents and young adults when implementing interventions. PMID:27338967

  18. Study Acoustic Emissions from Composites

    NASA Technical Reports Server (NTRS)

    Walker, James; Workman,Gary

    1998-01-01

    The purpose of this work will be to develop techniques for monitoring the acoustic emissions from carbon epoxy composite structures at cryogenic temperatures. Performance of transducers at temperatures ranging from ambient to cryogenic and the characteristics of acoustic emission from composite structures will be studied and documented. This entire effort is directed towards characterization of structures used in NASA propulsion programs such as the X-33.

  19. Acoustic Rectification in Dispersive Media

    NASA Technical Reports Server (NTRS)

    Cantrell, John H.

    2008-01-01

    It is shown that the shapes of acoustic radiation-induced static strain and displacement pulses (rectified acoustic pulses) are defined locally by the energy density of the generating waveform. Dispersive properties are introduced analytically by assuming that the rectified pulses are functionally dependent on a phase factor that includes both dispersive and nonlinear terms. The dispersion causes an evolutionary change in the shape of the energy density profile that leads to the generation of solitons experimentally observed in fused silica.

  20. Acoustics Research of Propulsion Systems

    NASA Technical Reports Server (NTRS)

    Gao, Ximing; Houston, Janice D.

    2014-01-01

    The liftoff phase induces some of the highest acoustic loading over a broad frequency for a launch vehicle. These external acoustic environments are used in the prediction of the internal vibration responses of the vehicle and components. Thus, predicting these liftoff acoustic environments is critical to the design requirements of any launch vehicle but there are challenges. Present liftoff vehicle acoustic environment prediction methods utilize stationary data from previously conducted hold-down tests; i.e. static firings conducted in the 1960's, to generate 1/3 octave band Sound Pressure Level (SPL) spectra. These data sets are used to predict the liftoff acoustic environments for launch vehicles. To facilitate the accuracy and quality of acoustic loading, predictions at liftoff for future launch vehicles such as the Space Launch System (SLS), non-stationary flight data from the Ares I-X were processed in PC-Signal in two forms which included a simulated hold-down phase and the entire launch phase. In conjunction, the Prediction of Acoustic Vehicle Environments (PAVE) program was developed in MATLAB to allow for efficient predictions of sound pressure levels (SPLs) as a function of station number along the vehicle using semiempirical methods. This consisted, initially, of generating the Dimensionless Spectrum Function (DSF) and Dimensionless Source Location (DSL) curves from the Ares I-X flight data. These are then used in the MATLAB program to generate the 1/3 octave band SPL spectra. Concluding results show major differences in SPLs between the hold-down test data and the processed Ares IX flight data making the Ares I-X flight data more practical for future vehicle acoustic environment predictions.

  1. Acoustic techniques in nuclear safeguards

    SciTech Connect

    Olinger, C.T.; Sinha, D.N.

    1995-07-01

    Acoustic techniques can be employed to address many questions relevant to current nuclear technology needs. These include establishing and monitoring intrinsic tags and seals, locating holdup in areas where conventional radiation-based measurements have limited capability, process monitoring, monitoring containers for corrosion or changes in pressure, and facility design verification. These acoustics applications are in their infancy with respect to safeguards and nuclear material management, but proof-of-principle has been demonstrated in many of the areas listed.

  2. Simplified Rotation In Acoustic Levitation

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Gaspar, M. S.; Trinh, E. H.

    1989-01-01

    New technique based on old discovery used to control orientation of object levitated acoustically in axisymmetric chamber. Method does not require expensive equipment like additional acoustic drivers of precisely adjustable amplitude, phase, and frequency. Reflecting object acts as second source of sound. If reflecting object large enough, close enough to levitated object, or focuses reflected sound sufficiently, Rayleigh torque exerted on levitated object by reflected sound controls orientation of object.

  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. ACOUSTIC RECTIFICATION IN DISPERSIVE MEDIA

    SciTech Connect

    Cantrell, John H.

    2009-03-03

    It is shown that the shapes of acoustic radiation-induced static strain and displacement pulses (rectified acoustic pulses) are defined locally by the energy density of the generating waveform. Dispersive properties are introduced analytically by assuming that the rectified pulses are functionally dependent on a phase factor that includes both dispersive and nonlinear terms. The dispersion causes an evolutionary change in the shape of the energy density profile that leads to the generation of solitons experimentally observed in fused silica.

  5. Acoustically-driven microfluidic systems

    SciTech Connect

    Wang, A W; Benett, W J; Tarte, L R

    2000-06-23

    We have demonstrated a non-contact method of concentrating and mixing particles in a plastic microfluidic chamber employing acoustic radiation pressure. A flaw cell package has also been designed that integrates liquid sample interconnects, electrical contacts and a removable sample chamber. Experiments were performed on 1, 3, 6, and 10 {micro}m polystyrene beads. Increased antibody binding to a solid-phase substrate was observed in the presence of acoustic mixing due to improve mass transport.

  6. A novel mechanism of cochlear excitation during simultaneous stimulation and pressure relief through the round window.

    PubMed

    Weddell, Thomas D; Yarin, Yury M; Drexl, Markus; Russell, Ian J; Elliott, Stephen J; Lukashkin, Andrei N

    2014-04-01

    The round window (RW) membrane provides pressure relief when the cochlea is excited by sound. Here, we report measurements of cochlear function from guinea pigs when the cochlea was stimulated at acoustic frequencies by movements of a miniature magnet which partially occluded the RW. Maximum cochlear sensitivity, corresponding to subnanometre magnet displacements at neural thresholds, was observed for frequencies around 20 kHz, which is similar to that for acoustic stimulation. Neural response latencies to acoustic and RW stimulation were similar and taken to indicate that both means of stimulation resulted in the generation of conventional travelling waves along the cochlear partition. It was concluded that the relatively high impedance of the ossicles, as seen from the cochlea, enabled the region of the RW not occluded by the magnet, to act as a pressure shunt during RW stimulation. We propose that travelling waves, similar to those owing to acoustic far-field pressure changes, are driven by a jet-like, near-field component of a complex pressure field, which is generated by the magnetically vibrated RW. Outcomes of research described here are theoretical and practical design principles for the development of new types of hearing aids, which use near-field, RW excitation of the cochlea. PMID:24501274

  7. A novel mechanism of cochlear excitation during simultaneous stimulation and pressure relief through the round window

    PubMed Central

    Weddell, Thomas D.; Yarin, Yury M.; Drexl, Markus; Russell, Ian J.; Elliott, Stephen J.; Lukashkin, Andrei N.

    2014-01-01

    The round window (RW) membrane provides pressure relief when the cochlea is excited by sound. Here, we report measurements of cochlear function from guinea pigs when the cochlea was stimulated at acoustic frequencies by movements of a miniature magnet which partially occluded the RW. Maximum cochlear sensitivity, corresponding to subnanometre magnet displacements at neural thresholds, was observed for frequencies around 20 kHz, which is similar to that for acoustic stimulation. Neural response latencies to acoustic and RW stimulation were similar and taken to indicate that both means of stimulation resulted in the generation of conventional travelling waves along the cochlear partition. It was concluded that the relatively high impedance of the ossicles, as seen from the cochlea, enabled the region of the RW not occluded by the magnet, to act as a pressure shunt during RW stimulation. We propose that travelling waves, similar to those owing to acoustic far-field pressure changes, are driven by a jet-like, near-field component of a complex pressure field, which is generated by the magnetically vibrated RW. Outcomes of research described here are theoretical and practical design principles for the development of new types of hearing aids, which use near-field, RW excitation of the cochlea. PMID:24501274

  8. 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.

  9. Opto-acoustic cell permeation

    SciTech Connect

    Visuri, S R; Heredia, N

    2000-03-09

    Optically generated acoustic waves have been used to temporarily permeate biological cells. This technique may be useful for enhancing transfection of DNA into cells or enhancing the absorption of locally delivered drugs. A diode-pumped frequency-doubled Nd:YAG laser operating at kHz repetition rates was used to produce a series of acoustic pulses. An acoustic wave was formed via thermoelastic expansion by depositing laser radiation into an absorbing dye. Generated pressures were measured with a PVDF hydrophone. The acoustic waves were transmitted to cultured and plated cells. The cell media contained a selection of normally- impermeable fluorescent-labeled dextran dyes. Following treatment with the opto-acoustic technique, cellular incorporation of dyes, up to 40,000 Molecular Weight, was noted. Control cells that did not receive opto-acoustic treatment had unremarkable dye incorporation. Uptake of dye was quantified via fluorescent microscopic analysis. Trypan Blue membrane exclusion assays and fluorescent labeling assays confirmed the vitality of cells following treatment. This method of enhanced drug delivery has the potential to dramatically reduce required drug dosages and associated side effects and enable revolutionary therapies.

  10. Acoustics Research of Propulsion Systems

    NASA Technical Reports Server (NTRS)

    Gao, Ximing; Houston, Janice

    2014-01-01

    The liftoff phase induces high acoustic loading over a broad frequency range for a launch vehicle. These external acoustic environments are used in the prediction of the internal vibration responses of the vehicle and components. Present liftoff vehicle acoustic environment prediction methods utilize stationary data from previously conducted hold-down tests to generate 1/3 octave band Sound Pressure Level (SPL) spectra. In an effort to update the accuracy and quality of liftoff acoustic loading predictions, non-stationary flight data from the Ares I-X were processed in PC-Signal in two flight phases: simulated hold-down and liftoff. In conjunction, the Prediction of Acoustic Vehicle Environments (PAVE) program was developed in MATLAB to allow for efficient predictions of sound pressure levels (SPLs) as a function of station number along the vehicle using semi-empirical methods. This consisted of generating the Dimensionless Spectrum Function (DSF) and Dimensionless Source Location (DSL) curves from the Ares I-X flight data. These are then used in the MATLAB program to generate the 1/3 octave band SPL spectra. Concluding results show major differences in SPLs between the hold-down test data and the processed Ares I-X flight data making the Ares I-X flight data more practical for future vehicle acoustic environment predictions.

  11. Acoustical evaluation of preschool classrooms

    NASA Astrophysics Data System (ADS)

    Yang, Wonyoung; Hodgson, Murray

    2003-10-01

    An investigation was made of the acoustical environments in the Berwick Preschool, Vancouver, in response to complaints by the teachers. Reverberation times (RT), background noise levels (BNL), and in-class sound levels (Leq) were measured for acoustical evaluation in the classrooms. With respect to the measured RT and BNL, none of the classrooms in the preschool were acceptable according to the criteria relevant to this study. A questionnaire was administered to the teachers to assess their subjective responses to the acoustical and nonacoustical environments of the classrooms. Teachers agreed that the nonacoustical environments in the classrooms were fair, but that the acoustical environments had problems. Eight different classroom configurations were simulated to improve the acoustical environments, using the CATT room acoustical simulation program. When the surface absorption was increased, both the RT and speech levels decreased. RASTI was dependent on the volumes of the classrooms when the background noise levels were high; however, it depended on the total absorption of the classrooms when the background noise levels were low. Ceiling heights are critical as well. It is recommended that decreasing the volume of the classrooms is effective. Sound absorptive materials should be added to the walls or ceiling.

  12. Studies on some important characteristics of radioemission from large EAS

    NASA Astrophysics Data System (ADS)

    Baishya, Runima

    The title of the thesis is Studies on some important characteristics of radioemission from large EAS. For this theoretical and experimental study frequencies selected are 50 KHz, 120 KHz, 2 MHz, 9 MHz, 110 MHz and 220 MHz. Experimental works are done at the Cosmic Ray Research Laboratory, Gauhati University, Guwahati, Assam, India, 781014 from 1991 to 1996. The thesis comprises of six chapters. Abstracts of different chapters are given below. Chapter 1. Introduction. In this chapter important characteristics of primary cosmic rays (CR) such as energy spectra, mass composition and origin are given. Longitudinal development of Extensive Air Shower (EAS) in the atmosphere, particle and radiation components of EAS, are also described. The present works aim at the following aspects of radioemission. (1) Characteristics of LF-MF-HF radioemission (i) Frequency spectrum (ii) Variation of fieldstrength with age parameter (s) (iii) Lateral distribution of fieldstrength. (2) Characteristics of VHF radioemission (i) Variation of fieldstrength with height of shower maximum (Hm) at 110 MHz and 220MHz. (ii) Correlation between fieldstrength and age parameter Scas (S cas < 1). (3) Comparison between modified Kahn and Lerche's model and modified Allan's model of radioemission. (i) Frequency spectrum (ii) Lateral distribution of fieldstrength at 110 MHz and 220 MHz. (4) A theoretical model on the basis of transition radiation for LF-MF-HF radioemission. Chapter 2 : Theoretical studies on radioemission (A Review). Theoretical and experimental investigations on radioemission made by different workers are reviewed in this chapter. A brief note on justification of the present work is also presented. Chapter 3: Experimental set-up.. Details of the experimental arrangements, design, fabrication and installation of various units are discussed in this chapter. The study is based on the ground level observations using microprocessor based data acquisition system. Particle detector channels

  13. [Electromagnetic urological stimulator].

    PubMed

    Zaslavskiĭ AOi; Markarov, G S; Gelis, Iu S

    1997-01-01

    The paper deals with an electromagnetic urological stimulator which generates a modulated low-frequency electromagnetic field of nonthermal intensity and its brief technical data. It presents a treatment regimen for urolithiasis and recommendations how to use the above therapeutical agent to stimulate urinary function in patients with urolithiasis in order to inoperatively eliminate urinary calculi and sand which form following extracorporeal shockwave lithotripsy.

  14. Stimulating your appetite.

    PubMed

    Whitfield, L

    1998-01-01

    A number of legal and illegal drugs can help stimulate appetite and are used for people with HIV to prevent wasting. Stimulating hunger is important because lower calorie intake and poor absorption of nutrients are associated with wasting. The uses and potential drawbacks of marijuana, thalidomide (Synovir), Marinol, and Megace are described. PMID:11365223

  15. 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.

  16. Surface acoustic wave microfluidics

    PubMed Central

    Ding, Xiaoyun; Li, Peng; Lin, Sz-Chin Steven; Stratton, Zackary S.; Nama, Nitesh; Guo, Feng; Slotcavage, Daniel; Mao, Xiaole; Shi, Jinjie; Costanzo, Francesco; Huang, Tony Jun

    2014-01-01

    The recent introduction of surface acoustic wave (SAW) technology onto lab-on-a-chip platforms has opened a new frontier in microfluidics. The advantages provided by such SAW microfluidics are numerous: simple fabrication, high biocompatibility, fast fluid actuation, versatility, compact and inexpensive devices and accessories, contact-free particle manipulation, and compatibility with other microfluidic components. We believe that these advantages enable SAW microfluidics to play a significant role in a variety of applications in biology, chemistry, engineering, and medicine. In this review article, we discuss the theory underpinning SAWs and their interactions with particles and the contacting fluids in which they are suspended. We then review the SAW-enabled microfluidic devices demonstrated to date, starting with devices that accomplish fluid mixing and transport through the use of travelling SAW; we follow that by reviewing the more recent innovations achieved with standing SAW that enable such actions as particle/cell focusing, sorting, and patterning. Finally, we look forward and appraise where the discipline of SAW microfluidics could go next. PMID:23900527

  17. An acoustic glucose sensor.

    PubMed

    Hu, Ruifen; Stevenson, Adrian C; Lowe, Christopher R

    2012-05-15

    In vivo glucose monitoring is required for tighter glycaemic control. This report describes a new approach to construct a miniature implantable device based on a magnetic acoustic resonance sensor (MARS). A ≈ 600-800 nm thick glucose-responsive poly(acrylamide-co-3-acrylamidophenylboronic acid) (poly(acrylamide-co-3-APB)) film was polymerised on the quartz disc (12 mm in diameter and 0.25 mm thick) of the MARS. The swelling/shrinking of the polymer film induced by the glucose binding to the phenylboronate caused changes in the resonance amplitude of the quartz disc in the MARS. A linear relationship between the response of the MARS and the glucose concentration in the range ≈ 0-15 mM was observed, with the optimum response of the MARS sensor being obtained when the polymer films contained ≈ 20 mol% 3-APB. The MARS glucose sensor also functioned under flow conditions (9 μl/min) with a response almost identical to the sensor under static or non-flow conditions. The results suggest that the MARS could offer a promising strategy for developing a small subcutaneously implanted continuous glucose monitor.

  18. Acoustic Signal Processing

    NASA Astrophysics Data System (ADS)

    Hartmann, William M.; Candy, James V.

    Signal processing refers to the acquisition, storage, display, and generation of signals - also to the extraction of information from signals and the re-encoding of information. As such, signal processing in some form is an essential element in the practice of all aspects of acoustics. Signal processing algorithms enable acousticians to separate signals from noise, to perform automatic speech recognition, or to compress information for more efficient storage or transmission. Signal processing concepts are the building blocks used to construct models of speech and hearing. Now, in the 21st century, all signal processing is effectively digital signal processing. Widespread access to high-speed processing, massive memory, and inexpensive software make signal processing procedures of enormous sophistication and power available to anyone who wants to use them. Because advanced signal processing is now accessible to everybody, there is a need for primers that introduce basic mathematical concepts that underlie the digital algorithms. The present handbook chapter is intended to serve such a purpose.

  19. Software for Acoustic Rendering

    NASA Technical Reports Server (NTRS)

    Miller, Joel D.

    2003-01-01

    SLAB is a software system that can be run on a personal computer to simulate an acoustic environment in real time. SLAB was developed to enable computational experimentation in which one can exert low-level control over a variety of signal-processing parameters, related to spatialization, for conducting psychoacoustic studies. Among the parameters that can be manipulated are the number and position of reflections, the fidelity (that is, the number of taps in finite-impulse-response filters), the system latency, and the update rate of the filters. Another goal in the development of SLAB was to provide an inexpensive means of dynamic synthesis of virtual audio over headphones, without need for special-purpose signal-processing hardware. SLAB has a modular, object-oriented design that affords the flexibility and extensibility needed to accommodate a variety of computational experiments and signal-flow structures. SLAB s spatial renderer has a fixed signal-flow architecture corresponding to a set of parallel signal paths from each source to a listener. This fixed architecture can be regarded as a compromise that optimizes efficiency at the expense of complete flexibility. Such a compromise is necessary, given the design goal of enabling computational psychoacoustic experimentation on inexpensive personal computers.

  20. Ion acoustic traveling waves

    NASA Astrophysics Data System (ADS)

    Webb, G. M.; Burrows, R. H.; Ao, X.; Zank, G. P.; Zank

    2014-04-01

    Models for traveling waves in multi-fluid plasmas give essential insight into fully nonlinear wave structures in plasmas, not readily available from either numerical simulations or from weakly nonlinear wave theories. We illustrate these ideas using one of the simplest models of an electron-proton multi-fluid plasma for the case where there is no magnetic field or a constant normal magnetic field present. We show that the traveling waves can be reduced to a single first-order differential equation governing the dynamics. We also show that the equations admit a multi-symplectic Hamiltonian formulation in which both the space and time variables can act as the evolution variable. An integral equation useful for calculating adiabatic, electrostatic solitary wave signatures for multi-fluid plasmas with arbitrary mass ratios is presented. The integral equation arises naturally from a fluid dynamics approach for a two fluid plasma, with a given mass ratio of the two species (e.g. the plasma could be an electron-proton or an electron-positron plasma). Besides its intrinsic interest, the integral equation solution provides a useful analytical test for numerical codes that include a proton-electron mass ratio as a fundamental constant, such as for particle in cell (PIC) codes. The integral equation is used to delineate the physical characteristics of ion acoustic traveling waves consisting of hot electron and cold proton fluids.

  1. Acoustic ground impedance meter

    NASA Technical Reports Server (NTRS)

    Zuckerwar, A. J.

    1981-01-01

    A compact, portable instrument was developed to measure the acoustic impedance of the ground, or other surfaces, by direct pressure-volume velocity measurement. A Helmholz resonator, constructed of heavy-walled stainless steel but open at the bottom, is positioned over the surface having the unknown impedance. The sound source, a cam-driven piston of known stroke and thus known volume velocity, is located in the neck of the resonator. The cam speed is a variable up to a maximum 3600 rpm. The sound pressure at the test surface is measured by means of a microphone flush-mounted in the wall of the chamber. An optical monitor of the piston displacement permits measurement of the phase angle between the volume velocity and the sound pressure, from which the real and imaginary parts of the impedance can be evaluated. Measurements using a 5-lobed cam can be made up to 300 Hz. Detailed design criteria and results on a soil sample are presented.

  2. Covert underwater acoustic communications.

    PubMed

    Ling, Jun; He, Hao; Li, Jian; Roberts, William; Stoica, Petre

    2010-11-01

    Low probability of detection (LPD) communications are conducted at a low received signal-to-noise ratio (SNR) to deter eavesdroppers to sense the presence of the transmitted signal. Successful detection at intended receiver heavily relies on the processing gain achieved by employing the direct-sequence spread-spectrum (DSSS) technique. For scenarios that lack a sufficiently low SNR to maintain LPD, another metric, referred to as low probability of interception (LPI), is of interest to protect the privacy of the transmitted information. If covert communications take place in underwater acoustic (UWA) environments, then additional challenges are present. The time-varying nature of the UWA channel prevents the employment of a long spreading waveform. Furthermore, UWA environments are frequency-selective channels with long memory, which imposes challenges to the design of the spreading waveform. In this paper, a covert UWA communication system that adopts the DSSS technique and a coherent RAKE receiver is investigated. Emphasis is placed on the design of a spreading waveform that not only accounts for the transceiver structure and frequency-selective nature of the UWA channel, but also possesses a superior LPI. The proposed techniques are evaluated using both simulated and SPACE'08 in-water experimental data.

  3. Passive Acoustic Vessel Localization

    NASA Astrophysics Data System (ADS)

    Suwal, Pasang Sherpa

    This thesis investigates the development of a low-cost passive acoustic system for localizing moving vessels to monitor areas where human activities such as fishing, snorkeling and poaching are restricted. The system uses several off-the-shelf sensors with unsynchronized clocks where the Time Difference of Arrival (TDOA) or time delay is extracted by cross-correlation of the signal between paired sensors. The cross-correlation function uses phase correlation or Phase Transform (PHAT) which whitens the cross-spectrum in order to de-emphasize dominant frequency components. Using the locations of pairs of sensors as foci, hyperbolic equations can be defined using the time delay between them. With three or more sensors, multiple hyperbolic functions can be calculated which intersect at a unique point: the boat's location. It is also found that increasing separation distances between sensors decreased the correlation between the signals. However larger separation distances have better localization capability than with small distances. Experimental results from the Columbia and Willamette Rivers are presented to demonstrate performance.

  4. Surface acoustic wave microfluidics.

    PubMed

    Ding, Xiaoyun; Li, Peng; Lin, Sz-Chin Steven; Stratton, Zackary S; Nama, Nitesh; Guo, Feng; Slotcavage, Daniel; Mao, Xiaole; Shi, Jinjie; Costanzo, Francesco; Huang, Tony Jun

    2013-09-21

    The recent introduction of surface acoustic wave (SAW) technology onto lab-on-a-chip platforms has opened a new frontier in microfluidics. The advantages provided by such SAW microfluidics are numerous: simple fabrication, high biocompatibility, fast fluid actuation, versatility, compact and inexpensive devices and accessories, contact-free particle manipulation, and compatibility with other microfluidic components. We believe that these advantages enable SAW microfluidics to play a significant role in a variety of applications in biology, chemistry, engineering and medicine. In this review article, we discuss the theory underpinning SAWs and their interactions with particles and the contacting fluids in which they are suspended. We then review the SAW-enabled microfluidic devices demonstrated to date, starting with devices that accomplish fluid mixing and transport through the use of travelling SAW; we follow that by reviewing the more recent innovations achieved with standing SAW that enable such actions as particle/cell focusing, sorting and patterning. Finally, we look forward and appraise where the discipline of SAW microfluidics could go next.

  5. Acoustics of the Intonarumori

    NASA Astrophysics Data System (ADS)

    Serafin, Stefania

    2005-04-01

    The Intonarumori were a family of musical instruments invented by the Italian futurist composer and painter Luigi Russolo. Each Intonarumori was made of a wooden parallelepiped sound box, inside which a wheel of different sizes and materials was setting into vibration a catgut or metal string. The pitch of the string was varied by using a lever, while the speed of the wheel was controlled by the performer using a crank. At one end of the string there was a drumhead that transmitted vibrations to the speaker. Unfortunately, all the original Intonarumori were destroyed after a fire during World War II. Since then, researchers have tried to understand the sound production mechanism of such instruments, especially by consulting the patents compiled by Russolo or by reading his book ``The art of noise.'' In this paper we describe the acoustics of the Intonarumori. Based on such description, we propose physical models that simulate such instruments. The intonarumori's string is modeled using a one dimensional waveguide, which is excited either by an impact or a friction model. The body of the instrument is modeled using a 3-D rectangular mesh, while the horn is considered as an omnidirectional radiator.

  6. Aquatic Acoustic Metrics Interface

    SciTech Connect

    2012-12-18

    Fishes and marine mammals may suffer a range of potential effects from exposure to intense underwater sound generated by anthropogenic activities such as pile driving, shipping, sonars, and underwater blasting. Several underwater sound recording (USR) devices have been built to acquire samples of the underwater sound generated by anthropogenic activities. Software becomes indispensable for processing and analyzing the audio files recorded by these USRs. The new Aquatic Acoustic Metrics Interface Utility Software (AAMI) is specifically designed for analysis of underwater sound recordings to provide data in metrics that facilitate evaluation of the potential impacts of the sound on aquatic animals. In addition to the basic functions, such as loading and editing audio files recorded by USRs and batch processing of sound files, the software utilizes recording system calibration data to compute important parameters in physical units. The software also facilitates comparison of the noise sound sample metrics with biological measures such as audiograms of the sensitivity of aquatic animals to the sound, integrating various components into a single analytical frame.

  7. Aquatic Acoustic Metrics Interface

    2012-12-18

    Fishes and marine mammals may suffer a range of potential effects from exposure to intense underwater sound generated by anthropogenic activities such as pile driving, shipping, sonars, and underwater blasting. Several underwater sound recording (USR) devices have been built to acquire samples of the underwater sound generated by anthropogenic activities. Software becomes indispensable for processing and analyzing the audio files recorded by these USRs. The new Aquatic Acoustic Metrics Interface Utility Software (AAMI) is specificallymore » designed for analysis of underwater sound recordings to provide data in metrics that facilitate evaluation of the potential impacts of the sound on aquatic animals. In addition to the basic functions, such as loading and editing audio files recorded by USRs and batch processing of sound files, the software utilizes recording system calibration data to compute important parameters in physical units. The software also facilitates comparison of the noise sound sample metrics with biological measures such as audiograms of the sensitivity of aquatic animals to the sound, integrating various components into a single analytical frame.« less

  8. Vaccarin attenuates the human EA.hy926 endothelial cell oxidative stress injury through inhibition of Notch signaling.

    PubMed

    Xie, Fengshan; Cai, Weiwei; Liu, Yanling; Li, Yue; Du, Bin; Feng, Lei; Qiu, Liying

    2015-01-01

    Endothelial cell injury is an essential component of atherosclerosis and hypertension. Atherosclerosis and other macrovascular diseases are the most common complications of diabetes. Vaccarin is a major flavonoid glycoside in Vaccariae semen, and is expected to be useful in the treatment of vascular diseases. The aim of the present study was to evaluate the possible effects of vaccarin in human umbilical vein endothelial cells (EA.hy926) induced by hydrogen peroxide (H2O2) and its underlying mechanism in the prevention and treatment of H2O2 injury. In this study, the EA.hy926 cells were exposed to 250, 500 and 1000 µM H2O2 for 2 and 4 h in the absence or presence of vaccarin, and the cell injury induced by H2O2 was examined via SRB. Cell migratory ability, lactate dehydrogenase (LDH) leakage, malondialdehyde (MDA) levels and decreasing superoxide dismutase (SOD) activity were evaluated by the wound healing assay and corresponding assay kits. Cell apoptosis was detected by flow cytometry with Annexin V-fluorescein isothiocyanate/propidium iodide Apoptosis Detection kit and Hoechst staining. Furthermore, western blot detected the protein expressions of Notch1, Hes1 and caspase-3. Following treatment with H2O2, it was found that H2O2 stimulated cell injury in a dose-dependent manner, including reducing cell viability and cell migratory ability, increasing LDH leakage and MDA levels, and decreasing SOD activity. H2O2 further accelerated cell apoptosis via activation of Notch1 and the downstream molecule Hes1. Preincubation with vaccarin was found to protect EA.hy926 cells from H2O2-induced cell oxidative stress injury, which promoted cell viability and cell migratory ability, inhibited the level of LDH and MDA, but enhanced the activity of SOD. In particular, in addition to downregulation Notch signaling, vaccarin treatments also downregulated caspase-3, a cell apoptotic pathway-related protein. These findings indicated that vaccarin may be able to selectively protect

  9. Methods for reconstructing acoustic quantities based on acoustic pressure measurements.

    PubMed

    Wu, Sean F

    2008-11-01

    This paper presents an overview of the acoustic imaging methods developed over the past three decades that enable one to reconstruct all acoustic quantities based on the acoustic pressure measurements taken around a target source at close distances. One such method that has received the most attention is known as near-field acoustical holography (NAH). The original NAH relies on Fourier transforms that are suitable for a surface containing a level of constant coordinate in a source-free region. Other methods are developed to reconstruct the acoustic quantities in three-dimensional space and on an arbitrary three-dimensional source surface. Note that there is a fine difference between Fourier transform based NAH and other methods that is largely overlooked. The former can offer a wave number spectrum, thus enabling visualization of various structural waves of different wavelengths that travel on the surface of a structure; the latter cannot provide such information, which is critical to acquire an in-depth understanding of the interrelationships between structural vibrations and sound radiation. All these methods are discussed in this paper, their advantages and limitations are compared, and the need for further development to analyze the root causes of noise and vibration problems is discussed.

  10. ACOUSTIC LINERS FOR TURBOFAN ENGINES

    NASA Technical Reports Server (NTRS)

    Minner, G. L.

    1994-01-01

    This program was developed to design acoustic liners for turbofan engines. This program combines results from theoretical models of wave alternation in acoustically treated passages with experimental data from full-scale fan noise suppressors. By including experimentally obtained information, the program accounts for real effects such as wall boundary layers, duct terminations, and sound modal structure. The program has its greatest use in generating a number of design specifications to be used for evaluation of trade-offs. The program combines theoretical and empirical data in designing annular acoustic liners. First an estimate of the noise output of the fan is made based on basic fan aerodynamic design variables. Then, using a target noise spectrum after alternation and the estimated fan noise spectrum, a design spectrum is calculated as their difference. Next, the design spectrum is combined with knowledge of acoustic liner performance and the liner design variables to specify the acoustic design. Details of the liner design are calculated by combining the required acoustic impedance with a mathematical model relating acoustic impedance to the physical structure of the liner. Input to the noise prediction part of the program consists of basic fan operating parameters, distance that the target spectrum is to be measured and the target spectrum. The liner design portion of the program requires the required alternation spectrum, desired values of length to height and several option selection parameters. Output from the noise prediction portion is a noise spectrum consisting of discrete tones and broadband noise. This may be used as input to the liner design portion of the program. The liner design portion of the program produces backing depths, open area ratios, and face plate thicknesses. This program is written in FORTRAN V and has been implemented in batch mode on a UNIVAC 1100 series computer with a central memory requirement of 12K (decimal) of 36 bit words.

  11. PORTABLE ACOUSTIC MONITORING PACKAGE (PAMP)

    SciTech Connect

    John l. Loth; Gary J. Morris; George M. Palmer; Richard Guiler; Deepak Mehra

    2003-07-01

    The 1st generation acoustic monitoring package was designed to detect and analyze weak acoustic signals inside natural gas transmission lines. Besides a microphone it housed a three-inch diameter aerodynamic acoustic signal amplifier to maximize sensitivity to leak induced {Delta}p type signals. The theory and test results of this aerodynamic signal amplifier was described in the master's degree thesis of our Research Assistant Deepak Mehra who is about to graduate. To house such a large three-inch diameter sensor required the use of a steel 300-psi rated 4 inch weld neck flange, which itself weighed already 29 pounds. The completed 1st generation Acoustic Monitoring Package weighed almost 100 pounds. This was too cumbersome to mount in the field, on an access port at a pipeline shut-off valve. Therefore a 2nd generation and truly Portable Acoustic Monitor was built. It incorporated a fully self-contained {Delta}p type signal sensor, rated for line pressures up to 1000 psi with a base weight of only 6 pounds. This is the Rosemont Inc. Model 3051CD-Range 0, software driven sensor, which is believed to have industries best total performance. Its most sensitive unit was purchased with a {Delta}p range from 0 to 3 inch water. This resulted in the herein described 2nd generation: Portable Acoustic Monitoring Package (PAMP) for pipelines up to 1000 psi. Its 32-pound total weight includes an 18-volt battery. Together with a 3 pound laptop with its 4-channel data acquisition card, completes the equipment needed for field acoustic monitoring of natural gas transmission pipelines.

  12. Acoustic communication in plant-animal interactions.

    PubMed

    Schöner, Michael G; Simon, Ralph; Schöner, Caroline R

    2016-08-01

    Acoustic communication is widespread and well-studied in animals but has been neglected in other organisms such as plants. However, there is growing evidence for acoustic communication in plant-animal interactions. While knowledge about active acoustic signalling in plants (i.e. active sound production) is still in its infancy, research on passive acoustic signalling (i.e. reflection of animal sounds) revealed that bat-dependent plants have adapted to the bats' echolocation systems by providing acoustic reflectors to attract their animal partners. Understanding the proximate mechanisms and ultimate causes of acoustic communication will shed light on an underestimated dimension of information transfer between plants and animals. PMID:27423052

  13. Reflective echo tomographic imaging using acoustic beams

    DOEpatents

    Kisner, Roger; Santos-Villalobos, Hector J

    2014-11-25

    An inspection system includes a plurality of acoustic beamformers, where each of the plurality of acoustic beamformers including a plurality of acoustic transmitter elements. The system also includes at least one controller configured for causing each of the plurality of acoustic beamformers to generate an acoustic beam directed to a point in a volume of interest during a first time. Based on a reflected wave intensity detected at a plurality of acoustic receiver elements, an image of the volume of interest can be generated.

  14. Acoustic communication in plant-animal interactions.

    PubMed

    Schöner, Michael G; Simon, Ralph; Schöner, Caroline R

    2016-08-01

    Acoustic communication is widespread and well-studied in animals but has been neglected in other organisms such as plants. However, there is growing evidence for acoustic communication in plant-animal interactions. While knowledge about active acoustic signalling in plants (i.e. active sound production) is still in its infancy, research on passive acoustic signalling (i.e. reflection of animal sounds) revealed that bat-dependent plants have adapted to the bats' echolocation systems by providing acoustic reflectors to attract their animal partners. Understanding the proximate mechanisms and ultimate causes of acoustic communication will shed light on an underestimated dimension of information transfer between plants and animals.

  15. [Unconscious Acoustical Stimuli Effects on Event-related Potentials in Humans].

    PubMed

    Kopeikina, E A; Choroshich, V V; Aleksandrov, A Y; Ivanova, V Y

    2015-01-01

    Unconscious perception essentially affects human behavior. The main results in this area obtained in experiments with visual stimuli. However, the acoustical stimuli play not less important role in behavior. The main idea of this paper is the electroencephalographic investigation of unconscious acoustical stimulation effects on electro-physiological activity of the brain. For this purpose, the event-related potentials were acquired under unconscious stimulus priming paradigm. The one syllable, three letter length, Russian words and pseudo-words with single letter substitution were used as primes and targets. As a result, we find out that repetition and alternative priming similarly affects the event-related potential's component with 200 ms latency after target application in frontal parietal and temporal areas. Under alternative priming the direction of potential amplitude modification nearby 400 ms was altered for word and semi-word targets. Alternative priming reliably increase ERP's amplitude in 400 ms locality with pseudo-word targets and decrease it under word targets. Taking into account, that all participants were unable to distinguish the applied prime stimuli, we can assume that the event-related potential changes evoked by unconscious perception of acoustical stimuli. The ERP amplitude dynamics revealed in current investigation demonstrate the opportunity of subliminal acoustical stimuli to modulate the electrical activity evoked by verbal acoustical stimulation. PMID:26237945

  16. Mars Acoustic Anemometer

    NASA Astrophysics Data System (ADS)

    Banfield, D. J.

    2012-12-01

    We have developed a very high performance anemometer (wind gauge) for use at Mars. This instrument has great scientific as well as strategic reasons to be included on all future missions to the surface of Mars. We will discuss why we set out to develop this instrument, as well as why the previous wind sensors for Mars are insufficient to meet the scientific and strategic needs at Mars. We will also discuss how the instrument works, and how it differs from terrestrial counterparts. Additionally, we will discuss the current status of the instrument. Measuring winds at Mars is important to better understand the atmospheric circulation at Mars, as well as exchange between the surface and atmosphere. The main conduit of transport of water, and hence its current stability at any particular location on Mars is controlled by these atmospheric motions and the exchange between surface and atmosphere. Mars' large-scale winds are moderately well understood from orbital observations, but the interaction with the surface can only be addressed adequately in situ. Previous anemometers have been 2-D (with the exception of REMS on MSL) and slow response (typically <1Hz), and relatively low sensitivity/accuracy (>1 m/s). Our instrument is capable of fully 3-D measurements, with fast response (>20 Hz) and great sensitivity/accuracy (~3 cm/s). This significant step forward in performance is important for the surface-atmosphere exchanges of heat, momentum and volatiles. In particular, our instrument could directly measure the heat and momentum fluxes between surface and atmosphere using eddy-flux techniques proven terrestrially. When combined with a fast response volatile analysis instrument (e.g., a TLS) we can also measure eddy fluxes of volatile transport. Such a study would be nearly impossible to carry out with preceding anemometers sent to Mars with insufficient response time and sensitivity to adequately sample the turbulent eddies. Additionally, our instrument, using acoustics

  17. Acoustic constituents of prosodic typology

    NASA Astrophysics Data System (ADS)

    Komatsu, Masahiko

    Different languages sound different, and considerable part of it derives from the typological difference of prosody. Although such difference is often referred to as lexical accent types (stress accent, pitch accent, and tone; e.g. English, Japanese, and Chinese respectively) and rhythm types (stress-, syllable-, and mora-timed rhythms; e.g. English, Spanish, and Japanese respectively), it is unclear whether these types are determined in terms of acoustic properties, The thesis intends to provide a potential basis for the description of prosody in terms of acoustics. It argues for the hypothesis that the source component of the source-filter model (acoustic features) approximately corresponds to prosody (linguistic features) through several experimental-phonetic studies. The study consists of four parts. (1) Preliminary experiment: Perceptual language identification tests were performed using English and Japanese speech samples whose frequency spectral information (i.e. non-source component) is heavily reduced. The results indicated that humans can discriminate languages with such signals. (2) Discussion on the linguistic information that the source component contains: This part constitutes the foundation of the argument of the thesis. Perception tests of consonants with the source signal indicated that the source component carries the information on broad categories of phonemes that contributes to the creation of rhythm. (3) Acoustic analysis: The speech samples of Chinese, English, Japanese, and Spanish, differing in prosodic types, were analyzed. These languages showed difference in acoustic characteristics of the source component. (4) Perceptual experiment: A language identification test for the above four languages was performed using the source signal with its acoustic features parameterized. It revealed that humans can discriminate prosodic types solely with the source features and that the discrimination is easier as acoustic information increases. The

  18. Sonification of acoustic emission data

    NASA Astrophysics Data System (ADS)

    Raith, Manuel; Große, Christian

    2014-05-01

    While loading different specimens, acoustic emissions appear due to micro crack formation or friction of already existing crack edges. These acoustic emissions can be recorded using suitable ultrasonic transducers and transient recorders. The analysis of acoustic emissions can be used to investigate the mechanical behavior of different specimens under load. Our working group has undertaken several experiments, monitored with acoustic emission techniques. Different materials such as natural stone, concrete, wood, steel, carbon composites and bone were investigated. Also the experimental setup has been varied. Fire-spalling experiments on ultrahigh performance concrete and pullout experiments on bonded anchors have been carried out. Furthermore uniaxial compression tests on natural stone and animal bone had been conducted. The analysis tools include not only the counting of events but the analysis of full waveforms. Powerful localization algorithms and automatic onset picking techniques (based on Akaikes Information Criterion) were established to handle the huge amount of data. Up to several thousand events were recorded during experiments of a few minutes. More sophisticated techniques like moment tensor inversion have been established on this relatively small scale as well. Problems are related to the amount of data but also to signal-to-noise quality, boundary conditions (reflections) sensor characteristics and unknown and changing Greens functions of the media. Some of the acoustic emissions recorded during these experiments had been transferred into audio range. The transformation into the audio range was done using Matlab. It is the aim of the sonification to establish a tool that is on one hand able to help controlling the experiment in-situ and probably adjust the load parameters according to the number and intensity of the acoustic emissions. On the other hand sonification can help to improve the understanding of acoustic emission techniques for training

  19. Virtual acoustic displays

    NASA Technical Reports Server (NTRS)

    Wenzel, Elizabeth M.

    1991-01-01

    A 3D auditory display can potentially enhance information transfer by combining directional and iconic information in a quite naturalistic representation of dynamic objects in the interface. Another aspect of auditory spatial clues is that, in conjunction with other modalities, it can act as a potentiator of information in the display. For example, visual and auditory cues together can reinforce the information content of the display and provide a greater sense of presence or realism in a manner not readily achievable by either modality alone. This phenomenon will be particularly useful in telepresence applications, such as advanced teleconferencing environments, shared electronic workspaces, and monitoring telerobotic activities in remote or hazardous situations. Thus, the combination of direct spatial cues with good principles of iconic design could provide an extremely powerful and information-rich display which is also quite easy to use. An alternative approach, recently developed at ARC, generates externalized, 3D sound cues over headphones in realtime using digital signal processing. Here, the synthesis technique involves the digital generation of stimuli using Head-Related Transfer Functions (HRTF's) measured in the two ear-canals of individual subjects. Other similar approaches include an analog system developed by Loomis, et. al., (1990) and digital systems which make use of transforms derived from normative mannikins and simulations of room acoustics. Such an interface also requires the careful psychophysical evaluation of listener's ability to accurately localize the virtual or synthetic sound sources. From an applied standpoint, measurement of each potential listener's HRTF's may not be possible in practice. For experienced listeners, localization performance was only slightly degraded compared to a subject's inherent ability. Alternatively, even inexperienced listeners may be able to adapt to a particular set of HRTF's as long as they provide adequate

  20. Sensory contribution to vocal emotion deficit in Parkinson's disease after subthalamic stimulation.

    PubMed

    Péron, Julie; Cekic, Sezen; Haegelen, Claire; Sauleau, Paul; Patel, Sona; Drapier, Dominique; Vérin, Marc; Grandjean, Didier

    2015-02-01

    Subthalamic nucleus (STN) deep brain stimulation in Parkinson's disease induces modifications in the recognition of emotion from voices (or emotional prosody). Nevertheless, the underlying mechanisms are still only poorly understood, and the role of acoustic features in these deficits has yet to be elucidated. Our aim was to identify the influence of acoustic features on changes in emotional prosody recognition following STN stimulation in Parkinson's disease. To this end, we analysed the performances of patients on vocal emotion recognition in pre-versus post-operative groups, as well as of matched controls, entering the acoustic features of the stimuli into our statistical models. Analyses revealed that the post-operative biased ratings on the Fear scale when patients listened to happy stimuli were correlated with loudness, while the biased ratings on the Sadness scale when they listened to happiness were correlated with fundamental frequency (F0). Furthermore, disturbed ratings on the Happiness scale when the post-operative patients listened to sadness were found to be correlated with F0. These results suggest that inadequate use of acoustic features following subthalamic stimulation has a significant impact on emotional prosody recognition in patients with Parkinson's disease, affecting the extraction and integration of acoustic cues during emotion perception.