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Articles 661 - 690 of 2906
Full-Text Articles in Physical Sciences and Mathematics
Digitizing Dinosaur National Monument's Carnegie Quarry, Rebecca Esplin
Digitizing Dinosaur National Monument's Carnegie Quarry, Rebecca Esplin
Theses and Dissertations
The Carnegie Quarry in northeastern Utah is world-renowned for the dinosaur skeletons it has produced and for its in situ display of dinosaur bones. The specimens excavated at Carnegie Quarry are displayed and curated in 20 repositories, most in North America. Data on these specimens in the forms of notes, photographs, publications, field maps, and so on, are scattered in an array of formats and institutions. The primary goal of this thesis is to develop a database linking these data with a digital map (GIS system) to make them readily accessible. To this end, a relational database was created using …
Machine Learning To Discover And Optimize Materials, Conrad Waldhar Rosenbrock
Machine Learning To Discover And Optimize Materials, Conrad Waldhar Rosenbrock
Theses and Dissertations
For centuries, scientists have dreamed of creating materials by design. Rather than discovery by accident, bespoke materials could be tailored to fulfill specific technological needs. Quantum theory and computational methods are essentially equal to the task, and computational power is the new bottleneck. Machine learning has the potential to solve that problem by approximating material behavior at multiple length scales. A full end-to-end solution must allow us to approximate the quantum mechanics, microstructure and engineering tasks well enough to be predictive in the real world. In this dissertation, I present algorithms and methodology to address some of these problems at …
A Coverage Metric To Aid In Testing Multi-Agent Systems, Jane Ostergar Linn
A Coverage Metric To Aid In Testing Multi-Agent Systems, Jane Ostergar Linn
Theses and Dissertations
Models are frequently used to represent complex systems in order to test the systems before they are deployed. Some of the most complicated models are those that represent multi-agent systems (MAS), where there are multiple decision makers. Brahms is an agent-oriented language that models MAS. Three major qualities affect the behavior of these MAS models: workframes that change the state of the system, communication activities that coordinate information between agents, and the schedule of workframes. The primary method to test these models that exists is repeated simulation. Simulation is useful insofar as interesting test cases are used that enable the …
Computational Exploration Of Vortex Nucleation In Type Ii Superconductors Using A Finite Element Method In Ginzburg-Landau Theory, Alden Roy Pack
Computational Exploration Of Vortex Nucleation In Type Ii Superconductors Using A Finite Element Method In Ginzburg-Landau Theory, Alden Roy Pack
Theses and Dissertations
Using a finite element method, we numerically solve the time-dependent Ginzburg-Landau equations of superconductivity to explore vortex nucleation in type II superconductors. We consider a cylindrical geometry and simulate the transition from a superconducting state to a mixed state. Using saddle-node bifurcation theory we evaluate the superheating field for a cylinder. We explore how surface roughness and thermal fluctuations influence vortex nucleation. This allows us to simulate material inhomogeneities that may lead to instabilities in superconducting resonant frequency cavities used in particle accelerators.
Computational Exploration Of Vortex Nucleation In Type Ii Superconductors Using A Finite Element Method In Ginzburg-Landau Theory, Alden Roy Pack
Computational Exploration Of Vortex Nucleation In Type Ii Superconductors Using A Finite Element Method In Ginzburg-Landau Theory, Alden Roy Pack
Theses and Dissertations
Using a finite element method, we numerically solve the time-dependent Ginzburg-Landau equations of superconductivity to explore vortex nucleation in type II superconductors. We consider a cylindrical geometry and simulate the transition from a superconducting state to a mixed state. Using saddle-node bifurcation theory we evaluate the superheating field for a cylinder. We explore how surface roughness and thermal fluctuations influence vortex nucleation. This allows us to simulate material inhomogeneities that may lead to instabilities in superconducting resonant frequency cavities used in particle accelerators.
Capacity Of Human Immunodeficiency Virus Targeting Chimeric Antigen Receptor T Cells To Eliminate Follicular Dendritic Cells Bearing Human Immunodeficiency Virus Immune Complexes, Matthew T. Ollerton
Capacity Of Human Immunodeficiency Virus Targeting Chimeric Antigen Receptor T Cells To Eliminate Follicular Dendritic Cells Bearing Human Immunodeficiency Virus Immune Complexes, Matthew T. Ollerton
Theses and Dissertations
An important obstacle to a functional cure for HIV/AIDS is the persistence of viral reservoirs found throughout the body in various cells and tissues. Reservoirs can be latently infected cells, or in the case of follicular dendritic cells (FDC), non-infected cells that trap infectious virus on their surface through immune complexes (HIV-IC). Although several strategies have been employed to target and eliminate viral reservoirs, they are short-lived and ineffective. In an attempt to provide a long-term approach, chimeric antigen receptor T (CAR-T) cells were designed to eliminate native HIV on FDCs. Although effective at eliminating HIV-infected cells, and halting spreading …
Bare Aluminum Oxidation, R. Steven Turley
Bare Aluminum Oxidation, R. Steven Turley
Faculty Publications
This paper computes the oxidation rate of bare evaporated aluminum thin films under high vacuum conditions and exposed to air.
40Ar/39Ar Ages, Compositions, And Likely Source Of The Eocene Fallout Tuffs In The Duchesne River Formation, Northeastern Utah, Michael Seth Jensen
40Ar/39Ar Ages, Compositions, And Likely Source Of The Eocene Fallout Tuffs In The Duchesne River Formation, Northeastern Utah, Michael Seth Jensen
Theses and Dissertations
Thin fallout tuffs in the Duchesne River Formation in the Uinta Basin, Utah are evidence that volcanism was active in northern Nevada and Utah in the late Eocene. The Uinta Basin is a sedimentary basin that formed during the Laramide orogeny. Ponded lakes of various salinity filled and emptied and during the late Eocene the northern rim was dominated by a wetland/floodplain depositional setting. Most of the tuffs have rhyolitic mineral assemblages including quartz, biotite, sanidine, and allanite. Rhyolitic glass shards were also found in one of the ash beds. Biotite compositions have Fe/(Fe+Mg) ratios typical of calc-alkaline igneous rocks …
40ar/39ar Ages, Compositions, And Likely Source Of The Eocene Fallout Tuffs In The Duchesne River Formation, Northeastern Utah, Michael Seth Jensen
40ar/39ar Ages, Compositions, And Likely Source Of The Eocene Fallout Tuffs In The Duchesne River Formation, Northeastern Utah, Michael Seth Jensen
Theses and Dissertations
Thin fallout tuffs in the Duchesne River Formation in the Uinta Basin, Utah are evidence that volcanism was active in northern Nevada and Utah in the late Eocene. The Uinta Basin is a sedimentary basin that formed during the Laramide orogeny. Ponded lakes of various salinity filled and emptied and during the late Eocene the northern rim was dominated by a wetland/floodplain depositional setting. Most of the tuffs have rhyolitic mineral assemblages including quartz, biotite, sanidine, and allanite. Rhyolitic glass shards were also found in one of the ash beds. Biotite compositions have Fe/(Fe+Mg) ratios typical of calc-alkaline igneous rocks …
Characterization Of Military Aircraft Jet Noise Using Wavepacket Analysis And Other Array Processing Methods, Blaine M. Harker
Characterization Of Military Aircraft Jet Noise Using Wavepacket Analysis And Other Array Processing Methods, Blaine M. Harker
Theses and Dissertations
Sound generation and radiation properties are studied of full-scale tactical jet engine noise. This is motivated by the high sound exposure levels from jet noise, particularly for tactical engines. Acoustic source reconstruction methods are implemented computationally on existing jet noise data. A comparative study is performed using numerical simulations to understand the capabilities of more advanced beamforming methods to successfully estimate the source properties of a distributed, partially correlated source distribution. The properties and limitations of each beamforming method are described. Having validated the methods, beamforming with regularization”via the Hybrid Method”is implemented on linear array measurements near an installed tactical …
Time Reversed Smoke Simulation, Jeremy Michael Oborn
Time Reversed Smoke Simulation, Jeremy Michael Oborn
Theses and Dissertations
Physics-based fluid simulation often produces unpredictable behavior that is difficult for artists to control. We present a new method for art directing smoke animation using time reversed simulation. Given a final fluid configuration, our method steps backward in time generating a sequence that, when played forward, is visually similar to traditional forward simulations. This will give artists better control by allowing them to start from any timestep of the simulation. We address a number of challenges associated with time reversal including generating a believable final configuration and reversing entropy.
Characterization Of Military Aircraft Jet Noise Using Wavepacket Analysis And Other Array Processing Methods, Blaine M. Harker
Characterization Of Military Aircraft Jet Noise Using Wavepacket Analysis And Other Array Processing Methods, Blaine M. Harker
Theses and Dissertations
Sound generation and radiation properties are studied of full-scale tactical jet engine noise. This is motivated by the high sound exposure levels from jet noise, particularly for tactical engines. Acoustic source reconstruction methods are implemented computationally on existing jet noise data. A comparative study is performed using numerical simulations to understand the capabilities of more advanced beamforming methods to successfully estimate the source properties of a distributed, partially correlated source distribution. The properties and limitations of each beamforming method are described. Having validated the methods, beamforming with regularization—via the Hybrid Method—is implemented on linear array measurements near an installed tactical …
Time Reversed Smoke Simulation, Jeremy Michael Oborn
Time Reversed Smoke Simulation, Jeremy Michael Oborn
Theses and Dissertations
Physics-based fluid simulation often produces unpredictable behavior that is difficultfor artists to control. We present a new method for art directing smoke animation using timereversed simulation. Given a final fluid configuration, our method steps backward in timegenerating a sequence that, when played forward, is visually similar to traditional forwardsimulations. This will give artists better control by allowing them to start from any timestepof the simulation. We address a number of challenges associated with time reversal includinggenerating a believable final configuration and reversing entropy.
Semiconductor Terahertz Electronics And Novel High-Speed Single-Shot Measurements, Parker Dean Salmans
Semiconductor Terahertz Electronics And Novel High-Speed Single-Shot Measurements, Parker Dean Salmans
Theses and Dissertations
Ultrafast spectroscopy is used to study essential characteristics of solid-state materials. We use ultrafast techniques to study semiconductors at THz frequencies, as well as demonstrate new single-shot measurement techniques. The future of electronics is in the THz regime. We study a crucial characteristic of semiconductors used in devices: the critical field at which the material becomes conductive. GaAs is a promising semiconductor for high-speed devices, and we use enhanced THz electric fields to measure the critical fields at 0.7, 0.9, 1.1, and 1.5 THz frequencies. Single-shot spectroscopy is a technique used to measure ultrafast time scale laser pulses. We show …
Evaluating The East Java Tsunami Hazard: What Can Newly-Discovered Imbricate Coastal Boulder Accumulations Near Pacitan And At Pantai Papuma, Indonesia Tell Us?, William Nile Meservy
Evaluating The East Java Tsunami Hazard: What Can Newly-Discovered Imbricate Coastal Boulder Accumulations Near Pacitan And At Pantai Papuma, Indonesia Tell Us?, William Nile Meservy
Theses and Dissertations
Our paleotsunami surveys of the southern Java coast led to the discovery of five imbricate coastal boulder fields near Pacitan, Indonesia that may date to the mid-to-late 19th century or prior and two similar fields at Pantai Papuma and Pantai Pasir Putih that were tsunami-emplaced during the 1994 7.9 Mw event in East Java. Estimated ages for the fields near Pacitan are based on historical records and radiocarbon analyses of coral boulders. The largest imbricated boulders in fields near Pacitan and in East Java are similar in size (approximately 3 m^3) and are primarily composed of platy beachrock dislodged from …
Development And Testing Of The Valence Multipole Model Oh Potential For Use In Molecular Dynamics Simulation, Charles Stephen Andros
Development And Testing Of The Valence Multipole Model Oh Potential For Use In Molecular Dynamics Simulation, Charles Stephen Andros
Theses and Dissertations
Here we describe the fitting and testing, via molecular dynamics simulation, of a bond-order potential for water with a unique force field parameterization. Most potentials for water, including some bond-order (reactive) potentials, are based on a traditional, many-body decomposition to describe water's structure with bond stretch, angle bend, electrostatics, and non-bonded terms. Our model uses an expanded version of the Bond Valence Model, the Valence Multipole Model, to describe all aspects of molecular structure using multibody, bond-order terms. Prior work successfully related these multibody, bond order terms to energy, provided the structures were close to equilibrium. The success of this …
Usable Secure Email Through Short-Lived Keys, Tyler Jay Monson
Usable Secure Email Through Short-Lived Keys, Tyler Jay Monson
Theses and Dissertations
Participants from recent secure email user studies have expressed a need to use secure email tools only a few times a year. At the same time, Internet users are expressing concerns over the permanence of personal information on the Internet. Support for short-lived keys has the potential to address both of these problems. However, the short-lived keys usability and security space is underdeveloped and unexplored. In this thesis, we present an exploration of the short-lived keys usability and security design space. We implement both a short-lived keys and a long-term keys secure email prototype. With these two prototypes, we conduct …
The Human Touch: How Non-Expert Users Perceive, Interpret, And Fix Topic Models, Tak Yeon Lee, Alison Smith, Kevin Seppi, Niklas Elmqvist, Jordan Boyd-Graber, Leah Findlater
The Human Touch: How Non-Expert Users Perceive, Interpret, And Fix Topic Models, Tak Yeon Lee, Alison Smith, Kevin Seppi, Niklas Elmqvist, Jordan Boyd-Graber, Leah Findlater
Faculty Publications
Topic modeling is a common tool for understanding large bodies of text, but is typically provided as a “take it or leave it” proposition. Incorporating human knowledge in unsupervised learning is a promising approach to create high-quality topic models. Existing interactive systems and modeling algorithms support a wide range of refinement operations to express feedback. However, these systems’ interactions are primarily driven by algorithmic convenience, ignoring users who may lack expertise in topic modeling. To better understand how non-expert users understand, assess, and refine topics, we conducted two user studies—an in-person interview study and an online crowdsourced study. These studies …
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 …
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. …
Exploring The Solvability Of The Jaynes-Cummings And Jaynes-Cummings-Like Models: Implementing Quantum Control, Austen Couvertier
Exploring The Solvability Of The Jaynes-Cummings And Jaynes-Cummings-Like Models: Implementing Quantum Control, Austen Couvertier
Student Works
In this paper we aim to explore the dynamics and overall solvability of the Jaynes-Cummings \& Jaynes-Cummings-Like models. As a lens to understand these dynamics, we focused on cases where the parameters of the system were made time-dependent. All previous work on solving the dynamics of the Jaynes-Cummings models has relied heavily on the use of differential methods and setting the parameters as time-independent constants which were zero or one. To account for this, we utilized the Wei-Norman method which allowed us to analytical solve the time-dependent Hamiltonian. Through the use of this method, we can understand the more general …
An Exploration Of Crum’S And Algebraic Crum Detection, Shae Machlus, Branton Campbell
An Exploration Of Crum’S And Algebraic Crum Detection, Shae Machlus, Branton Campbell
Student Works
- The cooperative rigid unit modes (CRUM's) of cubic perovskite were investigated at non-special k-points using ISODISTORT and Shared Shifts Mathematica code. CRUM's were generated by the T4 irrep on the T line which confirms previously published results.
- The solution space of the MtM CRUM detection method was determined and compared to that of the M method. Analysis by example and by theory showed the solution spaces of both methods are identical. MtM was realized to be effectively M with a lower tolerance. An improved row reduction routine is being developed that uses an adaptable ratio-driven tolerance instead of …
Reflectance Of Xuv Light On A Two Dimensional Conducting Rough Surface, Chelsea Thangavelu
Reflectance Of Xuv Light On A Two Dimensional Conducting Rough Surface, Chelsea Thangavelu
Student Works
A Fortran program is set up to solve for the reflectance of XUV light from a rough two dimensional surface, resembling experimental mirrors used to reflect XUV light. Because the roughness of the surface is on the order of magnitude of the wavelength of XUV light, our approach requires a Greene's Function instead of using traditional geometrical optics or physical optics. Our Fortran program calculates the impedance (Z) matrix which requires integration over Greene's Function at non-singular points. The Z matrix helps solve for the induced surface current J(x') at non-singular points. At singular points, the program implements a series …
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 A Location Detector Using Acoustical Energy Quantities, Jacey Young
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 …
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 …
2d Surface Creation Using Intel Mkl, R. Steven Turley
2d Surface Creation Using Intel Mkl, R. Steven Turley
Faculty Publications
This document illustrates how to use the Intel Math Kernel Library (MKL) to create surfaces with a given cut-off spatial frequency and rms surface height. They closely mimic typical surfaces our group has measured using atomic force microscopy (AFM).
Circular Integration Region, R. Steven Turley
Circular Integration Region, R. Steven Turley
Faculty Publications
This report explains how to transform a singular integration over the an arc of a circle into an integration over a unit square using various coordinate transformations include a Duffy transformation. Fortran code illustrating the algorithms is included along with unit test validations.
Using Page Method In The Two Point Method To Determine Sound Power, Christopher Reynolds
Using Page Method In The Two Point Method To Determine Sound Power, Christopher Reynolds
Student Works
Sound power is the energy emitted by a sound source per unit time. It is commonly used by industries to determine the noise (unwanted sound) of machinery. There are multiple recognized standards for determining the sound power of a source. The requirements for the ISO3741 standard are tedious and strict but can produce a low standard of deviation in the results. There is another method, the Two Point method, which less strict than the standards but the standard of deviation in the results vary. This paper discusses the performance of the PAGE method employed in the Two Point method to …
Magnetic Domain Morphology In [Co(4a)/Pt(7a] Thin Film, Jeremy Metzner
Magnetic Domain Morphology In [Co(4a)/Pt(7a] Thin Film, Jeremy Metzner
Student Works
A collection of results for multi-layered thin films and their magnetic domains.