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Articles 1 - 12 of 12
Full-Text Articles in Physical Sciences and Mathematics
Oxidization Of Al And A-Si As A Protective Layer, Yhoshua Wug
Oxidization Of Al And A-Si As A Protective Layer, Yhoshua Wug
Student Works
Arguably, the best chance to produce a IR-optical-UV-EUV mirror for a future space observatory is a multilayer mirror coated by a thin bare aluminum layer. Using an Al layer presents challenges that have to be overcome first. Al oxidizes rapidly as soon as it comes in contact with the atmosphere. One solution is to block the oxidation of Al by covering the mirror with a protective layer and remove it once the mirror is in space. freshly, deposited a-Si would be a good candidate for protecting the mirror. Removing it in space also presents some challenges. The best way to …
Observing Kelt Candidate Objects In The Search For Transiting Exoplanets, Maria Martinez
Observing Kelt Candidate Objects In The Search For Transiting Exoplanets, Maria Martinez
Student Works
The main goal of this project was to learn how to participate and be a part of a real observational team. We worked with the KELT exoplanet search project. While working with the KELT project we hoped to be able to confirm a candidate object as a planet. However, trying to discover a transiting planet was not our main goal for the summer. In addition, we also set out to learn how to work in an observatory, operate telescopes, and process data. The different objects we observed throughout the summer were not all determined to be transiting exoplanets, but we …
Developing Instrumentation For Fabricating And Characterizing Thin Film Aluminum Mirrors, P. Claire Segura
Developing Instrumentation For Fabricating And Characterizing Thin Film Aluminum Mirrors, P. Claire Segura
Student Works
The best material for constructing a mirror for a broad-bandwidth telescope that is also capable of reflecting EUV light is pure aluminum. In order to test how the reflectance of aluminum in the EUV range changes as it oxidizes, a system has been constructed that allows a thin aluminum mirror to be constructed inside of a vacuum, where its reflectance can then be tested immediately. Because the experiment must take place in a vacuum, it must also be controlled remotely through a computer program, which manages the mirror fabrication process as well as the collection and analysis of reflectance data. …
Differential Photometry Of High Mass X-Ray Binaries And Be Stars And Determining Standard Stars, Anne Blackwell
Differential Photometry Of High Mass X-Ray Binaries And Be Stars And Determining Standard Stars, Anne Blackwell
Student Works
Building off of the previously established Hα index (Joner & Hintz 2015), I use differential photometry to study high mass x-ray binaries and Be stars using the Hα index to define their level of activity. Specifically I focused of Cygnus X-1 and X Perseus. I took data on Cygnus X-1 (X Perseus will be studied later in the year) to look at its long and short term activity. Data analyzed using differential photometry is merged with previously collected spectroscopic data to show a seamless flow of results between techniques. I also defined the Hα values of 10 stars in the …
Quantum Dot Band Gap Measurements, John Ryan Peterson
Quantum Dot Band Gap Measurements, John Ryan Peterson
Student Works
This presentation was given during the summer of 2016 as part of the BYU REU program funded by the NSF. Here I give a brief explanation of our quantum dot synthesis as well as explain the use of absorption spectroscopy to measure indirect band gap energies of semiconductors. Our experimental setup is shown and recent improvements are explained. We report indirect band gaps of quantum dots containing varying amounts of cobalt oxide and manganese oxide and synthesized in the protein ferritin. The data show that the band gap can be tuned arbitrarily in a certain range by varying the concentrations …
Determining The Index Of Refraction Of Aluminum Fluoride In The Ultra Violet Spectrum, Zoe Hughes
Determining The Index Of Refraction Of Aluminum Fluoride In The Ultra Violet Spectrum, Zoe Hughes
Student Works
A NASA project called Large UV/Optical/Infrared Surveyor (LUVOIR) is looking into ways to coat a mirror for a new space telescope. We contributed to this project by investigating aluminum fluoride (AlF3) as a possible coating for the mirror. We measured the index of refraction of AlF3 in the wavelength range 6 – 49.5 nm by testing three sample mirrors, each made up of a silicon wafer with a coating of AlF3. We took data at the Advanced Light Source (ALS) in Berkeley, California and in the laboratory at Brigham Young University (BYU). There are discrepancies …
Direct Band Gap Measurements, John Ryan Peterson
Direct Band Gap Measurements, John Ryan Peterson
Student Works
This presentation was given during the summer of 2016 as part of the BYU REU program funded by the NSF. Here I give a brief explanation of our quantum dot synthesis and then explain the mechanism of photoluminsecence used to measure indirect band gap energies of semiconductors. Our experimental setup is shown. Direct band gaps of lead sulfide quantum dots synthesized in ferritin are reported. The data show that the band gap can be tuned arbitrarily in a certain range by varying the concentrations of the reactants. We compare stability of quantum dots in ferritin to quantum dots synthesized without …
Performance Of Phase And Amplitude Gradient Estimator Method For Calculating Energy Quantities In A Plane-Wave Tube Environment, Daxton A. Hawks
Performance Of Phase And Amplitude Gradient Estimator Method For Calculating Energy Quantities In A Plane-Wave Tube Environment, Daxton A. Hawks
Student Works
Acoustic intensity, energy densities, and impedance are useful quantities when considering sound fields. Calculating these energy quantities relies on measurements of acoustic pressure and particle velocity. Pressure and particle velocity can be directly measured, but direct measurements of particle velocity are difficult to make, and are normally inaccurate. A more common and effective way to find particle velocity is to estimate it using pressure measurements from two closely-spaced microphones. The traditional way of estimating particle velocity is severely limited by frequency. The PAGE method, developed at Brigham Young University, extends the frequency bandwidth at which accurate estimations can be made. …
Daxton Hawks Reu Prospectus, Daxton A. Hawks
Daxton Hawks Reu Prospectus, Daxton A. Hawks
Student Works
The purpose of my research is to investigate the ability of the PAGE method to improve the frequency bandwidth of calculations of energy-based quantities from multiple pressure microphones. I will accomplish this by investigating sound waves in both plane-wave and standing-wave environments. I will compare the PAGE method calculations for Ia, Ir, Ep, Ek, and Z to those of traditional and analytical expressions, based on careful ambient condition monitoring. Quantifying the bandwidth extension of the PAGE method for these energy-based quantities will lay a foundation for further application.
Preventing Oxidation Of Aluminum Films With Cadmium Of Zinc Barriers, Spencer B. Perry
Preventing Oxidation Of Aluminum Films With Cadmium Of Zinc Barriers, Spencer B. Perry
Student Works
The planned Large UV/Optical/Near-infrared Telescope (LUVOIR) is expected to launch sometime in the 2030s if NASA surveys recommend LUVOIR over several other projects in early developmental stages [1]. As the project title suggests, the proposed telescope would include large mirrors (between 8 and 16 meters) as part of the orbiting reflector telescope. My research focused on the preparation of aluminum mirrors with zinc or cadmium barrier layers that were designed to prevent oxidation of the aluminum.
Finding The First Stars, Eli D. Mcarthur
Finding The First Stars, Eli D. Mcarthur
Student Works
Minor perturbations resulting from a brief period of inflation at the time of the universe's birth seeded the growth of all structure in the universe. Using Enzo, a research code optimized for running cosmological simulations, we simulate the formation of the universe. We take into account the most current cosmological parameters and plot star formation rates of the universe for halos of varying mass from the beginning of time until today. By simulating star formation of the early universe, we verify that initially minuscule dark matter pockets resulting from inflationary perturbations attract more and more matter as the universe expands. …
Microfabrication With Smooth, Thin Cnt/Polymer Composite Sheets, Nathan Edward Boyer
Microfabrication With Smooth, Thin Cnt/Polymer Composite Sheets, Nathan Edward Boyer
Student Works
Carbon nanotube (CNT)/polymer composite sheets can be extremely high strength and lightweight, which makes them attractive for fabrication of mechanical structures. This thesis demonstrates a method whereby smooth, thin CNT/polymer composite sheets can be fabricated and patterned on the microscale using a process of photolithography and plasma etching. CNT/polymer composites were made from CNTs grown using chemical vapor deposition using supported catalyst growth and floating catalyst growth. The composite sheets had a roughness of approximately 30nm and were about 61¼m or 261¼m depending on whether they were made from supported catalyst grown or floating catalyst grown CNTs. The composites were …