Physical Sciences and Mathematics Commons^™

The Quantitative Assessment Of Pond Scum: An Examination Of The Biogeochemistry Of Phosphorus Cycling In The Belgrade Lakes, Abbey M. Sykes

Honors Theses

The internal recycling phosphorus in freshwater lake bottom sediments represents a significant source of hypolimnetic phosphorus (P) release for many of Maine’s lakes. In summer months, Maine lakes often thermally stratify and the lake hypolimnion develops anoxia, leading to a reduction in redox potential at the sediment-water interface. These reducing conditions facilitate the reductive dissolution of ferric iron, and, since phosphorus is often present in freshwater lake sediments as solid FeOOH-PO₄ complexes, results in release of soluble phosphorus into the water column. Our current study presents field and laboratory data from sediment fractionation extractions designed to quantify concentrations of …

A Generalized Polar-Coordinate Integration Formula, Oscillatory Integral Techniques, And Applications To Convolution Powers Of Complex-Valued Functions On $\Mathbb{Z}^D$, Huan Q. Bui

Honors Theses

In this thesis, we consider a class of function on $\mathbb{R}^d$, called positive homogeneous functions, which interact well with certain continuous one-parameter groups of (generally anisotropic) dilations. Generalizing the Euclidean norm, positive homogeneous functions appear naturally in the study of convolution powers of complex-valued functions on $\mathbb{Z}^d$. As the spherical measure is a Radon measure on the unit sphere which is invariant under the symmetry group of the Euclidean norm, to each positive homogeneous function $P$, we construct a Radon measure $\sigma_P$ on $S=\{\eta \in \mathbb{R}^d:P(\eta)=1\}$ which is invariant under the symmetry group of $P$. With this measure, we prove …

Mot-Based Lifetime Measurements Of Potassium-39 5p1/2 And 5p3/2 States, Huan Q. Bui

Honors Theses

This thesis presents measurements of the lifetimes of 5p1/2 and 5p3/2 of K39 via exciting a cloud of K39 atoms in a magneto-optical trap by a linearly-polarized pulse of 405 nm light followed polarization-specific, time-resolved fluorescence detection. We find that $\tau_{5p1/2} = $ 138.8 $\pm$ 1.6 ns, which is consistent with past measurements \cite{triumf}, \cite{berends} and calculations \cite{safranova}. The $\tau_{5p3/2}$ measurement is naturally more involved since quantum beats due to hyperfine and Zeeman effect are present. Our observation of $\tau_{5p3/2} =$ 137.6 $\pm$ 3.1 ns and $\tau_{5p3/2} =$ 136.0 $\pm$ 2.4 ns, obtained from two slightly different approaches, are compared …

Visualizing The Range Of Glaciers: Science, Art And Narrative, Claire E. Waichler

Honors Theses

Glaciers are sensitive indicators and data keepers of climatic change. The glaciers of the North Cascades, Washington, also have significant economic and cultural value as they are enmeshed in hydroelectricity generation, terrestrial and aquatic ecology, and human communities. My project approaches the current climate crisis by examining the past, present and future of the glaciers of the North Cascades through the two lenses of art and science. I review and contextualize the last century of glacier research in the North Cascades to identify patterns of glacier change and how this affects ecological and human communities. Overlaid upon my literature review, …

Pollen: A Secure, Decentralized Wireless Communication Platform, Max Perrello

Honors Theses

In this article, we detail an encrypted, internet-independent messaging platform, of which we built a prototype. This thesis also describes the challenges faced in the process, as well as potential future enhancements.

Convolutional Audio Source Separation Applied To Drum Signal Separation, Marius Orehovschi

Honors Theses

This study examined the task of drum signal separation from full music mixes via both classical methods (Independent Component Analysis) and a combination of Time-Frequency Binary Masking and Convolutional Neural Networks. The results indicate that classical methods relying on predefined computations do not achieve any meaningful results, while convolutional neural networks can achieve imperfect but musically useful results. Furthermore, neural network performance can be improved by data augmentation via transposition – a technique that can only be applied in the context of drum signal separation.

Grief, Loss, And Climate Change: Validation Of A Solastalgia Scale, Claire Luce

Theses and Dissertations

Climate change has been identified as a defining issue of this century (United Nations, n.d.). Climate change impacts human wellbeing including mental health. While much research has focused on the way that the effects of climate change cause increases in common mental disorders, mental health is not just the absence of these disorders (World Health Organization, 2014). Non-pathologized mental health responses to climate change, such as the grief and loss that results from climate change impacts, are a growing consideration for researchers. Solastalgia, or the distress experienced in the absence of the solace once provided by the environment in the …

Parametric, Nonparametric, And Semiparametric Linear Regression In Classical And Bayesian Statistical Quality Control, Chelsea L. Jones

Theses and Dissertations

Statistical process control (SPC) is used in many fields to understand and monitor desired processes, such as manufacturing, public health, and network traffic. SPC is categorized into two phases; in Phase I historical data is used to inform parameter estimates for a statistical model and Phase II implements this statistical model to monitor a live ongoing process. Within both phases, profile monitoring is a method to understand the functional relationship between response and explanatory variables by estimating and tracking its parameters. In profile monitoring, control charts are often used as graphical tools to visually observe process behaviors. We construct a …

Strongly Correlated Phases In Quantum Hall Systems, Amartya Saha

Theses and Dissertations--Physics and Astronomy

Quantum Hall systems have a one-body energy spectrum consisting of dispersion-less Landau levels. Electron-electron interactions thus dominate in partially filled Landau levels, which exhibit a myriad of strongly correlated phases such as quantum hall ferromagnets and fractional quantum Hall phases. We study two examples of these phenomena.

In the first project, we explore the ground state of a system with an interface between two semi-infinite regions with fillings ν= 4 and ν= 3 respectively. The width of the interface can be controlled by varying the background potential, which provides an additional tuning parameter. For a certain range of …

Numerical Approximation Of Lyapunov Exponents And Its Applications In Control Systems, Nakita K. Andrews

Electronic Theses and Dissertations

The progression of state trajectories with respect to time, and its stability properties can be described by a system of nonlinear differential equations. However, since most nonlinear dynamical systems cannot be solved by hand, one must rely on computer simulations to observe the behavior of the system. This work focuses on chaotic systems. The Lyapunov Exponent (LE) is frequently used in the quantitative studies of a chaotic system. Lyapunov exponents give the average rate of separation of nearby orbits in phase space, which can be used to determine the state of a system, e.g. stable or unstable. The objective of …

Advancements In Bio-Based Novel (Co)Monomers For Polymeric Materials, Khristal Anne Monroe

Electronic Theses and Dissertations

Most current research in the area of sustainable and environmentally friendly materials relate to the use of renewable sources for the fabrication of bio-based polymers and composites. Using plant-based derivatives is a common strategy. Pine sap can be distilled into turpentines (light fraction) and pine rosin (heavy fraction). Pine rosin is obtained as a brittle solid and its major component is abietic acid. This project aims at investigating a synthetic approach for the synthesis of a pine rosin-based polymer that can be potentially used for manufacturing a collection device for pine sap. The synthetic strategy consisted in the preparation of …

Design, Synthesis And Applications Of Nanoparticles In Suppression Of Mosquito-Born Flaviviridae Viruses, Maria R. Blahove

Electronic Theses and Dissertations

Recently, nanoparticles have become an origin of exploration in the chemistry field due to their unique medical uses. The current drug delivery models of nanoparticles often include a metal base with a drug conjugated to its surface. However this raises concerns regarding toxicity. A novel approach to solving this dilemma is the development of nanosized biocompatible polymer-based micelles, created from PEG-PCL-PEG triblock polymer, and formed around a drug of choice. The goal is to create a drug carrier nanoparticle system that is labile at a specific intracellular pH, without undue toxicity to the cell. This creates a drug-loaded nanoparticle that …

The Effects Of Nacl On The Triple Helix Structure Of Collagen And The Reinforcement Of Tung Oil-Based Polymers With Collagen Peptides, Christopher Dzorkpata

Electronic Theses and Dissertations

In this research, a collagen-reinforced bio-composite from tung oil was prepared using free radical initiation and thermal polymerization, leading to polyolefinic tung oil-based matrix. Two peptides (long and short) were synthesized and their secondary features were analyzed using circular dichroism spectroscopy. After this analysis, the long peptide exhibited more triple helix characteristics as compared to the short peptide. The full protein will ultimately have a better interaction with the tung oil, was used in the synthesis of the collagen-reinforced bio-composite. The presence of NaCl in the triple helix and its overall effect on the thermal and mechanical properties of the …

Hydroamidation With Acetamides And Trifluoroacetamides, Gordon H. Whitetree

Electronic Theses and Dissertations

The hydroamidation reaction is an attractive methodology for the construction of larger functional molecules. In our research, a baseline reactivity was established for the hydroamidation reaction using a set of N-alkyl and N-aryl (trifluoro)acetamides with methyl acrylate and acrylonitrile, various bases and varying reaction conditions. The combination of alkenes, acetamides, and trifluoroacetamides with base was crucial for reaction rate. N-aryl trifluoroacetamides exhibited near quantitative conversions in neat alkene with Diazabicycloundecene (DBU) as base. The less acidic N-aryl acetamides performed much faster in the presence of KOtBu and conversions of >95% were accomplished regularly but contained a large presence …

New Results On Cyclic Compositions And Multicompositions, Silvana Ramaj

Electronic Theses and Dissertations

Integer compositions, cyclic compositions, and lately k-compositions, are an important topic in combinatorics and number theory. In this paper, we will explain, the general approach of using generating functions to study number sequences involving compositions, cyclic compositions, k-compositions, and the number of parts in each of them. After generating the data, some properties are observed and proved. Also, some interesting bijections involving Pell numbers and the Jacobsthal sequence are given.

Learning From Multi-Class Imbalanced Big Data With Apache Spark, William C. Sleeman Iv

Theses and Dissertations

With data becoming a new form of currency, its analysis has become a top priority in both academia and industry, furthering advancements in high-performance computing and machine learning. However, these large, real-world datasets come with additional complications such as noise and class overlap. Problems are magnified when with multi-class data is presented, especially since many of the popular algorithms were originally designed for binary data. Another challenge arises when the number of examples are not evenly distributed across all classes in a dataset. This often causes classifiers to favor the majority class over the minority classes, leading to undesirable results …

Bayesian Techniques For Relating Genetic Polymorphisms To Diffusion Tensor Images Of Cocaine Users, Tmader Alballa

Theses and Dissertations

Past investigations utilizing Diffusion Tensor Imaging (DTI) have demonstrated that cocaine use disorder (CUD) yields white matter changes. We proposed three Bayesian techniques in order to explore the relationship between Fractional Anisotropy (FA), genetic data, and years of cocaine use (YCU). CUD participants exhibit abnormality in different areas of the brain versus non-drug using controls, which is measured by DTI. This dissertation is motivated by a neuroimaging genetic study in cocaine dependence, which found that there were relationships between several genes such as GAD and 5-HT₂R and CUD subjects.

In the first chapter, there is background on the …

Computational Study Of Radical Cation Rearrangements, Mi'kayla D. Word

Theses and Dissertations

A radical cation is a molecule that has one unpaired electron that holds a positive charge. The unpaired electron within a radical cation causes the molecule to be reactive. The high reactivity of these species allows for radical cations to be commonly studied experimentally using mass spectrometry and other multi-mass imaging techniques. However, these methods often cannot resolve the reaction mechanisms for these fast reactions. Specifically, radical cation rearrangement mechanisms are particularly unresolved within experiments. For this reason, radical cation rearrangements are computationally investigated to explain complex reaction pathways for processes to understand reactions leading to the initiation of detonation …

Performance In Calculus Ii For Students In Clear Calculus: A Causal Comparative Study, Ty Mckinney, Rebecca Dibbs

Pursue: Undergraduate Research Journal

Calculus is one of the greatest intellectual achievements of the world and is the main gateway for students that are heading into the fields that will power the economy of the 21st century. However, over 25% of students fail U.S. calculus courses each year and end up changing majors. It is important for educators and researchers to try to improve student success and find ways to increase STEM major retention. The purpose of this study was to compare the performance between students that are in traditional and non-traditional calculus II courses based on their preparation in either traditional or non-traditional …

Counting Conjugacy Classes Of Elements Of Finite Order In Compact Exceptional Groups, Qidong He

Honors Theses

Given a compact exceptional group $G$ and $m,s\in\mathbb{N}$, let $N(G,m)$ be the number of conjugacy classes of elements of order $m$ in $G$, and $N(G,m,s)$ the number of such classes whose elements have $s$ distinct eigenvalues. In string theory, the problem of enumerating certain classes of vacua in the string landscape can be rephrased in terms of the study of these quantities. We develop unified combinatorial algorithms based on Burnside's Lemma that can be used to compute both quantities for each of the five compact exceptional groups. Thus, we provide a combinatorial, alternative method to that of Djoković and extend …

Statistical And Machine Learning Approaches To Depressive Disorders Among Adults In The United States: From Factor Discovery To Prediction Evaluation, Minhwa Lee

Senior Independent Study Theses

According to the National Institutes of Mental Health (NIMH), depressive disorders (or major depression) are considered one of the most common and serious health risks in the United States. Our study focuses on extracting non-medical factors of depressive disorders diagnosis, such as overall health states, health risk behaviors, demography, and healthcare access, using the Behavioral Risk Factor Surveillance System (BRFSS) data set collected by the Centers for Disease Control and Prevention (CDC) in 2018.

We set the two objectives of our study about depressive disorders diagnosis in the United States as follows. First, we aim to utilize machine learning algorithms …

Learning Graphs For Object Tracking And Counting, Shengkun Li

Legacy Theses & Dissertations (2009 - 2024)

As important problems in computer vision, object tracking and counting attract increasing amounts of attention in recent years due to its wide range of applications, such as video surveillance, human- computer interaction, smart city. Despite much progress has been made in object tracking and counting with the arriving of deep neural networks (DNN), there still remains much room for improvement to satisfy the real-world applications.

Novel Functional Proteomics Techniques For Multiplex And Single Cell Cytokines Detection, Mohammed Abdullah

Legacy Theses & Dissertations (2009 - 2024)

Since the early stages of biological research, the vital role of molecules in living creatures has been investigated and documented. According to Francis Watson's definition of the central dogma of biology, proteins are the final product of molecular biology and can't transfer information to other proteins like DNA or mRNA. Therefore, they are considered as the functional molecules of biology making them are more clinically relevant. However, the available techniques to study the protein characters, which coined laterally as proteomics science, are not well developed as genomics techniques did. Since the first human genome project is finished, the cost of …

Novel Sensing Concept For Organophosphate Monitoring, Cheyenne Bowman

Legacy Theses & Dissertations (2009 - 2024)

Organophosphates are a group of insecticides that are commonly used as chemical warfare agents (CWAs), since they can act as nerve agents by inhibiting acetylcholinesterase. Acetylcholinesterase is a vital enzyme of the central nervous system (CNS). This enzyme facilitates the breakdown of acetylthiocholine into thiocholine and acetate. The major goal of the research will be to provide a preliminary rapid, sensitive, and reliable method for sensing organophosphates. Current methods are enzyme inhibition-based – that is, a decrease in absorbance or signal yields a positive indicator for the presence of analyte. Herein, two different novel approaches to organophosphate sensing are described.The …

An Examination Of The Arctic Environment And Arctic Cyclones During Periods Of Low And High Forecast Skill Of The Synoptic-Scale Flow, Kevin Biernat

Legacy Theses & Dissertations (2009 - 2024)

This dissertation compares Arctic environmental conditions and Arctic cyclones (ACs) between periods of low and high forecast skill of the synoptic-scale flow over the Arctic during summer, hereafter referred to as low-skill periods and high-skill periods, respectively. This dissertation also examines features and processes influencing the evolution and forecast skill of selected categories of ACs.

Legacy And Emerging Per- And Polyfluoroalkyl Substances : Analysis, Environmental Distribution, And Bioconcentration, Richard Anthony Brase

Legacy Theses & Dissertations (2009 - 2024)

Per- and polyfluoroalkyl substances (PFAS) constitute a broad class of anthropogenic chemicals that have been used in numerous industrial and consumer-product applications since the late 1940s. The environmental persistence of these compounds in combination with their widespread commercial use have led PFAS to be recognized as contaminants of concern on the global scale. Despite regulatory efforts calling for the decreased use of certain perfluorocarboxylic and -sulfonic acids referred to as “legacy” PFAS, these compounds continue to be detected in both environmental and biological matrices. Moreover, manufacturers have begun to replace the legacy PFAS with emerging alternatives for which the regulations …

A Comparison Of The Upscale Influence Of Various Planetary Boundary Layer Turbulence Parameterizations On The Evolution Of Extratropical Cyclones, Matthew Vaughan

Legacy Theses & Dissertations (2009 - 2024)

Subgrid-scale turbulence in numerical weather prediction models is typically handled by a PBL parameterization. These schemes attempt to represent turbulent mixing processes occurring below the resolvable scale of the model grid in the vertical direction, and they act upon temperature, moisture, and momentum within the boundary layer. This dissertation utilizes idealized and full-physics numerical model simulations to understand how variations in turbulent mixing parameterizations may influence sensible weather forecasts of baroclinic cyclones across a variety of spatial and temporal scales. Furthermore, a primary pathway through which PBL turbulence projects upscale during baroclinic cyclone events is identified using a combination of …

Finite Mixture Models : Applications To Length Of Stay For Delivery Hospitalizations, Eva Williford

Legacy Theses & Dissertations (2009 - 2024)

In the United States (U.S.), childbirth is the most common reason for hospitalization, and the maternal mortality rate per 100,000 (2017-2018) is markedly elevated in the U.S. (17.4) compared to neighboring Canada (10), the United Kingdom (7), and Japan (5) (Trends in Maternal Mortality, 2000 to 2017: Estimates by WHO, UNICEF, UNFPA, World Bank Group and the United Nations Population Division). These data, the increased focus on addressing severe maternal morbidity and mortality to improve patient outcomes and reduce healthcare costs is well deserved. These women often have a longer delivery length of stay (LOS) and experience complications of varying …

Seasonal Variations And Long-Term Trend Of Mineral Dust And The Effects Of Dust On Cloud And Precipitations, Yanda Zhang

Legacy Theses & Dissertations (2009 - 2024)

For its enormous emission rate and long-range transport ability, mineral dust is one of the most abundant aerosol species, contributing to about half of the global atmospheric aerosol dry mass burden. A series of studies demonstrated the significant influences of mineral dust on air quality, public health, biogeochemical cycles, and climate systems. In the atmosphere, mineral dust is known to have important impacts on the Earth system through direct effects (scattering and absorbing shortwave and longwave radiations), semi-direct effects (changing atmospheric temperature structure and cloud lifetime), and indirect effects (influencing cloud microphysics processes as cloud condensation nuclei (CCN) and ice-nucleating …

Aerosol And Terrain Effects On Winter Cloud And Precipitation Over New York State, Yuyi Du

Legacy Theses & Dissertations (2009 - 2024)

Prediction of regional weather and climate regarding precipitation for a region such as the Northeast US with its complex terrain and aerosol environment constitutes a major challenge. Furthermore, complex thermodynamic structures occur in and around New York State (NYS) owing to its complex topography paired with its coastal regions, ultimately affecting cloud and precipitation microphysics. The microphysical processes within the weather systems that produce orographic precipitation are not fully understood. These processes include, but are not limited to, liquid-ice interactions, ice growth through vapor deposition, riming, and aggregation, cloud-aerosol interactions, and melting and refreezing upon sedimentation to the surface. These …