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Articles 181 - 210 of 3757

Full-Text Articles in Physical Sciences and Mathematics

The Density Distribution Of The Material Around Betelgeuse, Iman Behbehani Sep 2025

The Density Distribution Of The Material Around Betelgeuse, Iman Behbehani

Dissertations, Theses, and Capstone Projects

Betelgeuse is a red supergiant star visible in the constellation Orion. Its windy and highly convective surface results in a complicated mass loss pattern difficult to understand and replicate in simulations. The ejected mass can form a shell around the star we consider the circumstellar material (CSM). In this study, we use ALMA interferometric observations to find the structure of Betelgeuse's CSM, and connect to the mass loss mechanisms that could form it. We measure a bipolar circumstellar structure with a position angle of 42.3$\pm 7.0^\circ$. We observe asymmetries in the form of hot spots in the north east of …


Developments In The Lithographic Engineering Of Bi2sr2cacu2o8+Delta Mesa Terahertz-Emitting Devices, Sarah Elghazoly Sep 2025

Developments In The Lithographic Engineering Of Bi2sr2cacu2o8+Delta Mesa Terahertz-Emitting Devices, Sarah Elghazoly

Dissertations, Theses, and Capstone Projects

Devices microfabricated from the high-temperature superconducting cuprate Bi2Sr2CaCu2O8+𝛿 (Bi-2212) are a promising source of coherent terahertz radiation within the ’terahertz gap’ (0.3- 1.5 THz). A current-biased mesa patterned into the surface of a single crystal will produce electromagnetic radiation in the terahertz regime due to the naturally occurring Josephson junctions formed by the stacks of superconducting cuprate oxide planes in the material separated by insulating BiO and SrO barrier layers. Previous research has shown that by fabricating these mesas such that the geometry supports resonant cavity Fabry-Perot modes, the junctions within the mesa …


Towards Automated Evolution Of Imperative Deep Learning Programs, Tatiana Castro-Vélez Sep 2025

Towards Automated Evolution Of Imperative Deep Learning Programs, Tatiana Castro-Vélez

Dissertations, Theses, and Capstone Projects

Software engineering (SE) is increasingly intersecting with data-centric domains such as machine learning (ML) and deep learning (DL). Similar to bugs in traditional software systems, defects can emerge in ML and DL systems. ML, including DL, systems are now widespread and rely on dynamic models defined by input data. Developers face the challenge of building dependable systems while addressing the demand for scalable software.

Efficiency is essential to support responsiveness with respect to ever-growing datasets. Traditional DL frameworks achieve scalability through deferred execution, enabling symbolic, graph-based deep neural network (DNN) computation. While efficient, this approach is error-prone, cumbersome, and difficult …


Starspot Inference Using Light Curve Inversion Techniques, Mohammad Refat Sep 2025

Starspot Inference Using Light Curve Inversion Techniques, Mohammad Refat

Dissertations, Theses, and Capstone Projects

Star spots are patches that are dark or bright on the surface of a star. They are tightly correlated to the magnetic activity of stars. One of the reasons we want to study star spots is to better understand where the active latitude of stars are located, which helps us understand planet habitability around low mass stars. The Starry package is a set of tools that can map the surface of stars and exoplanets using time series data, with spherical harmonics. Butterpy is a package that allows for the simulation of starspot evolution and their lightcurves. Fleck is a package …


How To Form A Gravitational-Wave Source: Quantifying Intermediate Evolutionary Stages In Isolated Binary Stellar Evolution, Ana Lam Sep 2025

How To Form A Gravitational-Wave Source: Quantifying Intermediate Evolutionary Stages In Isolated Binary Stellar Evolution, Ana Lam

Dissertations, Theses, and Capstone Projects

Gravitational-wave (GW) detections from double compact object (DCO) mergers provide crucial observational constraints for understanding massive stars across cosmic time. Coupled with these observations, binary population synthesis simulations become powerful tools for probing the formation, evolution, and ultimate fates of their progenitors---massive binary stars. However, complex evolutionary pathways, shaped by key intermediate stages such as mass transfer phases and supernovae, present a significant challenge to assess their impact. To address this, we develop a framework to quantify the influence of intermediate evolutionary stages on GW sources. By combining Sankey diagrams with survival factors, we systematically investigate how intermediate stages influence …


Effect Of Equation Of State On The Formation Of Binary Black Holes In Active Galactic Nucleus Disks, Theodore Edwards Sep 2025

Effect Of Equation Of State On The Formation Of Binary Black Holes In Active Galactic Nucleus Disks, Theodore Edwards

Dissertations, Theses, and Capstone Projects

Active galactic nucleus disks have been proposed as a possibly dominant location of the mergers of binary black holes detected by gravitational wave observatories. The nonlinear interactions between stellar mass black holes and disk gas determine when binaries will form from single objects on nearby orbits. Prior work has used smoothed particle hydrodynamics models in an isothermal disk to study this problem. However, the local equation of state near the midplane of an optically thick accretion disk is adiabatic rather than isothermal, even if the radiative equilibrium temperature is azimuthally isothermal. Therefore, we investigate the use of an adiabatic equation …


Investigating The Behavior Of Dwarf-Hosting Cosmic Filaments In Regions Of Average Density Within The Universe, Manuel E. Ramirez Hernandez Sep 2025

Investigating The Behavior Of Dwarf-Hosting Cosmic Filaments In Regions Of Average Density Within The Universe, Manuel E. Ramirez Hernandez

Dissertations, Theses, and Capstone Projects

The cosmic web is the large-scale structure of the universe, composed of elongated, overdense areas held together by gravity known as cosmic filaments. Within these filaments, dwarf galaxies are ubiquitous and make for excellent laboratories due to their small size. to determine the effects of cosmic web structures on dwarf galaxies. In this thesis, I laid the groundwork to investigate whether dwarf galaxy populations vary across different types of filaments. Filaments were extracted from the gas density field in the New Horizon simulation at $z=0$ using the topological feature finder DisPerSE. I determined the distances of galaxies to their nearest …


Leveraging Stellar Chemistry For A Global View Into The Atmospheres Of Brown Dwarfs And Giant Exoplanets, Emily Calamari Sep 2025

Leveraging Stellar Chemistry For A Global View Into The Atmospheres Of Brown Dwarfs And Giant Exoplanets, Emily Calamari

Dissertations, Theses, and Capstone Projects

In the era of the James Webb Space Telescope (JWST), it is now possible to examine substellar mass atmospheres in unparalleled detail and precision. However, unraveling the complicated thermodynamics and chemistry in these atmospheres remains a challenge. Atmospheric retrievals are a leading data-driven technique capable of recovering an object’s fundamental parameters such as mass, radius, effective temperature, gravity, cloud structure and composition and chemical abundances. However, in directly imaged or isolated worlds, constraining and/or interpreting these fundamental parameters can be difficult, particularly as retrieval models try to parameterize the overall impact of clouds.

For my dissertation, I turned to main …


Relevant Deformations Of Brane Brick Models, Georgios P. Goulas Sep 2025

Relevant Deformations Of Brane Brick Models, Georgios P. Goulas

Dissertations, Theses, and Capstone Projects

The thesis studies relevant deformations of 2d gauge theories with $\mathcal{N}=(0,2)$ supersymmetry, realized on the worldvolume of D1-branes probing toric Calabi-Yau 4-folds. Brane brick models are the primary means for engineering such theories and streamlining their connection to geometry. In this thesis, we relevant deformations of brane brick models, focusing on a specific class of deformations in which the initial and final theories are both described by brane brick models. Relevant deformations serve as an additional, systematic way of generating these theories, as well as uncovering connections between them. Within the framework of brane engineering, these deformations acquire a geometric …


Multi-Nuclear Magnetic Resonance (Nmr) Characterization Of Novel Materials, Tawhid Pranto Sep 2025

Multi-Nuclear Magnetic Resonance (Nmr) Characterization Of Novel Materials, Tawhid Pranto

Dissertations, Theses, and Capstone Projects

The increasing reliance on batteries in commercial products, coupled with the environmental challenges posed by climate change and the limitations of fossil fuel consumption, has created strong financial and environmental incentives to explore innovative energy storage solutions. Renewable energy sources are being actively developed, but their intermittent nature necessitates efficient storage technologies, driving significant research into improving the performance of batteries, fuel cells, and capacitors.

This thesis focuses on the application of advanced Nuclear Magnetic Resonance (NMR) spectroscopy to study and understand novel materials for energy storage applications, with an emphasis on electrolytes for rechargeable lithium-ion batteries and all-solid-state batteries. …


Nuclear Magnetic Resonance Characterization For The Study Of Beyond Lithium-Ion Battery Electrolytes, Allen Zheng Sep 2025

Nuclear Magnetic Resonance Characterization For The Study Of Beyond Lithium-Ion Battery Electrolytes, Allen Zheng

Dissertations, Theses, and Capstone Projects

To achieve a sustainable future, key issues in the energy and construction sectors such as the transition from fossil fuels to renewable energy sources and recycling of waste construction materials must be addressed. While fossil fuels offer a high energy density source of quick, consistent energy, renewable energy sources such as wind, solar, and hydroelectric offer intermittent energy output, requiring energy storage systems to maintain steady energy availability for consumers. Lithium-ion batteries (LIBs) are widely used in consumer electronics, electric vehicles, and grid storage due to their high energy density, low self-discharge, and rechargeability. However, they are limited by high …


Refining Orbits And Revealing Origins: A Study Of Giant Exoplanets Around Low-Mass Stars, Angeli Sandoval Sep 2025

Refining Orbits And Revealing Origins: A Study Of Giant Exoplanets Around Low-Mass Stars, Angeli Sandoval

Dissertations, Theses, and Capstone Projects

The study of gas giants around low-mass stars offers important insight into planet formation. Core accretion models predict that these planets should have a low likelihood of forming due to the limited disk masses of their host low-mass stars. However, NASA space missions such as Kepler and TESS have revealed an emerging population of Saturn- and Jupiter-like planets around M-dwarfs (referred to as giant exoplanets orbiting M-dwarfs or GEMS) that challenge these expectations. This thesis investigates the detection, confirmation, and analysis of GEMS through pipeline development and a detailed analysis of two systems.

In Chapter 1, I provide background information …


The Role Of Water In Peptide Behavior And Peptide-Based Water-Responsive Crystals, Janel Jannette Rivera Cancel Sep 2025

The Role Of Water In Peptide Behavior And Peptide-Based Water-Responsive Crystals, Janel Jannette Rivera Cancel

Dissertations, Theses, and Capstone Projects

Water plays a crucial role in shaping the behavior and function of biomolecules across the liquid, supercooled, and glassy states. This thesis presents a dual approach combining computational simulations and experimental investigations to explore the influence of water on biomolecular systems, particularly peptide-based materials. We employ molecular dynamics simulations to study the hydration-dependent structural dynamics of homopolymer peptides. Simulations were carried out across a range of temperatures and pressures to analyze changes in hydration and structural stability, shedding light on the behavior of peptides under supercooled and glassy conditions. These studies are especially relevant for understanding biomolecular stability in cryopreservation. …


Reinforcement Learning Based Resource Management In Edge Systems, Motahare Mounesan Sep 2025

Reinforcement Learning Based Resource Management In Edge Systems, Motahare Mounesan

Dissertations, Theses, and Capstone Projects

Modern end-user applications that are highly compute- and data-intensive, while being extremely latency- and accuracy-sensitive, are increasingly reliant on distributed computing. This paradigm spans a range of architectures, from cloud computing to in-device processing. Cloud computing, though scalable, often incurs high latency and cost, constraints that are particularly problematic for time-sensitive applications. In contrast, in-device computing on end or IoT devices is limited by resource constraints, making it inadequate for many complex workloads. Edge computing presents a compelling alternative by bringing computation closer to data sources, thereby reducing end-to-end latency and improving responsiveness. However, the inherent decentralized and dynamic nature …


Satellite-Host Galaxy Co-Evolution With Next-Generation Regulator Models, Austen Gabrielpillai Sep 2025

Satellite-Host Galaxy Co-Evolution With Next-Generation Regulator Models, Austen Gabrielpillai

Dissertations, Theses, and Capstone Projects

The evolution of satellites galaxies is an unsolved problem in galaxy formation. Recent observations such as the SAGA and ELVES surveys find tension in HI contents and star formation of satellites around their central host galaxies when compared to our own local environment, the Milky Way. These processes are potentially highly influenced by the host's circumgalactic medium (CGM), and to constrain these cases requires accurate and fast modeling of satellites-host interactions. In this work, we present our methodology for evolving z = 0 surviving satellites alongside their central galaxy in sapphire, a CGM regulator co-evolution model of galaxy formation. …


Geol 64: Planetary Geology - Syllabus, Dara Laczniak Aug 2025

Geol 64: Planetary Geology - Syllabus, Dara Laczniak

Open Educational Resources

This Open Educational Resources (OER) syllabus is for an introductory planetary geology course that utilizes results from space missions to expose students to the surface features, composition, geological activity, and probable history of the planets, moons, asteroids, and comets of the solar system. It also places space exploration into the context of larger societal issues such as global warming and natural resource availability and addresses topics such as the ethics of space exploration and hazards of space travel. This OER syllabus aims to foster student-centered learning, critical thinking, data analysis and communication skills, and creativity. Assigned readings are compiled into …


Trigonometry: A Brief Conversation, Carolyn D. King Phd, Evelyn Tam, Fei Ye Phd, Beata Carvajal Aug 2025

Trigonometry: A Brief Conversation, Carolyn D. King Phd, Evelyn Tam, Fei Ye Phd, Beata Carvajal

Open Educational Resources

These five units are specifically tailored to foster the mastery of a few selected trigonometry topics that comprise the one credit MA-121 Elementary Trigonometry course.  Each unit introduces the topic, provides space for practice, but more importantly, provides opportunities for students to reflect on the work in order to deepen their conceptual understanding.

These units have also been assigned to students of other courses such as pre-calculus and calculus as a review of trigonometric basics essential to those courses.  This is the third edition of the materials.  Based on suggestions from instructors Units 2 and 3 have been edited to …


Machine Learning And Crime Prevention, Emily Lizewski Aug 2025

Machine Learning And Crime Prevention, Emily Lizewski

Student Theses

Predictive policing uses machine learning to analyze crime patterns and help law enforcement better efficient use their resources. These tools can improve accuracy by highlighting complex trends in large sets of data. While this technology has its advantages, it also raises important ethical and social questions. Within this paper we looks at how predictive policing works, focusing on the machine learning models often used such as decision trees, random forests, gradient boosting, and models that factor in both time and location. It also explores how these tools might unintentionally reinforce biases already present in historical crime data. In reviewing the …


Geol 12 Natural Disasters Syllabus, Anestoria Shalkowski Aug 2025

Geol 12 Natural Disasters Syllabus, Anestoria Shalkowski

Open Educational Resources

Hazards are events which have the capabilities to damage property and or life. Understanding natural hazards and how these can become disasters are important in reducing the impacts of such events. This syllabus provides a description of the material to be examined and the expected student outcomes upon completion of the course.


Advanced Robotic Multimodal Imaging With Real-Time Motion Compensation For Dynamic Structural Health Monitoring, George Papaioannou, Christos Mitrogiannis, Mark Schweitzer, Maria Pappa, Pegah Khosravi, Apostolos Karantanas, Chris Ruberg, Shawn Owens, Nikolaos Michailidis Aug 2025

Advanced Robotic Multimodal Imaging With Real-Time Motion Compensation For Dynamic Structural Health Monitoring, George Papaioannou, Christos Mitrogiannis, Mark Schweitzer, Maria Pappa, Pegah Khosravi, Apostolos Karantanas, Chris Ruberg, Shawn Owens, Nikolaos Michailidis

Publications and Research

Modern composite materials promise superior performance and load-bearing capabilities, yet evaluating their structural integrity remains challenging. Current testing methods, such as visual, thermographic, ultrasonic, optical, electromagnetic, terahertz, shearography, X-ray, and neutron imaging, are hampered by long scan durations, limited field of view, suboptimal accuracy, and high costs, particularly when applied to large structures.

This paper addresses these issues by introducing a novel robotic multimodal imaging system that overcomes the limitations of traditional methods. This system dynamically captures both static and dynamic properties of materials using advanced motion compensation techniques. By integrating multiple radiographic modalities into a coordinated robotic platform, it …


Math 122: Precalculus Instructor Guide, Seth Lehman Aug 2025

Math 122: Precalculus Instructor Guide, Seth Lehman

Open Educational Resources

OER Instructor guide for Math 122: Precalculus at Queens College.


The Effect Of An Invasive Species (Lantana Camara) And A Fast-Growing Herb (Acanthus Pubescens) On The Plant And Animal Communities In Kibale National Park, Uganda, Kathleen Bufka Aug 2025

The Effect Of An Invasive Species (Lantana Camara) And A Fast-Growing Herb (Acanthus Pubescens) On The Plant And Animal Communities In Kibale National Park, Uganda, Kathleen Bufka

Theses and Dissertations

Fast-growing plant species, like Lantana camara and Acanthus pubescens, could threaten biodiversity in Kibale National Park, Uganda. I surveyed plants and wildlife in areas where these plants were frequently encountered compared to those areas where they are infrequent. I found mixed results based on plant traits and the animals considered. My findings support management efforts on these two species to prevent forest degradation.


Improved Rational Approximations Of Pi, Nelson Carella Jul 2025

Improved Rational Approximations Of Pi, Nelson Carella

Publications and Research

The irrationality exponent of a real number α is defined by maximal value μ(α) ≥ 1 such that the inequality |p/q − α| < 1/qμ(α) is true for finitely many rational approxi- mations by relatively prime pairs p/q. The earliest result introduced the upper bound μ(π) ≤ 42 for the irrationality exponent of π. Subsequently, it was improved by many authors. The more recent result introduced the improved upper bound μ(π) ≤ 7.6063. This note introduces an improved irrationality exponent μ(π) ≤ 3. The optimal value is expected to be μ(π) = 2.


Exploring Adversarial Threats To Neuralhash: A Perceptual Hashing Algorithm, Gurleen Kaur Jul 2025

Exploring Adversarial Threats To Neuralhash: A Perceptual Hashing Algorithm, Gurleen Kaur

Student Theses

Perceptual hashing algorithms are algorithms that generate content-based image hashes by extracting perceptual features from the images. Unlike cryptographic hashes, which exhibit significant changes with even slight input alterations, perceptual hashes do not change when modifications like compression, color correction and brightness are applied to the images. These hashes are designed to remain similar for inputs that are visually or perceptually alike, which has led to their widespread application in detecting duplicate images, finding similar images for reverse image search and to detecting inappropriate content of Child sexual abuse (CSAM) images by comparing image hashes with dataset of known perceptual …


Collaborative Class Zine: Weekly Reflection Assignment With Powerpoint Template, Brett Whysel Jul 2025

Collaborative Class Zine: Weekly Reflection Assignment With Powerpoint Template, Brett Whysel

Open Educational Resources

Abstract

This collaborative class zine assignment uses a shared PowerPoint format to deepen student learning while building community. Students contribute visual reflections (graphics, diagrams, quotes, or doodles) weekly or periodically throughout the semester. Faculty provide reflection prompts about key takeaways and unclear concepts (sample prompts included). The resource includes both sample LMS instructions and a ready-to-use PowerPoint zine template that works across all disciplines. By combining metacognitive reflection with creative expression, students consolidate learning by finding new connections and applications. The collaborative format creates community connections and joy while students learn from peers' diverse perspectives.


"Chatgpt Told Me To Say It": Ai Chatbots And Class Participation Apprehension In University Students, Daisuke Akiba Jul 2025

"Chatgpt Told Me To Say It": Ai Chatbots And Class Participation Apprehension In University Students, Daisuke Akiba

Publications and Research

The growing prevalence of AI chatbots in everyday life has prompted educators to explore their potential applications in promoting student success, including support for classroom engagement and communication. This exploratory study emerged from semester-long observations of class participation apprehensions in an introductory educational psychology course, examining how chatbots might scaffold students toward active and independent classroom contribution. Four students experiencing situational participation anxiety voluntarily participated in a pilot intervention using AI chatbots as virtual peer partners. Following comprehensive training in AI use and prompt design given to the entire class, participants employed systematic consultation frameworks for managing classroom discourse trepidations. …


Ideal Mathematical Pendulum: Examples Of Physics Problem Conditions Expressed Primarily Through Diagrams, Vasiliy Znamenskiy Jul 2025

Ideal Mathematical Pendulum: Examples Of Physics Problem Conditions Expressed Primarily Through Diagrams, Vasiliy Znamenskiy

Open Educational Resources

This article explores an innovative approach to physics education centered on the formulation of problems using visual diagrams with minimal textual description. Departing from traditional word-heavy methods, the proposed technique leverages schematic drawings as the primary mode of problem presentation. This visual-first strategy facilitates intuitive understanding, promotes spatial reasoning, and supports the development of abstract thinking in students. The method is especially effective in diverse classrooms where language barriers may hinder comprehension. By engaging learners through image-based tasks, the approach reduces cognitive load, fosters independent discovery of physical principles, and enhances overall conceptual clarity. Examples from mechanics and oscillations illustrate …


Can We Discover Physical Models Using Machine Learning? A Case Study Of Galaxy Sizes, Festa Buçinca-Çupallari, Ariyeh Maller, Viviana Acquaviva, Austen Gabrielpillai, Rachel S. Somerville Jul 2025

Can We Discover Physical Models Using Machine Learning? A Case Study Of Galaxy Sizes, Festa Buçinca-Çupallari, Ariyeh Maller, Viviana Acquaviva, Austen Gabrielpillai, Rachel S. Somerville

Publications and Research

We explore the ability of machine learning methods to discover underlying equations of physics by searching for the equations governing galaxy size in a semianalytic model. This case study allows us to evaluate the process as we know the ground truth. We find that we fail to find an equation to predict galaxy size on the entire data set, but are successful when we separate out disk galaxies where we expect the physics driving galaxy size to be different than in bulge-dominated systems. We are also able to find an equation for bulge size, but not without adding an additional …


8-Page Zine Extra Credit Assignment, Ricaute Rogers Jul 2025

8-Page Zine Extra Credit Assignment, Ricaute Rogers

Open Educational Resources

This is an 8-page minizine extra credit assignment that put into practice the concepts learned in CIS100.


Full-Stack Web Applications: Infrastructure, Development Pipelines & Devsecops, Yassine Chahid, Patrick Slattery Jul 2025

Full-Stack Web Applications: Infrastructure, Development Pipelines & Devsecops, Yassine Chahid, Patrick Slattery

Publications and Research

This research explores emerging development methodologies and technologies which facilitate the deployment and maintenance of software applications. It evaluates architectural styles for the development of software such as monolithic (legacy) and microservice models, with a focus on their key differences such as scalability or project structure through to the development of an application. By examining methodologies such as Agile and continuous integration/continuous development pipelines along with the deployment tools Docker and Git for version/release control, the study analyzes how these innovations speed up development, improve existing practices, and serve as the foundation for development operations. Cloud solutions for tasks such …