Physical Sciences and Mathematics Commons^™

Water Management And Corrosion Performance From Protective Polymer Coatings With Spatially Controlled Hydrophilic Domains, Jessica M. Davison

Dissertations

Metallic corrosion has become an annual multibillion-dollar problem for the industrialized world and global contamination issue through the process of repair, removing, and reapplying protective coatings. Typical corrosion resistant coatings are comprised of polymeric coating layers with anti-corrosive pigments, plasticizers, sacrificial additives, and/or other formulation materials, which are formulated to prevent, detect, and manage corrosion. Our counterintuitive approach was to improve upon the understanding of how, when, where, and why environmental contaminants (reactants, mainly water and electrolytes) driving corrosion, propagate and accumulate as localized hydrophilicity shifts within a model polymer coated substrate. Herein, hydrogel particles (HGP) were synthesized of defines …

Fairness And Privacy In Machine Learning Algorithms, Neha Bhargava

Master of Science in Computer Science Theses

Roughly 2.5 quintillion bytes of data is generated daily in this digital era. Manual processing of such huge amounts of data to extract useful information is nearly impossible but with the widespread use of machine learning algorithms and their ability to process enormous data in a fast, cost-effective, and scalable way has proven to be a preferred choice to glean useful insights and solve business problems in many domains. With this widespread use of machine learning algorithms there has always been concerns about the ethical issues that may arise from the use of this modern technology. While achieving high accuracies, …

Decreasing Trash In Local Creeks: A Program Evaluation Of The City Of San Jose’S Direct Discharge Trash Control Program, Lakeisha Bryant

Master's Projects

The entire San Francisco Bay was once a navigable waterway in the 1850s during the Gold Rush era. Large amounts of sediment from upstream erosion and mining flowed to the bay resulting in the downsizing of the bay’s square miles (Environmental Protection Agency, 2022). As a result of intense development on the bay shores and adjacent lands, the bay faces several challenges that affect its water quality and threatens aquatic ecosystems. Pesticides, mercury, metals, and pathogens are just a few substances in the bay that cause unhealthy conditions for aquatic life and threaten human health. California’s Water Resources Control Board …

Two Substellar Survivor Candidates; One Found And One Missing, T. Von Hippel, N. Walters, J. Farihi, T.R. Marsh, E. Breedt, P.W. Cauley, J.J. Hermes

Publications

This study presents observations of two possible substellar survivors of post-main sequence engulfment, currently orbiting white dwarf stars. Infrared and optical spectroscopy of GD 1400 reveal a 9.98 h orbital period, where the benchmark brown dwarf has ��2 = 68 ± 8 MJup, ��eff ≈ 2100 K, and a cooling age under 1 Gyr. A substellar mass in the lower range of allowed values is favoured by the gravitational redshift of the primary. Synthetic brown dwarf spectra are able to reproduce the observed CO bands, but lines below the bandhead are notably overpredicted. The known infrared excess towards PG 0010+281 …

Computer Clinical Decision Support That Automates Personalized Clinical Care: A Challenging But Needed Healthcare Delivery Strategy, Michael Lanspa, James Orme, Terry P Clemmer, Lindell K Weaver, Frank O Thomas, Colin K Grissom, Ellie Hirshberg, Thomas D East, Carrie Jane Wallace, Michael P Young, Dean F Sittig, Mary Suchyta, James E Pearl, Antinio Pesenti, Michela Bombino, Eduardo Beck, Katherine A Sward, Charlene Weir, Shobha Phansalkar, Gordon R Bernard, B Taylor Thompson, Roy Brower, Jonathon Truwit, Jay Steingrub, R Duncan Hiten, Douglas F Willson, Jerry J Zimmerman, Vinay Nadkarni, Adrienne G Randolph, Martha A Q Curley, Christopher J L Newth, Jacques Lacroix, Michael S D Agus, Kang Hoe Lee, Bennett P Deboisblanc, Frederick Alan Moore, R Scott Evans, Dean K Sorenson, Anthony Wong, Michael V Boland, Willard H Dere, Alan Crandall, Julio Facelli, Stanley M Huff, Peter J Haug, Ulrike Pielmeier, Stephen E Rees, Dan S Karbing, Steen Andreassen, Eddy Fan, Roberta M Goldring, Kenneth I Berger, Beno W Oppenheimer, E Wesley Ely, Brian W Pickering, David A Schoenfeld, Irena Tocino, Russell S Gonnering, Peter J Pronovost, Lucy A Savitz, Didier Dreyfuss, Arthur S Slutsky, James D Crapo, Michael R Pinsky, Brent James, Donald M Berwick

Faculty, Staff and Student Publications

How to deliver best care in various clinical settings remains a vexing problem. All pertinent healthcare-related questions have not, cannot, and will not be addressable with costly time- and resource-consuming controlled clinical trials. At present, evidence-based guidelines can address only a small fraction of the types of care that clinicians deliver. Furthermore, underserved areas rarely can access state-of-the-art evidence-based guidelines in real-time, and often lack the wherewithal to implement advanced guidelines. Care providers in such settings frequently do not have sufficient training to undertake advanced guideline implementation. Nevertheless, in advanced modern healthcare delivery environments, use of eActions (validated clinical decision …

Scientists And Activists Work To Save The Planet, Myriam G. Vidal Valero

Capstones

Climate change and human intervention in nature are affecting people, ecosystems and ways of living all over the world. This portfolio of environmental pieces showcases the dire consequences of not addressing these issues, how solutions can be reached and the challenges facing those who try to change things.

Towards A Machine Learning-Based Digital Twin For Non-Invasive Human Bio-Signal Fusion, Izaldein Al-Zyoud, Fedwa Laamarti, Xiaocong Ma, Diana Tobón, Abdulmotaleb Elsaddik

Computer Vision Faculty Publications

Human bio-signal fusion is considered a critical technological solution that needs to be advanced to enable modern and secure digital health and well-being applications in the metaverse. To support such efforts, we propose a new data-driven digital twin (DT) system to fuse three human physiological bio-signals: heart rate (HR), breathing rate (BR), and blood oxygen saturation level (SpO2). To accomplish this goal, we design a computer vision technology based on the non-invasive photoplethysmography (PPG) technique to extract raw time-series bio-signal data from facial video frames. Then, we implement machine learning (ML) technology to model and measure the bio-signals. We accurately …

Matemáticas Financieras Aplicadas, Odair Triana Calderón

Ciencias Administrativas, Económicas y Contables

Teniendo en cuenta que las matemáticas son una herramienta fundamental en las Ciencias Administrativas, especialmente en las finanzas. MATEMÁTICAS FINANCIERAS APLICADAS, busca dar solución a aquellos problemas de tipo económico y financiero que se presentan en una economía, organización o núcleo familiar, mediante la utilización de modelos matemáticos y la aplicación en Microsoft Excel.

El texto realiza un estudio de problemas de inversión y financiación, donde el cálculo de intereses con base en un capital y atendiendo a variables como el tiempo y las tasas de rendimiento, permite el desarrollo de casos utilizando el interés simple e interés compuesto.

Por …

Proposal For A Definitive Search For Gut-Scale Qcd Axions, L. Brouwer, S. Chaudhuri, H. M. Cho, J. Corbin, C. S. Dawson, A. Droster, J. W. Foster, J. T. Fry, P. W. Graham, R. Henning, K. D. Irwin, F. Kadribasic, Y. Kahn, A. Keller, R. Kolevatov, S. Kuenstner, A. F. Leder, D. Li, J. L. Ouellet, K. M. W. Pappas, A. Phipps, N. M. Rapidis, B. R. Safdi, C. P. Salemi, M. Simanovskaia, J. Singh, E. C. Van Assendelft, K. Van Bibber, K. Wells, L. Winslow, W. J. Wisniewski, Betty A. Young

Physics

The QCD axion is a leading dark matter candidate that emerges as part of the solution to the strong 𝐶⁢𝑃 problem in the Standard Model. The coupling of the axion to photons is the most common experimental probe, but much parameter space remains unexplored. The coupling of the QCD axion to the Standard Model scales linearly with the axion mass; therefore, the highly motivated region 0.4–120 neV, corresponding to a GUT-scale axion, is particularly difficult to reach. This paper presents the design requirements for a definitive search for GUT-scale axions and reviews the technological advances needed to enable this program.

Complete Equitable Decompositions, Joseph Paul Drapeau

Theses and Dissertations

A well-known result in spectral graph theory states that if a graph has an equitable partition then the eigenvalues of the associated divisor graph are a subset of the graph's eigenvalues. A natural question question is whether it is possible to recover the remaining eigenvalues of the graph. Here we show that if a graph has a Hermitian adjacency matrix then the spectrum of the graph can be decomposed into a collection of smaller graphs whose eigenvalues are collectively the remaining eigenvalues of the graph. This we refer to as a complete equitable decomposition of the graph.

Developing A Quantitative Understanding Of U-Substitution In First-Semester Calculus, Leilani Camille Heaton Fonbuena

Theses and Dissertations

In much of calculus teaching there is an overemphasis on procedures and manipulation of symbols and insufficient emphasis on conceptual understanding of calculus topics. As such students to struggle to understand and use calculus ideas in applied settings. Research shows that learning calculus topics from a quantitative reasoning-perspective results in more powerful and flexible conceptions of calculus topics like integration. However, topics beyond introducing integrals and the Fundamental Theorem of Calculus, like u-substitution, have yet to be explored from a quantity-based perspective. In this study, I conducted a set of two clinical interviews where we discussed quantitative meanings of integrals, …

Testing Detrital Zircon Age Bias In Tectonic Provenance: Examples From Modern Alluvium In The South Island, New Zealand, Will Sparhawk Fisher

Theses - ALL

Detrital zircon (DZ) grains from 13 drainages across the South Island, New Zealand, were U-Pb dated to ascertain how accurately their ages reflect the geologic record of exposed bedrock. With the proliferation of inexpensive and easily accessible ion microprobes and laser ablation inductively coupled plasma mass spectrometers, DZ dating has become the dominant chronometer for elucidating tectonic systematics. Zircon’s physical and chemical resilience makes it an ideal candidate for U-Pb geochronometry, but is also a potential source of bias. Zircon’s resilience in sedimentary systems means it rarely occurs as first order detritus. N = 966 zircon grains from Modern alluvium …

Interactive White Boards In A Secondary Mathematics Classroom, Leann Bolhuis

Mathematics Graduate Theses

"A Formal Portfolio Submitted to the Faculty of the DEPARTMENT OF MATHEMATICS & COMPUTER SCIENCE In Partial Fulfillment of the Requirements For the Degree of MASTER OF SCIENCE IN MATHEMATICS".

Literature Review On Water Desalination Plant Production And Brine Disposal Methods, Grace Kollars

Department of Environmental Studies: Undergraduate Student Theses

Water scarcity is an issue all around the world because people have a lack of clean and available drinking water. One way this issue can be eased and people can have more access to water is implementing water desalination plants around the world. Since most of the water on earth cannot be drunk, there are ways to turn the over abundance of salty waters we have on this planet into fresh, drinkable water to ease the water insecurity. There are many methods out there that can be used for water desalination, most of them involving membrane technologies. The most efficient …

Eastern Redcedar Reduces Regeneration And Diversity In The Forests Of The Niobrara River Valley, Abigail Ridder

Department of Environmental Studies: Undergraduate Student Theses

Boundary forests are found growing interdigitated with grasslands across the Great Plains. The Niobrara River valley boundary forest has a unique composition of species not seen anywhere else in North America. Encroachment of eastern redcedar (Juniperus virginiana L.) into grasslands and forests is significantly increasing eastern redcedar’s presence in the Niobrara River Valley as well as in the rest of the Great Plains region. This tree species is capable of significantly decreasing recruitment and diversity in grasslands, which can change the composition of the entire ecosystem. However, the effect of eastern redcedar on recruitment and diversity of naturally forested ecosystems …

Analyzing Recycling Options For Wind Turbine Blade Waste, Awinita Bunner

Department of Environmental Studies: Undergraduate Student Theses

The purpose of this study was to conduct a systematic literature review to identify recycling options for wind turbine blade waste. Wind energy is a rapidly growing energy source due to its renewability and accessibility. However, the turbines that produce this energy have blades that must be replaced throughout the turbine’s lifetime. The standard disposal method of decommissioned blades is the landfill. However, problems are arising within states as landfills are being overrun by the wind turbine blades once they reach their end-of-life. Conducting this study aims to provide a list of recycling options and provide an evaluation of each …

Outdoor Recreation And Its Effect On Our Relationship With The Environment, Martin Brannaman

Department of Environmental Studies: Undergraduate Student Theses

This study was conducted at the University of Nebraska Outdoor Adventure Center. This study employed a pre-post retrospective assessment looking at individuals' connection with nature after embarking on a direct outdoor experience. A direct outdoor experience is when an individual is outside and not surrounded by manmade structures (Kil, 2016). I believe that after a direct outdoor experience the sample group will have a significant change in their connection to nature. The objective is to measure change in a group's connection to nature, through the Connectedness to Nature Scale (CNS, Mayer & Frantz, 2004). The population was a group of …

Examining The Impact Of Covid-19 On The Education And Development Of American Students, Riley Fortin '25

Student Research

After the COVID-19 pandemic, the vast majority of American children have fallen behind on core subjects due to the ultimate ineffectiveness of remote learning. This study attempts to discover the degree to which children have fallen behind through the trends in the National Association of Educational Procurement’s two most recent testing years. A database accessed from Google has been analyzed, filtered by state and visualized in tables in order to indicate any possible trends as a result of remote learning brought on by the pandemic. By looking at data in seven different states across the country, there is a notable …

Sexual And Reproductive Health Disparities For Lgbtq+ Patients, Lauren Del Rosario

Student Research

As of 2022, 7.1% of Americans identify as LGBTQ. Members of the LGBTQ+ community in the United States experience greater health disparities than their heterosexual counterparts due to structural inequity: in addition to having minority status within the United States, there is a lack of education and research about LGBTQ+ health-related issues as well as restrictive policies that limit access to health care and other health benefits. As a result, the LGBTQ+ community is more prone to developing certain conditions, have less access to health care, and have worse health outcomes. However, LGBTQ+ visibility has increased dramatically within the last …

Structural Reasoning With Rational Expressions, Dana Steinhorst

Theses and Dissertations

Many students struggle to make sense of algebraic expressions in math. This lack of understanding results in students making symbolic manipulation errors, hindering their procedural fluency. Researchers believe these errors are linked to students' lack of structural reasoning. While research has shown that students rarely engage in expert structural reasoning, little is known about how students actually reason structurally. In this study, I interviewed six high school calculus students to study the way they identified, matched, and evaluated structures as they solved problems involving rational expressions and equations. I analyzed the participant interviews and outlined the matching process they used …

Determination Of A Catalytic Mechanism By Time Resolved Fourier Transform Infrared Spectroscopy And Time Domain Analysis Of Data From Fourier Transform Ion Cyclotron Resonance Mass Spectrometry, Jacob T. Davis

Theses and Dissertations

Heterobimetallic catalysts offer large potential for efficient and selective catalysis of a wide range of reactions. Better understanding of these catalytic mechanisms could yield further improvement in their catalytic abilities. Cp(CO)2Fe-Cu(IPr) (IPr = N,N-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) is a catalyst that has been reported to catalyze arene borylation. The catalytic mechanism of this catalyst that had been previously proposed had the initial step being a metal-metal cleavage. However, computational modeling suggested an alternate mechanism that could be more energetically favorable. Rather than a metal-metal cleavage as the initial step, we proposed a photoactivated carbonyl dissociation. To support this proposition, we performed time resolved …

Zeros Of A Family Of Complex-Valued Harmonic Rational Functions, Alexander Lee

Theses and Dissertations

The Fundamental Theorem of Algebra is a useful tool in determining the number of zeros of complex-valued polynomials and rational functions. It does not, however, apply to complex-valued harmonic polynomials and rational functions generally. In this thesis, we determine behaviors of the family of complex-valued harmonic functions $f_{c}(z) = z^{n} + \frac{c}{\overline{z}^{k}} - 1$ that defy intuition for analytic polynomials. We first determine the sum of the orders of zeros by using the harmonic analogue of Rouch\'e's Theorem. We then determine useful geometry of the critical curve and its image in order to count winding numbers by applying the harmonic …

An Imaging Mass Spectrometry Investigation Into The N-Linked Glycosylation Landscape Of Pancreatic Ductal Adenocarcinoma And The Development Of Associated Tools For Enhanced Glycan Separation And Characterization, Colin Mcdowell

MUSC Theses and Dissertations

The severity of pancreatic ductal adenocarcinoma (PDAC) is largely attributed to a failure to detect the disease before metastatic spread has occurred. CA19-9, a carbohydrate biomarker, is used clinically to surveille disease progression, but due to specificity challenges is not suitable for early discovery. As CA19-9 and other prospective markers are glycan epitopes, there is great clinical interest in understanding the glycobiology of pancreatic cancer. Unfortunately, few studies have been able to link glycosylation changes directly to pancreatic tumors and instead have focused on peripheral glycan alterations in the serum of PDAC patients. To address this gap in our understanding, …

Transposición Didáctica Para La Enseñanza De La Matemática Avanzada Por Medio De Gamificación, Juan David Firigua Bejarano, Karen Giset Duarte Moyano, Jesús Antonio Villarraga Palomino

Educación

El presente proyecto de investigación, tuvo como propósito diseñar escenarios gamificados acordes a la Transposición Didáctica en la enseñanza y aprendizaje de conceptos de matemática avanzada; Teselados, Fractales, Geometría Esférica, Teoría de Grafos y Topología. Esta investigación se fundamentó en la teoría de la Transposición Didáctica propuesta por Chevallard (1997) y las dinámicas de los entornos Gamificados por Werbach y Hunter (2015). Se desarrolló una metodología de enfoque cualitativo, dirigido a estudiantes del grado décimo del Colegio Fundación Manuel Aya, Fusagasugá, la muestra la conformo sesenta y siete (67) estudiantes. Para esto, se caracterizó la población por medio de diversas …

Spatial Validation Of Agent-Based Models, Kristoffer Wikstrom, Hal T. Nelson

Public Administration Faculty Publications and Presentations

This paper adapts an existing techno–social agent-based model (ABM) in order to develop a new framework for spatially validating ABMs. The ABM simulates citizen opposition to locally unwanted land uses, using historical data from an energy infrastructure siting process in Southern California. Spatial theory, as well as the model’s design, suggest that adequate validation requires multiple tests rather than relying solely on a single test-statistic. A pattern-oriented modeling approach was employed that first mapped real and simulated citizen comments across the US Census tract. The suite of spatial tests included Global Moran’s I, complemented with bivariate correlations, as well as …

Single-Shot, Ultrafast, Multi-Frame X-Ray Imaging Of Defect-Bearing Ablator Materials In Extreme Conditions, Daniel S. Hodge

Theses and Dissertations

Characterization of the dynamic behavior of defect-bearing ablator materials subjected to extreme conditions is essential in advancing fusion energy as an reliable and abundant energy source. By understanding how materials evolve spatially and temporally we can minimize hydrodynamic instabilities, which are major contributing factors to energy yield degradation in inertial confinement fusion (ICF) experiments. In this thesis we demonstrate the capabilities of an ultrafast x-ray imaging (UXI) detector, the Icarus V2, where we capture multiple frames of single void-bearing sample compressed by a high-intensity laser shockwave. Using the Matter in Extreme Conditions (MEC) instrument at the Linac Coherent Light Source …

Mussel Squeeze: Dissolved Oxygen And Temperature Can “Squeeze” Zebra Mussels Out Of Invaded Reservoirs, Crysta Gantz, Rich Miller, Steve Wells, Mark D. Sytsma, Angela Strecker

Environmental Science and Management Faculty Publications and Presentations

Zebra mussels (Dreissena polymorpha) are an aquatic invasive species that cause extensive economic and ecological impacts and are a management priority in areas outside of their native range. Survivorship and distribution of zebra mussels within a waterbody are thought to be influenced by temperature and dissolved oxygen conditions, but detailed information to confirm the importance of these environmental controls is necessary to inform management efforts. We measured planktonic zebra mussel veliger density and adult survivorship in San Justo Reservoir in central California to determine distribution and timing of spawning in relation to temperature and dissolved oxygen throughout winter, spring, and …

Identity Work To Teach Mathematics For Social Justice, Navy B. Dixon

Theses and Dissertations

In this thesis, mathematics educators are conceptualized as individuals with multiple, simultaneous figured worlds that inform their decisions while planning. The study explores how two mathematics educators negotiated and orchestrated their figured worlds to plan two mathematics lessons for social justice. The results highlight how numerous the figured worlds each participant surfaced through background interviews. Some of the figured worlds were elicited by the interview questions (i.e., Race, Family, Social Justice Teaching) but other figured worlds organically surfaced through the interviews (i.e., Sexuality, Community, Activism, Critical Information Consumption). A discursive analysis of a selection of these figured worlds revealed conceptualizations …

Issues In Melanoma Detection: Semisupervised Deep Learning Algorithm Development Via A Combination Of Human And Artificial Intelligence, Mena Kozman, Carly Stender, Luca Giancardo, Cui Tao

Faculty, Staff and Student Publications

BACKGROUND: Automatic skin lesion recognition has shown to be effective in increasing access to reliable dermatology evaluation; however, most existing algorithms rely solely on images. Many diagnostic rules, including the 3-point checklist, are not considered by artificial intelligence algorithms, which comprise human knowledge and reflect the diagnosis process of human experts.

OBJECTIVE: In this paper, we aimed to develop a semisupervised model that can not only integrate the dermoscopic features and scoring rule from the 3-point checklist but also automate the feature-annotation process.

METHODS: We first trained the semisupervised model on a small, annotated data set with disease and dermoscopic …

Enhanced Structural Control Of Soft-Templated Mesoporous Inorganic Thin Films By Inert Processing Conditions, Maximilliano Jesus Jara Fornerod, Alberto Alvarez-Fernandez, Eric R. Williams, Miximillian W.A. Skoda, Beatriz Prieto-Simon, Nicolas H. Voelcker, Morgan Stefik, Marc-Oliver Coppens, Stefan Guldin

Faculty Publications

Mesoporous thin films are widely used for applications in need of high surface area and efficient mass and charge transport properties. A well-established fabrication process involves the supramolecular assembly of organic molecules (e.g., block copolymers and surfactants) with inorganic materials obtained by sol-gel chemistry. Typically, subsequent calcination in air removes the organic template and reveals the porous inorganic network. A significant challenge for such coatings is the anisotropic shrinkage due to the volume contraction related to solvent evaporation, inorganic condensation, and template removal, affecting the final porosity as well as pore shape, size, arrangement, and accessibility. Here, we show that …