Engineering Commons^™

E-Cadherin Force Transmission And Stiffness Sensing, Mazen Mezher

Mechanical & Aerospace Engineering Theses & Dissertations

E-cadherin is the chief mediator of cell-cell adhesion between epithelial cells and is a known mechanosensor. Force transmission and stiffness sensing are two crucial aspects of E-cadherin mechanobiology.

E-cadherin has an extracellular adhesive region, a transmembrane region and an intracellular region that binds to adhesion-associated proteins. Here, we assessed how different factors affect the level of force transmission (i) from inside the cell such as adhesion-associated proteins, (ii) on the cell membrane, such as growth factor receptors and (iii) outside the cell, such as different binding partners in adhesion. To study the level of force transmission inside the cell, we …

Human Psychology Factors Influencing Agile Team Autonomy In Post-Pandemic Remote Software Organizations, Ravikiran Kalluri

Engineering Management & Systems Engineering Theses & Dissertations

Agile project management methods are gaining in popularity in the software industry as software development teams are being asked to be adaptive to market needs and resilient to change and uncertainty. With increasing market uncertainty, global competition, and time-to-market pressure, it is becoming a challenge to develop an innovative product and deliver it on-time without the opportunity that comes from team autonomy to experiment and learn from failures in a remote workplace. To resolve this challenge, it is critical to understand the myriad human psychological factors in play that influence Agile team autonomy in a remote work environment.

The role …

Nb3Sn Coating Of Twin Axis Cavity And Other Complex Srf Cavity Structures, Jayendrika Kumari Tiskumara

Physics Theses & Dissertations

In the field of Accelerator Science, for the low cost and increased quality factor, thin films coated niobium cavities are used in the modern SRF research. Within the potential substances, Nb₃Sn has shown higher critical temperature than niobium. Here the tin vapor diffusion method is used as the preferred technique to coat niobium cavities. So far, only elliptical cavities have been coated with Nb₃Sn and this technique has not yet been applied to cavities with complex geometries, which are also helpful in the accelerator science field. The Half-wave resonator could provide us data across frequencies of …

Validation Of Meta Motion Imu Sensors Through Measurement Of Knee Angles During Gait, Kerri Caruso

Biomedical Engineering Theses & Dissertations

The implementation of inertial measurement units (IMU) in the biomechanical field has become increasingly popular due to their robustness, simplicity, accuracy, and the ability to move research out of a lab and into the real world. In this study, the MetaMotion IMU sensors are assessed for validity against a dynamometer and the Vicon motion capture system. Both systems have proven their measuring accuracies in the biomechanics world and are used as the truth source for this validation study. In the first part of this study, the sensors are assessed for various common sensor errors. Individual sensor components of the IMU, …

Fusion Bonding Behavior Of 3d Printed Pa6/Cf Composites Via Post Fabrication Compaction, Gonzalo Fernandez Mediavilla

Mechanical & Aerospace Engineering Theses & Dissertations

Additive manufacturing (AM) is becoming a robust production technology for aerospace, healthcare, and construction industries among others. Fused Deposition Modelling (FDM) is one of the methods most used to 3D print products. FDM has limitation due to interlayer adhesion and restriction imposed by the printing direction. Specially with AM composites, as reinforced nylon PA6 with short fibers, parts show more strength along the direction of the filament due to the alignment of the carbon fibers, but weaker in other directions. The proposed method to solve this issue is to print parts separately and join them together by fusion bonding. PA6/CF …

Fabrication Of Solid Oxide Fuel Cell Components Using Stereolithography 3d Printing, Hannah Dyer

Mechanical & Aerospace Engineering Theses & Dissertations

Transitioning from fossil fuel supplied energy to renewable technology must meet cost efficient parameters throughout the manufacturing process while possessing the characteristics of a functioning and reliable power source. With a significant demand in renewable energy products, developmental techniques require adaptive approaches and procedures for novel materials in the manufacturing phase. This report proposes how a solid oxide fuel cell (SOFC), a renewable energy system, can employ additive manufacturing for directly 3D printing its components by utilizing stereolithography (SLA) 3D printing techniques. Fabrication of the printed components from the mixtures were first mixed with varying concentrations of ceramic powder and …

Cardiac Ablation And Stimulation With Nanosecond Pulsed Electric Fields (Nspefs), Federica Serra

Biomedical Engineering Theses & Dissertations

Surgical ablation of cardiac tissue is the definitive treatment for the most common arrhythmia, atrial fibrillation. In current medical practice, myocardial tissue is often ablated by the application of radiofrequency (RF) currents which are delivered through an electrode to create lesions that block the electrical pathways that sustain reentrant arrhythmias and restore the normal heart rhythm. An alternative to RF is cryoablation, during which the endocardial or epicardial tissue is brought in contact with a cryoprobe. Both RF ablation and cryoablation have significant limitations. In RF ablation, tissue is heated in order to ablate it, but it is an open …

An Experimental And Numerical Investigation Of The In-Plane Shear Behavior Of Cantilever Cross-Laminated Timber Diaphragms, Bibek Bhardwaj

All Dissertations

This research focuses on investigating the behavior of Cross Laminated Timber (CLT) diaphragms under in-plane shear loads through an experimental, analytical, and numerical approach. Full-scale destructive tests were conducted on cantilever CLT diaphragms to measure their response to cyclic loading. The results showed that the ultimate capacity of the diaphragms was primarily influenced by the fasteners used and exceeded the LRFD capacity. The primary energy dissipation mechanism was through the slip of diaphragm components and rotation of CLT panels due to fastener deformations. The strain data revealed that the diaphragms exhibited deep-beam-like behavior, with resistance to tensile and compressive forces …

Characterization Of Lignin And Cellulose Biopolymers Structure – Function Relationships, Zachariah Pittman

All Dissertations

Biomass is vital to ongoing efforts to secure a sustainable future. While many of our efforts focus on finding alternative forms of energy, biomass among them, only biomass has the potential to serve as a sustainable materials feedstock. However, biomass is heterogenous, complicating the upgrading processes needed to manufacture commodity and performance products. For example, plant biomass consists largely of cellulose, a crystalline polysaccharide, and lignin, a highly stable polyaromatic. The specific properties of cellulose and lignin depend greatly on the plant, harvesting conditions, and isolation procedures. Thus, accurate and reliable determination of the fundamental properties of biomass is crucial …

Modeling The Impact Of Scheduling Risks On Multi-Team Agile Projects, Bria Marie Booth

Theses and Dissertations

Agile project management allows for a quick response to a changing project environment. This opens possible avenues for new opportunities, but also may expose ongoing projects to previously unknown or unexpected threats. Risks must be continuously monitored as a product is worked on to avoid lost potential. This paper will propose a discrete event simulation model that multi-team projects may use to predict the impact to the project’s schedule. Using discrete event simulation early in the project’s planning cycle offers a greater understanding of the possible or probable impact of risks on the schedule. This would help to prepare project …

Study Of The Stability Of Heparin/Collagen Layer-By-Layer Coatings, Hector M. Apodaca Reyes

Chemical Engineering Undergraduate Honors Theses

Pairing heparin with collagen-based medical implants has opened a whole new area of research for enhancing the desired effect of current implants. In fact, heparin (HEP) and collagen (COL) layer-by-layer (LbL) coatings have shown impressive results in forming polyelectrolyte multilayers. It has been already seen on skin grafts, nerve guide conduits (NGCs), and drug delivery devices yielding promising results. Due to being a simple, cost-efficient, and versatile option to fabricate thin biomimetic films, this self-assembly technique is one of the most effective methods to immobilize extracellular matrix (collagen and heparin) onto medical devices and implants. Even though previous studies have …

Rilem Tc 266-Mrp: Round-Robin Rheological Tests On High Performance Mortar And Concrete With Adapted Rheology—Rheometers, Mixtures And Procedures, Dimitri Feys, Mohammed Sonebi, Sofiane Amziane, Chafika Djelal, Khadija El-Cheikh, Shirin Fataei, Markus Greim, Irina Ivanova, Helena Keller, Kamal Khayat, Laurent Libessart, Viktor Mechtcherine, Ivan Navarrete, Arnaud Perrot

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Recent developments in understanding the rheology of mortar and concrete as well as applying this understanding in the practice of construction necessitate an accurate assessment of materials' rheological properties. It is well known that different rheometers for mortar and concrete deliver different results, as this was shown over 15 years ago in two measuring campaigns comparing concrete rheometers. Considering newly developed rheometers, including those to evaluate interface rheology and structural build-up at rest, as well as additional measurement procedures and data interpretation techniques, a new comparison campaign was carried out in 2018 at the Université d'Artois, in Bethune, France. This …

An Integrated Experimental And Modeling Approach To Design Rotating Algae Biofilm Reactors (Rabrs) Via Optimizing Algae Biofilm Productivity, Nutrient Recovery, And Energy Efficiency, Gerald Benjamin Jones

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Microalgae biofilms have been demonstrated to recover nutrients from wastewater and serve as biomass feedstock for bioproducts. However, there is a need to develop a platform to quantitatively describe microalgae biofilm production, which can provide guidance and insights for improving biomass areal productivity and nutrient uptake efficiency. This paper proposes a unified experimental and theoretical framework to investigate algae biofilm growth on a rotating algae biofilm reactor (RABR). The experimental laboratory setups are used to conduct controlled experiments on testing environmental and operational factors for RABRs. We propose a differential-integral equation-based mathematical model for microalgae biofilm cultivation guided by laboratory …

Automation Of Life Cycle Assessment, Jacob Hickman

Graduate Theses and Dissertations

An automation program, named Jacob LCA, was created to help perform life cycle assessment (LCA). The program uses a template file to perform controlled and consistently ordered actions with the LCA program, SimaPro, and effectively removes the need for manual user input. It can be set to run using data from one or more life cycle inventory (LCI) files, which allows for rapid iteration and testing of data. It also partially addresses some of the limitations of LCA by establishing a procedure through which temporal and spatial variations in data can be integrated into LCI files and then passed to …

Using Immersive Technology To Improve Mechanical Design: Use Cases, A Review Of Current Technology, And An Experiment In Requirement Elicitation In Virtual Reality, William Hawthorne

All Theses

There has been a growing trend in the use of immersive technologies within engineering design. This research is focused on understanding how Virtual Reality (VR) technologies support design reviews. Modern tools including virtual reality hardware and software were tested for current capabilities and challenges. In a review of literature, two key gaps are identified: the rapid advancements of VR and AR technology and limited formal studies to determine the costs and benefits of immersive technology within engineering design reviews. This research has resulted in three key outcomes. First, use cases of immersive reality technologies are identified, through the lens of …

Characterization Of Novel Self-Healing Polymer Blends For Additive Manufacturing, Truman James Word

Open Access Theses & Dissertations

This dissertation begins with an overview of novel polymer systems which have been developed by the Polymer Extrusion Lab at the University of Texas at El Paso. Many composite polymer systems have been created using many different polymers as well as ceramics and metals primarily in the form of powders added to the bulk polymer. The bulk of this work entails a study that was conducted to develop and characterize the mechanical, shape memory and self-healing properties of three polymer blends: polylactic acid (PLA) combined with maleated styrene-ethylene-butylene-styrene (SEBS-g-MA), acrylonitrile butadiene styrene (ABS) combined with maleated styrene-ethylene-butylene-styrene (SEBS-g-MA), and polylactic …

A Study To Determine Performance Characteristics Of The Mississippi Cowling - Piper Archer Vs. Piper Warrior, Zilvinas Visockas

Theses and Dissertations

Today, aviation is one of the most technologically advanced and innovative sectors in the world. With fast-depleting natural resources, increasing environmental pollution, and continuous growth in fuel cost, efficiency has become industry’s top priority. Engineers are making gradual improvements that offer overall increase in aircraft’s performance. Drag is critical factor in aviation as it directly impacts aircraft’s fuel efficiency, range, and speed. During the design phase, engineers invest significant effort and expense in attempting to minimize the drag profile by implementing aerodynamic shapes and constantly reducing component weights. One of the real-life examples of such engineering attempts is Piper Archer, …

A Step-By-Step Guide To Identify The Most Reliable Inventory Management System For Small Businesses Using Discrete Event Simulation And Pros And Cons Analysis: A Case Study At Camid-Florida Tech, Djalma Batista Oliveira Filho

Theses and Dissertations

According to the Department of Labor Statistics (2022), 20.6% of small businesses fail in their first year of operation, 42.6% fail after five years, and over 62.6% fail by their tenth year. One factor that can affect continued viability is the lack of knowledge and experience among small and medium-sized firms in inventory management. Despite the fact that inventory control is one of these businesses' most ignored management responsibilities, the expense of procuring inventory often accounts for a considerable portion of their budget. Due to poor inventory management or an inability to appropriately supervise their inventory, small firms may have …

Efficient Modelling Of Random Access Memory Cell: An Approach Using Qca Nanocomputing, Ali Newaz Bahar, Angshuman Khan

Turkish Journal of Electrical Engineering and Computer Sciences

Quantum-dot cellular automata (QCA) is innovative and potentially fruitful nanotechnology that provides a solution for transistor-based circuits with enhanced switching frequency, large-scale integration, and low power consumption. The random-access memory (RAM) cell is a fundamental component that is designed to operate quickly and effectively since memory is a core part of the semiconductor industry, thus the QCA family. The RAM cell design in this work is based on a multiplexer structure and is implemented without using coplanar crossovers of QCA technology. QCADesigner-2.0.3, a standard QCA layout design and verification tool, is used in the simulation and validation processes for the …

Catalytic Water Photolysis For Generating Renewable Hydrogen Fuel, Dr. Niveditha Nanda

Open Access Theses & Dissertations

Modern advances have enabled rapid industrialization and urbanization. However, the consequences of global modernization have included significant pollution to the air and water resources. Consequently, many changes to energy use must come to address and mitigate damages to our future. Solar energy derived hydrogen gas is a clean, renewable fuel that does not produce carbon dioxide or other pollutants. My research investigates the use of heterogeneous photocatalysis, by focusing on solar photochemical energy conversion, which is the making of hydrogen from water using sunlight. The production of clean, renewable hydrogen fuel will enable the utilization of low-cost, pollution-free energy resources …

Fiscal Year 2021 Fhwa-536 Report For The Kentucky Transportation Cabinet, Doug Kreis, Candice Wallace, Bryan Gibson, Sarah Mccormack

Kentucky Transportation Center Research Report

No abstract provided.

Point Heat Source Correlation To Microstructural Evolution In Advanced Manufacturing, Mark Anderson

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Although there are different ways that advanced manufacturing can be performed, the use of single-point heat sources has become the standard to control a final product’s properties. It is imperative to understand how the heat source used in the different advanced manufacturing processes affect the microstructure of interest. The intimate relationship between the heat source and microstructure allows for controlling and tailoring a part’s properties. Utilizing different microstructural analysis, the cross-correlation of various point heat sources to developed microstructure was conducted in this dissertation.

Laser powder bed fusion allows for unique print-to-part protocols, but the dynamics of the process makes …

Assessment Of Bridge Pier Response To Fire, Vehicle Impact, And Air Blast, Chen Fang, Qusai Alomari, Daniel G. Linzell

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Highway bridges exposed to intentional or unintentional fire followed by combined vehicle impact and air blast are at risk of significant damage and, possibly, collapse. Limited studies examining the complex effects of these extreme demands on bridge support elements and parametrizing their response and damage are found in the open literature. Research that is presented is part of an ongoing numerical investigation examining round, multi-column, reinforced concrete (RC), bridge pier behavior subject to multi-hazard scenarios involving fire, vehicle impact, and air blast. Detailed nonlinear finite element analysis models of single columns and multi-column piers supported by a pile foundation system …

Trace Dna Detection Using Diamond Dye: A Recovery Technique To Yield More Dna, Leah Davis

Master's Theses

This study aspires to find a new screening approach to trace DNA recovery techniques to yield a higher quantity of trace DNA from larger items of evidence. It takes the path of visualizing trace DNA on items of evidence with potential DNA so analysts can swab a more localized area rather than attempting to recover trace DNA through the general swabbing technique currently used for trace DNA recovery. The first and second parts consisted of observing trace DNA interaction with Diamond Dye on porous and non-porous surfaces.

The third part involved applying the Diamond Dye solution by spraying it onto …

Program And Proceedings: Nebraska Academy Of Sciences 1880–2023, 143rd Anniversary Year, One Hundred-Thirty-Third Annual Meeting, April 21, 2023

Nebraska Academy of Sciences: Programs and Proceedings

Program

Aeronautics and Space Science

Humans Past and Present

Applied Science and Technology Section

Biology

Biomedical Sciences

Chemistry

Earth Sciences

Environmental Science

Physics

Science Education

2023 Maiben Lecture: Jason Bartz

2023 Friend of Science Award: Ray Ward and Jim Lewis

A Comparison Of Optical Measurement Methods For The Growth Of S. Cerevisiae, Jackson Black

Chemical Engineering Undergraduate Honors Theses

Genetic engineering of living organisms provides the opportunity to express and harvest different proteins from cell surfaces. Yeast (S. cerevisiae) is one such organism and is capable of being grown on an industrial scale. Cellular concentration is an important parameter to monitor while fermentation processes are underway, in order to control the environment inside the growth medium and maximize yields. Spectrophotometry is a conventional method for measuring concentration, but is limited by a narrow absorbance range, and the need for on-site periodic sampling. A continuous method of measurement, as provided by Bug Labs BE2100 non-invasive biomass monitor, would …

Measuring Plume Concentration Variations Under Neutral Atmospheric Conditions, Daniel Williams

Chemical Engineering Undergraduate Honors Theses

Hazardous gases are increasingly becoming a large safety concern as the world continues to grow and industrialize. The modeling of when hazardous gases breach containment is an extremely important objective of consequence assessment planning and response. To improve the understanding of the variability inherent in passive gas releases, a test program to demonstrate the variability of gas concentration measurements at different location in a passive gas plume released from an area source in the ultra-low speed wind tunnel at the Chemical Hazards Research Center. A Flame Ionization Detector was used to measure the concentration of the source cloud. Methane was …

Synthesis, Radiolabeling And Evaluation Of A Suite Of Tracers With 44Sc For Detecting Extracellular Dna, Zhiyao Li

McKelvey School of Engineering Graduate Student Theses & Dissertations

Neutrophil extracellular traps involve the rapid translocation of DNA to the outside of the cell under certain stimuli. This structure forms a fibrous network that is able to limit the spread of pathogens and to kill microorganisms. It has also been shown to be present in various pathological processes such as inflammation, autoimmune diseases, and cancer metastasis. Currently, the formation process of NETs in vivo is being extensively studied. However noninvasive detection and quantitation has yet to be achieved. A class of PET tracers are described here that consists of a DNA dye as the backbone that is labeled with …

Analytical And Experimental Investigation Of Interphase And Dispersion Effects On The Mechanical Stiffness Of Cellulose Nanocomposites, Will Goldberg

McKelvey School of Engineering Graduate Student Theses & Dissertations

The effect of dispersion and interphase properties on the elastic behavior of cellulose nanocomposites was investigated using a number of composite models, experimental data and a thorough literature review. Cellulose nanocomposites consisting of soy protein isolate (SPI) and cellulose nanocrystals (CNC) or polydopamine coated cellulose nanocrystals (PD-CNC) were prepared via solution casting method and tested for mechanical stiffness. These outcomes were compared to standard composite models as well as novel methods adapted from the literature that incorporate data regarding dispersion quality and interphase properties. The literature review verified that both dispersion and interphase properties are highly dependent on interfacial chemistry …

Engineered Material Systems For Mimicking Tissue And Disease, Margrethe Ruding

McKelvey School of Engineering Graduate Student Theses & Dissertations

This thesis comprises two studies involving design and application of soft material systems. The goal of the first study was to design, fabricate, and characterize hydrogel lattice structures with consistent, controllable, anisotropic mechanical properties. Lattices, based on four types of unit cells (cubic, diamond, vintile, and Weaire-Phelan), were printed using stereolithography (SLA) of polyethylene glycol diacrylate (PEGDA). In order to create structural anisotropy in the lattices, unit cell design files were scaled in one direction by a factor of two in each layer and then printed. The mechanical properties of the scaled lattices were measured in shear and compression and …