A comparative analysis of colour preferences in temperate and tropical social bees

Science.gov (United States)

Balamurali, G. S.; Nicholls, Elizabeth; Somanathan, Hema; Hempel de Ibarra, Natalie

2018-02-01

The spontaneous occurrence of colour preferences without learning has been demonstrated in several insect species; however, the underlying mechanisms are still not understood. Here, we use a comparative approach to investigate spontaneous and learned colour preferences in foraging bees of two tropical and one temperate species. We hypothesised that tropical bees utilise different sets of plants and therefore might differ in their spontaneous colour preferences. We tested colour-naive bees and foragers from colonies that had been enclosed in large flight cages for a long time. Bees were shortly trained with triplets of neutral, UV-grey stimuli placed randomly at eight locations on a black training disk to induce foraging motivation. During unrewarded tests, the bees' responses to eight colours were video-recorded. Bees explored all colours and displayed an overall preference for colours dominated by long or short wavelengths, rather than a single colour stimulus. Naive Apis cerana and Bombus terrestris showed similar choices. Both inspected long-wavelength stimuli more than short-wavelength stimuli, whilst responses of the tropical stingless bee Tetragonula iridipennis differed, suggesting that resource partitioning could be a determinant of spontaneous colour preferences. Reward on an unsaturated yellow colour shifted the bees' preference curves as predicted, which is in line with previous findings that brief colour experience overrides the expression of spontaneous preferences. We conclude that rather than determining foraging behaviour in inflexible ways, spontaneous colour preferences vary depending on experimental settings and reflect potential biases in mechanisms of learning and decision-making in pollinating insects.

A comparative analysis of colour preferences in temperate and tropical social bees.

Science.gov (United States)

Balamurali, G S; Nicholls, Elizabeth; Somanathan, Hema; Hempel de Ibarra, Natalie

2018-01-02

The spontaneous occurrence of colour preferences without learning has been demonstrated in several insect species; however, the underlying mechanisms are still not understood. Here, we use a comparative approach to investigate spontaneous and learned colour preferences in foraging bees of two tropical and one temperate species. We hypothesised that tropical bees utilise different sets of plants and therefore might differ in their spontaneous colour preferences. We tested colour-naive bees and foragers from colonies that had been enclosed in large flight cages for a long time. Bees were shortly trained with triplets of neutral, UV-grey stimuli placed randomly at eight locations on a black training disk to induce foraging motivation. During unrewarded tests, the bees' responses to eight colours were video-recorded. Bees explored all colours and displayed an overall preference for colours dominated by long or short wavelengths, rather than a single colour stimulus. Naive Apis cerana and Bombus terrestris showed similar choices. Both inspected long-wavelength stimuli more than short-wavelength stimuli, whilst responses of the tropical stingless bee Tetragonula iridipennis differed, suggesting that resource partitioning could be a determinant of spontaneous colour preferences. Reward on an unsaturated yellow colour shifted the bees' preference curves as predicted, which is in line with previous findings that brief colour experience overrides the expression of spontaneous preferences. We conclude that rather than determining foraging behaviour in inflexible ways, spontaneous colour preferences vary depending on experimental settings and reflect potential biases in mechanisms of learning and decision-making in pollinating insects.

Subjective preference evaluation of sound fields by performing singers

Science.gov (United States)

Noson, Dennis

2003-08-01

A model of the auditory process is proposed for performing singers, which incorporates the added signal from bone conduction, as well as the psychological distance for subjective preference of the performer from the acoustic sound field of the stage. The explanatory power of previous scientific studies of vocal stage acoustics has been limited by a lack of an underlying theory of performer preference. Ando's theory, using the autocorrelation function (ACF) for parametrizing temporal factors, was applied to interpretation of singer sound field preference determined by the pair comparison method. Melisma style singing (no lyrics) was shown to increase the preferred delay time of reflections from a mean of 14 ms with lyrics to 23 ms without (pThesis advisor: Yoichi Ando Copies of this thesis are available from the author by inquiry at BRC Acoustics, 1741 First Avenue South, Seattle, WA 98134 USA. E-mail address: dnoson@brcacoustics.com

Towards a social functional account of laughter: Acoustic features convey reward, affiliation, and dominance.

Science.gov (United States)

Wood, Adrienne; Martin, Jared; Niedenthal, Paula

2017-01-01

Recent work has identified the physical features of smiles that accomplish three tasks fundamental to human social living: rewarding behavior, establishing and managing affiliative bonds, and negotiating social status. The current work extends the social functional account to laughter. Participants (N = 762) rated the degree to which reward, affiliation, or dominance (between-subjects) was conveyed by 400 laughter samples acquired from a commercial sound effects website. Inclusion of a fourth rating dimension, spontaneity, allowed us to situate the current approach in the context of existing laughter research, which emphasizes the distinction between spontaneous and volitional laughter. We used 11 acoustic properties extracted from the laugh samples to predict participants' ratings. Actor sex moderated, and sometimes even reversed, the relation between acoustics and participants' judgments. Spontaneous laughter appears to serve the reward function in the current framework, as similar acoustic properties guided perceiver judgments of spontaneity and reward: reduced voicing and increased pitch, increased duration for female actors, and increased pitch slope, center of gravity, first formant, and noisiness for male actors. Affiliation ratings diverged from reward in their sex-dependent relationship to intensity and, for females, reduced pitch range and raised second formant. Dominance displayed the most distinct pattern of acoustic predictors, including increased pitch range, reduced second formant in females, and decreased pitch variability in males. We relate the current findings to existing findings on laughter and human and non-human vocalizations, concluding laughter can signal much more that felt or faked amusement.

On Architectural Acoustics Design using Computer Simulation

DEFF Research Database (Denmark)

Schmidt, Anne Marie Due; Kirkegaard, Poul Henning

2004-01-01

The acoustical quality of a given building, or space within the building, is highly dependent on the architectural design. Architectural acoustics design has in the past been based on simple design rules. However, with a growing complexity in the architectural acoustic and the emergence of potent...... room acoustic simulation programs it is now possible to subjectively analyze and evaluate acoustic properties prior to the actual construction of a facility. With the right tools applied, the acoustic design can become an integrated part of the architectural design process. The aim of the present paper...... this information is discussed. The conclusion of the paper is that the application of acoustical simulation programs is most beneficial in the last of three phases but that an application of the program to the two first phases would be preferable and possible with an improvement of the interface of the program....

Dynamics of beam-driven Langmuir and ion-acoustic waves including electrostatic decay

International Nuclear Information System (INIS)

Li, B.; Willes, A.J.; Robinson, P.A.; Cairns, I.H.

2003-01-01

The evolution of Langmuir waves and ion-acoustic waves stimulated by a hot electron beam in an initially homogeneous plasma is investigated numerically in time, position, and wave number space. Quasilinear interactions between the beam particles and Langmuir waves, nonlinear interactions between the Langmuir and ion-acoustic waves through Langmuir decay processes, and spontaneous emission are taken into account in the kinetic theory employed. For illustrative parameters of those in the solar wind near 1 a.u., nonlinear Langmuir decays are observed to transfer the beam-driven Langmuir waves rapidly out of resonance. The scattered Langmuir waves then undergo further decays, moving sequentially toward small wave numbers, until decay is kinematically prohibited. The main features of the evolution of Langmuir and ion-acoustic waves are spatially inhomogeneous. The scattered Langmuir spectra increase and eventually reach or exceed the beam-driven Langmuir spectra at a given spatial location (except in regions where further decays proceed). The ion-acoustic waves are relatively weak and subject to damping at the later stages of their evolution. The development of fine structures in the product Langmuir and ion-acoustic waves are observed, due to depletion of their energy by decay and dominant damping effects, respectively. The propagation of the beam is essentially unaffected by the operation of the decay process. The decay process is thus slaved to the primary beam-plasma evolution, as assumed in previous studies. A variation of the ratio of electron temperature to ion temperature is found to affect not only the ion-acoustic wave levels through effects on the damping rate, but also the dynamics of decay via effects on the decay rate. The latter was not addressed in previous studies. Furthermore, spontaneous emission of ion-acoustic waves is found to affect the dynamics of decay, thus its inclusion is necessary to correctly model the Langmuir and ion-acoustic spectra

Spontaneous expression of magnetic compass orientation in an epigeic rodent: the bank vole, Clethrionomys glareolus

Science.gov (United States)

Oliveriusová, Ludmila; Němec, Pavel; Pavelková, Zuzana; Sedláček, František

2014-07-01

Magnetoreception has been convincingly demonstrated in only a few mammalian species. Among rodents, magnetic compass orientation has been documented in four species of subterranean mole rats and two epigeic (i.e. active above ground) species—the Siberian hamster and the C57BL/6J mouse. The mole rats use the magnetic field azimuth to determine compass heading; their directional preference is spontaneous and unimodal, and their magnetic compass is magnetite-mediated. By contrast, the primary component of orientation response is learned in the hamster and the mouse, but both species also exhibit a weak spontaneous bimodal preference in the natural magnetic field. To determine whether the magnetic compass of wild epigeic rodents features the same functional properties as that of laboratory rodents, we investigated magnetic compass orientation in the bank vole Clethrionomys glareolus (Cricetidae, Rodentia). The voles exhibited a robust spontaneous bimodal directional preference, i.e. built nests and slept preferentially along the north-south axis, and deflected their directional preference according to a shift in the direction of magnetic north, clearly indicating that they were deriving directional information from the magnetic field. Thus, bimodal, axially symmetrical directional choice seems to be a common feature shared by epigeic rodents. However, spontaneous directional preference in the bank vole appeared to be more pronounced than that reported in the hamster and the mouse. These findings suggest that bank voles are well suited for future studies investigating the adaptive significance and mechanisms of magnetic orientation in epigeic rodents.

Great apes prefer cooked food.

Science.gov (United States)

Wobber, Victoria; Hare, Brian; Wrangham, Richard

2008-08-01

The cooking hypothesis proposes that a diet of cooked food was responsible for diverse morphological and behavioral changes in human evolution. However, it does not predict whether a preference for cooked food evolved before or after the control of fire. This question is important because the greater the preference shown by a raw-food-eating hominid for the properties present in cooked food, the more easily cooking should have been adopted following the control of fire. Here we use great apes to model food preferences by Paleolithic hominids. We conducted preference tests with various plant and animal foods to determine whether great apes prefer food items raw or cooked. We found that several populations of captive apes tended to prefer their food cooked, though with important exceptions. These results suggest that Paleolithic hominids would likewise have spontaneously preferred cooked food to raw, exapting a pre-existing preference for high-quality, easily chewed foods onto these cooked items. The results, therefore, challenge the hypothesis that the control of fire preceded cooking by a significant period.

Trends in preference, programming and design of concert halls for symphonic music

DEFF Research Database (Denmark)

Gade, Anders Christian

2008-01-01

This paper discusses the evolution in taste regarding concert hall acoustics and how this can be reflected in the new halls being built today. The clients' and listener's preferences are not only based on listening in existing halls; but also on listening to reproduced music recorded with microph......This paper discusses the evolution in taste regarding concert hall acoustics and how this can be reflected in the new halls being built today. The clients' and listener's preferences are not only based on listening in existing halls; but also on listening to reproduced music recorded...

Neural correlates of the affective properties of spontaneous and volitional laughter types.

Science.gov (United States)

Lavan, Nadine; Rankin, Georgia; Lorking, Nicole; Scott, Sophie; McGettigan, Carolyn

2017-01-27

Previous investigations of vocal expressions of emotion have identified acoustic and perceptual distinctions between expressions of different emotion categories, and between spontaneous and volitional (or acted) variants of a given category. Recent work on laughter has identified relationships between acoustic properties of laughs and their perceived affective properties (arousal and valence) that are similar across spontaneous and volitional types (Bryant & Aktipis, 2014; Lavan et al., 2016). In the current study, we explored the neural correlates of such relationships by measuring modulations of the BOLD response in the presence of itemwise variability in the subjective affective properties of spontaneous and volitional laughter. Across all laughs, and within spontaneous and volitional sets, we consistently observed linear increases in the response of bilateral auditory cortices (including Heschl's gyrus and superior temporal gyrus [STG]) associated with higher ratings of perceived arousal, valence and authenticity. Areas in the anterior medial prefrontal cortex (amPFC) showed negative linear correlations with valence and authenticity ratings across the full set of spontaneous and volitional laughs; in line with previous research (McGettigan et al., 2015; Szameitat et al., 2010), we suggest that this reflects increased engagement of these regions in response to laughter of greater social ambiguity. Strikingly, an investigation of higher-order relationships between the entire laughter set and the neural response revealed a positive quadratic profile of the BOLD response in right-dominant STG (extending onto the dorsal bank of the STS), where this region responded most strongly to laughs rated at the extremes of the authenticity scale. While previous studies claimed a role for right STG in bipolar representation of emotional valence, we instead argue that this may in fact exhibit a relatively categorical response to emotional signals, whether positive or negative

The lipid-sensor candidates CD36 and GPR120 are differentially regulated by dietary lipids in mouse taste buds: impact on spontaneous fat preference.

Directory of Open Access Journals (Sweden)

Céline Martin

Full Text Available BACKGROUND: Recent studies in rodents and humans suggest that the chemoreception of long-chain fatty acids (LCFA in oral cavity is involved in the spontaneous preference for fatty foods and might contribute to the obesity risk. CD36 and GPR120 are LCFA receptors identified in rodent taste bud cells. The fact that CD36 or GPR120 gene inactivation leads to a decrease in the preference for lipids raises the question of the respective role(s played by these gustatory lipid-sensor candidates. METHODOLOGY/PRINCIPAL FINDINGS: Using a combination of biochemical, nutritional and behavioural studies in wild-type, CD36(+/-and CD36(-/- mice, it was found that: 1° CD36 and GPR120 display different diurnal rhythms in the gustatory circumvallate papillae, CD36 mRNA levels being down-regulated during the dark period in contrast to GPR120, 2° this change is due to food intake and strictly dependent of the presence of lipids in the diet, 3° CD36 protein levels are also rapidly but transiently decreased by the food intake, a two-fold drop in CD36 protein levels being found 1 h after refeeding, followed by a progressive return to the pre-prandial values, 4° this down-regulation, which has a post-transcriptional origin, seems sufficient to alter the spontaneous fat preference, independently to change in the GPR120 gene expression. CONCLUSIONS/SIGNIFICANCE: In contrast to GPR120, CD36 appears to be a food-sensitive lipid sensor in the gustatory circumvallate papillae. Lipid-mediated change in lingual CD36 expression might modulate the motivation for fat during a meal, initially high and then gradually decreasing secondary to the food intake. This short-term lipid-mediated effect is reminiscent of sensory-specific satiety. These findings, which highlight the role played by CD36 in the oro-sensory perception of dietary lipids, raise the possibility of novel pharmacological strategies to modify attraction for fatty foods and decrease obesity risks.

Rhythm perturbations in acoustically paced treadmill walking after stroke.

Science.gov (United States)

Roerdink, Melvyn; Lamoth, Claudine J C; van Kordelaar, Joost; Elich, Peter; Konijnenbelt, Manin; Kwakkel, Gert; Beek, Peter J

2009-09-01

In rehabilitation, acoustic rhythms are often used to improve gait after stroke. Acoustic cueing may enhance gait coordination by creating a stable coupling between heel strikes and metronome beats and provide a means to train the adaptability of gait coordination to environmental changes, as required in everyday life ambulation. To examine the stability and adaptability of auditory-motor synchronization in acoustically paced treadmill walking in stroke patients. Eleven stroke patients and 10 healthy controls walked on a treadmill at preferred speed and cadence under no metronome, single-metronome (pacing only paretic or nonparetic steps), and double-metronome (pacing both footfalls) conditions. The stability of auditory-motor synchronization was quantified by the variability of the phase relation between footfalls and beats. In a separate session, the acoustic rhythms were perturbed and adaptations to restore auditory-motor synchronization were quantified. For both groups, auditory-motor synchronization was more stable for double-metronome than single-metronome conditions, with stroke patients exhibiting an overall weaker coupling of footfalls to metronome beats than controls. The recovery characteristics following rhythm perturbations corroborated the stability findings and further revealed that stroke patients had difficulty in accelerating their steps and instead preferred a slower-step response to restore synchronization. In gait rehabilitation practice, the use of acoustic rhythms may be more effective when both footfalls are paced. In addition, rhythm perturbations during acoustically paced treadmill walking may not only be employed to evaluate the stability of auditory-motor synchronization but also have promising implications for evaluation and training of gait adaptations in neurorehabilitation practice.

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

Energy Technology Data Exchange (ETDEWEB)

Gardner, E.A.; Apfel, R.E. (Yale Univ., New Haven, CT (United States). 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.

Acoustic-wave sensor for ambient monitoring of a photoresist-stripping agent

Science.gov (United States)

Pfeifer, K.B.; Hoyt, A.E.; Frye, G.C.

1998-08-18

The acoustic-wave sensor is disclosed. The acoustic-wave sensor is designed for ambient or vapor-phase monitoring of a photoresist-stripping agent such as N-methylpyrrolidinone (NMP), ethoxyethylpropionate (EEP) or the like. The acoustic-wave sensor comprises an acoustic-wave device such as a surface-acoustic-wave (SAW) device, a flexural-plate-wave (FPW) device, an acoustic-plate-mode (APM) device, or a thickness-shear-mode (TSM) device (also termed a quartz crystal microbalance or QCM) having a sensing region on a surface thereof. The sensing region includes a sensing film for sorbing a quantity of the photoresist-stripping agent, thereby altering or shifting a frequency of oscillation of an acoustic wave propagating through the sensing region for indicating an ambient concentration of the agent. According to preferred embodiments of the invention, the acoustic-wave device is a SAW device; and the sensing film comprises poly(vinylacetate), poly(N-vinylpyrrolidinone), or poly(vinylphenol). 3 figs.

Acoustic analysis after radiotherapy in T1 vocal cord carcinoma: a new approach to the analysis of voice quality

International Nuclear Information System (INIS)

Rovirosa, Angeles; Martinez-Celdran, Eugenio; Ortega, Alicia; Ascaso, Carlos; Abellana, Rosa; Velasco, Mercedes; Bonet, Montserrat; Herrera, Carmen; Casas, Francesc; Francisco, Rosa Maria; Arenas, Meritxell; Hernandez, Victor; Sanchez-Reyes, Alberto; Leon, Concha; Traserra, Jordi; Biete, Albert

2000-01-01

Purpose: The study of acoustic voice parameters (fundamental frequency, jitter, shimmer, and harmonics-to-noise ratio) in extended vowel production, oral reading of a standard paragraph, spontaneous speech and a song in irradiated patients for Tis-T1 vocal cord carcinoma. Methods and Materials: Eighteen male patients irradiated for Tis-T1 vocal cord carcinoma and a control group of 31 nonirradiated subjects of the same age were included in a study of acoustic voice analysis. The control group had been rigorously selected for voice quality and the irradiated group had previous history of smoking in two-thirds of the cases and a vocal cord biopsy. Radiotherapy patients were treated with a 6MV Linac receiving a total dose of 66 Gy, 2 Gy/day, with median treatment areas of 28 cm 2 . Acoustic voice analysis was performed 1 year after radiotherapy, the voice of patients in extended vowel production, oral reading of a standard paragraph, spontaneous speech, and in a song was tape registered and analyzed by a Kay Elemetric's Computerized Speech Lab (model CSL no. 4300). Fundamental frequency, jitter, shimmer, and harmonics-to-noise ratio were obtained in each case. Mann Whitney analysis was used for statistical tests. Results: The irradiated group presented higher values of fundamental frequency, jitter, shimmer, and harmonics-to-noise ratio. Mann-Whitney analysis showed significant differences for fundamental frequency and jitter in vowel production, oral reading, spontaneous speech, and song. Shimmer only showed differences in vowel production and harmonics-to-noise ratio in oral reading and song. Conclusions: In our study only fundamental frequency and jitter showed significant increased values to the control group in all the acoustic situations. Sustained vowel production showed the worst values of the acoustic parameters in comparison with the other acoustic situations. This study seems to suggest that more work should be done in this field

Drawing versus Writing: The Role of Preference in Regulating Short-Term Affect

Science.gov (United States)

Drake, Jennifer E.; Hodge, Adeline

2015-01-01

In a pilot study we investigated whether the most effective medium for regulating short-term affect depends on one's preference for drawing or writing, and also investigated the emotion regulation strategy (distraction versus expression) spontaneously chosen when drawing and writing. Eighty undergraduates indicated their preference for drawing or…

Flow-induced and acoustically induced vibration experience in operating gas-cooled reactors

International Nuclear Information System (INIS)

Halvers, L.J.

1977-03-01

An overview has been presented of flow-induced and acoustically induced vibration failures that occurred in the past in gas-cooled graphite-moderated reactors, and the importance of this experience for the Gas-Cooled Fast-Breeder Reactor (GCFR) project has been assessed. Until now only failures in CO 2 -cooled reactors have been found. No problems with helium-cooled reactors have been encountered so far. It is shown that most of the failures occurred because flow-induced and acoustically induced dynamic loads were underestimated, while at the same time not enough was known about the influence of environmental parameters on material behavior. All problems encountered were solved. The comparison of the influence of the gas properties on acoustically induced and flow-induced vibration phenomena shows that the interaction between reactor design and the thermodynamic properties of the primary coolant precludes a general preference for either carbon dioxide or helium. The acoustic characteristics of CO 2 and He systems are different, but the difference in dynamic loadings due to the use of one rather than the other remains difficult to predict. A slight preference for helium seems, however, to be justified

Spontaneous high-gamma band activity reflects functional organization of auditory cortex in the awake macaque.

Science.gov (United States)

Fukushima, Makoto; Saunders, Richard C; Leopold, David A; Mishkin, Mortimer; Averbeck, Bruno B

2012-06-07

In the absence of sensory stimuli, spontaneous activity in the brain has been shown to exhibit organization at multiple spatiotemporal scales. In the macaque auditory cortex, responses to acoustic stimuli are tonotopically organized within multiple, adjacent frequency maps aligned in a caudorostral direction on the supratemporal plane (STP) of the lateral sulcus. Here, we used chronic microelectrocorticography to investigate the correspondence between sensory maps and spontaneous neural fluctuations in the auditory cortex. We first mapped tonotopic organization across 96 electrodes spanning approximately two centimeters along the primary and higher auditory cortex. In separate sessions, we then observed that spontaneous activity at the same sites exhibited spatial covariation that reflected the tonotopic map of the STP. This observation demonstrates a close relationship between functional organization and spontaneous neural activity in the sensory cortex of the awake monkey. Copyright © 2012 Elsevier Inc. All rights reserved.

Dust acoustic waves in a dc glow-discharge plasma

International Nuclear Information System (INIS)

Molotkov, V.I.; Nefedov, A.P.; Torchinskii, V.M.; Fortov, V.E.; Khrapak, A.G.

1999-01-01

The spontaneous excitation of low-frequency oscillations of the macroparticle density in ordered dust structures levitating in standing striations of a dc glow discharge is discovered. It is concluded on the basis of a simplified linear model of an ideal collisionless plasma that the observed instability is caused by the drift motion of ions relative to the dust, which leads to the excitation of dust acoustic oscillations of the plasma

Acoustic properties of TiNiMoFe base alloys

International Nuclear Information System (INIS)

Gyunter, V.Eh.; Chernyshev, V.I.; Chekalkin, T.L.

2000-01-01

The regularity of changing the acoustic properties of the TiNi base alloys in dependence on the alloy composition and impact temperature is studied. It is shown that the oscillations of the TiNiMoFe base alloys within the temperature range of the B2 phase existence and possible appearance of the martensite under the load differ from the traditional materials oscillations. After excitation of spontaneous oscillations within the range of M f ≤ T ≤ M d there exists the area of long-term and low-amplitude low-frequency acoustic oscillations. It is established that free low-frequency oscillations of the TH-10 alloy sample are characterized by the low damping level in the given temperature range [ru

Spontaneous swallow frequency compared with clinical screening in the identification of dysphagia in acute stroke.

Science.gov (United States)

Crary, Michael A; Carnaby, Giselle D; Sia, Isaac

2014-09-01

The aim of this study was to compare spontaneous swallow frequency analysis (SFA) with clinical screening protocols for identification of dysphagia in acute stroke. In all, 62 patients with acute stroke were evaluated for spontaneous swallow frequency rates using a validated acoustic analysis technique. Independent of SFA, these same patients received a routine nurse-administered clinical dysphagia screening as part of standard stroke care. Both screening tools were compared against a validated clinical assessment of dysphagia for acute stroke. In addition, psychometric properties of SFA were compared against published, validated clinical screening protocols. Spontaneous SFA differentiates patients with versus without dysphagia after acute stroke. Using a previously identified cut point based on swallows per minute, spontaneous SFA demonstrated superior ability to identify dysphagia cases compared with a nurse-administered clinical screening tool. In addition, spontaneous SFA demonstrated equal or superior psychometric properties to 4 validated, published clinical dysphagia screening tools. Spontaneous SFA has high potential to identify dysphagia in acute stroke with psychometric properties equal or superior to clinical screening protocols. Copyright © 2014 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Acoustic analysis and mood classification of pain-relieving music.

Science.gov (United States)

Knox, Don; Beveridge, Scott; Mitchell, Laura A; MacDonald, Raymond A R

2011-09-01

Listening to preferred music (that which is chosen by the participant) has been shown to be effective in mitigating the effects of pain when compared to silence and a variety of distraction techniques. The wide range of genre, tempo, and structure in music chosen by participants in studies utilizing experimentally induced pain has led to the assertion that structure does not play a significant role, rather listening to preferred music renders the music "functionally equivalent" as regards its effect upon pain perception. This study addresses this assumption and performs detailed analysis of a selection of music chosen from three pain studies. Music analysis showed significant correlation between timbral and tonal aspects of music and measurements of pain tolerance and perceived pain intensity. Mood classification was performed using a hierarchical Gaussian Mixture Model, which indicated the majority of the chosen music expressed contentment. The results suggest that in addition to personal preference, associations with music and the listening context, emotion expressed by music, as defined by its acoustical content, is important to enhancing emotional engagement with music and therefore enhances the level of pain reduction and tolerance. © 2011 Acoustical Society of America

Active micromixer using surface acoustic wave streaming

Science.gov (United States)

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

2011-05-17

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

Feedback control of acoustic musical instruments: collocated control using physical analogs.

Science.gov (United States)

Berdahl, Edgar; Smith, Julius O; Niemeyer, Günter

2012-01-01

Traditionally, the average professional musician has owned numerous acoustic musical instruments, many of them having distinctive acoustic qualities. However, a modern musician could prefer to have a single musical instrument whose acoustics are programmable by feedback control, where acoustic variables are estimated from sensor measurements in real time and then fed back in order to influence the controlled variables. In this paper, theory is presented that describes stable feedback control of an acoustic musical instrument. The presentation should be accessible to members of the musical acoustics community who may have limited or no experience with feedback control. First, the only control strategy guaranteed to be stable subject to any musical instrument mobility is described: the sensors and actuators must be collocated, and the controller must emulate a physical analog system. Next, the most fundamental feedback controllers and the corresponding physical analog systems are presented. The effects that these controllers have on acoustic musical instruments are described. Finally, practical design challenges are discussed. A proof explains why changing the resonance frequency of a musical resonance requires much more control power than changing the decay time of the resonance. © 2012 Acoustical Society of America.

Acoustical contribution calculation and analysis of compressor shell based on acoustic transfer vector method

Science.gov (United States)

Chen, Xiaol; Guo, Bei; Tuo, Jinliang; Zhou, Ruixin; Lu, Yang

2017-08-01

Nowadays, people are paying more and more attention to the noise reduction of household refrigerator compressor. This paper established a sound field bounded by compressor shell and ISO3744 standard field points. The Acoustic Transfer Vector (ATV) in the sound field radiated by a refrigerator compressor shell were calculated which fits the test result preferably. Then the compressor shell surface is divided into several parts. Based on Acoustic Transfer Vector approach, the sound pressure contribution to the field points and the sound power contribution to the sound field of each part were calculated. To obtain the noise radiation in the sound field, the sound pressure cloud charts were analyzed, and the contribution curves in different frequency of each part were acquired. Meanwhile, the sound power contribution of each part in different frequency was analyzed, to ensure those parts where contributes larger sound power. Through the analysis of acoustic contribution, those parts where radiate larger noise on the compressor shell were determined. This paper provides a credible and effective approach on the structure optimal design of refrigerator compressor shell, which is meaningful in the noise and vibration reduction.

Subjective study of preferred listening conditions in Italian Catholic churches

Science.gov (United States)

Martellotta, Francesco

2008-10-01

The paper describes the results of research aimed at investigating the preferred subjective listening conditions inside churches. The effect of different musical motifs (spanning Gregorian chants to symphonic music) was investigated and regression analysis was performed in order to point out the relationship between subjective ratings and acoustical parameters. In order to present realistic listening conditions to the subjects a small subset of nine churches was selected among a larger set of acoustic data collected in several Italian churches during a widespread on-site survey. The subset represented different architectural styles and shapes, and was characterized by average listening conditions. For each church a single source-receiver combination with fixed relative positions was chosen. Measured binaural impulse responses were cross-talk cancelled and then convolved with five anechoic motifs. Paired comparisons were finally performed, asking a trained panel of subjects their preference. Factor analysis pointed out a substantially common underlying pattern characterizing subjective responses. The results show that preferred listening conditions vary as a function of the musical motif, depending on early decay time for choral music and on a combination of initial time delay and lateral energy for instrumental music.

Individual, contextual, and age-related acoustic variation in Simakobu (Simias concolor loud calls.

Directory of Open Access Journals (Sweden)

Wendy M Erb

Full Text Available Primate loud calls have the potential to encode information about the identity, arousal, age, or physical condition of the caller, even at long distances. In this study, we conducted an analysis of the acoustic features of the loud calls produced by a species of Asian colobine monkey (simakobu, Simias concolor. Adult male simakobu produce loud calls spontaneously and in response to loud sounds and other loud calls, which are audible more than 500 m. Individual differences in calling rates and durations exist, but it is unknown what these differences signal and which other acoustic features vary among individuals. We aimed to describe the structure and usage of calls and to examine acoustic features that vary within and among individuals. We determined the context of 318 loud calls and analyzed 170 loud calls recorded from 10 adult males at an undisturbed site, Pungut, Siberut Island, Indonesia. Most calls (53% followed the loud call of another male, 31% were spontaneous, and the remaining 16% followed a loud environmental disturbance. The fundamental frequency (F0 decreased while inter-unit intervals (IUI increased over the course of loud call bouts, possibly indicating caller fatigue. Discriminant function analysis indicated that calls were not well discriminated by context, but spontaneous calls had higher peak frequencies, suggesting a higher level of arousal. Individual calls were distinct and individuals were mainly discriminated by IUI, call duration, and F0. Loud calls of older males had shorter IUI and lower F0, while middle-aged males had the highest peak frequencies. Overall, we found that calls were individually distinct and may provide information about the age, stamina, and arousal of the calling male, and could thus be a way for males and females to assess competitors and mates from long distances.

Acoustic cloaking and transformation acoustics

International Nuclear Information System (INIS)

Chen Huanyang; Chan, C T

2010-01-01

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

Enhancement and suppression of opto-acoustic parametric interactions using optical feedback

International Nuclear Information System (INIS)

Zhang Zhongyang; Zhao Chunnong; Ju, L.; Blair, D. G.

2010-01-01

A three mode opto-acoustic parametric amplifier (OAPA) is created when two orthogonal optical modes in a high finesse optical cavity are coupled via an acoustic mode of the cavity mirror. Such interactions are predicted to occur in advanced long baseline gravitational wave detectors. They can have high positive gain, which leads to strong parametric instability. Here we show that an optical feedback scheme can enhance or suppress the parametric gain of an OAPA, allowing exploration of three-mode parametric interactions, especially in cavity systems that have insufficient optical power to achieve spontaneous instability. We derive analytical equations and show that optical feedback is capable of controlling predicted instabilities in advanced gravitational wave detectors within a time scale of 13∼10 s.

Walking to the beat of different drums: practical implications for the use of acoustic rhythms in gait rehabilitation.

Science.gov (United States)

Roerdink, Melvyn; Bank, Paulina J M; Peper, C Lieke E; Beek, Peter J

2011-04-01

Acoustic rhythms are frequently used in gait rehabilitation, with positive instantaneous and prolonged transfer effects on various gait characteristics. The gait modifying ability of acoustic rhythms depends on how well gait is tied to the beat, which can be assessed with measures of relative timing of auditory-motor coordination. We examined auditory-motor coordination in 20 healthy elderly individuals walking to metronome beats with pacing frequencies slower than, equal to, and faster than their preferred cadence. We found that more steps were required to adjust gait to the beat, the more the metronome rate deviated from the preferred cadence. Furthermore, participants anticipated the beat with their footfalls to various degrees, depending on the metronome rate; the faster the tempo, the smaller the phase advance or phase lead. Finally, the variability in the relative timing between footfalls and the beat was smaller for metronome rates closer to the preferred cadence, reflecting superior auditory-motor coordination. These observations have three practical implications. First, instantaneous effects of acoustic stimuli on gait characteristics may typically be underestimated given the considerable number of steps required to attune gait to the beat in combination with the usual short walkways. Second, a systematic phase lead of footfalls to the beat does not necessarily reflect a reduced ability to couple gait to the metronome. Third, the efficacy of acoustic rhythms to modify gait depends on metronome rate. Gait is coupled best to the beat for metronome rates near the preferred cadence. Copyright © 2011 Elsevier B.V. All rights reserved.

Stereotactic radiosurgery for acoustic neuroma: a Canadian perspective

International Nuclear Information System (INIS)

Ross, I.B.; Tator, C.H.

1998-01-01

Stereotactically delivered radiation is now an accepted treatment for patients with acoustic neuroma. In some cases, patient preference may be the reason for its selection, while in others neurosurgeons may select it for patients who are elderly or have significant risk factors for conventional surgery. The majority of patients with acoustic neuroma treatment with stereotactic radiosurgery have been treated with the Gamma Knife, with follow ups of over 25 years in some instances. Other radiosurgical modalities utilizing the linear accelerator have been developed and appear promising, but there is no long-term: follow up. Canada does not possess a Gamma Knife facility, and its government-funded hospital and medical insurance agencies have made it difficult for patients to obtain reimbursement for Gamma Knife treatments in other countries. We review the literature to date on the various forms of radiation treatment for acoustic neuroma and discuss the current issues facing physicians and patients in Canada who wish to obtain their treatment of choice. (author)

Do women prefer more complex music around ovulation?

Science.gov (United States)

Charlton, Benjamin D; Filippi, Piera; Fitch, W Tecumseh

2012-01-01

The evolutionary origins of music are much debated. One theory holds that the ability to produce complex musical sounds might reflect qualities that are relevant in mate choice contexts and hence, that music is functionally analogous to the sexually-selected acoustic displays of some animals. If so, women may be expected to show heightened preferences for more complex music when they are most fertile. Here, we used computer-generated musical pieces and ovulation predictor kits to test this hypothesis. Our results indicate that women prefer more complex music in general; however, we found no evidence that their preference for more complex music increased around ovulation. Consequently, our findings are not consistent with the hypothesis that a heightened preference/bias in women for more complex music around ovulation could have played a role in the evolution of music. We go on to suggest future studies that could further investigate whether sexual selection played a role in the evolution of this universal aspect of human culture.

Do women prefer more complex music around ovulation?

Directory of Open Access Journals (Sweden)

Benjamin D Charlton

Full Text Available The evolutionary origins of music are much debated. One theory holds that the ability to produce complex musical sounds might reflect qualities that are relevant in mate choice contexts and hence, that music is functionally analogous to the sexually-selected acoustic displays of some animals. If so, women may be expected to show heightened preferences for more complex music when they are most fertile. Here, we used computer-generated musical pieces and ovulation predictor kits to test this hypothesis. Our results indicate that women prefer more complex music in general; however, we found no evidence that their preference for more complex music increased around ovulation. Consequently, our findings are not consistent with the hypothesis that a heightened preference/bias in women for more complex music around ovulation could have played a role in the evolution of music. We go on to suggest future studies that could further investigate whether sexual selection played a role in the evolution of this universal aspect of human culture.

Magnetic and spontaneous Barkhausen noise techniques used in investigation of a martensitic transformation

Science.gov (United States)

Capò Sànchez, J.; Huallpa, E.; Farina, P.; Padovese, L. R.; Goldenstein, H.

2011-10-01

Magnetic Barkhausen noise (MBN) was used to characterize the progress of austenite to martensite phase transformation while cooling steel specimens, using a conventional Barkhausen noise emission setup stimulated by an alternating magnetic field. The phase transformation was also followed by electrical resistivity measurements and by optical and scanning electron microscopy. MBN measurements on a AISI D2 tool steel austenitized at 1473 K and cooled to liquid nitrogen temperature presented a clear change near 225 K during cooling, corresponding to the MS (martensite start) temperature, as confirmed by resistivity measurements. Analysis of the resulting signals suggested a novel experimental technique that measures spontaneous magnetic emission during transformation, in the absence of any external field. Spontaneous magnetic noise emission measurements were registered in situ while cooling an initially austenitic sample in liquid nitrogen, showing that local microstructural changes, corresponding to an avalanche or "burst" phenomena, could be detected. This spontaneous magnetic emission (SME) can thus be considered a new experimental tool for the study of martensite transformations in ferrous alloys, at the same level as acoustic emission.

Using spontaneous commentary of nursing home residents to develop resident-centered measurement tools: A case study.

Science.gov (United States)

Bangerter, Lauren R; Abbott, Katherine; Heid, Allison; Eshraghi, Karen; Van Haitsma, Kimberly

Nursing home (NH) residents routinely complete surveys that assess their health, well-being, preferences, and care needs. Such surveys reveal important information, however, are largely based on the concerns of providers as opposed to the concerns of residents. Thus, researchers must enhance efforts to ensure that these surveys are guided by the priorities, needs, and concerns of residents. We present a case study to demonstrate how spontaneous commentary of NH residents holds particular efficacy for ensuring that measurement tools are guided by the needs, concerns, and priorities of residents. Spontaneous comments from NH residents (N = 370) collected as part of a study developing the Preferences for Everyday Living Inventory for NH residents (PELI-NH) were used to refine the PELI-NH across key phases of measurement development. This work demonstrates how the spontaneous commentary of NH residents may contribute to the refinement of NH measurement tools, and allow researchers to base these tools on the needs and priorities of NH residents. Copyright © 2017 Elsevier Inc. All rights reserved.

Acute Abdomen Due to Uncontrolled Use of Warfarin: Spontaneous Intra-abdominal

Directory of Open Access Journals (Sweden)

Fatih Dal

2017-12-01

Full Text Available Warfarin is an oral anticoagulant, which is commonly used in the treatment and prophylaxis of thromboembolic conditions. Bleeding is the primary adverse effect associated with warfarin. The majority of warfarin-related bleedings are spontaneous minor hemorrhages occurring in the subcutaneous or intramuscular tissues and can be treated by decreasing the dose of oral anticoagulants. However, although rare, it is possible to encounter spontaneous major bleedings with increased risk of mortality. Conservative approach is the preferred initial therapy for hemodynamically stable patients with major intra-abdominal hemorrhages that we define as the intermediate group patients. Nevertheless, surgery is required for hemodynamically unstable patients with acute abdominal pain in cases of ongoing active hemorrhage, generalized peritonitis, obstruction, acute abdomen, intestinal ischemia, and perforation. In this article, we present a rare case of acute abdomen and spontaneous intra-abdominal hemorrhage resulting from uncontrolled use of warfarin and a new classification requirement.

Acoustical sensing of cardiomyocyte cluster beating

Energy Technology Data Exchange (ETDEWEB)

Tymchenko, Nina; Kunze, Angelika [Dept. of Applied Physics, Chalmers University of Technology, 412 96 Göteborg (Sweden); Dahlenborg, Kerstin [Cellectis, 413 46 Göteborg (Sweden); Svedhem, Sofia, E-mail: sofia.svedhem@chalmers.se [Dept. of Applied Physics, Chalmers University of Technology, 412 96 Göteborg (Sweden); Steel, Daniella [Cellectis, 413 46 Göteborg (Sweden)

2013-06-14

Highlights: •An example of the application of QCM-D to live cell studies. •Detection of human pluripotent stem cell-derived cardiomyocyte cluster beating. •Clusters were studied in a thin liquid film and in a large liquid volume. •The QCM-D beating profile provides an individual fingerprint of the hPS-CMCs. -- Abstract: Spontaneously beating human pluripotent stem cell-derived cardiomyocytes clusters (CMCs) represent an excellent in vitro tool for studies of human cardiomyocyte function and for pharmacological cardiac safety assessment. Such testing typically requires highly trained operators, precision plating, or large cell quantities, and there is a demand for real-time, label-free monitoring of small cell quantities, especially rare cells and tissue-like structures. Array formats based on sensing of electrical or optical properties of cells are being developed and in use by the pharmaceutical industry. A potential alternative to these techniques is represented by the quartz crystal microbalance with dissipation monitoring (QCM-D) technique, which is an acoustic surface sensitive technique that measures changes in mass and viscoelastic properties close to the sensor surface (from nm to μm). There is an increasing number of studies where QCM-D has successfully been applied to monitor properties of cells and cellular processes. In the present study, we show that spontaneous beating of CMCs on QCM-D sensors can be clearly detected, both in the frequency and the dissipation signals. Beating rates in the range of 66–168 bpm for CMCs were detected and confirmed by simultaneous light microscopy. The QCM-D beating profile was found to provide individual fingerprints of the hPS-CMCs. The presented results point towards acoustical assays for evaluation cardiotoxicity.

Summary and consensus in 7th International Conference on acoustic neuroma: An update for the management of sporadic acoustic neuromas

Directory of Open Access Journals (Sweden)

Hao Wu

2016-12-01

Full Text Available Sporadic vestibular schwannoma (acoustic neuroma is a benign tumor arising from cochleovestibular nerve. Nowadays, various specialties and medical centers are treating this disease, and the multidisciplinary collaboration is the trend. In an effort to promote a uniform standard for reporting clinical results, even for treatment indications, the mainly controversies were posed and discussed during the 7th International Conference on acoustic neuroma, and the agreement was summarized by the Committee of this conference. The main symptoms grading and tumor stage should note its name of classification for making them comparable. The goal of the modern managements for vestibular schwannoma is to improve the quality of life with lower mortality, lower morbidity and better neurological function preservation. The experience of surgical team and their preference might be a major factor for the outcome. Because of lacking of long-term follow-up large data after radiotherapy, and with the development of microsurgery, radiotherapy is now less recommended except for recurrent cases or elderly patients. Keywords: Sporadic acoustic neuroma, Vestibular schwannoma, Management, Symptoms grading, Tumor stage, Microsurgery, Radiotherapy

Zebra mussel control using acoustic energy

International Nuclear Information System (INIS)

Tiller, G.W.; Gaucher, T.A.; Menezes, J.K.; Dolat, S.W.

1992-01-01

A practical and economical device or method that reduces zebra mussel colonization without detrimental side effects is highly desirable. An ideal method is one that could be installed near, on, or in existing raw water intakes and conduits. It must have a known effect that is limited to a defined area, should have maximum effects on a targeted species, and preferably have a low life cycle cost than the current alternative methods of control and maintenance. Underwater sound could be such a desirable solution, if found to be an effective control measure for zebra mussels. Although sound most often applies specifically to acoustic energy that is audible to humans, 20 Hertz (Hz) to 20 kiloHertz (kHz), in this report we will use the terms sound and acoustic to include acoustic energy between 100 Hz and 100 MegaHertz (MHz). This research on zebra mussel biofouling is designed to effect the early developmental stages in the life cycle of Dreissena polymorpha (Pallas). Vulnerable stages in the development of D. polymorpha that might yield to site-specific acoustic deterrence measures include the free-swimming larval veliger stage, the postveliger pre-attachment demersal stage, and the immediate post-attachment stage. The proposed applications include surface treatment to prevent, reduce or eliminate colonization on underwater structures, and the stream treatment to reduce or eliminate (destroy) mussel larvae entrained in a moving volume of water

Auditory selectivity for the acoustic properties of conspecific mate-attracting signals in lower vertebrates and songbirds

OpenAIRE

Gerhardt, Carl

2015-01-01

H Carl GerhardtDivision of Biological Sciences, University of Missouri, Columbia, MO, USAAbstract: The interplay between conspecific senders and receivers both maintains the usual species specificity of acoustic communication and yet offers the potential for speciation provided that signals and preferences change in a parallel or coupled way. Acoustic signals commonly function in mate attraction and contribute to reproductive success. Such signals are especially prevalent in some lower verteb...

Measurements of the power spectrum and dispersion relation of self-excited dust acoustic waves

Science.gov (United States)

Nosenko, V.; Zhdanov, S. K.; Kim, S.-H.; Heinrich, J.; Merlino, R. L.; Morfill, G. E.

2009-12-01

The spectrum of spontaneously excited dust acoustic waves was measured. The waves were observed with high temporal resolution using a fast video camera operating at 1000 frames per second. The experimental system was a suspension of micron-size kaolin particles in the anode region of a dc discharge in argon. Wave activity was found at frequencies as high as 450 Hz. At high wave numbers, the wave dispersion relation was acoustic-like (frequency proportional to wave number). At low wave numbers, the wave frequency did not tend to zero, but reached a cutoff frequency instead. The cutoff value declined with distance from the anode. We ascribe the observed cutoff to the particle confinement in this region.

Management of paediatric spontaneous pneumothorax: a multicentre retrospective case series.

Science.gov (United States)

Robinson, Paul D; Blackburn, Carol; Babl, Franz E; Gamage, Lalith; Schutz, Jacquie; Nogajski, Rebecca; Dalziel, Stuart; Donald, Colin B; Druda, Dino; Krieser, David; Neutze, Jocelyn; Acworth, Jason; Lee, Mark; Ngo, Peter K

2015-10-01

Paediatric guidelines are lacking for management of spontaneous pneumothorax. Adult patient-focused guidelines (British Thoracic Society 2003 and 2010) introduced aspiration as first-line intervention for primary spontaneous pneumothorax (PSP) and small secondary spontaneous pneumothoraces (SSP). Paediatric practice is unclear, and evidence for aspiration success rates is urgently required to develop paediatric-specific recommendations. Retrospective analysis of PSP and SSP management at nine paediatric emergency departments across Australia and New Zealand (2003-2010) to compare PSP and SSP management. 219 episodes of spontaneous pneumothorax occurred in 162 children (median age 15 years, 71% male); 155 PSP episodes in 120 children and 64 SSP episodes in 42 children. Intervention in PSP vs SSP episodes occurred in 55% (95% CI 47% to 62%) vs 70% (60% to 79%), pmanagement, PSP and SSP management did not differ and ICC insertion was the continuing preferred intervention. Overall success of aspiration was lower than reported results for adults, although success was greater for small than for large pneumothoraces. Paediatric prospective studies are urgently required to determine optimal paediatric interventional management strategies. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Paternal Effort in Relation to Acoustically Mediated Mate Choice in a Neotropical Frog

Science.gov (United States)

Pettitt, Beth Ann

One aspect of communication not normally considered in studies of anuran amphibians involves the extent to which acoustic signals indicate the quality of parental care a male provides. My research examined this question in the golden rocket frog (Anomaloglossus beebei), a Neotropical dendrobatid that exhibits acoustically mediated mate choice and biparental care. I investigated the function of the male advertisement call of A. beebei in the context of female mate choice by testing the predictions of four hypotheses that have been proposed to explain the relationship between mate signals and male parental care quality. In addition, I conducted a series of studies on acoustic variability, female preferences for advertisement call traits and the importance of male parental care on offspring survival.

Managing Measurement Uncertainty in Building Acoustics

Directory of Open Access Journals (Sweden)

Chiara Scrosati

2015-12-01

Full Text Available In general, uncertainties should preferably be determined following the principles laid down in ISO/IEC Guide 98-3, the Guide to the expression of uncertainty in measurement (GUM:1995. According to current knowledge, it seems impossible to formulate these models for the different quantities in building acoustics. Therefore, the concepts of repeatability and reproducibility are necessary to determine the uncertainty of building acoustics measurements. This study shows the uncertainty of field measurements of a lightweight wall, a heavyweight floor, a façade with a single glazing window and a façade with double glazing window that were analyzed by a Round Robin Test (RRT, conducted in a full-scale experimental building at ITC-CNR (Construction Technologies Institute of the National Research Council of Italy. The single number quantities and their uncertainties were evaluated in both narrow and enlarged range and it was shown that including or excluding the low frequencies leads to very significant differences, except in the case of the sound insulation of façades with single glazing window. The results obtained in these RRTs were compared with other results from literature, which confirm the increase of the uncertainty of single number quantities due to the low frequencies extension. Having stated the measurement uncertainty for a single measurement, in building acoustics, it is also very important to deal with sampling for the purposes of classification of buildings or building units. Therefore, this study also shows an application of the sampling included in the Italian Standard on the acoustic classification of building units on a serial type building consisting of 47 building units. It was found that the greatest variability is observed in the façade and it depends on both the great variability of window’s typologies and on workmanship. Finally, it is suggested how to manage the uncertainty in building acoustics, both for one single

The Neurobiology of Sexual Partner Preferences in Rams

Science.gov (United States)

Roselli, Charles E.; Stormshak, Fred

2009-01-01

The question of what causes a male animal to seek out and choose a female as opposed to another male mating partner is unresolved and remains an issue of considerable debate. The most developed biologic theory is the perinatal organizational hypothesis, which states that perinatal hormone exposure mediates sexual differentiation of the brain. Numerous animal experiments have assessed the contribution of perinatal testosterone and/or estradiol exposure to the development of a male-typical mate preference, but almost all have used hormonally manipulated animals. In contrast, variations in sexual partner preferences occur spontaneously in domestic rams, with as many as 8% of the population exhibiting a preference for same-sex mating partners (male-oriented rams). Thus, the domestic ram is an excellent experimental model to study possible links between fetal neuroendocrine programming of neural mechanisms and adult sexual partner preferences. In this review, we present an overview of sexual differentiation in relation to sexual partner preferences. We then summarize results that test the relevance of the organizational hypothesis to expression of same-sex sexual partner preferences in rams. Finally, we demonstrate that the sexual differentiation of brain and behavior in sheep do not depend critically on aromatization of testosterone to estradiol. PMID:19446078

The neurobiology of sexual partner preferences in rams.

Science.gov (United States)

Roselli, Charles E; Stormshak, Fred

2009-05-01

The question of what causes a male animal to seek out and choose a female as opposed to another male mating partner is unresolved and remains an issue of considerable debate. The most developed biologic theory is the perinatal organizational hypothesis, which states that perinatal hormone exposure mediates sexual differentiation of the brain. Numerous animal experiments have assessed the contribution of perinatal testosterone and/or estradiol exposure to the development of a male-typical mate preference, but almost all have used hormonally manipulated animals. In contrast, variations in sexual partner preferences occur spontaneously in domestic rams, with as many as 8% of the population exhibiting a preference for same-sex mating partners (male-oriented rams). Thus, the domestic ram is an excellent experimental model to study possible links between fetal neuroendocrine programming of neural mechanisms and adult sexual partner preferences. In this review, we present an overview of sexual differentiation in relation to sexual partner preferences. We then summarize results that test the relevance of the organizational hypothesis to expression of same-sex sexual partner preferences in rams. Finally, we demonstrate that the sexual differentiation of brain and behavior in sheep does not depend critically on aromatization of testosterone to estradiol.

Cannabinoid-induced conditioned place preference in the spontaneously hypertensive rat-an animal model of attention deficit hyperactivity disorder.

Science.gov (United States)

Pandolfo, Pablo; Vendruscolo, Leandro F; Sordi, Regina; Takahashi, Reinaldo N

2009-08-01

Cannabis preparations are the most widely consumed illicit drugs, and their use typically begins in adolescence. The prevalence of cannabis abuse is higher in patients with attention deficit/hyperactivity disorder (ADHD) than in the general population, yet, knowledge about the motivational properties of cannabinoids in animal models of ADHD are lacking. To compare the motivational effects of the synthetic cannabinoid agonist WIN55,212-2 (WIN) in adolescent and adult spontaneously hypertensive rats (SHR), a validated animal model of ADHD, and Wistar rats, representing a "normal" genetically heterogeneous population. We also asked whether the effects of WIN depended (1) on the activation of the cerebral subtype of cannabinoid receptors, namely, the CB(1) cannabinoid receptor and (2) on putative changes by WIN in blood pressure. WIN was tested under an unbiased conditioned place preference (CPP) paradigm. Blood pressure after WIN administration was also monitored in additional groups of rats. In the Wistar rats, WIN produced place aversion only in the adult but not adolescent rats. In contrast, WIN produced CPP in both adolescent and adult SHR rats. The behavioral effects of WIN were CB(1)-mediated and not related to blood pressure. The contrasting effects of WIN in Wistar and SHR, and the higher resistance of adolescent rats to the aversive and rewarding effects of WIN in these two strains suggests that both adolescence and the ADHD-like profile exhibited by the SHR strain constitute factors that influence the motivational properties of cannabinoids.

Use of acoustic vortices in acoustic levitation

DEFF Research Database (Denmark)

Cutanda Henriquez, Vicente; Santillan, Arturo Orozco; Juhl, Peter Møller

2009-01-01

Acoustic fields are known to exert forces on the surfaces of objects. These forces are noticeable if the sound pressure is sufficiently high. Two phenomena where acoustic forces are relevant are: i) acoustic levitation, where strong standing waves can hold small objects at certain positions......, counterbalancing their weight, and ii) acoustic vortices, spinning sound fields that can impinge angular momentum and cause rotation of objects. In this contribution, both force-creating sound fields are studied by means of numerical simulations. The Boundary Element Method is employed to this end. The simulation...... of acoustical vortices uses an efficient numerical implementation based on the superposition of two orthogonal sound fields with a delay of 90° between them. It is shown that acoustic levitation and the use of acoustic vortices can be combined to manipulate objects in an efficient and controlled manner without...

Acoustic emission

International Nuclear Information System (INIS)

Nichols, R.W.

1976-01-01

The volume contains six papers which together provide an overall review of the inspection technique known as acoustic emission or stress wave emission. The titles are: a welder's introduction to acoustic emission technology; use of acoustic emission for detection of defects as they arise during fabrication; examples of laboratory application and assessment of acoustic emission in the United Kingdom; (Part I: acoustic emission behaviour of low alloy steels; Part II: fatigue crack assessment from proof testing and continuous monitoring); inspection of selected areas of engineering structures by acoustic emission; Japanese experience in laboratory and practical applications of acoustic emission to welded structures; and ASME acoustic emission code status. (U.K.)

Effects of acoustical stimuli delivered through hearing aids on tinnitus.

Science.gov (United States)

Sweetow, Robert W; Sabes, Jennifer Henderson

2010-01-01

The use of acoustic signals to mask, mix with, or ease the distress associated with tinnitus has been clinically employed for decades. It has been proposed that expanding acoustic options for tinnitus sufferers due to personal preferences is desirable. Fractal tones incorporate many useful characteristics of music while avoiding certain features that could be distracting to some individuals. To assess the effects on relaxation, tinnitus annoyance, tinnitus handicap, and tinnitus reaction from the use of a hearing aid that incorporates combinations of amplification, fractal tones, and white noise. Participants listened to experimental hearing aids containing several acoustic options and were asked to rate the signals in terms of their effect on relaxation and tinnitus annoyance. They subsequently wore the hearing aids for 6 mo and completed tinnitus handicap and reaction scales. Fourteen hearing-impaired adults with primary complaints of subjective tinnitus. Participants were tested wearing hearing aids containing several programs including amplification only, fractal tones only, and a combination of amplification, noise, and/or fractal tones. The fractal tones (now commercially available as the "Zen" feature) were generated by the Widex Mind hearing aid. Rating procedures were conducted in the laboratory, and tinnitus reaction and handicap were assessed during and following a 6 mo field trial. Data were collected at the initial visit, one week, 1 mo, 3 mo, and 6 mo. Nonparametric statistics included Wilcoxon matched-pairs signed-rank, chi(2), and repeated-measures analyses of variance. Thirteen of 14 participants reported that their tinnitus annoyance, as measured by the Tinnitus Annoyance Scale, was reduced for at least one of the amplified conditions (with or without fractal tones or noise), relative to the unaided condition. Nine assigned a lower tinnitus annoyance rating when listening to fractal tones alone versus the amplification-alone condition. There was a

The contrast between alveolar and velar stops with typical speech data: acoustic and articulatory analyses.

Science.gov (United States)

Melo, Roberta Michelon; Mota, Helena Bolli; Berti, Larissa Cristina

2017-06-08

This study used acoustic and articulatory analyses to characterize the contrast between alveolar and velar stops with typical speech data, comparing the parameters (acoustic and articulatory) of adults and children with typical speech development. The sample consisted of 20 adults and 15 children with typical speech development. The analyzed corpus was organized through five repetitions of each target-word (/'kap ə/, /'tapə/, /'galo/ e /'daɾə/). These words were inserted into a carrier phrase and the participant was asked to name them spontaneously. Simultaneous audio and video data were recorded (tongue ultrasound images). The data was submitted to acoustic analyses (voice onset time; spectral peak and burst spectral moments; vowel/consonant transition and relative duration measures) and articulatory analyses (proportion of significant axes of the anterior and posterior tongue regions and description of tongue curves). Acoustic and articulatory parameters were effective to indicate the contrast between alveolar and velar stops, mainly in the adult group. Both speech analyses showed statistically significant differences between the two groups. The acoustic and articulatory parameters provided signals to characterize the phonic contrast of speech. One of the main findings in the comparison between adult and child speech was evidence of articulatory refinement/maturation even after the period of segment acquisition.

'Who's a good boy?!' Dogs prefer naturalistic dog-directed speech.

Science.gov (United States)

Benjamin, Alex; Slocombe, Katie

2018-05-01

Infant-directed speech (IDS) is a special speech register thought to aid language acquisition and improve affiliation in human infants. Although IDS shares some of its properties with dog-directed speech (DDS), it is unclear whether the production of DDS is functional, or simply an overgeneralisation of IDS within Western cultures. One recent study found that, while puppies attended more to a script read with DDS compared with adult-directed speech (ADS), adult dogs displayed no preference. In contrast, using naturalistic speech and a more ecologically valid set-up, we found that adult dogs attended to and showed more affiliative behaviour towards a speaker of DDS than of ADS. To explore whether this preference for DDS was modulated by the dog-specific words typically used in DDS, the acoustic features (prosody) of DDS or a combination of the two, we conducted a second experiment. Here the stimuli from experiment 1 were produced with reversed prosody, meaning the prosody and content of ADS and DDS were mismatched. The results revealed no significant effect of speech type, or content, suggesting that it is maybe the combination of the acoustic properties and the dog-related content of DDS that modulates the preference shown for naturalistic DDS. Overall, the results of this study suggest that naturalistic DDS, comprising of both dog-directed prosody and dog-relevant content words, improves dogs' attention and may strengthen the affiliative bond between humans and their pets.

Spontaneous mutation by mutagenic repair of spontaneous lesions in DNA

International Nuclear Information System (INIS)

Hastings, P.J.; Quah, S.-K.; Borstel, R.C. von

1976-01-01

It is stated that strains of yeast carrying mutations in many of the steps in pathways repairing radiation-induced damage to DNA have enhanced spontaneous mutation rates. Most strains isolated because they have enhanced spontaneous mutation carry mutations in DNA repair systems. This suggests that much spontaneous mutation arises by mutagenic repair of spontaneous lesions. (author)

Translational illusion of acoustic sources by transformation acoustics.

Science.gov (United States)

Sun, Fei; Li, Shichao; He, Sailing

2017-09-01

An acoustic illusion of creating a translated acoustic source is designed by utilizing transformation acoustics. An acoustic source shifter (ASS) composed of layered acoustic metamaterials is designed to achieve such an illusion. A practical example where the ASS is made with naturally available materials is also given. Numerical simulations verify the performance of the proposed device. The designed ASS may have some applications in, e.g., anti-sonar detection.

Observation of frequency cutoff for self-excited dust acoustic waves

Science.gov (United States)

Nosenko, V.; Zhdanov, S. K.; Morfill, G. E.; Kim, S.-H.; Heinrich, J.; Merlino, R. L.

2009-11-01

Complex (dusty) plasmas consist of fine solid particles suspended in a weakly ionized gas. Complex plasmas are excellent model systems to study wave phenomena down to the level of individual ``atoms''. Spontaneously excited dust acoustic waves were observed with high temporal resolution in a suspension of micron-size kaolin particles in a dc discharge in argon. Wave activity was found at frequencies as high as 400 Hz. At high wave numbers, the wave dispersion relation was acoustic-like (frequency proportional to wave number). At low wave numbers, the wave frequency did not tend to zero, but reached a cutoff frequency fc instead. The value of fc declined with distance from the anode. We propose a simple model that explains the observed cutoff by particle confinement in plasma. The existence of a cutoff frequency is very important for the propagation of waves: the waves excited above fc are propagating, and those below fc are evanescent.

Acoustic transducer

Science.gov (United States)

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.

Fundamentals of Acoustics. Psychoacoustics and Hearing. Acoustical Measurements

Science.gov (United States)

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.

Communication Acoustics

DEFF Research Database (Denmark)

Blauert, Jens

Communication Acoustics deals with the fundamentals of those areas of acoustics which are related to modern communication technologies. Due to the advent of digital signal processing and recording in acoustics, these areas have enjoyed an enormous upswing during the last 4 decades. The book...... the book a source of valuable information for those who want to improve or refresh their knowledge in the field of communication acoustics - and to work their way deeper into it. Due to its interdisciplinary character Communication Acoustics is bound to attract readers from many different areas, such as......: acoustics, cognitive science, speech science, and communication technology....

Chicks prefer to peck at insect-like elongated stimuli moving in a direction orthogonal to their longer axis.

Science.gov (United States)

Clara, Elena; Regolin, Lucia; Vallortigara, Giorgio; Rogers, Lesley J

2009-11-01

Spontaneous preferences towards possible prey have been little investigated using targets in motion. Preferences of domestic chicks (Gallus gallus) to peck at video-images of stimuli representing live insects moving along their longer body axis (i.e. "forwards") or along the shorter body axis (i.e. "sideways") were investigated. Chicks presented with both types of stimulus displayed a significant preference for pecking at stimuli moving sideways. This preference was already present on day 1 post-hatching, and it strengthened on day 6 for those chicks that had experienced pecking at live insects. Head angles used to fixate the stimuli prior to pecking were also analysed and were consistent (i.e. 30 degrees -35 degrees and 60 degrees -65 degrees ) with those reported for fixation of non-edible targets (larger stimuli at a distance). In a first control experiment the same video-presented stimuli were used but the insect's legs were removed to reduce flickering. In a second control experiment, paper-printed images of the whole insect were used. In both cases, the sideways direction of movement was clearly preferred. Overall, our data show that chicks have a spontaneous preference to peck at video-images resembling live insects moving along their shorter body axis. Sideways movement may constitute a crucial signal attracting chicks' attention and enhancing predatory responses possibly because of stronger stimulation of motion detectors.

Enlarged acceptance angle of a finite size detector in photoacoustic imaging using acoustic lenses

NARCIS (Netherlands)

Xia, W.; Piras, D.; Heijblom, Michelle; van Hespen, Johannes C.G.; Steenbergen, Wiendelt; Manohar, Srirang; van Veldhoven, Spiridon; Prins, Christian; van Leeuwen, Ton

2011-01-01

A large surface area transducer is preferable to be used to detect extremely weak photoacoustic signals in mammography due to its high sensitivity. The lateral resolution is limited by the small acceptance angle of such a transducer. We introduce an excellent material for an acoustic lens used to

Acoustic source for generating an acoustic beam

Science.gov (United States)

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.

Acoustic calibration apparatus for calibrating plethysmographic acoustic pressure sensors

Science.gov (United States)

Zuckerwar, Allan J. (Inventor); Davis, David C. (Inventor)

1995-01-01

An apparatus for calibrating an acoustic sensor is described. The apparatus includes a transmission material having an acoustic impedance approximately matching the acoustic impedance of the actual acoustic medium existing when the acoustic sensor is applied in actual in-service conditions. An elastic container holds the transmission material. A first sensor is coupled to the container at a first location on the container and a second sensor coupled to the container at a second location on the container, the second location being different from the first location. A sound producing device is coupled to the container and transmits acoustic signals inside the container.

Music preferences with hearing aids: effects of signal properties, compression settings, and listener characteristics.

Science.gov (United States)

Croghan, Naomi B H; Arehart, Kathryn H; Kates, James M

2014-01-01

Current knowledge of how to design and fit hearing aids to optimize music listening is limited. Many hearing-aid users listen to recorded music, which often undergoes compression limiting (CL) in the music industry. Therefore, hearing-aid users may experience twofold effects of compression when listening to recorded music: music-industry CL and hearing-aid wide dynamic-range compression (WDRC). The goal of this study was to examine the roles of input-signal properties, hearing-aid processing, and individual variability in the perception of recorded music, with a focus on the effects of dynamic-range compression. A group of 18 experienced hearing-aid users made paired-comparison preference judgments for classical and rock music samples using simulated hearing aids. Music samples were either unprocessed before hearing-aid input or had different levels of music-industry CL. Hearing-aid conditions included linear gain and individually fitted WDRC. Combinations of four WDRC parameters were included: fast release time (50 msec), slow release time (1,000 msec), three channels, and 18 channels. Listeners also completed several psychophysical tasks. Acoustic analyses showed that CL and WDRC reduced temporal envelope contrasts, changed amplitude distributions across the acoustic spectrum, and smoothed the peaks of the modulation spectrum. Listener judgments revealed that fast WDRC was least preferred for both genres of music. For classical music, linear processing and slow WDRC were equally preferred, and the main effect of number of channels was not significant. For rock music, linear processing was preferred over slow WDRC, and three channels were preferred to 18 channels. Heavy CL was least preferred for classical music, but the amount of CL did not change the patterns of WDRC preferences for either genre. Auditory filter bandwidth as estimated from psychophysical tuning curves was associated with variability in listeners' preferences for classical music. Fast

Stakeholder Engagement in Trial Design: Survey of Visitors to Critically Ill Patients Regarding Preferences for Outcomes and Treatment Options during Weaning from Mechanical Ventilation.

Science.gov (United States)

Burns, Karen E A; Jacob, Sonu Karottaiyamvelil; Aguirre, Valeria; Gomes, Janice; Mehta, Sangeeta; Rizvi, Leena

2016-11-01

Stakeholder engagement in research is expected to provide unique insights, make research investments more accountable and transparent, and ensure that future research is applicable to patients and family members. To inform the design of a trial of strategies for weaning from mechanical ventilation, we sought to identify preferences of patient visitors regarding outcome and treatment measures. We conducted an interviewer-administered questionnaire of visitors of critically ill patients in two family waiting rooms serving three intensive care units (ICUs) in Toronto, Canada. Respondents rated the importance of general and ventilation-related outcomes in two hypothetical scenarios (before a first spontaneous breathing trial, and after a failed spontaneous breathing trial) and selected a preferred technique for the breathing trials. With regard to the patient they were visiting, respondents identified the most important outcome to them at ICU admission, during the ICU stay, and at ICU discharge. We analyzed 322 questionnaires (95.5% response rate). All outcomes were highly rated (average range: 7.82-9.74). Across scenarios, outcomes rated as most important were ICU and hospital survival (9.72, 9.70), avoiding complications (9.45), quality of life (9.394), patient comfort (9.393), and returning to previous living arrangements (9.31). Overall, the most important ventilation-related outcomes were being ventilator-free (8.95), avoiding reintubation (8.905), and passing a spontaneous breathing trial (8.903). Passing a spontaneous breathing trial assumed greater importance after an initial failed attempt. "Time to event" outcomes were less important to visitors. We did not identify a preferred spontaneous breathing trial technique. Although ICU survival was the most important outcome at ICU admission and during the ICU stay, visitors rated quality of life higher than hospital survival at ICU discharge. Visitors to critically ill patients prioritized two general outcomes (ICU

Acoustic wave simulation using an overset grid for the global monitoring system

Science.gov (United States)

Kushida, N.; Le Bras, R.

2017-12-01

The International Monitoring System of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) has been monitoring hydro-acoustic and infrasound waves over the globe. Because of the complex natures of the oceans and the atmosphere, computer simulation can play an important role in understanding the observed signals. In this regard, methods which depend on partial differential equations and require minimum modelling, are preferable. So far, to our best knowledge, acoustic wave propagation simulations based on partial differential equations on such a large scale have not been performed (pp 147 - 161 of ref [1], [2]). The main difficulties in building such simulation codes are: (1) considering the inhomogeneity of medium including background flows, (2) high aspect ratio of computational domain, (3) stability during long time integration. To overcome these difficulties, we employ a two-dimensional finite different (FDM) scheme on spherical coordinates with the Yin-Yang overset grid[3] solving the governing equation of acoustic waves introduces by Ostashev et. al.[4]. The comparison with real recording examples in hydro-acoustic will be presented at the conference. [1] Paul C. Etter: Underwater Acoustic Modeling and Simulation, Fourth Edition, CRC Press, 2013. [2] LIAN WANG et. al.: REVIEW OF UNDERWATER ACOUSTIC PROPAGATION MODELS, NPL Report AC 12, 2014. [3] A. Kageyama and T. Sato: "Yin-Yang grid": An overset grid in spherical geometry, Geochem. Geophys. Geosyst., 5, Q09005, 2004. [4] Vladimir E. Ostashev et. al: Equations for finite-difference, time-domain simulation of sound propagation in moving inhomogeneous media and numerical implementation, Acoustical Society of America. DOI: 10.1121/1.1841531, 2005.

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

Science.gov (United States)

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

Interior acoustic cloak

Directory of Open Access Journals (Sweden)

Wael Akl

2014-12-01

Full Text Available Acoustic cloaks have traditionally been intended to externally surround critical objects to render these objects acoustically invisible. However, in this paper, the emphasis is placed on investigating the application of the acoustic cloaks to the interior walls of acoustic cavities in an attempt to minimize the noise levels inside these cavities. In this manner, the acoustic cloaks can serve as a viable and efficient alternative to the conventional passive noise attenuation treatments which are invariably heavy and bulky. The transformation acoustics relationships that govern the operation of this class of interior acoustic cloaks are presented. Physical insights are given to relate these relationships to the reasons behind the effectiveness of the proposed interior acoustic cloaks. Finite element models are presented to demonstrate the characteristics of interior acoustic cloaks used in treating the interior walls of circular and square cavities both in the time and frequency domains. The obtained results emphasize the effectiveness of the proposed interior cloaks in eliminating the reflections of the acoustic waves from the walls of the treated cavities and thereby rendering these cavities acoustically quiet. It is important to note here that the proposed interior acoustic cloaks can find applications in acoustic cavities such as aircraft cabins and auditoriums as well as many other critical applications.

Responsive acoustic surfaces

DEFF Research Database (Denmark)

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

2011-01-01

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

Flat acoustic lens by acoustic grating with curled slits

KAUST Repository

Peng, Pai

2014-10-01

We design a flat sub-wavelength lens that can focus acoustic wave. We analytically study the transmission through an acoustic grating with curled slits, which can serve as a material with tunable impedance and refractive index for acoustic waves. The effective parameters rely on the geometry of the slits and are independent of frequency. A flat acoustic focusing lens by such acoustic grating with gradient effective refractive index is designed. The focusing effect is clearly observed in simulations and well predicted by the theory. We demonstrate that despite the large impedance mismatch between the acoustic lens and the matrix, the intensity at the focal point is still high due to Fabry-Perot resonance.

Parametric Room Acoustic workflows with real-time acoustic simulation

DEFF Research Database (Denmark)

Parigi, Dario

2017-01-01

The paper investigates and assesses the opportunities that real-time acoustic simulation offer to engage in parametric acoustics workflow and to influence architectural designs from early design stages......The paper investigates and assesses the opportunities that real-time acoustic simulation offer to engage in parametric acoustics workflow and to influence architectural designs from early design stages...

'I love Rock 'n' Roll'--music genre preference modulates brain responses to music.

Science.gov (United States)

Istók, Eva; Brattico, Elvira; Jacobsen, Thomas; Ritter, Aileen; Tervaniemi, M

2013-02-01

The present study examined the effect of participants' music genre preference on the neural processes underlying evaluative and cognitive judgements of music using the event-related potential technique. To this aim, two participant groups differing in their preference for Latin American and Heavy Metal music performed a liking judgement and a genre classification task on a variety of excerpts of either music genre. A late positive potential (LPP) was elicited in all conditions between 600 and 900 ms after stimulus onset. During the genre classification task, an early negativity was elicited by the preferred compared to the non-preferred music at around 230-370 ms whereas the non-preferred genre was characterized by a larger LPP. The findings suggest that evaluative and cognitive judgements of music are accompanied by affective responses and that the valence of music may spontaneously modulate early processes of music categorization even when no overt liking judgement is required. Copyright © 2012 Elsevier B.V. All rights reserved.

Does Spontaneous Favorability to Power (vs. Universalism) Values Predict Spontaneous Prejudice and Discrimination?

Science.gov (United States)

Souchon, Nicolas; Maio, Gregory R; Hanel, Paul H P; Bardin, Brigitte

2017-10-01

We conducted five studies testing whether an implicit measure of favorability toward power over universalism values predicts spontaneous prejudice and discrimination. Studies 1 (N = 192) and 2 (N = 86) examined correlations between spontaneous favorability toward power (vs. universalism) values, achievement (vs. benevolence) values, and a spontaneous measure of prejudice toward ethnic minorities. Study 3 (N = 159) tested whether conditioning participants to associate power values with positive adjectives and universalism values with negative adjectives (or inversely) affects spontaneous prejudice. Study 4 (N = 95) tested whether decision bias toward female handball players could be predicted by spontaneous attitude toward power (vs. universalism) values. Study 5 (N = 123) examined correlations between spontaneous attitude toward power (vs. universalism) values, spontaneous importance toward power (vs. universalism) values, and spontaneous prejudice toward Black African people. Spontaneous positivity toward power (vs. universalism) values was associated with spontaneous negativity toward minorities and predicted gender bias in a decision task, whereas the explicit measures did not. These results indicate that the implicit assessment of evaluative responses attached to human values helps to model value-attitude-behavior relations. © 2016 The Authors. Journal of Personality Published by Wiley Periodicals, Inc.

Ca2+ signaling in taste bud cells and spontaneous preference for fat: unresolved roles of CD36 and GPR120.

Science.gov (United States)

Abdoul-Azize, Souleymane; Selvakumar, Subramaniam; Sadou, Hassimi; Besnard, Philippe; Khan, Naim Akhtar

2014-01-01

Recent compelling evidences from rodent and human studies raise the possibility for an additional sixth taste modality devoted to oro-gustatory perception of dietary lipids. Understanding the mechanisms underlying oro-gustatory detection of dietary fat is critical for the prevention and treatment of obesity. A number of studies have suggested that lingual CD36, a glycoprotein, highly expressed by circumvallate papillae of the tongue, is implicated in the perception of dietary fat taste. G protein-coupled receptors (GPCRs) are important signaling molecules for many aspects of cellular functions. It has been shown that these receptors, particularly GPR120, are also involved in lipid taste perception. We have shown that dietary long-chain fatty acids (LCFAs), in CD36-positive taste bud cells (TBC), induce increases in free intracellular Ca(2+) concentrations, [Ca(2+)]i, by recruiting Ca(2+) from endoplasmic reticulum (ER) pool via inositol 1,4,5-triphosphate production, followed by Ca(2+) influx via opening of store-operated Ca(2+) (SOC) channels. GPR120 is also coupled to increases in [Ca(2+)]i by dietary fatty acids. We observed that stromal interaction molecule 1 (STIM1), a sensor of Ca(2+) depletion in the ER, mediated fatty acid-induced Ca(2+) signaling and spontaneous preference for fat in the mouse. In this review article, we discuss the recent advances and unresolved roles of CD36 and GPR120 in lipid taste signaling in taste bud cells. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

A numerical study on acoustic behavior in gas turbine combustor with acoustic resonator

International Nuclear Information System (INIS)

Park, I Sun; Sohn, Chae Hoon

2005-01-01

Acoustic behavior in gas turbine combustor with acoustic resonator is investigated numerically by adopting linear acoustic analysis. Helmholtz-type resonator is employed as acoustic resonator to suppress acoustic instability passively. The tuning frequency of acoustic resonator is adjusted by varying its length. Through harmonic analysis, acoustic-pressure responses of chamber to acoustic excitation are obtained and the resonant acoustic modes are identified. Acoustic damping effect of acoustic resonator is quantified by damping factor. As the tuning frequency of acoustic resonator approaches the target frequency of the resonant mode to be suppressed, mode split from the original resonant mode to lower and upper modes appears and thereby complex patterns of acoustic responses show up. Considering mode split and damping effect as a function of tuning frequency, it is desirable to make acoustic resonator tuned to broad-band frequencies near the maximum frequency of those of the possible upper modes

Acoustical Imaging

CERN Document Server

Litniewski, Jerzy; Kujawska, Tamara; 31st International Symposium on Acoustical Imaging

2012-01-01

The International Symposium on Acoustical Imaging is a unique forum for advanced research, covering new technologies, developments, methods and theories in all areas of acoustics. This interdisciplinary Symposium has been taking place continuously since 1968. In the course of the years the proceedings volumes in the Acoustical Imaging Series have become a reference for cutting-edge research in the field. In 2011 the 31st International Symposium on Acoustical Imaging was held in Warsaw, Poland, April 10-13. Offering both a broad perspective on the state-of-the-art as well as  in-depth research contributions by the specialists in the field, this Volume 31 in the Series contains an excellent collection of papers in six major categories: Biological and Medical Imaging Physics and Mathematics of Acoustical Imaging Acoustic Microscopy Transducers and Arrays Nondestructive Evaluation and Industrial Applications Underwater Imaging

Topological Acoustics

Science.gov (United States)

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.

Spontaneous Movements of a Computer Mouse Reveal Egoism and In-group Favoritism

Science.gov (United States)

Maliszewski, Norbert; Wojciechowski, Łukasz; Suszek, Hubert

2017-01-01

The purpose of the project was to assess whether the first spontaneous movements of a computer mouse, when making an assessment on a scale presented on the screen, may express a respondent’s implicit attitudes. In Study 1, the altruistic behaviors of 66 students were assessed. The students were led to believe that the task they were performing was also being performed by another person and they were asked to distribute earnings between themselves and the partner. The participants performed the tasks under conditions with and without distractors. With the distractors, in the first few seconds spontaneous mouse movements on the scale expressed a selfish distribution of money, while later the movements gravitated toward more altruism. In Study 2, 77 Polish students evaluated a painting by a Polish/Jewish painter on a scale. They evaluated it under conditions of full or distracted cognitive abilities. Spontaneous movements of the mouse on the scale were analyzed. In addition, implicit attitudes toward both Poles and Jews were measured with the Implicit Association Test (IAT). A significant association between implicit attitudes (IAT) and spontaneous evaluation of images using a computer mouse was observed in the group with the distractor. The participants with strong implicit in-group favoritism of Poles revealed stronger preference for the Polish painter’s work in the first few seconds of mouse movement. Taken together, these results suggest that spontaneous mouse movements may reveal egoism (in-group favoritism), i.e., processes that were not observed in the participants’ final decisions (clicking on the scale). PMID:28163689

Spontaneous Movements of a Computer Mouse Reveal Egoism and In-group Favoritism.

Science.gov (United States)

Maliszewski, Norbert; Wojciechowski, Łukasz; Suszek, Hubert

2017-01-01

The purpose of the project was to assess whether the first spontaneous movements of a computer mouse, when making an assessment on a scale presented on the screen, may express a respondent's implicit attitudes. In Study 1, the altruistic behaviors of 66 students were assessed. The students were led to believe that the task they were performing was also being performed by another person and they were asked to distribute earnings between themselves and the partner. The participants performed the tasks under conditions with and without distractors. With the distractors, in the first few seconds spontaneous mouse movements on the scale expressed a selfish distribution of money, while later the movements gravitated toward more altruism. In Study 2, 77 Polish students evaluated a painting by a Polish/Jewish painter on a scale. They evaluated it under conditions of full or distracted cognitive abilities. Spontaneous movements of the mouse on the scale were analyzed. In addition, implicit attitudes toward both Poles and Jews were measured with the Implicit Association Test (IAT). A significant association between implicit attitudes (IAT) and spontaneous evaluation of images using a computer mouse was observed in the group with the distractor. The participants with strong implicit in-group favoritism of Poles revealed stronger preference for the Polish painter's work in the first few seconds of mouse movement. Taken together, these results suggest that spontaneous mouse movements may reveal egoism (in-group favoritism), i.e., processes that were not observed in the participants' final decisions (clicking on the scale).

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

KAUST Repository

Al Jahdali, Rasha

2016-01-19

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

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

KAUST Repository

Al Jahdali, Rasha; Wu, Ying

2016-01-01

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

Vibro-acoustics

CERN Document Server

Nilsson, Anders

2015-01-01

This three-volume book gives a thorough and comprehensive presentation of vibration and acoustic theories. Different from traditional textbooks which typically deal with some aspects of either acoustic or vibration problems, it is unique of this book to combine those two correlated subjects together. Moreover, it provides fundamental analysis and mathematical descriptions for several crucial phenomena of Vibro-Acoustics which are quite useful in noise reduction, including how structures are excited, energy flows from an excitation point to a sound radiating surface, and finally how a structure radiates noise to a surrounding fluid. Many measurement results included in the text make the reading interesting and informative. Problems/questions are listed at the end of each chapter and the solutions are provided. This will help the readers to understand the topics of Vibro-Acoustics more deeply. The book should be of interest to anyone interested in sound and vibration, vehicle acoustics, ship acoustics and inter...

Acoustics an introduction

CERN Document Server

Kuttruff, Heinrich

2006-01-01

This definitive textbook provides students with a comprehensive introduction to acoustics. Beginning with the basic physical ideas, Acoustics balances the fundamentals with engineering aspects, applications and electroacoustics, also covering music, speech and the properties of human hearing. The concepts of acoustics are exposed and applied in:room acousticssound insulation in buildingsnoise controlunderwater sound and ultrasoundScientifically thorough, but with mathematics kept to a minimum, Acoustics is the perfect introduction to acoustics for students at any level of mechanical, electrical or civil engineering courses and an accessible resource for architects, musicians or sound engineers requiring a technical understanding of acoustics and their applications.

Interior acoustic cloak

OpenAIRE

Wael Akl; A. Baz

2014-01-01

Acoustic cloaks have traditionally been intended to externally surround critical objects to render these objects acoustically invisible. However, in this paper, the emphasis is placed on investigating the application of the acoustic cloaks to the interior walls of acoustic cavities in an attempt to minimize the noise levels inside these cavities. In this manner, the acoustic cloaks can serve as a viable and efficient alternative to the conventional passive noise attenuation treatments which a...

Acoustic energy harvesting based on a planar acoustic metamaterial

Science.gov (United States)

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.

Panel acoustic contribution analysis.

Science.gov (United States)

Wu, Sean F; Natarajan, Logesh Kumar

2013-02-01

Formulations are derived to analyze the relative panel acoustic contributions of a vibrating structure. The essence of this analysis is to correlate the acoustic power flow from each panel to the radiated acoustic pressure at any field point. The acoustic power is obtained by integrating the normal component of the surface acoustic intensity, which is the product of the surface acoustic pressure and normal surface velocity reconstructed by using the Helmholtz equation least squares based nearfield acoustical holography, over each panel. The significance of this methodology is that it enables one to analyze and rank relative acoustic contributions of individual panels of a complex vibrating structure to acoustic radiation anywhere in the field based on a single set of the acoustic pressures measured in the near field. Moreover, this approach is valid for both interior and exterior regions. Examples of using this method to analyze and rank the relative acoustic contributions of a scaled vehicle cabin are demonstrated.

Springer Handbook of Acoustics

CERN Document Server

Rossing, Thomas D

2007-01-01

Acoustics, the science of sound, has developed into a broad interdisciplinary field encompassing the academic disciplines of physics, engineering, psychology, speech, audiology, music, architecture, physiology, neuroscience, and others. The Springer Handbook of Acoustics is an unparalleled modern handbook reflecting this richly interdisciplinary nature edited by one of the acknowledged masters in the field, Thomas Rossing. Researchers and students benefit from the comprehensive contents spanning: animal acoustics including infrasound and ultrasound, environmental noise control, music and human speech and singing, physiological and psychological acoustics, architectural acoustics, physical and engineering acoustics, signal processing, medical acoustics, and ocean acoustics. This handbook reviews the most important areas of acoustics, with emphasis on current research. The authors of the various chapters are all experts in their fields. Each chapter is richly illustrated with figures and tables. The latest rese...

Convergent acoustic field of view in echolocating bats

DEFF Research Database (Denmark)

Jakobsen, Lasse; Ratcliffe, John M; Surlykke, Annemarie

2013-01-01

Most echolocating bats exhibit a strong correlation between body size and the frequency of maximum energy in their echolocation calls (peak frequency), with smaller species using signals of higher frequency than larger ones. Size-signal allometry or acoustic detection constraints imposed on wavel......Most echolocating bats exhibit a strong correlation between body size and the frequency of maximum energy in their echolocation calls (peak frequency), with smaller species using signals of higher frequency than larger ones. Size-signal allometry or acoustic detection constraints imposed...... on wavelength by preferred prey size have been used to explain this relationship. Here we propose the hypothesis that smaller bats emit higher frequencies to achieve directional sonar beams, and that variable beam width is critical for bats. Shorter wavelengths relative to the size of the emitter translate...... into more directional sound beams. Therefore, bats that emit their calls through their mouths should show a relationship between mouth size and wavelength, driving smaller bats to signals of higher frequency. We found that in a flight room mimicking a closed habitat, six aerial hawking vespertilionid...

Dust-acoustic instability in an inductive gas-discharge plasma

International Nuclear Information System (INIS)

Zobnin, A.V.; Usachev, A.D.; Petrov, O.F.; Fortov, V.E.

2002-01-01

Spontaneous excitation of a dust-particle density wave is observed in a dust cloud levitating in the region of the diffused edge of an rf inductive low-pressure gas-discharge plasma. The main physical parameters of this wave and of the background plasma are measured. The analytic model proposed for the observed phenomenon is based on the theory of dust sound and successfully correlates with experimental data in a wide range of experimental conditions. The effect of variable charge of dust particles on the evolution of the observed dust-plasma instability is studied analytically. It is shown that the necessary condition for the development of the dust-acoustic instability is the presence of a dc electric field in the dust cloud region

Numerical investigation of symmetry breaking and critical behavior of the acoustic streaming field in high-intensity discharge lamps

International Nuclear Information System (INIS)

Baumann, Bernd; Schwieger, Joerg; Wolff, Marcus; Manders, Freddy; Suijker, Jos

2015-01-01

For energy efficiency and material cost reduction it is preferred to drive high-intensity discharge lamps at frequencies of approximately 300 kHz. However, operating lamps at these high frequencies bears the risk of stimulating acoustic resonances inside the arc tube, which can result in low frequency light flicker and even lamp destruction. The acoustic streaming effect has been identified as the link between high frequency resonances and low frequency flicker. A highly coupled three-dimensional multiphysics model has been set up to calculate the acoustic streaming velocity field inside the arc tube of high-intensity discharge lamps. It has been found that the velocity field suffers a phase transition to an asymmetrical state at a critical acoustic streaming force. In certain respects the system behaves similar to a ferromagnet near the Curie point. It is discussed how the model allows to investigate the light flicker phenomenon. Concerning computer resources the procedure is considerably less demanding than a direct approach with a transient model. (paper)

Spontaneous acute spinal subdural hematoma: spontaneous recovery from severe paraparesis--case report and review.

Science.gov (United States)

Payer, Michael; Agosti, Reto

2010-11-01

Spontaneous idiopathic acute spinal subdural hematomas are highly exceptional. Neurological symptoms are usually severe, and rapid diagnosis with MRI is mandatory. Surgical evacuation has frequently been used therapeutically; however, spontaneous recovery in mild cases has also been reported. We present a case of spontaneous recovery from severe paraparesis after spontaneous acute SSDH, and review the English-speaking literature.

Acoustic Neuroma Association

Science.gov (United States)

... EVENTS DONATE NEWS Home Learn Back Learn about acoustic neuroma AN Facts What is acoustic neuroma? Diagnosing ... Brain Freeze ? READ MORE Read More What is acoustic neuroma? Identifying an AN Learn More Get Info ...

Mode of Delivery Preferences in a Diverse Population of Pregnant Women

Science.gov (United States)

YEE, Lynn M.; KAIMAL, Anjali J.; HOUSTON, Kathryn A.; WU, Erica; THIET, Mari-Paule; NAKAGAWA, Sanae; CAUGHEY, Aaron B.; FIROUZIAN, Atoosa; KUPPERMANN, Miriam

2014-01-01

OBJECTIVE To assess women’s preferences for vaginal versus cesarean delivery in four contexts: prior cesarean, twins, breech presentation, and absent indication for cesarean. STUDY DESIGN Cross-sectional study of pregnant women at 24-40 weeks gestation. After assessing stated preferences for vaginal or cesarean delivery, we used the standard gamble metric to measure the strength of these preferences and the time tradeoff metric to determine how women value the potential processes and outcomes associated with these two delivery approaches. RESULTS Among the 240 participants, 90.8% had a stated preference for vaginal delivery. Across the four contexts, these women indicated that, on average, they would accept a 59-75% chance of an attempted vaginal birth ending in a cesarean before choosing a planned cesarean, indicating strong preferences for spontaneous, uncomplicated vaginal delivery. Variations in preferences for labor processes emerged. While uncomplicated labor ending in vaginal birth was assigned mean utilities of 0.993 or higher (on a 0-to-1 scale with higher scores indicating more preferred outcomes), the need for oxytocin, antibiotics, or operative vaginal delivery resulted in lower mean scores, comparable to those assigned to uncomplicated cesarean delivery. Substantially lower scores (ranging from 0.432 to 0.598) were obtained for scenarios ending in severe maternal or neonatal morbidity. CONCLUSIONS While most women expressed strong preferences for vaginal delivery, their preferences regarding interventions frequently employed to achieve that goal varied. These data underscore the importance of educating patients about the process of labor and delivery to facilitate incorporation of informed patient preferences in shared decision making regarding delivery approach. PMID:25446662

Development of ion-acoustic double layers through ion-acoustic fluctuations

International Nuclear Information System (INIS)

Sekar, A.N.; Saxena, Y.C.

1985-01-01

Experimental results on the formation of ion acoustic double layers resembling asymmetric ion-holes are presented. In a double plasma device, modified suitably to inject electron beam into the target plasma, modulation of the beam through step potential leads to excitation of ion-acoustic fluctuation. The ion-acoustic fluctuation, growing away from the grids separating source and target plasmas, developed into weak asymmetric ion-acoustic double layer. The observations are in qualitative agreement with theoretical models and computer simulations. (author)

Acoustic tweezers via sub-time-of-flight regime surface acoustic waves.

Science.gov (United States)

Collins, David J; Devendran, Citsabehsan; Ma, Zhichao; Ng, Jia Wei; Neild, Adrian; Ai, Ye

2016-07-01

Micrometer-scale acoustic waves are highly useful for refined optomechanical and acoustofluidic manipulation, where these fields are spatially localized along the transducer aperture but not along the acoustic propagation direction. In the case of acoustic tweezers, such a conventional acoustic standing wave results in particle and cell patterning across the entire width of a microfluidic channel, preventing selective trapping. We demonstrate the use of nanosecond-scale pulsed surface acoustic waves (SAWs) with a pulse period that is less than the time of flight between opposing transducers to generate localized time-averaged patterning regions while using conventional electrode structures. These nodal positions can be readily and arbitrarily positioned in two dimensions and within the patterning region itself through the imposition of pulse delays, frequency modulation, and phase shifts. This straightforward concept adds new spatial dimensions to which acoustic fields can be localized in SAW applications in a manner analogous to optical tweezers, including spatially selective acoustic tweezers and optical waveguides.

Acoustic textiles

CERN Document Server

Nayak, Rajkishore

2016-01-01

This book highlights the manufacturing and applications of acoustic textiles in various industries. It also includes examples from different industries in which acoustic textiles can be used to absorb noise and help reduce the impact of noise at the workplace. Given the importance of noise reduction in the working environment in several industries, the book offers a valuable guide for companies, educators and researchers involved with acoustic materials.

Architectural acoustics

National Research Council Canada - National Science Library

Long, Marshall

2014-01-01

.... Beginning with a brief history, it reviews the fundamentals of acoustics, human perception and reaction to sound, acoustic noise measurements, noise metrics, and environmental noise characterization...

Bilateral spontaneous hemotympanum: Case report

Directory of Open Access Journals (Sweden)

Economou Nicolas C

2006-10-01

Full Text Available Abstract Background The most common causes of hemotympanum are therapeutic nasal packing, epistaxis, blood disorders and blunt trauma to the head. Hemotympanum is characterized as idiopathic, when it is detected in the presence of chronic otitis media. A rare case of spontaneous bilateral hemotympanum in a patient treated with anticoagulants is presented herein. Case presentation A 72-year-old male presented with acute deterioration of hearing. In the patient's medical history aortic valve replacement 1 year before presentation was reported. Since then he had been administered regularly coumarinic anticoagulants, with INR levels maintained between 3.4 and 4.0. Otoscopy revealed the presence of bilateral hemotympanum. The audiogram showed symmetrical moderately severe mixed hearing loss bilaterally, with the conductive component predominating. Tympanograms were flat bilaterally with absent acoustic reflexes. A computerized tomography scan showed the presence of fluid in the mastoid and middle ear bilaterally. Treatment was conservative and consisted of a 10-day course of antibiotics, anticongestants and temporary interruption of the anticoagulant therapy. After 3 weeks, normal tympanic membranes were found and hearing had returned to previous levels. Conclusion Anticoagulant intake should be included in the differential diagnosis of hemotympanum, because its detection and appropriate treatment may lead to resolution of the disorder.

Spontaneous Scalarization of Black Holes and Compact Stars from a Gauss-Bonnet Coupling.

Science.gov (United States)

Silva, Hector O; Sakstein, Jeremy; Gualtieri, Leonardo; Sotiriou, Thomas P; Berti, Emanuele

2018-03-30

We identify a class of scalar-tensor theories with coupling between the scalar and the Gauss-Bonnet invariant that exhibit spontaneous scalarization for both black holes and compact stars. In particular, these theories formally admit all of the stationary solutions of general relativity, but these are not dynamically preferred if certain conditions are satisfied. Remarkably, black holes exhibit scalarization if their mass lies within one of many narrow bands. We find evidence that scalarization can occur in neutron stars as well.

Spontaneous laterality in mouse Crl:CD1.

Science.gov (United States)

Maciejewska, Maria; Zięba, Katarzyna; Szymańska, Justyna; Warońska, Magdalena

2016-01-01

Lateralization developed very early in evolution and it is a characteristic of a wide range of representatives from the animal kingdom. The aim of the present study was to examine the spontaneous laterality in mice (Mus musculus) with the T-maze test. We wanted to check if this kind of functional asymmetry occurs at a population level, and also if there are gender differences in this regard. The study involved 40 mice Crl:CD1. The research procedure was simple: mice had to choose one arm of the T-shaped apparatus to find the exit. The animals performed the 10 trails one after another. We took into account only the animals' fist reactions while preparing results. Most of the animals (68%) chose the right arm of the maze. The lateralization was stronger among females--75% of them had preferences for the right side. The majority of animals, which preferred the right side, were from the food deprivation group. However, the results did not unequivocally resolve whether mice evince the functional asymmetry at the population level, or whether there are gender differences in this area. Further research with a larger group and multiple observations for each animal are required to answer these questions.

Supersonic acoustic intensity with statistically optimized near-field acoustic holography

DEFF Research Database (Denmark)

Fernandez Grande, Efren; Jacobsen, Finn

2011-01-01

The concept of supersonic acoustic intensity was introduced some years ago for estimating the fraction of the flow of energy radiated by a source that propagates to the far field. It differs from the usual (active) intensity by excluding the near-field energy resulting from evanescent waves...... to the information provided by the near-field acoustic holography technique. This study proposes a version of the supersonic acoustic intensity applied to statistically optimized near-field acoustic holography (SONAH). The theory, numerical results and an experimental study are presented. The possibility of using...

Acoustic Metamaterials in Aeronautics

Directory of Open Access Journals (Sweden)

Giorgio Palma

2018-06-01

Full Text Available Metamaterials, man-made composites that are scaled smaller than the wavelength, have demonstrated a huge potential for application in acoustics, allowing the production of sub-wavelength acoustic absorbers, acoustic invisibility, perfect acoustic mirrors and acoustic lenses for hyper focusing, and acoustic illusions and enabling new degrees of freedom in the control of the acoustic field. The zero, or even negative, refractive sound index of metamaterials offers possibilities for the control of acoustic patterns and sound at sub-wavelength scales. Despite the tremendous growth in research on acoustic metamaterials during the last decade, the potential of metamaterial-based technologies in aeronautics has still not been fully explored, and its utilization is still in its infancy. Thus, the principal concepts mentioned above could very well provide a means to develop devices that allow the mitigation of the impact of civil aviation noise on the community. This paper gives a review of the most relevant works on acoustic metamaterials, analyzing them for their potential applicability in aeronautics, and, in this process, identifying possible implementation areas and interesting metabehaviors. It also identifies some technical challenges and possible future directions for research with the goal of unveiling the potential of metamaterials technology in aeronautics.

Calibration of acoustic emission transducers

International Nuclear Information System (INIS)

Leschek, W.C.

1976-01-01

A method is described for calibrating an acoustic emission transducer to be used in a pre-set frequency range. The absolute reception sensitivity of a reference transducer is determined at frequencies selected within the frequency range. The reference transducer and the acoustic emission transducer are put into acoustic communication with the surface of a limited acoustic medium representing an equivalent acoustic load appreciably identical to that of the medium in which the use of the acoustic emission transducer is intended. A blank random acoustic noise is emitted in the acoustic medium in order to establish a diffuse and reverberating sound field, after which the output responses of the reference transducer and of the acoustic emission transducer are obtained with respect to the diffuse and reverberating field, for selected frequencies. The output response of the acoustic emission transducer is compared with that of the reference transducer for the selected frequencies, so as to determine the reception sensitivity of the acoustic emission transducer [fr

Acoustical and optical radiation pressure and the development of single beam acoustical tweezers

International Nuclear Information System (INIS)

Thomas, Jean-Louis; Marchiano, Régis; Baresch, Diego

2017-01-01

Studies on radiation pressure in acoustics and optics have enriched one another and have a long common history. Acoustic radiation pressure is used for metrology, levitation, particle trapping and actuation. However, the dexterity and selectivity of single-beam optical tweezers are still to be matched with acoustical devices. Optical tweezers can trap, move and position micron size particles, biological samples or even atoms with subnanometer accuracy in three dimensions. One limitation of optical tweezers is the weak force that can be applied without thermal damage due to optical absorption. Acoustical tweezers overcome this limitation since the radiation pressure scales as the field intensity divided by the speed of propagation of the wave. However, the feasibility of single beam acoustical tweezers was demonstrated only recently. In this paper, we propose a historical review of the strong similarities but also the specificities of acoustical and optical radiation pressures, from the expression of the force to the development of single-beam acoustical tweezers. - Highlights: • Studies on radiation pressure in acoustics and optics have enriched one another and have a long common history. • Acoustic radiation pressure is used for metrology, levitation, particle trapping and actuation. • However, the dexterity and selectivity of single-beam optical tweezers are still to be matched with acoustical devices. • Optical tweezers can trap, move and positioned micron size particles with subnanometer accuracy in three dimensions. • One limitation of optical tweezers is the weak force that can be applied without thermal damage due to optical absorption. • Acoustical tweezers overcome this limitation since the force scales as the field intensity divided by its propagation speed. • However, the feasibility of single beam acoustical tweezers was demonstrated only recently. • We propose a review of the strong similarities but also the specificities of acoustical

Radiation acoustics and its applications

International Nuclear Information System (INIS)

Lyamshev, L.M.

1992-01-01

Radiation acoustics is a new branch of acoustics, developing on the boundary of acoustics, nuclear physics, elementary particles and high-energy physics. Its fundamentals are laying in the research of acoustical effects due to the interaction of penetrating radiation with matter. The study of radiation-acoustical effects leads to the new opportunities in the penetration radiation research (acoustical detection, radiation-acoustical dosimetry), study of the physical parameters of matter, in a solution of some applied problems of nondestructive testing, and also for the radiation-acoustical influence on physical and chemical structure of the matter. Results of theoretical and experimental investigations are given. Different mechanisms of the sound generation by penetrating radiation of liquids and solids are considered. Some applications - the radiation acoustical microscopy and visualisation, the acoustical detection of high energy X-ray particles and possibility of using of high energy neutrino beams in geoacoustics - are discussed

Parametric Room Acoustic Workflows

DEFF Research Database (Denmark)

Parigi, Dario; Svidt, Kjeld; Molin, Erik

2017-01-01

The paper investigates and assesses different room acoustics software and the opportunities they offer to engage in parametric acoustics workflow and to influence architectural designs. The first step consists in the testing and benchmarking of different tools on the basis of accuracy, speed...... and interoperability with Grasshopper 3d. The focus will be placed to the benchmarking of three different acoustic analysis tools based on raytracing. To compare the accuracy and speed of the acoustic evaluation across different tools, a homogeneous set of acoustic parameters is chosen. The room acoustics parameters...... included in the set are reverberation time (EDT, RT30), clarity (C50), loudness (G), and definition (D50). Scenarios are discussed for determining at different design stages the most suitable acoustic tool. Those scenarios are characterized, by the use of less accurate but fast evaluation tools to be used...

Acoustic Neuroma

Science.gov (United States)

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

High-Frequency Seafloor Acoustics

CERN Document Server

Jackson, Darrell R

2007-01-01

High-Frequency Seafloor Acoustics is the first book in a new series sponsored by the Office of Naval Research on the latest research in underwater acoustics. This exciting new title provides ready access to experimental data, theory, and models relevant to high-frequency seafloor acoustics and will be of interest to sonar engineers and researchers working in underwater acoustics. The physical characteristics of the seafloor affecting acoustic propagation and scattering are covered, including physical and geoacoustic properties and surface roughness. Current theories for acoustic propagation in sediments are presented along with corresponding models for reflection, scattering, and seafloor penetration. The main text is backed up by an extensive bibliography and technical appendices.

Acoustic evaluation of wood quality in standing trees. Part I, Acoustic wave behavior

Science.gov (United States)

Xiping Wang; Robert J. Ross; Peter Carter

2007-01-01

Acoustic wave velocities in standing trees or live softwood species were measured by the time-of-flight (TOF) method. Tree velocities were compared with acoustic velocities measured in corresponding butt logs through a resonance acoustic method. The experimental data showed a skewed relationship between tree and log acoustic measurements. For most trees tested,...

Spontaneous external gallbladder perforation

International Nuclear Information System (INIS)

Noeldge, G.; Wimmer, B.; Kirchner, R.

1981-01-01

Spontaneous perforation of the gallbladder is one complication of cholelithiasis. There is a greater occurence of free perforation in the peritoneal cavity with bilary pertonitis, followed by the perforation into the stomach, small intestine and colon. A single case of the nowadays rare spontaneous perforation in and through the abdominal wall will be reported. Spontaneous gallbladder perforation appears nearly asymptomatic in its clinical course because of absent biliary peritonitis. (orig.) [de

Quasi-Free-Standing Graphene Monolayer on a Ni Crystal through Spontaneous Na Intercalation

Directory of Open Access Journals (Sweden)

Young S. Park

2014-07-01

Full Text Available Graphene on metal substrates often shows different electronic properties from isolated graphene because of graphene-substrate interactions. One needs to remove the metals with acids and then to transfer graphene to weakly interacting substrates to recover electrical properties inherent in graphene. This process is not easy and besides causes undesirable tears, defects, and impurities in graphene. Here, we report a method to recover the electronic structure of graphene from a strongly interacting Ni substrate by spontaneous Na intercalation. In order to characterize the intercalation process, the density-functional-theory calculations and angle-resolved photoemission-spectroscopy (ARPES and scanning-tunneling-microscopy (STM measurements are carried out. From the density-functional-theory calculations, Na atoms energetically prefer interface intercalation to surface adsorption for the graphene/Ni(111 surface. Unlike most intercalants, Na atoms intercalate spontaneously at room temperature due to a tiny diffusion barrier, which is consistent with our temperature-dependent ARPES and core-level photoemission spectroscopy, and with our submonolayer ARPES and STM results at room temperature. As a result of the spontaneous intercalation, the electronic structure of graphene is almost recovered, as confirmed by the Dirac cone with a negligible band gap in ARPES and the sixfold symmetry in STM.

Room Acoustics

Science.gov (United States)

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.

Acoustic scaling: A re-evaluation of the acoustic model of Manchester Studio 7

Science.gov (United States)

Walker, R.

1984-12-01

The reasons for the reconstruction and re-evaluation of the acoustic scale mode of a large music studio are discussed. The design and construction of the model using mechanical and structural considerations rather than purely acoustic absorption criteria is described and the results obtained are given. The results confirm that structural elements within the studio gave rise to unexpected and unwanted low-frequency acoustic absorption. The results also show that at least for the relatively well understood mechanisms of sound energy absorption physical modelling of the structural and internal components gives an acoustically accurate scale model, within the usual tolerances of acoustic design. The poor reliability of measurements of acoustic absorption coefficients, is well illustrated. The conclusion is reached that such acoustic scale modelling is a valid and, for large scale projects, financially justifiable technique for predicting fundamental acoustic effects. It is not appropriate for the prediction of fine details because such small details are unlikely to be reproduced exactly at a different size without extensive measurements of the material's performance at both scales.

CALCULATION OF ACOUSTIC EFFICIENCY OF PORTABLE ACOUSTIC SCREEN

Directory of Open Access Journals (Sweden)

Aleksandr Skvortsov

2016-03-01

Full Text Available The research of influence of life environment adverse factors on physical development and health of population is an actual problem of ecology. The aspects of the most actual problems of the modern world, namely environmental industrial noise pollution are considered in the article. Industrial facilities everywhere have noisy equipment. Noise is a significant factors of negative influenceon people and environment. Combined effects of noise and of other physical pollutions on people may cause amplification of their negative impact. If the noise pollution level from the object in a residential area exceeds the permissible levels (MPL, noise protection measures can be initiated. Today, the most common design decisions for noise protection are sound absorbing construction, noise screens and barriers, acousting housings, soundproff cabins. Many of them are popular, others are less known. The article deals with one of the most wide spread means of noise protection – a portable acoustic screen. The aim of the research is to determine the efficiency of portable acoustic screens. It is shown that the installation of such structures can reduce the average value of the sound level. The authors analyzed acoustic screens as device to reduce noise pollution. The authors offer a potable acoustic screen differing from the used easyness, mobility, minimum price and good sound protective properties. Effectiveness, a sound absorption coefficient and sound conductivity coefficient of a portable acoustic screen are evaluated. The descriptions of the algorithm calculations and the combination of technical solutions have practical originality. The results of the research demonstrate the advantages of the proposed solutions for reducing noise levels in the agro-industrial complex.

How acoustic signals scale with individual body size: common trends across diverse taxa

OpenAIRE

Rafael L. Rodríguez; Marcelo Araya-Salas; David A. Gray; Michael S. Reichert; Laurel B. Symes; Matthew R. Wilkins; Rebecca J. Safran; Gerlinde Höbel

2015-01-01

We use allometric analysis to explore how acoustic signals scale on individual body size and to test hypotheses about the factors shaping relationships between signals and body size. Across case studies spanning birds, crickets, tree crickets, and tree frogs, we find that most signal traits had low coefficients of variation, shallow allometric scalings, and little dispersion around the allometric function. We relate variation in these measures to the shape of mate preferences and the level of...

Effects of subsampling of passive acoustic recordings on acoustic metrics.

Science.gov (United States)

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.

Definition of spontaneous reconnection

International Nuclear Information System (INIS)

Schindler, K.

1984-01-01

The author discusses his view of driven versus spontaneous. There is a close link between ''spontaneous'' and ''instability.'' One of the prominent examples for instability is the thermal convection instability. Just to remind you, if you heat a fluid layer from below, it takes a certain Rayleigh number to make it unstable. Beyond the onset point you find qualitatively new features. That is called ''spontaneous,'' and this is a bit more than semantics. It's a new qualitative property that appears and it is spontaneous although we have an energy flux through the system. It's a misconception, to call this ''driven'' pointing at the energy flux through it. Of course, the convection would not exist without this energy flux. But what makes it ''spontaneous'' is that without any particular external signal, a new qualitative feature appears. And this is what is called an ''instability'' and ''spontaneous.'' From these considerations the author got a little reassured of what distinction should be made in the field of the magnetosphere. If we have a smooth energy transport into the magnetosphere and suddenly we have this qualitatively new feature (change of B-topology) coming up; then, using this terminology we don't have a choice other than calling this spontaneous or unstable, if you like. If we ''tell'' the system where it should make its neutral line and where it should make its plasmoids, then, it is driven. And this provides a very clear-cut observational distinction. The author emphasizes the difference he sees is a qualitative difference, not only a quantitative one

Anti-sound and Acoustical Cloaks

Directory of Open Access Journals (Sweden)

Veturia CHIROIU

2016-12-01

Full Text Available The principles by which the acoustics can be mimicked in order to reduce or cancel the vibrational field are based on anti-sound concept which can be materialized by acoustic cloaks. Geometric transformations open an elegant way towards the unconstrained control of sound through acoustic metamaterials. Acoustic cloaks can be achieved through geometric transformations which bring exotic metamaterial properties into the acoustic equations. Our paper brings new ideas concerning the technological keys for manufacturing of novel metamaterials based on the spatial compression of Cantor structures, and the architecture of 3D acoustic cloaks in a given frequency band, with application to architectural acoustics.

Acoustical and optical radiation pressure and the development of single beam acoustical tweezers

Science.gov (United States)

Thomas, Jean-Louis; Marchiano, Régis; Baresch, Diego

2017-07-01

Studies on radiation pressure in acoustics and optics have enriched one another and have a long common history. Acoustic radiation pressure is used for metrology, levitation, particle trapping and actuation. However, the dexterity and selectivity of single-beam optical tweezers are still to be matched with acoustical devices. Optical tweezers can trap, move and position micron size particles, biological samples or even atoms with subnanometer accuracy in three dimensions. One limitation of optical tweezers is the weak force that can be applied without thermal damage due to optical absorption. Acoustical tweezers overcome this limitation since the radiation pressure scales as the field intensity divided by the speed of propagation of the wave. However, the feasibility of single beam acoustical tweezers was demonstrated only recently. In this paper, we propose a historical review of the strong similarities but also the specificities of acoustical and optical radiation pressures, from the expression of the force to the development of single-beam acoustical tweezers.

Acoustic transparency and slow sound using detuned acoustic resonators

DEFF Research Database (Denmark)

Santillan, Arturo Orozco; Bozhevolnyi, Sergey I.

2011-01-01

We demonstrate that the phenomenon of acoustic transparency and slowsound propagation can be realized with detuned acoustic resonators (DAR), mimicking thereby the effect of electromagnetically induced transparency (EIT) in atomic physics. Sound propagation in a pipe with a series of side...

Computational Ocean Acoustics

CERN Document Server

Jensen, Finn B; Porter, Michael B; Schmidt, Henrik

2011-01-01

Since the mid-1970s, the computer has played an increasingly pivotal role in the field of ocean acoustics. Faster and less expensive than actual ocean experiments, and capable of accommodating the full complexity of the acoustic problem, numerical models are now standard research tools in ocean laboratories. The progress made in computational ocean acoustics over the last thirty years is summed up in this authoritative and innovatively illustrated new text. Written by some of the field's pioneers, all Fellows of the Acoustical Society of America, Computational Ocean Acoustics presents the latest numerical techniques for solving the wave equation in heterogeneous fluid–solid media. The authors discuss various computational schemes in detail, emphasizing the importance of theoretical foundations that lead directly to numerical implementations for real ocean environments. To further clarify the presentation, the fundamental propagation features of the techniques are illustrated in color. Computational Ocean A...

Acoustic Test Results of Melamine Foam with Application to Payload Fairing Acoustic Attenuation Systems

Science.gov (United States)

Hughes, William O.; McNelis, Anne M.

2014-01-01

A spacecraft at launch is subjected to a harsh acoustic and vibration environment resulting from the passage of acoustic energy, created during the liftoff of a launch vehicle, through the vehicle's payload fairing. In order to ensure the mission success of the spacecraft it is often necessary to reduce the resulting internal acoustic sound pressure levels through the usage of acoustic attenuation systems. Melamine foam, lining the interior walls of the payload fairing, is often utilized as the main component of such a system. In order to better understand the acoustic properties of melamine foam, with the goal of developing improved acoustic attenuation systems, NASA has recently performed panel level testing on numerous configurations of melamine foam acoustic treatments at the Riverbank Acoustical Laboratory. Parameters assessed included the foam's thickness and density, as well as the effects of a top outer cover sheet material and mass barriers embedded within the foam. This testing followed the ASTM C423 standard for absorption and the ASTM E90 standard for transmission loss. The acoustic test data obtained and subsequent conclusions are the subjects of this paper.

Passive listening to preferred motor tempo modulates corticospinal excitability.

Science.gov (United States)

Michaelis, Kelly; Wiener, Martin; Thompson, James C

2014-01-01

Rhythms are an essential characteristic of our lives, and auditory-motor coupling affects a variety of behaviors. Previous research has shown that the neural regions associated with motor system processing are coupled to perceptual rhythmic and melodic processing such that the perception of rhythmic stimuli can entrain motor system responses. However, the degree to which individual preference modulates the motor system is unknown. Recent work has shown that passively listening to metrically strong rhythms increases corticospinal excitability, as indicated by transcranial magnetic stimulation (TMS). Furthermore, this effect is modulated by high-groove music, or music that inspires movement, while neuroimaging evidence suggests that premotor activity increases with tempos occurring within a preferred tempo (PT) category. PT refers to the rate of a hypothetical endogenous oscillator that may be indicated by spontaneous motor tempo (SMT) and preferred perceptual tempo (PPT) measurements. The present study investigated whether listening to a rhythm at an individual's PT preferentially modulates motor system excitability. SMT was obtained in human participants through a tapping task in which subjects were asked to tap a response key at their most comfortable rate. Subjects listened a 10-beat tone sequence at 11 log-spaced tempos and rated their preference for each (PPT). We found that SMT and PPT measurements were correlated, indicating that preferred and produced tempos occurred at a similar rate. Crucially, single-pulse TMS delivered to left M1 during PPT judgments revealed that corticospinal excitability, measured by motor-evoked potentials (MEPs), was modulated by tempos traveling closer to individual PT. However, the specific nature of this modulation differed across individuals, with some exhibiting an increase in excitability around PT and others exhibiting a decrease. These findings suggest that auditory-motor coupling induced by rhythms is preferentially

Acoustical qualification of Teatro Nuovo in Spoleto before refurbishing works

Science.gov (United States)

Cocchi, Alessandro; Cesare Consumi, Marco; Shimokura, Ryota

2004-05-01

To qualify the acoustical quality of an opera house two different approaches are now available: one is based on responses of qualified listeners (subjective judgments) compared with objective values of selected parameters, the other on comparison tests conducted in suited rooms and on a model of the auditory brain system (preference). In the occasion of the refurbishment of an opera house known for the Two Worlds Festival edited yearly by the Italian Composer G. C. Menotti, a large number of measurements were taken with different techniques, so it is possible to compare the different methods and also the results with some geometrical criterion, based on the most simple rules of musical harmony, now neglected as our attention is attracted to computer simulations, computer aided measurement techniques and similar modern methods. From this work some link between well known acoustical parameters (not known at the time when architects sketched the shape of ancient opera houses) and geometrical criteria (well known at the time when ancient opera houses were built) will be shown.

Density-near-zero using the acoustically induced transparency of a Fano acoustic resonator

KAUST Repository

Elayouch, A.

2017-01-05

We report experimental results of near-zero mass density involving an acoustic metamaterial supporting Fano resonance. For this, we designed and fabricated an acoustic resonator with two closely coupled modes and measured its transmission properties. Our study reveals that the phenomenon of acoustically induced transparency is accompanied by an effect of near-zero density. Indeed, the dynamic effective parameters obtained from experimental data show the presence of a frequency band where the effective mass density is close to zero, with high transmission levels reaching 0.7. Furthermore, we demonstrate that such effective parameters lead to wave guiding in a 90-degrees-bent channel. This kind of acoustic metamaterial can, therefore, give rise to acoustic functions like controlling the wavefront, which may lead to very promising applications in acoustic cloacking or imaging.

Introducing passive acoustic filter in acoustic based condition monitoring: Motor bike piston-bore fault identification

Science.gov (United States)

Jena, D. P.; Panigrahi, S. N.

2016-03-01

Requirement of designing a sophisticated digital band-pass filter in acoustic based condition monitoring has been eliminated by introducing a passive acoustic filter in the present work. So far, no one has attempted to explore the possibility of implementing passive acoustic filters in acoustic based condition monitoring as a pre-conditioner. In order to enhance the acoustic based condition monitoring, a passive acoustic band-pass filter has been designed and deployed. Towards achieving an efficient band-pass acoustic filter, a generalized design methodology has been proposed to design and optimize the desired acoustic filter using multiple filter components in series. An appropriate objective function has been identified for genetic algorithm (GA) based optimization technique with multiple design constraints. In addition, the sturdiness of the proposed method has been demonstrated in designing a band-pass filter by using an n-branch Quincke tube, a high pass filter and multiple Helmholtz resonators. The performance of the designed acoustic band-pass filter has been shown by investigating the piston-bore defect of a motor-bike using engine noise signature. On the introducing a passive acoustic filter in acoustic based condition monitoring reveals the enhancement in machine learning based fault identification practice significantly. This is also a first attempt of its own kind.

Acoustic comfort in eating establishments

DEFF Research Database (Denmark)

Svensson, David; Jeong, Cheol-Ho; Brunskog, Jonas

2014-01-01

The subjective concept of acoustic comfort in eating establishments has been investigated in this study. The goal was to develop a predictive model for the acoustic comfort, by means of simple objective parameters, while also examining which other subjective acoustic parameters could help explain...... the feeling of acoustic comfort. Through several layers of anal ysis, acoustic comfort was found to be rather complex, and could not be explained entirely by common subjective parameters such as annoyance, intelligibility or privacy. A predictive model for the mean acoustic comfort for an eating establishment...

Springer handbook of acoustics

CERN Document Server

2014-01-01

Acoustics, the science of sound, has developed into a broad interdisciplinary field encompassing the academic disciplines of physics, engineering, psychology, speech, audiology, music, architecture, physiology, neuroscience, and electronics. The Springer Handbook of Acoustics is also in his 2nd edition an unparalleled modern handbook reflecting this richly interdisciplinary nature edited by one of the acknowledged masters in the field, Thomas Rossing. Researchers and students benefit from the comprehensive contents. This new edition of the Handbook features over 11 revised and expanded chapters, new illustrations, and 2 new chapters covering microphone arrays  and acoustic emission.  Updated chapters contain the latest research and applications in, e.g. sound propagation in the atmosphere, nonlinear acoustics in fluids, building and concert hall acoustics, signal processing, psychoacoustics, computer music, animal bioacousics, sound intensity, modal acoustics as well as new chapters on microphone arrays an...

Acoustical Imaging

CERN Document Server

Akiyama, Iwaki

2009-01-01

The 29th International Symposium on Acoustical Imaging was held in Shonan Village, Kanagawa, Japan, April 15-18, 2007. This interdisciplinary Symposium has been taking place every two years since 1968 and forms a unique forum for advanced research, covering new technologies, developments, methods and theories in all areas of acoustics. In the course of the years the volumes in the Acoustical Imaging Series have developed and become well-known and appreciated reference works. Offering both a broad perspective on the state-of-the-art in the field as well as an in-depth look at its leading edge research, this Volume 29 in the Series contains again an excellent collection of seventy papers presented in nine major categories: Strain Imaging Biological and Medical Applications Acoustic Microscopy Non-Destructive Evaluation and Industrial Applications Components and Systems Geophysics and Underwater Imaging Physics and Mathematics Medical Image Analysis FDTD method and Other Numerical Simulations Audience Researcher...

Battlefield acoustics

CERN Document Server

Damarla, Thyagaraju

2015-01-01

This book presents all aspects of situational awareness in a battlefield using acoustic signals. It starts by presenting the science behind understanding and interpretation of sound signals. The book then goes on to provide various signal processing techniques used in acoustics to find the direction of sound source, localize gunfire, track vehicles, and detect people. The necessary mathematical background and various classification and fusion techniques are presented. The book contains majority of the things one would need to process acoustic signals for all aspects of situational awareness in one location. The book also presents array theory, which is pivotal in finding the direction of arrival of acoustic signals. In addition, the book presents techniques to fuse the information from multiple homogeneous/heterogeneous sensors for better detection. MATLAB code is provided for majority of the real application, which is a valuable resource in not only understanding the theory but readers, can also use the code...

Acoustic insulator for combined well equipment of acoustic and radioactivity logging

International Nuclear Information System (INIS)

Arkad'ev, E.A.; Gorbachev, Yu.I.; Dseban', I.P.; Yagodov, G.I.

1977-01-01

The design of an acoustic insulator for cobined well equipment of acoustic and radioactivity logaing made on the basis of studying the velocity of elastic waves propagation and attenuation in cable structures of various marks is described. It is shown that the cable probe of electric loggign equipment which is recommended as an acoustic insulator for combined well equipment has the necessary sound-insulating properties

Acoustic and streaming velocity components in a resonant waveguide at high acoustic levels.

Science.gov (United States)

Daru, Virginie; Reyt, Ida; Bailliet, Hélène; Weisman, Catherine; Baltean-Carlès, Diana

2017-01-01

Rayleigh streaming is a steady flow generated by the interaction between an acoustic wave and a solid wall, generally assumed to be second order in a Mach number expansion. Acoustic streaming is well known in the case of a stationary plane wave at low amplitude: it has a half-wavelength spatial periodicity and the maximum axial streaming velocity is a quadratic function of the acoustic velocity amplitude at antinode. For higher acoustic levels, additional streaming cells have been observed. Results of laser Doppler velocimetry measurements are here compared to direct numerical simulations. The evolution of axial and radial velocity components for both acoustic and streaming velocities is studied from low to high acoustic amplitudes. Two streaming flow regimes are pointed out, the axial streaming dependency on acoustics going from quadratic to linear. The evolution of streaming flow is different for outer cells and for inner cells. Also, the hypothesis of radial streaming velocity being of second order in a Mach number expansion, is not valid at high amplitudes. The change of regime occurs when the radial streaming velocity amplitude becomes larger than the radial acoustic velocity amplitude, high levels being therefore characterized by nonlinear interaction of the different velocity components.

Controlling sound with acoustic metamaterials

DEFF Research Database (Denmark)

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

2016-01-01

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......-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...

Education in acoustics in Argentina

Science.gov (United States)

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.

Spontaneous intracranial hypotension.

LENUS (Irish Health Repository)

Fullam, L

2012-01-31

INTRODUCTION: Spontaneous\\/primary intracranial hypotension is characterised by orthostatic headache and is associated with characteristic magnetic resonance imaging findings. CASE REPORT: We present a case report of a patient with typical symptoms and classical radiological images. DISCUSSION: Spontaneous intracranial hypotension is an under-recognised cause of headache and can be diagnosed by history of typical orthostatic headache and findings on MRI brain.

Review of Progress in Acoustic Levitation

Science.gov (United States)

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

2018-04-01

Acoustic levitation uses acoustic radiation forces to counteract gravity and suspend objects in mid-air. Although acoustic levitation was first demonstrated almost a century ago, for a long time, it was limited to objects much smaller than the acoustic wavelength levitating at fixed positions in space. Recent advances in acoustic levitation now allow not only suspending but also rotating and translating objects in three dimensions. Acoustic levitation is also no longer restricted to small objects and can now be employed to levitate objects larger than the acoustic wavelength. This article reviews the progress of acoustic levitation, focusing on the working mechanism of different types of acoustic levitation devices developed to date. We start with a brief review of the theory. Then, we review the acoustic levitation methods to suspend objects at fixed positions, followed by the techniques that allow the manipulation of objects. Finally, we present a brief summary and offer some future perspectives for acoustic levitation.

Interaction of surface plasmon polaritons and acoustic waves inside an acoustic cavity.

Science.gov (United States)

Khokhlov, Nikolai; Knyazev, Grigoriy; Glavin, Boris; Shtykov, Yakov; Romanov, Oleg; Belotelov, Vladimir

2017-09-15

In this Letter, we introduce an approach for manipulation of active plasmon polaritons via acoustic waves at sub-terahertz frequency range. The acoustic structures considered are designed as phononic Fabry-Perot microresonators where mirrors are presented with an acoustic superlattice and the structure's surface, and a plasmonic grating is placed on top of the acoustic cavity so formed. It provides phonon localization in the vicinity of the plasmonic grating at frequencies within the phononic stop band enhancing phonon-light interaction. We consider phonon excitation by shining a femtosecond laser pulse on the plasmonic grating. Appropriate theoretical model was used to describe the acoustic process caused by the pump laser pulse in the GaAs/AlAs-based acoustic cavity with a gold grating on top. Strongest modulation is achieved upon excitation of propagating surface plasmon polaritons and hybridization of propagating and localized plasmons. The relative changes in the optical reflectivity of the structure are more than an order of magnitude higher than for the structure without the plasmonic film.

Acoustic biosensors.

Science.gov (United States)

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. © 2016 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

[Spontaneous bacterial peritonitis].

Science.gov (United States)

Velkey, Bálint; Vitális, Eszter; Vitális, Zsuzsanna

2017-01-01

Spontaneous bacterial peritonitis occurs most commonly in cirrhotic patients with ascites. Pathogens get into the circulation by intestinal translocation and colonize in peritoneal fluid. Diagnosis of spontaneous bacterial peritonitis is based on elevated polymorphonuclear leukocyte count in the ascites (>0,25 G/L). Ascites culture is often negative but aids to get information about antibiotic sensitivity in positive cases. Treatment in stable patient can be intravenous then orally administrated ciprofloxacin or amoxicillin/clavulanic acid, while in severe cases intravenous III. generation cephalosporin. Nosocomial spontaneous bacterial peritonitis often caused by Gram-positive bacteria and multi-resistant pathogens can also be expected thus carbapenem should be the choice of the empiric treatment. Antibiotic prophylaxis should be considered. Norfloxacin is used most commonly, but changes are expected due to increase in quinolone resistance. As a primary prophylaxis, a short-term antibiotic treatment is recommended after gastrointestinal bleeding for 5 days, while long-term prophylaxis is for patients with low ascites protein, and advanced disease (400 mg/day). Secondary prophylaxis is recommended for all patients recovered from spontaneous bacterial peritonitis. Due to increasing antibiotic use of antibiotics prophylaxis is debated to some degree. Orv. Hetil., 2017, 158(2), 50-57.

Cave acoustics in prehistory: Exploring the association of Palaeolithic visual motifs and acoustic response.

Science.gov (United States)

Fazenda, Bruno; Scarre, Chris; Till, Rupert; Pasalodos, Raquel Jiménez; Guerra, Manuel Rojo; Tejedor, Cristina; Peredo, Roberto Ontañón; Watson, Aaron; Wyatt, Simon; Benito, Carlos García; Drinkall, Helen; Foulds, Frederick

2017-09-01

During the 1980 s, acoustic studies of Upper Palaeolithic imagery in French caves-using the technology then available-suggested a relationship between acoustic response and the location of visual motifs. This paper presents an investigation, using modern acoustic measurement techniques, into such relationships within the caves of La Garma, Las Chimeneas, La Pasiega, El Castillo, and Tito Bustillo in Northern Spain. It addresses methodological issues concerning acoustic measurement at enclosed archaeological sites and outlines a general framework for extraction of acoustic features that may be used to support archaeological hypotheses. The analysis explores possible associations between the position of visual motifs (which may be up to 40 000 yrs old) and localized acoustic responses. Results suggest that motifs, in general, and lines and dots, in particular, are statistically more likely to be found in places where reverberation is moderate and where the low frequency acoustic response has evidence of resonant behavior. The work presented suggests that an association of the location of Palaeolithic motifs with acoustic features is a statistically weak but tenable hypothesis, and that an appreciation of sound could have influenced behavior among Palaeolithic societies of this region.

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

International Nuclear Information System (INIS)

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

2010-01-01

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

Genetics Home Reference: primary spontaneous pneumothorax

Science.gov (United States)

... Home Health Conditions Primary spontaneous pneumothorax Primary spontaneous pneumothorax Printable PDF Open All Close All Enable Javascript ... view the expand/collapse boxes. Description Primary spontaneous pneumothorax is an abnormal accumulation of air in the ...

Localized Acoustic Surface Modes

KAUST Repository

Farhat, Mohamed

2015-08-04

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

Acoustic Signals and Systems

DEFF Research Database (Denmark)

2008-01-01

The Handbook of Signal Processing in Acoustics will compile the techniques and applications of signal processing as they are used in the many varied areas of Acoustics. The Handbook will emphasize the interdisciplinary nature of signal processing in acoustics. Each Section of the Handbook...... will present topics on signal processing which are important in a specific area of acoustics. These will be of interest to specialists in these areas because they will be presented from their technical perspective, rather than a generic engineering approach to signal processing. Non-specialists, or specialists...... from different areas, will find the self-contained chapters accessible and will be interested in the similarities and differences between the approaches and techniques used in different areas of acoustics....

Optical measurement of acoustic radiation pressure of the near-field acoustic levitation through transparent object

OpenAIRE

Nakamura, Satoshi; Furusawa, Toshiaki; Sasao, Yasuhiro; Katsura, Kogure; Naoki, Kondo

2013-01-01

It is known that macroscopic objects can be levitated for few to several hundred micrometers by near-field acoustic field and this phenomenon is called near-field acoustic levitation (NFAL). Although there are various experiments conducted to measure integrated acoustic pressure on the object surface, up to now there was no direct method to measure pressure distribution. In this study we measured the acoustic radiation pressure of the near-field acoustic levitation via pressure-sensitive paint.

Acoustic-Emergent Phonology in the Amplitude Envelope of Child-Directed Speech.

Directory of Open Access Journals (Sweden)

Victoria Leong

Full Text Available When acquiring language, young children may use acoustic spectro-temporal patterns in speech to derive phonological units in spoken language (e.g., prosodic stress patterns, syllables, phonemes. Children appear to learn acoustic-phonological mappings rapidly, without direct instruction, yet the underlying developmental mechanisms remain unclear. Across different languages, a relationship between amplitude envelope sensitivity and phonological development has been found, suggesting that children may make use of amplitude modulation (AM patterns within the envelope to develop a phonological system. Here we present the Spectral Amplitude Modulation Phase Hierarchy (S-AMPH model, a set of algorithms for deriving the dominant AM patterns in child-directed speech (CDS. Using Principal Components Analysis, we show that rhythmic CDS contains an AM hierarchy comprising 3 core modulation timescales. These timescales correspond to key phonological units: prosodic stress (Stress AM, ~2 Hz, syllables (Syllable AM, ~5 Hz and onset-rime units (Phoneme AM, ~20 Hz. We argue that these AM patterns could in principle be used by naïve listeners to compute acoustic-phonological mappings without lexical knowledge. We then demonstrate that the modulation statistics within this AM hierarchy indeed parse the speech signal into a primitive hierarchically-organised phonological system comprising stress feet (proto-words, syllables and onset-rime units. We apply the S-AMPH model to two other CDS corpora, one spontaneous and one deliberately-timed. The model accurately identified 72-82% (freely-read CDS and 90-98% (rhythmically-regular CDS stress patterns, syllables and onset-rime units. This in-principle demonstration that primitive phonology can be extracted from speech AMs is termed Acoustic-Emergent Phonology (AEP theory. AEP theory provides a set of methods for examining how early phonological development is shaped by the temporal modulation structure of speech across

Acoustic Emission Technology and Application

International Nuclear Information System (INIS)

Joo, Y. S.; Lim, S. H.; Eom, H. S.; Kim, J. H.; Jung, H. K.

2003-10-01

Acoustic emission is the elastic wave that is generated by the rapid release of energy from the localized sources within a material. After the observation of acoustic emission phenomenon in 1950, the research and further investigation had been performed. Acoustic emission examination becomes a rapidly matured nondestructive testing method with demonstrated capabilities for characterizing material behavior and for detecting the defect. It is of interest as a possible passive monitoring technique for detecting, locating and characterizing the defects in component and structure. Acoustic emission technology has recently strengthened the on-line monitoring application for the detection of incipient failures and the assurance of structural integrity. The field of acoustic emission testing is still growing vigorously and presents many challenges. Especially, acoustic emission has been successfully applied in the leak detection of primary pressure boundary of nuclear power plants. In this state-of-art report, the principle, measurement and field applications of acoustic emission technique is reviewed and summarized. Acoustic emission technology will contribute to the assurance of nuclear safety as the on-line monitoring technique of structural integrity of NSSS components and structures

Acoustic building infiltration measurement system

Science.gov (United States)

Muehleisen, Ralph T.; Raman, Ganesh

2018-04-10

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

The accidental (acoustical) tourist

Science.gov (United States)

Van Kirk, Wayne

2002-11-01

The acoustical phenomenon observed at an ancient temple in the Great Ball Court at Chichen Itza was described as ''little short of amazing--an ancient whispering gallery'' by Silvanus G. Morley, leader of the Carnegie Institute's archaeological team that excavated and restored these structures in the 1920s. Since then, many others have experienced the extraordinary acoustics at Chichen Itza and other Maya sites. Despite these reports, archaeologists and acousticians have until recently shown little interest in understanding these phenomena. After experiencing Chichen Itza's remarkable acoustics as a tourist in 1994, the author commenced collecting and disseminating information about acoustical phenomena there and at other Mayan sites, hoping to stimulate interest among archaeologists and acousticians. Were these designs accidental or intentional? If intentional, how was the knowledge obtained? How were acoustical features used? This paper highlights the author's collection of anecdotal reports of mysterious Mayan acoustics (http://http://www.ianlawton.com/pa1.htm), recommended reading for scientists and engineers who wish to pursue this fascinating study. Also recounted are some of the reactions of archaeologists-ranging from curious, helpful, and insightful to humorous and appalling--to outsiders' efforts to bring serious scientific attention to the new field of acoustical archaeology.

Acoustic field modulation in regenerators

Science.gov (United States)

Hu, J. Y.; Wang, W.; Luo, E. C.; Chen, Y. Y.

2016-12-01

The regenerator is a key component that transfers energy between heat and work. The conversion efficiency is significantly influenced by the acoustic field in the regenerator. Much effort has been spent to quantitatively determine this influence, but few comprehensive experimental verifications have been performed because of difficulties in modulating and measuring the acoustic field. In this paper, a method requiring two compressors is introduced and theoretically investigated that achieves acoustic field modulation in the regenerator. One compressor outputs the acoustic power for the regenerator; the other acts as a phase shifter. A RC load dissipates the acoustic power out of both the regenerator and the latter compressor. The acoustic field can be modulated by adjusting the current in the two compressors and opening the RC load. The acoustic field is measured with pressure sensors instead of flow-field imaging equipment, thereby greatly simplifying the experiment.

Ares I Scale Model Acoustic Tests Instrumentation for Acoustic and Pressure Measurements

Science.gov (United States)

Vargas, Magda B.; Counter, Douglas D.

2011-01-01

The Ares I Scale Model Acoustic Test (ASMAT) was a development test performed at the Marshall Space Flight Center (MSFC) East Test Area (ETA) Test Stand 116. The test article included a 5% scale Ares I vehicle model and tower mounted on the Mobile Launcher. Acoustic and pressure data were measured by approximately 200 instruments located throughout the test article. There were four primary ASMAT instrument suites: ignition overpressure (IOP), lift-off acoustics (LOA), ground acoustics (GA), and spatial correlation (SC). Each instrumentation suite incorporated different sensor models which were selected based upon measurement requirements. These requirements included the type of measurement, exposure to the environment, instrumentation check-outs and data acquisition. The sensors were attached to the test article using different mounts and brackets dependent upon the location of the sensor. This presentation addresses the observed effect of the sensors and mounts on the acoustic and pressure measurements.

Agorá Acoustics - Effects of arcades on the acoustics of public squares

DEFF Research Database (Denmark)

Paini, Dario; Gade, Anders Christian; Rindel, Jens Holger

2005-01-01

This paper is part of a PhD work, dealing with the acoustics of the public squares (‘Agorá Acoustics’), especially when music (amplified or not) is played. Consequently, our approach will be to evaluate public squares using the same set of acoustics concepts for subjective evaluation and objective...... measurements as applied for concert halls and theatres. In this paper the acoustical effects of arcades will be studied, in terms of reverberation (EDT and T30), clarity (C80), intelligibility (STI) and other acoustical parameters. For this purpose, also the theory of coupled rooms is applied and compared...... with results. An acoustic modelling program, ODEON 7.0, was used for this investigation. Three different sizes of public squares were considered. In order to evaluate the ‘real’ effects of the arcades on the open square, models of all three squares were designed both with and without arcades. The sound source...

Understanding acoustics an experimentalist’s view of acoustics and vibration

CERN Document Server

Garrett, Steven L

2017-01-01

This textbook provides a unified approach to acoustics and vibration suitable for use in advanced undergraduate and first-year graduate courses on vibration and fluids. The book includes thorough treatment of vibration of harmonic oscillators, coupled oscillators, isotropic elasticity, and waves in solids including the use of resonance techniques for determination of elastic moduli. Drawing on 35 years of experience teaching introductory graduate acoustics at the Naval Postgraduate School and Penn State, the author presents a hydrodynamic approach to the acoustics of sound in fluids that provides a uniform methodology for analysis of lumped-element systems and wave propagation that can incorporate attenuation mechanisms and complex media. This view provides a consistent and reliable approach that can be extended with confidence to more complex fluids and future applications. Understanding Acoustics opens with a mathematical introduction that includes graphing and statistical uncertainty, followed by five chap...

Ziprasidone-induced spontaneous orgasm.

Science.gov (United States)

Boora, K; Chiappone, K; Dubovsky, S; Xu, J

2010-06-01

Neuroleptic treatment in schizophrenic patients has been associated with sexual dysfunction, including impotence and decreased libido. Spontaneous ejaculation without sexual arousal during typical antipsychotic treatment is a rare condition that has been described with zuclopentixol, trifluoperazine, and thiothixene. Here, we are reporting a case of spontaneous orgasm with ziprasidone in a bipolar patient. This patient began to repeatedly experience spontaneous sexual arousal and orgasm, which she had never experienced in the past. Ziprasidone might be causing an increase in sexual orgasm by 5-HT2 receptor antagonism, which preclinical evidence suggests that it facilitates dopamine release in the cortex.

Investigation into the Effect of Acoustic Radiation Force and Acoustic Streaming on Particle Patterning in Acoustic Standing Wave Fields

Directory of Open Access Journals (Sweden)

Shilei Liu

2017-07-01

Full Text Available Acoustic standing waves have been widely used in trapping, patterning, and manipulating particles, whereas one barrier remains: the lack of understanding of force conditions on particles which mainly include acoustic radiation force (ARF and acoustic streaming (AS. In this paper, force conditions on micrometer size polystyrene microspheres in acoustic standing wave fields were investigated. The COMSOL® Mutiphysics particle tracing module was used to numerically simulate force conditions on various particles as a function of time. The velocity of particle movement was experimentally measured using particle imaging velocimetry (PIV. Through experimental and numerical simulation, the functions of ARF and AS in trapping and patterning were analyzed. It is shown that ARF is dominant in trapping and patterning large particles while the impact of AS increases rapidly with decreasing particle size. The combination of using both ARF and AS for medium size particles can obtain different patterns with only using ARF. Findings of the present study will aid the design of acoustic-driven microfluidic devices to increase the diversity of particle patterning.

Investigation into the Effect of Acoustic Radiation Force and Acoustic Streaming on Particle Patterning in Acoustic Standing Wave Fields

Science.gov (United States)

Yang, Yanye; Ni, Zhengyang; Guo, Xiasheng; Luo, Linjiao; Tu, Juan; Zhang, Dong

2017-01-01

Acoustic standing waves have been widely used in trapping, patterning, and manipulating particles, whereas one barrier remains: the lack of understanding of force conditions on particles which mainly include acoustic radiation force (ARF) and acoustic streaming (AS). In this paper, force conditions on micrometer size polystyrene microspheres in acoustic standing wave fields were investigated. The COMSOL® Mutiphysics particle tracing module was used to numerically simulate force conditions on various particles as a function of time. The velocity of particle movement was experimentally measured using particle imaging velocimetry (PIV). Through experimental and numerical simulation, the functions of ARF and AS in trapping and patterning were analyzed. It is shown that ARF is dominant in trapping and patterning large particles while the impact of AS increases rapidly with decreasing particle size. The combination of using both ARF and AS for medium size particles can obtain different patterns with only using ARF. Findings of the present study will aid the design of acoustic-driven microfluidic devices to increase the diversity of particle patterning. PMID:28753955

Endovascular Management of Recurrent Spontaneous Hemarthrosis After Arthroplasty

International Nuclear Information System (INIS)

Kolber, Marcin K.; Shukla, Pratik A.; Kumar, Abhishek; Zybulewski, Adam; Markowitz, Todd; Silberzweig, James E.

2017-01-01

PurposeRecurrent spontaneous hemarthrosis is an infrequent but debilitating late complication of joint replacement, affecting up to 1.6% of patients with arthroplasty of the affected joint. Repeated episodes of bleeding result in an inflammatory cascade that further propagates bleeding events. Open and arthroscopic synovectomy are often performed when conservative treatments fail. Transarterial embolization is increasingly utilized as a less invasive option; however, its role is not widely established. We performed a systematic literature review to report the safety and efficacy of transarterial embolization in treating recurrent hemarthrosis in the setting of prior arthroplasty.Materials and MethodsA systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines. A structured search was performed in PubMed, Web of Science, Embase, and SCOPUS databases of patients undergoing embolization for recurrent hemarthrosis after arthroplasty. Patients immediately post-operative, those embolized at first bleeding episode, and those with hemophilia were excluded. Demographic data, clinical information, angiographic findings, treatment, and outcomes were tabulated.ResultsThe search identified 119 titles of which 24 were deemed relevant, comprising 91 patients undergoing 99 embolization procedures. Mean time from prosthesis implantation was 32.2 months. Technical success was 99%. Mean follow-up time was 24.9 months. There were 10 recurrences (10%). Two cases were complicated by joint infection requiring arthroplasty revision.ConclusionsTransarterial embolization for recurrent spontaneous hemarthrosis may be safe and effective in patients having undergone arthroplasty of the affected joint.

Endovascular Management of Recurrent Spontaneous Hemarthrosis After Arthroplasty

Energy Technology Data Exchange (ETDEWEB)

Kolber, Marcin K.; Shukla, Pratik A.; Kumar, Abhishek; Zybulewski, Adam; Markowitz, Todd; Silberzweig, James E., E-mail: jsilberzweig@chpnet.org [Mount Sinai Beth Israel, Division of Vascular and Interventional Radiology, Department of Radiology (United States)

2017-02-15

PurposeRecurrent spontaneous hemarthrosis is an infrequent but debilitating late complication of joint replacement, affecting up to 1.6% of patients with arthroplasty of the affected joint. Repeated episodes of bleeding result in an inflammatory cascade that further propagates bleeding events. Open and arthroscopic synovectomy are often performed when conservative treatments fail. Transarterial embolization is increasingly utilized as a less invasive option; however, its role is not widely established. We performed a systematic literature review to report the safety and efficacy of transarterial embolization in treating recurrent hemarthrosis in the setting of prior arthroplasty.Materials and MethodsA systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines. A structured search was performed in PubMed, Web of Science, Embase, and SCOPUS databases of patients undergoing embolization for recurrent hemarthrosis after arthroplasty. Patients immediately post-operative, those embolized at first bleeding episode, and those with hemophilia were excluded. Demographic data, clinical information, angiographic findings, treatment, and outcomes were tabulated.ResultsThe search identified 119 titles of which 24 were deemed relevant, comprising 91 patients undergoing 99 embolization procedures. Mean time from prosthesis implantation was 32.2 months. Technical success was 99%. Mean follow-up time was 24.9 months. There were 10 recurrences (10%). Two cases were complicated by joint infection requiring arthroplasty revision.ConclusionsTransarterial embolization for recurrent spontaneous hemarthrosis may be safe and effective in patients having undergone arthroplasty of the affected joint.

Deep Water Acoustics

Science.gov (United States)

2016-06-28

the Deep Water project and participate in the NPAL Workshops, including Art Baggeroer (MIT), J. Beron- Vera (UMiami), M. Brown (UMiami), T...Kathleen E . Wage. The North Pacific Acoustic Laboratory deep-water acoustic propagation experiments in the Philippine Sea. J. Acoust. Soc. Am., 134(4...estimate of the angle α during PhilSea09, made from ADCP measurements at the site of the DVLA. Sim. A B1 B2 B3 C D E F Prof. # 0 4 4 4 5 10 16 20 α

Validation of an auditory sensory reinforcement paradigm: Campbell's monkeys (Cercopithecus campbelli) do not prefer consonant over dissonant sounds.

Science.gov (United States)

Koda, Hiroki; Basile, Muriel; Olivier, Marion; Remeuf, Kevin; Nagumo, Sumiharu; Blois-Heulin, Catherine; Lemasson, Alban

2013-08-01

The central position and universality of music in human societies raises the question of its phylogenetic origin. One of the most important properties of music involves harmonic musical intervals, in response to which humans show a spontaneous preference for consonant over dissonant sounds starting from early human infancy. Comparative studies conducted with organisms at different levels of the primate lineage are needed to understand the evolutionary scenario under which this phenomenon emerged. Although previous research found no preference for consonance in a New World monkey species, the question remained opened for Old World monkeys. We used an experimental paradigm based on a sensory reinforcement procedure to test auditory preferences for consonant sounds in Campbell's monkeys (Cercopithecus campbelli campbelli), an Old World monkey species. Although a systematic preference for soft (70 dB) over loud (90 dB) control white noise was found, Campbell's monkeys showed no preference for either consonant or dissonant sounds. The preference for soft white noise validates our noninvasive experimental paradigm, which can be easily reused in any captive facility to test for auditory preferences. This would suggest that human preference for consonant sounds is not systematically shared with New and Old World monkeys. The sensitivity for harmonic musical intervals emerged probably very late in the primate lineage.

Acoustic Levitation With Less Equipment

Science.gov (United States)

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.

Anisotropy of acoustic properties in paratellurite

International Nuclear Information System (INIS)

Parygin, Vladimir N.

1996-01-01

One of the peculiarities of the TeO 2 crystal consists of its strong acoustic anisotropy. This anisotropy demonstrates itself by acoustic energy walk-off and anisotropic distortion of an acoustic beam. Four constants completely characterise the acoustic anisotropy of the medium. In this paper these constants are calculated for various directions of the acoustic beam in crystal. (authors)

Variable-Position Acoustic Levitation

Science.gov (United States)

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.

Photo-acoustic and video-acoustic methods for sensing distant sound sources

Science.gov (United States)

Slater, Dan; Kozacik, Stephen; Kelmelis, Eric

2017-05-01

Long range telescopic video imagery of distant terrestrial scenes, aircraft, rockets and other aerospace vehicles can be a powerful observational tool. But what about the associated acoustic activity? A new technology, Remote Acoustic Sensing (RAS), may provide a method to remotely listen to the acoustic activity near these distant objects. Local acoustic activity sometimes weakly modulates the ambient illumination in a way that can be remotely sensed. RAS is a new type of microphone that separates an acoustic transducer into two spatially separated components: 1) a naturally formed in situ acousto-optic modulator (AOM) located within the distant scene and 2) a remote sensing readout device that recovers the distant audio. These two elements are passively coupled over long distances at the speed of light by naturally occurring ambient light energy or other electromagnetic fields. Stereophonic, multichannel and acoustic beam forming are all possible using RAS techniques and when combined with high-definition video imagery it can help to provide a more cinema like immersive viewing experience. A practical implementation of a remote acousto-optic readout device can be a challenging engineering problem. The acoustic influence on the optical signal is generally weak and often with a strong bias term. The optical signal is further degraded by atmospheric seeing turbulence. In this paper, we consider two fundamentally different optical readout approaches: 1) a low pixel count photodiode based RAS photoreceiver and 2) audio extraction directly from a video stream. Most of our RAS experiments to date have used the first method for reasons of performance and simplicity. But there are potential advantages to extracting audio directly from a video stream. These advantages include the straight forward ability to work with multiple AOMs (useful for acoustic beam forming), simpler optical configurations, and a potential ability to use certain preexisting video recordings. However

Magnetoactive Acoustic Metamaterials.

Science.gov (United States)

Yu, Kunhao; Fang, Nicholas X; Huang, Guoliang; Wang, Qiming

2018-04-11

Acoustic metamaterials with negative constitutive parameters (modulus and/or mass density) have shown great potential in diverse applications ranging from sonic cloaking, abnormal refraction and superlensing, to noise canceling. In conventional acoustic metamaterials, the negative constitutive parameters are engineered via tailored structures with fixed geometries; therefore, the relationships between constitutive parameters and acoustic frequencies are typically fixed to form a 2D phase space once the structures are fabricated. Here, by means of a model system of magnetoactive lattice structures, stimuli-responsive acoustic metamaterials are demonstrated to be able to extend the 2D phase space to 3D through rapidly and repeatedly switching signs of constitutive parameters with remote magnetic fields. It is shown for the first time that effective modulus can be reversibly switched between positive and negative within controlled frequency regimes through lattice buckling modulated by theoretically predicted magnetic fields. The magnetically triggered negative-modulus and cavity-induced negative density are integrated to achieve flexible switching between single-negative and double-negative. This strategy opens promising avenues for remote, rapid, and reversible modulation of acoustic transportation, refraction, imaging, and focusing in subwavelength regimes. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Electron/electron acoustic instability

International Nuclear Information System (INIS)

Gary, S.P.

1987-01-01

The electron acoustic wave becomes a normal mode of an unmagnetized collisionless plasma in the presence of two electron components with similar densities, but strongly disparate temperatures. The characteristic frequency of this mode is the plasma frequency of the cooler electron component. If these two electron components have a relative drift speed several times the thermal speed of the cooler component, the electron/electron acoustic instability may arise. This paper describes the parametric dependences of the threshold drift speed and maximum growth rate of this instability, and compares these with the same properties of the electron/ion acoustic instability. Under the condition of zero current, the electron/ion acoustic instability typically has the lower threshold drift speed, so that observation of the electron/electron acoustic instability is a strong indication of the presence of an electrical current in the plasma

Acoustic imaging system

Science.gov (United States)

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.

Perspective: Acoustic metamaterials in transition

KAUST Repository

Wu, Ying

2017-12-15

Acoustic metamaterials derive their novel characteristics from the interaction between acoustic waves with designed structures. Since its inception seventeen years ago, the field has been driven by fundamental geometric and physical principles that guide the structure design rules as well as provide the basis for wave functionalities. Recent examples include resonance-based acoustic metasurfaces that offer flexible control of acoustic wave propagation such as focusing and re-direction; parity-time (PT)-symmetric acoustics that utilizes the general concept of pairing loss and gain to achieve perfect absorption at a single frequency; and topological phononics that can provide one-way edge state propagation. However, such novel functionalities are not without constraints. Metasurface elements rely on resonances to enhance their coupling to the incident wave; hence, its functionality is limited to a narrow frequency band. Topological phononics is the result of the special lattice symmetry that must be fixed at the fabrication stage. Overcoming such constraints naturally forms the basis for further developments. We identify two emergent directions: Integration of acoustic metamaterial elements for achieving broadband characteristics as well as acoustic wave manipulation tasks more complex than the single demonstrative functionality; and active acoustic metamaterials that can adapt to environment as well as to go beyond the constraints on the passive acoustic metamaterials. Examples of a successful recent integration of multi-resonators in achieving broadband sound absorption can be found in optimal sound-absorbing structures, which utilize causality constraint as a design tool in realizing the target-set absorption spectrum with a minimal sample thickness. Active acoustic metamaterials have also demonstrated the capability to tune bandgaps as well as to alter property of resonances in real time through stiffening of the spring constants, in addition to the PT symmetric

Canada Basin Acoustic Propagation Experiment (CANAPE)

Science.gov (United States)

2015-09-30

acoustic communications, acoustic navigation, or acoustic remote sensing of the ocean interior . RELATED PROJECTS The 2015 CANAPE pilot study was a...1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Canada Basin Acoustic Propagation Experiment (CANAPE...ocean structure. Changes in sea ice and the water column affect both acoustic propagation and ambient noise. This implies that what was learned

Transmission acoustic microscopy investigation

Science.gov (United States)

Maev, Roman; Kolosov, Oleg; Levin, Vadim; Lobkis, Oleg

The nature of acoustic contrast, i.e. the connection of the amplitude and phase of the output signal of the acoustic microscope with the local values of the acoustic parameters of the sample (density, elasticity, viscosity) is a central problem of acoustic microscopy. A considerable number of studies have been devoted to the formation of the output signal of the reflection scanning acoustic microscope. For the transmission acoustic microscope (TAM) this problem has remained almost unstudied. Experimental investigation of the confocal system of the TAM was carried out on an independently manufactured laboratory mockup of the TAM with the working frequency of the 420 MHz. Acoustic lenses with the radius of curvature of about 500 microns and aperture angle of 45 deg were polished out in the end faces of two cylindrical sound conductors made from Al2O3 single crystals with an axis parallel to the axis C of the crystal (the length of the sound conductor is 20 mm; diameter, 6 mm). At the end faces of the sound conductor, opposite to the lenses, CdS transducers with a diameter of 2 mm were disposed. The electric channel of the TAM provided a possibility for registering the amplitude of the microscope output signal in the case of the dynamic range of the 50 dB.

What Is an Acoustic Neuroma

Science.gov (United States)

... CALENDAR DONATE NEWS Home Learn Back Learn about acoustic neuroma AN Facts What is acoustic neuroma? Diagnosing ... Italian Japanese Korean Portuguese Romanian Spanish What is Acoustic Neuroma? Each heading slides to reveal information. Important ...

Acoustical measurements of sound fields between the stage and the orchestra pit inside an historical opera house

Science.gov (United States)

Sato, Shin-Ichi; Prodi, Nicola; Sakai, Hiroyuki

2004-05-01

To clarify the relationship of the sound fields between the stage and the orchestra pit, we conducted acoustical measurements in a typical historical opera house, the Teatro Comunale of Ferrara, Italy. Orthogonal factors based on the theory of subjective preference and other related factors were analyzed. First, the sound fields for a singer on the stage in relation to the musicians in the pit were analyzed. And then, the sound fields for performers in the pit in relation to the singers on the stage were considered. Because physical factors vary depending on the location of the sound source, performers can move on the stage or in the pit to find the preferred sound field.

Zebrafish response to robotic fish: preference experiments on isolated individuals and small shoals

International Nuclear Information System (INIS)

Polverino, G; Abaid, N; Kopman, V; Porfiri, M; Macrì, S

2012-01-01

Recently developed bioinspired robots imitate their live counterparts in both aspect and functionality. Nevertheless, whether these devices can be integrated within the ecological niche inspiring their design is seldom tested experimentally. An elemental research question concerns the feasibility of modulating spontaneous behaviour of animal systems through bioinspired robotics. The following study explores the possibility of engineering a robotic fish capable of influencing the behaviour of live zebrafish (Danio rerio) in a dichotomous preference test. While we observe that the preference for the robotic fish never exceeds the preference for a conspecific, our data show that the robot is successful in attracting both isolated individuals and small shoals and that such capability is influenced by its bioinspired features. In particular, we find that the robot's undulations enhance its degree of attractiveness, despite the noise inherent in the actuation system. This is the first experimental evidence that live zebrafish behaviour can be influenced by engineered robots. Such robotic platforms may constitute a valuable tool to investigate the bases of social behaviour and uncover the fundamental determinants of animal functions and dysfunctions. (paper)

Shallow-Water Mud Acoustics

Science.gov (United States)

2015-09-30

1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Shallow-Water Mud Acoustics William L. Siegmann...models and methods that explain observed material and acoustic properties of different physical types of shallow-ocean mud sediments. Other goals...are to assess prior data relating to the acoustic properties of mud and to provide guidance in the development and interpretation of experiments. A

Tutorial on architectural acoustics

Science.gov (United States)

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).

Micromachined silicon acoustic delay line with improved structural stability and acoustic directivity for real-time photoacoustic tomography

Science.gov (United States)

Cho, Young; Kumar, Akhil; Xu, Song; Zou, Jun

2017-03-01

Recent studies have shown that micromachined silicon acoustic delay lines can provide a promising solution to achieve real-time photoacoustic tomography without the need for complex transducer arrays and data acquisition electronics. However, as its length increases to provide longer delay time, the delay line becomes more vulnerable to structural instability due to reduced mechanical stiffness. In addition, the small cross-section area of the delay line results in a large acoustic acceptance angle and therefore poor directivity. To address these two issues, this paper reports the design, fabrication, and testing of a new silicon acoustic delay line enhanced with 3D printed polymer micro linker structures. First, mechanical deformation of the silicon acoustic delay line (with and without linker structures) under gravity was simulated by using finite element method. Second, the acoustic crosstalk and acoustic attenuation caused by the polymer micro linker structures were evaluated with both numerical simulation and ultrasound transmission testing. The result shows that the use of the polymer micro linker structures significantly improves the structural stability of the silicon acoustic delay lines without creating additional acoustic attenuation and crosstalk. In addition, a new tapered design for the input terminal of the delay line was also investigate to improve its acoustic directivity by reducing the acoustic acceptance angle. These two improvements are expected to provide an effective solution to eliminate current limitations on the achievable acoustic delay time and out-of-plane imaging resolution of micromachined silicon acoustic delay line arrays.

Handbook of Engineering Acoustics

CERN Document Server

Möser, Michael

2013-01-01

This book examines the physical background of engineering acoustics, focusing on empirically obtained engineering experience as well as on measurement techniques and engineering methods for prognostics. Its goal is not only to describe the state of art of engineering acoustics but also to give practical help to engineers in order to solve acoustic problems. It deals with the origin, the transmission and the methods of the abating different kinds of air-borne and structure-borne sounds caused by various mechanisms – from traffic to machinery and flow-induced sound. In addition the modern aspects of room and building acoustics, as well as psychoacoustics and active noise control, are covered.

Ion-acoustic plasma turbulence

International Nuclear Information System (INIS)

Bychenkov, V.Y.; Silin, V.P.

1982-01-01

A theory is developed of the nonlinear state that is established in a plasma as a result of development of ion-acoustic instability. Account is taken simultaneously of the linear induced scattering of the waves by the ions and of the quasilinear relaxation of the electrons by the ion-acoustic pulsations. The distribution of the ion-acoustic turbulence in frequency and in angle is obtained. An Ohm's law is established and expressions are obtained for the electronic heat flux and for the relaxation time of the electron temperature in a turbulent plasma. Anomalously large absorption and scattering of the electromagnetic waves by the ion-acoustic pulsations is predicted

A new definition for acoustic dose

International Nuclear Information System (INIS)

Duck, F A

2011-01-01

This paper discusses a recent proposal for definitions of acoustic dose and acoustic dose-rate. Acoustic dose is defined as the energy deposited by absorption of an acoustic wave per unit mass of the medium supporting the wave. Its time-derivative, acoustic dose-rate, Q m , in W kg -1 is central to the prediction of both rate of temperature rise and radiation force. These quantities have spatial and temporal dependency, depending on the local field parameters (acoustic pressure, particle velocity, intensity) and local material properties (absorption coefficient, α a , and mass density, ρ 0 ). Spatial and/or temporal averaging can be applied where appropriate. For plane-wave monochromatic conditions in a homogeneous medium, Q m =2α a I/ρ 0 , (I is the time-averaged intensity), a simple expression which may also incorporate frequency dependencies of energy deposition. Acoustic dose and acoustic does-rate are exact analogues for Specific Absorption and Specific Absorption Rate (SAR), quantities central to radiofrequency (RF) and microwave dosimetry. Acoustic dosimetry in the presence of tissue/gas interfaces remains a considerable challenge.

Fundamentals of Shallow Water Acoustics

CERN Document Server

Katsnelson, Boris; Lynch, James

2012-01-01

Shallow water acoustics (SWA), the study of how low and medium frequency sound propagates and scatters on the continental shelves of the world's oceans, has both technical interest and a large number of practical applications. Technically, shallow water poses an interesting medium for the study of acoustic scattering, inverse theory, and propagation physics in a complicated oceanic waveguide. Practically, shallow water acoustics has interest for geophysical exploration, marine mammal studies, and naval applications. Additionally, one notes the very interdisciplinary nature of shallow water acoustics, including acoustical physics, physical oceanography, marine geology, and marine biology. In this specialized volume, the authors, all of whom have extensive at-sea experience in U.S. and Russian research efforts, have tried to summarize the main experimental, theoretical, and computational results in shallow water acoustics, with an emphasis on providing physical insight into the topics presented.

The Development of the Acoustic Design of NASA Glenn Research Center's New Reverberant Acoustic Test Facility

Science.gov (United States)

Hughes, William O.; McNelis, Mark E.; Hozman, Aron D.; McNelis, Anne M.

2011-01-01

The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) is leading the design and build of the new world-class vibroacoustic test capabilities at the NASA GRC s Plum Brook Station in Sandusky, Ohio. Benham Companies, LLC is currently constructing modal, base-shake sine and reverberant acoustic test facilities to support the future testing needs of NASA s space exploration program. The large Reverberant Acoustic Test Facility (RATF) will be approximately 101,000 ft3 in volume and capable of achieving an empty chamber acoustic overall sound pressure level (OASPL) of 163 dB. This combination of size and acoustic power is unprecedented amongst the world s known active reverberant acoustic test facilities. The key to achieving the expected acoustic test spectra for a range of many NASA space flight environments in the RATF is the knowledge gained from a series of ground acoustic tests. Data was obtained from several NASA-sponsored test programs, including testing performed at the National Research Council of Canada s acoustic test facility in Ottawa, Ontario, Canada, and at the Redstone Technical Test Center acoustic test facility in Huntsville, Alabama. The majority of these tests were performed to characterize the acoustic performance of the modulators (noise generators) and representative horns that would be required to meet the desired spectra, as well as to evaluate possible supplemental gas jet noise sources. The knowledge obtained in each of these test programs enabled the design of the RATF sound generation system to confidently advance to its final acoustic design and subsequent on-going construction.

Select Internet Resources on Acoustics

Directory of Open Access Journals (Sweden)

Angela R. Davis

2016-12-01

Full Text Available Merriam-Webster (2016 defines acoustics as, “a science that deals with the production, control, transmission, reception, and effects of sounds.” According to Rossing (2014, the study of acoustics began in ancient Greece with Pythagoras’ study of vibrating strings on musical instruments. Since those early beginnings, famous scientists including Rayleigh, Alexander Graham Bell, and Thomas Edison, have helped expand the field of acoustics to include architectural, physical, engineering, structural, underwater, physiological and psychological, musical acoustics, and speech. Acoustics is a highly interdisciplinary field and researchers may need resources from physics, medicine, and engineering to understand all aspects of their research.

Spontaneous acoustic emission of a corrugated shock wave in the presence of a reflecting surface

International Nuclear Information System (INIS)

Wouchuk, J.G.; Lopez Cavada, J.

2004-01-01

An analytic model to study perturbation evolution in the space between a corrugated shock and a piston surface is presented. The conditions for stable oscillation patterns are obtained by looking at the poles of the exact Laplace transform. It is seen that besides the standard D'yakov-Kontorovich (DK) mode of oscillation, the shock surface can exhibit an additional finite set of discrete frequencies, due to the interaction with the piston which reflects sound waves from behind. The additional eigenmodes are excited when the shock is launched at t=0 + . The first eigenmode (the DK mode) is always present, if the Hugoniot curve has the correct slope in the V-p plane. However, the additional frequencies could be excited for strong enough shocks. The predictions of the model are verified for particular cases by studying a van der Waals gas, as in the work of Bates and Montgomery [Phys. Fluids 11, 462 (1999); Phys. Rev. Lett. 84, 1180 (2000)]. Only acoustic emission modes are considered

Spontaneous rib fractures.

Science.gov (United States)

Katrancioglu, Ozgur; Akkas, Yucel; Arslan, Sulhattin; Sahin, Ekber

2015-07-01

Other than trauma, rib fracture can occur spontaneously due to a severe cough or sneeze. In this study, patients with spontaneous rib fractures were analyzed according to age, sex, underlying pathology, treatment, and complications. Twelve patients who presented between February 2009 and February 2011 with spontaneous rib fracture were reviewed retrospectively. The patients' data were evaluated according to anamnesis, physical examination, and chest radiographs. The ages of the patients ranged from 34 to 77 years (mean 55.91 ± 12.20 years), and 7 (58.4%) were male. All patients had severe cough and chest pain. The fractures were most frequently between 4th and 9th ribs; multiple rib fractures were detected in 5 (41.7%) patients. Eight (66.7%) patients had chronic obstructive pulmonary disease, 2 (16.7%) had bronchial asthma, and 2 (16.7%) had osteoporosis. Bone densitometry revealed a high risk of bone fracture in all patients. Patients with chronic obstructive pulmonary disease or bronchial asthma had been treated with high-dose steroids for over a year. Spontaneous rib fracture due to severe cough may occur in patients with osteoporosis, chronic obstructive pulmonary disease, or bronchial asthma, receiving long-term steroid therapy. If these patients have severe chest pain, chest radiography should be performed to check for bone lesions. © The Author(s) 2015.

Handbook of Signal Processing in Acoustics

CERN Document Server

Havelock, David; Vorländer, Michael

2009-01-01

The Handbook of Signal Processing in Acoustics presents signal processing as it is practiced in the field of acoustics. The Handbook is organized by areas of acoustics, with recognized leaders coordinating the self-contained chapters of each section. It brings together a wide range of perspectives from over 100 authors to reveal the interdisciplinary nature of signal processing in acoustics. Success in acoustic applications often requires juggling both the acoustic and the signal processing parameters of the problem. This handbook brings the key issues from both into perspective and is complementary to other reference material on the two subjects. It is a unique resource for experts and practitioners alike to find new ideas and techniques within the diversity of signal processing in acoustics.

Targeted Acoustic Data Processing for Ocean Ecological Studies

Science.gov (United States)

Sidorovskaia, N.; Li, K.; Tiemann, C.; Ackleh, A. S.; Tang, T.; Ioup, G. E.; Ioup, J. W.

2015-12-01

The Gulf of Mexico is home to many species of deep diving marine mammals. In recent years several ecological studies have collected large volumes of Passive Acoustic Monitoring (PAM) data to investigate the effects of anthropogenic activities on protected and endangered marine mammal species. To utilize these data to their fullest potential for abundance estimates and habitat preference studies, automated detection and classification algorithms are needed to extract species acoustic encounters from a continuous stream of data. The species which phonate in overlapping frequency bands represent a particular challenge. This paper analyzes the performance of a newly developed automated detector for the classification of beaked whale clicks in the Northern Gulf of Mexico. Current used beaked whale classification algorithms rely heavily on experienced human operator involvement in manually associating potential events with a particular species of beaked whales. Our detection algorithm is two-stage: the detector is triggered when the species-representative phonation band energy exceeds the baseline detection threshold. Then multiple event attributes (temporal click duration, central frequency, frequency band, frequency sweep rate, Choi-Williams distribution shape indices) are measured. An attribute vector is then used to discriminate among different species of beaked whales present in the Gulf of Mexico and Risso's dolphins which were recognized to mask the detections of beaked whales in the case of widely used energy-band detectors. The detector is applied to the PAM data collected by the Littoral Acoustic Demonstration Center to estimate abundance trends of beaked whales in the vicinity of the 2010 oil spill before and after the disaster. This algorithm will allow automated processing with minimal operator involvement for new and archival PAM data. [The research is supported by a BP/GOMRI 2015-2017 consortium grant.

Relaxation time of acoustically disturbed plasma

International Nuclear Information System (INIS)

Mkrtchyan, K.S.; Abrahamyan, A.S.

2005-01-01

The conservation time of an acoustic structure in plasma after relieving of external acoustic influence is investigated. Dependences of the conservation time on discharge parameters are presented. It is asserted that the plasma becomes an anisotropic uniaxial medium with an acoustic superlattice under the acoustic influence

Airy acoustical-sheet spinner tweezers

Science.gov (United States)

Mitri, F. G.

2016-09-01

The Airy acoustical beam exhibits parabolic propagation and spatial acceleration, meaning that the propagation bending angle continuously increases before the beam trajectory reaches a critical angle where it decays after a propagation distance, without applying any external bending force. As such, it is of particular importance to investigate its properties from the standpoint of acoustical radiation force, spin torque, and particle dynamics theories, in the development of novel particle sorting techniques and acoustically mediated clearing systems. This work investigates these effects on a two-dimensional (2D) circular absorptive structure placed in the field of a nonparaxial Airy "acoustical-sheet" (i.e., finite beam in 2D), for potential applications in surface acoustic waves and acousto-fluidics. Based on the characteristics of the acoustic field, the beam is capable of manipulating the circular cylindrical fluid cross-section and guides it along a transverse or parabolic trajectory. This feature of Airy acoustical beams could lead to a unique characteristic in single-beam acoustical tweezers related to acoustical sieving, filtering, and removal of particles and cells from a section of a small channel. The analysis developed here is based on the description of the nonparaxial Airy beam using the angular spectrum decomposition of plane waves in close association with the partial-wave series expansion method in cylindrical coordinates. The numerical results demonstrate the ability of the nonparaxial Airy acoustical-sheet beam to pull, propel, or accelerate a particle along a parabolic trajectory, in addition to particle confinement in the transverse direction of wave propagation. Negative or positive radiation force and spin torque causing rotation in the clockwise or the anticlockwise direction can occur depending on the nondimensional parameter ka (where k is the wavenumber and a is the radius) and the location of the cylinder in the beam. Applications in

Department of Cybernetic Acoustics

Science.gov (United States)

The development of the theory, instrumentation and applications of methods and systems for the measurement, analysis, processing and synthesis of acoustic signals within the audio frequency range, particularly of the speech signal and the vibro-acoustic signal emitted by technical and industrial equipments treated as noise and vibration sources was discussed. The research work, both theoretical and experimental, aims at applications in various branches of science, and medicine, such as: acoustical diagnostics and phoniatric rehabilitation of pathological and postoperative states of the speech organ; bilateral ""man-machine'' speech communication based on the analysis, recognition and synthesis of the speech signal; vibro-acoustical diagnostics and continuous monitoring of the state of machines, technical equipments and technological processes.

Implicit and explicit preferences for physical attractiveness in a romantic partner: a double dissociation in predictive validity.

Science.gov (United States)

Eastwick, Paul W; Eagly, Alice H; Finkel, Eli J; Johnson, Sarah E

2011-11-01

Five studies develop and examine the predictive validity of an implicit measure of the preference for physical attractiveness in a romantic partner. Three hypotheses were generally supported. First, 2 variants of the go/no-go association task revealed that participants, on average, demonstrate an implicit preference (i.e., a positive spontaneous affective reaction) for physical attractiveness in a romantic partner. Second, these implicit measures were not redundant with a traditional explicit measure: The correlation between these constructs was .00 on average, and the implicit measures revealed no reliable sex differences, unlike the explicit measure. Third, explicit and implicit measures exhibited a double dissociation in predictive validity. Specifically, explicit preferences predicted the extent to which attractiveness was associated with participants' romantic interest in opposite-sex photographs but not their romantic interest in real-life opposite-sex speed-daters or confederates. Implicit preferences showed the opposite pattern. This research extends prior work on implicit processes in romantic relationships and offers the first demonstration that any measure of a preference for a particular characteristic in a romantic partner (an implicit measure of physical attractiveness, in this case) predicts individuals' evaluation of live potential romantic partners.

Spontaneous tension haemopneumothorax.

Science.gov (United States)

Patterson, Benjamin Oliver; Itam, Sarah; Probst, Fey

2008-10-31

We present a patient with sudden onset progressive shortness of breath and no history of trauma, who rapidly became haemodynamically compromised with a pneumothorax and pleural effusion seen on chest radiograph. He was treated for spontaneous tension pneumothorax but this was soon revealed to be a tension haemopneumothorax. He underwent urgent thoracotomy after persistent bleeding to explore an apical vascular abnormality seen on CT scanning. To our knowledge this is the first such case reported.Aetiology and current approach to spontaneous haemothorax are discussed briefly.

Acoustic Liners for Turbine Engines

Science.gov (United States)

Jones, Michael G (Inventor); Grady, Joseph E (Inventor); Kiser, James D. (Inventor); Miller, Christopher (Inventor); Heidmann, James D. (Inventor)

2016-01-01

An improved acoustic liner for turbine engines is disclosed. The acoustic liner may include a straight cell section including a plurality of cells with straight chambers. The acoustic liner may also include a bent cell section including one or more cells that are bent to extend chamber length without increasing the overall height of the acoustic liner by the entire chamber length. In some cases, holes are placed between cell chambers in addition to bending the cells, or instead of bending the cells.

Acoustic communication for Maya Autonomous Underwater Vehicle - performance evaluation of acoustic modem

Digital Repository Service at National Institute of Oceanography (India)

Afzulpurkar, S.; Maurya, P.; Navelkar, G.S.; Desa, E.S.; Mascarenhas, A.A.M.Q.; Dabholkar, N.A.; Madhan, R.; Prabhudesai, S.P.

traffic. This necessitates monitoring the AUV status and data quality through an acoustic link which needs to perform reliably under such conditions, at long range. To address these situations partially, acoustic communication capability is planned...

Acoustical and optical radiation pressures and the development of single beam acoustical tweezers

OpenAIRE

Thomas , Jean-Louis; Marchiano , Régis; Baresch , Diego

2017-01-01

International audience; Studies on radiation pressure in acoustics and optics have enriched one another and have a long common history. Acoustic radiation pressure is used for metrology, levitation, particle trapping and actuation. However, the dexterity and selectivity of single-beam optical tweezers are still to be matched with acoustical devices. Optical tweezers can trap, move and positioned micron size particles, biological samples or even atoms with subnanometer accuracy in three dimens...

Development of acoustic particle detector

International Nuclear Information System (INIS)

Matsuyama, Tadayoshi; Hinode, Fujio; Konno, Osamu

1999-01-01

To detect acoustic sign from electron, determination of acoustic radiation from high energy electron and detector were studied. When charge particles pass through medium, energy loss generates local expansion and contraction of medium and pressure compression wave. We need caustic element with 10 -5 Pa the minimum acoustic receive sensitivity and from 10 to 100 kHz frequency sensitivity characteristic. Elements were made by Low-Q materials, piezoelectric materials (PZT). Various sharp of elements were constructed and measured. 50 mm spherical element showed 38 m V/Pa, the best sensitivity. Our developed acoustic element could detect acoustic radiation generated by electron beam from accelerator. The wave sharp detected proved the same as bipolar wave, which was given theoretically. The pressure generated by beam was proportional to the energy loss E. 200 MeV electron beam existed about 95% particles on the incident axis. So that acoustic detector on the axis proved to detect sound wave generated on the beam axis. (S.Y.)

Modelling the effects of environmental conditions on the acoustic occurrence and behaviour of Antarctic blue whales.

Directory of Open Access Journals (Sweden)

Fannie W Shabangu

Full Text Available Harvested to perilously low numbers by commercial whaling during the past century, the large scale response of Antarctic blue whales Balaenoptera musculus intermedia to environmental variability is poorly understood. This study uses acoustic data collected from 586 sonobuoys deployed in the austral summers of 1997 through 2009, south of 38°S, coupled with visual observations of blue whales during the IWC SOWER line-transect surveys. The characteristic Z-call and D-call of Antarctic blue whales were detected using an automated detection template and visual verification method. Using a random forest model, we showed the environmental preferences pattern, spatial occurrence and acoustic behaviour of Antarctic blue whales. Distance to the southern boundary of the Antarctic Circumpolar Current (SBACC, latitude and distance from the nearest Antarctic shores were the main geographic predictors of blue whale call occurrence. Satellite-derived sea surface height, sea surface temperature, and productivity (chlorophyll-a were the most important environmental predictors of blue whale call occurrence. Call rates of D-calls were strongly predicted by the location of the SBACC, latitude and visually detected number of whales in an area while call rates of Z-call were predicted by the SBACC, latitude and longitude. Satellite-derived sea surface height, wind stress, wind direction, water depth, sea surface temperatures, chlorophyll-a and wind speed were important environmental predictors of blue whale call rates in the Southern Ocean. Blue whale call occurrence and call rates varied significantly in response to inter-annual and long term variability of those environmental predictors. Our results identify the response of Antarctic blue whales to inter-annual variability in environmental conditions and highlighted potential suitable habitats for this population. Such emerging knowledge about the acoustic behaviour, environmental and habitat preferences of

Modelling the effects of environmental conditions on the acoustic occurrence and behaviour of Antarctic blue whales.

Science.gov (United States)

Shabangu, Fannie W; Yemane, Dawit; Stafford, Kathleen M; Ensor, Paul; Findlay, Ken P

2017-01-01

Harvested to perilously low numbers by commercial whaling during the past century, the large scale response of Antarctic blue whales Balaenoptera musculus intermedia to environmental variability is poorly understood. This study uses acoustic data collected from 586 sonobuoys deployed in the austral summers of 1997 through 2009, south of 38°S, coupled with visual observations of blue whales during the IWC SOWER line-transect surveys. The characteristic Z-call and D-call of Antarctic blue whales were detected using an automated detection template and visual verification method. Using a random forest model, we showed the environmental preferences pattern, spatial occurrence and acoustic behaviour of Antarctic blue whales. Distance to the southern boundary of the Antarctic Circumpolar Current (SBACC), latitude and distance from the nearest Antarctic shores were the main geographic predictors of blue whale call occurrence. Satellite-derived sea surface height, sea surface temperature, and productivity (chlorophyll-a) were the most important environmental predictors of blue whale call occurrence. Call rates of D-calls were strongly predicted by the location of the SBACC, latitude and visually detected number of whales in an area while call rates of Z-call were predicted by the SBACC, latitude and longitude. Satellite-derived sea surface height, wind stress, wind direction, water depth, sea surface temperatures, chlorophyll-a and wind speed were important environmental predictors of blue whale call rates in the Southern Ocean. Blue whale call occurrence and call rates varied significantly in response to inter-annual and long term variability of those environmental predictors. Our results identify the response of Antarctic blue whales to inter-annual variability in environmental conditions and highlighted potential suitable habitats for this population. Such emerging knowledge about the acoustic behaviour, environmental and habitat preferences of Antarctic blue whales is

Focusing of Acoustic Waves through Acoustic Materials with Subwavelength Structures

KAUST Repository

Xiao, Bingmu

2013-05-01

In this thesis, wave propagation through acoustic materials with subwavelength slits structures is studied. Guided by the findings, acoustic wave focusing is achieved with a specific material design. By using a parameter retrieving method, an effective medium theory for a slab with periodic subwavelength cut-through slits is successfully derived. The theory is based on eigenfunction solutions to the acoustic wave equation. Numerical simulations are implemented by the finite-difference time-domain (FDTD) method for the two-dimensional acoustic wave equation. The theory provides the effective impedance and refractive index functions for the equivalent medium, which can reproduce the transmission and reflection spectral responses of the original structure. I analytically and numerically investigate both the validity and limitations of the theory, and the influences of material and geometry on the effective spectral responses are studied. Results show that large contrasts in impedance and density are conditions that validate the effective medium theory, and this approximation displays a better accuracy for a thick slab with narrow slits in it. Based on the effective medium theory developed, a design of a at slab with a snake shaped" subwavelength structure is proposed as a means of achieving acoustic focusing. The property of focusing is demonstrated by FDTD simulations. Good agreement is observed between the proposed structure and the equivalent lens pre- dicted by the theory, which leads to robust broadband focusing by a thin at slab.

Rhesus macaques form preferences for brand logos through sex and social status based advertising.

Science.gov (United States)

Acikalin, M Yavuz; Watson, Karli K; Fitzsimons, Gavan J; Platt, Michael L

2018-01-01

Like humans, monkeys value information about sex and status, inviting the hypothesis that our susceptibility to these factors in advertising arises from shared, ancestral biological mechanisms that prioritize social information. To test this idea, we asked whether rhesus macaques (Macaca mulatta) show choice behavior that is similar to humans in response to sex and social status in advertising. Our results show that monkeys form preferences for brand logos repeatedly paired with images of macaque genitals and high status monkeys. Moreover, monkeys sustain preferences for these brand logos even though choosing them provided no tangible rewards, a finding that cannot be explained by a decision mechanism operating solely on material outcomes. Together, our results endorse the hypothesis that the power of sex and status in advertising emerges from the spontaneous engagement of shared, ancestral neural circuits that prioritize information useful for navigating the social environment. Finally, our results show that simple associative conditioning is sufficient to explain the formation of preferences for brand logos paired with sexual or status-based images.

Acoustic emission linear pulse holography

Science.gov (United States)

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

1983-10-25

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

Acoustic communication in plant-animal interactions.

Science.gov (United States)

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. Copyright © 2016 Elsevier Ltd. All rights reserved.

A chimpanzee recognizes synthetic speech with significantly reduced acoustic cues to phonetic content.

Science.gov (United States)

Heimbauer, Lisa A; Beran, Michael J; Owren, Michael J

2011-07-26

A long-standing debate concerns whether humans are specialized for speech perception, which some researchers argue is demonstrated by the ability to understand synthetic speech with significantly reduced acoustic cues to phonetic content. We tested a chimpanzee (Pan troglodytes) that recognizes 128 spoken words, asking whether she could understand such speech. Three experiments presented 48 individual words, with the animal selecting a corresponding visuographic symbol from among four alternatives. Experiment 1 tested spectrally reduced, noise-vocoded (NV) synthesis, originally developed to simulate input received by human cochlear-implant users. Experiment 2 tested "impossibly unspeechlike" sine-wave (SW) synthesis, which reduces speech to just three moving tones. Although receiving only intermittent and noncontingent reward, the chimpanzee performed well above chance level, including when hearing synthetic versions for the first time. Recognition of SW words was least accurate but improved in experiment 3 when natural words in the same session were rewarded. The chimpanzee was more accurate with NV than SW versions, as were 32 human participants hearing these items. The chimpanzee's ability to spontaneously recognize acoustically reduced synthetic words suggests that experience rather than specialization is critical for speech-perception capabilities that some have suggested are uniquely human. Copyright © 2011 Elsevier Ltd. All rights reserved.

How females of chirping and trilling field crickets integrate the 'what' and 'where' of male acoustic signals during decision making.

Science.gov (United States)

Gabel, Eileen; Gray, David A; Matthias Hennig, R

2016-11-01

In crickets acoustic communication serves mate selection. Female crickets have to perceive and integrate male cues relevant for mate choice while confronted with several different signals in an acoustically diverse background. Overall female decisions are based on the attractiveness of the temporal pattern (informative about the 'what') and on signal intensity (informative about the 'where') of male calling songs. Here, we investigated how the relevant cues for mate choice are integrated during the decision process by females of five different species of chirping and trilling field crickets. Using a behavioral design, female preferences in no-choice and choice situations for male calling songs differing in pulse rate, modulation depth, intensities, chirp/trill arrangements and temporal shifts were examined. Sensory processing underlying decisions in female field crickets is rather similar as combined evidence suggested that incoming song patterns were analyzed separately by bilaterally paired networks for pattern attractiveness and pattern intensity. A downstream gain control mechanism leads to a weighting of the intensity cue by pattern attractiveness. While remarkable differences between species were observed with respect to specific processing steps, closely related species exhibited more similar preferences than did more distantly related species.

Electrostatic ion acoustic waves

International Nuclear Information System (INIS)

Hasegawa, A.

1983-01-01

In this paper, certain aspects of plasma physics are illustrated through a study of electrostatic ion acoustic waves. The paper consists of three Sections. Section II deals with linear properties of the ion acoustic wave including derivation of the dispersions relation with the effect of Landau damping and of an ambient magnetic field. The section also introduces the excitation processes of the ion acoustic wave due to an electron drift or to a stimulated Brillouin scattering. The nonlinear properties are introduced in Section III and IV. In Section III, incoherent nonlinear effects such as quasilinear and mode-coupling saturations of the instability are discussed. The coherent nonlinear effects such as the generation of ion acoustic solitons, shocks and weak double layers are presented in Section IV. (Auth.)

Spontaneous tension haemopneumothorax

Directory of Open Access Journals (Sweden)

Itam Sarah

2008-10-01

Full Text Available Abstract We present a patient with sudden onset progressive shortness of breath and no history of trauma, who rapidly became haemodynamically compromised with a pneumothorax and pleural effusion seen on chest radiograph. He was treated for spontaneous tension pneumothorax but this was soon revealed to be a tension haemopneumothorax. He underwent urgent thoracotomy after persistent bleeding to explore an apical vascular abnormality seen on CT scanning. To our knowledge this is the first such case reported. Aetiology and current approach to spontaneous haemothorax are discussed briefly.

Spontaneous compactification to homogeneous spaces

International Nuclear Information System (INIS)

Mourao, J.M.

1988-01-01

The spontaneous compactification of extra dimensions to compact homogeneous spaces is studied. The methods developed within the framework of coset space dimensional reduction scheme and the most general form of invariant metrics are used to find solutions of spontaneous compactification equations

Highly Localized Acoustic Streaming and Size-Selective Submicrometer Particle Concentration Using High Frequency Microscale Focused Acoustic Fields.

Science.gov (United States)

Collins, David J; Ma, Zhichao; Ai, Ye

2016-05-17

Concentration and separation of particles and biological specimens are fundamental functions of micro/nanofluidic systems. Acoustic streaming is an effective and biocompatible way to create rapid microscale fluid motion and induce particle capture, though the >100 MHz frequencies required to directly generate acoustic body forces on the microscale have traditionally been difficult to generate and localize in a way that is amenable to efficient generation of streaming. Moreover, acoustic, hydrodynamic, and electrical forces as typically applied have difficulty manipulating specimens in the submicrometer regime. In this work, we introduce highly focused traveling surface acoustic waves (SAW) at high frequencies between 193 and 636 MHz for efficient and highly localized production of acoustic streaming vortices on microfluidic length scales. Concentration occurs via a novel mechanism, whereby the combined acoustic radiation and streaming field results in size-selective aggregation in fluid streamlines in the vicinity of a high-amplitude acoustic beam, as opposed to previous acoustic radiation induced particle concentration where objects typically migrate toward minimum pressure locations. Though the acoustic streaming is induced by a traveling wave, we are able to manipulate particles an order of magnitude smaller than possible using the traveling wave force alone. We experimentally and theoretically examine the range of particle sizes that can be captured in fluid streamlines using this technique, with rapid particle concentration demonstrated down to 300 nm diameters. We also demonstrate that locations of trapping and concentration are size-dependent, which is attributed to the combined effects of the acoustic streaming and acoustic forces.

Coupled Acoustic-Mechanical Bandgaps

DEFF Research Database (Denmark)

Jensen, Jakob Søndergaard; Kook, Junghwan

2016-01-01

medium and the presence of acoustic resonances. It is demonstrated that corrugation of the plate structure can introduce bending wave bandgaps and bandgaps in the acoustic domain in overlapping and audible frequency ranges. This effect is preserved also when taking the physical coupling between the two...... domains into account. Additionally, the coupling is shown to introduce extra gaps in the band structure due to modal interaction and the appearance of a cut-on frequency for the fundamental acoustic mode....

Atlantic Herring Acoustic Surveys

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC Advanced Sampling Technologies Research Group conducts annual fisheries acoustic surveys using state-of-the-art acoustic, midwater trawling, and underwater...

Breakdown of antiferromagnet order in polycrystalline NiFe/NiO bilayers probed with acoustic emission

Science.gov (United States)

Lebyodkin, M. A.; Lebedkina, T. A.; Shashkov, I. V.; Gornakov, V. S.

2017-07-01

Magnetization reversal of polycrystalline NiFe/NiO bilayers was investigated using magneto-optical indicator film imaging and acoustic emission techniques. Sporadic acoustic signals were detected in a constant magnetic field after the magnetization reversal. It is suggested that they are related to elastic waves excited by sharp shocks in the NiO layer with strong magnetostriction. Their probability depends on the history and number of repetitions of the field cycling, thus testifying the thermal-activation nature of the long-time relaxation of an antiferromagnetic order. These results provide evidence of spontaneous thermally activated switching of the antiferromagnetic order in NiO grains during magnetization reversal in ferromagnet/antiferromagnet (FM/AFM) heterostructures. The respective deformation modes are discussed in terms of the thermal fluctuation aftereffect in the Fulcomer and Charap model which predicts that irreversible breakdown of the original spin orientation can take place in some antiferromagnetic grains with disordered anisotropy axes during magnetization reversal of exchange-coupled FM/AFM structures. The spin reorientation in the saturated state may induce abrupt distortion of isolated metastable grains because of the NiO magnetostriction, leading to excitation of shock waves and formation of plate (or Lamb) waves.

Tunable coupled surface acoustic cavities

Science.gov (United States)

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

2012-06-01

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

Tethys Acoustic Metadata Database

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Tethys database houses the metadata associated with the acoustic data collection efforts by the Passive Acoustic Group. These metadata include dates, locations...

Case of spontaneous ventriculocisternostomy

Energy Technology Data Exchange (ETDEWEB)

Yamane, Kanji; Yoshimoto, Hisanori; Harada, Kiyoshi; Uozumi, Tohru [Hiroshima Univ. (Japan). School of Medicine; Kuwabara, Satoshi

1983-05-01

The authors experienced a case of spontaneous ventriculocisternostomy diagnosed by CT scan with metrizamide and Conray. Patient was 23-year-old male who had been in good health until one month before admission, when he began to have headache and tinnitus. He noticed bilateral visual acuity was decreased about one week before admission and vomiting appeared two days before admission. He was admitted to our hospital because of bilateral papilledema and remarkable hydrocephalus diagnosed by CT scan. On admission, no abnormal neurological signs except for bilateral papilledema were noted. Immediately, right ventricular drainage was performed. Pressure of the ventricle was over 300mmH/sub 2/O and CSF was clear. PVG and PEG disclosed an another cavity behind the third ventricle, which was communicated with the third ventricle, and occlusion of aqueduct of Sylvius. Metrizamide CT scan and Conray CT scan showed a communication between this cavity and quadrigeminal and supracerebellar cisterns. On these neuroradiological findings, the diagnosis of obstructive hydrocephalus due to benign aqueduct stenosis accompanied with spontaneous ventriculocisternostomy was obtained. Spontaneous ventriculocisternostomy was noticed to produce arrest of hydrocephalus, but with our case, spontaneous regression of such symptoms did not appeared. By surgical ventriculocisternostomy (method by Torkildsen, Dandy, or Scarff), arrest of hydrocephalus was seen in about 50 to 70 per cent, which was the same results as those of spontaneous ventriculocisternostomy. It is concluded that VP shunt or VA shunt is thought to be better treatment of obstructive hydrocephalus than the various kinds of surgical ventriculocisternostomy.

Aerosol behaviour in an acoustic field

International Nuclear Information System (INIS)

Malherbe, C.

1985-01-01

The average size of an aerosol submitted to acoustic waves is increased. This results from coagulation of the finest particles on the largest ones. The mechanisms responsible for acoustic agglomeration are mentioned. An experimental apparatus was developed in order to control the evolution of aerosol distribution in an acoustic field. Important deposition on the walls of the agglomeration chamber was observed as a consequence of the acoustically induced turbulent flow. Finally, a dimensionless relationship was established between deposition rates and particle diameters as a function of experimental parameters (aeraulic and acoustic conditions, etc...) [fr

Spontaneous Intracranial Hypotension without Orthostatic Headache

Directory of Open Access Journals (Sweden)

Tülay Kansu

2009-03-01

Full Text Available We report 2 cases of spontaneous intracranial hypotension that presented with unilateral abducens nerve palsy, without orthostatic headache. While sixth nerve palsies improved without any intervention, subdural hematoma was detected with magnetic resonance imaging. We conclude that headache may be absent in spontaneous intracranial hypotension and spontaneous improvement of sixth nerve palsy can occur, even after the development of a subdural hematoma

Spontaneous intraorbital hematoma: case report

Directory of Open Access Journals (Sweden)

Vinodan Paramanathan

2010-12-01

Full Text Available Vinodan Paramanathan, Ardalan ZolnourianQueen's Hospital NHS Foundation Trust, Burton on Trent, Staffordshire DE13 0RB, UKAbstract: Spontaneous intraorbital hematoma is an uncommon clinical entity seen in ophthalmology practice. It is poorly represented in the literature. Current evidence attributes it to orbital trauma, neoplasm, vascular malformations, acute sinusitis, and systemic abnormalities. A 65-year-old female presented with spontaneous intraorbital hematoma manifesting as severe ocular pains, eyelid edema, proptosis, and diplopia, without a history of trauma. Computer tomography demonstrated a fairly well defined extraconal lesion with opacification of the paranasal sinuses. The principal differential based on all findings was that of a spreading sinus infection and an extraconal tumor. An unprecedented finding of a spontaneous orbital hematoma was discovered when the patient was taken to theater. We discuss the rarity of this condition and its management.Keywords: hemorrhage, ophthalmology, spontaneous, intra-orbital, hematoma

Broadband unidirectional acoustic cloak based on phase gradient metasurfaces with two flat acoustic lenses

Science.gov (United States)

Wang, Xiao-Peng; Wan, Le-Le; Chen, Tian-Ning; Song, Ai-Ling; Wang, Fang

2016-07-01

Narrow bandwidth and bulky configuration are the main obstacles for the realization and application of invisible cloaks. In this paper, we present an effective method to achieve broadband and thin acoustic cloak by using an acoustic metasurface (AMS). In order to realize this cloak, we use slitted unit cells to design the AMS due to the advantage of less energy loss, broad operation bandwidth, and subwavelength thickness. According to the hyperboloidal phase profile along the AMS, the incident plane waves can be focused at a designed focal spot by the flat lens. Furthermore, broadband acoustic cloak is obtained by combining two identical flat lenses. The incident plane waves are focused at the center point in between of the two lenses by passing through one lens, and then recovered by passing through the other one. However, they cannot reach the cloaked regions in between of the two lenses. The simulation results can verify the non-detectability effect of the acoustic cloak. Our study results provide an available and simple approach to experimentally achieve the acoustic cloak, which can be used in acoustic non-detectability for large objects.

Determination of the viscous acoustic field for liquid drop positioning/forcing in an acoustic levitation chamber in microgravity

Science.gov (United States)

Lyell, Margaret J.

1992-01-01

The development of acoustic levitation systems has provided a technology with which to undertake droplet studies as well as do containerless processing experiments in a microgravity environment. Acoustic levitation chambers utilize radiation pressure forces to position/manipulate the drop. Oscillations can be induced via frequency modulation of the acoustic wave, with the modulated acoustic radiation vector acting as the driving force. To account for tangential as well as radial forcing, it is necessary that the viscous effects be included in the acoustic field. The method of composite expansions is employed in the determination of the acoustic field with viscous effects.

Novel Fiber-Optic Ring Acoustic Emission Sensor.

Science.gov (United States)

Wei, Peng; Han, Xiaole; Xia, Dong; Liu, Taolin; Lang, Hao

2018-01-13

Acoustic emission technology has been applied to many fields for many years. However, the conventional piezoelectric acoustic emission sensors cannot be used in extreme environments, such as those with heavy electromagnetic interference, high pressure, or strong corrosion. In this paper, a novel fiber-optic ring acoustic emission sensor is proposed. The sensor exhibits high sensitivity, anti-electromagnetic interference, and corrosion resistance. First, the principle of a novel fiber-optic ring sensor is introduced. Different from piezoelectric and other fiber acoustic emission sensors, this novel sensor includes both a sensing skeleton and a sensing fiber. Second, a heterodyne interferometric demodulating method is presented. In addition, a fiber-optic ring sensor acoustic emission system is built based on this method. Finally, fiber-optic ring acoustic emission experiments are performed. The novel fiber-optic ring sensor is glued onto the surface of an aluminum plate. The 150 kHz standard continuous sinusoidal signals and broken lead signals are successfully detected by the novel fiber-optic ring acoustic emission sensor. In addition, comparison to the piezoelectric acoustic emission sensor is performed, which shows the availability and reliability of the novel fiber-optic ring acoustic emission sensor. In the future, this novel fiber-optic ring acoustic emission sensor will provide a new route to acoustic emission detection in harsh environments.

Screening for spontaneous preterm birth

NARCIS (Netherlands)

van Os, M.A.; van Dam, A.J.E.M.

2015-01-01

Preterm birth is the most important cause of perinatal morbidity and mortality worldwide. In this thesis studies on spontaneous preterm birth are presented. The main objective was to investigate the predictive capacity of mid-trimester cervical length measurement for spontaneous preterm birth in a

Acoustic logic gates and Boolean operation based on self-collimating acoustic beams

International Nuclear Information System (INIS)

Zhang, Ting; Xu, Jian-yi; Cheng, Ying; Liu, Xiao-jun; Guo, Jian-zhong

2015-01-01

The reveal of self-collimation effect in two-dimensional (2D) photonic or acoustic crystals has opened up possibilities for signal manipulation. In this paper, we have proposed acoustic logic gates based on the linear interference of self-collimated beams in 2D sonic crystals (SCs) with line-defects. The line defects on the diagonal of the 2D square SCs are actually functioning as a 3 dB splitter. By adjusting the phase difference between two input signals, the basic Boolean logic functions such as XOR, OR, AND, and NOT are achieved both theoretically and experimentally. Due to the non-diffracting property of self-collimation beams, more complex Boolean logic and algorithms such as NAND, NOR, and XNOR can be realized by cascading the basic logic gates. The achievement of acoustic logic gates and Boolean operation provides a promising approach for acoustic signal computing and manipulations

Early pregnancy angiogenic markers and spontaneous abortion

DEFF Research Database (Denmark)

Andersen, Louise B; Dechend, Ralf; Karumanchi, S Ananth

2016-01-01

BACKGROUND: Spontaneous abortion is the most commonly observed adverse pregnancy outcome. The angiogenic factors soluble Fms-like kinase 1 and placental growth factor are critical for normal pregnancy and may be associated to spontaneous abortion. OBJECTIVE: We investigated the association between...... maternal serum concentrations of soluble Fms-like kinase 1 and placental growth factor, and subsequent spontaneous abortion. STUDY DESIGN: In the prospective observational Odense Child Cohort, 1676 pregnant women donated serum in early pregnancy, gestational week ..., interquartile range 71-103). Concentrations of soluble Fms-like kinase 1 and placental growth factor were determined with novel automated assays. Spontaneous abortion was defined as complete or incomplete spontaneous abortion, missed abortion, or blighted ovum

Use of acoustic field in gas cleaning

International Nuclear Information System (INIS)

Boulaud, D.; Madelaine, G.; Malherbe, C.

1985-01-01

The use of acoustic field in gas cleaning can be done in two ways: the first is the conditioning of an aerosol by acoustic agglomeration before filtration by conventional methods (cyclones, granular beds, etc.), the second is the collection efficiency improvement of granular bed filters exposed to an acoustic field. In a first part, experimental results are given on the acoustic agglomeration of a polydisperse aerosol of mass concentration between 0.5 and 1 g/m 3 . An important effect of wall precipitation of particles is described and deposition velocity due to the presence of an acoustic field are measured as a function of particle diameter, sound pressure level and acoustic frequency. A dimensionless relationship between the deposition velocity and particle relaxation time is established for these results. At the end of this part energetic criteria for the use of acoustic agglomeration in a gas cleaning train is given. In a second part, experimental results are given to the influence of acoustic field on the collection efficiency of monodispersed aerosols ranging from 0.1 to 1 μm. For these both uses of acoustic field in industrial gas cleaning the different alternatives for the acoustic field generation are discussed

Sinusoidal Representation of Acoustic Signals

Science.gov (United States)

Honda, Masaaki

Sinusoidal representation of acoustic signals has been an important tool in speech and music processing like signal analysis, synthesis and time scale or pitch modifications. It can be applicable to arbitrary signals, which is an important advantage over other signal representations like physical modeling of acoustic signals. In sinusoidal representation, acoustic signals are composed as sums of sinusoid (sine wave) with different amplitudes, frequencies and phases, which is based on the timedependent short-time Fourier transform (STFT). This article describes the principles of acoustic signal analysis/synthesis based on a sinusoid representation with focus on sine waves with rapidly varying frequency.

Acoustic loading effects on oscillating rod bundles

International Nuclear Information System (INIS)

Lin, W.H.

1980-01-01

An analytical study of the interaction between an infinite acoustic medium and a cluster of circular rods is described. The acoustic field due to oscillating rods and the acoustic loading on the rods are first solved in a closed form. The acoustic loading is then used as a forcing function for rod responses, and the acousto-elastic couplings are solved simultaneously. Numerical examples are presented for several cases to illustrate the effects of various system parameters on the acoustic reaction force coefficients. The effect of the acoustic loading on the coupled eigenfrequencies are discussed

Spontaneous emission by moving atoms

International Nuclear Information System (INIS)

Meystre, P.; Wilkens, M.

1994-01-01

It is well known that spontaneous emission is not an intrinsic atomic property, but rather results from the coupling of the atom to the vacuum modes of the electromagnetic field. As such, it can be modified by tailoring the electromagnetic environment into which the atom can radiate. This was already realized by Purcell, who noted that the spontaneous emission rate can be enhanced if the atom placed inside a cavity is resonant with one of the cavity is resonant with one of the cavity modes, and by Kleppner, who discussed the opposite case of inhibited spontaneous emission. It has also been recognized that spontaneous emission need not be an irreversible process. Indeed, a system consisting of a single atom coupled to a single mode of the electromagnetic field undergoes a periodic exchange of excitation between the atom and the field. This periodic exchange remains dominant as long as the strength of the coupling between the atom and a cavity mode is itself dominant. 23 refs., 6 figs

ISAT: The mega-fauna acoustic tracking system

KAUST Repository

De la Torre, Pedro; Smith, Egan Lloyd; Sancheti, Ajay; Salama, Khaled N.; Berumen, Michael L.

2013-01-01

The acoustic tracking module of the Integrated Satellite and Acoustic Telemetry (iSAT) system is discussed in detail. iSAT is capable of detecting the relative direction of an acoustic source by measuring the order of arrival (OOA) of the acoustic

Acoustic Neuroma Educational Video

Medline Plus

Full Text Available ... Facts What is acoustic neuroma? Diagnosing Symptoms Side Effects Keywords Questions to ask Choosing a healthcare provider ... Surgery What is acoustic neuroma Diagnosing Symptoms Side effects Question To Ask Treatment Options Back Overview Observation ...

Acoustic Neuroma Educational Video

Medline Plus

Full Text Available ... Facts What is acoustic neuroma? Diagnosing Symptoms Side Effects Keywords World Language Videos Questions to ask Choosing ... Surgery What is acoustic neuroma Diagnosing Symptoms Side effects Question To Ask Treatment Options Back Overview Observation ...

A Case of Multiple Spontaneous Keloid Scars

Directory of Open Access Journals (Sweden)

Abdulhadi Jfri

2015-07-01

Full Text Available Keloid scars result from an abnormal healing response to cutaneous injury or inflammation that extends beyond the borders of the original wound. Spontaneous keloid scars forming in the absence of any previous trauma or surgical procedure are rare. Certain syndromes have been associated with this phenomenon, and few reports have discussed the evidence of single spontaneous keloid scar, which raises the question whether they are really spontaneous. Here, we present a 27-year-old mentally retarded single female with orbital hypertelorism, broad nasal bridge, repaired cleft lip and high-arched palate who presented with progressive multiple spontaneous keloid scars in different parts of her body which were confirmed histologically by the presence of typical keloidal collagen. This report supports the fact that keloid scars can appear spontaneously and are possibly linked to a genetic factor. Furthermore, it describes a new presentation of spontaneous keloid scars in the form of multiple large lesions in different sites of the body.

Novel Fiber-Optic Ring Acoustic Emission Sensor

Directory of Open Access Journals (Sweden)

Peng Wei

2018-01-01

Full Text Available Acoustic emission technology has been applied to many fields for many years. However, the conventional piezoelectric acoustic emission sensors cannot be used in extreme environments, such as those with heavy electromagnetic interference, high pressure, or strong corrosion. In this paper, a novel fiber-optic ring acoustic emission sensor is proposed. The sensor exhibits high sensitivity, anti-electromagnetic interference, and corrosion resistance. First, the principle of a novel fiber-optic ring sensor is introduced. Different from piezoelectric and other fiber acoustic emission sensors, this novel sensor includes both a sensing skeleton and a sensing fiber. Second, a heterodyne interferometric demodulating method is presented. In addition, a fiber-optic ring sensor acoustic emission system is built based on this method. Finally, fiber-optic ring acoustic emission experiments are performed. The novel fiber-optic ring sensor is glued onto the surface of an aluminum plate. The 150 kHz standard continuous sinusoidal signals and broken lead signals are successfully detected by the novel fiber-optic ring acoustic emission sensor. In addition, comparison to the piezoelectric acoustic emission sensor is performed, which shows the availability and reliability of the novel fiber-optic ring acoustic emission sensor. In the future, this novel fiber-optic ring acoustic emission sensor will provide a new route to acoustic emission detection in harsh environments.

Density-near-zero using the acoustically induced transparency of a Fano acoustic resonator

KAUST Repository

Elayouch, A.; Addouche, M.; Farhat, Mohamed; El-Amin, Mohamed; Bagci, Hakan; Khelif, A.

2017-01-01

We report experimental results of near-zero mass density involving an acoustic metamaterial supporting Fano resonance. For this, we designed and fabricated an acoustic resonator with two closely coupled modes and measured its transmission properties

Distinct Temporal Coordination of Spontaneous Population Activity between Basal Forebrain and Auditory Cortex

Directory of Open Access Journals (Sweden)

Josue G. Yague

2017-09-01

Full Text Available The basal forebrain (BF has long been implicated in attention, learning and memory, and recent studies have established a causal relationship between artificial BF activation and arousal. However, neural ensemble dynamics in the BF still remains unclear. Here, recording neural population activity in the BF and comparing it with simultaneously recorded cortical population under both anesthetized and unanesthetized conditions, we investigate the difference in the structure of spontaneous population activity between the BF and the auditory cortex (AC in mice. The AC neuronal population show a skewed spike rate distribution, a higher proportion of short (≤80 ms inter-spike intervals (ISIs and a rich repertoire of rhythmic firing across frequencies. Although the distribution of spontaneous firing rate in the BF is also skewed, a proportion of short ISIs can be explained by a Poisson model at short time scales (≤20 ms and spike count correlations are lower compared to AC cells, with optogenetically identified cholinergic cell pairs showing exceptionally higher correlations. Furthermore, a smaller fraction of BF neurons shows spike-field entrainment across frequencies: a subset of BF neurons fire rhythmically at slow (≤6 Hz frequencies, with varied phase preferences to ongoing field potentials, in contrast to a consistent phase preference of AC populations. Firing of these slow rhythmic BF cells is correlated to a greater degree than other rhythmic BF cell pairs. Overall, the fundamental difference in the structure of population activity between the AC and BF is their temporal coordination, in particular their operational timescales. These results suggest that BF neurons slowly modulate downstream populations whereas cortical circuits transmit signals on multiple timescales. Thus, the characterization of the neural ensemble dynamics in the BF provides further insight into the neural mechanisms, by which brain states are regulated.

Controlling Sample Rotation in Acoustic Levitation

Science.gov (United States)

Barmatz, M. B.; Stoneburner, J. D.

1985-01-01

Rotation of acoustically levitated object stopped or controlled according to phase-shift monitoring and control concept. Principle applies to square-cross-section levitation chamber with two perpendicular acoustic drivers operating at same frequency. Phase difference between X and Y acoustic excitation measured at one corner by measuring variation of acoustic amplitude sensed by microphone. Phase of driver adjusted to value that produces no rotation or controlled rotation of levitated object.

Acoustic Neuroma Educational Video

Medline Plus

Full Text Available ... 30041 770-205-8211 info@ANAUSA.org The world’s #1 acoustic neuroma resource Click to learn more... ... is acoustic neuroma? Diagnosing Symptoms Side Effects Keywords World Language Videos Questions to ask Choosing a healthcare ...

Classroom acoustics as a consideration for inclusive education in South Africa.

Science.gov (United States)

Van Reenen, Coralie; Karusseit, Catherine

2017-09-08

It can hardly be disputed that a school environment should be conducive or, at the very least, not prohibitive to effective learning. The provision of fair, equal and barrier-free access to education is referred to as inclusive education. South Africa supports a policy of inclusive schooling, striving to accommodate all children, including those with disabilities, in mainstream schools. This article sets out to prove that noise control in classrooms is a relevant, yet neglected, aspect of inclusive classroom design in South Africa and requires specific attention. The objectives of this study are to: (1) establish the impact that noise has on learners with sensory, language or learning impairments; (2) establish the preferred listening conditions for these learners by examining prior research and guidelines available in other countries; and (3) outline the current South African regulations pertaining to classroom acoustics and assess them against the preferred listening environment. This research was conducted as a systematic review with reference to the South African context. Local and international research and guidelines were used as references, providing an overview and evaluation of data concerning noise and learning. Noise is disadvantageous for learners, particularly those with sensory, language or learning impairments. Research and international guidelines show that the ideal ambient level is 30 dBA - 35 dBA, allowing the achievement of an ideal signal-to-noise ratio (SNR) of +15 dB, and the ideal reverberation time is 0.4 s - 0.6 s. Various South African regulations discussed are inconsistent regarding ambient noise level (ranging from 35 dBA - 50 dBA) and say little about reverberation time for classrooms. South African regulations regarding classroom acoustics require revision to ensure inclusion of all learners with disabilities. The current status does not enforce barrier-free environments in mainstream schools for children with sensory, language or

Waveform-preserved unidirectional acoustic transmission based on impedance-matched acoustic metasurface and phononic crystal

Science.gov (United States)

Song, Ai-Ling; Chen, Tian-Ning; Wang, Xiao-Peng; Wan, Le-Le

2016-08-01

The waveform distortion happens in most of the unidirectional acoustic transmission (UAT) devices proposed before. In this paper, a novel type of waveform-preserved UAT device composed of an impedance-matched acoustic metasurface (AMS) and a phononic crystal (PC) structure is proposed and numerically investigated. The acoustic pressure field distributions and transmittance are calculated by using the finite element method. The subwavelength AMS that can modulate the wavefront of the transmitted wave at will is designed and the band structure of the PC structure is calculated and analyzed. The sound pressure field distributions demonstrate that the unidirectional acoustic transmission can be realized by the proposed UAT device without changing the waveforms of the output waves, which is the distinctive feature compared with the previous UAT devices. The physical mechanism of the unidirectional acoustic transmission is discussed by analyzing the refraction angle changes and partial band gap map. The calculated transmission spectra show that the UAT device is valid within a relatively broad frequency range. The simulation results agree well with the theoretical predictions. The proposed UAT device provides a good reference for designing waveform-preserved UAT devices and has potential applications in many fields, such as medical ultrasound, acoustic rectifiers, and noise insulation.

Dose and diameter relationships for facial, trigeminal, and acoustic neuropathies following acoustic neuroma radiosurgery

International Nuclear Information System (INIS)

Flickinger, John C.; Kondziolka, Douglas; Lunsford, L. Dade

1996-01-01

Purpose and objective: To define the relationships between dose and tumor diameter for the risks of developing trigeminal, facial, and acoustic neuropathies after acoustic neuroma radiosurgery, a large single-institution experience was analyzed. Materials and methods: Two hundred and thirty-eight patients with unilateral acoustic neuromas who underwent Gamma knife radiosurgery between 1987-1994 with 6-91 months of follow-up (median 30 months) were studied. Minimum tumor doses were 12-20 Gy (median 15 Gy). Transverse tumor diameter varied from 0.3-5.5 cm (median 2.1 cm). The relationships of dose and diameter to the development of cranial neuropathies were delineated by multivariate logistic regression. Results: The development of post-radiosurgery neuropathies affecting cranial nerves V, VII, and VIII were correlated with minimum tumor dose and transverse tumor diameter (P min for VIII where P=0.10). A comparison of the dose-diameter response curves showed the acoustic nerve to be the most sensitive to doses of 12-16 Gy and the facial nerve to be the least sensitive. Conclusion: The risks of developing trigeminal, facial, and acoustic neuropathies following acoustic neuroma radiosurgery can be predicted from the transverse tumor diameter and the minimum tumor dose using models constructed from data presently available

Acoustic spin pumping in magnetoelectric bulk acoustic wave resonator

Directory of Open Access Journals (Sweden)

N. I. Polzikova

2016-05-01

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

Acoustic spin pumping in magnetoelectric bulk acoustic wave resonator

Energy Technology Data Exchange (ETDEWEB)

Polzikova, N. I., E-mail: polz@cplire.ru; Alekseev, S. G.; Pyataikin, I. I.; Kotelyanskii, I. M.; Luzanov, V. A.; Orlov, A. P. [Kotel’nikov Institute of Radio Engineering and Electronics of Russian Academy of Sciences, Mokhovaya 11, building 7, Moscow, 125009 (Russian Federation)

2016-05-15

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

Ares I Scale Model Acoustic Test Instrumentation for Acoustic and Pressure Measurements

Science.gov (United States)

Vargas, Magda B.; Counter, Douglas

2011-01-01

Ares I Scale Model Acoustic Test (ASMAT) is a 5% scale model test of the Ares I vehicle, launch pad and support structures conducted at MSFC to verify acoustic and ignition environments and evaluate water suppression systems Test design considerations 5% measurements must be scaled to full scale requiring high frequency measurements Users had different frequencies of interest Acoustics: 200 - 2,000 Hz full scale equals 4,000 - 40,000 Hz model scale Ignition Transient: 0 - 100 Hz full scale equals 0 - 2,000 Hz model scale Environment exposure Weather exposure: heat, humidity, thunderstorms, rain, cold and snow Test environments: Plume impingement heat and pressure, and water deluge impingement Several types of sensors were used to measure the environments Different instrument mounts were used according to the location and exposure to the environment This presentation addresses the observed effects of the selected sensors and mount design on the acoustic and pressure measurements

Low frequency acoustic properties of bilayer membrane acoustic metamaterial with magnetic oscillator

Directory of Open Access Journals (Sweden)

Nansha Gao

2017-07-01

Full Text Available A bilayer membrane acoustic metamaterial was proposed to overcome the influence of the mass law on traditional acoustic materials and obtain a lightweight thin-layer structure that can effectively isolate low frequency noise. The finite element analysis (FEA results agree well with the experimental results. It is proved that the sound transmission losses (STLs of the proposed structures are higher than those of same surface density acoustic materials. The introduction of the magnetic mass block is different from the traditional design method, in which only a passive mass block is fixed on the membrane. The magnetic force will cause tension in the membrane, increase membrane prestress, and improve overall structural stiffness. The effects of the geometry size on the STLs are discussed in detail. The kind of method presented in this paper can provide a new means for engineering noise control. Keywords: Bilayer membrane acoustic metamaterial, Low frequency sound insulation, Sound transmission loss, Magnet oscillator

Hidden acoustic information revealed by intentional nonlinearity

Science.gov (United States)

Dowling, David R.

2017-11-01

Acoustic waves are omnipresent in modern life and are well described by the linearized equations of fluid dynamics. Once generated, acoustic waves carry and collect information about their source and the environment through which they propagate, respectively, and this information may be retrieved by analyzing recordings of these waves. Because of this, acoustics is the primary means for observation, surveillance, reconnaissance, and remote sensing in otherwise opaque environments, such as the Earth's oceans and crust, and the interior of the human body. For such information-retrieval tasks, acoustic fields are nearly always interrogated within their recorded frequency range or bandwidth. However, this frequency-range restriction is not general; acoustic fields may also carry (hidden) information at frequencies outside their bandwidth. Although such a claim may seem counter intuitive, hidden acoustic-field information can be revealed by re-introducing a marquee trait of fluid dynamics: nonlinearity. In particular, an intentional quadratic nonlinearity - a form of intra-signal heterodyning - can be used to obtain acoustic field information at frequencies outside a recorded acoustic field's bandwidth. This quadratic nonlinearity enables a variety of acoustic remote sensing applications that were long thought to be impossible. In particular, it allows the detrimental effects of sparse recordings and random scattering to be suppressed when the original acoustic field has sufficient bandwidth. In this presentation, the topic is developed heuristically, with a just brief exposition of the relevant mathematics. Hidden acoustic field information is then revealed from simulated and measured acoustic fields in simple and complicated acoustic environments involving frequencies from a few Hertz to more than 100 kHz, and propagation distances from tens of centimeters to hundreds of kilometers. Sponsored by ONR, NAVSEA, and NSF.

Guided acoustic wave inspection system

Science.gov (United States)

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.

Spontaneous pneumothorax in silicotuberculosis of lung

International Nuclear Information System (INIS)

Kolenic, J.; Jurgova, T.; Zimacek, J.; Vajo, J.; Krchnavy, M.

1995-01-01

The authors describe the case of 62 years old man with the appearance of spontaneous pneumothorax, in whom the basic pulmonary disease was silicotuberculosis of the lung. At clinic of occupational diseases in Kosice have been evidence 965 cases of silicosis and silicotuberculosis. From 1971 they have now the first case of spontaneous pneumothorax. The authors make discussion about possible mechanical and biochemical factors, which cause relatively low incidence of spontaneous pneumothorax in silicosis of the lung. (authors)

Nonlinear frequency shift of a coherent dust-acoustic wave in the presence of dust-acoustic turbulence

International Nuclear Information System (INIS)

Yi Sumin; Ryu, C.-M.; Yoon, Peter H.

2003-01-01

The nonlinear frequency shift of a low-frequency, coherent dust-acoustic wave in the presence of higher frequency dust-acoustic turbulence is investigated in the framework of weak turbulence theory. It is found that the frequency shift of the dust-acoustic wave in an unmagnetized dusty plasma is always positive irrespective of the propagation direction of the coherent wave. It is also found that turbulent waves propagating in the same direction as the coherent wave are shown to give rise to a much higher frequency shift than the opposite case. Finally, it is shown that the nonlinear frequency shift of a dust-acoustic wave is more pronounced than in the case of the customary ion-acoustic waves in fully ionized plasmas

The deep sea Acoustic Detection system AMADEUS

International Nuclear Information System (INIS)

Naumann, Christopher Lindsay

2008-01-01

As a part of the ANTARES neutrino telescope, the AMADEUS (ANTARES Modules for Acoustic Detection Under the Sea) system is an array of acoustical sensors designed to investigate the possibilities of acoustic detection of ultra-high energy neutrinos in the deep sea. The complete system will comprise a total of 36 acoustic sensors in six clusters on two of the ANTARES detector lines. With an inter-sensor spacing of about one metre inside the clusters and between 15 and 340 metres between the different clusters, it will cover a wide range of distances as will as provide a considerable lever arm for point source triangulation. Three of these clusters have already been deployed in 2007 and have been in operation since, currently yielding around 2GB of acoustic data per day. The remaining three clusters are scheduled to be deployed in May 2008 together with the final ANTARES detector line. Apart from proving the feasibility of operating an acoustic detection system in the deep sea, the main aim of this project is an in-depth survey of both the acoustic properties of the sea water and the acoustic background present at the detector site. It will also serve as a platform for the development and refinement of triggering, filtering and reconstruction algorithms for acoustic particle detection. In this presentation, a description of the acoustic sensor and read-out system is given, together with examples for the reconstruction and evaluation of the acoustic data.

De-Dopplerization of Acoustic Measurements

Science.gov (United States)

2017-08-10

accurate measurement of aircraft location to resample the time signal to account for the compression and expansion of acoustic wavefronts. Correcting...AFRL-RH-WP-TR-2017-0043 DE-DOPPLERIZATION OF ACOUSTIC MEASUREMENTS Frank Mobley, PhD 711 HPW/RHCB Wright-Patterson AFB OH...TITLE AND SUBTITLE DE-DOPPLERIZATION OF ACOUSTIC MEASUREMENTS 5a. CONTRACT NUMBER In-House 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER

Spontaneous body movements in spatial cognition

Directory of Open Access Journals (Sweden)

Sergiu eTcaci Popescu

2012-05-01

Full Text Available People often perform spontaneous body movements during spatial tasks such as giving complex directions or orienting themselves on maps. How are these spontaneous gestures related to spatial problem-solving? We measured spontaneous movements during a perspective-taking task inspired by map reading. Analyzing the motion data to isolate rotation and translation components of motion in specific geometric relation to the task, we found out that most participants executed spontaneous miniature rotations of the head that were significantly related to the main task parameter. These head rotations were as if participants were trying to align themselves with the orientation on the map either in the image plane or on the ground plane, but with tiny amplitudes, typically below 1% of the actual movements. Our results are consistent with a model of sensorimotor prediction driving spatial reasoning. The efference copy of planned movements triggers this prediction mechanism. The movements themselves may then be mostly inhibited; the small spontaneous gestures that we measure are the visible traces of these planned but inhibited actions.

Acoustic emission

International Nuclear Information System (INIS)

Straus, A.; Lopez Pumarega, M.I.; Di Gaetano, J.O.; D'Atellis, C.E.; Ruzzante, J.E.

1990-01-01

This paper is related to our activities on acoustic emission (A.E.). The work is made with different materials: metals and fibre reinforced plastics. At present, acoustic emission transducers are being developed for low and high temperature. A test to detect electrical discharges in electrical transformers was performed. Our experience in industrial tests to detect cracks or failures in tanks or tubes is also described. The use of A.E. for leak detection is considered. Works on pattern recognition of A.E. signals are also being performed. (Author)

Theory and modeling of cylindrical thermo-acoustic transduction

Energy Technology Data Exchange (ETDEWEB)

Tong, Lihong, E-mail: lhtong@ecjtu.edu.cn [School of Civil Engineering and Architecture, East China Jiaotong University, Nanchang, Jiangxi (China); Lim, C.W. [Department of Architecture and Civil Engineering, City University of Hong Kong, Kowloon, Hong Kong SAR (China); Zhao, Xiushao; Geng, Daxing [School of Civil Engineering and Architecture, East China Jiaotong University, Nanchang, Jiangxi (China)

2016-06-03

Models both for solid and thinfilm-solid cylindrical thermo-acoustic transductions are proposed and the corresponding acoustic pressure solutions are obtained. The acoustic pressure for an individual carbon nanotube (CNT) as a function of input power is investigated analytically and it is verified by comparing with the published experimental data. Further numerical analysis on the acoustic pressure response and characteristics for varying input frequency and distance are also examined both for solid and thinfilm-solid cylindrical thermo-acoustic transductions. Through detailed theoretical and numerical studies on the acoustic pressure solution for thinfilm-solid cylindrical transduction, it is concluded that a solid with smaller thermal conductivity favors to improve the acoustic performance. In general, the proposed models are applicable to a variety of cylindrical thermo-acoustic devices performing in different gaseous media. - Highlights: • Theory and modeling both for solid and thinfilm-solid cylindrical thermo-acoustic transductions are proposed. • The modeling is verified by comparing with the published experimental data. • Acoustic response characteristics of cylindrical thermo-acoustic transductions are predicted by the proposed model.

Spontaneous pneumothorax in diffuse cystic lung diseases.

Science.gov (United States)

Cooley, Joseph; Lee, Yun Chor Gary; Gupta, Nishant

2017-07-01

Diffuse cystic lung diseases (DCLDs) are a heterogeneous group of disorders with varying pathophysiologic mechanisms that are characterized by the presence of air-filled lung cysts. These cysts are prone to rupture, leading to the development of recurrent spontaneous pneumothoraces. In this article, we review the epidemiology, clinical features, and management DCLD-associated spontaneous pneumothorax, with a focus on lymphangioleiomyomatosis, Birt-Hogg-Dubé syndrome, and pulmonary Langerhans cell histiocytosis. DCLDs are responsible for approximately 10% of apparent primary spontaneous pneumothoraces. Computed tomography screening for DCLDs (Birt-Hogg-Dubé syndrome, lymphangioleiomyomatosis, and pulmonary Langerhans cell histiocytosis) following the first spontaneous pneumothorax has recently been shown to be cost-effective and can help facilitate early diagnosis of the underlying disorders. Patients with DCLD-associated spontaneous pneumothorax have a very high rate of recurrence, and thus pleurodesis should be considered following the first episode of spontaneous pneumothorax in these patients, rather than waiting for a recurrent episode. Prior pleurodesis is not a contraindication to future lung transplant. Although DCLDs are uncommon, spontaneous pneumothorax is often the sentinel event that provides an opportunity for diagnosis. By understanding the burden and implications of pneumothoraces in DCLDs, clinicians can facilitate early diagnosis and appropriate management of the underlying disorders.

Acoustic constituents of prosodic typology

Science.gov (United States)

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

Acoustics Critical Readiness Review

Science.gov (United States)

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.

Acoustic tweezers: patterning cells and microparticles using standing surface acoustic waves (SSAW).

Science.gov (United States)

Shi, Jinjie; Ahmed, Daniel; Mao, Xiaole; Lin, Sz-Chin Steven; Lawit, Aitan; Huang, Tony Jun

2009-10-21

Here we present an active patterning technique named "acoustic tweezers" that utilizes standing surface acoustic wave (SSAW) to manipulate and pattern cells and microparticles. This technique is capable of patterning cells and microparticles regardless of shape, size, charge or polarity. Its power intensity, approximately 5x10(5) times lower than that of optical tweezers, compares favorably with those of other active patterning methods. Flow cytometry studies have revealed it to be non-invasive. The aforementioned advantages, along with this technique's simple design and ability to be miniaturized, render the "acoustic tweezers" technique a promising tool for various applications in biology, chemistry, engineering, and materials science.

Acoustic communication in plant–animal interactions

NARCIS (Netherlands)

Schöner, M.G.; Simon, R.; Schöner, C.R.

2016-01-01

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

A low frequency acoustic insulator by using the acoustic metasurface to a Helmholtz resonator

Science.gov (United States)

Zhao, Xiang; Cai, Li; Yu, Dianlong; Lu, Zhimiao; Wen, Jihong

2017-06-01

Acoustic metasurfaces (AMSs) are able to manipulate wavefronts at an anomalous angle through a subwavelength layer. Their application provide a new way to control sound waves in addition to traditional materials. In this work, we introduced the AMS into the design of a Helmholtz resonator (HR) and studied the acoustic transmission through the modified HR in a pipe with one branch. The variation of sound insulation capacity with the phase gradient of the AMS was studied, and the results show that the AMS can remarkably lower the frequency band of the sound insulation without increasing the size. Our investigation provides a new degree of freedom for acoustic control with a Helmholtz resonator, which is of great significance in acoustic metasurface theory and sound insulation design.

FEL gain optimisation and spontaneous radiation

Energy Technology Data Exchange (ETDEWEB)

Bali, L.M.; Srivastava, A.; Pandya, T.P. [Lucknow Univ. (India)] [and others

1995-12-31

Colson have evaluated FEL gains for small deviations from perfect electron beam injection, with radiation of the same polarisation as that of the wiggler fields. We find that for optimum gain the polarisation of the optical field should be the same as that of the spontaneous emission under these conditions. With a helical wiggler the axial oscillations resulting from small departures from perfect electron beam injection lead to injection dependent unequal amplitudes and phases of the spontaneous radiation in the two transverse directions. Viewed along the axis therefore the spontaneous emission is elliptically polarised. The azimuth of the ellipse varies with the difference of phase of the two transverse components of spontaneous emission but the eccentricity remains the same. With planar wigglers the spontaneous emission viewed in the axial direction is linearly polarised, again with an injection dependent azimuth. For optimum coherent gain of a radiation field its polarisation characteristics must be the same as those of the spontaneous radiation with both types of wiggler. Thus, with a helical wiggler and the data reported earlier, an increase of 10% in the FEL gain at the fundamental frequency and of 11% at the fifth harmonic has been calculated in the small gain per pass limit. Larger enhancements in gain may result from more favourable values of input parameters.

Applied acoustics concepts, absorbers, and silencers for acoustical comfort and noise control alternative solutions, innovative tools, practical examples

CERN Document Server

Fuchs, Helmut V

2013-01-01

The author gives a comprehensive overview of materials and components for noise control and acoustical comfort. Sound absorbers must meet acoustical and architectural requirements, which fibrous or porous material alone can meet. Basics and applications are demonstrated, with representative examples for spatial acoustics, free-field test facilities and canal linings. Acoustic engineers and construction professionals will find some new basic concepts and tools for developments in order to improve acoustical comfort. Interference absorbers, active resonators and micro-perforated absorbers of different materials and designs complete the list of applications.

Acoustic effects of single electrostatic discharges

International Nuclear Information System (INIS)

Orzech, Łukasz

2015-01-01

Electric discharges, depending on their character, can emit different types of energy, resulting in different effects. Single electrostatic discharges besides generation of electromagnetic pulses are also the source of N acoustic waves. Their specified parameters depending on amount of discharging charge enable determination of value of released charge in a function of acoustic descriptor (e.g. acoustic pressure). Presented approach is the basics of acoustic method for measurement of single electrostatic discharges, enabling direct and contactless measurement of value of charge released during ESD. Method for measurement of acoustic effect of impact of a single electrostatic discharge on the environment in a form of pressure shock wave and examples of acoustic descriptors in a form of equation Q=f(p a ) are described. The properties of measuring system as well as the results of regression static analyses used to determine the described relationships are analysed in details. (paper)

Anal acoustic reflectometry

DEFF Research Database (Denmark)

Mitchell, Peter J; Klarskov, Niels; Telford, Karen J

2011-01-01

Anal acoustic reflectometry is a new technique of assessing anal sphincter function. Five new variables reflecting anal canal function are measured: the opening and closing pressure, the opening and closing elastance, and hysteresis.......Anal acoustic reflectometry is a new technique of assessing anal sphincter function. Five new variables reflecting anal canal function are measured: the opening and closing pressure, the opening and closing elastance, and hysteresis....

Acoustic analysis of a piping system

International Nuclear Information System (INIS)

Misra, A.S.; Vijay, D.K.

1996-01-01

Acoustic pulsations in the Darlington Nuclear Generating Station, a 881 MW CANDU, primary heat transport piping system caused fuel bundle failures under short term operations. The problem was successfully analyzed using the steady-state acoustic analysis capability of the ABAQUS program. This paper describes in general, modelling of low amplitude acoustic pulsations in a liquid filled piping system using ABAQUS. The paper gives techniques for estimating the acoustic medium properties--bulk modulus, fluid density and acoustic damping--and modelling fluid-structure interactions at orifices and elbows. The formulations and techniques developed are benchmarked against the experiments given in 3 cited references. The benchmark analysis shows that the ABAQUS results are in excellent agreement with the experiments

Spontaneous Bacterial Peritonitis in Subclinical Hypothyroidism

Directory of Open Access Journals (Sweden)

Dalip Gupta

2013-11-01

Full Text Available Hypothyroidism is an uncommon cause of ascites. Here we describe a case of a 75 year-old female patient with spontaneous bacterial peritonitis and subclinical hypothyroidism that resolved with thyroid replacement and antibiotic therapy respectively. Ascitic fluid analysis revealed a gram-positive bacterium on gram staining. A review of the literature revealed just one other reported case of myxoedema ascites with concomitant spontaneous bacterial peritonitis and no case has till been reported of spontaneous bacterial peritonitis in subclinical hypothyroidism.

Multiscale modeling of acoustic shielding materials

NARCIS (Netherlands)

Gao, K.; Dommelen, van J.A.W.; Geers, M.G.D.

2012-01-01

It is very important to protect high-tech systems from acoustic excitation when operating in a noisy environment. Some passive absorbing materials such as acoustic foams can improve the performance which depends on the interaction of the acoustic wave and the microstructure of the foam.

Agrammatic aphasia verb and argument patterns in Kiswahili-English spontaneous language

Directory of Open Access Journals (Sweden)

Hillary K. Sang

2015-06-01

Full Text Available Background: The spontaneous and narrative language of Kiswahili agrammatic aphasic and non-brain-damaged speakers was analysed. The bilingual participants were also tested in English to enable comparisons of verb production in the two languages. The significance of this study was to characterise bilingual Kiswahili-English spontaneous agrammatic output. This was done by describing Kiswahili-English bilingual output data with a specific focus on the production of verbs. The description involves comparison of verb and argument production in Kiswahili and English. Methods and procedures: The participants recruited for this study were drawn from two groups of participants (six non-fluent aphasic/agrammatic speakers and six non-braindamaged. From each participant, a sample of spontaneous output was tape-recorded in English and Kiswahili based on the description and narration of the Flood rescue picture’ and the ‘Cookie theft picture’. The data elicited were compared for each subject and between the participants and relevant verb parameters have been analysed. The variables that were studied included mean length of utterance (MLU, inflectional errors, verb tokens and types, copulas and auxiliaries. Further, all verbs produced were classified as per their argument structure. Results: The results from English data supported previous findings on agrammatic output. The agrammatic participants produced utterances with shorter MLU and simpler sentence structure. However, Kiswahili data surprisingly showed reversed results, with agrammatic speakers producing longer utterances than non-brain-damaged (NBD controls. The results also revealed selective impairment in some agrammatic speakers who made inflectional errors. The verb argument structure showed contrasting results, with agrammatic speakers preferring transitive verbs whilst the NBD speakers used more intransitive verbs. Conclusions: The study attempts for the first time to characterise English

Spontaneous mutation rates and the rate-doubling dose

International Nuclear Information System (INIS)

Von Borstel, R.C.; Moustaccki, E.; Latarjet, R.

1978-01-01

The amount of radiation required to double the frequency of mutations or tumours over the rate of those that occur spontaneously is called the rate-doubling dose. An equivalent concept has been proposed for exposure to other environmental mutagens. The doubling dose concept is predicated on the assumption that all human populations have the same spontaneous mutation rate, and that this spontaneous mutation rate is known. It is now established for prokaryotes and lower eukaryotes that numerous genes control the spontaneous mutation rate, and it is likely that the same is true for human cells as well. Given that the accepted mode of evolution of human populatons is from small, isolated groups of individuals, it seems likely that each population would have a different spontaneous mutation rate. Given that a minimum of twenty genes control or affect the spontaneous mutation rate, and that each of these in turn is susceptible to spontaneously arising or environmentally induced mutations, it seems likely that every individual within a population (except for siblings from identical multiple births) will have a unique spontaneous mutation rate. If each individual in a population does have a different spontaneous mutation rate, the doubling dose concept, in rigorous terms, is fallacious. Therefore, as with other concepts of risk evaluation, the doubling dose concept is subject to criticism. Nevertheless, until we know individual spontaneous mutation rates with precision, and can evaluate risks based on this information, the doubling dose concept has a heuristic value and is needed for practical assessment of risks for defined populations. (author)

Acoustical heat pumping engine

Science.gov (United States)

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.

A Treatise on Acoustic Radiation. Volume 2. Acoustic Transducers

Science.gov (United States)

1983-01-01

Newton) V (meter/sec) acoustical p (Newton/meter2 ) U (meter 3/sec) To display Eq. 1.53.1 in simple form we take time to be given by exp(- iot ) and choose...if all the C-component edges and e-drivers are in the tree, all the L-component "A edges and idrivers are in the cotree, all the algebraic equations...momentum and mass of the elastic field then become, (a) Al - V -T + F 278 W-4. ,-,- * * * 4 % • *.• Design of Acoustic Transducers IOT (b) I + VV-s

Acoustic emission technique and its applications

International Nuclear Information System (INIS)

Sato, Ichiya; Sasaki, Soji

1976-01-01

Acoustic emission technique is described. The characteristics of acoustic emission signal, measurement techniques, and its application are explained. The acoustic signals are grouped into continuous and burst types. The continuous signal is due to plastic deformation, and the burst type is due to the generation and growth of cracks. The latter can be used for the identification of the position of cracks. The frequency of the acoustic emission is in the range from several tens of KHz to two MHz. Piezoelectric ceramics are used as the oscillators of sensors. The dynamic behavior of acoustic emission can be observed with a two-channel acoustic emission measuring apparatus. Multi-channel method was developed at Hitachi, Ltd., and is used for large structures. General computer identification method and simple zone identification method are explained. Noise elimination is important for the measurement, and the methods were studied. Examples of application are the observation of acoustic emission in the plastic deformation of steel, the tensile test of large welded material with natural defects, and others. The method will be used for the diagnosis and observation of large structures, the test and quality control of products. (Kato, T.)

Network science and the effects of music preference on functional brain connectivity: from Beethoven to Eminem.

Science.gov (United States)

Wilkins, R W; Hodges, D A; Laurienti, P J; Steen, M; Burdette, J H

2014-08-28

Most people choose to listen to music that they prefer or 'like' such as classical, country or rock. Previous research has focused on how different characteristics of music (i.e., classical versus country) affect the brain. Yet, when listening to preferred music--regardless of the type--people report they often experience personal thoughts and memories. To date, understanding how this occurs in the brain has remained elusive. Using network science methods, we evaluated differences in functional brain connectivity when individuals listened to complete songs. We show that a circuit important for internally-focused thoughts, known as the default mode network, was most connected when listening to preferred music. We also show that listening to a favorite song alters the connectivity between auditory brain areas and the hippocampus, a region responsible for memory and social emotion consolidation. Given that musical preferences are uniquely individualized phenomena and that music can vary in acoustic complexity and the presence or absence of lyrics, the consistency of our results was unexpected. These findings may explain why comparable emotional and mental states can be experienced by people listening to music that differs as widely as Beethoven and Eminem. The neurobiological and neurorehabilitation implications of these results are discussed.

Predicting and auralizing acoustics in classrooms

DEFF Research Database (Denmark)

Christensen, Claus Lynge

2005-01-01

Although classrooms have fairly simple geometries, this type of room is known to cause problems when trying to predict their acoustics using room acoustics computer modeling. Some typical features from a room acoustics point of view are: Parallel walls, low ceilings (the rooms are flat), uneven...

The Acoustical Apparatus of Rudolph Koenig.

Science.gov (United States)

Greenslade, Thomas B., Jr.

1992-01-01

Discusses the history of Rudolph Koenig's contribution to the development of acoustical apparatus. Contributions include the clock fork to determine absolute acoustic frequencies, a forerunner of the oscilloscope called the manometric flame, and an acoustic interference apparatus used in the Fourier synthesis of musical sounds. (MDH)

Aero-acoustic Computations of Wind Turbines

DEFF Research Database (Denmark)

Shen, Wen Zhong; Michelsen, Jess; Sørensen, Jens Nørkær

2002-01-01

A numerical algorithm for acoustic noise generation is extended to 3D flows. The approach involves two parts comprising a viscous incompressible flow part and an inviscid acoustic part. In order to simulate noise generated from a wind turbine, the incompressible and acoustic equations are written...

Acoustic perturbation equations and Lighthill's acoustic analogy for the human phonation

Czech Academy of Sciences Publication Activity Database

Zoerner, S.; Šidlof, Petr; Huppe, A.; Kaltenbacher, M.

2013-01-01

Roč. 19, 060309 (2013), s. 1-8 ISSN 1939-800X. [ICA 2013 - Meetings on Acoustics. Montreal, 02.06.2013-07.06.2013] R&D Projects: GA ČR(CZ) GAP101/11/0207 Institutional support: RVO:61388998 Keywords : vocal folds * CFD * computational aeroacoustics Subject RIV: BI - Acoustics http://asadl.org/poma/ resource /1/pmarcw/v19/i1/p060309_s1? view =print

Sustainable Acoustic Metasurfaces for Sound Control

Directory of Open Access Journals (Sweden)

Paola Gori

2016-01-01

Full Text Available Sound attenuation with conventional acoustic materials is subject to the mass law and requires massive and bulky structures at low frequencies. A possible alternative solution is provided by the use of metamaterials, which are artificial materials properly engineered to obtain properties and characteristics that it is not possible to find in natural materials. Theory and applications of metamaterials, already consolidated in electromagnetism, can be extended to acoustics; in particular, they can be applied to improve the properties of acoustical panels. The design of acoustic metasurfaces that could effectively control transmitted sound in unconventional ways appears a significant subject to be investigated, given its wide-ranging possible applications. In this contribution, we investigate the application of a metasurface-inspired technique to achieve the acoustical insulation of an environment. The designed surface has subwavelength thickness and structuring and could be realized with cheap, lightweight and sustainable materials. We present a few examples of such structures and analyze their acoustical behavior by means of full-wave simulations.

Visually Evoked Spiking Evolves While Spontaneous Ongoing Dynamics Persist

Science.gov (United States)

Huys, Raoul; Jirsa, Viktor K.; Darokhan, Ziauddin; Valentiniene, Sonata; Roland, Per E.

2016-01-01

Neurons in the primary visual cortex spontaneously spike even when there are no visual stimuli. It is unknown whether the spiking evoked by visual stimuli is just a modification of the spontaneous ongoing cortical spiking dynamics or whether the spontaneous spiking state disappears and is replaced by evoked spiking. This study of laminar recordings of spontaneous spiking and visually evoked spiking of neurons in the ferret primary visual cortex shows that the spiking dynamics does not change: the spontaneous spiking as well as evoked spiking is controlled by a stable and persisting fixed point attractor. Its existence guarantees that evoked spiking return to the spontaneous state. However, the spontaneous ongoing spiking state and the visual evoked spiking states are qualitatively different and are separated by a threshold (separatrix). The functional advantage of this organization is that it avoids the need for a system reorganization following visual stimulation, and impedes the transition of spontaneous spiking to evoked spiking and the propagation of spontaneous spiking from layer 4 to layers 2–3. PMID:26778982

A low frequency acoustic insulator by using the acoustic metasurface to a Helmholtz resonator

Directory of Open Access Journals (Sweden)

Xiang Zhao

2017-06-01

Full Text Available Acoustic metasurfaces (AMSs are able to manipulate wavefronts at an anomalous angle through a subwavelength layer. Their application provide a new way to control sound waves in addition to traditional materials. In this work, we introduced the AMS into the design of a Helmholtz resonator (HR and studied the acoustic transmission through the modified HR in a pipe with one branch. The variation of sound insulation capacity with the phase gradient of the AMS was studied, and the results show that the AMS can remarkably lower the frequency band of the sound insulation without increasing the size. Our investigation provides a new degree of freedom for acoustic control with a Helmholtz resonator, which is of great significance in acoustic metasurface theory and sound insulation design.

Principles of musical acoustics

CERN Document Server

Hartmann, William M

2013-01-01

Principles of Musical Acoustics focuses on the basic principles in the science and technology of music. Musical examples and specific musical instruments demonstrate the principles. The book begins with a study of vibrations and waves, in that order. These topics constitute the basic physical properties of sound, one of two pillars supporting the science of musical acoustics. The second pillar is the human element, the physiological and psychological aspects of acoustical science. The perceptual topics include loudness, pitch, tone color, and localization of sound. With these two pillars in place, it is possible to go in a variety of directions. The book treats in turn, the topics of room acoustics, audio both analog and digital, broadcasting, and speech. It ends with chapters on the traditional musical instruments, organized by family. The mathematical level of this book assumes that the reader is familiar with elementary algebra. Trigonometric functions, logarithms and powers also appear in the book, but co...

Vibro-acoustic modeling and analysis of a coupled acoustic system comprising a partially opened cavity coupled with a flexible plate

Science.gov (United States)

Shi, Shuangxia; Su, Zhu; Jin, Guoyong; Liu, Zhigang

2018-01-01

This paper is concerned with the modeling and solution method of a three-dimensional (3D) coupled acoustic system comprising a partially opened cavity coupled with a flexible plate and an exterior field of semi-infinite size, which is ubiquitously encountered in architectural acoustics and is a reasonable representation of many engineering occasions. A general solution method is presented to predict the dynamic behaviors of the three-dimensional (3D) acoustic coupled system, in which the displacement of the plate and the sound pressure in the cavity are respectively constructed in the form of the two-dimensional and three-dimensional modified Fourier series with several auxiliary functions introduced to ensure the uniform convergence of the solution over the entire solution domain. The effect of the opening is taken into account via the work done by the sound pressure acting at the coupling aperture that is contributed from the vibration of particles on the acoustic coupling interface and on the structural-acoustic coupling interface. Both the acoustic coupling between finite cavity and exterior field and the structural-acoustic coupling between flexible plate and interior acoustic field are considered in the vibro-acoustic modeling of the three-dimensional acoustic coupled acoustic system. The dynamic responses of the coupled structural-acoustic system are obtained using the Rayleigh-Ritz procedure based on the energy expressions for the coupled system. The accuracy and effectiveness of the proposed method are validated through numerical examples and comparison with results obtained by the boundary element analysis. Furthermore, the influence of the opening and the cavity volume on the acoustic behaviors of opened cavity system is studied.

Low frequency acoustic properties of a honeycomb-silicone rubber acoustic metamaterial

Science.gov (United States)

Gao, Nansha; Hou, Hong

2017-04-01

In order to overcome the influence of mass law on traditional acoustic materials and obtain a lightweight thin-layer structure which can effectively isolate the low frequency noises, a honeycomb-silicone rubber acoustic metamaterial was proposed. Experimental results show that the sound transmission loss (STL) of acoustic metamaterial in this paper is greatly higher than that of monolayer silicone rubber metamaterial. Based on the band structure, modal shapes, as well as the sound transmission simulation, the sound insulation mechanism of the designed honeycomb-silicone rubber structure was analyzed from a new perspective, which had been validated experimentally. Side length of honeycomb structure and thickness of the unit structure would affect STL in damping control zone. Relevant conclusions and design method provide a new concept for engineering noise control.

Peritonitis - spontaneous bacterial

Science.gov (United States)

Spontaneous bacterial peritonitis (SBP); Ascites - peritonitis; Cirrhosis - peritonitis ... who are on peritoneal dialysis for kidney failure. Peritonitis may have other causes . These include infection from ...

Extraordinary acoustic transmission through annuluses in air and its applications in acoustic beam splitter and concentrator

International Nuclear Information System (INIS)

Ge, Yong; Liu, Shu-sen; Yuan, Shou-qi; Xia, Jian-ping; Guan, Yi-jun; Sun, Hong-xiang; Zhang, Shu-yi

2016-01-01

We report an extraordinary acoustic transmission through two layer annuluses made of metal cylinders in air both numerically and experimentally. The effect arises from the enhancement and reconstruction of the incident source induced by different Mie-resonance modes of the annuluses. The proposed system takes advantages of the consistency in the waveform between the input and output waves, the high amplitude amplification of output waves, and the easy adjustment of structure. More interestingly, we investigate the applications of the extraordinary acoustic transmission in the acoustic beam splitter and acoustic concentrator. Our finding should have an impact on ultrasonic applications.

Acoustically assisted diffusion through membranes and biomaterials

International Nuclear Information System (INIS)

Floros, J.D.; Liang, H.

1994-01-01

Part of a special section on the symposium ''Ultrasonic Applications in the Food Industry.'' The use of high-intensity ultrasound in food processing is reviewed. Acoustic radiation, or sound, can be used to monitor various operations or products or to alter a process or product; however, the direct use of sound to improve food processes is not very popular. High-intensity acoustic radiation induces various changes as it passes through a medium, largely as a result of heating, cavitation, agitation and shear stresses, compression and rarefaction, and turbulence. The diffusion of sound through a medium is influenced by factors such as the temperature, acoustic intensity, acoustic frequency, direction of the acoustic wave, pulsation of the acoustic wave, and properties of the medium. Some potential applications of acoustic energy in food processes are increased drying efficiency, acceleration of diffusion through polymeric and biological membranes, and enhanced diffusion through porous materials

Transfer of spontaneously hatching or hatched blastocyst yields better pregnancy rates than expanded blastocyst transfer

Directory of Open Access Journals (Sweden)

Natachandra M Chimote

2013-01-01

Full Text Available Context: Blastocyst stage embryo transfer (ET has become routine practice in recent years. However, probably due to limitations of assisted hatching techniques, expanded blastocyst transfer (EBT is still the preferred mode. Inexplicably, not much consideration has been given to spontaneously hatching/hatched blastocyst transfer (SHBT. Aim: This study aimed to investigate developmental potential of spontaneously hatching/hatched blastocyst against EBT in in vitro fertilization (IVF cycles. Settings and Design: Prospective study of 146 women undergoing their first IVF- ET cycle. SUBJECTS AND Methods: On the basis of blastocyst status, women were classified into SHBT and EBT groups. Intracytoplasmic sperm injection cycles were excluded to remove male factor bias. Implantation rate (IR, clinical pregnancy rate, and live birth rate were the main outcome measures. Statistical Analysis: Graph-pad Prism 5 statistical package. Results: SHBT group showed significantly higher blastocyst formation rate (53.3 ± 17.5 vs. 43.1 ± 14.5%, P = 0.0098, top-quality blastocysts (71.8 vs. 53.7%, P = 0.0436, IR (43.6 vs. 27.9%, P = 0.0408, pregnancy rate (59.4 vs. 45.1%, P = 0.0173, and live birth rate (36.8 vs. 22.8%, P = 0.003 compared to EBT group. Multiple pregnancy rates remained comparable between the two groups. Implantation correlated strongly with top-quality blastocysts (Pearson, r = 0.4441 in SHBT group, while the correlation was nonsignificant in EBT group. Conclusion: Extending culture of expanded blastocysts by a few hours to allow transfer of spontaneously hatching/hatched blastocysts gives higher implantation and pregnancy rates with no added risk of multiple gestations. Spontaneously hatching/hatched blastocysts have a better potential to implant and develop into a positive pregnancy.

Search for spontaneous fission of 226Ra and systematics of the spontaneous fission, α-decay and cluster decay probabilities

International Nuclear Information System (INIS)

Mikheev, V.L.; Tret'yakova, S.P.; Golovchenko, A.N.; Timofeeva, O.V.; Hussonnois, M.; Le Naour, C.

1998-01-01

The low limit of the 226 Ra spontaneous fission half-life corresponding to T 1/2 ≥ 4 · 10 18 years is measured. The 226 Ra spontaneous fission probability proved to be about 50 times less than the value expected from the known systematics, connecting the ratios of theα-decay and spontaneous fission probabilities with the fissility parameter Z 2 /A. It is shown that the probabilities of spontaneous fission, α-decay and cluster decay can be systematized in the same way according to the difference between the decay products Coulomb energy near the scission point and decay energy Q

Dorsomedial prefontal cortex supports spontaneous thinking per se.

Science.gov (United States)

Raij, T T; Riekki, T J J

2017-06-01

Spontaneous thinking, an action to produce, consider, integrate, and reason through mental representations, is central to our daily experience and has been suggested to serve crucial adaptive purposes. Such thinking occurs among other experiences during mind wandering that is associated with activation of the default mode network among other brain circuitries. Whether and how such brain activation is linked to the experience of spontaneous thinking per se remains poorly known. We studied 51 healthy subjects using a comprehensive experience-sampling paradigm during 3T functional magnetic resonance imaging. In comparison with fixation, the experiences of spontaneous thinking and spontaneous perception were related to activation of wide-spread brain circuitries, including the cortical midline structures, the anterior cingulate cortex and the visual cortex. In direct comparison of the spontaneous thinking versus spontaneous perception, activation was observed in the anterior dorsomedial prefrontal cortex. Modality congruence of spontaneous-experience-related brain activation was suggested by several findings, including association of the lingual gyrus with visual in comparison with non-verbal-non-visual thinking. In the context of current literature, these findings suggest that the cortical midline structures are involved in the integrative core substrate of spontaneous thinking that is coupled with other brain systems depending on the characteristics of thinking. Furthermore, involvement of the anterior dorsomedial prefrontal cortex suggests the control of high-order abstract functions to characterize spontaneous thinking per se. Hum Brain Mapp 38:3277-3288, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Maternal smoking predicts the risk of spontaneous abortion

DEFF Research Database (Denmark)

Nielsen, Ann; Hannibal, Charlotte Gerd; Lindekilde, Bodil Eriksen

2006-01-01

BACKGROUND: Few studies have examined smoking prior to pregnancy and the occurrence of spontaneous abortion, as most studies have addressed the risk of spontaneous abortion in relation to smoking during pregnancy. However, results are not entirely consistent. The aim of the present study...... was to assess the risk of spontaneous abortion considering smoking prior to pregnancy. METHODS: We performed a nested case-control study using prospective data from a population-based cohort comprising 11,088 women aged 20-29 years. From this cohort, women who experienced either a spontaneous abortion (n=343......) or who gave birth (n=1,578) during follow-up were selected. Associations between self-reported smoking at enrollment and subsequent spontaneous abortion were analyzed by means of multiple logistic regression. RESULTS: The risk of spontaneous abortion in relation to pre-pregnancy smoking showed a clear...

Holograms for acoustics.

Science.gov (United States)

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

2016-09-22

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.

Proposed frustrated-total-reflection acoustic sensing method

International Nuclear Information System (INIS)

Hull, J.R.

1981-01-01

Modulation of electromagnetic energy transmission through a frustrated-total-reflection device by pressure-induced changes in the index of refraction is proposed for use as an acoustic detector. Maximum sensitivity occurs for angles of incidence near the critical angle. The minimum detectable pressure in air is limited by Brownian noise. Acoustic propagation losses and diffraction of the optical beam by the acoustic signal limit the minimum acoustic wavelength to lengths of the order of the spatial extent of the optical beam. The response time of the method is fast enough to follow individual acoustic waves

Acoustic cavitation studies

Science.gov (United States)

Crum, L. A.

1981-09-01

The primary thrust of this study was toward a more complete understanding of general aspects of acoustic cavitation. The effect of long-chain polymer additives on the cavitation threshold was investigated to determine if they reduced the acoustic cavitation threshold in a similar manner to the observed reduction in the cavitation index in hydrodynamic cavitation. Measurements were made of the acoustic cavitation threshold as a function of polymer concentration for additives such as guar gum and polyethelene oxide. The measurements were also made as a function of dissolved gas concentration, surface tension and viscosity. It was determined that there was a significant increase in the acoustic cavitation threshold for increased concentrations of the polymer additives (measurable effects could be obtained for concentrations as low as a few parts per million). One would normally expect that an additive that reduces surface tension to decrease the pressure required to cause a cavity to grow and thus these additives, at first thought, should reduce the threshold. However, even in the hydrodynamic case, the threshold was increased. In both of the hydrodynamic cases considered, the explanation for the increased threshold was given in terms of changed fluid dynamics rather than changed physical properties of the fluid.

Advanced Active Acoustics Lab (AAAL)

Data.gov (United States)

Federal Laboratory Consortium — The Advanced Active Acoustics Lab (AAAL) is a state-of-the-art Undersea Warfare (USW) acoustic data analysis facility capable of both active and passive underwater...

An Experimental Introduction to Acoustics

Science.gov (United States)

Black, Andy Nicholas; Magruder, Robert H.

2017-11-01

Learning and understanding physics requires more than studying physics texts. It requires doing physics. Doing research is a key opportunity for students to connect physical principles with their everyday experience. A powerful way to introduce students to research and technique is through subjects in which they might find interest. Presented is an experiment that serves to introduce an advanced undergraduate or high school student to conducting research in acoustics via an experiment involving a standard dreadnought acoustic guitar, recording industry-related equipment, and relevant industrial analysis software. This experimental process is applicable to a wide range of acoustical topics including both acoustic and electric instruments. Also, the student has a hands-on experience with relevant audio engineering technology to study physical principles.

Acoustic holograms of active regions

International Nuclear Information System (INIS)

Chou, Dean-Yi

2008-01-01

We propose a method to study solar magnetic regions in the solar interior with the principle of optical holography. A magnetic region in the solar interior scatters the solar background acoustic waves. The scattered waves and background waves could form an interference pattern on the solar surface. We investigate the feasibility of detecting this interference pattern on the solar surface, and using it to construct the three-dimensional scattered wave from the magnetic region with the principle of optical holography. In solar acoustic holography, the background acoustic waves play the role of reference wave; the magnetic region plays the role of the target object; the interference pattern, acoustic power map, on the solar surface plays the role of the hologram.

Acoustic holograms of active regions

Energy Technology Data Exchange (ETDEWEB)

Chou, Dean-Yi [Physics Department, National Tsing Hua University, Hsinchu, 30013, Taiwan (China)], E-mail: chou@phys.nthu.edu.tw

2008-10-15

We propose a method to study solar magnetic regions in the solar interior with the principle of optical holography. A magnetic region in the solar interior scatters the solar background acoustic waves. The scattered waves and background waves could form an interference pattern on the solar surface. We investigate the feasibility of detecting this interference pattern on the solar surface, and using it to construct the three-dimensional scattered wave from the magnetic region with the principle of optical holography. In solar acoustic holography, the background acoustic waves play the role of reference wave; the magnetic region plays the role of the target object; the interference pattern, acoustic power map, on the solar surface plays the role of the hologram.

Radiological evaluation of acoustic neurinoma

Energy Technology Data Exchange (ETDEWEB)

Lee, Jong Tae; Park, Chang Yun; Choi, Byung So [Yonsei University College of Medicine, Seoul (Korea, Republic of)

1974-04-15

All 25 patients surgically proven acoustic neurinoma was analysed clinically, radiographically at Severance Hospital of Yonsei Univ. The patients not proved surgically in spite of clinical diagnosis of acoustic neurinoma was excluded from this study. The results are summarized as follows; The clinical findings are; 1. The incidence of tumor in female was twice more frequent than in male and the range of age was 20-50 years peak of age at onset of symptom. 2. The clinical symptoms were variable from unilateral hearing impairment or less (100%), headache (84%) to tinnitus (60%) in order of frequency. 3. The tumor growth in the left cerebellopontine angle was twice more than in the right side with the radio of 16:8. However, in one case bilateral simultaneous growth of acoustic neurinoma was noted. The radiological findings are: The best radiographic method to study the shape and size of internal acoustic canal to demonstrate erosion or destruction of petrous pyramida was considered to be straight frontal view and tomography of the skull in our series. 1. The shape of internal acoustic canal in tumors were straight (in 2 cases), bulbous (in 12 cases), and flared (in 11 cases). Particularly there was erosion or destruction of petrous bone in all of the flared cases of canal. 2. The acoustic meatal erosion was mainly suprameatal in 14 cases of 17 which was noted definite erosion radiographically. 3. The difference of height (vertical diameter) of both side of acoustic canal were follows; 6 cases among 25 was in the range of 0-2 mm measurement, remainder was more than 2 mm. Hence the variation in greater than 1 mm in between both sides of canal in same patient should be regard as abnormal as of acoustic neurinoma. 4. The carotid angiogram shows hydrocephalic pattern in 12 cases among 17. 5. In the vertebral angiogram of 8 cases, anterolateral displacement of basilar artery (in 6 caes), the upward displacement of superior cerebellar artery (in 4 cases) was common findings

Radiological evaluation of acoustic neurinoma

International Nuclear Information System (INIS)

Lee, Jong Tae; Park, Chang Yun; Choi, Byung So

1974-01-01

All 25 patients surgically proven acoustic neurinoma was analysed clinically, radiographically at Severance Hospital of Yonsei Univ. The patients not proved surgically in spite of clinical diagnosis of acoustic neurinoma was excluded from this study. The results are summarized as follows; The clinical findings are; 1. The incidence of tumor in female was twice more frequent than in male and the range of age was 20-50 years peak of age at onset of symptom. 2. The clinical symptoms were variable from unilateral hearing impairment or less (100%), headache (84%) to tinnitus (60%) in order of frequency. 3. The tumor growth in the left cerebellopontine angle was twice more than in the right side with the radio of 16:8. However, in one case bilateral simultaneous growth of acoustic neurinoma was noted. The radiological findings are: The best radiographic method to study the shape and size of internal acoustic canal to demonstrate erosion or destruction of petrous pyramida was considered to be straight frontal view and tomography of the skull in our series. 1. The shape of internal acoustic canal in tumors were straight (in 2 cases), bulbous (in 12 cases), and flared (in 11 cases). Particularly there was erosion or destruction of petrous bone in all of the flared cases of canal. 2. The acoustic meatal erosion was mainly suprameatal in 14 cases of 17 which was noted definite erosion radiographically. 3. The difference of height (vertical diameter) of both side of acoustic canal were follows; 6 cases among 25 was in the range of 0-2 mm measurement, remainder was more than 2 mm. Hence the variation in greater than 1 mm in between both sides of canal in same patient should be regard as abnormal as of acoustic neurinoma. 4. The carotid angiogram shows hydrocephalic pattern in 12 cases among 17. 5. In the vertebral angiogram of 8 cases, anterolateral displacement of basilar artery (in 6 caes), the upward displacement of superior cerebellar artery (in 4 cases) was common findings

Acoustic Purcell Effect for Enhanced Emission

KAUST Repository

Landi, Maryam

2018-03-13

We observe that our experimentally measured emission power enhancement of a speaker inside a previously proposed metacavity agrees with our numerically calculated enhancement of the density of states (DOS) of the source-cavity system. We interpret the agreement by formulating a relation between the emitted sound power and the acoustic DOS. The formulation is an analog to Fermi’s golden rule in quantum emission. The formulation complements the radiation impedance theory in traditional acoustics for describing sound emission. Our study bridges the gap between acoustic DOS and the acoustic Purcell effect for sound emission enhancement.

Acoustic Purcell Effect for Enhanced Emission

KAUST Repository

Landi, Maryam; Zhao, Jiajun; Prather, Wayne E.; Wu, Ying; Zhang, Likun

2018-01-01

We observe that our experimentally measured emission power enhancement of a speaker inside a previously proposed metacavity agrees with our numerically calculated enhancement of the density of states (DOS) of the source-cavity system. We interpret the agreement by formulating a relation between the emitted sound power and the acoustic DOS. The formulation is an analog to Fermi’s golden rule in quantum emission. The formulation complements the radiation impedance theory in traditional acoustics for describing sound emission. Our study bridges the gap between acoustic DOS and the acoustic Purcell effect for sound emission enhancement.

Evaluating the Acoustic Benefits of Over-the-Rotor Acoustic Treatments Installed on the Advanced Noise Control Fan

Science.gov (United States)

Gazella, Matthew R.; Takakura, Tamuto; Sutliff, Daniel L.; Bozak, Richard F.; Tester, Brian J.

2017-01-01

Over the last 15 years, over-the-rotor acoustic treatments have been evaluated by NASA with varying success. Recently, NASA has been developing the next generation of over-the-rotor acoustic treatments for fan noise reduction. The NASA Glenn Research Centers Advanced Noise Control Fan was used as a Low Technology Readiness Level test bed. A rapid prototyped in-duct array consisting of 50 microphones was employed, and used to correlate the in-duct analysis to the far-field acoustic levels and to validate an existing beam-former method. The goal of this testing was to improve the Technology Readiness Level of various over-the-rotor acoustic treatments by advancing the understanding of the physical mechanisms and projecting the far-field acoustic benefit.

Nonlinear acoustics of water-saturated marine sediments

DEFF Research Database (Denmark)

Jensen, Leif Bjørnø

1976-01-01

Interest in the acoustic qualities of water-saturated marine sediments has increased considerably during recent years. The use of sources of high-intensity sound in oil propsecting, in geophysical and geological studies of bottom and subbottom materials and profiles and recently in marine...... archaeology has emphasized the need of information about the nonlinear acoustic qualities of water-saturated marine sediments. While the acoustic experiments and theoretical investigations hitherto performed have concentrated on a determination of the linear acoustic qualities of water-saturated marine...... sediments, their parameters of nonlinear acoustics are still unexplored. The strong absorption, increasing about linearly with frequency, found in most marine sediments and the occurrence of velocity dispersion by some marine sediments restrict the number of nonlinear acoustic test methods traditionally...

Osteonecrosis or spontaneous fractures following renal transplantation

International Nuclear Information System (INIS)

Andresen, J.; Nielsen, H.E.; Aarhus Univ.

1981-01-01

31 renal transplant recipients with posttransplant development of osteonecrosis or spontaneous fractures were evaluated with regard to age, duration of dialysis before transplantation. Determination of metacarpal bone mass at the time of transplantation and registration of bone resorption and soft tissue calcification at the time of transplantation and at the time of onset of osteonecrosis and spontaneous fractures were made. Apart from the increased mean age in patients with spontaneous fractures no difference was seen between the groups. Osteonecrosis and spontaneous fractures occurred in areas of trabecular bone. It seems most likely that after renal transplantation the patients show bone complications of different localization. (orig.) [de

Acoustic-noise-optimized diffusion-weighted imaging.

Science.gov (United States)

Ott, Martin; Blaimer, Martin; Grodzki, David M; Breuer, Felix A; Roesch, Julie; Dörfler, Arnd; Heismann, Björn; Jakob, Peter M

2015-12-01

This work was aimed at reducing acoustic noise in diffusion-weighted MR imaging (DWI) that might reach acoustic noise levels of over 100 dB(A) in clinical practice. A diffusion-weighted readout-segmented echo-planar imaging (EPI) sequence was optimized for acoustic noise by utilizing small readout segment widths to obtain low gradient slew rates and amplitudes instead of faster k-space coverage. In addition, all other gradients were optimized for low slew rates. Volunteer and patient imaging experiments were conducted to demonstrate the feasibility of the method. Acoustic noise measurements were performed and analyzed for four different DWI measurement protocols at 1.5T and 3T. An acoustic noise reduction of up to 20 dB(A) was achieved, which corresponds to a fourfold reduction in acoustic perception. The image quality was preserved at the level of a standard single-shot (ss)-EPI sequence, with a 27-54% increase in scan time. The diffusion-weighted imaging technique proposed in this study allowed a substantial reduction in the level of acoustic noise compared to standard single-shot diffusion-weighted EPI. This is expected to afford considerably more patient comfort, but a larger study would be necessary to fully characterize the subjective changes in patient experience.

An acoustic analysis of laughter produced by congenitally deaf and normally hearing college students1

Science.gov (United States)

Makagon, Maja M.; Funayama, E. Sumie; Owren, Michael J.

2008-01-01

Relatively few empirical data are available concerning the role of auditory experience in nonverbal human vocal behavior, such as laughter production. This study compared the acoustic properties of laughter in 19 congenitally, bilaterally, and profoundly deaf college students and in 23 normally hearing control participants. Analyses focused on degree of voicing, mouth position, air-flow direction, temporal features, relative amplitude, fundamental frequency, and formant frequencies. Results showed that laughter produced by the deaf participants was fundamentally similar to that produced by the normally hearing individuals, which in turn was consistent with previously reported findings. Finding comparable acoustic properties in the sounds produced by deaf and hearing vocalizers confirms the presumption that laughter is importantly grounded in human biology, and that auditory experience with this vocalization is not necessary for it to emerge in species-typical form. Some differences were found between the laughter of deaf and hearing groups; the most important being that the deaf participants produced lower-amplitude and longer-duration laughs. These discrepancies are likely due to a combination of the physiological and social factors that routinely affect profoundly deaf individuals, including low overall rates of vocal fold use and pressure from the hearing world to suppress spontaneous vocalizations. PMID:18646991

A Case of Spontaneously Resolved Bilateral Primary Spontaneous Pneumothorax

Directory of Open Access Journals (Sweden)

Hasan Kahraman

2014-03-01

Full Text Available A condition of intrapleural air-space accumulation in individuals without any history of trauma or lung disease is called as primary spontaneous pneumothorax (PSP. Sixteen-years-old male patient admitted with complains of chest pain and dyspnea beginning 3 day ago. On physical examination, severity of breath sounds decreased on right side. Chest radiograph was taken and right-sided pneumothorax was detected and tube thoracostomy was inserted. Two months ago the patient referred to a doctor with similar complaints and physical examination and chest radiograph were reported as normal. The radiograph was retrospectively examined and bilateral PSP was detected. We presented the case duo to spontaneous recovery of bilateral PSP is seen very rarely and so contributes data to the literature. In patients admitted to the clinic with chest pain and shortness of breath, pneumothorax should be considered at differential diagnosis.

Pattern recognition methods for acoustic emission analysis

International Nuclear Information System (INIS)

Doctor, P.G.; Harrington, T.P.; Hutton, P.H.

1979-07-01

Models have been developed that relate the rate of acoustic emissions to structural integrity. The implementation of these techniques in the field has been hindered by the noisy environment in which the data must be taken. Acoustic emissions from noncritical sources are recorded in addition to those produced by critical sources, such as flaws. A technique is discussed for prescreening acoustic events and filtering out those that are produced by noncritical sources. The methodology that was investigated is pattern recognition. Three different pattern recognition techniques were applied to a data set that consisted of acoustic emissions caused by crack growth and acoustic signals caused by extraneous noise sources. Examination of the acoustic emission data presented has uncovered several features of the data that can provide a reasonable filter. Two of the most valuable features are the frequency of maximum response and the autocorrelation coefficient at Lag 13. When these two features and several others were combined with a least squares decision algorithm, 90% of the acoustic emissions in the data set were correctly classified. It appears possible to design filters that eliminate extraneous noise sources from flaw-growth acoustic emissions using pattern recognition techniques

Perspective: Acoustic metamaterials in transition

KAUST Repository

Wu, Ying; Yang, Min; Sheng, Ping

2017-01-01

Acoustic metamaterials derive their novel characteristics from the interaction between acoustic waves with designed structures. Since its inception seventeen years ago, the field has been driven by fundamental geometric and physical principles

Maternal underweight and the risk of spontaneous abortion

DEFF Research Database (Denmark)

Helgstrand, Stine; Andersen, Anne-Marie Nybo

2005-01-01

BACKGROUND: To evaluate the risk of spontaneous abortion in relation to maternal pre-pregnant underweight. METHODS: The study was designed as a cohort study within the framework of the Danish National Birth Cohort (DNBC). The participants were a total of 23 821 women recruited consecutively...... spontaneous abortion. Relative risk of spontaneous abortion was calculated as Hazard Ratios using Cox regression with delayed entry. RESULTS: The outcome measure was spontaneous abortion. The hazard ratio for spontaneous abortion in women with a pre-pregnant body mass index (BMI) below 18.5 was 1.24 (95......% confidence limits 0.95-1.63) compared to women with pre-pregnant BMI 18.5-24.9. Women with a BMI of 25 or more had a smaller increase in risk of spontaneous abortion. Adjustment for maternal age, parity, previous miscarriages, and lifestyle factors did not affect the estimates substantially, neither did...

Hot topics: Signal processing in acoustics

Science.gov (United States)

Gaumond, Charles F.

2005-09-01

Signal processing in acoustics is a multidisciplinary group of people that work in many areas of acoustics. We have chosen two areas that have shown exciting new applications of signal processing to acoustics or have shown exciting and important results from the use of signal processing. In this session, two hot topics are shown: the use of noiselike acoustic fields to determine sound propagation structure and the use of localization to determine animal behaviors. The first topic shows the application of correlation on geo-acoustic fields to determine the Greens function for propagation through the Earth. These results can then be further used to solve geo-acoustic inverse problems. The first topic also shows the application of correlation using oceanic noise fields to determine the Greens function through the ocean. These results also have utility for oceanic inverse problems. The second topic shows exciting results from the detection, localization, and tracking of marine mammals by two different groups. Results from detection and localization of bullfrogs are shown, too. Each of these studies contributed to the knowledge of animal behavior. [Work supported by ONR.

Physics of thermo-acoustic sound generation

Science.gov (United States)

Daschewski, M.; Boehm, R.; Prager, J.; Kreutzbruck, M.; Harrer, A.

2013-09-01

We present a generalized analytical model of thermo-acoustic sound generation based on the analysis of thermally induced energy density fluctuations and their propagation into the adjacent matter. The model provides exact analytical prediction of the sound pressure generated in fluids and solids; consequently, it can be applied to arbitrary thermal power sources such as thermophones, plasma firings, laser beams, and chemical reactions. Unlike existing approaches, our description also includes acoustic near-field effects and sound-field attenuation. Analytical results are compared with measurements of sound pressures generated by thermo-acoustic transducers in air for frequencies up to 1 MHz. The tested transducers consist of titanium and indium tin oxide coatings on quartz glass and polycarbonate substrates. The model reveals that thermo-acoustic efficiency increases linearly with the supplied thermal power and quadratically with thermal excitation frequency. Comparison of the efficiency of our thermo-acoustic transducers with those of piezoelectric-based airborne ultrasound transducers using impulse excitation showed comparable sound pressure values. The present results show that thermo-acoustic transducers can be applied as broadband, non-resonant, high-performance ultrasound sources.

The Vocational Preference Inventory Scores and Environmental Preferences

Science.gov (United States)

Kunce, Joseph T.; Kappes, Bruno Maurice

1976-01-01

This study investigated the relationship between vocational interest measured by the Vocational Preference Inventory (VPI) and preferences of 175 undergraduates for structured or unstructured environments. Males having clear-cut preferences for structured situations had significantly higher Realistic-Conventional scores than those without…

PORTABLE ACOUSTIC MONITORING PACKAGE (PAMP)

Energy Technology Data Exchange (ETDEWEB)

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.

Spontaneous deregulation

NARCIS (Netherlands)

Edelman, Benjamin; Geradin, Damien

Platform businesses such as Airbnb and Uber have risen to success partly by sidestepping laws and regulations that encumber their traditional competitors. Such rule flouting is what the authors call “spontaneous private deregulation,” and it’s happening in a growing number of industries. The authors

ISAT: The mega-fauna acoustic tracking system

KAUST Repository

De la Torre, Pedro

2013-06-01

The acoustic tracking module of the Integrated Satellite and Acoustic Telemetry (iSAT) system is discussed in detail. iSAT is capable of detecting the relative direction of an acoustic source by measuring the order of arrival (OOA) of the acoustic signal to each hydrophone in a triangular array. The characteristics of the hydrophones, the projector, and the target acoustic signal used for iSAT are described. Initially it is designed to study the movements of whale sharks (Rhincodon typus), but it could potentially be used to describe high resolution movements of other marine species. © 2013 IEEE.

Design of the Acoustic Signal Receiving Unit of Acoustic Telemetry While Drilling

Directory of Open Access Journals (Sweden)

Li Zhigang

2016-01-01

Full Text Available Signal receiving unit is one of the core units of the acoustic telemetry system. A new type of acoustic signal receiving unit is designed to solve problems of the existing devices. The unit is a short joint in whole. It not only can receive all the acoustic signals transmitted along the drill string, without losing any signal, but will not bring additional vibration and interference. In addition, the structure of the amplitude transformer is designed, which can amplify the signal amplitude and improve the receiving efficiency. The design of the wireless communication module makes the whole device can be used in normal drilling process when the drill string is rotating. So, it does not interfere with the normal drilling operation.

Acoustic levitation of a large solid sphere

International Nuclear Information System (INIS)

Andrade, Marco A. B.; Bernassau, Anne L.; Adamowski, Julio C.

2016-01-01

We demonstrate that acoustic levitation can levitate spherical objects much larger than the acoustic wavelength in air. The acoustic levitation of an expanded polystyrene sphere of 50 mm in diameter, corresponding to 3.6 times the wavelength, is achieved by using three 25 kHz ultrasonic transducers arranged in a tripod fashion. In this configuration, a standing wave is created between the transducers and the sphere. The axial acoustic radiation force generated by each transducer on the sphere was modeled numerically as a function of the distance between the sphere and the transducer. The theoretical acoustic radiation force was verified experimentally in a setup consisting of an electronic scale and an ultrasonic transducer mounted on a motorized linear stage. The comparison between the numerical and experimental acoustic radiation forces presents a good agreement.

Acoustic levitation of a large solid sphere

Energy Technology Data Exchange (ETDEWEB)

Andrade, Marco A. B., E-mail: marcobrizzotti@gmail.com [Institute of Physics, University of São Paulo, São Paulo 05508-090 (Brazil); Bernassau, Anne L. [School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom); Adamowski, Julio C. [Department of Mechatronics and Mechanical Systems Engineering, Escola Politécnica, University of São Paulo, São Paulo 05508-030 (Brazil)

2016-07-25

We demonstrate that acoustic levitation can levitate spherical objects much larger than the acoustic wavelength in air. The acoustic levitation of an expanded polystyrene sphere of 50 mm in diameter, corresponding to 3.6 times the wavelength, is achieved by using three 25 kHz ultrasonic transducers arranged in a tripod fashion. In this configuration, a standing wave is created between the transducers and the sphere. The axial acoustic radiation force generated by each transducer on the sphere was modeled numerically as a function of the distance between the sphere and the transducer. The theoretical acoustic radiation force was verified experimentally in a setup consisting of an electronic scale and an ultrasonic transducer mounted on a motorized linear stage. The comparison between the numerical and experimental acoustic radiation forces presents a good agreement.

Acoustic levitation of a large solid sphere

Science.gov (United States)

Andrade, Marco A. B.; Bernassau, Anne L.; Adamowski, Julio C.

2016-07-01

We demonstrate that acoustic levitation can levitate spherical objects much larger than the acoustic wavelength in air. The acoustic levitation of an expanded polystyrene sphere of 50 mm in diameter, corresponding to 3.6 times the wavelength, is achieved by using three 25 kHz ultrasonic transducers arranged in a tripod fashion. In this configuration, a standing wave is created between the transducers and the sphere. The axial acoustic radiation force generated by each transducer on the sphere was modeled numerically as a function of the distance between the sphere and the transducer. The theoretical acoustic radiation force was verified experimentally in a setup consisting of an electronic scale and an ultrasonic transducer mounted on a motorized linear stage. The comparison between the numerical and experimental acoustic radiation forces presents a good agreement.

Transmission characteristics of acoustic amplifier in thermoacoustic engine

International Nuclear Information System (INIS)

Sun Daming; Qiu Limin; Wang Bo; Xiao Yong

2008-01-01

Thermoacoustic engines are promising in practical applications for the merits of simple configuration, reliable operation and environmentally friendly working gas. An acoustic amplifier can increase the output pressure amplitude of a thermoacoustic engine (TE) and improve the matching between the engine and its load. In order to make full use of an acoustic amplifier, the transmission characteristics are studied based on linear thermoacoustic theory. Computational and experimental results show that the amplifying ability of an acoustic amplifier is mainly determined by its geometry parameters and output resistance impedance. The amplifying ability of an acoustic amplifier with appropriate length and diameter reaches its maximum when the output resistance impedance is infinite. It is also shown that the acoustic amplifier consumes an amount of acoustic power when amplifying pressure amplitude and the acoustic power consumption increases with amplifying ratio. Furthermore, a novel cascade acoustic amplifier is proposed, which has a much stronger amplifying ability with reduced acoustic power consumption. In experiments, a two-stage cascade acoustic amplifier amplifies the pressure ratio from 1.177 to 1.62 and produces a pressure amplitude of 0.547 MPa with nitrogen of 2.20 MPa as working gas. Good agreements are obtained between the theoretical analysis and experimental results. This research is instructive for comprehensively understanding the mechanism and making full use of the acoustic amplifier

Nanoliter-droplet acoustic streaming via ultra high frequency surface acoustic waves.

Science.gov (United States)

Shilton, Richie J; Travagliati, Marco; Beltram, Fabio; Cecchini, Marco

2014-08-06

The relevant length scales in sub-nanometer amplitude surface acoustic wave-driven acoustic streaming are demonstrated. We demonstrate the absence of any physical limitations preventing the downscaling of SAW-driven internal streaming to nanoliter microreactors and beyond by extending SAW microfluidics up to operating frequencies in the GHz range. This method is applied to nanoliter scale fluid mixing. © 2014 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A case of spontaneous ventriculocisternostomy

International Nuclear Information System (INIS)

Yamane, Kanji; Yoshimoto, Hisanori; Harada, Kiyoshi; Uozumi, Tohru; Kuwabara, Satoshi.

1983-01-01

The authors experienced a case of spontaneous ventriculocisternostomy diagnosed by CT scan with metrizamide and Conray. Patient was 23-year-old male who had been in good health until one month before admission, when he began to have headache and tinnitus. He noticed bilateral visual acuity was decreased about one week before admission and vomiting appeared two days before admission. He was admitted to our hospital because of bilateral papilledema and remarkable hydrocephalus diagnosed by CT scan. On admission, no abnormal neurological signs except for bilateral papilledema were noted. Immediately, right ventricular drainage was performed. Pressure of the ventricle was over 300mmH 2 O and CSF was clear. PVG and PEG disclosed an another cavity behind the third ventricle, which was communicated with the third ventricle, and occlusion of aqueduct of Sylvius. Metrizamide CT scan and Conray CT scan showed a communication between this cavity and quadrigeminal and supracerebellar cisterns. On these neuroradiological findings, the diagnosis of obstructive hydrocephalus due to benign aqueduct stenosis accompanied with spontaneous ventriculocisternostomy was obtained. Spontaneous ventriculocisternostomy was noticed to produce arrest of hydrocephalus, but with our case, spontaneous regression of such symptoms did not appeared. By surgical ventriculocisternostomy (method by Torkildsen, Dandy, or Scarff), arrest of hydrocephalus was seen in about 50 to 70 per cent, which was the same results as those of spontaneous ventriculocisternostomy. It is concluded that VP shunt or VA shunt is thought to be better treatment of obstructive hydrocephalus than the various kinds of surgical ventriculocisternostomy. (J.P.N.)

Sea Turtle Acoustic Telemetry Data

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Acoustic transmitters attached to sea turtles captured in various fishing gear enable the animals to be passively tracked. Acoustic receivers set up in an array...

Acoustic non-diffracting Airy beam

International Nuclear Information System (INIS)

Lin, Zhou; Guo, Xiasheng; Tu, Juan; Ma, Qingyu; Wu, Junru; Zhang, Dong

2015-01-01

The acoustic non-diffracting Airy beam as its optical counterpart has unique features of self-bending and self-healing. The complexity of most current designs handicaps its applications. A simple design of an acoustic source capable of generating multi-frequency and broad-band acoustic Airy beam has been theoretically demonstrated by numerical simulations. In the design, a piston transducer is corrugated to induce spatial phase variation for transducing the Airy function. The piston's surface is grooved in a pattern that the width of each groove corresponds to the half wavelength of Airy function. The resulted frequency characteristics and its dependence on the size of the piston source are also discussed. This simple design may promote the wide applications of acoustic Airy beam particularly in the field of medical ultrasound

PVT Degradation Studies: Acoustic Diagnostics

Energy Technology Data Exchange (ETDEWEB)

Dib, Gerges [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Tucker, Brian J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kouzes, Richard T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Smith, Philip J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2017-04-01

Under certain environmental conditions, polyvinyl toluene (PVT) plastic scintillator has been observed to undergo internal fogging. This document reports on a study of acoustic techniques to determine whether they can provide a diagnostic for the fogging of PVT. Different ultrasound techniques were employed for detecting the level of internal fogging in PVT, including wave velocity measurements, attenuation, nonlinear acoustics, and acoustic microscopy. The results indicate that there are linear relations between the wave velocity and wave attenuation with the level of internal fogging. The effects of fogging on ultrasound wave attenuation is further verified by acoustic microscopy imaging, where regions with fog in the specimen demonstration higher levels of attenuation compared to clear regions. Results from the nonlinear ultrasound measurements were inconclusive due to high sensitivities to transducer coupling and fixture variabilities.

Relationships between acoustic emissions and microstructures

International Nuclear Information System (INIS)

Rao, G.V.; Gopal, R.

1979-01-01

Results of a systematic study of 'microstructure-deformation-acoustic emission' relationships on two widely used pressure retaining component materials, namely A533-B nuclear pressure vessel steel and a 7075 aluminum alloy, are presented. The study consists of conducting acoustic monitored tensile tests on a variety of quenched and aged microstructures in the two alloy systems and extensive microstructural characterization of test specimens by light optic and electron microscopy techniques. The results suggest a consistent relationship between acoustic emissions and microdeformation mechanisms. The role of specific microstructural constituents in generating acoustic emissions in the two alloys is discussed. (author)

Acoustic lenses

International Nuclear Information System (INIS)

Kittmer, C.A.

1983-03-01

Acoustic lenses focus ultrasound to produce pencil-like beams with reduced near fields. When fitted to conventional (flat-faced) transducers, such lenses greatly improve the ability to detect and size defects. This paper describes a program developed to design acoustic lenses for use in immersion or contact inspection, using normal or angle beam mode with flat or curved targets. Lens surfaces are circular in geometry to facilitate machining. For normal beam inspection of flat plate, spherical or cylindrical lenses are used. For angle beam or curved surface inspections, a compound lens is required to correct for the extra induced aberration. Such a lens is aspherical with one radius of curvature in the plane of incidence, and a different radius of curvature in the plane perpendicular to the incident plane. The resultant beam profile (i.e., location of the acoustic focus, beam diameter, 6 dB working range) depends on the degree of focusing and the transducer used. The operating frequency and bandwidth can be affected by the instrumentation used. Theoretical and measured beam profiles are in good agreement. Various applications, from zone focusing used for defect sizing in thick plate, to line focusing for pipe weld inspection, are discussed

Cerebellar interaction with the acoustic reflex.

Science.gov (United States)

Jastreboff, P J

1981-01-01

The involvement of the cerebellar vermis in the acoustic reflex was analyzed in 12 cats, decerebrated or in pentobarbital anesthesia. Anatomical data suggested the existence of a connection of lobules VIII with the ventral cochlear nucleus. Single cell recording and evoked potential techniques demonstrated the existence of the acoustic projection to lobulus VIII. Electrical stimulation of this area changed the tension of the middle ear muscle and caused evoked potential responses in the caudal part of the ventral cochlear nucleus. Electrical stimulation of the motor nucleus of the facial nerve evoked a slow wave in the recording taken from the surrounding of the cochlear round window. A hypothesis is proposed which postulates the involvement of the acoustic reflex in space localization of acoustic stimuli and the action of cerebellar vermis in order to assure the stability and plasticity of the acoustic reflex arc.

Building Acoustics

Science.gov (United States)

Cowan, James

This chapter summarizes and explains key concepts of building acoustics. These issues include the behavior of sound waves in rooms, the most commonly used rating systems for sound and sound control in buildings, the most common noise sources found in buildings, practical noise control methods for these sources, and the specific topic of office acoustics. Common noise issues for multi-dwelling units can be derived from most of the sections of this chapter. Books can be and have been written on each of these topics, so the purpose of this chapter is to summarize this information and provide appropriate resources for further exploration of each topic.

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

DEFF Research Database (Denmark)

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

2009-01-01

It is a requirement of conventional Near-field Acoustic Holography that the measurement area covers the entire surface of the source. In the case of Patch Near-field Acoustic Holography (patch NAH), the measurement area can be reduced to cover only a specific area of the source which...... is of particular interest (known as the “patch” or “source patch”). The area of the source beyond this patch is not of interest in the analysis. However, its acoustic output may nevertheless contribute to the total sound field in the measurement plane, and influence the reconstruction of the field close...... to the patch. The purpose of this paper is to investigate how the acoustic radiation from outside the patch area influences the reconstruction of the sound field close to the source. The reconstruction is based on simulated measurements of sound pressure and particle velocity. The methods used in this paper...

Practical acoustic emission testing

CERN Document Server

2016-01-01

This book is intended for non-destructive testing (NDT) technicians who want to learn practical acoustic emission testing based on level 1 of ISO 9712 (Non-destructive testing – Qualification and certification of personnel) criteria. The essential aspects of ISO/DIS 18436-6 (Condition monitoring and diagnostics of machines – Requirements for training and certification of personnel, Part 6: Acoustic Emission) are explained, and readers can deepen their understanding with the help of practice exercises. This work presents the guiding principles of acoustic emission measurement, signal processing, algorithms for source location, measurement devices, applicability of testing methods, and measurement cases to support not only researchers in this field but also and especially NDT technicians.

Tipping point analysis of ocean acoustic noise

Science.gov (United States)

Livina, Valerie N.; Brouwer, Albert; Harris, Peter; Wang, Lian; Sotirakopoulos, Kostas; Robinson, Stephen

2018-02-01

We apply tipping point analysis to a large record of ocean acoustic data to identify the main components of the acoustic dynamical system and study possible bifurcations and transitions of the system. The analysis is based on a statistical physics framework with stochastic modelling, where we represent the observed data as a composition of deterministic and stochastic components estimated from the data using time-series techniques. We analyse long-term and seasonal trends, system states and acoustic fluctuations to reconstruct a one-dimensional stochastic equation to approximate the acoustic dynamical system. We apply potential analysis to acoustic fluctuations and detect several changes in the system states in the past 14 years. These are most likely caused by climatic phenomena. We analyse trends in sound pressure level within different frequency bands and hypothesize a possible anthropogenic impact on the acoustic environment. The tipping point analysis framework provides insight into the structure of the acoustic data and helps identify its dynamic phenomena, correctly reproducing the probability distribution and scaling properties (power-law correlations) of the time series.

A new, simple electrostatic-acoustic hybrid levitator

Science.gov (United States)

Lierke, E. G.; Loeb, H.; Gross, D.

1990-01-01

Battelle has developed a hybrid levitator by combining the known single-axis acoustic standing wave levitator with a coaxial DC electric field. The resulting Coulomb forces on the charged liquid or solid sample support its weight and, together with the acoustic force, center the sample. Liquid samples with volumes approximately less than 100 micro-liters are deployed from a syringe reservoir into the acoustic pressure node. The sample is charged using a miniature high voltage power supply (approximately less than 20 kV) connected to the syringe needle. As the electric field, generated by a second miniature power supply, is increased, the acoustic intensity is reduced. The combination of both fields allows stable levitation of samples larger than either single technique could position on the ground. Decreasing the acoustic intensity reduces acoustic convection and sample deformation. Neither the electrostatic nor the acoustic field requires sample position sensing or active control. The levitator, now used for static and dynamic fluid physics investigations on the ground, can be easily modified for space operations.

Tipping point analysis of ocean acoustic noise

Directory of Open Access Journals (Sweden)

V. N. Livina

2018-02-01

Full Text Available We apply tipping point analysis to a large record of ocean acoustic data to identify the main components of the acoustic dynamical system and study possible bifurcations and transitions of the system. The analysis is based on a statistical physics framework with stochastic modelling, where we represent the observed data as a composition of deterministic and stochastic components estimated from the data using time-series techniques. We analyse long-term and seasonal trends, system states and acoustic fluctuations to reconstruct a one-dimensional stochastic equation to approximate the acoustic dynamical system. We apply potential analysis to acoustic fluctuations and detect several changes in the system states in the past 14 years. These are most likely caused by climatic phenomena. We analyse trends in sound pressure level within different frequency bands and hypothesize a possible anthropogenic impact on the acoustic environment. The tipping point analysis framework provides insight into the structure of the acoustic data and helps identify its dynamic phenomena, correctly reproducing the probability distribution and scaling properties (power-law correlations of the time series.

Acoustic signal analysis in the creeping discharge

International Nuclear Information System (INIS)

Nakamiya, T; Sonoda, Y; Tsuda, R; Ebihara, K; Ikegami, T

2008-01-01

We have previously succeeded in measuring the acoustic signal due to the dielectric barrier discharge and discriminating the dominant frequency components of the acoustic signal. The dominant frequency components appear over 20kHz of acoustic signal by the dielectric barrier discharge. Recently surface discharge control technology has been focused from practical applications such as ozonizer, NO X reactors, light source or display. The fundamental experiments are carried to examine the creeping discharge using the acoustic signal. When the high voltage (6kV, f = 10kHz) is applied to the electrode, the discharge current flows and the acoustic sound is generated. The current, voltage waveforms of creeping discharge and the sound signal detected by the condenser microphone are stored in the digital memory scope. In this scheme, Continuous Wavelet Transform (CWT) is applied to discriminate the acoustic sound of the micro discharge and the dominant frequency components are studied. CWT results of sound signal show the frequency spectrum of wideband up to 100kHz. In addition, the energy distributions of acoustic signal are examined by CWT

4th Pacific Rim Underwater Acoustics Conference

CERN Document Server

Xu, Wen; Cheng, Qianliu; Zhao, Hangfang

2016-01-01

These proceedings are a collection of 16 selected scientific papers and reviews by distinguished international experts that were presented at the 4th Pacific Rim Underwater Acoustics Conference (PRUAC), held in Hangzhou, China in October 2013. The topics discussed at the conference include internal wave observation and prediction; environmental uncertainty and coupling to sound propagation; environmental noise and ocean dynamics; dynamic modeling in acoustic fields; acoustic tomography and ocean parameter estimation; time reversal and matched field processing; underwater acoustic localization and communication as well as measurement instrumentations and platforms. These proceedings provide insights into the latest developments in underwater acoustics, promoting the exchange of ideas for the benefit of future research.

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

Science.gov (United States)

Clare, Elizabeth L; Holderied, Marc W

2015-09-01

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

Large-scale assessment of olfactory preferences and learning in Drosophila melanogaster: behavioral and genetic components

Directory of Open Access Journals (Sweden)

Elisabetta Versace

2015-09-01

Full Text Available In the Evolve and Resequence method (E&R, experimental evolution and genomics are combined to investigate evolutionary dynamics and the genotype-phenotype link. As other genomic approaches, this methods requires many replicates with large population sizes, which imposes severe restrictions on the analysis of behavioral phenotypes. Aiming to use E&R for investigating the evolution of behavior in Drosophila, we have developed a simple and effective method to assess spontaneous olfactory preferences and learning in large samples of fruit flies using a T-maze. We tested this procedure on (a a large wild-caught population and (b 11 isofemale lines of Drosophila melanogaster. Compared to previous methods, this procedure reduces the environmental noise and allows for the analysis of large population samples. Consistent with previous results, we show that flies have a preference for orange vs. apple odor. With our procedure wild-derived flies exhibit olfactory learning in the absence of previous laboratory selection. Furthermore, we find genetic differences in the olfactory learning with relatively high heritability. We propose this large-scale method as an effective tool for E&R and genome-wide association studies on olfactory preferences and learning.

Quantifying emissions from spontaneous combustion

Energy Technology Data Exchange (ETDEWEB)

NONE

2013-09-01

Spontaneous combustion can be a significant problem in the coal industry, not only due to the obvious safety hazard and the potential loss of valuable assets, but also with respect to the release of gaseous pollutants, especially CO2, from uncontrolled coal fires. This report reviews methodologies for measuring emissions from spontaneous combustion and discusses methods for quantifying, estimating and accounting for the purpose of preparing emission inventories.

Acoustic and categorical dissimilarity of musical timbre: Evidence from asymmetriesbetween acoustic and chimeric sounds

Directory of Open Access Journals (Sweden)

Kai eSiedenburg

2016-01-01

Full Text Available This paper investigates the role of acoustic and categorical information in timbre dissimilarity ratings. Using a Gammatone-filterbank-based sound transformation, we created tones that were rated as less familiar than recorded tones from orchestral instruments and that were harder to associate with an unambiguous sound source (Exp. 1. A subset of transformed tones, a set of orchestral recordings, and a mixed set were then rated on pairwise dissimilarity (Exp. 2A. We observed that recorded instrument timbres clustered into subsets that distinguished timbres according to acoustic and categorical properties. For the subset of cross-category comparisons in the mixed set, we observed asymmetries in the distribution of ratings, as well as a stark decay of inter-rater agreement. These effects were replicated in a more robust within-subjects design (Exp. 2B and cannot be explained by acoustic factors alone. We finally introduced a novel model of timbre dissimilarity based on partial least-squares regression that compared the contributions of both acoustic and categorical timbre descriptors. The best model fit (R^2 = .88 was achieved when both types of descriptors were taken into account. These findings are interpreted as evidence for an interplay of acoustic and categorical information in timbre dissimilarity perception.

A Century of Acoustic Metrology

DEFF Research Database (Denmark)

Rasmussen, Knud

1998-01-01

The development in acoustic measurement technique over the last century is reviewed with special emphasis on the metrological aspect.......The development in acoustic measurement technique over the last century is reviewed with special emphasis on the metrological aspect....

A programmable nonlinear acoustic metamaterial

Directory of Open Access Journals (Sweden)

Tianzhi Yang

2017-09-01

Full Text Available Acoustic metamaterials with specifically designed lattices can manipulate acoustic/elastic waves in unprecedented ways. Whereas there are many studies that focus on passive linear lattice, with non-reconfigurable structures. In this letter, we present the design, theory and experimental demonstration of an active nonlinear acoustic metamaterial, the dynamic properties of which can be modified instantaneously with reversibility. By incorporating active and nonlinear elements in a single unit cell, a real-time tunability and switchability of the band gap is achieved. In addition, we demonstrate a dynamic “editing” capability for shaping transmission spectra, which can be used to create the desired band gap and resonance. This feature is impossible to achieve in passive metamaterials. These advantages demonstrate the versatility of the proposed device, paving the way toward smart acoustic devices, such as logic elements, diode and transistor.

Acoustic agglomeration methods and apparatus

Science.gov (United States)

Barmatz, M. B. (Inventor)

1984-01-01

Methods are described for using acoustic energy to agglomerate fine particles on the order of one micron diameter that are suspended in gas, to provide agglomerates large enough for efficient removal by other techniques. The gas with suspended particles, is passed through the length of a chamber while acoustic energy at a resonant chamber mode is applied to set up one or more acoustic standing wave patterns that vibrate the suspended particles to bring them together so they agglomerate. Several widely different frequencies can be applied to efficiently vibrate particles of widely differing sizes. The standing wave pattern can be applied along directions transversed to the flow of the gas. The particles can be made to move in circles by applying acoustic energy in perpendicular directions with the energy in both directions being of the same wavelength but 90 deg out of phase.

ACOUSTIC EFFECTS ON BINARY AEROELASTICITY MODEL

Directory of Open Access Journals (Sweden)

Kok Hwa Yu

2011-10-01

Full Text Available Acoustics is the science concerned with the study of sound. The effects of sound on structures attract overwhelm interests and numerous studies were carried out in this particular area. Many of the preliminary investigations show that acoustic pressure produces significant influences on structures such as thin plate, membrane and also high-impedance medium like water (and other similar fluids. Thus, it is useful to investigate the structure response with the presence of acoustics on aircraft, especially on aircraft wings, tails and control surfaces which are vulnerable to flutter phenomena. The present paper describes the modeling of structural-acoustic interactions to simulate the external acoustic effect on binary flutter model. Here, the binary flutter model which illustrated as a rectangular wing is constructed using strip theory with simplified unsteady aerodynamics involving flap and pitch degree of freedom terms. The external acoustic excitation, on the other hand, is modeled using four-node quadrilateral isoparametric element via finite element approach. Both equations then carefully coupled and solved using eigenvalue solution. The mentioned approach is implemented in MATLAB and the outcome of the simulated result are later described, analyzed and illustrated in this paper.

Pattern-formation under acoustic driving forces

Science.gov (United States)

Valverde, Jose Manuel

2015-07-01

Chemical and metallurgical processes enhanced by high intensity acoustic waves, thermoacoustic engines and refrigerators, fuel rods in nuclear reactors, heat exchanger tubes, offshore and vibrating structures, solar thermal collectors, acoustic levitators, microfluidic devices, cycling, musical acoustics, blood flow through veins/arteries, hearing in the mammalian ear, carbon nanotube loudspeakers, etc. The evolution of a myriad of processes involving the oscillation of viscous fluids in the presence of solid boundaries is up to a certain extent influenced by acoustic streaming. In addition to the sound field, viscous energy dissipation at the fluid-solid boundary causes a time-independent fluid circulation, which can lead to a significant enhancement of heat, mass and momentum transfer at large oscillation amplitudes. A particularly relevant phenomenon that can be notably affected by acoustic streaming is the promotion of sound waves by temperature gradients or viceversa (thermoacoustics), which is at the basis of potentially efficient and environmental friendly engines and refrigerators that have attracted a renewed interest in the last years. In the present manuscript, historical developments and the underlying basic physics behind acoustic streaming and thermoacoustics are reviewed from an unifying perspective.

International Conference on Acoustics and Vibration

CERN Document Server

Chaari, Fakher; Walha, Lasaad; Abdennadher, Moez; Abbes, Mohamed; Haddar, Mohamed

2017-01-01

The book provides readers with a snapshot of recent research and industrial trends in field of industrial acoustics and vibration. Each chapter, accepted after a rigorous peer-review process, reports on a selected, original piece of work presented and discussed at International Conference on Acoustics and Vibration (ICAV2016), which was organized by the Tunisian Association of Industrial Acoustics and Vibration (ATAVI) and held March 21-23, in Hammamet, Tunisia. The contributions, mainly written by north African authors, covers advances in both theory and practice in a variety of subfields, such as: smart materials and structures; fluid-structure interaction; structural acoustics as well as computational vibro-acoustics and numerical methods. Further topics include: engines control, noise identification, robust design, flow-induced vibration and many others.This book provides a valuable resource for both academics and professionals dealing with diverse issues in applied mechanics. By combining advanced theori...

30th International Acoustical Imaging Symposium

CERN Document Server

Jones, Joie; Lee, Hua

2011-01-01

The International Symposium on Acoustical Imaging is a unique forum for advanced research, covering new technologies, developments, methods and theories in all areas of acoustics. This interdisciplinary Symposium has been taking place every two years since 1968. In the course of the years the proceedings volumes in the Acoustical Imaging Series have become a reference for cutting-edge research in the field. In 2009 the 30th International Symposium on Acoustical Imaging was held in Monterey, CA, USA, March 1-4. Offering both a broad perspective on the state-of-the-art as well as  in-depth research contributions by the specialists in the field, this Volume 30 in the Series contains an excellent collection of forty three papers presented in five major categories: Biomedical Imaging Acoustic Microscopy Non-Destructive Evaluation Systems Analysis Signal Analysis and Image Processing Audience Researchers in medical imaging and biomedical instrumentation experts.

Saturation of ion-acoustic turbulence

International Nuclear Information System (INIS)

Bychenkov, V.Yu.; Gradov, O.M.

1985-01-01

The time evolution of ion-acoustic turbulence is investigated taking into consideration both the scattering of electrons and the induced scattering of waves by the ions. The growth rate of the ion-acoustic turbulence is studied as the function of the wave number, including the long-wave ion sound excitations. It is shown that the relaxation of the ion-acoustic turbulence leads to the quasistationary noise distributions, which are the products of distributions according to the wave number and to the angle. The spectra conform to the stationary theory. (D.Gy.)

Microfluidic device for acoustic cell lysis

Science.gov (United States)

Branch, Darren W.; Cooley, Erika Jane; Smith, Gennifer Tanabe; James, Conrad D.; McClain, Jaime L.

2015-08-04

A microfluidic acoustic-based cell lysing device that can be integrated with on-chip nucleic acid extraction. Using a bulk acoustic wave (BAW) transducer array, acoustic waves can be coupled into microfluidic cartridges resulting in the lysis of cells contained therein by localized acoustic pressure. Cellular materials can then be extracted from the lysed cells. For example, nucleic acids can be extracted from the lysate using silica-based sol-gel filled microchannels, nucleic acid binding magnetic beads, or Nafion-coated electrodes. Integration of cell lysis and nucleic acid extraction on-chip enables a small, portable system that allows for rapid analysis in the field.

Micromachined silicon acoustic delay line with 3D-printed micro linkers and tapered input for improved structural stability and acoustic directivity

International Nuclear Information System (INIS)

Cho, Y; Kumar, A; Xu, S; Zou, J

2016-01-01

Recent studies have shown that micromachined silicon acoustic delay lines can provide a promising solution to achieve real-time photoacoustic tomography without the need for complex transducer arrays and data acquisition electronics. To achieve deeper imaging depth and wider field of view, a longer delay time and therefore delay length are required. However, as the length of the delay line increases, it becomes more vulnerable to structural instability due to reduced mechanical stiffness. In this paper, we report the design, fabrication, and testing of a new silicon acoustic delay line enhanced with 3D printed polymer micro linker structures. First, mechanical deformation of the silicon acoustic delay line (with and without linker structures) under gravity was simulated by using finite element method. Second, the acoustic crosstalk and acoustic attenuation caused by the polymer micro linker structures were evaluated with both numerical simulation and ultrasound transmission testing. The result shows that the use of the polymer micro linker structures significantly improves the structural stability of the silicon acoustic delay lines without creating additional acoustic attenuation and crosstalk. In addition, the improvement of the acoustic acceptance angle of the silicon acoustic delay lines was also investigated to better suppress the reception of unwanted ultrasound signals outside of the imaging plane. These two improvements are expected to provide an effective solution to eliminate current limitations on the achievable acoustic delay time and out-of-plane imaging resolution of micromachined silicon acoustic delay line arrays. (paper)

The Acoustic and Peceptual Effects of Series and Parallel Processing

Directory of Open Access Journals (Sweden)

Melinda C. Anderson

2009-01-01

Full Text Available Temporal envelope (TE cues provide a great deal of speech information. This paper explores how spectral subtraction and dynamic-range compression gain modifications affect TE fluctuations for parallel and series configurations. In parallel processing, algorithms compute gains based on the same input signal, and the gains in dB are summed. In series processing, output from the first algorithm forms the input to the second algorithm. Acoustic measurements show that the parallel arrangement produces more gain fluctuations, introducing more changes to the TE than the series configurations. Intelligibility tests for normal-hearing (NH and hearing-impaired (HI listeners show (1 parallel processing gives significantly poorer speech understanding than an unprocessed (UNP signal and the series arrangement and (2 series processing and UNP yield similar results. Speech quality tests show that UNP is preferred to both parallel and series arrangements, although spectral subtraction is the most preferred. No significant differences exist in sound quality between the series and parallel arrangements, or between the NH group and the HI group. These results indicate that gain modifications affect intelligibility and sound quality differently. Listeners appear to have a higher tolerance for gain modifications with regard to intelligibility, while judgments for sound quality appear to be more affected by smaller amounts of gain modification.

Evanescent Acoustic Wave Scattering by Targets and Diffraction by Ripples Graduate Traineeship Award in Ocean Acoustics

National Research Council Canada - National Science Library

Osterhoudt, Curtis F; Marston, Philip L

2007-01-01

.... The purpose of his research was to improve the understanding of the way that acoustic evanescent waves interact with targets buried in sediments in situations encountered in underwater acoustics...

Digital Controller For Acoustic Levitation

Science.gov (United States)

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.

Independent preferences

DEFF Research Database (Denmark)

Vind, Karl

1991-01-01

A simple mathematical result characterizing a subset of a product set is proved and used to obtain additive representations of preferences. The additivity consequences of independence assumptions are obtained for preferences which are not total or transitive. This means that most of the economic ...... theory based on additive preferences - expected utility, discounted utility - has been generalized to preferences which are not total or transitive. Other economic applications of the theorem are given...

Magnetic field induced random pulse trains of magnetic and acoustic noises in martensitic single-crystal Ni2MnGa

Science.gov (United States)

Daróczi, Lajos; Piros, Eszter; Tóth, László Z.; Beke, Dezső L.

2017-07-01

Jerky magnetic and acoustic noises were evoked in a single variant martensitic Ni2MnGa single crystal (produced by uniaxial compression) by application of an external magnetic field along the hard magnetization direction. It is shown that after reaching the detwinning threshold, spontaneous reorientation of martensite variants (twins) leads not only to acoustic emission but magnetic two-directional noises as well. At small magnetic fields, below the above threshold, unidirectional magnetic emission is also observed and attributed to a Barkhausen-type noise due to magnetic domain wall motions during magnetization along the hard direction. After the above first run, in cycles of decreasing and increasing magnetic field, at low-field values, weak, unidirectional Barkhausen noise is detected and attributed to the discontinuous motion of domain walls during magnetization along the easy magnetization direction. The magnetic noise is also measured by constraining the sample in the same initial variant state along the hard direction and, after the unidirectional noise (as obtained also in the first run), a two-directional noise package is developed and it is attributed to domain rotations. From the statistical analysis of the above noises, the critical exponents, characterizing the power-law behavior, are calculated and compared with each other and with the literature data. Time correlations within the magnetic as well as acoustic signals lead to a common scaled power function (with β =-1.25 exponent) for both types of signals.

Theoretical analysis of leaky surface acoustic waves of point-focused acoustic lens and some experiments

International Nuclear Information System (INIS)

Ishikawa, Isao; Suzuki, Yoshiaki; Ogura, Yukio; Katakura, Kageyoshi

1997-01-01

When a point-focused acoustic lens in the scanning acoustic microscope (SAM) is faced to test specimen and defocused to some extent, two effective echoes can be obtained. One is the echo of longitudinal wave, which is normally incident upon the specimen of an on-axis beam in the central region of the lens and is reflected normal to the lens surface, hence detected by the transducer. The other is of leaky surface acoustic waves(LSAW), which are mode converted front a narrow beam of off-axis longitudinal wave, then propagate across the surface of the specimen and reradiate at angles normal to the lens surface, thus detected by the transducer. These two echoes are either interfered or separated with each other depending ell the defocused distance. It turned out theoretically that the LSAW have a narrow focal spot in the central region of the point-focused acoustic lens, whose size is approximately 40% of the LSAW wavelength. On top of that, a wavelength of LSAW is about 50% short as that of longitudinal wave. So, It is expected that high resolution images can be obtained provided LSAW are used in the scanning acoustic microscope.

Acoustic rainbow trapping by coiling up space

KAUST Repository

Ni, Xu

2014-11-13

We numerically realize the acoustic rainbow trapping effect by tapping an air waveguide with space-coiling metamaterials. Due to the high refractive-index of the space-coiling metamaterials, our device is more compact compared to the reported trapped-rainbow devices. A numerical model utilizing effective parameters is also calculated, whose results are consistent well with the direct numerical simulation of space-coiling structure. Moreover, such device with the capability of dropping different frequency components of a broadband incident temporal acoustic signal into different channels can function as an acoustic wavelength division de-multiplexer. These results may have potential applications in acoustic device design such as an acoustic filter and an artificial cochlea.

Acoustic rainbow trapping by coiling up space

KAUST Repository

Ni, Xu; Wu, Ying; Chen, Ze-Guo; Zheng, Li-Yang; Xu, Ye-Long; Nayar, Priyanka; Liu, Xiao-Ping; Lu, Ming-Hui; Chen, Yan-Feng

2014-01-01

We numerically realize the acoustic rainbow trapping effect by tapping an air waveguide with space-coiling metamaterials. Due to the high refractive-index of the space-coiling metamaterials, our device is more compact compared to the reported trapped-rainbow devices. A numerical model utilizing effective parameters is also calculated, whose results are consistent well with the direct numerical simulation of space-coiling structure. Moreover, such device with the capability of dropping different frequency components of a broadband incident temporal acoustic signal into different channels can function as an acoustic wavelength division de-multiplexer. These results may have potential applications in acoustic device design such as an acoustic filter and an artificial cochlea.

Ipsilateral masking between acoustic and electric stimulations.

Science.gov (United States)

Lin, Payton; Turner, Christopher W; Gantz, Bruce J; Djalilian, Hamid R; Zeng, Fan-Gang

2011-08-01

Residual acoustic hearing can be preserved in the same ear following cochlear implantation with minimally traumatic surgical techniques and short-electrode arrays. The combined electric-acoustic stimulation significantly improves cochlear implant performance, particularly speech recognition in noise. The present study measures simultaneous masking by electric pulses on acoustic pure tones, or vice versa, to investigate electric-acoustic interactions and their underlying psychophysical mechanisms. Six subjects, with acoustic hearing preserved at low frequencies in their implanted ear, participated in the study. One subject had a fully inserted 24 mm Nucleus Freedom array and five subjects had Iowa/Nucleus hybrid implants that were only 10 mm in length. Electric masking data of the long-electrode subject showed that stimulation from the most apical electrodes produced threshold elevations over 10 dB for 500, 625, and 750 Hz probe tones, but no elevation for 125 and 250 Hz tones. On the contrary, electric stimulation did not produce any electric masking in the short-electrode subjects. In the acoustic masking experiment, 125-750 Hz pure tones were used to acoustically mask electric stimulation. The acoustic masking results showed that, independent of pure tone frequency, both long- and short-electrode subjects showed threshold elevations at apical and basal electrodes. The present results can be interpreted in terms of underlying physiological mechanisms related to either place-dependent peripheral masking or place-independent central masking.

Temperature Preference in IAF Hairless and Hartley Guinea Pigs (Cavia porcellus).

Science.gov (United States)

Kleven, Gale A; Joshi, Prianca

2016-03-01

The Hairless strain of guinea pigs (Cavia porcellus) is the result of a spontaneous recessive mutation first identified at the Institute Armand Frappier (IAF) in 1978. Despite the longstanding availability of this strain, little is known about its thermoregulatory behavior. The aim of this study was to determine temperature preference in Hartley and Hairless guinea pigs by observing each strain in a ring-shaped apparatus containing a nonlinear temperature gradient. Temperatures were maintained by separately controlled heating mats lining the apparatus. Set point temperatures ranged from 24 to 38 °C. Guinea pigs (Hartley female, Hairless female, and Hairless male guinea pigs; n = 8 each group) were placed either singly or in pairs at 1 of the 8 randomized starting points within the apparatus. Subjects were observed for 30 min and coded for location within the temperature gradient by both frequency and duration. When placed singly in the apparatus, all 3 groups spent more time in the 30 °C zones. However, when placed as pairs with a cagemate, Hartley female guinea pigs spent more time in the cooler range of temperatures from 24 to 30 °C, whereas Hairless guinea pigs preferred a range of 30 to 38 °C. These results confirm a temperature preference of 30 ± 2 °C for both Hartley and Hairless guinea pigs when singly housed. However, data from the paired housing condition suggest that context plays an important role in thermoregulatory behavior.

Spontaneous calf haematoma: case report.

Science.gov (United States)

Zubaidah, N H; Liew, N C

2014-02-01

Spontaneous calf haematoma is a rare condition and few case reports have been published in the English literature. Common conditions like deep vein thrombosis and traumatic gastrocnemius muscle tear need to be considered when a patient presents with unilateral calf swelling and tenderness. Ultrasound and Magnetic Resonance Imaging are essential for confirmation of diagnosis. The purpose of this paper is to report on a rare case of spontaneous calf hematoma and its diagnosis and management.

When less is best: female brown-headed cowbirds prefer less intense male displays.

Science.gov (United States)

O'Loghlen, Adrian L; Rothstein, Stephen I

2012-01-01

Sexual selection theory predicts that females should prefer males with the most intense courtship displays. However, wing-spread song displays that male brown-headed cowbirds (Molothrus ater) direct at females are generally less intense than versions of this display that are directed at other males. Because male-directed displays are used in aggressive signaling, we hypothesized that females should prefer lower intensity performances of this display. To test this hypothesis, we played audiovisual recordings showing the same males performing both high intensity male-directed and low intensity female-directed displays to females (N = 8) and recorded the females' copulation solicitation display (CSD) responses. All eight females responded strongly to both categories of playbacks but were more sexually stimulated by the low intensity female-directed displays. Because each pair of high and low intensity playback videos had the exact same audio track, the divergent responses of females must have been based on differences in the visual content of the displays shown in the videos. Preferences female cowbirds show in acoustic CSD studies are correlated with mate choice in field and captivity studies and this is also likely to be true for preferences elucidated by playback of audiovisual displays. Female preferences for low intensity female-directed displays may explain why male cowbirds rarely use high intensity displays when signaling to females. Repetitive high intensity displays may demonstrate a male's current condition and explain why these displays are used in male-male interactions which can escalate into physical fights in which males in poorer condition could be injured or killed. This is the first study in songbirds to use audiovisual playbacks to assess how female sexual behavior varies in response to variation in a male visual display.

Acoustic integrated extinction

OpenAIRE

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 der...

Spontaneous ripple formation in phosphorene: electronic properties and possible applications.

Science.gov (United States)

Zhou, Yungang; Yang, Li; Zu, Xiaotao; Gao, Fei

2016-06-09

According to the Mermin-Wagner theorem and theory of elasticity, long-range order in two-dimensional (2D) crystals will be inevitably destroyed due to a thermal fluctuation. Thus, a 2D lattice prefers a corrugation meaning that a 2D crystal is easy to present a ripple. In this work, we, via employing ab initio molecular dynamics (AIMD) simulations, for the first time evidenced that the inherent dynamics of phosphorene would lead to a spontaneous formation of ripples at room temperature. The height of a ripple closely associates with the temperature and the width. Via density functional theory (DFT) calculations, we further demonstrated that the emergence of ripples would remarkably reduce the bandgap of phosphorene. Via the construction of the unique phosphorene structure, we finally found that such a rippled structure is expected to be used in the light-emitting field. These results give us further knowledge of phosphorene, which goes beyond the current scope of phosphorene limited to the flat lattice.

F. VON HAYEK’S THEORY OF SPONTANEOUS ORDER

Directory of Open Access Journals (Sweden)

О. Nesterenko

2013-04-01

Full Text Available The essence and the genesis of spontaneous order are disclosed in the context of critical analysis of constructivism. The author’s approach to the definition of the characteristic features of the spontaneous order is proposed. The dichotomy of the order is revealed towards the economic sphere in form of spontaneous order and organization.

Acoustic Center or Time Origin?

DEFF Research Database (Denmark)

Staffeldt, Henrik

1999-01-01

The paper discusses the acoustic center in relation to measurements of loudspeaker polar data. Also, it presents the related concept time origin and discusses the deviation that appears between positions of the acoustic center found by wavefront based and time based measuring methods....

Modulation of photonic structures by surface acoustic waves

International Nuclear Information System (INIS)

Mauricio M de Lima Jr; Santos, Paulo V

2005-01-01

This paper reviews the interaction between coherently stimulated acoustic phonons in the form of surface acoustic waves with light beams in semiconductor based photonic structures. We address the generation of surface acoustic wave modes in these structures as well as the technological aspects related to control of the propagation and spatial distribution of the acoustic fields. The microscopic mechanisms responsible for the interaction between light and surface acoustic modes in different structures are then reviewed. Particular emphasis is given to the acousto-optical interaction in semiconductor microcavities and its application in photon control. These structures exhibit high optical modulation levels under acoustic excitation and are compatible with integrated light sources and detectors

Spontaneous pneumomediastinum after bench press training.

Science.gov (United States)

Nishino, Tomoya

2017-04-01

Spontaneous pneumomediastinum is often associated with asthma and mainly affects adolescent males with a tall, thin body habitus. A 17-year-old man complained of chest and pharyngeal pain after bench press training and spontaneous pneumomediastinum was diagnosed. It should be considered in the differential diagnosis of chest pain of uncertain cause.

Spontaneous cooperation for prosocials, but not for proselfs: Social value orientation moderates spontaneous cooperation behavior

Science.gov (United States)

Mischkowski, Dorothee; Glöckner, Andreas

2016-01-01

Cooperation is essential for the success of societies and there is an ongoing debate whether individuals have therefore developed a general spontaneous tendency to cooperate or not. Findings that cooperative behavior is related to shorter decision times provide support for the spontaneous cooperation effect, although contrary results have also been reported. We show that cooperative behavior is better described as person × situation interaction, in that there is a spontaneous cooperation effect for prosocial but not for proself persons. In three studies, one involving population representative samples from the US and Germany, we found that cooperation in a public good game is dependent on an interaction between individuals’ social value orientation and decision time. Increasing deliberation about the dilemma situation does not affect persons that are selfish to begin with, but it is related to decreasing cooperation for prosocial persons that gain positive utility from outcomes of others and score high on the related general personality trait honesty/humility. Our results demonstrate that the spontaneous cooperation hypothesis has to be qualified in that it is limited to persons with a specific personality and social values. Furthermore, they allow reconciling conflicting previous findings by identifying an important moderator for the effect. PMID:26876773

Acoustic Characterization of Mesoscale Objects

Energy Technology Data Exchange (ETDEWEB)

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.

Acoustic parametric pumping of spin waves

Science.gov (United States)

Keshtgar, Hedyeh; Zareyan, Malek; Bauer, Gerrit E. W.

2014-11-01

Recent experiments demonstrated generation of spin currents by ultrasound. We can understand this acoustically induced spin pumping in terms of the coupling between magnetization and lattice waves. Here we study the parametric excitation of magnetization by longitudinal acoustic waves and calculate the acoustic threshold power. The induced magnetization dynamics can be detected by the spin pumping into an adjacent normal metal that displays the inverse spin Hall effect.

Acoustic parametric pumping of spin waves

OpenAIRE

Keshtgar, Hedyeh; Zareyan, Malek; Bauer, Gerrit E. W.

2013-01-01

Recent experiments demonstrated generation of spin currents by ultrasound. We can understand this acoustically induced spin pumping in terms of the coupling between magnetization and lattice waves. Here we study the parametric excitation of magnetization by longitudinal acoustic waves and calculate the acoustic threshold power. The induced magnetization dynamics can be detected by the spin pumping into an adjacent normal metal that displays the inverse spin Hall effect.

Acoustic Metacages for Omnidirectional Sound Shielding

OpenAIRE

Shen, Chen; Xie, Yangbo; Li, Junfei; Cummer, Steven A.; Jing, Yun

2017-01-01

Conventional sound shielding structures typically prevent fluid transport between the exterior and interior. A design of a two-dimensional acoustic metacage with subwavelength thickness which can shield acoustic waves from all directions while allowing steady fluid flow is presented in this paper. The structure is designed based on acoustic gradient-index metasurfaces composed of open channels and shunted Helmholtz resonators. The strong parallel momentum on the metacage surface rejects in-pl...

The Testing Behind The Test Facility: The Acoustic Design of the NASA Glenn Research Center's World-Class Reverberant Acoustic Test Facility

Science.gov (United States)

Hozman, Aron D.; Hughes, William O.; McNelis, Mark E.; McNelis, Anne M.

2011-01-01

The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) is leading the design and build of the new world-class vibroacoustic test capabilities at the NASA GRC's Plum Brook Station in Sandusky, Ohio, USA. Benham Companies, LLC is currently constructing modal, base-shake sine and reverberant acoustic test facilities to support the future testing needs of NASA's space exploration program. The large Reverberant Acoustic Test Facility (RATF) will be approximately 101,000 cu ft in volume and capable of achieving an empty chamber acoustic overall sound pressure level (OASPL) of 163 dB. This combination of size and acoustic power is unprecedented amongst the world's known active reverberant acoustic test facilities. The key to achieving the expected acoustic test spectra for a range of many NASA space flight environments in the RATF is the knowledge gained from a series of ground acoustic tests. Data was obtained from several NASA-sponsored test programs, including testing performed at the National Research Council of Canada's acoustic test facility in Ottawa, Ontario, Canada, and at the Redstone Technical Test Center acoustic test facility in Huntsville, Alabama, USA. The majority of these tests were performed to characterize the acoustic performance of the modulators (noise generators) and representative horns that would be required to meet the desired spectra, as well as to evaluate possible supplemental gas jet noise sources. The knowledge obtained in each of these test programs enabled the design of the RATF sound generation system to confidently advance to its final acoustic design and subsequent on-going construction.

Anomalous acoustic dispersion in architected microlattice metamaterials

Science.gov (United States)

KröDel, Sebastian; Palermo, Antonio; Daraio, Chiara

The ability to control dispersion in acoustic metamaterials is crucial to realize acoustic filtering and rectification devices as well as perfect imaging using negative refractive index materials. Architected microlattice metamaterials immersed in fluid constitute a versatile platform for achieving such control. We investigate architected microlattice materials able to exploit locally resonant modes of their fundamental building blocks that couple with propagating acoustic waves. Using analytical, numerical and experimental methods we find that such lattice materials show a hybrid dispersion behavior governed by Biot's theory for long wavelengths and multiple scattering theory when wave frequency is close to the resonances of the building block. We identify the relevant geometric parameters to alter and control the group and phase velocities in this class of acoustic metamaterials. Furthermore, we fabricate small-scale acoustic metamaterial samples using high precision SLA additive manufacturing and test the resulting materials experimentally using a customized ultrasonic setup. This work paves the way for new acoustic devices based on microlattice metamaterials.

Theory of the acoustic instability and behavior of the phase velocity of acoustic waves in a weakly ionized plasma

International Nuclear Information System (INIS)

Torosyan, O.S.; Mkrtchyan, A.R.

2003-01-01

The amplification of acoustic waves due to the transfer of thermal energy from electrons to the neutral component of a glow discharge plasma is studied theoretically. It is shown that, in order for acoustic instability (sound amplification) to occur, the amount of energy transferred should exceed the threshold energy, which depends on the plasma parameters and the acoustic wave frequency. The energy balance equation for an electron gas in the positive column of a glow discharge is analyzed for conditions typical of experiments in which acoustic wave amplification has been observed. Based on this analysis, one can affirm that, first, the energy transferred to neutral gas in elastic electron-atom collisions is substantially lower than the threshold energy for acoustic wave amplification and, second, that the energy transferred from electrons to neutral gas in inelastic collisions is much higher than that transferred in elastic collisions and thus may exceed the threshold energy. It is also shown that, for amplification to occur, there should exist some heat dissipation mechanism more efficient than gas heat conduction. It is suggested that this may be convective radial mixing within a positive column due to acoustic streaming in the field of an acoustic wave. The features of the phase velocity of sound waves in the presence of acoustic instability are investigated

Surface acoustic wave dust deposition monitor

Science.gov (United States)

Fasching, G.E.; Smith, N.S. Jr.

1988-02-12

A system is disclosed for using the attenuation of surface acoustic waves to monitor real time dust deposition rates on surfaces. The system includes a signal generator, a tone-burst generator/amplifier connected to a transmitting transducer for converting electrical signals into acoustic waves. These waves are transmitted through a path defining means adjacent to a layer of dust and then, in turn, transmitted to a receiving transducer for changing the attenuated acoustic wave to electrical signals. The signals representing the attenuated acoustic waves may be amplified and used in a means for analyzing the output signals to produce an output indicative of the dust deposition rates and/or values of dust in the layer. 8 figs.

Spontaneous emergence, imitation and spread of alternative foraging techniques among groups of vervet monkeys.

Directory of Open Access Journals (Sweden)

Erica van de Waal

Full Text Available Animal social learning has become a subject of broad interest, but demonstrations of bodily imitation in animals remain rare. Based on Voelkl and Huber's study of imitation by marmosets, we tested four groups of semi-captive vervet monkeys presented with food in modified film canisters ("aethipops'. One individual was trained to take the tops off canisters in each group and demonstrated five openings to them. In three groups these models used their mouth to remove the lid, but in one of the groups the model also spontaneously pulled ropes on a canister to open it. In the last group the model preferred to remove the lid with her hands. Following these spontaneous differentiations of foraging techniques in the models, we observed the techniques used by the other group members to open the canisters. We found that mouth opening was the most common technique overall, but the rope and hands methods were used significantly more in groups they were demonstrated in than in groups where they were not. Our results show bodily matching that is conventionally described as imitation. We discuss the relevance of these findings to discoveries about mirror neurons, and implications of the identity of the model for social transmission.

Holographic acoustic elements for manipulation of levitated objects

Science.gov (United States)

Marzo, Asier; Seah, Sue Ann; Drinkwater, Bruce W.; Sahoo, Deepak Ranjan; Long, Benjamin; Subramanian, Sriram

2015-10-01

Sound can levitate objects of different sizes and materials through air, water and tissue. This allows us to manipulate cells, liquids, compounds or living things without touching or contaminating them. However, acoustic levitation has required the targets to be enclosed with acoustic elements or had limited manoeuvrability. Here we optimize the phases used to drive an ultrasonic phased array and show that acoustic levitation can be employed to translate, rotate and manipulate particles using even a single-sided emitter. Furthermore, we introduce the holographic acoustic elements framework that permits the rapid generation of traps and provides a bridge between optical and acoustical trapping. Acoustic structures shaped as tweezers, twisters or bottles emerge as the optimum mechanisms for tractor beams or containerless transportation. Single-beam levitation could manipulate particles inside our body for applications in targeted drug delivery or acoustically controlled micro-machines that do not interfere with magnetic resonance imaging.

Acoustic of monolithic dome structures

Directory of Open Access Journals (Sweden)

Mostafa Refat Ismail

2018-03-01

The interior of monolithic domes have perfect, concave shapes to ensure that sound travels through the dome and perfectly collected at different vocal points. These dome structures are utilized for domestic use because the scale allows the focal points to be positioned across daily life activities, thereby affecting the sonic comfort of the internal space. This study examines the various acoustic treatments and parametric configurations of monolithic dome sizes. A geometric relationship of acoustic treatment and dome radius is established to provide architects guidelines on the correct selection of absorption needed to maintain the acoustic comfort of these special spaces.

Spontaneous ischaemic stroke in dogs

DEFF Research Database (Denmark)

Gredal, Hanne Birgit; Skerritt, G. C.; Gideon, P.

2013-01-01

Translation of experimental stroke research into the clinical setting is often unsuccessful. Novel approaches are therefore desirable. As humans, pet dogs suffer from spontaneous ischaemic stroke and may hence offer new ways of studying genuine stroke injury mechanisms.......Translation of experimental stroke research into the clinical setting is often unsuccessful. Novel approaches are therefore desirable. As humans, pet dogs suffer from spontaneous ischaemic stroke and may hence offer new ways of studying genuine stroke injury mechanisms....

Spontaneity and international marketing performance

OpenAIRE

Souchon, Anne L.; Hughes, Paul; Farrell, Andrew M.; Nemkova, Ekaterina; Oliveira, Joao S.

2016-01-01

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link. Purpose – The purpose of this paper is to ascertain how today’s international marketers can perform better on the global scene by harnessing spontaneity. Design/methodology/approach – The authors draw on contingency theory to develop a model of the spontaneity – international marketing performance relationship, and identify three potential m...

Classroom acoustics as a consideration for inclusive education in South Africa

Directory of Open Access Journals (Sweden)

Coralie van Reenen

2017-09-01

Full Text Available Background: It can hardly be disputed that a school environment should be conducive or, at the very least, not prohibitive to effective learning. The provision of fair, equal and barrier-free access to education is referred to as inclusive education. South Africa supports a policy of inclusive schooling, striving to accommodate all children, including those with disabilities, in mainstream schools. This article sets out to prove that noise control in classrooms is a relevant, yet neglected, aspect of inclusive classroom design in South Africa and requires specific attention. Objectives: The objectives of this study are to: (1 establish the impact that noise has on learners with sensory, language or learning impairments; (2 establish the preferred listening conditions for these learners by examining prior research and guidelines available in other countries; and (3 outline the current South African regulations pertaining to classroom acoustics and assess them against the preferred listening environment. Method: This research was conducted as a systematic review with reference to the South African context. Local and international research and guidelines were used as references, providing an overview and evaluation of data concerning noise and learning. Results: Noise is disadvantageous for learners, particularly those with sensory, language or learning impairments. Research and international guidelines show that the ideal ambient level is 30 dBA – 35 dBA, allowing the achievement of an ideal signal-to-noise ratio (SNR of +15 dB, and the ideal reverberation time is 0.4 s – 0.6 s. Various South African regulations discussed are inconsistent regarding ambient noise level (ranging from 35 dBA – 50 dBA and say little about reverberation time for classrooms. Conclusion: South African regulations regarding classroom acoustics require revision to ensure inclusion of all learners with disabilities. The current status does not enforce barrier

Room Acoustical Fields

CERN Document Server

Mechel, Fridolin

2013-01-01

This book presents the theory of room acoustical fields and revises the Mirror Source Methods for practical computational use, emphasizing the wave character of acoustical fields.  The presented higher methods include the concepts of “Mirror Point Sources” and “Corner sources which allow for an excellent approximation of complex room geometries and even equipped rooms. In contrast to classical description, this book extends the theory of sound fields describing them by their complex sound pressure and the particle velocity. This approach enables accurate descriptions of interference and absorption phenomena.

Rocket experiment on spontaneously and artificially stimulated VLF plasma waves in the ionosphere

International Nuclear Information System (INIS)

Matsumoto, H.; Miyatake, S.; Kimura, I.

1975-01-01

In situ active experiments on the nonlinear wave-wave and wave-particle interactions in the ionospheric plasma were performed by a Japanese sounding rocket K-9M-41. Both spontaneously and artificially stimulated plasma waves in the VLF range were observed. When a large amplitude electron plasma wave was transmitted from the rocket, parametrically excited ion acoustic waves were observed in addition to natural emissions such as whistlers, LHR emissions, and hisslike emissions. It was also found that 'risers' were triggered by the LHR emissions, which seem to be very similar to a phenomenon of the so-called ASE (artificially stimulated emissions). When a slow electron beam with energy lower than 3 eV was ejected from the rocket, a new type of periodic U-shaped discrete emission was observed which was excited through a wave-particle interaction. The frequency of these emissions is lower than the LHR frequency and decreases as the beam energy is increased. Spectrograms of the observed plasma are presented, and some are analyzed theoretically. (auth)

Analysis of the Spontaneous Abortion in Chinese Married Women

Institute of Scientific and Technical Information of China (English)

高尔生; 邓新清; 何更生; 方可娟; 唐威; 楼超华

1994-01-01

The spontaneous abortion is a common type of pregnant outcomes. The spontaneous abortion rate can be used to indicate the women's fecundity and the level of the reproductive health. It is also a sensitive indicator for determing the social, economic, and health status and prenatal care. To explore the preventive method for spontaneous abortion and improve women's health level, it is important to evaluate the status of spontaneous abortion and to determine the factors affecting

Acoustic engineering and technology '90

International Nuclear Information System (INIS)

1990-01-01

Acoustic monitoring, testing and diagnosis in machines, production processes and products enhance the uptimes and profitability of machinery and plants. 18 papers discuss the current state of the art of acoustic monitoring systems including integrated factory planning as well as industrial health, and noise protection. (DG) [de

Dual output acoustic wave sensor for molecular identification

International Nuclear Information System (INIS)

Frye, G.C.; Martin, S.J.

1991-01-01

This patent describes an apparatus for detecting and identifying at least one unknown chemical species. It comprises: an acoustic wave device capable of generating, transmitting and receiving an acoustic wave, means for measuring the velocity of an acoustic wave travelling through the material; means for simultaneously measuring the attenuation of the acoustic wave traveling through the coating material; sampling means to contact the acoustic wave device to the unknown chemical species; means for determining the changes in both the attenuation and velocity values of the acoustic wave upon sorption of the unknown chemical species into the coating material; and means for correlating the magnitudes of the changes of velocity with respect to the changes of the attenuations of the acoustic wave; and means for comparing the values of the velocity and attenuation changes to known values of velocity and attenuation of known chemical species in order to identify the unknown sorbed chemical species

Spontaneous Vesicle Recycling in the Synaptic Bouton

Directory of Open Access Journals (Sweden)

Sven eTruckenbrodt

2014-12-01

Full Text Available The trigger for synaptic vesicle exocytosis is Ca2+, which enters the synaptic bouton following action potential stimulation. However, spontaneous release of neurotransmitter also occurs in the absence of stimulation in virtually all synaptic boutons. It has long been thought that this represents exocytosis driven by fluctuations in local Ca2+ levels. The vesicles responding to these fluctuations are thought to be the same ones that release upon stimulation, albeit potentially triggered by different Ca2+ sensors. This view has been challenged by several recent works, which have suggested that spontaneous release is driven by a separate pool of synaptic vesicles. Numerous articles appeared during the last few years in support of each of these hypotheses, and it has been challenging to bring them into accord. We speculate here on the origins of this controversy, and propose a solution that is related to developmental effects. Constitutive membrane traffic, needed for the biogenesis of vesicles and synapses, is responsible for high levels of spontaneous membrane fusion in young neurons, probably independent of Ca2+. The vesicles releasing spontaneously in such neurons are not related to other synaptic vesicle pools and may represent constitutively releasing vesicles (CRVs rather than bona fide synaptic vesicles. In mature neurons, constitutive traffic is much dampened, and the few remaining spontaneous release events probably represent bona fide spontaneously releasing synaptic vesicles (SRSVs responding to Ca2+ fluctuations, along with a handful of CRVs that participate in synaptic vesicle turnover.

Physical acoustics principles and methods

CERN Document Server

Mason, Warren P

2012-01-01

Physical Acoustics: Principles and Methods, Volume IV, Part B: Applications to Quantum and Solid State Physics provides an introduction to the various applications of quantum mechanics to acoustics by describing several processes for which such considerations are essential. This book discusses the transmission of sound waves in molten metals. Comprised of seven chapters, this volume starts with an overview of the interactions that can happen between electrons and acoustic waves when magnetic fields are present. This text then describes acoustic and plasma waves in ionized gases wherein oscillations are subject to hydrodynamic as well as electromagnetic forces. Other chapters examine the resonances and relaxations that can take place in polymer systems. This book discusses as well the general theory of the interaction of a weak sinusoidal field with matter. The final chapter describes the sound velocities in the rocks composing the Earth. This book is a valuable resource for physicists and engineers.

Metasurface-based angle-selective multichannel acoustic refractor

Science.gov (United States)

Liu, Bingyi; Jiang, Yongyuan

2018-05-01

We theoretically study the angle-selective refractions of an impedance-matched acoustic gradient-index metasurface, which is integrated with a rigid bar array of a deep subwavelength period. An interesting refraction order appears under the all-angle incidence despite the existence of a critical angle, and notably, the odevity of the phase-discretization level apparently selects the transmitted diffraction orders. We utilize the strategy of multilayered media design to realize a three-channel acoustic refractor, which shows good promise for constructing multifunctional diffractive acoustic elements for acoustic communication.

Spontaneous Atraumatic Mediastinal Hemorrhage

Directory of Open Access Journals (Sweden)

Morkos Iskander BSc, BMBS, MRCS, PGCertMedEd

2013-04-01

Full Text Available Spontaneous atraumatic mediastinal hematomas are rare. We present a case of a previously fit and well middle-aged lady who presented with acute breathlessness and an increasing neck swelling and spontaneous neck bruising. On plain chest radiograph, widening of the mediastinum was noted. The bruising was later confirmed to be secondary to mediastinal hematoma. This life-threatening diagnostic conundrum was managed conservatively with a multidisciplinary team approach involving upper gastrointestinal and thoracic surgeons, gastroenterologists, radiologists, intensivists, and hematologists along with a variety of diagnostic modalities. A review of literature is also presented to help surgeons manage such challenging and complicated cases.

Spontaneous Retropharyngeal Emphysema: A Case Report | Chi ...

African Journals Online (AJOL)

... is a rare clinical condition in pediatric otolaryngology. The predominant symptoms are sore throat, odynophagia, dysphagia, and neck pain. Here, we report a case of spontaneous retropharyngeal emphysema. Keywords: Iatrogenic injury, retropharyngeal emphysema, spontaneous retropharyngeal emphysem, trauma ...

Spontaneous regression of pulmonary bullae

International Nuclear Information System (INIS)

Satoh, H.; Ishikawa, H.; Ohtsuka, M.; Sekizawa, K.

2002-01-01

The natural history of pulmonary bullae is often characterized by gradual, progressive enlargement. Spontaneous regression of bullae is, however, very rare. We report a case in which complete resolution of pulmonary bullae in the left upper lung occurred spontaneously. The management of pulmonary bullae is occasionally made difficult because of gradual progressive enlargement associated with abnormal pulmonary function. Some patients have multiple bulla in both lungs and/or have a history of pulmonary emphysema. Others have a giant bulla without emphysematous change in the lungs. Our present case had treated lung cancer with no evidence of local recurrence. He had no emphysematous change in lung function test and had no complaints, although the high resolution CT scan shows evidence of underlying minimal changes of emphysema. Ortin and Gurney presented three cases of spontaneous reduction in size of bulla. Interestingly, one of them had a marked decrease in the size of a bulla in association with thickening of the wall of the bulla, which was observed in our patient. This case we describe is of interest, not only because of the rarity with which regression of pulmonary bulla has been reported in the literature, but also because of the spontaneous improvements in the radiological picture in the absence of overt infection or tumor. Copyright (2002) Blackwell Science Pty Ltd

Acoustic and Categorical Dissimilarity of Musical Timbre: Evidence from Asymmetries Between Acoustic and Chimeric Sounds

Science.gov (United States)

Siedenburg, Kai; Jones-Mollerup, Kiray; McAdams, Stephen

2016-01-01

This paper investigates the role of acoustic and categorical information in timbre dissimilarity ratings. Using a Gammatone-filterbank-based sound transformation, we created tones that were rated as less familiar than recorded tones from orchestral instruments and that were harder to associate with an unambiguous sound source (Experiment 1). A subset of transformed tones, a set of orchestral recordings, and a mixed set were then rated on pairwise dissimilarity (Experiment 2A). We observed that recorded instrument timbres clustered into subsets that distinguished timbres according to acoustic and categorical properties. For the subset of cross-category comparisons in the mixed set, we observed asymmetries in the distribution of ratings, as well as a stark decay of inter-rater agreement. These effects were replicated in a more robust within-subjects design (Experiment 2B) and cannot be explained by acoustic factors alone. We finally introduced a novel model of timbre dissimilarity based on partial least-squares regression that compared the contributions of both acoustic and categorical timbre descriptors. The best model fit (R2 = 0.88) was achieved when both types of descriptors were taken into account. These findings are interpreted as evidence for an interplay of acoustic and categorical information in timbre dissimilarity perception. PMID:26779086

Individual differences in the spontaneous recruitment of brain regions supporting mental state understanding when viewing natural social scenes.

Science.gov (United States)

Wagner, Dylan D; Kelley, William M; Heatherton, Todd F

2011-12-01

People are able to rapidly infer complex personality traits and mental states even from the most minimal person information. Research has shown that when observers view a natural scene containing people, they spend a disproportionate amount of their time looking at the social features (e.g., faces, bodies). Does this preference for social features merely reflect the biological salience of these features or are observers spontaneously attempting to make sense of complex social dynamics? Using functional neuroimaging, we investigated neural responses to social and nonsocial visual scenes in a large sample of participants (n = 48) who varied on an individual difference measure assessing empathy and mentalizing (i.e., empathizing). Compared with other scene categories, viewing natural social scenes activated regions associated with social cognition (e.g., dorsomedial prefrontal cortex and temporal poles). Moreover, activity in these regions during social scene viewing was strongly correlated with individual differences in empathizing. These findings offer neural evidence that observers spontaneously engage in social cognition when viewing complex social material but that the degree to which people do so is mediated by individual differences in trait empathizing.

Enhanced sources of acoustic power surrounding AR 11429

International Nuclear Information System (INIS)

Donea, Alina; Hanson, Christopher

2013-01-01

Multi-frequency power maps of the local acoustic oscillations show acoustic enhancements (''acoustic-power halos'') at high frequencies surrounding large active region. Computational seismic holography reveals a high-frequency ''acoustic-emission halo'', or ''seismic glory'' surrounding large active regions. In this study, we have applied computational seismic holography to map the seismic seismic source density surrounding AR 11429. Studies of HMI/SDO Doppler data, shows that the ''acoustic halos'' and the ''seismic glories'' are prominent at high frequencies 5–8 mHz. We investigate morphological properties of acoustic-power and acoustic emission halos around an active region to see if they are spatially correlated. Details about the local magnetic field from vectormagnetograms of AR 11429 are included. We identify a 15'' region of seismic deficit power (dark moat) shielding the white-light boundary of the active region. The size of the seismic moat is related to region of intermediate magnetic field strength. The acoustic moat is circled by the halo of enhanced seismic amplitude as well as enhanced seismic emission. Overall, the results suggest that features are related. However, if we narrow the frequency band to 5.5 – 6.5 mHz, we find that the seismic source density dominates over the local acoustic power, suggesting the existence of sources that emit more energy downward into the solar interior than upward toward the solar surface.

Hybrid CFD/CAA Modeling for Liftoff Acoustic Predictions

Science.gov (United States)

Strutzenberg, Louise L.; Liever, Peter A.

2011-01-01

This paper presents development efforts at the NASA Marshall Space flight Center to establish a hybrid Computational Fluid Dynamics and Computational Aero-Acoustics (CFD/CAA) simulation system for launch vehicle liftoff acoustics environment analysis. Acoustic prediction engineering tools based on empirical jet acoustic strength and directivity models or scaled historical measurements are of limited value in efforts to proactively design and optimize launch vehicles and launch facility configurations for liftoff acoustics. CFD based modeling approaches are now able to capture the important details of vehicle specific plume flow environment, identifY the noise generation sources, and allow assessment of the influence of launch pad geometric details and sound mitigation measures such as water injection. However, CFD methodologies are numerically too dissipative to accurately capture the propagation of the acoustic waves in the large CFD models. The hybrid CFD/CAA approach combines the high-fidelity CFD analysis capable of identifYing the acoustic sources with a fast and efficient Boundary Element Method (BEM) that accurately propagates the acoustic field from the source locations. The BEM approach was chosen for its ability to properly account for reflections and scattering of acoustic waves from launch pad structures. The paper will present an overview of the technology components of the CFD/CAA framework and discuss plans for demonstration and validation against test data.

Video-assisted thoracoscopy treatment of spontaneous pneumothorax

International Nuclear Information System (INIS)

Chen Haitao; Ren Jian; Che Jiaming; Hang Junbiao; Qiu Weicheng; Chen Zhongyuan

2002-01-01

Objective: To propose a treatment protocol by video thoracoscopy in spontaneous pneumothorax. Methods: One hundred and three patients underwent Video-assisted thoracoscopy (VATS) treatment of spontaneous pneumothorax and hemothorax. Indications included recurrent pneumothorax, persistent air leakage following conservative therapy, complicated hemothorax and CT scan identified bullae formation. Results: No operative deaths occurred, conversion rate was 2.91%, recurrence rate was 0.97%, complication rate was 3.81% and mean postoperative hospital stay was 5.6 days. Conclusions: VATS treatment of spontaneous pneumothorax is better than open chest surgery and also superior than conservative therapy

Spontaneous Dissection of the Superior Mesenteric Artery

International Nuclear Information System (INIS)

Sheldon, Patrick J.; Esther, James B.; Sheldon, Elana L.; Sparks, Steven R.; Brophy, David P.; Oglevie, Steven B.

2001-01-01

Spontaneous dissection of the superior mesenteric artery (SMA) is a rare occurrence, especially when not associated with aortic dissection. Currently, only 28 cases appear to have been reported. Due to the scarcity of cases in the literature, the natural history of isolated, spontaneous SMA dissection is unclear. CT has been reported to be useful for the initial diagnosis of SMA dissection [2-5]. We present two recent cases of spontaneous SMA dissection in which enhanced spiral CT was instrumental in following the disease process and guiding clinical decision making

Resting-associated vocalization emitted by captive Asian house shrews (Suncus murinus: acoustic structure and variability in an unusual mammalian vocalization.

Directory of Open Access Journals (Sweden)

Irena Schneiderová

Full Text Available Shrews have rich vocal repertoires that include vocalizations within the human audible frequency range and ultrasonic vocalizations. Here, we recorded and analyzed in detail the acoustic structure of a vocalization with unclear functional significance that was spontaneously produced by 15 adult, captive Asian house shrews (Suncus murinus while they were lying motionless and resting in their nests. This vocalization was usually emitted repeatedly in a long series with regular intervals. It showed some structural variability; however, the shrews most frequently emitted a tonal, low-frequency vocalization with minimal frequency modulation and a low, non-vocal click that was clearly noticeable at its beginning. There was no effect of sex, but the acoustic structure of the analyzed vocalizations differed significantly between individual shrews. The encoded individuality was low, but it cannot be excluded that this individuality would allow discrimination of family members, i.e., a male and female with their young, collectively resting in a common nest. The question remains whether the Asian house shrews indeed perceive the presence of their mates, parents or young resting in a common nest via the resting-associated vocalization and whether they use it to discriminate among their family members. Additional studies are needed to explain the possible functional significance of resting-associated vocalizations emitted by captive Asian house shrews. Our study highlights that the acoustic communication of shrews is a relatively understudied topic, particularly considering that they are highly vocal mammals.

NEMO-SMO acoustic array: A deep-sea test of a novel acoustic positioning system for a km3-scale underwater neutrino telescope

Science.gov (United States)

Viola, S.; Ardid, M.; Bertin, V.; Enzenhöfer, A.; Keller, P.; Lahmann, R.; Larosa, G.; Llorens, C. D.; NEMO Collaboration; SMO Collaboration

2013-10-01

Within the activities of the NEMO project, the installation of a 8-floors tower (NEMO-Phase II) at a depth of 3500 m is foreseen in 2012. The tower will be installed about 80 km off-shore Capo Passero, in Sicily. On board the NEMO tower, an array of 18 acoustic sensors will be installed, permitting acoustic detection of biological sources, studies for acoustic neutrino detection and primarily acoustic positioning of the underwater structures. For the latter purpose, the sensors register acoustic signals emitted by five acoustic beacons anchored on the sea-floor. The data acquisition system of the acoustic sensors is fully integrated with the detector data transport system and is based on an “all data to shore” philosophy. Signals coming from hydrophones are continuously sampled underwater at 192 kHz/24 bit and transmitted to shore through an electro-optical cable for real-time analysis. A novel technology for underwater GPS time-stamping of data has been implemented and tested. The operation of the acoustic array will permit long-term test of sensors and electronics technologies that are proposed for the acoustic positioning system of KM3NeT.

Vibro-acoustics of lightweight sandwich structures

CERN Document Server

Lu, Tianjian

2014-01-01

Vibro-Acoustics of Lightweight Sandwich Structures introduces the study of the coupled vibration and acoustic behavior of lightweight sandwich structures in response to harmonic force and sound pressure. This book focuses on the theoretical modeling and experimental investigation of lightweight sandwich structures in order to provide a predictive framework for vibro-acoustic characteristics of typical engineering structures. Furthermore, by developing solution tools, it concentrates on the influence of key systematic parameters leading to effective guidance for optimal structure design toward lightweight, high-stiffness and superior sound insulation capability. This book is intended for researchers, scientists, engineers and graduate students in mechanical engineering especially in structural mechanics, mechanics and acoustics. Fengxian Xin and Tianjian Lu both work at the School of Aerospace, Xi’an Jiaotong University.

Endometriosis-related spontaneous diaphragmatic rupture.

Science.gov (United States)

Triponez, Frédéric; Alifano, Marco; Bobbio, Antonio; Regnard, Jean-François

2010-10-01

Non-traumatic, spontaneous diaphragmatic rupture is a rare event whose pathophysiology is not known. We report the case of endometriosis-related spontaneous rupture of the right diaphragm with intrathoracic herniation of the liver, gallbladder and colon. We hypothesize that the invasiveness of endometriotic tissue caused diaphragm fragility, which finally lead to its complete rupture without traumatic event. The treatment consisted of a classical management of diaphragmatic rupture, with excision of the endometriotic nodule followed by medical ovarian suppression for six months.

Acoustic Levitation With One Driver

Science.gov (United States)

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.

Experimental Acoustic Evaluation of an Auditorium

Directory of Open Access Journals (Sweden)

Marina Dana Ţopa

2012-01-01

Full Text Available The paper presents a case history: the acoustical analysis of a rectangular auditorium. The following acoustical parameters were evaluated: early decay time, reverberation time, clarity, definition, and center time. The excitation signal was linear sweep sine and additional analysis was carried out: peak-to-noise ratio, reverberation time for empty and occupied room, standard deviation of acoustical parameters, diffusion, and just noticeable differences analysis. Conclusions about room’s destination and modeling were drawn in the end.

Computational simulation of acoustic fatigue for hot composite structures

Science.gov (United States)

Singhal, S. N.; Nagpal, V. K.; Murthy, P. L. N.; Chamis, C. C.

1991-01-01

This paper presents predictive methods/codes for computational simulation of acoustic fatigue resistance of hot composite structures subjected to acoustic excitation emanating from an adjacent vibrating component. Select codes developed over the past two decades at the NASA Lewis Research Center are used. The codes include computation of (1) acoustic noise generated from a vibrating component, (2) degradation in material properties of the composite laminate at use temperature, (3) dynamic response of acoustically excited hot multilayered composite structure, (4) degradation in the first-ply strength of the excited structure due to acoustic loading, and (5) acoustic fatigue resistance of the excited structure, including propulsion environment. Effects of the laminate lay-up and environment on the acoustic fatigue life are evaluated. The results show that, by keeping the angled plies on the outer surface of the laminate, a substantial increase in the acoustic fatigue life is obtained. The effect of environment (temperature and moisure) is to relieve the residual stresses leading to an increase in the acoustic fatigue life of the excited panel.

[Treatment of giant acoustic neuromas].

Science.gov (United States)

Samprón, Nicolás; Altuna, Xabier; Armendáriz, Mikel; Urculo, Enrique

2014-01-01

To analyze the treatment modality and outcome of a series of patients with giant acoustic neuromas, a particular type of tumour characterised by their size (extracanalicular diameter of 4cm or more) and high morbidity and mortality. This was a retrospective unicentre study of patients with acoustic neuromas treated in a period of 12 years. In our institutional series of 108 acoustic neuromas operated on during that period, we found 13 (12%) cases of giant acoustic neuromas. We reviewed the available data of these cases, including presentation and several clinical, anatomical, and microsurgical aspects. All patients were operated on by the same neurosurgeon and senior author (EU) using the suboccipital retrosigmoid approach and complete microsurgical removal was achieved in 10 cases. In one case, near total removal was deliberately performed, in another case a CSF shunt was placed as the sole treatment measure, and in the remaining case no direct treatment was given. One patient died in the immediate postoperative period. One year after surgery, 4 patients showed facial nerve function of iii or more in the House-Brackman scale. The 4 most important prognostic characteristics of giant acoustic neuromas are size, adhesion to surrounding structures, consistency and vascularity. Only the first of these is evident in neuroimaging. Giant acoustic neuromas are characterised by high morbidity at presentation as well as after treatment. Nevertheless, the objective of complete microsurgical removal with preservation of cranial nerve function is attainable in some cases through the suboccipital retrosigmoid approach. Copyright © 2014 Sociedad Española de Neurocirugía. Published by Elsevier España. All rights reserved.

Design of acoustic devices by topology optimization

DEFF Research Database (Denmark)

Sigmund, Ole; Jensen, Jakob Søndergaard

2003-01-01

The goal of this study is to design and optimize structures and devices that are subjected to acoustic waves. Examples are acoustic lenses, sound walls, waveguides and loud speakers. We formulate the design problem as a topology optimization problem, i.e. distribute material in a design domain...... such that the acoustic response is optimized....

Controlling the acoustic streaming by pulsed ultrasounds.

Science.gov (United States)

Hoyos, Mauricio; Castro, Angélica

2013-01-01

We propose a technique based on pulsed ultrasounds for controlling, reducing to a minimum observable value the acoustic streaming in closed ultrasonic standing wave fluidic resonators. By modifying the number of pulses and the repetition time it is possible to reduce the velocity of the acoustic streaming with respect to the velocity generated by the continuous ultrasound mode of operation. The acoustic streaming is observed at the nodal plane where a suspension of 800nm latex particles was focused by primary radiation force. A mixture of 800nm and 15μm latex particles has been also used for showing that the acoustic streaming is hardly reduced while primary and secondary forces continue to operate. The parameter we call "pulse mode factor" i.e. the time of applied ultrasound divided by the duty cycle, is found to be the adequate parameter that controls the acoustic streaming. We demonstrate that pulsed ultrasound is more efficient for controlling the acoustic streaming than the variation of the amplitude of the standing waves. Copyright © 2012 Elsevier B.V. All rights reserved.

The acoustic reflex threshold in aging ears.

Science.gov (United States)

Silverman, C A; Silman, S; Miller, M H

1983-01-01

This study investigates the controversy regarding the influence of age on the acoustic reflex threshold for broadband noise, 500-, 1000-, 2000-, and 4000-Hz activators between Jerger et al. [Mono. Contemp. Audiol. 1 (1978)] and Jerger [J. Acoust. Soc. Am. 66 (1979)] on the one hand and Silman [J. Acoust. Soc. Am. 66 (1979)] and others on the other. The acoustic reflex thresholds for broadband noise, 500-, 1000-, 2000-, and 4000-Hz activators were evaluated under two measurement conditions. Seventy-two normal-hearing ears were drawn from 72 subjects ranging in age from 20-69 years. The results revealed that age was correlated with the acoustic reflex threshold for BBN activator but not for any of the tonal activators; the correlation was stronger under the 1-dB than under the 5-dB measurement condition. Also, the mean acoustic reflex thresholds for broadband noise activator were essentially similar to those reported by Jerger et al. (1978) but differed from those obtained in this study under the 1-dB measurement condition.

Transitivity of Preferences

Science.gov (United States)

Regenwetter, Michel; Dana, Jason; Davis-Stober, Clintin P.

2011-01-01

Transitivity of preferences is a fundamental principle shared by most major contemporary rational, prescriptive, and descriptive models of decision making. To have transitive preferences, a person, group, or society that prefers choice option "x" to "y" and "y" to "z" must prefer "x" to…

Acoustic forcing of a liquid drop

Science.gov (United States)

Lyell, M. J.

1992-01-01

The development of systems such as acoustic levitation chambers will allow for the positioning and manipulation of material samples (drops) in a microgravity environment. This provides the capability for fundamental studies in droplet dynamics as well as containerless processing work. Such systems use acoustic radiation pressure forces to position or to further manipulate (e.g., oscillate) the sample. The primary objective was to determine the effect of a viscous acoustic field/tangential radiation pressure forcing on drop oscillations. To this end, the viscous acoustic field is determined. Modified (forced) hydrodynamic field equations which result from a consistent perturbation expansion scheme are solved. This is done in the separate cases of an unmodulated and a modulated acoustic field. The effect of the tangential radiation stress on the hydrodynamic field (drop oscillations) is found to manifest as a correction to the velocity field in a sublayer region near the drop/host interface. Moreover, the forcing due to the radiation pressure vector at the interface is modified by inclusion of tangential stresses.

Acoustic streaming of a sharp edge.

Science.gov (United States)

Ovchinnikov, Mikhail; Zhou, Jianbo; Yalamanchili, Satish

2014-07-01

Anomalous acoustic streaming is observed emanating from sharp edges of solid bodies that are vibrating in fluids. The streaming velocities can be orders of magnitude higher than expected from the Rayleigh streaming at similar amplitudes of vibration. Acoustic velocity of fluid relative to a solid body diverges at a sharp edge, giving rise to a localized time-independent body force acting on the fluid. This force results in a formation of a localized jet. Two-dimensional numerical simulations are performed to predict acoustic streaming for low amplitude vibration using two methods: (1) Steady-state solution utilizing perturbation theory and (2) direct transient solution of the Navier-Stokes equations. Both analyses agree with each other and correctly predict the streaming of a sharp-edged vibrating blade measured experimentally. The origin of the streaming can be attributed to the centrifugal force of the acoustic fluid flow around a sharp edge. The dependence of this acoustic streaming on frequency and velocity is examined using dimensional analysis. The dependence law is devised and confirmed by numerical simulations.

Perception of recorded singing voice quality and expertise: cognitive linguistics and acoustic approaches.

Science.gov (United States)

Morange, Séverine; Dubois, Danièle; Fontaine, Jean-Marc

2010-07-01

The objective of the present pluridisciplinary study was to contribute to determine how a diversity of audience differently appreciates several versions resulting from different "restoration" treatments of one single original lyrical recording. We present here a joint analysis coupling psychological and linguistic analyses with acoustic descriptions on a unique research object: a Caruso's piece of song diversely remastered on commercial CDs. Thirty-two subjects were selected contrasted on age ("younger than 30 years" and "older than 60 years") related with their different experience of earlier technical recording devices (rendering through devices such as radio, 78rpm records, CD...) and on expertise concerning musical acoustics (acousticians and/or musicians vs ordinary music lovers). Eleven excerpts of reediting of an opera record interpreted by Caruso were selected from what could found on the market. The listening protocol involved a free categorization task and the selection of excerpts on preference judgments. Each task involved subjects' free commentaries about their choices as a joint output from psychological processing. A cluster analysis scaffold by a psycholinguistic processing of the verbal comments of the categories allowed to identify both commonalities and differences in groupings excerpts by the different groups of the subjects, along a diversity of criteria, varying according to age and expertise. Each excerpt can therefore be characterized both according to psychological and to acoustic criteria. This study has enabled us to develop the idea that a lyric voice is a multifaced object (cultural, esthetic, technical, physical), acoustic parameters being linked to the various sensory experiences and expertises of appraisers. Such pluridisciplinary research and the coupling of the correlated multiplicity of methodologies we developed acknowledge for a better understanding of listening practices and music-lover assessments here concerned with a

Spontaneous Scalarization: Dead or Alive?

Science.gov (United States)

Berti, Emanuele; Crispino, Luis; Gerosa, Davide; Gualtieri, Leonardo; Horbatsch, Michael; Macedo, Caio; Okada da Silva, Hector; Pani, Paolo; Sotani, Hajime; Sperhake, Ulrich

2015-04-01

In 1993, Damour and Esposito-Farese showed that a wide class of scalar-tensor theories can pass weak-field gravitational tests and exhibit nonperturbative strong-field deviations away from General Relativity in systems involving neutron stars. These deviations are possible in the presence of ``spontaneous scalarization,'' a phase transition similar in nature to spontaneous magnetization in ferromagnets. More than twenty years after the original proposal, binary pulsar experiments have severely constrained the possibility of spontaneous scalarization occurring in nature. I will show that these experimental constraints have important implications for the torsional oscillation frequencies of neutron stars and for the so-called ``I-Love-Q'' relations in scalar-tensor theories. I will also argue that there is still hope to observe strong scalarization effects, despite the strong experimental bounds on the original mechanism. In particular, I will discuss two mechanisms that could produce strong scalarization in neutron stars: anisotropy and multiscalarization. This work was supported by NSF CAREER Award PHY-1055103.

Detection of target phonemes in spontaneous and read speech.

Science.gov (United States)

Mehta, G; Cutler, A

1988-01-01

Although spontaneous speech occurs more frequently in most listeners' experience than read speech, laboratory studies of human speech recognition typically use carefully controlled materials read from a script. The phonological and prosodic characteristics of spontaneous and read speech differ considerably, however, which suggests that laboratory results may not generalise to the recognition of spontaneous speech. In the present study listeners were presented with both spontaneous and read speech materials, and their response time to detect word-initial target phonemes was measured. Responses were, overall, equally fast in each speech mode. However, analysis of effects previously reported in phoneme detection studies revealed significant differences between speech modes. In read speech but not in spontaneous speech, later targets were detected more rapidly than targets preceded by short words. In contrast, in spontaneous speech but not in read speech, targets were detected more rapidly in accented than in unaccented words and in strong than in weak syllables. An explanation for this pattern is offered in terms of characteristic prosodic differences between spontaneous and read speech. The results support claims from previous work that listeners pay great attention to prosodic information in the process of recognising speech.

Industrial installation surveillance acoustic device

International Nuclear Information System (INIS)

Marini, Jean; Audenard, Bernard.

1981-01-01

The purpose of this invention is the detection of possible impacts of bodies migrating inside the installation, using acoustic sensors of the waves emitted at the time of impact of the migrating bodies. This device makes it possible to take into account only those acoustic signals relating to the impacts of bodies migrating in the area under surveillance, to the exclusion of any other acoustic or electric perturbing phenomenon. The invention has a preferential use in the case of a linear shape installation in which a fluid flows at high rate, such as a section of the primary system of a pressurized water nuclear reactor [fr

Spontaneous CP violation on the lattice

CERN Document Server

Laine, Mikko

2000-01-01

At finite temperatures around the electroweak phase transition, the thermodynamics of the MSSM can be described by a three-dimensional two Higgs doublet effective theory. This effective theory has a phase where CP is spontaneously violated. We study spontaneous CP violation with non-perturbative lattice simulations, and analyse whether one could end up in this phase for any physical MSSM parameter values.

Matrix method for acoustic levitation simulation.

Science.gov (United States)

Andrade, Marco A B; Perez, Nicolas; Buiochi, Flavio; Adamowski, Julio C

2011-08-01

A matrix method is presented for simulating acoustic levitators. A typical acoustic levitator consists of an ultrasonic transducer and a reflector. The matrix method is used to determine the potential for acoustic radiation force that acts on a small sphere in the standing wave field produced by the levitator. The method is based on the Rayleigh integral and it takes into account the multiple reflections that occur between the transducer and the reflector. The potential for acoustic radiation force obtained by the matrix method is validated by comparing the matrix method results with those obtained by the finite element method when using an axisymmetric model of a single-axis acoustic levitator. After validation, the method is applied in the simulation of a noncontact manipulation system consisting of two 37.9-kHz Langevin-type transducers and a plane reflector. The manipulation system allows control of the horizontal position of a small levitated sphere from -6 mm to 6 mm, which is done by changing the phase difference between the two transducers. The horizontal position of the sphere predicted by the matrix method agrees with the horizontal positions measured experimentally with a charge-coupled device camera. The main advantage of the matrix method is that it allows simulation of non-symmetric acoustic levitators without requiring much computational effort.

Spontaneous pneumothorax associated with lung cancer

International Nuclear Information System (INIS)

Sung, Dong Wook; Jung, Seung Hyae; Yoon, Yup; Lim, Jae Hoon; Cho, Kyu Soek; Yang, Moon Ho

1991-01-01

Spontaneous pneumothorax is a rare manifestation of lung cancer. Eight cases of pneumothorax found in 1648 patients with lung cancer from 1979-1990 are reported. Histopathologic types of cancer were adenocarcinoma in three cases, squamous cell carcinoma in two cases, bronchioloalveolar carcinoma in two cases, and metastatic renal cell carcinoma in one case. The primary tumor mass was not found even after thoracotomy in two cases. Spontaneous pneumothorax occurred on the ipsilateral side of the cancer. All the patients were more than 40 years old with a history of smoking 1-2 packs a day for 20 to 50 years, and had chronic lung diseases. The authors emphasize that bronchogenic carcinoma may be one of the causes of spontaneous pneumothorax in appropriate clinical settings

Time reversal signal processing in acoustic emission testing

Czech Academy of Sciences Publication Activity Database

Převorovský, Zdeněk; Krofta, Josef; Kober, Jan; Dvořáková, Zuzana; Chlada, Milan; Dos Santos, S.

2014-01-01

Roč. 19, č. 12 (2014) ISSN 1435-4934. [European Conference on Non-Destructive Testing (ECNDT 2014) /11./. Praha, 06.10.2014-10.10.2014] Institutional support: RVO:61388998 Keywords : acoustic emission (AE) * ultrasonic testing (UT) * signal processing * source location * time reversal acoustic s * acoustic emission * signal processing and transfer Subject RIV: BI - Acoustic s http://www.ndt.net/events/ECNDT2014/app/content/Slides/637_Prevorovsky.pdf

Systematic design of acoustic devices by topology optimization

DEFF Research Database (Denmark)

Jensen, Jakob Søndergaard; Sigmund, Ole

2005-01-01

We present a method to design acoustic devices with topology optimization. The general algorithm is exemplified by the design of a reflection chamber that minimizes the transmission of acoustic waves in a specified frequency range.......We present a method to design acoustic devices with topology optimization. The general algorithm is exemplified by the design of a reflection chamber that minimizes the transmission of acoustic waves in a specified frequency range....

Spontaneous generation in medieval Jewish philosophy and theology.

Science.gov (United States)

Gaziel, Ahuva

2012-01-01

The concept of life forms emerging from inanimate matter--spontaneous generation--was widely accepted until the nineteenth century. Several medieval Jewish scholars acknowledged this scientific theory in their philosophical and religious contemplations. Quite interestingly, it served to reinforce diverse, or even opposite, theological conclusions. One approach excluded spontaneously-generated living beings form the biblical account of creation or the story of the Deluge. Underlying this view is an understanding that organisms that generate spontaneously evolve continuously in nature and, therefore, do not require divine intervention in their formation or survival during disastrous events. This naturalistic position reduces the miraculous dimension of reality. Others were of the opinion that spontaneous generation is one of the extraordinary marvels exhibited in this world and, accordingly, this interpretation served to accentuate the divine aspect of nature. References to spontaneous generation also appear in legal writings, influencing practical applications such as dietary laws and actions forbidden on the Sabbath.

Ocean acoustic tomography

International Nuclear Information System (INIS)

Cornuelle, Bruce D; Worcester, Peter F; Dzieciuch, Matthew A

2008-01-01

Ocean acoustic tomography (OAT) was proposed in 1979 by Walter Munk and Carl Wunsch as an analogue to x-ray computed axial tomography for the oceans. The oceans are opaque to most electromagnetic radiation, but there is a strong acoustic waveguide, and sound can propagate for 10 Mm and more with distinct multiply-refracted ray paths. Transmitting broadband pulses in the ocean leads to a set of impulsive arrivals at the receiver which characterize the impulse response of the sound channel. The peaks observed at the receiver are assumed to represent the arrival of energy traveling along geometric ray paths. These paths can be distinguished by arrival time, and by arrival angle when a vertical array of receivers is available. Changes in ray arrival time can be used to infer changes in ocean structure. Ray travel time measurements have been a mainstay of long-range acoustic measurements, but the strong sensitivity of ray paths to range-dependent sound speed perturbations makes the ray sampling functions uncertain in real cases. In the ray approximation travel times are sensitive to medium changes only along the corresponding eigenrays. Ray theory is an infinite-frequency approximation, and its eikonal equation has nonlinearities not found in the acoustic wave equation. We build on recent seismology results (kernels for body wave arrivals in the earth) to characterize the kernel for converting sound speed change in the ocean to travel time changes using more complete propagation physics. Wave-theoretic finite frequency kernels may show less sensitivity to small-scale sound speed structure.

Spontaneous low-frequency oscillations in cerebral vessels

DEFF Research Database (Denmark)

Schytz, Henrik W; Hansson, Andreas; Phillip, Dorte

2010-01-01

). Analysis of CA by measurement of spontaneous oscillations in the low-frequency spectrum in cerebral vessels might be a useful tool for assessing risk and investigating different treatment strategies in carotid artery disease (CAD) and stroke. We reviewed studies exploring spontaneous oscillations...

Acoustic detection of pneumothorax

Science.gov (United States)

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 (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 (ppneumothorax states (pPneumothorax 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 (pPneumothorax 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.

Topological Acoustic Delay Line

Science.gov (United States)

Zhang, Zhiwang; Tian, Ye; Cheng, Ying; Wei, Qi; Liu, Xiaojun; Christensen, Johan

2018-03-01

Topological protected wave engineering in artificially structured media is at the frontier of ongoing metamaterials research that is inspired by quantum mechanics. Acoustic analogues of electronic topological insulators have recently led to a wealth of new opportunities in manipulating sound propagation with strikingly unconventional acoustic edge modes immune to backscattering. Earlier fabrications of topological insulators are characterized by an unreconfigurable geometry and a very narrow frequency response, which severely hinders the exploration and design of useful devices. Here we establish topologically protected sound in reconfigurable phononic crystals that can be switched on and off simply by rotating its three-legged "atoms" without altering the lattice structure. In particular, we engineer robust phase delay defects that take advantage of the ultrabroadband reflection-free sound propagation. Such topological delay lines serve as a paradigm in compact acoustic devices, interconnects, and electroacoustic integrated circuits.

Acoustic emission from polycrystalline graphites

International Nuclear Information System (INIS)

Ioka, I.; Yoda, S.; Oku, T.; Miyamoto, Y.

1987-01-01

Acoustic emission was monitored from polycrystalline graphites with different microstructure (pore size and pore volume) subjected to compressive loading. The graphites used in this study comprised five brands, that is, PGX, ISEM-1, IG-11, IG-15, and ISO-88. A root mean square (RMS) voltage and event counts of acoustic emission for graphites were measured during compressive loading. The acoustic emission was measured using a computed-based data acquisition and analysis system. The graphites were first deformed up to 80 % of the average fracture stress, then unloaded and reloaded again until the fracture occured. During the first loading, the change in RMS voltage for acoustic emission was detected from the initial stage. During the unloading, the RMS voltage became zero level as soon as the applied stress was released and then gradually rose to a peak and declined. The behavior indicated that the reversed plastic deformation occured in graphites. During the second loading, the RMS voltage gently increased until the applied stress exceeded the maximum stress of the first loading; there is no Kaiser effect in the graphites. A bicrystal model could give a reasonable explanation of this results. The empirical equation between the ratio of σ AE to σ f and σ f was obtained. It is considered that the detection of microfracture by the acoustic emission technique is effective in macrofracture prediction of polycrystalline graphites. (author)

Topology optimization for acoustic-structure interaction problems

DEFF Research Database (Denmark)

Yoon, Gil Ho; Jensen, Jakob Søndergaard; Sigmund, Ole

2006-01-01

We propose a gradient based topology optimization algorithm for acoustic-structure (vibro-acoustic) interaction problems without an explicit interfacing boundary representation. In acoustic-structure interaction problems, the pressure field and the displacement field are governed by the Helmholtz...... to subdomain interfaces evolving during the optimization process. In this paper, we propose to use a mixed finite element formulation with displacements and pressure as primary variables (u/p formulation) which eliminates the need for explicit boundary representation. In order to describe the Helmholtz......-dimensional acoustic-structure interaction problems are optimized to show the validity of the proposed method....

A study on the acoustical holography

International Nuclear Information System (INIS)

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

1979-01-01

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

Outdoor Acoustics as a General Discipline

DEFF Research Database (Denmark)

Rasmussen, Karsten Bo

1999-01-01

A tutorial paper exploring the characteristics of sound outdoors. Outdoor acoustics is contrasted to room acoustics. A number of important aspects of outdoor acoustics are exemplified and theoretical approaches are outlined. These are influence of ground impedance, influence of weather, screening...... to the application in question. In this way results providing a certain level of accuracy are obtained using methods which are balanced with the accuracy of the input data. Advanced measurement techniques are looked into and suggestions for future research are made...

Spontaneous rupture of vaginal enterocele

DEFF Research Database (Denmark)

Svendsen, J H; Galatius, H; Hansen, P K

1985-01-01

Spontaneous rupture of an enterocele is a rare complication. Only 24 cases including the present case have been reported in the literature. The patients were elderly and had had at least one vaginal operation. The patients were remarkably unaffected symptomatically on admission.......Spontaneous rupture of an enterocele is a rare complication. Only 24 cases including the present case have been reported in the literature. The patients were elderly and had had at least one vaginal operation. The patients were remarkably unaffected symptomatically on admission....

Acoustic Tomography in the Canary Basin: Meddies and Tides

Science.gov (United States)

Dushaw, Brian D.; Gaillard, Fabienne; Terre, Thierry

2017-11-01

An acoustic propagation experiment over 308 km range conducted in the Canary Basin in 1997-1998 was used to assess the ability of ocean acoustic tomography to measure the flux of Mediterranean water and Meddies. Instruments on a mooring adjacent to the acoustic path measured the southwestward passage of a strong Meddy in temperature, salinity, and current. Over 9 months of transmissions, the acoustic arrival pattern was an initial broad stochastic pulse varying in duration by 250-500 ms, followed eight stable, identified-ray arrivals. Small-scale sound speed fluctuations from Mediterranean water parcels littered around the sound channel axis caused acoustic scattering. Internal waves contributed more modest acoustic scattering. Based on simulations, the main effect of a Meddy passing across the acoustic path is the formation of many early-arriving, near-axis rays, but these rays are thoroughly scattered by the small-scale Mediterranean-water fluctuations. A Meddy decreases the deep-turning ray travel times by 10-30 ms. The dominant acoustic signature of a Meddy is therefore the expansion of the width of the initial stochastic pulse. While this signature appears inseparable from the other effects of Mediterranean water in this region, the acoustic time series indicates the steady passage of Mediterranean water across the acoustic path. Tidal variations caused by the mode-1 internal tides were measured by the acoustic travel times. The observed internal tides were partly predicted using a recent global model for such tides derived from satellite altimetry.

Laser-induced acoustic imaging of underground objects

Science.gov (United States)

Li, Wen; DiMarzio, Charles A.; McKnight, Stephen W.; Sauermann, Gerhard O.; Miller, Eric L.

1999-02-01

This paper introduces a new demining technique based on the photo-acoustic interaction, together with results from photo- acoustic experiments. We have buried different types of targets (metal, rubber and plastic) in different media (sand, soil and water) and imaged them by measuring reflection of acoustic waves generated by irradiation with a CO2 laser. Research has been focused on the signal acquisition and signal processing. A deconvolution method using Wiener filters is utilized in data processing. Using a uniform spatial distribution of laser pulses at the ground's surface, we obtained 3D images of buried objects. The images give us a clear representation of the shapes of the underground objects. The quality of the images depends on the mismatch of acoustic impedance of the buried objects, the bandwidth and center frequency of the acoustic sensors and the selection of filter functions.

Separation of acoustic waves in isentropic flow perturbations

International Nuclear Information System (INIS)

Henke, Christian

2015-01-01

The present contribution investigates the mechanisms of sound generation and propagation in the case of highly-unsteady flows. Based on the linearisation of the isentropic Navier–Stokes equation around a new pathline-averaged base flow, it is demonstrated for the first time that flow perturbations of a non-uniform flow can be split into acoustic and vorticity modes, with the acoustic modes being independent of the vorticity modes. Therefore, we can propose this acoustic perturbation as a general definition of sound. As a consequence of the splitting result, we conclude that the present acoustic perturbation is propagated by the convective wave equation and fulfils Lighthill’s acoustic analogy. Moreover, we can define the deviations of the Navier–Stokes equation from the convective wave equation as “true” sound sources. In contrast to other authors, no assumptions on a slowly varying or irrotational flow are necessary. Using a symmetry argument for the conservation laws, an energy conservation result and a generalisation of the sound intensity are provided. - Highlights: • First splitting of non-uniform flows in acoustic and non-acoustic components. • These result leads to a generalisation of sound which is compatible with Lighthill’s acoustic analogy. • A closed equation for the generation and propagation of sound is given

Potential-well model in acoustic tweezers.

Science.gov (United States)

Kang, Shih-Tsung; Yeh, Chih-Kuang

2010-06-01

Standing-wave acoustic tweezers are popularly used for non-invasive and non-contact particle manipulation. Because of their good penetration in biological tissue, they also show promising prospects for in vivo applications. According to the concept of an optical vortex, we propose an acoustics-vortex- based trapping model of acoustic tweezers. A four-element 1-MHz planar transducer was used to generate 1-MHz sine waves at 1 MPa, with adjacent elements being driven with a pi/2-rad phase difference. Each element was a square with a side length of 5.08 mm, with kerfs initially set at 0.51 mm. An acoustic vortex constituting the spiral motion of an acoustic wave around the beam axis was created, with an axial null. Applying Gor'kov's theory in the Rayleigh regime yielded the potential energy and radiation force for use in subsequent analysis. In the transverse direction, the vortex structure behaved as a series of potential wells that tended to drive a suspended particle toward the beam axis. They were highly fragmented in the near field that is very close to the transducer where there was spiral interference, and well-constructed in the far field. We found that the significant trapping effect was only present between these two regions in the transverse direction--particles were free to move along the beam axis, and a repulsive force was observed in the outer acoustic vortex. Because the steepness of the potential gradient near an axial null dominates the trapping effect, the far field of the acoustic vortex is inappropriate for trapping. Particles too close to the transducer are not sufficiently trapped because of the fragmented potential pattern. We suggest that the ideal distance from the transducer for trapping particles is in front of one-fourth of the Rayleigh distance, based on the superposition of the wavefronts. The maximum trapping force acting on a 13-mum polystyrene sphere in the produced acoustic vortex was 50.0 pN, and it was possible to trap

Acoustic cloaking in two dimensions: a feasible approach

Energy Technology Data Exchange (ETDEWEB)

Torrent, Daniel; Sanchez-Dehesa, Jose [Wave Phenomena Group, Department of Electronic Engineering, Polytechnic University of Valencia, C/ Camino de vera s.n., E-46022 Valencia (Spain)], E-mail: jsdehesa@upvnet.upv.es

2008-06-15

This work proposes an acoustic structure feasible to engineer that accomplishes the requirements of acoustic cloaking design recently introduced by Cummer and Schurig (2007 New J. Phys. 9 45). The structure, which consists of a multilayered composite made of two types of isotropic acoustic metamaterials, exactly matches the conditions for the acoustic cloaking. It is also shown that the isotropic metamaterials needed can be made of sonic crystals containing two types of material cylinders, whose elastic parameters should be properly chosen in order to satisfy (in the homogenization limit) the acoustic properties under request. In contrast to electromagnetic cloaking, the structure here proposed verifies the acoustic cloaking in a wide range of wavelengths; its performance is guaranteed for any wavelength above a certain cutoff defined by the homogenization limit of the sonic crystal employed in its fabrication.

Spontaneous emission spectra and simulating multiple spontaneous generation coherence in a five-level atomic medium

International Nuclear Information System (INIS)

Li Jiahua; Liu Jibing; Qi Chunchao; Chen Aixi

2006-01-01

We investigate the features of the spontaneous emission spectra in a coherently driven cold five-level atomic system by means of a radio frequency (rf) or microwave field driving a hyperfine transition within the ground state. It is shown that a few interesting phenomena such as spectral-line narrowing, spectral-line enhancement, spectral-line suppression, and spontaneous emission quenching can be realized by modulating the frequency and intensity of the rf-driving field in our system. In the dressed-state picture of the coupling and rf-driving fields, we find that this coherently driven atomic system has three close-lying levels so that multiple spontaneously generated coherence (SGC) arises. Our considered atomic model can be found in real atoms, such as rubidium or sodium, so a corresponding experiment can be done to observe the expected phenomena related to SGC reported by Fountoulakis et al. [Phys. Rev. A 73, 033811 (2006)], since no rigorous conditions are required

Orangutans (Pongo spp.) may prefer tools with rigid properties to flimsy tools.

Science.gov (United States)

Walkup, Kristina R; Shumaker, Robert W; Pruetz, Jill D

2010-11-01

Preference for tools with either rigid or flexible properties was explored in orangutans (Pongo spp.) through an extension of D. J. Povinelli, J. E. Reaux, and L. A. Theall's (2000) flimsy-tool problem. Three captive orangutans were presented with three unfamiliar pairs of tools to solve a novel problem. Although each orangutan has spontaneously used tools in the past, the tools presented in this study were novel to the apes. Each pair of tools contained one tool with rigid properties (functional) and one tool with flimsy properties (nonfunctional). Solving the problem required selection of a rigid tool to retrieve a food reward. The functional tool was selected in nearly all trials. Moreover, two of the orangutans demonstrated this within the first test trials with each of the three tool types. Although further research is required to test this statistically, it suggests either a preexisting preference for rigid tools or comprehension of the relevant features required in a tool to solve the task. The results of this study demonstrate that orangutans can recognize, or learn to recognize, relevant tool properties and can choose an appropriate tool to solve a problem. (PsycINFO Database Record (c) 2010 APA, all rights reserved).

A new class of spontaneously polarized materials

DEFF Research Database (Denmark)

Field, David; Plekan, Oksana; Cassidy, Andrew

2011-01-01

Very large electric fields form spontaneously within films of seemingly prosaic chemicals such as nitrous oxide or propane.We describe how the discovery of this unexpected phenomenon took place and how we attempt to understand the nature of the new class of spontaneously polarized materials...

Spontaneous rupture of choledochal cyst: case report

International Nuclear Information System (INIS)

Shin, Ho Seob; Nam, Kyung Jin; Lee, Jin Hwa; Kim, Chan Sung; Choi, Jong Cheol; Oh, Jong Young

2002-01-01

Spontaneous rupture of a choledochal cyst leading to biliary peritonitis is a rare complication which can be fatal if not promptly diagnosed. The authors report the ultrasound and CT findings of two cases of spontaneous choledochal cystic rupture and the biliary peritonitis which ensued

Spontaneous rupture of choledochal cyst: case report

Energy Technology Data Exchange (ETDEWEB)

Shin, Ho Seob; Nam, Kyung Jin; Lee, Jin Hwa; Kim, Chan Sung; Choi, Jong Cheol; Oh, Jong Young [Dong-a University College of Medicine, Pusan (Korea, Republic of)

2002-11-01

Spontaneous rupture of a choledochal cyst leading to biliary peritonitis is a rare complication which can be fatal if not promptly diagnosed. The authors report the ultrasound and CT findings of two cases of spontaneous choledochal cystic rupture and the biliary peritonitis which ensued.

Topology optimization in acoustics and elasto-acoustics via a level-set method

Science.gov (United States)

Desai, J.; Faure, A.; Michailidis, G.; Parry, G.; Estevez, R.

2018-04-01

Optimizing the shape and topology (S&T) of structures to improve their acoustic performance is quite challenging. The exact position of the structural boundary is usually of critical importance, which dictates the use of geometric methods for topology optimization instead of standard density approaches. The goal of the present work is to investigate different possibilities for handling topology optimization problems in acoustics and elasto-acoustics via a level-set method. From a theoretical point of view, we detail two equivalent ways to perform the derivation of surface-dependent terms and propose a smoothing technique for treating problems of boundary conditions optimization. In the numerical part, we examine the importance of the surface-dependent term in the shape derivative, neglected in previous studies found in the literature, on the optimal designs. Moreover, we test different mesh adaptation choices, as well as technical details related to the implicit surface definition in the level-set approach. We present results in two and three-space dimensions.

Spectral identification of sperm whales from Littoral Acoustic Demonstration Center passive acoustic recordings

Science.gov (United States)

Sidorovskaia, Natalia A.; Richard, Blake; Ioup, George E.; Ioup, Juliette W.

2005-09-01

The Littoral Acoustic Demonstration Center (LADC) made a series of passive broadband acoustic recordings in the Gulf of Mexico and Ligurian Sea to study noise and marine mammal phonations. The collected data contain a large amount of various types of sperm whale phonations, such as isolated clicks and communication codas. It was previously reported that the spectrograms of the extracted clicks and codas contain well-defined null patterns that seem to be unique for individuals. The null pattern is formed due to individual features of the sound production organs of an animal. These observations motivated the present studies of adapting human speech identification techniques for deep-diving marine mammal phonations. A three-state trained hidden Markov model (HMM) was used with the phonation spectra of sperm whales. The HHM-algorithm gave 75% accuracy in identifying individuals when it had been initially tested for the acoustic data set correlated with visual observations of sperm whales. A comparison of the identification accuracy based on null-pattern similarity analysis and the HMM-algorithm is presented. The results can establish the foundation for developing an acoustic identification database for sperm whales and possibly other deep-diving marine mammals that would be difficult to observe visually. [Research supported by ONR.