Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

2023

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 6661 - 6690 of 9778

Full-Text Articles in Engineering

Development Of Novel Turbomachinery Manufacturing Methods, Timothy P. Winkler Mar 2023

Development Of Novel Turbomachinery Manufacturing Methods, Timothy P. Winkler

Theses and Dissertations

Compact turbine engines are of increasing interest as a means of propulsion for small, lightweight, low cost, unmanned aerial systems. This study looks to leverage advancements in novel manufacturing technology to produce turbomachinery components while simultaneously reducing costs and manufacturing time. To determine the feasibility of drop-in replacements for stock components this study focused on several research areas. This included materials research on both polymer-reinforced and ceramic materials, specimen tensile testing to determine temperature-dependent material properties, finite element analysis of multiple candidate materials, design and fabrication of a spin test rig, and physical spin testing of manufactured components to predict …


Designing And Evaluating A Smartphone App To Increase Underserved Communities’ Data Representation In Transportation Policy And Planning, Courtney Cronley, Anna O'Dell, Noelle Fields, Stephen P. Mattingly, Nicole Iroz-Elardo, M. Christine Highfill, Rebecca Cole, Mary Kris Stringfellow Mar 2023

Designing And Evaluating A Smartphone App To Increase Underserved Communities’ Data Representation In Transportation Policy And Planning, Courtney Cronley, Anna O'Dell, Noelle Fields, Stephen P. Mattingly, Nicole Iroz-Elardo, M. Christine Highfill, Rebecca Cole, Mary Kris Stringfellow

School of Social Work Faculty Publications

The current global focus on transportation equity, as well as a move towards smart mobility, highlights the need for more representative transportation data to inform transportation planning. In this case study, an interdisciplinary research team describes the process of refining and evaluating the utility of a transportation daily diary mobile-phone-based app. The process is framed through transportation equity and diverse key stakeholder engagement. The team custom-designed the app, MyAmble, to capture successful transportation behaviors, as well as latent demand, defined as travel not taken but desired, among underserved populations. Stakeholder focus groups with subject matter expert (n = …


Fire Life Safety Design Of Technology Office, Jared Ellis Mar 2023

Fire Life Safety Design Of Technology Office, Jared Ellis

Fire Protection Engineering: Culminating Experience Project Reports

The subject building is an approximately 180,000 SF technology office; the location and some details are omitted for privacy of the project and client. It is a 3-story heavy timber frame (Type IIIA) over 1 level of concrete basement stepped into a hillside.

The building is compliant with the prescriptive building code for egress, fire alarm, and fire sprinkler systems. A NFPA 72 compliant fire detection, notification and communication system is provided. The building is fully sprinklered with a system that is hydraulically designed per NFPA 13, 2016 Section 11.2.3 Water Demand Requirements – Hydraulic Calculation Methods. Water supply is …


Mechanical Metamaterials, Brent A. Peluso, Oliver T. Parker Mar 2023

Mechanical Metamaterials, Brent A. Peluso, Oliver T. Parker

Mechanical Engineering

Mechanical metamaterials are an emerging design strategy aimed at tailoring lattice structures to achieve specific properties such as negative Poisson’s ratios and guiding wave propagation. These metamaterials have received increasing attention from various application domains, including medical devices, aerospace, automobile, and infrastructure. The scope of this project is to vary a single lattice parameter and quantify its effect on the structural properties of the given 3D lattice.


Planar Element Alignment System, Benjamin E. Lavigna, Benny F. Cruz, Samuel Gierhan, Jacob Q. Henriksen Mar 2023

Planar Element Alignment System, Benjamin E. Lavigna, Benny F. Cruz, Samuel Gierhan, Jacob Q. Henriksen

Mechanical Engineering

Precise alignment to the micron level is a necessity for microfluidic/micromechanical devices to function as designed. Because of this, a micro-alignment device was commissioned by Professor Hans Mayer on behalf of the Cal Poly Microfluidics Laboratory. Prototype creation was bounded by a set of requirements including, ability to align PDMS & Silicon wafer halves to ± 10 microns, total process speed of three minutes, and total budget of $3000. Some major design hurdles included an ability to verify alignment, possible non-planar alignment pieces, and an inability to contact any point on the face of the alignment pieces after bonding treatment. …


Validation Of Bottom-Up Gnss Radio Occultation Method To Measure D- And E-Region Electron Density, Dylan J. Shaver Mar 2023

Validation Of Bottom-Up Gnss Radio Occultation Method To Measure D- And E-Region Electron Density, Dylan J. Shaver

Theses and Dissertations

An in-depth validation of a new bottom-up approach using GNSS Radio Occultation (GNSS-RO) data to generate electron density profiles in the D- and E-region ionosphere. This comparison was completed using daytime ionosonde profiles when sporadic-E (Es) was not present, and corresponding FIRI profiles. The average GNSS-RO profile is a few kilometers higher in altitude than the ionosonde profiles at the minimum frequency, f min. When the ionosonde profiles are shifted so that the altitudes match at f min, they are in good agreement up to the E-region peak altitude, hmE. Below f min, the …


Simulation Of Neutron Generation From Laser-Driven Fusion In A Liquid D2o Sheet Using Novel Warpx Module, Colton R. Stoner Mar 2023

Simulation Of Neutron Generation From Laser-Driven Fusion In A Liquid D2o Sheet Using Novel Warpx Module, Colton R. Stoner

Theses and Dissertations

Using WarpX’s new nuclear fusion module, this work attempts to model an experimental system at the ELL at the AFIT with WarpX and draw conclusions about fusion products from resulting simulations. Recently, a table-top, high repetition rate, mixed radiation source was demonstrated at the ELL employing a HIL to fuse the deuterium nuclei present in a unique liquid target of heavy water. Analysis of the simulations predicted an isotropic output of neutrons from deuterium-deuterium fusion. These simulated neutrons were created in tens of femtoseconds from dense bodies of deuterons that were perturbed by the laser. However, it was found that …


Automated Additive Layering Of Vat Polymerized Plastic Organic Scintillators, Chandler J. Moore Mar 2023

Automated Additive Layering Of Vat Polymerized Plastic Organic Scintillators, Chandler J. Moore

Theses and Dissertations

The current technology for fast neutron detection imaging is limited in achieving the required high spatial resolution, strong neutron discrimination, and practical time of manufacturing. Traditional fabrication methods require days of thermal polymerization and hundreds of man-hours to produce average resolution pixelated scintillator arrays. The present work helps to eliminate this limitation by developing an additive manufacturing technique to construct such detectors for use in in dual particle imaging applications. In this work, fast-, light-curing resins are used in a prototype automated assembly machine, capable of layering of individual light-cured resin layers and optical segmentation with a self-bonded specular reflector, …


Pulsed Power Neutron Production With Deuterated Polymer Accelerator Targets, Anthony O. Hagey Mar 2023

Pulsed Power Neutron Production With Deuterated Polymer Accelerator Targets, Anthony O. Hagey

Theses and Dissertations

This document presents an investigation of the effect of deuterated polyethylene accelerator targets on the neutron fluence from a local mass injection dense plasma focus driven by the United States Naval Research Laboratory’s Hawk pulsed-power generator. After successful production of thin targets, the acquisition of thicker targets, and testing inside Hawk, it was found that the presence of a deuterated polyethylene target increased the neutron fluence. Results suggested that fluence can significantly increase with the presence of a deuterated target vs a nondeuterated target. Additive manufacturing printing was used as a production method in order to determine if deuterated accelerator …


Fabrication And Testing Of A Novel Layered Metascintillator For Neutron And Gamma Discrimination, Evan W. Threlkeld Mar 2023

Fabrication And Testing Of A Novel Layered Metascintillator For Neutron And Gamma Discrimination, Evan W. Threlkeld

Theses and Dissertations

By leveraging new developments in fast-curing of plastic scintillators, it is possible to fabricate multi-material plastic scintillators, or metascintillators, which offer improved and/or novel capabilities for radiation detection. This document proposes one geometry of metascintillator that uses layers of green and blue scintillating material to discriminate neutron/gamma radiation, details the devices necessary to fabricate it, and analyzes the metascintillator’s response to radiation. A model of the metascintillator using Geant4 and Python suggested that spectral-based neutron/gamma event discrimination is possible with 63% of gamma events and only 1% of neutron events being multi-color. Fabrication of a 500 µm per layer metascintillator …


The Electromagnetic Bayonet: Development Of A Scientific Computing Method For Aperture Antenna Optimization, Michael P. Ingold Mar 2023

The Electromagnetic Bayonet: Development Of A Scientific Computing Method For Aperture Antenna Optimization, Michael P. Ingold

Theses and Dissertations

The quiet zone of a radar range is the region over which a transmitted EM field approximates a uniform plane wave to within some finite error tolerance. Any target to be measured must physically fit within this quiet zone to prevent excess measurement error. Compact radar ranges offer significant operational advantages for performing RCS measurements but their quiet zone sizes are constrained by space limitations. In this work, a scientific computing approach is used to investigate whether equivalent-current transmitters can be designed that generate larger quiet zones than a conventional version at short range. A time-domain near-field solver, JefimenkoModels, was …


Belief Space Planning For Alternative Navigation In Gnss-Denied Environments, Timothy I. Machin Mar 2023

Belief Space Planning For Alternative Navigation In Gnss-Denied Environments, Timothy I. Machin

Theses and Dissertations

Robust alternative navigation for autonomous agents becomes critical without reliable GNSS. Autonomous agents utilize measurement updates to constrain uncertainty. Belief space planning builds graph structures of beliefs within environments based on probable paths, agent and measurement models, and information of the environment. The Rapidly-exploring Random Alt-Nav Belief Graph (RRBANG) algorithm leverages stochastic filtering to implement a range of alt-nav measurement capabilities for robust navigation in GNSS-denied environments.


Magnetic Anomaly Mapping For Navigation, Luke T. Bergeron Mar 2023

Magnetic Anomaly Mapping For Navigation, Luke T. Bergeron

Theses and Dissertations

Magnetic navigation (MagNav) has the potential to provide a global form of navigation that uses magnetic measurements of the Earth’s anomaly magnetic field and compares those measurements to a magnetic anomaly map in order to determine the user’s position. Widespread use of MagNav will require a database of fully-sampled, low-altitude magnetic anomaly maps. Existing magnetic anomaly map databases usually come from under- or poorly-sampled surveys. In this work, we provide an easy to follow MagNav anomaly map generation framework and set of survey collection metrics/requirements in an effort to help facilitate and standardize the creation of such a database. We …


Detection And Identification Of Covert Devices Using Infrared And Stacked Optics Detection, Michael A. Reyneke Mar 2023

Detection And Identification Of Covert Devices Using Infrared And Stacked Optics Detection, Michael A. Reyneke

Theses and Dissertations

This work investigates stacked optics detection methodologies to successfully detect and identify observational systems with a cyber-physical sensing tool, ODIN (Observational Device Identification Network). ODIN successfully detected the presence of stacked optics and LiDAR systems using night-vision devices with a 96.32% average accuracy rating, both overt and covertly placed, with objective lens diameters ranging from 17 mm to 50 mm at distances between 1 m to 5 m with and without commonly employed anti-reflective countermeasures. ODIN provides a foundation for counter- measure capabilities of NIR devices and stacked optical systems in stationary environments. Additionally, a pilot study on smartphone LiDAR …


Topological Variability In Water Distribution Networks, James M. Anderson Mar 2023

Topological Variability In Water Distribution Networks, James M. Anderson

Theses and Dissertations

Water distribution networks are critical infrastructure characterized by difficulties in their assessment and deteriorating performance due to aging components. Resilience analysis of networked infrastructure has replaced traditional risk analysis to focus on performance. Global Resilience Analysis can provide useful information to decision makers and system managers regarding repair and expansion of networks. Network performance has been found to be directly informed by network structure. This work leverages graph theory to assess network qualities that correlate with resiliency characteristics across 69 real world water networks. These networks are then grouped by their structural properties through k-means clustering and compared using parametric …


Investigation Of Possible Alternatives To Fossil Fuels For The Dod In Indopacom, Terrence W. Caploe Mar 2023

Investigation Of Possible Alternatives To Fossil Fuels For The Dod In Indopacom, Terrence W. Caploe

Theses and Dissertations

Energy security, greenhouse gas (GHG) emissions, and geopolitical concerns in the south pacific require diversification and independence from legacy energy sources in the Indo-Pacific Combatant Command (INDOPACOM) area of operation (AO). The United States Government has placed mandates and directives to minimize the impacts of GHG on the climate. These orders require divestment from GHG producing fuel sources by 2050. This study compares the energy alternates to Jet Propulsion 8 (JP8) as Ammonia, Hydrogen, and Lithium-ion Batteries. The study uses Life Cycle Assessment (LCA) tools to determine the environmental impacts of various energy candidates in the South Pacific. These results …


The Kinetics Of Biocontaminant Inactivation: A Comparative Study With Bacillus Globigii And Bacillus Anthracis, Leigh M. Durden Mar 2023

The Kinetics Of Biocontaminant Inactivation: A Comparative Study With Bacillus Globigii And Bacillus Anthracis, Leigh M. Durden

Theses and Dissertations

Bacillus anthracis has been a biological threat for decades and after the 2001 terrorist attack via the U.S. Postal Service where five people died, there was heightened awareness and inquiry on the subject (Goel, 2015; Greenberg et al., 2010; Nicholson & Galeano, 2003; Spotts Whitney et al., 2003). The health risk to humans makes this biological agent, a Tier 1 agent and one of the most likely to be used in an attack (Anthrax as a Bioterrorism Weapon | CDC, n.d.; Driks, 2009; Rose & Rice, 2014). B. anthracis is one of most resistant and potent biological warfare agents as …


Civilian And Military Civil Engineer Mission In The Space Domain, Linda E. Kuster Mar 2023

Civilian And Military Civil Engineer Mission In The Space Domain, Linda E. Kuster

Theses and Dissertations

Military and civil interest in space-based operations has increased dramatically in recent years due to the discovery of life sustaining properties such as water on Mars and advancements in cyber technology. Civilian sector discussions and research have centered on the establishment of permanent extraterrestrial infrastructure, while discussions from the military perspective have focused on providing reliable, resilient infrastructure, capable of withstanding cyber-based and kinetic attacks. Both perspectives account for known threats and sustainment methods required to ensure success in the space domain. With the existence of threats for the military and civilian missions, civil engineers will undoubtedly be critical to …


Illuminating The Unknown: A Mixed Methods Exploration Of The Dod Software Factory Ecosystem, Zachary O. Ryan Mar 2023

Illuminating The Unknown: A Mixed Methods Exploration Of The Dod Software Factory Ecosystem, Zachary O. Ryan

Theses and Dissertations

The Department of Defense’s (DoD) software factories are a collection of modern software acquisition programs that commonly employ the agile, network-based business strategies often found within commercial industries. Having been formally recognized by senior leaders for their revolutionary software development approaches, the software factories highlight a cultural shift within the DoD away from traditional organizational practices. As a result of the factories demonstrated successes, the number of programs employing non-traditional strategies is expanding. While this is notable, it also presents a challenge because a comprehensive understanding of the characteristics, structures, and behaviors of the DoD’s software factories does not currently …


Cost Estimating Relationships For Recurring T100 Flyaway Costs, Kyrie M. Rojo Mar 2023

Cost Estimating Relationships For Recurring T100 Flyaway Costs, Kyrie M. Rojo

Theses and Dissertations

This research investigates a dataset of over 80 Air Force and Navy aircraft and applies regression techniques to create two cost estimating relationships (CERs) for predicting recurring T100 flyaway costs, depending on where in the acquisition lifecycle the estimate takes place. The first CER explains 89 percent of the variation in the dataset and can be applied prior to Milestone B (MS B). The second CER explains 88 percent of the variation in the dataset and can be applied between MS B and MS C. Significant cost drivers identified include stealth, cohort, empty weight, the natural log of speed, legacy …


Net Zero Water Air Force Installations, Kenneth R. Mcknight Mar 2023

Net Zero Water Air Force Installations, Kenneth R. Mcknight

Theses and Dissertations

The United States continues to face problems of a reduction in quality and quantity of groundwater sources because water extraction exceeds natural source recharge. The Air Force has recognized the importance of these groundwater sources but has put minimal effort into determining their contribution to the depletion of these sources. The purpose of this study is to determine this contribution by determining whether Air Force installations are net zero water. This is done using a geospatial information system to determine the volume of water recharging groundwater sources associated with an Air Force installation. This volume is then compared to the …


Defense Industrial Base Mergers And Acquisitions In The Post-Cold War Era, Corey D. Mack Mar 2023

Defense Industrial Base Mergers And Acquisitions In The Post-Cold War Era, Corey D. Mack

Theses and Dissertations

The United States Department of Defense (DoD) relies on prime contractors for weapon system development, acquisition, and sustainability, but the increased consolidation of the Defense Industrial Base (DIB) through mergers and acquisitions (M&A) has raised concerns over reduced competition. This research consists of two studies. The first reviews existing literature to identify factors behind the DIB's increased M&A activity since the 1990s, such as DoD budget cuts and market structure. The second study examines the relationship between a prime contractor's financial health and M&A spending, finding a significant relationship between efficiency and M&A spending. Policymakers can use this information to …


Prediction Of Persistent Post-Traumatic Headache With Long Short-Term Memory Networks, Todd C. Campo Mar 2023

Prediction Of Persistent Post-Traumatic Headache With Long Short-Term Memory Networks, Todd C. Campo

Theses and Dissertations

Military members in combat situations are at a high risk for experiencing a Traumatic Brain Injury (TBI), often leaving them with Post-Traumatic Headache (PTH). There is currently a poor understanding of what factors predict if a patient will endure acute (short-term) PTH or Persistent PTH (PPTH). The Concussion Assessment, Research, and Education (CARE) Consortium dataset contains a variety of pre-and-post-injury concussion assessments taken by NCAA athletes and service academy cadets between 2014 and 2018. Participants in this study (n = 1769) suffered a TBI. Using this longitudinal data, three models were constructed: an LSTM model using the raw assessment scores, …


Improved Object Re-Identification Via More Efficient Embeddings, Ertugrul Bayraktar Mar 2023

Improved Object Re-Identification Via More Efficient Embeddings, Ertugrul Bayraktar

Turkish Journal of Electrical Engineering and Computer Sciences

Object reidentification (ReID) in cluttered rigid scenes is a challenging problem especially when same-looking objects coexist in the scene. ReID is accepted to be one of the most powerful tools for matching the correct identities to each individual object when issues such as occlusion, missed detections, multiple same-looking objects coexisting in the same scene, and disappearance of objects from the view and/or revisiting the same region arise. We propose a novel framework towards more efficient object ReID, improved object reidentification (IO-ReID), to perform object ReID in challenging scenes with real-time processing in mind. The proposed approach achieves distinctive and efficient …


Using Switchable Solvents For Enhanced Biodiesel Production, Eyad Abdel Rahman Sowan Mar 2023

Using Switchable Solvents For Enhanced Biodiesel Production, Eyad Abdel Rahman Sowan

Theses

This thesis presents a sustainable approach to biodiesel production using in-situ technology for direct conversion of microalgae-to-biodiesel. The proposed method operates on wet, untreated microalgae, thereby eliminating the cost/energy intensive drying and cell disruption steps. Owing to their favorable properties, the use of enzymes, specifically lipase, as a catalyst for the process was suggested over acid/base catalysts. However, the high cost of the enzyme necessitates its reuse at sustained activity for the process to be economically feasible. The use of non-toxic green solvents, such as switchable solvents, as an alternative to conventional organic solvents was a significant challenge for the …


A Modified Space Vector Modulation Based Rotor Flux Oriented Control Of Six-Phase Asymmetrical Induction Motor Drive, Krunal Shah, Rakesh Maurya Mar 2023

A Modified Space Vector Modulation Based Rotor Flux Oriented Control Of Six-Phase Asymmetrical Induction Motor Drive, Krunal Shah, Rakesh Maurya

Turkish Journal of Electrical Engineering and Computer Sciences

In view of the attractive features like improved torque density, reduction torque pulsation, superior fault tolerance, reduced power rating of voltage source converter, and sterling noise characteristics of six-phase asymmetrical induction motor (SPAIM) as compared to its three-phase counterpart, the SPAIM is considered for the study. In this paper, mathematical modelling of SPAIM is carried out in the synchronous reference frame and then indirect rotor field-oriented control (IRFOC) of SPAIM using a modified carrier wave-based space vector modulation (SVM) scheme is developed. A Simulink model of the proposed system configuration is developed and a simulation study is carried out. In …


A New Generation Of Dense-Graded Asphalt Mixtures With Superior Performance Against Stripping And Moisture Damage, Mostafa Elseifi, Zahid Hossain, Md. T.A. Sarkar, Hossam Abohamer, Mohammad Oyan Mar 2023

A New Generation Of Dense-Graded Asphalt Mixtures With Superior Performance Against Stripping And Moisture Damage, Mostafa Elseifi, Zahid Hossain, Md. T.A. Sarkar, Hossam Abohamer, Mohammad Oyan

Publications

The presence of moisture beneath the pavement surface is a matter of great concerns as it is responsible for significant distresses such as asphalt concrete (AC) stripping, fatigue cracking, rutting, and poor durability of asphalt mixes. The objective of this study was to evaluate and recommend an asphalt mixture design that would provide superior performance against AC stripping and cracking. To achieve this objective, a laboratory test factorial was developed to evaluate the use of nanomaterials, emerging anti-stripping agents, warm-mix asphalt technologies, and adhesion promotors. In the experimental program, the modified Lottman test (AASHTO T 283) and the Indirect Tensile …


Machine Learning Techniques For Stock Price Prediction And Graphic Signal Recognition, Junde Chen, Yuxin Wen, Y. A. Nanehkaran, M. D. Suzauddola, Weirong Chen, Defu Zhang Mar 2023

Machine Learning Techniques For Stock Price Prediction And Graphic Signal Recognition, Junde Chen, Yuxin Wen, Y. A. Nanehkaran, M. D. Suzauddola, Weirong Chen, Defu Zhang

Engineering Faculty Articles and Research

Stock market analysis is extremely important for investors because knowing the future trend and grasping the changing characteristics of stock prices will decrease the risk of investing capital for profit. Thereupon, the prediction of stock prices and identifying the graphic signals of candlestick charts, which are two crucial tasks in stock price analysis, attract much attention from investors owing to the returns and risks that coexist in financial markets. To introduce a reliable approach for addressing these challenges, this paper proposes the modeling strategies based on machine learning (ML) techniques. A vector autoregression (VAR)-based rolling prediction model is proposed for …


Quantum Algorithm For Mining Frequent Patterns For Association Rule Mining, Abdirahman Alasow, Marek Perkowski Mar 2023

Quantum Algorithm For Mining Frequent Patterns For Association Rule Mining, Abdirahman Alasow, Marek Perkowski

Electrical and Computer Engineering Faculty Publications and Presentations

Maximum frequent pattern generation from a large database of transactions and items for association rule mining is an important research topic in data mining. Association rule mining aims to discover interesting correlations, frequent patterns, associations, or causal structures between items hidden in a large database. By exploiting quantum computing, we propose an efficient quantum search algorithm design to discover the maximum frequent patterns. We modified Grover’s search algorithm so that a subspace of arbitrary symmetric states is used instead of the whole search space. We presented a novel quantum oracle design that employs a quantum counter to count the maximum …


Exploring Narratives Of Researcher Development For Student Researchers Abroad, Kirsten A. Davis, Teirra Holloman, Jessica Deters, David B. Knight Mar 2023

Exploring Narratives Of Researcher Development For Student Researchers Abroad, Kirsten A. Davis, Teirra Holloman, Jessica Deters, David B. Knight

School of Engineering Education Faculty Publications

Background: Research experiences for undergraduate and graduate students have the potential to provide significant learning experiences, but most research of these experiences focuses primarily on their outcomes. To better design such experiences for a diverse range of students, it is important to understand student narratives of researcher development and identify significant experiences in their development as researchers.

Purpose: In this study, we explored narratives of researcher development for seven US civil engineering students in an eight-week research experience in Australia. Through these narratives, we sought to identify categories of significant experiences to characterize the early stage of the researcher development …