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Articles 151 - 180 of 2828

Full-Text Articles in Engineering

Insect-Foundation: A Foundation Model And Large Multimodal Dataset For Vision-Language Insect Understanding, Thanh-Dat Truong, Hoang-Quan Nguyen, Xuan-Bac Nguyen, Ashley Dowling, Xin Li, Khoa Luu Oct 2025

Insect-Foundation: A Foundation Model And Large Multimodal Dataset For Vision-Language Insect Understanding, Thanh-Dat Truong, Hoang-Quan Nguyen, Xuan-Bac Nguyen, Ashley Dowling, Xin Li, Khoa Luu

Electrical Engineering and Computer Science Faculty Publications and Presentations

Multimodal conversational generative AI has shown impressive capabilities in various vision and language understanding through learning massive text-image data. However, current conversational models still lack knowledge about visual insects since they are often trained on the general knowledge of vision-language data. Meanwhile, understanding insects is a fundamental problem in precision agriculture, helping to promote sustainable development in agriculture. Therefore, this paper proposes a novel multimodal conversational model, Insect-LLaVA, to promote visual understanding in insect-domain knowledge. In particular, we first introduce a new large-scale Multimodal Insect Dataset with Visual Insect Instruction Data that enables the capability of learning the multimodal foundation …


Aminated Phenolated Lignin For Effective Anionic Dye Removal For Water Remediation, David Chem, Samantha Glidewell, Fatema Tarannum, Keisha B. Walters Oct 2025

Aminated Phenolated Lignin For Effective Anionic Dye Removal For Water Remediation, David Chem, Samantha Glidewell, Fatema Tarannum, Keisha B. Walters

Chemical Engineering Faculty Publications and Presentations

Lignin, a renewable biopolymer sourced from plant cell walls, is gaining attention due to its extensive availability from natural resources, native functional groups, low cost, and biodegradability in various applications. In recent years, lignin and its derivatives have been utilized as adsorbents, flocculants, and sterilants in a broad range of applications, including wastewater treatment and sustainable packaging. The growing global demand for clean water-driven by rapid industrialization, urban expansion, and agricultural intensification-has made effective wastewater treatment a pressing environmental priority. In this effort, a dual-functionalization strategy to transform raw lignin into a high-performance adsorbent for the removal of hazardous anionic …


Advances In Encapsulated Phase Change Materials For Integration In Thermal Management Applications, Muhammad Ghufran, David Huitink Oct 2025

Advances In Encapsulated Phase Change Materials For Integration In Thermal Management Applications, Muhammad Ghufran, David Huitink

Mechanical Engineering Faculty Publications and Presentations

Encapsulated phase change materials (ePCMs) have the potential to emerge as a key solution for efficient thermal management in various applications. This review paper explores the recent advancements in ePCMs for thermal energy storage and thermal management. We start with a basic overview of the PCMs and then performance enhancements of PCMs through the encapsulation, critical parameters for encapsulation, various encapsulation methods, and their evaluation are discussed. This review also discusses key properties and proposed figure of merit for ePCMs, impact of encapsulation on thermophysical properties, performance evaluation of ePCMs, thermal management needs, and the role of PCMs. The paper …


Evaluation Of Robotic Swabbing And Fluorescent Sensing To Monitor The Hygiene Of Food Contact Surfaces, Siavash Mahmoudi, Clark Griscom, Pouya Sohrabipour, Yang Tian, Chaitanya Palleria, Philip G. Crandall, Dongyi Wang Sep 2025

Evaluation Of Robotic Swabbing And Fluorescent Sensing To Monitor The Hygiene Of Food Contact Surfaces, Siavash Mahmoudi, Clark Griscom, Pouya Sohrabipour, Yang Tian, Chaitanya Palleria, Philip G. Crandall, Dongyi Wang

Biological and Agricultural Engineering Faculty Publications and Presentations

Effective environmental monitoring is critical for preventing microbial and allergenic cross-contamination. However, manual swabbing methods, commonly used to verify hygienic conditions, are prone to inconsistent results because of variability in pressure, coverage, and techniques. Two novel solutions will be explored to address these challenges: a robotic swabbing system with tactile sensing control, and a fluorescence/absorbance spectrometer for non-contact, protein-based residue detection. The robotic system was evaluated against trained and untrained humans, measuring water pickup, surface coverage, and pressure consistency. Concurrently, the fluorescence system analyzed model poultry protein soil to correlate spectral patterns with contamination levels. The robotic system demonstrated statistically …


The Fate Of Intra- And Extracellular Antibiotic Resistance Genes Through Advanced Wastewater Treatment Process, Celestene Adrianne Sebag Sep 2025

The Fate Of Intra- And Extracellular Antibiotic Resistance Genes Through Advanced Wastewater Treatment Process, Celestene Adrianne Sebag

Graduate Theses and Dissertations

More areas across the globe are becoming affected by water stress or water scarcity. The decrease in available freshwater due to overconsumption reveals the direct need to consider other sources for necessities such as drinking water or food production. Agricultural irrigation uses 70% of the world’s freshwater, making the focus on safe and reliable reclaimed water for agricultural reuse imperative. However, contaminants of emerging concern (CECs), such as antibiotics and their resulting antibiotic resistance genes (ARGs), can spread and affect human health if reclaimed water is not treated to the proper level. Antibiotics are widely used in human medicine and …


Switching Performance Optimization Of Sic Mosfets With Digital Active Gate Drivers, Liyang Du Sep 2025

Switching Performance Optimization Of Sic Mosfets With Digital Active Gate Drivers, Liyang Du

Graduate Theses and Dissertations

Silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (MOSFETs) have extensive applications in high-power density devices, but they exhibit quick switching transients that are problematic, including electromagnetic interference (EMI), voltage overshoot, and current imbalance between paralleled devices. The purpose of this dissertation is to maximize the switching performance of SiC MOSFETs using digital active gate drivers (AGDs). A three-level gate driving approach is presented to improve current sharing in paralleled SiC MOSFETs through turn-on voltage and gate signal delay adjustment. Closed-loop control with real-time feedback ensures high-reliability operation. For better practicability, a compact AGD structure of a single-path Class-B amplifier-based topology is …


Fpga-Based Overlay Accelerators With Massive Parallel Processing Units To Accelerate Deep Neural Networks, Ehsan Kabir Sep 2025

Fpga-Based Overlay Accelerators With Massive Parallel Processing Units To Accelerate Deep Neural Networks, Ehsan Kabir

Graduate Theses and Dissertations

Deep neural networks (DNNs) are widely used in applications such as classification, prediction, and regression. Various DNN architectures, such as convolutional neural networks (CNN), multilayer perceptrons (MLP), long short-term memory (LSTM), recurrent neural networks (RNN), and transformers, have become leading machine learning techniques in these applications. They require significant computational resources and have substantial memory demands due to intensive matrix-matrix multiplications and complex data flows. Hence, efficient utilization of on-chip computational and memory resources is essential to maximize parallelism and minimize latency. Designing an optimal tiling scheme that aligns effectively with the architecture is also necessary. Modern FPGAs are equipped …


Land8fire: A Complete Study On Wildfire Segmentation Through Comprehensive Review, Human-Annotated Multispectral Dataset, And Extensive Benchmarking, Anh Tran, Minh Tran, Esteban Marti, Jackson Cothren, Chase Rainwater, Sandra Eksioglu, Ngan Le Aug 2025

Land8fire: A Complete Study On Wildfire Segmentation Through Comprehensive Review, Human-Annotated Multispectral Dataset, And Extensive Benchmarking, Anh Tran, Minh Tran, Esteban Marti, Jackson Cothren, Chase Rainwater, Sandra Eksioglu, Ngan Le

Electrical Engineering and Computer Science Faculty Publications and Presentations

Early and accurate wildfire detection is critical for minimizing environmental damage and ensuring a timely response. However, existing satellite-based wildfire datasets suffer from limitations such as coarse ground truth, poor spectral coverage, and class imbalance, which hinder progress in developing robust segmentation models. In this paper, we introduce Land8Fire, a new large-scale wildfire segmentation dataset composed of over 20,000 multispectral image patches derived from Landsat 8 and manually annotated for high-quality fire masks. Building on the ActiveFire dataset, Land8Fire improves ground truth reliability and offers predefined splits for consistent benchmarking. We evaluate a range of state-of-the-art convolutional and transformer-based models, …


Novel Nanomaterials For Developing Bone Scaffolds And Tissue Regeneration, Nazim Uddin Emon, Lu Zhang, Shelby Dawn Osborne, Mark Allen Lanoue, Yan Huang, Z. Ryan Tian Aug 2025

Novel Nanomaterials For Developing Bone Scaffolds And Tissue Regeneration, Nazim Uddin Emon, Lu Zhang, Shelby Dawn Osborne, Mark Allen Lanoue, Yan Huang, Z. Ryan Tian

Cell and Molecular Biology Faculty Publications and Presentations

Nanotechnologies bring a rapid paradigm shift in hard and soft bone tissue regeneration (BTR) through unprecedented control over the nanoscale structures and chemistry of biocompatible materials to regenerate the intricate architecture and functional adaptability of bone. This review focuses on the transformative analyses and prospects of current and next-generation nanomaterials in designing bioactive bone scaffolds, emphasizing hierarchical architecture, mechanical resilience, and regenerative precision. Mainly, this review elucidated the innovative findings, new capabilities, unmet challenges, and possible future opportunities associated with biocompatible inorganic ceramics (e.g., phosphates, metallic oxides) and the United States Food and Drug Administration (USFDA) approved synthetic polymers, including …


Comparative Study On The Long-Term Performance Of Bmd Mixtures Prepared Using Different Sample Preparation Techniques And Superpave Mixtures Under Varying Pavement Structures, Amarjeet Tiwari Aug 2025

Comparative Study On The Long-Term Performance Of Bmd Mixtures Prepared Using Different Sample Preparation Techniques And Superpave Mixtures Under Varying Pavement Structures, Amarjeet Tiwari

Graduate Theses and Dissertations

Asphalt mix design has advanced significantly since the 1930s, with Balanced Mix Design (BMD) emerging to address durability concerns found in the Superpave method by optimizing binder content based on performance criteria. The performance of bituminous mixtures can be assessed through laboratory testing. These tests require proper sample preparation, and various techniques are employed for this purpose. Understanding the differences between these techniques is essential for the successful application of bituminous mixtures in the field. The objective of this study is to assess the differences in the predicted long-term performance of two sample preparation techniques, Lab Mix Lab Compacted (LMLC) …


Analysis And Predictive Modeling Of Stall And Spin Accidents In General Aviation Fixed-Wing Aircraft, Mehedi Hasan Aug 2025

Analysis And Predictive Modeling Of Stall And Spin Accidents In General Aviation Fixed-Wing Aircraft, Mehedi Hasan

Graduate Theses and Dissertations

Stall and spin accidents represent a persistent safety concern in General Aviation, with approximately 41% resulting in fatalities despite their relatively low occurrence. This study analyzes 1,079 General Aviation stall and spin accidents from 2008 to 2023 using the National Transportation Safety Board accident database. Our analysis identified the top phases of flight, injury outcomes, and causal factors in stall/spin accidents. Findings indicate that over 93% of stall/spin events involved General Aviation aircraft, with most accidents occurring during initial climb, takeoff, or low-altitude maneuvering. Pilot-related control errors, especially poor airspeed and angle-of-attack management, were the most common causes. To assess …


Engineered Interfaces For Enhanced Transient Liquid Phase Bonding In Electronics Assembly, John Russell Harris Aug 2025

Engineered Interfaces For Enhanced Transient Liquid Phase Bonding In Electronics Assembly, John Russell Harris

Graduate Theses and Dissertations

Growing applications in transportation make power density a key optimization target in the power electronics industry. More power in a shrinking environment leads to high heat flux and junction temperatures that damage silicon-based switching devices. Temperatures approaching 175℃ can result in false triggering of the device’s activated state, resulting in short circuits. Developing wide bandgap semi-conductors, such as gallium nitride and silicon carbide, are less susceptible to this complication as the energy from elevated temperature is a smaller fraction of what would be required to trigger the device. These devices are projected to function reliably in environments of up to …


Photochemical Fabrication And Tribological Evaluation Of Hexagonal Grooves With Corner Dimples On Cast Iron Surfaces, Steven Sonntag Aug 2025

Photochemical Fabrication And Tribological Evaluation Of Hexagonal Grooves With Corner Dimples On Cast Iron Surfaces, Steven Sonntag

Graduate Theses and Dissertations

The traditional honing process used to texture cylinder liners in internal combustion engines has long been recognized as suboptimal, as evidenced by the need for a break-in period before achieving peak performance. Although laser-based methods can produce micro-scale features with high precision, they are often cost-prohibitive and difficult to scale for large or complex components. This study explores photochemical machining (PCM) as a low-cost, scalable alternative for fabricating high-resolution surface textures—specifically, hexagonal grooves with corner dimples—on gray cast iron. The resulting textures exhibit uniform groove widths (~13 μm) and varied depths, demonstrating PCM’s capability to create high-resolution patterns with sub-micron …


High-Resolution Energy Efficient Selective Laser Sintering Of Copper Nanoparticles, Bo Shen Aug 2025

High-Resolution Energy Efficient Selective Laser Sintering Of Copper Nanoparticles, Bo Shen

Graduate Theses and Dissertations

Copper (Cu) is widely utilized in electronics and photonics applications due to its outstanding electrical and thermal conductivity. With increasing demand for miniaturization and higher precision in modern manufacturing, traditional selective laser sintering (SLS) techniques designed primarily for high-throughput production are becoming insufficient. These conventional methods struggle to deliver the resolution required for micro-scale fabrication and often cause thermal damage to sensitive substrates. Therefore, there is a growing necessity to develop compact and high-resolution laser sintering systems capable of precise microfabrication with minimal thermal influence. This study addresses this challenge by investigating nanosecond pulsed laser sintering as a method to …


Design, Modeling, Control, And Analysis Of A Modular Two-Wheeled Self-Balancing Robotic System, Mishek Jair Musa Aug 2025

Design, Modeling, Control, And Analysis Of A Modular Two-Wheeled Self-Balancing Robotic System, Mishek Jair Musa

Graduate Theses and Dissertations

Two-wheeled self-balancing robots have garnered substantial attention within the realms of research and innovation in academia and industrial settings. In particular, advances in control algorithms, machine learning, reinforcement learning, and sensor technologies have played a pivotal role in their development. Although primarily recognized for their utility in personal transportation in the commercial sector, these robots possess potential applications across various domains, including search and rescue, healthcare, material handling, logistics, etc., due to their active stabilization and exceptional maneuvering capabilities. A particular area of interest lies in the creation of modular self-balancing robots designed for seamless reconfiguration and enhanced human interaction. …


Controlling Electroless Deposition On Polymer Interfaces Towards Discrete Functional Particle Synthesis, Grecia Pierina Alvarado Munoz Aug 2025

Controlling Electroless Deposition On Polymer Interfaces Towards Discrete Functional Particle Synthesis, Grecia Pierina Alvarado Munoz

Graduate Theses and Dissertations

Electroless deposition is a process that facilitates the formation of metal layers on surfaces through the reduction of metal ions onto a surface in the presence of a sacrificial reducing agent. This process can be applied to synthesize conductive metal layers on insulators such as glass or polymers. The kinetics of heterogeneous deposition depend on the interfacial surface chemistry, including the presence of added catalyst materials, as well as the bulk chemical environment, such as the concentration of metal ions and sacrificial reductants. Furthermore, the homogeneous formation of metal nanoparticles may compete with the deposition reaction, adversely affecting the control …


Simulation Of Photochemical Effects On Air Quality, Grace Li Aug 2025

Simulation Of Photochemical Effects On Air Quality, Grace Li

Chemical Engineering Undergraduate Honors Theses

Nitrogen dioxide (NO2) and ozone (O3) are both EPA criteria air pollutants in the troposphere, largely generated by combustion and therefore present in significant concentrations in urban areas. Sunlight facilitates chemical reactions between pollutants and ambient air. Aerosols modulate the amount of available energy required to drive such photochemical reactions, ultimately impacting air quality. Simulating photolysis rates with FastJX software is a resource-efficient strategy to study how these aerosols can affect air quality.


Navigating Transportation Barriers: Older Adults’ Familiarity With New Mobility Options And Perceptions Toward Autonomous Vehicles In Arkansas, Arna Nishita Nithila, Suman Kumar Mitra, Michelle Gray, Alishia Juanelle Ferguson, Jennifer D. Webb Aug 2025

Navigating Transportation Barriers: Older Adults’ Familiarity With New Mobility Options And Perceptions Toward Autonomous Vehicles In Arkansas, Arna Nishita Nithila, Suman Kumar Mitra, Michelle Gray, Alishia Juanelle Ferguson, Jennifer D. Webb

Civil Engineering Faculty Publications and Presentations

The objective of this study is to analyze older adults’ familiarity with new transportation options (ride-hailing services, bike-share services, and shared e-scooter services) and their perception towards autonomous vehicles (fully autonomous cars), as well as how transportation barriers influence their familiarity and perceptions, in Arkansas, a predominantly rural state. Data from 775 older adults aged 60 years or older were collected between October 2021 and October 2022. To fulfill the study objective, the study used Latent Class Cluster Analysis to segment older adults into classes based on their familiarity with new transportation options and their perceptions of autonomous vehicles. The …


Growth And Characterization Of Thin Film Gase On Si(111) And Sio2/Si(001) Substrates By Molecular Beam Epitaxy, Christopher John Hocevar Aug 2025

Growth And Characterization Of Thin Film Gase On Si(111) And Sio2/Si(001) Substrates By Molecular Beam Epitaxy, Christopher John Hocevar

Graduate Theses and Dissertations

Gallium selenide (GaSe) is a thin-film semiconducting material with promising optoelectronic properties, including a tunable bandgap, high photosensitivity, and atomic-layer scalability. These characteristics make it suitable for devices such as photodiodes, FETs, MOSFETs, Hall effect sensors, and p–n diodes. In this study, GaSe thin films were grown on SiO2 and Si(111)-7×7 substrates using molecular beam epitaxy (MBE) to compare growth behavior across different substrates. The films were characterized using Raman spectroscopy, X-ray diffraction (XRD), atomic force microscopy (AFM), photoluminescence (PL) spectroscopy, and reflection high-energy electron diffraction (RHEED). RHEED confirmed the 7×7 reconstruction of the Si(111) surface and the amorphous nature …


Design And Validation Of A High-Frequency Multi-Output Dc-Dc Converter For Radar Power Applications, Tory Sutton Aug 2025

Design And Validation Of A High-Frequency Multi-Output Dc-Dc Converter For Radar Power Applications, Tory Sutton

Graduate Theses and Dissertations

Modern radar systems and advanced electronics demand compact, efficient, and reliable power solutions capable of delivering multiple tightly regulated voltage rails under strict size, weight, power, and reliability (SWaP-R) constraints. This thesis presents the design, implementation, and validation of a high-frequency (460 kHz – 1 MHz), multi-output DC-DC converter for a mission?critical radar platform, addressing both integration and performance requirements. The first implementation, an isolated modular converter (IMC), utilizes isolated silicon?based DC-DC modules to deliver twelve isolated voltage outputs from a single input. This approach provided robust electrical isolation, simplified system integration, and minimized design risk, making it well-suited for …


Autoregressive Temporal Modeling For Advanced Tracking-By-Diffusion, Pha Nguyen, Rishi Madhok, Bhiksha Raj, Khoa Luu Aug 2025

Autoregressive Temporal Modeling For Advanced Tracking-By-Diffusion, Pha Nguyen, Rishi Madhok, Bhiksha Raj, Khoa Luu

Electrical Engineering and Computer Science Faculty Publications and Presentations

Object tracking is a widely studied computer vision task with video and instance analysis applications. While paradigms such as tracking-by-regression,-detection,-attention have advanced the field, generative modeling offers new potential. Although some studies explore the generative process in instance-based understanding tasks, they rely on prediction refinement in the coordinate space rather than the visual domain. Instead, this paper presents Tracking-by-Diffusion, a novel paradigm for object tracking in video, leveraging visual generative models via the perspective of autoregressive models. This paradigm demonstrates broad applicability across point, box, and mask modalities while uniquely enabling textual guidance. We present DIFTracker, a framework that utilizes …


Polymer-Enhanced Nanopore Sensing, Eugene Gyasi Agyemang Aug 2025

Polymer-Enhanced Nanopore Sensing, Eugene Gyasi Agyemang

Graduate Theses and Dissertations

The resistive pulse technique characterizes single analytes by detecting fluctuations in the ion current as they pass through a narrow orifice connecting two electrolyte-filled chambers, each containing a single electrode. The amplitude, shape, frequency, and duration of these fluctuations primarily provide information about the analyte’s size, shape, concentration, and net surface charge, respectively. One configuration for resistive pulse measurements is of an electrolyte-filled nanopipette immersed in a bath, where the nanopipette tip acts as the nanoscale orifice. It was previously shown that incorporating the large quantities polymer polyethylene glycol (PEG 8K, 50% w/v) into the external electrolyte bath dramatically enhanced …


Synthesis, Structural Characterization And Optical Studies Of Silver-Indium-(Zinc)-Chalcogenide Fluorescent Quantum Dots, Sujal Acharya Aug 2025

Synthesis, Structural Characterization And Optical Studies Of Silver-Indium-(Zinc)-Chalcogenide Fluorescent Quantum Dots, Sujal Acharya

Graduate Theses and Dissertations

Developing a non-toxic, high-performance fluorescent nanomaterial is crucial for overcoming the environmental and health restrictions of current cadmium, and lead based quantum dots (QDs), which limit the application of quantum dots in optoelectronics and bioimaging. In this thesis, we synthesized environmentally friendly AgInS2 QDs by a colloidal method, systematically altering the In/Ag precursor ratio from 2 to 6 to study the impact on their optical and photophysical properties. Our goals were to find the optimal stoichiometry for maximum quantum efficiency and stability. We also investigated further improving optical and photophysical properties through shelling with ZnS. The emission spectra appeared broad, …


Simulation- And Machine Learning-Based Methods For Inland Waterway Operation And Maintenance Decision-Making, Maryam Aghamohammadghasem Aug 2025

Simulation- And Machine Learning-Based Methods For Inland Waterway Operation And Maintenance Decision-Making, Maryam Aghamohammadghasem

Graduate Theses and Dissertations

The U.S. inland waterway transportation system (IWTS) is an essential part of the country's multimodal freight transportation network. In addition to seasonal droughts and floods, the operations of the IWTS may be disrupted by random malfunctions and scheduled maintenance of its critical components. Among these critical components, locks play a key role in the operation of navigable inland waterways, and lock-induced disruptions to the supply chains of related industries, such as agriculture and manufacturing, often result in significant economic losses. To assess the performance of the U.S. IWTS, we develop a PyNetLogo simulation tool to capture the movements and delays …


Tribology Of Textured Surfaces, Min Zou, Mahyar Afshar-Mohajer, Robert A. Fleming Jul 2025

Tribology Of Textured Surfaces, Min Zou, Mahyar Afshar-Mohajer, Robert A. Fleming

Mechanical Engineering Faculty Publications and Presentations

Surface texturing has emerged as a transformative approach to improving friction, lubrication, and wear across a wide range of mechanical components. From bio-inspired micro-dimples to engineered macro-grooves, texture designs are increasingly applied in biomedical implants, bearings, seals, and automotive systems. This Special Issue, “Tribology of Textured Surfaces,” compiles 14 papers that collectively cover fabrication techniques, multi-scale optimization, predictive modeling, and diverse application areas.   The following sections summarize the major themes of this Special Issue. Section 2 reviews the fabrication techniques and texture scales addressed by the authors. Section 3 examines modeling and numerical studies, while Section 4 categorizes the work …


Targeted Delivery Of Rapamycin Via Epidermal Growth Factor Receptors In Pancreatic Cancer Cells Inhibits Cell Proliferation And Induces Apoptosis, Adeolu S. Oluremi, Christofer Baldwin, Nickolas L. Gustavision, Mujeebat Bashiru, Adeniyi Nsiah Oyebade, Noureen Siraj, Raj Raghavendra Rao, N. Ali Jul 2025

Targeted Delivery Of Rapamycin Via Epidermal Growth Factor Receptors In Pancreatic Cancer Cells Inhibits Cell Proliferation And Induces Apoptosis, Adeolu S. Oluremi, Christofer Baldwin, Nickolas L. Gustavision, Mujeebat Bashiru, Adeniyi Nsiah Oyebade, Noureen Siraj, Raj Raghavendra Rao, N. Ali

Biomedical Engineering Faculty Publications and Presentations

Pancreatic cancer (PC) is aggressive and deadly; most PC cells overexpress an epidermal growth factor receptor (EGFR). EGFR-targeting peptide (GE11) was conjugated to gold nanoparticles (AuNPs) for delivering rapamycin (Rap), an mTOR inhibitor that reduces proliferation and induces apoptosis. Biophysical techniques confirmed the conjugation. Rap loading efficiency was 41.5%, with sustained release at a lower pH. Conjugates showed higher uptake in PANC-1 cells than unmodified AuNPs. It also inhibited proliferation and induced apoptosis via pathways involving reactive oxygen species, mitochondrial damage, and caspase activation. This approach represents a promising nanoparticle-based therapeutic strategy targeting PC cells, utilizing GE11-EGFR interactions to minimize …


Wind Tunnel Model Of The Jack Rabbit Ii Field Experiments In The Mock Urban Array: Part 2. Approach Wind Conditions And Particle Image Velocimetry Measurements Of Simulated Chlorine Releases, Paulo V. Lopez, Thomas O. Spicer, Chad T. Smith Jul 2025

Wind Tunnel Model Of The Jack Rabbit Ii Field Experiments In The Mock Urban Array: Part 2. Approach Wind Conditions And Particle Image Velocimetry Measurements Of Simulated Chlorine Releases, Paulo V. Lopez, Thomas O. Spicer, Chad T. Smith

Chemical Engineering Faculty Publications and Presentations

The Jack Rabbit II (JR-II) Mock Urban Environment field test was reproduced in a 1:50 scale physical model in the wind tunnel at the Chemical Hazards Research Center of the University of Arkansas. The agreement of the approaching wind characteristics between field test and model was verified using 3D Laser Doppler Velocimetry (LDV). 2D Particle Image Velocimetry (PIV) tests were conducted in the model to obtain velocity measurements in the MUE. Velocity measurements taken before and during a simulated chlorine release were compared. PIV results show the general flow complexity in the last rows of the MUE and the impact …


Oscillatory Flow Improves Hydrodynamic Ordering Of Soft Suspensions In Rectangular Channels, Paul C. Millett Jul 2025

Oscillatory Flow Improves Hydrodynamic Ordering Of Soft Suspensions In Rectangular Channels, Paul C. Millett

Mechanical Engineering Faculty Publications and Presentations

A computational study is presented that examines the hydrodynamic ordering of soft-particle suspensions within rectangular channels undergoing both steady and oscillatory flow. In these conditions, particles assemble into one-dimensional train-like configurations aligned in the flow direction. The results indicate that oscillatory flow facilitates a significant improvement in the ordering process, particularly for the assembly of multiple side-by-side trains within the channel. Several key parameters are systematically varied, including the Wolmersley number (Wo) representing the oscillatory frequency, the capillary number (Ca) representing the particle deformability, and the particle volume fraction (phi). It is found that optimal ordering occurs for a particular …


Enhanced Scratch Resistance Of Graphite Coating Using A Polydopamine Adhesive Underlayer, Adedoyin Abe, Min Zou Jul 2025

Enhanced Scratch Resistance Of Graphite Coating Using A Polydopamine Adhesive Underlayer, Adedoyin Abe, Min Zou

Mechanical Engineering Faculty Publications and Presentations

Graphite has great potential as a solid lubricant due to its low friction properties, but its poor adhesion to metal substrates limits its durability unless modified. This study explores the use of polydopamine (PDA), a bioinspired adhesive polymer, as an underlayer to enhance the adhesion and scratch resistance of graphite coatings applied to stainless steel (SS) substrates. Progressive load scratch tests were performed using a stainless steel ball counterface under normal loads ranging from 0.5 to 18 N. The PDA-modified coatings demonstrated significantly improved adhesion and durability, withstanding contact pressures up to 1.6 GPa without delamination or failure. In contrast, …


Leveraging Oxygen Mobility With Zirconia In Low-Temperature Plasma For Enhanced Methane Reforming To Syngas, Fnu Gorky, Levy Pile, Grace Jones, Apolo Nambo, Mourad Benamara, Maria L. Carreon Jul 2025

Leveraging Oxygen Mobility With Zirconia In Low-Temperature Plasma For Enhanced Methane Reforming To Syngas, Fnu Gorky, Levy Pile, Grace Jones, Apolo Nambo, Mourad Benamara, Maria L. Carreon

Chemical Engineering Faculty Publications and Presentations

Despite extensive efforts to optimize the single-step production of syngas, hydrocarbons, and oxygenates via plasma catalysis, several challenges remain unresolved. In particular, understanding the various reaction pathways is hindered by the complexity of the reactions and the diverse range of chemical products formed. In this study, our main objective is to evaluate and compare the influence of zirconia on reaction pathways, methane (CH4) and carbon dioxide (CO2) conversions (%), and syngas selectivity (%) relative to the plasma-only route. Experiments were conducted at a low radio-frequency plasma power of 50 Watts without external heating. The results demonstrated significantly enhanced conversions of …