Engineering Commons^™

Particle Migration In Large Cross-Section Ceramic On-Demand Extrusion Components, Austin J. Martin, Wenbin Li, Jeremy Lee Watts, Gregory E. Hilmas, Ming-Chuan Leu, Tieshu Huang

Materials Science and Engineering Faculty Research & Creative Works

Ceramic On-Demand Extrusion (CODE) is a direct ink writing process which allows for the creation of near theoretically dense ceramic components with large cross-sections due to oil-assisted drying. Yttria-stabilized zirconia (YSZ) colloidal pastes (∼d50 ≲ 1 µm) were used in CODE to produce dense (multi-road infill and ≳ 98% relative density), large continuous volume (> 1 cm3), and high fidelity (nozzle diameters ≲ 1 mm) structural ceramic components. However, many of these printed components underwent significant particle migration after forming. The reason for this particle migration defect was investigated using the coffee-ring effect for dilute solutions and rheological methods for …

Growing Grounds Farm, Santa Maria - Greenhouse Planter Bench Tables, Joseph Miller

Construction Management

This paper covers the planning, fundraising, design, construction, and installation associated with building the Growing Grounds Farm of Santa Maria greenhouse planter bench tables. Growing Grounds prides itself on nourishing the local community through a combination of horticulture therapy, and vocational training for individuals with severe and persistent mental illness. The farm offers various opportunities for socialization and interaction with coworkers and customers. After meeting with the farm managers, Anna Wiens and Keith Bartlett, it was clear that this project was of the highest priority. Upon agreement of the project, the farm managers and I determined the future vision and …

Urban Densification At Twin Creeks Apartments: High-Density Living With Low-Density Luxuries, Ryan Griswold

Construction Management

Urban sprawl is characterized by the rapid growth of the extent of cities and towns. In the United States, urban sprawl is greatly influenced by housing density. In the past half-century, developers have favored constructing and consumers have preferred living in neighborhoods of detached, single-family homes. This is because low-density living provides more housing services, or additional benefits, than most high-density developments, such as apartments and townhomes. Residents of low-density living often have more privacy, outdoor space, interior natural light, and many other benefits over residents of higher-density developments. However, Twin Creeks Apartments, located in San Luis Obispo, California, is …

Decomposition Of The Skin-Friction Coefficient Of Compressible Boundary Layers, Dongdong Xu, Pierre Ricco, Lian Duan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

We derive an integral formula for the skin-friction coefficient of compressible boundary layers by extending the formula of Elnahhas and Johnson ["On the enhancement of boundary layer skin friction by turbulence: An angular momentum approach, "J. Fluid Mech. 940, A36 (2022)] for incompressible boundary layers. The skin-friction coefficient is decomposed into the sum of the contributions of the laminar coefficient, the change of the dynamic viscosity with the temperature, the Favre-Reynolds stresses, and the mean flow. This decomposition is applied to numerical data for laminar and turbulent boundary layers, and the role of each term on the wall-shear stress is …

Development Of Fibroblast/Endothelial Cell-Seeded Collagen Scaffolds For In Vitro Prevascularization, Daniela S. Masson-Meyers, Fahimeh Tabatabaei, Lane Steinhaus, Jeffrey M. Toth, Lobat Tayebi

Biomedical Engineering Faculty Research and Publications

The development of vascularized scaffolds remains one of the major challenges in tissue engineering, and co-culturing with endothelial cells is known as one of the possible approaches for this purpose. In this approach, optimization of cell culture conditions, scaffolds, and fabrication techniques is needed to develop tissue equivalents that will enable in vitro formation of a capillary network. Prevascularized equivalents will be more physiologically comparable to the native tissues and potentially prevent insufficient vascularization after implantation. This study aimed to culture human umbilical vein endothelial cells (HUVECs), alone or in co-culture with fibroblasts, on collagen scaffolds prepared by simple fabrication …

Future Of Augmented And Virtual Reality In Construction, Cameron Ghoddoucy

Construction Management

A series of virtual design contractors were interviewed regarding the future involvement of augmented and virtual reality software integration with construction processes. Within the construction industry, VDC specialists rely on Building Information Modeling (BIM) and Computer Aided Design (CAD) to create digital models that can be used to analyze the design of a building from all points of view. The interviewees responded to questions about software implementation advantages, and related user experiences. Six interviews were conducted, amongst three industry leading companies. Their assumptions of future AR and VR usage in construction were based on learned knowledge and prior field exploration. …

Evolution Of Coronal Magnetic Field Parameters During X5.4 Solar Flare, Seth H. Garland, Benjamin F. Akers, Vasyl B. Yurchyshyn, Robert D. Loper, Daniel J. Emmons

Faculty Publications

The coronal magnetic field over NOAA Active Region 11,429 during a X5.4 solar flare on 7 March 2012 is modeled using optimization based Non-Linear Force-Free Field extrapolation. Specifically, 3D magnetic fields were modeled for 11 timesteps using the 12-min cadence Solar Dynamics Observatory (SDO) Helioseismic and Magnetic Imager photospheric vector magnetic field data, spanning a time period of 1 hour before through 1 hour after the start of the flare. Using the modeled coronal magnetic field data, seven different magnetic field parameters were calculated for 3 separate regions: areas with surface |Bz| ≥ 300 G, areas of flare brightening seen …

Unmanned-Aircraft-System-Assisted Early Wildfire Detection With Air Quality Sensors †, Doaa Rjoub, Ahmad Alsharoa, Ala'eddin Masadeh

Electrical and Computer Engineering Faculty Research & Creative Works

Numerous Hectares of Land Are Destroyed by Wildfires Every Year, Causing Harm to the Environment, the Economy, and the Ecology. More Than Fifty Million Acres Have Burned in Several States as a Result of Recent Forest Fires in the Western United States and Australia. According to Scientific Predictions, as the Climate Warms and Dries, Wildfires Will Become More Intense and Frequent, as Well as More Dangerous. These Unavoidable Catastrophes Emphasize How Important Early Wildfire Detection and Prevention Are. the Energy Management System Described in This Paper Uses an Unmanned Aircraft System (UAS) with Air Quality Sensors (AQSs) to Monitor Spot …

Special Section On Local And Distributed Electricity Markets, Rui Bo, Linquan Bai, Antonio J. Conejo, Jianzhong Wu, Tao Jiang, Fei Ding, Babak Enayati

Electrical and Computer Engineering Faculty Research & Creative Works

Driven by the Goals of Clean Energy and Zero Carbon Emissions, the Power Industry is Undergoing Significant Transformations. the Rapid Growth of Diverse Distributed Energy Resources (DERs) at Grid Edge Such as Rooftop Photovoltaics (PVs) and Electric Vehicles is Transforming the Traditional Centralized Power Grid Management to a Decentralized, Bottom-Up, and Localized Control Paradigm. Establishing Local and Distribution-Level Electricity Markets Provides an Effective Solution to Managing Large Amounts of Small-Scale DERs. New Regulations Such as the Recent FERC Order 2222 in the U.S. Open the Door to DERs in the Wholesale Markets. through Coordinating the Local and Distribution-Level Markets with …

Deep Learning To Predict The Hydration And Performance Of Fly Ash-Containing Cementitious Binders, Taihao Han, Rohan Bhat, Sai Akshay Ponduru, Amit Sarkar, Jie Huang, Gaurav Sant, Hongyan Ma, Narayanan Neithalath, Aditya Kumar

Electrical and Computer Engineering Faculty Research & Creative Works

Fly ash (FA) – an industrial byproduct – is used to partially substitute Portland cement (PC) in concrete to mitigate concrete's environmental impact. Chemical composition and structure of FAs significantly impact hydration kinetics and compressive strength of concrete. Due to the substantial diversity in these physicochemical attributes of FAs, it has been challenging to develop a generic theoretical framework – and, therefore, theory-Based analytical models – that could produce reliable, a priori predictions of properties of [PC + FA] binders. in recent years, machine learning (ML) – which is purely data-driven, as opposed to being derived from theorical underpinnings – …

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 …

The Wideband Tunability Of Double Gunn Diodes, Latarence Butts, Samir M. El-Ghazaly

Electrical Engineering Faculty Publications and Presentations

Gunn diodes use the Ridley–Watkins–Hilsum effect to generate low noise millimeter wave signals for communication and sensing applications. However, Monte Carlo calculations indicate that the velocity–field characteristics of compensated GaAs contain a second peak due to phonon scattering. A novel device that leverages this double Ridley–Watkins–Hilsum effect to achieve ultra-wideband tunability of low-noise millimeter waves is proposed in this article. The second region of negative differential mobility is gradually introduced in seven mobility profiles, which are each simulated in eight device lengths. It is found that a 2.5 μm Gunn diode with a compensation ratio of 0.6 operating at …

Description Of Reaction And Vibrational Energetics Of Co2-Nh3interaction Using Quantum Computing Algorithms, Manh Tien Nguyen, Yueh-Lin Lee, Dominic Alfonso, Qing Shao, Yuhua Duan

Markey Cancer Center Faculty Publications

CO2 capture is critical to solving global warming. Amine-based solvents are extensively used to chemically absorb CO2. Thus, it is crucial to study the chemical absorption of CO2 by amine-based solvents to better understand and optimize CO2 capture processes. Here, we use quantum computing algorithms to quantify molecular vibrational energies and reaction pathways between CO2 and a simplified amine-based solvent model—NH3. Molecular vibrational properties are important to understanding kinetics of reactions. However, the molecule size correlates with the strength of anharmonicity effect on vibrational properties, which can be challenging to address using classical computing. Quantum computing can help enhance molecular …

The Effect Of Relative Humidity On Eddy Covariance Latent Heat Flux Measurements And Its Implication For Partitioning Into Transpiration And Evaporation, Weijie Zhang, Martin Jung, Mirco Migliavacca, Rafael Poyatos, Diego G. Miralles, Tarek S. El-Madany, Marta Galvagno, Arnaud Carrara, Nicola Arriga, Andreas Ibrom, Ivan Mammarella, Dario Papale, Jamie R. Cleverly, Michael Liddell, Georg Wohlfahrt, Christian Markwitz, Matthias Mauder, Eugenie Paul-Limoges, Marius Schmidt, Sebastian Wolf, Christian Brümmer, M. Altaf Arain, Silvano Fares, Tomomichi Kato, Jonas Ardö, Walter Oechel, Chad Hanson, Mika Korkiakoski, Sébastien Biraud, Rainer Steinbrecher, Dave Billesbach, Leonardo Montagnani, William Woodgate, Changliang Shao, Nuno Carvalhais, Markus Reichstein, Jacob A. Nelson

Department of Agricultural and Biological Systems Engineering: Faculty Publications

While the eddy covariance (EC) technique is a well-established method for measuring water fluxes (i.e., evaporation or 'evapotranspiration’, ET), the measurement is susceptible to many uncertainties. One such issue is the potential underestimation of ET when relative humidity (RH) is high (>70%), due to low-pass filtering with some EC systems. Yet, this underestimation for different types of EC systems (e.g. open-path or closed-path sensors) has not been characterized for synthesis datasets such as the widely used FLUXNET2015 dataset. Here, we assess the RH-associated underestimation of latent heat fluxes (LE, or ET) from different EC systems for 163 sites in …

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 …

Effects Of Calibration Errors On Dropped-Channel Polarimetric Synthetic Aperture Radar, Jacob C. Morrison

Theses and Dissertations

Compressed Sensing (CS) is a mathematical technique that can be applied to sparse data sets to allow for sub-Nyquist sampling. DCPCS is a CS technique that recovers the signal from unmeasured polarisation channels due to antenna crosstalk coupling the information onto the remaining channels. DCPCS reduces data storage/transmission and receiver hardware requirements. This thesis examines the robustness of DCPCS to calibration errors on the antenna crosstalk matrix. Although the antenna design problem is relaxed to a large region of acceptable crosstalk values, very accurate calibration may be required in a monostatic radar. This thesis also looks at the importance of …

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 …

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 …

Long-Term Asset Prioritization To Support District Planning, Melissa R. Sallberg

Theses and Dissertations

The United States Air Force (USAF) relies on its installations to project military power across the globe. However, due to the deferred infrastructure maintenance and recapitalization backlog of $33 billion as of 2019 (Wilson & Goldfein, 2019), it is more critical than ever for base-level community planners to focus their attention to the projects that will achieve each installation’s long-term goals. The recent incorporation of asset management principles into the USAF District Planning Process allows a unique opportunity to improve the existing scoring model for a holistic look at what matters to enterprise leaders and community planners making the plans …

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, …

Sea Level Rise Impacts On Wastewater Treatment Plants And Their Social Vulnerability Differences, David S. P. Robinson

Theses and Dissertations

Many of the United States’ major cities that have a high population are located along the coast. The number of people residing in low elevation coastal areas, be-low 10 meters, is increasing. Coastal areas may be affected by various short- and long-term climate hazards, such as sea level rise (SLR). Climate change induced SLR will threaten residents and infrastructure in low-lying coastal areas. A household’s capacity to respond to hazards is highly dependent on its socio-demographic situation which determines its social vulnerability. Wastewater treatment facilities area particularly critical piece of infrastructure often located in low-lying areas due to gravity fed …

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 …

Validation Of Digital System Models, James R. Winton

Theses and Dissertations

The Department of Defense is undergoing a Digital Transformation driven by Digital Engineering and Model-Based Systems Engineering. Document-based processes are being replaced by digital artifacts, pedigreed data, and an Authoritative Source of Truth for a system across its life cycle. As traditional Design-Build-Test transitions to a Model-Analyze-Build methodology, digital models will proliferate throughout the enterprise and require novel validation processes earlier in the development timeline. A new definition for digital system model validation is proposed to address the identified shortcomings in existing guidance. The proposed validation framework leverages the Systems Modeling Language, use cases, requirements, test cases, and a custom …

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 …

Inducing Sparsity Within High-Dimensional Remote Sensing Modalities For Lightning Prediction, Grace E. Metzgar

Theses and Dissertations

The uncertainty of lightning constantly threatens many weather-sensitive fields where the slightest presence of lightning can endanger valuable personnel and assets. The consequences of delaying operations have incited the research of methods that can accurately predict the location of future lightning strikes from the current weather conditions. High-dimensional remote sensing modalities contain information capable of detecting significant patterns and intensities within storms that could indicate the presence of lightning. This thesis induces sparsity into convolutional neural networks (CNNs) and remote sensing modalities through a combination of regularization and tensor decomposition techniques to call attention to sparse features that are most …

The Aerial Refueling Asset Basing And Assignment Problem, Camryn E. Deames

Theses and Dissertations

With growing tensions in the European theatre and Indo-Pacific theatre, the constraints of aerial refueling impede the missions of Air Mobility Command and USTRANSCOM in their execution of both the National Security Strategy and National Defense Strategy. Introducing and integrating semi-autonomous aerial refueling aircraft is a logical next step due to advantages in endurance, survivability, runway requirements, and fuel offloading capacity. This research frames the Aerial Refueling Asset Basing and Assignment Problem with two model approaches: a baseline model and a fuel shuttle concept model. Whereas the former model considers instances with only manned refuelers or only semi-autonomous refuelers, the …

Automated Registration Of Titanium Metal Imaging Of Aircraft Components Using Deep Learning Techniques, Nathan A. Johnston

Theses and Dissertations

Studies have shown a connection between early catastrophic engine failures with microtexture regions (MTRs) of a specific size and orientation on the titanium metal engine components. The MTRs can be identified through the use of Electron Backscatter Diffraction (EBSD) however doing so is costly and requires destruction of the metal component being tested. A new methodology of characterizing MTRs is needed to properly evaluate the reliability of engine components on live aircraft. The Air Force Research Lab Materials Directorate (AFRL/RX) proposed a solution of supplementing EBSD with two non-destructive modalities, Eddy Current Testing (ECT) and Scanning Acoustic Microscopy (SAM). Doing …

Analysis And Optimization Of Contract Data Schema, Franklin Sun

Theses and Dissertations

agement, development, and growth of U.S Air Force assets demand extensive organizational communication and structuring. These interactions yield substantial amounts of contracting and administrative information. Over 4 million such contracts as a means towards obtaining valuable insights on Department of Defense resource usage. This set of contracting data is largely not optimized for backend service in an analytics environment. To this end, the following research evaluates the efficiency and performance of various data structuring methods. Evaluated designs include a baseline unstructured schema, a Data Mart schema, and a snowflake schema. Overall design success metrics include ease of use by end …

Debris Survivability Study For Mega-Constellation Architectures, Joseph C. Canoy

Theses and Dissertations

The analysis for the overall theoretical debris survivabilty of mega-constellation architectures, with an emphasis on space-based ballistic missile defense constellation (SB-BMD), is explored via three extensive different Monte Carlo simulations: preliminary analysis of low Earth Orbit (LEO) mega-constellation survivabilty following a fragmentation event within the constellation, analysis of LEO mega-constellation survivability with a fragmentation event occurring on a satellite performing a maneuver to insert itself within the constellation, and the analysis of LEO mega-constellation survivabilty after a fragmentation event resulting from the destruction of a missile. The LEO mega-constellations represent the SB-BMD constellation. The first two analysis sections will include …

Investigation Of Hypersonic Near-Wake Relaminarization Over A 7 Degree Half-Angle Cone, Jesse L. Roberts

Theses and Dissertations

To investigate the potential for relaminarization in the near-wake of a 7-degree half-angle cone, a series of hypersonic wake experiments were conducted in the Air Force Research Laboratory Mach 6.1 Ludwieg tube. Relaminarization is a spatial phenomenon that occurs when a turbulent flow reverts to a laminar-like state at a downstream location, where turbulent fluctuations negligibly contribute to average flow properties. Although relaminarization has been documented in subsonic and supersonic flows, the current body of knowledge related to the occurrence of, and mechanisms that drive, relaminarization at hypersonic speeds is sparse. Measurements were obtained across a range of freestream unit …