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Full-Text Articles in Other Physics

Plant Root Hair Adhesion Mediated Through Variation In Sodium Ion Concentration, Natasha Mulenga Jan 2024

Plant Root Hair Adhesion Mediated Through Variation In Sodium Ion Concentration, Natasha Mulenga

Honors Program Theses

This study investigates the effects of sodium ion (Na+) concentration on the adhesion of Brassica Rapa root hairs using atomic force microscopy (AFM). Plant root hair adhesion to soil particles plays a crucial role in anchoring plants and facilitating nutrient uptake. Previous research has shown that calcium ions (Ca2+) cross-link pectin molecules in the cell wall, increasing rigidity and reducing adhesion. As Na+ binds to pectin without cross-linking, we expected that root hairs exposed to sodium chloride (NaCl) solutions would exhibit longer adhesive interactions and similar binding forces compared to those exposed to calcium chloride (CaCl2) solutions of equal concentrations. …


The Origins Of Phantom Partials In The Piano, Lauren M. Neldner Jan 2020

The Origins Of Phantom Partials In The Piano, Lauren M. Neldner

Honors Program Theses

Phantom partials are anomalous frequency components identifiable in the sound of the piano and occur at the sum and difference frequencies of two overtones. For several decades they have been identified as crucial components to the sound of the piano and assumed to be generated by the forced longitudinal motion of the string. Recent work has identified that contrary to common belief, most of the power is produced in the non-string components with the most likely source being the wooden structural components. This work presents experimental results for two plausible theories that could explain the origins of phantom partials in …


The Singing Cymbal: Is It Really Photon Momentum?, Thomas R. Moore, Samantha Collin, Nikki Etchenique Apr 2016

The Singing Cymbal: Is It Really Photon Momentum?, Thomas R. Moore, Samantha Collin, Nikki Etchenique

Student-Faculty Collaborative Research Publications

A simple demonstration that is occasionally used in the classroom to show that light carries momentum involves making an orchestral cymbal audibly ring using light from a common photoflash. A metal plate or a piece of foil can also be used, however, it appears that many people use a cymbal because the sound is easily heard at a reasonable distance. It is such an impressive example of the effects attributable to photon momentum that it is posted on the CERN website for educational under the name “singing cymbal.” Although it is an impressive demonstration, a series of simple classroom experiments …


Axial Vibrations Of Brass Wind Instrument Bells And Their Acoustical Influence: Theory And Simulations, Wilfried Kausel, Vasileios Chatziioannou, Thomas R. Moore, Britta R. Gorman, Michelle Rokni Jun 2015

Axial Vibrations Of Brass Wind Instrument Bells And Their Acoustical Influence: Theory And Simulations, Wilfried Kausel, Vasileios Chatziioannou, Thomas R. Moore, Britta R. Gorman, Michelle Rokni

Student-Faculty Collaborative Research Publications

Previous work has demonstrated that structural vibrations of brass wind instruments can audibly affect the radiated sound. Furthermore, these broadband effects are not explainable by assuming perfect coincidence of the frequency of elliptical structural modes with air column resonances. In this work a mechanism is proposed that has the potential to explain the broadband influences of structural vibrations on acoustical characteristics such as input impedance, transfer function, and radiated sound. The proposed mechanism involves the coupling of axial bell vibrations to the internal air column. The acoustical effects of such axial bell vibrations have been studied by extending an existing …


Normal Modes Of A Small Gamelan Gong, Robert Perrin, Daniel Elford, Luke Chambers, Gerry M. Swallowe, Thomas R. Moore, Sinin Hamdan, Benjamin J. Halkon Jan 2014

Normal Modes Of A Small Gamelan Gong, Robert Perrin, Daniel Elford, Luke Chambers, Gerry M. Swallowe, Thomas R. Moore, Sinin Hamdan, Benjamin J. Halkon

Faculty Publications

Studies have been made of the normal modes of a 20.7 cm diameter steel gamelan gong. A finite-element model has been constructed and its predictions for normal modes compared with experimental results obtained using electronic speckle pattern interferometry. Agreement was reasonable in view of the lack of precision in the manufacture of the instrument. The results agree with expectations for an axially symmetric system subject to small symmetry breaking. The extent to which the results obey Chladni's law is discussed. Comparison with vibrational and acoustical spectra enabled the identification of the small number of modes responsible for the sound output …


A Simple And Inexpensive Optical Technique To Help Students Visualize Mode Shapes, Thomas R. Moore, Ashley E. Cannaday, Sarah A. Zietlow Mar 2012

A Simple And Inexpensive Optical Technique To Help Students Visualize Mode Shapes, Thomas R. Moore, Ashley E. Cannaday, Sarah A. Zietlow

Student-Faculty Collaborative Research Publications

An imaging technique is introduced that is suitable for visualizing the mode shapes of vibrating structures in an educational setting. The method produces images similar to those obtained using electronic speckle pattern interferometry (ESPI) but it can be implemented for less than 1=10 the cost of a commercial ESPI system, and the apparatus is simple enough that it can be constructed by undergraduate students. This technique allows for real-time visualization of the normal modes and detection shapes of harmonically vibrating structures, including those with shapes that make generating Chladni patterns with sand or powder impossible. The theory of operation and …


Normal Modes Of The Indian Elephant Bell, Robert Perrin, Luke Chalmers, Daniel Elford, Gerry M. Swallowe, Thomas R. Moore Mar 2012

Normal Modes Of The Indian Elephant Bell, Robert Perrin, Luke Chalmers, Daniel Elford, Gerry M. Swallowe, Thomas R. Moore

Faculty Publications

The geometrical structure of the Indian elephant bell is presented and the requirements on its normal modes from group representation theory are described. These are in good agreement with the results of a finiteelement model (FEM) for a specific 16-tine case. The spectrum consists of a sequence of families of modes lying on saturation curves and so is completely different from those of conventional bells. Physical explanations for the occurrence of these families are presented in terms of the tines behaving as a closed loop of coupled cantilevers with constraints from the dome. Each family is found to consist of …


Modeling The Magnetic Pickup Of An Electric Guitar, Nicholas G. Horton, Thomas R. Moore Feb 2009

Modeling The Magnetic Pickup Of An Electric Guitar, Nicholas G. Horton, Thomas R. Moore

Student-Faculty Collaborative Research Publications

The magnetic pickup of an electric guitar uses electromagnetic induction to convert the motion of a ferromagnetic guitar string into an electrical signal. Although the magnetic pickup is often cited as an everyday application of Faraday's law, few sources mention the distortion that the pickup generates when converting string motion into an electric signal, and even fewer attempt to analyze and explain this distortion. By modeling the magnet and ferromagnetic wire as surfaces with magnetic charge, an intuitive model that accurately predicts the output of a magnetic guitar pickup can be constructed. More
importantly, this model can be understood and …


A Simple Design For An Electronic Speckle Pattern Interferometer, Thomas R. Moore Sep 2004

A Simple Design For An Electronic Speckle Pattern Interferometer, Thomas R. Moore

Faculty Publications

An electronic speckle pattern interferometer suitable for use in an undergraduate laboratory is described. This interferometer can be built for a small fraction of the cost of a commercial version and is simple and inexpensive to build and understand. The interferometer is useful for visualizing the normal modes of vibrating objects as well as changes in index of refraction.