Digital Commons Network^™

Traction Force Microscopy Using An Epifluorescence Microscope: Experimental Considerations And Caveats, Zaria Booth, Mazen Mezher, Rudra Patel, Venkat Maruthamuthu

Mechanical & Aerospace Engineering Faculty Publications

Forces exerted by cells due to their internal contractility play fundamental roles in a host of processes, including adhesion, migration, survival and differentiation. Traction force microscopy (TFM) enables the determination of forces exerted by cells or cell collectives on their environment, which is typically taken to be an extra-cellular matrix (ECM)-coated substrate. Sample preparation for TFM involves the plating of cells onto an environment embedded with fiducial markers. The imaging of these fiducial markers in the presence and absence of the cells then enables calculation of the displacement of localized regions of the environment, and, consequently, the spatial distribution of …

Scaffolds With Spatiotemporally Controlled Growth Factor Delivery And Cyclodextrin-Enabled Antagonism Of Growth Factor Receptor Sequestration Promote Cutaneous Wound Healing, Jelena Marjanovic, Veronica Jurczuk, Lilian Valadares Tose, Yarixa Cintron Diaz, Francisco Fernandez Lima, Beatriz Abdo Abujamra, Sara Danker, Sinan Jabori, Devinder Singh, Jamie L. Burgess, Joshua Tam, Mohamadmahdi Samandari, Rivka C. Stone, Stephen C. Davis, Robert S. Kirsner, Marjana Tomic-Canic, Fotis M. Andreopoulos, Ivan Jozic

Mechanical & Aerospace Engineering Faculty Publications

Chronic wounds present a major burden to patients, health care professionals, and health care systems worldwide, yet treatment options remain limited and often ineffective. Although initially promising, growth factor-based therapies displayed limited and underwhelming effectiveness largely due to poor bioavailabilbioity and impaired receptor function within the chronic wound microenvironment. Here we demonstrate that chronic wounds exhibit elevated cholesterol synthesis, which disrupts growth factor signaling by sequestering receptors within lipid rafts. To address this, we developed a novel therapy combining growth factors with cyclodextrin in an ECM-mimetic scaffold, enabling localized cholesterol modulation and improved receptor accessibility. We demonstrate that this approach …

Mass-Adaptive Admittance Control For Robotic Manipulators, Hossein Gholampour, Jonathon E. Slightam, Logan E. Beaver

Mechanical & Aerospace Engineering Faculty Publications

Handling objects with unknown or changing masses is a common challenge in robotics, often leading to errors or instability if the control system cannot adapt in realtime. In this paper, we present a novel approach that enables a six-degrees-of-freedom robotic manipulator to reliably follow waypoints while automatically estimating and compensating for unknown payload weight. Our method integrates an admittance control framework with a mass estimator, allowing the robot to dynamically update an excitation force to compensate for the payload mass. This strategy mitigates end-effector sagging and preserves stability when handling objects of unknown weights. We experimentally validated our approach in …

Optimal Manipulation Motion Action Planner Enabled By Physics Informed Neural Networks, Jonathon E. Slightam, Logan E. Beaver

Mechanical & Aerospace Engineering Faculty Publications

Autonomous robotic manipulation in unstructured environments faces many challenges and is hindered by capabilities that bridge the gap between perception and acting on the world. Action plans that are centric to object motion rather than end-of-arm tooling behavior may aid this. This paper presents an autonomous action planner for a feedback linearizeable system comprised of three base motions that can be leveraged on their own or in combination to give custom motion plans. The optimization routine for the three different types of motion are presented, which are integrated into physics informed neural networks. A component of this is the autonomy …

Representation In Engineering-Focused Children's Literature: A Critical Content Analysis, Angela Eckhoff

Teaching & Learning Faculty Publications

Children’s picturebooks have long been understood as a powerful medium for exploring aspects of children’s lives, experiences, and identities serving as mirrors which allow children to see themselves reflected, as windows through which they can gain insight into the experiences of others, and as sliding glass doors when children are connected to the story and characters in meaningful ways. Utilizing a critical content analytic approach, this research examined the identity markers and engineering practices found in contemporary children’s picturebooks with an engineering focus. The analysis yielded key themes that highlight the ways children can interact and connect to the characters …

Perceptions Of Stem Education And Artificial Intelligence: A Twitter (X) Sentiment Analysis, Demetrice Smith-Mutegi, Yoseph Mamo, Jinhee Kim, Helen Crompton, Matthew Mcconnell

Teaching & Learning Faculty Publications

Background, context, and purpose of the study: Artificial intelligence (AI) is becoming increasingly prevalent in science, technology, engineering, and mathematics (STEM) education, holding promising potential for supporting the design and implementation of quality STEM education. However, there is a lack of data-based research studying the diverse perceptions of AI in STEM education as conveyed on social media, the factors that influence those perceptions, or the change in those perceptions over time among public audiences. Results, the main findings: The purpose of this study was to examine public perceptions of AI in STEM education by analyzing X posts (Tweets) between 04/28/2020 …

Teaching To Whom And With Whom: The Role Of Context In Developing Preservice Teachers' Self-Efficacy For Teaching Engineering And Coding Via Robotics, Jennifer Kidd, Kristie Gutierrez, Min Jung Lee, Danielle Rhemer, Pilar Pazos, Krishna Kaipa, Stacie Ringleb, Orlando Ayala

Teaching & Learning Faculty Publications

Due to mandates for the inclusion of engineering and computer science standards for K-6 schools nationwide, there is a need to understand how teacher educators can help develop preservice teachers’ (PSTs’) teaching self-efficacy in these areas. To provide experience teaching and learning engineering and coding, PSTs in an instructional technology course were partnered with undergraduate engineering students in an electromechanical systems course to teach robotics lessons to fifth graders (10–11 year olds) over Zoom. A multi-case study approach explored teaching self-efficacy development for three preservice teachers during their robotics project experiences using multiple data sources, including surveys, reflections, interviews, and …

Rural Families' At-Home Stem Tinkering Stimulates Creativity, Self-Expression, And Social-Emotional Engagement, Kristie S. Gutierrez, Kylie J. Swanson, Margaret R. Blanchard

Teaching & Learning Faculty Publications

Introduction: Informal STEM learning experiences include visits to museums, zoos, and aquariums as well as experiments and other activities performed at home. Family involvement in these experiences has been linked to increased student interest and participation in STEM fields; yet, scant research has been conducted on at-home STEM.

Methods: This descriptive case study investigated the tinkering experiences of nine rural middle school students and their families who participated in a series of interactive, at-home activities. The overarching research question was, in what ways do families engage in at-home STEM interventions? Data analyses of at-home audio recordings were guided by the …

Teaching Engineering To Enhance Beginning Elementary Preservice Teachers' Engineering-Related Knowledge And Beliefs, Jennifer Kidd, Danielle Rhemer, Kristie Gutierrez, Stacie I. Ringleb, Krishnanand Kaipa, Orlando Ayala, Pilar Pazos, Francisco Cima, Isaac Kumi

Teaching & Learning Faculty Publications

Background

Teacher educators have begun exploring the most effective ways to prepare preservice teachers (PSTs) to engage elementary students in engineering design. However, this remains challenging as PSTs continue to report a lack of exposure to engineering during their K-12 school experiences. This study investigates the engineering-related knowledge and beliefs of PSTs in their first education course, collaborating in small teams to lead elementary students in engineering design challenges. We explored two different iterations to understand how the structure of the teaching experiences contributed to PST outcomes as a first step in identifying helpful approaches. In spring 2022, PSTs collaborated …

Examining The Practice Of Teacher Leadership Across Nevada: How Is Context Associated With Practice?, Peter Wiens, Kaavonia Hinton, Ami Pritchard

Teaching & Learning Faculty Publications

Teacher leadership (TL) is recognized as vital to creating effective schools with demonstrated benefits to principals, teachers, and students. Teacher leadership is defined in this study as teachers leading from within and beyond the classroom in both formal and informal capacities. TL can take the form of a variety of behaviours such as professional learning, the leading of professional development, collaboration, shared leadership, and equity leadership. While there are commonalities, the practical applications of TL can vary greatly from context to context. Even within specific policy contexts, TL can vary from school to school. This article analyzed the responses of …

A Deep Dive In Preservice Teacher Self-Efficacy Development For Teaching Robotics (Rtp), Jennifer Jill Kidd, Kristie Gutierrez, Min Jung Lee, Danielle Marie Rhemer, Krishnanand Kaipa, Pilar Pazos, Stacie I. Ringleb, Orlando M. Ayala, Francisco Cima, Isaac Koduah Kumi

Teaching & Learning Faculty Publications

Nationwide K–6 engineering and coding standards have made it increasingly important to prepare elementary preservice teachers (PSTs) to teach these subjects confidently and effectively. Robotics, which combines coding and engineering, provides a rich context for developing PSTs’ expertise and self-efficacy. This study builds on prior work in which PSTs in an instructional technology course collaborated with undergraduate engineering students to co-teach robotics lessons to fifth graders. Using a multiple-embedded case study approach, we examine how the interactions and teaching roles within these partnerships influenced PSTs’ teaching self-efficacy. Drawing on reflections, lesson recordings, surveys, and interviews, we present the cases of …

Exploring Physics Teacher Identity: Pathways Toward Equitable Instruction Among Teachers, Clausell Mathis, Jomo Mutegi, Turhan Carroll, Maya Patel, Andrea Wooley

Teaching & Learning Faculty Publications

Physics teacher identity encompasses teachers' beliefs and views toward being a physics teacher. Physics teacher identity is influenced by teachers' perspectives on physics teaching and learning. Previous studies on teacher identity in general suggest that the construct is complex and malleable. Studies further suggest that it influences instructional methods, student engagement, and classroom environment. However, within physics education, there has yet to be an examination of how physics teacher identity influences "equitable" teaching approaches. This qualitative study sought to identify various dimensions of physics teacher identity and its implications for physics education research. We interviewed secondary and postsecondary physics teachers …

Dominance Of Leading Business Schools In Top Journals: Insights For Increasing Institutional Representation, Rodrigo Romero-Silva, Erika Marsillac, Sander De Leeuw

Information Technology & Decision Sciences Faculty Publications

The competitive push for business schools to publish in prestigious journals has resulted in a disproportionate number of papers in prestigious Management and Operations Research/Management Science (OR/MS) journals coming from a select group of institutions. Our analysis shows the Matthew effect of prestigious journals favors established schools with 51.2% of papers in 18 Management ABS 4* journals and 61.3% of papers in 3 OR/MS ABS 4* journals involving authors from the 100 top business schools identified by the University of Texas at Dallas (UTD). Citation patterns are similarly concentrated among papers authored by scholars from UTD-listed business schools, with nearly …

Why Ai Monitoring Faces Resistance And What Healthcare Organizations Can Do About It: An Emotion-Based Perspective, Karl Werder, Lan Cao, Eun Hee Park, Balasubramaniam Ramesh

Information Technology & Decision Sciences Faculty Publications

Continuous monitoring of patients' health facilitated by artificial intelligence (AI) has enhanced the quality of health care, that is, the ability to access effective care. However, AI monitoring often encounters resistance to adoption by decision makers. Healthcare organizations frequently assume that the resistance stems from patients' rational evaluation of the technology's costs and benefits. Recent research challenges this assumption and suggests that the resistance to AI monitoring is influenced by the emotional experiences of patients and their surrogate decision makers. We develop a framework from an emotional perspective, provide important implications for healthcare organizations, and offer recommendations to help reduce …

Application Of Fuzzy Logic For Evaluation Of Student Performance, M. Tomovic, C. Tomovic, V. Jovanovic, S. Bawab

Engineering Technology Faculty Publications

The evaluation of student performance is a multifaceted process that traditionally relies on rigid grading systems, often failing to capture the complexity of student abilities and learning dynamics. This paper explores the application of fuzzy logic to enhance the accuracy and adaptability of student performance evaluation. By leveraging fuzzy logic principles, such as membership functions and linguistic variables, we model and assess the various factors influencing student performance—ranging from academic grades to engagement, participation, and personal learning styles. The approach allows for the representation of imprecise, uncertain, and subjective data, offering a more holistic view of a student’s progress. We …

Understanding Roof Systems Of Metal Buildings, Michael W. Seek, Vincent E. Sagan

Engineering Technology Faculty Publications

[Introduction] A metal building is a system with complex behavior that, when properly accounted for, provides an efficient structural solution. To help the engineer properly design for this behavior, the Metal Building Manufacturers (MBMA) has recently released the Roof Framing Design Guide for Metal Building Systems, 2nd Edition (Roof Framing Design Guide).

Collaborative Online Interactive Laboratory On Software Defined Radio Fundamentals, Otilia Popescu, Dimitrie C. Popescu, Emanuel Puschita

Engineering Technology Faculty Publications

Teaching of fundamentals of communication systems varies widely across programs in US and abroad, mainly due to the type of undergraduate engineering programs and the depth of the communications field within the curricula. The variety is spread across electrical engineering and electrical engineering technology programs, and programs with focus on telecommunications or which only offer core or elective courses in communications. Adding to the variety, some programs include hands-on laboratory courses, others include simulation-based laboratories most of the time using Matlab, while others may only include lecture courses with no labs. The accessibility of the new software defined radio (SDR) …

Ambulatory Arterial Stiffness Index: Regression Method Comparison And Its Association With Pulse Pressure And Circadian Patterns, José R. Ayala-Hernández, Cristina López-Sánchez, Orlando M. Ayala, Camilo E. Palencia-Tejedor

Engineering Technology Faculty Publications

The Arterial Stiffness Index (AASI) is a calculation obtained through Ambulatory Blood Pressure Monitoring (ABPM), and is an indirect measure of the elastic properties of the arterial wall; but there is heterogeneity in its scope as a predictor of vascular wall health. A comparison is made between linear regression and exponential regression of the AASI, as well as an analysis of variance, according to circadian patterns and pulse pressure (PP) values. This work is an analytical observational study in 106 individuals, most of them women (63%) with a mean age of 53 ± 17.32 years. The coefficient of determination (r2) …

Building Cyber Resilience: Educational Programs In K-12 Education, Mildred Jones, Vukica Jovanovic, Petros Katsioloudis

Engineering Technology Faculty Publications

The article discusses the challenges of teaching cybersecurity in K-12 education. Topics mentioned include the lack of access to resources and appropriate professional development, the career and technical education cybersecurity pathways, the fundamental pathways for cybersecurity and information technology and the results of program evaluation in several local community high schools from 2021 and 2022.

Developing Entrepreneurial Mindsets In Construction Management Through Experiential Projects, Dalya Ismael

Engineering Technology Faculty Publications

Entrepreneurial Minded Learning (EML), a framework supported by the Kern Entrepreneurial Engineering Network (KEEN), promotes critical thinking and innovation by encouraging students to explore real-world problems through the 3Cs: Curiosity, Creating Value, and Connections. In construction management education, the focus often remains on technical skills and project execution, neglecting the development of entrepreneurial skills like adaptability, value creation, and stakeholder engagement, leaving a gap in preparing students for the challenges of the industry. To bridge this gap, micro-moment activities were introduced prior to the main project to prime students for EML-based thinking. These short, focused exercises encouraged students to solve …

Gramseq-Dta: A Grammar-Based Drug-Target Affinity Prediction Approach Fusing Gene Expression Information, Kasul Debnath, Pratip Rana, Preetam Ghosh

Computer Science Faculty Publications

Drug–target affinity (DTA) prediction is a critical aspect of drug discovery. The meaningful representation of drugs and targets is crucial for accurate prediction. Using 1D string-based representations for drugs and targets is a common approach that has demonstrated good results in drug–target affinity prediction. However, these approach lacks information on the relative position of the atoms and bonds. To address this limitation, graph-based representations have been used to some extent. However, solely considering the structural aspect of drugs and targets may be insufficient for accurate DTA prediction. Integrating the functional aspect of these drugs at the genetic level can enhance …

Cost-Effective Hierarchical Cobalt Nanostructured Laser-Induced Graphene For Enhanced Uric Acid Detection, Anju Joshi, Gymama Slaughter

Center for Bioelectronics Publications

This study presents an innovative, cost-effective strategy to develop a flexible, enzyme-free biosensor for the sensitive detection of uric acid (UA). Utilizing electrochemically modified cobalt nanostructured on laser-induced graphene electrodes (CoNCs/LIG), this approach surpasses traditional noble metal-based electrocatalysts in sensitivity and affordability. The one-step electrochemical modification method is efficient and straightforward, enabling the uniform deposition of hierarchical flower-like cobalt nanostructures. These structures synergistically enhance the performance of the LIG, resulting in a broad detection range of 5 to 700 µM with a sensitivity of 6.75 µA µM^-¹ cm^-² and a low detection limit of 3.66 µM for UA. …

Nanomaterial-Enabled Enhancements In Thylakoid-Based Biofuel Cells, Amit Sarode, Gymama Slaughter

Center for Bioelectronics Publications

Thylakoid-based photosynthetic biofuel cells (TBFCs) harness the inherent light-driven electron transfer pathways of photosynthesis to enable sustainable solar-to-electrical energy conversion. While TBFCs offer a unique route toward biohybrid energy systems, their practical deployment is hindered by sluggish electron transfer kinetics, unstable redox mediators, and inefficient interfacing between biological and electrode components. This review critically examines recent advances in TBFCs, with a focus on three key surface engineering strategies: (i) incorporation of nanostructured materials to enhance electrode conductivity and surface area; (ii) application of redox mediators to facilitate charge transfer between photosynthetic proteins and electrodes; and (iii) functional exploitation of individual …

Topographic Forcing Of Submesoscale Instability In The Antarctic Circumpolar Current, Laur Ferris, Donglai Gong, John Klinck

CCPO Publications

Subpolar frontal zones are characterized by energetic storms, intense seasonal cycles, and close connectivity with surrounding continental shelf topography. At the same time, predicting the ocean state depends on appropriate partition of resolved and parameterized dynamics, the latter of which requires understanding the dynamical processes generating diffusivity throughout the water column. While submesoscale frontal instabilities are shown to produce turbulent kinetic energy (TKE) and mixing in the surface boundary layer (SBL) of the global ocean, their development in complex dynamical regimes (e.g., elevated preexisting turbulence, large ageostrophic shear, or in proximity to topographic boundaries) is less understood. This study investigates …

Assessing Porosity Limit In Freeze-Cast Sintered Lithium Titanate (Li₄Ti₅O₁₂) Materials, Rohan Parai, Dipankar Ghosh

Mechanical & Aerospace Engineering Faculty Publications

This study aims to assess the lower limit of porosity that can be achieved in freeze-cast sintered lithium titanate (LTO) materials while maintaining the characteristic pore directionality. LTO materials were fabricated with solid loading varying in the range of 30–37 vol.%. Sucrose and cationic dispersant were used to vary viscosity and total solute concentration in the aqueous LTO suspensions. Two series of suspension compositions were selected for freeze-casting. In one series, aqueous suspensions were prepared by mixing deionized (DI) water, sucrose, and LTO powder, while in the other series, aqueous suspensions were prepared by mixing DI water, sucrose, cationic dispersant …

Morphing Shape Metastructures Using The Hybrid Position Feedback Control And Bistable Structural Elements, Mehmet Simsek, Thomas E. Alberts, Onur Bilgen

Mechanical & Aerospace Engineering Faculty Publications

This research introduces a new multi-degree-of-freedom metastructure concept utilizing a hybrid position feedback controller. An arbitrary number of bistable segments, or structural elements, are connected serially or in parallel to form a distributed bistable structure, or a so-called metastructure. The hybrid controller, an unstable-then-stable second-order single-degree-of-freedom system, leverages the resonant mode of a bistable system to destabilize it and dynamically induce snap-through between equilibria. The metastructure inherits multiple bistable positions, maintaining equilibrium shapes without consuming power and enabling many equilibrium configurations. Two geometric configurations are proposed and analyzed using a modified hybrid feedback control approach, which rejects forces from neighboring …

Side-By-Side Evaluation Of The Outgassing Rate And Ultimate Pressure Achieved Inside Tubes Made Of Low-Carbon And Stainless Steel, Aiman H. Al-Allaq, Md Abdullah Mamun, Matt Poelker, Abdelmageed Elmustafa

Mechanical & Aerospace Engineering Faculty Publications

The hydrogen outgassing rate of a vacuum chamber made of AISI 1020 low-carbon steel was found to be notably smaller than a similar chamber made of AISI 316L stainless steel following heat treatment at 150 degrees C. When the chambers were baked at 400 degrees C, the outgassing rate of the 1020 low-carbon steel chamber was approximately 2000 times smaller than that of the 316L stainless-steel chamber. After quantifying hydrogen outgassing rates, vacuum chambers made of 1020 low-carbon steel and 316L stainless steel were heated for a prescribed duration and then pumped with an ion pump and nonevaporable getter pump …

Polymorphism And Mechanical Behavior In Hot-Pressed 3d-Printed Polyamide Composite: Effects Of Pressure And Temperature, John Barber, Patricia Revolinsky, Jimesh Bhagatji, Diego Pedrazzoli, Sergii Kravchenko, Oleksandr Kravchenko

Mechanical & Aerospace Engineering Faculty Publications

The aim of this work is to study the effect of high-temperature compaction (HTC) upon the polymorphism and the mechanical behavior of an additively manufactured (AM) carbon fiber-reinforced polyamide (PA6). Different pressure and temperature levels during HTC were tested to determine the overall effect on the mechanical behavior and material crystalline composition. Treated, carbon fiber-reinforced PA6 samples were analyzed using differential scanning calorimetry, X-ray diffraction, thermogravimetric analysis, scanning electron microscopy, and three-point bending testing. When considered with respect to as-printed samples, an HTC temperature of 190 °C combined with 80 psi pressure resulted in an increased flexural modulus and strength …

Optimizing Material Selection And Operational Conditions For Xhv Systems: Lessons From Aisi 1020 And 316l Comparative Studies, Aiman H. Al-Allaq, Md Abdullah Mamun, Matt Poelker, Abdelmageed Elmustafa

Mechanical & Aerospace Engineering Faculty Publications

In this study, AISI 1020 low-carbon steel was investigated as a cost-effective alternative to SS316L stainless steel for reaching extreme high vacuum (XHV) conditions. After being baked at 400°C, a vacuum chamber made of low-carbon steel material exhibited an outgassing rate approximately 2000 times smaller than a similar chamber made of stainless steel. Its activation energy for hydrogen diffusion (27 kJ/mol) is less than half that of stainless steel (60.3 kJ/mol), indicating more efficient hydrogen removal during bakeout. MolFlow+ simulations supported the experimental data and demonstrated the importance of system geometry optimization and minimizing stainless steel content for achieving optimal …

Rheology Of Alumina Suspensions Subjected To Alternating Current Electric Fields For Freeze-Casting, Sivakumar Chithamallu, Ruksana Baby, Jacob L. Jones, Dipankar Ghosh

Mechanical & Aerospace Engineering Faculty Publications

Alternating current (AC) electric field can extrinsically tune freeze‐cast microstructure, originating from field‐induced increase in viscosity of ceramic suspensions. However, the changes that occur in a ceramic suspension and rheological behavior, ultimately affecting freeze‐cast microstructure, are not well understood. Moreover, the effects of AC electrokinetic forces and temperature on viscosity need to be decoupled. The viscosity and temperature of ceramic suspensions subjected to AC field and direct heating were measured, revealing that the increase in viscosity is due to AC dielectrophoretic forces rather than field‐induced heating of suspension. The shear thinning behavior of suspensions characterized using a power‐law model reveals …