Physical Sciences and Mathematics Commons^™

Geometrization Conditions For Perfect Fluids, Scalar Fields, And Electromagnetic Fields, Charles G. Torre, Dionisios Krongos

Charles G. Torre

Rainich-type conditions giving a spacetime “geometrization” of matter fields in general relativity are reviewed and extended. Three types of matter are considered: perfect fluids, scalar fields, and electromagnetic fields. Necessary and sufficient conditions on a spacetime metric for it to be part of a perfect fluid solution of the Einstein equations are given. Formulas for constructing the fluid from the metric are obtained. All fluid results hold for any spacetime dimension. Geometric conditions on a metric which are necessary and sufficient for it to define a solution of the Einstein-scalar field equations and formulas for constructing the scalar field from …

Rooted In Hell: Predicting Invasion Rates Of Phragmites Australis, Rachel Nydegger, Jacob P. Duncan, James A. Powell

Browse All Undergraduate research

Across the estuaries of the east coast and wetlands of the Great Lakes, the invasive grass Phragmites australis outcompetes other vegetation and destroys local ecosystems. Because its roots are tolerant to salinity that other plants find hellish, Phragmites invasions begin with vegetative spread of genetic clones in brackish marshlands. This plant can grow over three meters tall at densities of 50 stems/m2, provides poor wildlife habitat, and is very difficult to eradicate.

A discrete life stage model on a yearly time step captures seed survivorship in a seed bank, sexual and asexual recruitment into a juvenile age class, and differential …

Horizontal Phase Speed Distribution Of Gravity Waves Observed In Mesospheric Temperature Maps, Ahmad Talaei, Michael J. Taylor, Pierre-Dominique Pautet, Yucheng Zhao, Takashi S. Matsuda, Takuji Nakamura

Graduate Student Posters

The goal of the current work is to develop a method suitable for analyzing the horizontal phase speeds of atmospheric gravity waves from an extensive amount of gravity wave data obtained by the USU Advanced Mesospheric Temperature Mapper (AMTM) from Antarctica. The AMTM is a novel infrared digital imaging system that measures selected emission lines in the mesospheric OH (3,1) band to create intensity and temperature maps of the mesosphere. This analysis builds on the recent work by Matsuda et al 2014 using all-sky intensity data to investigate the horizontal phase speed distribution. In our analyses we applied this technique …

Satellite Measurements Of Mesospheric Gravity Wave Temperature Variances Over The Andes, Jonathan Pugmire, Michael Taylor, Yucheng Zhao, James M. Russell Iii

Graduate Student Posters

Utah State University’s Mesospheric Temperature Mapper (MTM) has operated continuously at the Andes Lidar Observatory on Cerro Pachon, Chile (30.3° S, 70.7° S) since August 2009. Its purpose is to quantify gravity wave (GW) activity as observed in OH rotational temperature measurements in the mesosphere at an altitude of ~87 km with a particular interest in investigating short period GWs and their seasonal variability. 5.5 years data to date.

The SABER instrument aboard the TIMED satellite provides complimentary data to measure temperature variances and GW potential energy (PE) to quantify the small-scale GWs propagating up into the mesosphere, and lower …

Electrical Properties Study Under Electron Beam Of Annealed And Coated Boron Nitride, Kevin Guerch, Thierry Paulmier, Jr Dennison, Justin Dekany, Sophie Guillemet-Fritsch, Pascal Lenormand

Conference Proceedings

The charging and relaxation kinetics of pyrolytic boron nitride (BN) substrates, BN with an aluminium oxide (BN/Al₂O₃) coating, and thermally-annealed alumina-coated boron nitride (an-BN/Al₂O₃) were investigated under low power electron irradiation (5 < E₀ < 20 keV, J_i = 10 nA.cm^-2 at room temperature) in the CEDRE facility at ONERA (Toulouse, France). Surface potentials of each ceramics configuration were measured over time using the Kelvin probe method. The influence of coating and annealing treatments to limit charging is discussed in this paper. A thorough study of a an–BN/Al₂O₃ sample was carried out …

Influence Of Thermal Treatment On Electrical And Physical Properties Of Coated Ceramics, K. Guerch, T. Paulmier, Justin Dekany, Jr Dennison, S. Guillemet-Fritsch, P. Lenormand

Presentations

Technical dielectric materials and ceramics are used in many different high technology industrial areas and especially for spacecraft applications. On satellites, these materials are subjected to extreme conditions due to the space plasma environment. To survive, these ceramic insulators must have exceptional electrical and thermal properties. Boron Nitride (BN) and Aluminum Oxide (Al 2O3) are used in particular because they combine good electrical insulation and high thermal conductivity. However, BN and Al2O3 used in spacecraft interiors are exposed to critical radiation demands, where these insulators are irradiated by electrons with high energies and flux. Charged particles are trapped in the …

Population Trend Of The World’S Monitored Seabirds, 1950-2010, Michelle Paleczny, Edd Hammill, Vasiliki Karpouzi, Daniel Pauly

Watershed Sciences Faculty Publications

Seabird population changes are good indicators of long-term and large-scale change in marine ecosystems, and important because of their many impacts on marine ecosystems. We assessed the population trend of the world’s monitored seabirds (1950–2010) by compiling a global database of seabird population size records and applying multivariate autoregressive state-space (MARSS) modeling to estimate the overall population trend of the portion of the population with sufficient data (i.e., at least five records). This monitored population represented approximately 19% of the global seabird population. We found the monitored portion of the global seabird population to have declined overall by 69.7% between …

Mechanisms Underlying The Prereversal Enhancement Of The Vertical Plasma Drift In The Low-Latitude Ionosphere, J. V. Eccles, J. P. St. Maurice, Robert W. Schunk

All Physics Faculty Publications

The evening prereversal enhancement (PRE) of the vertical plasma drift has important consequences for the Appleton density anomaly and the stability of the nighttime ionosphere. Simplified simulations were used to review the three competing theories of the PRE origin, to explore their relative importance, and to indentify their interdependence. The mechanisms involved in the generation and climatology of the PRE are, first, a curl-free electric field response to rapid changes in the vertical electric field associated with the nighttime F region dynamo; second, a divergence of Hall currents in the E region away from the magnetic equator; and, third, the …

Global Features Of The Disturbance Winds During Storm Time Deduced From Champ Observations, C. Xiong, H. Luhr, B. G. Fejer

All Physics Faculty Publications

A wind-driven disturbance dynamo has been postulated many decades ago. But due to the sparseness of thermospheric wind measurements, details of the phenomena could not be investigated. In this study we use the CHAMP zonal wind observations from 2001 to 2005 to investigate the global features of the disturbance winds during magnetically disturbed periods. The disturbance zonal wind is mainly westward, which increases with magnetic activity and latitude. At subauroral region, the westward zonal wind is strongly enhanced in the magnetic local time (MLT) sector from afternoon to midnight, which we relate to the plasma drift within the subauroral polarization …

Electrical Properties Of Annealed And Coated Boron Nitride Under Electron Beam Irradiation, Kevin Guerch, Thierry Paulmier, Jr Dennison, Justin Dekany, Sophia Guillemet-Fritsch, Pascal Lenormand

Presentations

Technical dielectric materials and ceramics are used in many different high technology industrial areas and especially for spacecraft applications. On satellites, these materials are subjected to extreme conditions due to the space plasma environment. To survive, these ceramic insulators must have exceptional electrical and thermal properties. Boron Nitride (BN) and Aluminum Oxide (Al2O3) are used in particular because they combine good electrical insulation and high thermal conductivity. However, BN and Al2O3 used in spacecraft interiors are exposed to critical radiation demands, where these insulators are irradiated by electrons with high energies and flux. Charged particles are trapped in the ceramics, …

Wolf Diet In An Agricultural Landscape Of North-Eastern Turkey, Claudia Capitani, Mark William Chynoweth, Josip Kusak, Emrah Çoban, Çağan H. Şekercioğlu

Wildland Resources Faculty Publications

In this study, we investigated wolf feeding ecology in Kars province, north-eastern Turkey, by analysing 72 scat samples collected in spring 2013. Ongoing camera trap surveys suggest that large wild ungulates are exceptionally rare in the region. On the contrary, livestock is abundant. Accordingly, scats analysis revealed that livestock constituted most of the biomass intake for wolves, although small mammals were the most frequent prey items. Wild ungulates were occasional prey, and although wolves make use of the main village garbage dump as a food source, garbage remains were scarce in scat samples. Wolf dependence on anthropogenic resources, primarily livestock, …

A Solution In Weyl Gravity With Planar Symmetry, James Thomas Wheeler

James Thomas Wheeler

We solve the Bach equation for Weyl gravity for the case of a static metric with planar symmetry. The solution is not conformal to the solution to the corresponding Einstein equation.

Recolonizing Wolves And Mesopredator Suppression Of Coyotes:Impacts On Pronghorn Population Dynamics, Kim Murray Berger, Mary M. Conner

Wildland Resources Faculty Publications

Food web theory predicts that the loss of large carnivores may contribute toelevated predation rates and, hence, declining prey populations, through the process ofmesopredator release. However, opportunities to test predictions of the mesopredator releasehypothesis are rare, and the extent to which changes in predation rates influence preypopulation dynamics may not be clear due to a lack of demographic information on the preypopulation of interest. We utilized spatial and seasonal heterogeneity in wolf distribution andabundance to evaluate whether mesopredator release of coyotes (Canis latrans), resulting fromthe extirpation of wolves (Canis lupus) throughout much of the United States, contributes tohigh rates of …

Physics Education: Analysis Of The Effects Of I>Clicker Usage In The Gen Ed Classroom On Content Learning, Collin Mortensen

Physics Capstone Projects

The modern classroom has a wide variety of tools and technology available as aids to assist in students’ content area learning. One of these tools which has gained increased popularity recently is the i>clicker, a remote device that allows students to answer questions posed by lecturers through media presentations such as PowerPoint. Lecturers are able to record and display the answers selected by the students in class, providing real-time feedback to students on material lectured on in class.

The goal of this study was to examine the effectiveness of the i>clicker device as an aid in content learning …

Suitability Of Nickel Chromium Wire Cutters As Deployable Release Mechanisms On Cubesats In Low Earth Orbit, James Gardiner

Physics Capstone Projects

This paper investigates the suitability of a nickel chromium wire cutter (NCWC) for use on the GASPACS (Get Away Special Passive Attitude Control Satellite) Mission. It is intended that when activated the NCWC will cut through a restraining wire and thereby release the stored energy of the deployable AeroBoom. Flight worthiness is based on favorable performance during functional testing to address known issues with the NCWC, such as wire burn through and cutting issues. In-depth testing discussed in this paper includes: Manufacturability of the NCWC, including analysis of possible acceptable performance errors induced from inefficiencies in the assembly process, functional …

Managing The Spread Of Alfalfa Stem Nematodes Ditylenchus Dipsaci: The Relationship Between Crop Rotation And Pest Re-Emergence, Scott Jordan

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Alfalfa is a critical cash/rotation crop in the western region of the United States, where it is common to find crops affected by the alfalfa stem nematode (Ditylenchus dipsaci). Understanding the spread dynamics associated with this pest would allow end-users to design better management programs and farming practices. This is of particular importance given that there are no nematicides available against alfalfa stem nematode and control strategies largely rely on crop rotation to non-host crops or by planting resistant varieties. I present a basic host-parasite model that describes the spread of the alfalfa stem nematode on alfalfa crops. With this …

Factors Related To Successful Completion Of Developmental Mathematics Courses, Jason Bagley

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The goal of this research was to identify factors that contribute to students’ achievement in developmental math courses. This research collected information on several factors which have been suggested to have an effect on student achievement, particularly in developmental math courses at Utah State University, and analyzed their effects on student achievement. The literature review identified several factors that appeared related to student achievement, but many of these studies only analyzed a few factors. Very few studies have tried to analyze multiple variables together to try and identify which factors contribute most to student achievement and which observations can be …

Advancement Of Computing On Large Datasets Via Parallel Computing And Cyberinfrastructure, Ahmet Artu Yildirim

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Large datasets require high processing power to compute, high-speed network connections to transmit, or high storage capacity to archive. With the advent of the internet, many in the science community and the public at large are faced with a need to manage, store, transmit and process large datasets in an efficient fashion to create value for all concerned. By example, large environmental researchers analyze large map data to extract hydrologic information from topography. However, processing these data and other tasks is hard – sometimes impossible – in minimal resource environments such as desktop systems.

This dissertation demonstrates novel approaches and …

Cultural Entropy: A Grounded Theory Study Of Early Childhood Experiences In Nature In The Arroyo Grande Creek Watershed, Nathaniel Miles Millard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Through support from a Quinney Fellowship and the Institute of Outdoor Recreation and Tourism in the Department of Environment and Society at Utah State University, the theory of cultural entropy emerged as an explanation for changing behavior across generations of people living in the Arroyo Grande Creek watershed. Through a trounded theory methodology data collection around early childhood experiences with nature leading towards positive civic engagement with the community, the theory of cultural entropy emerged along with a policy recommendation for reconnecting the community to the local watershed.

Lifelong residents participating in the research were found to have high levels …

The Role Of Thermospheric Neutral Winds In The Mid-Latitude Ionospheric Evening Anomalies, Levan Lomidze

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Earth's ionosphere, which is the ionized part of the upper atmosphere, plays a very important role in ground- and satellite-based radio communication and navigation. During the last half century, a considerable experimental, theoretical, and modeling effort has been directed towards understanding the physical processes that affect the variation of the ionization in the ionosphere at various spatial and temporal scales. Even though tremendous progress has been made in many directions of ionospheric research, many questions remain to be answered.

One of the intriguing features in the ionosphere is an anomalous evening enhancement that occurs over certain mid-latitude locations, where …

Geochemical Characterization Of The Mountain Home Geothermal System, Trevor Alex Atkinson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Mountain Home (MH) geothermal system of the western Snake River Plain (SRP) magmatic province was discovered in 2012 by the Snake River Geothermal Drilling Project. Artesian flowing water with a temperature of 150°C was encountered at a depth of 1745 m below ground surface (mbgs) and extensive mineralized fracture networks of pectolite-prehnite, calcite, and laumontite were discovered in the recovered core. The objectives of this study are to: 1) describe the thermal and compositional history of past geothermal fluids, and 2) compare these fluids to modern fluids in order to characterize the evolution of the MH geothermal system and …

Explicit Construction Of First Integrals For The Toda Flow On A Classical Simple Lie Algebra, Patrick Seegmiller

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Toda flow is a generalization of a dynamical system describing the interaction of particles in a one-dimensional crystal. The concepts and energy and conservation are prominent in the study of dynamical systems, and quantities which remain the same over the evolution of a system provide valuable insights into the system’s behavior. In the realm of mathematics these quantities are called first integrals, or integrals of motion. This paper provides a background for study of the Toda flow, a verification of its integrability, and programming code for finding these quantities which remain unchanged over the evolution of the system.

Optical Characterization Of Carbon Nanotube Forests, Brian D. Wood

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Carbon nanotube forests are vertically grown tubular formations of graphene. Due to their inherent microstructure and geometry, they are ideal light absorbers over a broad spectrum, making this material an excellent absorber in applications such as radiometry, optical calibration, and stray light suppression. Samples were made with several growth conditions and substrates to provide forests of different morphologies. Optical data of these samples were gathered by taking spectroscopic reflectance and transmittance measurements in the mid-infrared spectral range. Results were correlated to the various forest morphologies. From this, the conditions necessary to maximize the absorption of the forests were found and …

Improving Reuse Of Distributed Transaction Software With Transaction-Aware Aspects, Anas Ahmad Alsobeh

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Implementing crosscutting concerns for transactions is difficult, even using Aspect-Oriented Programming Languages (AOPLs) such as AspectJ. Many of these challenges arise because the context of a transaction-related crosscutting concern consists of loosely-coupled abstractions like dynamically-generated identifiers, timestamps, and tentative value sets of distributed resources. Current AOPLs do not provide joinpoints and pointcuts for weaving advice into high-level abstractions or contexts, like transaction contexts. Other challenges stem from the essential complexity in the nature of the data, operations on the data, or the volume of data, and accidental complexity comes from the way that the problem is being solved, even using …

Great Salt Lake Past And Present: Elevation And Salinity Changes To Utah's Great Salt Lake From Railroad Causeway Alterations, James S. White

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Utah's Great Salt Lake contributes and estimated $1.3 billion to the local and regional economy and is a vital food-source for migratory and resident birds. In 1959, the lake was fundamentally changed with construction of an earth-filled, semi-permeable railroad causeway which splits the lake into two "arms". The only flow interaction between these two arms is through the semi-permeable causeway material, and three openings in the causeway. In 2013, two of these causeway openings were closed, and a bridge was proposed to improve flow between arms. Four bridge designs were proposed. I modeled Great Salt Lake water and salt distribution …

Analytical Comparison Of Bovine Parentage Single Nucleotide Polymorphisms, Joshua Jeffrey Dallin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Often on cattle operations and dairy farms, where multiple bulls are exposed to cows either by live cover or artificial insemination, error can be present in parentage record keeping for breed registries or production use. Research has evolved to the integration of using single nucleotide polymorphisms (SNPs) to answer questions where cases of unknown parentage may exist. With the evolution of the research, differentiated panels have been created specifically for parentage analysis. Our objective was to complete an analytical comparison between two specific panels, a proven 88 parentage SNP panel and a recently developed 25 SNP panel. A smaller panel …

Computational Prediction And Rational Design Of Novel Clusters, Nanoparticles, And Solid State Materials, Alexander S. Ivanov

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The prediction of structure at the atomic level is one of the most fundamental challenges in materials science. Indeed, the structure is arguably the most important piece of information about a material, as it determines pretty much all properties of a material. Knowing the structure, one can analyze a large number of properties of a material, even before it is synthesized – the crucial importance of structure prediction for computational molecular design. This dissertation describes the technique of reliable theoretical predictions and presents the results on the successfully predicted unusual clusters, nanoparticles and solid state materials. The major part of …

Synthesis Of Fluorogenic Probes For Studying Biomass Degradation And Synthesis Of New Antifungal Aminoglycosides, Qian Zhang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

For the first project, a library of fifteen commercially purchased and synthetic fluorogenic probes were employed for the investigation of biomass degradation using extract of white-rot fungi. These discoveries prove that it is possible to employ fungi for selective degradation or release of hemicelluloses from biomass. This work is supported by Sun Grant Western Regional Center/DOT "Bioprospecting for Enzymes to Break Lignin-Hemicellulose Bond" ($300,000,09/01/2011-08/31/2013)

The second project is focused on synthesizing new aminoglycoside analogs and exploring the potential to revive traditional antibacterial kanamycin as new type of antifungal agents. Although aminoglycosides antibiotics are mainly used as antibacterial agents, this project …

The Onion Name System: Tor-Powered Distributed Dns For Tor Hidden Services, Jesse Victors

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Tor network is a third-generation onion router that aims to provide private and anonymous Internet access to its users. In recent years its userbase, network, and community have grown significantly in response to revelations of national and global electronic surveillance, and it remains one of the most popular anonymity networks in use today. Tor also provides access to anonymous servers known as hidden services – servers of unknown location and ownership that may provide websites, chat services, or an electronic dead drop. These hidden services can be accessed through any Tor-powered web browser but they suffer from usability challenges …

A Chronostratigraphic Record Of Arroyo Entrenchment And Aggradation In Kanab Creek, Southern Utah, Kirk F. Townsend

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study is to explore the processes that lead to the formation of arroyos. Arroyos are entrenched stream channels with steep sides that form by incision into valley-fill sediment, and are common features throughout the southwest United States. Many of these systems formed during the late AD 1800s and early 1900s in one of the most significant historic geomorphic events in the region. At this time, former river floodplains were abandoned, creating terraces. This caused a decline in local water tables and associated changes in stream discharge, vegetative communities, and the ability to irrigate once fertile floodplains. …