Dissertations / Theses on the topic 'Acoustics and physics'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Acoustics and physics.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
Kanapesky, Aaron Peter. "Acoustics as an Inspiration in Architecture." Thesis, Virginia Tech, 2017. http://hdl.handle.net/10919/78334.
Full textMaster of Architecture
Mahmud, Sakib. "Comparing the Performance of Bottom-Moored and Unmanned Surface Vehicle Towed Passive Acoustic Monitoring Platforms for Marine Mammal Detections." Thesis, University of Louisiana at Lafayette, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10636502.
Full textPassive acoustic monitoring (PAM) is a more effective method of monitoring cetaceans’ distribution and abundance than conventional visual surveys. Cetaceans are highly vocally active and produce identifiable acoustic signals during echolocation and communication. Three different PAM platforms recorded data in overlapping time periods in the vicinity of the 2010 Deepwater Horizon oil spill site: bottom-moored buoys (EARS), Unmanned Surface Vehicle towed arrays (USV), and subsurface glider-mounted hydrophones. Detection rates of the EARS and USV were compared to investigate their efficiency in detecting marine mammals. Detection events were obtained using independent detectors for each platform and then compared by feeding data through a common detector. Results from both detectors and platforms were compared, and a comparable trend of detection rates was found. The purpose of this study is to aid in the development of cost-efficient PAM methodology for mitigation and environmental impact assessment purposes.
Lefebvre, Antoine. "Computational acoustic methods for the design of woodwind instruments." Thesis, McGill University, 2011. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=97000.
Full textCette thèse présente des méthodes pour la conception d'instruments de musique à vent à l'aide de calculs scientifiques. La méthode des matrices de transfert pour le calcul de l'impédance d'entrée est décrite. Une méthode basée sur le calcul par Éléments Finis est appliquée à la détermination des paramètres des matrices de transfert des trous latéraux des instruments à vent, à partir desquels de nouvelles équations sont développées pour étendre la validité deséquations de la littérature. Des simulations par Éléments Finis de l'effet d'une clé suspendue au-dessus des trous latéraux donnent des résultats différents de la théorie pour les trous courts. La méthode est aussi appliquée à des trous sur un corps conique et nous concluons que les paramètres des matrices de transmission développées pour les tuyaux cylindriques sont également valides pour les tuyaux coniques.Une condition frontière pour l'approximation des pertes viscothermiques dans les calculs par Éléments Finis est développée et permet la simulation d'instruments complets. La comparaison des résultats de simulations d'instruments avec plusieurs trous ouverts ou fermés montre que la méthode des matrices de transfert présente des erreurs probablement attribuables aux interactions internes et externes entre les trous. Cet effet n'est pas pris en compte dans laméthode des matrices de transfert et pose une limite à la précision de cette méthode. L'erreur maximale est de l'ordre de 10 cents. L'effet de la courbure du corps de l'instrument est étudié avec la méthode des Éléments Finis. L'impédance de rayonnement du pavillon d'un instrument est calculée avec la méthode des matrices de transfert et comparée aux résultats de la méthode des Éléments Finis; nous concluons que la méthode des matrices de transfert n'estpas appropriée à la simulation des pavillons.Finalement, une méthode d'optimisation est présentée pour le calcul de la position et des dimensions des trous latéraux avec plusieurs contraintes, qui est basé sur l'estimation des fréquences de jeu avec la méthode des matrices de transfert. Plusieurs instruments simples sont conçus et des prototypes fabriqués et évalués.
Buckiewicz-Smith, Alexander. "Methods for measuring the acoustic response of wind instruments." Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=18800.
Full textCette thèse étudie des méthodes pour prendre des mesures acoustiques des corps et embouchures d'instruments à vent. Les réponses acoustiques et les méthodes existantes de mesure sont passées en revue. Mesures de multiples pressions et pression unique sont contrastées par un discussion des limitations sur la longueur de l'objet et la réponse en fréquences. Les mesures de réponse d'impulsion employant un signal d'entrée complexe sont discutée et des signaux utilisés pour mesurer l'acoustique de salles sont passés en revue. Les méthodes de construction et de déconvolution pour plusieurs types de signaux sont spécifiés et les façons dont la dégradation des signaux affecte les mesures sont discutées. Une nouvelle technique de réflectométrie d'impulsion qui peut employer ces signaux comme stimulus est présentée. Les signaux sont employés dans un modèle de guide d'ondes qui simule les scénarios défavorables de mesures et calculent les impédances. Des mesures de modèles sont alors comparées aux mesures réelles de fonction de réflexion de deux prototypes fabriqués pour montrer les limitations de la réflectométrie d'impulsion lors de calculs de l'impédance de longs objets. Les pertes viscothermiques et les caractéristiques de rayonnement d'extrémité ouverte mesurées en utilisant une installation de réflectométrie d'impulsion sont alors comparées à leurs valeurs théoriques prévues. En conclusion, l'impédance d'entrée calculée à partir de plusieurs embouchures de saxophones sont présentées ainsi qu'une nouvelle méthode pour mesurer la fréquence tubulaire de résonance d'une embouchure.
Shi, Yong. "Comparing theory and measurements of woodwind-like instrument acoustic radiation." Thesis, McGill University, 2009. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=32497.
Full textCette thèse propose une analyse des techniques de modélisation informatique des instruments de musique de la famille des bois à perce et trous arbitraires. Le modèle d'une structure acoustique simple implémenté avec Matlab est vérifié par des mesures expérimentales de la directivité du rayonnement. Les méthodes de calcul de l'impédance acoustique à l'entrée ainsi que de la pression acoustique à n'importe quelle position le long de l'instrument sont présentées. La procedure de calcul de la pression de radiation est détaillée pour le cas d'un tuyau cylindrique ouvert avec deux trous latéraux. Les formules de calcul du rayonnement en champ lointain et en champ proche sont données. Un système de mesure de la réponse impulsionnelle est utilisé pour mesurer la directivité de la radiation sur un prototype d'instrument ayant les caractéristiques de la famille des bois. La mesure et le traitement des données sont simulés en utilisant un modèle de guide d'ondes numérique pour tester la validité du système de mesure. Les mesures finales sont effectuées pour les cinq doigts de l'objet mesuré. Les résultats sont comparés aux valeurs théoriques pour évaluer la qualité du modèle. Des suggestions pour l'amélioration de la mesure et du modèle sont données.
Scherrer, Bertrand. "Physically-informed indirect acquisition of instrumental gestures on the classical guitar: Extracting the angle of release." Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=116950.
Full textLes guitaristes classiques peuvent apporter de multiples nuances aux sons de leur instrument grâce à un large éventail de techniques de jeu. Il leur est même possible d'identifier comment une guitare a été jouée par l'écoute attentive d'un enregistrement, en confrontant les sons entendus à leurs connaissances sur la pratique instrumentale. Ce dernier point suggère la présence d'informations sur les manipulations des instrumentistes dans les sons produits. L'objectif de ce travail de doctorat est donc de développer des méthodes automatiques permettant d'extraire une partie de ces informations à partir d'enregistrements des vibrations de l'instrument. Cette thèse se concentre sur un paramètre spécifique: l'angle avec lequel une corde quitte le doigt à la fin du pincement, désigné "angle de lâcher" par la suite. En effet, ce paramètre de jeu, au même titre que la position de pincement le long de la corde, a une influence claire sur le son produit. L'utilisation faite de connaissances physiques sur la production des sons de guitare classique est un élément central des travaux présentés dans cette thèse. En effet, des considérations physiques sont utilisées pour expliciter l'effet d'un changement de l'angle de lâcher sur les caractéristiques du signal sonore.Après avoir précisé le contexte de cette thèse par rapport aux travaux existant sur l'acquisition du geste sur la guitare classique, l'acoustique de l'instrument est abordée. Cette revue du fonctionnement de la guitare permet de dégager la structure sous-jacente des sons de guitare. Les techniques de jeux sont aussi présentées afin de montrer comment les guitaristes exploitent les degrés de liberté à leur portée pour modifier le son de leur instrument. La contribution majeure de cette thèse est ensuite détaillée: l'adaptation d'un modèle physique standard de corde de guitare afin d'y inclure l'effet de l'angle de lâcher, et de relier la variation de cet angle aux changements de contenu sonore. La mise au point d'un système d'analyse visant à extraire les paramètres des signaux de vitesse dépendant de l'angle de lâcher est ensuite abordée.La dernière partie de ce travail présente les résultats obtenus par la méthode d'extraction de l'angle de lâcher sur des signaux de vitesse mesurés. À la lumière de ces résultats, les forces et faiblesses de la méthode sont dégagées, ainsi que des pistes de recherche futures.
Freour, Vincent. "Acoustic and respiratory pressure control in brass instrument performance." Thesis, McGill University, 2014. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=121361.
Full textCette thèse présente une étude expérimentale et numérique sur le contrôle des pressions aéroacoustiques et quasi-statiques au sein de la colonne d'air formée par le musicien et son instrument dans le jeu du trombone.L'axe principal de ce travail s'articule autour de l'étude de l'interaction entre les lèvres du musicien et son conduit vocal. En premier lieu, une méthode de mesure est développée dans le but de quantifier les caractéristiques de couplage acoustique entre les lèvres, le résonateur formé par l'instrument, et les voies respiratoires en amont. Chez les sujets pouvant jouer sur le registre complet de l'instrument, le conduit vocal contribue de façon significative à la productiondu son dans le registre aigu. Deux catégories de stratégies sont proposées en fonction des caractéristiques de phase de l'impédance du conduit vocal à la fréquence fondamentale, ainsi que de la capacité à générer un maximum d'énergie acoustique. Afin d'étudier plus précisément l'influence du conduit vocal sur le comportement mécanique des lèvres d'un tromboniste, différentes conditions de couplage en amont sont simulées sur un système de bouche artificielle. Cette expérience permet de démontrer l'importance de l'ajustement de la phase de l'impédance en amont sur le comportement mécanique des lèvres. Les résultats obtenus mettent particulièrement en évidence les capacités d'une résonance de conduit vocal à déplacer la fréquence de jeu afin de potentiellement la rapprocher d'une fréquence de résonance mécanique des lèvres, produisant ainsi une efficacité maximale du système d'excitation. Des simulations numériques utilisant différents modèles physiques de lèvres et différentes conditions de couplage acoustique avec le conduit vocal confirment les hypothèses formulées; un couplage avec le conduit vocal à la fréquence fondamentale influence la fréquence de jeu. En conséquence, ces variations induisent des changements, d'une part de l'impédance acoustique chargeant les lèvres, et d'autre part de leur mobilité mécanique. Il en résulte différents degrés d'efficacité du mécanisme de production sonore en ce qui concerne l'énergie acoustique générée. Pour terminer, une étude quantitative de la dynamique du thorax est conduite sur un tromboniste. Différentes tâches musicales sont analysées en termes de pression développée par les muscles intercostaux et abdominaux, de l'activité du diaphragme, ainsi que de la résistance des lèvres et de la glotte à l'écoulement pendant le jeu. Cette étude a ainsi pour but d'évaluer les caractéristiques physiologiques du contrôle de la production du son et leurs relations à la gestion de la pression quasi-statique dans la cavité buccale. Elle suggère également de nouveaux éléments quant à l'influence du contrôle respiratoire sur l'effet acoustique du conduit vocal.
Medvid, Sophia V. "Analysis of The Vibrational Modes of a Brass Plate and Mellophone." Ohio University Honors Tutorial College / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ouhonors1587991088883357.
Full textOwens, Eli Thomas. "Investigating Granular Structure with Spatial and Temporal Methods." Thesis, North Carolina State University, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=3538538.
Full textThis dissertation reports studies of the internal structure of jammed granular materials and how granular sound propagation and vibrational modes are influenced by disorder in particle positions and contact forces. We investigate the role of particle scale forces on sound amplitude and speed, how to characterize the bulk pressure via the density of states, and force network modularity. We perform our experiments on a vertical, 2D, photoelastic granular material. Acoustic waves are excited from the bottom of the system and observed via particle scale sensors and a high speed camera. This novel combination of spatial and temporal measurements allows us to observe the role of force chains in sound propagation. The sound amplitude is largest through particles with strong contact forces, and we see that sound travels fastest along high force paths, giving rise to multiple sound speeds. Combining acoustic excitations with a method from thermal physics, we developed a new method to measure the density of modes, D(f). From D( f), we define a critical frequency, fc, that scales with the bulk pressure, and comparing D( f) to Debye scaling, we find an excess of low frequency modes. Disorder in the force chain network and particle configurations plays a crucial role in D(f), as Debye scaling is only recovered for high pressure, hexagonally ordered packings. Finally, we characterize the force network by dividing it into modules of highly connected nodes. These communities become progressively more ordered as the pressure on the system is increased and the force chains become more uniform. Together, these studies illustrate the importance of the force chains in understanding static and dynamic granular properties.
Yu, Jefferey C. H. "Collinear acousto-optic interactions in optical fibers using laser generated flexural acoustic waves." Thesis, McGill University, 1989. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=61782.
Full textZong, Jie. "Conversion efficiency improvement in acousto-optical modulation." Diss., The University of Arizona, 1999. http://hdl.handle.net/10150/298755.
Full textZhang, Wei. "Simulation and experimental study of room acoustics." Thesis, University of Ottawa (Canada), 2006. http://hdl.handle.net/10393/27311.
Full textHuan, C. H. A. "Phase transformation and nuclear resonance in acoustics." Thesis, University of Oxford, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379905.
Full textWolfe, Brian Thomas. "An analysis of texture, timbre, and rhythm in relation to form in Magnus Lindberg's "Gran Duo"." Thesis, The University of Oklahoma, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=3592105.
Full textGran Duo (1999-2000) by Magnus Lindberg (b. 1958) is the result of a commission by Sir Simon Rattle, former conductor of the City of Birmingham (England) Symphony Orchestra, and the Royal Festival Hall to commemorate the third millennium. Composed for twenty-four woodwinds and brass, Lindberg divides the woodwind and brass families into eight characters that serve as participants in an attentive twenty-minute conversation.
The document includes biographical information about the composition to further understand Lindberg’s writing style. The composer’s use of computer-assisted composition techniques inspires an alternative structural analysis of Gran Duo. Spectral graphs provide a supplementary tool for score study assisting with the verification of formal structural elements. A tempo chart allows the conductor to easily identify form and tempo relationships between each of the nineteen sections throughout the five-movement composition.
In order to reveal character areas and their relation to the structure of the work, the analysis of texture, timbre, and rhythm reveal the formal structure of the composition, which reflects a conversation between the brass and woodwinds in this setting for wind instruments.
Bromage, Seona. "Visualisation of the lip motion of brass instrument players, and investigations of an artificial mouth as a tool for comparative studies of instruments." Thesis, University of Edinburgh, 2007. http://hdl.handle.net/1842/1966.
Full textParris, Stephen. "Towards a harmonic approach to composing for central Javanese gamelan." Thesis, Mills College, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1589493.
Full textThe purpose of this thesis is to share the process behind the development of an approach to composing for central Javanese gamelans that utilizes vertical harmony. This paper will include my history with Javanese gamelan, work on the development of a piano tuning that would work with a gamelan, compositional works that led to the development of the system, a study of existing Javanese gamelan tunings, and a presentation of intervallic relationships and cadences that can be utilized with any gamelan. All of this is done with hope that others who may take interest in writing for central Javanese gamelan will have a new tool at their disposal, and to pique the interest of others in the rich world of possibilities that exist within the instruments.
There is also an explanation of the process of developing a piano tuning to be used with a traditional gamelan to perform the Concerto for PIano And Javanese Gamelan by Lou Harrison.
There is some brief discussion on the cognition of interval, and how the brain simplifies complex intervals, and begins to hear them as more simple intervals.
Adams, Matthew Michael. "Magnetic and acoustic investigations of turbulent spherical Couette flow." Thesis, University of Maryland, College Park, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10160544.
Full textThis dissertation describes experiments in spherical Couette devices, using both gas and liquid sodium. The experimental geometry is motivated by the Earth's outer core, the seat of the geodynamo, and consists of an outer spherical shell and an inner sphere, both of which can be rotated independently to drive a shear flow in the fluid lying between them. In the case of experiments with liquid sodium, we apply DC axial magnetic fields, with a dominant dipole or quadrupole component, to the system. We measure the magnetic field induced by the flow of liquid sodium using an external array of Hall effect magnetic field probes, as well as two probes inserted into the fluid volume. This gives information about possible velocity patterns present, and we extend previous work categorizing flow states, noting further information that can be extracted from the induced field measurements. The limitations due to a lack of direct velocity measurements prompted us to work on developing the technique of using acoustic modes to measure zonal flows. Using gas as the working fluid in our 60 cm diameter spherical Couette experiment, we identified acoustic modes of the container, and obtained excellent agreement with theoretical predictions. For the case of uniform rotation of the system, we compared the acoustic mode frequency splittings with theoretical predictions for solid body flow, and obtained excellent agreement. This gave us confidence in extending this work to the case of differential rotation, with a turbulent flow state. Using the measured splittings for this case, our colleagues performed an inversion to infer the pattern of zonal velocities within the flow, the first such inversion in a rotating laboratory experiment. This technique holds promise for use in liquid sodium experiments, for which zonal flow measurements have historically been challenging.
Baumbusch, Brian. "The lightbulb project| New music for new percussion instruments." Thesis, Mills College, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=1549992.
Full textThis thesis is about the process behind building, tuning, and composing music for a new set of metallophones called the "Lightbulb" instruments. This project began in 2011 and has continued to expand over the past two years: the first piece to be written for the instruments is titled Prana, and this thesis describes how the process of building and tuning the instruments informed the compositional process behind Prana. The premiere of Prana led to the formation of the Lightbulb Ensemble, which performs on these new instruments. The instruments and the group continue to develop.
Schuster, William. "Trailing edge noise produced by the scattering of boundary layer turbulence." Diss., The University of Arizona, 2002. http://hdl.handle.net/10150/280089.
Full textFan, Xiaobing 1960. "Numerical model for calculating the ultrasonic power deposition in layered medium." Thesis, The University of Arizona, 1992. http://hdl.handle.net/10150/278188.
Full textBozhko, Andrii. "Physical Boundary as a Source of Anomalies in Transport Processes in Acoustics and Electrodynamics." Thesis, University of North Texas, 2018. https://digital.library.unt.edu/ark:/67531/metadc1404590/.
Full textLazaridès, Ariane. "Classification trees for acoustic models : variations on a theme." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0016/MQ37139.pdf.
Full textIngemanson, Megan Lynn. "Experimental Characterization of Wind Turbine Blade Aerodynamic Noise." Thesis, University of California, Davis, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=1539643.
Full textWind turbine noise at low frequencies less than 300Hz is not only annoying to humans but has been proven to cause serious health issues. Additionally, animals are severely affected by wind turbines because a small increase in ambient noise (as is produced by wind turbines) significantly reduces their listening ability. In an attempt to better understand and characterize the aerodynamic noise of wind turbine blades, experimental testing was completed on PowerWorks 100kW and GudCraft WG700 blade specimens in the University of California, Davis Transportation Noise Control Center's anechoic chamber. Experimental testing and data analysis proved approximately 4.0dB to 6.0dB was produced due to the blades' geometric design for both blade specimens at low frequencies. This noise was maximized at the blades' leading edge along the central portion of the blades' radius. Theoretical prediction models have been used to determine that, for typical wind speeds and low frequencies, noise generated due to the tip passing frequency is clearly predominant.
Moisan, Jean-Francois. "Ultrasonic monitoring of die-casting process using clad buffer rod sensor." Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=32968.
Full textFor the materials the melt temperature will not exceed 600°C because the casting is made at the semi-solid state, between the solidus and liquidus, of the materials. A novel high performance buffer rod with a cooling system is integrated into the die. Therefore, ultrasonic measurements can be carried out with high signal-to-noise ratio at elevated temperatures.
LaJeunesse, Jeff. "Implications of heterogeneity in the shock wave propagation of dynamically shocked materials." Thesis, Marquette University, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1586700.
Full textThe field of shock physics as a whole has only recently begun to pay particular attention to modeling heterogeneous materials under shock loading. These materials are important because of their practicality in terms of creating stronger, more shock resistant materials. To understand why they absorb shock impact energy better than homogeneous materials means that the small-scale processes that occur during the shock loading of these heterogeneous materials needs to be understood. Recent computational experiments, called mesoscale simulations, have shown that explicitly incorporating small-scale heterogeneous features into hydrocode simulations allows the bulk shock response of the heterogeneous material to be observed while not requiring the use of empirically determined constitutive equations. Including these features in simulations can offer insights into the irreversible mechanisms that dominate the propagation of shock waves in heterogeneous materials.
Three cases where the mesoscale approach for modeling the dynamic shock loading of heterogeneous materials are presented. These materials fall into three categories: granular - dry sand, granular with binder - concrete, and granular contained in a metal foam with a binder - granular explosive contained in an aluminum foam. The processes in which shock waves propagate through each material are addressed and relationships between the three materials are discussed. Particle velocity profiles for dry sand and concrete was obtained from Harvard University and Eglin Air Force Base, respectively. Mesoscale simulations using CTH are conducted for each type of heterogeneous material and the results are compared to the experimental data.
Pitre, Kevin M. "Predicting Wind Noise Inside Porous Dome Filters for Infrasound Sensing on Mars." Thesis, University of Louisiana at Lafayette, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10244134.
Full textThe study described in this thesis aims to assess the effects of wind-generated noise on potential infrasound measurements on future Mars missions. Infrasonic sensing on Mars is being considered as a means to probe the long-scale atmospheric dynamics, thermal balance, and also to infer bolide impact statistics. In this study, a preliminary framework for predicting the principal wind noise mechanisms to the signal detected by a sensor placed inside a hemispherical porous dome on the Martian surface is developed. The method involves calculating the pressure power density spectra in the infrasonic range generated by turbulent interactions and filtered by dome shaped filters of varying porosities. Knowing the overall noise power spectrum will allow it to be subtracted from raw signals of interest and aid in the development of infrasound sensors for the Martian environment. In order to make these power spectral predictions, the study utilizes the Martian Climate Database (MCD) global circulation model, developed by Laboratoire de Meteorologie Dynamique in Paris, France. Velocity profiles are generated and used in semi empirical functions generated by von Kármán along with equations for describing the physical turbulent interactions. With these, turbulent interactions in the free atmosphere above the Martian surface are described. For interactions of turbulence with the porous filter, semi-empirical formulations are adapted to the Martian parameters generated by the MCD and plotted alongside contributions in the free atmosphere outside and inside the dome to obtain the total wind noise contribution from turbulence. In conclusion, the plots of power spectral densities versus frequency are analyzed to determine what porosity filter would provide the best wind-noise suppression when measured at the center the dome. The study shows that 55% (0.02 to 5 Hz) and 80% (6 to 20 Hz) porosities prove to be the better of the five porosities tested.
Bergmeier, Gene Georg 1972. "Sonic booms from unsteady sources." Thesis, The University of Arizona, 1997. http://hdl.handle.net/10150/291664.
Full textHadley, Mark Lyndon. "Tracking sperm whales using passive acoustics and particle filters." Thesis, University of Southampton, 2011. https://eprints.soton.ac.uk/192589/.
Full textNguyen, Phu Duy. "Physics Based Approach for Seafloor Classification." PDXScholar, 2017. https://pdxscholar.library.pdx.edu/open_access_etds/4060.
Full textMoe, John Einar. "Near and far-field acoustic scattering through and from two dimensional fluid-fluid rough interfaces /." Thesis, Connect to this title online; UW restricted, 1996. http://hdl.handle.net/1773/6019.
Full textKruse, Matthew Thomas 1964. "Smooth, cusped, and discontinuous traveling waves in the periodic fluid resonance equation." Diss., The University of Arizona, 1998. http://hdl.handle.net/10150/282759.
Full textKozell, Monte Allen. "Investigation of the Acoustic Response of a Confined Mesoscopic Water Film Utilizing a Combined Atomic Force Microscope and Shear Force Microscope Technique." Thesis, Portland State University, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10824892.
Full textAn atomic force microscopy beam-like cantilever is combined with an electrical tuning fork to form a shear force probe that is capable of generating an acoustic response from the mesoscopic water layer under ambient conditions while simultaneously monitoring force applied in the normal direction and the electrical response of the tuning fork shear force probe. Two shear force probes were designed and fabricated. A gallium ion beam was used to deposit carbon as a probe material. The carbon probe material was characterized using energy dispersive x-ray spectroscopy and scanning transmission electron microscopy. The probes were experimentally validated by demonstrating the ability to generate and observe acoustic response of the mesoscopic water layer.
AUMOND, Pierre. "Modélisation numérique pour l'acoustique environnementale : simulation de champs météorologiques et intégration dans un modèle de propagation." Phd thesis, UNIVERSITE DU MAINE, 2011. http://tel.archives-ouvertes.fr/tel-00850700.
Full textKULKARNI, PRASHANT M. "EXPERIMENTAL FORMULATION OF FOUR-POLE PARAMETERS FOR ANALYTICAL-EXPERIMENTAL HYBRID MODELING OF ACOUSTIC SYSTEMS." University of Cincinnati / OhioLINK, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1069348253.
Full textGruell, Michael S. "Simulation of the acoustic pulse expected from the interaction of ultra-high energy neutrinos and seawater." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2006. http://library.nps.navy.mil/uhtbin/hyperion/06Mar%5FGruell.pdf.
Full textAdvocat, Amy. "[A] New tonal world: The Bohlen-Pierce Scale." Thesis, McGill University, 2010. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=96150.
Full textCe document compare la gamme Bohlen-Pierce d'autres systmes d'accord octave et non-octave-bass, tablissant des parallles entre soi et le systme la plus utilis, temprament de I2-gal. Ces parallles mnent la possibilit qu'il peut tre des rgles harmoniques applicables la gamme BohlenPierce qui sont analogues la pratique musicale courante. Ces rgles thorises sont alors appliques quelques exemples du corps croissant de compositions musicales crites la gamme Bohlen-Pierce. Il-y-a aussi inclus des arguments qui support la prfrence d'utilisation des timbres impair-partiels dans la performance de cette gamme, qui ferait l'invention de la clarinette Bohlen-Pierce un point tournant majeur dans la dveloppement de cette gamme. Certains compositions etudi a t ecris pour la prformance sur clarinet Bohlen-Pierce par cette auteure .
Thirunavukkarasu, Senganal. "Impedance Matching for Discrete, Periodic Media and Application to Two-Scale Wave Propagation Models." Thesis, North Carolina State University, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3690210.
Full textMurray, Alasdair Robert John. "Airborne and underwater response of acoustic structures." Thesis, University of Exeter, 2014. http://hdl.handle.net/10871/15426.
Full textThompson, Shannon C. "Resonance in Tongue Drums." Ohio University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1428423607.
Full textBonneau, Lenaïc. "Propagation d'ondes acoustiques guidées dans les milieux granulaires." Phd thesis, Université Paris-Diderot - Paris VII, 2009. http://pastel.archives-ouvertes.fr/pastel-00559001.
Full textUtami, Sentagi Sesotya. "An Acoustical Analysis of Domes Coupled to Rooms, with Special Application to the Darussholah Mosque, in East Java, Indonesia." Diss., CLICK HERE for online access, 2005. http://contentdm.lib.byu.edu/ETD/image/etd995.pdf.
Full textFischer, Jost. "Über Synchronisationsphänomene nichtlinearer akustischer Oszillatoren." Master's thesis, Universität Potsdam, 2012. http://opus.kobv.de/ubp/volltexte/2013/6361/.
Full textIn this study, synchronization properties observed in a system of nonlinear acoustic oscillators in form of two coupled organ pipes are investigated. From given measurements we extract the effects of synchronization one would expect typically. Furthermore we set our focus to the domains of transition into the synchronization region, when the system is complete synchronized and when it tears off, under the condition of different coupling strengths. We analyze and discuss the observed phenomena concerning their nonlinearities. Using numerical, fluid-dynamic and aeroacoustic simulation techniques we investigate how an organ pipe can be understand as a self-sustained, acoustic oscillator. With the results of the numerical simulations we show, how to reduce the complex fluid-dynamical interplay with the acoustic field inside the pipe to a self-sustained acoustic oscillator. For this process we use the coarse graining method.
Wang, Pai. "Discoveries in Phononic Crystals and Acoustic Metamaterials." Thesis, Harvard University, 2015. http://nrs.harvard.edu/urn-3:HUL.InstRepos:26718707.
Full textEngineering and Applied Sciences - Applied Math
Tocheff, Robert Dale. "Acoustical placement of voices in choral formations /." Connect to resource, 1990. http://rave.ohiolink.edu/etdc/view.cgi?acc%5Fnum=osu1248976452.
Full textJackson, Christophe E. "Acoustical analysis of trained and untrained singers onsite before and after prolonged voice use." Thesis, The University of Alabama at Birmingham, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=3561278.
Full textControlled acoustic environments are important in voice research. Recording environment affects the quality of voice recordings. While sound booths and anechoic chambers are examples of controlled acoustic environments widely used in research, they are both costly and not portable. The long-term goal of this project is to compare the voice usage and efficiency of trained and untrained singers onsite immediately before and after vocal performance. The specific goal of this project is the further of development a Portable Sound Booth (PSB) and standardization of onsite voice recording procedures under controlled conditions. We hypothesized that the simple and controlled acoustic environment provided by the PSB would enable consistent reliable onsite voice recordings and the immediate differences as a consequence of voice usage were measurable. Research has suggested that it would be possible to conduct onsite voice recordings. Proof of concept research titled "Construction and Characterization of a Portable Sound Booth for Onsite Measurement" was conducted before initiating the full research effort. Preliminary findings revealed that: (1) it was possible to make high-quality voice recordings onsite, (2) the use of a Portable Sound Booth (PSB) required further acoustic characterization of its inherent acoustic properties, and (3) testable differences before and after performance were evident. The specific aims were to (1) develop and refine onsite objective voice measurements in the PSB and (2) evaluate use of the PSB to measure voice quality changes before and after voice usage.
Shang, Alain. "Effects of acoustic properties on stimulated backward brillouin scattering in single mode optical fibers." Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=61056.
Full textThese six doped glasses are widely used as core and cladding material for optical fibers. Their acoustic properties can affect the backward stimulated Brillouin scattering since this scattering involves acoustic disturbances of the material. The SBBS threshold is evaluated theoretically taking the Bragg and the nonlinear coupling of the pump and Stokes into account.
Effects of different acoustic profiles of SMOFs on SBBS are experimentally investigated. (Abstract shortened by UMI.)
Nicolle, Alain J. (Alain Jean-René). "Two novel ultrasonic lenses." Thesis, McGill University, 1991. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=59916.
Full textThe cylindrical lens consists of a lead zirconate titanate (PZT) coated wire or optical fibre. The fabrication and evaluation of the lens is described. Ultrasonic measurements of miniature transducers and electronically controllable deflection are demonstrated. A novel laser ablation patterning technique is used to make an interdigital transducer with a 20$ mu$m resolution on the outer electrode of the lens for special applications. Finally, possible applications of the cylindrical lens are outlined.
Pereira, da Cunha Maurício. "Saw propagation and device modelling on arbitrarily oriented substrates." Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=28511.
Full textPapakyritsis, Ioannis. "Acoustic and Perceptual Effects of Dysarthria in Greek with a Focus on Lexical Stress." Thesis, University of Louisiana at Lafayette, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3615293.
Full textThe field of motor speech disorders in Greek is substantially underresearched. Additionally, acoustic studies on lexical stress in dysarthria are generally very rare (Kim et al. 2010). This dissertation examined the acoustic and perceptual effects of Greek dysarthria focusing on lexical stress. Additional possibly deviant speech characteristics were acoustically analyzed. Data from three dysarthric participants and matched controls was analyzed using a case study design. The analysis of lexical stress was based on data drawn from a single word repetition task that included pairs of disyllabic words differentiated by stress location. This data was acoustically analyzed in terms of the use of the acoustic cues for Greek stress. The ability of the dysarthric participants to signal stress in single words was further assessed in a stress identification task carried out by 14 naïve Greek listeners. Overall, the acoustic and perceptual data indicated that, although all three dysarthric speakers presented with some difficulty in the patterning of stressed and unstressed syllables, each had different underlying problems that gave rise to quite distinct patterns of deviant speech characteristics. The atypical use of lexical stress cues in Anna's data obscured the prominence relations of stressed and unstressed syllables to the extent that the position of lexical stress was usually not perceptually transparent. Chris and Maria on the other hand, did not have marked difficulties signaling lexical stress location, although listeners were not 100% successful in the stress identification task. For the most part, Chris' atypical phonation patterns and Maria's very slow rate of speech did not interfere with lexical stress signaling. The acoustic analysis of the lexical stress cues was generally in agreement with the participants' performance in the stress identification task. Interestingly, in all three dysarthric participants, but more so in Anna, targets stressed on the 1st syllable were more impervious to error judgments of lexical stress location than targets stressed on the 2nd syllable, although the acoustic metrics did not always suggest a more appropriate use of lexical stress cues in 1st syllable position. The findings contribute to our limited knowledge of the speech characteristics of dysarthria across different languages.
Stoyko, Darryl Keith. "Using the singularity frequencies of guidedwaves to obtain a pipe's properties and detect and size notches." Thesis, University of Manitoba (Canada), 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3582897.
Full textA survey of relevant literature on the topic of wave propagation and scattering in pipes is given first. This review is followed by a theoretical framework which is pertinent to wave propagation in homogeneous, isotropic, pipes. Emphasis is placed on approximate solutions stemming from a computer based, Semi-Analytical Finite Element (SAFE) formulation. A modal analysis of the dynamic response of homogeneous, isotropic pipes, when subjected to a transient ultrasonic excitation, demonstrates that dominant features, i.e., singularities in an unblemished pipe’s displacement Frequency Response Function (FRF) coincide with its cutoff frequencies. This behaviour is confirmed experimentally. A novel technique is developed to deduce such a pipe’s wall thickness and elastic properties from three cutoff frequencies. The resulting procedure is simulated numerically and verified experimentally. Agreement between the new ultrasonic procedure and traditional destructive tests is within experimental uncertainty. Then a hybrid-SAFE technique is used to simulate waves scattered by various open rectangular notches. The simulations show, for the first time, that singularities distinct from the unblemished pipe’s cutoff frequencies arise in a displacement FRF when an axisymmetric notch is introduced. They also suggest that the new singularities depend on the properties of the parent pipe and the finite element region but effects are local to a notch. It is demonstrated further that the difference between the frequency at which a singularity introduced by a notch occurs and the nearest corresponding unblemished pipe’s cutoff frequency is a function of the notch’s dimensions. By plotting contours of constant frequency differences, it is shown that it is usually possible to characterize the notch’s dimensions by using two modes. However, the frequency difference for a third mode may be also needed occasionally. The more general case of nonaxisymmetric notches is shown to be a straightforward extension of the axisymmetric case.