Digital Commons Network^™

Model-Based Estimates Of The Timing Of Brine Flux Into The Victoria Land Basin From The Mcmurdo Dry Valleys, Antarctica, Valerie Nicole Voisin

Graduate Research Theses & Dissertations

Submarine groundwater discharge (SGD) at a continental scale is one of the least constrained components of the hydrologic cycle and may represent a significant flux of iron and silica waters to the global ocean. Quantifying SGD along the Antarctic margin is complicated by complex subglacial and subsurface hydrogeology and limited observational data. Airborne transient electromagnetic (AEM) surveys have identified extensive high-salinity subsurface brines in the McMurdo Dry Valleys (MDV) that are hydrologically connected to surface features in the MDV (e.g. Taylor Glacier, saline lakes) and are potentially a significant source of SGD to McMurdo Sound. A 2D numerical model was …

Wildlife Ecology And Conservation In A Suburban Preserve Matrix: Applications Of Long-Term Monitoring Data, John Peter Vanek

Graduate Research Theses & Dissertations

Wildlife is important to humans, offering economic, nutritional, ecological, and socio-cultural value. However, vertebrate biodiversity is being lost at rates 100 times greater than the background extinction rate, threatening human livelihood via the loss of ecosystem services. These human-induced species losses are primarily due to habitat destruction, which is increasingly tied to urban development. Conservation of wildlife resources is therefore imperative in a world where more than 50% of the human population, and 80% of people living in the United States, now live in urban areas. In this dissertation, I demonstrate how monitoring data can be applied to answer questions …

Mid-Career Elementary Teachers' Perceptions Of Elements That Contribute To Job Satisfaction And Intent To Remain In The Field, Sarah Elizabeth Westberg

Graduate Research Theses & Dissertations

This dissertation examined the experiences and perceptions of mid-career elementary teachers by exploring elements contributing to their level of job satisfaction and intent to remain in the field. Participants for the study were identified from those who responded to a questionnaire that they received via their district email addresses. All four participants were teachers with 6-17 years of teaching experience who had considered leaving the field.

Data collection strategies included a series of three interviews with each teacher, as well as responses to two writing prompts. Through analysis of the qualitative data, several common themes emerged, thus providing insight into …

Micro-Macro Mathematical Modeling Analysis Of An Al-Air Battery, Christopher Charles Welch

Graduate Research Theses & Dissertations

The aluminum-air battery is a very promising electrical energy storage system for portable electronics and electric vehicles because it is safe, inexpensive, and has a very high energy density. With the [EMIm]Cl-AlCl3 room-temperature ionic liquid (RTIL) electrolyte, by controlling the acidity, H2 evolution and dendrite formation are prevented and the Al2O3 passive film on the anode can be partially dissolved (cracked), so the battery’s lifespan is extended and even allows battery charging. Still, the Al2O3 passive film on the anode and Al2O3 deposition on the cathode remain issues which negatively affect battery performance. While these phenomena have been experimentally observed, …

Examining Reflective Practice Through Lesson Study, Amanda L. Wojcik

Graduate Research Theses & Dissertations

The purpose of this qualitative study was to examine a team of elementary teachers’ reflective practice through lesson study. The study focused on how three first-grade teachers described their reflective practice during and after lesson study and how they reflected-in, -on, and -for-action during three lesson studies. The teachers each participated in four individual interviews, three stimulated recall interviews, and observations during the lesson studies when they taught research lessons and engaged in post-lesson discussions.

Data from the interviews and lesson study observations were analyzed using qualitative methods and through the lens of Schön’s theory of reflection. Ten sub-themes were …

Effects Of Differential Instructional Time In Algebra On Standardized Assessment And Semester Grade Outcomes, Michael S. Wojtowicz

Graduate Research Theses & Dissertations

Building off of other studies that examined the effectiveness of double-dose algebra programs such as Nomi and Allensworth (2009), this dissertation compared the performance outcomes of students enrolled in one of two alternatives to traditional high school algebra, a double-dose and a single-dose algebra program. This work utilized multiple linear regression to assess the degree of association between student race/ethnicity and selected demographic characteristics, including gender, free and reduced lunch status, and IEP status, on standardized assessment and end of semester mathematics course grade outcomes, while controlling for initial mathematics placement test results. This project assessed these outcomes for students …

Adaptive Object Detection For Autonomous Vehicles, Christopher Wolfe

Graduate Research Theses & Dissertations

Autonomous vehicles are gradually entering our daily lives. The goal of fully autonomous commercially available vehicles is becoming closer to reality each day as the contributions from researchers and various institutions are being added to the overall body of knowledge. Object detection is a critical component of an autonomous or semi-autonomous vehicle and draws extensively on results from many fields such as image processing and statistics. In this thesis, we consider ideas from the study of real-time computing and control systems to present a novel method of real-time adaptive object detection. We present a conceptual framework of the method as …

Fundamental Study Of Supported Metal Catalysts Prepared By Metal In Lithium Solution For Energy Science, Haiping Xu

Graduate Research Theses & Dissertations

Electrochemical carbon dioxide reduction reaction (CO2RR) is a promising technique for energy conversion and storage from intermittent electricity sources (ie. wind and solar). By coupling electrochemical CO2 reduction (CO2R) to a renewable energy source atmospheric CO2 could be converted back into a fuel such as ethanol, or a commodity chemical such as ethanol or acetic acid. These products could then be consumed for energy or used to generate more valuable chemical products effectively removing CO2 from the atmosphere. To commercialize this process, it is highly desired to prepare catalysts that selectively reduce CO2 at low overpotential with long durability. Research …

Qualitative Perspectives On The Strange Trails Of Persistence In Stem, Erika Johanna Zocher

Graduate Research Theses & Dissertations

In 2019, a Midwestern state university was awarded a $1 million NSF S-STEM grant to support scholarships for academically gifted, Pell Grant-eligible undergraduates enrolled in one of six designated STEM majors. Educational research was also funded by this grant, with the goal of identifying and contextualizing supports and challenges that impact persistence in STEM within the setting of a near-peer-mentored social support group during the fall of 2019. The purpose of this group was to provide social support and foster a sense of belonging for the twelve scholars. Such support is important for guiding students towards personal development and degree …

Copper And Gold In Vapors And Liquids As A Function Of Hcl At 700°C And 100 Mpa, Corrie A. Lucchesi

Graduate Research Theses & Dissertations

Porphyry ore deposits are major sources of copper (Cu) and gold (Au) and form when a magmatic volatile phase (MVP) exsolves from a porphyritic intermediate to felsic melt and transports metals to surrounding country rock where they precipitate in an ore zone. There is a consensus that the chloride concentration of the MVP has a direct relationship to the concentration of Cu and Au in the MVP, but the role of dissolved HCl on Cu and Au concentrations has not been addressed. It is hypothesized that increasing HCl concentrations in the MVP will result in higher concentrations of Cu and …

A Computational Study Of Binary Linear And Quadratic Programming And Solvers, William Cody Mackelfresh

Graduate Research Theses & Dissertations

In this thesis we study and compare computational capability of two solvers, Gurobi and BiqCrunch, and their capabilities to solve various binary quadratic and linear programming problems. We review two types of programming models for three types of combinatorial optimization problems, namely Max-Cut, Max Independent Set, and Max-$k$-Cluster. We also review the Reformulation-Linearization Technique (RLT) and Semidefinite Programming (SDP) approaches for solving these models, go over the software and hardware used to solve these problems, and finally review the numerical results obtained by solving the problems.

Case Study: Examining Perceptions Of Students With Low Vision In Online Courses, Asma Fuad Marghalani

Graduate Research Theses & Dissertations

This qualitative case study explored the most helpful accommodations for students with low vision in online courses. Utilizing online surveys and individual interviews, this case study took place at a U.S. public university in the Midwest. The theoretical framework for this study was Universal Design for Learning (UDL). The findings indicate that students with low vision prefer receiving text and audio information. Additionally, the findings showed that extended time was the most helpful accommodation, alternative formats for materials, headings, and color-contrasting for online content were the most helpful accessibility aspects, and screen readers were the most helpful assistive technology. The …

Development Of An Electron-Beam Halo Diagnostics, Christopher James Marshall

Graduate Research Theses & Dissertations

Electron beam halos defined as the peripheral fraction of the beam that does not contribute to the front end application. Particles located in the halo can cause damage to the particle accelerator and lower the power and quality of the beam. Being able to measure the beam halo could provide insight on the halo-formation mechanism and ultimately will improve the overall performance and quality of the beam. A halo diagnostic was designed, and a prototype built and commissioned. The diagnostics relies on detecting optical radiation by the electron beam and masking its core to enhance the detection of the halo. …

Transitional Math In Illinois: A Quantitative Study On Eligible And Enrolled Students, Whitney Lynn Martino

Graduate Research Theses & Dissertations

Completing a post-secondary degree is crucial to being competitive in the current job market. By 2020, the majority of all jobs in the United States require post-secondary education and training; however, barriers to access and attainment exist among individuals working to obtain post-secondary degrees, and there is an overall slowdown in post-secondary attainment. Students entering college identified as under-prepared is one of the attainment barriers to a post-secondary degree. This is particularly problematic at open admissions institutions like community colleges. When students arrive at college academically unprepared, they are often required to take developmental or remedial education coursework. In response …

Estimating Paleotemperatures In The Amundsen Sea For The Last 620,000 Years Through Diatom Morphometrics (Iodp Expedition 379), Joseph Robert Mastro

Graduate Research Theses & Dissertations

As global climate continues to rapidly change over the coming decades, West Antarctica will continue to be a significant area of concern due to its susceptibility to marine ice sheet collapse. Past collapses during Pleistocene interglacials have been hypothesized but uncertainty exists with respect to the precise timing of specific collapse events. Drill core samples collected from the Amundsen Sea continental rise during IODP Expedition 379 allow for analysis of a more continuous record of Pleistocene glacial-interglacial cycles. Here we report paleotemperature estimates from the Amundsen Sea spanning the last 620 kyr with the objective of identifying likely late Pleistocene …

Association Of Various Physiological And Fitness Markers To Body Fat Percentage In Physically Inactive Adults, Anthony Mckee

Graduate Research Theses & Dissertations

Obesity can dramatically and negatively affect many aspects of normal physiological functioning. Obesity is defined as abnormal or excessive body fat accumulation that presents a risk to health. Body mass index (BMI) is a widely used approach to quantify body fat in large group settings; however, this method has significant shortcomings with accuracy and estimation. More direct measures such as bioelectrical impedance analysis (BIA) can provide a more reliable and accurate assessment of body fat mass and, therefore reduce the shortcomings of BMI when assessing possible associations with health- and performance-related variables. A plethora of research studies has been conducted …

The Impact Of Attributional Style On Adolescent Stress And Mental Health: Exploring Domain-Specific Stressors, Lauren Therese Mcneela

Graduate Research Theses & Dissertations

The present study examined the relation between domain-specific stressors (i.e., interpersonal versus noninterpersonal) and adolescent internalizing and externalizing symptoms among 118 high school students (Mage = 16.65 years old; 64% female; 79.8% Caucasian). Additionally, this study assessed the impact of negative attributional style on each of these associations, furthering the current literature on the Cognitive Diathesis-Stress model among adolescents. Using the lavaan package of RStudio (Rosseel, 2012), path analyses were run to examine the relationship between domain-specific stressor and adolescent outcomes. The present study found that interpersonal, but not noninterpersonal stressors were associated with internalizing symptoms, while neither interpersonal nor …

Examination Of Practices Used By Ap Computer Science Teachers With Higher Than Average Female Enrollment, Derek J. Miller

Graduate Research Theses & Dissertations

This dissertation examines the practices employed by AP Computer Science A teachers that can help recruit and retain female students in computer science. A survey was sent to teachers to see what practices they used in their classrooms and what practices they thought had the biggest influence on female student recruitment and retention. Of the five practice categories (recruitment, pedagogical, curricular, extracurricular, and mentoring), the survey respondents thought recruitment was the most influential and curricular was the least influential. After the survey, 12 teachers were chosen for interviews because they had a higher enrollment of female students than the rest …

Partial Shading In Photovoltaic Cells Using Fuzzy Logic Tuned Particle Swarm Optimization Method Of Maximum Power Point Tracking Control, Nauman Moiz Mohammed Abdul

Graduate Research Theses & Dissertations

This paper dealt with the study of a newly modified fuzzy adaptive particle swarm

optimization controller and compared it with various existing conventional and advanced

controllers. A traditional PSO controller has the problems of oscillations and slow convergence. It is modified using fuzzy logic to decrease the number of oscillations and optimize

the convergence speed to produce a better efficient output. This controller is built to adapt

under various solar irradiances and partial solar conditions on the solar panels. This controller is then tested along with other various controllers, results recorded and studied. The

simulations are performed on the MatLab …

Rational Design Of Memory-Based Sensors: The Case Of Molecular Calorimeters, Obianuju Augusta Nwokolo

Graduate Research Theses & Dissertations

Thermodynamic characterization is crucial for understanding molecular interactions. However, methodologies for measuring heat changes in small open systems are extremely limited. We document a new approach for designing molecular sensors that function as calorimeters: sensors based on memory. To design a memory-based sensor, we take advantage of the unique kinetic properties of nucleic acid scaffolds. Particularly, we elaborate on the differences in folding and unfolding rates in nucleic acid quadruplexes. DNA-based i-motifs unfold fast in response to small heats but do not fold back when the system is equilibrated with surroundings. We translated this behaviour into a molecular memory function …

A Multi-Constraint Predictive Control System With Auxiliary Emergency Controllerfor Autonomous Vehicles, Farhad Partovi Ebrahimpour

Graduate Research Theses & Dissertations

In the last few years, several research groups and companies have worked on developing autonomous vehicles. Among the first automation layers, the safety layer plays a significant role in this field. However, considering safety should not diminish the importance of the efficiency of the vehicle in terms of path tracking with the desired speed. This thesis introduces a multi-constraint predictive control algorithm along with a safety layer to guarantee object avoidance in emergency situations. First, there is a quick review of autonomous cars and their functionalities. In the following, a controller switching mechanism is proposed and designed. It switches the …

Molecular Dynamic Simulations Of Mechanical Properties In Nb-Nbc Core-Shell Nanowires And Nodes, Austin Pauga

Graduate Research Theses & Dissertations

Nanoporous materials have attracted attention recently because of their extensive range of possible applications. These nanoporous materials are comprised of nanowires and nodes. A node joins three or more nanowires of different orientations. Current research has focused on nanowires and nodes composed of metallic single crystals and core-shells. Nanoporous materials experience brittle failure from the rupture of the weakest feature, overloading the other remaining structural features. To alter the deformation behavior of the network nodes, a ceramic layer has been added around the metal. Coating the metallic ligaments with ceramic shell increases the buckling capacity of each ligament and further …

Principals’ Legal Literacy About Tenured-Teacher Evaluation In Illinois, Elizabeth Pohlmann

Graduate Research Theses & Dissertations

This dissertation examines the legal literacy of principals related to the evaluation of tenured teachers. The quality of teachers, while varied, is important. The evaluation of tenured teachers provides a significant opportunity to impact the quality of teachers and the teacher workforce. This study explores principals’ knowledge of the legal framework in Illinois to identify gaps in knowledge regarding the tenured teacher evaluation process and the associated legal constraints (what do they have to do) and opportunities (what can they do).

In this study, a survey aligned with the legal requirements for tenured teacher evaluation is used to measure principal …

Construction Of Confidence Intervals For Parameter Estimates Of T-Distribution, Margaret Remus

Graduate Research Theses & Dissertations

Constructing confidence intervals is a standard statistical practice to estimate parameters of a distribution. Estimation of the parameters of a t-distribution can be computationally intensive. As a result, there are not clear defined formulas for the construction of confidence intervals for those estimates. Using the Normal confidence interval equation does not offer an accurate interval. Therefore, this paper will outline potential alternative methods for building confidence intervals to estimate the mean of a t-distribution. This paper will offer several methods and simulations to determine which method is best for constructing confidence intervals for varying sample sizes and degrees of freedom. …

Excess Credit Accumulation Impact On Degree Attainment For Community College Students, Stacy Riley

Graduate Research Theses & Dissertations

This study was conducted to examine the relationship between excess credit accumulation and timely degree completion for community college degree-seeking students. The research model used in this study is based on quantitative logistic and linear regression models, whereby the dependent variable was degree attainment within 150% of normal time and time to degree measured in months respectively. This study included all students admitted to a technical diploma or associate degree program excluding one-course technical diplomas over a five-year period (2011-2016) for a total of 27,133 observations at a southeastern Wisconsin technical college.

The study’s findings showed there was no statistically …

Microfiltration Membrane Pore Functionalization Approaches For Chloro-Organic Remediation To Heavy Metal Sorption, Mohammad Saiful Islam

Theses and Dissertations--Chemical and Materials Engineering

Microfiltration polyvinylidene fluoride (PVDF) membranes have distinct advantage for open structure in terms of high internal surface area and ease of access in the pore domain. Functionalization of PVDF membranes with different functional groups (-COOH, -OH, -SH) enables responsive (pH, temperature) properties to membrane, tuning of effective pore size, controlling permeate flux. PVDF microfiltration membrane functionalization with suitable responsive polymer such as poly acrylic acid (PAA) to incorporate carboxyl (-COOH) group enables further modification of functionalized PAA-PVDF membranes for different application ranging from catalysis, bio reactor to heavy metal sorption platform. As a catalytic reactor bed, this PAA-PVDF membranes are …

Heart Tissue Reconstruction By Light-Controlled Cell Adhesion, Patterning And Alignment On Decellularized Scaffolds, Cong Li

Theses and Dissertations--Chemical and Materials Engineering

There is an urgent demand for engineered tissues and organs because of extremely limited donor tissues available for transplant. The challenge of tissue rejection has motivated many researchers to try to remove all of the cells from a heart and then add back in patient matched cells. These recellularized hearts are a promising avenue towards a functional bioartifical heart that is less likely to be rejected. Decellularized extracellular matrix (ECM) scaffolds generated from animal hearts do not have the cellular components that elicit immune rejection in patient, and they also preserve the native heart tissue structure. While decellularization techniques are …

Effects Of Hole Transporting Layers And Surface Ligands On Interface Energetics And Photovoltaic Performance Of Methylammonium Lead Iodide Perovskites, So Min Park

Theses and Dissertations--Chemical and Materials Engineering

Organic metal halide perovskites are promising materials for various optoelectronic device applications such as light emitting diodes (LED) and photovoltaic (PV) cells. Perovskite solar cells (PSCs) have shown dramatic increases in power conversion efficiency over the previous ten years, far exceeding the rate of improvement of all other PV technologies. PSCs have attracted significant attention due to their strong absorbance throughout the visible region, high charge carrier mobilities, color tunability, and ability to make ultralight weight devices. However, organic metal halide perovskites still face several challenges. For example, their environmental stability issue must be overcome to enable widespread commercialization. Meeting …

How Christian College Student Leaders Discover Purpose, Emmanuel Ayiku

Masters Theses

Among college students, research has revealed that 76% of them reported that they search for meaning in life (Dunn & Hammer, 2015). Spirituality is one specific way in which students begin their search for meaning. A qualitative approach was used to examine the perspectives of how six Christian college student leaders from three different campus ministries found their purpose. By examining and understanding purpose from one subset of religious students who serve in a leadership position, we may gain insight into the interplay of meaning-making, purpose, and leadership. This study concluded that faith or spirituality played an important role in …

The Impact Of Testing On Students, Teachers, And Families, Ashley Retz

Masters Theses

No abstract provided.