Digital Commons Network^™

Axisymmetric Finite Element Modeling Of Adhesive Joint Between A Laminated Composite And Metal Cylinder, Casey A. Talbot

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Because lowering weight as much as possible is desirable in all applications designed to go to space, the use of composite materials is desirable. Composites are materials that are made up of two or more separate materials usually with significantly different characteristics which remain separate and distinct in their completed state. Fiber-reinforced epoxy composites, in general, are very strong and light. Because most space structures cannot solely be made of composites, a method to join them with metals is needed. Adhesive joining, or gluing, has been determined to be the most promising option.

For the joining technique to be used, …

Predictive Modeling And Analysis Of Student Academic Performance In An Engineering Dynamics Course, Shaobo Huang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Engineering dynamics is a fundamental sophomore-level course required for many engineering students. This course is also one of the most challenging courses in which many students fail because it requires students to have not only solid mathematical skills but also a good understanding of dynamics concepts and principles.

The overall goal of this study was to develop a validated set of mathematical models to predict student academic performance in an engineering dynamics course taught in the College of Engineering at Utah State University. The predictive models will help the instructor to understand how well or how poorly the students in …

The Potential For Growth In Foreign Direct Investment In The Horticultural Sector Of Armenia, Mikayel Khachatryan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study examines why foreign investors choose to invest in companies in Armenia and is specifically attempting to understand how to attract more investment into the fruit and vegetable companies of Armenia. Investment by foreigners in domestic companies is referred to as foreign direct investment of FDI. The research was completed by gathering information from foreign firms that are already investing in companies in Armenia. This was done by conducting a face-to-face questionnaire with business managers of these companies in Yerevan, Armenia during August and December of 2010. The information gathered from these interviews was used in a statistical analysis …

Pedestrian Leadership And Egress Assistance Simulation Environment (Please), Kyle D. Feuz

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Pedestrian simulation models are used in many different applications including, the design of safer buildings, the validation of fire codes, and automatic video surveillance and tracking. By improving the simulation model used, each of the application areas can experience similar improvements in accuracy. Current simulation models fail to address key concerns in representing pedestrian knowledge and in accurately modeling group formation. This project has at its core the goal of bringing attention these areas of concern and providing an initial look at ways to solve these problems.

The Pedestrian Leadership and Egress Assistance Simulation Environment (PLEASE) is developed specifically to …

A Dynamic State Metabolic Journey: From Mass Spectrometry To Network Analysis Via Estimation Of Kinetic Parameters, Arockia Ranjitha Dhanasekaran

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The term "metabolism" refers to the chemical processes occurring in a living organism to convert the food consumed into the energy needed to maintain a living state. Metabolism consists of two states, namely, a dynamic state and a steady state. In the dynamic state, the rate of chemical conversion of a substance is proportional to the amount of substance available, whereas in the steady state this rate is constant and independent of the amount of substance present (Chapter 4 Figure 1). Like all other fields of engineering, metabolic engineering involves the analysis and synthesis of metabolism. Molecular biological tools for …

Designing Predictive Mathematical Models For The Metabolic Pathways Associated With Polyhydroxybutyrate Synthesis In Escherichia Coli, Angela Dixon

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Plastics are a versatile and widely used material. However, traditional plastics are derived from petrochemicals and are not biodegradable. Polymers synthesized from microorganisms that have similar properties to plastic are potential biodegradable replacements. The objective of this project is to use mathematical modeling as a tool to engineer a strain of bacteria optimized for the production of bio-plastics.

Production costs can be reduced by using a bacterial strain specifically optimized for bio-plastic production. By reducing production costs, bio-plastics will be able to commercially compete with traditional plastics. Society will benefit as bio-plastics replace traditional plastics. Fossil fuels will not be …

Accelerating Production Of Slow-Growing Intermountain West Native Plants By Modifying Their Microclimate, Sam A. Miller

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Water shortages are a recurring problem in the western US. As much as 70% of yearly municipal water consumption may be used to irrigate urban landscapes. Significant water savings can be realized by installing low water landscapes, where turfgrass is replaced by low water trees, shrubs, grasses, and perennials. Intermountain West (IMW) native trees and shrubs are excellent candidates for low water landscaping. However, due to their slow initial growth, many native trees and shrubs are simply unavailable to consumers, as they are not cost effective for nursery growers to produce. In an effort to accelerate the yearly growth rates …

The Interrelationship Between The Bio- And Sequence Stratigraphy Of The Middle Cambrian Spence Shale Of Northern Utah And Southern Idaho, Eva Lyon

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This project was undertaken with the objective of discerning the relationship between sea level change and changes in the fauna of the Spence Shale. A combination of field and lab work was employed to undertake this research. The Spence Shale is rich in fossils from the earliest period of visible life on this planet. It provides a unique window onto the evolution of life and changes in the Earth at this time. It is important to study this relationship between sea level and life changes as these conditions are constantly changing, particularly in this day and age. A better understanding …

Determining Co2 Storage Potential: Characterization Of Seal Integrity And Reservoir Failure In Exposed Analogs, Daniel Corey Barton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Sequestration of carbon dioxide (CO₂) into subsurface porous sandstone is proposed as a method for reducing accumulation of anthropogenic emissions of CO₂ into the atmosphere. Natural exposures of reservoir and top-seal pairs in central and southeastern Utah are identified as analogs to proposed CO₂ injection targets. Reservoir and top-seal pairs in natural analog exposures are analyzed in tandem to evaluate evidence for paleo-migration of fluids and/or hydrocarbons from the reservoir through the top seal. The San Rafael Swell and Monument Uplift exhibit similar structure and exposures of Jurassic units yet differ in amount and type of …

Measuring The Differences In Spatial Ability Between A Face-To-Face And A Synchronous Distance Education Undergraduate Engineering Graphics Course, Scott D. Greenhalgh

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A study was conducted in the Engineering and Technology Education Department at Utah State University by Scott Greenhalgh and Gary Stewardson to measure and compare a face-to-face engineering graphics course with a synchronous distance education engineering graphics course by identifying the impact of the teacher's physical presence on students' spatial ability. This study is unique because it involves laboratory classes in a science, technology, engineering, and math (STEM) field with greater emphasis on hands-on laboratory experiences and skills rather than mastery of information and knowledge. The potential for impact of the study extends beyond a few courses in a specific …

Bayesian Data-Driven Models For Irrigation Water Management, Alfonso F. Torres-Rua

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A crucial decision in the real-time management of today’s irrigation systems involves the coordination of diversions and delivery of water to croplands. Since most irrigation systems experience significant lags between when water is diverted and when it should be delivered, an important technical innovation in the next few years will involve improvements in short-term irrigation demand forecasting.

The main objective of the researches presented was the development of these critically important models: (1) potential evapotranspiration forecasting; (2) hydraulic model error correction; and (3) estimation of aggregate water demands. These tools are based on statistical machine learning or data-driven modeling. These, …

Test Data Extraction And Comparison With Test Data Generation, Ali Raza

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Testing an integrated information system that relies on data from multiple sources can be a challenge, particularly when the data is confidential. This thesis describes a novel test data extraction approach, called semantic-based test data extraction for integrated systems (iSTDE) that solves many of the problems associated with creating realistic test data for integrated information systems containing confidential data. iSTDE reads a consistent cross-section of data from the production databases, manipulates that data to obscure individual identities while still preserving overall semantic data characteristics that are critical to thorough system testing, and then moves that test data to …

Zeolite‐Based Algae Biofilm Rotating Photobioreactor For Algae And Biomass Production, Ashton M. Young

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Alkaline conditions induced by algae growth in wastewater stabilization ponds create deprotonated ammonium ions that result in ammonia gas (NH₃) volatilization. If algae are utilized to remediate wastewater through uptake of phosphorus, the resulting nitrogen loss will hinder this process because algae generally require a stoichiometric molar ratio of N₁₆P₁. Lower ratios of N/P due to loss of ammonia gas will limit the growth and yield of algae, and therefore will reduce phosphorus removal from the water phase into the algae phase. In order to reduce nitrogen loss through volatilization, an ammonium selective zeolite, …

Dislocation Density-Based Finite Element Method Modeling Of Ultrasonic Consolidation, Deepankar Pal

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A dislocation density-based constitutive model has been developed and implemented into a crystal plasticity quasi-static finite element framework. This approach captures the statistical evolution of dislocation structures and grain fragmentation at the bonding interface when sufficient boundary conditions pertaining to the Ultrasonic Consolidation (UC) process are prescribed.

The hardening is incorporated using statistically stored and geometrically necessary dislocation densities (SSDs and GNDs), which are dislocation analogs of isotropic and kinematic hardening, respectively. Since the macroscopic global boundary conditions during UC involves cyclic sinosuidal simple shear loading along with constant normal pressure, the cross slip mechanism has been included in the …

A Two-Dimensional Numerical Simulation Of Plasma Wake Structure Around A Cubesat, Rajendra Mitharwal

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A numerical model was developed to understand the time evolution of a wake structure around a CubeSat moving in a plasma with transonic speed. A cubeSat operates in the F2 layer of ionosphere with an altitude of 300 − 600 Km. The average plasma density varies between 10⁻⁶cm⁻³ − 10⁻⁹cm⁻³ and the temperature of ions and electrons is found between 0.1−0.2 eV. The study of a wake structure can provide insights for its effects on the measurements obtained from space instruments. The CubeSat is modeled to have a metal surface, which is a realistic …

Ecologically-Based Manipulation Practices For Managing Bromus Tectorum-Infested Rangelands, Beth Fowers

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Cheatgrass (Bromus tectorum) is an invasive annual grass common in several semiarid plant communities in the western U.S. B. tectorum presence increases fire frequency and size, reducing species diversity, and leading to annual species-dominated systems with inconsistent livestock forage potential and degraded wildlife habitat value. Most efforts to manage B. tectorum-dominated rangelands have focused on controlling the plant itself rather than addressing the causes of vegetation change. An alternative approach, ecologically-based invasive plant management (EBIPM), identifies treatments that can alter factors associated with the causes of succession, leading to a more desirable vegetation state. This study utilized …

Autonomous Aerial Manipulation Using A Quadrotor, Vaibhav Ghadiok

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This paper presents an implementation of autonomous indoor aerial gripping using a low-cost, custom-built quadrotor. Such research extends the typical functionality of micro air vehicles (MAV) from passive observation and sensing to dynamic interaction with the environment. To achieve this, three major challenges are overcome: precise positioning, sensing and manipulation of the object, and stabilization in the presence of disturbance due to interaction with the object. Navigation in both indoor and outdoor unstructured, Global Positioning System-denied (GPS-denied) environments is achieved using a visual Simultaneous Localization and Mapping (SLAM) algorithm that relies on an onboard monocular camera. A secondary camera, capable …

Estimating Yield Of Irrigated Potatoes Using Aerial And Satellite Remote Sensing, Saravanan Sivarajan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Multispectral aerial and satellite remote sensing plays a major role in crop yield prediction due to its ability to detect crop growth conditions on spatial and temporal scales in a cost effective manner. Many empirical relationships have been established in the past between spectral vegetation indices and leaf area index, fractional ground cover, and crop growth rates for different crops through ground sampling. Remote sensing-based vegetation index (VI) yield models using airborne and satellite data have been developed only for grain crops like barley, corn, wheat, and sorghum. So it becomes important to validate and extend the VI-based model for …

Structural Identification And Damage Identification Using Output-Only Vibration Measurements, Shutao Xing

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This dissertation studied the structural identification and damage detection of civil engineering structures. Several issues regarding structural health monitoring were addressed.

The data-driven subspace identification algorithm was investigated for modal identification of bridges using output-only data. This algorithm was tested through a numerical truss bridge with abrupt damage as well as a real concrete highway bridge with actual measurements. Stabilization diagrams were used to analyze the identified results and determine the modal characteristics. The identification results showed that this identification method is quite effective and accurate.

The influence of temperature fluctuation on the frequencies of a highway concrete bridge was …

Reducing Reliance On Supplemental Winter Feeding In Elk (Cervus Canadensis): An Applied Management Experiment At Deseret Land And Livestock Ranch, Utah, Dax L. Mangus

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wildlife managers have fed elk in North America for nearly 100 years. Giving winter feed to elk can compensate for a shortage of natural winter range and may boost elk populations while also helping prevent commingling with livestock and depredation of winter feed intended for livestock. In contrast to these benefits of supplemental feeding, there are economic and environmental costs associated with feeding, and elk herds that winter on feeding grounds have a higher risk of contracting and transmitting disease. Brucellosis is of primary concern now, and Chronic Wasting Disease may be in the future. Many see the discontinuation of …

Spatiotemporal Modeling Of Threats To Big Sagebrush Ecological Sites In Northern Utah, Alexander J. Hernandez

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study tested the performance of classification, regression, and ordination techniques to evaluate the spatiotemporal dynamics of threats to big sagebrush ecological sites. The research was focused on invasion by annual exotic grasses and encroachment by woodlands.

We sought to identify those areas that have had a persistent coverage of cheatgrass (Bromus tectorum) in big sagebrush ecological sites. We took advantage of the contrast in greenness between multi-temporal (within one year) remotely sensed vegetation indices captured in the spring and summer to find a distinct phenological signature that allowed mapping cheatgrass. We utilized support vector machines (SVM) to classify three …

"Struggling" Adolescent Writers Describe Their Writing Experience: A Descriptive Case Study, F. Jean Mcpherron

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Four adolescents identified as struggling writers in an English language arts classroom were interviewed about their perceptions of a writing task--how they judged their capability to succeed, how they ranked their passion, persistence, and confidence about writing, and how they responded to classroom activity. Student perceptions of self-efficacy and the related self-beliefs of motivation and interest as well as self-regulation were stated and implied as students described a planning worksheet, instructional scaffolding, peer interactions, and ownership of their writing. Wersch's view of mediated action and Engestrom's model of activity systems were the lens through which the students' descriptions were analyzed. …

Comprehensive High School Reform: The Lived Experience Of Teachers And The Smaller Learning Community Initiative, Richard K. Nye

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In an era of comprehensive school reform, it appears that the voice of teachers is seldom solicited or recognized in the process of planning and implementing school-wide reform. The primary purpose of this study was to report the lived experiences of teachers at Timberton North High School (pseudonym) as it related to the Smaller Learning Community (SLC) reform initiative. Research questions addressed how the faculty experienced the SLC initiative and how their experiences were different from their perceived notion of what SLCs were trying to accomplish and in what ways SLCs initiated a socially constructed understanding of educational purposes. This …

From Hillslopes To Canyons, Studies Of Erosion At Differing Time And Spatial Scales Within The Colorado River Drainage, Christopher Tressler

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis includes two different studies in an attempt to investigate and better understand the key characteristics of landscape evolution. In the first study, the rate of surface particle creep was investigated through the use of Terrestrial lidar at an archaeological site in Grand Canyon National Park. The second study developed ways to quantify metrics of the Colorado River drainage and reports the role of bedrock strength in the irregular profile of the trunk Colorado River drainage.

Archaeological sites along the Colorado River corridor in Grand Canyon National Park are eroding due to a variety of surficial processes. The nature …

Orchestrating Classrooms: A Collaborative Inquiry Study Of Novice Teacher Community Building, Leah G. Welte

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Creating a community of learners with and among students in a collaborative classroom environment provides the keystone for developing the skills necessary for success in the 21^st century. Some preservice teachers envision that community building can enhance the learning experience for them and their students and want to learn and employ the necessary strategies. This study examined whether such a desirous group of novice teachers could identify the key factors they believed comprise community building and could successfully establish a community of learners during their first full year of teaching, supported by participation in a collaborative inquiry group.

Four …

Evaluation And Improvements On Row-Column Order Bias And Grid Orientation Bias Of The Progressive Morphological Filter Of Lidar Data, Kody Potter

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis reviews algorithms that have been developed for classifying lidar data and identifies a progressive morphological filter for evaluation and improvement. Two potential weaknesses evaluated include the row-column order bias and grid orientation bias.

Four different row-column orderings were developed to test for bias associated with the order choice. Moreover, a method rotating the filter grid to a series of angles was developed for testing bias associated with grid orientation. Measures of success of the improvements include Type I and II errors, where results are compared with a hand-produced "truth" dataset. Two datasets, one urban, the other rural, were …

Sedimentological Controls On Fracture Distribution And The Network Development Within Meseverde Group Lithofacies, Uinta Basin, Utah, Ryan Christopher Sonntag

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Mesaverde Group, within the Uinta Basin, Utah, is a source of current significant production and contains several trillion cubic feet of undiscovered natural gas resources. Due to the low permeability of the matrix rock, understanding the geometry and properties of natural fractures is critical to the development of effective ways of finding and producing natural gas. In order to evaluate and model the potential connectivity of hydraulically induced fractures to natural fractures at depth, we examine the nature of the natural fracture network using scanline sampling, imagery analyses, core analyses, and microstructural analyses. Regional fracture sets identified include: N-S …

Graph Kernels And Applications In Bioinformatics, Marco Alvarez Vega

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nowadays, machine learning techniques are widely used for extracting knowledge from data in a large number of bioinformatics problems. It turns out that in many of such problems, data observations can be naturally represented by discrete structures such as graphs, networks, trees, or sequences. For example, a protein can be seen as a cloud of interconnected atoms lying on a 3-dimensional space. The focus of this dissertation is on the development and application of machine learning techniques to bioinformatics problems wherein the data can be represented by graphs. In particular, we focus our attention on proteins, which are essential elements …

Study Of Geomagnetic Disturbances And Ring Current Variability During Storm And Quiet Times Using Wavelet Analysis And Ground-Based Magnetic Data From Multiple Stations, Zhonghua Xu

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The magnetosphere-ionosphere contains a number of current systems. These currents vary on a wide range of spatial and temporal scales and physically couple with each other. To study the complicated behaviors of these coupled current systems, the ground-based magnetometer has been a useful tool, but the recorded magnetometer data are always multi-scaled and intermittent due to the nature of these current systems. To distinguish these geomagnetic effects with multiple temporal and frequency scales, the wavelet analysis technique is especially suitable because of its special abilities of presenting information in both temporal and frequency domains. In this dissertation, the geomagnetic disturbances …

Anisotropic Compressive Pressure-Dependent Effective Thermal Conductivity Of Granular Beds, R. Daniel Garrett

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In situ planetary effective thermal conductivity measurements are typically made using a long needle-like probe, which measures effective thermal conductivity in the probe's radial (horizontal) direction. The desired effective vertical thermal conductivity for heat flow calculations is assumed to be the same as the measured effective horizontal thermal conductivity. However, it is known that effective thermal conductivity increases with increasing compressive pressure on granular beds and horizontal stress in a granular bed under gravity is related to the vertical stress through Jaky's at-rest earth pressure coefficient. No research has been performed previously on determining the anisotropic effective thermal conductivity of …