Physical Sciences and Mathematics Commons^™

Assessing Beaver Dam Dynamics In The Logan-Little Bear Watershed, Connor Penrod

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

This paper seeks to address a knowledge gap concerning how flood events impact beaver dams over time. To address this gap, I took four time-snapshots of beaver dams, mapping them across the Utah portion of the Logan-Little Bear watershed, from 2009 to 2016 to bookend a large flood event in 2011. I assessed dam status (intact, breached, or blown out) for each dam mapped to assess the impact of the large spring runoff on the dam status. Assessing dam status over time allowed me to assess the change in condition over time, from before to several years after, while also …

Water Entry Of Spheres At Various Contact Angles, Nathan B. Spiers, Mohammad M. Mansoor, Jesse Belden, Tadd T. Truscott

Mechanical and Aerospace Engineering Faculty Publications

It is well known that the water entry of a sphere causes cavity formation above a critical impact velocity as a function of the solid-liquid contact angle (Duez et al. 2007). Using a rough sphere with a contact angle of 120^◦, Aristoff & Bush (2009) showed that there are four different cavity shapes dependent on the Bond and Weber numbers (i.e., quasi-static, shallow, deep and surface). We experimentally alter the Bond number, Weber number and contact angle of smooth spheres and find two key additions to the literature: 1) Cavity shape also depends on the contact angle; 2) …

Investigations Into Factors Affecting The Wpd-Loop In The Protein Tyrosine Phosphatases Yoph And Ptp1b, Gwendolyn Moise

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The research in this dissertation documents connections between the primary amino acid sequence of proteins, the dynamics of proteins, and their catalytic function. This research project studied two proteins called protein-tyrosine phosphatases (PTPs): the human enzyme PTP1B, and the bacterial enzyme YopH. PTP1B is a human enzyme that down regulates the insulin receptor on the outer cellular membrane, and causes the insulin receptor to be less responsive to insulin. A deeper knowledge of how PTP1B is different from other human PTPs might be useful in designing drugs to increase insulin sensitivity in diabetics. Yersinia Pestis is the bacteria that caused …

The Effect Of Warmer Winters On The Demography Of An Outbreak Insect Is Hidden By Intraspecific Competition, Devin W. Goodsman, Guenchik Grosklos, Brian H. Aukema, Caroline Whitehouse, Katherine P. Bleiker, Nate G. Mcdowell, Richard S. Middleton, Chonggang Xu

Mathematics and Statistics Faculty Publications

Warmer climates are predicted to increase bark beetle outbreak frequency, severity, and range. Even in favorable climates, however, outbreaks can decelerate due to resource limitation, which necessitates the inclusion of competition for limited resources in analyses of climatic effects on populations. We evaluated several hypotheses of how climate impacts mountain pine beetle reproduction using an extensive 9‐year dataset, in which nearly 10,000 trees were sampled across a region of approximately 90,000 km², that was recently invaded by the mountain pine beetle in Alberta, Canada. Our analysis supports the hypothesis of a positive effect of warmer winter temperatures on …

Longitudinal Thermal And Solute Dynamics In Regulated Rivers, Muhammad Rezaul Haider

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Dam releases increase river stage and can reverse groundwater movement into and out of the river. As the flood, thermal, and solute waves travel downstream in a regulated river, the size of the waves is anticipated to be affected both by river processes and exchanges with near river groundwater. This study established a modeling framework to quantify the influences of the groundwater exchanges on the temperatures and solute concentration dynamics along regulated rivers. The wave properties, volume of exchanges, conservative solute mass exchanges, and heat energy exchanges were calculated as a function of time and distance downstream. Results show that …

Significant Impacts Of Radiation Physics In The Wrf Model On The Precipitation And Dynamics Of The West African Monsoon, R. Li, J. Jin, Shih-Yu (Simon) Wang, R. R. Gillies

Plants, Soils, and Climate Faculty Publications

Precipitation from the West African Monsoon (WAM) provides food security and supports the economy in the region. As a consequence of the intrinsic complexities of the WAM’s evolution, accurate simulations of the WAM and its precipitation regime, through the application of regional climate models, are challenging. We used the coupled Weather Research and Forecasting (WRF) and Community Land Model (CLM) to explore impacts of radiation physics on the precipitation and dynamics of the WAM. Our results indicate that the radiation physics schemes not only produce biases in radiation fluxes impacting radiative forcing, but more importantly, result in large bias in …

Information Flow In The Spatiotemporal Dynamics Of Cellular Automata, Akshay Thakre

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

Decision making in natural systems, such as the body's immune response to a potential pathogen or a bacterial colony's initiation of fruiting due to food scarcity, is distributed over many cells that posses only local information, and not determined globally. Understanding how accurate decisions can be made in such systems where no individual decisions maker has complete information has important implications in distributed software and can provide insights into the biological evolution of complexity. In this work, the process of distributed decision making is modeled using the majority problem in cellular automata, and information theoretic measures of Kolmogorov complexity are …

Assessing North American Influenza Dynamics With Hierarchical Spatio-Temporal Models, Jessica Anderson

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

We present a general statistical modeling framework to characterize continental-level influenza dynamics in the United States for the purposes of examining state-level epidemiological sources and sinks. The methods we describe depend directly on state-level influenza data that are updated weekly and available on the internet. Advances in search engine query analysis have provided powerful new tools for collecting epidemiological data and, when used in conjunction with sophisticated statistical models, allow for the identification and quantification of the flow of influenza across the continental United States. Our proposed methods, when conditioned on this comprehensive search query product, can provide unprecedented scientific …

Charge Dynamics In Highly Insulating Space Craft Materials, Alec Sim, John R. Dennison

All Physics Faculty Publications

We present a preliminary report on the theoretical and experimental study of transport models in highly insulating materials. The report is developed in four sections; first we give background on the nature of the problems in space craft charging, the contributions and connections made by the Utah State material physics group. Second we discuss the density of states to explore the connections between material composition and the microscopic and macroscopic transport equations. Third from Maxwell’s equations we present an overview of the transport equations. Finally we present preliminary results using experimental data on KaptonTM, the transport equations and relevant expressions …

Dynamics Of Spatial Pattern Formation: Cases Of Spikes And Droplets, Yuya Sasaki

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis studies the gradient system that forms spatial patterns such that the minimum distances of pairs among various points are maximized in the end. As this problem innately involves singularity issues, an extended system of the gradient system is proposed. Motivated by the spatial pattern suggested by a numerical example, this extended system is applied to a three-point problem and then to a two-point problem in a quotient space of ℝ² modulo a lattice.

Soil Organic Carbon Dynamics Along A Climatic Gradient In A Southern Appalachian Spruce-Fir Forest, C. E. Tewksbury, H. Van Miegroet

Watershed Sciences Faculty Publications

A field study was conducted in a high-elevation spruce–fir (Picea rubens Sarg. – Abies fraseri (Pursh.) Poir) forest in the Great Smoky Mountains National Park to assess the effect of temperature on soil C storage and dynamics. In eight plots along an elevation gradient (1500–1900 m), we measured soil temperature, forest floor and mineral soil C, litter decomposition, soil respiration, and forest floor mean residence time. Mean annual soil temperature and annual degree-days above 5 °C were inversely correlated with elevation. Total soil C (166–241 Mg·ha–1) showed no trend with elevation, while forest floor C accumulation (16.3–35.9 Mg·ha–1) decreased significantly …

A Multi-Diagnostic Investigation Of Mesospheric Bore Phenomenon, S. M. Smith, Michael J. Taylor, G. R. Swenson, C. Y. She, W. Hocking, J. Baumgardner, M. Mendillo

All Physics Faculty Publications

Imaging measurements of a bright wave event in the nighttime mesosphere were made on 14 November 1999 at two sites separated by over 500 km in the southwestern United States. The event was characterized by a sharp onset of a series of extensive wavefronts that propagated across the entire sky. The waves were easily visible to the naked eye, and the entire event was observed for at least 5 1 2 hours. The event was observed using three wide-angle imaging systems located at the Boston University field station at McDonald Observatory (MDO), Fort Davis, Texas, and the Starfire Optical Range …

River Meandering Dynamics, Boyd F. Edwards, D. H. Smith

All Physics Faculty Publications

The Ikeda, Parker, and Sawai river meandering model is reexamined using a physical approach employing an explicit equation of motion. For periodic river shapes as seen from above, a cross-stream surface elevation gradient creates a velocity shear that is responsible for the decay of small-wavelength meander bends, whereas secondary currents in the plane perpendicular to the downstream direction are responsible for the growth of large-wavelength bends. A decay length D=H/2C_f involving the river depth H and the friction coefficient C_f sets the scale for meandering, giving the downstream distance required for the fluid velocity profile to recover from …

Fourth Siam Conference On Applications Of Dynamical Systems, Siam Activity Group On Dynamical Systems

All U.S. Government Documents (Utah Regional Depository)

No abstract provided.

The Role Of Diffusion In The Binding Of Carbon Monoxide To Protoheme In High-Viscosity Solvents, David Peak

All Physics Faculty Publications

Studies of the flash photolysis of heme‐bearing proteins have often assessed the role of ligand diffusion in very approximate ways and a disagreement about the importance of ligand diffusion exists in the literature as a result. This paper provides a somewhat more sytematic analysis of diffusional effects than has been given previously for the simple case of ligand–protoheme binding. The model developed here is fit to the available data for the ligand CO in glycerol–water solvents. The fit suggests that diffusional motions become important for the kinetics of this system for temperatures below 270 K and that these motions are …

Population Dynamics And Harvest Of Canada Geese In Utah, John Tautin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A twenty-one year (1952-72) accumulation of banding data for Canada geese in Utah was studied to determine the distribution and chronology of the harvest of the geese and the effects that hunting regulations have had upon harvests and population parameters. The banding data were also used in an attempt to develop a population model capable of predicting population trends and desirable survival rates.

Within Utah, the bulk of the annual harvest (78 percent) takes place in the northern portion of the State in the vicinity of the Great Salt Lake marshes. In Northern Utah the harvest peaks on the opening …