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Articles 1 - 7 of 7

Full-Text Articles in Physics

Shaping Carbon Nanotube Forests For Field Emission, Benjamin Pound Apr 2014

Shaping Carbon Nanotube Forests For Field Emission, Benjamin Pound

Student Showcase

Field emission is a phenomenon where electrons are extracted from a conducting material by an external electric field. This effect has been used for electron sources for many applications, from electron microscopes to flat-panel displays. One undesirable feature of field emitters is that they often require high turn-on voltages. One way to improve the field emission is to decrease the tip size. In previous works, single carbon nanotubes (CNTs) with nanometer tip sizes have been used as field emitters, and have achieved currents comparable or higher than commercial field emitters at relatively low operating voltages. However, the single CNT field ...


Overtone Analysis Of A Holtkamp Organ Using Fourier Methods, Mario Harper, David Berg Apr 2013

Overtone Analysis Of A Holtkamp Organ Using Fourier Methods, Mario Harper, David Berg

Student Showcase

This research is a study of the similarities and differences of the four sound families (principal, flute, reed, and string) of the organ, specifically, we used the organ located in the Kent Hall at USU. This experiment focuses on the mechanics of the organ, turning sound into mathematical signals, and performing Fourier analysis using computer methods. We conclude that a certain family of pipes (flute pipe family) had the most similarities to the “natural” series while the reed family was the most variant. We show the steps taken in our experiment and attempt to explain the variance and correlation of ...


Functionalizing Carbon Nanotube Forests, Ben Pound, F. K. Shen Apr 2013

Functionalizing Carbon Nanotube Forests, Ben Pound, F. K. Shen

Student Showcase

A carbon nanotube forest is an array of carbon nanotubes vertically aligned and entangled. Because the aspect ratio of each tube can be more than 1000, the forest will greatly increase the number of potential binding sites on the surface for chemical and biological detector applications, if each bundle of tubes can be functionalized with specific molecules. The 1,5-diaminoaphthalene can be a versatile linker molecule for proteins. In this study, we characterize the concentration of 1,5-diaminoaphthalene in solvent by fluorescence spectroscopy. It appears, however, that the solvent collapses the carbon nanotube forest, resulting in no detectable fluorescence emission ...


Resolving Ionospheric E-Region Modeling Challenges: The Solar Photon Flux Dependence, Joseph B. Jensen, Jan J. Sojka, Michael David, Kent Tobiska, Robert W. Schunk, Tom Woods, Frank Eparvier Apr 2013

Resolving Ionospheric E-Region Modeling Challenges: The Solar Photon Flux Dependence, Joseph B. Jensen, Jan J. Sojka, Michael David, Kent Tobiska, Robert W. Schunk, Tom Woods, Frank Eparvier

Student Showcase

No abstract provided.


Simulation Chamber For Space Environment Survivability Testing, Robert H. Johnson, Lisa D. Montierth Apr 2013

Simulation Chamber For Space Environment Survivability Testing, Robert H. Johnson, Lisa D. Montierth

Student Showcase

A vacuum chamber was designed and built that simulates the space environment making possible the testing of material modification due to exposure of solar radiation. Critical environmental components required include an ultra high vacuum (10-9 Torr), a UV/VIS/NIR solar spectrum source, an electron gun and charge plasma, temperature extremes, and long exposure duration. To simulate the solar spectrum, a solar simulator was attached to the chamber with a range of 200nm to 2000nm. The exposure time can be accelerated by scaling the solar intensity up to four suns. A Krypton lamp imitates the 120 nm ultraviolet hydrogen Lymann ...


Galaxy Inclination And Surface Brightness, Jordan C. Rozum, Shane L. Larson Jan 2013

Galaxy Inclination And Surface Brightness, Jordan C. Rozum, Shane L. Larson

Student Showcase

The distribution of spiral and bar galaxy inclination angles is expected to be uniform. However, analysis of several major galaxy catalogs shows this is not the case; galaxies oriented near edge-on are significantly more common in these catalogs. In an attempt to explain this discrepancy, we have developed a galaxy simulation code to compute the appearance of a spiral type galaxy as a function of its morphological parameters. We examine the dependence of observed brightness upon inclination angle by using smooth luminous mass density and interstellar medium (ISM) density distributions. The luminous mass component is integrated along a particular line ...


Micrometeoroid From Misse Examined To Understand The Effects Of The Space Environment On Space Suit Materials, Kelby T. Peterson Apr 2012

Micrometeoroid From Misse Examined To Understand The Effects Of The Space Environment On Space Suit Materials, Kelby T. Peterson

Student Showcase

Samples that were part of the Materials International Space Station Experiment (MISSE) experienced varying effects whilst exposed to the space environment; perhaps the most intriguing effect was the crater created by a micrometeoroid impact into a thin film of Vapor Deposited Aluminum (VDA) coated Mylar. Approximately 180 samples of various materials used in space-component design were flown on MISSE-6 and spent 18 months suspended off the side of the International Space Station. The Utah State University SUSpECS project was a unique student experiment that allowed for pre- and post-flight analysis of these material samples which were returned in pristine condition ...