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Full-Text Articles in Physical Sciences and Mathematics

Applying Synchrotron Saxs And Xas To Study The Microstructure Of Energy Conversion And Storage Materials, Lingzhe Fang Jan 2024

Applying Synchrotron Saxs And Xas To Study The Microstructure Of Energy Conversion And Storage Materials, Lingzhe Fang

Graduate Research Theses & Dissertations

The microstructure of energy conversion and storage materials is a key determinant of physical properties and electrochemical performance. Synchrotron X-ray techniques, with their strengths of high flux and exceptional brightness, play an irreplaceable role in understanding nano and sub-nano structures. This helps the study of reaction mechanisms and benefits material design in energy conversion and storage area. Electrifying CO2 transformation using renewable energy offers a carbon-neutral solution to CO2 recycling and fuel generation. Among various feedstocks from the CO2 reduction reaction, CO, HCOOH, and CH4 have approached the performance thresholds for industry implementation. The application of single atom catalysts (SACs) …


Theory Of Ultrafast Spin Crossover In Divalent Iron Systems, William Baker Jan 2024

Theory Of Ultrafast Spin Crossover In Divalent Iron Systems, William Baker

Graduate Research Theses & Dissertations

A theory to account for the ultrafast, i.e. femtosecond timescale, singlet to quintet spin crossover in divalent iron molecules is developed. The model considers an iron cluster with ligands extending in all 6 cardinal directions initially at rest in a low spin singlet ground state. An optical excitation excites an electron from the d orbitals to the ligands, changing the system from the metal centered (MC) singlet state to the metal to ligand charge transfer (MLCT) singlet state. Experimentally, it is known that the system eventually relaxes into the quintet MC state, but there are no satisfactory explanations that model …


Mixed Mechanisms Of Multi-Site Phosphorylation, Suha Jayyousi Dajani Jan 2024

Mixed Mechanisms Of Multi-Site Phosphorylation, Suha Jayyousi Dajani

Graduate Research Theses & Dissertations

Multi-site phosphorylation is an important mechanism in cell biology that regulates protein function and activity. It also plays a critical role in a wide variety of cellular processes that control intra-cellular signaling. Studies on mono- and dual-site phosphorylation have been conducted theoretically and experimentally by researchers. However, there is little research on triple-site and multi-site mixed mechanism phosphorylation.

The aim of this research is to study and identify the number of positive steady states (multistationarity) in a mathematical model of a triple-site mixed mechanism, processive and distributive, phosphorylation network. This research is accomplished by means of ordinary differential equations, Jacobian …


Railroad Condition Monitoring Using Distributed Acoustic Sensing And Deep Learning Techniques, Md Arifur Rahman Jan 2024

Railroad Condition Monitoring Using Distributed Acoustic Sensing And Deep Learning Techniques, Md Arifur Rahman

Electronic Theses and Dissertations

Proper condition monitoring has been a major issue among railroad administrations since it might cause catastrophic dilemmas that lead to fatalities or damage to the infrastructure. Although various aspects of train safety have been conducted by scholars, in-motion monitoring detection of defect occurrence, cause, and severity is still a big concern. Hence extensive studies are still required to enhance the accuracy of inspection methods for railroad condition monitoring (CM). Distributed acoustic sensing (DAS) has been recognized as a promising method because of its sensing capabilities over long distances and for massive structures. As DAS produces large datasets, algorithms for precise …


Accounting For Variability Due To Resampling Using Bootstrapping, Dipendra Phuyal Jan 2024

Accounting For Variability Due To Resampling Using Bootstrapping, Dipendra Phuyal

Electronic Theses and Dissertations

Bradley Efron (1979) introduced bootrapping. Typically a researcher is interested in studying a process which generates individuals. The collection of individuals the process has(actual) or could have (conceptual) generated is the population. The collection of conceptual members of the population is an uncountable collection. Hence, the population is anuncountable collection of individuals. The collection of individuals the process has generated (actual individuals) is representative of what the process can generate and will bereferred to as the representative sample. The size of this sample is a nonnegative integervalued random variable N which may be a constant random variable such as in …


Classification In Supervised Statistical Learning With The New Weighted Newton-Raphson Method, Toma Debnath Jan 2024

Classification In Supervised Statistical Learning With The New Weighted Newton-Raphson Method, Toma Debnath

Electronic Theses and Dissertations

In this thesis, the Weighted Newton-Raphson Method (WNRM), an innovative optimization technique, is introduced in statistical supervised learning for categorization and applied to a diabetes predictive model, to find maximum likelihood estimates. The iterative optimization method solves nonlinear systems of equations with singular Jacobian matrices and is a modification of the ordinary Newton-Raphson algorithm. The quadratic convergence of the WNRM, and high efficiency for optimizing nonlinear likelihood functions, whenever singularity in the Jacobians occur allow for an easy inclusion to classical categorization and generalized linear models such as the Logistic Regression model in supervised learning. The WNRM is thoroughly investigated …


Applications Of Independent And Identically Distributed (Iid) Random Processes In Polarimetry And Climatology, Dan Kestner Jan 2024

Applications Of Independent And Identically Distributed (Iid) Random Processes In Polarimetry And Climatology, Dan Kestner

Dissertations, Master's Theses and Master's Reports

The unifying theme of this thesis is the characterization of “perfect randomness,” i.e., independent and identically distributed (IID) stochastic processes as these are applied in physical science. Two specific and mathematically distinct applications are chosen: (i) Radar and optical polarimetry; (ii) Analysis of time series in meteorology. In (i), IID process of a special kind, namely, with a distribution defined by symmetry, is used to link its multivariate Gaussian density to uniformity on the Poincaré sphere. This “statistical ellipsometry” approach is then used to relate polarimetric mismatches or imbalances to ellipsometric variables and suitably chosen cross-correlation measures. In (ii), recently …


Anomaly Mapping Of Heavy And Light Rare Earth Elements In Central Upper Peninsula Of Michigan Using Geostatistics And Fractal Analysis, Sunday Joseph Jan 2024

Anomaly Mapping Of Heavy And Light Rare Earth Elements In Central Upper Peninsula Of Michigan Using Geostatistics And Fractal Analysis, Sunday Joseph

Dissertations, Master's Theses and Master's Reports

Rare earth elements (REEs) have gained significant global importance due to their critical role in supporting the transition towards reduced carbon emissions through industrial applications. REEs serve as essential raw materials for various critical components in modern infrastructure, defense systems, and technological advancements. Geochemical and geophysical data are pivotal in assessing the potential of REEs. Geochemical data provide direct insights into the elemental composition of rocks and soils, offering valuable information on the potential presence and dispersion of REEs. However, the complex geological processes that influence the distribution of REEs often exhibit intricate spatial patterns that may not be fully …


Understanding The Controls Of Seasonal Stream Temperature And Hydrological Monitoring Of Forested Watersheds In The Western Upper Peninsula Of Michigan, Eli A. Paulen Jan 2024

Understanding The Controls Of Seasonal Stream Temperature And Hydrological Monitoring Of Forested Watersheds In The Western Upper Peninsula Of Michigan, Eli A. Paulen

Dissertations, Master's Theses and Master's Reports

Accurately predicting stream temperature is vital to protect the environment and its most sensitive aquatic species. Tools for forecasting stream temperature rely on in situ data that affect thermal response of natural water systems. Stream and meteorological data were analyzed from the western Upper Peninsula of Michigan for the 2016-2023 water years to determine which factors affected stream temperatures. Through the application of multivariable linear regression models, our analysis identified air temperature as the primary determinant of stream temperature. However, the air-stream temperature relationship varied significantly over temporal scales, improving with increasing in time averaging. The air-stream temperature relationship was …


Establishing A Two-Color Fluorescence Probe Assay For The Simultaneous Screening Of Glut5 And Glut2 Fructose Transporters In Live Cells, Oluwanifesimi Mary Afolabi Jan 2024

Establishing A Two-Color Fluorescence Probe Assay For The Simultaneous Screening Of Glut5 And Glut2 Fructose Transporters In Live Cells, Oluwanifesimi Mary Afolabi

Dissertations, Master's Theses and Master's Reports

The mammalian facilitative glucose transporter (GLUT) family comprises 14 members that mediate the transport of hexoses across cell membranes. GLUT5 is the only member specific to fructose, and together with GLUT2, which transports fructose in addition to glucose, they make up the primary fructose transporters in humans. This study introduces a novel two-color fluorescence assay designed to simultaneously monitor the activity of GLUT5 and GLUT2 in live cells. 2,5-anhydro-D-mannitol (2,5-AM) a GLUT5 targeting compound has facilitated the development of various fructose-mimicking probes with a wide range of properties, such as radioactive imaging, fluorescent, photoactive, and drug delivery capabilities. Effective and …


New Method For Computing The Euclidean Condition Number With Rim-C, Cody Mccarthy Jan 2024

New Method For Computing The Euclidean Condition Number With Rim-C, Cody Mccarthy

Dissertations, Master's Theses and Master's Reports

The condition number, being critical to solving linear systems, has many impor-
tant applications. Specifically for robust control analysis, the Euclidean norm has
widespread use over the 1-norm and ∞-norm such as determining a control system’s
stability to uncertainty [1]. Much work has been done with estimating the Euclidean
condition number, but current algorithms for computing said condition number, with
large matrices, tend to run slow as well as requiring a large amount of computa-
tional resources. This report seeks to provide a more time efficient algorithm that
utilizes MATLAB’s eigs, svds, and normest commands as well as the recently …


A Virtual Time Driven Simulator For Devs Models, Ronald R. Stempien Jan 2024

A Virtual Time Driven Simulator For Devs Models, Ronald R. Stempien

Dissertations, Master's Theses and Master's Reports

When simulating a system that includes some software component, simulation authors are faced with the problem of how to appropriately model the software within the simulation. While many formal methods for modeling software exist, in some contexts these may not be appropriate or viable for a given simulation. Instead, simulation authors may model a computer within the simulation, and run the software in question “as is” on the modeled machine. In this work, we introduce a theoretical framework to allow for the use of hardware virtualization technologies as a hardware accelerator for CPU models in Discrete Event System Specification (DEVS) …


Novel Analytical Approaches For The Study Of Energy And Nutrient Flow In Streams, Michelle Catherine Kelly Jan 2024

Novel Analytical Approaches For The Study Of Energy And Nutrient Flow In Streams, Michelle Catherine Kelly

Dissertations, Master's Theses and Master's Reports

This dissertation applied novel modeling, experimental and statistical approaches to overcome the challenges of measuring and analyzing energy and nutrient cycling in streams through 3 studies: (1) determining the predictors of respiration and denitrification in streams across the United States, (2) simultaneous estimation of denitrification and nitrogen (N) fixation rates, and (3) the impact of C lability metrics on the interpretation of C degradation in DOM incubation experiments. In the first study, I used predictive modeling approaches to show that respiration and denitrification were positively correlated across the landscape but were predicted by factors at different spatial scales. Denitrification rates …


Response Of Open Volcanic Systems To Static Stress Changes, Aimee Zimmerman Jan 2024

Response Of Open Volcanic Systems To Static Stress Changes, Aimee Zimmerman

Dissertations, Master's Theses and Master's Reports

Large earthquakes of magnitude 7.0 or greater can alter volcanic emissions and even trigger eruptions at nearby volcanoes. The stress changes imparted by large earthquakes can cause otherwise stable conditions within the magmatic system to be disturbed, potentially inducing volcanic activity. The extent of the triggering potential is still unknown due to insufficient understanding of the mechanisms involved. We model static stress changes for 174 earthquake-volcano pairs from 2000-2023 at volcanoes within 500 km, computing changes in both the normal stress perpendicular to the direction of horizontal maximum stress and dilatational strain. We then use thermal satellite data to measure …


Dynamic Memory Management For Key-Value Store, Yuchen Wang Jan 2024

Dynamic Memory Management For Key-Value Store, Yuchen Wang

Dissertations, Master's Theses and Master's Reports

To minimize the latency of accessing back-end servers, modern web services often use in-memory key-value (k-v) stores at the front end to cache frequently accessed objects. Due to the limited memory capacity, these stores must be configured with a fixed amount of memory. Consequently, cache replacement is required when the footprint of the accessed objects exceeds the cache size.

This thesis presents a comprehensive exploration of advanced dynamic memory management techniques for k-v stores. The first study conducts a detailed analysis of K-LRU, a random sampling-based replacement policy, proposing a dynamic K configuration scheme to exploit the potential miss ratio …


How Increased Ransomware Attacks Have Impacted Hospitals In The United States, Mackenzie Dotson Jan 2024

How Increased Ransomware Attacks Have Impacted Hospitals In The United States, Mackenzie Dotson

Theses, Dissertations and Capstones

Introduction: The healthcare industry, particularly hospitals, have fallen prey to the alarming rise of ransomware attacks. In recent years, highly sophisticated cybergroups, armed with substantial funds and advanced technology, have intensified their focus on hospitals. Despite the advice against it, most hospitals have paid the ransom in order to regain access to their electronic systems and patient data, underlining the severity of these attacks.

Purpose of the Study: The purpose of this research was to evaluate the effects of ransomware attacks on hospitals in the US to determine if the patients were at risk due to hackers withholding patient information …


Charged Excitons And Trions In The Semiconductor Quantum Dot: Electronic Structure And Effect Of External Fields, Jayden Leonard Jan 2024

Charged Excitons And Trions In The Semiconductor Quantum Dot: Electronic Structure And Effect Of External Fields, Jayden Leonard

Theses, Dissertations and Capstones

In this thesis, we are studying the electronic structures and optical properties of charged excitons and trions (i.e., the exciton-associated quasi-particles in semiconductor materials) in quantum dots which have a three-dimensional confinement configuration. We also consider the effects of an external electric and magnetic field on the charged excitons. Initially theorized in 1958, charged excitons are a fairly new phenomenon in physics in which an exciton (i.e., an electron coupled with an electron hole) is coupled with either another electron or another hole (giving either a ‘negative exciton’ or ‘positive exciton’ accordingly). In the completely confined configuration like the quantum …


Developing Machine Learning And Time-Series Analysis Methods With Applications In Diverse Fields, Muhammed Aljifri Jan 2024

Developing Machine Learning And Time-Series Analysis Methods With Applications In Diverse Fields, Muhammed Aljifri

Theses and Dissertations

This dissertation introduces methodologies that combine machine learning models with time-series analysis to tackle data analysis challenges in varied fields. The first study enhances the traditional cumulative sum control charts with machine learning models to leverage their predictive power for better detection of process shifts, applying this advanced control chart to monitor hospital readmission rates. The second project develops multi-layer models for predicting chemical concentrations from ultraviolet-visible spectroscopy data, specifically addressing the challenge of analyzing chemicals with a wide range of concentrations. The third study presents a new method for detecting multiple changepoints in autocorrelated ordinal time series, using the …


Penalized Interpolating B-Splines And Their Applications, Kylee L. Hartman-Caballero Jan 2024

Penalized Interpolating B-Splines And Their Applications, Kylee L. Hartman-Caballero

Theses and Dissertations

One of the most studied data analysis techniques in Numerical Analysis is interpolation. Interpolation is used in a variety of fields, namely computer graphic design and biomedical research. Among interpolation techniques, cubic splines have been viewed as the standard since at least the 1960s, due to their ease of computation, numerical stability, and the relative smoothness of the interpolating curve. However, cubic splines have notable drawbacks, such as their lack of local control and necessary knowledge of boundary conditions. Arguably a more versatile interpolation technique is the use of B-splines. B-splines, a relative of Bézier curves, allow local control through …


Identifying Nutrient Dynamics And Relative Groundwater Contribution In Wetlands At Fish Lake Environmental Center, Lapeer Mi, Rose Allen Jan 2024

Identifying Nutrient Dynamics And Relative Groundwater Contribution In Wetlands At Fish Lake Environmental Center, Lapeer Mi, Rose Allen

Senior Honors Theses and Projects

Wetlands are complex ecosystems that are dependent on hydrologic processes and water chemistry. Understanding the role that water chemistry and nutrients play in wetland ecosystems is crucial to wetland management and restoration. The Fish Lake Environmental Education Center near Lapeer Michigan, is glacially influenced, and contains a large bog. Between the bog and lake there are multiple kettles that contain ephemeral wetlands in the spring. Bogs are primarily precipitation sourced, whereas the kettle wetlands may be a combination of precipitation and groundwater sourced. Previous studies indicated that groundwater flow direction is towards Fish Lake, but it was unclear to what …


Design, Synthesis, And Characterization Of Complex Chalcogenides For Energy Storage And Energy Conversion Applications, Srikanth Balijapelly Jan 2024

Design, Synthesis, And Characterization Of Complex Chalcogenides For Energy Storage And Energy Conversion Applications, Srikanth Balijapelly

Doctoral Dissertations

"Through this investigation, complex chalcogenides with the combination of main group metals, transition metals, and rare earth metals have been synthesized using the building block approach and their structure-property relationships are evaluated. The main emphasis of research is on rationally designing new materials for applications in sodium and lithium ion conducting solid electrolytes, cathodes, thermoelectrics, and nonlinear optics. Along with the experimental studies, theoretical calculations are also employed to better understand the physicochemical properties of the synthesized compounds.

The first part of the research will discuss designing alkali ion containing complex chalcogenides using the building block approach. This investigation resulted …


Extracting Social Network Model Parameters From Social Science Literature, Isaac Batts Jan 2024

Extracting Social Network Model Parameters From Social Science Literature, Isaac Batts

Theses and Dissertations--Computer Science

When looking at computer modeling of social situations, much of the social science literature does not include ready-to-use statistics or parameters to be included in a social model. I explore studies related to speaking about racism (and other forms of bias), and interventions designed to diminish the occurrence of biased behavior, and use those readings to synthesize plausible parameters for a social computer model.


Scene Understanding And Spatial Analysis Using Scene Graph Enhanced By Hall's Proxemics Zones In Smart Homes, Debaleen Das Spandan Jan 2024

Scene Understanding And Spatial Analysis Using Scene Graph Enhanced By Hall's Proxemics Zones In Smart Homes, Debaleen Das Spandan

MSU Graduate Theses

Voice-controlled smart assistants have received widespread popularity. It plays a pivotal role in smart homes by providing a natural and convenient interface for interacting with smart devices. However, these assistants are unable to serve persons with physical disabilities and speech impairments. Therefore, non-verbal communication methods, such as eye tracking, gesture recognition, and context awareness can complement and overcome some of these limitations to enhance user experience in smart homes. To address this issue, I am investigating non-verbal communication methods to make smart home technology more accessible and intuitive. In this research, I focus on proxemics, i.e., the study of distance …


Photoluminescence Of Beryllium-Related Defects In Gallium Nitride, Mykhailo Vorobiov, Mykhailo Vorobiov Jan 2024

Photoluminescence Of Beryllium-Related Defects In Gallium Nitride, Mykhailo Vorobiov, Mykhailo Vorobiov

Theses and Dissertations

This study explores the potential of beryllium (Be) as an alternative dopant to magnesium (Mg) for achieving higher hole concentrations in gallium nitride (GaN). Despite Mg prominence as an acceptor in optoelectronic and high-power devices, its deep acceptor level at 0.22 eV above the valence band limits its effectiveness. By examining Be, this research aims to pave the way to overcoming these limitations and extend the findings to aluminum nitride and aluminum gallium nitride (AlGaN) alloy. Key contributions of this work include. i)Identification of three Be-related luminescence bands in GaN through photoluminescence spectroscopy, improving the understanding needed for further material …


Edge Colored And Edge Ordered Graphs, Per Gustin Wagenius Jan 2024

Edge Colored And Edge Ordered Graphs, Per Gustin Wagenius

Graduate College Dissertations and Theses

In this work, the current state of the field of edge-colored graphs is surveyed. Anew concept of unshrinkable edge colorings is introduced which is useful for rainbow subgraph problems and interesting in its own right. This concept is analyzed in some depth. Building upon the linear edge ordering described in a recent work from Gerbner, Methuku, Nagy, Pálvölgyi, Tardos, and Vizer, edge-ordering graphs with the cyclic group is introduced and some results are given on this and a related counting problem.


Managing Inventory With A Database, David Bartlett Jan 2024

Managing Inventory With A Database, David Bartlett

Williams Honors College, Honors Research Projects

Large commercial companies often use warehouses to store and organize their product inventory. However, manually keeping track of inventory through physical means can be a tedious process and is at risk for a variety of potential issues. It is very easy for records to be inaccurate or duplicated, especially if large reorganizations are undertaken, as this can cause issues such as duplicate product ID numbers. Therefore, it was decided that an inventory management system utilizing a SQL database should be created. The system needed to have capabilities including allowing the entry of product information, the ability to search database records …


Utilizing Suas-Based Remote Sensing For Sustainable Outdoor Recreational Trail Design And Monitoring, Isaac C. Kinder Jan 2024

Utilizing Suas-Based Remote Sensing For Sustainable Outdoor Recreational Trail Design And Monitoring, Isaac C. Kinder

Graduate Theses, Dissertations, and Problem Reports

This study utilizes sUAS-based remote sensing and hydrologic models to analyze and predict locations susceptible to water-based trail erosion. Erosion is frequently cited as the most significant environmental impact of trails and often requires costly design and management considerations. A professionally designed trail totaling 4 km in length was segmented based on presence or absence of water-based erosion for analyses and then flown with sUAS technology. Three Logistic regression (LR) models were generated utilizing several hydrologic terrain models of varying resolutions to determine the effects of spatial resolution on the models’ predictive accuracies. Receiver operator characteristics, kappa, and overall accuracy …


Educators’ Beliefs About Using Academic Acceleration With Gifted Math Students And Others: Barriers And Opportunities, Jason Gorgia Jan 2024

Educators’ Beliefs About Using Academic Acceleration With Gifted Math Students And Others: Barriers And Opportunities, Jason Gorgia

Theses, Dissertations and Capstones

This study examined the perceptions of educators (i.e., math teachers, administrators, and others) for insight into the absence of acceleration as a common pedagogical strategy in mathematics, despite longstanding research supporting the practice for students gifted in math and the interest frequently articulated by policymakers and educators in boosting American K-12 students’ math achievement. Educators from 48 states responded to scale-based and open-ended questions about math acceleration through an online survey where 713 of 818 respondents were teachers, balanced almost evenly among elementary, middle, and high schools, and among urban, suburban, and rural settings. The responses of teachers and non-teaching …


Environmental Impact Assessment Of The Horseshoe Bend Trail Reconstruction, Ian Caldwell, Kathleen Castleberry, Julia Grams, Sascha Knight, Emily Panteleeff Jan 2024

Environmental Impact Assessment Of The Horseshoe Bend Trail Reconstruction, Ian Caldwell, Kathleen Castleberry, Julia Grams, Sascha Knight, Emily Panteleeff

College of the Environment Graduate and Undergraduate Publications

This is an Environmental Impact Assessment (EIA) on the proposed action of constructing a new section of the Horseshoe Bend Trail along the State Route 542 corridor to Mt. Baker in Whatcom County, Washington. The construction of a new section of trail will renew access to the popular trail, which was washed out in 2021. Impacts to elements of the natural and built environment are examined, with emphasis on riparian and water quality impacts. The proposed action, alternative action, and no action are all considered, along with positives, negatives, and no impacts of each.


Assisted Regeneration Of Threatened Whitebark Pine After Wildfires In North Cascades National Park, Dylan Braund, Clara Magsarili, Ben Molenhouse, Bridget Miller, Zalan Szanyi Jan 2024

Assisted Regeneration Of Threatened Whitebark Pine After Wildfires In North Cascades National Park, Dylan Braund, Clara Magsarili, Ben Molenhouse, Bridget Miller, Zalan Szanyi

College of the Environment Graduate and Undergraduate Publications

This assessment evaluates the environmental effects of seeding whitebark pine seed caches in two burn sites located within the North Cascades National Park Service Complex (NOCA) in Washington State. The goal of these efforts would be to reestablish stands of whitebark pines lost to wildfire.