Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons™

Open Access. Powered by Scholars. Published by Universities.®

2025

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 451 - 480 of 12193

Full-Text Articles in Physical Sciences and Mathematics

Tidal Interactions In Strong Field Gravity, Maria Jose Rodriguez Dec 2025

Tidal Interactions In Strong Field Gravity, Maria Jose Rodriguez

Funded Research Records

No abstract provided.


Collaborative Research: Evolution Of The Tristan-Gough-Walvis Ridge Hotspot System: Age And Composition Of Expedition 391/397t Volcanic Basement, Katherine Elizabeth Potter Dec 2025

Collaborative Research: Evolution Of The Tristan-Gough-Walvis Ridge Hotspot System: Age And Composition Of Expedition 391/397t Volcanic Basement, Katherine Elizabeth Potter

Funded Research Records

No abstract provided.


Collaborative Research: Rapid: Fault Rupture And Spring Sampling Of The 2023 Kahramanmaras, Turkey, Earthquake Sequence Ruptures, Alexis Ault, Dennis Lowell Newell Dec 2025

Collaborative Research: Rapid: Fault Rupture And Spring Sampling Of The 2023 Kahramanmaras, Turkey, Earthquake Sequence Ruptures, Alexis Ault, Dennis Lowell Newell

Funded Research Records

No abstract provided.


Representation Theory In Unoriented And Non-Semisimple Physics, Matthew Bruce Young Dec 2025

Representation Theory In Unoriented And Non-Semisimple Physics, Matthew Bruce Young

Funded Research Records

No abstract provided.


Dryland Soil Carbon Inventory, Brooke Osborne Dec 2025

Dryland Soil Carbon Inventory, Brooke Osborne

Funded Research Records

No abstract provided.


How Novices Write Code: Discovering Best Practices And How They Can Be Adopted, John Martin Edwards Dec 2025

How Novices Write Code: Discovering Best Practices And How They Can Be Adopted, John Martin Edwards

Funded Research Records

No abstract provided.


Exceptional Holography, Oscar Varela Dec 2025

Exceptional Holography, Oscar Varela

Funded Research Records

No abstract provided.


Re: Approval Letter For The Revised Butte Priority Soils Operable Unit (Bpsou) Butte Treatment Lagoons (Btl) Groundwater Treatment System Annual Operations, Maintenance, And Monitoring (Om&M) Plan – 2023 (Dated October 29, 2025), Emma Rott Dec 2025

Re: Approval Letter For The Revised Butte Priority Soils Operable Unit (Bpsou) Butte Treatment Lagoons (Btl) Groundwater Treatment System Annual Operations, Maintenance, And Monitoring (Om&M) Plan – 2023 (Dated October 29, 2025), Emma Rott

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.


Engineered Multifunctional Drug-Loaded Dendrimer Nanoparticles For Glaucoma: Triple Mechanism Via Antioxidant Activity, Iron Chelation, And Enhanced Ocular Transport, Burhan Ates, Ashish Trital, Vimalin Jeyalatha Mani, Lei Xu, Jonathan Kenlee, Nuran Ercal, Hu Yang Dec 2025

Engineered Multifunctional Drug-Loaded Dendrimer Nanoparticles For Glaucoma: Triple Mechanism Via Antioxidant Activity, Iron Chelation, And Enhanced Ocular Transport, Burhan Ates, Ashish Trital, Vimalin Jeyalatha Mani, Lei Xu, Jonathan Kenlee, Nuran Ercal, Hu Yang

Chemistry Faculty Research & Creative Works

In this study, we developed multifunctional nanoparticles based on polyamidoamine (PAMAM) dendrimers functionalized with caffeic acid (CA) and poly (ethylene glycol) maleimide (PEGM) for the topical delivery of hydrophobic antiglaucoma drugs brimonidine (BM) and betaxolol (BX). The PAMAM-CA and PAMAM-CA-PEGM conjugates exhibited antioxidant and iron-chelating activities in a dose-dependent manner. BM- and BX-loaded dendrimer nanoparticles produced using a multi-inlet vortex mixer showed uniform spherical morphology (∼80 nm by TEM) and hydrated sizes of ∼135-144 nm by DLS. Both nano formulations demonstrated high cytocompatibility with human corneal epithelial cells and were nonirritant in the HET-CAM assay, with PEGM further improving cytocompatibility. …


Time-Resolved Ultrafast Infrared Spectroscopic Interrogation Of Intramolecular Reaction Coordinates, Valerie Winkler Dec 2025

Time-Resolved Ultrafast Infrared Spectroscopic Interrogation Of Intramolecular Reaction Coordinates, Valerie Winkler

Arts & Sciences Graduate Student Theses and Dissertations

Light-induced chemical transformations are practical across many chemical and biological systems. From intramolecular hydrogen-bonding coordinates to reactions which alter the carbon framework of a molecule, the application of light can induce conformational changes that can subsequently be harnessed for a variety of tasks. However, molecular-level mechanistic insight about photo-induced chemical reactions remains difficult to acquire using current methodologies. In this dissertation, several intramolecular reactions are investigated and characterized, ranging from ground- and excited-state intramolecular proton transfers to the photochemical synthesis of a complex organic cyclization structure. The reaction coordinates are directly interrogated by utilizing ultrafast infrared spectroscopic techniques, such as …


Buffer Vs. Swabs: Efficacy Of Carrier Nucleic Acids In Robotic Extractions, Shawn Cecil Dec 2025

Buffer Vs. Swabs: Efficacy Of Carrier Nucleic Acids In Robotic Extractions, Shawn Cecil

Honors Projects

This study compared the efficiency of two carrier nucleic acid methods, specifically using salmon sperm DNA (spDNA), in robotic solid-phase extractions of cotton swab samples. Robotic extractions reduce processing time and workload but result in substantially lower DNA recovery than manual organic extraction. This research tested 10 µg of spDNA being added to the lysis buffer or pre-treating the swabs with it before DNA was added. Both methods showed a significant increase in recovery compared to extractions with no carrier. In the buffer extractions, recovery ranged from 69.4% to 117.5% and the swabs being pre-treated ranged from 84.2% to 125.8% …


Smart Pireps: Leveraging Technology To Simplify Pilot Weather Reporting In General Aviation, Emma Hellwege Dec 2025

Smart Pireps: Leveraging Technology To Simplify Pilot Weather Reporting In General Aviation, Emma Hellwege

Honors Projects

This honors project examines how emerging aviation technologies can support or automate components of Pilot Weather Reports (PIREPs) to improve reporting accuracy, reduce pilot workload, and increase participation within the general aviation (GA) community. PIREPs provide essential real-time weather observations—such as turbulence, icing, and visibility—that supplement automated systems and enhance situational awareness for pilots, air traffic control, and meteorologists. However, reports are vastly underutilized due to workload constraints, inconsistent training, voice-only submission methods, and technological disparities across the GA fleet.

Through a structured analysis of federal aviation documentation, sensor capabilities, human factors research, and recent advancements in automation, this study …


Understanding Enso Through Mathematical Models, Maria I. Sanchez Muniz Dec 2025

Understanding Enso Through Mathematical Models, Maria I. Sanchez Muniz

Open Educational Resources

This assignment introduces students to conceptual models of the El Niño–Southern Oscillation (ENSO) and guides them through a structured investigation of their physical and mathematical foundations. Students analyze the recharge–oscillator and delayed–oscillator frameworks, explore how differential equations capture ocean–atmosphere interactions, and evaluate parameter-driven changes in oscillatory behavior. A key component of the work is the guided use of generative AI as a research tool: students employ AI models to locate peer-reviewed literature, interrogate model extensions, and refine their understanding of complex mechanisms, while synthesizing all final explanations in their own words. By blending classical climate modeling with modern AI-supported inquiry, …


Systematics And Systems Theory: Reconstructability Analysis Of The Tetrad, Martin Zwick Dec 2025

Systematics And Systems Theory: Reconstructability Analysis Of The Tetrad, Martin Zwick

Complex Systems Faculty Publications and Presentations

This talk discusses the relationship between systems theory, specifically Reconstructability Analysis, and Systematics, a systems theory-like framework of number symbolism developed by John G. Bennett, which he presented in his four-volume magnum opus, The Dramatic Universe. The talk, given to a community of people interested in Bennett's ideas, focuses on Martin Zwick's paper "Ideas and Graphs: the Tetrad of Activity" archived at https://archives.pdx.edu/ds/psu/36249.


Examining The Intersectional And Structural Issues Of Routine Healthcare Utilization And Access Inequities For Lgb People With Chronic Diseases, Shiya Cao, Mehreen Mirza, Sophia Silovsky, Nicole Tresvalles, Lucia Qin, Sarah Susnea Dec 2025

Examining The Intersectional And Structural Issues Of Routine Healthcare Utilization And Access Inequities For Lgb People With Chronic Diseases, Shiya Cao, Mehreen Mirza, Sophia Silovsky, Nicole Tresvalles, Lucia Qin, Sarah Susnea

Statistical and Data Sciences: Faculty Publications

In the United States, although the gaps in health insurance coverage by sexual orientation have been closing since the implementation of the Affordable Care Act and legalization of same-sex marriage, the LGB group (i.e., lesbian, gay, bisexual) continues to report healthcare utilization and access inequities such as more delayed or unmet care. The extant research has often examined healthcare utilization and access inequities due to affordability (e.g., out-of-pocket costs). However, healthcare utilization and access inequities are only partially explained by cost reasons; there are non-cost reasons that have not been adequately empirically examined. The present study innovatively includes discrimination structural …


Adaptive Image Acquisition Algorithms For Resource-Constrained Single-Photon Cameras, Yeganeh Jalalpour, Wu-Chi Feng Dec 2025

Adaptive Image Acquisition Algorithms For Resource-Constrained Single-Photon Cameras, Yeganeh Jalalpour, Wu-Chi Feng

Computer Science Faculty Publications and Presentations

Emerging single-photon camera (SPC) technologies have unique challenges in data acquisition and processing. Unlike conventional sensors that produce a single 8- to 16-bit brightness value per pixel, SPCs record photon arrivals with many more samples per pixel, using high floating-point precision for each photon collected. This means that they must handle potentially millions of timestamps, especially at higher spatial resolutions and in the presence of ambient light, creating bottlenecks within the pixel circuitry. To address these challenges associated with SPCs, this paper proposes adaptive algorithms designed to efficiently distribute hardware resources among groups of pixels. By selectively subsampling the data …


Stream Behavior Characterization Of Marin County Coastal Watersheds And Their Influence On Salmonid Habitat, Ellie L. Murdoch Dec 2025

Stream Behavior Characterization Of Marin County Coastal Watersheds And Their Influence On Salmonid Habitat, Ellie L. Murdoch

Master's Theses

Coastal watersheds in California are increasingly affected by climatic variability, threatening stream behavior, ecological function, and salmonid habitat suitability. This study evaluated streamflow behavior of seven watersheds in Marin County, California, with detailed analysis of Corte Madera, Olema, and Redwood watersheds, which are not influenced by reservoir releases. Using USGS stream gauge records, PRISM climate data, SSURGO soils, and geologic and vegetation information, streamflow metrics critical to salmonid life cycles were quantified for water years 2014 to 2023. Watersheds with greater storage capacity, such as Redwood, exhibited muted hydrologic responses, including delayed flow activation, lower peak flows, slower recession rates, …


Hint-Guided Video Frame Interpolation For Video Compression, Pan Tan, Wu-Chi Feng Dec 2025

Hint-Guided Video Frame Interpolation For Video Compression, Pan Tan, Wu-Chi Feng

Computer Science Faculty Publications and Presentations

Traditional video compression continues to advance, but the gainsin efficiency are diminishing and come at the cost of higher compu-tational complexity. Despite achieving competitive rate-distortionresults, current neural video codecs (NVCs) generally lack sup-port for a wide range of quality levels, often requiring multiplemodels to achieve flexible rate control, which increases both train-ing cost and deployment complexity. To address the limitations ofboth traditional codecs and current NVCs, we propose a hybridvideo compression framework that integrates traditional codecswith hint-guided video frame interpolation (VFI), a learning-basedtechnique for synthesizing intermediate frames. By using decodedreference frames and leveraging compressed-domain hints to guideinterpolation, our method improves …


Dynamic, Reconfigurable, And Hierarchical Biosynthetic Composites Via Collagen Self-Assembly Within Highly Crowded Microgel Pastes, Elif Narbay, Abbygail Caine, Sanika Pandit, Gabrielle Montgomery, Marion Harper, E. Daniel Cárdenas-Vásquez, Hatte Hamilton, Megan Hicks, Daniel Mattar, Kyle Choy, Marco Bisoffi, L. Andrew Lyon Dec 2025

Dynamic, Reconfigurable, And Hierarchical Biosynthetic Composites Via Collagen Self-Assembly Within Highly Crowded Microgel Pastes, Elif Narbay, Abbygail Caine, Sanika Pandit, Gabrielle Montgomery, Marion Harper, E. Daniel Cárdenas-Vásquez, Hatte Hamilton, Megan Hicks, Daniel Mattar, Kyle Choy, Marco Bisoffi, L. Andrew Lyon

Engineering Faculty Articles and Research

The fabrication of a new class of biomimetic biomaterials is reported using nanostructured microgel pastes formed from “overpacked” assemblies of ultrasoft poly(N-isopropyl acrylamide-co-acrylic acid) microgels and their composites with collagen. Despite the solid-like nature of microgel pastes, collagen fibrillogenesis is robust and rapid, with a 3D collagen network forming throughout the paste volume. Structural organization within the composite is interrogated via a suite of microscopy methods, while rheological characterization provides insight into the static and dynamic mechanical properties of the materials. Long-range fibrillogenesis is enabled by local crowding, dynamics, and spatial reconfigurability of pastes at the …


A (Mini) Mathematics Research Experience In A Math Teachers’ Circle Session, Michelle Manes, Linda Venenciano, Seanyelle Yagi Dec 2025

A (Mini) Mathematics Research Experience In A Math Teachers’ Circle Session, Michelle Manes, Linda Venenciano, Seanyelle Yagi

Journal of Math Circles

We describe a single Math Teachers’ Circle session during which a group of teachers collectively engaged in a “mini mathematics research experience.” This provides a model for providing research experiences for mathematics teachers through content-based professional development programs. We conjecture that these experiences will have many of the same benefits as research experiences for teachers in lab sciences.


Timss 2023 – Infographic: Future Pd Needs Of Maths Teachers, Jo Earp Dec 2025

Timss 2023 – Infographic: Future Pd Needs Of Maths Teachers, Jo Earp

Teacher infographics

The IEA’s Trends in International Mathematics and Science Study (TIMSS) is a global assessment measuring student achievement in years 4 and 8. Teachers from participating schools also complete a questionnaire. Today’s infographic looks at the topics that mathematics teachers reported needing professional development on in the future.


Model For Calculating Impact Force For Individualized Hip Fracture Prediction During A Fall, Alisha Agarwal, Daniel Kargilis, Nishtha Gupta, Michael Chang, Rui Feng, Gregory Chang, Chamith S. Rajapakse Dec 2025

Model For Calculating Impact Force For Individualized Hip Fracture Prediction During A Fall, Alisha Agarwal, Daniel Kargilis, Nishtha Gupta, Michael Chang, Rui Feng, Gregory Chang, Chamith S. Rajapakse

Student Papers, Posters & Projects

Osteoporotic-related weakening of bone is a common cause of hip fractures. The standard of care for the diagnosis and management of osteoporosis is the dual-energy x-ray absorptiometry bone mineral density T-scores. Many individuals considered nonosteoporotic, however, still sustain fractures since these tools do not incorporate vital bone parameters and subject-specific characteristics. The purpose of this work was to (1) develop a simple analytical model for estimating the force exerted on the femur during a fall (i.e., impact force) based on measurable patient metrics and (2) define a quantifiable fracture risk index by comparing finite-element-derived bone strength and impact force, which …


Exploring Healthcare Providers' Perceptions Of Virtual Reality In Lung Cancer Treatment Preparedness: A Mixed-Methods Feasibility Study For The Development Of Everybreathmatters, Safa Elkefi, Rongyi Wu, Steven K. Feiner, Lanyi Chen, Guy Hembroff, Alicia K. Matthews Dec 2025

Exploring Healthcare Providers' Perceptions Of Virtual Reality In Lung Cancer Treatment Preparedness: A Mixed-Methods Feasibility Study For The Development Of Everybreathmatters, Safa Elkefi, Rongyi Wu, Steven K. Feiner, Lanyi Chen, Guy Hembroff, Alicia K. Matthews

Michigan Tech Publications

This study examined healthcare providers' perceptions of the benefits, challenges, and design preferences for Virtual Reality (VR)-based interventions to support treatment preparedness in lung cancer care. Our study involves 50 surveys and 10 interview responses, in a mixed-method design. We conducted descriptive statistics and thematic analysis through a hybrid inductive-deductive approach. Analysis of the quantitative data helped us capture demographic characteristics, VR familiarity, and perceived VR usefulness. Qualitative analysis gave us a deeper understanding of the VR tool design and Implementation. Descriptive statistics and Fisher's exact tests were used to assess associations, while thematic analysis was conducted on interview transcripts. …


Capstone Reflection: Developing A Muslim Prayer App For Psu Students, Jeremiah Su Dec 2025

Capstone Reflection: Developing A Muslim Prayer App For Psu Students, Jeremiah Su

University Honors Theses

This thesis examines the development process of the Muslim Student Association (MSA) App, a computer science capstone project. The app strives to help the Muslim community at Portland State University (PSU) and the Portland area by consolidating essential information for prayers, such as local prayer times, nearby masjids, and the direction of Qibla. The team behind this project was developed by 6 computer science developers, a majority of whom were from the Muslim culture and background. This paper describes the entire capstone development process from the perspective of a developer who is not rooted in Muslim customs. It also describes …


A Study Of The Stratigraphic And Petrological Characteristics Of Section (10,323-10,325 Ft), Prevost 1- 11, Bay County, Michigan, Hajir Al Harthi Dec 2025

A Study Of The Stratigraphic And Petrological Characteristics Of Section (10,323-10,325 Ft), Prevost 1- 11, Bay County, Michigan, Hajir Al Harthi

Honors Theses

This study presents a detailed petrological characterization of a short core section (10,323-10,325 ft) from the Prevost 1-11, Bay County, Michigan. This work is part of a broader carbon capture, utilization, and storage (CCUS) project to determine whether the Glenwood Formation could be an effective confining unit (CU) for carbon dioxide (CO2) injection in the underlying St. Peter Sandstone. The methods used to collect petrological data include standard core description, Xray fluorescence spectroscopy (XRF), powder X-ray diffraction (XRD), thin section microscopy, and scanning electron microscopy (SEM) including backscattered electron (BSE), energydispersive X-ray spectroscopy (EDS), and secondary electron (SE) modes. These …


Early Warning Detection Of Gravitational Waves With Sgnl, Megan Norris Dec 2025

Early Warning Detection Of Gravitational Waves With Sgnl, Megan Norris

Honors Theses

Gravitational waves (GWs) provide a whole new spectrum with which to observe astrophysical events. Multi-messenger observations including GWs are of particular interest, and these are best facilitated by early warning searches of GWs, which are typically aimed at detecting binary neutron star (BNS) mergers. This work provides an introductory overview of gravitational waves and summarizes the origins and basic physical properties of neutron stars and black holes in binary systems, focusing on BNS mergers and the detection of gravitational waves with LIGO using a modeled search. We assess the performance of a new GW search pipeline called SGNL to evaluate …


Environmental Risk Assessment Of Textile Waste From Bio-Engineered Fibers In The Fashion Industry, Aayush Pankaj Agarwal, Harshit Soral, Irmak Aktan, Karol Montserrat Gonzalez Saad, Maria Daniela Saa Espinosa, Sheetal Suhas Dhanuka, Yi Yang Dec 2025

Environmental Risk Assessment Of Textile Waste From Bio-Engineered Fibers In The Fashion Industry, Aayush Pankaj Agarwal, Harshit Soral, Irmak Aktan, Karol Montserrat Gonzalez Saad, Maria Daniela Saa Espinosa, Sheetal Suhas Dhanuka, Yi Yang

Harrisburg University Dissertations and Theses

The global fashion industry generates over 92 million tons of textile waste annually, a figure projected to increase significantly by 2030. Bio-engineered fibers, including bacterial cellulose, mycelium-based leather, and recombinant protein textiles emerge as sustainable alternatives to conventional fibers. Despite their promise, recent evidence suggests that these fibers may pose environmental risks at the end-of-life stage, such as incomplete biodegradation in landfills, microfiber shedding, and chemical leaching from dyes and coatings. The purpose of this study is to examine how these risks are represented through scientific literature, corporate sustainability reports, and policy frameworks, and to identify strategies for integrating risk …


A Predictive Model For Multi- Week Respiratory Risk From Red Tide On Florida’S Gulf Coast., Elmer S. Ochaeta Dec 2025

A Predictive Model For Multi- Week Respiratory Risk From Red Tide On Florida’S Gulf Coast., Elmer S. Ochaeta

Computer Science and Engineering Faculty Publications

Florida’s Gulf Coast red tide (Karenia brevis) can put toxins into the air, making people cough, irritating the throat, and worsening asthma or other breathing problems especially when winds blow from the ocean toward the beach. Right now, most public updates don’t really help with the question people actually ask when planning a weekend or vacation: “Will going to or close to the beach be risky in the next few weeks?”.

In this project, I build a weekly early warning system that estimates respiratory risk for specific beaches and predicts that risk 2 to 4 weeks ahead. The study covers …


Enhancing Breast Cancer Detection In Mammographic Imaging Using Explainable Clinical Decision Support System And Framework, Ahed Abugabah, Prashant Kumar Shukla, Piyush Kumar Shukla, Abhishek Dwivedi Dec 2025

Enhancing Breast Cancer Detection In Mammographic Imaging Using Explainable Clinical Decision Support System And Framework, Ahed Abugabah, Prashant Kumar Shukla, Piyush Kumar Shukla, Abhishek Dwivedi

All Works

Breast cancer remains one of the leading causes of mortality among women worldwide, where early and precise detection plays a vital role in improving survival rates and treatment outcomes. However, conventional deep learning approaches often encounter challenges in handling dense mammographic tissues and lack transparency in decision-making, limiting their clinical reliability. To address these limitations, this study introduces TransYOLO-GJO, an explainable and optimized detection framework that integrates transformer-based attention mechanisms into the YOLOv9 architecture and leverages the Golden Jackal Optimization (GJO) algorithm for hyperparameter tuning. The transformer encoder enhances contextual feature extraction, particularly in dense breast regions, while GJO dynamically …


Toward Understanding Multi-Agent Decision Making In Complex Societies, Jonathan Skaggs Dec 2025

Toward Understanding Multi-Agent Decision Making In Complex Societies, Jonathan Skaggs

Theses and Dissertations

This dissertation investigates Multi Agent Decision Making (MADM) within Complex Societies (CS), systems of interdependent agents whose collective behaviors emerge from local interactions. Such emergent dynamics are nonlinear and difficult to predict, posing significant challenges towards understanding how individual decisions scale to societal outcomes. Existing approaches often fall short of capturing the combined attributes of CS, including asymmetry, decentralization, and adaptivity. To address this gap, we introduce new models and analyses of agent strategies that explain how cooperation and stability can arise in CS. Structured around three interrelated projects, this dissertation enhances our comprehension of MADM in CS. The research …