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2022

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Articles 17161 - 17190 of 18310

Full-Text Articles in Physical Sciences and Mathematics

Investigating Spatiotemporal Kinetics, Dynamics, And Mechanism Of Exosome Release, Anarkali Mahmood Jan 2022

Investigating Spatiotemporal Kinetics, Dynamics, And Mechanism Of Exosome Release, Anarkali Mahmood

Electronic Theses and Dissertations

Exosomes are small lipid-based vesicles that can carry biomolecules from one cell to another. While exosomes are crucial to maintain homeostasis in healthy cells, they are exploited by unhealthy cells to aid disease progression. Exosomes likely facilitate disease progression via the transfer of disease-causing biomolecules from unhealthy to healthy cells. Exosomes are generated in Multivesicular endosomes (MVEs) and are then secreted into the extracellular space to travel to other cells. Despite being a crucial step, very little is known about exosomes release mechanism and dynamics. To further our understanding of exosomes, specifically their secretion, my work has focused on investigating …


Measurements Of Atmospheric Radicals, Heather L. Runberg Jan 2022

Measurements Of Atmospheric Radicals, Heather L. Runberg

Electronic Theses and Dissertations

Atmospheric particulate matter (PM) is a global health concern. PM2.5 is formed primarily through combustion processes such as automobile use and industrial activity. Natural sources of PM2.5 result from events like volcanos and wildfires. Upon inhalation, PM2.5 is small enough to travel deep into the lungs where it can form reactive oxygen species (ROS), such as hydroxyl radical (OH), causing oxidative damage to pulmonary tissues. PM2.5 has been linked to cardiopulmonary diseases such as asthma, chronic obstructive pulmonary disease (COPD), and high blood pressure.

PM2.5 is small enough to remain aloft and travel many hundreds …


Osiris-Rex Surface Imaging To Constrain Properties Of The Asteroid (101955) Bennu, Alicia Allen Jan 2022

Osiris-Rex Surface Imaging To Constrain Properties Of The Asteroid (101955) Bennu, Alicia Allen

Honors Undergraduate Theses

This study used images taken from the OSIRIS-REx spacecraft sample-return mission and projected onto a three-dimensional shape model to determine surface properties of the asteroid (101955) Bennu. Two major projects were completed. For the first project, images of the pre-sampled Nightingale site and post-sampled Nightingale were compared to determine how the TAGSAM sampling maneuver effected the surface of the asteroid directly at the sampling site and in the surrounding area. This analysis demonstrated how spacecraft can potentially affect a small body during this and future sample-return missions. For the second project, several craters on Bennu’s surface were selected and all …


Investigation Of Catalysis Of Nitration By Cytochrome P450s, Lannika Johnson Jan 2022

Investigation Of Catalysis Of Nitration By Cytochrome P450s, Lannika Johnson

Honors Undergraduate Theses

TxtE is a protein related to cytochrome P450 enzymes, which catalyze a number of reactions that typically involve oxygen and not nitrogen. It has been discovered that TxtE can nitrate tryptophan through an unusual reaction in which it uses nitric oxide (NO) as a nitrogen donor to install the nitro group despite NO typically being considered toxic to bacteria. This project will determine if all cytochromes P450 can catalyze nitration as long as they are given NO. This will have an impact on understanding drug delivery and metabolism for which nitration is important.


Examining Cooperative System Responses Against Grid Integrity Attacks, Alexander D. Parady Jan 2022

Examining Cooperative System Responses Against Grid Integrity Attacks, Alexander D. Parady

Honors Undergraduate Theses

Smart grid technologies are integral to society’s transition to sustainable energy sources, but they do not come without a cost. As the energy sector shifts away from a century’s reliance on fossil fuels and centralized generation, technology that actively monitors and controls every aspect of the power infrastructure has been widely adopted, resulting in a plethora of new vulnerabilities that have already wreaked havoc on critical infrastructure. Integrity attacks that feedback false data through industrial control systems, which result in possible catastrophic overcorrections and ensuing failures, have plagued grid infrastructure over the past several years. This threat is now at …


Comparative Evaluation Of Assemblers For Metagenomic Data Analysis, Matheus Pavini Franco Ferreira Jan 2022

Comparative Evaluation Of Assemblers For Metagenomic Data Analysis, Matheus Pavini Franco Ferreira

Honors Undergraduate Theses

Metagenomics is a cultivation-independent approach for obtaining the genomic composition of microbial communities. Microbial communities are ubiquitous in nature. Microbes which are associated with the human body play important roles in human health and disease. These roles span from protecting us against infections from other bacteria, to being the causes of these diseases. A deeper understanding of these communities and how they function inside our bodies allows for advancements in treatments and preventions for these diseases. Recent developments in metagenomics have been driven by the emergence of Next-Generation Sequencing technologies and Third-Generation Sequencing technologies that have enabled cost-effective DNA sequencing …


The Effects Of Viscous Damping On Rogue Wave Formation And Permanent Downshift In The Nonlinear Schrödinger Equation, Evelyn Smith Jan 2022

The Effects Of Viscous Damping On Rogue Wave Formation And Permanent Downshift In The Nonlinear Schrödinger Equation, Evelyn Smith

Honors Undergraduate Theses

This thesis investigates the effect of viscous damping on rogue wave formation and permanent downshift using the higher-order nonlinear Schrödinger equation (HONLS). The strength of viscous damping is varied and compared to experiments with only linear damped HONLS.

Stability analysis of the linear damped HONLS equation shows that instability stabilizes over time. This analysis also provides an instability criterion in the case of HONLS with viscous damping.

Numerical experiments are conducted in the two unstable mode regime using perturbations of the Stokes wave as initial data. With only linear damping permanent downshift is not observed and rogue wave formation is …


Instanton Counting, Matrix Models, And Characters, Spencer Tamagni Jan 2022

Instanton Counting, Matrix Models, And Characters, Spencer Tamagni

Honors Undergraduate Theses

In this thesis we study symmetries of quantum field theory visible only at the non-perturbative level, which arise from large deformations of the integration contour in the path integral. We exposit the recently-developed theory of qq-characters that organizes such symmetries in the case of N = 2 supersymmetric gauge theories in four dimensions. We sketch the physical origin of such observables from intersecting branes in string theory, and the mathematical origin as certain
equivariant integrals over Nakajima quiver varieties. We explain some of the main applications, including the derivation of Seiberg-Witten geometry for quiver gauge theories and the relations to …


Genetic Algorighm Representation Selection Impact On Binary Classification Problems, Stephen V. Maldonado Jan 2022

Genetic Algorighm Representation Selection Impact On Binary Classification Problems, Stephen V. Maldonado

Honors Undergraduate Theses

In this thesis, we explore the impact of problem representation on the ability for the genetic algorithms (GA) to evolve a binary prediction model to predict whether a physical therapist is paid above or below the median amount from Medicare. We explore three different problem representations, the vector GA (VGA), the binary GA (BGA), and the proportional GA (PGA). We find that all three representations can produce models with high accuracy and low loss that are better than Scikit-Learn’s logistic regression model and that all three representations select the same features; however, the PGA representation tends to create lower weights …


Synthesis And Characterization Of Silver-Gold Nanocage With Enhanced Thermal Stability, Victoria Ten Jan 2022

Synthesis And Characterization Of Silver-Gold Nanocage With Enhanced Thermal Stability, Victoria Ten

Honors Undergraduate Theses

Silver-gold nanocages have attracted considerable research interest recently due to their excellent performance in the fields of biomedicine and photocatalysis. These applications oftentimes manipulate at elevated temperatures and therefore impose demands on the thermal stability of the cage structures. To better understand this subject, in this work, we systematically evaluated the thermal stability of two nanocages with different wall thicknesses of 3.8 nm and 13 nm, both in the solution-phase (diethylene glycol) and solid-phase (in-situ STEM). The results revealed that the nanocages with thicker walls exhibited better thermal stabilities in both phases. By monitoring and analyzing the morphology changes of …


Heterogenous Reduction Of Co2 Over Boron-Rich Alb2, Jose C. Berger Jan 2022

Heterogenous Reduction Of Co2 Over Boron-Rich Alb2, Jose C. Berger

Honors Undergraduate Theses

Evidence suggests that the recent drastic changes in the global climate have been caused by greenhouse gases, especially CO­2. As a result, scientists are aiming to develop processes that either minimize the production of these gases or convert them into products of higher value. To that end, the catalytic properties of a two-dimensional boron-rich material were investigated. Herein is reported that such a material can reduce CO2 into benzene, C3 species, and C4 species at relatively low temperatures (225-450 ℃) and pressures (0.38 MPa). Current data suggest that a low-temperature induction period (e.g., 225 ℃) …


Photocatalytic Hydrogen Production Over Boron Rich Solids, Emma E. Blanco Jan 2022

Photocatalytic Hydrogen Production Over Boron Rich Solids, Emma E. Blanco

Honors Undergraduate Theses

The greenhouse emission produced from the combustion of fossil fuels, such as methane (CH) and carbon dioxide (CO2), are linked to global warming crisis because of their ability to absorb heat emitted to space by the Earth’s atmosphere. Over the last century, methane is estimated to have the Global Warming Potential (GWP) estimated to be 28-36 times larger than carbon dioxide. Although it is released in smaller quantities, methane traps nearly 90 times more heat than CO2. While recent research efforts has focused on the capture and conversion of CO2, these efforts …


Information Systems Security Countermeasures: An Assessment Of Older Workers In Indonesian Small And Medium-Sized Businesses, Hari Samudra Roosman Jan 2022

Information Systems Security Countermeasures: An Assessment Of Older Workers In Indonesian Small And Medium-Sized Businesses, Hari Samudra Roosman

CCE Theses and Dissertations

Information Systems (IS) misuse can result in cyberattacks such as denial-of-service, phishing, malware, and business email compromise. The study of factors that contribute to the misuse of IS resources is well-documented and empirical research has supported the value of approaches that can be used to deter IS misuse among employees; however, age and cultural nuances exist. Research focusing on older workers and how they can help to deter IS misuse among employees and support cybersecurity countermeasures within developing countries is in its nascent stages. The goal of this study was two-fold. The first goal was to assess what older workers …


An Empirical Investigation Of The Evidence Recovery Process In Digital Forensics, Kevin Parviz Jan 2022

An Empirical Investigation Of The Evidence Recovery Process In Digital Forensics, Kevin Parviz

CCE Theses and Dissertations

The widespread use of the digital media in committing crimes, and the steady increase of their storage capacity has created backlogs at digital forensic labs. The problem is exacerbated especially in high profile crimes. In many such cases the judicial proceedings mandate full analysis of the digital media, when doing so is rarely accomplished or practical. Prior studies have proposed different phases for forensic analysis, to lessen the backlog issues. However, these phases are not distinctly differentiated, and some proposed solutions may not be practical. This study utilized several past police forensic analyses. Each case was chosen for having five …


Exploring The Existing And Unknown Side Effects Of Privacy Preserving Data Mining Algorithms, Hima Bindu Sadashiva Reddy Jan 2022

Exploring The Existing And Unknown Side Effects Of Privacy Preserving Data Mining Algorithms, Hima Bindu Sadashiva Reddy

CCE Theses and Dissertations

The data mining sanitization process involves converting the data by masking the sensitive data and then releasing it to public domain. During the sanitization process, side effects such as hiding failure, missing cost and artificial cost of the data were observed. Privacy Preserving Data Mining (PPDM) algorithms were developed for the sanitization process to overcome information loss and yet maintain data integrity. While these PPDM algorithms did provide benefits for privacy preservation, they also made sure to solve the side effects that occurred during the sanitization process. Many PPDM algorithms were developed to reduce these side effects. There are several …


A One-Dimensional Field Dislocation Mechanics Model Using Discontinuous Galerkin Method, Ja'nya Breeden, Dow Drake, Jay Gopalakrishnan, Saurabh Puri Jan 2022

A One-Dimensional Field Dislocation Mechanics Model Using Discontinuous Galerkin Method, Ja'nya Breeden, Dow Drake, Jay Gopalakrishnan, Saurabh Puri

Mathematics and Statistics Faculty Publications and Presentations

A numerical solution strategy for a one-dimensional field dislocation mechanics (FDM) model using the Discontinuous Galerkin (DG) method is developed. The FDM model is capable of simulating the dynamics of discrete, nonsingular dislocations using a partial differential equation involving a conservation law for the Burgers vector content with constitutive input for nucleation and velocity. Modeling of individual dislocation lines with an equilibrium compact core structure in the context of this continuum elastoplastic framework requires a non-convex stored energy density. Permanent deformation and stress redistribution caused by the dissipative transport of dislocations is modeled using thermodynamics-based constitutive laws. A DG method …


Bodipy–Pyrene Donor–Acceptor Sensitizers For Triplet–Triplet Annihilation Upconversion: The Impact Of The Bodipy-Core On Upconversion Efficiency, Natalia Kiseleva, Mikhail Filatov, Jan C. Fischer, Milian Kaiser, Marius Jakoby, Dimitry Busko, Ian A. Howard, Bryce Richards, Andrey Turshatov Jan 2022

Bodipy–Pyrene Donor–Acceptor Sensitizers For Triplet–Triplet Annihilation Upconversion: The Impact Of The Bodipy-Core On Upconversion Efficiency, Natalia Kiseleva, Mikhail Filatov, Jan C. Fischer, Milian Kaiser, Marius Jakoby, Dimitry Busko, Ian A. Howard, Bryce Richards, Andrey Turshatov

Articles

Triplet–triplet annihilation upconversion (TTA-UC) is an important type of optical process with applications in biophotonics, solar energy harvesting and photochemistry. In most of the TTA-UC systems, the formation of triplet excited states takes place via spin–orbital interactions promoted by heavy atoms. Given the crucial role of heavy atoms (especially noble metals, such as Pd and Pt) in promoting intersystem crossing (ISC) and, therefore, in production of UC luminescence, the feasibility of using more readily available and inexpensive sensitizers without heavy atoms remains a challenge. Here, we investigated sensitization of TTA-UC using BODIPY–pyrene heavy-atom-free donor–acceptor dyads with different numbers of alkyl …


Analysis Of Copper(Ii) Using The Ascorbate/Oxygen System – A Valuable Undergraduate Resource, Sean Tobin, John Cassidy, Kevin Kurian, Tony Betts Jan 2022

Analysis Of Copper(Ii) Using The Ascorbate/Oxygen System – A Valuable Undergraduate Resource, Sean Tobin, John Cassidy, Kevin Kurian, Tony Betts

Articles

In deionised water, ascorbic acid (AH−), through oxidation by oxygen in the presence of copper(II), was found to degrade with zero-order kinetics. The magnitude of the reaction rate varied directly with the copper(II) concentration. At a higher pH (7.4), the same reaction was found to be pseudo-first order. Once again, the magnitude of the rate increased linearly with copper(II) concentration at a micromolar level. Dissolved oxygen levels, in excess AH− and trace copper(II), displayed similar kinetics under both conditions. Monitoring of either AH− levels or dissolved oxygen concentration was found to be a useful novel undergraduate practical laboratory for trace …


All-Optical Modulator Based On A Microfibre Coil Resonator Functionalized With Mxene, Pengfei Wang, Shi Li, Fengzi Ling, Gerald Farrell, Elfed Lewis, Yu Yin Jan 2022

All-Optical Modulator Based On A Microfibre Coil Resonator Functionalized With Mxene, Pengfei Wang, Shi Li, Fengzi Ling, Gerald Farrell, Elfed Lewis, Yu Yin

Articles

A novel all-optical modulator based on a microfibre coil resonator (MCR) functionalized using MXene is reported. The MCR was manufactured by winding a tapered fibre on a polycarbonate (PC) resin cylinder with low refractive index to support the microfibre, which also forms a fluidic channel coil. The MXene dispersion was injected into the channel to allow the deposition of an MXene layer using a photodeposition process. The transmission spectra were tuned using a tunable laser with a centre wavelength of 1550 nm and the light-matter interaction resulting from the photo-thermal effect and MXene absorption provide the all-optical modulation in this …


On The Polytopal Generalization Of Sperner’S Lemma, Amit Harlev Jan 2022

On The Polytopal Generalization Of Sperner’S Lemma, Amit Harlev

HMC Senior Theses

We introduce and prove Sperner’s lemma, the well known combinatorial analogue of the Brouwer fixed point theorem, and then attempt to gain a better understanding of the polytopal generalization of Sperner’s lemma conjectured in Atanassov (1996) and proven in De Loera et al. (2002). After explaining the polytopal generalization and providing examples, we present a new, simpler proof of a slightly weaker result that helps us better understand the result and why it is correct. Some ideas for how to generalize this proof to the complete result are discussed. In the last two chapters we provide a brief introduction to …


Games For One, Games For Two: Computationally Complex Fun For Polynomial-Hierarchical Families, Kye Shi Jan 2022

Games For One, Games For Two: Computationally Complex Fun For Polynomial-Hierarchical Families, Kye Shi

HMC Senior Theses

In the first half of this thesis, we explore the polynomial-time hierarchy, emphasizing an intuitive perspective that associates decision problems in the polynomial hierarchy to combinatorial games with fixed numbers of turns. Specifically, problems in �� are thought of as 0-turn games, ���� as 1-turn “puzzle” games, and in general ��ₖ�� as ��-turn games, in which decision problems answer the binary question, “can the starting player guarantee a win?” We introduce the formalisms of the polynomial hierarchy through this perspective, alongside definitions of ��-turn CIRCUIT SATISFIABILITY games, whose ��ₖ��-completeness is assumed from prior work (we briefly justify this assumption …


Algebraic Invariants Of Knot Diagrams On Surfaces, Ryan Martinez Jan 2022

Algebraic Invariants Of Knot Diagrams On Surfaces, Ryan Martinez

HMC Senior Theses

In this thesis we first give an introduction to knots, knot diagrams, and algebraic structures defined on them accessible to anyone with knowledge of very basic abstract algebra and topology. Of particular interest in this thesis is the quandle which "colors" knot diagrams. Usually, quandles are only used to color knot diagrams in the plane or on a sphere, so this thesis extends quandles to knot diagrams on any surface and begins to classify the fundamental quandles of knot diagrams on the torus.

This thesis also breifly looks into Niebrzydowski Tribrackets which are a different algebraic structure which, in future …


Smoothed Bounded-Confidence Opinion Dynamics On The Complete Graph, Solomon Valore-Caplan Jan 2022

Smoothed Bounded-Confidence Opinion Dynamics On The Complete Graph, Solomon Valore-Caplan

HMC Senior Theses

We present and analyze a model for how opinions might spread throughout a network of people sharing information. Our model is called the smoothed bounded-confidence model and is inspired by the bounded-confidence model of opinion dynamics proposed by Hegselmann and Krause. In the Hegselmann–Krause model, agents move towards the average opinion of their neighbors. However, an agent only factors a neighbor into the average if their opinions are sufficiently similar. In our model, we replace this binary threshold with a logarithmic weighting function that rewards neighbors with similar opinions and minimizes the effect of dissimilar ones. This weighting function can …


Check Yourself Before You Wrek Yourself: Unpacking And Generalizing Randomized Extended Kaczmarz, William Gilroy Jan 2022

Check Yourself Before You Wrek Yourself: Unpacking And Generalizing Randomized Extended Kaczmarz, William Gilroy

HMC Senior Theses

Linear systems are fundamental in many areas of science and engineering. With the advent of computers there now exist extremely large linear systems that we are interested in. Such linear systems lend themselves to iterative methods. One such method is the family of algorithms called Randomized Kaczmarz methods.
Among this family, there exists a Randomized Kaczmarz variant called Randomized
Extended Kaczmarz which solves for least squares solutions in inconsistent linear systems.
Among Kaczmarz variants, Randomized Extended Kaczmarz is unique in that it modifies input system in a special way to solve for the least squares solution. In this work we …


An Adaptive Hegselmann–Krause Model Of Opinion Dynamics, Phousawanh Peaungvongpakdy Jan 2022

An Adaptive Hegselmann–Krause Model Of Opinion Dynamics, Phousawanh Peaungvongpakdy

HMC Senior Theses

Models of opinion dynamics have been used to understand how the spread
of information in a population evolves, such as the classical Hegselmann–
Krause model (Hegselmann and Krause, 2002). One extension of the model
has been used to study the impact of media ideology on social media
networks (Brooks and Porter, 2020). In this thesis, we explore various
models of opinions and propose our own model, which is an adaptive
version of the Hegselmann–Krause model. The adaptive version implements
the social phenomenon of homophily—the tendency for like-minded agents to
associate together. This is done by having agents dissolve connections …


Results On The Generalized Covering Radius Of Error Correcting Codes, Benjamin Langton Jan 2022

Results On The Generalized Covering Radius Of Error Correcting Codes, Benjamin Langton

HMC Senior Theses

The recently proposed generalized covering radius is a fundamental property of error correcting codes. This quantity characterizes the trade off between time and space complexity of certain algorithms when a code is used in them. However, for the most part very little is known about the generalized covering radius. My thesis seeks to expand on this field in several ways. First, a new upper bound on this quantity is established and compared to previous bounds. Second, this bound is used to derive a new algorithm for finding codewords within the generalized covering radius of a given vector, and also to …


An Exploration Of Voting With Partial Orders, Mason Acevedo Jan 2022

An Exploration Of Voting With Partial Orders, Mason Acevedo

HMC Senior Theses

In this thesis, we discuss existing ideas and voting systems in social choice theory. Specifically, we focus on the Kemeny rule and the Borda count. Then, we begin trying to understand generalizations of these voting systems in a setting where voters can submit partial rankings on their ballot, instead of complete rankings.


Crowdsensing Application On Coalition Game Using Gps And Iot Parking In Smart Cities, Hasan Abu Hilal, Narmeen Abu Hilal, Ala’ Abu Hilal, Tariq Abu Hilal Jan 2022

Crowdsensing Application On Coalition Game Using Gps And Iot Parking In Smart Cities, Hasan Abu Hilal, Narmeen Abu Hilal, Ala’ Abu Hilal, Tariq Abu Hilal

All Works

This paper provides an overview of crowdsensing and some of its applications. Crowdsensing is a part of the collecting data situations also; it’s built on a data system on multiple customer interactions. Moreover, writing the general information of the smart cities can be used to boost to received number frequency to send messages. This work mentioned the Crowdsensing layers that describe Mobile crowdsensing. The article focuses on crowdsensing layers, developed an application in Coalition Game using crowdsensing in terms of GPS. In addition, this paper discussed the Mobile crowdsensing system and how important the cloud is in serving the wireless …


On Modelling And Analyzing Composite Resources’ Consumption Cycles Using Time Petri-Nets, Amel Benna, Fatma Masmoudi, Mohamed Sellami, Zakaria Maamar, Rachid Hadjidj Jan 2022

On Modelling And Analyzing Composite Resources’ Consumption Cycles Using Time Petri-Nets, Amel Benna, Fatma Masmoudi, Mohamed Sellami, Zakaria Maamar, Rachid Hadjidj

All Works

ICT community cornerstones (IoT in particular) gain competitive advantage from using physical resources. This paper adopts Time Petri-Nets (TPNs) to model and analyze the consumption cycles of composite resources. These resources consist of primitive, and even other composite, resources that are associated with consumption properties and could be subject to disruptions. These properties are specialized into unlimited, shareable, limited, limited-but-renewable, and non-shareable, and could impact the availability of resources. This impact becomes a concern when disruptions suspend ongoing consumption cycles to make room for the unplanned consumptions. Resuming the suspended consumption cycles depends on the resources’ consumption properties. To ensure …


Multicolor Ramsey And List Ramsey Numbers For Double Stars, Jake Ruotolo Jan 2022

Multicolor Ramsey And List Ramsey Numbers For Double Stars, Jake Ruotolo

Honors Undergraduate Theses

The core idea of Ramsey theory is that complete disorder is impossible. Given a large structure, no matter how complex it is, we can always find a smaller substructure that has some sort of order. For a graph H, the k-color Ramsey number r(H; k) of H is the smallest integer n such that every k-edge-coloring of Kn contains a monochromatic copy of H. Despite active research for decades, very little is known about Ramsey numbers of graphs. This is especially true for r(H; k) when k is at least 3, also known as the multicolor Ramsey number of …