Physical Sciences and Mathematics Commons^™

Grassland Bird Responses To Bison And Prescribed Fire Disturbances At Nachusa Grasslands And Kankakee Sands, Antonio Del Valle

Graduate Research Theses & Dissertations

Grazing from native herbivores such as bison (Bison bison), in combination with prescribed fire, are applied to tallgrass prairies by managers to recreate important disturbance patterns in this ecosystem. Bird communities may be indirectly impacted by these disturbances through their direct impact on plants that provides critical breeding habitat for grassland birds. The objectives of this research are to determine the impacts that bison and prescribed fire have on grassland breeding birds in two tallgrass prairie preserves, Kankakee Sands and Nachusa Grasslands. Birds, vegetation structure, and bison activity were surveyed systematically at these two preserves in 2020 and 2021. Prescribed …

Magnetic Charge Ordering Of Pinwheel Artificial Spin Ice In In-Plane External Magnetic Fields And Its Application For Tunable Vortex Pinning, Timothy Draher

Graduate Research Theses & Dissertations

Pinwheel artificial spin ice (ASI) systems fabricated using permalloy nanobars offer tunable control of superconducting vortices in an ASI-superconductor hybrid. Vortex pinningis achieved by tuning the ordering of the ASI’s magnetic charge distribution via an external field to create an optimal potential energy landscape to which superconducting vortex motion can be impeded or pinned. Magnetic charge ordering in a pinwheel ASI is visualized using MuMax3 micromagnetic simulations to aid in characterizing the correlation of charge ordering amongst the spin ice system with the application of the external field. Vortex pinning is characterized in a sample of pinwheel spin ice patterned …

Transport Of Polyethylene Microplastic Spheres In A Sandy Aquifer, Alyssa Marie Graveline

Graduate Research Theses & Dissertations

Microplastic particles are currently listed as a Contaminant of Emerging Concern (CEC) since they are in much of Earth’s water systems and recent studies indicate plastic particles can sorb toxic contaminants. Microplastics (MP) are defined as plastic particles under 5 mm in length. Currently, there is a paucity of data on the transport of MP in the subsurface. This study investigated the transport, filtration, retardation, and influence of 5-100ߎm plastic polyethylene spheres in a shallow sandy aquifer over a distance of 1m by utilizing two forced hydraulic gradient tracer studies. Slug tests were used to estimate hydraulic conductivity prior and …

Methods For Computing The Global Optimum Of Non-Convex Objectives, Isaac Michael Hawn

Graduate Research Theses & Dissertations

\begin{abstract}In this thesis, we concern ourselves with solving the unconstrained optimization problem % \begin{gather*} \text{Minimize}\; f(x)\\\text{subject to}\; x\in X \end{gather*} % where $f\colon\mathbb{R}^N\to \mathbb{R}$ is a non-convex function, possibly with infinitely many local minima. Solving such a problem, especially in higher dimensions often proves to be an extraordinarily difficult task, either in time complexity or in the methodology itself. Indeed, mathematicians must often resort to algorithms which make use of problem structure and which may not generalize well. In this thesis, we present two algorithms which solve this problem, albeit with their own shortcomings.

First, we present a new, $N$-dimensional …

Forecasting Bitcoin, Ethereum And Litecoin Prices Using Machine Learning, Sai Prabhu Jaligama

Graduate Research Theses & Dissertations

This research aims to predict the cryptocurrencies Bitcoin, Litecoin and Ethereum using Time Series Modelling with daily data of closing price from 16th of October 2018 to 9th of September 2021for a total of 1073 days. Augmented Dickey Fuller test was first used to check stationarity of the time series, then two forecasting algorithms called ARIMA, and PROPHET were used to make predictions. The findings show similar results for both the models for each of Bitcoin, Ethereum and Litecoin. The results achieved show modelling cryptocurrencies which are volatile using a single variable produces satisfying results.

Impact Of Prairie Restoration On Geochemistry And Microbial Communities In Groundwater, Kayla Koenig

Graduate Research Theses & Dissertations

Prairie restoration is important for reversing the loss of biodiversity and repairing ecosystem functions humanity is dependent on diverse ecosystems. This study looks at the impact of the beginning phases of prairie restoration on groundwater geochemistry and microbial communities the relationship between them. This research project studied the geochemistry and microbial communities in five wells before, during, and after the beginning phases of the first year of a prairie restoration on the Northern Illinois University campus. Water samples were collected bimonthly for a year and analyzed on an Ion Chromatograph. Microbial samples were collected monthly and underwent DNA extraction, amplification, …

Impact Of Public And Private Investments On Economic Growth Of Developing Countries, Faruque Ahamed

Graduate Research Theses & Dissertations

This paper aims to study the impact of public and private investments on the economic growth of developing countries. The study uses panel data from 39 developing countries covering the periods 1990-2019. The study is based on the neoclassical growth models or exogenous growth models in which land, labor, capital accumulation, etc., and technology proved substantial for economic growth. The paper uses the impact on overall GDP growth and GDP per capita growth. The study used a mixed-effect regression model and a Bayesian logistic regression model to derive the findings. For private investments, domestic credit has a positive association, but …

Analyzing Multistationarity In A Model Of A Dual Phosphorylation Network, Killian Kearney Anderson

Graduate Research Theses & Dissertations

Otero-Muras, Banga, and Alonso in [18] state biological reaction systems exhibit multistationarity, a system with at least two positive steady states. According to Otero-Muras,Banga, and Alonso in [18], initial conditions within the system, however, dictate the number of stable states in that system. Furthermore, multistationarity is an important componenet present in biological reaction systems that manage cellular responses [18]. Signal pathways regulating cell maturation, cell replication, and cell death rely on such systems [18]. Given the importance of multistationarity in biological reaction systems, it is necessary to construct a mathematical model, one in which multistationarity will be configured. More importantly, …

Precise Phase Space Control For Future Linear Colliders, Tianzhe Xu

Graduate Research Theses & Dissertations

The design of future linear colliders is highly constrained by their cost and footprint. Phase space partitioning offers an attractive path towards cost and complexity reduction through precise tailoring of particle beam distributions. In this dissertation, we discuss a phase space manipulation technique for generating flat electron beams---a type of beam distribution of particular interest to linear colliders. We report the experimental generation of flat beams with transverse-emittance ratio up to 200 at Argonne Wakefield Accelerator facility. We further expand the technique by combining it with transverse-to-longitudinal emittance exchange. We present the conceptual design of an electron injector capable of …

Counterexample To Eremenko's Conjecture, Paradise Low

Graduate Research Theses & Dissertations

Eremenko’s Conjecture is a long-standing problem in complex dynamics that asks whetherevery connected component of the set of escaping points of a transcendental entire function is unbounded. It was finally proven false in a paper by Mart ́ı-Pete, Lasse Rempe, and James Waterman that constructs a counterexample to the conjecture. This thesis seeks to pro- vide a background on Eremenko’s Conjecture, discuss the partial results surrounding it, and explain the construction of the counterexample in Mart ́ı-Pete, et al.’s paper.

Comparison Of Topsoil Moisture In E3sm Model Simulations And In-Situ Observations Over Illinois, Jacinda Lee Mayer

Graduate Research Theses & Dissertations

Soil moisture stimulates land-atmosphere interactions by modifying energy and water fluxes in the boundary layer and it plays an important role in climate change studies. The objective of this research is to quantify the spatial and temporal variations of the Illinois Climate Network’s (ICN) observed topsoil moisture, as well as evaluate how accurately the new climate model, E3SM, is simulating soil moisture compared to the observed data during 2003-2014. Observed topsoil moisture averaged over growing season during the 12-year period indicates a general dry-north and wet-south pattern in Illinois, and northeast and southwest become drier with the progression of the …

Development Of Ph-Sensitive And Amine-Reactive Lifters For The Detection Of Latent Fingermarks, Andrei Gregory Mlakar

Graduate Research Theses & Dissertations

Latent fingermarks are among the most common forms of physical evidence left at crime scenes. Being composed largely of eccrine and sebaceous secretions, they are typically invisible unless they are treated with, e.g., powders or cyanoacrylate fumes. Drawbacks to these and other commonly used methods, however, may include limited substrate compatibility, safety hazards, inability to detect older marks, and the need for expensive instrumentation and expert practitioners. Fingermarks on curved, reflective, patterned, or luminescent substrates are particularly challenging to image with most common techniques. After treatment, fingermarks on such difficult substrates may be transferred to, or “lifted” by, flexible adhesives, …

Third-Integer Resonant Extraction Regulation System For Mu2e, Aakaash Narayanan

Graduate Research Theses & Dissertations

A third-integer resonant slow extraction system is being developed for Fermilab's Delivery Ring to deliver protons to the upcoming Mu2e experiment. The timescale of the extraction (or spill) duration is 43 milliseconds, which is extremely short and unprecedented. Additionally, the experiment's strict and challenging requirements on the quality of the spill at this time scale has led to the development of a new Spill Regulation System (SRS) design. The SRS primarily consists of three components - slow regulation, fast regulation, and harmonic content suppressor. Contributions to the first two components of the SRS, i.e., Slow Regulation and Fast Regulation subsystems, …

Engagement Detection Using Prosodic Cues: An Approach For Measuring Child Emotional Engagement Level In Child-Robot Interaction Scenario, Mustafa Oztoprak

Graduate Research Theses & Dissertations

The ultimate goal of advanced child-robot interaction is to develop a high-level intelligencecommunication channel in a closed-loop configuration with the child as the focal point of the instructional scenario. This goal can be met by establishing efficient sensing mechanisms on the robot’s side, such as automatic engagement measuring, which will allow the robot to alter its behavior or even the instructional scenario’s execution.Recent researches, regarding engagement recognition systems mostly based on facial or multi-modal features.We would like to investigate this topic using prosodic cues only. We believe speech characteristics are more likely to be related to child speaker engagement level.This …

Search For Charged Higgs Bosons In The Tau+Nu Final State With 139 Inverse Fb Of Pp Collision Data At Sqrt(S)=13 Tev With The Atlas Experiment, Elliot Wesley Parrish

Graduate Research Theses & Dissertations

This dissertation uses 139 inverse fb of pp collision data collected at a center of mass energy of sqrt(s)=13 TeV by the ATLAS detector to search for charged Higgs bosons decaying to a tau lepton and a neutrino in association with a top quark. Two subchannels are defined based on the leptonic decay (tau+lepton) or hadronic decay (tau+jets) of the associated top quark. Parameterized Neural Networks are investigated and optimized to improve signal separation from background in both subchannels across a wide charged Higgs boson mass range of 80 GeV to 3000 GeV. Expected exclusion limits at 95% confidence on …

Monitoring Plants Growth In Indoor Vertical Farms Using Computer Vision And Ai Techniques, Bhama Krishna Pillutla

Graduate Research Theses & Dissertations

Climatic conditions like temperature, drought, and heavy metals disturb plant cell structures and, ultimately, plant growth that significantly affects crop production. Due to increasing climate change, maize crop yields are projected to decline by 24% by the end of century. With the increase in food demands and decrease in agricultural land and water resources, the space for effective farming is left much desired. Though limited to a few crops at this moment, Indoor Vertical Farming is one technique that requires much less land space, water, soil, and sunlight when compared to traditional farming. Vertical farming allows artificial control of temperature, …

Modeling Of Sub-Terahertz Wakefield Structures For Electron-Bunch Acceleration, Cassandra Phillips

Graduate Research Theses & Dissertations

Dielectric-lined waveguides have been extensively studied to potentially support high-gradient acceleration in beam-driven dielectric wakefield acceleration (DWFA) and for beam manipulations. In this thesis, we investigate the wakefield generated by a relativistic bunch passing through a dielectric waveguide with different transverse sections. I specifically consider the case of a structure consisting of two dielectric slabs, along with rectangular and square structures. Numerical simulations performed with the fine-difference time-domain WarpX program reveal interesting features of the transverse wake and possible experiments at the Argonne Wakefield Accelerator (AWA) are proposed.

Climate Change Impacts On Baseflow Contributions In A Semi-Arid, Snowmelt-Dominated Basin Within The Upper Colorado River Basin, Kaelyn Quinlan

Graduate Research Theses & Dissertations

The Upper Colorado River Basin (UCRB) is a significant water resource in the southwestern United States, providing water to Colorado, New Mexico, Utah, and Wyoming. (Reclamation, 2012). Communities and industries within these states are dependent on the Colorado River’s water availability and accessibility. Growing population and development demands, in conjunction with climate change, can have drastic consequences for the ecosystems and municipalities dependent on these reservoirs. It is critical that as watersheds within this region are strained under increased demands and decreased inputs, water use practices use informed decision-making to manage the budget and quality of its water resources.

I …

Modeling And Visualization Of Long-Term Public Opinion On Covid-19 Vaccine, Ashiqur Rahman

Graduate Research Theses & Dissertations

The coronavirus pandemic created significant dependence on social media. While the social web was crucial in spreading timely information and informing the public, misinformation has also spread with little to no oversight. Several works have focused on identifying misinformation and topic analysis in COVID-19 (SARS-COV-2) tweets. While most of the previous studies focus on a shorter time frame, we analyzed a larger dataset starting from the beginning of the pandemic until the end of December 2021. Our work focuses on a novel area that identifies the motivating and demotivating topics of COVID-19 vaccination and analyzes these topics based on time, …

Conductors For Maximal Orders Of Group Rings Over Local Fields, Brooke Randazzo

Graduate Research Theses & Dissertations

This dissertation examines conductors for maximal orders of group rings, $FD$, contained in integral group rings, $\mathcal{O}_F D$, where $D$ is a finite group, $F$ a local field, and $\mathcal{O}_F$ its discrete valuation ring. (Given two rings $R \subseteq S$, the conductor of $S$ in $R$, if it exists, is the largest ideal of $S$ contained in $R$.) First, we use a theorem of Jacobinski to make this conductor explicit where $F$ is a particular extension of $\mathbb{Q}_p$ of varying ramification index and $D$ is any elementary abelian $p$-group. Next, we examine this conductor problem for this same $F$ within …

Covidalert - A Wristwatch-Based System To Alert Users From Face Touching, Mrinmoy Roy

Graduate Research Theses & Dissertations

Worldwide 219 million people have been infected and 4.5 million have lost their lives in ongoing Covid-19 pandemic. Until vaccines became widely available, precautions and safety measures like wearing masks, physical distancing, avoiding face touching were some of the primary means to curb the spread of virus. Face touching is a compulsive human behavior that can not be prevented without constantly making a conscious effort, even then it is inevitable. To address this problem, we have designed a smartwatch-based solution, CovidAlert, that leverages Random Forest algorithm trained on accelerometer and gyroscope data from the smartwatch to detect hand transition to …

A Study Of Π – Π Stacking Interactions In Rhenium Carbonyl Complexes Based On Backbone Functionalized Bis(Pyrazolyl)Methane Ligands, Balamani Guduru

Masters Theses

π – π Stacking interactions are one of the most important non-covalent inter-molecular forces, which play an important role in the architecture of 1D and 2D networks of supramolecular chemistry. This associative contact involves the attractive interactions of aromatic molecules with each other. To describe and study the strength of the π – π stacking interactions, four new bis(pyrazolyl)ethanamine ligands having different aromatic groups (1-pyrenyl, 1-naphthyl, 2-naphthyl, and 9-anthracenyl) known for their propensity to be involved in π – π stacking interactions were prepared by the reaction of one equivalent of bis(pyrazolyl)ethanamine with one equivalent of the corresponding aromatic aldehyde. …

Synthesis And In Situ Characterization Of Intercalated Transition Metal Oxide Nanomaterials Investigated For Novel Cathode Applications, Ahamed Ullah

Theses and Dissertations--Chemistry

To develop an effective battery cathode material that can be useful for future batteries, the thermal stability and ion diffusion dynamics need to be well understood. In situ transmission electron microscopy (TEM) is a popular and proven technique to study the evolution of local structures during the dynamic processes in the cathode materials. This dissertation will demonstrate the application of high-resolution imaging and in situ heating and biasing in the TEM to study the structure and composition, morphology change, and ion diffusion in the cathode materials.

The three chapters in this dissertation will be focused on the two cathode materials: …

Fundamental Study Of Dopant Effect And Toxicity In Perovskite Materials, Xun Li

Graduate Research Theses & Dissertations

This dissertation comprehensively studies the research on organic-inorganic hybrid perovskite to solve the toxicity issue of perovskite-based solar cells under practical conditions, understand the doping effect on hybrid perovskite materials in optoelectronic applications, and improve the photovoltaic performance of perovskite-based solar cells by composition tailoring. Specifically, an innovative and simple chemical approach was invented for on-device sequestration of toxic Pb leakage caused by severe device damage. To mimic the practical conditions, the sequestration of lead leakage was conducted under cold water, warm water, acid water, dripping water, and water with competitive ions. Crucially, it was found that at least 96% …

Exploring The Morphometrics Of The Diatom Fragilariopsis Kerguelensis As A Proxy For Paleo-Sea Surface Temperature In The Late Pleistocene-Holocene Southern Ocean, Joseph Anthony Ruggiero

Graduate Research Theses & Dissertations

The Southern Ocean has played a large role in moderating global climate since its inception in the Oligocene. With the onset of anthropogenic global warming, it is now more necessary than ever that we understand the world’s climate during periods of rapidly fluctuating temperature in the past. Climatic forecasts are informed by paleoenvironmental conditions of the past during these turbulent periods, which we can examine using proxy data. This thesis assesses a potential proxy for Sea Surface Temperature (SST) through morphometric analysis of the Southern Ocean diatom Fragilariopsis kerguelensis in the Amundsen Sea, West Antarctica. This proxy is based off …

Modeling The Broader Impact Of Science And Health Using Social Media, Abdul Rahman Shaikh

Graduate Research Theses & Dissertations

Research and development have always initiated innovation and breakthroughs in technology. These technological advancements in recent years have provided a global medium for research to be disseminated through online platforms. These web-based platforms and the interactions that take place on them affect the dissemination, impact, and perception of online information. This thesis investigates the broader impact of science and health using social media posts, online patents, videos, and images by building machine learning and topic models. First, this study predicts patent citations to scientific research and identifies important factors essential to economic impact. We found that the citation of research …

Studies Of Vector Boson Scattering In The Semileptonic Zv Channel With The Cms Detector At √S = 13 Tev, Ramanpreet Singh

Graduate Research Theses & Dissertations

This dissertation reports on the search for the vector boson scattering (VBS) in semileptonicZV channel, where the Z boson decays to a pair of leptons (electrons or muons), and the other vector boson V (either W or Z) decays hadronically to a pair of jets, in association of two large pseudorapidity jets i.e. ZVjj → l+l−jjjj, l = e or μ. The search used 137 fb−1 of proton-proton collision data collected by the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) with center-of-mass energy (√s) of 13 TeV from 2016 to 2018. VBS is a key process …

Compact Wakefield Accelerator With Advanced Beam Manipulations, Wei Hou Tan

Graduate Research Theses & Dissertations

Beam-driven structure wakefield acceleration is an advanced accelerator concept proposedto develop accelerators with much smaller footprints than conventional state-of-the-art accelerators at a similar energy scale. The concept relies on the generation of electromagnetics wakefields through the interaction of a highly charged “drive” beam with a structure, such as a waveguide, to accelerate a following bright “witness” beam with produced wakefields. This dissertation discusses three aspects critical to structure-wakefield accelerators: the manipulation of the drive beam for efficient wakefield acceleration, the development of a photoinjector capable of producing bright witness electron beams, and the investigation of beam instability in a wakefield …

The Design And Synthesis Of New Organic Dithiols For Environmental Applications, Shashika Nadishani Bandara

Theses and Dissertations--Chemistry

A thiol molecule, 2,6-pyridinediamidoethanethiol (PB9), was synthesized based on the pyridine-2,6-dicarboxamide scaffold with appended cysteamine groups. PB9 acts as an effective chelator for Pb(II) due to multiple binding sites (N₃S₂) through irreversible binding precipitating Pb(II). Removal of aqueous Pb(II) from solution was demonstrated by exploring the effects of time, initial PB9:Pb(II) ratios, pH, exposure time, and solution temperature. After 15 min the Pb(II) concentrations were reduced from 50.00 ppm to 0.30 ppm (99.4%) and 0.25 ppm (99.5%) for PB9:Pb ratios of 1:1 and 2:1, respectively. Removal of > 93% Pb(II) was observed over multiple pH values with …

1,2-Diamination Of Alkenes Via Reduction Of 1,2,3-Triazolinium Ions, Setareh Saryazdi

Theses and Dissertations--Chemistry

1,2-Diamine substructures are prevalent functional motifs in natural products, pharmaceutical compounds, and ligands. The interesting functionalities of 1,2-diamines have inspired many synthetic chemists to design various methodologies for preparing these structures from simple precursors such as alkenes. In this work, we described two different but related methods using simple and easily accessible reagents for 1,2-diamination of alkenes. In the first method, an alkene undergoes 1,3-dipolar cycloaddition with an organic azide to form a 1,2,3-triazoline. Subsequent N-alkylation of the generated 1,2,3-triazoline gives the 1,2,3-triazolinium ion, which is then hydrogenated over Raney Ni with a balloon of H₂ to produce …