Physical Sciences and Mathematics Commons^™

Novel Integrated Sachs-Wolfe Effect From Early Dark Energy, Tristan L. Smith, J. T. Giblin Jr., M. Amin, M. Gerhardinger, E. Florio, M. Cerep, S. Daniels

Physics & Astronomy Faculty Works

We study the nonlinear effects of minimally coupled, massless, cosmological scalar fields on the cosmic microwave background (CMB). These fields can exhibit postrecombination parametric resonance and subsequent nonlinear evolution leading to novel contributions to the gravitational potential. We compute the resulting contributions to the CMB temperature anisotropies through the time variation of the gravitational potential (i.e., the integrated Sachs-Wolfe (ISW) effect). We find that fields that constitute 5% of the total energy density and become dynamical at z_c ≃ 10⁴ can produce marginally observable ISW signals at multipoles ℓ ≃ 2000. Fields that become dynamical at earlier times …

Comparative Analysis Of Interacting Stepped Dark Radiation, N. Schöneberg, G. F. Abellán, T. Simon, A. Bartlett, Y. Patel, Tristan L. Smith

Physics & Astronomy Faculty Works

Models that address both the Hubble and S₈ tensions with the same mechanism generically cause a prerecombination suppression of the small scale matter power spectrum. Here we focus on two such models. Both models introduce a self-interacting dark radiation fluid scattering with dark matter, which has a step in its abundance around some transition redshift. In one model, the interaction is weak and with all of the dark matter whereas in the other it is strong but with only a fraction of the dark matter. The weakly interacting case is able to address both tensions simultaneously and provide a …

Advances In Cellulose Nanomaterial-Based Foams For Environmental Applications, Md Musfiqur Rahman

Electronic Theses and Dissertations

The use of metal-oxide nanoparticles adsorbents is limited to fixed-bed columns in industrial-scale water treatment applications. This limitation is commonly attributed to the tendency of nanoparticles to aggregate, the use of non-sustainable and inefficient polymeric resins as supporting materials, or a lack of adsorption capacity. Foams and aerogels derived from cellulose nanomaterials have unique characteristics, such as high porosity and low density, which enables their use in a variety of environmental applications, including water treatment. However, the overall use of cellulose nanomaterial-based foams in various environmental sectors is limited due to the high cost of production associated with time- and …

The Impact Of Conservation Land On Property Taxes And Municipal Budgets In Maine: A Mixed-Methods Study, Abigail Bennett

Electronic Theses and Dissertations

This study is an interdisciplinary project done in collaboration with the Municipal Budget and Conservation Working group, a group of stakeholders that formed in 2018 to study conservation and town budgets. We use mixed methods to explore the impacts of conservation and municipal budgets in Maine. We use regression analysis on 21 years of panel data to identify causal relationships between conservation and mill rates, controlling for economic and town budget factors. We found statistically significant but small effects on average, with a 1% increase in conserved acres in a town associated with average tax bill increases of $1 or …

Toughness Of Recursively Partitionable Graphs, Calum Buchanan, Brandon Du Preez, K. E. Perry, Puck Rombach

Theory and Applications of Graphs

A simple graph G = (V,E) on n vertices is said to be recursively partitionable (RP) if G ≃ K1, or if G is connected and satisfies the following recursive property: for every integer partition a₁, a₂, . . . , a_k of n, there is a partition {A₁,A₂, . . . ,A_k} of V such that each |A_i| = a_i, and each induced subgraph G[A_i] is RP (1 ≤ i ≤ k). We show that if S is a …

Optimization Of Transition-Metal Inclusive Carbon Aerogels For Electrochemical Energy Applications, Allen Dalton Davis

Electronic Theses & Dissertations

The ever-growing need for energy alongside rising concerns for climate change demands the development of renewable energy technologies. Hydrogen fuel cells are a promising technology that can serve to either supplement energy generation or act as a lone power source. Yet for these devices to be truly green, the hydrogen that serves as fuel must be procured from a renewable resource. Electrolytic water splitting is a process that allows for the dissociation of water into H₂ and O₂. For this process to be practical, the electrolyzer needs to demonstrate high efficiency and stability, as well as a …

Microplate-Like Metal Pyrophosphate Engineered On Ni-Foam Towards Multifunctional Electrode Material For Energy Conversion And Storage, Rishabh Srivastava

Electronic Theses & Dissertations

High clean energy demand, dire need for sustainable development, and low carbon footprints are the few intuitive challenges, leading researchers to aim for research and development for high-performance energy devices. The development of materials used in energy devices is currently focused on enhancing the performance, electronic properties, and durability of devices. Tunning the attributes of transition metals using pyrophosphate (P₂O₇) ligand moieties can be a promising approach to meet the requirements of energy devices such as water electrolyzers and supercapacitors, although such a material’s configuration is rarely exposed for this purpose of study.

Herein, we grow …

From Pong To Narrative: The Evolution Of Ai In Gaming, Muhammad Assaf

ART 108: Introduction to Games Studies

As video games evolve, the role of artificial intelligence also referred to as AI has been essential. Games have come a long way from being small and having rudimentary logic to being extremely complex and narrative-driven. This research paper will dive into the vast history of AI in gaming, following its path from the simple ball-paddle mechanics of Pong, to the intricate entanglements presented in modern games such as Fortnite, Call of Duty, League of Legends, and more. The interplay between game design and AI development doesn’t just show how far we have come in technological advancement, but rather it …

Exploring The Shift In Player Enthusiasm Towards Games, David Daniel

ART 108: Introduction to Games Studies

Video games, providing a constant source of excitement have been an integral part of the lives of many enthusiasts, helping shape childhoods and providing a source of entertainment and social interaction between friends and strangers. From the joy of unboxing the Wii with siblings back in the day, all the way to playing multiplayer battle royales and among us with our friends over the pandemic, the gaming platform has been an ever changing and dynamic experience. However, with time, a noticeable split emerged among peers who once shared the same joy of running home and putting on the headset. Some …

Computer Simulation Of Adsorption Of C60 Fullerene Molecule On Reconstructed Defective Si(100) Surfacee Content Of The Body Element Is Displayed In Your Browser, I. Urolov, Ishmumin Yadgarov, Ganiboy Raxmanov

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

In this work, based on the molecular dynamics (MD) method, the adsorption processes of C₆₀ fullerene molecules on the reconstructed defective silicon Si(100) surface with different configurations were simulated in the LAMMPS open package program. Second-order Brenner interatomic potential was used to determine interactions between Si-Si, C-C and Si-C atoms. The interaction of various shaped defect areas with the C₆₀ molecule on the surface of reconstructed silicon Si(100) was studied. As a result of calculations, stable adsorption states were determined by comparing the energy of C₆₀ molecule adsorption to the defective silicon Si(100) surface and the Si-C …

Boundary Value Problem With The Bitsadze-Samarsky Condition For A Loaded Equation Of Parabolic-Hyperbolic Type In A Doubly Connected Region, Bozor Islomov, Oybek Yunusov

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

This paper is devoted to the study of a nonlocal boundary value problem for a loaded equation of parabolic-hyperbolic type in a special domain.Using representations of the general regular solution, are proven the unique solvability of the problem posed.

Ascot App, Milla Penelope Markovic

Honors Thesis

The Ascot App is a research tool for acquiring and analyzing data. The app comprises of both mobile and web platforms, each serving a unique purpose. The mobile side allows users to input data through the app’s form, which is uploaded to a database for further processing and analysis. The web app, which is still under development as of April of 2024, allows users to manage their research project and download data in the form of a parsed CSV. These components ensure a seamless process for research teams to record data with persistence and security while allowing for analysis.

Ascot …

Spatial And Temporal Variability In Snow Properties And Firn Volume Across The Juneau Icefield In Southeast Alaska, Mikaila Mannello

Electronic Theses and Dissertations

Glaciers are important freshwater resources which have far reaching impacts on a range of local to global systems and processes, including ecosystems and societies. As global climate continues to change, the response of glaciers has largely been reductions in ice mass and widespread retreat. A high degree of accumulation and ablation occurs in the near surface which is exposed to the atmosphere. The Juneau Icefield (JIF) has, up until the mid-2010s, historically responded climate change anomalously where its main drainage, Taku Glacier (here forward referred to its native name T’aakú Kwáan Sít’i), has been advancing while all other JIF outlet …

Modeling Forest Growth Using Sentinel-2-Derived Variables And Site Data, Peter G. Larson

Electronic Theses and Dissertations

Growing stock volume (GSV) is an important metric for determining economic yield, carbon sequestration and other ecosystem services. GSV has traditionally been estimated in situ by measuring individual trees in a stand. This process is slow and expensive, and, as a result, is not a viable means to estimate GSV on a large scale. It is also not feasible in places that are difficult to access and in places that do not have reliable management records. Multispectral optical sensors mounted on satellites are an important technology for monitoring forest resources because they offer the possibility of measuring forest resources quickly …

Investigating Bremsstrahlung Radiation In Tungsten Targets: A Geant4 Simulation Study, Sindor Ashurov, Satimboy Palvanov, Abror Tuymuradov, Dilmurod Tuymurodov

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

Bremsstrahlung radiation, a pivotal phenomenon in high-energy physics, presents numerous applications and implications in both theoretical studies and practical scenarios. This article explores the Bremsstrahlung radiation of electrons in tungsten (W) targets of varying widths subjected to different energy beams using GEANT4 simulations. By systematically altering the target widths and electron beam energies, we assess the corresponding effects on radiation yield and spectrum. The findings contribute to a deeper understanding of Bremsstrahlung processes in high-$Z$ materials and offer valuable insights for applications ranging from radiation therapy to materials analysis.

Holomorphic Motion Of Julia Sets Of Polynomial-Like Maps, And Continuity Of Compact Sets And Their Green Functions, Bazarbaev Sardor, Sobir Boymurodov

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

In this paper, we study holomorphic motion of Julia sets of polynomial-like maps. In particular, we prove that in the stable family of polynomial-like maps if all the continuos functions move continuously by parameter then the Julia sets move holomorphically. Moreover, we also study the relation between continuity of regular compact sets and their Green functions.

Translation-Invariant Gibbs Measures For Potts Model With Competing Interactions With A Countable Set Of Spin Values On Cayley Tree, Zarinabonu Mustafoyeva

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

In the present paper we consider of an infinite system of functional equations for the Potts model with competing interactions and countable spin values Φ = {0, 1, ..., } on a Cayley tree of order k. We study translation-invariant Gibbs measures that gives the description of the solutions of some infinite system of equations. For any k ≥ 1 and any fixed probability measure ν we show that the set of translation-invariant splitting Gibbs measures contains one and two points for odd k and even k, respectively, independently on parameters of the Potts model with a countable …

An Analogue Of Hartogs Lemma For Separately Harmonic Functions With Variable Radius Of Harmonicity, Sevdiyor Imomkulov, Sultanbay Abdikadirov

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

In this note we prove that if a function u(x,y) is separately harmonic in a domain D × V_r = D × {y∈ℝ²:|y|<r,  r>1} ⊂ ℝⁿ × ℝ² and for each fixed point x⁰ ∈ D the function u(x⁰,y) of variable y continues harmonically into the great circle {y∈ℝ²:|y|<R(x⁰),  R(x⁰)>r}, then it continues harmonically into a domain {(x …

On Geometry Of Two Dimensional Surfaces In Four Dimensional Euclid Space, Abdigappar Narmanov, Bekzod Diyarov

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

Geometry of two-dimensional surfaces in E⁴ is an essential part of differential geometry and studied by many authors [4, 5, 6, 10]. In this paper, we give some surface in four dimensional Euclid space E⁴ with nonzero Gauss curvature which is a orbit of the system of two vector fields. Smoothness is the smoothness of the class C^∞.

Solar-Powered Microgrids In Northern California: An Opportunity For Resilience, Marina Riddle

Master's Projects and Capstones

Planned and unplanned power outages have been increasing in frequency and duration, negatively impacting all public sectors, and threatening public safety. These outages are deadly to those who rely on medical devices. As climate change-fueled extreme weather events (wildfires, earthquakes, storms, etc.) also increase in frequency, our electrical grid must be prepared to bounce back. Microgrids provide necessary redundancy and reliability. Through a novel GIS suitability analysis, based on solar radiation, land use type, local energy demand, distance to transmission lines, distance to roads, and slope, optimal locations for solar-powered microgrids throughout Northern California were determined. The counties of Fresno, …

An Analysis Of The Debate And How It Changed Everything: Narratology Vs. Ludology, Robert Veloya

ART 108: Introduction to Games Studies

Video games will rot your brain. Something that people have told us during its inception into the modern world; however, little did they know that the video game industry will one day take its place in the world as one of the best mediums to tell a story and challenge its audience. The video game industry is an ever-growing industry where innovation flows through its veins causing it to grow into a field that is more immersive and compelling. Video games have also evolved into a field of study, a discipline that dives deep into what makes them a unique …

Context-Driven Behavior: Improved Contextual Reasoning For Context-Aware Agents, Christian L. Wilson

Electronic Theses and Dissertations

Over the last three decades, a considerable amount of research has been dedicated to improving an artificial agent's ability to recognize and deal effectively with context. In this paper, I discuss a framework for a novel form of contextual reasoning. Unlike existing contextual reasoning frameworks, which allow an agent to apply its contextual knowledge after it is operating in an instance of a known context, the model I discuss allows an agent to reason about context proactively. With a proactive model, an agent forecasts the future contexts it will encounter, then takes steps to ensure its behaviors are appropriate for …

A Map-Algebra-Inspired Approach For Interacting With Wireless Sensor Networks, Cyber-Physical Systems Or Internet Of Things, David Almeida

Electronic Theses and Dissertations

The typical approach for consuming data from wireless sensor networks (WSN) and Internet of Things (IoT) has been to send data back to central servers for processing and analysis. This thesis develops an alternative strategy for processing and acting on data directly in the environment referred to as Active embedded Map Algebra (AeMA). Active refers to the near real time production of data, and embedded refers to the architecture of distributed embedded sensor nodes. Network macroprogramming, a style of programming adopted for wireless sensor networks and IoT, addresses the challenges of coordinating the behavior of multiple connected devices through a …

Quantifying Tidewater Glacier-Fjord Environments In The Rapidly Changing Regions Of West And South Greenland, Sydney Baratta

Electronic Theses and Dissertations

The Greenland Ice Sheet has undergone rapid mass loss over the last four decades, primarily through solid and liquid discharge at marine-terminating outlet glaciers. The acceleration of these glaciers is in part due to the increase in temperature of ocean water in contact with the glacier terminus. However, quantifying meltwater injection and heat transport can be challenging due to iceberg abundance, which threatens instrument survival and fjord accessibility. Additionally, acceleration and retreat of tidewater glaciers onto land can change glacier forcing, altering fjord water-meltwater dynamics. Here, we couple in situ and remote sensing methods to quantify the upper-layer fjord dynamics …

Nonsmooth Epidemic Models With Evolutionary Game Theory, Cameron Morin

Electronic Theses and Dissertations

This thesis explores the utilization of game theory and nonsmooth functions to enhance the accuracy of epidemiological simulations. Traditional sensitivity analysis encounters difficulties when dealing with nondifferentiable points in nonsmooth functions. However, by incorporating recent advancements in nonsmooth analysis, sensitivity analysis techniques have been adapted to accommodate these complex functions. In pursuit of more accurate simulations, evolutionary game theory, primarily the replicator equation, is introduced, modeling individuals’ decision making processes when observing others’ choices. The SEIR model is explored in depth, and additional complexities are incorporated, leading to the creation of an expanded SEIR model, the Be-SEIMR model.

Confined Feni Alloy Nanoparticles In Carbon Nanotubes For Photothermal Oxidative Dehydrogenation Of Ethane By Carbon Dioxide, Jinqiang Zhang, Meng Li, Xiaojie Tan, Lei Shi, Kun Xie, Xiaoli Zhao, Shuaijun Wang, Shiyong Zhao, Huayang Zhang, Xiaoguang Duan, Haijun Chen, Yuezhao Zhu, Mingbo Wu, Hongqi Sun, Shaobin Wang

Research outputs 2022 to 2026

Oxidative dehydrogenation of ethane with CO2 (ODEC) is an attractive reaction for reduction of carbon footprints and ethene production. In this work, we present photothermal catalysis on confined bimetal catalysts for ODEC. Carbon nanotubes confined non-noble bimetal alloy (i.e., CoNi@CNTs and FeNi@CNTs) catalysts were prepared and FeNi@CNTs showed effective performance in photothermal catalytic ODEC to ethene. Experiments and simulations reveal that UV and visible lights (420 – 490 nm) are responsible for ODEC and non-oxidative dehydrogenation of ethane, respectively, to ethene. Additionally, ODEC to ethene is preferred to C-C cracking to methane on FeNi@CNTs in light ( > 490 nm)-induced thermocatalysis. …

Population Dynamics And Bifurcations In Predator-Prey Systems With Allee Effect, Yanni Zeng

Electronic Thesis and Dissertation Repository

This thesis investigates a series of nonlinear predator-prey systems incorporating the Allee effect using differential equations. The main goal is to determine how the Allee effect affects population dynamics. The stability and bifurcations of the systems are studied with a hierarchical parametric analysis, providing insights into the behavioral changes of the population within the systems. In particular, we focus on the study of the number and distribution of limit cycles (oscillating solutions) and the existence of multiple stable states, which cause complex dynamical behaviors. Moreover, including the prey refuge, we examine how our method benefits the low-density animals and affects …

Nuclear Power: Extremely Dangerous, Perfectly Safe, Or Somewhere In Between?, Jackson Still

Quest

Multiple Genre Argument

Research in progress for ENGL 1301: Composition I

Faculty Mentor: W. Scott Cheney, Ph.D.

Standard research papers and five-paragraph essays can train students to blend quotations and organize paragraphs, but advanced writing in the disciplines and the workplace requires much more robust and nuanced thinking. To this end, the Multiple Genre Argument (MGA) pushes students into new writing situations where they create fictional genres to supplement traditional research—a challenging and often confusing task. Learning new skills requires becoming more comfortable with encountering this kind of difficulty and uncertainty. In their book Writing Analytically, David Rosenwasser and Jill …

Test Event Example 12/14/23, Metzalli Demolastname

Annual Research Symposium

No abstract provided.

Rapid Cryogenic Electrical Characterization Of Materials And Devices Using Gifford-Mcmahon Cryocoolers, Margaret Marte, Bernardo Langa Jr., Patrick Johnson, Deepak Sapkota, Kathryn Evancho, Bernadeta Srijanto, Dale Hensley, Kasra Sardashti

Journal of the South Carolina Academy of Science

Thin-film heterostructures are necessary building blocks for superconducting and phononic quantum computing devices. Many new generations of quantum hardware demand extensive materials research to optimize performances at cryogenic temperatures (below 10 K). Here, we demonstrate compact cryogenic measurement systems capable of reaching sub-10K temperatures in less than three hours with the ability to measure AC/DC resistance and dielectric properties of thin-film materials. Our platform utilizes Gifford-McMahon (GM) cryocoolers as effective tools for providing high throughput cooling-warming cycles. We successfully used the GM-based measurement systems to measure 1) the superconducting transition temperature for Nb thin films (Tc ~7.8 K), and 2) …