Physical Sciences and Mathematics Commons^™

Tissue Mimicking Materials For Multi-Modality Breast Phantoms, G. Fiaschetti, Jacinta Browne, M. Cavagnaro, L. Farina, G. Ruvio

Conference Papers

The paper proposes two different Tissue Mimicking Material (TMM) techniques for the development of breast phantoms which are suitable for multi-modality imaging. In particular, the focus is on the behavior of dielectric and acoustic properties when fat, sodium chloride and sugar are added to the mixtures.

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 …

Validating Sidescan Sonar As A Fish Survey Tool Over Artificial Reefs, Michael A. Bollinger, Richard J. Kline

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Visual observation methods via SCUBA are commonly used to survey artificial reef fish, although conditions in the Gulf of Mexico often make surveys difficult or even dangerous for divers. In this study, sidescan sonar was used to quantify water-column fish abundance and was compared to the established visual observation methods on SCUBA over four reef sites. Calibrated intensity values measured from sidescan sonar echo returns were used to estimate fish body length and to calculate scaled biomass (g/m2 reef) from a pooled fish length–weight relationship of commonly observed reef fish in the area. Sidescan sonar methods were equivalent to SCUBA …

Acoustic And Seismic Fields Of Hydraulic Jumps At Varying Froude Numbers, Timothy J. Ronan, Jonathan M. Lees, T. Dylan Mikesell, Jacob F. Anderson, Jeffrey B. Johnson

Geosciences Faculty Publications and Presentations

Mechanisms that produce seismic and acoustic wavefields near rivers are poorly understood because of a lack of observations relating temporally dependent river conditions to the near-river seismoacoustic fields. This controlled study at the Harry W. Morrison Dam (HWMD) on the Boise River, Idaho, explores how temporal variation in fluvial systems affects surrounding acoustic and seismic fields. Adjusting the configuration of the HWMD changed the river bathymetry and therefore the form of the standing wave below the dam. The HWMD was adjusted to generate four distinct wave regimes that were parameterized through their dimensionless Froude numbers (Fr) and …

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 …

A Multibeam Bathymetric Investigation Of Changes In Bedform Morphology Of The Little River Inlet As A Result Of Hurricane Matthew, Malarie O'Brien

Honors Theses

A hybrid scholarly-research paper on the use of multibeam sonar data in seafloor mapping and seafloor analysis was written to satisfy Honors Program requirements. Literature review of multibeam sonar technology explored the improving concept of mapping the seafloor via acoustic methods. The review also investigated improvements and applications of multibeam data analysis techniques, which have the ability to map the seafloor as well as characterize the seafloor by morphology or sediment content. The review then explored previous studies conducted on the Little River Inlet, SC, finding the inlet to be particularly understudied in the field of sediment morphology. Three multibeam …

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.

Theoretical And Experimental Investigation Of A Quadspectral Nonlinearity Indicator, Kyle Glen Miller

Theses and Dissertations

Understanding the impact of jet noise and other high-amplitude sound sources can be improved by quantifying the nonlinearity in a signal with a single-microphone measurement. An ensemble-averaged, frequency-domain version of the generalized Burgers equation has been used to derive a quantitative expression for the change in spectral levels (in decibels) over distance due to geometric spreading, thermoviscous absorption, and nonlinearity, respectively. The nonlinearity indicator, called νN , is based on the quadspectral Morfey-Howell indicator, which has been used in the past to characterize nonlinearity in noise waveforms. Unlike the Morfey-Howell indicator, the νN indicator has direct physical significance, giving a …

Sediment Supply Versus Local Hydraulic Controls On Sediment Transport And Storage In A River With Large Sediment Loads, David J. Dean, David J. Topping, John C. Schmidt, Ronald E. Griffiths, Thomas A. Sabol

Watershed Sciences Faculty Publications

The Rio Grande in the Big Bend region of Texas, USA, and Chihuahua and Coahuila, Mexico, undergoes rapid geomorphic changes as a result of its large sediment supply and variable hydrology; thus, it is a useful natural laboratory to investigate the relative importance of flow strength and sediment supply in controlling alluvial channel change. We analyzed a suite of sediment transport and geomorphic data to determine the cumulative influence of different flood types on changing channel form. In this study, physically based analyses suggest that channel change in the Rio Grande is controlled by both changes in flow strength and …

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 …

Is Heyser Still Relevant?, Douglas R. Jones

Douglas R Jones

The author, highlighting excerpts from the writings of Richard C. Heyser, argues that Heyser continues to be relevant in the field of audio engineering nearly three decades after his death. Using material from the Richard C. Heyser Collection, held in the Columbia College Chicago Archives & Special Collections, the author chose comments from the collection, both published and unpublished "which should be at least intriguing and possibly down right shocking."

On Some Recent Experimental Results Concerning Turbulent Coanda Wall Jets, Caroline P. Lubert

Department of Mathematics and Statistics - Faculty Scholarship

The Coanda effect is the tendency of a stream of fluid to stay attached to a convex surface, rather than follow a straight line in its original direction. As a result, in such jets mixing takes place between the jet and the ambient air as soon as the jet issues from its exit nozzle, causing air to be entrained. This air-jet mixture adheres to the nearby surface. Whilst devices employing the Coanda effect usually offer substantial flow deflection, and enhanced turbulence levels and entrainment compared with conventional jet flows, these prospective advantages are generally accompanied by significant disadvantages including a …

Mapping Thunder Sources By Inverting Acoustic And Electromagnetic Observations, J. F. Anderson, J. B. Johnson, R. O. Arechiga, R. J. Thomas

Geosciences Faculty Publications and Presentations

We present a new method of locating current flow in lightning strikes by inversion of thunder recordings constrained by Lightning Mapping Array observations. First, radio frequency (RF) pulses are connected to reconstruct conductive channels created by leaders. Then, acoustic signals that would be produced by current flow through each channel are forward modeled. The recorded thunder is considered to consist of a weighted superposition of these acoustic signals. We calculate the posterior distribution of acoustic source energy for each channel with a Markov Chain Monte Carlo inversion that fits power envelopes of modeled and recorded thunder; these results show which …

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 …

Observational And Theoretical Investigation Of Cylindrical Line Source Blast Theory Using Meteors, Elizabeth A. Silber

Electronic Thesis and Dissertation Repository

During their passage through the atmosphere meteoroids produce a hypersonic shock which may be recorded at the ground in the form of infrasound. The first objective of this project was to use global infrasound measurements to estimate the influx of large (meter/decameter) objects to Earth and investigate which parameters of their ablation and disruption can be determined using infrasound records. A second objective was to evaluate and extend existing cylindrical line source blast theory for meteoroids by combining new observations with earlier analytical models, and validate these against centimetre-sized optical meteor observations.

The annual terrestrial influx of large meteoroids (kinetic …

Inverse Methods For Sound Speed Estimation In The Ocean, Tao Lin

Dissertations

This dissertation presents theoretical and computational approaches for estimating sound-speed in the ocean under different conditions. The first part of the dissertation discusses a fast approach for solving the inverse problem of estimating sediment sound-speed based on the Deift-Trubowitz trace formula. Under certain assumptions, this algorithm can recover the sound speed profile in the seabed using pressure field measurements in the water column at low frequencies. The inversion algorithm requires solving a non-linear integral equation. In the past, Stickler and Zhou employed a first order Born approximation for solving the integral equation. This work introduces two new methods. The first …

Interpretation Of Biological Activity Using An Acoustic Backscatter Sensor (Abs), Courtney Elliton

Honors Theses

Acoustics aid in the description of complex processes, such as the suspension of sand particles exposed to local hydrodynamic forces above a rippled bed (Cacchione, et al., 2008). Acoustic data can be applied to several aspects of the marine environment such as marine chemistry, biology, geology, and ecology. The acoustic data collected in this study was part of a larger, grant-funded project that focused on sediment transport and settlement preference on two offshore hardbottoms following beach renourishment along the heavily developed coast in northeastern South Carolina. Acoustic data collection was used in the larger project to describe changes in sediment …

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 …