Engineering Commons^™

Identity Construction In The Work Of Mario Benedetti, Grace Jennings, Andrew F. Milacci

Liberty University Research Week

Undergraduate

Textual or Investigative

"Inclusive Inquiry." 14th Annual Research Week: Event Proceedings, University Of The Incarnate Word

Excellence Summit (Research Week) Archived Proceedings

Presentations of completed and ongoing research activity conducted by graduate and undergraduate students and faculty at University of the Incarnate Word. Coordinated and presented by the Office of Research and Graduate Studies.

Non Uniform Rational B-Splines And Lagrange Approximations For Time-Harmonic Acoustic Scattering: Accuracy And Absorbing Boundary Conditions, S.M. Dsouza, T. Khajah, X. Antoine, S.P.A. Bordas, S. Natarajan

Mechanical Engineering Faculty Publications and Presentations

The paper aims to evaluate the performance of the Lagrange-based finite element method and the non-uniform rational B-splines isogeometric analysis of time-harmonic acoustic exterior scattering problems using high-order local absorbing boundary conditions, in particular based on the Karp's and Wilcox's far-field expansions. The analysis of accuracy and convergence of both methods is achieved by observing the effect of the order of the approximating polynomial, the number of degrees of freedom, the wave number, and the absorbing boundary conditions tuning parameters. It is concluded that, regardless of the polynomial order, IGA provides a higher accuracy per degree of freedom compared to …

Hybrid Lattice Boltzmann Agglomeration Method For Modeling Transport Phenomena In Polymer Electrolyte Membrane Fuel Cells, P. Satjaritanun, F. C. Cetinbas, S. Hirano, I. V. Zenyuk, R. K. Ahluwalia, Sirivatch Shimpalee

Faculty Publications

The Hybrid Lattice Boltzmann Agglomeration Method (HLBAM) was employed to model transport phenomena and electrochemical kinetics in the catalyst layer of a polymer electrolyte membrane fuel cell (PEMFC). This work showed the advantages of using a direct modeling-based HLBAM approach, which incorporates the detailed structure of catalyst layers from X-ray computed tomography as well as local transport variables related characteristics and effective properties from the hybrid catalyst microstructure. The local transport variables and effective properties from the hybrid catalyst model were used to simulate the electrochemical kinetics inside the detailed structure of the catalyst layer. HLBAM can predict the distribution …

Modeling Considerations For Built-Up Compression Members In Communication Towers, Ghada M. El-Mahdy P.Eng., Ceng, Amro A. Alawamry

Civil Engineering

It is a well-established fact that built-up compression members exhibit extra flexibility than their equivalent solid members due to the shear action which effects the overall stability. This is usually taken into consideration by using a modified slenderness ratio for buckling modes that involve relative deformation of the interconnectors. Built-up members are often used as space truss members in communication towers. When modeling communication towers in structural analysis programs like SAP2000, the built-up member is usually defined as a single member element with a double section cross section. This does not catch the increase in deflection in the member due …

Evaluating Evapotranspiration Values In Rwanda Using The Fao-56 Pm, Turc, And Hargreaves-Samani Equations, Elizabeth Uwase

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Evapotranspiration (ET) is an important component of the hydrologic cycle and involves exchange of water between the surrounding water bodies, soil, crop surfaces, and the atmosphere. Therefore, this research was aimed at determining ET and its trend across Rwanda using climatic data measured at five sites. Equations were used to calculate ET using extra-terrestrial radiations, solar radiations, evapotranspiration using the FAO-56 guidelines - Turc method (1961) and Hargreaves-Samani (HS) method (1983). The obtained data from the weather stations were analyzed using the two methods and graphs were plotted for visualization. The average monthly reference evapotranspiration for both equations ranges from …

Gravel Liquefaction Assessment With The Dynamic Penetration Test At Non-Liquefaction Sites In Valdez, Alaska And L'Aquila, Italy, Nicholas James Linton

Theses and Dissertations

The development of a reliable, and cost-effective in-situ method for characterizing the liquefaction potential of gravelly soils is a considerable challenge for engineers and researchers. The ability to accurately characterize the liquefaction potential of gravelly soils is an important consideration at port facilities and dams for example. The Dynamic Penetration Test (DPT) provides a reliable and cost-effective method for evaluating the liquefaction resistance of gravelly soils. Probabilistic liquefaction triggering curves based on DPT field data have been developed from data collected at 47 sites in China. However, using the DPT-based liquefaction curves for locations outside of the Chengdu plain in …

Visible-To-Thermal Transfer Learning For Facial Landmark Detection, Domenick D. Poster, Shuowen Hu, Nathan J. Short, Benjamin S. Riggan, Nasser M. Nasrabadi

Department of Electrical and Computer Engineering: Faculty Publications

There has been increasing interest in face recognition in the thermal infrared spectrum. A critical step in this process is face landmark detection. However, landmark detection in the thermal spectrum presents a unique set of challenges compared to in the visible spectrum: inherently lower spatial resolution due to longer wavelength, differences in phenomenology, and limited availability of labeled thermal face imagery for algorithm development and training. Thermal infrared imaging does have the advantage of being able to passively acquire facial heat signatures without the need for active or ambient illumination in low light and nighttime environments. In such scenarios, thermal …

Intelligent Management Of Constrained Links For Distributed Autonomy, Troy R. Johnson, Nathan A. Jensen

Space Dynamics Laboratory Publications

This paper addresses one of the main underlying obstacles overlooked when adding autonomy to a cooperative cluster of nodes working together to complete global objectives. Whether these nodes are ground, sea, air, or space vehicles, a constrained link is used to distribute information between the vehicles. The limited bandwidth of the constrained link must be shared between all nodes and becomes a pinch point for distributed autonomy. Intelligently managing the shared information and controlling how it is replicated across all nodes is vital. Lack of communication results in poor team performance. Intermittent connectivity and delayed intelligence sharing leads to the …

Evaluation Of Vertical And Horizontal Wells For Utilization In Carbon Sequestration, Michael R. Bohnet

Honors Capstones

No abstract provided.

Heterogeneously Integrated Photonic Modulators And High-Volume Manufacturing Of Related Technologies, Nicholas Adam Boynton

Electrical and Computer Engineering ETDs

Silicon photonics is an attractive approach to cost-effective integrated optics due to the infrastructure established for silicon CMOS electronics. The material properties of silicon however are not ideal for optical devices. Specifically, silicon lacks the ability to easily produce light-emitting devices due to its indirect bandgap, and has a centro-symmetric crystal structure which does not facilitate the Pockels effect required for linear modulation. Conversely, lithium niobate is an excellent optical material due to its strong Pockels effect but, is a notoriously difficult material to process. One method of simultaneously overcoming the material limitations of silicon and the fabrication limitations of …

Mastering Uncoordinated Flight: Slips And Skids, Nihad E. Daidzic

Aviation Department Publications

FAA Safety Webinar (GL15103784) held online at 9:00 CST on Saturday, April 10, 2021.

Automated Scenario Generation Using Halton Sequences For The Verification Of Autonomous Vehicle Behavior In Simulation, Andrew Ferree

Doctoral Dissertations and Master's Theses

As autonomous vehicles continue to develop, verifying their safety remains a large hurdle to mass adoption. One component of this is testing, however it has been shown that it is impractical to statistically prove an autonomous vehicle’s safety using real-world testing alone. Therefore, simulation tools and other virtual testing methods are being employed to assist with the verification process. Testing in simulation still faces some of the challenges of the real world, such as the difficulty in exhaustively testing the system in all scenarios it will encounter. Manual scenario creation is time consuming and does not guarantee scenario coverage. Pseudo-random …

Centrifugally Spun Mats Based On Biopolyesters/Hydroxyapatite And Their Potential As Bone Scaffolds, Victoria M. Padilla-Gainza, Heriberto Rodríguez-Tobías, Graciela Morales, Eduardo Saucedo, Karen Lozano, Vanessa Montaño-Machado,, Diego Mantovani

Mechanical Engineering Faculty Publications

This work studied the potential of centrifugal spinning for the production of fibrous materials based on poly(D,L-lactic acid) (PDLLA) and poly(3-hydroxybutyrate) (PHB) with hydroxyapatite nanoparticles (n-Hap). The influence of n-Hap concentration (5, 10, and 15 wt.%) and spinneret angular speed on the final fiber morphology were analyzed. Further experimental evaluations were implemented to determine the effect of n-Hap on the thermal and mechanical performance. The optimum parameters that show a balance among high yield production of homogeneous fibers with the smallest fiber average diameter were found to be at 5 wt.% of n-Hap processed at 7000 rpm for PDLLA, and …

Machine Learning Meets Internet Of Things: From Theory To Practice, Bharath Sudharsan, Pankesh Patel

Publications

Standalone execution of problem-solving Artificial Intelligence (AI) on IoT devices produces a higher level of autonomy and privacy. This is because the sensitive user data collected by the devices need not be transmitted to the cloud for inference. The chipsets used to design IoT devices are resource-constrained due to their limited memory footprint, fewer computation cores, and low clock speeds. These limitations constrain one from deploying and executing complex problem-solving AI (usually an ML model) on IoT devices. Since there is a high potential for building intelligent IoT devices, in this tutorial, we teach researchers and developers; (i) How to …

Covid-19: Insights Into Virus-Receptor Interactions, Azadeh Sepahvandi, Maryann Ghaffari, Amir Hossein Bahmanpour, Fathollah Moztarzadeh, Payam Zarrintaj, Hasan Uludağ, Masoud Mozafari

Faculty Publications

The recent outbreak of Coronavirus Disease 2019 (COVID-19) calls for rapid mobilization of scientists to probe and explore solutions to this deadly disease. A limited understanding of the high transmissibility of SARS-CoV-2 (Severe acute respiratory syndrome coronavirus 2) relative to other coronavirus strains guides a deeper investigation into the virus/receptor interactions. The cutting-edge studies in thermodynamic and kinetic properties of interactions such as protein-protein interplays have been reviewed in many modeling and analysis studies. Highlighting the thermodynamic assessments of biological interactions and emphasizing the boosted transmissibility of SARS-CoV-2 despite its high similarity in structure and sequence with other coronavirus strains …

Application Of A Self-Disinfecting Surface For Hemodialysis, Katie Christensen, Sierra Flores, Ivy Hansen, Cody Paraso, Andrea Peterson

Biological Engineering

The Biological Engineering Department at Utah State University (USU) is collaborating with Fresenius Medical Care (FMC) to develop a novel method of bacterial reduction for hemodialysis systems.

In the United States, approximately 34% of reported hemodialysis hospitalizations have been due to infections [1]. The water inlet line was identified as an area with potential to introduce bacteria into the system.

Nutrient Management: Heterotrophic Nitrification, Zac Mcclellan, Jaden Storrer, Anna Scribner, Jayce Bradley

Biological Engineering

The removal of nitrogen in the form of ammonia from wastewater is an important yet expensive step in treatment often done in two stages, typically by different autotrophic nitrifiers:

- Nitrification: Ammonia is converted to Nitrite and Nitrate.

- Denitrification: Nitrate is converted to nitrogen gas (N2)

Heterotrophic nitrifiers like Alcaligenes faecalis are able to perform both processes and reduce the two step treatment process to one.

Previously, experiments were performed on Alcaligenes faecalis in a synthetic wastewater environment to determine the kinetic constants for a substrate-dependent ammonia removal rate (Michaelis Mentin Kinetics).

Changing The Process In Educational Field And Air Navigation Through Advances In Hologram Technology, Camilo Fernandez Sr.

Journal of Aviation Technology and Engineering

The objective of this piece is to propose reasons that change the way air traffic controllers and others learn and work in air navigation, but also how they can improve workloads, due to the implementation of holographic radar. This research also aims to describe how this could reduce the cognitive load of an operator, thanks to the improvement of visual perspective and capacity of analysis, in order to more easily control an aircraft.

Seeing that the visual facilitation is well known, radar is able to represent in three dimensions and in detail that which could not previously be perceived. This …

Design Of Rotorcraft Performance-Based Navigation Routes And Procedures: Current Challenges And Prospects, Carlos Gonzaga Lopez

Journal of Aviation Technology and Engineering

Helicopters play a relevant role in society due to their extraordinary versatility. However, they are particularly vulnerable to adverse weather conditions as the majority of operations are carried out under visual flight rules. This is partly due to the shortage of tailored helicopter instrument flight procedures and routes. The emergence of the performance-based navigation concept supported by the latest satellite navigation technologies has opened up new possibilities for rotorcraft operations in the last few years. This paper presents an extensive overview of the state of the art in the design of performance-based navigation routes for helicopters from two main standpoints: …

Combined Trajectory, Propulsion And Battery Mass Optimization For Solar-Regenerative High-Altitude Long-Endurance Aircraft, Nathaniel Spencer Gates

Theses and Dissertations

This thesis presents the work of two significant projects. In the first project, a suite of benchmark problems for grid energy management are presented which demonstrate several issues characteristic to the dynamic optimization of these systems. These benchmark problems include load following, cogeneration, tri-generation, and energy storage, and each one assumes perfect foresight of the entire time horizon. The Gekko Python package for dynamic optimization is introduced and two different solution methods are discussed and applied to solving these benchmarks. The simultaneous solve mode out-performs the sequential solve mode in each benchmark problem across a wide range of time horizons …

Effect Of Defects Part Ii: Multiscale Effect Of Microvoids, Orientation Of Rivet Holes On The Damage Propagation, And Ultimate Failure Strength Of Composites, Vahid Tavaf, Mohammadsadegh Saadatzi, Sourav Banerjee

Faculty Publications

Material properties at the vicinity of the cut-outs in composites are not entirely defect-free. The nteraction of multiple cutouts like rivet holes, the repercussion of their configuration on crack propagation, and ultimate strength were predicted using Peridynamic method and the results are reported in this article. The effect of microscale defects at the vicinity of the cutouts on macroscale damage propagation were shown to have quantifiable manifestation. This study focused on two to four holes in unidirectional composite plates with 0°, 45°, and 90° fiber directions, while the vicinity of a hole was considered degraded. Numerical results were validated using …

Identification Of Active Surface Species In Molten Carbonates Using In Situ Raman Spectroscopy, Peng Zhang, Tao Wu, Kevin Huang

Faculty Publications

Here we report the results of a study on active surface species of a pristine and modified (Li-Na)₂CO₃ eutectic using in situ Raman spectroscopy technique. The effects of gas compositions, temperature, time, and alkaline earth have been systematically studied. The species of CO₄^2–, HCO₄^–, and C₂O₅^2– are identified as the three major active species on the surface of (Li-Na)₂CO₃ eutectic by a combined Raman spectroscopy and theoretical density functional theory calculations. The results further reveal that CO₄^2–, HCO₄^–, …

Investigation Of Coo Ato For Solar Cells And Infrared Sheaths, Manopriya Devisetty Subramanyam

USF Tampa Graduate Theses and Dissertations

Solar as an energy source is expected to grow fastest from now to 2050. Increasing the efficiency is usually achieved by increasing the short circuit current density (JSC) and/or the fill factor. Improving the efficiency of solar cells will be an ongoing effort.Structurally solar technologies can be classified into two types, wafer-based and thin-film-based. Wafer solar cells have been used in this study. The anti-reflective layer on top of solar cells has been fabricated by a process called electrospinning to tune the solar cells' top surface with the desired thickness and dimensions of the nanofibers. The nanofibers' dimensions, shape, and …

A Systematic Review Of Urban Navigation Systems For Visually Impaired People, Fatmaelzahraa Eltaher Ph.D, Ayman Taha, Jane Courtney, Susan Mckeever

Articles

Blind and Visually impaired people (BVIP) face a range of practical difficulties when undertaking outdoor journeys as pedestrians. Over the past decade, a variety of assistive devices have been researched and developed to help BVIP navigate more safely and independently. In~addition, research in overlapping domains are addressing the problem of automatic environment interpretation using computer vision and machine learning, particularly deep learning, approaches. Our aim in this article is to present a comprehensive review of research directly in, or relevant to, assistive outdoor navigation for BVIP. We breakdown the navigation area into a series of navigation phases and tasks. We …

A Flexible Piezoelectric Energy Harvester-Based Single-Layer Ws2 Nanometer 2d Material For Self-Powered Sensors, Quan Wang, Kyung-Bum Kim, Sang Bum Woo, Yooseob Song, Tae Hyun Sung

Civil Engineering Faculty Publications

A piezoelectric sensor is a typical self-powered sensor. With the advantages of a high sensitivity, high frequency band, high signal-to-noise ratio, simple structure, light weight, and reliable operation, it has gradually been applied to the field of smart wearable devices. Here, we first report a flexible piezoelectric sensor (FPS) based on tungsten disulfide (WS₂) monolayers that generate electricity when subjected to human movement. The generator maximum voltage was 2.26 V, and the produced energy was 55.45 μJ of the electrical charge on the capacitor (capacity: 220 μF) when applying periodic pressing by 13 kg. The generator demonstrated here …

Fundamental Dislocation Solutions For Infinite And Semi-Infinite Media, Luo Li Mr

Mechanical Engineering ETDs

Much research has gone into determining stress fields of dislocation, as the understanding of dislocations is fundamental to understanding metal or crystal plasticity. In this thesis, the stress field of a rectangular dislocation loop in an infinite isotropic solid is developed for a Volterra-type dislocation with three non-zero Burgers vector components. Also, the stress and strain fields of a rectangular dislocation loop in an isotropic solid, which is a semi-infinite medium, are obtained here for a Volterra-type dislocation. Moreover, analytical and numerical verifications of the developed stress/strain fields are performed. This is done by ensuring the satisfaction of the equilibrium …

Solid–Liquid Interface Temperature Measurement Of Evaporating Droplet Using Thermoresponsive Polymer Aqueous Solution, Hyung Ju Lee, Chan Ho Jeong, Dae Yun Kim, Chang Kyoung Choi, Seong Hyuk Lee

Michigan Tech Publications, Part 1

The present study aims to measure the solid–liquid interface temperature of an evaporating droplet on a heated surface using a thermoresponsive polymer. Poly(N-isopropylacrylamide) (pNIPAM) was used owing to its sensitive optical and mechanical properties to the temperature. We also measured the refractive index variation of the pNIPAM solution by using the surface plasmon resonance imaging (SPRi). In particular, the present study proposed a new method to measure the solid–liquid interface temperature using the correlation among reflectance, refractive index, and temperature. It was found that the reflectance of a pNIPAM solution decreased after the droplet deposition. The solid–liquid interface temperature, estimated …

Autonomous Shock Sensing Using Bi-Stable Triboelectric Generators And Mems Electrostatic Levitation Actuators, Mohammad Mousavi, Mohammad Alzgool, Shahrzad Towfighian

Mechanical Engineering Faculty Scholarship

This work presents an automatic threshold shock-sensing trigger system that consists of a bi-stable triboelectric transducer and a levitation-based electrostatic mechanism. The bi-stable mechanism is sensitive to mechanical shocks and releases impact energy when the shock is strong enough. A triboelectric generator produces voltage when it receives a mechanical shock. The voltage is proportional to the mechanical shock. When the voltage exceed a certain level, the initially pulled-in Microelectromechanical system (MEMS) switch is opened and can disconnect the current in a safety electronic system. The MEMS switch combines two mechanisms of gap-closing (parallel-plate electrodes) with electrostatic levitation (side electrodes) to …

Evaluation Of Permanent Concrete Barriers To Mash 2016, Samuel Elias Hovde

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

The objective of this research project was to develop evaluation criteria for permanent concrete barriers to MASH 2016 TL-3 and TL-4 without crash testing and then to evaluate permanent concrete barrier standards provided by the sponsoring agencies of the Midwest Pooled Fund Program. A literature review was conducted to determine evaluation criteria for stability, shape, strength, and anchorage, and a database of permanent concrete barrier crash tests was compiled. A survey was conducted to collect barrier standards from the members of the Midwest Pooled Fund Program, and barriers were selected and evaluated according to the determined methodology. A total of …