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Articles 30991 - 31020 of 302582

Full-Text Articles in Physical Sciences and Mathematics

A Coarse Approach To The Freudenthal Compactification And Ends Of Groups, Hussain S. Rashed May 2022

A Coarse Approach To The Freudenthal Compactification And Ends Of Groups, Hussain S. Rashed

Doctoral Dissertations

The main purpose of this work is to present a coarse counterpart to the Freudenthal compactification and its corona (the space of ends) that generalizes the Freudenthal compactification of a Freudenthal topological space X (connected, locally connected, locally compact and σ-compact) and its corona; then applying it to groups as coarse space to obtain generalizations to many well-known results in the theory of ends of groups. To this end, we present two constructions:

1. The Coarse Freudenthal compactification of a proper metric space which is a coarse compactification that coincides with the Freudenthal compactification when the metric space is geodesic. …


Bayesian Spatial Model Development Of Soil Core Organic Matter As A Proxy For Blue Carbon Stocks Within The Chesapeake Bay, Christian Longo May 2022

Bayesian Spatial Model Development Of Soil Core Organic Matter As A Proxy For Blue Carbon Stocks Within The Chesapeake Bay, Christian Longo

Undergraduate Honors Theses

Blue carbon is carbon captured and stored within bodies of water and their ecosystems. Blue carbon stocks are very important due to their ability to store carbon away from the atmosphere. The destruction of these stocks can accelerate climate change. In particular, we wish to assess blue carbon stock within the Chesapeake Bay. Previous studies have only used geographical features to predict blue carbon stock levels. The big picture question this thesis was meant to answer is: What is the best approach for building a statistical model that factors in both spatial parameters and geographical features to predict blue carbon …


An Atomic Magnetometer Based On Nonlinear Magneto-Optical Polarization Rotation, Jiahui Li May 2022

An Atomic Magnetometer Based On Nonlinear Magneto-Optical Polarization Rotation, Jiahui Li

Undergraduate Honors Theses

Magnetometers with high precision and accuracy have wide applications across various areas. We are developing an atomic magnetometer based on nonlinear magneto-optical rotation (NMOR). The magnetometer measures the polarization rotation of a light field, which is proportional to the magnetic field strength. However, such a magnetometer usually has a limited operation range and stops working for fields stronger than the Earth's magnetic field. To overcome this shortage, we implement frequency and amplitude modulation that induces side frequencies in the Fourier space which allows us to measure strong magnetic fields, up to 200 mG. We have achieved 60 pT sensitivity for …


Development Of A Vector Magnetometer Based On Electromagnetically Induced Transparency In 87rb Atomic Vapor, Alexander Toyryla May 2022

Development Of A Vector Magnetometer Based On Electromagnetically Induced Transparency In 87rb Atomic Vapor, Alexander Toyryla

Undergraduate Honors Theses

We present progress towards the development of an atomic magnetometer capable of accurate scalar and vector magnetic field measurements with high sensitivity and no need for external calibration. The proposed device will use the interaction between a bi-chromatic laser field and rubidium vapor to derive magnetic field magnitude and direction from measured amplitudes of Electromagnetically Induced Transparency (EIT) resonances. Since the proposed method requires precision control of light polarization, we observe the performance capabilities of a liquid crystal device to dynamically rotate the polarization of the laser field. Another goal in this project is to establish a polarization locking mechanism …


High Spatial And Temporal Resolution Census Data Reveal Communities At Risk Along The Wildland-Urban Interface (Wui) In California, Usa, Shenyue Jia, Slade Lazeweski, Jessica E. Viner, Wesley Ho, Brian Hoover May 2022

High Spatial And Temporal Resolution Census Data Reveal Communities At Risk Along The Wildland-Urban Interface (Wui) In California, Usa, Shenyue Jia, Slade Lazeweski, Jessica E. Viner, Wesley Ho, Brian Hoover

Institute for ECHO Articles and Research

We tracked census tract level population change along California's wild land-urban interface (WUI) during the past decade (2010-2019), an ecological sensitive region transitioning from developed land to wilderness. Our results from Mann-Kendall analysis, a method employed for monotonic trend detection showed that about one-third (29.1%) of census tracts in California’s WUI have seen a significant population increase from 2010 to 2019, affecting 12.7% population in California. The population increase along WUI is largely driven by the sixteen counties in the San Francisco Bay Area (10) and Southern California (6). We also found that higher proportion of WUI residents in Bay …


Diffusion Of A Salt In An Aqueous Media, Aldaly Pineda Hernandez May 2022

Diffusion Of A Salt In An Aqueous Media, Aldaly Pineda Hernandez

Chemical Engineering Undergraduate Honors Theses

Diffusion is defined as the net transfer of a molecule from a high concentration region to a low concentration region. The concept of diffusion is used in a very important process called "desalination." Desalination is a separation process used to reduce the salt content dissolved in brackish water to make it suitable for human consumption, irrigation, and industrial use.

In desalination plants, it is important to monitor the constantly changing salt content of water, partly due to the diffusive effect. The main purpose of this experiment was to study the diffusion of NaCl in water at two NaCl concentrations. The …


Big Business, Small Plastic, Hannah Johnson May 2022

Big Business, Small Plastic, Hannah Johnson

Senior Honors Projects

No abstract provided.


Understanding The Public Perception Of Available Scientific Resources In Coastal Southern Maine, James Gallagher May 2022

Understanding The Public Perception Of Available Scientific Resources In Coastal Southern Maine, James Gallagher

Senior Honors Projects

I have focused my education as an undergrad towards the effective communication of scientific fact to non-scientific groups. This area of study has recently been dubbed Science Communication and it encompasses the effective articulation, communication, and education of scientific topics to people who haven’t dedicated their lives to scientific study. A major component of effective Scientific Communication is understanding your audience and what kind of communication strategies are best for a chosen demographic.

I grew up in Ocean Park Maine, a small town on the coast of Southern Maine which drove my interest in Marine Science. With my experience in …


Reinforcement Learning In A Quantum Network, Roy Pace May 2022

Reinforcement Learning In A Quantum Network, Roy Pace

Honors Theses

No abstract provided.


Beyond The Covid-19 Pandemic, Havovi Joshi May 2022

Beyond The Covid-19 Pandemic, Havovi Joshi

Asian Management Insights

From the editor


Aflatoxin In Dairy Cattle Water Troughs, Julie A. Scott May 2022

Aflatoxin In Dairy Cattle Water Troughs, Julie A. Scott

Water Resources Science and Technology Theses and Graduate Research Reports

One of the most commonly found mycotoxins, aflatoxin, has been an emerging concern for the milk and dairy industry and a continued concern for the human food supply and cattle feed industry. There is a possibility of this carcinogenic mycotoxin being found in water and several studies have found them in water storage tanks, treated wastewater systems, and even in bottled water. With the potential presence in water, this study explores the possibility of aflatoxin in water troughs found on dairy farms which could be one of the exposures to cattle linked to causing aflatoxin in milk. Trough water samples …


Hepatocellular Carcinoma Image-Guided Intervention: Quantitative Characterization Of Reagents For Thermochemical Ablation, Emily A. Thompson May 2022

Hepatocellular Carcinoma Image-Guided Intervention: Quantitative Characterization Of Reagents For Thermochemical Ablation, Emily A. Thompson

Dissertations & Theses (Open Access)

Thermochemical ablation (TCA) is a minimally invasive therapy under development for hepatocellular carcinoma, a leading cause of cancer death worldwide. TCA utilizes acid-base chemistry delivered simultaneously to induce local ablation when administered. When delivered via a mixing catheter placed directly into the tumor, acid (e.g., AcOH) and base (e.g., NaOH) react to completion at the catheter tip, producing the acetate salt, water, and releasing heat (Δ>50°C) in sufficient quantities to induce lethal osmotic and thermal stress in tumor cells. However, these two reagents are not distinguishable from tissues with noninvasive imaging modalities, which makes monitoring the delivery of TCA …


The Effect Of Pesticides And Ultraviolet Radiation On Coastal Invertebrates And The Need For More Research On Multiple Stressors And Predator-Prey Interactions, Chase Robinson May 2022

The Effect Of Pesticides And Ultraviolet Radiation On Coastal Invertebrates And The Need For More Research On Multiple Stressors And Predator-Prey Interactions, Chase Robinson

Honors Theses

No abstract provided.


Development Of Classroom Tools For A Risc-V Embedded System, Lucas Phillips May 2022

Development Of Classroom Tools For A Risc-V Embedded System, Lucas Phillips

Undergraduate Honors Theses

RISC-V is an open-source instruction set that has been gaining popularity in recent years, and, with support from large chip manufacturers like Intel and the benefits of its open-source nature, RISC-V devices are likely to continue gaining momentum. Many courses in a computer science program involve development on an embedded device. Usually, this device is of the ARM architecture, like a Raspberry Pi. With the increasing use of RISC-V, it may be beneficial to use a RISC-V embedded device in one of these classroom environments. This research intends to assist development on the SiFive HiFive1 RevB, which is a RISC-V …


Exploring The Effects Of Varied Land Use On Elemental Concentrations Within Streams, Logan Jennings May 2022

Exploring The Effects Of Varied Land Use On Elemental Concentrations Within Streams, Logan Jennings

Biological and Agricultural Engineering Undergraduate Honors Theses

It is well documented that human activity influences the chemistry of surrounding waters. As such, it is possible that there is a link between land use within a watershed and the chemical composition of the stream. The objectives of this study are to determine if varied land use does affect the concentrations of macronutrients and trace elements present in the streams of Northwest Arkansas, and if so, to determine what extent urban and agricultural development are responsible for these changes. Water samples were collected across 19 streams in the Northwest Arkansas region between January and March of 2022. Water samples …


The Design Of A Efficient Production And Purification Of Fibroblast Growth Factor 2, Mandeep Kaur May 2022

The Design Of A Efficient Production And Purification Of Fibroblast Growth Factor 2, Mandeep Kaur

Chemistry & Biochemistry Undergraduate Honors Theses

Chronic wounds pose a major problem in the United States with an estimate of twenty-five million dollars a year spent on associated treatments. Growth factors can be used as a potential treatment for chronic wounds since they promote cell proliferation and angiogenesis. This study employs one specific growth factor, fibroblast growth factor 2 (FGF2) so that it could potentially be used in future treatment. Wild-type FGF2 is thermally unstable, and it has a mean elimination time of 7.6 hours. This study attempted to improve upon its stability through a mutation on the heparin binding loop. The mutation performed was K134E. …


Detecting The Intensity Of Denial-Of-Service Cyber Attacks Using Supervised Machine Learning, Abigail Hubbard May 2022

Detecting The Intensity Of Denial-Of-Service Cyber Attacks Using Supervised Machine Learning, Abigail Hubbard

Undergraduate Honors Theses

Denial-of-Service (DoS) attacks are aimed at shutting a machine or network down to block users from accessing it. These attacks can be difficult to detect and can cost millions in damages or lost earnings. Since the first DoS attack occurred in 1999, the way DoS attacks have been launched has become more complicated, making them more elusive and harder to detect. The first step to detect and mitigate a DoS attack is for a system to identify the malicious traffic.

In this experiment, we aim to identify the malicious traffic within ten seconds. To do this the project was divided …


Permaculture As An Ecopedagogy Curriculum And Alternative Theory Of Development : An Exploration Of The Ecological Consciousness Of Rural Western Kenyan Farmers Using Photo-Voice With A Farmer Field School During Covid-19, David Yisrael Epstein May 2022

Permaculture As An Ecopedagogy Curriculum And Alternative Theory Of Development : An Exploration Of The Ecological Consciousness Of Rural Western Kenyan Farmers Using Photo-Voice With A Farmer Field School During Covid-19, David Yisrael Epstein

Legacy Theses & Dissertations (2009 - 2024)

This dissertation explores two main questions of farmers in Western Kenya – how they see farming as a creative process and their role in that – and how change is made possible in their community. I explore stories from farmers themselves, using photographs they have taken and stories they tell about those photographs, which answer these two questions. In doing so, I attempt to understand the degree to which collective action has taken root in a community exposed to a permaculture based curriculum within a farmer field school. It also importantly seeks to understand what happens when such a curriculum …


Long-Term Trends And Variability Of Pm₂.₅ Mass, Chemical Components, And Sources Over Nys, Hesham Abdelmonem Hassan May 2022

Long-Term Trends And Variability Of Pm₂.₅ Mass, Chemical Components, And Sources Over Nys, Hesham Abdelmonem Hassan

Legacy Theses & Dissertations (2009 - 2024)

Eighteen years of ambient PM2.5 mass and major components are used in this study to harmonize the carbonaceous fraction of PM2.5 data, and to examine long-term trends and seasonal variability changes. The major decreasing trend of PM2.5 mass and major inorganic ions reflects the ambient concentration response to clean air regulations and policies.Although elemental carbon shows a decreasing trend in agreement with most other PM2.5 components, organic carbon shows a different behavior of no-trend to slightly increasing trend in some sites. Organic carbon behavior indicates the growing role of non-combustion sources at the expense of decreasing combustion sources. Seasonal trends …


Stubbornly Merging Discrete Vector Fields, Douglas W. Lenseth May 2022

Stubbornly Merging Discrete Vector Fields, Douglas W. Lenseth

Legacy Theses & Dissertations (2009 - 2024)

We address the basic question in discrete Morse theory of combining discrete gradientfields that are partially defined on subsets of the given complex. This is a well-posed question when the discrete gradient field V is generated using a fixed algorithm which has a local nature. One example is ProcessLowerStars, a widely used algorithm for computing persistent homology associated to a grayscale image in 2D or 3D. While the algorithm for V may be inherently local, being computed within stars of vertices and so embarrassingly parallelizable, in practical use it is natural to want to distribute the computation over patches Pi, …


An Entropic Approach To Dynamics, Pedro Henrique Moreira Pessoa May 2022

An Entropic Approach To Dynamics, Pedro Henrique Moreira Pessoa

Legacy Theses & Dissertations (2009 - 2024)

The present thesis deals with different aspects of probability, the method of maximum entropy, information geometry, and dynamical systems and their applications to statistical physics and complex systems. Those topics come together in the framework for dynamics termed entropic dynamics. Work on the topic was initiated by my PhD advisor Professor Ariel Caticha and many colleagues at University at Albany as a method for explaining the dynamical processes in quantum mechanics from first principles of probability theory.


Signal Yields And Detector Modeling In Xenon Time Projection Chambers, And Results Of An Effective Field Theory Dark Matter Search Using Lux Data, Gregory Ransford Carl Rischbieter May 2022

Signal Yields And Detector Modeling In Xenon Time Projection Chambers, And Results Of An Effective Field Theory Dark Matter Search Using Lux Data, Gregory Ransford Carl Rischbieter

Legacy Theses & Dissertations (2009 - 2024)

The nature of dark matter continues to be one of the biggest remaining mysteries in physics. Astrophysical measurements indicate that dark matter makes up more than a quarter of the Universe's total energy density, and it is well-motivated that dark matter is comprised of Weakly Interacting Massive Particles (WIMPs). Direct detection techniques utilizing liquid and gaseous noble elements have become the primary method of probing the potential non-gravitational interactions between WIMPs and Standard Model matter, with the leading technology being the dual-phase Time Projection Chamber (TPC). The Large Underground Xenon (LUX) and its second-generation successor, LUX-ZEPLIN (LZ), are two xenon …


Gas-Phase Proton Affinities For Twenty Of The Proline-Containing Dipeptides, Henry Cardwell May 2022

Gas-Phase Proton Affinities For Twenty Of The Proline-Containing Dipeptides, Henry Cardwell

Undergraduate Honors Theses

Peptide fragmentation plays a crucial role in the analysis of proteins through mass spectrometry-based proteomics. Most proteomics experiments take place in the low-energy regime and are governed by the mobile proton model which predicts random cleavages along the peptide backbone; however, there sometimes arise circumstances where the mobile proton model fails causing sequencing algorithms to misidentify peptides. One such example is noted in the “proline effect” wherein proline-containing peptides preferentially fragment N-terminal. While it has been established that the “proline effect” is due to the rigidity and basicity of the proline N-terminus, a further understanding of the factors influencing the …


Co-Planar Waveguides For Microwave Atom Chips, Morgan Logsdon May 2022

Co-Planar Waveguides For Microwave Atom Chips, Morgan Logsdon

Undergraduate Honors Theses

This thesis describes research to develop co-planar waveguides (CPW) for coupling microwaves from mm-scale coaxial cables into 50 μm-scale microstrip transmission lines of a microwave atom chip. This new atom chip confines and manipulates atoms using spin-specific microwave AC Zeeman potentials and is particularly well suited for trapped atom interferometry. The coaxial-to-microstrip coupler scheme uses a focused CPW (FCPW) that shrinks the microwave field mode while maintaining a constant 50 Ω impedance for optimal power coupling. The FCPW development includes the simulation, design, fabrication, and testing of multiple CPW and microstrip prototypes using aluminum nitride substrates. Notably, the FCPW approach …


Climate Change And Conservation Of Milkweed: Evidence Of Extensive Admixture Between Common Milkweed And Poke Milkweed, Elizabeth Davies May 2022

Climate Change And Conservation Of Milkweed: Evidence Of Extensive Admixture Between Common Milkweed And Poke Milkweed, Elizabeth Davies

Undergraduate Honors Theses

Global climate change can drive many changes in species interactions. One primary way it affects species is by changing climates, causing species to expand their ranges and allowing them to interact with species from whom they were previously isolated. In plants, new species interactions can result in hybridization – the creation of hybrid offspring between two separate species. This hybridization can increase gene flow between the species and lead to introgression, the transfer of genetic material from one species to another through hybrid backcrossing with the parent species. My thesis investigates hybridization in the model system Asclepias (milkweed) by analyzing …


Chemical Analysis Of Organic Compounds In Dew Water, Monica Dibley May 2022

Chemical Analysis Of Organic Compounds In Dew Water, Monica Dibley

Undergraduate Honors Theses

Water films on outdoor surfaces, such as dew, can act as a reservoir for organic molecules deposited from the atmosphere and they present a potential reactive medium for chemical transformations. To better understand the flux of volatile organic compounds from evaporating films, the composition and reactivity of the complex mixture of dissolved organic material (DOM) found in these films need to be characterized. Previous studies have measured the salts and the small organic molecules in dew collected on clean Teflon surfaces or condensers. Here, we expand on this by probing the organic chemicals found on natural outdoor surfaces covered in …


Investigation Of Tertiary Impact Cratering And Relation To Impact Physics Theory, Mikayla Huffman May 2022

Investigation Of Tertiary Impact Cratering And Relation To Impact Physics Theory, Mikayla Huffman

Undergraduate Honors Theses

Extraterrestrial impact crater formation is important in many subfields of planetary science, including geochronology, planetary formation, and dynamic fragmentation theory. Current dynamic fragmentation theory lacks scale dependence and relies heavily on terrestrial data. Exploring a range of impact and ejecta velocities as is produced by cratering events on the Moon may bridge the gap between heavily terrestrial-based theory and planetary data. The secondary craters of secondary craters deemed “tertiary craters,” have been theorized, but planetary images have not been of sufficient resolution to effectively search for them until recently. Tertiary craters are formed by relatively low-velocity fragments ejected by nearby …


Modern Theory Of Copositive Matrices, Yuqiao Li May 2022

Modern Theory Of Copositive Matrices, Yuqiao Li

Undergraduate Honors Theses

Copositivity is a generalization of positive semidefiniteness. It has applications in theoretical economics, operations research, and statistics. An $n$-by-$n$ real, symmetric matrix $A$ is copositive (CoP) if $x^T Ax \ge 0$ for any nonnegative vector $x \ge 0.$ The set of all CoP matrices forms a convex cone. A CoP matrix is ordinary if it can be written as the sum of a positive semidefinite (PSD) matrix and a symmetric nonnegative (sN) matrix. When $n < 5,$ all CoP matrices are ordinary. However, recognizing whether a given CoP matrix is ordinary and determining an ordinary decomposition (PSD + sN) is still an unsolved problem. Here, we give an overview on modern theory of CoP matrices, talk about our progress on the ordinary recognition and decomposition problem, and emphasis the graph theory aspect of ordinary CoP matrices.


Demonstration Of Cyberattacks And Mitigation Of Vulnerabilities In A Webserver Interface For A Cybersecure Power Router, Benjamin Allen May 2022

Demonstration Of Cyberattacks And Mitigation Of Vulnerabilities In A Webserver Interface For A Cybersecure Power Router, Benjamin Allen

Computer Science and Computer Engineering Undergraduate Honors Theses

Cyberattacks are a threat to critical infrastructure, which must be secured against them to ensure continued operation. A defense-in-depth approach is necessary to secure all layers of a smart-grid system and contain the impact of any exploited vulnerabilities. In this undergraduate thesis a webserver interface for smart-grid devices communicating over Modbus TCP was developed and exposed to SQL Injection attacks and Cross-Site Scripting attacks. Analysis was performed on Supply-Chain attacks and a mitigation developed for attacks stemming from compromised Content Delivery Networks. All attempted attacks were unable to exploit vulnerabilities in the webserver due to its use of input sanitization …


Analysis Of Gpu Memory Vulnerabilities, Jarrett Hoover May 2022

Analysis Of Gpu Memory Vulnerabilities, Jarrett Hoover

Computer Science and Computer Engineering Undergraduate Honors Theses

Graphics processing units (GPUs) have become a widely used technology for various purposes. While their intended use is accelerating graphics rendering, their parallel computing capabilities have expanded their use into other areas. They are used in computer gaming, deep learning for artificial intelligence and mining cryptocurrencies. Their rise in popularity led to research involving several security aspects, including this paper’s focus, memory vulnerabilities. Research documented many vulnerabilities, including GPUs not implementing address space layout randomization, not zeroing out memory after deallocation, and not initializing newly allocated memory. These vulnerabilities can lead to a victim’s sensitive data being leaked to an …