Physical Sciences and Mathematics Commons^™

Relative Selection Strength: Quantifying Effectsize In Habitat- And Step-Selection Inference, Tal Avgar, Subhash R. Lele, Jonah L. Keim, Mark S. Boyce

Wildland Resources Faculty Publications

Habitat-selection analysis lacks an appropriate measure of the ecological significance of the statistical estimates-a practical interpretation of the magnitude of the selection coefficients. There is a need for a standard approach that allows relating the strength of selection to a change in habitat conditions across space, a quantification of the estimated effect size that can be compared both within and across studies. We offer a solution, based on the epidemiological risk ratio, which we term the relative selection strength (RSS). For a "used-available" design with an exponential selection function, the RSS provides an appropriate interpretation of the magnitude of the …

Usu Space Environment Effects Materials Test Facility Flyer, Jr Dennison

Posters

No abstract provided.

Piping Water From Rural Counties To Fuel Growth In Las Vegas, Nevada: Water Transfer Risks In The Arid Usa West, Lisa Welsh, Joanna Endter-Wada

Environment and Society Faculty Publications

The Southern Nevada Water Authority (SNWA) plans to build a 300-mile pipeline to transfer groundwater from five rural basins in north-eastern Nevada south to the greater Las Vegas metropolitan area. Relying on the path dependence literature, we trace the policy choices and legal battles that have led to southern Nevada’s proposed Groundwater Development Project. We find that policy decisions over time, often initiated by powerful water policy entrepreneurs, have fuelled southern Nevada’s rapid growth and development. After emphasising water demand management for more than two decades, SNWA has revived its controversial plans to increase water supplies by importing water from …

The Relationship Between Species Richness And Ecosystem Variability Is Shaped By The Mechanism Of Coexistence, Andrew T. Tredennick, Peter B. Adler, Frederick R. Adler

Wildland Resources Faculty Publications

Theory relating species richness to ecosystem variability typically ignores the potential for environmental variability to promote species coexistence. Failure to account for fluctuation-dependent coexistence may explain deviations from the expected negative diversity–ecosystem variability relationship, and limits our ability to predict the consequences of increases in environmental variability. We use a consumer-resource model to explore how coexistence via the temporal storage effect and relative nonlinearity affects ecosystem variability. We show that a positive, rather than negative, diversity–ecosystem variability relationship is possible when ecosystem function is sampled across a natural gradient in environmental variability and diversity. We also show how fluctuation-dependent coexistence …

Physiological Health Parameters Among College Students To Promote Chronic Disease Prevention And Health Promotion, David R. Black, Daniel C. Coster, Samantha R. Paige

Mathematics and Statistics Faculty Publications

This study aimed to provide physiologic health risk parameters by gender and age among college students enrolled in a U.S. Midwestern University to promote chronic disease prevention and ameliorate health. A total of 2615 college students between 18 and 25 years old were recruited annually using a series of cross-sectional designs during the spring semester over an 8-year period. Physiologic parameters measured included body mass index (BMI), percentage body fat (%BF), blood serum cholesterol (BSC), and systolic (SBP) and diastolic (DBP) blood pressure. These measures were compared to data from NHANES to identify differences in physiologic parameters among 18-25 year …

Rayleigh-Lidar Observations Of Mid-Latitude Mesospheric Densities, Brandon S. Hustead, Lucas R. Priskos, Jonathan L. Price, Joshua P. Herron

Physics Capstone Projects

This research is an analysis of absolute densities throughout the mesosphere (45 km to 90 km). Although much research has gone into the study of temperatures and their variations occurring in our atmosphere, little has been done to research the densities and their variations. Due to the remoteness of the middle atmosphere there is a high degree of difficulty in making observations in the mesosphere. There are currently three major types of ground-based instruments used to sense the mesosphere remotely. They are atmospheric radars, LIDARs and optical spectrometers. As far as measuring density in the mesosphere LIDAR is the most …

The Use Of Plenoptic Cameras In Astronomy, James R. Hamilton

Physics Capstone Projects

Since light-field imaging cameras are starting to become more in the world today, the question that arises is, “Could these cameras help advance the science when they are used in conjunction with telescopes and microscopes?” With their use in microscopy having been partially settled and no information about their use with telescopes, this experiment was setup to start the ascertainment of the use of light-field imaging cameras with telescopes. With the use of an older plenoptic camera, it was ascertained that a new light-field imaging camera might compare with the conventional digital camera of today.

Effects Of Temperature And Radiation Dose On Radiation Induced Conductivity, Jr Dennison

Presentations

No abstract provided.

Effects Of Temperature And Radiation Dose On Radiation Induced Conductivity, Jr Dennison

Presentations

Radiation induced conductivity (RIC) is an important conduction mechanism in highly disordered insulating materials exposed to ionizing radiation. Measurements of RIC as a function of dose rate and exposure time of polymeric and glassy insulators will be presented. RIC results from excitation of carriers into conduction states by the ionizing radiation. The measurements will be discussed in terms of models for the distribution of localized disordered states. The effects of temperature and radiation damage from ionizing radiation on the density and occupation of trap states, and how this affects RIC, will also be discussed.

Wormholes: Gates To The Stars?, Samuel Shreeve

Physics Capstone Projects

One of the most consistently fascinating results of Albert Einstein’s theory of general relativity is the prediction of wormholes – astronomical objects which are, among other things, capable of serving as a connection between two distant regions of space. The simplest class of wormholes are Schwarzschild wormholes – wormholes that behave as non-rotating, non-charged black holes, except that the event horizon serves as a connection to another wormhole elsewhere, instead of a point of no return.

This research presentation analyzes the attributes that make a Schwarzschild wormhole unsuitable for human travel, and examines the conditions that would have to hold …

Arduino And Raspberry Pi In A Laboratory Setting, Dustin Johnston

Physics Capstone Projects

The purpose of this research project was to study the use of Arduino and Raspberry Pi’s and investigate the practicality of integrating them into the intermediate and advance laboratory classes. After purchasing diverse types of sensors to use with Arduino and Raspberry Pi, the sensors were then performance tested. The types of sensors that were characterized were an accelerometer, altimeter, barometric pressure, gyroscopic, humidity, magnetic, temperature, and vibrational sensors. Using this analysis, the existing labs can be upgraded and their manuals can be updated and improved to use these sensors where appropriate. This will allow students to learn valuable programming …

Rayleigh-Lidar Observations Of Mesospheric Densities, Lucas R. Priskos, Brandon S. Hustead, Jonathan L. Price, Joshua P. Herron

Physics Capstone Projects

The goal of this project is to take relative densities of the mesosphere (altitude 45-90 km) from data that has been collected and convert them into absolute densities. It is then possible to look at how these densities vary with altitude and season. The data was collected using a Rayleigh-scatter LIDAR at the Atmospheric LIDAR Observatory. This is a part of the Center for Atmospheric and Space Sciences and is located on the Utah State University Campus. It spans a total of 11 years beginning in 1993 and ending in 2004. The collected data is used to create a composite …

Investigating The Weddell Sea Anomaly Using Tie-Gcm, Daesean K. Jones

Physics Capstone Projects

The ionosphere is a region of Earth’s upper atmosphere that is embedded in the thermosphere and parts of the exosphere and mesosphere. The ionosphere is a layer of electrons and electrically charged atoms and molecules that are created by atmospheric absorption of solar radiation. It is subdivided into many layers but for this report, only the F-layer will be of interest. In the F-layer, extreme ultraviolet (EUV) solar radiation ionizes atomic oxygen and in this layer, an intriguing feature occurs. This feature involves an anomalous evening phenomenon over a fixed geographic location, where the electron density during the nighttime is …

Enhanced Test Facility For Survivability And Characterization Of Evolving Multiscale Materials In Extreme Plasma Environments, Jr Dennison

Posters

No abstract provided.

Tilt Classifications In Perfect Fluid Cosmology, Bryant Ward

Physics Capstone Projects

We classify all known perfect fluid cosmological solutions of the Einstein equations according to whether they are tilted or non-tilted. A non-tilted universe will have observers who see a homogeneous, isotropic universe with matter at rest with respect to them. A tilted universe will have observers who see matter moving relative to them. These classifications are useful when considering fluid models of the universe in that the Hubble parameter and expansion are observer dependent and can be different in a tilted versus a non-tilted universe. This gives more insight when fitting these models with observations of our real universe. We …

Hemispherical Grid Retarding Field Analyzer Redesign For Secondary Electron Emission Studies, Greg Wilson, Jr Dennison

Conference Proceedings

A redesign of the Hemispherical Grid Retarding Field Analyzer is discussed in relationship to multilayer charging models. In order to accurately extend single layer charging models to dynamic multilayer scenarios, precise measurements of electron emission as well as the net surface potential must be made. By learning from the previous design and thinking of future applications, the new instrument will greatly enhance our ability to precisely measure materials undergoing energetic electron bombardment.

Of Mice And Materials: Payoffs Of Unsgc Research Infrastructure Awards, Jr Dennison, Kent Hartley, Lisa Phillipps, Justin Dekany, Robert H. Johnson, James S. Dyer

Presentations

A versatile test facility has been designed and built to study space environments effects on small satellites and system components. Testing for potentially environmental-induced modifications of small satellites is critical to avoid possible deleterious or catastrophic effects over the duration of space mission. This is increasingly more important as small satellite programs have longer mission lifetimes, expand to more harsh environments (such as polar or geosynchronous orbits), make more diverse and sensitive measurements, minimize shielding to reduce mass, and utilize more compact and sensitive electronics (often including untested off-the-shelf components). The vacuum chamber described here is particularly well suited for …

Of Mice And Materials: Payoffs Of Unsgc Research Infrastructure Awards, Jr Dennison

Presentations

No abstract provided.

Hemispherical Grid Retarding Field Analyzer Redesign For Secondary Electron Emission Studies, Greg Wilson, Jr Dennison

Presentations

A redesign of the Hemispherical Grid Retarding Field Analyzer is discussed in relationship to multilayer charging models. In order to accurately extend single layer charging models to dynamic multilayer scenarios, precise measurements of electron emission as well as the net surface potential must be made. By learning from the previous design and thinking of future applications, the new instrument will greatly enhance our ability to precisely measure materials undergoing energetic electron bombardment.

Reducing The Contact Time Of Bouncing Droplets Using Macro-Textured Surfaces, Andrew Merritt

Physics Capstone Projects

This study was designed to investigate the possibility of using visible surface features to decrease the amount of time a droplet remains in contact with a hydrophobic surface. Hydrophobic and superhydrophobic surfaces have long been a focus for scientists studying fluids. However, a majority of studies have focused on surfaces with hydrophobic properties rooted in their chemical makeup or other features invisible to the naked eye. In this study, the contact reduction induced by a simple needle protruding from a hydrophobic surface is investigated.

Uv Degradation Of Polycarbonate, Katie Gamaunt

Physics Capstone Projects

The decrease in visible and ultraviolet transmission spectra of polymeric and glass spacecraft materials has been measured to determine the extent of degradation due to high-energy UV radiation similar to the solar spectrum (both above and below the stratosphere, which is where most of the UV radiation is absorbed). This project looked at the effects that the atmosphere has in regards to blocking UV radiation and thus, slowing down the UV degradation process. A polycarbonate sample was exposed to radiation from a focused high intensity deuterium lamp source, which generates radiation in the UVA and UVB spectrum. A particularly severe …

Explorations In Hybrid Rocket Technology: Arc-Track Ignition In 3d-Printed Rockets, Richard Harvey

Physics Capstone Projects

A new rocket ignition mechanism developed at Utah State University, arc-track ignition, is very promising, but its underlying physics are poorly understood. An engineering/physics joint team was formed to investigate the process and suggest avenues for improvement of the technology. The objectives of the team evolved over the course of seven months of research. By the nature of this approach, understanding was extended in many ways, but few results were conclusive.

Two accomplishments overshadow the others: the discovery of a new arc-track ignition method, and cataloging of materials compatible with arc-track ignition technology. Thin film arc-track ignition has the promise …

Community Supported Agriculture At Indian Creek Nature Center's Sugar Grove Farm: Sustainable Farming For Iowa, Erin Anzalone

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

Agriculture is the largest revenue source for the state of Iowa and the state’s two priority crops are corn and soybeans. Farming practices that emphasize monoculture production of these crops can reduce biological diversity and habitat for all-important pollinators, and exacerbate runoff and erosion that sends nutrient-rich soil, herbicides, and pesticides into streams and rivers. The industrial agriculture model is lucrative now, but unsustainable for Iowa over the long run. Sugar Grove Farm, a subset of Indian Creek Nature Center (ICNC), plans to grow a variety of food crops on a large-scale, economically sustainable farm, and support low-income households in …

Management Of Predators, Prey, And Aviation Safety At Naval Air Station Patuxent River, Maryland: Can Coyotes Help Reduce Deer Strike Hazards?, Robert Lewis

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

In the past 100 years, coyotes (Canis latrans) have expanded their range eastward. During their expansion, coyotes hybridized with gray wolves (Canis lupus) in the north and red wolves (Canis rufus) in the south. Coyotes were historically occupants of the plains, but now may be found in environments as varied as the sagebrush steppe, deserts, swamps, and inner cities. St. Mary’s County, MD, home to Naval Air Station Patuxent River (Pax River), was one of the last counties in the country to be colonized by coyotes. Pax River is a research and development/flight test and evaluation center, and houses numerous …

Comparison Of Survival Curves Between Cox Proportional Hazards, Random Forests, And Conditional Inference Forests In Survival Analysis, Brandon Weathers

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

Survival analysis methods are a mainstay of the biomedical fields but are finding increasing use in other disciplines including finance and engineering. A widely used tool in survival analysis is the Cox proportional hazards regression model. For this model, all the predicted survivor curves have the same basic shape, which may not be a good approximation to reality. In contrast the Random Survival Forests does not make the proportional hazards assumption and has the flexibility to model survivor curves that are of quite different shapes for different groups of subjects. We applied both techniques to a number of publicly available …

(Uranium-Thorium)/Helium Thermochronologic Constraints On Secondary Iron-Oxide Mineralization In Southwestern New Mexico, Michael Channer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Southwestern New Mexico experienced protracted volcanism from ~60 Ma to 500 ka and associated epithermal mineralization. We apply hematite (U-Th)/He (hematite He) thermochronology to fracture-hosted hematite in the Lordsburg Mining District to resolve the timing of mineralization related to hydrothermal fluid circulation. We interpret hematite He dates with integrated field and structural observations, scanning electron microscopy to characterize hematite texture and grain size distribution, and zircon U-Pb and zircon (U-Th)/He (zircon He) chronology to constrain the timing of host rock formation and the ambient low-temperature thermal history, respectively. Undeformed hematite fills fractures cut a brecciated rhyolite and preserve open voids. …

To What Extent Might Beaver Dam Building Buffer Water Storage Losses Associated With A Declining Snowpack?, Konrad Hafen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Dams built by North American Beaver create natural water storage and slow water as it moves through streams. In portions of streams with beaver dams, these effects have been observed to decrease the peak magnitude of floods and increase base flow during annual summer droughts. In the western United States changes to streamflow patterns have been observed in recent decades with large spring floods coming earlier in the year, causing annual summer droughts to start earlier and last longer. These changes are linked to decreasing snowpack which acts as the most significant natural water storage reservoir by holding onto precipitation …

Inventory, Assessment And Preliminary Management Planning For Utah's Sovereign Land Along The Bear River, Matthew Coombs

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

ABSTRACT

Inventory, Assessment and Preliminary Management Planning for

Utah’s Sovereign Land along the Bear River

by

Matthew S. Coombs

Master of Science in Bioregional Planning

Utah State University, 2017

Major Professor: Richard E. Toth

Department: Environment and Society

The Utah Division of Forestry, Fire and State Lands (FFSL) is responsible for the management of state-owned sovereign land in Utah, which includes the bed and banks of the Bear River in Cache and Box Elder Counties. The purpose of this project is to provide relevant background information and data to support the future development of a comprehensive management plan for the …

A Comparison Of Statistical Methods Relating Pairwise Distance To A Binary Subject-Level Covariate, Rachael Stone

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

A community ecologist provided a motivating data set involving a certain animal species with two behavior groups, along with a pairwise genetic distance matrix among individuals. Many community ecologists have analyzed similar data sets with a method known as the Hopkins method, testing for an association between the subject-level covariate (behavior group) and the pairwise distance. This community ecologist wanted to know if they used the Hopkins method, would their results be meaningful? Their question inspired this thesis work, where a different data set was used for confidentiality reasons. Multiple methods (Hopkins method, ADONIS, ANOSIM, and Distance Regression) were used …

Image Segmentation Using De-Textured Images, Yaswanth Kodavali

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

Image segmentation is one of the fundamental problems in computer vision. The outputs of segmentation are used to extract regions of interest and carry out identification or classification tasks. For these tasks to be reliable, segmentation has to be made more reliable. Although there are exceptionally well-built algorithms available today, they perform poorly in many instances by producing over-merged (combining many unrelated objects) or under-merged (one object appeared as many) results. This leads to far fewer or more segments than expected. Such problems primarily arise due to varying textures within a single object and/or common textures near borders of adjacent …