Physics Commons^™

A Computational Investigation Of Wood Selection For Acoustic Guitar, Jonah Osterhus

Senior Honors Theses

The acoustic guitar is a stringed instrument, often made of wood, that transduces vibrational energy of steel strings into coupled vibrations of the wood and acoustic pressure waves in the air. Variations in wood selection and instrument geometry have been shown to affect the timbre of the acoustic guitar. Computational methods were utilized to investigate the impact of material properties on acoustic performance. Sitka spruce was deemed the most suitable wood for guitar soundboards due to its acoustic characteristics, strength, and uniform aesthetic. Mahogany was deemed to be the best wood for the back and sides of the guitar body …

Long-Range Aceo Phenomena In Microfluidic Channel, Diganta Dutta, Keifer Smith, Xavier Palmer

Electrical & Computer Engineering Faculty Publications

Microfluidic devices are increasingly utilized in numerous industries, including that of medicine, for their abilities to pump and mix fluid at a microscale. Within these devices, microchannels paired with microelectrodes enable the mixing and transportation of ionized fluid. The ionization process charges the microchannel and manipulates the fluid with an electric field. Although complex in operation at the microscale, microchannels within microfluidic devices are easy to produce and economical. This paper uses simulations to convey helpful insights into the analysis of electrokinetic microfluidic device phenomena. The simulations in this paper use the Navier–Stokes and Poisson Nernst–Planck equations solved using COMSOL …

Coupled Oscillators: Protein And Acoustics, Angelique N. Mcfarlane

Theses

This work encompassed three different vibrational energy transfer studies of coupled resonators (metal, topological, and microtubule comparison) inspired by the lattices of microtubules from regular and cancerous cells. COMSOL Multiphysics 5.4 was utilized to design the experiment. The simulation starts with an acoustic pressure study to examine the vibrational modes present in coupled cylinders, representing α-, β-tubulin heterodimers. The Metal Study consisted of 3 models (monomer, dimer, and trimer) to choose the correct height (40 mm) and mode (Mode 1) for study. The Topological Study was run to predict and understand how the lattice structure changes over a parametric sweep …

Acoustic Parameters As Discriminators Of Wall Events In Pico Dark Matter Search Data, Lucia Volkova

University Honors Program Senior Projects

Bubble chambers are one of several detector types that particle physicists use to search for the as-yet-undetected dark matter. The PICO collaboration – formed from the merger of the similar PICASSO and COUPP experiments – runs such a bubble detector using superheated fluorocarbons (with and without iodine). Bubbles that form along chamber walls exhibit different behavior than those which nucleate in the bulk of the target liquid due to shape distortions from the wall boundary; in previous analyses when searching for dark matter, these wall events have been cut from the data to control for the differing behavior using information …

A Method For Automatic Detection Of Tongued And Slurred Note Transitions In Clarinet Playing, Whitney L. Coyle, Jack D. Gabriel

Faculty Publications

This study offers a simple method to characterize two transition types in passages of music in order to automatically distinguish slurred transitions from tongued transitions in musical settings. Data were recorded from musicians playing a clarinet with a sensor-equipped mouthpiece measuring blowing pressure in the mouth and pressure in the mouthpiece. This method allows for comparing transitions in different musical contexts, playing regimes, and between players. The method is highly reliable in automatically detecting transition types in recorded clarinet playing in both simple and more complex passages.

The Fourier Spectrum Of A Singing Wine Glass, Reuben Leatherman, Justin Charles Dunlap, Ralf Widenhorn

Physics Faculty Publications and Presentations

The phenomenon of the singing wineglass is familiar to many. Most people have run a finger along the rim of a wine glass with the right speed and pressure to get it to whistle a tone or perhaps heard a glass harmonica being played. However, have you ever noticed and wondered why the vibrations caused by a finger on a glass produce a pulsating sound, rather than a steady, constant-amplitude vibration? Further exploration reveals that the sound and pulsations of a wine glass vary depending on the way the wine glass is stimulated. In this paper, we investigate and model …

An Investigation Of Clarinet Playing Using A Sensor-Equipped Mouthpiece, Camille Adkison

Honors Program Theses

The purpose of this study is to characterize clarinet playing techniques through measurements of the pressure in the clarinet mouthpiece while a musician plays and to investigate the methods by which clarinet players transition from note to note, termed articulations. The results provide information about the clarinet-player system that can be incorporated in future models of the clarinet. The work reported here involves the use of a recent technological development, the sensor-equipped mouthpiece. Using the sensor-equipped mouthpiece, researchers are able to record pressure in the musician's mouth and the clarinet mouthpiece. Six clarinet players of varying experience levels were asked …

Practice Room Acoustics: What Matters To Musicians About The Practice Space, Yu-Tien Chou

Senior Projects Spring 2019

Why do people always prefer the practice room in the corner on the second floor than the others? What’s the reason why string players often go for the “dryer” room than the wind players? Wondering why brass players often occupy the resonant room? This paper is here to decipher all the mysteries behind all of the questions above by the acoustic analysis suggested by Bonnelo and the other supplying papers on sound absorbing materials. The question to be answered is how the rooms are different from each other in terms of their dimensions and damping surfaces. Eventually, construct a criteria …

An Acoustical Analogue Of A Galactic-Scale Gravitational-Wave Detector, Michael T. Lam, Joseph D. Romano, Joey Key, M. E. Normandin, ‪Jeffrey S. Hazboun

Physics and Astronomy Faculty Publications and Presentations

By precisely monitoring the “ticks” of Nature's most precise clocks (millisecond pulsars), scientists are trying to detect the “ripples in spacetime” (gravitational waves) produced by the inspirals of supermassive black holes in the centers of distant merging galaxies. Here, we describe a relatively simple demonstration that uses two metronomes and a microphone to illustrate several techniques used by pulsar astronomers to search for and detect gravitational waves. An adapted version of this demonstration could be used as an instructional laboratory investigation at the undergraduate level.

Three Dimensional Passive Localization For Single Path Arrival With Unknown Starting Conditions, Britt Aguda

University of New Orleans Theses and Dissertations

Introduced in this paper is the time difference of arrival (TDoA) conic approximation method (TCAM), a technique for passive localization in three dimensions with unknown starting conditions. The TDoA of a mutually detected signal across pairs of detectors is used to calculate the relative angle between the signal source and the center point of the separation between the detectors in the pair. The relative angle is calculated from the TDoA using a mathematical model called the TDoA approximation of the zenith angle (TAZA). The TAZA angle defines the opening angle of a conic region of probability that contains the signal …

Underwater Acoustic Signal Analysis Toolkit, Kirk Bienvenu Jr

University of New Orleans Theses and Dissertations

This project started early in the summer of 2016 when it became evident there was a need for an effective and efficient signal analysis toolkit for the Littoral Acoustic Demonstration Center Gulf Ecological Monitoring and Modeling (LADC-GEMM) Research Consortium. LADC-GEMM collected underwater acoustic data in the northern Gulf of Mexico during the summer of 2015 using Environmental Acoustic Recording Systems (EARS) buoys. Much of the visualization of data was handled through short scripts and executed through terminal commands, each time requiring the data to be loaded into memory and parameters to be fed through arguments. The vision was to develop …

Developing A Location Detector Using Acoustical Energy Quantities, Jacey Young

Student Works

In this paper, development through the use of LabVIEW for an acoustical energy quantity detector is discussed. This detector uses the quantity of sound intensity to locate the direction of a sound source in three dimensional space with relation to the center of a spherical microphone probe placed directly under a web camera. The direction and the magnitude of the sound intensity are then used to generate an arrow pointing in the direction of the sound source and position it on top the web camera's image of the surrounding area. These quantities are then also used to highlight an area …

Vector Acoustic Intensity Around A Tuning Fork, Daniel A. Russell, Justin Junell, Daniel O. Ludwigsen

Daniel Ludwigsen

The acoustic intensity vector field around a tuning fork is investigated. Theory for a longitudinal quadrupole source predicts a well-defined transition between near-field and far-field, with significant circulation of sound energy in the near-field. Vector components of the time-averaged intensity were measured using a two-microphone intensity probe and found to agree well with predictions from theory. The vector intensity map is interpreted, and shown to provide useful information about the near-field of an acoustic source.

Better Understanding Of Resonance Through Modeling And Visualization, Daniel O. Ludwigsen, Cayla Jewett, Matthew Jusczcyk

Daniel Ludwigsen

Students encounter cavity resonance and waveguide phenomena in acoustics courses and texts, where the study is usually limited to cases with simple geometries: parallelepipeds, cylinders, and spheres. Long-wavelength approximations help with situations of more complexity, as in the classic Helmholtz resonator. At Kettering University, we are beginning to employ finite element modeling in our acoustics classes to help undergraduates better understand the acoustic modes of actual structures. This approach to the time-independent wave equation (the Helmholtz equation) was first used in a research and measurements class to investigate two classic resonance problems. The first problem was a study of resonance …

Acoustic Testing And Modeling: An Advanced Undergraduate Laboratory, Daniel A. Russell, Daniel O. Ludwigsen

Daniel Ludwigsen

This paper describes an advanced laboratory course in acoustics, specifically targeted for students with an interest in engineering applications at a school with a strongly integrated industrial co-op program. The laboratory course is developed around a three-pronged approach to problem solving that combines and integrates theoretical models, computational models, and experimental data. The course is structured around modules that begin with fundamental concepts and build laboratory skills and expand the knowledge base toward a final project. Students keep a detailed laboratory notebook, write research papers in teams, and must pass laboratory certification exams. This paper describes the course layout and …

Bowing Behavior Of Strings With Non-Uniform Mass Density, Andrew J. Brandt

Summer Research

An investigation into the behavior of non-uniform strings when bowed while varying bowing position and force applied to map the minimum force curve on the Schelleng diagram. Strings investigated include uniform, cosinusoidal variation, and impedance discontinuity strings.

Simulating A Guitar With A Conventional Sonometer, Zily Burstein, Christina M. Gower, Gabriele U. Varieschi

Gabriele Varieschi

In this paper we present a simple way to convert a conventional sonometer into a simulated fretted instrument, such as a guitar or similar, by adding a fingerboard to the sonometer. In particular, we use this modified apparatus in relation to the problem of the instrument intonation, i.e., how to obtain correctly tuned notes on these string instruments. The experimental procedures presented in this study can become a more structured laboratory activity to be used in general physics courses or acoustics classes.

The Acoustics Of Harmon Mutes, Zachary T. Armstrong

Summer Research

The acoustic properties of trumpets have been studied thoroughly, but little to no previous work has been done regarding the acoustics of trumpet mutes. Harmon mutes have a distinctively "buzzy" sound when they are used in performance and it is the opinion of a large number of trumpet players who use Harmon mutes that they should be dented before they are used in performance. The work presented here is an attempt to determine the acoustical properties of Harmon mutes and how they change when the mute is dented. If Harmon mutes are better understood, then a more informed decision as …

Vibrational Patterns In Curved Metal Plates, Samuel D. Berling

Summer Research

This summer, I investigated the factors affecting the vibrational patterns of curved metal plates. This research was inspired by the musical saw instrument which is played by bending a large handsaw into an s-curve and then bowing it like a violin. In our results, we identified the local confinement of the vibrational patterns due to the plate's curvature, the variation of resonant frequencies due to the geometry of the plate, and we determined that the stress in the metal created by bending the plate into its shape has a negligible effect on the resonant frequencies.

Coupling Of Transverse And Longitudinal Waves In Piano Strings, Nikki Etchenique, Samantha Collin, Thomas R. Moore

Student-Faculty Collaborative Research Publications

The existence of longitudinal waves in vibrating piano strings has been previously established, as has their importance in producing the characteristic sound of the piano. Modeling of the coupling between the transverse and longitudinal motion of strings indicates that the amplitude of the longitudinal waves are quadratically related to the transverse displacement of the string, however, experimental verification of this relationship is lacking. In the work reported here this relationship is tested by driving the transverse motion of a piano string at only two frequencies, which simplifies the task of unambiguously identifying the constituent signals. The results indicate that the …

The Physics Of Music Course As An Introduction To Science, Gordon Ramsey

Physics: Faculty Publications and Other Works

Our Physics of Music course is an integration of physics and music. We start with the mathematical structure of music, including scales, harmonies and chords. We discuss musical styles and how they differ. After an introduction of physics concepts, including waves,resonances, forces, energy and fluid flow, the physical structure of instruments in the various groups are studied. Connection is made of the instruments and how they reproduce the mathematical nature of music. Finally, venue acoustics are investigated. The course integrates different styles of learning by integrating different learning modes. The classes include lecture/demonstration, discussion, in-class laboratories and a final individual …

Temperature-Dependent Photoluminescence Of Ge/Si And Ge 1-Ysn Y/Si, Indicating Possible Indirect-To-Direct Bandgap Transition At Lower Sn Content, Mee-Yi Ryu, Thomas R. Harris, Yung Kee Yeo, Richard T. Beeler, John Kouvetakis

Faculty Publications

Temperature (T)-dependent photoluminescence (PL) has been investigated for both p-Ge and n-Ge_1-ySn_y films grown on Si substrates. For the p-Ge, strong direct bandgap (E_D) along with weak indirect bandgap related (E_ID) PL at low temperatures (LTs) and strong E_D PL at room temperature (RT) were observed. In contrast, for the n-Ge_1-ySn_y, very strong dominant E_ID PL at LT and strong E_D PL were observed at RT. This T-dependent PL study indicates that the indirect-to-direct bandgap transitions of Ge_1-ySn …

Experimental Analysis Of Energy-Based Acoustic Arrays For Measurement Of Rocket Noise Fields, Jarom Henry Giraud

Theses and Dissertations

Microphone arrays are useful for measuring acoustic energy quantities (e.g. acoustic intensity) in the near-field of a full-scale solid rocket motor. Proper characterization of a rocket plume as a noise source will allow for more accurate predictions in engineering models that design for protection of structures, payloads and personnel near the rockets. Acoustic intensity and energy density quantities were measured in three rocket noise fields and have shown that the apparent source region of the rocket becomes smaller and moves upstream as frequency increases. Theoretical results accounting for some scattering and finite-difference errors arising in these types of energy-based measurements …

Vector Acoustic Intensity Around A Tuning Fork, Daniel A. Russell, Justin Junell, Daniel O. Ludwigsen

Physics Publications

The acoustic intensity vector field around a tuning fork is investigated. Theory for a longitudinal quadrupole source predicts a well-defined transition between near-field and far-field, with significant circulation of sound energy in the near-field. Vector components of the time-averaged intensity were measured using a two-microphone intensity probe and found to agree well with predictions from theory. The vector intensity map is interpreted, and shown to provide useful information about the near-field of an acoustic source.

Experimental And Numerical Analysis Of Coupling Between Musical Drumheads, Ben Boe

Summer Research

The low frequency vibrations of two-headed musical drums are known to couple. However, little is known regarding the factors that determine the degree of coupling at higher frequencies. In this study the effects that depth, diameter and head tension have on the tendency of the drumheads to couple are investigated. Commercial finite element software was used to model a wide range of drums and to identify trends of coupling according to these factors. The numerical results were used to guide which parameters should be tested in the lab. Experimentally, two oppositely facing Electronic Speckle-Pattern Interferometry systems were used to optically …

High-Frequency Rapid B-Mode Ultrasound Imaging For Real-Time Monitoring Of Lesion Formation And Gas Body Activity During High-Intensity Focused Ultrasound Ablation, Madhu Sudhan Reddy Gudur, Ronald Kumon, Yun Zhou, Cheri X. Deng

Physics Publications

Abstract:

The goal of this study was to examine the ability of high-frame-rate, high-resolution imaging to monitor tissue necrosis and gas-body activities formed during high-intensity focused ultrasound (HIFU) application. Ex vivo porcine cardiac tissue specimens (n = 24) were treated with HIFU exposure (4.33 MHz, 77 to 130 Hz pulse repetition frequency (PRF), 25 to 50% duty cycle, 0.2 to 1 s, 2600 W/cm2). RF data from Bmode ultrasound imaging were obtained before, during, and after HIFU exposure at a frame rate ranging from 77 to 130 Hz using an ultrasound imaging system with a center frequency of 55 MHz. …

Simulating A Guitar With A Conventional Sonometer, Zily Burstein, Christina M. Gower, Gabriele U. Varieschi

Physics Faculty Works

In this paper we present a simple way to convert a conventional sonometer into a simulated fretted instrument, such as a guitar or similar, by adding a fingerboard to the sonometer. In particular, we use this modified apparatus in relation to the problem of the instrument intonation, i.e., how to obtain correctly tuned notes on these string instruments. The experimental procedures presented in this study can become a more structured laboratory activity to be used in general physics courses or acoustics classes.

Acoustic Testing And Modeling: An Advanced Undergraduate Laboratory, Daniel A. Russell, Daniel O. Ludwigsen

Physics Publications

This paper describes an advanced laboratory course in acoustics, specifically targeted for students with an interest in engineering applications at a school with a strongly integrated industrial co-op program. The laboratory course is developed around a three-pronged approach to problem solving that combines and integrates theoretical models, computational models, and experimental data. The course is structured around modules that begin with fundamental concepts and build laboratory skills and expand the knowledge base toward a final project. Students keep a detailed laboratory notebook, write research papers in teams, and must pass laboratory certification exams. This paper describes the course layout and …

On The Measurement Of Angular Dependent Sound Transmission Through Airborne Supercritical Plates, Matthew D. Shaw

Theses and Dissertations

A method of measuring angular dependence of acoustic transmission through supercritical plates in air is discussed. The coincidence effect occurs in a supercritical plate when the component of the acoustic wave number parallel to the plate matches the bending wave number in the plate. The transmission of sound is a maximum at the angle where this trace wave number matching occurs. The theory of the coincidence effect is well-defined for unbounded thin plates using plane-wave excitation. However, experimental results for finite plates are known to diverge from theory, especially near grazing angles. An experimental setup has been developed in order …

Quantifying Multiple Types Of Damping Acting On Bronze-Wound Guitar Strings, Jonathan Christian

Purdue Polytechnic Masters Theses

The goal of this study was to quantify the contributions of multiple damping types acting on guitar strings for each mode over a wide frequency range so that design variables could be identified to one day create frequency based damping in guitar strings. Structural dynamic testing was used to obtain the time-response of a vibrating string in open air and in a vacuum. From this signal, each harmonic was filtered and the decay envelope was curve-fitted with a function that was a linear summation of decay functions. From the curve-fits, the damping coefficients for aerodynamic, friction, and material damping were …