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Exploring The Experiences Of African American Female Students In Engineering: A Narrative Literature Review, Anissa Guerin, Phd Jun 2024

Exploring The Experiences Of African American Female Students In Engineering: A Narrative Literature Review, Anissa Guerin, Phd

Tapestry: Journal of Research in Education

Abstract

This narrative literature review delves into the experiences of African American female students in engineering, addressing their persistent underrepresentation in the field despite advancements in postsecondary education. By examining a broad range of research, the study explores the unique challenges faced by these students and investigates tools for their persistence and degree completion. The theoretical framework draws from intersectionality theory, emphasizing the intersecting identities of race and gender in shaping these experiences. Methodologically, a narrative literature review approach was employed, facilitating a comprehensive analysis of existing scholarship. Data collection involved rigorous criteria focusing specifically on empirical research or original …


Rotational Rheometry Test Of Portland Cement-Based Materials – A Systematic Literature Review, Laura Silvestro, Artur Spat Ruviaro, Geannina Lima, Luís Urbano Durlo Tambara Júnior, Dimitri Feys, Ana Paula Kirchheim Jun 2024

Rotational Rheometry Test Of Portland Cement-Based Materials – A Systematic Literature Review, Laura Silvestro, Artur Spat Ruviaro, Geannina Lima, Luís Urbano Durlo Tambara Júnior, Dimitri Feys, Ana Paula Kirchheim

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This Study Systematically Reviews 62 Papers on the Use of Rotational Rheometry to Assess the Fresh State Behavior of Portland Cement-Based Materials. the Research Highlights the Wide Variation in Test Methods and Aims to Provide a Comprehensive overview. Findings Reveal that 50.0% of Studies Employed Vane Geometry, despite its Limitations in Providing Transformation Equations. Regarding Dynamic Shearing Tests, 67.0% Followed a Consensus using a Pre-Shearing Step and a Stepwise Routine with Stabilization Times ≥ 10 S. While the Bingham Model is Commonly Used, the Study Emphasizes the Importance of Considering Shear-Thinning Behavior in Cementitious Materials. Models Like Herschel-Bulkley and Modified …


Understanding The Mechanical And Electrochemical Impacts Of Binder Systems On Silicon Anodes In Lithium-Ion Batteries, Fei Sun Jun 2024

Understanding The Mechanical And Electrochemical Impacts Of Binder Systems On Silicon Anodes In Lithium-Ion Batteries, Fei Sun

Theses and Dissertations

Silicon has emerged as a promising alternative to traditional graphite as an anode material in battery technology, primarily due to its high theoretical capacity and abundance. However, its application is hindered by significant challenges, including severe volume expansion in the active material (~275%) during cycling, which can lead to a series of electrode failure issues. Polymer binder plays an essential role in addressing these challenges as it accommodates silicon's volume expansion and the rearrangement of particles. This work conducted an analysis of how different binders influence mechanical and electrochemical properties of silicon electrodes. Our findings are supported by a series …


Tool Life Characterization In Refill Friction Stir Spot Welding, Ruth Guadalupe Belnap Jun 2024

Tool Life Characterization In Refill Friction Stir Spot Welding, Ruth Guadalupe Belnap

Theses and Dissertations

As light-weighting becomes a priority for the automotive industry, refill friction stir spot welding emerges with enormous potential to supplement or replace conventional spot joining processes. This thesis addresses the limitations of current tooling options by examining materials beyond steel for use in RFSSW. Contained herein is an analysis of weld quality as a function of tool material, a production evaluation of RFSSW using various tool materials, and an assessment of long-term performance of a tungsten carbide tool. Over the course of this research, tungsten carbide emerged as a viable candidate for long-lasting RFSSW tooling.


California 4-H Computer Science Education Pathway, Steven M. Worker, Roshan Nayak, Fe Moncloa Jun 2024

California 4-H Computer Science Education Pathway, Steven M. Worker, Roshan Nayak, Fe Moncloa

Journal of Extension

Young people need digital competency and confidence to effectively harness computing power to solve problems and design solutions; a core component is improving young people’s computational thinking. Unfortunately, access to computer science education is lacking for all youth, and in particular for youth who live in lower-income households, who are Black or Latino, or live in rural areas. With funding from Google, through the National 4-H Council, California 4-H embarked on a three-year project to build the capacity of 4-H professionals, volunteers, and teenagers to facilitate computer science education with youth. Our programming was effective as assessed with survey methodology. …


The Impact Of Emojis On User Engagement With Trolling Content In Online Platforms, Diya Saraf Jun 2024

The Impact Of Emojis On User Engagement With Trolling Content In Online Platforms, Diya Saraf

Computer Science and Engineering Senior Theses

This thesis examines the impact of emojis on user engagement within online discussions, particularly focusing on the trolling behavior on social media platforms such as Reddit. The central problem addressed is understanding how different types of emojis—in emotional, informational, and popularity-based categories—affect user interactions and engagement in online communications. Through a robust methodological approach, combining quantitative data analysis and Random Forest regression modeling, this research meticulously analyzes emoji usage patterns and their correlations with engagement metrics like upvotes and comments.

The results highlight that emotional and popular emojis significantly enhance engagement by facilitating emotional expression and connection among users. In …


Ragu Conversational Menu Assistant: An Llm Retrieval Augmented Generation Approach, Sam Abdel, Seth Mak, Aaron Pham, Christopher Michael Jun 2024

Ragu Conversational Menu Assistant: An Llm Retrieval Augmented Generation Approach, Sam Abdel, Seth Mak, Aaron Pham, Christopher Michael

Computer Science and Engineering Senior Theses

This project introduces a novel Conversational Menu Assistant leveraging Retrieval Augmented Generation (RAG) techniques within a modified Large Language Model (LLM) framework to enhance dining experiences by providing personalized menu assistance. The main innovation lies in the system’s ability to integrate up-to-date menu information from various sources, including web scraping, into its responses, thereby circumventing the limitations commonly associated with LLMs, such as the need for frequent retraining and the challenge of handling dynamic information. Our solution addresses the pressing issue of reducing the workload on restaurant servers and streamlining the ordering process by offering precise menu details, personalized recommendations …


Characterizing The Potential For Failure In Environment Testing Due To Bolted-Joint Friction Nonlinearity And Bilinearity, Brennen Clark Jun 2024

Characterizing The Potential For Failure In Environment Testing Due To Bolted-Joint Friction Nonlinearity And Bilinearity, Brennen Clark

Theses and Dissertations

Nonlinear behavior in systems complicates the analysis and design of many systems in engineering. In vibration engineering, typical methods such as modal analysis fail or require significant adjustment in the presence of nonlinearity. Understanding and modeling nonlinear behavior is becoming more important in many modern engineering applications. One area that is relatively unexplored is how nonlinearity affects environment testing. This can cover a wide variety of subtopics, but this thesis focuses on failures that can occur in a system which are not predicted by corresponding linearized systems. To further limit the scope of this work, and to provide a context …


Evaluating Computational Predictions Of Magnetic Resonance Acoustic Radiation Force Imaging For Breast Cancer Focused Ultrasound Surgery, Chloe K. Nelson Jun 2024

Evaluating Computational Predictions Of Magnetic Resonance Acoustic Radiation Force Imaging For Breast Cancer Focused Ultrasound Surgery, Chloe K. Nelson

Theses and Dissertations

Purpose: In magnetic resonance-guided focused ultrasound (MRgFUS) therapies performed in highly heterogeneous tissues such as the breast, the focal location must be located and characterized to guide successful treatments of tumors. Treatment time can be minimized by a priori prediction of the focal location through computational models. The purpose of this work is to evaluate numerical simulations of focused ultrasound (FUS) on their predictions of the focal location. Those simulations are compared to clinical magnetic resonance acoustic radiation force imaging (MR-ARFI) data collected during in vivo treatment of breast tumors. Methods: The focal location was evaluated prior to MRgFUS treatment …


Specification, Enforcement, And Measurement Of Integrity Policies, Kevin Dennis Jun 2024

Specification, Enforcement, And Measurement Of Integrity Policies, Kevin Dennis

USF Tampa Graduate Theses and Dissertations

The first step to improving an organization's security posture is to define the organization's security goals. At a technical level, these goals are expressed as security policies. Security policies are predicates over programs, that return true or false if the program adheres to the policy. Defining these policies correctly is thus essential to ensuring the overarching security goals are met, but it is often quite difficult to translate human-oriented goals into their technical policy counterparts. In addition, these policies must be specified so that they are enforceable while minimizing false positives and false negatives. Integrity policies, which specify how data …


Ocean Rain Detection And Wind Retrieval Through Deep Learning Architectures On Advanced Scatterometer Data, Matthew Yoshinori Otani Mckinney Jun 2024

Ocean Rain Detection And Wind Retrieval Through Deep Learning Architectures On Advanced Scatterometer Data, Matthew Yoshinori Otani Mckinney

Theses and Dissertations

The Advanced Scatterometer (ASCAT) is a satellite-based remote sensing instrument designed for measuring wind speed and direction over the Earth's oceans. This thesis aims to expand and improve the capabilities of ASCAT by adding rain detection and advancing wind retrieval. Additionally, this expansion to ASCAT serves as evidence of Artificial Intelligence (AI) techniques learning both novel and traditional methods in remote sensing. I apply semantic segmentation to ASCAT measurements to detect rain over the oceans, enhancing capabilities to monitor global precipitation. I use two common neural network architectures and train them on measurements from the Tropical Rainfall Measuring Mission (TRMM) …


Enhancing Urban Parking Efficiency Through Machine Learning Model Integration, Sai Sneha Channamallu, Sharareh Kermanshachi, Jay Michael Rosenberger, Apurva Pamidimukkala Jun 2024

Enhancing Urban Parking Efficiency Through Machine Learning Model Integration, Sai Sneha Channamallu, Sharareh Kermanshachi, Jay Michael Rosenberger, Apurva Pamidimukkala

Open Initiatives Grant Funded Publications-Archive

An increase in vehicular traffic and a scarcity of parking spaces are creating significant challenges for urban parking management. This study aims to tackle these issues that escalate congestion and pollution and decrease urban productivity, by utilizing machine learning models to accurately predict parking space availability and categorize occupancy levels. It employs a dataset from a college campus garage collected from January 2022 to June 2023 and analyzes the performance of random forest, decision tree, linear regression, and support vector models by comparing them, using multiple evaluation metrics. The results revealed that the random forest model was the most reliable, …


New Generation Graphenes In Cement-Based Materials: Production, Property Enhancement, And Life Cycle Analysis, Sahil Surehali, Sayee Srikarah Volaity, Aswathy Simon, Ranjith Divigalpitiya, Aditya Kumar, Narayanan Neithalath Jun 2024

New Generation Graphenes In Cement-Based Materials: Production, Property Enhancement, And Life Cycle Analysis, Sahil Surehali, Sayee Srikarah Volaity, Aswathy Simon, Ranjith Divigalpitiya, Aditya Kumar, Narayanan Neithalath

Materials Science and Engineering Faculty Research & Creative Works

Several studies have explored the use of graphene to improve the properties of cement-based materials. However, most commercially available graphenes are expensive, not amenable to mass production, and have high embodied energy and emissions, making their use in concrete less attractive, despite the beneficial mechanical property attributes. This paper discusses the use of two novel graphene types, fractal graphene (FG) and reactive graphene (RG), obtained through a cost-effective and scalable detonation synthesis, in cement-based materials. FG and RG are sheets containing 6-10 layers, with lateral dimensions of 20-50 nm and a z-axis thickness of RG, when added at very small …


Design And Characterization Of 3d-Printed Hydrogel Lattices With Consistent Structural And Mechanical Anisotropy, Daniel Yoon Jun 2024

Design And Characterization Of 3d-Printed Hydrogel Lattices With Consistent Structural And Mechanical Anisotropy, Daniel Yoon

McKelvey School of Engineering Graduate Student Theses & Dissertations

This thesis explores the use of 3D printing to fabricate soft hydrogel lattice structures with consistent properties, including varying levels of mechanical anisotropy. Magnetic resonance elastography (MRE) is a non-invasive imaging tool to estimate and characterize the mechanical properties of tissue. MRE “phantoms” (physical surrogate models) have been used to assess how well MRE can measure and estimate mechanical properties. While gel phantoms generally simulate brain tissue, almost all have been isotropic. Prior studies have shown that white matter brain tissue is structurally and mechanically anisotropic. To validate anisotropic MRE, phantoms with controllable, reproducible anisotropic material properties are needed. This …


Capstone Review: Filament Unit Multiplexing Engine, Gal Cohen Jun 2024

Capstone Review: Filament Unit Multiplexing Engine, Gal Cohen

University Honors Theses

The Filament Unit Multiplexing Engine (FUME) is a Mechanical Engineering capstone project sponsored by Portland State University's Electronic Prototyping Lab (EPL). The project addresses the need for an automated system to manage 3D printing operations. The current manual process of selecting and routing a spool of filament to one of the available 3D printers is labor-intensive and limits the efficiency of the lab's 3D printing farm. FUME aims to create a custom solution tailored for a multi-user, multi-spool, and multi-printer environment. The designed system includes key components: a spool holder, an engine, a track and shuttle system, and a funnel. …


Bridging Design And Perception: Novel Tools And Technologies For Creating Effective Human-Robot Interactions, Benjamin Dossett Jun 2024

Bridging Design And Perception: Novel Tools And Technologies For Creating Effective Human-Robot Interactions, Benjamin Dossett

Electronic Theses and Dissertations

This thesis explores human perception of robots through the use of novel tools and technologies. First, the impact of Augmented Reality (AR) data presentation on human perception of robots is investigated. A study conducted with the AR human-robot teaming system found that robot performance significantly influenced participants’ perceptions, overshadowing the impact of matching or mismatching robot confidence feedback. Second, the DU Want to Build-A-Bot platform is presented, which enables participatory robot design and opens the door for novel research of how robot design affects human perception. The Build-A-Bot platform enables the collection of diverse robot designs, facilitating machine learning analysis …


Spin And Charge Transport In Metallic Ferrimagnets And Disordered Magnetic Oxides, Leopoldo A. Hernandez Jun 2024

Spin And Charge Transport In Metallic Ferrimagnets And Disordered Magnetic Oxides, Leopoldo A. Hernandez

Electronic Theses and Dissertations

Recent efforts have been exploring the use of thin film synthetic ferrimagnets and disordered magnetic oxides for applications in spintronic devices. Due to the antiferromagnetic exchange interaction, ferrimagnetic materials offer the ultrafast dynamics of the antiferromagnetic exchange, with a net magnetization that can be influenced externally. With two, or more, competing ferromagnet sublattices, interesting properties arise that depend on the final magnetic landscape after growth of the material and it’s inherent magnetic anisotropy energies. Properties such as magnetic compensation temperatures, and perpendicular magnetic anisotropy are attractive for applications in spintronic memory and logic devices, some already being implemented in MRAM …


Effect Of Oxidation Of Graphene On Agglomeration And The Mechanical Properties Of Thermosetting Resins, Matthew A. Reil Jun 2024

Effect Of Oxidation Of Graphene On Agglomeration And The Mechanical Properties Of Thermosetting Resins, Matthew A. Reil

Electronic Theses and Dissertations

Thermosetting resins are used extensively worldwide in applications ranging from adhesives to structural components. However, these resins generally fail in a brittle fracture mode which is undesirable in most situations. Graphene (G) and its derivatives have been considered as additives to epoxy for material property enhancement and varied results have been reported in the literature. In this work, the effects of the oxidation of G to graphene oxide (GO) on polymer interactions and plate agglomeration were studied by classical molecular dynamics (MD). Results from those simulations concluded that agglomerates were likely present in all G-based nanocomposites. The effect of these …


Incremental Quantities Based Permissive Overreaching Transfer Trip Scheme For Protecting Inverter-Based Renewable Resources, Osama Zangoti Jun 2024

Incremental Quantities Based Permissive Overreaching Transfer Trip Scheme For Protecting Inverter-Based Renewable Resources, Osama Zangoti

Electronic Theses and Dissertations

The power generation landscape evolves, with the increase of inverter-based resources (IBRs) such as solar photovoltaics and wind turbines, providing sustainable and clean energy sources. The shift towards IBRs mitigates climate change, creating considerable challenges to traditional power system protection due to their low fault current. Conventional protection schemes are designed around the internal dynamic of synchronous generators where they can supply an elevated fault current. This thesis explores a protection scheme designed to enhance the security of IBRs. The incremental characteristics of voltage and current coupled with the Permissive Overreaching Transfer Trip scheme (POTT) provide a remarkable ability to …


Aging-Related Changes In The Mechanical Properties Of Single Cells, Amarnath Singam, Chandrabali Bhattacharya, Seungman Park Jun 2024

Aging-Related Changes In The Mechanical Properties Of Single Cells, Amarnath Singam, Chandrabali Bhattacharya, Seungman Park

Mechanical Engineering Faculty Research

Mechanical properties, along with biochemical and molecular properties, play crucial roles in governing cellular function and homeostasis. Cellular mechanics are influenced by various factors, including physiological and pathological states, making them potential biomarkers for diseases and aging. While several methods such as AFM, particle-tracking microrheology, optical tweezers/stretching, magnetic tweezers/twisting cytometry, microfluidics, and micropipette aspiration have been widely utilized to measure the mechanical properties of single cells, our understanding of how aging affects these properties remains limited. To fill this knowledge gap, we provide a brief overview of the commonly used methods to measure single-cell mechanical properties. We then delve into …


Design, Prototyping, And Characterization Of A Micro-Force Sensor Intended For Tissue Assessment In Confined Spaces, Shashank S. Kumat, Panos S. Shiakolas Jun 2024

Design, Prototyping, And Characterization Of A Micro-Force Sensor Intended For Tissue Assessment In Confined Spaces, Shashank S. Kumat, Panos S. Shiakolas

Open Initiatives Grant Funded Publications-Archive

The quantitative characterization of soft tissue viscoelastic properties can aid in disease prognosis and diagnosis. Existing technologies present challenges to measuring localized in vivo tissue relaxation data while meeting load and geometric constraints. This research presents the design, prototype, and characterization of a micro-force sensor that could enable better access to confined spaces of the human body. The novel design of the uniaxial micro-force sensor has an external diameter of less than or equal to 3.5 mm and 1 N load capacity for transurethral palpation of the bladder interior wall. The conceptual design of the micro-force sensor and a finite …


Atom Probe Tomography Of Segregation At Grain Boundaries And Gas Bubbles In Neutron Irradiated U-10 Wt% Mo Fuel, Maalavan Arivu, Andrew Hoffman, Mukesh Bachhav, Assel Aitkaliyeva, Yaqiao Wu, Brandon Miller, Dennis Keiser, Jian Gan, Haiming Wen Jun 2024

Atom Probe Tomography Of Segregation At Grain Boundaries And Gas Bubbles In Neutron Irradiated U-10 Wt% Mo Fuel, Maalavan Arivu, Andrew Hoffman, Mukesh Bachhav, Assel Aitkaliyeva, Yaqiao Wu, Brandon Miller, Dennis Keiser, Jian Gan, Haiming Wen

Materials Science and Engineering Faculty Research & Creative Works

During Neutron Irradiation to Fission Densities > 5.2 X 1021 Fiss/cm3, Xe Agglomerates Forming Gas Bubbles of Varying Size within the U-Mo Fuel Matrix. Herein, Segregation of Fission Products to Xe Bubbles and Grain Boundaries (GB) Were Studied using Atom Probe Tomography (APT). Segregation Behavior Was Found to Vary among GBs, Small Bubbles (<10 >Nm), and Larger Bubbles (>10 Nm). Solid Fission Products Were Enriched at GBs and Larger Bubbles, But Not at Small Bubbles. a Denuded Zone Was Identified Adjacent to a > 10 Nm Xe Gas Bubble and a GB.


Patient-Specific Musculoskeletal Modeling Of Total Shoulder Arthroplasty, Brendan M. Curran Jun 2024

Patient-Specific Musculoskeletal Modeling Of Total Shoulder Arthroplasty, Brendan M. Curran

Electronic Theses and Dissertations

Total shoulder arthroplasty (TSA) is often considered a surgery of last resort for patients with debilitating pathologies of the glenohumeral joint such as osteoarthritis, humeral head fracture, and advancing rotator cuff tears. TSA replaces the articulation between the humeral head and the glenoid fossa, with the goals of relieving pain and restoring function. Two types of total shoulder implants are available: Anatomic Total Shoulder Arthroplasty (aTSA) and Reverse Total Shoulder Arthroplasty (rTSA). TSA survivorship is lower than that of the survivorship seen in total knee and hip replacements [1]. Shoulder muscle moment arms and lines of action have been measured …


Statistical Modeling Of Knee Morphology And Material Properties Considering Diverse Populations, Gabrielle Jeannine Kindy Jun 2024

Statistical Modeling Of Knee Morphology And Material Properties Considering Diverse Populations, Gabrielle Jeannine Kindy

Electronic Theses and Dissertations

Total Knee Arthroplasty (TKA) is a widely performed surgical procedure aimed at alleviating pain and restoring function in patients with severe knee osteoarthritis. Despite its general success, disparities in postoperative outcomes have been observed across different racial and ethnic groups, with minority populations often experiencing less favorable results. One potential avenue for improving the generalizability of orthopaedic implants is using Statistical Shape and Intensity Models (SSIMs), which can be used to incorporate patient variability directly into the orthopaedic medical device development workflow through population-based finite element analysis.

This work aimed to construct an SSIM from a diverse subject set, incorporating …


Academic Success In First-Year Engineering Students At Private Higher Education Institutions In Egypt: Key Factors, Wassim Alexan Jun 2024

Academic Success In First-Year Engineering Students At Private Higher Education Institutions In Egypt: Key Factors, Wassim Alexan

Theses and Dissertations

This research aimed to identify the key factors contributing to the success of first-year engineering students at private higher education institutions (HEIs) in Egypt. It specifically examined how various independent variables influence the success of these students, measured as the dependent variable. By analyzing these relationships, the study seeks to pinpoint key success factors (KSFs) for first year engineering students in this specific educational context. The research work employed a mixed methods approach, utilizing both quantitative and qualitative research methods. The quantitative analysis involved collecting data through a survey administered to a sample of first year engineering students at private …


Monterecycle: An Application For Streamlining Tracking Of Recyclables In Uruguay, Aayooshi Dharmadhakari, Danny Walsh, Eason Ke, Kamya Krishnan Jun 2024

Monterecycle: An Application For Streamlining Tracking Of Recyclables In Uruguay, Aayooshi Dharmadhakari, Danny Walsh, Eason Ke, Kamya Krishnan

Computer Science and Engineering Senior Theses

Recycling is a crucial process that has a positive impact on nature, cleans the environment, and saves time and money. Classifying recyclables by material and recycling these items accordingly helps make our world more environmentally-friendly and a better place to live.

In the recycling system in Montevideo, Uruguay, third-party contractors hired by San Vicente transport clients’ recyclables to a central recycling center or to a person that does recycling. In the past, San Vicente has transported recyclables though horse and buggy transportation. However, there has been a push from the city to replace the horses with motorcycles to reduce animal …


Differentiating Dynamic System Outcomes In Cam Photosynthesis Through Sonification, Duncan Turley Jun 2024

Differentiating Dynamic System Outcomes In Cam Photosynthesis Through Sonification, Duncan Turley

Civil and Environmental Engineering Undergraduate Honors Theses

Sonification is a powerful tool that is harnessed by modern engineers to represent information through audio, and is beginning to be used to interpret more complex data sets. Sonification can be used to facilitate the listeners' ability to grasp microscopic or complex changes in the state of a system. This study uses the assigning of sound patterns to model outputs that indicate chaotic or non-chaotic systems in Crassulacean acid metabolism photosynthesis. Using sound allows the interpretation of chaotic data without the more time intensive processes typically used, such as of Fast Fourier Transformations. Based on past research, it is known …


Technologies For Wearable Seizure Detection: A Systematic Review, Rhema Losli Jun 2024

Technologies For Wearable Seizure Detection: A Systematic Review, Rhema Losli

University Honors Theses

Knowing when a seizure occurred is helpful because this information can be used to evaluate the effectiveness of seizure interventions and possibly alert caregivers to emergency situations. The current practice for recording seizures outside of a hospital and without sensors is through keeping a self-reported seizure diary. This practice may be unreliable if the diary is not updated or the person having the seizure does not realize it is happening. Wearable seizure detectors aim to solve this problem by reliably recording when a seizure happened and either sending out an alert or storing the data for later analysis. In this …


Preservation Of Biomass In Underground Capsules Using An Open-Source Wireless Water Activity Sensor System: Capstone Review, Joshua Varughese Jun 2024

Preservation Of Biomass In Underground Capsules Using An Open-Source Wireless Water Activity Sensor System: Capstone Review, Joshua Varughese

University Honors Theses

This paper highlights the progression of a two-term senior capstone project in the ECE department at Portland State University. Sponsored by Dr. David Burnett from PSU's WEST Lab, the project aims to produce an affordable wireless monitoring system for water activity. The example scenario focuses on carbon sequestration where wood biomass is buried underground in enclosed capsules. For optimal sequestration, microorganisms capable of decaying the wood and releasing carbon back into the environment must be eliminated. Water activity, a key metric for measuring microbial activity, must be below 0.61 to prevent microbial survival. The system this project was designed for …


Chemical Herding As A Multiplicative Factor For Top-Down Manipulation Of Colloids, Mark N. Mcdonald, Douglas R. Tree, Cameron K. Peterson Jun 2024

Chemical Herding As A Multiplicative Factor For Top-Down Manipulation Of Colloids, Mark N. Mcdonald, Douglas R. Tree, Cameron K. Peterson

Faculty Publications

Colloidal particles can create reconfigurable nanomaterials, with applications such as color-changing, self-repairing, and self-regulating materials and reconfigurable drug delivery systems. However, top-down methods for manipulating colloids are limited in the scale they can control. We consider here a new method for using chemical reactions to multiply the effects of existing top-down colloidal manipulation methods to arrange large numbers of colloids with single-particle precision, which we refer to as chemical herding. Using simulation-based methods, we show that if a set of chemically active colloids (herders) can be steered using external forces (i.e., electrophoretic, dielectrophoretic, magnetic, or optical forces), then a larger …